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Sample records for cell inductively coupled

  1. Inductively coupled hydrogen plasma processing of AZO thin films for heterojunction solar cell applications

    International Nuclear Information System (INIS)

    Zhou, H.P.; Xu, S.; Zhao, Z.; Xiang, Y.

    2014-01-01

    Highlights: • A high-density plasma reactor of inductively coupled plasma source is used in this work. • The conductivity and transmittance can be enhanced simultaneously in the hydrogen process. • The formation of additional donors and passivation due to the hydrogen plasma processing. • The photovoltaic improvement due to the improved AZO layer and hetero-interface quality in the solar cells. - Abstract: Al-doped ZnO (AZO) thin films deposited by means of RF magnetron sputtering were processed in a low frequency inductively coupled plasma of H 2 , aiming at heterojunction (HJ) solar cell applications. A variety of characterization results show that the hydrogen plasma processing exerts a significant influence on the microstructures, electrical and optical properties of the AZO films. The incorporation of hydrogen under the optimum treatment simultaneously promoted the transmittance and conductivity due to the hydrogen associated passivation effect on the native defects and the formation of shallow donors in the films, respectively. A p-type c-Si based HJ solar cell with a front AZO contact was also treated in as-generated non-equilibrium hydrogen plasma and the photovoltaic performance of the solar cell was prominently improved. The underlying mechanism was discussed in terms of the beneficial impacts of high-density hydrogen plasma on the properties of AZO itself and the hetero-interfaces involved in the HJ structure (interface defect and energy band configuration)

  2. Inductively coupled helium plasma torch

    Science.gov (United States)

    Montaser, Akbar; Chan, Shi-Kit; Van Hoven, Raymond L.

    1989-01-01

    An inductively coupled plasma torch including a base member, a plasma tube and a threaded insert member within the plasma tube for directing the plasma gas in a tangential flow pattern. The design of the torch eliminates the need for a separate coolant gas tube. The torch can be readily assembled and disassembled with a high degree of alignment accuracy.

  3. Optoelectronic properties of Black-Silicon generated through inductively coupled plasma (ICP) processing for crystalline silicon solar cells

    Science.gov (United States)

    Hirsch, Jens; Gaudig, Maria; Bernhard, Norbert; Lausch, Dominik

    2016-06-01

    The optoelectronic properties of maskless inductively coupled plasma (ICP) generated black silicon through SF6 and O2 are analyzed by using reflection measurements, scanning electron microscopy (SEM) and quasi steady state photoconductivity (QSSPC). The results are discussed and compared to capacitively coupled plasma (CCP) and industrial standard wet chemical textures. The ICP process forms parabolic like surface structures in a scale of 500 nm. This surface structure reduces the average hemispherical reflection between 300 and 1120 nm up to 8%. Additionally, the ICP texture shows a weak increase of the hemispherical reflection under tilted angles of incidence up to 60°. Furthermore, we report that the ICP process is independent of the crystal orientation and the surface roughness. This allows the texturing of monocrystalline, multicrystalline and kerf-less wafers using the same parameter set. The ICP generation of black silicon does not apply a self-bias on the silicon sample. Therefore, the silicon sample is exposed to a reduced ion bombardment, which reduces the plasma induced surface damage. This leads to an enhancement of the effective charge carrier lifetime up to 2.5 ms at 1015 cm-3 minority carrier density (MCD) after an atomic layer deposition (ALD) with Al2O3. Since excellent etch results were obtained already after 4 min process time, we conclude that the ICP generation of black silicon is a promising technique to substitute the industrial state of the art wet chemical textures in the solar cell mass production.

  4. Evaluation of an inductively-coupled plasma with an extended-sleeve torch as an atomization cell for laser-excited fluorescence spectrometry.

    Science.gov (United States)

    Kosinski, M A; Uchida, H; Winefordner, J D

    1983-05-01

    An inductively-coupled plasma (ICP) with an extended-sleeve torch has been evaluated as an atomization cell for laser-excited fluorescence spectrometry. Limits of detection for 20 lines are given. The detection power is almost equivalent to that obtained by excitation with a hollow-cathode lamp. Interelement effects and spectral interferences are discussed.

  5. A fully-implicit Particle-In-Cell Monte Carlo Collision code for the simulation of inductively coupled plasmas

    Science.gov (United States)

    Mattei, S.; Nishida, K.; Onai, M.; Lettry, J.; Tran, M. Q.; Hatayama, A.

    2017-12-01

    We present a fully-implicit electromagnetic Particle-In-Cell Monte Carlo collision code, called NINJA, written for the simulation of inductively coupled plasmas. NINJA employs a kinetic enslaved Jacobian-Free Newton Krylov method to solve self-consistently the interaction between the electromagnetic field generated by the radio-frequency coil and the plasma response. The simulated plasma includes a kinetic description of charged and neutral species as well as the collision processes between them. The algorithm allows simulations with cell sizes much larger than the Debye length and time steps in excess of the Courant-Friedrichs-Lewy condition whilst preserving the conservation of the total energy. The code is applied to the simulation of the plasma discharge of the Linac4 H- ion source at CERN. Simulation results of plasma density, temperature and EEDF are discussed and compared with optical emission spectroscopy measurements. A systematic study of the energy conservation as a function of the numerical parameters is presented.

  6. Inductively and capacitively coupled plasmas at interface: A comparative study towards highly efficient amorphous-crystalline Si solar cells

    Science.gov (United States)

    Guo, Yingnan; Ong, Thiam Min Brian; Levchenko, I.; Xu, Shuyan

    2018-01-01

    A comparative study on the application of two quite different plasma-based techniques to the preparation of amorphous/crystalline silicon (a-Si:H/c-Si) interfaces for solar cells is presented. The interfaces were fabricated and processed by hydrogen plasma treatment using the conventional plasma-enhanced chemical vacuum deposition (PECVD) and inductively coupled plasma chemical vapour deposition (ICP-CVD) methods The influence of processing temperature, radio-frequency power, treatment duration and other parameters on interface properties and degree of surface passivation were studied. It was found that passivation could be improved by post-deposition treatment using both ICP-CVD and PECVD, but PECVD treatment is more efficient for the improvement on passivation quality, whereas the minority carrier lifetime increased from 1.65 × 10-4 to 2.25 × 10-4 and 3.35 × 10-4 s after the hydrogen plasma treatment by ICP-CVD and PECVD, respectively. In addition to the improvement of carrier lifetimes at low temperatures, low RF powers and short processing times, both techniques are efficient in band gap adjustment at sophisticated interfaces.

  7. Determination of Se at low concentration in coal by collision/reaction cell technology inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Henn, Alessandra S.; Rondan, Filipe S.; Mesko, Marcia F.; Mello, Paola A.; Perez, Magali; Armstrong, Joseph; Bullock, Liam A.; Parnell, John; Feldmann, Joerg; Flores, Erico M. M.

    2018-05-01

    A method is proposed for the determination of selenium at low concentration in coal by collision/reaction cell technology inductively coupled plasma mass spectrometry (CRC-ICP-MS). Samples were decomposed by high pressure microwave-assisted wet digestion (MAWD) using 250 mg of coal, a mixture of 5 mL of 14.4 mol L-1 HNO3 and 1 mL of 40% HF and 70 min of heating program (200 °C and 40 bar). Hydrogen gas used in the collision/reaction cell was investigated to minimize the argon-based interferences at m/z 77, 78 and 80. The rejection parameter (RPq) and the H2 gas flow rate were set to 0.45 and 4.8 mL min-1, respectively. The use of H2 in the cell resulted in other polyatomic interferences, such as 76Ge1H+, 79Br1H+ and 81Br1H+, which impaired Se determination using 77Se, 80Se and 82Se isotopes, thus Se determination was carried out by monitoring only 78Se isotope. Selenium was determined in certified reference materials of coal (NIST 1635 and SARM 20) and an agreement better than 95% was observed between the results obtained by CRC-ICP-MS and the certified values. Under optimized conditions, the instrumental limit of detection was 0.01 μg L-1 and the method limit of detection was 0.01 μg g-1, which was suitable for Se determination at very low concentration in coal.

  8. Superconducting Resonant Inductive Power Coupling, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed effort will develop a technology to wirelessly and efficiently transfer power over hundreds of meters via resonant inductive coupling. The key...

  9. The characterization of plasma-surface interactions using the inductively coupled gaseous electronics conference reference cell platform

    Science.gov (United States)

    Joseph, Eric Andrew

    rates and sample surface chemistry of a hybrid polydimethylsiloxane material. Depending on the percentage of oxygen admixed in the tetrafluoromethane feedgas, the etch could be tailored from energy dependent to energy independent. Tweaking the process in an inductively coupled plasma further improved the etch rate such that it was twice as high as those published in a capacitive plasma process. The resultant stoichiometry of the etched films was also found to depend on the feedgas chemistry as the refractive index of the material increased by 7% when pure oxygen was used and decreased by 6% when pure tetrafluoromethane was used. (Abstract shortened by UMI.)

  10. LASER ABLATION-INDUCTIVELY COUPLED PLASMA-ATOMIC EMISSION SPECTROSCOPY STUDY AT THE 222-S LABORATORY USING HOT-CELL GLOVE BOX PROTOTYPE SYSTEM

    International Nuclear Information System (INIS)

    Lockrem, L.L.; Owens, J.W.; Seidel, C.M.

    2009-01-01

    This report describes the installation, testing and acceptance of the Waste Treatment and Immobilization Plant procured laser ablation-inductively coupled plasma-atomic emission spectroscopy (LA-ICP-AES) system for remotely analyzing high-level waste samples in a hot cell environment. The 2005-003; ATS MP 1027, Management Plan for Waste Treatment Plant Project Work Performed by Analytical Technical Services. The APD group at the 222-S laboratory demonstrated acceptable turnaround time (TAT) and provide sufficient data to assess sensitivity, accuracy, and precision of the LA-ICP-AES method

  11. LASER ABLATION-INDUCTIVELY COUPLED PLASMA-ATOMIC EMISSION SPECTROSCOPY STUDY AT THE 222-S LABORATORY USING HOT-CELL GLOVE BOX PROTOTYPE SYSTEM

    International Nuclear Information System (INIS)

    Seidel, C.M.; Jain, J.; Owens, J.W.

    2009-01-01

    This report describes the installation, testing, and acceptance of the Waste Treatment and Immobilization Plant (WTP) procured laser ablation-inductively coupled plasma-atomic emission spectroscopy (LA-ICP-AES) system for remotely analyzing high-level waste (HLW) samples in a hot cell environment. The work was completed by the Analytical Process Development (APD) group in accordance with Task Order 2005-003; ATS MP 1027, Management Plan for Waste Treatment Plant Project Work Performed by Analytical Technical Services. The APD group at the 222-S Laboratory demonstrated acceptable turnaround time (TAT) and provide sufficient data to assess sensitivity, accuracy, and precision of the LA-ICP-AES method

  12. The application of inductively coupled plasma dynamic reaction cell mass spectrometry for measurement of selenium isotopes, isotope ratios and chromatographic detection of selenoamino acids

    DEFF Research Database (Denmark)

    Sloth, Jens Jørgen; Larsen, Erik Huusfeldt

    2000-01-01

    . A linear relationship (r mass from the Se-80 reference isotope. This indicated that the error was caused by mass bias. The slope of the curve at -3.0% error per mass unit can be used for correction of the measured......Inductively coupled plasma dynamic reaction cell mass spectrometry (ICP-DRC-MS) was characterised for the detection of the six naturally occurring selenium isotopes. The potentially interfering argon dimers at the selenium masses m/z 74, 76, 78 and 80 were reduced in intensity by approximately five...... ratios was close to the theoretical values for selenium concentrations at 1 and 10 ng ml(-1). The accuracy of the isotope ratios, however, was improved by correcting the count rate of all selenium isotopes equivalent to the formation of SeH at 9.6 +/- 0.5% one mass unit above the selenium isotopes...

  13. Investigation of the antimicrobial activity at safe levels for eukaryotic cells of a low power atmospheric pressure inductively coupled plasma source.

    Science.gov (United States)

    Barbieri, Daniela; Boselli, Marco; Cavrini, Francesca; Colombo, Vittorio; Gherardi, Matteo; Landini, Maria Paola; Laurita, Romolo; Liguori, Anna; Stancampiano, Augusto

    2015-06-08

    Low power atmospheric pressure inductively coupled thermal plasma sources integrated with a quenching device (cold ICP) for the efficient production of biologically active agents have been recently developed for potential biomedical applications. In the present work, in vitro experiments aimed at assessing the decontamination potential of a cold ICP source were carried out on bacteria typically associated with chronic wounds and designed to represent a realistic wound environment; further in vitro experiments were performed to investigate the effects of plasma-irradiated physiological saline solution on eukaryotic cells viability. A thorough characterization of the plasma source and process, for what concerns ultraviolet (UV) radiation and nitric oxide production as well as the variation of pH and the generation of nitrates and nitrites in the treated liquid media, was carried out to garner fundamental insights that could help the interpretation of biological experiments. Direct plasma treatment of bacterial cells, performed at safe level of UV radiation, induces a relevant decontamination, both on agar plate and in physiological saline solution, after just 2 min of treatment. Furthermore, the indirect treatment of eukaryotic cells, carried out by covering them with physiological saline solution irradiated by plasma, in the same conditions selected for the direct treatment of bacterial cells does not show any noticeable adverse effect to their viability. Some considerations regarding the role of the UV radiation on the decontamination potential of bacterial cells and the viability of the eukaryotic ones will be presented. Moreover, the effects of pH variation, nitrate and nitrite concentrations of the plasma-irradiated physiological saline solution on the decontamination of bacterial suspension and on the viability of eukaryotic cells subjected to the indirect treatment will be discussed. The obtained results will be used to optimize the design of the ICP source

  14. Determination of chromium, iron and selenium in foodstuffs of animal origin by collision cell technology, inductively coupled plasma mass spectrometry (ICP-MS), after closed vessel microwave digestion

    International Nuclear Information System (INIS)

    Dufailly, Vincent; Noel, Laurent; Guerin, Thierry

    2006-01-01

    The determination of chromium ( 52 Cr), iron ( 56 Fe) and selenium ( 80 Se) isotopes in foodstuffs of animal origin has been performed by collision cell technology (CCT) mode using an inductively coupled plasma mass spectrometry (ICP-MS) as detector after closed vessel microwave digestion. To significantly decrease the argon-based interferences at mass to charge ratios (m/z): 52 ( 40 Ar 12 C), 56 ( 40 Ar 16 O) and 80 ( 40 Ar 40 Ar), the gas-flow rates of a helium and hydrogen mixture used in the hexapole collision cell were optimised to 1.5 ml min -1 H 2 and 0.5 ml min -1 He and the quadrupole bias was adjusted daily between -2 and -15 mV. Limits of quantification (LOQ) of 0.025, 0.086 and 0.041 mg kg -1 for Cr, Fe and Se, respectively, in 6% HNO 3 were estimated under optimized CCT conditions. These LOQ were improved by a factor of approximately 10 for each element compared to standard mode. Precision under repeatability, intermediate precision reproducibility and trueness have been tested on nine different certified reference materials in foodstuffs of animal origin and on an external proficiency testing scheme. The results obtained for chromium, iron and selenium were in all cases in good agreement with the certified values and trueness was improved, compared to those obtained in standard mode

  15. High-Speed, Integrated Ablation Cell and Dual Concentric Injector Plasma Torch for Laser Ablation-Inductively Coupled Plasma Mass Spectrometry.

    Science.gov (United States)

    Douglas, David N; Managh, Amy J; Reid, Helen J; Sharp, Barry L

    2015-11-17

    In recent years, laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) has gained increasing importance for biological analysis, where ultratrace imaging at micrometer resolution is required. However, while undoubtedly a valuable research tool, the washout times and sensitivity of current technology have restricted its routine and clinical application. Long periods between sampling points are required to maintain adequate spatial resolution. Additionally, temporal signal dispersion reduces the signal-to-noise ratio, which is a particular concern when analyzing discrete samples, such as individual particles or cells. This paper describes a novel, two-volume laser ablation cell and integrated ICP torch designed to minimize aerosol dispersion for fast, efficient sample transport. The holistic design utilizes a short, continuous diameter fused silica conduit, which extends from the point of ablation, through the ICP torch, and into the base of the plasma. This arrangement removes the requirement for a dispersive component for argon addition, and helps to keep the sample on axis with the ICP cone orifice. Hence, deposition of sample on the cones is theoretically reduced with a resulting improvement in the absolute sensitivity (counts per unit mole). The system described here achieved washouts of 1.5, 3.2, and 4.9 ms for NIST 612 glass, at full width half, 10%, and 1% maximum, respectively, with an 8-14-fold improvement in absolute sensitivity, compared to a single volume ablation cell. To illustrate the benefits of this performance, the system was applied to a contemporary bioanalytical challenge, specifically the analysis of individual biological cells, demonstrating similar improvements in performance.

  16. Accurate Determination of Platinum, Palladium, and Rhodium in Ryegrass using Collision Cell Inductively Coupled Plasma Mass Spectrometry with Xenon as Collision Gas

    International Nuclear Information System (INIS)

    Amr, M.A.

    2011-01-01

    Inductively coupled plasma mass spectrometry with an octupole collision cell was used for determination of Pt, Pd and Rh in ryegrass (Lolium multiflorum) which was grown hydroponically. Xenon was used as a collision gas to reduce serious polyatomic interferences formed by combination of matrix elements such as CI, Cu, Hf, Sr, Zn, Zr, Y and REE with O, N, C, and Ar. The detection limits for Pt, Pd and Rh in spiked ryegrass are 1.8, 4.2, and 0.8 ppt, respectively. The results for Pt, Pd and Rh in reference materials (NIST SRM 2557, recycled monolith auto catalyst) are in agreement with the certified values. The bioaccumulation of Pt, Pd and Rh by ryegrass grown hydroponically with nutrient solutions containing Pt, Pd and Rh was studied. The obtained results showed that most of the studied metals were accumulated in roots, and only a small fraction was metabolized and transported to leaves. The highest bioaccumulation factors were obtained for Pd and Rh in roots and for Pt in leaves

  17. Inductively coupled plasma-atomic emission spectroscopy

    International Nuclear Information System (INIS)

    Winge, R.K.; Fassel, V.A.; Peterson, V.J.; Floyd, M.A.

    1985-01-01

    This atlas of inductively coupled plasma-atomic emission spectroscopy records the spectra of the elements in a way that would reveal the general nature of the spectra, in all their simplicity or complexity; and offers a definitive summary of the most prominent spectral lines of the elements, i.e., those most likely to be useful for the determination of trace and ultratrace concentrations; it provides reliable estimates, based on the recorded experimental spectra, of the powers of detection of the listed prominent lines; and assesses the very important problem of spectral interferences. The atlas is composed of three main sections. Part I is concerned with the historical aspects of compilations of spectral information. Part II is based on 232 wavelength scans of 70 elements. Each of the wavelength scans covers an 80 nm spectral region. These scans allow a rapid comparison of the background and spectral line intensities emitted in the ICP and provide a ready means for identification of the most prominent lines of each element and for estimation of the trace element analytical capabilities of these lines. A listing of 973 prominent lines with associated detection limits is also presented. Part III addresses the problem of spectral interferences. On this topic a detailed collection of coincidence profiles is presented for 281 of the most prominent lines, each with profiles of ten of the most prevalent concomitants superimposed. (Auth.)

  18. Titanium oxidation by rf inductively coupled plasma

    International Nuclear Information System (INIS)

    Valencia-Alvarado, R; López-Callejas, R; Barocio, S R; Mercado-Cabrera, A; Peña-Eguiluz, R; Muñoz-Castro, A E; Rodríguez-Méndez, B G; De la Piedad-Beneitez, A; De la Rosa-Vázquez, J M

    2014-01-01

    The development of titanium dioxide (TiO 2 ) films in the rutile and anatase phases is reported. The films have been obtained from an implantation/diffusion and sputtering process of commercially pure titanium targets, carried out in up to 500 W plasmas. The experimental outcome is of particular interest, in the case of anatase, for atmospheric pollution degradation by photocatalysis and, as to the rutile phase, for the production of biomaterials required by prosthesis and implants. The reactor employed consists in a cylindrical pyrex-like glass vessel inductively coupled to a 13.56 MHz RF source. The process takes place at a 5×10 −2 mbar pressure with the target samples being biased from 0 to -3000 V DC. The anatase phase films were obtained from sputtering the titanium targets over glass and silicon electrically floated substrates placed 2 cm away from the target. The rutile phase was obtained by implantation/diffusion on targets at about 700 °C. The plasma was developed from a 4:1 argon/oxygen mixture for ∼5 hour processing periods. The target temperature was controlled by means of the bias voltage and the plasma source power. The obtained anatase phases did not require annealing after the plasma oxidation process. The characterization of the film samples was conducted by means of x-ray diffraction, scanning electron microscopy, x-ray photoelectron spectroscopy and Raman spectroscopy

  19. Multi-element Analysis of variable sample matrices using collision/reaction cell inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Zahran, N.F.; Helal, A.I.; Amr, M.A.; Amr, M.A.; Al-saad, K.A.

    2008-01-01

    An ICP-MS with an octopole reaction/collision cell is used for the multielement determination of trace elements in water, plants, and soil samples. The use of a reaction or collision gas reduces serious spectral interferences from matrix elements such as Ar Cl or Ar Na. The background equivalent concentration (BEC) is reduced one order of magnitude at helium flow rate of 1 mL/min. Certified reference material namely , NIST Water-1643d, Tomato leaves 1573a, and Montana soil 2711 are used. The trace elements Mn, Fe, Co, Ni, Cu, Zn, As, Mo, Cd and Pb are determined in the different matrices with a accuracy better than 8% to the certified values

  20. Effect of capacitive coupling in a miniature inductively coupled plasma source

    International Nuclear Information System (INIS)

    Takao, Yoshinori; Eriguchi, Koji; Ono, Kouichi

    2012-01-01

    Two-dimensional axisymmetric particle-in-cell simulations with a Monte Carlo collision algorithm (PIC-MCC) have been conducted to investigate the effect of capacitive coupling in a miniature inductively coupled plasma source (mICP) by using two models: an inductive model and a hybrid model. The mICP is 3 mm in radius and 6 mm in height with a three-turn planar coil, where argon plasma is sustained. In the inductive model, the coil is assumed to be electrostatically shielded, and thus the discharge is purely inductive coupling. In the hybrid model, we assume that the different turns of the coil act like electrodes in capacitive discharge to include the effect of capacitive coupling. The voltage applied to these electrodes decreases linearly from the powered end of the coil towards the grounded end. The numerical analysis has been performed for rf frequencies in the range of 100-1000 MHz, and the power absorbed by the plasma in the range of 5-50 mW at a fixed pressure of 500 mTorr. The PIC-MCC results show that potential oscillations at the plasma-dielectric interface are not negligible, and thus the major component of the absorbed power is caused by the axial motion of electrons in the hybrid model, although almost all of the power absorption is due to the azimuthal motion of electrons in the inductive model. The effect of capacitive coupling is more significant at lower rf frequencies and at higher absorbed powers under the calculation conditions examined. Moreover, much less coil currents are required in the hybrid model.

  1. Evaluation of the multi-element capabilities of collision/reaction cell inductively coupled plasma-mass spectrometry in wine analysis.

    Science.gov (United States)

    Grindlay, Guillermo; Mora, Juan; de Loos-Vollebregt, Margaretha T C; Vanhaecke, Frank

    2014-10-01

    This work explores the multi-element capabilities of inductively coupled plasma-mass spectrometry with collision/reaction cell technology (CCT-ICP-MS) for the simultaneous determination of both spectrally interfered and non-interfered nuclides in wine samples using a single set of experimental conditions. The influence of the cell gas type (i.e. He, He+H2 and He+NH3), cell gas flow rate and sample pre-treatment (i.e. water dilution or acid digestion) on the background-equivalent concentration (BEC) of several nuclides covering the mass range from 7 to 238u has been studied. Results obtained in this work show that, operating the collision/reaction cell with a compromise cell gas flow rate (i.e. 4 mL min(-1)) improves BEC values for interfered nuclides without a significant effect on the BECs for non-interfered nuclides, with the exception of the light elements Li and Be. Among the different cell gas mixtures tested, the use of He or He+H2 is preferred over He+NH3 because NH3 generates new spectral interferences. No significant influence of the sample pre-treatment methodology (i.e. dilution or digestion) on the multi-element capabilities of CCT-ICP-MS in the context of simultaneous analysis of interfered and non-interfered nuclides was observed. Nonetheless, sample dilution should be kept at minimum to ensure that light nuclides could be quantified in wine. Finally, a direct 5-fold aqueous dilution is recommended for the simultaneous trace and ultra-trace determination of spectrally interfered and non-interfered elements in wine by means of CCT-ICP-MS. The use of the CCT is mandatory for interference-free ultra-trace determination of Ti and Cr. Only Be could not be determined when using the CCT due to a deteriorated limit of detection when compared to conventional ICP-MS. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Determination of chromium, iron and selenium in foodstuffs of animal origin by collision cell technology, inductively coupled plasma mass spectrometry (ICP-MS), after closed vessel microwave digestion

    Energy Technology Data Exchange (ETDEWEB)

    Dufailly, Vincent [Agence Francaise de Securite Sanitaire des Aliments - Laboratoire d' Etudes et de Recherches sur la Qualite des Aliments et des procedees agroalimentaires - Unite des Contaminants Inorganiques et Mineraux de l' Environnement, 23, avenue du General de Gaulle, F-94706 Maisons-Alfort Cedex (France); Noel, Laurent [Agence Francaise de Securite Sanitaire des Aliments - Laboratoire d' Etudes et de Recherches sur la Qualite des Aliments et des procedees agroalimentaires - Unite des Contaminants Inorganiques et Mineraux de l' Environnement, 23, avenue du General de Gaulle, F-94706 Maisons-Alfort Cedex (France); Guerin, Thierry [Agence Francaise de Securite Sanitaire des Aliments - Laboratoire d' Etudes et de Recherches sur la Qualite des Aliments et des procedees agroalimentaires - Unite des Contaminants Inorganiques et Mineraux de l' Environnement, 23, avenue du General de Gaulle, F-94706 Maisons-Alfort Cedex (France)]. E-mail: t.guerin@afssa.fr

    2006-04-21

    The determination of chromium ({sup 52}Cr), iron ({sup 56}Fe) and selenium ({sup 80}Se) isotopes in foodstuffs of animal origin has been performed by collision cell technology (CCT) mode using an inductively coupled plasma mass spectrometry (ICP-MS) as detector after closed vessel microwave digestion. To significantly decrease the argon-based interferences at mass to charge ratios (m/z): 52 ({sup 40}Ar{sup 12}C), 56 ({sup 40}Ar{sup 16}O) and 80 ({sup 40}Ar{sup 40}Ar), the gas-flow rates of a helium and hydrogen mixture used in the hexapole collision cell were optimised to 1.5 ml min{sup -1} H{sub 2} and 0.5 ml min{sup -1} He and the quadrupole bias was adjusted daily between -2 and -15 mV. Limits of quantification (LOQ) of 0.025, 0.086 and 0.041 mg kg{sup -1} for Cr, Fe and Se, respectively, in 6% HNO{sub 3} were estimated under optimized CCT conditions. These LOQ were improved by a factor of approximately 10 for each element compared to standard mode. Precision under repeatability, intermediate precision reproducibility and trueness have been tested on nine different certified reference materials in foodstuffs of animal origin and on an external proficiency testing scheme. The results obtained for chromium, iron and selenium were in all cases in good agreement with the certified values and trueness was improved, compared to those obtained in standard mode.

  3. Multi-element analysis of urine using dynamic reaction cell inductively coupled plasma mass spectrometry (ICP-DRC-MS — A practical application

    Directory of Open Access Journals (Sweden)

    Renata Brodzka

    2013-04-01

    Full Text Available Objectives: The method for the determination of As, Al, Cd, Ni, Pb (toxic elements and Cr, Co, Cu, Fe, Mn, Zn (essential elements in human urine by the use of Inductively Coupled Plasma Mass Spectrometry (quadrupole ICP-MS DRCe Elan, Perkin Elmer with the dynamic reaction cell (DRC was developed. Materials and Methods: The method has been applied for multi-element analysis of the urine of 16 non-exposed healthy volunteers and 27 workers employed in a copper smelter. The analysis was conducted after initial 10-fold dilution of the urine samples with 0,1% nitric acid. Rhodium was used as an internal standard. The method validation parameters such as detection limit, sensitivity, precision were described for all elements. Accuracy of the method was checked by the regular use of certified reference materials ClinCheck®-Control Urine (Recipe as well as by participation of the laboratory in the German External Quality Assessment Scheme (G-EQUAS. Results: The detection limits (DL 3s of the applied method were 0.025, 0.007, 0.002, 0.004, 0.004, 0.086, 0.037, 0.009, 0.016, 0.008, 0.064 (μg/l for Al, As, Cd, Cr, Co, Cu, Fe, Mn, Ni, Pb, Zn in urine, respectively. For each element linearity with correlation coefficient of at least 0.999 was determined. Spectral interferences from some of the ions were removed using DRC-e with addition of alternative gas: methane for cobalt, copper, cadmium, chromium, iron, manganese, nickel and rhodium, and oxygen for arsenic. Conclusions: The developed method allows to determine simultaneously eleven elements in the urine with low detection limits, high sensitivity and good accuracy. Moreover, the method is appropriate for the assessment of both environmental and occupational exposure.

  4. Exploiting dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS) for sequential determination of trace elements in blood using a dilute-and-shoot procedure

    International Nuclear Information System (INIS)

    Lemos Batista, Bruno; Lisboa Rodrigues, Jairo; Andrade Nunes, Juliana; Oliveira Souza, Vanessa Cristina de; Barbosa, Fernando

    2009-01-01

    Inductively coupled plasma mass spectrometry with quadrupole (q-ICP-MS) and dynamic reaction cell (DRC-ICP-MS) were evaluated for sequential determination of As, Cd, Co, Cr, Cu, Mn, Pb, Se, Tl, V and Zn in blood. The method requires as little as 100 μL of blood. Prior to analysis, samples (100 μL) were diluted 1:50 in a solution containing 0.01% (v/v) Triton X-100 and 0.5% (v/v) nitric acid. The use of the DRC was only mandatory for Cr, Cu, V and Zn. For the other elements the equipment may be operated in a standard mode (q-ICP-MS). Ammonia was used as reaction gas. Selection of best flow rate of ammonium gas and optimization of the quadrupole dynamic band-pass tuning parameter (RPq) were carried out, using a ovine base blood for Cr and V and a synthetic matrix solution (SMS) for Zn and Cu diluted 1:50 and spiked to contain 1 μg L -1 of each element. Method detection limits (3 s) for 75 As, 114 Cd, 59 Co, 51 Cr, 63 Cu 55 Mn, 208 Pb, 82 Se, 205 Tl, 51 V, and 64 Zn were 14.0, 3.0, 11.0, 7.0, 280, 9.0, 3.0, 264, 0.7, 6.0 and 800 ng L -1 , respectively. Method validation was accomplished by the analysis of blood Reference Materials produced by the L'Institut National de Sante Publique du Quebec (Canada).

  5. Progress in antenna coupled kinetic inductance detectors

    NARCIS (Netherlands)

    Baryshev, A.; Baselmans, J.J.A.; Freni, A.; Gerini, G.; Hoevers, H.; Iacono, A.; Neto, A.

    2011-01-01

    This paper describes the combined Dutch efforts toward the development of large wideband focal plane array receivers based on kinetic inductance detectors (KIDs). Taking into account strict electromagnetic and detector sensitivity requirements for future ground and space based observatories, this

  6. Determination of glyphosate and AMPA in surface and waste water using high-performance ion chromatography coupled to inductively coupled plasma dynamic reaction cell mass spectrometry (HPIC-ICP-DRC-MS).

    Science.gov (United States)

    Popp, Maximilian; Hann, Stephan; Mentler, Axel; Fuerhacker, Maria; Stingeder, Gerhard; Koellensperger, Gunda

    2008-05-01

    A novel method employing high-performance cation chromatography in combination with inductively coupled plasma dynamic reaction cell mass spectrometry (ICP-DRC-MS) for the simultaneous determination of the herbicide glyphosate (N-phosphonomethylglycine) and its main metabolite aminomethyl phosphonic acid (AMPA) is presented. P was measured as (31)P(16)O(+) using oxygen as reaction gas. For monitoring the stringent target value of 0.1 μg L(-1) for glyphosate, applicable for drinking and surface water within the EU, a two-step enrichment procedure employing Chelex 100 and AG1-X8 resins was applied prior to HPIC-ICP-MS analysis. The presented approach was validated for surface water, revealing concentrations of 0.67 μg L(-1) glyphosate and 2.8 μg L(-1) AMPA in selected Austrian river water samples. Moreover, investigations at three waste water-treatment plants showed that elimination of the compounds at the present concentration levels was not straightforward. On the contrary, all investigated plant effluents showed significant amounts of both compounds. Concentration levels ranged from 0.5-2 μg L(-1) and 4-14 μg L(-1) for glyphosate and AMPA, respectively.

  7. Determination of As and Se in crude oil diluted in xylene by inductively coupled plasma mass spectrometry using a dynamic reaction cell for interference correction on 80Se

    International Nuclear Information System (INIS)

    Albuquerque, Fernanda Inda de; Duyck, Christiane B.; Fonseca, Teresa Cristina O.; Saint'Pierre, Tatiana D.

    2012-01-01

    Arsenic and selenium can be found in crude oils and represent an important source of pollution when released to the environment during any stage of extraction or refinery. These elements present low sensitivity in the direct determination by inductively coupled plasma mass spectrometry (ICP-MS), due to their high ionization potential, and are also prone to spectral interferences. Hydride generation (HG) can be alternatively employed for the separation of these analytes from the sample matrix and introduction into the instrument. However, the required sample preparation usually increases the analysis time. In this work, a method was developed for the determination of As and Se in crude oil by ICP-MS, after sample dilution in xylene. The use of a dynamic reaction cell (DRC) allowed for the overcoming of Ar 2 + interference on 80 Se, but was not necessary for As, since interference on m/z 75 was not observed. The optimized operational conditions for 75 As and 80 Se were: 1350 W of RF power, 0.4 L min −1 of Ar nebulizer and 0.7 L min −1 of Ar auxiliary flow rates. The DRC conditions for 80 Se were 0.5 L min −1 of methane and rejection parameter q (Rpq) of 0.2. The analyses were carried out by analyte addition and the limits of detection (LOD) were 0.04 μg kg −1 for As and 0.1 μg kg −1 for Se. The accuracy was verified by the analysis of residual fuel oil certified material, with agreement at a 95% confidence level. Nine Brazilian crude oil samples were analyzed and the results compared to those obtained by hydride generation ICP-MS. In this case, samples were decomposed with nitric acid in a digester block, the analytes pre-reduced with HCl 6 mol L −1 and the determination carried out by external calibration. Although better instrumental LODs were obtained by HG (0.002 μg kg −1 of As and 0.04 μg kg −1 of Se), the direct determination of As and Se in crude oil diluted in xylene by DRC-ICP-MS showed to be an adequate and a faster method. - Highlights

  8. Development of induction cells at CAEP

    International Nuclear Information System (INIS)

    Wang Huacen; Zhang Kaizhi; Cheng Nian'an; Zhang Wenwei; Lai Qinggui; Wen Long; Zhang Linwen; Deng Jianjun; Ding Bonan

    2002-01-01

    The effects to develop induction cells for induction linac and radiography at CAEP are introduced and reviewed in this paper. During the past two decades, several kinds of cells have been designed and tested, and some of them have been used for construction of induction linac, such as Dragon-1 and 12 MeV, and a Synthetic Test Stand (STS) for comprehensive linac technology study. The structure, test results and performance in the induction linac of these cells are given

  9. High efficiency nebulization for helium inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Jorabchi, Kaveh; McCormick, Ryan; Levine, Jonathan A.; Liu Huiying; Nam, S.-H.; Montaser, Akbar

    2006-01-01

    A pneumatically-driven, high efficiency nebulizer is explored for helium inductively coupled plasma mass spectrometry. The aerosol characteristics and analyte transport efficiencies of the high efficiency nebulizer for nebulization with helium are measured and compared to the results obtained with argon. Analytical performance indices of the helium inductively coupled plasma mass spectrometry are evaluated in terms of detection limits and precision. The helium inductively coupled plasma mass spectrometry detection limits obtained with the high efficiency nebulizer at 200 μL/min are higher than those achieved with the ultrasonic nebulizer consuming 2 mL/min solution, however, precision is generally better with high efficiency nebulizer (1-4% vs. 3-8% with ultrasonic nebulizer). Detection limits with the high efficiency nebulizer at 200 μL/min solution uptake rate approach those using ultrasonic nebulizer upon efficient desolvation with a heated spray chamber followed by a Peltier-cooled multipass condenser

  10. Determination of 90Sr / 238U ratio by double isotope dilution inductively coupled plasma mass spectrometer with multiple collection in spent nuclear fuel samples with in situ 90Sr / 90Zr separation in a collision-reaction cell

    Science.gov (United States)

    Isnard, H.; Aubert, M.; Blanchet, P.; Brennetot, R.; Chartier, F.; Geertsen, V.; Manuguerra, F.

    2006-02-01

    Strontium-90 is one of the most important fission products generated in nuclear industry. In the research field concerning nuclear waste disposal in deep geological environment, it is necessary to quantify accurately and precisely its concentration (or the 90Sr / 238U atomic ratio) in irradiated fuels. To obtain accurate analysis of radioactive 90Sr, mass spectrometry associated with isotope dilution is the most appropriated method. But, in nuclear fuel samples the interference with 90Zr must be previously eliminated. An inductively coupled plasma mass spectrometer with multiple collection, equipped with an hexapole collision cell, has been used to eliminate the 90Sr / 90Zr interference by addition of oxygen in the collision cell as a reactant gas. Zr + ions are converted into ZrO +, whereas Sr + ions are not reactive. A mixed solution, prepared from a solution of enriched 84Sr and a solution of enriched 235U was then used to quantify the 90Sr / 238U ratio in spent fuel sample solutions using the double isotope dilution method. This paper shows the results, the reproducibility and the uncertainties that can be obtained with this method to quantify the 90Sr / 238U atomic ratio in an UOX (uranium oxide) and a MOX (mixed oxide) spent fuel samples using the collision cell of an inductively coupled plasma mass spectrometer with multiple collection to perform the 90Sr / 90Zr separation. A comparison with the results obtained by inductively coupled plasma mass spectrometer with multiple collection after a chemical separation of strontium from zirconium using a Sr spec resin (Eichrom) has been performed. Finally, to validate the analytical procedure developed, measurements of the same samples have been performed by thermal ionization mass spectrometry, used as an independent technique, after chemical separation of Sr.

  11. electrical-thermal coupling of induction machine for improved

    African Journals Online (AJOL)

    user

    This paper summarizes the electrical-thermal coupling of induction machine for improved thermal performance. The interaction of its electrical and mechanical parts leads to an increase in temperature which if not properly monitored may lead to breakdown of the machine. The paper therefore, set out to study the effect of ...

  12. Design And Construction Of Wireless Charging System Using Inductive Coupling

    Directory of Open Access Journals (Sweden)

    Do Lam Mung

    2015-06-01

    Full Text Available Abstract Wireless charging system described by using the method of inductive coupling. In this project oscillation circuit converts DC energy to AC energytransmitter coil to transmit magnetic field by passing frequency and then induce the receiver coil. The properties of Induction coupling are wavemagnetic field-wideband rangevery shortcm efficiencyhight and operation frequencyLF-bandseveral handred kHz.The project shows as a small charging for 5V battery of phone in this method. The system bases on coupling magnetic field then designed and constructed as two parts. There are transmitter part and receiver part. The transmitter coil transmitter part transmits coupling magnetic field to receiver coil receiver part by passing frequency at about 1.67MHz. The Amperes law Biot-Savart law and Faraday law are used to calculate the inductive coupling between the transmitter coil and the receiver coil. The calculation of this law shows how many power transfer in receiver part when how many distance between the transmitter coil and the receiver coil. The system is safe for users and neighbouring electronic devices. To get more accurate wireless charging system it needs to change the design of the following keywords.

  13. Hypoxia-inducible factors: coupling glucose metabolism and redox regulation with induction of the breast cancer stem cell phenotype.

    Science.gov (United States)

    Semenza, Gregg L

    2017-02-01

    Reduced oxygen availability (hypoxia) leads to increased production of reactive oxygen species (ROS) by the electron transport chain. Here, I review recent work delineating mechanisms by which hypoxia-inducible factor 1 (HIF-1) mediates adaptive metabolic responses to hypoxia, including increased flux through the glycolytic pathway and decreased flux through the tricarboxylic acid cycle, in order to decrease mitochondrial ROS production. HIF-1 also mediates increased flux through the serine synthesis pathway and mitochondrial one-carbon (folate cycle) metabolism to increase mitochondrial antioxidant production (NADPH and glutathione). Dynamic maintenance of ROS homeostasis is required for induction of the breast cancer stem cell phenotype in response to hypoxia or cytotoxic chemotherapy. Consistently, inhibition of phosphoglycerate dehydrogenase, the first enzyme of the serine synthesis pathway, in breast cancer cells impairs tumor initiation, metastasis, and response to cytotoxic chemotherapy. I discuss how these findings have important implications for understanding the logic of the tumor microenvironment and for improving therapeutic responses in women with breast cancer. © 2016 The Author.

  14. Two Superconducting Charge Qubits Coupled by a Josephson Inductance

    Science.gov (United States)

    Watanabe, Michio; Yamamoto, Tsuyoshi; Pashkin, Yuri A.; Astafiev, Oleg; Nakamura, Yasunobu; Tsai, Jaw-Shen

    2007-03-01

    When the quantum oscillations [Pashkin et al., Nature 421, 823 (2003)] and the conditional gate operation [Yamamoto et al., Nature 425, 941 (2003)] were demonstrated using superconducting charge qubits, the charge qubits were coupled capacitively, where the coupling was always on and the coupling strength was not tunable. This fixed coupling, however, is not ideal because for example, it makes unconditional gate operations difficult. In this work, we aimed to tunably couple two charge qubits. We fabricated circuits based on the theoretical proposal by You, Tsai, and Nori [PRB 68, 024510 (2003)], where the inductance of a Josephson junction, which has a much larger junction area than the qubit junctions, couples the qubits and the coupling strength is controlled by the external magnetic flux. We confirmed by spectroscopy that the large Josephson junction was indeed coupled to the qubits and that the coupling was turned on and off by the external magnetic flux. In the talk, we will also discuss the quantum oscillations in the circuits.

  15. A Tightly Coupled Non-Equilibrium Magneto-Hydrodynamic Model for Inductively Coupled RF Plasmas

    Science.gov (United States)

    2016-02-29

    Journal Article 3. DATES COVERED (From - To) 12 May 2015 – 06 Oct 2015 4. TITLE AND SUBTITLE A Tightly Coupled Non- Equilibrium Magneto-Hydrodynamic...development a tightly coupled magneto-hydrodynamic model for Inductively Coupled Radio- Frequency (RF) Plasmas. Non Local Thermodynamic Equilibrium (NLTE...effects are described based on a hybrid State-to-State (StS) approach. A multi-temperature formulation is used to account for thermal non- equilibrium

  16. Methodology for monitoring gold nanoparticles and dissolved gold species in culture medium and cells used for nanotoxicity tests by liquid chromatography hyphenated to inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    López-Sanz, Sara; Fariñas, Nuria Rodríguez; Vargas, Rosario Serrano; Martín-Doimeadios, Rosa Del Carmen Rodríguez; Ríos, Ángel

    2017-03-01

    An analytical methodology based on coupling reversed-phase liquid chromatography (HPLC) to an inductively coupled plasma mass spectrometry (ICP-MS) has been developed for the characterization and identification of gold nanoparticles (AuNPs) and gold dissolved species (Au 3+ ) in culture medium (Dulbecco's Modified Eagle Medium, DMEM) and HeLa cells (a human cervical adenocarcinoma cell line) used in nanotoxicity tests. The influence of the culture medium was also studied and the method applied for nanotoxicity tests. It was also observed that AuNPs can undergo an oxidation process in the supernatants and only a small amount of AuNPs and dissolved Au 3+ was associated with cells. To evaluate the biological impact of AuNPs, a classical viability assay onto HeLa cells was performed using cellular media DMEM in the presence of increasing dosage of 10nm AuNPs. The results showed that 10nm AuNPs exhibit a slight toxic effect. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Non-local heating theory inductively coupled plasma discharge

    International Nuclear Information System (INIS)

    Yoon, N.S.; You, K.I.; Hwang, S.M.; Choi, D.I.

    1998-01-01

    Recently developed one- and two-dimensional non-local heating theories of planar type inductively coupled plasma discharge are reviewed and some extensions of the results are presented. The important results of the one- and two-dimensional theories are integrated into the representative concepts of surface impedance and impedance of plasma respectively. Relevant physics are discussed and the works in progress are presented. (author)

  18. Analysis of the Coupling Coefficient in Inductive Energy Transfer Systems

    Directory of Open Access Journals (Sweden)

    Rafael Mendes Duarte

    2014-01-01

    Full Text Available In wireless energy transfer systems, the energy is transferred from a power source to an electrical load without the need of physical connections. In this scope, inductive links have been widely studied as a way of implementing these systems. Although high efficiency can be achieved when the system is operating in a static state, it can drastically decrease if changes in the relative position and in the coupling coefficient between the coils occur. In this paper, we analyze the coupling coefficient as a function of the distance between two planar and coaxial coils in wireless energy transfer systems. A simple equation is derived from Neumann’s equation for mutual inductance, which is then used to calculate the coupling coefficient. The coupling coefficient is computed using CST Microwave Studio and compared to calculation and experimental results for two coils with an excitation signal of up to 10 MHz. The results showed that the equation presents good accuracy for geometric parameters that do not lead the solution of the elliptic integral of the first kind to infinity.

  19. A versatile new torch for inductively coupled plasma spectrometry

    International Nuclear Information System (INIS)

    Ebdon, L.; Mowthorpe, D.J.; Cave, M.R.

    1980-01-01

    A modified torch for optical emission spectrometry with an inductively coupled plasma source is described. The demountable torch incorporates a flared intermediate tube, a capillary injector tube and interchangeable jets at the gas inlets. The optimised performance of the torch is compared with that of a conventional torch. The new torch can be operated over a wide range of gas flows and shows considerable promise in work with an argon-cooled plasma. The ability to operate at high or low gas flow rates, and the possibility of interchanging tubes and jets easily illustrate the versatility of the new design. (Auth.)

  20. SU-8 etching in inductively coupled oxygen plasma

    DEFF Research Database (Denmark)

    Rasmussen, Kristian Hagsted; Keller, Stephan Sylvest; Jensen, Flemming

    2013-01-01

    Structuring or removal of the epoxy based, photo sensitive polymer SU-8 by inductively coupled plasma reactive ion etching (ICP-RIE) was investigated as a function of plasma chemistry, bias power, temperature, and pressure. In a pure oxygen plasma, surface accumulation of antimony from the photo......-initiator introduced severe roughness and reduced etch rate significantly. Addition of SF6 to the plasma chemistry reduced the antimony surface concentration with lower roughness and higher etch rate as an outcome. Furthermore the etch anisotropy could be tuned by controlling the bias power. Etch rates up to 800 nm...

  1. Development of a low-cost inductively coupled argon plasma

    International Nuclear Information System (INIS)

    Ripson, P.A.M.

    1983-01-01

    The aim of this investigation is to drastically reduce running costs of an inductively coupled plasma. This is done by reducing the argon consumption from 20 l/min to about 1 l/min. First, a sample introduction system operating on 0.1 l/min of carrier argon is described. This system ensures a high ratio of plasma argon and carrier argon even at the low total argon consumptions intended. Next, the developed low consumption plasma is presented. In the proposed design, air is blown perpendicularly against the outside of the torch. A different coil has been developed to make air-cooling efficient. Preliminary data on coupling efficiency for the air-cooled plasma are presented. A similarly low argon consumption has been achieved with water as an external coolant medium. It is concluded that a cheaper alternative to the current ICP has become available. (Auth.)

  2. Microwave Kinetic Inductance Detector with Selective Polarization Coupling

    Science.gov (United States)

    Wollack, Edward; U-yen, Kongpop; Stevenson, Thomas; Brown, Ari; Moseley, Samuel; Hsieh, Wen-Ting

    2013-01-01

    A conventional low-noise detector requires a technique to both absorb incident power and convert it to an electrical signal at cryogenic temperatures. This innovation combines low-noise detector and readout functionality into one device while maintaining high absorption, controlled polarization sensitivity, and broadband detection capability. The resulting far-infrared detectors can be read out with a simple approach, which is compact and minimizes thermal loading. The proposed microwave kinetic inductance detector (MKID) consists of three basic elements. The first is the absorptive section in which the incident power is coupled to a superconducting resonator at far-infrared frequency above its superconducting critical frequency (where superconductor becomes normal conductor). This absorber's shape effectively absorbs signals in the desired polarization state and is resonant at the radio frequency (RF) used for readout of the device. Control over the metal film used in the absorber allows realization of structures with either a 50% broadband or 100% resonance absorptance over a 30% fractional bandwidth. The second element is a microwave resonator - which is realized from the thin metal films used to make the absorber as transmission lines - whose resonance frequency changes due to a variation in its kinetic inductance. The resonator's kinetic inductance is a function of the power absorbed by the device. A low-loss dielectric (mono-crystalline silicon) is used in a parallel-plate transmission line structure to realize the desired superconducting resonators. There is negligible coupling among the adjacent elements used to define the polarization sensitivity of each detector. The final component of the device is a microwave transmission line, which is coupled to the resonator, and allows detection of changes in resonance frequency for each detector in the focal plane array. The spiral shape of the detector's absorber allows incident power with two polarizations to

  3. Electron energy distributions in a magnetized inductively coupled plasma

    International Nuclear Information System (INIS)

    Song, Sang-Heon; Yang, Yang; Chabert, Pascal; Kushner, Mark J.

    2014-01-01

    Optimizing and controlling electron energy distributions (EEDs) is a continuing goal in plasma materials processing as EEDs determine the rate coefficients for electron impact processes. There are many strategies to customize EEDs in low pressure inductively coupled plasmas (ICPs), for example, pulsing and choice of frequency, to produce the desired plasma properties. Recent experiments have shown that EEDs in low pressure ICPs can be manipulated through the use of static magnetic fields of sufficient magnitudes to magnetize the electrons and confine them to the electromagnetic skin depth. The EED is then a function of the local magnetic field as opposed to having non-local properties in the absence of the magnetic field. In this paper, EEDs in a magnetized inductively coupled plasma (mICP) sustained in Ar are discussed with results from a two-dimensional plasma hydrodynamics model. Results are compared with experimental measurements. We found that the character of the EED transitions from non-local to local with application of the static magnetic field. The reduction in cross-field mobility increases local electron heating in the skin depth and decreases the transport of these hot electrons to larger radii. The tail of the EED is therefore enhanced in the skin depth and depressed at large radii. Plasmas densities are non-monotonic with increasing pressure with the external magnetic field due to transitions between local and non-local kinetics

  4. Cs-Ba separation using N 2O as a reactant gas in a Multiple Collector-Inductively Coupled Plasma Mass Spectrometer collision-reaction cell: Application to the measurements of Cs isotopes in spent nuclear fuel samples

    Science.gov (United States)

    Granet, M.; Nonell, A.; Favre, G.; Chartier, F.; Isnard, H.; Moureau, J.; Caussignac, C.; Tran, B.

    2008-11-01

    In the general frameworks of the nuclear fuel cycle and environmental research field, the Cs isotopic composition must be known with high precision and accuracy. The direct determination of Cs isotopes by mass spectrometry techniques is generally hampered by the presence of Ba isobaric interferences however. Here we present a new method which takes advantage of the collision-reaction cell based Multiple Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICPMS) and allows to analyse Cs isotopes in the presence of Ba without prior separation step. The addition of N 2O gas in the cell leads to an antagonistic behavior of Cs + and Ba + as the latter reacts with the gas to form BaO + and BaOH + products whereas Cs + remains unreactive. The efficiency of the method was demonstrated for an UOx sample by comparing the results obtained (1) from the measurements of pure Cs fractions and (2) from Fission Products fractions containing more than 30 ionisable elements in addition to Cs, Ba, and where U and Pu were previously removed by using ion exchange resin. An excellent agreement is achieved between each set of experiments with an external reproducibility always better than 0.5% (RSD, k = 2). This study confirms the strong potential of collision-reaction cell to measure Cs isotopes in presence of interfering Ba, precluding therefore former systematic chemical separations.

  5. Cs-Ba separation using N{sub 2}O as a reactant gas in a Multiple Collector-Inductively Coupled Plasma Mass Spectrometer collision-reaction cell: Application to the measurements of Cs isotopes in spent nuclear fuel samples

    Energy Technology Data Exchange (ETDEWEB)

    Granet, M. [Commissariat a l' Energie Atomique, DEN/DPC/SECR/LANIE, 91191 Gif-sur-Yvette Cedex (France)], E-mail: mathieu.granet@cea.fr; Nonell, A.; Favre, G. [Commissariat a l' Energie Atomique, DEN/DPC/SECR/LANIE, 91191 Gif-sur-Yvette Cedex (France); Chartier, F. [Commissariat a l' Energie Atomique, DEN/DPC, 91191 Gif-sur-Yvette Cedex (France); Isnard, H.; Moureau, J.; Caussignac, C.; Tran, B. [Commissariat a l' Energie Atomique, DEN/DPC/SECR/LANIE, 91191 Gif-sur-Yvette Cedex (France)

    2008-11-15

    In the general frameworks of the nuclear fuel cycle and environmental research field, the Cs isotopic composition must be known with high precision and accuracy. The direct determination of Cs isotopes by mass spectrometry techniques is generally hampered by the presence of Ba isobaric interferences however. Here we present a new method which takes advantage of the collision-reaction cell based Multiple Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICPMS) and allows to analyse Cs isotopes in the presence of Ba without prior separation step. The addition of N{sub 2}O gas in the cell leads to an antagonistic behavior of Cs{sup +} and Ba{sup +} as the latter reacts with the gas to form BaO{sup +} and BaOH{sup +} products whereas Cs{sup +} remains unreactive. The efficiency of the method was demonstrated for an UOx sample by comparing the results obtained (1) from the measurements of pure Cs fractions and (2) from Fission Products fractions containing more than 30 ionisable elements in addition to Cs, Ba, and where U and Pu were previously removed by using ion exchange resin. An excellent agreement is achieved between each set of experiments with an external reproducibility always better than 0.5% (RSD, k = 2). This study confirms the strong potential of collision-reaction cell to measure Cs isotopes in presence of interfering Ba, precluding therefore former systematic chemical separations.

  6. Using Some Coupled Numerical Models in Problems of Designing an Inductive Electrothermal Equipment

    Directory of Open Access Journals (Sweden)

    LEUCA Teodor

    2014-05-01

    Full Text Available This paper focuses on the numerical modeling of coupling the electromagnetic and the thermal field, in the process of inductive heating, for inductive electrothermal equipments. Numerical results are carried out by using a FLUX2D application.

  7. Wave stimulated phenomena in inductively coupled magnetized plasmas

    International Nuclear Information System (INIS)

    Shamrai, K P; Shinohara, S; Virko, V F; Slobodyan, V M; Virko, Yu V; Kirichenko, G S

    2005-01-01

    Linear and nonlinear wave phenomena and their influence on the discharge performance are considered in the helicon plasma (HP) and magnetized inductively coupled plasma (MICP). Magnetic field configuration is shown to result in strong variation in the efficiency of plasma production caused by alterations of the character of wave processes rather than by the particle confinement. Effects of magnetic configuration are found to be dominant in operation of the compact HP with permanent magnet. Low frequency turbulence in the megahertz range is revealed to be inherent for both the HP and MICP and to depend strongly on the magnetic configuration. Enhanced axial electric field arising in front of the metal end plate in the HP is argued to be a potential source of the nonlinear effects

  8. Diagnostic studies of ion beam formation in inductively coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Jenee L. [Iowa State Univ., Ames, IA (United States)

    2015-01-01

    This dissertation describes a variety of studies focused on the plasma and the ion beam in inductively coupled plasma mass spectrometry (ICP-MS). The ability to use ICP-MS for measurements of trace elements in samples requires the analytes to be efficiently ionized. Updated ionization efficiency tables are discussed for ionization temperatures of 6500 K and 7000 K with an electron density of 1 x 1015 cm-3. These values are reflective of the current operating parameters of ICP-MS instruments. Calculations are also discussed for doubly charged (M2+) ion formation, neutral metal oxide (MO) ionization, and metal oxide (MO+) ion dissociation for similar plasma temperature values. Ionization efficiency results for neutral MO molecules in the ICP have not been reported previously.

  9. A new nebulizer for inductively coupled plasma spectrometry

    International Nuclear Information System (INIS)

    Rademeyer, C.D.; Collins, C.; Butler, L.; Human, C.

    1989-01-01

    A nebulizer for use in Inductively Coupled Plasma Emission Spectroscopy (ICP-ES) is designed. An unusual concept is used to generate the aerosol. The system is mechanically reliable, relatively simple and cheap to construct compared to the currently available commercial systems. The effect of geometrical design parameters (e.g. the droplet size mass distribution of the aerosol particles) on performance of the system is presented. The analytical merit of the newly designed system is determined by measuring its analytical performance. Detection limits and analytical range are measured for Cu, Ag, Au, Pt, Pb, Cd, V, Fe, Mn, Mo, B, Se and Zn. These values are compared with detection limits and analytical ranges obtained with commercial systems. The persistence of memory effects is found to be the major disadvantage of the system. Results are presented showing these effects and possible ways to eliminate them. (author)

  10. Low-pressure water-cooled inductively coupled plasma torch

    Science.gov (United States)

    Seliskar, Carl J.; Warner, David K.

    1988-12-27

    An inductively coupled plasma torch is provided which comprises an inner tube, including a sample injection port to which the sample to be tested is supplied and comprising an enlarged central portion in which the plasma flame is confined; an outer tube surrounding the inner tube and containing water therein for cooling the inner tube, the outer tube including a water inlet port to which water is supplied and a water outlet port spaced from the water inlet port and from which water is removed after flowing through the outer tube; and an r.f. induction coil for inducing the plasma in the gas passing into the tube through the sample injection port. The sample injection port comprises a capillary tube including a reduced diameter orifice, projecting into the lower end of the inner tube. The water inlet is located at the lower end of the outer tube and the r.f. heating coil is disposed around the outer tube above and adjacent to the water inlet.

  11. Matrix effects in inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiaoshan [Iowa State Univ., Ames, IA (United States)

    1995-07-07

    The inductively coupled plasma is an electrodeless discharge in a gas (usually Ar) at atmospheric pressure. Radio frequency energy generated by a RF power source is inductively coupled to the plasma gas through a water cooled load coil. In ICP-MS the "Fassel" TAX quartz torch commonly used in emission is mounted horizontally. The sample aerosol is introduced into the central flow, where the gas kinetic temperature is about 5000 K. The aerosol is vaporized, atomized, excited and ionized in the plasma, and the ions are subsequently extracted through two metal apertures (sampler and skimmer) into the mass spectrometer. In ICP-MS, the matrix effects, or non-spectroscopic interferences, can be defined as the type of interferences caused by dissolved concomitant salt ions in the solution. Matrix effects can be divided into two categories: (1) signal drift due to the deposition of solids on the sampling apertures; and/or (2) signal suppression or enhancement by the presence of the dissolved salts. The first category is now reasonably understood. The dissolved salts, especially refractory oxides, tend to deposit on the cool tip of the sampling cone. The clogging of the orifices reduces the ion flow into the ICP-MS, lowers the pressure in the first stage of ICP-MS, and enhances the level of metal oxide ions. Because the extent of the clogging increases with the time, the signal drifts down. Even at the very early stage of the development of ICP-MS, matrix effects had been observed. Houk et al. found out that the ICP-MS was not tolerant to solutions containing significant amounts of dissolved solids.

  12. Matrix effects in inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Chen, Xiaoshan.

    1995-01-01

    The inductively coupled plasma is an electrodeless discharge in a gas (usually Ar) at atmospheric pressure. Radio frequency energy generated by a RF power source is inductively coupled to the plasma gas through a water cooled load coil. In ICP-MS the open-quotes Fasselclose quotes TAX quartz torch commonly used in emission is mounted horizontally. The sample aerosol is introduced into the central flow, where the gas kinetic temperature is about 5000 K. The aerosol is vaporized, atomized, excited and ionized in the plasma, and the ions are subsequently extracted through two metal apertures (sampler and skimmer) into the mass spectrometer. In ICP-MS, the matrix effects, or non-spectroscopic interferences, can be defined as the type of interferences caused by dissolved concomitant salt ions in the solution. Matrix effects can be divided into two categories: (1) signal drift due to the deposition of solids on the sampling apertures; and/or (2) signal suppression or enhancement by the presence of the dissolved salts. The first category is now reasonably understood. The dissolved salts, especially refractory oxides, tend to deposit on the cool tip of the sampling cone. The clogging of the orifices reduces the ion flow into the ICP-MS, lowers the pressure in the first stage of ICP-MS, and enhances the level of metal oxide ions. Because the extent of the clogging increases with the time, the signal drifts down. Even at the very early stage of the development of ICP-MS, matrix effects had been observed. Houk et al. found out that the ICP-MS was not tolerant to solutions containing significant amounts of dissolved solids

  13. Development of a method based on inductively coupled plasma-dynamic reaction cell-mass spectrometry for the simultaneous determination of phosphorus, calcium and strontium in bone and dental tissue

    International Nuclear Information System (INIS)

    De Muynck, David; Vanhaecke, Frank

    2009-01-01

    A method, based on the use of a quadrupole-based inductively coupled plasma-mass spectrometry instrument equipped with a quadrupole-based collision/reaction cell (dynamic reaction cell, DRC), was developed for the simultaneous determination of phosphorus, calcium and strontium in bone and dental (enamel and dentine) tissue. The use of NH 3 , introduced at a gas flow rate of 0.8 mL min -1 in the dynamic reaction cell, combined with a rejection parameter q (RPq) setting of 0.65, allows interference-free determination of calcium via its low-abundant isotopes 42 Ca, 43 Ca and 44 Ca, and of strontium via its isotopes 86 Sr and 88 Sr that are freed from overlap due to the occurrence of ArCa + and/or Ca 2 + ions. Also the determination of phosphorus ( 31 P, mono-isotopic) was shown to be achievable using the same dynamic reaction cell operating conditions. The bone certified reference materials NIST SRM 1400 Bone Ash and NIST SRM 1486 Bone Meal were used for validation of the measurement protocol that was shown capable of providing accurate and reproducible results. Detection limits of P, Ca and Sr in dental tissue digests were established as 3 μg L -1 for P, 2 μg L -1 for Ca and 0.2 μg L -1 for Sr. This method can be used to simultaneously (i) evaluate the impact of diagenesis on the elemental and isotopic composition of buried skeletal tissue via its Ca/P ratio and (ii) determine its Sr concentration. The measurement protocol was demonstrated as fit-for-purpose by the analysis of a set of teeth of archaeological interest for their Ca/P ratio and Sr concentration.

  14. Effect of inter-tissue inductive coupling on multi-frequency imaging of intracranial hemorrhage by magnetic induction tomography

    Science.gov (United States)

    Xiao, Zhili; Tan, Chao; Dong, Feng

    2017-08-01

    Magnetic induction tomography (MIT) is a promising technique for continuous monitoring of intracranial hemorrhage due to its contactless nature, low cost and capacity to penetrate the high-resistivity skull. The inter-tissue inductive coupling increases with frequency, which may lead to errors in multi-frequency imaging at high frequency. The effect of inter-tissue inductive coupling was investigated to improve the multi-frequency imaging of hemorrhage. An analytical model of inter-tissue inductive coupling based on the equivalent circuit was established. A set of new multi-frequency decomposition equations separating the phase shift of hemorrhage from other brain tissues was derived by employing the coupling information to improve the multi-frequency imaging of intracranial hemorrhage. The decomposition error and imaging error are both decreased after considering the inter-tissue inductive coupling information. The study reveals that the introduction of inter-tissue inductive coupling can reduce the errors of multi-frequency imaging, promoting the development of intracranial hemorrhage monitoring by multi-frequency MIT.

  15. Effect of microstructure of TiN film on properties as bipolar plate coatings in polymer electrolyte membrane fuel cell prepared by inductively coupled plasma assisted magnetron sputtering

    International Nuclear Information System (INIS)

    Feng, Kai; Li, Zhuguo

    2013-01-01

    As potential application in bipolar plate of polymer electrolyte membrane fuel cell, the microstructure, corrosion resistance and the electrical conductivity of titanium nitride (TiN) and Si doped titanium nitride (Ti 0.9 Si 0.1 N) films deposited by magnetron sputtering with different bias voltages are investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscope (AFM), electrochemical test and four-point probe method, respectively. XRD, SEM and AFM results reveal that the texture and topography of TiN film depend on the bias voltage and incorporation of Si. When the bias voltage is − 20 V and − 30 V, the TiN and Ti 0.9 Si 0.1 N films exhibit a dense (111) plane preferred growth, denser structure and smoother surface topography. The potentiodynamic test results indicate that the TiN and Ti 0.9 Si 0.1 N films have higher chemical inertness and better corrosion resistance. The films can satisfy the requirement of current density for bipolar plate materials. Incorporation of Si element into TiN film makes the passive current density more stable. Four-point probe measurement results show that the resistivity of both TiN and Ti 0.9 Si 0.1 N films reaches minimum when the deposition bias voltage is − 20 V. - Highlights: • Dense TiN and Ti 0.9 Si 0.1 N films are deposited by magnetron sputtering. • Preferred growth orientation of TiN depends on the bias voltage and Si doping. • TiN and Ti 0.9 Si 0.1 N films have excellent corrosion resistance. • Surface conductivity of TiN and Ti 0.9 Si 0.1 N films evolves with bias voltage

  16. Simultaneous determination of Cr(iii) and Cr(vi) using reversed-phased ion-pairing liquid chromatography with dynamic reaction cell inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Wolf, R.E.; Morrison, J.M.; Goldhaber, M.B.

    2007-01-01

    A method for the simultaneous determination of Cr(iii) and Cr(vi) species in waters, soil leachates and synthetic bio-fluids is described. The method uses reversed-phase ion-pairing liquid chromatography to separate the chromium species and a dynamic reaction cell (DRC??) equipped ICP-MS for detection of chromium. Separation of the chromium species is carried out in less than 2 min. Cr(iii) is complexed with ethylenediaminetetraacetic acid (EDTA) prior to separation by mixing samples with the mobile phase containing 2.0 mM tetrabutylammonium hydroxide (TBAOH), 0.5 mM EDTA (dipotassium salt), and 5% (vol/vol) methanol, adjusted to pH 7.6. The interfering 40Ar 12C+ background peak at mass 52 was reduced by over four orders of magnitude to less than 200 cps by using 0.65 mL min-1 ammonia as a reaction gas and an RPq setting on the DRC of 0.75. Method detection limits (MDLs) of 0.09 ??g L-1 for Cr(iii) and 0.06 ??g L-1 for Cr(vi) were obtained based on peak areas at mass 52 for 50 ??L injections of low level spikes. Reproducibility at 2 ??g L-1 was 3% RSD for 5 replicate injections. The tolerance of the method to various levels of common cations and anions found in natural waters and to matrix constituents found in soil leachates and simulated gastric and lung fluids was tested by performing spike recovery calculations for a variety of samples. ?? The Royal Society of Chemistry.

  17. Determination of {sup 90}Sr in soil samples using inductively coupled plasma mass spectrometry equipped with dynamic reaction cell (ICP-DRC-MS)

    Energy Technology Data Exchange (ETDEWEB)

    Feuerstein, J.; Boulyga, S.F.; Galler, P.; Stingeder, G. [Department of Chemistry, Division of Analytical Chemistry-VIRIS Laboratory, University of Natural Resources and Applied Life Sciences, Muthgasse 18, A-1190 Vienna (Austria); Prohaska, T. [Department of Chemistry, Division of Analytical Chemistry-VIRIS Laboratory, University of Natural Resources and Applied Life Sciences, Muthgasse 18, A-1190 Vienna (Austria)], E-mail: thomas.prohaska@boku.ac.at

    2008-11-15

    A rapid method is reported for the determination of {sup 90}Sr in contaminated soil samples in the vicinity of the Chernobyl Nuclear Power Plant by ICP-DRC-MS. Sample preparation and measurement procedures focus on overcoming the isobaric interference of {sup 90}Zr, which is present in soils at concentrations higher by more than six orders of magnitude than {sup 90}Sr. Zirconium was separated from strontium in two steps to reduce the interference by {sup 90}Zr{sup +} ions by a factor of more than 10{sup 7}: (i) by ion exchange using a Sr-specific resin and (ii) by reaction with oxygen as reaction gas in a dynamic reaction cell (DRC) of a quadrupole ICP-MS. The relative abundance sensitivity of the ICP-MS was studied systematically and the peak tailing originating from {sup 88}Sr on mass 90 u was found to be about 3 x 10{sup -9}. Detection limits of 4 fg g{sup -1} (0.02 Bq g{sup -1}) were achieved when measuring Sr solutions containing no Zr. In digested uncontaminated soil samples after matrix separation as well as in a solution of 5 {mu}g g{sup -1} Sr and 50 ng g{sup -1} Zr a detection limit of 0.2 pg g{sup -1} soil (1 Bq g{sup -1} soil) was determined. {sup 90}Sr concentrations in three soil samples collected in the vicinity of the Chernobyl Nuclear Power Plant were 4.66 {+-} 0.27, 13.48 {+-} 0.68 and 12.9 {+-} 1.5 pg g{sup -1} corresponding to specific activities of 23.7 {+-} 1.3, 68.6 {+-} 3.5 and 65.6 {+-} 7.8 Bq g{sup -1}, respectively. The ICP-DRC-MS results were compared to the activities measured earlier by radiometry. Although the ICP-DRC-MS is inferior to commonly used radiometric methods with respect to the achievable minimum detectable activity it represents a time- and cost-effective alternative technique for fast monitoring of high-level {sup 90}Sr contamination in environmental or nuclear industrial samples down to activities of about 1 Bq g{sup -1}.

  18. -3000 V dc bias Ti oxidation by inductively coupled plasma

    International Nuclear Information System (INIS)

    Valencia-Alvarado, R; Lopez-Callejas, R; Barocio, S R; Mercado-Cabrera, A; Pena-Eguiluz, R; Munoz-Castro, A E; De la Piedad-Beneitez, A; De la Rosa-Vazquez, J

    2008-01-01

    Broadening the outer oxidized layer of titanium by means of plasmas commands considerable interest in the biomedical research area due to its potential in human biocompatibility enhancement. Some early results of titanium substrate superficial oxidation experiments which have been conducted in a cylindrical vessel inductively coupled to a 13.56 MHz RF generator with a 500 W output are presented. The oxidation process was carried out in a 20 % oxygen and 80 % argon mixture at work pressures in the 5x10 -3 -1 mbar range, while the samples were dc biased down to -3000 V. The substrate temperature appears to be directly dependent on this voltage, reaching 685 deg. C at the maximum bias when a diffusive oxidation process gives rise to the TiO 2 and α-TiO rutile phases. These were characterized by means of x-ray diffraction and scanning electron microscopy revealing atomic percentage concentrations of oxygen, with respect to those of titanium, between 68 and 13 at.%. The optimum modified layer depth reached 5 μm at a 5x10 -2 mbar work pressure.

  19. Experimental study of reduced size inductively coupled plasma torches

    International Nuclear Information System (INIS)

    Allemand, C.D.; Barnes, R.M.; Wohlers, C.C.

    1979-01-01

    A new design of inductively coupled plasma torches embodies smooth contours and sharp edges to achieve laminar flow for sample confinement and an optimized ratio of the diameter of the two outer tubes to ease maintenance and operation of the discharge. Results are presented for a 13-mm and a 9-mm version of the new configuration and are compared to data for a standard 8-mm version. For spectrochemical analyses, the detection limits obtained with the 13-mm torch were about the same as obtained with the standard 18-mm and those obtained with the 9-mm torch were similar or poorer. The theoretical prediction that smaller torches require higher magnetic flux densities was confirmed quantitatively by operation of the 9-mm torch. The 13-mm torch consumed less power and gas than the standard 18-mm torch at equivelent analytical performance level. The torches were compared for the determination of Al, As, Ba, Ca, Cd, Co, Cr(II), Cr(I), Cu, Fe, K, Mg, Mn, Mo, P, Pb, Sn, Sr, Ti, U, V, and Zn

  20. Uranium quantification in semen by inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Todorov, Todor; Ejnik, John W.; Guandalini, Gustavo S.; Xu, Hanna; Hoover, Dennis; Anderson, Larry W.; Squibb, Katherine; McDiarmid, Melissa A.; Centeno, Jose A.

    2013-01-01

    In this study we report uranium analysis for human semen samples. Uranium quantification was performed by inductively coupled plasma mass spectrometry. No additives, such as chymotrypsin or bovine serum albumin, were used for semen liquefaction, as they showed significant uranium content. For method validation we spiked 2 g aliquots of pooled control semen at three different levels of uranium: low at 5 pg/g, medium at 50 pg/g, and high at 1000 pg/g. The detection limit was determined to be 0.8 pg/g uranium in human semen. The data reproduced within 1.4–7% RSD and spike recoveries were 97–100%. The uranium level of the unspiked, pooled control semen was 2.9 pg/g of semen (n = 10). In addition six semen samples from a cohort of Veterans exposed to depleted uranium (DU) in the 1991 Gulf War were analyzed with no knowledge of their exposure history. Uranium levels in the Veterans’ semen samples ranged from undetectable (<0.8 pg/g) to 3350 pg/g. This wide concentration range for uranium in semen is consistent with known differences in current DU body burdens in these individuals, some of whom have retained embedded DU fragments.

  1. Silicon dioxide etching yield measurements with inductively coupled fluorocarbon plasmas

    International Nuclear Information System (INIS)

    Chae, Heeyeop; Vitale, Steven A.; Sawin, Herbert H.

    2003-01-01

    Oxide etching yield has been measured directly with inductively coupled fluorocarbon plasmas. The yields measurement technique of this work can provide useful information for feature profile evolution modeling, which is essential to understand various issues in oxide etching such as reactive ion etching (RIE) lag, inverse RIE lag, etch stop, microtrenching, bowing, etc. Etching and deposition yields per ion were measured using quartz crystal microbalance (QCM) as a function of ion bombardment energy, ion-to-neutral flux ratio, and ion-impinging angle. C 2 HF 5 , C 2 F 6 , C 2 H 4 F 2 , and C 4 F 8 were used for the oxide etching. Oxide etching mechanism with those gases is complex because etching and deposition are involved at the same time. In highly selective processes fluorocarbon deposition plays important role in determining etching characteristics. Two fluorocarbon deposition mechanisms are identified in this work: neutral deposition and ion-enhanced deposition. The low-energy ions are believed to enhance the deposition rates by creating active sites and fluorocarbon neutrals deposit on the active sites with higher sticking probability. A surface kinetic model is suggested to explain the ion-enhanced mechanism and shows good agreement with experimental data. Angular yield measurement shows that when fluorocarbon deposition is relatively severe, etching yield decreases significantly as the incident angle increases and deposit fluorocarbon at a high incident angle above 60 deg. C

  2. Time to Reconsider Stem Cell Induction Strategies

    Directory of Open Access Journals (Sweden)

    Hans-Werner Denker

    2012-12-01

    Full Text Available Recent developments in stem cell research suggest that it may be time to reconsider the current focus of stem cell induction strategies. During the previous five years, approximately, the induction of pluripotency in somatic cells, i.e., the generation of so-called ‘induced pluripotent stem cells’ (iPSCs, has become the focus of ongoing research in many stem cell laboratories, because this technology promises to overcome limitations (both technical and ethical seen in the production and use of embryonic stem cells (ESCs. A rapidly increasing number of publications suggest, however, that it is now possible to choose instead other, alternative ways of generating stem and progenitor cells bypassing pluripotency. These new strategies may offer important advantages with respect to ethics, as well as to safety considerations. The present communication discusses why these strategies may provide possibilities for an escape from the dilemma presented by pluripotent stem cells (self-organization potential, cloning by tetraploid complementation, patenting problems and tumor formation risk.

  3. Excellent Silicon Surface Passivation Achieved by Industrial Inductively Coupled Plasma Deposited Hydrogenated Intrinsic Amorphous Silicon Suboxide

    Directory of Open Access Journals (Sweden)

    Jia Ge

    2014-01-01

    Full Text Available We present an alternative method of depositing a high-quality passivation film for heterojunction silicon wafer solar cells, in this paper. The deposition of hydrogenated intrinsic amorphous silicon suboxide is accomplished by decomposing hydrogen, silane, and carbon dioxide in an industrial remote inductively coupled plasma platform. Through the investigation on CO2 partial pressure and process temperature, excellent surface passivation quality and optical properties are achieved. It is found that the hydrogen content in the film is much higher than what is commonly reported in intrinsic amorphous silicon due to oxygen incorporation. The observed slow depletion of hydrogen with increasing temperature greatly enhances its process window as well. The effective lifetime of symmetrically passivated samples under the optimal condition exceeds 4.7 ms on planar n-type Czochralski silicon wafers with a resistivity of 1 Ωcm, which is equivalent to an effective surface recombination velocity of less than 1.7 cms−1 and an implied open-circuit voltage (Voc of 741 mV. A comparison with several high quality passivation schemes for solar cells reveals that the developed inductively coupled plasma deposited films show excellent passivation quality. The excellent optical property and resistance to degradation make it an excellent substitute for industrial heterojunction silicon solar cell production.

  4. An investigation of algebraic quantum dynamics for mesoscopic coupled electric circuits with mutual inductance

    International Nuclear Information System (INIS)

    Pahlavani, H.; Kolur, E. Rahmanpour

    2016-01-01

    Based on the electrical charge discreteness, the Hamiltonian operator for the mutual inductance coupled quantum mesoscopic LC circuits has been found. The persistent current on two driven coupled mesoscopic electric pure L circuits (two quantum loops) has been obtained by using algebraic quantum dynamic approach. The influence of the mutual inductance on energy spectrum and quantum fluctuations of the charge and current for two coupled quantum electric mesoscopic LC circuits have been investigated.

  5. Influence of operating frequency and coupling coefficient on the efficiency of microfabricated inductively coupled plasma sources

    International Nuclear Information System (INIS)

    Iza, F; Hopwood, J

    2002-01-01

    Microfabricated inductively coupled plasma (mICP) generators, operating at 690 and 818 MHz, have been constructed and characterized. The mICP consists of a single-turn coil that is 5 mm in diameter and a microfabricated matching network. Ion densities of ∼9x10 10 cm -3 in argon at 400 mTorr consuming only 1 W were obtained. This ion density is three times larger than previous mICP sources under the same conditions. The influence of the frequency of operation and the coupling coefficient on the power efficiency has also been studied. Contrary to what was observed in former generations of mICP sources operating at lower frequencies, the efficiency of the new mICP sources decreases as the frequency increases. A model that incorporates the electron inertia, the power dependence of the plasma resistance and the frequency dependence of the coil resistance agrees with the new experimental results as well as with the results of previous mICP sources. It was also observed that bringing the coil closer to the plasma increases the coupling coefficient of the ICP sources and thereby improves the efficiency of the device. The improvement in efficiency, however, is limited by the non-scalable plasma sheath width near the coil

  6. Skeletal Muscle Cell Induction from Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Yusaku Kodaka

    2017-01-01

    Full Text Available Embryonic stem cells (ESCs and induced pluripotent stem cells (iPSCs have the potential to differentiate into various types of cells including skeletal muscle cells. The approach of converting ESCs/iPSCs into skeletal muscle cells offers hope for patients afflicted with the skeletal muscle diseases such as the Duchenne muscular dystrophy (DMD. Patient-derived iPSCs are an especially ideal cell source to obtain an unlimited number of myogenic cells that escape immune rejection after engraftment. Currently, there are several approaches to induce differentiation of ESCs and iPSCs to skeletal muscle. A key to the generation of skeletal muscle cells from ESCs/iPSCs is the mimicking of embryonic mesodermal induction followed by myogenic induction. Thus, current approaches of skeletal muscle cell induction of ESCs/iPSCs utilize techniques including overexpression of myogenic transcription factors such as MyoD or Pax3, using small molecules to induce mesodermal cells followed by myogenic progenitor cells, and utilizing epigenetic myogenic memory existing in muscle cell-derived iPSCs. This review summarizes the current methods used in myogenic differentiation and highlights areas of recent improvement.

  7. Design of an Improved Type Rotary Inductive Coupling Structure for Rotatable Contactless Power Transfer System

    Directory of Open Access Journals (Sweden)

    Lee Jia-You

    2015-01-01

    Full Text Available This paper is aimed at analyzing the rotary inductive coupling structure of contactless rotary transformer. The main feature of the proposed rotatable contactless power transfer system is which winding is coaxial-interlayered for improving the magnetic coupling capability. There is no ferrite core used in the secondary-side of the rotary inductive coupling structure, this helps to ease the exerted force that is stress by the secondary-side on spindle. In order to verify the feasibility of the proposed contactless power transfer system for rotary applications, an inductive powered rotary machinery and the control system have been integrated. The experimental results show that the maximum power transfer efficiency of the proposed rotary inductive coupling structure is about 94.8%. The maximum output power received in the load end is 1030 W with transmission efficiency of 88%.

  8. Multi-elemental characterization of tunnel and road dusts in Houston, Texas using dynamic reaction cell-quadrupole-inductively coupled plasma–mass spectrometry: Evidence for the release of platinum group and anthropogenic metals from motor vehicles

    International Nuclear Information System (INIS)

    Spada, Nicholas; Bozlaker, Ayse; Chellam, Shankararaman

    2012-01-01

    Highlights: ► Analytical method for PGEs, main group, transition and rare earth metals developed. ► Comprehensive characterization of road and tunnel dust samples was accomplished. ► PGEs in dusts arise from autocatalyst attrition. ► Mobile sources also contributed to Cu, Zn, Ga, As, Mo, Cd, Sn, Sb, Ba, W and Pb. ► All other elements, including rare earths arose from crustal sources. - Abstract: Platinum group elements (PGEs) including Rh, Pd, and Pt are important tracers for vehicular emissions, though their measurement is often challenging and difficult to replicate in environmental campaigns. These challenges arise from sample preparation steps required for PGE quantitation, which often cause severe isobaric interferences and spectral overlaps from polyatomic species of other anthropogenically emitted metals. Consequently, most previous road dust studies have either only quantified PGEs or included a small number of anthropogenic elements. Therefore a novel analytical method was developed to simultaneously measure PGEs, lanthanoids, transition and main group elements to comprehensively characterize the elemental composition of urban road and tunnel dusts. Dust samples collected from the vicinity of high-traffic roadways and a busy underwater tunnel restricted to single-axle (predominantly gasoline-driven) vehicles in Houston, TX were analyzed for 45 metals with the newly developed method using dynamic reaction cell-quadrupole-inductively coupled plasma–mass spectrometry (DRC-q-ICP–MS). Average Rh, Pd and Pt concentrations were 152 ± 52, 770 ± 208 and 529 ± 130 ng g −1 respectively in tunnel dusts while they varied between 6 and 8 ng g −1 , 10 and 88 ng g −1 and 35 and 131 ng g −1 in surface road dusts. Elemental ratios and enrichment factors demonstrated that PGEs in dusts originated from autocatalyst attrition/abrasion. Strong evidence is also presented for mobile source emissions of Cu, Zn, Ga, As, Mo, Cd, Sn, Sb, Ba, W and Pb. However

  9. Modelling of Continual Induction Hardening in Quasi-Coupled Formulation

    Czech Academy of Sciences Publication Activity Database

    Barglik, J.; Doležel, Ivo; Karban, P.; Ulrych, B.

    2005-01-01

    Roč. 24, č. 1 (2005), s. 251-260 ISSN 0332-1649 Grant - others:PSRC(PL) 4T08C 04823 Institutional research plan: CEZ:AV0Z20570509 Keywords : mathematical modelling * electromagnetism * induction Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.188, year: 2005

  10. Low wireless power transfer using inductive coupling for mobile phone charger

    International Nuclear Information System (INIS)

    Fareq, M; Fitra, M; Irwanto, M; Hasan, Syafruddin; Arinal, M

    2014-01-01

    A wireless power transfer (WPT) using inductive coupling for mobile phone charger is studied. The project is offer to study and fabricate WPT using inductive coupling for mobile phone charger that will give more information about distance is effect for WPT performance and WPT is not much influenced by the presence of hands, books and types of plastics. The components used to build wireless power transfer can be divided into 3 parts components, the transceiver for power transmission, the inductive coils in this case as the antenna, receiver and the rectifier which act convert AC to DC. Experiments have been conducted and the wireless power transfer using inductive coupling is suitable to be implemented for mobile phone charger.

  11. Near field resonant inductive coupling to power electronic devices dispersed in water

    NARCIS (Netherlands)

    Kuipers, J.; Bruning, H.; Bakker, S.; Rijnaarts, H.H.M.

    2012-01-01

    The purpose of this research was to investigate inductive coupling as a way to wirelessly power electronic devices dispersed in water. The most important parameters determining this efficiency are: (1) the coupling between transmitting and receiving coils, (2) the quality factors of the transmitting

  12. Interfacing capillary electrophoresis with inductively coupled plasma mass spectrometry by direct injection nebulization for selenium speciation

    DEFF Research Database (Denmark)

    Bendahl, Lars; Gammelgaard, Bente; Jons, O.

    2001-01-01

    A demountable direct injection high efficiency nebulizer operating at low sample uptake rates was developed and used for coupling of capillary electrophoresis (CE) with inductively coupled plasma mass spectrometry (ICP-MS). When the nebulizer was used for continuous sample introduction, detection...

  13. Induction of RAGE Shedding by Activation of G Protein-Coupled Receptors

    Science.gov (United States)

    Metz, Verena V.; Kojro, Elzbieta; Rat, Dorothea; Postina, Rolf

    2012-01-01

    The multiligand Receptor for Advanced Glycation End products (RAGE) is involved in various pathophysiological processes, including diabetic inflammatory conditions and Alzheimes disease. Full-length RAGE, a cell surface-located type I membrane protein, can proteolytically be converted by metalloproteinases ADAM10 and MMP9 into a soluble RAGE form. Moreover, administration of recombinant soluble RAGE suppresses activation of cell surface-located RAGE by trapping RAGE ligands. Therefore stimulation of RAGE shedding might have a therapeutic value regarding inflammatory diseases. We aimed to investigate whether RAGE shedding is inducible via ligand-induced activation of G protein-coupled receptors (GPCRs). We chose three different GPCRs coupled to distinct signaling cascades: the V2 vasopressin receptor (V2R) activating adenylyl cyclase, the oxytocin receptor (OTR) linked to phospholipase Cβ, and the PACAP receptor (subtype PAC1) coupled to adenylyl cyclase, phospholipase Cβ, calcium signaling and MAP kinases. We generated HEK cell lines stably coexpressing an individual GPCR and full-length RAGE and then investigated GPCR ligand-induced activation of RAGE shedding. We found metalloproteinase-mediated RAGE shedding on the cell surface to be inducible via ligand-specific activation of all analyzed GPCRs. By using specific inhibitors we have identified Ca2+ signaling, PKCα/PKCβI, CaMKII, PI3 kinases and MAP kinases to be involved in PAC1 receptor-induced RAGE shedding. We detected an induction of calcium signaling in all our cell lines coexpressing RAGE and different GPCRs after agonist treatment. However, we did not disclose a contribution of adenylyl cyclase in RAGE shedding induction. Furthermore, by using a selective metalloproteinase inhibitor and siRNA-mediated knock-down approaches, we show that ADAM10 and/or MMP9 are playing important roles in constitutive and PACAP-induced RAGE shedding. We also found that treatment of mice with PACAP increases the amount of

  14. Computational Finite Element Software Assisted Development of a 3D Inductively Coupled Power Transfer System

    Directory of Open Access Journals (Sweden)

    P. Raval

    2014-02-01

    Full Text Available To date inductively coupled power transfer (ICPT systems have already found many practical applications including battery charging pads. In fact, current charging platforms tend to largely support only one- or two-dimensional planar movement in load. This paper proposes a new concept of extending the aspect ratios of the operating power transfer volume of ICPT systems to support arbitrary three dimensional load movements with respect to the primary coils. This is done by use of modern finite element method analysis software to propose the primary and secondary magnetic structures of such an ICPT system. Firstly, two primary magnetic structures are proposed based on contrasting modes of operation and different field directions. This includes a single-phase and multi-phase current model. Next, a secondary magnetic structure is customized to be compatible with both primary structures. The resulting system is shown to produce a 3D power transfer volume for battery cell charging applications.

  15. Experimental demonstration of the equivalence of inductive and strongly coupled magnetic resonance wireless power transfer

    Science.gov (United States)

    Ricketts, David S.; Chabalko, Matthew J.; Hillenius, Andrew

    2013-02-01

    In this work, we show experimentally that wireless power transfer (WPT) using strongly coupled magnetic resonance (SCMR) and traditional induction are equivalent. We demonstrate that for a given coil separation, and to within 4%, strongly coupled magnetic resonance and traditional induction produce the same theoretical efficiency of wireless power transfer versus distance. Moreover, we show that the difference between traditional induction and strongly coupled magnetic resonance is in the implementation of the impedance matching network where strongly coupled magnetic resonance uses the mini-loop impedance match. The mini-loop impedance mach provides a low-loss, high-ratio impedance transformation that makes it desirable for longer distance wireless power transfer, where large impedance transformations are needed to maximize power transfer.

  16. Ultra-wide bandwidth improvement of piezoelectric energy harvesters through electrical inductance coupling

    Science.gov (United States)

    Abdelmoula, H.; Abdelkefi, A.

    2015-11-01

    The design and analysis of innovative ultra-wide bandwidth piezoelectric energy harvesters are deeply investigated. An electrical inductance is considered in the harvester's circuit to be connected in series or parallel to a load resistance. A lumped-parameter model is used to model the electromechanical response of the harvester when subjected to harmonic excitations. A linear comprehensive analysis is performed to investigate the effects of an electrical inductance on the coupled frequencies and damping of the harvester. It is shown that including an electrical inductance connected in series or in parallel to an electrical load resistance can result in the appearance of a second coupled frequency of electrical type. The results show that the inclusion of an inductance may give the opportunity to tune one of the coupled frequencies of mechanical and electrical types to the available excitation frequency in the environment. Using the gradient method, an optimization analysis is then performed to determine the optimum values of the electrical inductance and load resistance that maximize the harvested power. It is demonstrated that, for each excitation frequency, there is a combination of optimum values of the electrical inductance and resistance in such a way an optimum constant value of the harvested power is found. Numerical analysis is then performed to show the importance of considering an additional inductance in the harvester's circuitry in order to design broadband energy harvesters. The results show that the presence of the second coupled frequency of electrical type due to the inductance gives the possibility to design optimal broadband inductive-resistive piezoelectric energy harvesters with minimum displacement due to shunt damping effect.

  17. Determination of As and Se in crude oil diluted in xylene by inductively coupled plasma mass spectrometry using a dynamic reaction cell for interference correction on {sup 80}Se

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, Fernanda Inda de [Departamento de Quimica, Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), Rua Marques de Sao Vicente 225, 22451-900 Rio de Janeiro, RJ (Brazil); Duyck, Christiane B., E-mail: cbduyck@vm.uff.br [Departamento de Quimica, Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), Rua Marques de Sao Vicente 225, 22451-900 Rio de Janeiro, RJ (Brazil); Departamento de Quimica, Universidade Federal Fluminense (UFF), Outeiro Sao Joao Batista s/n, Centro, 24020-150, Niteroi, RJ (Brazil); Fonseca, Teresa Cristina O. [Centro de Pesquisas Leopoldo A. Miguez de Mello da Petrobras (CENPES) (Brazil); Saint' Pierre, Tatiana D. [Departamento de Quimica, Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), Rua Marques de Sao Vicente 225, 22451-900 Rio de Janeiro, RJ (Brazil)

    2012-05-15

    Arsenic and selenium can be found in crude oils and represent an important source of pollution when released to the environment during any stage of extraction or refinery. These elements present low sensitivity in the direct determination by inductively coupled plasma mass spectrometry (ICP-MS), due to their high ionization potential, and are also prone to spectral interferences. Hydride generation (HG) can be alternatively employed for the separation of these analytes from the sample matrix and introduction into the instrument. However, the required sample preparation usually increases the analysis time. In this work, a method was developed for the determination of As and Se in crude oil by ICP-MS, after sample dilution in xylene. The use of a dynamic reaction cell (DRC) allowed for the overcoming of Ar{sub 2}{sup +} interference on {sup 80}Se, but was not necessary for As, since interference on m/z 75 was not observed. The optimized operational conditions for {sup 75}As and {sup 80}Se were: 1350 W of RF power, 0.4 L min{sup -1} of Ar nebulizer and 0.7 L min{sup -1} of Ar auxiliary flow rates. The DRC conditions for {sup 80}Se were 0.5 L min{sup -1} of methane and rejection parameter q (Rpq) of 0.2. The analyses were carried out by analyte addition and the limits of detection (LOD) were 0.04 {mu}g kg{sup -1} for As and 0.1 {mu}g kg{sup -1} for Se. The accuracy was verified by the analysis of residual fuel oil certified material, with agreement at a 95% confidence level. Nine Brazilian crude oil samples were analyzed and the results compared to those obtained by hydride generation ICP-MS. In this case, samples were decomposed with nitric acid in a digester block, the analytes pre-reduced with HCl 6 mol L{sup -1} and the determination carried out by external calibration. Although better instrumental LODs were obtained by HG (0.002 {mu}g kg{sup -1} of As and 0.04 {mu}g kg{sup -1} of Se), the direct determination of As and Se in crude oil diluted in xylene by DRC

  18. Ground states and excitations of inductively coupled fluxonium qubits

    Science.gov (United States)

    Brierley, R. T.; Meier, H.; Kou, A.; Glazman, L. I.; Girvin, S. M.

    2015-03-01

    We consider fluxonium qubits arranged in a one dimensional array, where the inductors are shared between neighboring qubits. For an infinite system with small charging energies, there are a series of different phases that depend on the applied magnetic flux and the ratio of the inductive and Josephson energies. For small flux and large Josephson energy, the behavior of the classical ground state is similar to the Frenkel-Kontorova model, while when the flux is half a flux quantum it is similar to an Ising antiferromagnet. A realistic finite system will not exhibit a phase transition but some features of the infinite-size limit should persist. We investigate theoretically the ground and low-lying excited states for experimentally relevant parameters. We discuss how the nature of the ground state changes, and what experimental signatures would be expected.

  19. Experimental analysis and simulation calculation of the inductances of loosely coupled transformer

    Science.gov (United States)

    Kerui, Chen; Yang, Han; Yan, Zhang; Nannan, Gao; Ying, Pei; Hongbo, Li; Pei, Li; Liangfeng, Guo

    2017-11-01

    The experimental design of iron-core wireless power transmission system is designed, and an experimental model of loosely coupled transformer is built. Measuring the air gap on both sides of the transformer 15mm inductor under the parameters. The feasibility and feasibility of using the finite element method to calculate the coil inductance parameters of the loosely coupled transformer are analyzed. The system was modeled by ANSYS, and the magnetic field was calculated by finite element method, and the inductance parameters were calculated. The finite element method is used to calculate the inductive parameters of the loosely coupled transformer, and the basis for the accurate compensation of the capacitance of the wireless power transmission system is established.

  20. Coupling of electromagnetic and thermal codes. Induction heating; Couplage des codes electromagnetique et thermique. Le chauffage par induction

    Energy Technology Data Exchange (ETDEWEB)

    Colombani, M. [CEDRAT, (France)

    1997-12-31

    The development and adjustment of induction heating systems is quite delicate because two different subjects of physics are involved: magnetism (Foucault currents) and thermal engineering. Moreover, the magnetic and electrical properties depends on the temperature and the dissipated power depends on the magnetic and electrical properties and on the electrical excitation sources (geometry, intensity, frequency). The CEDRAT company has been involved since several years in the development of modeling softwares which allow to analyze these kind of problems. The most used is the FLUX2D software, developed by CEDRAT RECHERCHE in collaboration with the LEG (CNRS-INPG) and EdF, and which is used in several domains of applications (electric motors, actuators, high-voltage devices, magnetic recording, induction heating etc..). This software is based on a finite-element calculation method and, in the case of induction heating, it can perform different types of modeling: magnetic, thermal, temperature-dependant properties, weak and strong coupling, coupling with the electric circuit equations etc.. (J.S.)

  1. Induced magnetic-field effects in inductively coupled plasmas

    International Nuclear Information System (INIS)

    Cohen, R.H.; Rognlien, T.D.

    1995-01-01

    In inductive plasma sources, the rapid spatial decay of the electric field arising from the skin effect produces a large radio frequency (RF) magnetic field via Faraday's law. We previously determined that this magnetic field leads to a reduction of the electron density in the skin region, as well as a reduction in the collisionless heating rate. The electron deficit leads to the formation of an electrostatic potential which pulls electrons in to restore quasineutrality. Here we calculate the electron density including both the induced and electrostatic fields. If the wave frequency is not too low, the ions respond only to the averaged fields, and hence the electrostatic field is oscillatory, predominantly at the second harmonic of the applied field. We calculate the potential required to establish a constant electron density, and compare with numerical orbit-code calculations. For times short compared to ion transit times, the quasineutral density is just the initial ion density. For timescales long enough that the ions can relax, the density profile can be found from the solution of fluid equations with an effective (ponderomotive-like) potential added. Although the time-varying electrostatic potential is an extra source of heating, the net effect of the induced magnetic and electrostatic fields through trapping, early turning, and direct heating is a significant reduction in collisionless heating for parameters of interest

  2. Induction Chemotherapy for p16 Positive Oropharyngeal Squamous Cell Carcinoma

    OpenAIRE

    Saito, Yuki; Ando, Mizuo; Omura, Go; Yasuhara, Kazuo; Yoshida, Masafumi; Takahashi, Wataru; Yamasoba, Tatsuya

    2016-01-01

    Objectives/Hypothesis We aimed to determine the effectiveness of induction chemotherapy for treating p16?positive oropharyngeal cancer in our department. Study Design This was a retrospective case series to assess treatment effectiveness. Methods We administered induction chemotherapy to patients with stage III to IV oropharyngeal p16?positive squamous cell carcinoma between 2008 and 2013. Induction chemotherapy was administered using combinations of docetaxel, cisplatin, and 5?fluorouracil. ...

  3. The Inductive Coupling of the Magnets in MICE and its Effect on Quench Protection

    International Nuclear Information System (INIS)

    Green, Michael A.; Witte, Holger

    2005-01-01

    The inductive coupling between various MICE magnet circuits is described. The consequences of this coupling on magnet charging and quenching are discussed. Magnet quench protection is achieved through the use of quench-back. Calculations of the quenching of a magnet due to quench-back resulting from circulating currents induced in the magnet mandrel due to quenching of an adjacent magnet are discussed. This report describes how the MICE magnet channel will react when magnets in that channel are quenched

  4. Numerical simulation of nonequilibrium inductive plasma flow coupled with electromagnetic field calculation

    Science.gov (United States)

    Yu, Minghao; Takahashi, Yusuke; Kihara, Hisashi; Abe, Ken-ichi; Yamada, Kazuhiko; Abe, Takashi

    2014-12-01

    Numerical investigation of nonequilibrium inductively coupled plasma (ICP) flow was carried out to study the physical properties of the flow inside a 10-kW ICP torch with the working gas being nitrogen. The flow field was described by two-dimensional compressible axisymmetric Navier-Stokes (N-S) equations that took into account 5 species and 8 chemical reactions. The magnetic vector-potential equations were tightly coupled with the flow-field equations to describe the heating process by inductive discharge. A four-temperature model was adopted to model thermal nonequilibrium process in the discharge torch. The characteristics of ICP flow such as thermal nonequilibrium, inductive discharge, and strong effects of Lorentz forces became clear through the present study.

  5. In situ calibration of inductively coupled plasma-atomic emission and mass spectroscopy

    Science.gov (United States)

    Braymen, Steven D.

    1996-06-11

    A method and apparatus for in situ addition calibration of an inductively coupled plasma atomic emission spectrometer or mass spectrometer using a precision gas metering valve to introduce a volatile calibration gas of an element of interest directly into an aerosol particle stream. The present situ calibration technique is suitable for various remote, on-site sampling systems such as laser ablation or nebulization.

  6. Polymerization by plasma of trichloroethylene by means of resistive and inductive coupling

    International Nuclear Information System (INIS)

    Vasquez, M.; Cruz, G.; Olayo, M.G.; Timoshina, T.; Morales, J.; Olayo, R.

    2004-01-01

    It was carried out the polymerization for plasma of the trichloroethylene by means of two types of coupling, resistive and inductive with the objective of studying the structure, morphology and the electric properties of the polymers obtained under these conditions. The structure and morphology of the polymers were studied by means of EDS and FT-IR spectroscopies. (Author)

  7. High-Q cavity-induced fluxon bunching in inductively coupled Josephson junctions

    DEFF Research Database (Denmark)

    Madsen, S.; Grønbech-Jensen, Niels; Pedersen, Niels Falsig

    2008-01-01

    We consider fluxon dynamics in a stack of inductively coupled long Josephson junctions connected capacitively to a common resonant cavity at one of the boundaries. We study, through theoretical and numerical analyses, the possibility for the cavity to induce a transition from the energetically...

  8. Atlas of atomic spectral lines of plutonium emitted by an inductively coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Edelson, M.C.; DeKalb, E.L.; Winge, R.K.; Fassel, V.A.

    1986-09-01

    Optical emission spectra from high-purity Pu-242 were generated with a glovebox-enclosed inductively coupled plasma (ICP) source. Spectra covering the 2280 to 7008 Angstrom wavelength range are presented along with general commentary on ICP-Pu spectroscopy.

  9. Determination of Arsenic in Sinus Wash and Tap Water by Inductively Coupled Plasma-Mass Spectrometry

    Science.gov (United States)

    Donnell, Anna M.; Nahan, Keaton; Holloway, Dawone; Vonderheide, Anne P.

    2016-01-01

    Arsenic is a toxic element to which humans are primarily exposed through food and water; it occurs as a result of human activities and naturally from the earth's crust. An experiment was developed for a senior level analytical laboratory utilizing an Inductively Coupled Plasma-Mass Spectrometer (ICP-MS) for the analysis of arsenic in household…

  10. Inductively coupled plasma and ion sources: History and state-of-the-art

    International Nuclear Information System (INIS)

    Hopwood, J.

    1994-01-01

    Over 100 years ago Hittorf first generated an electrodeless ''ring'' discharge by electromagnetic induction and began a 40 year controversy as to the true physical origin of such a discharge. Even Tesla advocated that these plasmas were merely the result of large electrostatic potential differences rather than electric fields induced by high frequency currents. Through clever experiments using crude spark gaps and leyden jars, the inductive nature of the discharge was confirmed in the late 1920's by MacKinnon, thus supporting the theories and experiments of Sir J.J. Thomson, perhaps the most staunch advocate of the induction mechanism. Today the authors routinely exploit the intense plasmas which are generated by induction. In this talk, the characteristics of inductively coupled plasma (ICP) and ion sources will be reviewed and future applications of intense plasma sources will be discussed. The inductively coupled plasma is Joule heated at moderate gas pressures, but the electromagnetic field penetration of these dense plasmas is limited by the plasma skin depth, typically a few millimeters to a few centimeters. The induction plasma is thus edge heated, a fact that constrains uniformity over large areas if helical induction coils are used. Flat, spiral coils may be used to improve uniformity by driving the plasma using a planar geometry. Issues of dimensional and frequency scaling will be discussed as they apply to large diameter sources. Ion beams extracted from ICPs are used for many applications including space propulsion, high power neutral beams, and materials processing. Broad ion beam (∼10 cm) current densities in excess of 100 mA-cm 2 at 100 keV are obtained in pulsed mode operation. Recently, however, more consumer-oriented applications of less intense ICPs are emerging

  11. Induction of apoptosis by eugenol in human breast cancer cells

    International Nuclear Information System (INIS)

    Vidhya, N.; Niranjali Devaraj, S.

    2011-01-01

    In the present study, potential anticancer effect of eugenol on inhibition of cell proliferation and induction of apoptosis in human MCF-7 breast cancer cells was investigated. Induction of cell death by eugenol was evaluated following MTT assay and monitoring lactate dehydrogenase released into the culture medium for cell viability and cytotoxicity, giemsa staining for morphological alterations, fluorescence microscopy analysis of cells using ethidium bromide and acridine orange and quantitation of DNA fragments for induction of apoptosis. Effect of eugenol on intracellular redox status of the human breast cancer cells was assessed by determining the level of glutathione and lipid peroxidation products (TBARS). Eugenol treatment inhibited the growth and proliferation of human MCF-7 breast cancer cells through induction of cell death, which was dose and time dependent. Microscopic examination of eugenol treated cells showed cell shrinkage, membrane blebbing and apoptotic body formation. Further, eugenol treatment also depleted the level of intracellular glutathione and increased the level of lipid peroxidation. The dose dependent increase in the percentage of apoptotic cells and DNA fragments suggested that apoptosis was involved in eugenol induced cell death and apoptosis might have played a role in the chemopreventive action of eugenol. (author)

  12. Establishing human heart chromium, cobalt and vanadium concentrations by inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Day, Patrick L; Eckdahl, Steven J; Maleszewski, Joseph J; Wright, Thomas C; Murray, David L

    2017-05-01

    Chromium, cobalt, and vanadium are used in metallic joint prosthesis. Case studies have associated elevated heart tissue cobalt concentrations with myocardial injury. To document the long term heart metal ion concentrations, a validated inductively coupled plasma mass spectroscopy (ICP-MS) method was needed. The method utilized a closed-vessel microwave digestion system to digest the samples. An ICP-MS method utilizing Universal Cell Technology was used to determine our target analyte concentrations. Accuracy was verified using reference materials. Precision, sensitivity, recovery and linearity studies were performed. This method was used to establish a reference range for a non-implant containing cohort of 80 autopsy human heart tissues RESULTS: This method demonstrated an analytic measurement range of 0.5-100ng/mL for each element. Accuracy was within ±10% of target value for each element. Within-run precision for each element was below 20% CV. The chromium, vanadium and cobalt concentrations (mean±SD) were 0.1523±0.2157μg/g, 0.0094±0.0211μg/g and 0.1039±0.1305μg/g respectively in 80 non-implant containing human heart tissue samples. This method provides acceptable recovery of the chromium, cobalt and vanadium in heart tissue; allowing assessment of the effects of metallic joint prosthesis on myocardial health. Copyright © 2017 Elsevier GmbH. All rights reserved.

  13. Neutral Gas Temperature Estimates in an Inductively Coupled CF4 Plasma by Fitting Diatomic Emission Spectra

    Science.gov (United States)

    Cruden, Brett A.; Rao, M. V. V. S.; Sharma, Surendra P.; Meyyappan, M.

    2001-01-01

    This work examines the accuracy of plasma neutral temperature estimates by fitting the rotational band envelope of different diatomic species in emission. Experiments are performed in an inductively coupled CF4 plasma generated in a Gaseous Electronics Conference reference cell. Visible and ultraviolet emission spectra are collected at a power of 300 W (approximately 0.7 W/cc) and pressure of 30 mtorr. The emission bands of several molecules (CF, CN, C2, CO, and SiF) are fit simultaneously for rotational and vibrational temperatures and compared. Four different rotational temperatures are obtained: 1250 K for CF and CN, 1600 K for CO, 1800 K for C2, and 2300 K for SiF. The vibrational temperatures obtained vary from 1750-5950 K, with the higher vibrational temperatures generally corresponding to the lower rotational temperatures. These results suggest that the different species have achieved different degrees of equilibration between the rotational and vibrational modes and may not be equilibrated with the translational temperatures. The different temperatures are also related to the likelihood that the species are produced by ion bombardment of the surface, with etch products like SiF, CO, and C2 having higher temperatures than species expected to have formed in the gas phase.

  14. Analysis of Trace Elements in Rat Bronchoalveolar Lavage Fluid by Inductively Coupled Plasma Mass Spectrometry.

    Science.gov (United States)

    Qamar, Wajhul; Al-Ghadeer, Abdul Rahman; Ali, Raisuddin; Abuelizz, Hatem A

    2017-08-01

    The main objective was to determine the elemental profile of the lung lining fluid of rats which are used as model animals in various experiments. Lung lining fluid elemental constitution obtained after bronchoalveolar lavage fluid (BALF) was analyzed by inductively coupled plasma mass spectrometry (ICP-MS) to determine the biological trace elements along with calcium and magnesium. BALF was collected from healthy rats using a tracheal cannula. However, cells in BALF were counted to monitor any underlying inflammatory lung condition. Cell free BALF samples were processed and analyzed for the elements including magnesium (Mg), calcium (Ca), chromium (Cr), manganese (Mn), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), selenium (Se), bromine (Br), and iodine (I). In view of this, calcium concentration was the highest (6318.08 ± 3094.3 μg/L) and copper concentration was the lowest (0.89 ± 0.21 μg/L). The detected elements, from high to low concentration, include Ca > Mg > Fe > Br > I > Cr > Ni > Zn > Mn > Se > Cu. Pearson's correlation analysis revealed no significant correlation between cell count and concentration of any of the element detected in BALF. Correlation analysis also revealed significant positive correlation among Fe, I, Cr, Ni, and Mn. Ca was found to be correlated negatively with Cu and positively with Se. Br and Mg found to be positively correlated with each other. Zn remained the only element that was not found to be correlated with any of the elements in the rat BALF.

  15. Induction-heating MOCVD reactor with significantly improved heating efficiency and reduced harmful magnetic coupling

    Science.gov (United States)

    Li, Kuang-Hui; Alotaibi, Hamad S.; Sun, Haiding; Lin, Ronghui; Guo, Wenzhe; Torres-Castanedo, Carlos G.; Liu, Kaikai; Valdes-Galán, Sergio; Li, Xiaohang

    2018-04-01

    In a conventional induction-heating III-nitride metalorganic chemical vapor deposition (MOCVD) reactor, the induction coil is outside the chamber. Therefore, the magnetic field does not couple with the susceptor well, leading to compromised heating efficiency and harmful coupling with the gas inlet and thus possible overheating. Hence, the gas inlet has to be at a minimum distance away from the susceptor. Because of the elongated flow path, premature reactions can be more severe, particularly between Al- and B-containing precursors and NH3. Here, we propose a structure that can significantly improve the heating efficiency and allow the gas inlet to be closer to the susceptor. Specifically, the induction coil is designed to surround the vertical cylinder of a T-shaped susceptor comprising the cylinder and a top horizontal plate holding the wafer substrate within the reactor. Therefore, the cylinder coupled most magnetic field to serve as the thermal source for the plate. Furthermore, the plate can block and thus significantly reduce the uncoupled magnetic field above the susceptor, thereby allowing the gas inlet to be closer. The results show approximately 140% and 2.6 times increase in the heating and susceptor coupling efficiencies, respectively, as well as a 90% reduction in the harmful magnetic flux on the gas inlet.

  16. Induction-heating MOCVD reactor with significantly improved heating efficiency and reduced harmful magnetic coupling

    KAUST Repository

    Li, Kuang-Hui

    2018-02-23

    In a conventional induction-heating III-nitride metalorganic chemical vapor deposition (MOCVD) reactor, the induction coil is outside the chamber. Therefore, the magnetic field does not couple with the susceptor well, leading to compromised heating efficiency and harmful coupling with the gas inlet and thus possible overheating. Hence, the gas inlet has to be at a minimum distance away from the susceptor. Because of the elongated flow path, premature reactions can be more severe, particularly between Al- and B-containing precursors and NH3. Here, we propose a structure that can significantly improve the heating efficiency and allow the gas inlet to be closer to the susceptor. Specifically, the induction coil is designed to surround the vertical cylinder of a T-shaped susceptor comprising the cylinder and a top horizontal plate holding the wafer substrate within the reactor. Therefore, the cylinder coupled most magnetic field to serve as the thermal source for the plate. Furthermore, the plate can block and thus significantly reduce the uncoupled magnetic field above the susceptor, thereby allowing the gas inlet to be closer. The results show approximately 140% and 2.6 times increase in the heating and susceptor coupling efficiencies, respectively, as well as a 90% reduction in the harmful magnetic flux on the gas inlet.

  17. Induction of apoptotic cell death by putrescine

    DEFF Research Database (Denmark)

    Takao, Koichi; Rickhag, Karl Mattias; Hegardt, Cecilia

    2006-01-01

    that overexpression of a metabolically stable ODC in CHO cells induced a massive cell death unless the cells were grown in the presence of the ODC inhibitor alpha-difluoromethylornithine (DFMO). Cells overexpressing wild-type (unstable) ODC, on the other hand, were not dependent on the presence of DFMO...

  18. Estimation of rare earth elements in gadolinium oxide by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Kumar, Sanjukta A.; Venkataramani, B.; Kotekar, M.K.

    2007-01-01

    A method was developed for the direct determination of trace quantities of rare earth elements (REEs) in gadolinium oxide dissolved in nitric acid by inductively coupled plasma mass spectrometry. The matrix suppression effect of Gd on the ion peak signals of REEs impurities was effectively compensated with spiking In as an internal standard. The recoveries of spiked sample for REEs were found to be in the range of 91-109% by using the proposed method. The relative standard deviation varied between 1.5 to 6%. The methodology had been found to be suitable for the direct determination of trace REEs in Gd 2 O 3 and the results obtained from this method keep in good agreement with that acquired from inductively coupled plasma emission spectrometry. (author)

  19. A Method to Construct Plasma with Nonlinear Density Enhancement Effect in Multiple Internal Inductively Coupled Plasmas

    International Nuclear Information System (INIS)

    Chen Zhipeng; Li Hong; Liu Qiuyan; Luo Chen; Xie Jinlin; Liu Wandong

    2011-01-01

    A method is proposed to built up plasma based on a nonlinear enhancement phenomenon of plasma density with discharge by multiple internal antennas simultaneously. It turns out that the plasma density under multiple sources is higher than the linear summation of the density under each source. This effect is helpful to reduce the fast exponential decay of plasma density in single internal inductively coupled plasma source and generating a larger-area plasma with multiple internal inductively coupled plasma sources. After a careful study on the balance between the enhancement and the decay of plasma density in experiments, a plasma is built up by four sources, which proves the feasibility of this method. According to the method, more sources and more intensive enhancement effect can be employed to further build up a high-density, large-area plasma for different applications. (low temperature plasma)

  20. Laser sampling system for an inductively-coupled atomic emission spectrometer. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-15

    A laser sampling system was attached to a Perkin Elmer Optima 3000 inductively-coupled plasma, atomic emission spectrometer that was already installed and operating in the Chemistry and Geochemistry Department at the Colorado School of Mines. The use of the spectrometer has been highly successful. Graduate students and faculty from at least four different departments across the CSM campus have used the instrument. The final report to NSF is appended to this final report. Appendices are included which summarize several projects utilizing this instrument: acquisition of an inductively-coupled plasma atomic emission spectrometer for the geochemistry program; hydrogen damage susceptibility assessment for high strength steel weldments through advanced hydrogen content analysis, 1996 and 1997 annual reports; and methods for determination of hydrogen distribution in high strength steel welds.

  1. External control of the synchronization dynamics of two inductively coupled glow discharge plasma sources

    Science.gov (United States)

    Chaubey, Neeraj; Mukherjee, S.; Sen, A.

    2017-10-01

    An experimental investigation of the influence of an external periodic forcing on the synchronization dynamics of two inductively coupled plasma sources is reported. The driven response of the coupled system is found to have a rich structure in the parameter space of the frequency and the amplitude of the external driver. In particular, there is a strong impact on the nature of the phase-flip transitions between anti-phase and in-phase synchronized states of the system and the frequency bifurcation structure of the collective states. The external driver provides a convenient tool for accessing various collective states of the system and controlling the collective dynamics of the two coupled systems through a proper choice of its frequency and amplitude. Our experimental results are qualitatively supported by numerical simulation results from a theoretical model of two environmentally coupled van der Pol equations, one of which is also driven externally.

  2. Separation of actinides using capillary extraction chromatography-inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Peterson, Dominic S; Montoya, Velma M

    2009-08-01

    Trace levels of actinides have been separated on capillary extraction chromatography columns. Detection of the actinides was achieved using an inductively coupled plasma mass spectrometer, which was coupled with the extraction chromatography system. In this study, we compare 30-cm long, 4.6 mm i.d. columns to capillary columns (750 microm i.d.) with lengths from 30 cm up to 150 cm. The columns that were tested were packed with TRU resin. We were able to separate a mixture of five actinides ((232)Th, (238)U, (237)Np, (239)Pu, and (241)Am). This work has application to rapid bioassay as well as automated separations of actinide materials.

  3. Test of the performance and characteristics of a prototype inductive power coupling for electric highway systems

    Energy Technology Data Exchange (ETDEWEB)

    Bolger, J.G.; Ng, L.S.; Green, M.I.; Wallace, R.I.

    1978-07-01

    Development of an inductively coupled power system for highway applications was begun in 1976. The power system was designed to provide energy to vehicles that also carry a supply of stored energy, thus providing a large measure of operational flexibility to the vehicles and reducing the necessary inventory of powered roadways. The highway power system can support the high-speed, long-range portions of driving cycles, while the stored energy can meet the requirements of driving on non-powered streets. The system thus has been referred to as a ''dual-mode'' system because of the use of the two sources of energy. The results of testing a prototype coupling are presented. No physical contact between the vehicle and the power source is required, i.e., the coupling magnetically links the power system of the vehicle to a power source in the roadway (inductive coupling). Tests were performed to determine the magnetic force and flux distribution, electrical characteristics, thermal efforts and acoustic noise. The test equipment and methods are discussed. The tests confirmed the technical feasibility of this type of non-contacting electrical power coupling, and demonstrated that its components are suited to ordinary materials and manufacturing processes. The test results were found to be consistent with expected characteristics in all important respects.

  4. Quality assurance in the elemental analysis of foods by inductively coupled plasma spectroscopy

    Science.gov (United States)

    Wolnik, Karen A.; Fricke, Fred L.; Gaston, Cynthia M.

    The U.S. Food and Drug Administration, Department of Agriculture, and Environmental Protection Agency are conducting a joint study of elemental background levels in raw agricultural crops. More than three thousand samples have been analysed for 12 elements by inductively coupled plasma-optical emission spectroscopy (ICP). A quality assurance program has been designed to assure the accuracy and reliability of these analyses. The development and rationale for this program are described and illustrated by analytical results.

  5. Measurement of titanium in hip-replacement patients by inductively coupled plasma optical emission spectroscopy.

    Science.gov (United States)

    Harrington, Chris F; McKibbin, Craig; Rahanu, Monika; Langton, David; Taylor, Andrew

    2017-05-01

    Background Patients with metal-on-metal hip replacements require testing for cobalt and chromium. There may also be a need to test for titanium, which is used in the construction of the femoral stem in total hip replacements. It is not possible to use quadrupole inductively coupled plasma mass spectrometry due to interferences. Methods Titanium was measured using inductively coupled plasma optical emission spectroscopy using the emission line at 336.1 nm and Y (internal standard) at 371.0 nm. Internal quality control materials were prepared for blood and serum and concentrations assigned using a sector field-inductively coupled plasma mass spectrometer. A candidate whole blood certified reference material was also evaluated. Results The method had detection and quantitation limits of 0.6 and 1.9 µg/L, respectively. The respective bias (%) and measurement uncertainty ( U) (k = 2) were 3.3% and 2.0 µg/L (serum) and - 1.0% and 1.4 µg/L (whole blood). The respective repeatability and intermediate precision (%) were 5.1% and 10.9% (serum) and 2.4% and 8.6% (whole blood). The concentration of titanium was determined in patients' samples, serum (median = 2.4 µg/L, n = 897) and whole blood (median = 2.4 µg/L, n = 189). Serum is recommended for monitoring titanium in patients, since the concentration is higher than in whole blood and the matrix less problematic. In hip fluid samples, the concentrations were much higher (mean 58.5 µg/L, median 5.1 µg/L, n = 83). Conclusions A method based on inductively coupled plasma optical emission spectroscopy was developed and validated for measuring titanium in clinical samples.

  6. Study of hard diamond-like carbon films deposited in an inductively coupled plasma source

    International Nuclear Information System (INIS)

    Yu Shiji; Ma Tengcai

    2003-01-01

    Chemical vapor deposition of the hard diamond-like carbon (DLC) films was achieved using an inductively coupled plasma source (ICPS). The microscopy, microhardness, deposition rate and structure characteristic of the DLC films were analyzed. It is shown that the ICPS is suitable for the hard DLC film deposition at relatively low substrate negative bias voltage, and the substrate negative bias voltage greatly affects chemical vapor deposition of the DLC film and its quality

  7. Induction of Functional Hair-Cell-Like Cells from Mouse Cochlear Multipotent Cells

    Directory of Open Access Journals (Sweden)

    Quanwen Liu

    2016-01-01

    Full Text Available In this paper, we developed a two-step-induction method of generating functional hair cells from inner ear multipotent cells. Multipotent cells from the inner ear were established and induced initially into progenitor cells committed to the inner ear cell lineage on the poly-L-lysine substratum. Subsequently, the committed progenitor cells were cultured on the mitotically inactivated chicken utricle stromal cells and induced into hair-cell-like cells containing characteristic stereocilia bundles. The hair-cell-like cells exhibited rapid permeation of FM1-43FX. The whole-cell patch-clamp technique was used to measure the membrane currents of cells differentiated for 7 days on chicken utricle stromal cells and analyze the biophysical properties of the hair-cell-like cells by recording membrane properties of cells. The results suggested that the hair-cell-like cells derived from inner ear multipotent cells were functional following differentiation in an enabling environment.

  8. Induction and identification of rabbit peripheral blood derived dendritic cells

    Science.gov (United States)

    Zhou, Jing; Yang, FuYuan; Chen, WenLi

    2012-03-01

    Purpose: To study a method of the induction of dendritic cells (DCs) from rabbit peripheral blood. Methods: Peripheral blood cells were removed from rabbit, filtered through nylon mesh. Peripheral blood mononuclear cells (PBMC) were isolated from the blood cells by Ficoll-Hypaque centrifugation (density of 1.077g/cm3).To obtain DCs, PBMC were cultured in RPMI1640 medium containing 10% fetal calf serum, 50U/mL penicillin and streptomycin, referred to subsequently as complete medium, at 37°C in 5% CO2 atmosphere for 4 hours. Nonadherent cells were aspirated, adherent cells were continued incubated in complete medium, supplemented with granulocyte/macrophage colony-stimulating factor (GM-CSF, 50ng/ml),and interleukin 4 (IL-4, 50ng/ml) for 9 days. Fluorescein labeled antibodies(anti-CD14, anti-HLA-DR, anti-CD86) were used to sign cells cultured for 3,6,9 days respectively, Then flow cytometry was performed. Results: Ratio of anti-HLA-DR and anti-CD86 labeled cells increased with induction time extension, in contrast with anti-CD14. Conclusion: Dendritic cells can be effectively induced by the method of this experiment, cell maturation status increased with induction time extension.

  9. Symmetric Absorber-Coupled Far-Infrared Microwave Kinetic Inductance Detector

    Science.gov (United States)

    U-yen, Kongpop (Inventor); Wollack, Edward J. (Inventor); Brown, Ari D. (Inventor); Stevenson, Thomas R. (Inventor); Patel, Amil A. (Inventor)

    2016-01-01

    The present invention relates to a symmetric absorber-coupled far-infrared microwave kinetic inductance detector including: a membrane having an absorber disposed thereon in a symmetric cross bar pattern; and a microstrip including a plurality of conductor microstrip lines disposed along all edges of the membrane, and separated from a ground plane by the membrane. The conducting microstrip lines are made from niobium, and the pattern is made from a superconducting material with a transition temperature below niobium, including one of aluminum, titanium nitride, or molybdenum nitride. The pattern is disposed on both a top and a bottom of the membrane, and creates a parallel-plate coupled transmission line on the membrane that acts as a half-wavelength resonator at readout frequencies. The parallel-plate coupled transmission line and the conductor microstrip lines form a stepped impedance resonator. The pattern provides identical power absorption for both horizontal and vertical polarization signals.

  10. Slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry for steelmaking flue dust analysis

    Science.gov (United States)

    Coedo, A. G.; Dorado, T.; Padilla, I.; Maibusch, R.; Kuss, H.-M.

    2000-02-01

    A commercial atomic absorption graphite furnace (AAGF), with a self-made adapter and valve system, was used as a slurry sampling cell for electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS). The system was applied to the determination of As, Sn, Sb, Se, Te, Bi, Cd, V, Ti and Mo in steelmaking flue dusts. Experimental conditions with respect to ETV and ICP-MS operating parameters were optimized. Compared to aqueous solutions, slurry samples were found to present better analyte transport. Microgram amounts of Rh were used to reduce the difference in analyte response in sensitivity for aqueous solutions of the tested analytes. No such increasing effect was observed for slurry samples and aqueous standards. An added quantity of Rh acting as modifier/carrier resulted in an increase for the same analytes in matrix-slurry solutions, even the addition of an extra Rh quantity has resulted in a decrease in the signals. The effect of Triton X-100 (used as a dispersant agent) on analyte intensity and precision was also studied. External calibration from aqueous standards spiked with 100 μg ml -1 Rh was performed to quantified 0.010 g/100 ml slurry samples. Results are presented for a certified reference electrical arc furnace flue dust (EAF): CRM-876-1 (Bureau of Analysis Samples Ltd., Cleveland, UK), a reference sample of coke ashes X-3705 (from AG der Dillinger Hüttenwerke, Germany), and a representative sample of EAF flue dust from a Spanish steelmaking company (CENIM-1). For the two reference materials an acceptable agreement with certificate values was achieved, and the results for the CENIM sample matched with those obtained from conventional nebulization solution.

  11. Review of inductively coupled plasmas: Nano-applications and bistable hysteresis physics

    Science.gov (United States)

    Lee, Hyo-Chang

    2018-03-01

    Many different gas discharges and plasmas exhibit bistable states under a given set of conditions, and the history-dependent hysteresis that is manifested by intensive quantities of the system upon variation of an external parameter has been observed in inductively coupled plasmas (ICPs). When the external parameters (such as discharge powers) increase, the plasma density increases suddenly from a low- to high-density mode, whereas decreasing the power maintains the plasma in a relatively high-density mode, resulting in significant hysteresis. To date, a comprehensive description of plasma hysteresis and a physical understanding of the main mechanism underlying their bistability remain elusive, despite many experimental observations of plasma bistability conducted under radio-frequency ICP excitation. This fundamental understanding of mode transitions and hysteresis is essential and highly important in various applied fields owing to the widespread use of ICPs, such as semiconductor/display/solar-cell processing (etching, deposition, and ashing), wireless light lamp, nanostructure fabrication, nuclear-fusion operation, spacecraft propulsion, gas reformation, and the removal of hazardous gases and materials. If, in such applications, plasma undergoes a mode transition and hysteresis occurs in response to external perturbations, the process result will be strongly affected. Due to these reasons, this paper comprehensively reviews both the current knowledge in the context of the various applied fields and the global understanding of the bistability and hysteresis physics in the ICPs. At first, the basic understanding of the ICP is given. After that, applications of ICPs to various applied fields of nano/environmental/energy-science are introduced. Finally, the mode transition and hysteresis in ICPs are studied in detail. This study will show the fundamental understanding of hysteresis physics in plasmas and give open possibilities for applications to various applied

  12. Effect of coupling currents on the dynamic inductance during fast transient in superconducting magnets

    Directory of Open Access Journals (Sweden)

    V. Marinozzi

    2015-03-01

    Full Text Available We present electromagnetic models aiming to calculate the variation of the inductance in a magnet due to dynamic effects such as the variation of magnetization or the coupling with eddy currents. The models are studied with special regard to the calculation of the inductance in superconducting magnets which are affected by interfilament coupling currents. The developed models have been compared with experimental data coming from tests of prototype Nb_{3}Sn magnets designed for the new generation of accelerators. This work is relevant for the quench protection study of superconducting magnets: quench is an unwanted event, when part of the magnet becomes resistive; in these cases, the current should be discharged as fast as possible, in order to maintain the resistive zone temperature under a safe limit. The magnet inductance is therefore a relevant term for the description of the current discharge, especially for the high-field new generation superconducting magnets for accelerators, and this work shows how to calculate the correct value during rapid current changes, providing a mean for simulations of the reached temperature.

  13. Specific Aspects Regarding Coupled Numerical Modeling of Inverter and Load Equipments in an Induction Heating Installation

    Directory of Open Access Journals (Sweden)

    Claudiu MICH-VANCEA

    2008-05-01

    Full Text Available The most propitious projection of inductiveelectrothermic installation requires a deep study ofcoupled electrothermic and circuits problems; thereforethe present paper follows the same line. Research inspecific literature have emphasized that induction heatinghas a much higher efficiency if the supply of the charge(inductor – piece is done at frequencies other thatindustrial one. [1]. Due to material alter depending ontemperature and, implicitly, the variation of the electricalparameters of the heating installation it is necessary totackle the projection of these inductive electrothermicinstallation projected through coupled numericalmodeling of the inverter circuit and of the heatingthrough induction process. The paper presents thenumerical modeling of the continuous current –alternating current conversion bridge (inverter withelements of static switch – over, the type of commandsignal (PWM of elements of static switch of power, thenumerical modeling of the heating throughelectromagnetic induction process and aspects ofcorrelation regarding the functioning/ working of theinstallation depending on the parameters of the load. Theparameters get modified due to material alter dependingon temperature during the heating process.

  14. Global model of instabilities in low-pressure inductively coupled chlorine plasmas

    Science.gov (United States)

    Despiau-Pujo, Emilie; Chabert, Pascal

    2009-10-01

    Experimental studies have shown that low-pressure inductive discharges operating with electronegative gases are subject to instabilities near the transition between capacitive (E) and inductive (H) modes. A global model, consisting of two particle balance equations and one energy balance equation, has been previously proposed to describe the instability mechanism in SF6/ArSF6 [1]. This model, which agrees qualitatively well with experimental observations, leaves significant quantitative differences. In this paper, the model is revisited with Cl2 as the feedstock gas. An alternative treatment of the inductive power deposition is evaluated and chlorine chemistry is included. Old and new models are systematically compared. The alternative inductive coupling description slightly modifies the results. The effect of gas chemistry is even more pronounced. The instability window is smaller in pressure and larger in absorbed power, the frequency is higher and the amplitudes of oscillations are reduced. The feedstock gas is weakly dissociated ( 16%) and Cl2^+ is the dominant positive ion, which is consistent with the moderate electron density during the instability cycle. [1] M.A. Lieberman, A.J. Lichtenberg, and A.M. Marakhtanov, Appl. Phys. Lett. 75 (1999) 3617

  15. Induction of differentiation in neoplastic cells.

    Science.gov (United States)

    Freshney, R I

    1985-01-01

    There is now clear evidence that cells cultured from human and animal tumours can be induced to differentiate in vitro by recognised hormones, regulatory peptides, polar solvents and cytotoxic drugs. Examples can be found from several different types of tumour with the bulk of the data deriving from neuroblastoma and myeloid leukaemia. There is no clear correlation of inducer with cell type, other than some specific peptides like MSH, and agents such as dimethyl sulphoxide and dexamethasone have wide ranging activity. Steroid hormone action may require interaction between different cell types, and the inability of tumours to differentiate in situ may implicate reduced cell-cell interaction, possibly due to degradation of extracellular matrix, or to alteration of the stromal phenotype by tumour-derived factors such as peptides or prostaglandins. When differentiation has been demonstrated, it has been possible, in some cases, to correlate increased differentiation with reduced malignancy by in vitro characterisation or tumorigenicity. Conditions which induce differentiation in rat mammary carcinoma and mouse myeloma also reduce tumour growth in vivo. Clinical trials have not provided any conclusive evidence for a therapeutic benefit so far, but relatively few trials have been carried out. There is clearly a need for further investigation both in vitro and in vivo to select optimal conditions and combinations of agents for clinical evaluation.

  16. The coupling of capillary electrophoresis-inductively coupled plasma mass spectrometer as a speciation instrument for actinides at trace level

    International Nuclear Information System (INIS)

    Delorme, A.

    2004-01-01

    An interface between the separation technique (capillary electrophoresis) and the analytical technique (Inductively Coupled Plasma - Mass Spectrometer) was developed. In that sense, bibliographic and parametric studies allowed to define necessary conditions for the good working of both techniques. The results obtained led to the realisation of an interface capillary electrophoresis / ICP-MS (CE / ICP-MS). This one was experimentally validated on classical separations (alkalis / earth-alkalis and lanthanides) and the detection limit of the analytical system was determined equal to 4 x 10 -11 mol.L -1 for plutonium. This result exhibits a gain in detection limit of a factor higher than 10 4 compared to the capillary electrophoresis in standard detection (UV). The studies were made in order to check the capacity of the CE / ICP-MS coupling as a speciation instrument for actinides at trace level and to define the associated analytical procedures. The coupling turned out to be a suited instrument for the determination of absolute electrophoretic mobilities at infinite dilution (physico-chemical property which allows to predict the migration time of an ion under an electrical field in a given electrolyte), for the determination of thermodynamic constants and for the separation of different actinide oxidation states in solution. (author)

  17. Coplanar UHF RFID tag antenna with U-shaped inductively coupled feed for metallic applications.

    Directory of Open Access Journals (Sweden)

    Karrar Naji Salman

    Full Text Available In this paper, we present a novel compact, coplanar, tag antenna design for metallic objects. Electrically small antenna has designed for a UHF RFID (860-960 MHz based on a proximity-coupled feed through. Furthermore, two symmetrical Via-loaded coplanar grounds fed by a U-shaped inductively coupled feed through an embedded transmission line. This configuration results in an antenna with dimensions of 31 × 19.5 × 3.065 mm3 at 915 MHz, and the total gain for the antenna is 0.12 dBi. The Via-loaded coplanar and U-shaped inductively coupled feeds allow the antenna to provide flexible tuning in terms of antenna impedance. In addition, a figure of merit is applied for the proposed tag antenna, and the results are presented. The read range is measured to be 4.2 m, which is very close to simulated values. This antenna measurement shows very good agreement with simulations.

  18. Online Coupling of Flow-Field Flow Fractionation and Single Particle Inductively Coupled Plasma-Mass Spectrometry: Characterization of Nanoparticle Surface Coating Thickness and Aggregation State

    Science.gov (United States)

    Surface coating thickness and aggregation state have strong influence on the environmental fate, transport, and toxicity of engineered nanomaterials. In this study, flow-field flow fractionation coupled on-line with single particle inductively coupled plasma-mass spectrometry i...

  19. Inductively coupled plasma mass spectrometry for stable isotope metabolic tracer studies of living systems

    Energy Technology Data Exchange (ETDEWEB)

    Luong, Elise [Iowa State Univ., Ames, IA (United States)

    1999-05-10

    This dissertation focuses on the development of methods for stable isotope metabolic tracer studies in living systems using inductively coupled plasma single and dual quadrupole mass spectrometers. Sub-nanogram per gram levels of molybdenum (Mo) from human blood plasma are isolated by the use of anion exchange alumina microcolumns. Million-fold more concentrated spectral and matrix interferences such as sodium, chloride, sulfate, phosphate, etc. in the blood constituents are removed from the analyte. The recovery of Mo from the alumina column is 82 ± 5% (n = 5). Isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS) is utilized for the quantitative ultra-trace concentration determination of Mo in bovine and human blood samples. The average Mo concentration in reference bovine serum determined by this method is 10.2 ± 0.4 ng/g, while the certified value is 11.5 ± 1.1 ng/g (95% confidence interval). The Mo concentration of one pool of human blood plasma from two healthy male donors is 0.5 ± 0.1 ng/g. The inductively coupled plasma twin quadrupole mass spectrometer (ICP-TQMS) is used to measure the carbon isotope ratio from non-volatile organic compounds and bio-organic molecules to assess the ability as an alternative analytical method to gas chromatography combustion isotope ratio mass spectrometry (GC-combustion-IRMS). Trytophan, myoglobin, and β-cyclodextrin are chosen for the study, initial observation of spectral interference of 13C+ with 12C 1H+ comes from the incomplete dissociation of myoglobin and/or β-cyclodextrin.

  20. Heating mechanism in one-dimensional bounded magnetized inductively coupled plasma

    International Nuclear Information System (INIS)

    Mao Ming; Wang Younian

    2006-01-01

    A self-consistent nonlocal kinetic model has been established to investigate the electron heating mechanism in an one-dimensional bounded magnetized inductively coupled plasma (MICP) under low pressures. The interaction function of electrons with rf electric field and electron energy distribution function (EEDF) are determined by solving the linearized Boltzmann equation incorporating with the Maxwell equations. The numerical results show that the presence of the direct-current (dc) magnetic field plays an important role in the EEDF and high-energy electrons are efficiently heated by the Azbel-Kaner resonances under the anomalous skin-effect conditions

  1. Recent Developments in Trace, Ultratrace and Isotope Ratio Measurements in Inductively Coupled Plasma Mass Spectrometry

    International Nuclear Information System (INIS)

    Zahran, N. F.

    2004-01-01

    Inductively coupled plasma mass spectrometry (ICP-MS) and Laser Ablation (LA-ICP-MS) are recent techniques for trace, ultratrace and isotope ratio measurements. Main features of these techniques and their figure of merit and capabilities are discussed. An overview of ICP-MS instrument is presented in addition to its precision, accuracy and detection limits. Uses of ICP-MS in environmental monitoring in some cases for detection of some radio nuclides are presented. Two geological applications namely, zircon grains analysis and age dating of Rb-Sr method are presented. Zn elemental and isotopic analyses in blood and serum as a biological application is shown. (Author)

  2. Solid Carbon Produced in an Inductively Coupled Plasma Torch with a Titan Like Atmosphere

    Directory of Open Access Journals (Sweden)

    D. Vacher

    2013-01-01

    Full Text Available Solid carbon is deposited on the surfaces of an inductively coupled plasma torch operating with a Titan like atmosphere plasma gas. The frame of the initial research is the study of the radiative properties of plasma encountered around a spacecraft during its hypersonic entry in upper layers of planetary atmosphere. Deposition of carbon is observed not only on the quartz tube outside the inductor but also on the ceramic protection of the torch injector. Carbon exhibits two types of morphology more or less dense and it is analyzed by various analytic devices as MEB, SEM, TEM, EDS and Raman spectroscopy. The gathered carbon powder shows the presence of nanostructured particles.

  3. Direct measurement of uranium in seawater by inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Qiao, Jixin; Xu, Yihong

    2018-01-01

    A simple method for direct measurement of uranium (238U) in seawater using triple quadrupole inductively coupled plasma mass spectrometry (ICP-MS) was established. The method provides a good analytical performance with respect to detection limit, accuracy, precision and sample throughput. During...... samples taken from large volume of seawater stored in immovable containers for relatively long period (i.e., several months), the uranium concentration and salinity data showed slightly increasing trends with the increase of water depth in the container. Therefore, cautions need to be paid in sampling...

  4. Characterization of silicon isotropic etch by inductively coupled plasma etcher for microneedle array fabrication

    International Nuclear Information System (INIS)

    Ji, J; Tay, F E H; Miao Jianmin; Sun Jianbo

    2006-01-01

    This work investigates the isotropic etching properties in inductively coupled plasma (ICP) etcher for microneedle arrays fabrication. The effects of process variables including powers, gas and pressure on needle structure generation are characterized by factorial design of experiment (DOE). The experimental responses of vertical etching depth, lateral etching length, ratio of vertical etching depth to lateral etching length and photoresist etching rate are reported. The relevance of the etching variables is also presented. The obtained etching behaviours for microneedle structure generation will be applied to develop recipes to fabricate microneedles in designed dimensions

  5. Characterization of silicon isotropic etch by inductively coupled plasma etcher for microneedle array fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Ji, J [Mechanical Engineering National University of Singapore, 119260, Singapore (Singapore); Tay, F E H [Mechanical Engineering National University of Singapore, 119260, Singapore (Singapore); Miao Jianmin [MicroMachines Center, School of Mechanical and Aerospace Engineering, Nanyang Technologica l University, 50 Nanyang Avenue, 639798 (Singapore); Sun Jianbo [MicroMachines Center, School of Mechanical and Aerospace Engineering, Nanyang Technologica l University, 50 Nanyang Avenue, 639798 (Singapore)

    2006-04-01

    This work investigates the isotropic etching properties in inductively coupled plasma (ICP) etcher for microneedle arrays fabrication. The effects of process variables including powers, gas and pressure on needle structure generation are characterized by factorial design of experiment (DOE). The experimental responses of vertical etching depth, lateral etching length, ratio of vertical etching depth to lateral etching length and photoresist etching rate are reported. The relevance of the etching variables is also presented. The obtained etching behaviours for microneedle structure generation will be applied to develop recipes to fabricate microneedles in designed dimensions.

  6. Inductive coupling between overhead power lines and nearby metallic pipelines. A neural network approach

    Directory of Open Access Journals (Sweden)

    Levente Czumbil

    2015-12-01

    Full Text Available The current paper presents an artificial intelligence based technique applied in the investigation of electromagnetic interference problems between high voltage power lines (HVPL and nearby underground metallic pipelines (MP. An artificial neural network (NN solution has been implemented by the authors to evaluate the inductive coupling between HVPL and MP for different constructive geometries of an electromagnetic interference problem considering a multi-layer soil structure. Obtained results are compared to solutions provided by a finite element method (FEM based analysis and considered as reference. The advantage of the proposed method yields in a simplified computation model compared to FEM, and implicitly a lower computational time.

  7. The determination of transition probabilities with an inductively-coupled plasma discharge

    International Nuclear Information System (INIS)

    Nieuwoudt, G.

    1984-03-01

    The 27 MHz inductively-coupled plasma discharge (ICP) is used for the determination of relative transition probabilities of the 451, 459 and 470 nm argon spectral lines. The temperature of the argon plasma is determined with hydrogen as thermometric specie, because of the accurate transition probabilities ( approximately 1% uncertainty) there of. The relative transition probabilities of the specific argon spectral lines were determined by substitution of the measured spectral radiances thereof, together with the hydrogen temperature, in the two-line equation of temperature measurement

  8. The influence of gas pressure on E↔H mode transition in argon inductively coupled plasmas

    OpenAIRE

    Xiao Zhang; Zhong-kai Zhang; Jin-xiang Cao; Yu Liu; Peng-cheng Yu

    2018-01-01

    Considering the gas pressure and radio frequency power change, the mode transition of E↔H were investigated in inductively coupled plasmas. It can be found that the transition power has almost the same trend decreasing with gas pressure, whether it is in H mode or E mode. However, the transition density increases slowly with gas pressure from E to H mode. The transition points of E to H mode can be understood by the propagation of electromagnetic wave in the plasma, while the H to E should be...

  9. Determination of trace amounts of cerium in paint by inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    Wong, K.L.

    1981-01-01

    The determination of Ce in paint by inductively coupled plasma atomic emission spectrometry (ICP-OES) is described, and the detection limit of ICP-OES of 0.0004 ppM is compared with that of other methods. The effects of the major elemental components of paint, Si, Pb, Cr, and Na on the ICP-OES determination of Ce were studied. The interference of 400 ppM of the other ions on the determination of 10 ppM Ce was small (0 to 3% error). The method is applicable to the range of 0.2 to 700 ppM Ce

  10. Computation and analysis of the electron transport properties for nitrogen and air inductively-coupled plasmas

    Science.gov (United States)

    Yu, Minghao; Kihara, Hisashi; Abe, Ken-ichi; Takahashi, Yusuke

    2015-06-01

    A relatively simple method for calculating accurately the third-order electron transport properties of nitrogen and air thermal plasmas is presented. The electron transport properties, such as the electrical conductivity and the electron thermal conductivity, were computed with the best and latest available collision cross-section data in the temperature and pressure ranges of T = 300 - 15000 K and p = 0.01 - 1.0 atm, respectively. The results obtained under the atmospheric pressure condition showed good agreements with the experimental and the high-accuracy theoretical results. The presently-introduced method has good application potential in numerical simulations of nitrogen and air inductively-coupled plasmas.

  11. Induction of cell death by chemotherapeutic methylating agents

    International Nuclear Information System (INIS)

    Quiros Barrantes, Steve

    2012-01-01

    The mechanism of cell death induced by O 6 MeG has been investigated and inhibition of homologous recombination as a strategy for sensitization of tumor cells against methylating agents S N 1. Dependence of the cell cycle was determined toxic responses triggered by O''6 MeG and evaluated by proliferation assays if apoptotic cells have originated exclusively from the second post-treatment cycle. Dependence of O''6 MeG was found at DSB formation. The activation of the control points of the cell cycle and induction of apoptosis is generated during the second cell cycle. Additionally, a portion of the cells has been determined that triggers apoptosis in subsequent generations in the second cell cycle. Inhibition of homologous recombination has been a reasonable strategy to increase S N 1 alkylating agent effectiveness. Evidence has been provided in NHEJ dependent inhibition of DNA-PK that not significantly sensitizes the glioblastoma cells against temozolomide [es

  12. Cell design for the DARHT linear induction accelerators

    International Nuclear Information System (INIS)

    Burns, M.; Allison, P.; Earley, L.; Liska, D.; Mockler, C.; Ruhe, J.; Tucker, H.; Walling, L.

    1991-01-01

    The Dual-Axis Radiographic Hydrotest (DARHT) facility will employ two linear induction accelerators to produce intense, bremsstrahlung x- ray pulses for flash radiography. The accelerator cell design for a 3- kA, 16--20 MeV, 60-ns flattop, high-brightness electron beam is presented. The cell is optimized for high-voltage stand-off while also minimizing the its transverse impedance. Measurements of high- voltage and rf characteristics are summarized. 7 refs., 5 figs

  13. Two-dimensional simulation of a miniaturized inductively coupled plasma reactor

    International Nuclear Information System (INIS)

    Nam, Sang Ki; Economou, Demetre J.

    2004-01-01

    A two-dimensional self-consistent simulation of a miniaturized inductively coupled plasma (mICP) reactor was developed. The coupled equations for plasma power deposition, electron temperature, and charged and neutral species densities, were solved to obtain the spatial distribution of an argon discharge. The effect of control parameters, such as power and pressure, on the evolution of plasma density and electron temperature was investigated. Strong ion density gradients were observed which can make spatially resolved Langmuir probe measurements particularly challenging. Simulation results were in reasonable agreement with available experimental data. The neutral gas temperature was predicted to be close to the wall temperature, due to the small length scale of the mICP, allowing for efficient heat transfer

  14. Induction of RNA interference in dendritic cells.

    Science.gov (United States)

    Li, Mu; Qian, Hua; Ichim, Thomas E; Ge, Wei-Wen; Popov, Igor A; Rycerz, Katarzyna; Neu, John; White, David; Zhong, Robert; Min, Wei-Ping

    2004-01-01

    Dendritic cells (DC) reside at the center of the immunological universe, possessing the ability both to stimulate and inhibit various types of responses. Tolerogenic/regulatory DC with therapeutic properties can be generated through various means of manipulations in vitro and in vivo. Here we describe several attractive strategies for manipulation of DC using the novel technique of RNA interference (RNAi). Additionally, we overview some of our data regarding yet undescribed characteristics of RNAi in DC such as specific transfection strategies, persistence of gene silencing, and multi-gene silencing. The advantages of using RNAi for DC genetic manipulation gives rise to the promise of generating tailor-made DC that can be used effectively to treat a variety of immunologically mediated diseases.

  15. Reduction of cell growth and induction of apoptosis in osteosarcoma cells by silver nanoparticles

    Directory of Open Access Journals (Sweden)

    Toktam Rajabnia

    2017-09-01

    Conclusion: Since silver nanoparticles can reduce the proliferation of Saos-2 cells and to eradicate them by induction of apoptosis, these nanoparticles can be taken as a candidate for treating osteosarcoma cells.

  16. Binary gene induction and protein expression in individual cells

    Directory of Open Access Journals (Sweden)

    Conolly Rory B

    2006-04-01

    Full Text Available Abstract Background Eukaryotic gene transcription is believed to occur in either a binary or a graded fashion. With binary induction, a transcription activator (TA regulates the probability with which a gene template is switched from the inactive to the active state without affecting the rate at which RNA molecules are produced from the template. With graded, also called rheostat-like, induction the gene template has continuously varying levels of transcriptional activity, and the TA regulates the rate of RNA production. Support for each of these two mechanisms arises primarily from experimental studies measuring reporter proteins in individual cells, rather than from direct measurement of induction events at the gene template. Methods and results In this paper, using a computational model of stochastic gene expression, we have studied the biological and experimental conditions under which a binary induction mode operating at the gene template can give rise to differentially expressed "phenotypes" (i.e., binary, hybrid or graded at the protein level. We have also investigated whether the choice of reporter genes plays a significant role in determining the observed protein expression patterns in individual cells, given the diverse properties of commonly-used reporter genes. Our simulation confirmed early findings that the lifetimes of active/inactive promoters and half-lives of downstream mRNA/protein products are important determinants of various protein expression patterns, but showed that the induction time and the sensitivity with which the expressed genes are detected are also important experimental variables. Using parameter conditions representative of reporter genes including green fluorescence protein (GFP and β-galactosidase, we also demonstrated that graded gene expression is more likely to be observed with GFP, a longer-lived protein with low detection sensitivity. Conclusion The choice of reporter genes may determine whether protein

  17. Low-energy states in a chain of inductively coupled Josephson junctions

    Science.gov (United States)

    Meier, Hendrik; Brierley, Richard T.; Kou, Angela; Girvin, Steven M.; Glazman, Leonid I.

    2015-03-01

    We investigate a long chain of inductively coupled Josephson junctions penetrated by an external magnetic field. In the limit of infinite junction capacitances, we determine the classical ground state and find that the competition between Josephson and inductive forces leads to a rich phase phase diagram as a function of magnetic flux per plaquette ϕe and the ratio l2 =EJ /EL of Josephson (EJ) and inductive (EL) energies. At large l, kinks in the superconducting phase set in as a function of ϕe similarly to vortices in type-II superconductors. Upon further increasing ϕe, the interplay between kink-kink interaction and pinning on the lattice leads to a Frenkel-Kontorova-type (devil's) staircase of phases distinguished by different rational kink densities. At ϕe equal to half a flux quantum, the system bears similarity to a classical Ising antiferromagnet, possibly with a long-ranged exchange. Inclusion of a finite junction capacitances is similar to placing the Ising chain in a transverse magnetic field (the quantum Ising model). Using this similarity, we investigate the quantum dynamics of a chain of fluxonium qubits.

  18. Resonant RF network antennas for large-area and large-volume inductively coupled plasma sources

    International Nuclear Information System (INIS)

    Hollenstein, Ch; Howling, A A; Guittienne, Ph

    2013-01-01

    Large-area and large-volume radio frequency (RF) plasmas are produced by different arrangements of an elementary electrical mesh consisting of two conductors interconnected by a capacitor at each end. The obtained cylindrical and planar RF networks are resonant and generate very high RF currents. The input impedance of such RF networks shows the behaviour of an RLC parallel resonance equivalent circuit. The real impedance at the resonance frequency is of great advantage for power matching compared with conventional inductive devices. Changes in the RLC equivalent circuit during the observed E–H transition will allow future interpretation of the plasma–antenna coupling. Furthermore, high power transfer efficiencies are found during inductively coupled plasma (ICP) operation. For the planar RF antenna network it is shown that the E–H transition occurs simultaneously over the entire antenna. The underlying physics of these discharges induced by the resonant RF network antenna is found to be identical to that of the conventional ICP devices described in the literature. The resonant RF network antenna is a new versatile plasma source, which can be adapted to applications in industry and research. (paper)

  19. Trace metal analysis of road dust by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Powell, M.J.; Liu, L.; Gnanalingham, N.; Peters, L.

    2000-01-01

    Dust from roads in an air impingement zone close to anthropogenic sources of air pollutants can be a concern for people living in the immediate vicinity. The Ministry of the Environment (MOE) has conducted a case study to monitor the concentration of uranium, strontium, thorium and arsenic in road dust from one such area. A method for the analysis of road dust by inductively coupled plasma mass spectrometry (ICP-MS) has been developed with detection limits in the ng/1 range. A digestion technique has been developed by conducting experiments using single and combinations of acids in open-vessel wet digestions. Accuracy has been determined by the use of matrix representative certified reference materials (CRMs). Digestion precision was determined by elemental concentration measurements of the most representative CRM through replicates. Spike recovery data were from 95% to 110% for all elements, and inter-method comparison studies between hydride generation atomic absorption spectrometry (AAS) inductively coupled plasma atomic emission spectrometry (ICP-AES) and ICP-MS for arsenic and strontium show good agreement. (author)

  20. Inductively coupled plasma-mass spectrometry: an initial assessment of the VG isotopes Plasmaquad

    International Nuclear Information System (INIS)

    Brown, R.M.; Pickford, C.J.

    1985-04-01

    The Chemical Analysis Group has been approached by a British Scientific instrument maker regarding the possibility of the group participating in a Department of Trade and Industry sponsored scheme whereby we would have a 12 month period to assess the advantages and disadvantages of a new analytical technique, Inductively Coupled Plasma-Mass Spectrometry. This report details our initial assessment of the instrument, carried out in order to decide whether to participate in the scheme. We have attempted to discover whether the instrument meets the claims made of it in advertising literature, and have attempted to compare the technique with another, proven technique, Inductively Coupled Plasma - Optical Emission Spectroscopy. The Plasmaquad offers excellent sensitivity for almost all of the elements of the periodic table, giving a distinct improvement over the Chemical Analysis Group's present capabilities for many elements. The isotope ratio measuring ability is important, as the Group has no such capability at the moment and a demand for this type of measurement is foreseen. Our conclusions, while inevitably somewhat subjective, form the basis for recommending Harwell to participate in the scheme. (author)

  1. Minimally-invasive Laser Ablation Inductively Coupled Plasma Mass Spectrometry analysis of model ancient copper alloys

    Energy Technology Data Exchange (ETDEWEB)

    Walaszek, Damian [University of Warsaw, Faculty of Chemistry, Biological and Chemical Research Centre, Żwirki i Wigury 101, 02-089 Warszawa (Poland); Laboratory for Analytical Chemistry, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Senn, Marianne; Wichser, Adrian [Laboratory for Analytical Chemistry, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Faller, Markus [Laboratory for Jointing Technology and Corrosion, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Wagner, Barbara; Bulska, Ewa [University of Warsaw, Faculty of Chemistry, Biological and Chemical Research Centre, Żwirki i Wigury 101, 02-089 Warszawa (Poland); Ulrich, Andrea [Laboratory for Analytical Chemistry, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland)

    2014-09-01

    This work describes an evaluation of a strategy for multi-elemental analysis of typical ancient bronzes (copper, lead bronze and tin bronze) by means of laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS).The samples originating from archeological experiments on ancient metal smelting processes using direct reduction in a ‘bloomery’ furnace as well as historical casting techniques were investigated with the use of the previously proposed analytical procedure, including metallurgical observation and preliminary visual estimation of the homogeneity of the samples. The results of LA-ICPMS analysis were compared to the results of bulk composition obtained by X-ray fluorescence spectrometry (XRF) and by inductively coupled plasma mass spectrometry (ICPMS) after acid digestion. These results were coherent for most of the elements confirming the usefulness of the proposed analytical procedure, however the reliability of the quantitative information about the content of the most heterogeneously distributed elements was also discussed in more detail. - Highlights: • The previously proposed procedure was evaluated by analysis of model copper alloys. • The LA-ICPMS results were comparable to the obtained by means of XRF and ICPMS. • LA-ICPMS results indicated the usefulness of the proposed analytical procedure.

  2. Inductively coupled plasma etching of poly-SiC in SF6 chemistries

    Science.gov (United States)

    Kuah, S. H.; Wood, P. C.

    2005-07-01

    A study was made to find a low-cost and robust etching solution for silicon carbide (SiC) using a commercially available inductively coupled plasma etching tool. Sulfur hexafluoride (SF6) was selected because of its high degree of F dissociation and nonhazardous nature. A parametric study of the etching characteristics of poly-SiC in inductively coupled plasma (ICP) SF6 chemistries was performed. Etch chemistry was found to greatly affect etch rate, selectivity, and the postetch surface condition. Etch rates as high as 5884 A˚/min were achieved with high SiC/Cr selectivity (36) using a SF6/CF4/He gas mixture, but the etched surface was relatively rough (134 A˚ rms). He addition was found to increase the SiC etch rate, and this effect is believed to be caused by increased ionization of SF6 in the plasma and the resulting increases in the SF3+ and fluorine (F) radical concentrations. The formation of pillar-like structures and sidewall deposition was observed on the etched SiC surfaces under some conditions. These unwanted etch byproducts exhibited a high concentration of chromium (Cr) and fluorine. However, an argon (Ar) plasma preclean of the substrate, high ICP, and/or bias powers, and CF4 addition reduced the pillar formation significantly.

  3. Determination of trace elements in petroleum products by inductively coupled plasma techniques: A critical review

    Science.gov (United States)

    Sánchez, Raquel; Todolí, José Luis; Lienemann, Charles-Philippe; Mermet, Jean-Michel

    2013-10-01

    The fundamentals, applications and latter developments of petroleum products analysis through inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS) are revisited in the present bibliographic survey. Sample preparation procedures for the direct analysis of fuels by using liquid sample introduction systems are critically reviewed and compared. The most employed methods are sample dilution, emulsion or micro-emulsion preparation and sample decomposition. The first one is the most widely employed due to its simplicity. Once the sample has been prepared, an organic matrix is usually present. The performance of the sample introduction system (i.e., nebulizer and spray chamber) depends strongly upon the nature and properties of the solution finally obtained. Many different devices have been assayed and the obtained results are shown. Additionally, samples can be introduced into the plasma by using an electrothermal vaporization (ETV) device or a laser ablation system (LA). The recent results published in the literature showing the feasibility, advantages and drawbacks of latter alternatives are also described. Therefore, the main goal of the review is the discussion of the different approaches developed for the analysis of crude oil and its derivates by inductively coupled plasma (ICP) techniques.

  4. Radiation induction of multiaberrant cells in Allium cepa L.

    Energy Technology Data Exchange (ETDEWEB)

    Kutsokon, N.K.; Rashydov, N.M.; Grodzinsky, D.M.

    2008-07-01

    'Rogue' cells determined by human geneticists as the cells with many chromosome aberrations. The main enigma of this phenomenon is its levels are unexpected higher in many studies. Frequently, these cells emergence in human are linked with radiation or viruses. 'Rogue' cells supposed to be very important in mutagenesis, oncogenesis and even in evolution process. We use plant assay (Allium cepa L.) to analyze the induction of cells with many chromosome aberration of different types. Cytogenetic damage of gamma-irradiation as frequency of multiaberrant cells in the root tip cells of Allium was determined. The empiric numbers of cells with many aberrations were compared with those expected in theoretical distributions (Poisson, geometric and Pascal). The frequency of multiaberrant cells in root tip cells was increased up to 83,33 +- 10,76 % under gamma-irradiation in various doses. Gamma-irradiation induced more multiaberrant cells in A. cepa meristems than expected in theoretical distributions. We supposed dependency of chromosome aberrations origin in the same cell after irradiation. The data obtained elucidate that under gamma-irradiation accumulation of aberrations in aberrant cells are not random, the appearance of one aberration in cell induced the appearance of others in the same cell. (author)

  5. Induction of chromosome aberrations in two lines of cultured cells using different types of radiation

    International Nuclear Information System (INIS)

    Zoetelief, J.; Dingjan-Hirschi, E.S.; Hasper, J.; Janse, H.C.; Barendsen, G.W.

    The induction of chromosome aberrations has been investigated in two lines of cultured cells for different types of radiation. The obtained results are compared with information on induction of cell reproductive death and malignant transformation. (Auth.)

  6. Analytical capabilities of an inductively coupled plasma Mattauch Herzog mass spectrometer

    Science.gov (United States)

    Solyom, David A.; Gron, Ole A.; Barnes, James H., IV; Hieftje, Gary M.

    2001-09-01

    An inductively coupled plasma (ICP) has been coupled to a custom-designed Mattauch-Herzog mass spectrometer, replacing a glow-discharge source used in earlier research. Adaptation to an ICP source required significant modifications to address concerns regarding shielding from RF radiation and coupling between the ICP and mass spectrometer. The detrimental impact of fringing magnetic fields on the earlier performance of the instrument's detector has also been addressed. Current figures of merit utilizing ultrasonic nebulization include sensitivities in the 10 8-10 9 cps ppm -1 isotope -1 regime and detection limits of 1-500 pg/l (ppq). Isotope-ratio accuracy and precision are 1% relative error and 1-2% relative standard deviation, respectively. Resolving power (5% valley) exceeds 400. Unfortunately, spectral peak shapes are somewhat disappointing and lead to abundance sensitivity values in the 10 3-10 4 range. Although the instrument is designed for use with a multichannel array detector, all results reported here were obtained in scanning mode to separate limitations of the spectrometer from those of the detector.

  7. Sulfur analysis by inductively coupled plasma-mass spectrometry: A review

    Energy Technology Data Exchange (ETDEWEB)

    Giner Martínez-Sierra, J.; Galilea San Blas, O.; Marchante Gayón, J.M.; García Alonso, J.I., E-mail: jiga@uniovi.es

    2015-06-01

    In recent years the number of applications of sulfur (S) analysis using inductively coupled plasma mass spectrometry (ICP-MS) as detector has increased significantly. In this article we describe in some depth the application of ICP-MS for S analysis with emphasis placed on the sulfur-specific detection by hyphenated techniques such as LC, GC, CE and LA coupled on-line to ICP-MS. The different approaches available for sulfur isotope ratio measurements by ICP-MS are also detailed. Particular attention has been paid to the quantification of peptides/proteins and the analysis of metallopeptides/metalloproteins via sulfur by LC–ICP-MS. Likewise, the speciation analysis of metal-based pharmaceuticals and metallodrugs and non-metal selective detection of pharmaceuticals via S are highlighted. Labeling procedures for metabolic applications are also included. Finally, the measurement of natural variations in S isotope composition with multicollector ICP-MS instruments is also covered in this review. - Highlights: • Emphasis placed on the sulfur-specific detection by chromatographic techniques coupled on-line to ICP-MS. • Different instrumental approaches available for sulfur measurements by ICP-MS. • Quantification of proteins and the analysis of metalloproteins via sulfur by LC-ICP-MS. • Labelling procedures for metabolic applications are also included. • The measurement of natural variations in S isotope composition with multicollector ICP-MS.

  8. Coupling an induction motor type generator to ac power lines. [making windmill generators compatible with public power lines

    Science.gov (United States)

    Nola, F. J. (Inventor)

    1984-01-01

    A system for coupling an induction motor type generator to an A.C. power line includes an electronic switch means that is controlled by a control system and is regulated to turn on at a relatively late point in each half cycle of its operation. The energizing power supplied by the line to the induction motor type generator is decreased and the net power delivered to the line is increased.

  9. Developments and trends in inductively coupled plasma mass spectrometry and its influence on the recent advances in trace element analysis

    International Nuclear Information System (INIS)

    Balaram, V.

    1995-01-01

    A brief introduction to the various instrumental methods such as atomic absorption spectrometry, x-ray fluorescence spectrometry, neutron activation analysis, inductively coupled plasma atomic emission spectrometry, thermal ionization mass spectrometry, etc. are presented highlighting their relative merits and demerits. The history and developments of inductively coupled plasma mass spectrometry (ICP-MS) and its advantages and limitations over other multi-element instrumental techniques are reviewed. Extended capabilities by hyphenating ICP-MS to various other well-known sample introduction techniques such as flow-injection, electrothermal vaporization, chromatographic methods and laser ablation are discussed in brief. The recent development of high resolution multi-collector double-focusing magnetic mass spectrometer with inductively coupled plasma at atmospheric pressure as source is also discussed. Some of the areas where more developments can be expected in future are suggested. (author). 77 refs., 4 tabs., 3 figs

  10. Ion energy distribution functions in inductively coupled radio-frequency discharges emdash Mixtures of Cl2/BCl3/Ar

    International Nuclear Information System (INIS)

    Nichols, C.A.; Woodworth, J.R.; Hamilton, T.W.

    1998-01-01

    We have used a gridded energy analyzer to measure positive ion energy distributions and fluxes at the grounded electrode of a high-density rf discharge. We present details of ion energies and fluxes in discharges containing mixtures of chlorine, boron trichloride and argon. These feedstock mixtures have been used extensively in the patterning of metal films for semiconductor interconnects. Our experiments were carried out in a Gaseous Electronics Conference Reference Cell which had been modified to produce inductively coupled discharges. The 15-cm-diam bottom electrode was grounded for these experiments. Stainless steel, anodized aluminum, and silicon were used as bottom electrode materials to understand the effects of various chamber boundary conditions on the ion energy parameters. In most cases, the ion energy distributions had a single peak, well separated from zero energy with a 1.0 endash 3.0 eV full width at half maximum. These peaks were typically centered at 12 endash 16 eV, with ion energy increasing as pressure decreased. Addition of BCl 3 to a Cl 2 discharge resulted in a reduction of total ion flux of more than a factor of 2, e.g., from 5 to 2.5 mA/cm 2 (20 mTorr, 200 W). The ion fluxes decreased with increasing pressures in BCl 3 /Cl 2 mixtures, while increasing with pressure in pure Cl 2 discharges. Addition of Ar to several mixtures of BCl 3 /Cl 2 changed the ion fluxes and mean ion energies by less than 15%. At high pressures or low inductive rf powers, the distributions can split into two overlapping peaks separated by as much as 8 eV. This splitting is indicative of capacitive coupling between the rf coil and the discharge. Insertion of a Faraday shield between the coil and the discharge removed most of the splitting. copyright 1998 American Vacuum Society. thinsp

  11. A Practical Guide on Coupling a Scanning Mobility Sizer and Inductively Coupled Plasma Mass Spectrometer (SMPS-ICPMS)

    Science.gov (United States)

    Tarik, Mohamed; Foppiano, Debora; Hess, Adrian; Ludwig, Christian

    2017-01-01

    A large variety of analytical methods are available to characterize particles in aerosols and suspensions. The choice of the appropriate technique depends on the properties to be determined. In many fields information about particle size and chemical composition are of great importance. While in aerosol techniques particle size distributions of gas-borne particles are determined online, their elemental composition is commonly analyzed offline after an appropriate sampling and preparation procedure. To obtain both types of information online and simultaneously, a hyphenated setup was recently developed, including a Scanning Mobility Particle Sizer (SMPS) and an Inductively Coupled Plasma Mass Spectrometer (ICPMS). This allows first to classify the particles with respect to their mobility diameter, and then to determine their number concentration and elemental composition in parallel. A Rotating Disk Diluter (RDD) is used as the introduction system, giving more flexibility regarding the use of different aerosol sources. In this work, a practical guide is provided describing the different steps for establishing this instrumentation, and how to use this analysis tool. The versatility of this hyphenated technique is demonstrated in example measurements on three different aerosols generated out of a) a salt solution, b) a suspension, and c) emitted by a thermal process. PMID:28745635

  12. Development and application of acousto-optic background correction for inductively coupled plasma atomic emission spectrometry.

    Science.gov (United States)

    Miller, Heather M; Spudich, Thomas M; Carnahan, Jon W

    2003-06-01

    In two configurations, a solid-state acousto-optic (AO) deflector or modulator is mounted in a 0.5 m monochromator for background correction with inductively coupled plasma atomic emission spectrometry (ICP-AES). A fused silica acousto-optic modulator (AOM) is used in the ultraviolet (UV) spectral region applications while a glass AO deflector (AOD) is used for the visible (VIS) region. The system provides rapid sequential observation of adjacent on- and off-line wavelengths for background correction. Seventeen elements are examined using pneumatic nebulization (PN) and electrothermal vaporization (ETV) sample introduction. Calibration plots were obtained with each sample introduction technique. Potable water and vitamin tablets were analyzed. Flame atomic absorption (FAA) was used to verify the accuracy of the AO background correction system.

  13. Capillary electrophoresis interfaced to inductively coupled plasma mass spectrometry for element selective detection in arsenic speciation.

    Science.gov (United States)

    Michalke, B; Schramel, P

    1998-09-01

    A method is presented to separate and detect six arsenic species by capillary electrophoresis (CE) interfaced to inductively coupled plasma mass spectrometry (ICP-MS). CE was used as a highly resolving separation system, whereas ICP-MS served as an element selective detector providing low detection limits. The special mode of operation included sample stacking and a differentiation of separation and detection. This provided separation and detection of six As species, uncharged and anionic, to be monitored within a single run. Detection limits were calculated according to IUPAC recommendation at 15 microg As/L for As (III), dimethyl arsinic acid (DA), monomethyl arsonic acid (MA) and As (V), or 65 microg As/L for arsenobetaine (AsB) and arsenocholine (AsC). Investigations were focused on possibly occurring interferences, e.g., ArCl+ interference at the monoisotope 75As. Finally, real samples from biomedical field (urine) and environmental field (sewage sludge) were analyzed.

  14. Simulation of a large size inductively coupled plasma generator and comparison with experimental data

    Science.gov (United States)

    Lei, Fan; Li, Xiaoping; Liu, Yanming; Liu, Donglin; Yang, Min; Yu, Yuanyuan

    2018-01-01

    A two-dimensional axisymmetric inductively coupled plasma (ICP) model with its implementation in the COMSOL (Multi-physics simulation software) platform is described. Specifically, a large size ICP generator filled with argon is simulated in this study. Distributions of the number density and temperature of electrons are obtained for various input power and pressure settings and compared. In addition, the electron trajectory distribution is obtained in simulation. Finally, using experimental data, the results from simulations are compared to assess the veracity of the two-dimensional fluid model. The purpose of this comparison is to validate the veracity of the simulation model. An approximate agreement was found (variation tendency is the same). The main reasons for the numerical magnitude discrepancies are the assumption of a Maxwellian distribution and a Druyvesteyn distribution for the electron energy and the lack of cross sections of collision frequencies and reaction rates for argon plasma.

  15. Inductively Coupled Plasma: Fundamental Particle Investigations with Laser Ablation and Applications in Magnetic Sector Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Saetveit, Nathan Joe [Iowa State Univ., Ames, IA (United States)

    2008-01-01

    Particle size effects and elemental fractionation in laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) are investigated with nanosecond and femtosecond laser ablation, differential mobility analysis, and magnetic sector ICP-MS. Laser pulse width was found to have a significant influence on the LA particle size distribution and the elemental composition of the aerosol and thus fractionation. Emission from individual particles from solution nebulization, glass, and a pressed powder pellet are observed with high speed digital photography. The presence of intact particles in an ICP is shown to be a likely source of fractionation. A technique for the online detection of stimulated elemental release from neural tissue using magnetic sector ICP-MS is described. Detection limits of 1 μg L-1 or better were found for P, Mn, Fe, Cu, and Zn in a 60 μL injection in a physiological saline matrix.

  16. Determination of Rare Earth Elements in Thai Monazite by Inductively Coupled Plasma and Nuclear Analytical techniques

    International Nuclear Information System (INIS)

    Busamongkol, Arporn; Ratanapra, Dusadee; Sukharn, Sumalee; Laoharojanaphand, Sirinart

    2003-10-01

    The inductively coupled plasma atomic emission spectroscopy (ICP-AES) for the determination of individual rare-earth elements (REE) was evaluated by comparison with instrumental neutron activation analysis (INAA) and x-ray fluorescence spectrometry (XRF). The accuracy and precision of INAA and ICP-AES were evaluated by using standard reference material IGS-36, a monazite concentrate. For INAA, the results were close to the certified value while ICP-AES were in good agreement except for some low concentration rare earth. The techniques were applied for the analysis of some rare earth elements in two Thai monazite samples preparing as the in-house reference material for the Rare Earth Research and Development Center, Chemistry Division, Office of Atoms for Peace. The analytical results obtained by these techniques were in good agreement with each other

  17. Inductively Coupled Plasma-Induced Etch Damage of GaN p-n Junctions

    International Nuclear Information System (INIS)

    SHUL, RANDY J.; ZHANG, LEI; BACA, ALBERT G.; WILLISON, CHRISTI LEE; HAN, JUNG; PEARTON, S.J.; REN, F.

    1999-01-01

    Plasma-induced etch damage can degrade the electrical and optical performance of III-V nitride electronic and photonic devices. We have investigated the etch-induced damage of an Inductively Coupled Plasma (ICP) etch system on the electrical performance of mesa-isolated GaN pn-junction diodes. GaN p-i-n mesa diodes were formed by Cl 2 /BCl 3 /Ar ICP etching under different plasma conditions. The reverse leakage current in the mesa diodes showed a strong relationship to chamber pressure, ion energy, and plasma flux. Plasma induced damage was minimized at moderate flux conditions (≤ 500 W), pressures ≥2 mTorr, and at ion energies below approximately -275 V

  18. A comprehensive study of different gases in inductively coupled plasma torch operating at one atmosphere

    International Nuclear Information System (INIS)

    Punjabi, Sangeeta B.; Joshi, N. K.; Mangalvedekar, H. A.; Lande, B. K.; Das, A. K.; Kothari, D. C.

    2012-01-01

    A numerical study is done to understand the possible operating regimes of RF-ICP torch (3 MHz, 50 kW) using different gases for plasma formation at atmospheric pressure. A two dimensional numerical simulation of RF-ICP torch using argon, nitrogen, oxygen, and air as plasma gas has been investigated using computational fluid dynamic (CFD) software fluent (c) . The operating parameters varied here are central gas flow, sheath gas flow, RF-power dissipated in plasma, and plasma gas. The temperature contours, flow field, axial, and radial velocity profiles were investigated under different operating conditions. The plasma resistance, inductance of the torch, and the heat distribution for various plasma gases have also been investigated. The plasma impedance of ICP torch varies with different operating parameters and plays an important role for RF oscillator design and power coupling. These studies will be useful to decide the design criteria for ICP torches required for different material processing applications.

  19. Determination of elemental content off rocks by laser ablation inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Lichte, F.E.

    1995-01-01

    A new method of analysis for rocks and soils is presented using laser ablation inductively coupled plasma mass spectrometry. It is based on a lithium borate fusion and the free-running mode of a Nd/YAG laser. An Ar/N2 sample gas improves sensitivity 7 ?? for most elements. Sixty-three elements are characterized for the fusion, and 49 elements can be quantified. Internal standards and isotopic spikes ensure accurate results. Limits of detection are 0.01 ??g/g for many trace elements. Accuracy approaches 5% for all elements. A new quality assurance procedure is presented that uses fundamental parameters to test relative response factors for the calibration.

  20. Nonlinear electromagnetic fields in 0.5 MHz inductively coupled plasmas

    DEFF Research Database (Denmark)

    Ostrikov, K.N.; Tsakadze, E.L.; Xu, S.

    2003-01-01

    Radial profiles of magnetic fields in the electrostatic (E) and electromagnetic (H) modes of low-frequency (similar to500 kHz) inductively coupled plasmas have been measured using miniature magnetic probes. In the low-power (similar to170 W) E-mode, the magnetic field pattern is purely linear......, with the fundamental frequency harmonics only. After transition to higher-power (similar to1130 W) H-mode, the second-harmonic nonlinear azimuthal magnetic field B-phi(2omega) that is in 4-6 times larger than the fundamental frequency component B-phi(omega), has been observed. A simplified plasma fluid model...... explaining the generation of the second harmonics of the azimuthal magnetic field in the plasma source is proposed. The nonlinear second harmonic poloidal (r-z) rf current generating the azimuthal magnetic field B-phi(2omega) is attributed to nonlinear interactions between the fundamental frequency radial...

  1. Filterless preconcentration, flow injection analysis and detection by inductively-coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    The influence of interferences in the analysis of elements by inductively-coupled-plasma mass-spectrometry (ICP-MS) may be significantly diminished by utilising a protocol of flow-injection analysis (FIA). The method is based on filterless preconcentration of metallic elements at the walls...... of a knotted reactor that was made of nylon tubings. In the load mode, the preconcentration was accomplished by precipitation of metallic species in alkaline-buffered carriers onto the inner walls of the hydrofilic tube. After a preconcen-tration period of 40-120 seconds using sample volumes of 4-10 m...... of 10-30 were obtained in the analysis of aluminium, of chromium and of iron, which resulted in detection limits (3) down to 20 g/L at a sampling frequency of 50 per hour. The preconcentration protocol improves the selectivity thus allowing direct determination of the elements in saline media. Anionic...

  2. Inductively Coupled Plasma: Fundamental Particle Investigations with Laser Ablation and Applications in Magnetic Sector Mass Spectrometry

    International Nuclear Information System (INIS)

    Nathan Joe Saetveit

    2008-01-01

    Particle size effects and elemental fractionation in laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) are investigated with nanosecond and femtosecond laser ablation, differential mobility analysis, and magnetic sector ICP-MS. Laser pulse width was found to have a significant influence on the LA particle size distribution and the elemental composition of the aerosol and thus fractionation. Emission from individual particles from solution nebulization, glass, and a pressed powder pellet are observed with high speed digital photography. The presence of intact particles in an ICP is shown to be a likely source of fractionation. A technique for the online detection of stimulated elemental release from neural tissue using magnetic sector ICP-MS is described. Detection limits of 1 (micro)g L -1 or better were found for P, Mn, Fe, Cu, and Zn in a 60 (micro)L injection in a physiological saline matrix

  3. The effect of hydrogen on B4C coatings fabrication in inductively coupled plasma torch

    Directory of Open Access Journals (Sweden)

    Q. J. Guo

    2018-02-01

    Full Text Available Boron carbide (B4C coatings are prepared by an RF inductively coupled plasma (ICP torch with different amounts of hydrogen introduced into the sheath gas. The effects of the added hydrogen on the characteristics of the plasma are diagnosed by optical emission spectroscopy and high speed photography. The effects on the melting of B4C particles in the plasma are studied by scanning electron microscopy (SEM. The microstructure of the B4C coatings was determined with SEM imaging and x-ray diffraction analysis. The results show that adding hydrogen to the sheath gas leads to plasma contraction, which results in higher gas temperature of plasma. It also enhances B4C particles spheroidizing and improves the compactness of B4C coatings. Plasma processing does not change the main phase of boron carbide. The obtained results on B4C coatings on Cu substrates allows for improving the B4C coatings fabrication process.

  4. Standard practice for alternate actinide calibration for inductively coupled plasma-mass spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2004-01-01

    1.1 This practice provides guidance for an alternate linear calibration for the determination of selected actinide isotopes in appropriately prepared aqueous solutions by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). This alternate calibration is mass bias adjusted using thorium-232 (232Th) and uranium-238 (238U) standards. One of the benefits of this standard practice is the ability to calibrate for the analysis of highly radioactive actinides using calibration standards at much lower specific activities. Environmental laboratories may find this standard practice useful if facilities are not available to handle the highly radioactive standards of the individual actinides of interest. 1.2 The instrument response for a series of determinations of known concentration of 232Th and 238U defines the mass versus response relationship. For each standard concentration, the slope of the line defined by 232Th and 238U is used to derive linear calibration curves for each mass of interest using interference equ...

  5. Laser ablation inductively coupled plasma mass spectrometry. An alternative technique for monitoring 90Sr

    International Nuclear Information System (INIS)

    TsingHai Wang; Yan-Chen Lai; Yi-Kong Hsieh; Chu-Fang Wang

    2017-01-01

    Developing a rapid detection method for monitoring released 90 Sr remains a challenge to analytical chemists, particularly considering its low concentration and significant interferences in environmental samples. We proposed a concept as an alternative to detect 90 Sr on the surface of fish scales using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The high affinity of fish scales to Sr is capable of preconcentrating 90 Sr that minimizes isobaric interferences from 90 Zr + or 89 YH + , while tailing effect by abundant 88 Sr can be effectively reduced by adjusting the forward power of ICP-MS component. Adopting dried droplets of internal standards further allows a semiquantification of 90 Sr content on the surface of fish scales, which also arises an opportunity to monitoring the bioaccumulation of 90 Sr after Fukushima Daiichi nuclear disaster. (author)

  6. Removal of model proteins by means of low-pressure inductively coupled plasma discharge

    Energy Technology Data Exchange (ETDEWEB)

    Kylian, O; Rauscher, H; Gilliland, D; Bretagnol, F; Rossi, F [European Commission, Joint Research Centre, Institute for Health and Consumer Protection, Via E Fermi 2749, 21027 Ispra (Italy)], E-mail: francois.rossi@jrc.it

    2008-05-07

    Surgical instruments are intended to come into direct contact with the patients' tissues and thus interact with their first immune defence system. Therefore they have to be cleaned, sterilized and decontaminated, in order to prevent any kind of infections and inflammations or to exclude the possibility of transmission of diseases. From this perspective, the removal of protein residues from their surfaces constitutes new challenges, since certain proteins exhibit high resistance to commonly used sterilization and decontamination techniques and hence are difficult to remove without inducing major damages to the object treated. Therefore new approaches must be developed for that purpose and the application of non-equilibrium plasma discharges represents an interesting option. The possibility to effectively remove model proteins (bovine serum albumin, lysozyme and ubiquitin) from surfaces of different materials (Si wafer, glass, polystyrene and gold) by means of inductively coupled plasma discharges sustained in different argon containing mixtures is demonstrated and discussed in this paper.

  7. Removal of model proteins by means of low-pressure inductively coupled plasma discharge

    Science.gov (United States)

    Kylián, O.; Rauscher, H.; Gilliland, D.; Brétagnol, F.; Rossi, F.

    2008-05-01

    Surgical instruments are intended to come into direct contact with the patients' tissues and thus interact with their first immune defence system. Therefore they have to be cleaned, sterilized and decontaminated, in order to prevent any kind of infections and inflammations or to exclude the possibility of transmission of diseases. From this perspective, the removal of protein residues from their surfaces constitutes new challenges, since certain proteins exhibit high resistance to commonly used sterilization and decontamination techniques and hence are difficult to remove without inducing major damages to the object treated. Therefore new approaches must be developed for that purpose and the application of non-equilibrium plasma discharges represents an interesting option. The possibility to effectively remove model proteins (bovine serum albumin, lysozyme and ubiquitin) from surfaces of different materials (Si wafer, glass, polystyrene and gold) by means of inductively coupled plasma discharges sustained in different argon containing mixtures is demonstrated and discussed in this paper.

  8. Laser ablation microprobe inductively coupled plasma mass spectrometry study on diffusion of uranium into cement materials

    International Nuclear Information System (INIS)

    Sugiyama, D.; Chida, T.; Cowper, M.

    2008-01-01

    The diffusion of uranium (U(VI)) in solid cement monoliths of ordinary portland cement (OPC) and low-heat portland cement containing 30 wt.% fly ash (FAC) was measured by an in-diffusion technique. Detailed sharp depth profiles of uranium in the solid cement matrices were successively and quantitatively measured using laser ablation microprobe inductively coupled plasma mass spectrometry (LAMP-ICP-MS), and the apparent (D a ) and effective (D e ) diffusion coefficient of uranium in cement matrix were calculated as: D a =∝ 4 x 10 -16 m 2 s -1 and D e =∝ 3 x 10 -11 m 2 s -1 for OPC, and D a =∝ 2 x 10 -17 m 2 s -1 and D e =∝ 6 x 10 -13 m 2 s -1 for FAC. (orig.)

  9. Effect of Skimmer Cone Material on the Spectra of Inductively Coupled Plasma Mass Spectrometry

    International Nuclear Information System (INIS)

    Amr, M.A.; Zahran, N.F.; Helal, A.I.

    2002-01-01

    The inductively coupled plasma ion source for mass spectrometry is very sensitive for multielement analysis with detection limits down to sub part per trillion (ppt). Polyatomic ions which could be formed in the mass spectra may interfere in the analysis of some element. Experimental conditions have great influences on the formation of polyatomic ions. The present work demonstrates that the skimmer materials (Au, Ag, Ni, and Cu) are participating in the formation of polyatomic ions, meanwhile the sampler materials have no real effect. The mechanism of formation of polyatomic ions is explained. Heats of formation of polyatomic species formed from the skimmer materials such as: Au X, Ag X, Ni X and Cu X; where X= Ar, O, N, C and H are calculated by Gaussian program (G 94 W)

  10. Trace elemental composition of curry by inductively coupled plasma optical emission spectrometry (ICP-OES).

    Science.gov (United States)

    Gonzálvez, A; Armenta, S; De La Guardia, M

    2008-01-01

    A methodology based on inductively coupled plasma optical emission spectrometry (ICP-OES) after microwave-assisted acid digestion was developed to determine the content of traces elements in curry samples from the Spanish market. The methodology was validated in terms of accuracy by the analysis of citrus and tomato leaf reference materials achieving comparable results with the certified values. The trace metal content of curry samples was compared with data available from previously published reports concerning Indian samples, especially in terms of heavy metal composition, in order to guarantee the quality of the commercially available spices in the European countries. Values found for the analysis of arsenic, lead and cadmium were significantly lower than the maximum limit allowed by European Union statutory limits for heavy metals and lower than those obtained for Indian curry leaves reported by Indian research teams by using neutron activation and γ-ray analysis.

  11. OPTIMAL CONTROL OF A NONLINEAR COUPLED ELECTROMAGNETIC INDUCTION HEATING SYSTEM WITH POINTWISE STATE CONSTRAINTS

    Directory of Open Access Journals (Sweden)

    Irwin Yousept

    2010-07-01

    Full Text Available An optimal control problem arising in the context of 3D electromagnetic induction heating is investigated. The state equation is given by a quasilinear stationary heat equation coupled with a semilinear time harmonic eddy current equation. The temperature-dependent electrical conductivity and the presence of pointwise inequality state-constraints represent the main challenge of the paper. In the first part of the paper, the existence and regularity of the state are addressed. The second part of the paper deals with the analysis of the corresponding linearized equation. Some suffcient conditions are presented which guarantee thesolvability of the linearized system. The final part of the paper is concerned with the optimal control. The aim of the optimization is to find the optimal voltage such that a desired temperature can be achieved optimally. The corresponding first-order necessary optimality condition is presented.

  12. Multi-elemental analysis of aqueous geological samples by inductively coupled plasma-optical emission spectrometry

    Science.gov (United States)

    Todorov, Todor I.; Wolf, Ruth E.; Adams, Monique

    2014-01-01

    Typically, 27 major, minor, and trace elements are determined in natural waters, acid mine drainage, extraction fluids, and leachates of geological and environmental samples by inductively coupled plasma-optical emission spectrometry (ICP-OES). At the discretion of the analyst, additional elements may be determined after suitable method modifications and performance data are established. Samples are preserved in 1–2 percent nitric acid (HNO3) at sample collection or as soon as possible after collection. The aqueous samples are aspirated into the ICP-OES discharge, where the elemental emission signals are measured simultaneously for 27 elements. Calibration is performed with a series of matrix-matched, multi-element solution standards.

  13. Inductively Coupled Plasma-Induced Etch Damage of GaN p-n Junctions

    Energy Technology Data Exchange (ETDEWEB)

    SHUL,RANDY J.; ZHANG,LEI; BACA,ALBERT G.; WILLISON,CHRISTI LEE; HAN,JUNG; PEARTON,S.J.; REN,F.

    1999-11-03

    Plasma-induced etch damage can degrade the electrical and optical performance of III-V nitride electronic and photonic devices. We have investigated the etch-induced damage of an Inductively Coupled Plasma (ICP) etch system on the electrical performance of mesa-isolated GaN pn-junction diodes. GaN p-i-n mesa diodes were formed by Cl{sub 2}/BCl{sub 3}/Ar ICP etching under different plasma conditions. The reverse leakage current in the mesa diodes showed a strong relationship to chamber pressure, ion energy, and plasma flux. Plasma induced damage was minimized at moderate flux conditions ({le} 500 W), pressures {ge}2 mTorr, and at ion energies below approximately -275 V.

  14. Iodine Solid Source Inductively Coupled Plasma Etching of InP

    Science.gov (United States)

    Matsutani, Akihiro; Ohtsuki, Hideo; Koyama, Fumio

    2005-04-01

    We have demonstrated vertical and smooth inductively coupled plasma (ICP) dry etching of InP using solid iodine as a gas source at a low process temperature of 90°C. We prepared a solid iodine crystal in the ICP etching chamber as the etching gas source. Iodine gas was supplied from the solid source at a high vapor pressure into the process chamber. Vertical and smooth etching was realized under the condition of low temperature and low power. The typical etching rate was 0.4 μm/min. We believe that solid I2-ICP etching is a very simple and useful process for InP-based device fabrication with a resist mask.

  15. In vivo determination of aluminum, cobalt, chromium, copper, nickel, titanium and vanadium in oral mucosa cells from orthodontic patients with mini-implants by Inductively coupled plasma-mass spectrometry (ICP-MS).

    Science.gov (United States)

    Martín-Cameán, Ana; Jos, Angeles; Puerto, Maria; Calleja, Ana; Iglesias-Linares, Alejandro; Solano, Enrique; Cameán, Ana M

    2015-10-01

    Miniscrews are used as orthodontic anchorage devices in the dentistry clinical practice but the in vivo metallic release from these structures has been not previously investigated. The aim of this study was to determine the content of Al, Co, Cr, Cu, Ni, Ti and V in oral mucosa cells of control subjects, patients under orthodontic treatment and with both, orthodontic treatment and miniscrew, in order to know the contribution of these mini-implants to the total metallic content. ICP-MS measurements revealed the following ascending order: Cr

  16. Plasma analysis of inductively coupled impulse sputtering of Cu, Ti and Ni

    Science.gov (United States)

    Loch, D. A. L.; Aranda Gonzalvo, Y.; Ehiasarian, A. P.

    2017-06-01

    Inductively coupled impulse sputtering (ICIS) is a new development in the field of highly ionised pulsed PVD processes. For ICIS the plasma is generated by an internal inductive coil, replacing the need for a magnetron. To understand the plasma properties, measurements of the current and voltage waveforms at the cathode were conducted. The ion energy distribution functions (IEDFs) were measured by energy resolved MS and plasma chemistry was analysed by OES and then compared to a model. The target was operated in pulsed DC mode and the coil was energised by pulsed RF power, with a duty cycle of 7.5%. At a constant pressure (14 Pa) the set peak RF power was varied from 1000-4000 W. The DC voltage to the target was kept constant at 1900 V. OES measurements have shown a monotonic increase in intensity with increasing power. Excitation and ionisation processes were single step for ICIS of Ti and Ni and multi-step for Cu. The latter exhibited an unexpectedly steep rise in ionisation efficiency with power. The IEDFs measured by MS show the material- and time-dependant plasma potential in the range of 10-30 eV, ideal for increased surface mobility without inducing lattice defects. A lower intensity peak, of high energetic ions, is visible at 170 eV during the pulse.

  17. Characterization of stationary and pulsed inductively coupled RF discharges for plasma sterilization

    Energy Technology Data Exchange (ETDEWEB)

    Gans, T [Institute for Plasma and Atomic Physics, CPST, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); Osiac, M [Institute for Plasma and Atomic Physics, CPST, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); O' Connell, D [Institute for Plasma and Atomic Physics, CPST, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); Kadetov, V A [Institute for Plasma and Atomic Physics, CPST, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); Czarnetzki, U [Institute for Plasma and Atomic Physics, CPST, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); Schwarz-Selinger, T [Centre for Interdisciplinary Plasma Science, Max-Planck-Institute for Plasma Physics, 85748 Garching (Germany); Halfmann, H [Institute for Electrical Engineering and Plasma Technology, CPST, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); Awakowicz, P [Institute for Electrical Engineering and Plasma Technology, CPST, Ruhr-Universitaet Bochum, 44780 Bochum (Germany)

    2005-05-01

    Sterilization of bio-medical materials using radio frequency (RF) excited inductively coupled plasmas (ICPs) has been investigated. A double ICP has been developed and studied for homogenous treatment of three-dimensional objects. Sterilization is achieved through a combination of ultraviolet light, ion bombardment and radical treatment. For temperature sensitive materials, the process temperature is a crucial parameter. Pulsing of the plasma reduces the time average heat strain and also provides additional control of the various sterilization mechanisms. Certain aspects of pulsed plasmas are, however, not yet fully understood. Phase resolved optical emission spectroscopy and time resolved ion energy analysis illustrate that a pulsed ICP ignites capacitively before reaching a stable inductive mode. Time resolved investigations of the post-discharge, after switching off the RF power, show that the plasma boundary sheath in front of a substrate does not fully collapse for the case of hydrogen discharges. This is explained by electron heating through super-elastic collisions with vibrationally excited hydrogen molecules.

  18. Consequences of atomic layer etching on wafer scale uniformity in inductively coupled plasmas

    Science.gov (United States)

    Huard, Chad M.; Lanham, Steven J.; Kushner, Mark J.

    2018-04-01

    Atomic layer etching (ALE) typically divides the etching process into two self-limited reactions. One reaction passivates a single layer of material while the second preferentially removes the passivated layer. As such, under ideal conditions the wafer scale uniformity of ALE should be independent of the uniformity of the reactant fluxes onto the wafers, provided all surface reactions are saturated. The passivation and etch steps should individually asymptotically saturate after a characteristic fluence of reactants has been delivered to each site. In this paper, results from a computational investigation are discussed regarding the uniformity of ALE of Si in Cl2 containing inductively coupled plasmas when the reactant fluxes are both non-uniform and non-ideal. In the parameter space investigated for inductively coupled plasmas, the local etch rate for continuous processing was proportional to the ion flux. When operated with saturated conditions (that is, both ALE steps are allowed to self-terminate), the ALE process is less sensitive to non-uniformities in the incoming ion flux than continuous etching. Operating ALE in a sub-saturation regime resulted in less uniform etching. It was also found that ALE processing with saturated steps requires a larger total ion fluence than continuous etching to achieve the same etch depth. This condition may result in increased resist erosion and/or damage to stopping layers using ALE. While these results demonstrate that ALE provides increased etch depth uniformity, they do not show an improved critical dimension uniformity in all cases. These possible limitations to ALE processing, as well as increased processing time, will be part of the process optimization that includes the benefits of atomic resolution and improved uniformity.

  19. Analysis of non-equilibrium phenomena in inductively coupled plasma generators

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, W.; Panesi, M., E-mail: mpanesi@illinois.edu [University of Illinois at Urbana-Champaign, Urbana, Illinois 61822 (United States); Lani, A. [Von Karman Institute for Fluid Dynamics, Rhode-Saint-Genèse (Belgium)

    2016-07-15

    This work addresses the modeling of non-equilibrium phenomena in inductively coupled plasma discharges. In the proposed computational model, the electromagnetic induction equation is solved together with the set of Navier-Stokes equations in order to compute the electromagnetic and flow fields, accounting for their mutual interaction. Semi-classical statistical thermodynamics is used to determine the plasma thermodynamic properties, while transport properties are obtained from kinetic principles, with the method of Chapman and Enskog. Particle ambipolar diffusive fluxes are found by solving the Stefan-Maxwell equations with a simple iterative method. Two physico-mathematical formulations are used to model the chemical reaction processes: (1) A Local Thermodynamics Equilibrium (LTE) formulation and (2) a thermo-chemical non-equilibrium (TCNEQ) formulation. In the TCNEQ model, thermal non-equilibrium between the translational energy mode of the gas and the vibrational energy mode of individual molecules is accounted for. The electronic states of the chemical species are assumed in equilibrium with the vibrational temperature, whereas the rotational energy mode is assumed to be equilibrated with translation. Three different physical models are used to account for the coupling of chemistry and energy transfer processes. Numerical simulations obtained with the LTE and TCNEQ formulations are used to characterize the extent of non-equilibrium of the flow inside the Plasmatron facility at the von Karman Institute. Each model was tested using different kinetic mechanisms to assess the sensitivity of the results to variations in the reaction parameters. A comparison of temperatures and composition profiles at the outlet of the torch demonstrates that the flow is in non-equilibrium for operating conditions characterized by pressures below 30 000 Pa, frequency 0.37 MHz, input power 80 kW, and mass flow 8 g/s.

  20. Atlas of Atomic Spectral Lines of Neptunium Emitted by Inductively Coupled Plasma

    Energy Technology Data Exchange (ETDEWEB)

    DeKalb, E.L. and Edelson, M. C.

    1987-08-01

    Optical emission spectra from high-purity Np-237 were generated with a glovebox-enclosed inductively coupled plasma (ICP) source. Spectra covering the 230-700 nm wavelength range are presented along with general commentary on the methodology used in collecting the data. The Ames Laboratory Nuclear Safeguards and Security Program has been charged with the task of developing optical spectroscopic methods to analyze the composition of spent nuclear fuels. Such materials are highly radioactive even after prolonged 'cooling' and are chemically complex. Neptunium (Np) is a highly toxic by-product of nuclear power generation and is found, in low abundance, in spent nuclear fuels. This atlas of the optical emission spectrum of Np, as produced by an inductively coupled plasma (ICP) spectroscopic source, is part of a general survey of the ICP emission spectra of the actinide elements. The ICP emission spectrum of the actinides originates almost exclusively from the electronic relaxation of excited, singly ionized species. Spectral data on the Np ion emission spectrum (i.e., the Np II spectrum) have been reported by Tomkins and Fred [1] and Haaland [2]. Tomkins and Fred excited the Np II spectrum with a Cu spark discharge and identified 114 Np lines in the 265.5 - 436.3 nm spectral range. Haaland, who corrected some spectral line misidentifications in the work of Tomkins and Fred, utilized an enclosed Au spark discharge to excite the Np II spectrum and reported 203 Np lines within the 265.4 - 461.0 nm wavelength range.

  1. Atlas of Atomic Spectral Lines of Neptunium Emitted by an Inductively Coupled Plasma

    International Nuclear Information System (INIS)

    DeKalb, E.L.; Edelson, M.C.

    1987-01-01

    Optical emission spectra from high-purity Np-237 were generated with a glovebox-enclosed inductively coupled plasma (ICP) source. Spectra covering the 230-700 nm wavelength range are presented along with general commentary on the methodology used in collecting the data. The Ames Laboratory Nuclear Safeguards and Security Program has been charged with the task of developing optical spectroscopic methods to analyze the composition of spent nuclear fuels. Such materials are highly radioactive even after prolonged 'cooling' and are chemically complex. Neptunium (Np) is a highly toxic by-product of nuclear power generation and is found, in low abundance, in spent nuclear fuels. This atlas of the optical emission spectrum of Np, as produced by an inductively coupled plasma (ICP) spectroscopic source, is part of a general survey of the ICP emission spectra of the actinide elements. The ICP emission spectrum of the actinides originates almost exclusively from the electronic relaxation of excited, singly ionized species. Spectral data on the Np ion emission spectrum (i.e., the Np II spectrum) have been reported by Tomkins and Fred (1) and Haaland (2). Tomkins and Fred excited the Np II spectrum with a Cu spark discharge and identified 114 Np lines in the 265.5 - 436.3 nm spectral range. Haaland, who corrected some spectral line misidentifications in the work of Tomkins and Fred, utilized an enclosed Au spark discharge to excite the Np II spectrum and reported 203 Np lines within the 265.4 - 461.0 nm wavelength range.

  2. Serum/plasma methylmercury determination by isotope dilution gas chromatography-inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Douglas C., E-mail: douglas.baxter@alsglobal.com [ALS Scandinavia AB, Aurorum 10, 977 75 Lulea (Sweden); Faarinen, Mikko [ALS Scandinavia AB, Aurorum 10, 977 75 Lulea (Sweden); Osterlund, Helene; Rodushkin, Ilia [ALS Scandinavia AB, Aurorum 10, 977 75 Lulea (Sweden); Division of Geosciences, Lulea University of Technology, 977 87 Lulea (Sweden); Christensen, Morten [ALS Scandinavia AB, Maskinvaegen 2, 183 53 Taeby (Sweden)

    2011-09-09

    Highlights: {center_dot} We determine methylmercury in serum and plasma using isotope dilution calibration. {center_dot} Separation by gas chromatography and detection by inductively coupled plasma mass spectrometry. {center_dot} Data for 50 specimens provides first reference range for methylmercury in serum. {center_dot} Serum samples shown to be stable for 11 months in refrigerator. - Abstract: A method for the determination of methylmercury in plasma and serum samples was developed. The method uses isotope dilution with {sup 198}Hg-labeled methylmercury, extraction into dichloromethane, back-extraction into water, aqueous-phase ethylation, purge and trap collection, thermal desorption, separation by gas chromatography, and mercury isotope specific detection by inductively coupled plasma mass spectrometry. By spiking 2 mL sample with 1.2 ng tracer, measurements in a concentration interval of (0.007-2.9) {mu}g L{sup -1} could be performed with uncertainty amplification factors <2. A limit of quantification of 0.03 {mu}g L{sup -1} was estimated at 10 times the standard deviation of concentrations measured in preparation blanks. Within- and between-run relative standard deviations were <10% at added concentration levels of 0.14 {mu}g L{sup -1}, 0.35 {mu}g L{sup -1} and 2.8 {mu}g L{sup -1}, with recoveries in the range 82-110%. Application of the method to 50 plasma/serum samples yielded a median (mean; range) concentration of methylmercury of 0.081 (0.091; <0.03-0.19) {mu}g L{sup -1}. This is the first time methylmercury has been directly measured in this kind of specimen, and is therefore the first estimate of a reference range.

  3. Induction Chemotherapy for p16 Positive Oropharyngeal Squamous Cell Carcinoma.

    Science.gov (United States)

    Saito, Yuki; Ando, Mizuo; Omura, Go; Yasuhara, Kazuo; Yoshida, Masafumi; Takahashi, Wataru; Yamasoba, Tatsuya

    2016-04-01

    We aimed to determine the effectiveness of induction chemotherapy for treating p16-positive oropharyngeal cancer in our department. This was a retrospective case series to assess treatment effectiveness. We administered induction chemotherapy to patients with stage III to IV oropharyngeal p16-positive squamous cell carcinoma between 2008 and 2013. Induction chemotherapy was administered using combinations of docetaxel, cisplatin, and 5-fluorouracil. We measured the survival rates using the Kaplan-Meier method and log-rank test. We reviewed 23 patients (18 men and 5 women; age, 42-79 years). Induction chemotherapy resulted in partial or complete remission (20 patients) and in stable (2 patients) or progressive (1 patient) disease. In partial or complete remission, subsequent radiotherapy was performed in 16 patients, chemoradiotherapy in two, and transoral resection in two. In stable or progressive disease, subsequent open surgery was performed. Overall, one patient died of cervical lymph node metastasis, one died of kidney cancer, and one died of myocardial infarction. Event-free, distant-metastasis-free survival was present for 20 patients. The 3-year disease-specific survival was 95%; the overall survival was 87%. Two patients required gastrostomies during chemoradiotherapy and three required tracheotomies, but these were closed in all patients. The therapeutic response to induction chemotherapy for p16-positive oropharyngeal cancer was good. Partial or complete remission was achieved in almost 90% patients, and control of local and distant metastases was possible when it was followed by radiotherapy alone or with transoral resection of the primary tumor. A multicenter study is required to confirm these findings. 4.

  4. Si-compatible cleaning process for graphene using low-density inductively coupled plasma.

    Science.gov (United States)

    Lim, Yeong-Dae; Lee, Dae-Yeong; Shen, Tian-Zi; Ra, Chang-Ho; Choi, Jae-Young; Yoo, Won Jong

    2012-05-22

    We report a novel cleaning technique for few-layer graphene (FLG) by using inductively coupled plasma (ICP) of Ar with an extremely low plasma density of 3.5 × 10(8) cm(-3). It is known that conventional capacitively coupled plasma (CCP) treatments destroy the planar symmetry of FLG, giving rise to the generation of defects. However, ICP treatment with extremely low plasma density is able to remove polymer resist residues from FLG within 3 min at a room temperature of 300 K while retaining the carbon sp(2)-bonding of FLG. It is found that the carrier mobility and charge neutrality point of FLG are restored to their pristine defect-free state after the ICP treatment. Considering the application of graphene to silicon-based electronic devices, such a cleaning method can replace thermal vacuum annealing, electrical current annealing, and wet-chemical treatment due to its advantages of being a low-temperature, large-area, high-throughput, and Si-compatible process.

  5. Effects of assistant anode on planar inductively coupled magnetized argon plasma in plasma immersion ion implantation

    International Nuclear Information System (INIS)

    Tang, Deli; Chu, Paul K.

    2003-01-01

    The enhancement of planar radio frequency (RF) inductively coupled argon plasma is studied in the presence of an assistant anode and an external magnetic field at low pressure. The influence of the assistant anode and magnetic field on the efficiency of RF power absorption and plasma parameters is investigated. An external axial magnetic field is coupled into the plasma discharge region by an external electromagnetic coil outside the discharge chamber and an assistant cylindrical anode is inserted into the discharge chamber to enhance the plasma discharge. The plasma parameters and density profile are measured by an electrostatic Langmuir probe at different magnetic fields and anode voltages. The RF power absorption by the plasma can be effectively enhanced by the external magnetic field compared with the nonmagnetized discharge. The plasma density can be further increased by the application of a voltage to the assistant anode. Owing to the effective power absorption and enhanced plasma discharge by the assistant anode in a longitudinal magnetic field, the plasma density can be enhanced by more than a factor of two. Meanwhile, the nonuniformity of the plasma density is less than 10% and it can be achieved in a process chamber with a diameter of 600 mm

  6. Double plasma system with inductively coupled source plasma and quasi-quiescent target plasma

    International Nuclear Information System (INIS)

    Massi, M.; Maciel, H.S.

    1995-01-01

    Cold plasmas have successfully been used in the plasma-assisted material processing industry. An understanding of the physicochemical mechanisms involved in the plasma-surface interaction is needed for a proper description of deposition and etching processes at material surfaces. Since these mechanisms are dependent on the plasma properties, the development of diagnostic techniques is strongly desirable for determination of the plasma parameters as well as the characterization of the electromagnetic behaviour of the discharge. In this work a dual discharge chamber, was specially designed to study the deposition of thin films via plasma polymerization process. In the Pyrex chamber an inductively coupled plasma can be excited either in the diffuse low density E-mode or in the high density H-mode. This plasma diffuses into the cylindrical stainless steel chamber which is covered with permanent magnets to produce a multidipole magnetic field configuration at the surface. By that means a double plasma is established consisting of a RF source plasma coupled to a quasi-quiescent target plasma. The preliminary results presented here refer to measurements of the profiles of plasma parameters along the central axis of the double plasma apparatus. Additionally a spectrum analysis performed by means of a Rogowski coil probe immersed into the source plasma is also presented. The discharge is made in argon with pressure varying from 10 -2 to 1 torr, and the rf from 10 to 150 W

  7. Effect of radiation doses rate on SOS response induction in irradiated Escherichia coli Cells

    International Nuclear Information System (INIS)

    Cuetara Lugo, Elizabeth B.; Fuentes Lorenzo, Jorge L.; Almeida Varela, Eliseo; Prieto Miranda, Enrique F.; Sanchez Lamar, Angel; Llagostera Casal, Montserrat

    2005-01-01

    The present work is aimed to study the effect of radiation dose rate on the induction of SOS response in Escherichia coli cells. We measured the induction of sul A reporter gene in PQ-37 (SOS Chromotest) cells. Lead devises were built with different diameter and these were used for diminishing the dose rate of PX- -30M irradiator. Our results show that radiation doses rate significantly modifies the induction of SOS response. Induction factor increases proportionally to doses rate in Escherichia coli cells defective to nucleotide excision repair (uvrA), but not in wild type cells. We conclude that the dose rate affects the level of induction of SOS response

  8. Induction of differentiation of murine embryonal carcinoma cells by ouabain

    International Nuclear Information System (INIS)

    Zimmerman, B.T.

    1986-01-01

    Embryonal carcinoma (EC) cells can be induced to differentiate by ouabain at concentrations which inhibit Na + , K + -ATPase activity as measured by inhibition of 86 Rb + uptake. Since the pharmacologic action of ouabain is thought to be specific, the authors investigated the role of Na + , K + -ATPase inhibition and specific metabolic consequences of this inhibition in the induction of EC differentiation, and explored whether this might be a common mode of action for a variety of structurally diverse inducers. The Na + , K + -ATPase maintains ionic gradients in cells. However, results of studies utilizing specific ionophores, channel blockers, and media deficient in specific components failed to demonstrate a consistent role for ion flux or concentration in the differentiation process. The Na + , K + -ATPase is a major consumer of ATP. They therefore examined the effect of Na + , K + -ATPase inhibition on the adenylate energy charge as measured by high performance liquid chromatography of adenylate nucleotides. Ouabain was found to significantly decrease the energy charge in sensitive cells suggesting a role for suppression of ATP turnover is triggering differentiation. However, direct inhibition of glycolysis also induced differentiation without decreasing the energy charge, suggesting that reduction of the energy charge is not a common mechanism for induction of differentiation of EC

  9. Determination of platinum surface contamination in veterinary and human oncology centres using inductively coupled plasma mass spectrometry

    NARCIS (Netherlands)

    Janssens, T.; Brouwers, E. E M; de Vos, J. P.; de Vries, N.; Schellens, J. H M; Beijnen, J. H.

    2015-01-01

    The objective of this study was to determine the surface contamination with platinum-containing antineoplastic drugs in veterinary and human oncology centres. Inductively coupled plasma mass spectrometry was used to measure platinum levels in surface samples. In veterinary and human oncology

  10. AC electrokinetic drug delivery in dentistry using an interdigitated electrode assembly powered by inductive coupling.

    Science.gov (United States)

    Ivanoff, Chris S; Wu, Jie Jayne; Mirzajani, Hadi; Cheng, Cheng; Yuan, Quan; Kevorkyan, Stepan; Gaydarova, Radostina; Tomlekova, Desislava

    2016-10-01

    AC electrokinetics (ACEK) has been shown to deliver certain drugs into human teeth more effectively than diffusion. However, using electrical wires to power intraoral ACEK devices poses risks to patients. The study demonstrates a novel interdigitated electrode arrays (IDE) assembly powered by inductive coupling to induce ACEK effects at appropriate frequencies to motivate drugs wirelessly. A signal generator produces the modulating signal, which multiplies with the carrier signal to produce the amplitude modulated (AM) signal. The AM signal goes through the inductive link to appear on the secondary coil, then rectified and filtered to dispose of its carrier signal, and the positive half of the modulating signal appears on the load. After characterizing the device, the device is validated under light microscopy by motivating carboxylate-modified microspheres, tetracycline, acetaminophen, benzocaine, lidocaine and carbamide peroxide particles with induced ACEK effects. The assembly is finally tested in a common dental bleaching application. After applying 35 % carbamide peroxide to human teeth topically or with the IDE at 1200 Hz, 5 Vpp for 20 min, spectrophotometric analysis showed that compared to diffusion, the IDE enhanced whitening in specular optic and specular optic excluded modes by 215 % and 194 % respectively. Carbamide peroxide absorbance by the ACEK group was two times greater than diffusion as measured by colorimetric oxidation-reduction and UV-Vis spectroscopy at 550 nm. The device motivates drugs of variable molecular weight and structure wirelessly. Wireless transport of drugs to intraoral targets under ACEK effects may potentially improve the efficacy and safety of drug delivery in dentistry.

  11. Extracellular adenosine controls NKT-cell-dependent hepatitis induction.

    Science.gov (United States)

    Subramanian, Meenakshi; Kini, Radhika; Madasu, Manasa; Ohta, Akiko; Nowak, Michael; Exley, Mark; Sitkovsky, Michail; Ohta, Akio

    2014-04-01

    Extracellular adenosine regulates inflammatory responses via the A2A adenosine receptor (A2AR). A2AR deficiency results in much exaggerated acute hepatitis, indicating nonredundancy of adenosine-A2AR pathway in inhibiting immune activation. To identify a critical target of immunoregulatory effect of extracellular adenosine, we focused on NKT cells, which play an indispensable role in hepatitis. An A2AR agonist abolished NKT-cell-dependent induction of acute hepatitis by concanavalin A (Con A) or α-galactosylceramide in mice, corresponding to downregulation of activation markers and cytokines in NKT cells and of NK-cell co-activation. These results show that A2AR signaling can downregulate NKT-cell activation and suppress NKT-cell-triggered inflammatory responses. Next, we hypothesized that NKT cells might be under physiological control of the adenosine-A2AR pathway. Indeed, both Con A and α-galactosylceramide induced more severe hepatitis in A2AR-deficient mice than in WT controls. Transfer of A2AR-deficient NKT cells into A2AR-expressing recipients resulted in exaggeration of Con A-induced liver damage, suggesting that NKT-cell activation is controlled by endogenous adenosine via A2AR, and this physiological regulatory mechanism of NKT cells is critical in the control of tissue-damaging inflammation. The current study suggests the possibility to manipulate NKT-cell activity in inflammatory disorders through intervention to the adenosine-A2AR pathway. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. [Determination of 24 minerals in human milk by inductively coupled plasma mass spectrometry with microwave digestion].

    Science.gov (United States)

    Sun, Zhongqing; Yue, Bing; Yang, Zhenyu; Li, Xiaowei; Wu, Yongning; Yin, Shian

    2013-05-01

    To determine the levels of 24 minerals in human milk by inductively coupled plasma mass spectrometry with microwave digestion. The samples were digested by microwave. The contents of minerals were determined by inductively coupled plasma mass spectrometry. The standard reference minerals of 1849a and 1568a from National Institute of Science and Technology were used for quality control. The accuracy and reproduability for this method were evaluated with mix standards and 1849a and 1568a standard reference materials. The ranges of the levels of sodium, magnesium, phosphorus, potassium, calcium, aluminum, chromium, arsenic, selenium, iron, zinc, manganese, copper, molybdenum, vanadium, cobalt, nickel, gallium, cadmium, silver, strontium, cesium, barium, lead in human milk was 34.97-415.83 mg/kg, 19.00-39.52 mg/kg, 102.13-274.53 mg/kg, 351.19-713.99 mg/kg, 180.08-349.64 mg/kg, 0.06-0.44 mg/kg, 0.9-7.37 microg/kg, 0.92-2.72 microg/kg, 0.20-21.15 microg/kg, 0.10-0.70 mg/kg, 0.56-3.25 mg/kg, 3.00-16.12 micro.g/kg, 62.16-591.69 microg/kg, 0.02-6.91 microg/kg, 5.99-13.70 microg/kg, 0.07-2.11 microg/kg, 0.77-209.26 microg/kg, 0.005-0.28 microg/kg, 0.02-0.23 microg/kg, 0.02-0.71 microg/kg, 36.89-132.26 microg/kg, 0.01-4.72 microg/kg, 0.83-28.16 microg/kg, 2.5-5.3 microg/kg, respectively. The levels of minerals in human milk in present study were consisted with other similar studies. The experiment examined the levels of minerals in human milk satisfactorily. The method has high accuracy and good reproducibility, which could be used for understanding the levels of minerals in human milk.

  13. Inductively coupled plasma-atomic emission spectroscopy glovebox assembly system at the West Valley Demonstration Project

    International Nuclear Information System (INIS)

    Marlow, J.H.; McCarthy, K.M.; Tamul, N.R.

    1999-01-01

    The inductively coupled plasma/atomic emission spectroscopy [ICP/AES (ICP)] system for elemental analyses in support of vitrification processing was first installed in 1986. The initial instrument was a Jobin Yvon (JY) Model JY-70 ICP that consisted of sequential and simultaneous spectrometers for analysis of nonradioactive samples as radioactive surrogates. The JY-70 ICP continued supporting nonradioactive testing during the Functional and Checkout Testing of Systems (FACTS) using the full-scale melter with ''cold'' (nonradioactive) testing campaigns. As a result, the need for another system was identified to allow for the analysis of radioactive samples. The Mass Spec (Spectrometry) Lab was established for the installation of the modified ICP system for handling radioactive samples. The conceptual setup of another ICP was predicated on the use of a hood to allow ease of accessibility of the torch, nebulizer, and spray chamber, and the minimization of air flow paths. However, reconsideration of the radioactive sample dose rate and contamination levels led to the configuration of the glovebox system with a common transfer interface box for the ICP and the inductively coupled plasma-mass spectrometer (ICP-MS) glovebox assemblies. As a result, a simultaneous Model JY-50P ICP with glovebox was installed in 1990 as a first generation ICP glovebox system. This was one of the first ICP glovebox assemblies connected with an ICP-MS glovebox system. Since the economics of processing high-level radioactive waste (HLW) required the availability of an instrument to operate 24 hours a day throughout the year without any downtime, a second generation ICP glovebox assembly was designed, manufactured, and installed in 1995 using a Model JY-46P ICP. These two ICP glovebox systems continue to support vitrification of the HLW into canisters for storage. The ICP systems have been instrumental in monitoring vitrification batch processing. To date, remote sample preparation and

  14. Inductively coupled plasma -- Atomic emission spectroscopy glove box assembly system at the West Valley Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Marlow, J.H.; McCarthy, K.M.; Tamul, N.R.

    1999-12-17

    The inductively coupled plasma/atomic emission spectroscopy [ICP/AES (ICP)] system for elemental analyses in support of vitrification processing was first installed in 1986. The initial instrument was a Jobin Yvon (JY) Model JY-70 ICP that consisted of sequential and simultaneous spectrometers for analysis of nonradioactive samples as radioactive surrogates. The JY-70 ICP continued supporting nonradioactive testing during the Functional and Checkout Testing of Systems (FACTS) using the full-scale melter with ``cold'' (nonradioactive) testing campaigns. As a result, the need for another system was identified to allow for the analysis of radioactive samples. The Mass Spec (Spectrometry) Lab was established for the installation of the modified ICP system for handling radioactive samples. The conceptual setup of another ICP was predicated on the use of a hood to allow ease of accessibility of the torch, nebulizer, and spray chamber, and the minimization of air flow paths. However, reconsideration of the radioactive sample dose rate and contamination levels led to the configuration of the glovebox system with a common transfer interface box for the ICP and the inductively coupled plasma-mass spectrometer (ICP-MS) glovebox assemblies. As a result, a simultaneous Model JY-50P ICP with glovebox was installed in 1990 as a first generation ICP glovebox system. This was one of the first ICP glovebox assemblies connected with an ICP-MS glovebox system. Since the economics of processing high-level radioactive waste (HLW) required the availability of an instrument to operate 24 hours a day throughout the year without any downtime, a second generation ICP glovebox assembly was designed, manufactured, and installed in 1995 using a Model JY-46P ICP. These two ICP glovebox systems continue to support vitrification of the HLW into canisters for storage. The ICP systems have been instrumental in monitoring vitrification batch processing. To date, remote sample preparation

  15. Apoptosis-Like Cell Death Induction and Aberrant Fibroblast Properties in Human Incisional Hernia Fascia

    Science.gov (United States)

    Diaz, Ramon; Quiles, Maria T.; Guillem-Marti, Jordi; Lopez-Cano, Manuel; Huguet, Pere; Ramon-y-Cajal, Santiago; Reventos, Jaume; Armengol, Manel; Arbos, Maria A.

    2011-01-01

    Incisional hernia often occurs following laparotomy and can be a source of serious problems. Although there is evidence that a biological cause may underlie its development, the mechanistic link between the local tissue microenvironment and tissue rupture is lacking. In this study, we used matched tissue-based and in vitro primary cell culture systems to examine the possible involvement of fascia fibroblasts in incisional hernia pathogenesis. Fascia biopsies were collected at surgery from incisional hernia patients and non-incisional hernia controls. Tissue samples were analyzed by histology and immunoblotting methods. Fascia primary fibroblast cultures were assessed at morphological, ultrastructural, and functional levels. We document tissue and fibroblast loss coupled to caspase-3 activation and induction of apoptosis-like cell-death mechanisms in incisional hernia fascia. Alterations in cytoskeleton organization and solubility were also observed. Incisional hernia fibroblasts showed a consistent phenotype throughout early passages in vitro, which was characterized by significantly enhanced cell proliferation and migration, reduced adhesion, and altered cytoskeleton properties, as compared to non-incisional hernia fibroblasts. Moreover, incisional hernia fibroblasts displayed morphological and ultrastructural alterations compatible with autophagic processes or lysosomal dysfunction, together with enhanced sensitivity to proapoptotic challenges. Overall, these data suggest an ongoing complex interplay of cell death induction, aberrant fibroblast function, and tissue loss in incisional hernia fascia, which may significantly contribute to altered matrix maintenance and tissue rupture in vivo. PMID:21641387

  16. A generalized electron energy probability function for inductively coupled plasmas under conditions of nonlocal electron kinetics

    Science.gov (United States)

    Mouchtouris, S.; Kokkoris, G.

    2018-01-01

    A generalized equation for the electron energy probability function (EEPF) of inductively coupled Ar plasmas is proposed under conditions of nonlocal electron kinetics and diffusive cooling. The proposed equation describes the local EEPF in a discharge and the independent variable is the kinetic energy of electrons. The EEPF consists of a bulk and a depleted tail part and incorporates the effect of the plasma potential, Vp, and pressure. Due to diffusive cooling, the break point of the EEPF is eVp. The pressure alters the shape of the bulk and the slope of the tail part. The parameters of the proposed EEPF are extracted by fitting to measure EEPFs (at one point in the reactor) at different pressures. By coupling the proposed EEPF with a hybrid plasma model, measurements in the gaseous electronics conference reference reactor concerning (a) the electron density and temperature and the plasma potential, either spatially resolved or at different pressure (10-50 mTorr) and power, and (b) the ion current density of the electrode, are well reproduced. The effect of the choice of the EEPF on the results is investigated by a comparison to an EEPF coming from the Boltzmann equation (local electron kinetics approach) and to a Maxwellian EEPF. The accuracy of the results and the fact that the proposed EEPF is predefined renders its use a reliable alternative with a low computational cost compared to stochastic electron kinetic models at low pressure conditions, which can be extended to other gases and/or different electron heating mechanisms.

  17. Inductively Coupled Plasma Optical Emission Spectrometry for Rare Earth Elements Analysis

    Science.gov (United States)

    He, Man; Hu, Bin; Chen, Beibei; Jiang, Zucheng

    2017-01-01

    Inductively coupled plasma optical emission spectrometry (ICP-OES) merits multielements capability, high sensitivity, good reproducibility, low matrix effect and wide dynamic linear range for rare earth elements (REEs) analysis. But the spectral interference in trace REEs analysis by ICP-OES is a serious problem due to the complicated emission spectra of REEs, which demands some correction technology including interference factor method, derivative spectrum, Kalman filtering algorithm and partial least-squares (PLS) method. Matrix-matching calibration, internal standard, correction factor and sample dilution are usually employed to overcome or decrease the matrix effect. Coupled with various sample introduction techniques, the analytical performance of ICP-OES for REEs analysis would be improved. Compared with conventional pneumatic nebulization (PN), acid effect and matrix effect are decreased to some extent in flow injection ICP-OES, with higher tolerable matrix concentration and better reproducibility. By using electrothermal vaporization as sample introduction system, direct analysis of solid samples by ICP-OES is achieved and the vaporization behavior of refractory REEs with high boiling point, which can easily form involatile carbides in the graphite tube, could be improved by using chemical modifier, such as polytetrafluoroethylene and 1-phenyl-3-methyl-4-benzoyl-5-pyrazone. Laser ablation-ICP-OES is suitable for the analysis of both conductive and nonconductive solid samples, with the absolute detection limit of ng-pg level and extremely low sample consumption (0.2 % of that in conventional PN introduction). ICP-OES has been extensively employed for trace REEs analysis in high-purity materials, and environmental and biological samples.

  18. Comparison of femtosecond and nanosecond laser ablation inductively coupled plasma mass spectrometry for uranium isotopic measurements

    Energy Technology Data Exchange (ETDEWEB)

    Havrilla, George Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); McIntosh, Kathryn Gallagher [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Judge, Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dirmyer, Matthew R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Campbell, Keri [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gonzalez, Jhanis J. [Applied Spectra Inc., Fremont, CA (United States)

    2016-10-20

    Feasibility tests were conducted using femtosecond and nanosecond laser ablation inductively coupled plasma mass spectrometry for rapid uranium isotopic measurements. The samples used in this study consisted of a range of pg quantities of known 235/238 U solutions as dried spot residues of 300 pL drops on silicon substrates. The samples spanned the following enrichments of 235U: 0.5, 1.5, 2, 3, and 15.1%. In this direct comparison using these particular samples both pulse durations demonstrated near equivalent data can be produced on either system with respect to accuracy and precision. There is no question that either LA-ICP-MS method offers the potential for rapid, accurate and precise isotopic measurements of U10Mo materials whether DU, LEU or HEU. The LA-ICP-MS equipment used for this work is commercially available. The program is in the process of validating this work for large samples using center samples strips from Y-12 MP-1 LEU-Mo Casting #1.

  19. Inductively coupled plasma mass spectrometry in the analysis of biological samples and pharmaceutical drugs

    Science.gov (United States)

    Ossipov, K.; Seregina, I. F.; Bolshov, M. A.

    2016-04-01

    Inductively coupled plasma mass spectrometry (ICP-MS) is widely used in the analysis of biological samples (whole blood, serum, blood plasma, urine, tissues, etc.) and pharmaceutical drugs. The shortcomings of this method related to spectral and non-spectral interferences are manifested in full measure in determination of the target analytes in these complex samples strongly differing in composition. The spectral interferences are caused by similarity of masses of the target component and sample matrix components. Non-spectral interferences are related to the influence of sample matrix components on the physicochemical processes taking place during formation and transportation of liquid sample aerosols into the plasma, on the value and spatial distribution of plasma temperature and on the transmission of the ion beam from the interface to mass spectrometer detector. The review is devoted to analysis of different mechanisms of appearance of non-spectral interferences and to ways for their minimization or elimination. Special attention is paid to the techniques of biological sample preparation, which largely determine the mechanisms of the influence of sample composition on the results of element determination. The ways of lowering non-spectral interferences by instrumental parameter tuning and application of internal standards are considered. The bibliography includes 189 references.

  20. Self-consistent simulation study on magnetized inductively coupled plasma for 450 mm semiconductor wafer processing

    International Nuclear Information System (INIS)

    Lee, Ho-Jun; Kim, Yun-Gi

    2012-01-01

    The characteristics of weakly magnetized inductively coupled plasma (MICP) are investigated using a self-consistent simulation based on the drift–diffusion approximation with anisotropic transport coefficients. MICP is a plasma source utilizing the cavity mode of the low-frequency branch of the right-hand circularly polarized wave. The model system is 700 mm in diameter and has a 250 mm gap between the radio-frequency window and wafer holder. The model chamber size is chosen to verify the applicability of this type of plasma source to the 450 mm wafer process. The effects of electron density distribution and external axial magnetic field on the propagation properties of the plasma wave, including the wavelength modulation and refraction toward the high-density region, are demonstrated. The restricted electron transport and thermal conductivity in the radial direction due to the magnetic field result in small temperature gradient along the field lines and off-axis peak density profile. The calculated impedance seen from the antenna terminal shows that MICP has a resistance component that is two to threefold higher than that of ICP. This property is practically important for large-size, low-pressure plasma sources because high resistance corresponds to high power-transfer efficiency and stable impedance matching characteristics. For the 0.665 Pa argon plasma, MICP shows a radial density uniformity of 6% within 450 mm diameter, which is much better than that of nonmagnetized ICP.

  1. Levels of Essential Elements in Different Medicinal Plants Determined by Using Inductively Coupled Plasma Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Eid I. Brima

    2018-01-01

    Full Text Available The objective of this study was to investigate the content of essential elements in medicinal plants in the Kingdom of Saudi Arabia (KSA. Five different medical plants (mahareeb (Cymbopogon schoenanthus, sheeh (Artemisia vulgaris, harjal (Cynanchum argel delile, nabipoot (Equisetum arvense, and cafmariam (Vitex agnus-castus were collected from Madina city in the KSA. Five elements Fe, Mn, Zn, Cu, and Se were determined by using inductively coupled plasma mass spectrometry (ICP-MS. Fe levels were the highest and Se levels were the lowest in all plants. The range levels of all elements in all plants were as follows: Fe 193.4–1757.9, Mn 23.6–143.7, Zn 15.4–32.7, Se 0.13–0.92, and Cu 11.3–21.8 µg/g. Intakes of essential elements from the medical plants in infusion were calculated: Fe 4.6–13.4, Mn 6.7–123.2, Zn 7.0–42.7, Se 0.14–1.5, and Cu 1.5–5.0 µg/dose. The calculated intakes of essential elements for all plants did not exceed the daily intake set by the World Health Organization (WHO and European Food Safety Authority (EFSA. These medicinal plants may be useful sources of essential elements, which are vital for health.

  2. Improved planar radio frequency inductively coupled plasma configuration in plasma immersion ion implantation

    International Nuclear Information System (INIS)

    Tang, D.L.; Fu, R.K.Y.; Tian, X.B.; Chu, P.K.

    2003-01-01

    Plasmas with higher density and better uniformity are produced using an improved planar radio frequency (rf) inductively coupled plasma configuration in plasma immersion ion implantation (PIII). An axial magnetic field is produced by external electromagnetic coils outside the discharge chamber. The rf power can be effectively absorbed by the plasma in the vicinity of the electron gyrofrequency due to the enhanced resonant absorption of electromagnetic waves in the whistler wave range, which can propagate nearly along the magnetic field lines thus greatly increases the plasma density. The plasma is confined by a longitudinal multipolar cusp magnetic field made of permanent magnets outside the process chamber. It can improve the plasma uniformity without significantly affecting the ion density. The plasma density can be increased from 3x10 9 to 1x10 10 cm -3 employing an axial magnetic field of several Gauss at 1000 W rf power and 5x10 -4 Torr gas pressure. The nonuniformity of the plasma density is less than 10% and can be achieved in a process chamber with a diameter of 600 mm. Since the plasma generation and process chambers are separate, plasma extinction due to the plasma sheath touching the chamber wall in high-energy PIII can be avoided. Hence, low-pressure, high-energy, and high-uniformity ion implantation can be accomplished using this setup

  3. Determination of metals content from wines by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Iordache, Andreea-Maria; Geana, Elisabeta-Irina

    2009-01-01

    Full text: Wine is a widely consumed beverage with thousands of years of tradition. Wine composition strongly determines its quality besides having a great relevance on wine characterization, tipyfication and frauds detection. Wine composition is influenced by many and diverse factors corresponding to the specific production area, such as grape variety, soil and climate, culture, yeast, winemaking practices, transport and storage. Daily consumption of wine in moderate quantities contributes significantly to the requirements of the human organism for essential elements such as Cr, Cu, Zn, Fe, Mn, Co, Ni and Sr. On the other hand, several metals, such as Pb and Cd , are known to be potentially toxic. The objective of this work was to develop a method to determine the metals content in wine samples from Romania. Three samples of difference white wines available in the supermarket was analyzed for identify the presence of: Cr, Cu, Zn, Fe, Mn, Pb, Cd, Co, Ni and Sr by inductively coupled plasma mass spectrometry (ICP-MS). (authors)

  4. Methods for detecting and correcting inaccurate results in inductively coupled plasma-atomic emission spectrometry

    Science.gov (United States)

    Chan, George C. Y. [Bloomington, IN; Hieftje, Gary M [Bloomington, IN

    2010-08-03

    A method for detecting and correcting inaccurate results in inductively coupled plasma-atomic emission spectrometry (ICP-AES). ICP-AES analysis is performed across a plurality of selected locations in the plasma on an unknown sample, collecting the light intensity at one or more selected wavelengths of one or more sought-for analytes, creating a first dataset. The first dataset is then calibrated with a calibration dataset creating a calibrated first dataset curve. If the calibrated first dataset curve has a variability along the location within the plasma for a selected wavelength, errors are present. Plasma-related errors are then corrected by diluting the unknown sample and performing the same ICP-AES analysis on the diluted unknown sample creating a calibrated second dataset curve (accounting for the dilution) for the one or more sought-for analytes. The cross-over point of the calibrated dataset curves yields the corrected value (free from plasma related errors) for each sought-for analyte.

  5. Unique applications of solvent removal in inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Minnich, Michael [Iowa State Univ., Ames, IA (United States)

    1997-01-10

    Inductively coupled plasma mass spectrometry (ICP-MS) is the technique of choice for rapid, high precision, semiquantitative elemental and isotopic analysis for over 70 elements. Less than 20 years after the first mass spectrum was obtained by ICP-MS, this technique has applications in clinical chemistry, geochemistry, the semiconductor industry, the nuclear industry, environmental chemistry, and forensic chemistry. The determination of many elements, though, by ICP-MS is complicated by spectral interferences from background species, interelement spectral overlaps, and polyatomic ions of matrix elements. The emphasis of this thesis is the unique applications of solvent removal using cryogenic and membrane desolvation. Chapter 1 is a general introduction providing background information concerning the need for these methods and some information about the methods themselves. Chapter 5 discusses general conclusions and general observations pertaining to this work. Chapters 2, 3, and 4 have been processed separately for inclusion on the database. Chapter 2 describes a method to screen urine samples for vanadium using cryogenic desolvation. Chapter 3 compares solvent removal by cryogenic and membrane desolvation. Chapter 4 describes the use of cool plasma conditions for the determination of potassium in the presence of excess sodium by ICP-MS.

  6. Determination of zinc stable isotopes in biological materials using isotope dilution inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Patterson, K.Y.; Veillon, Claude

    1992-01-01

    A method is described for using isotope dilution to determine both the amount of natural zinc and enriched isotopes of zinc in biological samples. Isotope dilution inductively coupled plasma mass spectrometry offers a way to quantify not only the natural zinc found in a sample but also the enriched isotope tracers of zinc. Accurate values for the enriched isotopes and natural zinc are obtained by adjusting the mass count rate data for measurable instrumental biases. Analytical interferences from the matrix are avoided by extracting the zinc from the sample matrix using diethylammonium diethyldithiocarbamate. The extraction technique separates the zinc from elements which form interfering molecular ions at the same nominal masses as the zinc isotopes. Accuracy of the method is verified using standard reference materials. The detection limit is 0.06 μg Zn per sample. Precision of the abundance ratios range from 0.3-0.8%. R.S.D. for natural zinc concentrations is about 200-600 μg g -1 . The accuracy and precision of the measurements make it possible to follow enriched isotopic tracers of zinc in biological samples in metabolic tracer studies. (author). 19 refs.; 1 fig., 4 tabs

  7. Etching characteristics of Au thin films using inductively coupled Cl2/Ar plasma

    International Nuclear Information System (INIS)

    Chang, Yun Seong; Kim, Dong Pyo; Kim, Chang Il; Sim, Kwee Bo; Chang, Eui Goo

    2003-01-01

    In this study, Au thin films were etched with a Cl 2 /Ar gas combination using inductively coupled plasma. The etch properties were measured for different gas mixing ratios of Cl 2 /(Cl 2 +Ar) while the other process conditions were fixed at a rf power of 700 W, a dc bias voltage of -150 V, a chamber pressure of 15 m Torr and a substrate temperature of 30 .deg. C. The highest etch rate of the Au thin film was 3500 A/min and the selectivity of Au to SiO 2 was 4.4 at a Cl 2 /(CI 2 +Ar) gas mixing ratio of 0.2. The surface reaction of the etched Au thin films was investigated using x-ray photoelectron spectroscopy (XPS) analysis. There is a chemical reaction between Cl and Au. Au-Cl is hard to remove from the surface because of its high melting point. The etching products can be sputtered by Ar ion bombardment. We obtained the clean and steep profile

  8. Profiling metals in Cordyceps sinensis by using inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Wei, Xin; Hu, Hankun; Zheng, Baogeng; Arslan, Zikri; Huang, Hung-Chung; Mao, Weidong; Liu, Yi-Ming

    2017-01-28

    Cordyceps sinensis ( C. sinensis ) is a natural product that has diverse nutritional and medicinal values. Since the availability of natural C. sinensis becomes limited its authentication and quality control is of high significance. Herein we report on profiling of metals in C. sinensis by using inductively coupled plasma mass spectrometry (ICP-MS). The analysis reveals that C. sinensis contains a wide array of essential elements, including P, Mg, Zn, Cu, Fe, etc. Toxic metals detected are Cd, Pb, and As. In all five samples analyzed Pb contents are below 2.0 ppm. Arsenic level in C. sinensis caterpillar is significantly higher than that in its mycelium and varies from 3.0 to 32 ppm likely due to soil contamination. It's for the first time demonstrated in this work that clustering analysis on the proposed metal profiles consisting of 24 elements is very useful to identify "abnormal" C. sinensis samples, thus adding another dimension to the effective means for authentication and quality assessment of this highly demanded previous natural product.

  9. The determination of mercury in whole blood and urine by inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Nixon, David E.; Burritt, Mary F.; Moyer, Thomas P.

    1999-08-01

    An inductively coupled mass spectrometric (ICP-MS) method for the determination of mercury in whole blood and urine was developed. Gold and dichromate in hydrochloric acid were evaluated as agents to reduce mercury spray chamber memory. Dichromate with hydrochloric acid was found to be superior to gold. We evaluated the rapid introduction of sample to promote equilibrium and the rapid introduction of wash solutions after the sample analyses to minimize mercury memory. This ‘fast pump’ mode (2.5 ml/min) was used for 20 s at the beginning and end of each sample-wash cycle. The mercury detection limit is 0.15 μg/l in the original sample before dilution. Regressions and correlation coefficients for ICP-MS vs. target concentrations for interlaboratory comparison samples from the Centre de Toxicologie du Quebec were: whole blood: y=1.0x-0.6; r=0.9801; n=27 and urine: y=0.84x+8; r=0.9915; n=42. Patient samples were analyzed by ICP-MS and cold vapor atomic absorption spectrometry (CVAAS). Regressions and correlations for patient samples were: urines: y=0.93x+1; r=0.8763; n=456 and whole blood: y=1.1x+0.2; r=0.9357; n=251. ICP-MS correlation with CVAAS for 29 urine samples containing 15-150 μg Hg/specimen was: y=0.94x+4; r=0.9864.

  10. Synthesis of ultrafine particles and processing of nano-structured films with inductively coupled plasma

    International Nuclear Information System (INIS)

    Nutsch, G.; Blum, J.; Herrmann, A.; Schwenk, A.; Weiss, K.-H.

    2001-01-01

    The inductively coupled plasma (ICP) at atmospheric pressure is particularly suited for melting and evaporation of materials. The electrodeless ICP can be generated without limitation of the kind of plasma forming gases. Therefore, using an argon-oxygen gas mixture as sheath gas of the ICP nanoparticles can be processed by combustion of metal-organic liquid precursors injected in the hot plasma core. By this way, nanoparticles of alumina, titania and of a perovskite type oxide are produced. The powder particles are collected by an electrostatic filter. They are characterized by a log-normal size distribution with a median diameter of about 10 nm depending on the plasma parameters used. Interesting metastable phases and exactly doped, very pure materials can be obtained. Nanophase coatings synthesized by the ICP are made from the same precursor materials. For depositions, the plasma jet has to be supersonic. Impinging onto the substrate placed near the nozzle thin and dense coatings are obtained. The composition and the grain size of as-deposited coatings are analyzed by XRD. (author)

  11. Determination of 238U in marine organisms by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Ishii, Toshiaki; Nakahara, Motokazu; Matsuba, Mitsue; Ishikawa, Masafumi

    1991-01-01

    Determination of 238 U in fifty-five species of marine organisms was carried out by inductively coupled plasma mass spectrometry which showed some advantages such as high sensitivity, wide dynamic range and small interferences from matrices for the analysis of high mass elements. The concentrations of 238 U in soft tissues of marine animals ranged from 0.076 to 5000 ng/g wet wt. Especially, the branchial heart of cephalopod molluscs showed the specific accumulation of 238 U. The concentration factor of the branchial heart of Octopus vulgaris, which indicated the highest value, was calculated to be about 10 3 by comparing it with the concentration of 238 U (3.2±0.2 ng/ml) in coastal seawaters of Japan. The concentrations of 238 U in hard tissues of marine invertebrates were similar to those in soft tissues. In contrast, hard tissues like bone, scale, fin, etc. of fishes showed much higher concentrations of 238 U than soft tissues like muscle and liver. The concentrations of 238 U of twenty species of algae ranged from 10 to 3700 ng/g dry wt. (author)

  12. Determination of trace elements in refined gold samples by inductively coupled plasma atomic emission spectrometry

    Directory of Open Access Journals (Sweden)

    Steharnik Mirjana

    2013-01-01

    Full Text Available This paper presents a method for determination the trace contents of silver, copper, iron, palladium, zinc and platinum in refined gold samples. Simultaneous inductively coupled plasma atomic emission spectrometer with radial torch position and cross flow nebulizer was used for determination. In order to compare the different calibration strategies, two sets of calibration standards were prepared. The first set was based on matrix matched calibration standards and the second was prepared without the addition of matrix material. Detection limits for matrix matching calibrations were higher for some elements than those without matrix matching. In addition, the internal standardization method was applied and experiments indicated that indium was the best option as internal standard. The obtained results for gold sample by matrix matching and matrix free calibrations were compared with the obtained results by standard addition method. The accuracy of the methods was tested performing recovery test. Recoveries for spiked sample were in the range of 90-115 %. The accuracy of the methods was also tested by analysis of certified reference material of high pure goldAuGHP1. The best results were achieved by matrix free calibration and standard addition method using indium as internal standard at wavelength of 230 nm. [Projekat Ministarstva nauke Republike Srbije, br. 34024: Development of Technologies for Recycling of Precious, Rare and Associated Metals from Solid Waste in Serbia to High Purity Products

  13. Heteroepitaxial growth of wafer scale highly oriented graphene using inductively coupled plasma chemical vapor deposition

    International Nuclear Information System (INIS)

    Gao, Libo; Xu, Hai; Li, Linjun; Loh, Kian Ping; Yang, Yang; Fu, Qiang; Bao, Xinhe

    2016-01-01

    The chemical vapor deposition (CVD) of graphene on Cu has attracted much attention because of its industrial scalability. Herein, we report inductively coupled plasma-assisted CVD of epitaxially grown graphene on (111)-textured Cu film alloyed with a small amount of Ni, where large area high quality graphene film can be grown in less than 5 min at 800 °C, thus affording industrial scalability. The epitaxially grown graphene films on (111)-textured Cu contain grains which are predominantly aligned with the Cu lattice and about 10% of 30°-rotated grains (anti-grains). Such graphene films are exclusively monolayer and possess good electrical conductivity, high carrier mobility, and room temperature quantum Hall effect. Magnetoresistance measurements reveal that the reduction of the grain sizes from 150 nm to 50 nm produce increasing Anderson localization and the appearance of a transport gap. Owing to the presence of grain boundaries in these anti-grains, epitaxially grown graphene films possess n-type characteristics and exhibit ultra-high sensitivity to adsorbates. (letter)

  14. Generating high-efficiency neutral beams by using negative ions in an inductively coupled plasma source

    International Nuclear Information System (INIS)

    Samukawa, Seiji; Sakamoto, Keisuke; Ichiki, Katsunori

    2002-01-01

    To minimize radiation damage caused by charge buildup or ultraviolet and x-ray photons during etching, we developed a high-performance neutral-beam etching system. The neutral-beam source consists of an inductively coupled plasma (ICP) source and parallel top and bottom carbon plates. The bottom carbon plate has numerous apertures for extracting neutral beams from the plasma. When a direct current (dc) bias is applied to the top and bottom plates, the generated positive or negative ions are accelerated toward the bottom plate. Most of them are then efficiently converted into neutral atoms, either by neutralization in charge-transfer collisions with gas molecules during ion transport and with the aperture sidewalls in the bottom plate, or by recombination with low-energy electrons near the end of the bottom plate. We found that negative ions are more efficiently converted into neutral atoms than positive ions. The neutralization efficiency of negative ions was almost 100%, and the maximum neutral flux density was equivalent to 4.0 mA/cm2. A neutral beam can thus be efficiently produced from the ICP source and apertures in our new neutral-beam source

  15. Study of electron-extraction characteristics of an inductively coupled radio-frequency plasma neutralizer

    Science.gov (United States)

    Jianwu, HE; Longfei, MA; Senwen, XUE; Chu, ZHANG; Li, DUAN; Qi, KANG

    2018-01-01

    Inductively coupled radio-frequency (RF) plasma neutralizer (RPN) is an insert-free device that can be employed as an electron source in electric propulsion applications. Electron-extraction characteristics of the RPN are related to the bulk plasma parameters and the device’s geometry. Therefore, the effects of different electron-extraction apertures and operational parameters upon the electron-extraction characteristics are investigated according to the global nonambipolar flow and sheath model. Moreover, these models can also be used to explain why the electron-extraction characteristics of the RPN strongly depend upon the formation of the anode spot. During the experimental study, two types of anode spots are observed. Each of them has unique characteristics of electron extraction. Moreover, the hysteresis of an anode spot is observed by changing the xenon volume-flow rates or the bias voltages. In addition, the rapid ignited method, gas-utilization factor, electron-extraction cost and other factors that need to be considered in the design of the RPN are also discussed.

  16. Some Temperature Effects on AISI-304 Nitriding in an Inductively Coupled RF Plasma

    International Nuclear Information System (INIS)

    Valencia-Alvarado, R.; Barocio, S. R.; Mercado-Cabrera, A.; Pena-Eguiluz, R.; Munoz-Castro, A. E.; Piedad-Beneitez, A. de la; Rosa-Vazquez, J. de la; Lopez-Callejas, R.; Godoy-Cabrera, O. G.

    2006-01-01

    Some recent results obtained from nitriding AISI 304 stainless steel samples, 1.2 cm in diameter and 0.5 cm thick are reported here in the case of an 85% hydrogen and 15% nitrogen mixture work gas. The process was carried out from 300 to 400 W for (13.56 MHz) inductively coupled plasma within a 60 cm long pyrex glass tube 3.5 cm in diameter where the samples were biased up to -300 V with respect to earth. The resulting hardness appears to be a function of the substrate temperature which varied from 200 deg. C at a 0 V bias to 550 deg. C at -300 V. The plasma density at 400 W reached 3x1010 cm-3 with a 4 eV electron temperature. Prior to nitriding, all the samples were polished with 0.05 μm diamond paste, leading to a 30 nm average roughness (Ra). After nitriding at -300 V, the Ra rose until ∼400 nm while hardness values of 1500 HV under 300 g loads were measured. X ray diffraction indicates that the extended phase amplitude (γN), Fe and Cr nitride depends on the substrate temperature

  17. Thin TiO2 films deposited by implantation and sputtering in RF inductively coupled plasmas

    International Nuclear Information System (INIS)

    Valencia-Alvarado, R; López-Callejas, R; Barocio, S R; Mercado-Cabrera, A; Peña-Eguiluz, R; Muñoz-Castro, A E; Rodríguez-Méndez, B G; De la Piedad-Beneitez, A; De la Rosa-Vázquez, J M

    2012-01-01

    The achievement of titanium dioxide (TiO 2 ) thin films in the rutile crystalline phase is reported. The samples result from the implantation of oxygen ions of Ti in argon/oxygen plasma generated by inductively coupled RF at a commercial 13.56 MHz frequency. Simultaneously, a sputtering process is conducted on the titanium target in order to produce TiO 2 thin films in the anatase phase over silicon and glass substrates. Both implantation and sputtering processes shared the same 500 W plasma with the target, polarized between 0 and -3 kV. The substrates were placed between 2 and 3 cm from the target, this distance being found to be determinant of the TiO 2 deposition rate. The rutile phase in the target was obtained at temperatures in the order of 680 degrees C and the anatase (unbiased) one at about 300 degrees C without any auxiliary heating. The crystalline phases were characterized by x ray diffraction and Raman spectroscopy. The morphology and average roughness were established by means of scanning electronic and atomic force microscopy, whereas the reaction products generated during the oxidation process were analyzed by mass spectrometry. Finally, the stoichiometric composition was measured by means of X-ray photoelectron spectroscopy.

  18. Recycling nebulization-sample introduction system for inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    Kato, Kaneharu; Takashima, Kyoichiro

    1989-01-01

    A recycling nebulization-sample introduction system which exhibits the long-term stability of analyte emission signals while consuming small sample volumes was constructed for inductively coupled plasma atomic emission spectrometry. The present system is composed of five main parts: i.e., a spherical cyclone spray chamber, two commercial concentric nebulizers, two 3-way stopcocks, an aerosol transport tube with heater, and a commercial concentric three-tube plasma torch. It is based on the spray chamber where the two nebulizers are mounted (twin-nebulizer configuration): one is for introduction of a sample or a rinse solution into the spray chamber, and the other one is for recycling nebulization of the solution introduced. The nebulizers are easily demountable symmetrically and horizontally outside the spray chamber. Analytical performance and nebulization characteristics are described in comparison with a conventional sample introduction system. A stable signal of analyte emission intensity was extended to 20 min for 1 ml of sample under the ordinary condition of 0.6l/min carrier gas flow rate. (author)

  19. Study of plasma parameters influencing fractionation in laser ablation-inductively coupled plasma-mass spectrometry

    Science.gov (United States)

    Gäckle, M.; Merten, D.

    2010-12-01

    Methods permitting to test the influence of the matrix as well as of its local and temporal distribution on the plasma conditions in laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) are developed. For this purpose, the MS interface is used as plasma probe allowing to investigate the average plasma condition within the ICP zone observed in terms of temporal and spatial distribution of the matrix. Inserted matrix particles, particularly when being atomized and ionized, can cause considerable changes in both electron density and plasma temperature thus influencing the ionization equilibrium of the individual analytes. In this context, the plasma probe covers a region of the plasma for which no local thermodynamic equilibrium can be assumed. The differences in temperature, identified within the region of the plasma observed, amounted up to 3000 K. While in the central region conditions were detected that would not allow efficient atomization and ionization of the matrix, these conditions improve considerably towards the margin of the area observed. Depending on the nature as well as on the temporally and locally variable density of the matrix, this can lead to varying intensity ratios of the analytes and explain fractionation effects. By means of a derived equation it is shown that the deviation of the intensity ratio from the concentration ratio turns out to be more serious the higher the difference of the ionization potential of the analytes observed, the lower the plasma temperature and the higher the matrix concentration within the area observed.

  20. Unexpected properties of the inductively coupled plasma induced defect in germanium

    Energy Technology Data Exchange (ETDEWEB)

    Coelho, S.M.M., E-mail: sergio@up.ac.za; Auret, F.D.; Janse van Rensburg, P.J.; Nel, J.M.

    2014-04-15

    Inductively coupled plasma (ICP) etching of germanium introduces a single defect, the E{sub 0.31} electron trap, for a large range of argon partial pressures from 4×10{sup –3} to 6.5×10{sup –4} mbar that correspond to ion energies of 8 to 60 eV. Ge of three crystallographic orientations, (1 0 0), (1 1 0) and (1 1 1), treated with 20 and 60 eV ICP had defect concentration profiles that were similar in appearance, with a maximum concentration of 10{sup 14} cm{sup −3} extending more than a µm into the material, approximately three orders of magnitude deeper than what TRIM simulations predicted. All profiles were measured using Laplace deep level transient spectroscopy (L-DLTS), a technique that is sensitive to defect concentrations as low as 10{sup 11} cm{sup −3}. Isochronal annealing of samples showed concentration curves broadening after a 400 K anneal and decreasing to the 10{sup 13} cm{sup −3} level after a 450 K anneal. Unannealed samples measured after a year exhibited similar decreases in defect concentration without broadening of their profiles. A 550 K anneal lowered the defect concentration to levels below the L-DLTS detection limit. Thereafter additional plasma treatment of the surface failed to reintroduce this defect indicating that the structure required for the formation of E{sub 0.31} was no longer present in the region under observation.

  1. Determination of stable cesium and strontium in rice samples by inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Srinuttrakul, W.; Yoshida, S.

    2017-06-01

    For long-term radiation dose assessment models, food ingestion is one of the major exposure pathways to human. In general, the stable isotopes can serve as analogues of radioisotopes. In this study, rice samples were collected from 30 paddy fields in Si Sa Ket, Yasothon and Roi Et in the northeast of Thailand in November 2014. The concentrations of stable cesium (Cs-133) and strontium (Sr-88) in polished rice were determined by inductively coupled plasma mass spectrometry (ICP-MS). The standard reference material of rice flour (NIST 1568a) with spiked Cs and Sr was used to validate the analytical method. The concentration of Cs in polished rice from Si Sa Ket, Yasothon and Roi Et was 0.158 ± 0.167 mg kg-1, 0.090 ± 0.117 mg kg-1 and 0.054 ± 0.031 mg kg-1, respectively. The concentration of Sr in polished rice from Si Sa Ket, Yasothon and Roi Et was 0.351 ± 0.108 mg kg-1, 0.364 ± 0.215 mg kg-1 and 0.287 ± 0.102 mg kg-1, respectively. Comparison of the results with Japanese data before the Fukushima Di-ichi nuclear power plant accident showed that the concentrations of both Cs and Sr for Thai rice were higher than those for Japanese rice.

  2. Dry etching of ITO by magnetic pole enhanced inductively coupled plasma for display and biosensing devices

    Energy Technology Data Exchange (ETDEWEB)

    Meziani, T. [European Commission, Joint Research Centre, Institute for Health and Consumer Protection, 21020 Ispra (Vatican City State, Holy See,) (Italy)]. E-mail: tarik.meziani@jrc.it; Colpo, P. [European Commission, Joint Research Centre, Institute for Health and Consumer Protection, 21020 Ispra (Va) (Italy)]. E-mail: pascal.colpo@jrc.it; Lambertini, V. [Centro Ricerche Fiat, Strada Torino 50, 10043 Orbassano (TO) (Italy); Ceccone, G. [European Commission, Joint Research Centre, Institute for Health and Consumer Protection, 21020 Ispra (Va) (Italy); Rossi, F. [European Commission, Joint Research Centre, Institute for Health and Consumer Protection, 21020 Ispra (Va) (Italy)

    2006-03-15

    The dry etching of indium tin oxide (ITO) layers deposited on glass substrates was investigated in a high density inductively coupled plasma (ICP) source. This innovative low pressure plasma source uses a magnetic core in order to concentrate the electromagnetic energy on the plasma and thus provides for higher plasma density and better uniformity. Different gas mixtures were tested containing mainly hydrogen, argon and methane. In Ar/H{sub 2} mixtures and at constant bias voltage (-100 V), the etch rate shows a linear dependence with input power varying the same way as the ion density, which confirms the hypothesis that the etching process is mainly physical. In CH{sub 4}/H{sub 2} mixtures, the etch rate goes through a maximum for 10% CH{sub 4} indicating a participation of the radicals to the etching process. However, the etch rate remains quite low with this type of gas mixture (around 10 nm/min) because the etching mechanism appears to be competing with a deposition process. With CH{sub 4}/Ar mixtures, a similar feature appeared but the etch rate was much higher, reaching 130 nm/min at 10% of CH{sub 4} in Ar. The increase in etch rate with the addition of a small quantity of methane indicates that the physical etching process is enhanced by a chemical mechanism. The etching process was monitored by optical emission spectroscopy that appeared to be a valuable tool for endpoint detection.

  3. Ion Clouds in the Inductively Coupled Plasma Torch: A Closer Look through Computations.

    Science.gov (United States)

    Aghaei, Maryam; Lindner, Helmut; Bogaerts, Annemie

    2016-08-16

    We have computationally investigated the introduction of copper elemental particles in an inductively coupled plasma torch connected to a sampling cone, including for the first time the ionization of the sample. The sample is inserted as liquid particles, which are followed inside the entire torch, i.e., from the injector inlet up to the ionization and reaching the sampler. The spatial position of the ion clouds inside the torch as well as detailed information on the copper species fluxes at the position of the sampler orifice and the exhausts of the torch are provided. The effect of on- and off-axis injection is studied. We clearly show that the ion clouds of on-axis injected material are located closer to the sampler with less radial diffusion. This guarantees a higher transport efficiency through the sampler cone. Moreover, our model reveals the optimum ranges of applied power and flow rates, which ensure the proper position of ion clouds inside the torch, i.e., close enough to the sampler to increase the fraction that can enter the mass spectrometer and with minimum loss of material toward the exhausts as well as a sufficiently high plasma temperature for efficient ionization.

  4. A new air-cooled argon/helium-compatible inductively coupled plasma torch.

    Science.gov (United States)

    Miyahara, Hidekazu; Iwai, Takahiro; Kaburaki, Yuki; Kozuma, Tomokazu; Shigeta, Kaori; Okino, Akitoshi

    2014-01-01

    A new inductively coupled plasma (ICP) torch with an air-cooling system has been designed and developed for both argon and helium plasma. The same torch and impedance-matching network could be used to generate stable Ar- and He-ICP. The torch consists of three concentric quartz tubes. The carrier gas, plasma gas, and cooling gas flow through the intervals between each tube. In an experiment, it was found that Ar-ICP could form a stable plasma under the following conditions: RF power of 1 kW, plasma gas flow rate of 11 L min(-1), and cooling gas flow rate of 20 L min(-1). For He-ICP, an input RF power of 2 kW, which is two-times higher than that of a conventional He-ICP, could be constantly applied to the plasma with plasma gas and cooling gas flow rates of 15 and 20 L min(-1), respectively. Using this torch, it is possible to realize lower plasma gas consumption for Ar- and He-ICP and a high-power drive for He-ICP. It has been found that the air-cooling gas stabilizes the shape of the plasma due to the pressure difference between the cooling gas and the plasma gas.

  5. Upcycling Waste Lard Oil into Vertical Graphene Sheets by Inductively Coupled Plasma Assisted Chemical Vapor Deposition

    Directory of Open Access Journals (Sweden)

    Angjian Wu

    2017-10-01

    Full Text Available Vertical graphene (VG sheets were single-step synthesized via inductively coupled plasma (ICP-enhanced chemical vapor deposition (PECVD using waste lard oil as a sustainable and economical carbon source. Interweaved few-layer VG sheets, H2, and other hydrocarbon gases were obtained after the decomposition of waste lard oil. The influence of parameters such as temperature, gas proportion, ICP power was investigated to tune the nanostructures of obtained VG, which indicated that a proper temperature and H2 concentration was indispensable for the synthesis of VG sheets. Rich defects of VG were formed with a high I D / I G ratio (1.29, consistent with the dense edges structure observed in electron microscopy. Additionally, the morphologies, crystalline degree, and wettability of nanostructure carbon induced by PECVD and ICP separately were comparatively analyzed. The present work demonstrated the potential of our PECVD recipe to synthesize VG from abundant natural waste oil, which paved the way to upgrade the low-value hydrocarbons into advanced carbon material.

  6. Elemental Bioimaging by Means of Fast Scanning Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry

    Science.gov (United States)

    Wehe, Christoph A.; Thyssen, Georgina M.; Herdering, Christina; Raj, Indra; Ciarimboli, Giuliano; Sperling, Michael; Karst, Uwe

    2015-08-01

    One of the most common setups for elemental bioimaging, the hyphenation of a laser ablation (LA) system and an inductively coupled plasma mass spectrometer (ICP-MS), was expanded by adding full scan mass spectrometric information as another dimension of information. While most studies deal with the analysis of typically not more than up to 10 isotopes per scan cycle, a fast scanning quadrupole mass analyzer was utilized to record the full mass spectrum of interest in this work. Mass-to-charge ratios from 6 to 250 were observed within one cycle. Besides the x- and y-position on the ablated sample and the intensity, the m/z-ratio served as fourth variable for each pixel of the obtained data, closing thereby the gap between "inorganic" and "organic" mass spectrometric imaging techniques. The benefits of this approach include an improved control of interferences, the discovery of unexpected elemental distributions, the possibility to plot isotopic ratios, and to integrate the intensities of a certain number of mass channels recorded for each isotope, thus virtually increasing sensitivity. The respective data are presented for dried droplets as well as embedded animal and human tissue slices. Limits of detection were calculated and found to be in accordance with counting statistics. A dedicated software macro was developed for data manipulation prior to common evaluation and image creation.

  7. Environmental samples analysis by Atomic Absorption Spectrophotometry and Inductively Coupled Plasma-Optical Emission Spectroscopy

    International Nuclear Information System (INIS)

    Popescu, I.V.; Iordan, M.; Stihi, C.; Bancuta, A.; Busuioc, G.; Dima, G.; Ciupina, V.; Belc, M.; Vlaicu, Gh.; Marian, R.

    2002-01-01

    Biological samples are interesting from many aspects of environmental monitoring. By analyzing tree leaves conclusions can be drown regarding the metal loading in the growth medium. So that, starting from assumption that the pollution factors from environmental medium can modify the normal concentration of elements, we decided to control the presence of toxic elements and the deviation from normal state of elements in leaves of different trees from areas situated at different distances of pollution source. The aim of this work is to determine the elemental composition of tree leaves using Atomic Absorption Spectrophotometry (AAS) method and Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) method. Using AAS spectrophotometer SHIMADZU we identified and determined the concentration of: Cd, Co, Cu, Zn, Mn, Cr, Fe, Se, Pb with an instrumental error less than 1% for most of the elements analyzed. The same samples were analyzed by ICP-OES spectrometer, BAIRD ICP2070-Sequential Plasma spectrometer. We identified and determined in leaves of different trees the concentration of Mg, Ca, and Sr with a precision less than 6%. (authors)

  8. Quantitative images of metals in plant tissues measured by laser ablation inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Becker, J.S.; Dietrich, R.C.; Matusch, A.; Pozebon, D.; Dressler, V.L.

    2008-01-01

    Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used for quantitative imaging of toxic and essential elements in thin sections (thickness of 30 or 40 μm) of tobacco plant tissues. Two-dimensional images of Mg, Fe, Mn, Zn, Cu, Cd, Rh, Pt and Pb in leaves, shoots and roots of tobacco were produced. Sections of the plant tissues (fixed onto glass slides) were scanned by a focused beam of a Nd:YAG laser in a laser ablation chamber. The ablated material was transported with argon as carrier gas to the ICP ion source at a quadrupole ICP-MS instrument. Ion intensities of the investigated elements were measured together with 13 C + , 33 S + and 34 S + within the entire plant tissue section. Matrix matching standards (prepared using powder of dried tobacco leaves) were used to constitute calibration curves, whereas the regression coefficient of the attained calibration curves was typically 0.99. The variability of LA-ICP-MS process, sample heterogeneity and water content in the sample were corrected by using 13 C + as internal standard. Quantitative imaging of the selected elements revealed their inhomogeneous distribution in leaves, shoots and roots

  9. Studies of selenium and xenon in inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Bricker, Tonya [Iowa State Univ., Ames, IA (United States)

    1994-07-27

    Since its development, inductively coupled plasma mass spectrometry (ICP-MS) has been a widely used analytical technique. ICP-MS offers low detection limits, easy determination of isotope ratios, and simple mass spectra from analyte elements. ICP-MS has been successfully employed for many applications including geological, environmental, biological, metallurgical, food, medical, and industrial. One specific application important to many areas of study involves elemental speciation by using ICP-MS as an element specific detector interfaced to liquid chromatography. Elemental speciation information is important and cannot be obtained by atomic spectrometric methods alone which measure only the total concentration of the element present. Part 1 of this study describes the speciation of selenium in human serum by size exclusion chromatography (SEC) and detection by ICP-MS. Although ICP-MS has been widely sued, room for improvement still exists. Difficulties in ICP-MS include noise in the background, matrix effects, clogging of the sampling orifice with deposited solids, and spectral interference caused by polyatomic ions. Previous work has shown that the addition of xenon into the central channel of the ICP decreases polyatomic ion levels. In Part 2 of this work, a fundamental study involving the measurement of the excitation temperature is carried out to further understand xenon`s role in the reduction of polyatomic ions. 155 refs.

  10. Determination of myo-inositol hexakisphosphate (phytate) in urine by inductively coupled plasma atomic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Grases, F.; Perello, J.; Isern, B.; Prieto, R.M

    2004-05-10

    Myo-inositol hexakisphosphate (phytate) is a substance present in urine with an important role in preventing calcium renal calculi development. In spite of this, the use of urinary phytate levels on stone-formers' evaluation and treatment is still notably restricted as a consequence of the enormous difficulty to analyze this substance in urine. In this paper, a simple procedure for routinary urinary phytate determination based on phosphorus determination through inductively coupled plasma atomic emission spectrometry is described. The method only requires a previous separation of phytate from other components by column anion exchange chromatography. The working linear range used was 0-2 mg l{sup -1} phosphorus (0-7 mg l{sup -1} phytate). The limit of detection was 64 {mu}g l{sup -1} of phytate and the limit of quantification was 213 {mu}g l{sup -1}. The relative standard deviation (R.S.D.) for 1.35 mg l{sup -1} phytate was 2.4%. Different urine samples were analyzed using an alternative analytical methodology based on gas chromatography (GC)/mass detection used for inositol determination (phytate was previously hydrolyzed), resulting both methods comparable using as criterion to assess statistical significance P<0.05.

  11. Analytical performance of an inductively coupled plasma optical emission spectrometry with Dual View configuration

    Directory of Open Access Journals (Sweden)

    Silva Júlio C. J.

    2003-01-01

    Full Text Available The analytical performance of axially and radially viewed inductively coupled plasma optical emission spectrometers (AX-ICP OES and RD-ICP OES, respectively were evaluated in terms of the Mg II/Mg I ratio, matrix effects, and detection limits (LOD. All solutions were made in either 1% v v-1 nitric acid or in a 10% v v-1 water-soluble tertiary amine solution (CFA-C adjusted to pH 8. Using a nebulization gas flow-rate of 0.5 L min-1 and applied power of 1.3 kW, Mg II/Mg I ratio was at least 15 in any medium for both configurations. Under robust conditions, plasma processes were practically not affected by the presence of 0.1% m v-1 of Ca, K, or Na in both configurations. However, interference effects were observed with non-robust conditions, mainly with AX-ICP OES in both media. The best detection limits were obtained using AX-ICP OES under robust conditions, with solutions prepared in the amine medium.

  12. Inductively coupled plasma induced deep levels in epitaxial n-GaAs

    Energy Technology Data Exchange (ETDEWEB)

    Auret, F.D.; Janse van Rensburg, P.J.; Meyer, W.E.; Coelho, S.M.M. [Department of Physics, University of the Pretoria, Lynnwood Road, Pretoria 0002 (South Africa); Kolkovsky, Vl. [Technische Universitaet, Dresden, 01062 Dresden (Germany); Botha, J.R.; Nyamhere, C. [Department of Physics, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth 6031 (South Africa); Venter, A., E-mail: andre.venter@nmmu.ac.za [Department of Physics, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth 6031 (South Africa)

    2012-05-15

    The electronic properties of defects introduced by low energy inductively coupled Ar plasma etching of n-type (Si doped) GaAs were investigated by deep level transient spectroscopy (DLTS) and Laplace DLTS. Several prominent electron traps (E{sub c}-0.046 eV, E{sub c}-0.186 eV, E{sub c}-0.314 eV. E{sub c}-0.528 eV and E{sub c}-0.605 eV) were detected. The metastable defect E{sub c}-0.046 eV having a trap signature similar to E1 is observed for the first time. E{sub c}-0.314 eV and E{sub c}-0.605 eV are metastable and appear to be similar to the M3 and M4 defects present in dc H-plasma exposed GaAs.

  13. Low-frequency, high-density, inductively coupled plasma sources: Operation and applications

    Science.gov (United States)

    Xu, S.; Ostrikov, K. N.; Li, Y.; Tsakadze, E. L.; Jones, I. R.

    2001-05-01

    Operation regimes, plasma parameters, and applications of the low-frequency (˜500 kHz) inductively coupled plasma (ICP) sources with a planar external coil are investigated. It is shown that highly uniform, high-density (ne˜9×1012 cm-3) plasmas can be produced in low-pressure argon discharges with moderate rf powers. The low-frequency ICP sources operate in either electrostatic (E) or electromagnetic (H) regimes in a wide pressure range without any Faraday shield or an external multipolar magnetic confinement, and exhibit high power transfer efficiency, and low circuit loss. In the H mode, the ICP features high level of uniformity over large processing areas and volumes, low electron temperatures, and plasma potentials. The low-density, highly uniform over the cross-section, plasmas with high electron temperatures and plasma and sheath potentials are characteristic to the electrostatic regime. Both operation regimes offer great potential for various plasma processing applications. As examples, the efficiency of the low-frequency ICP for steel nitriding and plasma-enhanced chemical vapor deposition of hydrogenated diamond-like carbon (DLC) films, is demonstrated. It appears possible to achieve very high nitriding rates and dramatically increase micro-hardness and wear resistance of the AISI 304 stainless steel. It is also shown that the deposition rates and mechanical properties of the DLC films can be efficiently controlled by selecting the discharge operating regime.

  14. Depleted uranium analysis in blood by inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Todorov, T.I.; Xu, H.; Ejnik, J.W.; Mullick, F.G.; Squibb, K.; McDiarmid, M.A.; Centeno, J.A.

    2009-01-01

    In this study we report depleted uranium (DU) analysis in whole blood samples. Internal exposure to DU causes increased uranium levels as well as change in the uranium isotopic composition in blood specimen. For identification of DU exposure we used the 235U/238U ratio in blood samples, which ranges from 0.00725 for natural uranium to 0.002 for depleted uranium. Uranium quantification and isotopic composition analysis were performed by inductively coupled plasma mass spectrometry. For method validation we used eight spiked blood samples with known uranium concentrations and isotopic composition. The detection limit for quantification was determined to be 4 ng L-1 uranium in whole blood. The data reproduced within 1-5% RSD and an accuracy of 1-4%. In order to achieve a 235U/238U ratio range of 0.00698-0.00752% with 99.7% confidence limit a minimum whole blood uranium concentration of 60 ng L??1 was required. An additional 10 samples from a cohort of veterans exposed to DU in Gulf War I were analyzed with no knowledge of their medical history. The measured 235U/ 238U ratios in the blood samples were used to identify the presence or absence of DU exposure within this patient group. ?? 2009 The Royal Society of Chemistry.

  15. Studies of selenium and xenon in inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Bricker, T.

    1994-01-01

    Since its development, inductively coupled plasma mass spectrometry (ICP-MS) has been a widely used analytical technique. ICP-MS offers low detection limits, easy determination of isotope ratios, and simple mass spectra from analyte elements. ICP-MS has been successfully employed for many applications including geological, environmental, biological, metallurgical, food, medical, and industrial. One specific application important to many areas of study involves elemental speciation by using ICP-MS as an element specific detector interfaced to liquid chromatography. Elemental speciation information is important and cannot be obtained by atomic spectrometric methods alone which measure only the total concentration of the element present. Part 1 of this study describes the speciation of selenium in human serum by size exclusion chromatography (SEC) and detection by ICP-MS. Although ICP-MS has been widely sued, room for improvement still exists. Difficulties in ICP-MS include noise in the background, matrix effects, clogging of the sampling orifice with deposited solids, and spectral interference caused by polyatomic ions. Previous work has shown that the addition of xenon into the central channel of the ICP decreases polyatomic ion levels. In Part 2 of this work, a fundamental study involving the measurement of the excitation temperature is carried out to further understand xenon's role in the reduction of polyatomic ions. 155 refs

  16. Fabrication of SiC nanopillars by inductively coupled SF6/O2 plasma etching

    Science.gov (United States)

    Choi, J. H.; Latu-Romain, L.; Bano, E.; Dhalluin, F.; Chevolleau, T.; Baron, T.

    2012-06-01

    In this paper, we demonstrate a top-down fabrication technique for nanometre scale silicon carbide (SiC) pillars using inductively coupled plasma etching. A set of experiments in SF6-based plasma was carried out in order to realize high aspect ratio SiC nanopillars. The etched SiC nanopillars using a small circular mask pattern (115 nm diameter) show high aspect ratio (7.4) with a height of 2.2 µm at an optimum bias voltage (300 V) and pressure (6 mTorr). Under the optimal etching conditions using a large circular mask pattern with 370 nm diameter, the obtained SiC nanopillars exhibit high anisotropy features (6.4) with a large etch depth (>7 µm). The etch characteristic of the SiC nanopillars under these conditions shows a high etch rate (550 nm min-1) and a high selectivity (over 60 for Ni). We also studied the etch profile of the SiC nanopillars and mask evolution over the etching time. As the mask pattern size shrinks in nanoscale, vertical and lateral mask erosion plays a crucial role in the etch profile of the SiC nanopillars. Long etching process makes the pillars appear with a hexagonal shape, coming from the crystallographic structure of α-SiC. It is found that the feature of pillars depends not only on the etching process parameters, but also on the crystallographic structure of the SiC phase.

  17. Sulfur-based absolute quantification of proteins using isotope dilution inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Lee, Hyun-Seok; Heun Kim, Sook; Jeong, Ji-Seon; Lee, Yong-Moon; Yim, Yong-Hyeon

    2015-10-01

    An element-based reductive approach provides an effective means of realizing International System of Units (SI) traceability for high-purity biological standards. Here, we develop an absolute protein quantification method using double isotope dilution (ID) inductively coupled plasma mass spectrometry (ICP-MS) combined with microwave-assisted acid digestion for the first time. We validated the method and applied it to certify the candidate protein certified reference material (CRM) of human growth hormone (hGH). The concentration of hGH was determined by analysing the total amount of sulfur in hGH. Next, the size-exclusion chromatography method was used with ICP-MS to characterize and quantify sulfur-containing impurities. By subtracting the contribution of sulfur-containing impurities from the total sulfur content in the hGH CRM, we obtained a SI-traceable certification value. The quantification result obtained with the present method based on sulfur analysis was in excellent agreement with the result determined via a well-established protein quantification method based on amino acid analysis using conventional acid hydrolysis combined with an ID liquid chromatography-tandem mass spectrometry. The element-based protein quantification method developed here can be generally used for SI-traceable absolute quantification of proteins, especially pure-protein standards.

  18. EVALUATION OF CORROSION OF ENGINEERING CERAMICS BY ATOMIC EMISSION SPECTROMETRY IN INDUCTIVELY COUPLED PLASMA

    Directory of Open Access Journals (Sweden)

    DAGMAR GALUSKOVÁ

    2014-03-01

    Full Text Available An analytical method has been developed and verified, facilitating chemical analysis of saline aqueous solutions from corrosion tests of two types of engineering ceramics, i.e. polycrystalline alumina, and silicon nitride. The method is capable of providing complementary information related to mechanisms of corrosion and kinetics of dissolution of the two main components of the ceramics, i.e. Al in α-Al2O3, and Si in Si3N4. A radially viewed inductively coupled plasma atomic emission spectroscopy was used, and the operating conditions for the analysis were optimised. The method was validated. Internal standardisation, matrix matching, standard addition technique and direct measurement without matrix correction were applied, and the results were critically discussed. The technique of internal standard was shown to be the most sensitive. The method exhibited satisfactory precision (relative standard deviation up to 5 %, analytical recoveries from 95 to 100 %, and acceptable limits of detection based on 3σ criterion of 0.095 mg∙l-1 for Al (measured at 308.215 nm and 0.099 mg∙l-1 for Si (at 251.611 nm.

  19. New methodical and instrumental developments in laser ablation inductively coupled plasma mass spectrometry1

    Science.gov (United States)

    Hoffmann, E.; Lüdke, C.; Skole, J.; Stephanowitz, H.; Wollbrandt, J.; Becker, W.

    2002-10-01

    Many tasks in bulk analysis, micro analysis and depth profile analysis can be solved advantageously by laser ablation inductively coupled plasma mass spectrometry (Laser ICP-MS) in particular, when both the chemical and elemental distributions in the sample are to be determined. However, the analyst has to take into account that the analytical precision and accuracy of the Laser ICP-MS is influenced decisively by signal standardization, the homogeneity of the samples as well as calibration standards and the mass-spectrometric measuring mode, which is usually sequential when performed with scanning mass spectrometers such as quadrupol- or sector-based instruments. Using the ablated mass as standard, an excellent level of the analytical precision and accuracy (relative standard deviation R.S.D.ASIC) was developed, which permits a time resolution of 1 ns. The analytical performance of the TOF when used in combination with an ICP is demonstrated in terms of resolution, ion extraction rate, detection limits and dynamic range. The determination of 39K + and 40Ca + at trace level can be realized in a cool plasma condition (high central gas flow) only with a small interference by 40Ar +. Detection limits of 23 elements were measured with typical values in the lower nanograms per liter range. The ion extraction rates, measured for a sample mass of 1 ng in terms of counts per second divided by the relative isotope abundance, are one order of magnitude higher than those obtained with a quadrupol-based instrument.

  20. Fundamental and methodological investigations for the improvement of elemental analysis by inductively coupled plasma mass soectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, Christopher Hysjulien [Ames Lab., Ames, IA (United States)

    2012-01-01

    This dissertation describes a variety of studies meant to improve the analytical performance of inductively coupled plasma mass spectrometry (ICP-MS) and laser ablation (LA) ICP-MS. The emission behavior of individual droplets and LA generated particles in an ICP is studied using a high-speed, high frame rate digital camera. Phenomena are observed during the ablation of silicate glass that would cause elemental fractionation during analysis by ICP-MS. Preliminary work for ICP torch developments specifically tailored for the improvement of LA sample introduction are presented. An abnormal scarcity of metal-argon polyatomic ions (MAr{sup +}) is observed during ICP-MS analysis. Evidence shows that MAr{sup +} ions are dissociated by collisions with background gas in a shockwave near the tip of the skimmer cone. Method development towards the improvement of LA-ICP-MS for environmental monitoring is described. A method is developed to trap small particles in a collodion matrix and analyze each particle individually by LA-ICP-MS.

  1. Inductively coupled plasma mass spectrometer with laser ablation metal ions release detection in the human mouth

    Science.gov (United States)

    Kueerova, Hana; Dostalova, Tatjana; Prochazkova, J.

    2002-06-01

    Presence of more dental alloys in oral cavity often causes pathological symptoms. Due to various and multi-faced symptomatology, they tend to be a source of significant problems not only for the patient but also for the dentist. Metal ions released from alloys can cause subjective and objective symptoms in mouth. The aim of this study was detection of metal elements presence in saliva. There were 4 groups of examined persons: with intact teeth (15 individuals) with metallic restorations, pathological currents 5-30 (mu) A, multi-faced subjective symptomatology and uncharacteristic objective diagnosis (32 patients), with metallic restorations and no subjective symptoms (14 persons) and with metallic restorations, without pathological currents and with problems related to galvanism (13 patients). Presence of 14 metal elements was checked by inductively coupled plasma mass spectrometer with laser ablation. Nd:YAG laser detector was used. There were significant differences in content of silver, gold and mercury between persons with intact teeth and other three groups. There were no differences found between subjects with and without galvanic currents, and presence of subjective and objective symptoms.

  2. Plutonium determination in seawater by inductively coupled plasma mass spectrometry: A review.

    Science.gov (United States)

    Cao, Liguo; Bu, Wenting; Zheng, Jian; Pan, Shaoming; Wang, Zhongtang; Uchida, Shigeo

    2016-05-01

    Knowing the concentration and isotopic ratio of Pu in seawater is of critical importance for assessing Pu contamination and investigating oceanic processes. In recent decades, the concentration of (239+240)Pu in seawater, particularly for surface seawater, has presented an exponential decreasing trend with time; thus determination of Pu in seawater has become a challenge nowadays. Here, we have summarized and critically discussed a variety of reported analytical methods for Pu determination in seawater sample based on inductively coupled plasma mass spectrometry (ICP-MS) analytical technique for rapid ultra-trace detection of Pu. Generally, pretreatments for seawater sample include co-precipitation, valence adjustment and chemical separation and purification procedures, all of which are comprehensively reviewed. Overall, the selected anion-exchange, extraction resins and operation condition are important for decontamination of interference from matrix elements and achieving satisfactory chemical yields. In addition, other mass spectrometric and radiometric detections are briefly addressed and compared with the focus on assessing ICP-MS. Finally, we discuss some issues and prospects in determination and application of Pu isotopes in seawater samples for future research. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Transient plasma potential in pulsed dual frequency inductively coupled plasmas and effect of substrate biasing

    Directory of Open Access Journals (Sweden)

    Anurag Mishra

    2016-09-01

    Full Text Available An electron emitting probe in saturated floating potential mode has been used to investigate the temporal evolution of plasma potential and the effect of substrate RF biasing on it for pulsed dual frequency (2 MHz/13.56 MHz inductively coupled plasma (ICP source. The low frequency power (P2MHz has been pulsed at 1 KHz and a duty ratio of 50%, while high frequency power (P13.56MHz has been used in continuous mode. The substrate has been biased with a separate bias power at (P12.56MHz Argon has been used as a discharge gas. During the ICP power pulsing, three distinct regions in a typical plasma potential profile, have been identified as ‘initial overshoot’, pulse ‘on-phase’ and pulse ‘off-phase’. It has been found out that the RF biasing of the substrate significantly modulates the temporal evolution of the plasma potential. During the initial overshoot, plasma potential decreases with increasing RF biasing of the substrate, however it increases with increasing substrate biasing for pulse ‘on-phase’ and ‘off-phase’. An interesting structure in plasma potential profile has also been observed when the substrate bias is applied and its evolution depends upon the magnitude of bias power. The reason of the evolution of this structure may be the ambipolar diffusion of electron and its dependence on bias power.

  4. Exploration of robust operating conditions in inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Tromp, John W.; Pomares, Mario; Alvarez-Prieto, Manuel; Cole, Amanda; Ying Hai; Salin, Eric D.

    2003-01-01

    'Robust' conditions, as defined by Mermet and co-workers for inductively coupled plasma (ICP)-atomic emission spectrometry, minimize matrix effects on analyte signals, and are obtained by increasing power and reducing nebulizer gas flow. In ICP-mass spectrometry (MS), it is known that reduced nebulizer gas flow usually leads to more robust conditions such that matrix effects are reduced. In this work, robust conditions for ICP-MS have been determined by optimizing for accuracy in the determination of analytes in a multi-element solution with various interferents (Al, Ba, Cs, K, Na), by varying power, nebulizer gas flow, sample introduction rate and ion lens voltage. The goal of the work was to determine which operating parameters were the most important in reducing matrix effects, and whether different interferents yielded the same robust conditions. Reduction in nebulizer gas flow and in sample input rate led to a significantly decreased interference, while an increase in power seemed to have a lesser effect. Once the other parameters had been adjusted to their robust values, there was no additional improvement in accuracy attainable by adjusting the ion lens voltage. The robust conditions were universal, since, for all the interferents and analytes studied, the optimum was found at the same operating conditions. One drawback to the use of robust conditions was the slightly reduced sensitivity; however, in the context of 'intelligent' instruments, the concept of 'robust conditions' is useful in many cases

  5. Acrolein induction of oxidative stress and degranulation in mast cells.

    Science.gov (United States)

    Hochman, Daniel J; Collaco, Christopher R; Brooks, Edward G

    2014-08-01

    Increases in asthma worldwide have been associated epidemiologically with expanding urban air pollution. The mechanistic relationship between airway hyper-responsiveness, inflammation, and ambient airborne triggers remains ambiguous. Acrolein, a ubiquitous aldehyde pollutant, is a product of incomplete combustion reactions. Acrolein is abundant in cigarette smoke, effluent from industrial smokestacks, diesel exhaust, and even hot oil cooking vapors. Acrolein is a potent airway irritant and can induce airway hyper-responsiveness and inflammation in the lungs of animal models. In the present study, we utilized the mast cell analog, RBL-2H3, to interrogate the responses of cells relevant to airway inflammation and allergic responses as a model for the induction of asthma-like conditions upon exposure to acrolein. We hypothesized that acrolein would induce oxidative stress and degranulation in airway mast cells. Our results indicate that acrolein at 1 ppm initiated degranulation and promoted the generation of reactive oxygen species (ROS). Introduction of antioxidants to the system significantly reduced both ROS generation and degranulation. At higher levels of exposure (above 100 ppm), RBL-2H3 cells displayed signs of severe toxicity. This experimental data indicates acrolein can induce an allergic inflammation in mast cell lines, and the initiation of degranulation was moderated by the application of antioxidants. Copyright © 2012 Wiley Periodicals, Inc., a Wiley company.

  6. Enhanced power coupling efficiency in inductive discharges with RF substrate bias driven at consecutive harmonics with adjustable phase

    Science.gov (United States)

    Berger, Birk; Steinberger, Thomas; Schüngel, Edmund; Koepke, Mark; Mussenbrock, Thomas; Awakowicz, Peter; Schulze, Julian

    2017-11-01

    Inductive discharges with radio-frequency (RF) substrate bias are frequently used for various technological applications. We operate such a hybrid discharge with a phase-locked RF substrate bias at twice the frequency of the inductive coupling with fixed but adjustable phase between both RF sources in neon at low pressures of a few Pa. The ion flux to the substrate is found to be a function of this relative phase in the H-mode at constant RF powers as long as some residual capacitive coupling of the planar coil is present. For distinct choices of the phase, Phase Resolved Optical Emission Spectroscopy measurements show that energetic beam electrons generated by the expanding boundary sheaths (i) are well confined, (ii) are accelerated efficiently, and (iii) propagate vertically through the inductive skin layer at the times of maximum azimuthal induced electric field within the fundamental RF period. This enhances the inductive stochastic electron heating, the power coupling efficiency, and finally the ion flux.

  7. Direct analysis of samples by mass spectrometry: From elements to bio-molecules using laser ablation inductively couple plasma mass spectrometry and laser desorption/ionization mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Perdian, David C. [Iowa State Univ., Ames, IA (United States)

    2009-01-01

    Mass spectrometric methods that are able to analyze solid samples or biological materials with little or no sample preparation are invaluable to science as well as society. Fundamental research that has discovered experimental and instrumental parameters that inhibit fractionation effects that occur during the quantification of elemental species in solid samples by laser ablation inductively coupled plasma mass spectrometry is described. Research that determines the effectiveness of novel laser desorption/ionization mass spectrometric methods for the molecular analysis of biological tissues at atmospheric pressure and at high spatial resolution is also described. A spatial resolution is achieved that is able to analyze samples at the single cell level.

  8. RBE of neutrons for induction of cell reproductive death and chromosome aberrations in three cell lines

    International Nuclear Information System (INIS)

    Zoetelief, J.; Kuijpers, W.C.; Baten-Wittwer, A.; Barendsen, G.W.

    1983-01-01

    The authors have compared the RBE values for induction of dicentrics and centric rings with those for cell inactivation and with the mean or effective quality factors (Q) recommended for radiation protection. The induction of cell reproductive death and chromosome aberrations has been investigated in plateau phase cultures of established lines of a rat rhabdomyosarcoma, a rat ureter carcinoma and Chinese hamster cells for single doses of 300 kV X-rays and 0.5, 4.2 and 15 MeV neutrons. The different cell lines show considerable variations in sensitivity and the RBE values obtained are presented in tabular form. The mean RBE values for the rat rhabdomyosarcoma cells are lower than those for the other two relatively resistant cell lines. Those for the Chinese hamster cells extrapolated to levels according to low doses of X-rays are in good agreement with the quoted Q values. (Auth./C.F.)

  9. Reactivity of lanthanoid mono-cations with ammonia: A combined inductively coupled plasma mass spectrometry and computational investigation

    International Nuclear Information System (INIS)

    Quemet, Alexandre; Brennetot, Rene; Vitorge, Pierre; Cimas, Alvaro; Liu, Shengsi; Gagliardi, Laura; Salpin, Jean-Yves; Tortajada, Jeanine; Spezia, Riccardo; Gaigeot, Marie-Pierre; Marsden, Colin

    2013-01-01

    The behavior of La + , Sm + , Eu + and Gd + with NH 3 (g) and ND 3 (g) was studied to understand gas phase chemical reactions used for separations in the reaction cell of a quadrupole inductively coupled plasma mass spectrometer (ICP-MS). For Ln + = La + and Gd + , the primary reaction channel is the formation of the LnNH + protonated nitride leading to H 2 elimination. The LnNH(NH 3 ) 1-5 + ammonia complexes of the Ln protonated nitride are further generated. Sm + and Eu + are less reactive: the protonated nitride is not detected, and only small amounts of Ln(NH 3 ) 0-6 + are observed. Quantum chemical calculations at the DFT, MP2, CCSD(T) and CASPT2 levels of theory were employed to explore the potential energy surfaces. For the La + and Gd + ions of f-block elements, the reaction pathways are composed of three steps: first the formation of LnNH 3 + , then the isomerization to HLnNH 2 + , and finally the loss of H 2 associated with the formation of an LnN triple bond in the final product LnNH + . On the other hand, the isomerization leading to triple bond formation with H 2 loss did not proceed for Sm + and Eu + ions. (authors)

  10. Capillary electrophoresis coupled with inductively coupled mass spectrometry as an alternative to cloud point extraction based methods for rapid quantification of silver ions and surface coated silver nanoparticles

    OpenAIRE

    Qu, Haiou; Mudalige, Thilak K.; Linder, Sean W.

    2015-01-01

    Speciation and accurate quantification of ionic silver and metallic silver nanoparticles are critical to investigate silver toxicity and to determine the shelf-life of products that contain nano silver under various storage conditions. We developed a rapid method for quantification of silver ions and silver nanoparticles using capillary electrophoresis (CE) interfaced with inductively-coupled plasma mass spectrometry (ICPMS). The addition of 2-mercaptopropionylglycine (tiopronin) to the backg...

  11. Dynamic investigation of mode transition in inductively coupled plasma with a hybrid model

    International Nuclear Information System (INIS)

    Zhao Shuxia; Gao Fei; Wang Younian

    2009-01-01

    Industrial inductively coupled plasma (ICP) sources are always operated in low gas pressure 10-100 mTorr, therefore in order to accurately investigate the mode transition of ICP, we developed our pure fluid model (2009 J. Appl. Phys. 105 083306) into a hybrid fluid/Monte Carlo (MC) model, where the MC part is exploited to take in more dynamic characteristics of electrons and self-consistently calculate the rate coefficients and electron temperature used in the fluid module, and more crucially to study the electron energy distribution function (EEDF) evolution with mode transition. Due to the introduction of the nonlocal property of the electrons at relatively low pressures, the dependences of the plasma density on the coil current, including the mode transitions, are distinctly different at low and high pressures when simulated by this improved hybrid model (HM), while the trends for different pressures obtained from the original pure fluid model (PFM) are the same in all cases. Furthermore, the computed peaks of the electron density profile by the HM shift from the discharge centre in the E mode to the intense inductive field heating area (about half of the radius of the reaction chamber under the dielectric window) in H mode. In addition, the electron temperature profiles of two modes under different pressures simulated by HM are totally higher than the results of PFM. When the pressure is low, there is a minimum exhibited in the bulk plasma of the electron temperature profiles of the E mode, and along with the mode transition the distribution area of low temperature is substantially reduced. Moreover, this phenomenon disappears when the gas pressure is increased. Accompanied by this, the calculated EEDF of the E mode in the low pressure also demonstrates an absolutely dominant low energy electron fraction (about ≤5 eV); while transforming to the H discharge most of the electrons carry an energy of 1-10 eV. The tendencies of the calculated EEDF evolution with

  12. Workshop: Theory an Applications of Coupled Cell Networks

    Science.gov (United States)

    2006-03-22

    Economia and Centro de Matematica , Universidade do Porto) Application of coupled cell systems have been made to a wide range of problems in the physical and...Departamento de Matematica Pura da Faculdade de Ciencias do Porto) As pointed by [1], in the class of coupled cell networks that permits self-coupling

  13. Enhancement of the c-axis texture of aluminum nitride by an inductively coupled plasma reactive sputtering process

    International Nuclear Information System (INIS)

    Yeh, C.-M.; Chen, C.H.; Gan, J.-Y.; Kou, C.S.; Hwang, J.

    2005-01-01

    Inductively coupled plasma reactive sputtering technique has been applied to grow highly oriented aluminum nitride on Si(111) at high process pressure. An inductive coil of 3 and 1/4 turns was introduced to generate a plasma zone near the substrate holder, which provides additional energy to the radicals inside the plasma zone. The full width at half-maximum of the X-ray rocking curve of AlN(0002) is reduced from 7.90 deg. to 4.05 deg. when the inductive coil power is raised from 0 to 180 W. The enhancement of the c-axis texture of AlN is attributed to the increase of the density of the sputtered Al atoms of high energy

  14. Effect of single aerosol droplets on plasma impedance in the inductively coupled plasma

    International Nuclear Information System (INIS)

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

    2012-01-01

    The impedance of an inductively coupled plasma was indirectly monitored by two different means—through a RF-probe coil placed inside the torch housing and from tapping the phase-detector signal of the impedance-matching network. During single-droplet introduction, temporal spikes in both the RF-probe coil and the phase-detector signals were readily observed, indicating a momentary change in plasma impedance. The changes in plasma impedance were found to be due solely to plasma perturbation by droplet introduction, and not to an artifact caused by imperfect automatic impedance matching. The temporal changes in plasma impedance were found to be directly proportional to the temporally integrated atomic emission of hydrogen, which is assumed in turn to be directly proportional to the volume of the introduced droplet. A small satellite droplet, with an estimated diameter of 27 μm (i.e., ∼ 10 pL in volume), caused a readily measurable change in plasma impedance. By assuming that the change in RF-probe voltage is directly proportional to the variation in RF power delivered by the load coil, the instantaneous power change coupled to the plasma during single-droplet introduction was estimated. Typical increases in peak RF power and total energy coupled to the plasma, for a single 50-μm droplet introduction, were thereby estimated to be around 8 to 11 W and 0.03 to 0.04 J, respectively. This impedance change was also exploited as a trigger to signal the droplet-introduction event into the plasma. This trigger signal was obtained through a combination of the RF-probe and the phase-detector signals and offered typical jitter from 1 to 2 ms. With the proper choice of a trigger threshold, no trigger misfire resulted and the achievable efficiencies of the trigger signal were 99.95, 97.18 and 74.33% for plasma forward power levels of 900, 1200, and 1500 W, respectively. The baseline noise on the RF-probe coil and the phase-detector signals, which increase with plasma forward

  15. Liquid sample introduction in inductively coupled plasma atomic emission and mass spectrometry — Critical review

    Energy Technology Data Exchange (ETDEWEB)

    Bings, N.H., E-mail: bings@uni-mainz.de; Orlandini von Niessen, J.O.; Schaper, J.N.

    2014-10-01

    Inductively coupled plasma optical emission spectroscopy (ICP-OES) and mass spectrometry (ICP-MS) can be considered as the most important tools in inorganic analytical chemistry. Huge progress has been made since the first analytical applications of the ICP. More stable RF generators, improved spectrometers and detection systems were designed along with the achievements gained from advanced microelectronics, leading to overall greatly improved analytical performance of such instruments. In contrast, for the vast majority of cases liquid sample introduction is still based on the pneumatic principle as described in the late 19th century. High flow pneumatic nebulizers typically demand the use of spray chambers as “aerosol filters” in order to match the prerequisites of an ICP. By this, only a small fraction of the nebulized sample actually contributes to the measured signal. Hence, the development of micronebulizers was brought forward. Those systems produce fine aerosols at low sample uptake rates, but they are even more prone for blocking or clogging than conventional systems in the case of solutions containing a significant amount of total dissolved solids (TDS). Despite the high number of publications devoted to liquid sample introduction, it is still considered the Achilles' heel of atomic spectrometry and it is well accepted, that the technology used for liquid sample introduction is still far from ideal, even when applying state-of-the-art systems. Therefore, this review is devoted to offer an update on developments in the field liquid sample introduction that had been reported until the year 2013. The most recent and noteworthy contributions to this field are discussed, trends are highlighted and future directions are outlined. The first part of this review provides a brief overview on theoretical considerations regarding conventional pneumatic nebulization, the fundamentals on aerosol generation and discusses characteristics of aerosols ideally

  16. Controlled Dissolution of Surface Layers for Elemental Analysis by Inductively Coupled Plasma-Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lorge, Susan Elizabeth [Iowa State Univ., Ames, IA (United States)

    2007-01-01

    Determining the composition of thin layers is increasingly important for a variety of industrial materials such as adhesives, coatings and microelectronics. Secondary ion mass spectrometry (SIMS), Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), glow discharge optical emission spectroscopy (GDOES), glow discharge mass spectrometry (GDMS), and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) are some of the techniques that are currently employed for the direct analysis of the sample surface. Although these techniques do not suffer from the contamination problems that often plague sample dissolution studies, they do require matrix matched standards for quantification. Often, these standards are not readily available. Despite the costs of clean hoods, Teflon pipette tips and bottles, and pure acids, partial sample dissolution is the primary method used in the semiconductor industry to quantify surface impurities. Specifically, vapor phase decomposition (VPD) coupled to ICP-MS or total reflection x-ray fluorescence (TXRF) provides elemental information from the top most surface layers at detection sensitivities in the 107-1010atoms/cm2 range. The ability to quantify with standard solutions is a main advantage of these techniques. Li and Houk applied a VPD-like technique to steel. The signal ratio of trace element to matrix element was used for quantification. Although controlled dissolution concentrations determined for some of the dissolved elements agreed with the certified values, concentrations determined for refractory elements (Ti, Nb and Ta) were too low. LA-ICP-MS and scanning electron microscopy (SEM) measurements indicated that carbide grains distributed throughout the matrix were high in these refractory elements. These elements dissolved at a slower rate than the matrix element, Fe. If the analyte element is not removed at a rate similar to the matrix element a true

  17. Inductively coupled plasma etch damage in (-201) Ga2O3 Schottky diodes

    Science.gov (United States)

    Yang, Jiancheng; Ahn, Shihyun; Ren, F.; Khanna, Rohit; Bevlin, Kristen; Geerpuram, Dwarakanath; Pearton, S. J.; Kuramata, A.

    2017-04-01

    Bulk, single-crystal Ga2O3 was etched in BCl3/Ar inductively coupled plasmas as a function of ion impact energy. For pure Ar, the etch rate (R) was found to increase with ion energy (E) as predicted from a model of ion enhanced sputtering by a collision-cascade process, R ∝(E0.5 - ETH0.5), where the threshold energy for Ga2O3, ETH, was experimentally determined to be ˜75 eV. When BCl3 was added, the complexity of the ion energy distribution precluded, obtaining an equivalent threshold. Electrically active damage introduced during etching was quantified using Schottky barrier height and diode ideality factor measurements obtained by evaporating Ni/Au rectifying contacts through stencil masks onto the etched surfaces. For low etch rate conditions (˜120 Å min-1) at low powers (150 W of the 2 MHz ICP source power and 15 W rf of 13.56 MHz chuck power), there was only a small decrease in reverse breakdown voltage (˜6%), while the barrier height decreased from 1.2 eV to 1.01 eV and the ideality factor increased from 1.00 to 1.06. Under higher etch rate (˜700 Å min-1) and power (400 W ICP and 200 W rf) conditions, the damage was more significant, with the reverse breakdown voltage decreasing by ˜35%, the barrier height was reduced to 0.86 eV, and the ideality factor increased to 1.2. This shows that there is a trade-off between the etch rate and near-surface damage.

  18. Effect of electron thermal motion on plasma heating in a magnetized inductively coupled plasma

    International Nuclear Information System (INIS)

    Aman-ur-Rehman; Pu Yikang

    2007-01-01

    Power absorbed inside the magnetized inductively coupled plasma (MICP) is calculated using three different warm MICP models and is then compared with the result of the cold MICP model. The comparison shows that in the propagating region (ω e vertical bar), under the cavity resonance conditions, warm plasma heating S warm is significantly less than the cold plasma heating S cold , unless the distance traveled by the electrons due to their thermal motion, during the effective wave period, becomes significantly less than the wavelength of the cavity wave. Furthermore, in the propagating region, when ω≅ vertical bar Ω e vertical bar, there appears a valley on the plot of η(ω)=S warm /S cold versus ω showing the negative effect of electron thermal motion on plasma heating. This valley widens and gets smoother with an increase in the plasma length. In the nonpropagating region (ω> vertical bar Ω e vertical bar), the maximum value of η(ω) exists when ω- vertical bar Ω e vertical bar ≅v th /δ, showing that, in the presence of the external magnetic field, the thermal motion of the electrons leads to a Doppler shift of the frequencies, at which collisionless heating is the dominant mode of electron heating. Furthermore, in the nonpropagating region, when ω≅ vertical bar Ω e vertical bar, the skin depth of the right circularly polarized electric field decreases with magnetic field. This decrease in the skin depth results in an increase of collisionless heating under the Doppler-shifted wave particle resonant condition of ω- vertical bar Ω e vertical bar ≅v th /δ. It is also observed that, for large plasma length, the results of all the three warm MICP models are consistent with each other

  19. Determination of total tin in canned food using inductively coupled plasma atomic emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Perring, Loic; Basic-Dvorzak, Marija [Department of Quality and Safety Assurance, Nestle Research Centre, P.O. Box 44, Vers chez-les-Blanc, 1000, Lausanne (Switzerland)

    2002-09-01

    Tin is considered to be a priority contaminant by the Codex Alimentarius Commission. Tin can enter foods either from natural sources, environmental pollution, packaging material or pesticides. Higher concentrations are found in processed food and canned foods. Dissolution of the tinplate depends on the of food matrix, acidity, presence of oxidising reagents (anthocyanin, nitrate, iron and copper) presence of air (oxygen) in the headspace, time and storage temperature. To reduce corrosion and dissolution of tin, nowadays cans are usually lacquered, which gives a marked reduction of tin migration into the food product. Due to the lack of modern validated published methods for food products, an ICP-AES (Inductively coupled plasma-atomic emission spectroscopy) method has been developed and evaluated. This technique is available in many laboratories in the food industry and is more sensitive than atomic absorption. Conditions of sample preparation and spectroscopic parameters for tin measurement by axial ICP-AES were investigated for their ruggedness. Two methods of preparation involving high-pressure ashing or microwave digestion in volumetric flasks were evaluated. They gave complete recovery of tin with similar accuracy and precision. Recoveries of tin from spiked products with two levels of tin were in the range 99{+-}5%. Robust relative repeatabilities and intermediate reproducibilities were <5% for different food matrices containing >30 mg/kg of tin. Internal standard correction (indium or strontium) did not improve the method performance. Three emission lines for tin were tested (189.927, 283.998 and 235.485 nm) but only 189.927 nm was found to be robust enough with respect to interferences, especially at low tin concentrations. The LOQ (limit of quantification) was around 0.8 mg/kg at 189.927 nm. A survey of tin content in a range of canned foods is given. (orig.)

  20. Studies of the inductively coupled plasma via tomographic reconstruction: II. Experimental system

    International Nuclear Information System (INIS)

    Marshall, K.A.; Monnig, C.A.; Rayson, G.D.; Hieftje, G.M.

    1986-01-01

    Spatially resolved diagnostic studies of the Inductively Coupled Plasma (ICP) have generally relied upon the Abel inversion process to transform lateral projection data into radially resolved emission or absorption profiles. Unfortunately, Abel transformation is known to possess several significant drawbacks. The validity of the radial profiles obtained from the Abel-inversion process is significantly degraded by even small amounts of noise in the lateral emission data. In addition, the Abel-inversion technique requires a cylindrically symmetrical object in order to faithfully produce reconstructions. One method of avoiding these problems is to use the more general method of tomographic reconstruction for spatially resolved studies in the ICP. The experimental requirements of tomographic reconstruction, however, necessitate a rather elaborate experimental system. The large number of angular projections, resolution elements per projection, and the sheer volume of data collected makes tomographic reconstruction prohibitively time consuming if an automated, multi-channel collection scheme is not employed. In this study, an experimental system was designed to permit tomographic characterization of a laboratory ICP. The system employs a z-theta translation stage, a silicon intensified target vidicon detector and a laboratory computer for system automation (see figure). A typical data collection scheme is to obtain 60 projections with 100-point resolution per projection. These profiles are collected every 2 mm on the vertical axis, requiring 15 profiles over a 30 mm plasma height. This process results in approximately 90,000 data points, which can be collected within an hour on this system. Tomographic reconstruction is achieved with the use of a VAX-780 computer. The system employed is described and the operating characteristics of the apparatus are discussed

  1. Measurements of β or α emitter long lived radionuclides using inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Provitina, O.

    1993-01-01

    The measurement of long-lived radionuclides is highly important for characterizing nuclear wastes for their later storage. The main techniques for characterizing these isotopes are α spectrometry, β counting and γ spectrometry. The large period of these isotopes leads to low specific activity needing time consuming measurements in order to obtain significant signals. Moreover, the radiometric techniques are often limited by problems of interferences involving several steps of pretreatments. Among these steps, the specific extraction with crown ethers is highly selective for the separation of 99 Tc, 129 I and 135 Cs particularly. The radiometric techniques are here replaced by inductively coupled plasma mass spectroscopy (ICP-MS) the advantages of which are: few interferences, sensitivity which does not depend on the radiologic period as compared to radiochemistry. ICP-MS can then measure 237 Np in enriched uranium matrix and thereby reduce by a factor of 4 the sample pretreatment and the duration of the analysis usually performed by α spectrometry. Another technique, electrothermal vaporization (ETV), is consequently used. Crown ether extraction-ETV-ICP-MS is employed for measuring the long lived radionuclides 99 Tc and 129 I. The conditions of the extraction and the parameters of the ETV and the ICP-MS are studied and optimized. The methods optimized (extraction, electrothermal vaporization) are validated in the case of 99 Tc, in real samples. The spike method is required to quantify technetium, the quantification with calibration leading to bad results. The results obtained are in good agreement with the expected values. Extraction of technetium on anionic resin and its measurement by the spike method with pneumatic nebulization-ICP-MS is also performed on other samples. Measured values are also in agreement with expected values, but the method of extraction is more time consuming (half a day) than the extraction with crown ether (one hour). (author). 54 figs

  2. Determination of Mercury in Aerosol by Inductively Coupled Plasma Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Hofer Iris

    2017-12-01

    Full Text Available Based on the knowledge gained from published studies, a new analytical method has been developed for the quantification of mercury (Hg in the gas-vapor phase of mainstream cigarette smoke and in heated tobacco aerosol generated by a tobacco heating system (THS using Inductively Coupled Plasma Mass Spectrometry (ICP-MS. From a preliminary test, the mercury concentration in the particulate matter of mainstream smoke from Kentucky reference cigarettes 3R4F generated under the International Organization for Standardization (ISO smoking regimen was compared with the mercury concentration in the gasvapor phase to assure that mercury is only measurable in the gas-vapor phase, as reported in an earlier published study. The particulate matter was collected using an electrostatic precipitation trap and was analyzed by ICP-MS after a mineralization step. The gas-vapor phase was trapped in the same smoking run as for the particulate matter using two impingers containing a nitric acid-hydrochloric acid-gold solution. The impingers were connected in series behind the electrostatic precipitation trap and the combined impinger solution was analyzed by ICP-MS after sample dilution without further sample treatment. The addition of gold has shown to be efficient for maintaining mercury in an ionized form in the impinger solution and to minimize the mercury memory effect in the sample introduction system of the ICP-MS. Only mercury in the gas-vapor phase could be quantified whereas the signal for mercury in the particulate matter was found close to those of blank solutions and was not measurable, as already mentioned in an earlier study. Following this preliminary test, the electrostatic precipitation trap was replaced by a Cambridge filter pad for the separation of the gas-vapor phase from the particulate matter where only mercury in the gas-vapor phase was quantified.

  3. The influence of gas pressure on E↔H mode transition in argon inductively coupled plasmas

    Science.gov (United States)

    Zhang, Xiao; Zhang, Zhong-kai; Cao, Jin-xiang; Liu, Yu; Yu, Peng-cheng

    2018-03-01

    Considering the gas pressure and radio frequency power change, the mode transition of E↔H were investigated in inductively coupled plasmas. It can be found that the transition power has almost the same trend decreasing with gas pressure, whether it is in H mode or E mode. However, the transition density increases slowly with gas pressure from E to H mode. The transition points of E to H mode can be understood by the propagation of electromagnetic wave in the plasma, while the H to E should be illustrated by the electric field strength. Moreover, the electron density, increasing with the pressure and power, can be attributed to the multiple ionization, which changes the energy loss per electron-ion pair created. In addition, the optical emission characteristics in E and H mode is also shown. The line ratio of I750.4 and I811.5, taken as a proxy of the density of metastable state atoms, was used to illustrate the hysteresis. The 750.4 nm line intensity, which has almost the same trend with the 811.5 nm line intensity in H mode, both of them increases with power but decreases with gas pressure. The line ratio of 811.5/750.4 has a different change rule in E mode and H mode, and at the transition point of H to E, it can be one significant factor that results in the hysteresis as the gas pressure change. And compared with the 811.5 nm intensity, it seems like a similar change rule with RF power in E mode. Moreover, some emitted lines with lower rate constants don't turn up in E mode, while can be seen in H mode because the excited state atom density increasing with the electron density.

  4. Characteristics of an ion funnel as ion guide in an inductively coupled plasma mass spectrometer

    International Nuclear Information System (INIS)

    Egorova, Tatiana; Dietiker, Rolf; Hattendorf, Bodo; Günther, Detlef

    2012-01-01

    The characteristics of an electrodynamic ion funnel as an alternative ion optics element for inductively coupled plasma mass spectrometry (ICPMS) were investigated in this work. Therefore the ion lens of a conventional ICPMS system has been removed and a custom made ion funnel was installed instead. The effects of the radiofrequency-amplitude and frequency and the axial funnel potential on the ion transmission have been investigated for different configurations. Under optimum conditions the ion current was in average 10-fold lower than with the un-modified instrument, while CeO + /Ce + ratios increased ten-fold. Nonetheless, confinement of atomic ions from the ICP inside the ion funnel could be achieved by optimizing radiofrequency and DC potentials at the funnel electrodes as indicated by an increase in the ion signal intensities relative to the field-free case. With the ion funnel being partially enclosed, gases, such as N 2 and H 2 , could be introduced which can reduce the abundance of Ar + and Ar-based polyatomic ions by one (H 2 ) to three (N 2 ) orders of magnitude. Based on these experiments, however H 2 would be more favorable since it did not affect the transmission of low m/z analyte ions to a great extent. - Highlights: ► An electrodynamic ion funnel was inserted in the vacuum interface of an ICPMS. ► Ion transmission was investigated in dependence on operating parameters. ► The influence on mass resolving power was studied. ► Atomic ions with low mass (< 100 m/z) can be guided by the funnel.

  5. Copper Determination in Gunshot Residue by Cyclic Voltammetric and Inductive Coupled Plasma-Optical Emission Spectroscopy

    Directory of Open Access Journals (Sweden)

    Mohd Hashim Nurul’Afiqah Hashimah

    2016-01-01

    Full Text Available Analysis of gunshot residue (GSR is a crucial evidences for a forensic analyst in the fastest way. GSR analysis insists a suitable method provides a relatively simple, rapid and precise information on the spot at the crime scene. Therefore, the analysis of Cu(II in GSR using cyclic voltammetry (CV on screen printed carbon electrode (SPCE is a better choice compared to previous alternative methods such as Inductive Coupled Plasma-Optical Emission Spectroscopy (ICP-OES those required a long time for analysis. SPCE is specially designed to handle with microvolumes of sample such as GSR sample. It gives advantages for identification of copper in GSR on-site preliminary test to prevent the sample loss on the process to be analyzed in the laboratory. SPCE was swabbed directly on the shooter’s arm immediately after firing and acetate buffer was dropped on SPCE before CV analysis. For ICP-OES analysis, cotton that had been soaked in 0.5 M nitric acid was swabbed on the shooter’s arm immediately after firing and kept in a tightly closed sampling tube. Gold coated SPCE that had been through nanoparticles modification exhibits excellent performance on voltammograms. The calibration was linear from 1 to 50 ppm of copper, the limit of detection for copper was 0.3 ppm and a relative standard deviation was 6.1 %. The method was successfully applied to the determination of copper in GSR. The Cu determination on SPCE was compared and validated by ICP-OES method with 94 % accuracy.

  6. Neutral gas temperatures measured within a high-density, inductively coupled plasma abatement device

    International Nuclear Information System (INIS)

    Tonnis, Eric J.; Graves, David B.

    2002-01-01

    The neutral temperature within a cylindrical, inductively coupled plasma source has been studied for rare gas and molecular plasmas using the technique of optical emission thermometry. By adding small quantities of N 2 to the gas feeds as an actinometer, the neutral temperature of the discharge can be estimated by simulation and fitting of the rotationally unresolved second positive band (C 3 Π u -B 3 Π g ). In this work, the neutral temperature was estimated using this technique for flowing discharges of argon, helium, neon, nitrogen, and oxygen as a function of pressure and power. It was found that the neutral temperature for all of the discharges studied increased roughly proportional to the logarithm of the pressure. An increase in neutral temperature was also observed with increases in power; however, the dependence did not follow a simple functional form. The rare gases exhibited temperatures significantly above room temperature under high power (1200 W) and high pressure (∼1 Torr) conditions with argon approaching 2000 K. Molecular discharges such as N 2 and O 2 exhibited significantly higher temperatures (approaching 2500 K) than the rare gases even though they are expected to have lower plasma densities at the same pressure and power. It is believed that Franck-Condon heating of the gases during electron impact dissociation, vibrational excitation/thermalization, and exothermic wall reactions may all play important roles in producing such elevated temperatures. Simple, zero-dimensional plasma modeling indicates that neutral temperature elevation will result in significant increases in discharge electron temperature and electron-impact reaction rate coefficients under the same operating conditions

  7. Surface properties of indium tin oxide treated by Cl2 inductively coupled plasma

    International Nuclear Information System (INIS)

    He, Kongduo; Yang, Xilu; Yan, Hang; Gong, Junyi; Zhong, Shaofeng; Ou, Qiongrong; Liang, Rongqing

    2014-01-01

    Graphical abstract: - Highlights: • The work function of chlorinated ITO increases initially by up to 1 eV. • The chlorinated ITO keeps an increment of work function of 0.3 eV after 100 days. • The WF decrease curves can be fitted with double exponential functions. • The desorption of unstable Cl in the surface leads to the rapid decrease of WF. • The core levels of In 3d5 and Sn 3d5 and O 1s shift toward higher binding energies. - Abstract: The effects of Cl 2 inductively coupled plasma (ICP) treatment on the time dependence of work function (WF) and surface properties of indium tin oxide (ITO) were investigated. Kelvin probe (KP) measurements show that the WF after Cl 2 ICP treatment is close to 5.9 eV. The WF decrease curve of Cl 2 plasma treated ITO is fitted with double exponential functions with an adjusted R-square of 0.99. The mechanism under the decrease process is discussed by X-ray photoelectron spectroscopy (XPS). The ITO WF decrease after Cl 2 ICP treatment performs much better than that after O 2 ICP treatment and the chlorinated ITO keeps a WF increment of 0.3 eV compared with that without plasma treatment after 100 days. Other properties of chlorinated ITO surface such as morphology and transmittance change slightly. The results are significant for the understanding of degradation of Cl 2 plasma treated ITO and the fabrication of organic semiconductor devices

  8. Computer simulations of an oxygen inductively coupled plasma used for plasma-assisted atomic layer deposition

    International Nuclear Information System (INIS)

    Tinck, S; Bogaerts, A

    2011-01-01

    In this paper, an O 2 inductively coupled plasma used for plasma enhanced atomic layer deposition of Al 2 O 3 thin films is investigated by means of modeling. This work intends to provide more information about basic plasma properties such as species densities and species fluxes to the substrate as a function of power and pressure, which might be hard to measure experimentally. For this purpose, a hybrid model developed by Kushner et al is applied to calculate the plasma characteristics in the reactor volume for different chamber pressures ranging from 1 to 10 mTorr and different coil powers ranging from 50 to 500 W. Density profiles of the various oxygen containing plasma species are reported as well as fluxes to the substrate under various operating conditions. Furthermore, different orientations of the substrate, which can be placed vertically or horizontally in the reactor, are taken into account. In addition, special attention is paid to the recombination process of atomic oxygen on the different reactor walls under the stated operating conditions. From this work it can be concluded that the plasma properties change significantly in different locations of the reactor. The plasma density near the cylindrical coil is high, while it is almost negligible in the neighborhood of the substrate. Ion and excited species fluxes to the substrate are found to be very low and negligible. Finally, the orientation of the substrate has a minor effect on the flux of O 2 , while it has a significant effect on the flux of O. In the horizontal configuration, the flux of atomic oxygen can be up to one order of magnitude lower than in the vertical configuration.

  9. Evaporation preconcentration of trace elements in rainwater for inductively coupled plasma emission spectrometry

    International Nuclear Information System (INIS)

    Nishikawa, Masataka; Ambe, Yoshinari; Mizoguchi, Tsuguo

    1985-01-01

    An evaporation preconcentration of rainwater sample was studied for the analysis of trace elements by inductively coupled plasma emission spectrometry (ICP-AES). The evaporation preconcentration procedure is favorable for multi-elements analysis by ICP-AES because most of the elements, except for mercury and other volatile ones, can be enriched simultaneously. A conventional type of rotary evaporator was reformed setting a newly designed sample vessel made of teflon inside the glass bottle which can be separated into two parts, and compared to the former type of evaporator having a vessel made of hard glass. From the experiments using twice distilled water it was found that small amount of B, Na, Mg, Si, and Ca dissolved out from the surface of the glass vessel giving some positive error. From the teflon vessel, however, no contamination of elements was detected. When removing the cotent from the vessel into a measuring cylinder, adhesion of tiny amount of concentrated sample water occurred on the surface of the vessel to cause an error in the calculation of the enrichment factor. It was found that the volume of the adhered solution on the surface of a glass flask was nearly constant (0.5 ml) independently of the volume of the solution under this conditions, and using this value the correction of the result was possible. Such an adhesion, on the other hand, was not observed for the case of teflon vessel within the accuracy of our experiments. In conculusion, although the improved rotary evaporator with a teflon vessel is not more time-saving than a conventional glass evaporator, it is more advantageous in the following items; (1) No dissolution of element from the surface of the cocentration vessel; (2) High efficiency in preconcentration of rain samples (1000 ml to 1 ml); (3) No backward flow of condensed water on the glass part of the evaporator into the teflon vessel. (author)

  10. Directed induction of functional motor neuron-like cells from genetically engineered human mesenchymal stem cells.

    Directory of Open Access Journals (Sweden)

    Hwan-Woo Park

    Full Text Available Cell replacement using stem cells is a promising therapeutic approach to treat degenerative motor neuron (MN disorders, such as amyotrophic lateral sclerosis and spinal cord injury. Human bone marrow-derived mesenchymal stem cells (hMSCs are a desirable cell source for autologous cell replacement therapy to treat nervous system injury due to their plasticity, low immunogenicity, and a lower risk of tumor formation than embryonic stem cells. However, hMSCs are inefficient with regards to differentiating into MN-like cells. To solve this limitation, we genetically engineered hMSCs to express MN-associated transcription factors, Olig2 and Hb9, and then treat the hMSCs expressing Olig2 and Hb9 with optimal MN induction medium (MNIM. This method of induction led to higher expression (>30% of total cells of MN markers. Electrophysiological data revealed that the induced hMSCs had the excitable properties of neurons and were able to form functional connections with muscle fibers in vitro. Furthermore, when the induced hMSCs were transplanted into an injured organotypic rat spinal cord slice culture, an ex vivo model of spinal cord injury, they exhibited characteristics of MNs. The data strongly suggest that induced Olig2/Hb9-expressing hMSCs were clearly reprogrammed and directed toward a MN-like lineage. We propose that methods to induce Olig2 and Hb9, followed by further induction with MNIM have therapeutic potential for autologous cell replacement therapy to treat degenerative MN disorders.

  11. Inductively coupled plasma mass spectrometer installation modifications in a radioactive contaminated laboratory for the analysis of DOE radioactive waste streams

    International Nuclear Information System (INIS)

    Giaquinto, J.M.; Keller, J.M.; Meeks, A.M.

    1997-04-01

    The operation and maintenance of a complex analytical instrument such as an inductively coupled plasma mass spectrometer in a radioactive contaminated environment presents unique problems and challenges that have to be considered in the purchasing and installation process. Considerations such as vendor experience, typical radiation levels, sample matrices encountered during sample analysis, instrument accessibility for maintenance, and upkeep must be incorporated into the decision process. The Radioactive Materials Analytical Laboratory (RMAL) at Oak Ridge National Laboratory (ORNL) recently purchased and installed an inductively coupled plasma mass spectrometer for the analysis of Department of Energy (DOE) radioactive waste streams. This presentation will outline the purchasing decision, installation of the instrument, and how the modifications needed to operate in a radioactive contaminated laboratory do not significantly impact the daily operation and maintenance requirements of the instrument. Also, a contamination survey of the system will be presented which demonstrates the contamination levels in the instrument from the sample introduction system to the detector

  12. Inductively coupled plasma mass spectrometer installation modifications in a radioactive contaminated laboratory for the analysis of DOE radioactive waste streams

    International Nuclear Information System (INIS)

    Giaquinto, J.M.; Keller, J.M.; Meeks, A.M.

    1998-01-01

    The operation and maintenance of a complex analytical instrument such as an inductively coupled plasma mass spectrometer in a radioactive contaminated environment presents unique problems and challenges that have to be considered in the purchasing and installation process. Considerations such as vendor experience, typical radiation levels, sample matrices encountered during sample analysis, instrument accessibility for maintenance, and upkeep must be incorporated into the decision process. The Radioactive Materials Analytical Laboratory (RMAL) at Oak Ridge National Laboratory (ORNL) recently purchased and installed an inductively coupled plasma mass spectrometer for the analysis of Department of Energy (DOE) radioactive waste streams. This presentation will outline the purchasing decision, installation of the instrument, and how the modifications needed to operate in a radioactive contaminated laboratory do not significantly impact the daily operation and maintenance requirements of the instrument. Also, a contamination survey of the system will be presented which demonstrates the contamination levels in the instrument from the sample introduction system to the detector. (author)

  13. Preparation of thin Si:H films in an inductively coupled plasma reactor and analysis of their surface roughness

    International Nuclear Information System (INIS)

    Zhao Wenfeng; Chen Junfang; Meng Ran; Wang Yang; Wang Hui; Guo Chaofeng; Xue Yongqi

    2010-01-01

    An important concern in the deposition of Si:H films is to obtain smooth surfaces. Herein, we deposit the thin Si:H films using Ar-diluted SiH 4 as feedstock gas in an inductively coupled plasma reactor. And we carry a real-time monitor on the deposition process by using optical emission spectrum technology in the vicinity of substrate and diagnose the Ar plasma radial distribution by Langmuir probe. Surface detecting by AFM and surface profilometry in large scale shows that the thin Si:H films have small surface roughness. Distributions of both the ion density and the electron temperature are homogeneous at h = 0.5 cm. Based on these experimental results, it can be proposed inductively coupled plasma reactor is fit to deposit the thin film in large scale. Also, Ar can affect the reaction process and improve the thin Si:H films characteristics.

  14. Matrix separation by chelation to prepare biological materials for isotopic zinc analysis by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Durrant, S.F.; Krushevska, A.; Amarasiriwardena, D.; Argentine, M.D.; Romon-Guesnier, S.; Barnes, R.M.

    1994-01-01

    Following an evaluation of three chelating resins [Chelex-100, poly(dithiocarbamate) (PDTC) and carboxymethylated poly(ethyleneimine)-poly(methylenepolyphenylene) isocyanate (CPPI)], a procedure was established with the last of these for the separation of Zn from biological matrix elements prior to 70 Zn: 68 Zn isotopic analysis by inductively coupled plasma mass spectrometry (ICP-MS). The method was verified by establishing Zn recoveries and by determining its effectiveness in removing Cl and Na from buffered test solutions. Calcium, Na, and Zn concentration data were determined by inductively coupled plasma atomic emission spectrometry. Chlorine was measured by electrothermal vaporization ICP-MS. The efficacy of the technique was demonstrated by the determination of zinc isotope ratios in bovine milk and human urine. (Author)

  15. Elemental analysis using instrumental neutron activation analysis and inductively coupled plasma atomic emission spectrometry: a comparative study

    International Nuclear Information System (INIS)

    Chung, Yong Sam; Choi, Kwang Soon; Moon, Jong Hwa; Kim, Sun Ha; Lim, Jong Myoung; Kim, Young Jin; Quraishi, Shamshad Begum

    2003-05-01

    Elemental analyses for certified reference materials were carried out using instrumental neutron activation analysis and inductively coupled plasma-atomic emission spectrometry. Five Certified Reference Materials (CRM) were selected for the study on comparative analysis of environmental samples. The CRM are Soil (NIST SRM 2709), Coal fly ash (NIST SRM 1633a), urban dust (NIST SRM 1649a) and air particulate on filter media (NIST SRM 2783 and human hair (GBW 09101)

  16. GaAs/AlGaAs ridge lasers with etched mirrors formed by an inductively coupled plasma reactor

    Science.gov (United States)

    Horst, S. C.; Agarwala, S.; King, O.; Fitz, J. L.; Smith, S. D.

    1997-09-01

    Etched mirrors for semiconductor lasers are necessary for optoelectronic integrated circuit applications. This letter reports on the use of an inductively coupled plasma (ICP) reactor to create etched mirrors on GaAs/AlGaAs ridge lasers. Etch chemistries consisting of boron trichloride and chlorine were used to achieve both smooth and vertical mirror surfaces. Optical measurements indicate that devices fabricated with ICP etched mirrors are comparable to devices formed by cleaved mirrors.

  17. T-potential based model of induction heating of thin conductive plates in hard-coupled formulation

    Czech Academy of Sciences Publication Activity Database

    Doležel, Ivo; Ulrych, B.; Kropík, P.

    2011-01-01

    Roč. 87, č. 3 (2011), s. 41-44 ISSN 0033-2097 R&D Projects: GA ČR GA102/09/1305 Institutional research plan: CEZ:AV0Z20570509 Keywords : induction heating * T-potential * hard-coupled formulation Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.244, year: 2011 http://pe.org.pl/

  18. Determination of trace and ultra-trace elements in Dergaon meteorite by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Balaram, V.; Gnaneswara Rao, T.; Anjaiah, K.V.; Phukon, N.; Majumdar, A.C.

    2003-01-01

    In this paper, a detailed methodology for high precision measurement of several trace and ultra-trace elements including REE and PGE have been presented using effective sample preparation techniques and inductively coupled plasma mass spectrometry. Discussion is focussed on aspects, such as total dissolution and recovery of all elements, minimization of oxide and doubly-charged and other polyatomic ion interferences, calibration by matrix matching standards, accuracy and precision

  19. The influence of laser-particle interaction in laser induced breakdown spectroscopy and laser ablation inductively coupled plasma spectrometry

    Science.gov (United States)

    Lindner, Helmut; Loper, Kristofer H.; Hahn, David W.; Niemax, Kay

    2011-02-01

    Particles produced by previous laser shots may have significant influence on the analytical signal in laser-induced breakdown spectroscopy (LIBS) and laser ablation inductively coupled plasma (LA-ICP) spectrometry if they remain close to the position of laser sampling. The effects of these particles on the laser-induced breakdown event are demonstrated in several ways. LIBS-experiments were conducted in an ablation cell at atmospheric conditions in argon or air applying a dual-pulse arrangement with orthogonal pre-pulse, i.e., plasma breakdown in a gas generated by a focussed laser beam parallel and close to the sample surface followed by a delayed crossing laser pulse in orthogonal direction which actually ablates material from the sample and produces the LIBS plasma. The optical emission of the LIBS plasma as well as the absorption of the pre-pulse laser was measured. In the presence of particles in the focus of the pre-pulse laser, the plasma breakdown is affected and more energy of the pre-pulse laser is absorbed than without particles. As a result, the analyte line emission from the LIBS plasma of the second laser is enhanced. It is assumed that the enhancement is not only due to an increase of mass ablated by the second laser but also to better atomization and excitation conditions favored by a reduced gas density in the pre-pulse plasma. Higher laser pulse frequencies increase the probability of particle-laser interaction and, therefore, reduce the shot-to-shot line intensity variation as compared to lower particle loadings in the cell. Additional experiments using an aerosol chamber were performed to further quantify the laser absorption by the plasma in dependence on time both with and without the presence of particles. The overall implication of laser-particle interactions for LIBS and LA-ICP-MS/OES are discussed.

  20. Formation Of Carbon Oxides In CH4/O2 Plasmas Produced By Inductively Coupled RF Discharges At Low Pressure

    International Nuclear Information System (INIS)

    Moeller, Ivonne; Soltwisch, Henning

    2003-01-01

    The formation of CO and CO2 has been studied in inductively coupled rf (13.56 MHz) discharges with varied mixtures of CH4 and O2 as feed gases at a total pressure of 10 Pa, flow rates of <10 sccm, and input powers of <500 W. The primary diagnostic tool has been TDLAS (tunable diode laser absorption spectroscopy) to measure absolute concentrations of molecular species as well as their kinetic and rovibrational temperatures. Of particular interest is the sudden transition between different modes of power coupling (capacitive and inductive mode, resp.) and the related changes of the plasma composition. We have found that the power threshold for this transition exhibits a clear hysteresis and depends on the oxygen content. Comparing the ratio of the CO- and CO2-concentrations in capacitive mode with corresponding data from a parallel-plate discharge, clear differences have been observed. The findings can partly be explained on the basis of plasma-chemical reaction chains using tabulated cross-sections in combination with estimations of the electron energy distribution function. Some observations (as, e.g. the presence of CO in inductively coupled plasmas that are fed by pure oxygen) cannot be understood from volume reactions only but point to an important role of surface processes, which depend on the materials of the discharge chamber and on its history and cleaning method

  1. Increasing the magnetic-field capability of the magneto-inertial fusion electrical discharge system using an inductively coupled coil

    Science.gov (United States)

    Barnak, D. H.; Davies, J. R.; Fiksel, G.; Chang, P.-Y.; Zabir, E.; Betti, R.

    2018-03-01

    Magnetized high energy density physics (HEDP) is a very active and relatively unexplored field that has applications in inertial confinement fusion, astrophysical plasma science, and basic plasma physics. A self-contained device, the Magneto-Inertial Fusion Electrical Discharge System, MIFEDS [G. Fiksel et al., Rev. Sci. Instrum. 86, 016105 (2015)], was developed at the Laboratory for Laser Energetics to conduct magnetized HEDP experiments on both the OMEGA [T. R. Boehly et al., Opt. Commun. 133, 495-506 (1997)] and OMEGA EP [J. H. Kelly et al., J. Phys. IV France 133, 75 (2006) and L. J. Waxer et al., Opt. Photonics News 16, 30 (2005)] laser systems. Extremely high magnetic fields are a necessity for magnetized HEDP, and the need for stronger magnetic fields continues to drive the redevelopment of the MIFEDS device. It is proposed in this paper that a magnetic coil that is inductively coupled rather than directly connecting to the MIFEDS device can increase the overall strength of the magnetic field for HEDP experiments by increasing the efficiency of energy transfer while decreasing the effective magnetized volume. A brief explanation of the energy delivery of the MIFEDS device illustrates the benefit of inductive coupling and is compared to that of direct connection for varying coil size and geometry. A prototype was then constructed to demonstrate a 7-fold increase in energy delivery using inductive coupling.

  2. Induction of Programmed Cell Death in Human Alveolar Epithelial Cells Infected with Influenza Virus

    Directory of Open Access Journals (Sweden)

    Sh Shahsavandi

    2015-11-01

    Full Text Available Introduction: Avian influenza viruses are considered as a serious threat to human and animal health. An increase in expression of proinflammatory cytokines and type I IFN genes, as well as host cell death responses contribute to the pathogenesis of influenza infection. Hence, this study aimed to evaluate the growth dynamics of subacute avian influenza virus in human respiratory alveolar epithelium cells (A549. Methods: The A549 cell cultures were infected at MOIs 0.1 and 2.0 viral doses in the presence and absence of trypsin. The virus growth kinetics were elucidated by the plaque assay and the cell viability was determined by MTT at various times after the infection. The induction quality of programmed cell death as well as the signal transduction pathway of death were assessed by genomic DNA fragmentation and western blotting respectively. Results: The study findings indicated that although the H9N2 virus replication did produce a marked cytopathic effect on the alveolar cells, which led to a reduction in the cell viability, the viral titers were increased in the infected cells. The virus replication of in these cells indicated repression of host defense mechanism as well as activation of cell death. The induction of apoptosis in A549 cells was correlated with the increased virus titers as well as virus replication (p< 0.05. Conclusion: H9N2 avian influenza virus were demonstrated to induce apoptosis in human alveolar epithelial cells via the intrinsic pathway in a dose-dependent manner.

  3. Growth factor combination for chondrogenic induction from human mesenchymal stem cell

    International Nuclear Information System (INIS)

    Indrawattana, Nitaya; Chen Guoping; Tadokoro, Mika; Shann, Linzi H.; Ohgushi, Hajime; Tateishi, Tetsuya; Tanaka, Junzo; Bunyaratvej, Ahnond

    2004-01-01

    During the last decade, many strategies for cartilage engineering have been emerging. Stem cell induction is one of the possible approaches for cartilage engineering. The mesenchymal stem cells (MSCs) with their pluripotency and availability have been demonstrated to be an attractive cell source. It needs the stimulation with cell growth factors to make the multipluripotent MSCs differentiate into chondrogenic lineage. We have shown particular patterns of in vitro chondrogenesis induction on human bone marrow MSCs (hBMSCs) by cycling the growth factors. The pellet cultures of hBMSCs were prepared for chondrogenic induction. Growth factors: TGF-β3, BMP-6, and IGF-1 were used in combination for cell induction. Gene expression, histology, immunohistology, and real-time PCR methods were measured on days 21 after cell induction. As shown by histology and immunohistology, the induced cells have shown the feature of chondrocytes in their morphology and extracellular matrix in both inducing patterns of combination and cycling induction. Moreover, the real-time PCR assay has shown the expression of gene markers of chondrogenesis, collagen type II and aggrecan. This study has demonstrated that cartilage tissue can be created from bone marrow mesenchymal stem cells. Interestingly, the combined growth factors TGF-β3 and BMP-6 or TGF-β3 and IGF-1 were more effective for chondrogenesis induction as shown by the real-time PCR assay. The combination of these growth factors may be the important key for in vitro chondrogenesis induction

  4. Inhibiting HSP90 prevents the induction of myeloid-derived suppressor cells by melanoma cells.

    Science.gov (United States)

    Janssen, Nicole; Speigl, Lisa; Pawelec, Graham; Niessner, Heike; Shipp, Christopher

    2018-02-21

    Metastatic melanoma is the most dangerous form of skin cancer, with an ever-increasing incidence worldwide. Despite encouraging results with immunotherapeutic approaches, long-term survival is still poor. This is likely partly due to tumour-induced immune suppression mediated by myeloid-derived suppressor cells (MDSCs), which were shown to be associated with response to therapy and survival. Thus, identifying pathways responsible for MDSC differentiation may provide new therapeutic targets and improve efficacy of existing immunotherapies. Therefore, we've analysed mechanisms by which tumour cells contribute to the induction of MDSCs. Established melanoma cell lines were pre-treated with inhibitors of different pathways and tested for their capacity to alleviate T cell suppression via MDSC differentiation in vitro. Targeting HSP70/90 in melanoma cells resulted in reduced induction of immune suppressive cells on a phenotypic and functional basis, for which a more potent effect was observed when HSP90 was inhibited under hypoxic conditions. This initial study suggests a novel mechanism in tumour cells responsible for the induction of MDSC in melanoma. Copyright © 2018. Published by Elsevier Inc.

  5. Effect of caffeine on the ultraviolet light induction of SV40 virus from transformed hamster cells

    International Nuclear Information System (INIS)

    Zamansky, G.B.; Kleinman, L.F.; Little, J.B.; Black, P.H.; Kaplan, J.C.

    1976-01-01

    The effect of caffeine on the uv light induction of SV40 virus from two transformed hamster cell lines heterogeneous for the induction of infectious virus was studied. The amount of virus induced was significantly increased in both cell lines when exposure to uv light was followed by treatment with caffeine. Caffeine in the absence of uv irradiation did not stimulate virus induction, nor did it stimulate SV40 replication in a lytic infection. There was an apparent difference in the concentrations of caffeine which maximally stimulated SV40 virus induction in the two cell lines. This effect could not be explained by differences in cell survival after exposure to uv light and caffeine. Since caffeine is known to cause the accumulation of gaps formed in DNA during postreplication repair of uv-irradiated rodent cells, our results support the hypothesis that the formation of gaps or breaks in DNA is an important early step in virus induction

  6. Inductive couple plasma reactive ion etching characteristics of TiO{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Garay, Adrian Adalberto; Hwang, Su Min; Chung, Chee Won, E-mail: cwchung@inha.ac.kr

    2015-07-31

    Changes in the inductively coupled plasma reactive ion etching characteristics of TiO{sub 2} thin films in response to the addition of HBr, Cl{sub 2} and C{sub 2}F{sub 6} to Ar gas were investigated. As the HBr, Cl{sub 2} and C{sub 2}F{sub 6} concentration increased, the etch rate increased; however, the etch profile degree of anisotropy followed a different trend. As HBr concentration increased, the greatest anisotropic etch profile was obtained at 100% HBr, while the greatest anisotropic etch profile was obtained at concentrations of 25% when etching was conducted under C{sub 2}F{sub 6} and Cl{sub 2}. Field emission scanning electron microscopy revealed that 25% C{sub 2}F{sub 6} generated the greatest vertical etch profile; hence, etch parameters were varied at this concentration. The effects of rf power, dc-bias voltage and gas pressure on the etch rate and etch profile were also investigated. The etch rate and degree of anisotropy in the etch profile increased with increasing rf power and dc-bias voltage and decreasing gas pressure. X-ray photoelectron spectroscopy analysis of the films etched under a C{sub 2}F{sub 6}/Ar gas mixture revealed the existence of etch byproducts containing F (i.e. TiF{sub x}) over the film. C{sub x}F{sub y} compounds were not detected on the film surface, probably due to contamination with atmospheric carbon. - Highlights: • Reactive ion etching of TiO{sub 2} films under HBr, C{sub 2}F{sub 6}, and Cl{sub 2} gases was studied. • Etch rate and etch profile of TiO{sub 2} films were investigated under each gas chemistry. • The highest degree of anisotropy was achieved at 25% C{sub 2}F{sub 6}/Ar. • Strong etch conditions at 25% C{sub 2}F{sub 6}/Ar increased etch rate and degree of anisotropy. • X-ray photoelectron spectroscopy revealed the existence of F-containing etch residues.

  7. Laser ablation inductively coupled plasma optical emission spectrometry for analysis of pellets of plant materials

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Marcos S. [Departamento de Química, Universidade Federal de São Carlos, Rod. Washington Luís, km 235, 13565-905 São Carlos, SP (Brazil); Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, 13416-000 Piracicaba, SP (Brazil); Schenk, Emily R. [Department of Chemistry and Biochemistry, Florida International University, Miami, FL (United States); International Forensic Research Institute, Florida International University, Miami, FL (United States); Santos, Dário [Departamento de Ciências Exatas e da Terra, Universidade Federal de São Paulo, Rua Professor Arthur Riedel 275, Diadema, SP (Brazil); Krug, Francisco José [Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, 13416-000 Piracicaba, SP (Brazil); Almirall, José R., E-mail: almirall@fiu.edu [Department of Chemistry and Biochemistry, Florida International University, Miami, FL (United States); International Forensic Research Institute, Florida International University, Miami, FL (United States)

    2014-04-01

    An evaluation of laser ablation inductively coupled plasma optical emission spectroscopy (LAICP OES) for the direct analysis of pelleted plant material is reported. Ground leaves of orange citrus, soy and sugarcane were comminuted using a high-speed ball mill, pressed into pellets and sampled directly with laser ablation and analyzed by ICP OES. The limits of detection (LODs) for the method ranged from as low as 0.1 mg kg{sup −1} for Zn to as high as 94 mg kg{sup −1} for K but were generally below 6 mg kg{sup −1} for most of the elements of interest. A certified reference material consisting of a similar matrix (NIST SRM 1547 peach leaves) was used to check the accuracy of the calibration and the reported method resulted in an average bias of ∼ 5% for all the elements of interest. The precision for the reported method ranged from as low as 4% relative standard deviation (RSD) for Mn to as high as 17% RSD for Zn but averaged ∼ 6.5% RSD for all the elements (n = 10). The proposed method was tested for the determination of Ca, Mg, P, K, Fe, Mn, Zn and B, and the results were in good agreement with those obtained for the corresponding acid digests by ICP-OES, no differences being observed by applying a paired t-test at the 95% confidence level. The reported direct solid sampling method provides a fast alternative to acid digestion that results in similar and appropriate analytical figures of merit with regard to sensitivity, accuracy and precision for plant material analysis. - Highlights: • An evaluation of LA-ICP-OES for the direct analysis of pelleted plant material is reported. • Orange citrus, soy and sugarcane plants were pressed into pellets and sampled directly. • The element menu consisted of Ca, Mg, P, K, Fe, Mn, Zn and B. • LODs for the method ranged from 0.1 mg kg{sup −1} for Zn to 94 mg kg{sup −1} for K. • The precision ranged from 4% RSD for Mn to 17% RSD for Zn (∼ 6.5% RSD average)

  8. Self-consistent multidimensional electron kinetic model for inductively coupled plasma sources

    Science.gov (United States)

    Dai, Fa Foster

    Inductively coupled plasma (ICP) sources have received increasing interest in microelectronics fabrication and lighting industry. In 2-D configuration space (r, z) and 2-D velocity domain (νθ,νz), a self- consistent electron kinetic analytic model is developed for various ICP sources. The electromagnetic (EM) model is established based on modal analysis, while the kinetic analysis gives the perturbed Maxwellian distribution of electrons by solving Boltzmann-Vlasov equation. The self- consistent algorithm combines the EM model and the kinetic analysis by updating their results consistently until the solution converges. The closed-form solutions in the analytical model provide rigorous and fast computing for the EM fields and the electron kinetic behavior. The kinetic analysis shows that the RF energy in an ICP source is extracted by a collisionless dissipation mechanism, if the electron thermovelocity is close to the RF phase velocities. A criterion for collisionless damping is thus given based on the analytic solutions. To achieve uniformly distributed plasma for plasma processing, we propose a novel discharge structure with both planar and vertical coil excitations. The theoretical results demonstrate improved uniformity for the excited azimuthal E-field in the chamber. Non-monotonic spatial decay in electric field and space current distributions was recently observed in weakly- collisional plasmas. The anomalous skin effect is found to be responsible for this phenomenon. The proposed model successfully models the non-monotonic spatial decay effect and achieves good agreements with the measurements for different applied RF powers. The proposed analytical model is compared with other theoretical models and different experimental measurements. The developed model is also applied to two kinds of ICP discharges used for electrodeless light sources. One structure uses a vertical internal coil antenna to excite plasmas and another has a metal shield to prevent the

  9. 99Tc bioassay by inductively coupled plasma mass spectrometry (ICP-MS)

    International Nuclear Information System (INIS)

    Lewis, L.A.

    1998-05-01

    A means of analyzing 99 Tc in urine by inductively coupled plasma mass spectrometry (ICP-MS) has been developed. Historically, 99 Tc analysis was based on the radiometric detection of the 293 keV E Max beta decay product by liquid scintillation or gas flow proportional counting. In a urine matrix, the analysis of 99 Tc is plagued with many difficulties using conventional radiometric methods. Difficulties originate during chemical separation due to the volatile nature of Tc 2 O 7 or during radiation detection due to color or chemical quenching. A separation scheme for 99 Tc detection by ICP-MS is given and is proven to be a sensitive and robust analytical alternative. A comparison of methods using radiometric and mass quantitation of 99 Tc has been conducted in water, artificial urine, and real urine matrices at activity levels between 700 and 2,200 dpm/L. Liquid scintillation results based on an external standard quench correction and a quench curve correction method are compared to results obtained by ICP-MS. Each method produced accurate results, however the precision of the ICP-MS results is superior to that of liquid scintillation results. Limits of detection (LOD) for ICP-MS and liquid scintillation detection are 14.67 and 203.4 dpm/L, respectively, in a real urine matrix. In order to determine the basis for the increased precision of the ICP-MS results, the detection sensitivity for each method is derived and measured. The detection sensitivity for the 99 Tc isotope by ICP-MS is 2.175 x 10 -7 ± 8.990 x 10 -9 and by liquid scintillation is 7.434 x 10 -14 ± 7.461 x 10 -15 . A difference by seven orders of magnitude between the two detection systems allows ICP-MS samples to be analyzed for a period of 15 s compared to 3,600 s by liquid scintillation counting with a lower LOD

  10. Inductive heating kills cells that contribute to plaque: a proof-of-concept

    Directory of Open Access Journals (Sweden)

    Angelo Gaitas

    2015-04-01

    Full Text Available Inducing cell death by heating targeted particles shows promise in cancer treatment. Here, we aim to demonstrate the feasibility of extending the use of this technique to treat and remove vascular deposits and thrombosis. We used induction heating of macrophages, which are key contributors to atherosclerosis and have demonstrated clear feasibility for heating and destroying these cells using ferromagnetic and pure iron particles. Specifically, iron particles achieved maximum temperatures of 51 ± 0.5 °C and spherical particles achieved a maximum temperature of 43.9 ± 0.2 °C (N = 6 after 30 min of inductive heating. Two days of subsequent observation demonstrated that inductive heating led to a significant reduction in cell number. Prior to induction heating, cell density was 105,000 ± 20,820 cells/ml (N = 3. This number was reduced to 6,666 ± 4,410 cells/ml for the spherical particles and 16,666 ± 9,280 cells/ml for the iron particles 24 h after inductive heating. Though cell density increased on the second day following inductive heating, the growth was minimal. Cells grew to 26,667 ± 6,670 cells/ml and 30,000 ± 15,280 cells/ml respectively. Compared to cell cultures with iron and spherical particles that were not subjected to induction heating, we observed a 97% reduction in cell count for the spherical particles and a 91% reduction for the iron particles after the first 24 h. After 48 h we observed a 95% reduction in cell growth for both spherical and iron particles. Induction heating of microparticles was thus highly effective in reducing the macrophage population and preventing their growth. These results demonstrate the feasibility of targeting cells involved in atherosclerosis and warrant further research into potential clinical applications.

  11. Assessment of high precision, high accuracy Inductively Coupled Plasma-Optical Emission Spectroscopy to obtain concentration uncertainties less than 0.2% with variable matrix concentrations

    International Nuclear Information System (INIS)

    Rabb, Savelas A.; Olesik, John W.

    2008-01-01

    The ability to obtain high precision, high accuracy measurements in samples with complex matrices using High Performance Inductively Coupled Plasma-Optical Emission Spectroscopy (HP-ICP-OES) was investigated. The Common Analyte Internal Standard (CAIS) procedure was incorporated into the High Performance Inductively Coupled Plasma-Optical Emission Spectroscopy method to correct for matrix-induced changes in emission intensity ratios. Matrix matching and standard addition approaches to minimize matrix-induced errors when using High Performance Inductively Coupled Plasma-Optical Emission Spectroscopy were also assessed. The High Performance Inductively Coupled Plasma-Optical Emission Spectroscopy method was tested with synthetic solutions in a variety of matrices, alloy standard reference materials and geological reference materials

  12. Exploiting flow injection and sequential injection for trace metal determinations in conjunction with detection by electrothermal atomic absorption spectrometry and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    Despite their excellent analytical chemical capacities, Electrothermal Atomic Absorption Spectrometry (ETAAS) and Inductively Coupled Plasma Mass Spectrometry (ICPMS), nevertheless, often require suitable pretreatment of the sample material in order to obtain the necessary sensitivity...

  13. An inductively-coupled 64b organic RFID tag operating at 13.56MHz with a data rate of 787b/s

    NARCIS (Netherlands)

    Myny, K.; Winckel, S. van; Steudel, S.; Vicca, P.; Jonge, S. de; Beenhakkers, M.J.; Sele, C.W.; Aerle, N.A.J.M. van; Gelinck, G.H.; Genoe, J.; Heremans, P.L.

    2008-01-01

    A 64b inductively coupled organic RFID tag on foil is demonstrated at 13.56MHz. The digital logic foil comprises 414 pentacene transistors and is powered by a pentacene double half-wave rectifier, connected to an inductive antenna. The data rate is 787b/s with load modulation behind the rectifier

  14. Notch1 modulates mesenchymal stem cells mediated regulatory T-cell induction.

    Science.gov (United States)

    Del Papa, Beatrice; Sportoletti, Paolo; Cecchini, Debora; Rosati, Emanuela; Balucani, Chiara; Baldoni, Stefano; Fettucciari, Katia; Marconi, Pierfrancesco; Martelli, Massimo F; Falzetti, Franca; Di Ianni, Mauro

    2013-01-01

    Notch1 signaling is involved in regulatory T (Treg)-cell differentiation. We previously demonstrated that, when cocultured with CD3(+) cells, mesenchymal stem cells (MSCs) induced a T-cell population with a regulatory phenotype. Here, we investigated the molecular mechanism underlying MSC induction of human Treg cells. We show that the Notch1 pathway is activated in CD4(+) T cells cocultured with MSCs. Inhibition of Notch1 signaling through GSI-I or the Notch1 neutralizing antibody reduced expression of HES1 (the Notch1 downstream target) and the percentage of MSC-induced CD4(+) CD25(high) FOXP3(+) cells in vitro. Moreover, we demonstrate that FOXP3 is a downstream target of Notch signaling in human cells. No crosstalk between Notch1 and TGF-β signaling pathways was observed in our experimental system. Together, these findings indicate that activation of the Notch1 pathway is a novel mechanism in the human Treg-cell induction mediated by MSCs. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Functionalized magnetic nanowires for chemical and magneto-mechanical induction of cancer cell death

    KAUST Repository

    Martinez Banderas, Aldo Isaac

    2016-10-24

    Exploiting and combining different properties of nanomaterials is considered a potential route for next generation cancer therapies. Magnetic nanowires (NWs) have shown good biocompatibility and a high level of cellular internalization. We induced cancer cell death by combining the chemotherapeutic effect of doxorubicin (DOX)-functionalized iron NWs with the mechanical disturbance under a low frequency alternating magnetic field. (3-aminopropyl)triethoxysilane (APTES) and bovine serum albumin (BSA) were separately used for coating NWs allowing further functionalization with DOX. Internalization was assessed for both formulations by confocal reflection microscopy and inductively coupled plasma-mass spectrometry. From confocal analysis, BSA formulations demonstrated higher internalization and less agglomeration. The functionalized NWs generated a comparable cytotoxic effect in breast cancer cells in a DOX concentration-dependent manner, (~60% at the highest concentration tested) that was significantly different from the effect produced by free DOX and non-functionalized NWs formulations. A synergistic cytotoxic effect is obtained when a magnetic field (1 mT, 10 Hz) is applied to cells treated with DOX-functionalized BSA or APTES-coated NWs, (~70% at the highest concentration). In summary, a bimodal method for cancer cell destruction was developed by the conjugation of the magneto-mechanical properties of iron NWs with the effect of DOX producing better results than the individual effects.

  16. Functionalized magnetic nanowires for chemical and magneto-mechanical induction of cancer cell death.

    Science.gov (United States)

    Martínez-Banderas, Aldo Isaac; Aires, Antonio; Teran, Francisco J; Perez, Jose Efrain; Cadenas, Jael F; Alsharif, Nouf; Ravasi, Timothy; Cortajarena, Aitziber L; Kosel, Jürgen

    2016-10-24

    Exploiting and combining different properties of nanomaterials is considered a potential route for next generation cancer therapies. Magnetic nanowires (NWs) have shown good biocompatibility and a high level of cellular internalization. We induced cancer cell death by combining the chemotherapeutic effect of doxorubicin (DOX)-functionalized iron NWs with the mechanical disturbance under a low frequency alternating magnetic field. (3-aminopropyl)triethoxysilane (APTES) and bovine serum albumin (BSA) were separately used for coating NWs allowing further functionalization with DOX. Internalization was assessed for both formulations by confocal reflection microscopy and inductively coupled plasma-mass spectrometry. From confocal analysis, BSA formulations demonstrated higher internalization and less agglomeration. The functionalized NWs generated a comparable cytotoxic effect in breast cancer cells in a DOX concentration-dependent manner, (~60% at the highest concentration tested) that was significantly different from the effect produced by free DOX and non-functionalized NWs formulations. A synergistic cytotoxic effect is obtained when a magnetic field (1 mT, 10 Hz) is applied to cells treated with DOX-functionalized BSA or APTES-coated NWs, (~70% at the highest concentration). In summary, a bimodal method for cancer cell destruction was developed by the conjugation of the magneto-mechanical properties of iron NWs with the effect of DOX producing better results than the individual effects.

  17. Electrical description of a magnetic pole enhanced inductively coupled plasma source: Refinement of the transformer model by reverse electromagnetic modeling

    International Nuclear Information System (INIS)

    Meziani, T.; Colpo, P.; Rossi, F.

    2006-01-01

    The magnetic pole enhanced inductively coupled source (MaPE-ICP) is an innovative low-pressure plasma source that allows for high plasma density and high plasma uniformity, as well as large-area plasma generation. This article presents an electrical characterization of this source, and the experimental measurements are compared to the results obtained after modeling the source by the equivalent circuit of the transformer. In particular, the method applied consists in performing a reverse electromagnetic modeling of the source by providing the measured plasma parameters such as plasma density and electron temperature as an input, and computing the total impedance seen at the primary of the transformer. The impedance results given by the model are compared to the experimental results. This approach allows for a more comprehensive refinement of the electrical model in order to obtain a better fitting of the results. The electrical characteristics of the system, and in particular the total impedance, were measured at the inductive coil antenna (primary of the transformer). The source was modeled electrically by a finite element method, treating the plasma as a conductive load and taking into account the complex plasma conductivity, the value of which was calculated from the electron density and electron temperature measurements carried out previously. The electrical characterization of the inductive excitation source itself versus frequency showed that the source cannot be treated as purely inductive and that the effect of parasitic capacitances must be taken into account in the model. Finally, considerations on the effect of the magnetic core addition on the capacitive component of the coupling are made

  18. Th17 Cell Induction by Adhesion of Microbes to Intestinal Epithelial Cells.

    Science.gov (United States)

    Atarashi, Koji; Tanoue, Takeshi; Ando, Minoru; Kamada, Nobuhiko; Nagano, Yuji; Narushima, Seiko; Suda, Wataru; Imaoka, Akemi; Setoyama, Hiromi; Nagamori, Takashi; Ishikawa, Eiji; Shima, Tatsuichiro; Hara, Taeko; Kado, Shoichi; Jinnohara, Toshi; Ohno, Hiroshi; Kondo, Takashi; Toyooka, Kiminori; Watanabe, Eiichiro; Yokoyama, Shin-Ichiro; Tokoro, Shunji; Mori, Hiroshi; Noguchi, Yurika; Morita, Hidetoshi; Ivanov, Ivaylo I; Sugiyama, Tsuyoshi; Nuñez, Gabriel; Camp, J Gray; Hattori, Masahira; Umesaki, Yoshinori; Honda, Kenya

    2015-10-08

    Intestinal Th17 cells are induced and accumulate in response to colonization with a subgroup of intestinal microbes such as segmented filamentous bacteria (SFB) and certain extracellular pathogens. Here, we show that adhesion of microbes to intestinal epithelial cells (ECs) is a critical cue for Th17 induction. Upon monocolonization of germ-free mice or rats with SFB indigenous to mice (M-SFB) or rats (R-SFB), M-SFB and R-SFB showed host-specific adhesion to small intestinal ECs, accompanied by host-specific induction of Th17 cells. Citrobacter rodentium and Escherichia coli O157 triggered similar Th17 responses, whereas adhesion-defective mutants of these microbes failed to do so. Moreover, a mixture of 20 bacterial strains, which were selected and isolated from fecal samples of a patient with ulcerative colitis on the basis of their ability to cause a robust induction of Th17 cells in the mouse colon, also exhibited EC-adhesive characteristics. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Determination of selenoprotein P in human plasma by solid phase extraction and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Bendahl, L.; Sidenius, U.; Gammelgaard, Bente

    2000-01-01

    A method based on solid phase extraction was developed for the determination of selenoprotein P as selenium in human plasma. Separation of selenoprotein P from other selenium-containing proteins was accomplished by immobilized metal-ion affinity chromatography. The selenium content was subsequently...... measured by inductively coupled plasma mass spectrometry (ICP-MS) monitoring the Se-82 isotope. Linear response was observed in the concentration range 0.3-70.8 mu g/l selenium as selenoprotein P with a correlation coefficient of 0.9994. The precision expressed as relative standard deviation was better...

  20. Inductively coupled plasma-atomic emission spectroscopy: a computer controlled, scanning monochromator system for the rapid determination of the elements

    Energy Technology Data Exchange (ETDEWEB)

    Floyd, M.A.

    1980-03-01

    A computer controlled, scanning monochromator system specifically designed for the rapid, sequential determination of the elements is described. The monochromator is combined with an inductively coupled plasma excitation source so that elements at major, minor, trace, and ultratrace levels may be determined, in sequence, without changing experimental parameters other than the spectral line observed. A number of distinctive features not found in previously described versions are incorporated into the system here described. Performance characteristics of the entire system and several analytical applications are discussed.

  1. Comparison of inductively coupled plasma mass spectrometry with inductively coupled plasma atomic emission spectrometry and instrumental neutron activation analysis for the determination of rare earth elements in Greek bauxites

    International Nuclear Information System (INIS)

    Fore the determination of rare earth elements (REE) in bauxitic materials the techniques of inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma atomic emission spectrometry (ICP-AES) and instrumental neutron activation analysis (INAA) were compared. In the NIST (National Institute of Standards and Technology) bauxites SRM 697 Dominican, and SRM 69 b Arkansas, the concentration of some REEs were determined. With the reference bauxite BX-N of the ARNT (Association Nationale de la Recherche Technique) the precision and accuracy of ICP-AES for the determination of REEs in bauxites was tested. Furthermore, Greek bauxites of the Parnassos-Giona area were investigated. In a comparison of the three methods it was possible to calculate from the data series the precision of each method, which showed that the tendency found in the deviations for the different REEs is in accordance with published values. Also the limits of detection for REEs in bauxites were calculated and found to be in the same range as those in the literature. (author)

  2. Determination of hafnium at the 10(-4)% level (relative to zirconium content) using neutron activation analysis, inductively coupled plasma mass spectrometry and inductively coupled plasma atomic emission spectrometry.

    Science.gov (United States)

    Smolik, Marek; Polkowska-Motrenko, Halina; Hubicki, Zbigniew; Jakóbik-Kolon, Agata; Danko, Bożena

    2014-01-02

    Hafnium at the very low level of 1-8 ppm (in relation to zirconium) was determined in zirconium sulfate solutions (originating from investigations of the separation of ca. 44 ppm Hf from zirconium by means of the ion exchange method) by using three independent methods: inductively coupled plasma mass spectrometry (ICP MS), neutron activation analysis (NAA) and inductively coupled plasma atomic emission spectrometry (ICP-AES). The results of NAA and ICP MS determinations were consistent with each other across the entire investigated range (the RSD of both methods did not exceed 38%). The results of ICP-AES determination were more diverse, particularly at less than 5 ppm Hf (RSD was significantly higher: 29-253%). The ion exchange method exploiting Diphonix(®) resin proved sufficient efficiency in Zr-Hf separation when the initial concentration ratio of the elements ([Zr]0/[Hf]0) ranged from 1200 to ca. 143,000. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Electroporation of cells using EM induction of ac fields by a magnetic stimulator

    International Nuclear Information System (INIS)

    Chen, C; Robinson, M P; Evans, J A; Smye, S W; O'Toole, P

    2010-01-01

    This paper describes a method of effectively electroporating mammalian cell membranes with pulsed alternating-current (ac) electric fields at field strengths of 30-160 kV m -1 . Although many in vivo electroporation protocols entail applying square wave or monotonically decreasing pulses via needles or electrode plates, relatively few have explored the use of pulsed ac fields. Following our previous study, which established the effectiveness of ac fields for electroporating cell membranes, a primary/secondary coil system was constructed to produce sufficiently strong electric fields by electromagnetic induction. The primary coil was formed from the applicator of an established transcranial magnetic stimulation (TMS) system, while the secondary coil was a purpose-built device of a design which could eventually be implanted into tissue. The effects of field strength, pulse interval and cumulative exposure time were investigated using microscopy and flow cytometry. Results from experiments on concentrated cell suspensions showed an optimized electroporation efficiency of around 50%, demonstrating that electroporation can be practicably achieved by inducing such pulsed ac fields. This finding confirms the possibility of a wide range of in vivo applications based on magnetically coupled ac electroporation.

  4. Extraction inductively coupled plasma-optical emission spectrometry (ICP-OES). Determination of traces of phosphorus in tungsten

    International Nuclear Information System (INIS)

    Bauer, G.; Wegscheider, W.; Mueller, K.

    1989-01-01

    A method for the separation and preconcentration of traces of phosphorus from tungsten was developed. Solid phase extraction of the phosphovanadomolybdate complex performed on a micro-column was applied. Phosphorus was determined by optical emission spectroscopy (OES) with inductively coupled plasma (ICP) excitation. A limit of detection of 0,4 μg/g P with respect to the solid phase is obtained. By directly coupling the extraction/elution step to the ICP instrument a detection limit of 0,06 μg/g P in W was achieved. Besides, the complexity of spectral evaluation in ICP-OES determinations of traces in spectralline-rich matrices is discussed. (Authors)

  5. Influences of lamin A levels on induction of pluripotent stem cells

    Directory of Open Access Journals (Sweden)

    Bingfeng Zuo

    2012-09-01

    Lamin A is an inner nuclear membrane protein that maintains nuclear structure integrity, is involved in transcription, DNA damage response and genomic stability, and also links to cell differentiation, senescence, premature aging and associated diseases. Induced pluripotent stem (iPS cells have been successfully generated from various types of cells and used to model human diseases. It remains unclear whether levels of lamin A influence reprogramming of somatic cells to pluripotent states during iPS induction. Consistently, lamin A is expressed more in differentiated than in relatively undifferentiated somatic cells, and increases in expression levels with age. Somatic cells with various expression levels of lamin A differ in their dynamics and efficiency during iPS cell induction. Cells with higher levels of lamin A show slower reprogramming and decreased efficiency to iPS cells. Furthermore, depletion of lamin A by transient shRNA accelerates iPS cell induction from fibroblasts. Reduced levels of lamin A are associated with increased expression of pluripotent genes Oct4 and Nanog, and telomerase genes Tert and Terc. On the contrary, overexpression of lamin A retards somatic cell reprogramming to iPS-like colony formation. Our data suggest that levels of lamin A influence reprogramming of somatic cells to pluripotent stem cells and that artificial silencing of lamin A facilitates iPS cell induction. These findings may have implications in enhancing rejuvenation of senescent or older cells by iPS technology and manipulating lamin A levels.

  6. Hyphenation of ultra performance liquid chromatography (UPLC) with inductively coupled plasma mass spectrometry (ICP-MS) for fast analysis of bromine containing preservatives

    DEFF Research Database (Denmark)

    Bendahl, Lars; Hansen, Steen Honoré; Gammelgaard, Bente

    2006-01-01

    Ultra performance liquid chromatography (UPLC) was coupled to inductively coupled plasma mass spectrometry (ICP-MS) for fast analysis of three bromine-containing preservatives, monitoring the 79Br and 81Br isotopes simultaneously. Due to the efficiency of the 1.7 microm column packing material, t...

  7. A Maximum Efficiency Point Tracking Control Scheme Based on Different Cross Coupling of Dual-Receiver Inductive Power Transfer System

    Directory of Open Access Journals (Sweden)

    Ruikun Mai

    2017-02-01

    Full Text Available One of the most promising inductive power transfer applications is the wireless power supply for locomotives which may cancel the need for pantographs. In order to meet the dynamic and high power demands of wireless power supplies for locomotives, a relatively long transmitter track and multiple receivers are usually adopted. However, during the dynamic charging, the mutual inductances between the transmitter and receivers vary and the load of the locomotives also changes randomly, which dramatically affects the system efficiency. A maximum efficiency point tracking control scheme is proposed to improve the system efficiency against the variation of the load and the mutual inductances between the transmitter and receivers while considering the cross coupling between receivers. Firstly, a detailed theoretical analysis on dual receivers is carried out. Then a control scheme with three control loops is proposed to regulate the receiver currents to be the same, to regulate the output voltage and to search for the maximum efficiency point. Finally, a 2 kW prototype is established to validate the performance of the proposed method. The overall system efficiency (DC-DC efficiency reaches 90.6% at rated power and is improved by 5.8% with the proposed method under light load compared with the traditional constant output voltage control method.

  8. Contactless vector network analysis using diversity calibration with capacitive and inductive coupled probes

    Directory of Open Access Journals (Sweden)

    T. Zelder

    2007-06-01

    Full Text Available Contactless vector network analysis based on a diversity calibration is investigated for the measurement of embedded devices in planar circuits. Conventional contactless measurement systems based on two probes for each measurement port have the disadvantage that the signal-to-noise system dynamics strongly depends on the distance between the contactless probes.

    In order to avoid a decrease in system dynamics a diversity based measurement system is presented. The measurement setup uses one inductive and two capacitive probes. As an inductive probe a half magnetic loop in combination with a broadband balun is introduced. In order to eliminate systematic errors from the measurement results a diversity calibration algorithm is presented. Simulation and measurement results for a one-port configuration are shown.

  9. Power crowbar system coupled by a current transformer with very low leakage inductance

    International Nuclear Information System (INIS)

    Kitagawa, S.; Hirano, K.I.

    1976-01-01

    A reliable, efficient power crowbar system has been developed for fast pinch experiments. In order to reduce the effective impedance of series capacitor system, a current transformer with extremely low leakage inductance has been designed and used. Primary and secondary windings of the transformer are alternately arranged as closely as possible. As a result, the leakage inductance is reduced to 2 nH. It is demonstrated that a current of 390 kA, the rise time of which is 4.5 μsec, is sustained for 100 μsec. Much larger system is being built, which maintains a current of 1 MA over 1 msec. The life of crowbar gap switches is prolonged by the aid of a mechanically-driven metal-to-metal contact switch. Another crowbar switch system with a high coulomb rating is under consideration, in which a gap switch is used together with a saturable reactor and a current transformer

  10. Study on the RF inductively coupled plasma spheroidization of refractory W and W-Ta alloy powders

    Science.gov (United States)

    Chenfan, YU; Xin, ZHOU; Dianzheng, WANG; Neuyen VAN, LINH; Wei, LIU

    2018-01-01

    Spherical powders with good flowability and high stacking density are mandatory for powder bed additive manufacturing. Nevertheless, the preparation of spherical refractory tungsten and tungsten alloy powders is a formidable task. In this paper, spherical refractory metal powders processed by high-energy stir ball milling and RF inductively coupled plasma were investigated. By utilizing the technical route, pure spherical tungsten powders were prepared successfully, the flowability increased from 10.7 s/50 g to 5.5 s/50 g and apparent density increased from 6.916 g cm‑3 to 11.041 g cm‑3. Alloying element tantalum can reduce the tendency to micro-crack during tungsten laser melting and rapid solidification process. Spherical W-6Ta (%wt) powders were prepared in this way, homogeneous dispersion of tantalum in a tungsten matrix occurred but a small amount of flake-like shape particles appeared after high-energy stir ball milling. The flake-like shape particles can hardly be spheroidized in subsequent RF inductively coupled plasma process, might result from the unique suspended state of flaky particles under complex electric and magnetic fields as well as plasma-particle heat exchange was different under various turbulence models. As a result, the flake-like shape particles cannot pass through the high-temperature area of thermal plasma torch and cannot be spheroidized properly.

  11. Estimation of the quantification uncertainty from flow injection and liquid chromatography transient signals in inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Laborda, Francisco; Medrano, Jesus; Castillo, Juan R.

    2004-01-01

    The quality of the quantitative results obtained from transient signals in high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICPMS) and flow injection-inductively coupled plasma mass spectrometry (FI-ICPMS) was investigated under multielement conditions. Quantification methods were based on multiple-point calibration by simple and weighted linear regression, and double-point calibration (measurement of the baseline and one standard). An uncertainty model, which includes the main sources of uncertainty from FI-ICPMS and HPLC-ICPMS (signal measurement, sample flow rate and injection volume), was developed to estimate peak area uncertainties and statistical weights used in weighted linear regression. The behaviour of the ICPMS instrument was characterized in order to be considered in the model, concluding that the instrument works as a concentration detector when it is used to monitorize transient signals from flow injection or chromatographic separations. Proper quantification by the three calibration methods was achieved when compared to reference materials, although the double-point calibration allowed to obtain results of the same quality as the multiple-point calibration, shortening the calibration time. Relative expanded uncertainties ranged from 10-20% for concentrations around the LOQ to 5% for concentrations higher than 100 times the LOQ

  12. Experimental and simulation investigation of electrical and plasma parameters in a low pressure inductively coupled argon plasma

    Science.gov (United States)

    Jian, YANG; Angjian, WU; Xiaodong, LI; Yang, LIU; Fengsen, ZHU; Zhiliang, CHEN; Jianhua, YAN; Ruijuan, CHEN; Wangjun, SHEN

    2017-11-01

    The electrical and plasma parameters of a low pressure inductively coupled argon plasma are investigated over a wide range of parameters (RF power, flow rate and pressure) by diverse characterizations. The external antenna voltage and current increase with the augment of RF power, whereas decline with the enhancement of gas pressure and flow rate conversely. Compared with gas flow rate and pressure, the power transfer efficiency is significantly improved by RF power, and achieved its maximum value of 0.85 after RF power injected excess 125 W. Optical emission spectroscopy (OES) provides the local mean values of electron excited temperature and electron density in inductively coupled plasma (ICP) post regime, which vary in a range of 0.81 eV to 1.15 eV and 3.7× {10}16 {{{m}}}-3 to 8.7× {10}17 {{{m}}}-3, respectively. Numerical results of the average magnitudes of electron temperature and electron density in two-dimensional distribution exhibit similar variation trend with the experimental results under different operating condition by using COMSOL Multiphysics. By comprehensively understanding the characteristics in a low pressure ICP, optimized operating conditions could be anticipated aiming at different academic and industrial applications.

  13. Behavior of microorganisms in drinking water treatment by inductively coupled plasma system: Case study in ground water

    Science.gov (United States)

    Desmiarti, Reni; Hazmi, Ariadi; Martynis, Munas; Sutopo, Ulung Muhammad; Li, Fusheng

    2018-02-01

    Pathogenic bacteria, such as total coliforms (TC), fecal coliforms (FC) and other coliforms (OC), were removed from groundwater by inductively coupled plasma system treatment in continuous flow experiments. The objective of this study is to investigate the effect of flowrate and frequency on the behavior of microorganisms in drinking water treatment using inductively coupled plasma system (ICPS). The results showed that after 120 minutes of ICPS treatment, the removal efficiency with respect to TC, FC and OC decreased with increasing flowrate. The removal efficiency of FC was achieved at 100% in all runs. Compared to FC, the removal efficiencies with respect to TC and FC were lower than those with respect to TC and OC in the following order: FC >OC> TC. The disinfection yield of TC and OC significantly increased when the removal efficiency increased. The electromagnetic flux varied from 8.08±0.46 to 10.54±0.19 W/cm2. The results in the present work can be used to design a new technology for drinking water treatment to remove all pathogenic bacteria without using hazardous chemicals.

  14. Calibration of laser ablation inductively coupled plasma mass spectrometry using dried solution aerosols for the quantitative analysis of solid samples

    Energy Technology Data Exchange (ETDEWEB)

    Leach, James [Iowa State Univ., Ames, IA (United States)

    1999-02-12

    Inductively coupled plasma mass spectrometry (ICP-MS) has become the method of choice for elemental and isotopic analysis. Several factors contribute to its success. Modern instruments are capable of routine analysis at part per trillion levels with relative detection limits in part per quadrillion levels. Sensitivities in these instruments can be as high as 200 million counts per second per part per million with linear dynamic ranges up to eight orders of magnitude. With standards for only a few elements, rapid semiquantitative analysis of over 70 elements in an individual sample can be performed. Less than 20 years after its inception ICP-MS has shown to be applicable to several areas of science. These include geochemistry, the nuclear industry, environmental chemistry, clinical chemistry, the semiconductor industry, and forensic chemistry. In this introduction, the general attributes of ICP-MS will be discussed in terms of instrumentation and sample introduction. The advantages and disadvantages of current systems are presented. A detailed description of one method of sample introduction, laser ablation, is given. The paper also gives conclusions and suggestions for future work. Chapter 2, Quantitative analysis of solids by laser ablation inductively coupled plasma mass spectrometry using dried solution aerosols for calibration, has been removed for separate processing.

  15. Comparative analysis of barium titanate thin films dry etching using inductively coupled plasmas by different fluorine-based mixture gas.

    Science.gov (United States)

    Li, Yang; Wang, Cong; Yao, Zhao; Kim, Hong-Ki; Kim, Nam-Young

    2014-01-01

    In this work, the inductively coupled plasma etching technique was applied to etch the barium titanate thin film. A comparative study of etch characteristics of the barium titanate thin film has been investigated in fluorine-based (CF4/O2, C4F8/O2 and SF6/O2) plasmas. The etch rates were measured using focused ion beam in order to ensure the accuracy of measurement. The surface morphology of etched barium titanate thin film was characterized by atomic force microscope. The chemical state of the etched surfaces was investigated by X-ray photoelectron spectroscopy. According to the experimental result, we monitored that a higher barium titanate thin film etch rate was achieved with SF6/O2 due to minimum amount of necessary ion energy and its higher volatility of etching byproducts as compared with CF4/O2 and C4F8/O2. Low-volatile C-F compound etching byproducts from C4F8/O2 were observed on the etched surface and resulted in the reduction of etch rate. As a result, the barium titanate films can be effectively etched by the plasma with the composition of SF6/O2, which has an etch rate of over than 46.7 nm/min at RF power/inductively coupled plasma (ICP) power of 150/1,000 W under gas pressure of 7.5 mTorr with a better surface morphology.

  16. Ultra-sensitive quantification of lysozyme based on element chelate labeling and capillary electrophoresis-inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Yang, MingWei; Wu, WeiHua; Ruan, YaJuan; Huang, LiMei; Wu, Zujian; Cai, Yong; Fu, FengFu

    2014-02-17

    In this study, an ultra-sensitive method for the quantification of lysozyme based on the Gd(3+) diethylenetriamine-N,N,N',N″,N″-pentaacetic acid labeling and capillary electrophoresis-inductively coupled plasma mass spectrometry (CE-ICP-MS) was described. The Gd(3+)-tagged lysozyme was effectively separated by capillary electrophoresis (CE) and sensitively determined by inductively coupled plasma mass spectrometry (ICP-MS). Based on the gadolinium-tagging and CE-ICP-MS, the lysozyme was determined within 12 min with an extremely low detection limit of 3.89 attomole (3.89×10(-11) mol L(-1) for 100 nL of sample injection) and a RSDlysozyme in saliva samples with a recovery of 91-106%, suggesting that our method is sensitive and reliable. The success of the present method provides a new potential for the biological assays and sensitive detection of low-abundant proteins. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Cobalamin speciation using reversed-phase micro-high-performance liquid chromatography interfaced to inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Yanes, Enrique G.; Miller-Ihli, Nancy J.

    2004-01-01

    Micro-high-performance liquid chromatography interfaced to inductively coupled plasma mass spectrometry was optimized for the determination and separation of a mixture of cobalt containing species. Four cobalamin species (cyanocobalamin, hydroxocobalamin, methylcobalamin, and 5'-deoxyadenosylcobalamin) representing the various forms of vitamin B12 as well as the harmful corrinoid analogue cobinamide dicyanide were separated using reversed-phase microcapillary chromatography with columns containing C18 packing material with a 2-μm particle size. Selection of organic solvents for the separation took into consideration compatibility with the inductively coupled plasma mass spectrometer being used for element specific detection. Optimized method conditions included use of a methanol gradient and make-up solution for the nebulizer. Some issues associated with dead volume were overcome by the extension of the gradient program. The total analysis time was 52 min. The column-to-column variability was evaluated and was found to be very reasonable (9% RSD on average), confirming that this method is rugged and that the technology should be easily transferred to other laboratories

  18. Vertically aligned Si nanocrystals embedded in amorphous Si matrix prepared by inductively coupled plasma chemical vapor deposition (ICP-CVD)

    Energy Technology Data Exchange (ETDEWEB)

    Nogay, G. [Department of Physics, Middle East Technical University (METU), Ankara 06800 (Turkey); Center of Solar Energy Research and Application (GÜNAM), Middle East Technical University (METU), Ankara 06800 (Turkey); Saleh, Z.M., E-mail: zaki.saleh@aauj.edu [Center of Solar Energy Research and Application (GÜNAM), Middle East Technical University (METU), Ankara 06800 (Turkey); Department of Physics, Arab American University–Jenin (AAUJ), Jenin, Palestine (Country Unknown); Özkol, E. [Center of Solar Energy Research and Application (GÜNAM), Middle East Technical University (METU), Ankara 06800 (Turkey); Department of Chemical Engineering, Middle East Technical University (METU), Ankara 06800 (Turkey); Turan, R. [Department of Physics, Middle East Technical University (METU), Ankara 06800 (Turkey); Center of Solar Energy Research and Application (GÜNAM), Middle East Technical University (METU), Ankara 06800 (Turkey)

    2015-06-15

    Highlights: • Inductively-coupled plasma is used for nanostructured silicon at room temperature. • Low temperature deposition allows device processing on various substrates. • Deposition pressure is the most effective parameter in controlling nanostructure. • Films consist of quantum dots in a-Si matrix and exhibit columnar vertical growth. • Films are porous to oxygen infusion along columnar grain boundaries. - Abstract: Vertically-aligned nanostructured silicon films are deposited at room temperature on p-type silicon wafers and glass substrates by inductively-coupled, plasma-enhanced chemical vapor deposition (ICPCVD). The nanocrystalline phase is achieved by reducing pressure and increasing RF power. The crystalline volume fraction (X{sub c}) and the size of the nanocrystals increase with decreasing pressure at constant power. Columnar growth of nc-Si:H films is observed by high resolution transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM). The films exhibit cauliflower-like structures with high porosity that leads to slow but uniform oxidation after exposure to air at room temperature. Films deposited at low pressures exhibit photoluminescence (PL) signals that may be deconvoluted into three distinct Gaussian components: 760–810, 920–935, and 990–1000 nm attributable to the quantum confinement and interface defect states. Hydrogen dilution is manifested in significant enhancement of the PL, but it has little effect on the nanocrystal size and X{sub c}.

  19. Cobalamin speciation using reversed-phase micro-high-performance liquid chromatography interfaced to inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Yanes, Enrique G. E-mail: yanes@bhnrc.usda.gov; Miller-Ihli, Nancy J. E-mail: miller-ihli@bhnrc.usda.gov

    2004-06-18

    Micro-high-performance liquid chromatography interfaced to inductively coupled plasma mass spectrometry was optimized for the determination and separation of a mixture of cobalt containing species. Four cobalamin species (cyanocobalamin, hydroxocobalamin, methylcobalamin, and 5'-deoxyadenosylcobalamin) representing the various forms of vitamin B12 as well as the harmful corrinoid analogue cobinamide dicyanide were separated using reversed-phase microcapillary chromatography with columns containing C18 packing material with a 2-{mu}m particle size. Selection of organic solvents for the separation took into consideration compatibility with the inductively coupled plasma mass spectrometer being used for element specific detection. Optimized method conditions included use of a methanol gradient and make-up solution for the nebulizer. Some issues associated with dead volume were overcome by the extension of the gradient program. The total analysis time was 52 min. The column-to-column variability was evaluated and was found to be very reasonable (9% RSD on average), confirming that this method is rugged and that the technology should be easily transferred to other laboratories.

  20. Multi-elemental analysis of aqueous geochemical samples by quadrupole inductively coupled plasma-mass spectrometry (ICP-MS)

    Science.gov (United States)

    Wolf, Ruth E.; Adams, Monique

    2015-01-01

    Typically, quadrupole inductively coupled plasma-mass spectrometry (ICP-MS) is used to determine as many as 57 major, minor, and trace elements in aqueous geochemical samples, including natural surface water and groundwater, acid mine drainage water, and extracts or leachates from geological samples. The sample solution is aspirated into the inductively coupled plasma (ICP) which is an electrodeless discharge of ionized argon gas at a temperature of approximately 6,000 degrees Celsius. The elements in the sample solution are subsequently volatilized, atomized, and ionized by the ICP. The ions generated are then focused and introduced into a quadrupole mass filter which only allows one mass to reach the detector at a given moment in time. As the settings of the mass analyzer change, subsequent masses are allowed to impact the detector. Although the typical quadrupole ICP-MS system is a sequential scanning instrument (determining each mass separately), the scan speed of modern instruments is on the order of several thousand masses per second. Consequently, typical total sample analysis times of 2–3 minutes are readily achievable for up to 57 elements.

  1. Multi-elemental determination of trace elements in deep seawater by inductively coupled plasma mass spectrometry with resin preconcentration

    International Nuclear Information System (INIS)

    Sumida, Takashi; Nakazato, Tetsuya; Tao, Hiroaki

    2003-01-01

    A miniaturized column (ca. 3 mm i.d., 40 mm length), packed with a chelating resin (0.2 g) with iminodiacetic acid groups (Muromac A-1), was tested for the preconcentration of trace elements in seawater. After preconcentration, the column was washed with ammonium acetate buffer (pH 5.5) and water to remove the major elements, such as Ca and Mg, and was then eluted with 4 ml of 2 mol l -1 nitric acid. Twenty-six trace elements were determined by inductively coupled plasma mass spectrometry and inductively coupled plasma emission spectrometry. The necessary volume of the seawater sample was only 200 ml. The recoveries for most of the elements tested were over 90%, although those for Al, V and Th were around 70%. The trueness and precision were evaluated by analyzing a standard reference material of seawater (NASS-4, NRC Canada). The observed values obtained with the present method showed good agreement with the certified values. The present method was also applied to deep seawater samples collected at Muroto, Japan. A difference in the rare earth element pattern, especially the Ce anomaly, between the deep seawater sample and the surface seawater sample was observed, as well as the differences of the concentrations of many trace elements. (author)

  2. Determination of Trace Iron in Red Wine by Isotope Dilution Mass Spectrometry Using Multiple-Collector Inductively Coupled Plasma Mass Spectrometry

    International Nuclear Information System (INIS)

    Zhou Tao; Wang Jun; Lu Hai; Zhou Yuanjing; Li Haifeng

    2009-01-01

    This paper introduces determination of trace iron in red wine certified reference material by isotope dilution mass spectrometry (IDMS) method using a multiplecollector inductively coupled plasma mass spectrometry, equipped with a hexapole collision cell. The measurement procedure of iron isotopic abundance ratios was deeply researched. Reduced polyatomic ion interferences to iron isotopes ion by collision reaction using Ar and H 2 gas, high precise isotopic abundance ratios were achieved. Two relative measurement methods (ICP-MS and ICP-OES) were used to analyze trace iron in red wine. The results are compared with IDMS results, which indicate that they are accordant. The uncertainty analyses include each uncertainty factor in whole experiment and the uncertainty of used certified reference material and it shows that the procedure blank is not neglectable to detect limit and precision of the method. The establishment of IDMS method for analysis of trace iron in red wine supports the certification of certified reference materials. (authors)

  3. Investigations into the origins of polyatomic ions in inductively coupled plasma-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    McIntyre, Sally M. [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    An inductively coupled plasma-mass spectrometer (ICP-MS) is an elemental analytical instrument capable of determining nearly all elements in the periodic table at limits of detection in the parts per quadrillion and with a linear analytical range over 8-10 orders of magnitude. Three concentric quartz tubes make up the plasma torch. Argon gas is spiraled through the outer tube and generates the plasma powered by a looped load coil operating at 27.1 or 40.6 MHz. The argon flow of the middle channel is used to keep the plasma above the innermost tube through which solid or aqueous sample is carried in a third argon stream. A sample is progressively desolvated, atomized and ionized. The torch is operated at atmospheric pressure. To reach the reduced pressures of mass spectrometers, ions are extracted through a series of two, approximately one millimeter wide, circular apertures set in water cooled metal cones. The space between the cones is evacuated to approximately one torr. The space behind the second cone is pumped down to, or near to, the pressure needed for the mass spectrometer (MS). The first cone, called the sampler, is placed directly in the plasma plume and its position is adjusted to the point where atomic ions are most abundant. The hot plasma gas expands through the sampler orifice and in this expansion is placed the second cone, called the skimmer. After the skimmer traditional MS designs are employed, i.e. quadrupoles, magnetic sectors, time-of-flight. ICP-MS is the leading trace element analysis technique. One of its weaknesses are polyatomic ions. This dissertation has added to the fundamental understanding of some of these polyatomic ions, their origins and behavior. Although mainly continuing the work of others, certain novel approaches have been introduced here. Chapter 2 includes the first reported efforts to include high temperature corrections to the partition functions of the polyatomic ions in ICP-MS. This and other objections to preceeding

  4. Prevalence and pattern of sickle cell disease in premarital couples ...

    African Journals Online (AJOL)

    Context: Premarital haemoglobin screening is an important strategy for the control of Sickle Cell Disease. Aims: To determine the prevalence and pattern of sickle cell disease among premarital couples and to assess their attitude to the risk of sickle cell anaemia in their offspring. Settings and Design: A cross sectional ...

  5. Cellular Clocks : Coupled Circadian Dispatch and Cell Division Cycles

    NARCIS (Netherlands)

    Merrow, Martha; Roenneberg, Till

    2004-01-01

    Gating of cell division by the circadian clock is well known, yet its mechanism is little understood. Genetically tractable model systems have led to new hypotheses and questions concerning the coupling of these two cellular cycles.

  6. Expression of Aryl Hydrocarbon Hydroxylase Induction and Suppression of Tyrosine Aminotransferase Induction in Somatic-Cell Hybrids

    Science.gov (United States)

    Benedict, W. F.; Nebert, D. W.; Thompson, E. B.

    1972-01-01

    Aryl hydrocarbon hydroxylase activity is inducible in mouse 3T3 fibroblasts by benz[α]anthracene, whereas no detectable basal or inducible levels of this enzyme occur in rat-hepatoma tissue culture cells. Conversely, tyrosine aminotransferase activity is inducible in hepatoma cells by dexamethasone, whereas only low noninducible levels of this enzyme exist in 3T3 cells. In hybrids formed by fusion of these two parent lines, levels of inducible hydroxylase activity range from the same as, to more than 20-fold greater than, that in the 3T3 parent; aminotransferase levels remain very low and noninducible in all of these same hybrids. A majority of the 1S-chromosomal complement from each parent is retained in most of these hybrids. The kinetics of hydroxylase induction and degradation, responses of hydroxylase induction to actinomycin D and cycloheximide, and the relative thermolability of the control and induced activities are similar in the 3T3 parent and in the hybrids. Failure to inactivate any of the aminotransferase activity in the hybrids with antibody specific for the rat enzyme indicates that all of the basal noninducible aminotransferase activity is derived from the mouse 3T3 parent. Images PMID:4403306

  7. Detecting Lactococcus lactis Prophages by Mitomycin C-Mediated Induction Coupled to Flow Cytometry Analysis

    Directory of Open Access Journals (Sweden)

    Joana Oliveira

    2017-07-01

    Full Text Available Most analyzed Lactococcus lactis strains are predicted to harbor one or more prophage genomes within their chromosome; however, the true extent of the inducibility and functionality of such prophages cannot easily be deduced from sequence analysis alone. Chemical treatment of lysogenic strains with Mitomycin C is known to cause induction of temperate phages, though it is not always easy to clearly identify a lysogenic strain or to measure the number of released phage particles. Here, we report the application of flow cytometry as a reliable tool for the detection and enumeration of released lactococcal prophages using the green dye SYTO-9.

  8. Paraptosis cell death induction by the thiamine analog benfotiamine in leukemia cells.

    Directory of Open Access Journals (Sweden)

    Naomi Sugimori

    Full Text Available Benfotiamine is a synthetic thiamine analogue that stimulates transketolase, a cellular enzyme essential for glucose metabolism. Currently, benfotiamine is used to treat diabetic neuropathy. We recently reported that oral benfotiamine induced a temporary but remarkable recovery from acute myeloid leukemia in an elderly patient who was ineligible for standard chemotherapy due to dementia and renal failure. In the present study we present evidences that benfotiamine possess antitumor activity against leukemia cells. In a panel of nine myeloid leukemia cell lines benfotiamine impaired the viability of HL-60, NB4, K562 and KG1 cells and also inhibited the growing of primary leukemic blasts. The antitumor activity of benfotiamine is not mediated by apoptosis, necrosis or autophagy, but rather occurs though paraptosis cell death induction. Mechanistic studies revealed that benfotiamine inhibited the activity of constitutively active ERK1/2 and concomitantly increased the phosphorylation of JNK1/2 kinase in leukemic cells. In addition, benfotiamine induced the down regulation of the cell cycle regulator CDK3 which resulted in G1 cell cycle arrest in the sensitive leukemic cells. Moreover, combination index studies showed that benfotiamine enhanced the antiproliferative activities of cytarabine against leukemia cells. These findings suggest that benfotiamine has antitumor therapeutic potential.

  9. Use of a parallel path nebulizer for capillary-based microseparation techniques coupled with an inductively coupled plasma mass spectrometer for speciation measurements

    International Nuclear Information System (INIS)

    Yanes, Enrique G.; Miller-Ihli, Nancy J.

    2004-01-01

    A low flow, parallel path Mira Mist CE nebulizer designed for capillary electrophoresis (CE) was evaluated as a function of make-up solution flow rate, composition, and concentration, as well as the nebulizer gas flow rate. This research was conducted in support of a project related to the separation and quantification of cobalamin (vitamin B-12) species using microseparation techniques combined with inductively coupled plasma mass spectrometry (ICP-MS) detection. As such, Co signals were monitored during the nebulizer characterization process. Transient effects in the ICP were studied to evaluate the suitability of using gradients for microseparations and the benefit of using methanol for the make-up solution was demonstrated. Co signal response changed significantly as a function of changing methanol concentrations of the make-up solution and maximum signal enhancement was seen at 20% methanol with a 15 μl/min flow rate. Evaluation of the effect of changing the nebulizer gas flow rates showed that argon flows from 0.8 to 1.2 l/min were equally effective. The Mira Mist CE parallel path nebulizer was then evaluated for interfacing capillary microseparation techniques including capillary electrophoresis (CE) and micro high performance liquid chromatography (μHPLC) to inductively coupled plasma mass spectrometry (ICP-MS). A mixture of four cobalamin species standards (cyanocobalamin, hydroxocobalamin, methylcobalamin, and 5' deoxyadenosylcobalamin) and the corrinoid analogue cobinamide dicyanide were successfully separated using both CE-ICP-MS and μHPLC-ICP-MS using the parallel path nebulizer with a make-up solution containing 20% methanol with a flow rate of 15 μl/min

  10. Use of a parallel path nebulizer for capillary-based microseparation techniques coupled with an inductively coupled plasma mass spectrometer for speciation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Yanes, Enrique G. E-mail: yanes@bhnrc.usda.gov; Miller-Ihli, Nancy J. E-mail: miller-ihli@bhnrc.usda.gov

    2004-06-18

    A low flow, parallel path Mira Mist CE nebulizer designed for capillary electrophoresis (CE) was evaluated as a function of make-up solution flow rate, composition, and concentration, as well as the nebulizer gas flow rate. This research was conducted in support of a project related to the separation and quantification of cobalamin (vitamin B-12) species using microseparation techniques combined with inductively coupled plasma mass spectrometry (ICP-MS) detection. As such, Co signals were monitored during the nebulizer characterization process. Transient effects in the ICP were studied to evaluate the suitability of using gradients for microseparations and the benefit of using methanol for the make-up solution was demonstrated. Co signal response changed significantly as a function of changing methanol concentrations of the make-up solution and maximum signal enhancement was seen at 20% methanol with a 15 {mu}l/min flow rate. Evaluation of the effect of changing the nebulizer gas flow rates showed that argon flows from 0.8 to 1.2 l/min were equally effective. The Mira Mist CE parallel path nebulizer was then evaluated for interfacing capillary microseparation techniques including capillary electrophoresis (CE) and micro high performance liquid chromatography ({mu}HPLC) to inductively coupled plasma mass spectrometry (ICP-MS). A mixture of four cobalamin species standards (cyanocobalamin, hydroxocobalamin, methylcobalamin, and 5' deoxyadenosylcobalamin) and the corrinoid analogue cobinamide dicyanide were successfully separated using both CE-ICP-MS and {mu}HPLC-ICP-MS using the parallel path nebulizer with a make-up solution containing 20% methanol with a flow rate of 15 {mu}l/min.

  11. A low-power ASK demodulator for inductively coupled implantable electronics

    DEFF Research Database (Denmark)

    Gudnason, Gunnar

    2000-01-01

    An amplitude shift keying (ASK) demodulator is presented which is suitable for implantable electronic devices that are powered through an inductive link. The demodulator has been tested with carrier frequencies in the range 1-15 MHz, covering most commonly used frequencies. Data rates up to sever...... of transmitter designs with limited modulation capability. The power consumption is 60 μW from a 3 V supply. The circuit has been implemented in a standard CMOS process.......An amplitude shift keying (ASK) demodulator is presented which is suitable for implantable electronic devices that are powered through an inductive link. The demodulator has been tested with carrier frequencies in the range 1-15 MHz, covering most commonly used frequencies. Data rates up to several...... 100kbit/s are supported, suitable for complex implants such as stimulating electrode arrays or visual implants. The circuit is compatible with modulation depths in the range 10-100%. The low end of the range permits data transmission without significant reduction in power transfer, or the use...

  12. [Determination of Total Sulfur Dioxide in Chinese Herbal Medicines via Triple Quadrupole Inductively Coupled Plasma Mass Spectrometry].

    Science.gov (United States)

    Wang, Xiao-wei; Liu, Jing-fu; Guan, Hong; Wang, Xiao-yan; Shag, Bing; Zhang, Jing; Liu, Li-ping; Zhang, Ni-na

    2016-02-01

    As an important treatment method, sulfur fumigation plays an essential role in the production and preservation of traditional Chinese herbal medicines. Although there is strict regulation on the use of sulfur dioxide, the abuse of sulfur dioxide still occurred from time to time. And the public faces a high risk of exposure. Because of the poor precision and tedious preparation procedures of traditional recommended titration, the accurate and convenient determination of sulfur dioxide in Chinese herbal medicines is still a critical analytical task for medicines safety and the public health. In this study, an accurate, high-throughput, and convenient method for the absolute determination of SO₂ in Chinese herbal medicines based on triple quadrupole inductively coupled plasma mass spectrometry (ICP-MS/MS) technique is developed. The study compared the quantitative ability for sulfur when the ICP-MS operated under traditional single quadrupole (QMS) mode and novel triple quadrupole (MS/MS) mode with three Reaction/Collision cell condition (no gas, helium, and oxygen). The result indicated that when the concentration of sulfate ranging from 0.5 to 100 mg · L⁻¹, isotopic ³⁴S can be selected as quantitative ion either the ICP-MS operated under the QMS mode or MS/MS mode. The use of helium in the Reaction/Collision cell decreased the single intensity of background ions. Better than QMS mode, the MS/MS mode can effectively reduced background interference. But there are no significant differences about the linear range and limit of detection. However, when the ICP-MS operated under MS/MS mode and oxygen was used as reaction gas in the Reaction/Collision cell, the ICP-MS/MS provided an interference-free performance, the linear range and limit of detection improved significantly. Either ³²S or ³⁴S exhibits an excellent linearity (r > 0.999) over the concentration range of 0.02-100 mg · L⁻¹, with a limit of detection of 5.48 and 9.76 µg · L⁻¹ for

  13. Application of high performance liquid chromatography with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) for determination of chromium compounds in the air at the workplace.

    Science.gov (United States)

    Stanislawska, Magdalena; Janasik, Beata; Wasowicz, Wojciech

    2013-12-15

    The toxicity and bioavailability of chromium species are highly dependable on the form or species, therefore determination of total chromium is insufficient for a complete toxicological evaluation and risk assessment. An analytical method for determination of soluble and insoluble Cr (III) and Cr (VI) compounds in welding fume at workplace air has been developed. The total chromium (Cr) was determined by using quadruple inductively coupled plasma mass spectrometry (ICP-MS) equipped with a dynamic reaction cell (DRC(®)). Soluble trivalent and hexavalent chromium compounds were determined by high performance liquid chromatography with inductively coupled plasma mass spectrometry (HPLC-ICP-MS). A high-speed, reversed-phase CR C8 column (PerkinElmer, Inc., Shelton, CT, USA) was used for the speciation of soluble Cr (III) and soluble Cr (VI). The separation was accomplished by interaction of the chromium species with the different components of the mobile phase. Cr (III) formed a complex with EDTA, i.e. retained on the column, while Cr (VI) existed in the solutions as dichromate. Alkaline extraction (2% KOH and 3% Na2CO3) and anion exchange column (PRP-X100, PEEK, Hamilton) were used for the separation of the total Cr (VI). The results of the determination of Cr (VI) were confirmed by the analysis of the certified reference material BCR CRM 545 (Cr (VI) in welding dust). The results obtained for the certified material (40.2±0.6 g kg(-1)) and the values recorded in the examined samples (40.7±0.6 g kg(-1)) were highly consistent. This analytical method was applied for the determination of chromium in the samples in the workplace air collected onto glass (Whatman, Ø 37 mm) and membrane filters (Sartorius, 0.8 μm, Ø 37 mm). High performance liquid chromatography with inductively coupled plasma mass spectrometry is a remarkably powerful and versatile technique for determination of chromium species in welding fume at workplace air. Crown Copyright © 2013 Published by

  14. Battery-powered pulsed high density inductively coupled plasma source for pre-ionization in laboratory astrophysics experiments.

    Science.gov (United States)

    Chaplin, Vernon H; Bellan, Paul M

    2015-07-01

    An electrically floating radiofrequency (RF) pre-ionization plasma source has been developed to enable neutral gas breakdown at lower pressures and to access new experimental regimes in the Caltech laboratory astrophysics experiments. The source uses a customized 13.56 MHz class D RF power amplifier that is powered by AA batteries, allowing it to safely float at 3-6 kV with the electrodes of the high voltage pulsed power experiments. The amplifier, which is capable of 3 kW output power in pulsed (<1 ms) operation, couples electrical energy to the plasma through an antenna external to the 1.1 cm radius discharge tube. By comparing the predictions of a global equilibrium discharge model with the measured scalings of plasma density with RF power input and axial magnetic field strength, we demonstrate that inductive coupling (rather than capacitive coupling or wave damping) is the dominant energy transfer mechanism. Peak ion densities exceeding 5 × 10(19) m(-3) in argon gas at 30 mTorr have been achieved with and without a background field. Installation of the pre-ionization source on a magnetohydrodynamically driven jet experiment reduced the breakdown time and jitter and allowed for the creation of hotter, faster argon plasma jets than was previously possible.

  15. Battery-powered pulsed high density inductively coupled plasma source for pre-ionization in laboratory astrophysics experiments

    Science.gov (United States)

    Chaplin, Vernon H.; Bellan, Paul M.

    2015-07-01

    An electrically floating radiofrequency (RF) pre-ionization plasma source has been developed to enable neutral gas breakdown at lower pressures and to access new experimental regimes in the Caltech laboratory astrophysics experiments. The source uses a customized 13.56 MHz class D RF power amplifier that is powered by AA batteries, allowing it to safely float at 3-6 kV with the electrodes of the high voltage pulsed power experiments. The amplifier, which is capable of 3 kW output power in pulsed (<1 ms) operation, couples electrical energy to the plasma through an antenna external to the 1.1 cm radius discharge tube. By comparing the predictions of a global equilibrium discharge model with the measured scalings of plasma density with RF power input and axial magnetic field strength, we demonstrate that inductive coupling (rather than capacitive coupling or wave damping) is the dominant energy transfer mechanism. Peak ion densities exceeding 5 × 1019 m-3 in argon gas at 30 mTorr have been achieved with and without a background field. Installation of the pre-ionization source on a magnetohydrodynamically driven jet experiment reduced the breakdown time and jitter and allowed for the creation of hotter, faster argon plasma jets than was previously possible.

  16. Induction of neural stem cell-like cells (NSCLCs) from mouse astrocytes by Bmi1

    International Nuclear Information System (INIS)

    Moon, Jai-Hee; Yoon, Byung Sun; Kim, Bona; Park, Gyuman; Jung, Hye-Youn; Maeng, Isaac; Jun, Eun Kyoung; Yoo, Seung Jun; Kim, Aeree; Oh, Sejong; Whang, Kwang Youn; Kim, Hyunggee; Kim, Dong-Wook; Kim, Ki Dong; You, Seungkwon

    2008-01-01

    Recently, Bmi1 was shown to control the proliferation and self-renewal of neural stem cells (NSCs). In this study, we demonstrated the induction of NSC-like cells (NSCLCs) from mouse astrocytes by Bmi1 under NSC culture conditions. These NSCLCs exhibited the morphology and growth properties of NSCs, and expressed NSC marker genes, including nestin, CD133, and Sox2. In vitro differentiation of NSCLCs resulted in differentiated cell populations containing astrocytes, neurons, and oligodendrocytes. Following treatment with histone deacetylase inhibitors (trichostatin A and valproic acid), the potential of NSCLCs for proliferation, dedifferentiation, and self-renewal was significantly inhibited. Our data indicate that multipotent NSCLCs can be generated directly from astrocytes by the addition of Bmi1

  17. Mutation to ouabain-resistance in Chinese hamster cells: induction by ethyl methanesulphonate and lack of induction by ionising radiation

    International Nuclear Information System (INIS)

    Thacker, J.; Stephens, M.A.; Stretch, A.

    1978-01-01

    The spontaneous frequency of mutants resistant to growth inhibition by ouabian (OUAsup(R) mutants) was found to be about 5.10 -5 per viable cell in uncloned cultures of Chinese hamster V79-4 cells. In freshly-isolated clones or cultures started from a few cells this frequency was initially reduced to about 1.10 -6 in 1 mM ouabain. No increase in the frequency of OUAsup(R) mutants was found in cultures treated with γ-rays despite exploration of such variables as radiation dose, ouabain concentration, post-treatment interval before selection, cell density in selective medium, and clonal state of the cells at the time of adding ouabain (in situ vs. respreading method). A similar negative result was found for accelerated helium ions, for which the mutagenic effectiveness per unit dose has been shown to be about 10 times higher than γ-rays for the induction of thioguanine-resistant mutants in these cells. Recent evidence is reviewed in support of the suggestion that ionising radiation is unable to induce OUAsup(R) mutants because of the severity of the genetic damage it causes. (Auth.)

  18. Prostaglandin E2 and the protein kinase A pathway mediate arachidonic acid induction of c-fos in human prostate cancer cells

    Science.gov (United States)

    Chen, Y.; Hughes-Fulford, M.

    2000-01-01

    Arachidonic acid (AA) is the precursor for prostaglandin E2 (PGE2) synthesis and increases growth of prostate cancer cells. To further elucidate the mechanisms involved in AA-induced prostate cell growth, induction of c-fos expression by AA was investigated in a human prostate cancer cell line, PC-3. c-fos mRNA was induced shortly after addition of AA, along with a remarkable increase in PGE2 production. c-fos expression and PGE2 production induced by AA was blocked by a cyclo-oxygenase inhibitor, flurbiprofen, suggesting that PGE2 mediated c-fos induction. Protein kinase A (PKA) inhibitor H-89 abolished induction of c-fos expression by AA, and partially inhibited PGE2 production. Protein kinase C (PKC) inhibitor GF109203X had no significant effect on c-fos expression or PGE2 production. Expression of prostaglandin (EP) receptors, which mediate signal transduction from PGE2 to the cells, was examined by reverse transcription polymerase chain reaction in several human prostate cell lines. EP4 and EP2, which are coupled to the PKA signalling pathway, were expressed in all cells tested. Expression of EP1, which activates the PKC pathway, was not detected. The current study showed that induction of the immediate early gene c-fos by AA is mediated by PGE2, which activates the PKA pathway via the EP2/4 receptor in the PC-3 cells.

  19. Aluminium content of some processed foods, raw materials and food additives in China by inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Deng, Gui-Fang; Li, Ke; Ma, Jing; Liu, Fen; Dai, Jing-Jing; Li, Hua-Bin

    2011-01-01

    The level of aluminium in 178 processed food samples from Shenzhen city in China was evaluated using inductively coupled plasma-mass spectrometry. Some processed foods contained a concentration of up to 1226 mg/kg, which is about 12 times the Chinese food standard. To establish the main source in these foods, Al levels in the raw materials were determined. However, aluminium concentrations in raw materials were low (0.10-451.5 mg/kg). Therefore, aluminium levels in food additives used in these foods was determined and it was found that some food additives contained a high concentration of aluminium (0.005-57.4 g/kg). The results suggested that, in the interest of public health, food additives containing high concentrations of aluminium should be replaced by those containing less. This study has provided new information on aluminium levels in Chinese processed foods, raw materials and a selection of food additives.

  20. Accuracy and Precision in Elemental Analysis of Environmental Samples using Inductively Coupled Plasma-Atomic Emission Spectrometry

    International Nuclear Information System (INIS)

    Quraishi, Shamsad Begum; Chung, Yong-Sam; Choi, Kwang Soon

    2005-01-01

    Inductively Coupled Plasma-Atomic Emission Spectrometry followed by micro-wave digestion have been performed on different environmental Certified Reference Materials (CRMs). Analytical results show that accuracy and precision in ICP-AES analysis were acceptable and satisfactory in case of soil and hair CRM samples. The relative error of most of the elements in these two CRMs is within 10% with few exceptions and coefficient of variation is also less than 10%. Z-score as an analytical performance was also within the acceptable range (±2). ICP-AES was found as an inadequate method for Air Filter CRM due to incomplete dissolution, low concentration of elements and very low mass of the sample. However, real air filter sample could have been analyzed with high accuracy and precision by increasing sample mass during collection. (author)

  1. Spectrochemical pure cerium dioxide preparation and its quality control by inductively coupled plasma and mass spectrometry (ICP/MS)

    International Nuclear Information System (INIS)

    Da Silva Queiroz, C.A.; De Souza, J.E.; Abrao, A.

    1998-01-01

    Full text: A simple and economic procedure for the purification until 500 g CeO 2 batch is presented. The purified material will be used as spectrochemical standard. It is obtained by association of the fractional precipitation technique in the system REC 3 /H 2 O 2 /NH 4 OH to enrich the cerium up to 90% and then refined by ion exchange up to 99.9% CeO2. The 99,9% CeO 2 warranty control of purity was accomplished by inductively coupled plasma and mass spectrometry (ICP/ MS) and compared with activation analysis data, exhibiting impurities traces of same values of the international spec pure standard. The following results (average values) for the contaminant rare earths are (ppm):La(36), Pr(19), Nd(161), Sm(11), Eu(5,3),Gd(113),Tb(89),Dy(2),Ho(0.05),Er(1), Tm(0), Yb(11), Lu (19) and Y(2.1), respectively

  2. Application of a high resolution inductively coupled plasma mass spectrometer to the measurement of long-lived radionuclides

    International Nuclear Information System (INIS)

    Kim, C.-K.; Seki, Riki; Morita, Shigemitsu; Takaku, Yuichi; Igarashi, Yasuhito; Yamamoto, Masayoshi

    1991-01-01

    Some long-lived radionuclides, such as 99 Tc, 226 Ra, 232 Th, 237 Np, 238 U, 239 Pu and 240 Pu were measured using high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). By using HR-ICP-MS with an ultrasonic nebulizer, the detection limits of these nuclides were 0.002-0.2 pg ml -2 and the sensitivities were 10 times better than those obtained using HR-ICP-MS without the ultrasonic nebulizer. More accurate isotopic data were also obtained using HR-ICP-MS than with quadrupole ICP-MS at lower concentrations of the analyte because of the improvement in counting statistics that can be obtained with HR-ICP-MS due to the greater efficiency of ion transmission, A comparison of the measurement of the 240 Pu to 239 Pu ratio is shown. (Author)

  3. Development and evaluation of high resolution quadrupole mass analyzer and an inductively coupled plasma-Mach disk

    Energy Technology Data Exchange (ETDEWEB)

    Amad, Ma' an Hazem [Iowa State Univ., Ames, IA (United States)

    1999-12-10

    By definition a plasma is an electrically conducting gaseous mixture containing a significant concentration of cations and electrons. The Inductively Coupled Plasma (ICP) is an electrodeless discharge in a gas at atmospheric pressure. This discharge is an excellent one for vaporizing, atomizing, and ionizing elements. The early development of the ICP began in 1942 by Babat and then by Reed in the early 1960s. This was then followed by the pioneering work of Fassel and coworkers in the late 1960s. Commercial ICP spectrometers were introduced in the mid 1970s. A major breakthrough in the area of ICP took place in the early 1980s when the ICP was shown to be an excellent ion source for mass spectrometry.

  4. Classification of Antarctic algae by applying Kohonen neural network with 14 elements determined by inductively coupled plasma optical emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Balbinot, L. [Departamento de Quimica Analitica-Instituto de Quimica-Unicamp, PO Box 6154, CEP: 13083-971, Campinas, SP (Brazil); Smichowski, P. [Comision Nacional de Energia Atomica, Unidad de Actividad Quimica, Centro Atomico Constituyentes, Av. Gral Paz 1499, B1650KNA, San Martin, Provincia de Buenos Aires (Argentina); Farias, S. [Comision Nacional de Energia Atomica, Unidad de Actividad Quimica, Centro Atomico Constituyentes, Av. Gral Paz 1499, B1650KNA, San Martin, Provincia de Buenos Aires (Argentina); Arruda, M.A.Z. [Departamento de Quimica Analitica-Instituto de Quimica-Unicamp, PO Box 6154, CEP: 13083-971, Campinas, SP (Brazil); Vodopivez, C. [Instituto Antartico Argentino, Cerrito 1010, C1248AAZ, Buenos Aires (Argentina); Poppi, R.J. [Departamento de Quimica Analitica-Instituto de Quimica-Unicamp, PO Box 6154, CEP: 13083-971, Campinas, SP (Brazil)]. E-mail: ronei@iqm.unicamp.br

    2005-06-30

    Optical emission spectrometers can generate results, which sometimes are not easy to interpret, mainly when the analyses involve classifications. To make simultaneous data interpretation possible, the Kohonen neural network is used to classify different Antarctic algae according to their taxonomic groups from the determination of 14 analytes. The Kohonen neural network architecture used was 5x5 neurons, thus reducing 14-dimension input data to two-dimensional space. The input data were 14 analytes (As, Co, Cu, Fe, Mn, Sr, Zn, Cd, Cr, Mo, Ni, Pb, Se, V) with their concentrations, determined by inductively coupled plasma optical emission spectrometry in 11 different species of algae. Three taxonomic groups (Rhodophyta, Phaeophyta and Cholorophyta) can be differentiated and classified through only their Cu content.

  5. Investigation of InP etching mechanisms in a Cl2/H2 inductively coupled plasma by optical emission spectroscopy

    International Nuclear Information System (INIS)

    Gatilova, L.; Bouchoule, S.; Guilet, S.; Chabert, P.

    2009-01-01

    Optical emission spectroscopy (OES) has been used in order to investigate the InP etching mechanisms in a Cl 2 -H 2 inductively coupled plasma. The authors have previously shown that anisotropic etching of InP could be achieved for a H 2 percentage in the 35%-45% range where the InP etch rate also presents a local maximum [J. Vac. Sci. Technol. B 24, 2381 (2006)], and that anisotropic etching was due to an enhanced passivation of the etched sidewalls by a silicon oxide layer [J. Vac. Sci. Technol. B 26, 666 (2008)]. In this work, it is shown that this etching behavior is related to a maximum in the H atom concentration in the plasma. The possible enhancement of the sidewall passivation process in the presence of H is investigated by comparing OES measurements and etching results obtained for Cl 2 -H 2 and Cl 2 -Ar gas mixtures

  6. Classification of Antarctic algae by applying Kohonen neural network with 14 elements determined by inductively coupled plasma optical emission spectrometry

    International Nuclear Information System (INIS)

    Balbinot, L.; Smichowski, P.; Farias, S.; Arruda, M.A.Z.; Vodopivez, C.; Poppi, R.J.

    2005-01-01

    Optical emission spectrometers can generate results, which sometimes are not easy to interpret, mainly when the analyses involve classifications. To make simultaneous data interpretation possible, the Kohonen neural network is used to classify different Antarctic algae according to their taxonomic groups from the determination of 14 analytes. The Kohonen neural network architecture used was 5x5 neurons, thus reducing 14-dimension input data to two-dimensional space. The input data were 14 analytes (As, Co, Cu, Fe, Mn, Sr, Zn, Cd, Cr, Mo, Ni, Pb, Se, V) with their concentrations, determined by inductively coupled plasma optical emission spectrometry in 11 different species of algae. Three taxonomic groups (Rhodophyta, Phaeophyta and Cholorophyta) can be differentiated and classified through only their Cu content

  7. Sample treatment procedures for the determination of mineral constituents in honey by Inductively Coupled Plasma Optical Emission Spectrometry

    Directory of Open Access Journals (Sweden)

    Mendes Teresa M. F. F.

    2006-01-01

    Full Text Available Preparative methods for quantification of inorganic constituents in honey by Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES using microwave assisted digestion and ultrasonication procedures were developed. Analytical aspects such as matrix complexity, instrumental optimization and the essentiality/toxicity of the species K, Ca, Mg, Na, Fe, Mn, Zn, Cu, Co, Ni, Pb, Cd were considered. Parameters such as plasma power, nebulizer flow rate, torch configuration and the convenience of the use of yttrium as internal standard were evaluated. Recoveries between 93 and 107% (microwave digestion and between 90 to 110% (ultrasonication procedure and relative standard deviations lower than 10% were obtained. Samples of Brazilian honeys, from different parts of the country, were analysed and the results obtained provide relevant information about their mineral content.

  8. Determination of selenite and selenate in human urine by ion chromatography and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Jons, O.

    2000-01-01

    The selenium species selenite, selenate and selenomethionine were separated in aqueous solution by ion chromatography. The separation was performed on an IonPac AG11 in series with an AS11 anion exchange column by elution with 25 mM sodium hydroxide in 2% methanol. The Se-78 and Se-82 isotopes were...... monitored in the inductively coupled plasma mass spectrometry (ICP-MS) detector. When the chromatographic system was applied to analysis of urine samples diluted 1 + 1, the selenomethionine signal appeared in the front together with other unresolved selenium species, while the selenite and selenate signals...... and selenate, respectively, corresponding to absolute amounts of 8 and 16 pg, respectively. Calculations were based on peak height measurements of the Se-82 isotope. In 23 analysed urine samples, the concentration of selenite was in the range selenium...

  9. Comparison of ultraviolet femtosecond and nanosecond laser ablation inductively coupled plasma mass spectrometry analysis in glass, monazite, and zircon.

    Science.gov (United States)

    Poitrasson, Franck; Mao, Xianglei; Mao, Samuel S; Freydier, Rémi; Russo, Richard E

    2003-11-15

    We compared the analytical performance of ultraviolet femtosecond and nanosecond laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). The benefit of ultrafast lasers was evaluated regarding thermal-induced chemical fractionation, that is otherwise well known to limit LA-ICPMS. Both lasers had a Gaussian beam energy profile and were tested using the same ablation system and ICPMS analyzer. Resulting crater morphologies and analytical signals showed more straightforward femtosecond laser ablation processes, with minimal thermal effects. Despite a less stable energy output, the ultrafast laser yielded elemental (Pb/U, Pb/Th) and Pb isotopic ratios that were more precise, repeatable, and accurate, even when compared to the best analytical conditions for the nanosecond laser. Measurements on NIST glasses, monazites, and zircon also showed that femtosecond LA-ICPMS calibration was less matrix-matched dependent and therefore more versatile.

  10. The effect of SF6 addition in a Cl2/Ar inductively coupled plasma for deep titanium etching

    Science.gov (United States)

    Laudrel, E.; Tillocher, T.; Meric, Y.; Lefaucheux, P.; Boutaud, B.; Dussart, R.

    2018-05-01

    Titanium is a material of interest for the biomedical field and more particularly for body implantable devices. Titanium deep etching by plasma was carried out in an inductively coupled plasma with a chlorine-based chemistry for the fabrication of titanium-based microdevices. Bulk titanium etch rate was first studied in Cl2/Ar plasma mixture versus the source power and the self-bias voltage. The plasma was characterized by Langmuir probe and by optical emission spectroscopy. The addition of SF6 in the plasma mixture was investigated. Titanium etch rate was optimized and reached a value of 2.4 µm · min-1. The nickel hard mask selectivity was also enhanced. The etched titanium surface roughness was reduced significantly.

  11. A methodology development and validation of serum and blood multielemental analysis by inductively coupled high resolution mass spectrometry

    International Nuclear Information System (INIS)

    Monteiro, Lucilena Rebelo

    2000-01-01

    This work reports a methodology development and validation of elementary analysis in whole blood and serum samples, by using the inductively coupled high resolution mass spectrometry technique. Some figures of merit were studied, such as instrumental and procedure detection limits, long and short term stabilities, resolution, sensibility, and the technique precision and accuracy. These results were compared with available values from the same and other techniques found in current literature. The main spectral and non-spectral interference associated with biological samples were also studied, along with, the interference formation rates and some options to minimize its effects. Once the analytical methodology variables were found, it was made a small population assay, with 23 running athletes. This assay evaluate the methodology reliability in nutritional studies. The principal component analysis was applied in the individual correlation, in function of metal content in serum and in function of the clinical profile. (author)

  12. Inductively coupled plasma-induced defects in n-type GaN studied from Schottky diode characteristics

    International Nuclear Information System (INIS)

    Nakamura, W.; Tokuda, Y.; Ueda, H.; Kachi, T.

    2006-01-01

    Inductively coupled plasma-(ICP-)induced defects in n-type GaN have been studied from current-voltage (I-V) characteristics and deep-level transient spectroscopy (DLTS) for Schottky diodes fabricated on etched surfaces. The samples after ICP etching show the ohmic I-V characteristics. Schottky characteristics are obtained after annealing at 600 and 800 deg. C in N 2 , but are not restored to that of the control samples. DLTS shows that the effect of ICP etching is small on the region beyond 80 nm from the surface. These results suggest that there remain ICP-induced damage in the near-surface region after thermal annealing

  13. Investigations of the inductively coupled plasma source for analyzing NURE water samples at the Los Alamos Scientific Laboratory

    International Nuclear Information System (INIS)

    Apel, C.T.; Bieniewski, T.M.; Cox, L.E.; Steinhaus, D.W.

    1977-03-01

    A 3.4-meter direct-reading spectrograph is being used with an inductively coupled plasma source for the simultaneous determination of Ag, Bi, Cd, Cu, Nb, Ni, Pb, Sn, and W in water samples. We have attached a small digital computer to the system in order to obtain intensity data on each element once a second. After the intensities during a run on a sample have stabilized, the computer records the intensity data and outputs the average concentration for each element. To approach the published detection limits, a peristaltic pump must be used to force the water sample into the usual cross-flow nebulizer. We have studied several different nebulizer designs with the goal of improving efficiency and hence sensitivity. One design, the fritted-disk nebulizer, has an efficiency over 60 percent, as compared with the 5 percent efficiency of the original nebulizer

  14. Determination of daily intake of elements from Philippine total diet samples using inductively coupled plasma-atomic emission spectrometry

    International Nuclear Information System (INIS)

    Leon, G.C. de; Shiraishi, K.; Kawamura, H.; Igaraishi, Y.; Palattao, M.V.; Azanon, E.M.

    1990-10-01

    Total diet samples were analyzed for major elements (Na, K, Ca, Mg, P) and some minor trace elements (Fe, Zn, Mn, Al, Sr, Cu, Ba, Yt) using inductively coupled plasma-atomic emission spectrometry (ICP-AES). Samples analyzed were classified into sex and age groups. Results for some elements (Na, K, Mg, Zn, Cu, Mn) were compared with values from Bataan dietary survey calculated using the Philippine composition table. Exceot for Na, analytical results were similar to calculated values. Analytical results for Ca and Fe were also compared with the values from Food and Nutrition Research Institute. In general, values obtained in the study were lower than the FNRI values. Comparison of the analytical and calculated results with the Japanese and ICRP data showed that Philippine values were lower than foreign values. (Auth.). 22 refs., 9 tabs

  15. Determination of bromine and tin compounds in plastics using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS).

    Science.gov (United States)

    İzgi, Belgin; Kayar, Murat

    2015-07-01

    The polybrominated flame retardants and organotin compounds were screened in terms of bromine and tin content using laser ablation inductively coupled plasma mass spectrometry in plastics. The calibration standards were prepared using the fused-disk technique, and all samples were investigated under optimal conditions. Using a central composite experimental design, laser parameters, laser energy, pulse rate, scan rate and spot size were identified. The detection limits of the method were 1000 mgkg(-1) and 1600 mgkg(-1) for bromide and tin, whereas the relative standard deviation (%) values of the analysis were 9% and 6% (n=3) for ERM EC681k with 770 ± 70 mgkg(-1) Br and 86 ± 6 mgkg(-1) Sn respectively, and 106-115% of Br and 102-104% of Sn were observed for the tetrabromobisphenol A and butyltin trichloride spike plastics, respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Multiplexed microRNA detection using lanthanide-labeled DNA probes and laser ablation inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    de Bang, Thomas Christian; Shah, Pratik; Cho, Seok Keun

    2014-01-01

    coupled plasma mass spectrometry (LA-ICPMS). Three miRNAs from Arabidopsis thaliana were analyzed simultaneously with high specificity, and the sensitivity of the method was comparable to radioactive detection (low femtomol range). The perspective of the developed method is highly multiplexed......In the past decade, microRNAs (miRNAs) have drawn increasing attention due to their role in regulation of gene expression. Especially, their potential as biomarkers in disease diagnostics has motivated miRNA research, including the development of simple, accurate, and sensitive detection methods....... The narrow size range of miRNAs (20-24 nucleotides) combined with the chemical properties of conventional reporter tags has hampered the development of multiplexed miRNA assays. In this study, we have used lanthanide-labeled DNA probes for the detection of miRNAs on membranes using laser ablation inductively...

  17. Fabrication of single-crystal silicon nanotubes with sub-10 nm walls using cryogenic inductively coupled plasma reactive ion etching

    Science.gov (United States)

    Li, Zhiqin; Chen, Yiqin; Zhu, Xupeng; Zheng, Mengjie; Dong, Fengliang; Chen, Peipei; Xu, Lihua; Chu, Weiguo; Duan, Huigao

    2016-09-01

    Single-crystal silicon nanostructures have attracted much attention in recent years due in part to their unique optical properties. In this work, we demonstrate direct fabrication of single-crystal silicon nanotubes with sub-10 nm walls which show low reflectivity. The fabrication was based on a cryogenic inductively coupled plasma reactive ion etching process using high-resolution hydrogen silsesquioxane nanostructures as the hard mask. Two main etching parameters including substrate low-frequency power and SF6/O2 flow rate ratio were investigated to determine the etching mechanism in the process. With optimized etching parameters, high-aspect-ratio silicon nanotubes with smooth and vertical sub-10 nm walls were fabricated. Compared to commonly-used antireflection silicon nanopillars with the same feature size, the densely packed silicon nanotubes possessed a lower reflectivity, implying possible potential applications of silicon nanotubes in photovoltaics.

  18. Room temperature inductively coupled plasma etching of InAs/InSb in BCl 3/Cl 2/Ar

    KAUST Repository

    Sun, Jian

    2012-10-01

    Inductively coupled plasma (ICP) etching of InAs and InSb at room temperature has been investigated using BCl 3/Cl 2/Ar plasma. Specifically, the etch rate and post-etching surface morphology were investigated as functions of the gas composition, ICP power, process pressure, and RF chuck power. An optimized process has been developed, yielding anisotropic etching and very smooth surfaces with roughnesses of 0.25 nm for InAs, and 0.57 nm for InSb, which is comparable with the surface of epi-ready polished wafers. The process provides moderate etching rates of 820 /min for InAs and 2800 /min for InSb, and the micro-masking effect is largely avoided. © 2012 Elsevier B.V. All rights reserved.

  19. Determination of boron in the waters of Troia by inductively coupled plasma-atomic emission spectrometry (ICP-AES

    Directory of Open Access Journals (Sweden)

    HASAN OZCAN

    2005-10-01

    Full Text Available The inductively coupled plasma-atomic emission spectrometry method (ICP-EAS is proposed for the determination of boron in Troia water sources. In this study, boron samples were taken from 25 different locations during November 2002 and May 2003. The 249.773 nm boron emmision line was not affected by the samplematrix. The boron content was determined without further pretreatment of samples proposed ICP-AES method. An analysis of a given sample was completed in about 15 min. The determined boron concentrations in surface and ground water sources were between 0.00444–1.11200mgl-1. Inorder to compare the results obtained by the proposed method, selected water samples were also analysed titrimetically. Pearson correlation coefficient analysis showed that there is a close relationship between the ICP-AES and the titrimetric method and the determination coefficient (R2 was calculated to be 91.34 %.

  20. Standard test method for determining elements in waste streams by inductively coupled plasma-atomic emission spectroscopy

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    This test method covers the determination of trace, minor, and major elements in waste streams by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) following an acid digestion of the specimen. Waste streams from manufacturing processes of nuclear and nonnuclear materials can be analyzed. This test method is applicable to the determination of total metals. Results from this test method can be used to characterize waste received by treatment facilities and to formulate appropriate treatment recipes. The results are also usable to process control within waste treatment facilities. This test method is applicable only to waste streams that contain radioactivity levels which do not require special personnel or environmental protection. A list of the elements determined in waste streams and the corresponding lower reporting limit is included

  1. Determination of strontium and lead isotope ratios of grains using high resolution inductively coupled plasma mass spectrometer with single collector

    International Nuclear Information System (INIS)

    Shinozaki, Miyuki; Ariyama, Kaoru; Kawasaki, Akira; Hirata, Takafumi

    2010-01-01

    A method for determining strontium and lead isotope ratios of grains was developed. The samples investigated in this study were rice, barley and wheat. The samples were digested with nitric acid and hydrogen peroxide, and heated in a heating block. Strontium and lead were separated from the matrix by adding an acid digested solution into a column packed with Sr resin, which has selectivity for the absorption of strontium and lead. Strontium and lead isotope ratios were determined using a high-resolution inductively coupled plasma mass spectrometer (HR-ICP-MS) with a single collector. The intraday relative standard deviations of 87 Sr/ 86 Sr and lead isotope ratios ( 204 Pb/ 206 Pb, 207 Pb/ 206 Pb, 208 Pb/ 206 Pb) by HR-ICP-MS measurements were < 0.06% and around 0.1%, respectively. This method enabled us to determine strontium and lead isotope ratios in two days. (author)

  2. Online Determination of Sm, Eu and Yb in Environmental Samples by Inductively Coupled Plasma – Optical Emission Spectrometry

    Directory of Open Access Journals (Sweden)

    J. Dilip Kumar

    2007-01-01

    Full Text Available A procedure was developed for the determination of Sm, Eu and Yb in water samples by inductively coupled plasma-optical emission spectrometry (ICP-OES after preconcentration on synthesized 5-(4-pyridyl azo-8-quinolinol supported by Borassus flabellifer inflorescence (BFI. The sorbed element was subsequently eluted with 0.4 M HNO3 and the acid eluates were analyzed by ICP-OES. Under the optimal conditions, Sm, Eu and Yb in aqueous samples were concentrated 100-fold. Recoveries were obtained by the proposed method in the range of 98.6 -99.8%. This method was also applied for the analysis of spiked and natural water samples. The results provide strong evidence to support the hypothesis of an adsorption mechanism.

  3. Induction of non-rejoinable DNA breaks in mammalian cells by high LET radiations

    International Nuclear Information System (INIS)

    Ritter, M.A.

    1976-01-01

    Chinese hamster cells (V79-S171) were irradiated with x-rays and low-energy charged particles with an LET range of 9.5 to 827 keV/μm. The dependency of DNA strand break induction on LET and the fraction of breaks that could not rejoin during post-irradiation incubation were determined with alkaline sucrose gradient techniques. Results indicate that the efficiency of strand break induction decreases with increasing LET. The efficiency of non-rejoinable break induction, however, increases to 4.8 times the x-ray value at an LET of 150 keV/μm and then decreases with further LET increase. This peaked LET response for non-rejoinable break induction is very similar to the pattern that the RBE for cell killing exhibits as a function of LET

  4. Effect of caffeine on induction of endogenous type C virus in mouse cells in vitro

    International Nuclear Information System (INIS)

    Niwa, O.; Sugahara, T.

    1981-01-01

    The effect of caffeine on the expression of murine endogenous virus in mouse cells induced by radiation and chemicals was studied. Postirradiation treatment of K-BALB cells with caffeine enhanced cell killing as well as the induction of xenotropic virus after ultraviolet light irradiation. The degree of enhancement for the virus induction was comparable to that for cell killing. On the other hand, colony-forming ability and the expression of xenotropic virus of K-BALB cells after X-irradiation were unaffected by caffeine. These data suggest a linear relationship between the degree of endogenous virus expression and the amount of lethal damages after irradiation. For induction by halogenated pyrimidines, a 24-hr incubation of AKR2B cells with caffeine after 5-iodo-2'-deoxyuridine treatment resulted in marked suppression of the expression of ecotropic virus. On the contrary, in K-BALB cells, caffeine exerted only a small effect on 5-iodo-2'-deoxyuridine-induced expression of ecotropic and xenotropic viruses. These results indicate that, although using the same inducing agent, the pathway of endogenous virus induction may be different for AKR2B cells and for K-BALB cells

  5. Induction of non-responsiveness in human allergen-specific type 2 T helper cells.

    Science.gov (United States)

    Yssel, H; Fasler, S; Lamb, J; de Vries, J E

    1994-12-01

    Activation of allergen-reactive human T helper (Th)2 cells in the absence of professional antigen-presenting cells, induces non-responsiveness or anergy in these cells in vitro. This induction of anergy is accompanied by phenotypic modulation and altered cytokine production. Furthermore, peptide-treated Th2 cells fail to provide B-cell help for IgE synthesis. Recent studies indicate that impaired signal transduction via the T-cell receptor may account for the lack of responsiveness to antigenic stimulation. Here, we review present knowledge on the cell biology of non-responsive or anergic Th2 cells.

  6. Searching the most appropriate sample pretreatment for the elemental analysis of wines by inductively coupled plasma-based techniques.

    Science.gov (United States)

    Gonzálvez, A; Armenta, S; Pastor, A; de la Guardia, M

    2008-07-09

    Different sample preparation methods were evaluated for the simultaneous multielement analysis of wine samples by inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS). Microwave-assisted digestion in closed vessel, thermal digestion in open reactor, and direct sample dilution were considered for the determination of Li, Be, Na, Mg, Al, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Y, Mo, Cd, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Tl, Pb, and Bi in 12 samples of red wine from Valencia and Utiel-Requena protected designation of origin. ICP-MS allows the determination of 17 elements in most of the samples, and using ICP-OES, a maximum of 15 elements were determined. On comparing the sample pretreatment methodology, it can be concluded that the three assayed procedures provide comparable results for the concentration of Li, Na, Mg, Al, K, Ca, Mn, Fe, Zn, and Sr by ICP-OES. Furthermore, ICP-MS data found for Cu, Pb, and Ba were comparable. Digestion treatment provides comparable values using both total decomposition in open system and microwave-assisted treatment for Cu by ICP-OES and for Cr, Ni, and Zn by ICP-MS. Open vessel total digestion provides excess values for Cr, Mn, Fe, and Zn by ICP-OES and defect values for Se. However, direct measurement of diluted wine samples provided uncomparable results with the digestion treatment for Mn, Cu, Pb, Zn, Ba, and Bi by ICP-OES and for Mg, Cr, Fe, Ni, and Zn by ICP-MS. Therefore, it can be concluded that microwave-assisted digestion is the pretreatment procedure of choice for elemental analysis of wine by ICP-based techniques.

  7. Simultaneous determination of macronutrients, micronutrients and trace elements in mineral fertilizers by inductively coupled plasma optical emission spectrometry

    Science.gov (United States)

    de Oliveira Souza, Sidnei; da Costa, Silvânio Silvério Lopes; Santos, Dayane Melo; dos Santos Pinto, Jéssica; Garcia, Carlos Alexandre Borges; Alves, José do Patrocínio Hora; Araujo, Rennan Geovanny Oliveira

    2014-06-01

    An analytical method for simultaneous determination of macronutrients (Ca, Mg, Na and P), micronutrients (Cu, Fe, Mn and Zn) and trace elements (Al, As, Cd, Pb and V) in mineral fertilizers was optimized. Two-level full factorial design was applied to evaluate the optimal proportions of reagents used in the sample digestion on hot plate. A Doehlert design for two variables was used to evaluate the operating conditions of the inductively coupled plasma optical emission spectrometer in order to accomplish the simultaneous determination of the analyte concentrations. The limits of quantification (LOQs) ranged from 2.0 mg kg- 1 for Mn to 77.3 mg kg- 1 for P. The accuracy and precision of the proposed method were evaluated by analysis of standard reference materials (SRMs) of Western phosphate rock (NIST 694), Florida phosphate rock (NIST 120C) and Trace elements in multi-nutrient fertilizer (NIST 695), considered to be adequate for simultaneous determination. Twenty-one samples of mineral fertilizers collected in Sergipe State, Brazil, were analyzed. For all samples, the As, Ca, Cd and Pb concentrations were below the LOQ values of the analytical method. For As, Cd and Pb the obtained LOQ values were below the maximum limit allowed by the Brazilian Ministry of Agriculture, Livestock and Food Supply (Ministério da Agricultura, Pecuária e Abastecimento - MAPA). The optimized method presented good accuracy and was effectively applied to quantitative simultaneous determination of the analytes in mineral fertilizers by inductively coupled plasma optical emission spectrometry (ICP OES).

  8. Development of a direct hydride generation nebulizer for the determination of selenium by inductively coupled plasma optical emission spectrometry

    International Nuclear Information System (INIS)

    Carrion, Nereida; Murillo, Miguel; Montiel, Edie; Diaz, Dorfe

    2003-01-01

    A study was conducted to evaluate the performance of a new direct hydride generation nebulizer system for determination of hydride forming elements by inductively coupled plasma optical emission spectroscopy. This system was designed and optimized to obtain the highest sensitivity. Several experimental designs were used for these purposes. To optimize the individual parameters of the system, and to study the interaction between these parameters for both direct hydride generation nebulizers, a central composite orthogonal design with eight factors was set up. Significant behavioral differences were observed in the two direct hydride generation nebulizers studied. Finally, a 70 μm gas orifice nebulizer exhibits a better detection limit than the 120 μm nebulizer. Generally, for determination of selenium, this new direct hydride generation nebulizer system exhibits a linear dynamic range and detection limit (3σb) of 3 orders of magnitude and 0.2 μg l -1 for selenium, respectively. This new hydride generator is much simpler system that conventional hydride generation systems, which does not need to be changed to work in normal mode with the inductively coupled plasma, since this system may be used for hydride forming elements and those that do not form them. It produces a rapid response with low memory effect. It reduces the interference level of Ni, Co and Cu to 600, 500 and 5 mg l -1 , respectively. The accuracy of the system was verified by the determination of selenium in several standard reference materials of ambient, food and clinical sample matrices. No statistically significant differences (95 confidence level) were obtained between our method and the reference values

  9. Ultra-sensitive quantification of lysozyme based on element chelate labeling and capillary electrophoresis–inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Yang, MingWei; Wu, WeiHua; Ruan, YaJuan; Huang, LiMei; Wu, Zujian; Cai, Yong; Fu, FengFu

    2014-01-01

    Graphical abstract: An ultra-sensitive method for the determination of lysozyme was developed based on the Gd 3+ chelate labeling and CE–ICP–MS. The proposed method has an extremely low detection limit of 3.89 attomole and has been successfully used to detect lysozyme in saliva sample, showing excellent reliability. The success of the present method provides a new possibility for biological assays and clinical diagnoses. -- Highlights: •An ultra-sensitive method for detecting lysozyme based on CE–ICP–MS was described. •The proposed method has an extremely low detection limit of 3.89 attomole. •It can be used to detect trace lysozyme in saliva sample with a satisfied recovery. •The method provides a new potential for sensitive detection of low-abundant proteins. -- Abstract: In this study, an ultra-sensitive method for the quantification of lysozyme based on the Gd 3+ diethylenetriamine-N,N,N′,N″,N″-pentaacetic acid labeling and capillary electrophoresis–inductively coupled plasma mass spectrometry (CE–ICP–MS) was described. The Gd 3+ -tagged lysozyme was effectively separated by capillary electrophoresis (CE) and sensitively determined by inductively coupled plasma mass spectrometry (ICP–MS). Based on the gadolinium-tagging and CE–ICP–MS, the lysozyme was determined within 12 min with an extremely low detection limit of 3.89 attomole (3.89 × 10 −11 mol L −1 for 100 nL of sample injection) and a RSD < 6% (n = 5). The proposed method has been successfully used to detect lysozyme in saliva samples with a recovery of 91–106%, suggesting that our method is sensitive and reliable. The success of the present method provides a new potential for the biological assays and sensitive detection of low-abundant proteins

  10. Autophagy induction contributes to GDC-0349 resistance in head and neck squamous cell carcinoma (HNSCC) cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yajuan; Peng, Yi [Department of Radiation Oncology, Hubei Cancer Hospital, Wuhan (China); Tang, Hao [Department of Pathology, Hubei Cancer Hospital, Wuhan 430071 (China); He, Xiaojun; Wang, Zhaohua [Department of Radiation Oncology, Hubei Cancer Hospital, Wuhan (China); Hu, Desheng, E-mail: hudeshengvvip@sina.com [Department of Radiation Oncology, Hubei Cancer Hospital, Wuhan (China); Zhou, Xiaoyi, E-mail: zhouxy1218@126.com [Department of Radiation Oncology, Hubei Cancer Hospital, Wuhan (China)

    2016-08-19

    Dysregulation of mammalian target of rapamycin (mTOR) signaling contributes to head and neck squamous cell carcinoma (HNSCC) tumorigenesis and progression. In the current study, we tested the anti-HNSCC cell activity by GDC-0349, a selective ATP-competitive inhibitor of mTOR. We showed that GDC-0349 inhibited proliferation of established and primary human HNSCC cells bearing high-level of p-AKT/p-S6K. Further, it induced caspase-dependent apoptosis in the HNSCC cells. GDC-0349 blocked mTORC1 and mTORC2 activation, yet it simultaneously induced autophagy activation in HNSCC cells. The latter was evidenced by induction of LC3B-II, Beclin-1 and Autophagy-related (ATG)-7, as well as downregulation of p62. Autophagy inhibitors (3-methyladenine and bafilomycin A1) or ATG-7 siRNA dramatically potentiated GDC-0349’s cytotoxicity against HNSCC cells. Intriguingly, we showed that ceramide (C14), a pro-apoptotic sphingolipid, also induced ATG-7 degradation, and sensitized HNSCC cells to GDC-0349. Collectively, the preclinical study provided evidences to support GDC-0349 as a promising anti-HNSCC agent. GDC-0349 sensitization may be achieved via autophagy inhibition. - Highlights: • GDC-0349 inhibits proliferation of HNSCC cells bearing high-level of p-AKT/p-S6K. • GDC-0349 activates caspase-dependent apoptosis in HNSCC cells. • Simultaneous blockage of mTORC1/2 by GDC-0349 induces autophagy activation. • Autophagy inhibitor or ATG-7 siRNA potentiates GDC-0349’s cytotoxicity. • C14 ceramide downregulates ATG-7 and sensitizes HNSCC cells to GDC-0349.

  11. Induction of sos response in Escherichia Coli cells by gamma rays

    International Nuclear Information System (INIS)

    Fuentes Lorenzo, J.L.; Padron Soler, E.; Martin Hernandez, G.; Perez Tamayo, N.; del Sol Abascal, E.R.; Almeida Varela, E.

    1996-01-01

    The kinetics of sos response induction in Escherichia Coli cells was studied by means of the gene fusion SfiA:LacZ. In these cells, the specific beta galactosidase activity and the cellular growth rate showed an exponential behaviour. The sensitivity of the GC 2181 starin to gamma irradiation is equal to Do -1= 0.00088/Gy. The beta galactosidase activity

  12. Induction of apoptosis by xanthones from mangosteen in human leukemia cell lines.

    Science.gov (United States)

    Matsumoto, Kenji; Akao, Yukihiro; Kobayashi, Emi; Ohguchi, Kenji; Ito, Tetsuro; Tanaka, Toshiyuki; Iinuma, Munekazu; Nozawa, Yoshinori

    2003-08-01

    We examined the effects of six xanthones from the pericarps of mangosteen, Garcinia mangostana, on the cell growth inhibition of human leukemia cell line HL60. All xanthones displayed growth inhibitory effects. Among them, alpha-mangostin showed complete inhibition at 10 microM through the induction of apoptosis.

  13. Induction of cell cycle arrest and apoptosis by Ormenis eriolepis a ...

    African Journals Online (AJOL)

    Induction of cell cycle arrest and apoptosis by Ormenis eriolepis a Morrocan endemic plant in various human cancer cell lines. Lamiae Belayachi, Clara Aceves-Luquero, Nawel Merghoub, Silvia Fernández de Mattos, Saaïd Amzazi, Priam Villalonga, Youssef Bakri ...

  14. Numerical Simulation of Plasma-Dynamical Processes in the Technological Inductively Coupled RF Plasmatron with Gas Cooling

    Directory of Open Access Journals (Sweden)

    Yu. M. Grishin

    2016-01-01

    Full Text Available The electrodeless inductively coupled RF plasmatron (ICP torches became widely used in various fields of engineering, science and technology. Presently, owing to development of new technologies to produce very pure substances, nanopowders, etc., there is a steadily increasing interest in the induction plasma. This generates a need for a broad range of theoretical and experimental studies to optimize the design and technological parameters of different ICP equipment.The paper presents a numerical model to calculate parameters of inductively coupled RF plasmatron with gas-cooling flow. A finite volume method is used for a numerical solution of a system of Maxwell's and heat transfer equations in the application package ANSYS CFX (14.5. The pseudo-steady approach to solving problems is used.A numerical simulation has been computed in the application package ANSYS CFX (14.5 for a specific design option of the technological ICP, which has a three-coils inductor and current amplitude in the range J к = 50-170 A (3 MHz. The pure argon flows in the ICP. The paper discusses how the value of discharge current impacts on the thermodynamic parameters (pressure, temperature and the power energy in discharge zone. It shows that the ICP can generate a plasma stream with a maximum temperature of about 10 kK and an output speed of 10-15 m/s. The work determines a length of the plasma stream with a weight average temperature of more than 4 kK. It has been found that in order to keep the quartz walls in normal thermal state, the discharge current amplitude should not exceed 150 A. The paper shows the features of the velocity field distribution in the channel of the plasma torch, namely, the formation of vortex in the position of the first coil. The results obtained are important for calculating the dynamics of heating and evaporation of quartz particles in the manufacturing processes for plasma processing of quartz concentrate into high-purity quartz and

  15. Inductive differentiation of two neural lineages reconstituted in a microculture system from Xenopus early gastrula cells.

    Science.gov (United States)

    Mitani, S; Okamoto, H

    1991-05-01

    Neural induction of ectoderm cells has been reconstituted and examined in a microculture system derived from dissociated early gastrula cells of Xenopus laevis. We have used monoclonal antibodies as specific markers to monitor cellular differentiation from three distinct ectoderm lineages in culture (N1 for CNS neurons from neural tube, Me1 for melanophores from neural crest and E3 for skin epidermal cells from epidermal lineages). CNS neurons and melanophores differentiate when deep layer cells of the ventral ectoderm (VE, prospective epidermis region; 150 cells/culture) and an appropriate region of the marginal zone (MZ, prospective mesoderm region; 5-150 cells/culture) are co-cultured, but not in cultures of either cell type on their own; VE cells cultured alone yield epidermal cells as we have previously reported. The extent of inductive neural differentiation in the co-culture system strongly depends on the origin and number of MZ cells initially added to culture wells. The potency to induce CNS neurons is highest for dorsal MZ cells and sharply decreases as more ventrally located cells are used. The same dorsoventral distribution of potency is seen in the ability of MZ cells to inhibit epidermal differentiation. In contrast, the ability of MZ cells to induce melanophores shows the reverse polarity, ventral to dorsal. These data indicate that separate developmental mechanisms are used for the induction of neural tube and neural crest lineages. Co-differentiation of CNS neurons or melanophores with epidermal cells can be obtained in a single well of co-cultures of VE cells (150) and a wide range of numbers of MZ cells (5 to 100). Further, reproducible differentiation of both neural lineages requires intimate association between cells from the two gastrula regions; virtually no differentiation is obtained when cells from the VE and MZ are separated in a culture well. These results indicate that the inducing signals from MZ cells for both neural tube and neural

  16. Induction of DISE in ovarian cancer cells in vivo

    OpenAIRE

    Murmann, Andrea E.; McMahon, Kaylin M.; Haluck-Kangas, Ashley; Ravindran, Nandini; Patel, Monal; Law, Calvin Y.; Brockway, Sonia; Wei, Jian-Jun; Thaxton, C. Shad; Peter, Marcus E.

    2017-01-01

    The death receptor CD95/Fas can be activated by immune cells to kill cancer cells. shRNAs and siRNAs derived from CD95 or CD95 ligand (CD95L) are highly toxic to most cancer cells. We recently found that these sh/siRNAs kill cancer cells in the absence of the target by targeting the 3’UTRs of critical survival genes through canonical RNAi. We have named this unique form of off-target effect DISE (for death induced by survival gene elimination). DISE preferentially kills transformed cells and ...

  17. DNA strand break induction and rejoining in Chinese hamster cells as a function of radiation quality

    International Nuclear Information System (INIS)

    Ritter, M.A.

    1976-01-01

    Chinese Hamster cells (V79-S171) were irradiated with 300 kVp x-rays and low-energy charged particles, covering an LET range of about 1 to 2900 keV/μm. The LET dependence of DNA strand-break induction and the rejoining kinetics of these breaks during post-irradiation incubation were investigated using alkaline sucrose gradients. The break-induction studies indicated that strand-break efficiency generally decreases with increasing LET, that low-energy, heavy ions induce DNA breaks non-randomly, and that anoxia protects less against high-LET induction than against low-LET induction of DNA breaks. Strand-break rejoining studies indicate the presence of three classes of breaks: a fast-rejoining class (T 1 / 2 = 8 min), whose induction efficiency decreases rapidly with LET increase; a slow-rejoining class (T 1 / 2 appoximately equal to 90 min), whose induction efficiency decreased gradually with LET increase; and a non-rejoining class (remained open during post-irradiation incubation), whose induction efficiency demonstrated a peaked response as a function of LET. The RBE for induction of non-rejoining DNA breaks rose to a maximum of 4.9 at an LET of 150 keV/μm and then decreased with further LET increase. This peaked response agrees closely with RBE's from the literature that are based upon initial slopes of mammalian cell survival curves as a function of LET. The agreement implies that non-rejoining DNA breaks are causally related to the lethal, irreversible component of cell inactivation by radiation

  18. Induction of malignant plasma cell proliferation by eosinophils.

    Directory of Open Access Journals (Sweden)

    Tina W Wong

    Full Text Available The biology of the malignant plasma cells (PCs in multiple myeloma (MM is highly influenced by the bone marrow (BM microenvironment in which they reside. More specifically, BM stromal cells (SCs are known to interact with MM cells to promote MM cell survival and proliferation. By contrast, it is unclear if innate immune cells within this same space also actively participate in the pathology of MM. Our study shows for the first time that eosinophils (Eos can contribute to the biology of MM by enhancing the proliferation of some malignant PCs. We first demonstrate that PCs and Eos can be found in close proximity in the BM. In culture, Eos were found to augment MM cell proliferation that is predominantly mediated through a soluble factor(s. Fractionation of cell-free supernatants and neutralization studies demonstrated that this activity is independent of Eos-derived microparticles and a proliferation-inducing ligand (APRIL, respectively. Using a multicellular in vitro system designed to resemble the native MM niche, SCs and Eos were shown to have non-redundant roles in their support of MM cell growth. Whereas SCs induce MM cell proliferation predominantly through the secretion of IL-6, Eos stimulate growth of these malignant cells via an IL-6-independent mechanism. Taken together, our study demonstrates for the first time a role for Eos in the pathology of MM and suggests that therapeutic strategies targeting these cells may be beneficial.

  19. Investigations and system design for simultaneous energy and data transmission through inductively coupled resonances

    Science.gov (United States)

    Schmidt, C.; Lloret Fuentes, E.; Buchholz, M.

    2015-11-01

    Wireless Power Transfer (WPT) with simultaneous data transmission through coupled magnetic resonators is investigated in this paper. The development of this system is dedicated to serve as a basis for applications in the field of Ambient Assisted Living (AAL), for example tracking vital parameters remotely, charge and control sensors and so on. Due to these different scenarios we consider, it is important to have a system which is reliable under the circumstance of changing positioning of the receiving device. State of the art radio systems would be able to handle this. Nevertheless, energy harvesting from far field sources is not sufficient to power the devices additionally on mid-range distances. For this reason, coupled magnetic resonant circuits are proposed as a promising alternative, although suffering from more complex positioning dependency. Based on measurements on a simple prototype system, an equivalent circuit description is used to model the transmission system dependent on different transmission distances and impedance matching conditions. Additionally, the simulation model is used to extract system parameters such as coupling coefficients, coil resistance and self-capacitance, which cannot be calculated in a simple and reliable way. Furthermore, a mathematical channel model based on the schematic model has been built in MATLAB©. It is used to point out the problems occurring in a transmission system with variable transmission distance, especially the change of the passband's centre frequency and its bandwidth. Existing solutions dealing with this distance dependent behaviour, namely the change of the transmission frequency dependent on distance and the addition of losses to the resonators to increase the bandwidth, are considered as not inventive. First, changing the transmission frequency increases the complexity in the data transmission system and would use a disproportional total bandwidth compared to the actually available bandwidth

  20. Proliferation in culture of primordial germ cells derived from embryonic stem cell: induction by retinoic acid.

    Science.gov (United States)

    Makoolati, Zohreh; Movahedin, Mansoureh; Forouzandeh-Moghadam, Mehdi

    2016-12-01

    An in vitro system that supports primordial germ cells (PGCs) survival and proliferation is useful for enhancement of these cells and efficient transplantation in infertility disorders. One approach is cultivation of PGCs under proper conditions that allow self-renewal and proliferation of PGCs. For this purpose, we compared the effects of different concentrations of retinoic acid (RA), and the effect of PGCs co-culture (Co-C) with SIM mouse embryo-derived thioguanine- and ouabain-resistant (STO) cells on the proliferation of embryonic stem cells (ESCs)-derived PGCs. One-day-old embryoid body (EB) was cultured for 4 days in simple culture system in the presence of 5 ng/ml bone morphogenetic protein-4 (BMP4) (SCB group) for PGC induction. For PGC enrichment, ESCs-derived germ cells were cultured for 7 days in the presence of different doses (0-5  μM) of RA, both in the simple and STO Co-C systems. At the end of the culture period, viability and proliferation rates were assessed and expression of mouse vasa homologue (Mvh),  α6 integrin,  β1 integrin, stimulated by retinoic acid 8 (Stra8) and piwi (Drosophila)-like 2 (Piwil2) was evaluated using quantitative PCR. Also, the inductive effects were investigated immunocytochemically with Mvh and cadherin1 (CDH1) on the selected groups. Immunocytochemistry/PCR results showed higher expression of Mvh, the PGC-specific marker, in 3  μM RA concentrations on the top of the STO feeder layer. Meanwhile, assessment of the Stra8 mRNA and CDH1 protein, the specific makers for spermatogonia, showed no significant differences between groups. Based on the results, it seems that in the presence of 3 μM RA on top of the STO feeder layer cells, the majority of the cells transdifferentiated into germ cells were PGCs. © 2016 The Author(s).

  1. Precise determination of dissolved silica in seawater by ion-exclusion chromatography isotope dilution inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Nonose, Naoko; Cheong, Chikako; Ishizawa, Yukari; Miura, Tsutomu; Hioki, Akiharu

    2014-08-20

    Ion exclusion chromatograph (IEC) isotope dilution (ID) inductively coupled plasma mass spectrometry (ICP-MS) (IEC-ID-ICP-MS) was developed for measurement of dissolved silica in seawater, which was applied to production of certified reference materials (CRMs) of three concentration levels of nutrients (high, medium and low levels). IEC-ICP-MS has been employed to separate dissolved silica from seawater matrix. In the present study, in order to solve substantial problems due to spectral interference in ICP-MS and to improve the accuracy of IEC-ICP-MS beyond standard addition or conventional calibration methods, ID method was coupled with ICP-sector field mass spectrometry (operated under medium resolution,i.e., m/Δm=4000). In addition, effects of various operating parameters in ICP-MS on a silicon background level were also investigated to obtain lower background equivalent concentration (BEC). As a result, 3 ng g(-1) of the BEC and 0.5 % of relative standard uncertainties were achieved in the analyses of dissolved silica in seawater samples at concentration levels from 4.0 mg kg (-1) to 0.8 mg kg(-1) as silicon. The developed method was successfully validated by analyses of an artificial seawater containing a known amount of silicate and the seawater certified reference material MOOS-2 produced by the National Research Council Canada. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Induction of epithelial-mesenchymal transition (EMT) in breast cancer cells is calcium signal dependent.

    Science.gov (United States)

    Davis, F M; Azimi, I; Faville, R A; Peters, A A; Jalink, K; Putney, J W; Goodhill, G J; Thompson, E W; Roberts-Thomson, S J; Monteith, G R

    2014-05-01

    Signals from the tumor microenvironment trigger cancer cells to adopt an invasive phenotype through epithelial-mesenchymal transition (EMT). Relatively little is known regarding key signal transduction pathways that serve as cytosolic bridges between cell surface receptors and nuclear transcription factors to induce EMT. A better understanding of these early EMT events may identify potential targets for the control of metastasis. One rapid intracellular signaling pathway that has not yet been explored during EMT induction is calcium. Here we show that stimuli used to induce EMT produce a transient increase in cytosolic calcium levels in human breast cancer cells. Attenuation of the calcium signal by intracellular calcium chelation significantly reduced epidermal growth factor (EGF)- and hypoxia-induced EMT. Intracellular calcium chelation also inhibited EGF-induced activation of signal transducer and activator of transcription 3 (STAT3), while preserving other signal transduction pathways such as Akt and extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation. To identify calcium-permeable channels that may regulate EMT induction in breast cancer cells, we performed a targeted siRNA-based screen. We found that transient receptor potential-melastatin-like 7 (TRPM7) channel expression regulated EGF-induced STAT3 phosphorylation and expression of the EMT marker vimentin. Although intracellular calcium chelation almost completely blocked the induction of many EMT markers, including vimentin, Twist and N-cadherin, the effect of TRPM7 silencing was specific for vimentin protein expression and STAT3 phosphorylation. These results indicate that TRPM7 is a partial regulator of EMT in breast cancer cells, and that other calcium-permeable ion channels are also involved in calcium-dependent EMT induction. In summary, this work establishes an important role for the intracellular calcium signal in the induction of EMT in human breast cancer cells. Manipulation of

  3. Induction of T-cell memory by a dendritic cell vaccine: a computational model.

    Science.gov (United States)

    Pappalardo, Francesco; Pennisi, Marzio; Ricupito, Alessia; Topputo, Francesco; Bellone, Matteo

    2014-07-01

    Although results from phase III clinical trials substantially support the use of prophylactic and therapeutic vaccines against cancer, what has yet to be defined is how many and how frequent boosts are needed to sustain a long-lasting and protecting memory T-cell response against tumor antigens. Common experience is that such preclinical tests require the sacrifice of a relatively large number of animals, and are particularly time- and money-consuming. As a first step to overcome these hurdles, we have developed an ordinary differential equation model that includes all relevant entities (such as activated cytotoxic T lymphocytes and memory T cells), and investigated the induction of immunological memory in the context of wild-type mice injected with a dendritic cell-based vaccine. We have simulated the biological behavior both in the presence and in the absence of memory T cells. Comparing results of ex vivo and in silico experiments, we show that the model is able to envisage the expansion and persistence of antigen-specific memory T cells. The model might be applicable to more complex vaccination schedules and substantially in any biological condition of prime-boosting. The model is fully described in the article. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  4. Elemental analysis of glass by laser ablation inductively coupled plasma optical emission spectrometry (LA-ICP-OES).

    Science.gov (United States)

    Schenk, Emily R; Almirall, José R

    2012-04-10

    The elemental analysis of glass evidence has been established as a powerful discrimination tool for forensic analysts. Laser ablation inductively coupled plasma optical emission spectrometry (LA-ICP-OES) has been compared to laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and energy dispersive micro X-ray fluorescence spectroscopy (μXRF/EDS) as competing instrumentation for the elemental analysis of glass. The development of a method for the forensic analysis of glass coupling laser ablation to ICP-OES is presented for the first time. LA-ICP-OES has demonstrated comparable analytical performance to LA-ICP-MS based on the use of the element menu, Al (Al I 396.15 nm), Ba (Ba II 455.40 nm), Ca (Ca II 315.88 nm), Fe (Fe II 238.20 nm), Li (Li I 670.78 nm), Mg (Mg I 285.21 nm), Sr (Sr II 407.77 nm), Ti (Ti II 368.51 nm), and Zr (Zr II 343.82 nm). The relevant figures of merit, such as precision, accuracy and sensitivity, are presented and compared to LA-ICP-MS. A set of 41 glass samples was used to assess the discrimination power of the LA-ICP-OES method in comparison to other elemental analysis techniques. This sample set consisted of several vehicle glass samples that originated from the same source (inside and outside windshield panes) and several glass samples that originated from different vehicles. Different match criteria were used and compared to determine the potential for Type I and Type II errors. It was determined that broader match criteria is more applicable to the forensic comparison of glass analysis because it can reduce the affect that micro-heterogeneity inherent in the glass fragments and a less than ideal sampling strategy can have on the interpretation of the results. Based on the test set reported here, a plus or minus four standard deviation (± 4s) match criterion yielded the lowest possibility of Type I and Type II errors. The developed LA-ICP-OES method has been shown to perform similarly to LA-ICP-MS in the

  5. Direct lifts of coupled cell networks

    Science.gov (United States)

    Dias, A. P. S.; Moreira, C. S.

    2018-04-01

    In networks of dynamical systems, there are spaces defined in terms of equalities of cell coordinates which are flow-invariant under any dynamical system that has a form consistent with the given underlying network structure—the network synchrony subspaces. Given a network and one of its synchrony subspaces, any system with a form consistent with the network, restricted to the synchrony subspace, defines a new system which is consistent with a smaller network, called the quotient network of the original network by the synchrony subspace. Moreover, any system associated with the quotient can be interpreted as the restriction to the synchrony subspace of a system associated with the original network. We call the larger network a lift of the smaller network, and a lift can be interpreted as a result of the cellular splitting of the smaller network. In this paper, we address the question of the uniqueness in this lifting process in terms of the networks’ topologies. A lift G of a given network Q is said to be direct when there are no intermediate lifts of Q between them. We provide necessary and sufficient conditions for a lift of a general network to be direct. Our results characterize direct lifts using the subnetworks of all splitting cells of Q and of all split cells of G. We show that G is a direct lift of Q if and only if either the split subnetwork is a direct lift or consists of two copies of the splitting subnetwork. These results are then applied to the class of regular uniform networks and to the special classes of ring networks and acyclic networks. We also illustrate that one of the applications of our results is to the lifting bifurcation problem.

  6. [THE INDUCTION OF CD25 EXPRESSION IN Jurkat T CELLS].

    Science.gov (United States)

    Shatrova, A N; Mityushova, E V; Aksenov, N V; Marakhova, L L

    2015-01-01

    The expression of an α-subunit of interleukin-2 receptor (IL-2Rα) was assessed by quantifying activation-induced upregulation of CD25 in IL-2-independent Jurkat leukemic cell line. It has been found that in growing Jurkat culture within 24 h, phytohemagglutinin (PHA, 5 μg/ml) or PHA in combination with 12,13-phorbol dibutirate (PDBu, 10(-8)M) increase the number of CD25+ cells to 32.3 ± 3.4% (n = 11) and 44.8 ± 8.6% (n = 6) respectively. Interleukin-2 (IL-2, 200 U/ml) alone or in combination with PDBu did not induce CD25 expression in Jurkat cells. All the tested stimulatory agencies affected neither the proliferation status no the growth of Jurkat cell cultures. In contrast to human blood T cells, WHI-P131, a selective pharmacological inhibitor of JAK/STAT signaling and CD25 expression, did not decrease the number of induced CD25+ cells in Jurkat culture. Flow cytometry analysis revealed a dose-dependent decrease in the proportion of cells in G1 phase and an increase in the proportion of cells in G2/M phase in WHI-P131-treated Jurkat cultures. It has been also found that WHI-P131 induces G2/M arrest in the absence of PHA or PDBu. We have concluded that (1) the IL-2-independent T cells of Jurkat line had not loss the mechanism for IL-2Rα expression in response to T cell receptor activation, (2) in the transformed T cells, WHI-P131 can arrest cell cycle at G2/M phase and has effects on targets other than IL-2 receptor-associated tyrosine kinase JAK3.

  7. Induction of Microglial Activation by Mediators Released from Mast Cells

    Directory of Open Access Journals (Sweden)

    Xiang Zhang

    2016-04-01

    Full Text Available Background/Aims: Microglia are the resident immune cells in the brain and play a pivotal role in immune surveillance in the central nervous system (CNS. Brain mast cells are activated in CNS disorders and induce the release of several mediators. Thus, brain mast cells, rather than microglia, are the “first responders” due to injury. However, the functional aspects of mast cell-microglia interactions remain uninvestigated. Methods: Conditioned medium from activated HMC-1 cells induces microglial activation similar to co-culture of microglia with HMC-1 cells. Primary cultured microglia were examined by flow cytometry analysis and confocal microscopy. TNF- alpha and IL-6 were measured with commercial ELISA kits. Cell signalling was analysed by Western blotting. Results: In the present study, we found that the conditioned medium from activated HMC-1 cells stimulated microglial activation and the subsequent production of the pro-inflammatory factors TNF-α and IL-6. Co-culture of microglia and HMC-1 cells with corticotropin-releasing hormone (CRH for 24, 48 and 72 hours increased TNF-α and IL-6 production. Antagonists of histamine receptor 1 (H1R, H4R, proteinase-activated receptor 2 (PAR2 or Toll-like receptor 4 (TLR4 reduced HMC-1-induced pro-inflammatory factor production and MAPK and PI3K/AKT pathway activation. Conclusions: These results imply that activated mast cells trigger microglial activation. Interactions between mast cells and microglia could constitute a new and unique therapeutic target for CNS inflammation-related diseases.

  8. Vascular Cell Induction Culture System Using Arabidopsis Leaves (VISUAL) Reveals the Sequential Differentiation of Sieve Element-Like Cells

    Science.gov (United States)

    Kondo, Yuki; Nurani, Alif Meem; Saito, Chieko; Ichihashi, Yasunori; Saito, Masato; Yamazaki, Kyoko; Mitsuda, Nobutaka; Ohme-Takagi, Masaru; Fukuda, Hiroo

    2016-01-01

    Cell differentiation is a complex process involving multiple steps, from initial cell fate specification to final differentiation. Procambial/cambial cells, which act as vascular stem cells, differentiate into both xylem and phloem cells during vascular development. Recent studies have identified regulatory cascades for xylem differentiation. However, the molecular mechanism underlying phloem differentiation is largely unexplored due to technical challenges. Here, we established an ectopic induction system for phloem differentiation named Vascular Cell Induction Culture System Using Arabidopsis Leaves (VISUAL). Our results verified similarities between VISUAL-induced Arabidopsis thaliana phloem cells and in vivo sieve elements. We performed network analysis using transcriptome data with VISUAL to dissect the processes underlying phloem differentiation, eventually identifying a factor involved in the regulation of the master transcription factor gene APL. Thus, our culture system opens up new avenues not only for genetic studies of phloem differentiation, but also for future investigations of multidirectional differentiation from vascular stem cells. PMID:27194709

  9. Simultaneous measurement of sulfur and lead isotopes in sulfides using nanosecond laser ablation coupled with two multi-collector inductively coupled plasma mass spectrometers

    Science.gov (United States)

    Yuan, Honglin; Liu, Xu; Chen, Lu; Bao, Zhian; Chen, Kaiyun; Zong, Chunlei; Li, Xiao-Chun; Qiu, Johnson Wenhong

    2018-04-01

    We herein report the coupling of a nanosecond laser ablation system with a large-scale multi-collector inductively coupled plasma mass spectrometer (Nu1700 MC-ICPMS, NP-1700) and a conventional Nu Plasma II MC-ICPMS (NP-II) for the simultaneous laser ablation and determination of in situ S and Pb isotopic compositions of sulfide minerals. We found that the required aerosol distribution between the two spectrometers depended on the Pb content of the sample. For example, for a sulfide containing 100-3000 ppm Pb, the aerosol was distributed between the NP-1700 and the NP-II spectrometers in a 1:1 ratio, while for lead contents >3000 and effect, so a matrix-matched external standard was used for standard-sample bracketing correction. The NIST NBS 977 (NBS, National Bureau of Standards; NIST, National Institute of Standards & Technology) Tl (thallium) dry aerosol internal standard and the NIST SRM 610 (SRM, standard reference material) external standard were employed to obtain accurate results for the analysis of Pb isotopes. In tandem experiments where airflow conditions were similar to those employed during stand-alone analyses, small changes in the aerosol carrier gas flow did not significantly influence the accurate determination of S and Pb isotope ratios. In addition, careful optimization of the flow ratio of the aerosol carrier (He) and makeup (Ar) gases to match stand-alone analytical conditions allowed comparable S and Pb isotope ratios to be obtained within an error of 2 s analytical uncertainties. Furthermore, the results of tandem analyses obtained using our method were consistent with those of previously reported stand-alone techniques for the S and Pb isotopes of chalcopyrite, pyrite, galena, and sphalerite, thus indicating that this method is suitable for the simultaneous analysis of S and Pb isotopes of natural sulfide minerals, and provides an effective tool to determine S and Pb isotope compositions of sulfides formed through multi-stage deposition

  10. Availability of zinc from infant formula by in vitro methods (solubility and dialyzability) and size-exclusion chromatography coupled to inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Gomez, Beatriz Gomez; Perez-Corona, M Teresa; Madrid, Yolanda

    2016-12-01

    Zinc bioaccessibility from infant formula was estimated by in vitro methods (solubility and dialyzability) and size-exclusion chromatography (SEC) coupled to inductively coupled plasma-mass spectrometry (ICP-MS). Infant formula samples were first characterized in terms of Zn bound to lipids and proteins and Zn distribution in the aqueous soluble protein fraction. We found that Zn is not incorporated into the lipid fraction of the samples, being mainly associated with the protein fraction (around 100%). Fractionation of Zn-containing proteins in the soluble protein fraction was achieved by SEC-ICP-MS after performing protein extraction with a solution of 100mM (pH 6.8) Tris-HCl. The percentages of zinc in the soluble protein fraction in the soy-based and lactose-free infant formula were very low, around 7 and 24%, respectively, whereas the content of Zn in the soluble protein fraction of milk-based formula was around 90%. By SEC-ICP-MS, we found that Zn is associated with low-molecular weight compounds (around 10kDa) in all the infant formulas tested. The percentages of Zn estimated in the in vitro gastrointestinal digests of the infant formula ranged from 30 to 70% and from 1 to 10% for solubility and dialyzability assays, respectively. The dialyzability test resulted in lower than expected scores, as SEC-ICP-MS analysis of the gastrointestinal extracts revealed that Zn is bound to biomolecules with a molecular weight ranging from 1 to 7kDa, which suggests that dialysis data should be interpreted with caution. Speciation studies are a valuable tool for establishing availability of nutrients and for validating data from dialyzable in vitro methods. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  11. Induction of interdigitating cell processes in podocyte culture.

    Science.gov (United States)

    Yaoita, Eishin; Yoshida, Yutaka; Nameta, Masaaki; Takimoto, Hiroki; Fujinaka, Hidehiko

    2018-02-01

    Highly organized cell processes characterize glomerular podocytes in vivo. However, podocytes in culture have a simple morphology lacking cell processes, especially upon reaching confluence. Here, we aimed to establish culture conditions under which cultured podocytes extend cell processes at confluence. Among various culture conditions that could possibly cause phenotypic changes in podocytes, we examined the effects of heparin, all-trans retinoic acid, fetal bovine serum, and extracellular matrices on the morphology of podocytes in rat primary culture. Consequently, long arborized cell processes were observed to radiate extensively from the cell body only when cells were cultured in the presence of heparin and all-trans retinoic acid on laminin-coated dishes with decreasing concentrations of fetal bovine serum. Primary processes branching repeatedly into terminal processes and cell process insertion under adjacent cell bodies were evident by electron microscopy-based analysis. Immunostaining for podocin showed conspicuous elongations of intercellular junctions. Under these conditions, the expression levels of podocyte-specific proteins and genes were markedly upregulated. Thus, we succeeded in establishing culture conditions in which the cultured podocytes exhibit phenotypes similar to those under in vivo conditions. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  12. The application of the inductively coupled plasma system to the simultaneous determination of precious metals

    International Nuclear Information System (INIS)

    Watson, A.E.; Russell, G.M.; Middleton, H.R.; Davenport, F.F.

    1983-01-01

    This report describes the development of a spectrochemical technique using excitation by an inducticely coupled plasma (ICP) source for the simultaneous determination of the precious metals (defined here as gold, silver, and all the platinum-group metals except osmium) in a wide variety of samples from a plant for the extraction and refining of platinum metal. The limits of detection for the analytes were determined in various acid and salt media and, under the conditions used, ranged from 20 to 100ng/l. The analytes were determined in the presence of a thousandfold excess of each of the other precious metals used as a matrix element. Some severe interferences were noted but were ascribed to spectral-line overlap or to contamination of the matrix material. Various dissolution techniques, based upon standard procedures applied in the precious-metals industry, were used, depending on the particular type of material treated. The spectrometer was calibrated by the use of solutions containing the analytes, sodium chloride, and acid, with scandium as the internal standard. The accuracy and precision of the technique, established by the analysis of many samples of each type, were found to be satisfactory when close attention was paid to detail in the preparation of the analytical solution. The relative standard deviation of the method ranges from 0,005 to 0,05, depending on the element being determined

  13. Microfluidic high performance liquid chromatography-chip hyphenation to inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Bishop, David P; Blanes, Lucas; Wilson, Alexander B; Wilbanks, Thor; Killeen, Kevin; Grimm, Rudolf; Wenzel, Ross; Major, Derek; Macka, Mirek; Clarke, David; Schmid, Robin; Cole, Nerida; Doble, Philip A

    2017-05-12

    The Agilent Chip Cube Interface is a microfluidic chip-based technology originally designed for nanospray molecular mass spectrometry in which the sample enrichment, nano-column, tubing, connectors and spray tip were integrated into a single biocompatible chip. Here we describe the hyphenation of the Chip Cube Interface to ICP-MS via modification of the standard HPLC chip design and a new total consumption nebuliser suitable for flow rates as low as 300nLmin -1 . The potential of the instrument to eliminate common nanoLC - ICP-MS shortcomings such as leaks, blockages and band-broadening was demonstrated via analysis of cyanocobalamin in equine plasma. The method was linear over three orders of magnitude with an r 2 of 0.9999, the peak area repeatability was 1.9% (n=7), and the detection limit was 14ngmL -1 . This novel configuration of the Chip Cube Interface coupled to ICP-MS is a suitable platform for the analysis of biomolecules associated with trace metals and speciation applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Design of Low Inductance Switching Power Cell for GaN HEMT Based Inverter

    DEFF Research Database (Denmark)

    Gurpinar, Emre; Iannuzzo, Francesco; Yang, Yongheng

    2018-01-01

    In this paper, an ultra-low inductance power cell is designed for a three-Level Active Neutral Point Clamped (3LANPC) based on 650 V gallium nitride (GaN) HEMT devices. The 3L-ANPC topology with GaN HEMT devices and the selected modulation scheme suitable for wide-bandgap (WBG) devices...... are presented. The commutation loops, which mainly contribute to voltage overshoots and increase of switching losses, are discussed. The ultra-low inductance power cell design based on a four-layer Printed Circuit Board (PCB) with the aim to maximize the switching performance of GaN HEMTs is explained...

  15. Isoalantolactone inhibits UM-SCC-10A cell growth via cell cycle arrest and apoptosis induction.

    Directory of Open Access Journals (Sweden)

    Minjun Wu

    Full Text Available Isoalantolactone is a sesquiterpene lactone compound isolated from the roots of Inula helenium L. Previous studies have demonstrated that isoalantolactone possesses antifungal, anti-bacterial, anti-helminthic and anti-proliferative properties in a variety of cells, but there are no studies concerning its effects on head and neck squamous cell carcinoma (HNSCC. In the present study, an MTT assay demonstrated that isoalantolactone has anti-proliferative activity against the HNSCC cell line (UM-SCC-10A. Immunostaining identified that this compound induced UM-SCC-10A cell apoptosis but not necrosis. To explain the molecular mechanisms underlying its effects, flow cytometry and western blot analysis showed that the apoptosis was associated with cell cycle arrest during the G1 phase, up-regulation of p53 and p21, and down-regulation of cyclin D. Furthermore, our results revealed that induction of apoptosis through a mitochondrial pathway led to up-regulation of pro-apoptotic protein expression (Bax, down-regulation of anti-apoptotic protein expression (Bcl-2, mitochondrial release of cytochrome c (Cyto c, reduction of mitochondrial membrane potential (MMP and activation of caspase-3 (Casp-3. Involvement of the caspase apoptosis pathway was confirmed using caspase inhibitor Z-VAD-FMK pretreatment. Together, our findings suggest that isoalantolactone induced caspase-dependent apoptosis via a mitochondrial pathway and was associated with cell cycle arrest in the G1 phase in UM-SCC-10A cells. Therefore, isoalantolactone may become a potential drug for treating HNSCC.

  16. Single-cell protein induction dynamics reveals a period of vulnerability to antibiotics in persister bacteria

    OpenAIRE

    Gefen, Orit; Gabay, Chana; Mumcuoglu, Michael; Engel, Giora; Balaban, Nathalie Q.

    2008-01-01

    Phenotypic variability in populations of cells has been linked to evolutionary robustness to stressful conditions. A remarkable example of the importance of cell-to-cell variability is found in bacterial persistence, where subpopulations of dormant bacteria, termed persisters, were shown to be responsible for the persistence of the population to antibiotic treatments. Here, we use microfluidic devices to monitor the induction of fluorescent proteins under synthetic promoters and characterize ...

  17. Induction of artificial cancer stem cells from tongue cancer cells by defined reprogramming factors.

    Science.gov (United States)

    Harada, Koji; Ferdous, Tarannum; Cui, Dan; Kuramitsu, Yasuhiro; Matsumoto, Takuya; Ikeda, Eiji; Okano, Hideyuki; Ueyama, Yoshiya

    2016-07-27

    -2 (FGF-2) and epidermal Growth Factor (EGF). These findings suggest that artificial cancer stem cells obtained by the induction of cellular reprogramming may be useful for investigating the acquisition of potential malignancy as well as screening the CSCs-targeting drugs.

  18. Determination of Total Arsenic and Speciation in Apple Juice by Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry: An Experiment for the Analytical Chemistry Laboratory

    Science.gov (United States)

    He, Ping; Colon, Luis A.; Aga, Diana S.

    2016-01-01

    A two-part laboratory experiment was designed for upper-level analytical chemistry students to provide hands-on experience in the use of high performance liquid chromatography (HPLC) for separation and inductively coupled plasma mass spectrometry (ICP-MS) for detection. In the first part of the experiment, the students analyze total arsenic in…

  19. Flow injection on-line dilution for multi-element determination in human urine with detection by inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Wang, Jianhua; Hansen, Elo Harald; Gammelgaard, Bente

    2001-01-01

    A simple flow injection on-line dilution procedure with detection by inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of copper, zinc, arsenic, lead, selenium, nickel and molybdenum in human urine. Matrix effects were minimized by employing a dilution factor...

  20. High-resolution line-scan analysis of resin-embedded sediments using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS)

    NARCIS (Netherlands)

    Hennekam, Rick; Jilbert, Tom; Mason, Paul R D; de Lange, Gert J.; Reichart, Gert Jan

    2015-01-01

    Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) line-scanning is a promising technique for producing high-resolution (μm-scale) geochemical records on resin-embedded sediments. However, this approach has not yet been thoroughly tested on sediment samples of known elemental

  1. High-resolution line-scan analysis of resin-embedded sediments using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS)

    NARCIS (Netherlands)

    Hennekam, R.; Jilbert, T.; de Lange, G.J.; Reichart, G.J.

    2015-01-01

    Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) line-scanning is a promising technique for producing high-resolution (µm-scale) geochemical records on resin-embedded sediments. However, this approach has not yet been thoroughly tested on sediment samples of known elemental

  2. Comparative oxidation state specific analysis of arsenic species by high-performance liquid chromatography-inductively coupled-mass spectrometry and hydride generation-cryotrapping-atomic absorption spectrometry

    Science.gov (United States)

    The formation of methylarsonous acid (MAsIII) and dimethylarsinous acid (DMAsIII) in the course of inorganic arsenic (iAs) metabolism plays an important role in the adverse effects of chronic exposure to iAs. High-performance liquid chromatography-inductively coupled plasma-mass ...

  3. Polymerization by plasma of trichloroethylene by means of resistive and inductive coupling; Polimerizacion por plasmas de tricloroetileno por medio de acoplamiento resistivo e inductivo

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez, M.; Cruz, G.; Olayo, M.G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Timoshina, T. [IPN, ESIQIE, 07738 Mexico D.F. (Mexico); Morales, J.; Olayo, R. [UAM-I, 09340 Mexico D.F. (Mexico)

    2004-07-01

    It was carried out the polymerization for plasma of the trichloroethylene by means of two types of coupling, resistive and inductive with the objective of studying the structure, morphology and the electric properties of the polymers obtained under these conditions. The structure and morphology of the polymers were studied by means of EDS and FT-IR spectroscopies. (Author)

  4. Cell dedifferentiation, callus induction and somatic embryogenesis in Crataegus spp.

    Science.gov (United States)

    Taimori, N; Kahrizi, D; Abdossi, V; Papzan, A H

    2016-09-30

    The present study describes the effects of light conditions, different kinds and concentrations of auxins [Naphthylacetic acid (NAA) and dichlorophenoxyacetic acid (2,4-D)] with cytokinin (Kin) in MS medium on callus induction and embryogenesis in Crataegus pseudoheterophylla, C. aronia and C.meyeri. At first leave explants sections were cultured on different combinations of plant growth regulators in dark and light for callus initiation and light conditions to evaluation the percentage and duration of survival, callus diameter, callus fresh weight and dry. Results of effects of plant growth regulators and light conditions on callus initiation revealed that highest percentage of callus initiation leaves in treatment (0.5 mg/l 2.4-D+0.5 mg/l KIN) for species C.pseudoheterophylla in dark conditions (100%). Dark conditions (100%) were more effective on callogenesis than light conditions (Photoperiodicity of 16-h and at light intensity of 40 µmol m-2 s-1). The callus induction of in vitro (64-100%) leaves was better than the ex vitro ones (0-100%). The combination of 2,4-D and Kin of in vitro leaves callogenesis has been indicated faster (one weeks) than the other combinations. The results also showed that the highest percentage (100%) and survival duration (6 months) was found in species C. pseudoheterophylla and C. meyeri in 0.1 mg/l 2,4.D + 0.5 mg/l KIN and 0.5 mg/l 2,4.D + 0.5 mg/l Kin. The minimum survival (0%) was absorbed in species C. aronia in 1 mg/l NAA. Maximum callus (10.63 and 10.00 mm respectively) was shown in 0.1 mg/l 2,4.D + 0.5 mg/l Kin and 0.5 mg/l 2,4.D + 0.5 mg/l Kin and was not significant differences after five week among species. The results showed that the highest fresh (1081.49 mg) and dry weight (506.88 and 506.98 mg respectively) was absorbed in species C. pseudoheterophylla in 0.1 mg/l 2,4.D + 0.5 mg/l Kin and 0.5 mg/l 2,4.D + 0.5 mg/l Kin. The embryogenesis was not occurred in any plant growth regulator combinations and species. The

  5. Dendritic cells tip the balance towards induction of regulatory T cells upon priming in experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Paterka, Magdalena; Voss, Jan Oliver; Werr, Johannes; Reuter, Eva; Franck, Sophia; Leuenberger, Tina; Herz, Josephine; Radbruch, Helena; Bopp, Tobias; Siffrin, Volker; Zipp, Frauke

    2017-01-01

    Counter-balancing regulatory mechanisms, such as the induction of regulatory T cells (Treg), limit the effects of autoimmune attack in neuroinflammation. However, the role of dendritic cells (DCs) as the most powerful antigen-presenting cells, which are intriguing therapeutic targets in this context, is not fully understood. Here, we demonstrate that conditional ablation of DCs during the priming phase of myelin-specific T cells in experimental autoimmune encephalomyelitis (EAE) selectively aborts inducible Treg (iTreg) induction, whereas generation of T helper (Th)1/17 cells is unaltered. DCs facilitate iTreg induction by creating a milieu with high levels of interleukin (IL)-2 due to a strong proliferative response. In the absence of DCs, B220 + B cells take over priming of Th17 cells in the place of antigen-presenting cells (APCs), but not the induction of iTreg, thus leading to unregulated, severe autoimmunity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Induction of Primordial Germ Cells from Pluripotent Epiblast

    Directory of Open Access Journals (Sweden)

    Ying Ying

    2002-01-01

    Full Text Available The formation of germ cells during embryogenesis bears the ultimate importance for the continuation of every species. It becomes evident that mechanisms governing germ cell fate specification are not well conserved across the animal kingdom. In most of the invertebrate and nonmammalian vertebrate species, certain maternally derived factors are key to the establishment of germ cell lineage. In contrast, mouse primordial germ cells (PGCs are induced from the pluripotent epiblast cells before and during gastrulation by the extraembryonic cell-derived signals. The molecular identity for some of these signals has recently been revealed by genetic and epiblast culture experiments. Both bone morphogenetic proteins 4 (Bmp4 and 8b (Bmp8b are expressed in the extraembryonic ectoderm and are required for PGC formation. Furthermore, BMP4 or BMP8B alone are unable to induce PGCs from cultured epiblasts, while they can in combination, indicating they signal through separate receptor complexes. In addition, Bmp4 homozygous embryos cannot be induced to form PGCs by the synergistic action of BMP4 and BMP8B, suggesting that BMP4 proteins produced by pregastrula embryos are required for epiblast cells to maintain pluripotency. Moreover, Bmp2, a close relative of Bmp4, is expressed in visceral endoderm at the time of PGC specification, and inactivation of Bmp2 results in a reduction in PGC number, revealing a novel function of visceral endoderm in PGC generation in the mouse.

  7. Induction of apoptosis by opium in some tumor cell lines.

    Science.gov (United States)

    Khaleghi, M; Farsinejad, A; Dabiri, S; Asadikaram, G

    2016-09-30

    The current study is aimed at investigation of the opium effects on the apoptosis of different cell lines in culture medium and compares such effects with one another. The study is carried out on over 8 cell lines (AA8, AGS, Hela, HepG2, MCF7, N2a, PC12, WEHI). A 2.86 x 10-4 g/ml opium concentration was prepared and added to the culture medium of the cell lines for 48 hours. Cytotoxicity was tested by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. The apoptotic effect of opium on the cell lines was analyzed by Annexin-PI test. Opium with concentration of 2.86 x 10-4 g/ml in 48 hours significantly induces apoptosis in certain cell lines (i.e. AA8, N2a, WEHI), apoptosis and necrosis in some others (i.e. Hela, HepG2, MCF7, and PC12), and also solely necrosis in the AGS cell line. One could infer that the usage of opium with different levels in different tissues leads to certain disorders in some tissues and may have therapeutic effects under distinctive conditions (i.e. unchecked growth of cells) as confirmed by the results.

  8. Determination of Tributyltin in Seafood Based on Magnetic Molecularly Imprinted Polymers Coupled with High-Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Hua Yang

    2017-01-01

    Full Text Available In this study, Fe3O4 was adopted as a carrier for surface molecular imprinting with two-stage polymerization. First, the functional monomer (methacrylic acid, MAA was modified on the surface of Fe3O4, which was then polymerized with the template molecule (tributyltin, TBT, cross linking agent (ethylene glycol dimethacrylate, EGDMA, and porogen (acetonitrile, hereby successfully preparing Fe3O4@MIPs prone to specifically identify TBT. The physical properties of Fe3O4@MIPs were then characterized, and adsorption and selection capacities were also assessed. Compared with conventional imprinting polymers, this magnetic molecular imprinting polymer (MIP displayed significantly increased and more specific adsorption. Meanwhile, its pretreatment was simpler and faster due to magnetic separation characteristics. Using magnetic MIPs as adsorbents for enrichment and separation, detection limit, recovery rate, and linear range were 1.0 ng g−1, 79.74–95.72%, and 5 ng g−1~1000 ng g−1, respectively, for a number of seafood samples. High-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS was used to analyze Tegillarca granosa, mussels, large yellow croaker, and other specimens, with recovery rates of 79.74–95.72% and RSD of 1.3%–4.7%. Overall, this method has a shorter total analysis time, lower detection limit, and wider linear range and can be more effectively applied to determine MAA in seawater and seafood.

  9. Determination of low cadmium concentrations in wine by on-line preconcentration in a knotted reactor coupled to an inductively coupled plasma optical emission spectrometer with ultrasonic nebulization

    Energy Technology Data Exchange (ETDEWEB)

    Lara, R.F. [Inst. de Investigaciones Mineras, Universidad Nacional de San Juan (Argentina); Wuilloud, R.G.; Salonia, J.A. [Dept. of Analytical Chemistry, National University of San Luis (Argentina); Olsina, R.A.; Martinez, L.D. [Dept. of Analytical Chemistry, National University of San Luis (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina)

    2001-12-01

    An on-line cadmium preconcentration and determination system implemented with inductively coupled plasma optical emission spectrometry (ICP-OES) associated to flow injection (FI) with ultrasonic nebulization system (USN) was studied. The cadmium was retained as the cadmium-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol, Cd-(5-Br-PADAP), complex, at pH 9.5. The cadmium complex was removed from the knotted reactor (KR) with 3.0 mol/L nitric acid. A total enhancement factor of 216 was obtained with respect to ICP-OES using pneumatic nebulization (12 for USN and 18 for KR) with a preconcentration time of 60 s. The value of the detection limit for the preconcentration of 5 mL of sample solution was 5 ng/L. The precision for 10 replicate determinations at the 5 {mu}g/L Cd level was 2.9% relative standard deviation (RSD), calculated from the peak heights obtained. The calibration graph using the preconcentration system for cadmium was linear with a correlation coefficient of 0.9998 at levels near the detection limits up to at least 1000 {mu}g/L. The method was successfully applied to the determination of cadmium in wine samples. (orig.)

  10. Magnetic immunoassay coupled with inductively coupled plasma mass spectrometry for simultaneous quantification of alpha-fetoprotein and carcinoembryonic antigen in human serum

    Science.gov (United States)

    Zhang, Xing; Chen, Beibei; He, Man; Zhang, Yiwen; Xiao, Guangyang; Hu, Bin

    2015-04-01

    The absolute quantification of glycoproteins in complex biological samples is a challenge and of great significance. Herein, 4-mercaptophenylboronic acid functionalized magnetic beads were prepared to selectively capture glycoproteins, while antibody conjugated gold and silver nanoparticles were synthesized as element tags to label two different glycoproteins. Based on that, a new approach of magnetic immunoassay-inductively coupled plasma mass spectrometry (ICP-MS) was established for simultaneous quantitative analysis of glycoproteins. Taking biomarkers of alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) as two model glycoproteins, experimental parameters involved in the immunoassay procedure were carefully optimized and analytical performance of the proposed method was evaluated. The limits of detection (LODs) for AFP and CEA were 0.086 μg L- 1 and 0.054 μg L- 1 with the relative standard deviations (RSDs, n = 7, c = 5 μg L- 1) of 6.5% and 6.2% for AFP and CEA, respectively. Linear range for both AFP and CEA was 0.2-50 μg L- 1. To validate the applicability of the proposed method, human serum samples were analyzed, and the obtained results were in good agreement with that obtained by the clinical chemiluminescence immunoassay. The developed method exhibited good selectivity and sensitivity for the simultaneous determination of AFP and CEA, and extended the applicability of metal nanoparticle tags based on ICP-MS methodology in multiple glycoprotein quantifications.

  11. Capillary electrophoresis coupled with inductively coupled mass spectrometry as an alternative to cloud point extraction based methods for rapid quantification of silver ions and surface coated silver nanoparticles.

    Science.gov (United States)

    Qu, Haiou; Mudalige, Thilak K; Linder, Sean W

    2016-01-15

    Speciation and accurate quantification of ionic silver and metallic silver nanoparticles are critical to investigate silver toxicity and to determine the shelf-life of products that contain nano silver under various storage conditions. We developed a rapid method for quantification of silver ions and silver nanoparticles using capillary electrophoresis (CE) interfaced with inductively-coupled plasma mass spectrometry (ICPMS). The addition of 2-mercaptopropionylglycine (tiopronin) to the background electrolyte was used to facilitate the chromatographic separation of ionic silver and maintain the oxidation state of silver. The obtained limits of detection were 0.05 μg kg(-1) of silver nanoparticles and 0.03 μg kg(-1) of ionic silver. Nanoparticles of varied sizes (10-110 nm) with different surface coating, including citrate acid, lipoic acid, polyvinylpyrrolidone and bovine serum albumin (BSA) were successfully analyzed. Particularly good recoveries (>93%) were obtained for both ionic silver and silver nanoparticle in the presence of excess amount of BSA. The method was further tested with six commercially available dietary supplements which varied in concentration and matrix components. The summed values of silver ions and silver nanoparticles correlated well with the total silver concentration determined by ICPMS after acid digestion. This method can serve as an alternative to cloud point extraction technique when the extraction efficiency for protein coated nanoparticles is low. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Coupling and power transfer efficiency enhancement of modular and array of planar coils using in-plane ring-shaped inner ferrites for inductive heating applications

    Science.gov (United States)

    Kilic, V. T.; Unal, E.; Demir, H. V.

    2017-07-01

    We propose and demonstrate a highly effective method of enhancing coupling and power transfer efficiency in inductive heating systems composed of planar coils. The proposed method is based on locating ring-shaped ferrites in the inner side of the coils in the same plane. Measurement results of simple inductive heating systems constructed with either a single or a pair of conventional circular coils show that, with the in-plane inner ferrites, the total dissipated power of the system is increased by over 65%. Also, with three-dimensional full electromagnetic solutions, it is found that power transfer efficiency of the system is increased up to 92% with the inner ferrite placement. The proposed method is promising to be used for efficiency enhancement in inductive heating applications, especially in all-surface induction hobs.

  13. Considerations of particle vaporization and analyte diffusion in single-particle inductively coupled plasma-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Koon-Sing; Lui, Kwok-On; Lee, Kin-Ho; Chan, Wing-Tat, E-mail: wtchan@hku.hk

    2013-11-01

    The intensity of individual gold nanoparticles with nominal diameters of 80, 100, 150, and 200 nm was measured using single-particle inductively coupled plasma-mass spectrometry (ICP-MS). Since the particles are not perfectly monodisperse, a distribution of ICP-MS intensity was obtained for each nominal diameter. The distribution of particle mass was determined from the transmission electron microscopy (TEM) image of the particles. The distribution of ICP-MS intensity and the distribution of particle mass for each nominal diameter were correlated to give a calibration curve. The calibration curves are linear, but the slope decreases as the nominal diameter increases. The reduced slope is probably due to a smaller degree of vaporization of the large particles. In addition to the degree of particle vaporization, the rate of analyte diffusion in the ICP is an important factor that determines the measured ICP-MS intensity. Simulated ICP-MS intensity versus particle size was calculated using a simple computer program that accounts for the vaporization rate of the gold nanoparticles and the diffusion rate and degree of ionization of the gold atoms. The curvature of the simulated calibration curves changes with sampling depth because the effects of particle vaporization and analyte diffusion on the ICP-MS intensity are dependent on the residence time of the particle in the ICP. Calibration curves of four hypothetical particles representing the four combinations of high and low boiling points (2000 and 4000 K) and high and low analyte diffusion rates (atomic masses of 10 and 200 Da) were calculated to further illustrate the relative effects of particle vaporization and analyte diffusion. The simulated calibration curves show that the sensitivity of single-particle ICP-MS is smaller than that of the ICP-MS measurement of continuous flow of standard solutions by a factor of 2 or more. Calibration using continuous flow of standard solution is semi-quantitative at best. An

  14. Combinatorial strategies for the induction of immunogenic cell death

    Directory of Open Access Journals (Sweden)

    Lorenzo eGalluzzi

    2015-04-01

    Full Text Available The term immunogenic cell death (ICD is commonly employed to indicate a peculiar instance of regulated cell death (RCD that engages the adaptive arm of the immune system. The inoculation of cancer cells undergoing ICD into immunocompetent animals elicits a specific immune response associated with the establishment of immunological memory. Only a few agents are intrinsically endowed with the ability to trigger ICD. These include a few chemotherapeutics that are routinely employed in the clinic, like doxorubicin, mitoxantrone, oxaliplatin and cyclophosphamide, as well as some agents that have not yet been approved for use in humans. Accumulating clinical data indicate that the activation of adaptive immune responses against dying cancer cells is associated with improved disease outcome in patients affected by various neoplasms. Thus, novel therapeutic regimens that trigger ICD are urgently awaited. Here, we discuss current combinatorial approaches to convert otherwise non-immunogenic instances of RCD into bona fide ICD.

  15. Inflammasome-Dependent Induction of Adaptive NK Cell Memory

    NARCIS (Netherlands)

    van den Boorn, Jasper G.; Jakobs, Christopher; Hagen, Christian; Renn, Marcel; Luiten, Rosalie M.; Melief, Cornelis J. M.; Tüting, Thomas; Garbi, Natalio; Hartmann, Gunther; Hornung, Veit

    2016-01-01

    Monobenzone is a pro-hapten that is exclusively metabolized by melanocytes, thereby haptenizing melanocyte-specific antigens, which results in cytotoxic autoimmunity specifically against pigmented cells. Studying monobenzone in a setting of contact hypersensitivity (CHS), we observed that

  16. Asymmetrical flow field-flow fractionation coupled to inductively coupled plasma mass spectrometry for sizing SeNPs for packaging applications

    Science.gov (United States)

    Palomo-Siguero, María; Vera, Paula; Echegoyen, Yolanda; Nerin, Cristina; Cámara, Carmen; Madrid, Yolanda

    2017-06-01

    This paper describes the application of Asymmetrical Flow Field-Flow Fractionation (AF4) coupled to diode array detector (DAD) and inductively coupled plasma mass spectrometry (AF4-UV-ICP-MS) to characterize selenium nanoparticles (SeNPs) in an aqueous acrylic adhesive to be used in a multilayer food packaging material. SeNPs were synthesized using a solution-phase approach based on the reduction of selenite with ascorbic acid in presence of different stabilizers compatible with food industry such as polysaccharides (chitosan (poly(D-glucosamine) and hydroxyethylcellulose (HEC)) and non-ionic surfactants (Triton X-100 (t-octylphenoxypolyethoxyethanol), 2,4,7,9-tetramethyl 5decyne-4,7-diol ethoxylate, and isotridecanol ethoxylate). Several parameters such as pH, ascorbic acid and stabilizers concentration, and compatibility of the stabilizer with the adhesive were evaluated. SeNPs suspensions with spherical morphology were obtained except when isotridecanol ethoxylate was employed which provides SeNPs with a nanorod morphology. AF4-DAD-ICP-MS was further applied for sizing the different SeNPs preparations. DAD was used as detector for selecting the best AF4 separation conditions before coupling to ICP-MS to ensure unequivocal identification of NPs. AF4 calibration with polystyrene latex (PSL) beads of known sizes allowed size determination of the different SeNPs. The following estimated hydrodynamic sizes (expressed as the mean ± standard deviation, n = 6 replicates) were found: chitosan-SeNPs- (26 ± 3 nm), TritonX100-SeNPs (22 ± 10 nm) HEC- SeNPs (91 ± 8 nm) and 2,4,7,9-tetramethyl 5decyne-4,7-diol ethoxylate- SeNPs (59 ± 4 nm). The proposed methodology was successfully applied to the characterization in terms of size of aqueous acrylic adhesives containing SeNPs Results from AF4-ICP-MS and TEM shown that only those SeNPs obtained with non-ionic surfactants and HEC were compatible with the adhesive. The results reported here evidence the usefulness of AF4-ICP

  17. Simultaneous determination of macronutrients, micronutrients and trace elements in mineral fertilizers by inductively coupled plasma optical emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira Souza, Sidnei de [Laboratório de Química Analítica Ambiental (LQA), Departamento de Química, Centro de Ciências Exatas e Tecnologia, Universidade Federal de Sergipe (UFS), 49100-000, São Cristovão, SE (Brazil); Silvério Lopes da Costa, Silvânio [Laboratório de Química Analítica Ambiental (LQA), Departamento de Química, Centro de Ciências Exatas e Tecnologia, Universidade Federal de Sergipe (UFS), 49100-000, São Cristovão, SE (Brazil); Coordenação de Química, Universidade Federal de Alagoas (UFAL), Campus Arapiraca, 57309-005, Arapiraca, AL (Brazil); Santos, Dayane Melo; Santos Pinto, Jéssica dos; Garcia, Carlos Alexandre Borges [Laboratório de Química Analítica Ambiental (LQA), Departamento de Química, Centro de Ciências Exatas e Tecnologia, Universidade Federal de Sergipe (UFS), 49100-000, São Cristovão, SE (Brazil); and others

    2014-06-01

    An analytical method for simultaneous determination of macronutrients (Ca, Mg, Na and P), micronutrients (Cu, Fe, Mn and Zn) and trace elements (Al, As, Cd, Pb and V) in mineral fertilizers was optimized. Two-level full factorial design was applied to evaluate the optimal proportions of reagents used in the sample digestion on hot plate. A Doehlert design for two variables was used to evaluate the operating conditions of the inductively coupled plasma optical emission spectrometer in order to accomplish the simultaneous determination of the analyte concentrations. The limits of quantification (LOQs) ranged from 2.0 mg kg{sup −1} for Mn to 77.3 mg kg{sup −1} for P. The accuracy and precision of the proposed method were evaluated by analysis of standard reference materials (SRMs) of Western phosphate rock (NIST 694), Florida phosphate rock (NIST 120C) and Trace elements in multi-nutrient fertilizer (NIST 695), considered to be adequate for simultaneous determination. Twenty-one samples of mineral fertilizers collected in Sergipe State, Brazil, were analyzed. For all samples, the As, Ca, Cd and Pb concentrations were below the LOQ values of the analytical method. For As, Cd and Pb the obtained LOQ values were below the maximum limit allowed by the Brazilian Ministry of Agriculture, Livestock and Food Supply (Ministério da Agricultura, Pecuária e Abastecimento — MAPA). The optimized method presented good accuracy and was effectively applied to quantitative simultaneous determination of the analytes in mineral fertilizers by inductively coupled plasma optical emission spectrometry (ICP OES). - Highlights: • Determination of inorganic constituents in mineral fertilizers was proposed. • Experimental design methodology was used to optimize analytical method. • The sample preparation procedure using diluted reagents (HNO{sub 3} and H{sub 2}O{sub 2}) was employed. • The analytical method was satisfactorily to the determination of thirteen elements. • The

  18. Catechins activate muscle stem cells by Myf5 induction and stimulate muscle regeneration.

    Science.gov (United States)

    Kim, A Rum; Kim, Kyung Min; Byun, Mi Ran; Hwang, Jun-Ha; Park, Jung Il; Oh, Ho Taek; Kim, Hyo Kyeong; Jeong, Mi Gyeong; Hwang, Eun Sook; Hong, Jeong-Ho

    2017-07-22

    Muscle weakness is one of the most common symptoms in aged individuals and increases risk of mortality. Thus, maintenance of muscle mass is important for inhibiting aging. In this study, we investigated the effect of catechins, polyphenol compounds in green tea, on muscle regeneration. We found that (-)-epicatechin gallate (ECG) and (-)-epigallocatechin-3-gallate (EGCG) activate satellite cells by induction of Myf5 transcription factors. For satellite cell activation, Akt kinase was significantly induced after ECG treatment and ECG-induced satellite cell activation was blocked in the presence of Akt inhibitor. ECG also promotes myogenic differentiation through the induction of myogenic markers, including Myogenin and Muscle creatine kinase (MCK), in satellite and C2C12 myoblast cells. Finally, EGCG administration to mice significantly increased muscle fiber size for regeneration. Taken together, the results suggest that catechins stimulate muscle stem cell activation and differentiation for muscle regeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Interferon-α abrogates tolerance induction by human tolerogenic dendritic cells.

    Directory of Open Access Journals (Sweden)

    Nicole Bacher

    Full Text Available BACKGROUND: Administration of interferon-α (IFN-α represents an approved adjuvant therapy as reported for malignancies like melanoma and several viral infections. In malignant diseases, tolerance processes are critically involved in tumor progression. In this study, the effect of IFN-α on tolerance induction by human tolerogenic dendritic cells (DC was analyzed. We focussed on tolerogenic IL-10-modulated DC (IL-10 DC that are known to induce anergic regulatory T cells (iTregs. METHODOLOGY/PRINCIPAL FINDINGS: IFN-α promoted an enhanced maturation of IL-10 DC as demonstrated by upregulation of the differentiation marker CD83 as well as costimulatory molecules. IFN-α treatment resulted in an increased capacity of DC to stimulate T cell activation compared to control tolerogenic DC. We observed a strengthened T cell proliferation and increased IFN-γ production of CD4(+ and CD8(+ T cells stimulated by IFN-α-DC, demonstrating a restoration of the immunogenic capacity of tolerogenic DC in the presence of IFN-α. Notably, restimulation experiments revealed that IFN-α treatment of tolerogenic DC abolished the induction of T cell anergy and suppressor function of iTregs. In contrast, IFN-α neither affected the priming of iTregs nor converted iTregs into effector T cells. CONCLUSIONS/SIGNIFICANCE: IFN-α inhibits the induction of T cell tolerance by reversing the tolerogenic function of human DC.

  20. Mechanism of Induction: Induced Pluripotent Stem Cells (iPSCs).

    Science.gov (United States)

    Singh, Vimal Kishor; Kumar, Neeraj; Kalsan, Manisha; Saini, Abhishek; Chandra, Ramesh

    2015-01-01

    Induced Pluripotent Stem Cells (iPSCs) are self renewable and can differentiate to different types of adult cells, which has shown great promises in the field of regenerative medicine. iPSCs are reprogrammed from human somatic cells through ectopic expression of various transcription factors viz. Oct4, Sox2, Klf4, and c-Myc (OSKM). This novel technology enables derivation of patient specific cells, which possess a potential cure for many diseases. During the last decade, significant progresses have been achieved in enhancing the reprogramming efficiency, safety of iPSCs derivation, development of different delivery techniques by various research groups. Nevertheless, it is important to resolve and define the mechanism underlying the pluripotent stem cells. Major bottleneck which arises during iPSCs generation is the availability of source material (cells/tissues), difficulty to deliver transcription factors with no aberrant genetic modifications and limited reprogramming efficiency. Reprogramming may be achieved by employing different cocktails with number of different transcription factors, application of miRNA and some small molecules such as (Valproic acid, CHiR99021, Sodium butyrate, Vitamin C, Parnate etc). Similarly, various starting source materials have been demonstrated for iPSC based therapies including fibroblasts, cord blood, peripheral blood, keritinocytes, urine, etc., with their specific uses and limitations. Moreover, with the advent of many new reprogramming techniques, various direct delivery methods have been introduced such as using synthetic mRNA expressing pluripotent gene network has been shown to be an appropriate technique to deliver transcription factors and a dozen of small molecules which can replace transcription factors or enhance reprogramming efficiency. This article addresses the iPSCs technology mechanisms, progresses and current perspectives in the field.

  1. Genetic Induction of Cytolytic Susceptibility in Breast Cancer Cells

    Science.gov (United States)

    2001-07-01

    Sadovnikova et or HPV -E7-expressing human tumor cells may be rele- al., 1993). Furthermore, such CTL-inducing vaccination vant in vivo. Furthermore, neither the...gene was synthesized by polymerase chain reaction and replaced the CAT gene in the pOPRS- VICAT plasmid. This plasmid was cotransfected with the p3’SS...papillomaviruses ( HPV ) and adenoviruses (Ad) both transform cells by expressing functionally related oncogenes (Ad-ElA/E1B; HPV -E7/E6), only HPV are

  2. The induction of cellular senescence in dental follicle cells inhibits the osteogenic differentiation.

    Science.gov (United States)

    Morsczeck, Christian; Gresser, Jan; Ettl, Tobias

    2016-06-01

    Dental stem cells such as human dental follicle cells (DFCs) have opened new promising treatment alternatives for today's dental health issues such as periodontal tissue regeneration. However, cellular senescence represents a restricting factor to cultured stem cells, resulting in limited lifespan and reduced cell differentiation potential. Therefore, this study evaluated if and how DFCs exhibit features of cellular senescence after being expanded in cell culture. The cell proliferation of DFCs decreased, while the cell size increased during prolonged cell culture. Moreover, DFCs expressed the senescence-associated β-galactosidase after a prolonged cell culture. The onset of senescence inhibited both the induction of osteoblast markers RUNX2 and osteopontin and the biomineralization of DFCs after stimulation of the osteogenic differentiation. In conclusion, we showed that a prolonged cell culture induces cellular senescence and inhibits the osteogenic differentiation in DFCs.

  3. Inductively Coupled Plasma-Induced Electrical Damage on HgCdTe Etched Surface at Cryogenic Temperatures

    Science.gov (United States)

    Liu, L. F.; Chen, Y. Y.; Ye, Z. H.; Hu, X. N.; Ding, R. J.; He, L.

    2018-03-01

    Plasma etching is a powerful technique for transferring high-resolution lithographic patterns into HgCdTe material with low etch-induced damage, and it is important for fabricating small-pixel-size HgCdTe infrared focal plane array (IRFPA) detectors. P- to n-type conversion is known to occur during plasma etching of vacancy-doped HgCdTe; however, it is usually unwanted and its removal requires extra steps. Etching at cryogenic temperatures can reduce the etch-induced type conversion depth in HgCdTe via the electrical damage mechanism. Laser beam-induced current (LBIC) is a nondestructive photoelectric characterization technique which can provide information regarding the vertical and lateral electrical field distribution, such as defects and p-n junctions. In this work, inductively coupled plasma (ICP) etching of HgCdTe was implemented at cryogenic temperatures. For an Ar/CH4 (30:1 in SCCM) plasma with ICP input power of 1000 W and RF-coupled DC bias of ˜ 25 V, a HgCdTe sample was dry-etched at 123 K for 5 min using ICP. The sample was then processed to remove a thin layer of the plasma-etched region while maintaining a ladder-like damaged layer by continuously controlling the wet chemical etching time. Combining the ladder etching method and LBIC measurement, the ICP etching-induced electrical damage depth was measured and estimated to be about 20 nm. The results indicate that ICP etching at cryogenic temperatures can significantly suppress plasma etching-induced electrical damage, which is beneficial for defining HgCdTe mesa arrays.

  4. Apoptosis induction of epifriedelinol on human cervical cancer cell line

    African Journals Online (AJOL)

    Background: Present investigation evaluates the antitumor activity of epifriedelinol for the management of cervical cancer by inducing process of apoptosis. Methods: Human Cervical Cancer Cell Line, C33A and HeLa were selected for study and treated with epifriedelinol at a concentration of (50-1000 μg/ml). Cytotoxicity of ...

  5. Induction of apoptosis and cell proliferation inhibition by paclitaxel in ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-02-18

    Feb 18, 2009 ... also used molecular biology methods and morphological imaging ... C47H51NO14 and its molecular weight is 853.9 (Mastropaolo et al.,. 1995). ..... Biologia. 60: 325-330. Arican Özcan G (2005b). Cytoprotective effects of amifostine and cysteamine on cultured normal and tumor cells treated with paclitaxel.

  6. Analysis of individual cells identifies cell-to-cell variability following induction of cellular senescence.

    Science.gov (United States)

    Wiley, Christopher D; Flynn, James M; Morrissey, Christapher; Lebofsky, Ronald; Shuga, Joe; Dong, Xiao; Unger, Marc A; Vijg, Jan; Melov, Simon; Campisi, Judith

    2017-10-01

    Senescent cells play important roles in both physiological and pathological processes, including cancer and aging. In all cases, however, senescent cells comprise only a small fraction of tissues. Senescent phenotypes have been studied largely in relatively homogeneous populations of cultured cells. In vivo, senescent cells are generally identified by a small number of markers, but whether and how these markers vary among individual cells is unknown. We therefore utilized a combination of single-cell isolation and a nanofluidic PCR platform to determine the contributions of individual cells to the overall gene expression profile of senescent human fibroblast populations. Individual senescent cells were surprisingly heterogeneous in their gene expression signatures. This cell-to-cell variability resulted in a loss of correlation among the expression of several senescence-associated genes. Many genes encoding senescence-associated secretory phenotype (SASP) factors, a major contributor to the effects of senescent cells in vivo, showed marked variability with a subset of highly induced genes accounting for the increases observed at the population level. Inflammatory genes in clustered genomic loci showed a greater correlation with senescence compared to nonclustered loci, suggesting that these genes are coregulated by genomic location. Together, these data offer new insights into how genes are regulated in senescent cells and suggest that single markers are inadequate to identify senescent cells in vivo. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  7. Glycosylation of Candida albicans cell wall proteins is critical for induction of innate immune responses and apoptosis of epithelial cells.

    Directory of Open Access Journals (Sweden)

    Jeanette Wagener

    Full Text Available C. albicans is one of the most common fungal pathogen of humans, causing local and superficial mucosal infections in immunocompromised individuals. Given that the key structure mediating host-C. albicans interactions is the fungal cell wall, we aimed to identify features of the cell wall inducing epithelial responses and be associated with fungal pathogenesis. We demonstrate here the importance of cell wall protein glycosylation in epithelial immune activation with a predominant role for the highly branched N-glycosylation residues. Moreover, these glycan moieties induce growth arrest and apoptosis of epithelial cells. Using an in vitro model of oral candidosis we demonstrate, that apoptosis induction by C. albicans wild-type occurs in early stage of infection and strongly depends on intact cell wall protein glycosylation. These novel findings demonstrate that glycosylation of the C. albicans cell wall proteins appears essential for modulation of epithelial immunity and apoptosis induction, both of which may promote fungal pathogenesis in vivo.

  8. Induction of apoptosis in human breast cancer cell line MCF-7 by ...

    African Journals Online (AJOL)

    USER

    2010-07-12

    Jul 12, 2010 ... Induction of apoptosis in human breast cancer cell line. MCF-7 by phytochemicals from Gmelina asiatica. N. J. Merlin1, V. Parthasarathy1* and T. R. Santhoshkumar2. 1Department of Pharmacy, Annamalai University, Annamalai Nagar-608002, Tamil Nadu, India. 2Rajiv Gandhi Centre for Biotechnology, ...

  9. Autologous graft-versus-host disease induction in advanced breast cancer: role of peripheral bloodprogenitor cells

    NARCIS (Netherlands)

    Wall, E. van der; Horn, T.; Bright, E.; Passos-Coehlo, J-L.; Bond, S.; Clarke, B.; Altomonte, V.; McIntyre, K.; Vogelsang, G.; Noga, S.J.; Davis, J.M.; Thomassen, J.; Ohly, K.V.; Lee, S.M.; Fetting, J.; Armstrong, D.K.; Davidson, N.E.; Hess, A.D.; Kennedy, M.J.

    2000-01-01

    The purpose of the present study was to investigate the impact of the use of peripheral blood progenitor cells (PBPCs) on the induction of autologous graft-versus-host disease (GVHD) in patients with advanced breast cancer. 14 women with stage IIIB and 36 women with stage IV breast cancer received

  10. Transmural changes in mast cell density in rat heart after infarct induction in vivo

    NARCIS (Netherlands)

    Engels, W.; Reiters, P. H.; Daemen, M. J.; Smits, J. F.; van der Vusse, G. J.

    1995-01-01

    The cardiac distribution of mast cells was investigated after the induction of acute myocardial infarction in the rat. The left anterior descending coronary artery (LAD) was occluded by ligation in the infarct group, whereas in sham rats only a superficial ligature was placed beside the LAD. Rats of

  11. Quantification of plant cell coupling with live-cell microscopy

    DEFF Research Database (Denmark)

    Liesche, Johannes; Schulz, Alexander

    2015-01-01

    cell wall interface. Transport through plasmodesmata, the cell wall channels that directly connect plant cells, is regulated not only by a fixed size exclusion limit, but also by physiological and pathological adaptation. The noninvasive approach described here offers the possibility of precisely...... by confocal microscopy, loaded tracer is activated by UV illumination in a target cell and its spread to neighboring cells monitored. When combined with high-speed acquisition by resonant scanning or spinning disc confocal microscopy, the high signal-to-noise ratio of photoactivation allows collection...

  12. Evaluation of the mineral profile of textile materials using inductively coupled plasma optical emission spectrometry and chemometrics

    Energy Technology Data Exchange (ETDEWEB)

    Menezes, E.A.; Carapelli, R.; Bianchi, S.R. [Grupo de Analise Instrumental Aplicada, Departamento de Quimica, Universidade Federal de Sao Carlos, Sao Carlos, SP (Brazil); Embrapa Pecuaria Sudeste, C.P. 339, Sao Carlos, SP 13560-970 (Brazil); Souza, S.N.P. [Grupo de Analise Instrumental Aplicada, Departamento de Quimica, Universidade Federal de Sao Carlos, Sao Carlos, SP (Brazil); Matos, W.O. [Departamento de Quimica Analitica e Fisico-Quimica, Universidade Federal do Ceara, Fortaleza, CE (Brazil); Pereira-Filho, E.R. [Grupo de Analise Instrumental Aplicada, Departamento de Quimica, Universidade Federal de Sao Carlos, Sao Carlos, SP (Brazil); Nogueira, A.R.A., E-mail: anarita@cppse.embrapa.br [Embrapa Pecuaria Sudeste, C.P. 339, Sao Carlos, SP 13560-970 (Brazil)

    2010-10-15

    The content of Al, Ba, Ca, Cr, Cu, Fe, Ni, P, Zn, Cd and Pb was determined in textile material samples after microwave-assisted decomposition in a cavity oven and extraction with an artificial sweat solution. Radial viewing inductively coupled plasma optical emission spectrometry (ICP OES) was the main detection technique, but Cd and Pb were determined by thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) to increase the sensitivity. Principal components analysis (PCA) was applied to the data sets to characterize the samples with respect to their geographic origin and color difference. The PCA for Brazilian single-color samples showed separation, with one group consisting of blue and green textiles and another with all the other materials evaluated. The geographic origin study showed a clear separation between Brazilian and Chinese textiles. The metals amount extracted with sweat extractable solution were lower than limits values pointed by the International Testing and Certification System for Textiles, Oko Tex Standard 100, in the all considered classes. Recoveries varied from 85 to 112% for additions ranging from 3.0 to 25 mg kg{sup -1} for Ca and from 0.3 to 7.0 mg kg{sup -1} for all other analytes through the microwave-assisted decomposition procedure.

  13. Lead concentrations and isotope ratios in street dust determined by electrothermal atomic absorption spectrometry and inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Nageotte, S M; Day, J P

    1998-01-01

    A major source of environmental lead, particularly in urban areas, has been from the combustion of leaded petrol. Street dust has previously been used to assess urban lead contamination, and the dust itself can also be a potential source of lead ingestion, particularly to children. The progressive reduction of lead in petrol, in recent years, would be expected to have been reflected in a reduction of lead in urban dust. We have tested this hypothesis by repeating an earlier survey of Manchester street dust and carrying out a comparable survey in Paris. Samples were collected from streets and parks, lead was extracted by digestion with concentrated nitric acid and determined by electrothermal atomic absorption spectrometry. Lead isotope ratios were measured by inductively coupled plasma mass spectrometry. Results for Manchester show that lead concentrations have fallen by about 40% (street dust averages, 941 micrograms g-1 (ppm) in 1975 down to 569 ppm in 1997). In Paris, the lead levels in street dust are much higher and significant differences were observed between types of street (not seen in Manchester). Additionally, lead levels in parks were much lower than in Manchester. Samples collected under the Eiffel Tower had very high concentrations and lead isotope ratios showed that this was unlikely to be fallout from motor vehicles but could be due to the paint used on the tower. Isotope ratios measurements also revealed that lead additives used in France and the UK come from different sources.

  14. Determination of the elemental composition of ferromanganese formations certified reference materials by mass-spectrometry with inductively coupled plasma

    Directory of Open Access Journals (Sweden)

    N. V. Zarubina

    2014-01-01

    Full Text Available Contents of 41 elements in the Russian standard samples of ferromanganese nodules OOPE 601, OOPE 602, OOPE 603 and ore crust OOPE 604 were identified by mass-spectrometry with inductively-coupled plasma. Content of W was firstly presented in the sample OOPE-603. Relative standard deviation for most elements was in the range of 3-10%. A description of ICP-MS technique including sample preparation procedure and other instrumental parameters were given as well as analysis of ferromanganese nodules standard samples NOD-A-1 and NOD-P-1 of U.S. Geological Survey was demonstrated for validation. Normalized to chondrite distribution curves of REE in the studied samples were shown as an indicator of the internal consistency offound concentrations. The available literature data on the content of a wide range of elements and its comparison with the matter obtained by us was produced. Measured contents of elements in the established CRM may be useful in the analytical practice to evaluate precision of results. There is a lack of relevant information on a variety of geochemically important elements in the Russian standard samples of OOPE series and the new data can be taken into account in their certification.

  15. Determination of chromium in airborne particulate matter by high resolution and laser ablation inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Wang, C.-F.; Chin, C.-J.; Luo, S.-K.; Men, L.-C.

    1999-01-01

    This work presents an optimized sample digestion procedure for determining Cr in airborne particulate matter by inductively coupled plasma mass spectrometry (ICP-MS). High resolution (HR) ICP-MS is utilized to examine how the added acid mixture and subsequent evaporation process influence spectroscopic interference. Experimental results indicate that a two-step high pressure bomb acid digestion (1st step with HNO 3 +HClO 4 , and 2nd step with HF) procedure without evaporation is the optimum pre-treatment procedure for determining Cr by ICP-MS. In addition, laser ablation (LA) ICP-MS is used directly to analyze for Cr in airborne particulate matter. Results obtained by LA-ICP-MS correlate well with certified values and values obtained from the conventional acid digestion/HR-ICP-MS method. The detection limit for Cr in air particles by HR-ICP-MS with the proposed digestion method is -1 . Furthermore, LA-ICP-MS provides a rapid direct analytical technique with a detection limit of 0.05 μg/filter. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  16. Role of vibrationally excited HBr in a HBr/He inductively coupled plasma used for etching of silicon

    Science.gov (United States)

    Tinck, Stefan; Bogaerts, Annemie

    2016-06-01

    In this work, the role of vibrationally excited HBr (HBr(vib)) is computationally investigated for a HBr/He inductively coupled plasma applied for Si etching. It is found that at least 50% of all dissociations of HBr occur through HBr(vib). This additional dissociation pathway through HBr(vib) makes the plasma significantly more atomic. It also results in a slightly higher electron temperature (i.e. about 0.2 eV higher compared to simulation results where HBr(vib) is not included), as well as a higher gas temperature (i.e. about 50 K higher than without including HBr(vib)), due to the enhanced Franck-Condon heating through HBr(vib) dissociation, at the conditions investigated. Most importantly, the calculated etch rate with HBr(vib) included in the model is a factor 3 higher than in the case without HBr(vib), due to the higher fluxes of etching species (i.e. H and Br), while the chemical composition of the wafer surface shows no significant difference. Our calculations clearly show the importance of including HBr(vib) for accurate modeling of HBr-containing plasmas.

  17. Determination of total chlorine and bromine in solid wastes by sintering and inductively coupled plasma-sector field mass spectrometry

    International Nuclear Information System (INIS)

    Osterlund, Helene; Rodushkin, Ilia; Ylinenjaervi, Karin; Baxter, Douglas C.

    2009-01-01

    A sample preparation method based on sintering, followed by analysis by inductively coupled plasma-sector field mass spectrometry (ICP-SFMS) for the simultaneous determination of chloride and bromide in diverse and mixed solid wastes, has been evaluated. Samples and reference materials of known composition were mixed with a sintering agent containing Na 2 CO 3 and ZnO and placed in an oven at 560 deg. C for 1 h. After cooling, the residues were leached with water prior to a cation-exchange assisted clean-up. Alternatively, a simple microwave-assisted digestion using only nitric acid was applied for comparison. Thereafter the samples were prepared for quantitative analysis by ICP-SFMS. The sintering method was evaluated by analysis of certified reference materials (CRMs) and by comparison with US EPA Method 5050 and ion chromatography with good agreement. Median RSDs for the sintering method were determined to 10% for both chlorine and bromine, and median recovery to 96% and 97%, respectively. Limits of detection (LODs) were 200 mg/kg for chlorine and 20 mg/kg for bromine. It was concluded that the sintering method is suitable for chlorine and bromine determination in several matrices like sewage sludge, plastics, and edible waste, as well as for waste mixtures. The sintering method was also applied for determination of other elements present in anionic forms, such as sulfur, arsenic, selenium and iodine

  18. Preconcentration of heavy metals on activated carbon and their determination in fruits by inductively coupled plasma optical emission spectrometry.

    Science.gov (United States)

    Feist, Barbara; Mikula, Barbara

    2014-03-15

    A method of separation and preconcentration of cadmium, cobalt, copper, nickel, lead, and zinc at trace level using activated carbon is proposed. Activated carbon with the adsorbed trace metals was mineralised using a high-pressure microwave mineraliser. The heavy metals were determined after preconcentration by inductively coupled plasma optical emission spectrometry (ICP-OES). The influence of several parameters, such as pH, sorbent mass, shaking time was examined. Moreover, effects of inorganic matrix on recovery of the determined elements were studied. The experiment shows that foreign ions did not influence recovery of the determined elements. The detection limits (DL) of Cd, Co, Cu, Ni, Pb, and Zn were 0.17, 0.19, 1.60, 2.60, 0.92 and 1.50 μg L(-)(1), respectively. The recovery of the method for the determined elements was better than 95% with relative standard deviation from 1.3% to 3.7%. The preconcentration factor was 80. The proposed method was applied for determination of Cd, Co, Cu, Ni, Pb, and Zn in fruits materials. Accuracy of the proposed method was verified using certified reference material (NCS ZC85006 Tomato). Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Analysis of Mineral and Heavy Metal Content of Some Commercial Fruit Juices by Inductively Coupled Plasma Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Adriana Dehelean

    2013-01-01

    Full Text Available The presence of potentially toxic elements and compounds in foodstuffs is of intense public interest and thus requires rapid and accurate methods to determine the levels of these contaminants. Inductively coupled plasma mass spectrometry is a powerful tool for the determination of metals and nonmetals in fruit juices. In this study, 21 commercial fruit juices (apple, peach, apricot, orange, kiwi, pear, pineapple, and multifruit present on Romanian market were investigated from the heavy metals and mineral content point of view by ICP-MS. Our obtained results were compared with those reported in literature and also with the maximum admissible limit in drinking water by USEPA and WHO. For Mn the obtained values exceeded the limits imposed by these international organizations. Co, Cu, Zn, As, and Cd concentrations were below the acceptable limit for drinking water for all samples while the concentrations of Ni and Pb exceeded the limits imposed by USEPA and WHO for some fruit juices. The results obtained in this study are comparable to those found in the literature.

  20. On-line system for preconcentration and determination of metals in vegetables by Inductively Coupled Plasma Optical Emission Spectrometry

    International Nuclear Information System (INIS)

    Bezerra, Marcos A.; Santos, Walter N.L. dos; Lemos, Valfredo A.; Korn, Maria das Gracas A.; Ferreira, Sergio L.C.

    2007-01-01

    A procedure has been developed for the simultaneous determination of trace amounts of cadmium, copper, chromium, nickel and lead in digested vegetable samples. The method involves solid-phase extraction of the metals using a minicolumn of Amberlite XAD-4 modified with dihydroxybenzoic acid (DHB) and detection by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The elution of the metals from minicolumn was performed with 1.0 mol L -1 hydrochloric acid. Variables associated with flow preconcentration system performance, such as pH, buffer concentration, eluent concentration and sampling flow rate, were optimized. The developed procedure provides enrichment factors of 100, 72, 16, 91 and 53, for cadmium, copper, chromium, nickel and lead, respectively. Detection limits (3σ B ) were 0.02 (Cd), 0.23 (Cu), 0.58 (Cr), 0.060 (Ni) and 0.54 (Pb) μg L -1 . The procedure was applied for determination of metals in samples of guarana and cabbage. The accuracy of the method was checked by the analysis of a certified reference material (NIST 1571, Orchard leaves). Results found were in agreement with certified values

  1. Direct determination of mercury in cosmetic samples by isotope dilution inductively coupled plasma mass spectrometry after dissolution with formic acid

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Ying; Shi, Zeming; Zong, Qinxia; Wu, Peng; Su, Jing [Sichuan Provincial Key Laboratory of Nuclear Technology in Geology, College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059 (China); Liu, Rui, E-mail: liur.ray@gmail.com [Mineral Resources Chemistry Key Laboratory of Sichuan Higher Education Institutions, College of Materials and Chemistry and Chemical Engineering, Chengdu University of Technology, Chengdu 610059 (China)

    2014-02-17

    Graphical abstract: -- Highlights: •Simple, sensitive, and accurate method is established for mercury determination in cosmetics. •The sample preparation procedure is highly simplified. •Isotope dilution efficiently eliminates matrix effect. •First report of using formic acid based method in combination with PVG-ID-ICP MS for mercury quantitation in cosmetics. -- Abstract: A new method was proposed for the accurate determination of mercury in cosmetic samples based on isotopic dilution (ID)-photochemical vapor generation (PVG)-inductively coupled plasma mass spectrometry (ICP MS) measurement. Cosmetic samples were directly dissolved in formic acid solution and subsequently subjected to PVG for the reduction of mercury into vapor species following by ICP MS detection. Therefore, the risks of analyte contamination and loss were avoided. Highly enriched {sup 201}Hg isotopic spike is added to cosmetics and the isotope ratios of {sup 201}Hg/{sup 202}Hg were measured for the quantitation of mercury. With ID calibration, the influences originating from sample matrixes for the determination of mercury in cosmetic samples have been efficiently eliminated. The effects of several experimental parameters, such as the concentration of the formic acid, and the flow rates of carrier gas and sample were investigated. The method provided good reproducibility and the detection limits were found to be 0.6 pg mL{sup −1}. Finally, the developed method was successfully applied for the determination of mercury in six cosmetic samples and a spike test was performed to verify the accuracy of the method.

  2. Direct determination of mercury in cosmetic samples by isotope dilution inductively coupled plasma mass spectrometry after dissolution with formic acid

    International Nuclear Information System (INIS)

    Gao, Ying; Shi, Zeming; Zong, Qinxia; Wu, Peng; Su, Jing; Liu, Rui

    2014-01-01

    Graphical abstract: -- Highlights: •Simple, sensitive, and accurate method is established for mercury determination in cosmetics. •The sample preparation procedure is highly simplified. •Isotope dilution efficiently eliminates matrix effect. •First report of using formic acid based method in combination with PVG-ID-ICP MS for mercury quantitation in cosmetics. -- Abstract: A new method was proposed for the accurate determination of mercury in cosmetic samples based on isotopic dilution (ID)-photochemical vapor generation (PVG)-inductively coupled plasma mass spectrometry (ICP MS) measurement. Cosmetic samples were directly dissolved in formic acid solution and subsequently subjected to PVG for the reduction of mercury into vapor species following by ICP MS detection. Therefore, the risks of analyte contamination and loss were avoided. Highly enriched 201 Hg isotopic spike is added to cosmetics and the isotope ratios of 201 Hg/ 202 Hg were measured for the quantitation of mercury. With ID calibration, the influences originating from sample matrixes for the determination of mercury in cosmetic samples have been efficiently eliminated. The effects of several experimental parameters, such as the concentration of the formic acid, and the flow rates of carrier gas and sample were investigated. The method provided good reproducibility and the detection limits were found to be 0.6 pg mL −1 . Finally, the developed method was successfully applied for the determination of mercury in six cosmetic samples and a spike test was performed to verify the accuracy of the method

  3. Characterization of a 50kW Inductively Coupled Plasma Torch for Testing of Ablative Thermal Protection Materials

    Science.gov (United States)

    Greene, Benton R.; Clemens, Noel T.; Varghese, Philip L.; Bouslog, Stanley A.; Del Papa, Steven V.

    2017-01-01

    With the development of new manned spaceflight capabilities including NASA's Orion capsule and the Space-X Dragon capsule, there is a renewed importance of understanding the dynamics of ablative thermal protection systems. To this end, a new inductively coupled plasma torch facility is being developed at UT-Austin. The torch operates on argon and/or air at plasma powers up to 50 kW. In the present configuration the flow issues from a low-speed subsonic nozzle and the hot plume is characterized using slug calorimetry and emission spectroscopy. Preliminary measurements using emission spectroscopy have indicated that the torch is capable of producing an air plasma with a temperature between 6,000 K and 8,000 K depending on the power and flow settings and an argon plasma with a temperature of approximately 12,000 K. The operation envelope was measured, and heat flux measured for every point within the envelope using both a slug calorimeter and a Gardon gauge heat flux sensor. The torch was found to induce a stagnation point heat flux of between 90 and 225 W/sq cm.

  4. Studies on analysis of gallium and indium in zinc ores by inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    Hwang, Youn Ok; Sim, Sang Kwon; Sung, Hack Je; Yang, Myung Kwon

    1993-01-01

    The separation of gallium and indium from the matrix elements such as zinc and other ions, especially from Fe(III) ion was studied for the determination of trace level of them in zinc ores and zinc blendes by inductively coupled plasma atomic emission spectrometry(ICP-AES). Gallium and indium were extracted from the sample solution with a solvent of tributyl phosphate(TBP). The type and concentration of acid, interferences of other ions, the ratio of aqueous phase to organic phase, TBP concentration, sripping efficiency were optimized for the effective extraction. Gallium and indium were separated from other ions in the 5N hydrochloric acid solution of the samples by the extraction with 100% TBP. In this time, Fe(III) was reduced to Fe(II) with hydroxylamine hydrochloride to prevent its coextraction prior to the main extraction. After stripped from organic phase by the back-extraction with 0.02N HCl, they were determined in the aqueous phase by ICP-AES. This method was known to be quantitative from the overall extraction of more than 95%. (Author)

  5. Extraction of butyltins from sediments and their determination by liquid chromatography interfaced to inductively coupled plasma atomic emission detector

    Energy Technology Data Exchange (ETDEWEB)

    Rivaro, P.; Frache, R. [Genoa Univ., Genoa (Italy). Dipt. di Chimica e Chimica Industriale, Sez. di Chimica Analitica ed Ambientale

    2000-06-01

    A liquid-liquid extraction of the butyltin compounds from sediment, suitable for their subsequent following determination by high performance liquid chromatography-hydride generation inductively coupled plasma atomic emission detector system, is proposed. Recoveries of 86%, 80% and 42% for tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT) respectively were achieved. The relative detection limits of butyltin compounds by this method ranged from 27 to 62 ng of tin per gram of dry sediment. The method was applied to real sediment samples collected in the Venice lagoon (Italy). The results showed that, despite the restrictions on the use of butyltin contained in antifoulting paints, a considerable amount of organotin compounds is still present in Venice sediments. [Italian] E' stato messo a punto un metodo per l'estrazione di composti butilstannici da sedimenti, impiegando un'opportuna estrazione liquido-liquido per la successiva determinazione di tali composti mediante cromatografia liquida ad alta prestazione interfacciata tramite un sistema di generazione di idruri, ad uno spettrometro di emissione a plasma indotto per radiofrequenza. Sono stati ottenuti limiti di rilevabilita' tra i 27 e i 62 ng Sn/g sedimento, a seconda della specie butistannica considerata. La metodica e' stata impiegata per l'analisi di campioni di sedimento raccolti nella laguna di Venezia. I risultati ottenuti mostrano che, nonostante le limitazioni legislative sul loro impiego, considerevoli quantita' di composti butilstannici sono ancora presenti nei sedimenti.

  6. Measurements of neutral and ion composition, neutral temperature, and electron energy distribution function in a CF4 inductively coupled plasma

    International Nuclear Information System (INIS)

    Singh, Harmeet; Coburn, J.W.; Graves, David B.

    2001-01-01

    In this article, we present comprehensive measurements of the neutral number densities, ion number densities, and the electron energy distribution function in a CF 4 inductively coupled plasma at pressures between 1 and 30 mTorr, and deposited powers between 150 and 550 W. High degrees of dissociation are observed at the lower pressures. We believe this is a result of the large electron temperature at the lower pressures. The measurements of all the dominant radical and stable neutral species using appearance potential mass spectrometry allows the estimation of the neutral temperature at the neutral sampling aperture. The neutral temperature is also estimated from the change in the number density of a trace amount of argon added to CF 4 when the plasma is turned on. Neutral temperatures up to 930 K are measured at the sampling aperture. The increase in neutral temperature with power at a constant pressure results in a decrease in the total neutral number density at a constant pressure. The electron temperature is sensitive to the neutral number density, especially at low densities. This leads to a significant increase in the electron temperature with power, resulting in the higher degrees of dissociation observed at low pressures. The number densities of radicals and their corresponding ions are generally strongly correlated in the plasma. We show indirect evidence for large surface loss coefficients for C and CF radicals

  7. Standard test method for determination of impurities in nuclear grade uranium compounds by inductively coupled plasma mass spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This test method covers the determination of 67 elements in uranium dioxide samples and nuclear grade uranium compounds and solutions without matrix separation by inductively coupled plasma mass spectrometry (ICP-MS). The elements are listed in Table 1. These elements can also be determined in uranyl nitrate hexahydrate (UNH), uranium hexafluoride (UF6), triuranium octoxide (U3O8) and uranium trioxide (UO3) if these compounds are treated and converted to the same uranium concentration solution. 1.2 The elements boron, sodium, silicon, phosphorus, potassium, calcium and iron can be determined using different techniques. The analyst's instrumentation will determine which procedure is chosen for the analysis. 1.3 The test method for technetium-99 is given in Annex A1. 1.4 The values stated in SI units are to be regarded as standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish ...

  8. Line width and line shape analysis in the inductively coupled plasma by high resolution Fourier transform spectrometry

    International Nuclear Information System (INIS)

    Faires, L.M.; Palmer, B.A.; Brault, J.W.

    1984-01-01

    High resolution Fourier transform spectrometry has been used to perform line width and line shape analysis of eighty-one iron I emision lines in the spectral range 290 to 390nm originating in the normal analytical zone of an inductively coupled plasma. Computer programs using non-linear least squares fitting techniques for line shape analysis were applied to the fully resolved spectra to determine Gaussian and Lorentzian components of the total observed line width. The effect of noise in the spectrum on the precision of the line fitting technique was assessed, and the importance of signal to noise ratio for line shape analysis is discussed. Translational (Doppler) temperatures were calculated from the Gaussian components of the line width and were found to be on the order of 6300 0 K. The excitation temperature of iron I was also determined from the same spectral data by the spectroscopic slope method based on the Einstein-Boltzmann expression for spectral intensity and was found to be on the order of 4700 0 K. 31 references

  9. Measurement of excitation, ionization, and electron temperatures and positive ion concentrations in a 144 MHz inductively coupled radiofrequency plasma

    International Nuclear Information System (INIS)

    Walters, P.E.; Chester, T.L.; Winefordner, J.D.

    1977-01-01

    Diagnostic measurements of 144 MHz radiofrequency inductively coupled plasmas at pressures between 0.5 and 14 Torr have been made. Other variables studied included the gas type (Ar or Ne) and material in plasma (Ti or Tl). Parameters measured included excitation temperatures via the atomic Boltzmann plot and the two-line method, ionization electric probes. Excitation temperatures increased as the pressure of Ar or Ne plasmas decreased and reached a maximum of approx.9000 degreeK in the latter case and approx.6700 degreeK in the former case; Tl in the Ar plasma resulted in in a smaller rate of decrease of excitation temperature with increase of pressure of Ar. The ionization temperatures were lower than the excitation temperatures and were similar for both the Ar and Ne plasmas. Electron temperatures were about 10 times higher than the excitation temperatures indicating non-LTE behavior. Again, the electron temperatures indicating in Ne were considerably higher than in Ar. With the presence of metals, the electron temperatures with a metal in the Ar plasma were higher than in the absence. Positive ion concentrations were also measured for the various plasmas and were found to be similar (approx.10 18 m -3 ) in both the Ar and Ne plasmas. The presence of metals caused significant increase in the positive ion concentrations. From the results obtained, the optimum Ar pressure for Tl electrodeless discharge lamps operated at 144 MHz would be between 2 and 4 Torr

  10. Rapid determination of (237)Np and plutonium isotopes in urine by inductively-coupled plasma mass spectrometry and alpha spectrometry.

    Science.gov (United States)

    Maxwell, Sherrod L; Culligan, Brian K; Jones, Vernon D; Nichols, Sheldon T; Noyes, Gary W; Bernard, Maureen A

    2011-08-01

    A new rapid separation method was developed for the measurement of plutonium and neptunium in urine samples by inductively-coupled plasma mass spectrometry (ICP-MS) and/or alpha spectrometry with enhanced uranium removal. This method allows separation and preconcentration of plutonium and neptunium in urine samples using stacked extraction chromatography cartridges and vacuum box flow rates to facilitate rapid separations. There is an increasing need to develop faster analytical methods for emergency response samples. There is also enormous benefit to having rapid bioassay methods in the event that a nuclear worker has an uptake (puncture wound, etc.) to assess the magnitude of the uptake and guide efforts to mitigate dose (e.g., tissue excision and chelation therapy). This new method focuses only on the rapid separation of plutonium and neptunium with enhanced removal of uranium. For ICP-MS, purified solutions must have low salt content and low concentration of uranium due to spectral interference of (238)U(1)H(+) on m/z 239. Uranium removal using this method is enhanced by loading plutonium and neptunium initially onto TEVA resin, then moving plutonium to DGA resin where additional purification from uranium is performed with a decontamination factor of almost 1×10(5). If UTEVA resin is added to the separation scheme, a decontamination factor of ~3 × 10(6) can be achieved.

  11. Comparison of laser ablation and dried solution aerosol as sampling systems in inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Coedo, A G; Padilla, I; Dorado, M T

    2004-12-01

    This paper describes a study designed to determine the possibility of using a dried aerosol solution for calibration in laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The relative sensitivities of tested materials mobilized by laser ablation and by aqueous nebulization were established, and the experimentally determined relative sensitivity factors (RSFs) were used in conjunction with aqueous calibration for the analysis of solid steel samples. To such a purpose a set of CRM carbon steel samples (SS-451/1 to SS-460/1) were sampled into an ICP-MS instrument by solution nebulization using a microconcentric nebulizer with membrane desolvating (D-MCN) and by laser ablation (LA). Both systems were applied with the same ICP-MS operating parameters and the analyte signals were compared. The RSF (desolvated aerosol response/ablated solid response) values were close to 1 for the analytes Cr, Ni, Co, V, and W, about 1.3 for Mo, and 1.7 for As, P, and Mn. Complementary tests were carried out using CRM SS-455/1 as a solid standard for one-point calibration, applying LAMTRACE software for data reduction and quantification. The analytical results are in good agreement with the certified values in all cases, showing that the applicability of dried aerosol solutions is a good alternative calibration system for laser ablation sampling.

  12. Determination of selenomethionine, selenocysteine, and inorganic selenium in eggs by HPLC-inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lipiec, Elzbieta; Siara, Grzegorz [CNRS/UPPA, Laboratoire de Chimie Analytique Bio-Inorganique et Environnement, Pau (France); Warsaw University of Technology, Warsaw (Poland); Bierla, Katarzyna; Ouerdane, Laurent; Szpunar, Joanna [CNRS/UPPA, Laboratoire de Chimie Analytique Bio-Inorganique et Environnement, Pau (France)

    2010-05-15

    A method for the simultaneous determination of selenomethionine (SeMet), selenocysteine (SeCys), and selenite [Se(IV)] in chicken eggs was developed. A sample preparation protocol including defatting, protein denaturation, and carbamidomethylation was optimized in order to achieve complete protein digestion and to avoid SeCys losses. Quantification was carried out by reversed-phase HPLC-inductively coupled plasma mass spectrometry (ICP MS) after quantitative isolation of the selenium-containing fraction by size-exclusion liquid chromatography. The detection limits were 0.06, 0.003, and 0.01 {mu}g g{sup -1} (dry weight) for SeCys, Se(IV) and SeMet, respectively, and the precision was 5-10%. The end products of carbamidomethylation of the different selenium species were identified for the first time by electrospray QTOF MS after custom-designed 2D HPLC purification. Differences in selenium speciation in egg yolk and white were highlighted, the yolk containing more SeCys and the white more SeMet. An insight into selenium bioaccessibility in eggs was obtained by digestion with simulated gastric and gastrointestinal juices and size-exclusion HPLC-ICP MS. (orig.)

  13. Kinetic Temperature and Electron Density Measurement in an Inductively Coupled Plasma Torch using Degenerate Four-Wave Mixing

    Science.gov (United States)

    Schafer, Julia; Lyons, Wendy; Tong, WIlliam G.; Danehy, Paul M.

    2008-01-01

    Laser wave mixing is presented as an effective technique for spatially resolved kinetic temperature measurements in an atmospheric-pressure radio-frequency inductively-coupled plasma. Measurements are performed in a 1 kW, 27 MHz RF plasma using a continuous-wave, tunable 811.5-nm diode laser to excite the 4s(sup 3)P2 approaches 4p(sup 3)D3 argon transition. Kinetic temperature measurements are made at five radial steps from the center of the torch and at four different torch heights. The kinetic temperature is determined by measuring simultaneously the line shape of the sub-Doppler backward phase-conjugate degenerate four-wave mixing and the Doppler-broadened forward-scattering degenerate four-wave mixing. The temperature measurements result in a range of 3,500 to 14,000 K+/-150 K. Electron densities measured range from 6.1 (+/-0.3) x 10(exp 15)/cu cm to 10.1 (+/-0.3) x 10(exp 15)/cu cm. The experimental spectra are analyzed using a perturbative treatment of the backward phase-conjugate and forward-geometry wave-mixing theory. Stark width is determined from the collisional broadening measured in the phase-conjugate geometry. Electron density measurements are made based on the Stark width. The kinetic temperature of the plasma was found to be more than halved by adding deionized water through the nebulizer.

  14. Determination of selenoprotein P in human plasma by solid phase extraction and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Bendahl, L.; Sidenius, U.; Gammelgaard, Bente

    2000-01-01

    A method based on solid phase extraction was developed for the determination of selenoprotein P as selenium in human plasma. Separation of selenoprotein P from other selenium-containing proteins was accomplished by immobilized metal-ion affinity chromatography. The selenium content was subsequent...... than 2% in this range. The estimated limit of detection was 2 mu g/l and the experimentally verified quantification limit was 5 mu g/l, giving a relative standard deviation less than 2%. (C) 2000 Elsevier Science B.V. All rights reserved......A method based on solid phase extraction was developed for the determination of selenoprotein P as selenium in human plasma. Separation of selenoprotein P from other selenium-containing proteins was accomplished by immobilized metal-ion affinity chromatography. The selenium content was subsequently...... measured by inductively coupled plasma mass spectrometry (ICP-MS) monitoring the Se-82 isotope. Linear response was observed in the concentration range 0.3-70.8 mu g/l selenium as selenoprotein P with a correlation coefficient of 0.9994. The precision expressed as relative standard deviation was better...

  15. Standard practice for analysis of aqueous leachates from nuclear waste materials using inductively coupled plasma-atomic emission spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice is applicable to the determination of low concentration and trace elements in aqueous leachate solutions produced by the leaching of nuclear waste materials, using inductively coupled plasma-atomic emission spectroscopy (ICP-AES). 1.2 The nuclear waste material may be a simulated (non-radioactive) solid waste form or an actual solid radioactive waste material. 1.3 The leachate may be deionized water or any natural or simulated leachate solution containing less than 1 % total dissolved solids. 1.4 This practice should be used by analysts experienced in the use of ICP-AES, the interpretation of spectral and non-spectral interferences, and procedures for their correction. 1.5 No detailed operating instructions are provided because of differences among various makes and models of suitable ICP-AES instruments. Instead, the analyst shall follow the instructions provided by the manufacturer of the particular instrument. This test method does not address comparative accuracy of different devices...

  16. Multi-element analysis of water decoction of medicine food homology plants using inductively coupled plasma-tandem mass spectrometry

    Science.gov (United States)

    Fu, Liang; Shi, Shu-Yun; Chen, Xiao-Qing

    2017-07-01

    The concentration of twelve trace elements in the water decoction of medicine food homology plants (MFHP) was determined by inductively coupled plasma-tandem mass spectrometry (ICP-MS/MS). Water decoctions of MFHP were analyzed directly using the MS/MS mode after acidification by 1% (v/v) nitric acid. The polyatomic interferences were eliminated by oxygen mass shift, oxygen on-mass, and ammonia mass shift. The accuracy of the method was verified by analysis of standard reference materials. This method was utilized to investigate the water decoction composition of 16 common Chinese MFHPs. The trace elements in the water decoctions of different MFHPs presented significantly different dissolution ratios. The dissolution ratio of V was the lowest (4.21%-14.86%), whereas Zn showed the highest dissolution ratio (24.87%-86.80%). In addition, the dissolution ratio of heavy metallic elements in most MFHP was equal to or was lower than 30%. Therefore, consumption of MHFP decoction could decrease the heavy metal intake associated with MFHP use and reduce the risk of heavy metal poisoning.

  17. Gentle dry etching of P(VDF-TrFE) multilayer micro actuator structures by use of an inductive coupled plasma

    International Nuclear Information System (INIS)

    Edqvist, E; Snis, N; Johansson, S

    2008-01-01

    To fully utilize the actuator properties of poly(vinylidenefluoride) (P(VDF))-based polymers, the electric field has to be rather high and one way to accomplish this, in particular with low voltage drive signals, is to build multilayered structures. This paper focuses on how to structure poly(vinylidenefluoride-trifluoroethylene) P(VDF-TrFE) by presenting an etch method to create multilayered miniaturized actuators, with intermediate aluminium electrodes. To create inter-connect areas for the multilayer electrodes, a modified Bosch process in an inductive couple plasma (ICP) etcher is used to remove all P(VDF-TrFE) not covered by the electrodes. Since each electrode mask is slightly different from the others, the result is a staircase-like inter-electrode contact area that is connected from above using a conductive adhesive. The developed ICP etch results in high selective etching and a good agreement between theoretical and measured capacitance values. The manufactured cantilevers, consisting of a multilayer on top of a flexible printed circuit (FPC) board, were tested and the resonant stroke was confirmed to agree with expected values. The successful establishment of interlayer connections between the electrodes open up the possibility for batch fabrication of cheap low voltage micro actuators built on a standard substrate used in millions of commercial products

  18. Analysis of four toxic metals in a single rice seed by matrix solid phase dispersion -inductively coupled plasma mass spectrometry

    Science.gov (United States)

    He, Xiufen; Chen, Lixia; Chen, Xin; Yu, Huamei; Peng, Lixu; Han, Bingjun

    2016-12-01

    Toxic metals in rice pose great risks to human health. Metal bioaccumulation in rice grains is a criterion of breeding. Rice breeding requires a sensitive method to determine metal content in single rice grains to assist the variety selection. In the present study, four toxic metals of arsenic (As), cadmium (Cd), chromium (Cr) and lead (Pb) in a single rice grain were determined by a simple and rapid method. The developed method is based on matrix solid phase dispersion using multi-wall carbon nanotubes (MWCNTs) as dispersing agent and analyzed by inductively coupled plasma mass spectrometry. The experimental parameters were systematically investigated. The limits of detection (LOD) were 5.0, 0.6, 10 and 2.1 ng g-1 for As, Cd, Cr, and Pb, respectively, with relative standard deviations (n = 6) of rice samples analyzed by this method agreed well with those obtained by the standard microwave digestion. The amount of sample required was reduced approximately 100 fold in comparison with the microwave digestion. The method has a high application potential for other sample matrices and elements with high sensitivity and sample throughput.

  19. Possibilities of High Resolution Inductively Coupled Plasma Optical Emission Spectrometry in the Determination of Trace Elements in Environmental Materials

    Directory of Open Access Journals (Sweden)

    Nikolaya Velitchkova

    2013-01-01

    Full Text Available This paper presents new quantitative data for the spectral interferences obtained by high resolution 40.68 MHz radial viewing inductively coupled plasma optical emission spectrometry (HR-ICP-OES in the determination of Zn, Cd, Sb, Cu, Mn, Pb, Sn, Cr, U, and Ba in environmental materials in the presence of a complex matrix, containing Al, Ca, Fe, Mg, and Ti. The -concept for quantification of spectral interferences was used. The optimum line selection for trace analysis of a variety of multicomponent matrices requires the choice of prominent lines, which are free or negligibly influenced by line interference problems. The versatility of -concept as basic methodology was experimentally demonstrated in the determination of trace of elements in soil and drinking water. The detection limits are lower in comparison with corresponding threshold concentration levels for soil and drinking water in accordance with environmental regulations. This paper shows the possibilities of present day ICP-OES equipment in the direct determination of trace elements (without preconcentration of impurities in environmental samples.

  20. Degradation and modification of stainless-steel surface using Cl{sub 2}/Ar inductively coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Hanbyeol [Dept. of Control and Instrumentation Engineering, Korea University, 2511 Sejong-Ro (Korea, Republic of); Efremov, Alexander [Dept. of Electronic Devices and Materials Technology, State University of Chemistry and Technology, 7 F. Engels st., 153000 Ivanovo (Russian Federation); Yun, Sun Jin [Electronic and Telecommunications Research Institute, Daejon 305-350 (Korea, Republic of); Yeom, Geun Young [Dept. of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kim, Kyoung Bo [POSCO Global R and D Center, Open Innovation Lab., Incheon 406-840 (Korea, Republic of); Kwon, Kwang-Ho, E-mail: kwonkh@korea.ac.kr [Dept. of Control and Instrumentation Engineering, Korea University, 2511 Sejong-Ro (Korea, Republic of)

    2013-08-15

    The investigations of stainless steel (SS) etching behavior in the Cl{sub 2}/Ar inductively coupled plasma as well as the etched surface characteristics were carried out. It was found that an increase in Ar fraction in the Cl{sub 2}/Ar plasma from 0 to 100% at fixed gas pressure, input power and bias power results in decreasing both etching (degradation) rate of the SS surface (41.3–1.5 nm/min) and mean SS surface roughness (84–20 nm). Plasma diagnostics by Langmuir probes and 0-dimensional plasma modeling provided the data on plasma parameters, steady-state densities and fluxes of active species on the etched surface. It was shown that the maximum changes in mean roughness as well as in both polar and dispersive components of free surface energy correspond to a maximum value of Cl atom flux/ion flux ratio. Also, the linear correlation between free surface energy and mean roughness was obtained.

  1. Analytical performance of a low-gas-flow torch optimized for inductively coupled plasma atomic emission spectrometry

    Science.gov (United States)

    Montaser, A.; Huse, G.R.; Wax, R.A.; Chan, S.-K.; Golightly, D.W.; Kane, J.S.; Dorrzapf, A.F.

    1984-01-01

    An inductively coupled Ar plasma (ICP), generated in a lowflow torch, was investigated by the simplex optimization technique for simultaneous, multielement, atomic emission spectrometry (AES). The variables studied included forward power, observation height, gas flow (outer, intermediate, and nebulizer carrier) and sample uptake rate. When the ICP was operated at 720-W forward power with a total gas flow of 5 L/min, the signal-to-background ratios (S/B) of spectral lines from 20 elements were either comparable or inferior, by a factor ranging from 1.5 to 2, to the results obtained from a conventional Ar ICP. Matrix effect studies on the Ca-PO4 system revealed that the plasma generated in the low-flow torch was as free of vaporizatton-atomizatton interferences as the conventional ICP, but easily ionizable elements produced a greater level of suppression or enhancement effects which could be reduced at higher forward powers. Electron number densities, as determined via the series until line merging technique, were tower ht the plasma sustained in the low-flow torch as compared with the conventional ICP. ?? 1984 American Chemical Society.

  2. High-precision measurement of variations in calcium isotope ratios in urine by multiple collector inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Morgan, J.L.L.; Gordon, G.W.; Arrua, R.C.; Skulan, J.L.; Anbar, A.D.; Bullen, T.D.

    2011-01-01

    We describe a new chemical separation method to isolate Ca from other matrix elements in biological samples, developed with the long-term goal of making high-precision measurement of natural stable Ca isotope variations a clinically applicable tool to assess bone mineral balance. A new two-column procedure utilizing HBr achieves the purity required to accurately and precisely measure two Ca isotope ratios (44Ca/42Ca and 44Ca/43Ca) on a Neptune multiple collector inductively coupled plasma mass spectrometer (MC-ICPMS) in urine. Purification requirements for Sr, Ti, and K (Ca/Sr > 10000; Ca/Ti > 10000000; and Ca/K > 10) were determined by addition of these elements to Ca standards of known isotopic composition. Accuracy was determined by (1) comparing Ca isotope results for samples and standards to published data obtained using thermal ionization mass spectrometry (TIMS), (2) adding a Ca standard of known isotopic composition to a urine sample purified of Ca, and (3) analyzing mixtures of urine samples and standards in varying proportions. The accuracy and precision of δ44/42Ca measurements of purified samples containing 25 μg of Ca can be determined with typical errors less than ±0.2‰ (2σ).

  3. Measurement of airborne gunshot particles in a ballistics laboratory by sector field inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Diaz, Ernesto; Sarkis, Jorge E Souza; Viebig, Sônia; Saldiva, Paulo

    2012-01-10

    The present study aimed determines lead (Pb), antimony (Sb) and barium (Ba) as the major elements present in GSR in the environmental air of the Ballistics Laboratory of the São Paulo Criminalistics Institute (I.C.-S.P.), São Paulo, SP, Brazil. Micro environmental monitors (mini samplers) were located at selected places. The PM(2.5) fraction of this airborne was collected in, previously weighted filters, and analyzed by sector field inductively coupled plasma mass spectrometer (SF-HR-ICP-MS). The higher values of the airborne lead, antimony and barium, were found at the firing range (lead (Pb): 58.9 μg/m(3); barium (Ba): 6.9 μg/m(3); antimony (Sb): 7.3 μg/m(3)). The mean value of the airborne in this room during 6 monitored days was Pb: 23.1 μg/m(3); Ba: 2.2 μg/m(3); Sb: 1.5 μg/m(3). In the water tank room, the air did not show levels above the limits of concern. In general the airborne lead changed from day to day, but the barium and antimony remained constant. Despite of that, the obtained values suggest that the workers may be exposed to airborne lead concentration that can result in an unhealthy environment and could increase the risk of chronic intoxication. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  4. Visualizing fossilization using laser ablation-inductively coupled plasma-mass spectrometry maps of trace elements in Late Cretaceous bones

    Science.gov (United States)

    Koenig, A.E.; Rogers, R.R.; Trueman, C.N.

    2009-01-01

    Elemental maps generated by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) provide a previously unavailable high-resolution visualization of the complex physicochemical conditions operating within individual bones during the early stages of diagenesis and fossilization. A selection of LA-ICP-MS maps of bones collected from the Late Cretaceous of Montana (United States) and Madagascar graphically illustrate diverse paths to recrystallization, and reveal unique insights into geochemical aspects of taphonomic history. Some bones show distinct gradients in concentrations of rare earth elements and uranium, with highest concentrations at external bone margins. Others exhibit more intricate patterns of trace element uptake related to bone histology and its control on the flow paths of pore waters. Patterns of element uptake as revealed by LA-ICP-MS maps can be used to guide sampling strategies, and call into question previous studies that hinge upon localized bulk samples of fossilized bone tissue. LA-ICP-MS maps also allow for comparison of recrystallization rates among fossil bones, and afford a novel approach to identifying bones or regions of bones potentially suitable for extracting intact biogeochemical signals. ?? 2009 Geological Society of America.

  5. NEW METHOD FOR REMOVAL OF SPECTRAL INTERFERENCES FOR BERYLLIUM ASSAY USING INDUCTIVELY COUPLED PLASMA ATOMIC EMISSION SPECTROMETRY

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, S; Matthew Nelson, M; Linda Youmans, L; Maureen Bernard, M

    2008-01-14

    Beryllium has been used widely in specific areas of nuclear technology. Frequent monitoring of air and possible contaminated surfaces in U.S Department of Energy (DOE) facilities is required to identify potential health risks and to protect DOE workers from beryllium-contaminated dust. A new method has been developed to rapidly remove spectral interferences prior to beryllium (Be) measurement by inductively-coupled plasma atomic emission spectrometry (ICP-AES). The ion exchange separation removes uranium (U), thorium (Th), niobium (Nb), vanadium (V), molybdenum (Mo), zirconium (Zr), tungsten (W), iron (Fe), chromium (Cr), cerium (Ce), erbium (Er) and titanium (Ti). A stacked column consisting of Diphonix Resin{reg_sign} and TEVA Resin{reg_sign} reduces the levels of the spectral interferences so that low level Be measurements can be performed accurately. If necessary, an additional anion exchange separation can be used for further removal of interferences, particularly chromium. The method has been tested using spiked filters, spiked wipe samples and certified reference material standards with high levels of interferences added. The method provides very efficient removal of spectral interferences with very good accuracy and precision for beryllium on filters or wipes. A vacuum box system is employed to reduce analytical time and reduce labor costs.

  6. Determination of platinum surface contamination in veterinary and human oncology centres using inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Janssens, T; Brouwers, E E M; de Vos, J P; de Vries, N; Schellens, J H M; Beijnen, J H

    2015-09-01

    The objective of this study was to determine the surface contamination with platinum-containing antineoplastic drugs in veterinary and human oncology centres. Inductively coupled plasma mass spectrometry was used to measure platinum levels in surface samples. In veterinary and human oncology centres, 46.3 and 68.9% of the sampled surfaces demonstrated platinum contamination, respectively. Highest platinum levels were found in the preparation rooms (44.6 pg cm(-2)) in veterinary centres, while maximal levels in human centres were found in oncology patient-only toilets (725 pg cm(-2)). Transference of platinum by workers outside areas where antineoplastic drugs were handled was observed in veterinary and human oncology centres. In conclusion, only low levels of platinum contamination attributable to carboplatin were found in the sampled veterinary oncology centres. However, dispersion of platinum outside areas where antineoplastic drugs were handled was detected in veterinary and human oncology centres. Consequently, not only personnel, but also others may be exposed to platinum. © 2013 Blackwell Publishing Ltd.

  7. Determination of copper in uniformly-doped silicon thin film by isotope-dilution inductively coupled plasma mass spectrometry

    CERN Document Server

    Park, C J; Lee, D S

    2001-01-01

    Uniformly-doped silicon thin films were fabricated by ion beam sputter deposition. The thin films had four levels of copper dopant concentration ranging between 1 x 10 sup 1 sup 9 and 1 x 10 sup 2 sup 1 atoms/cm sup 3. Concentrations of Copper dopants were determined by the isotope dilution inductively coupled plasma mass spectrometry (ICP-MS) to provide certified reference data for the quantitative surface analysis by secondary ion mass spectrometry (SIMS). The copper-doped thin films were dissolved in a mixture of 1 M HF and 3 M HNO sub 3 spiked with appropriate amounts of sup 6 sup 5 Cu. For an accurate isotope ratio determination, both the detector dead time and the mass discrimination were appropriately corrected and isobaric interference from SiAr molecular ions was avoided by a careful sample pretreatment. An analyte recovery efficiency was obtained for the Cu spiked samples to evaluate accuracy of the method. Uncertainty of the determined copper concentrations, estimated following the EURACHEM Guide, ...

  8. PEMERIKSAAN KADAR MERKURI DAN KELUHAN KESEHATAN DALAM DARAH WANITA PEMAKAI KRIM PEMUTIH DENGAN METODA INDUCTIVELY COUPLED PLASMA

    Directory of Open Access Journals (Sweden)

    Dyna Putri Mayaserli

    2017-03-01

    Full Text Available Whitening cream is a mixture of chemicals or other materials that serve to lighten skin or fade black spots on the skin. Bleaching creams that contain mercury is very harmful for health. The purpose of this study is to examine and establish the levels of mercury in the blood of women users of whitening creams in the city of Padang. Blood samples examined as many as 10 samples and whitening creams as much as 5 samples. The qualitative analysis of the bleaching creams done with color test method, while the quantitative analysis of the blood samples used method ICP (Inductively Coupled Plasma. The results showed that of the five samples examined bleaching creams with color test, there are three positive samples contain mercury. while the results showed that the ten blood samples studied one sample contained mercury levels in the blood exceeds the normal value is 0.04435 mg / L. The use of whitening creams containing mercury can cause a variety of health complaints, ranging from skin discoloration, which in turn can cause black spots on the skin, allergies, skin irritation as well as the use of high doses can cause permanent brain damage, and can cause cancer.

  9. Accurate quantitation standards of glutathione via traceable sulfur measurement by inductively coupled plasma optical emission spectrometry and ion chromatography

    Science.gov (United States)

    Rastogi, L.; Dash, K.; Arunachalam, J.

    2013-01-01

    The quantitative analysis of glutathione (GSH) is important in different fields like medicine, biology, and biotechnology. Accurate quantitative measurements of this analyte have been hampered by the lack of well characterized reference standards. The proposed procedure is intended to provide an accurate and definitive method for the quantitation of GSH for reference measurements. Measurement of the stoichiometrically existing sulfur content in purified GSH offers an approach for its quantitation and calibration through an appropriate characterized reference material (CRM) for sulfur would provide a methodology for the certification of GSH quantity, that is traceable to SI (International system of units). The inductively coupled plasma optical emission spectrometry (ICP-OES) approach negates the need for any sample digestion. The sulfur content of the purified GSH is quantitatively converted into sulfate ions by microwave-assisted UV digestion in the presence of hydrogen peroxide prior to ion chromatography (IC) measurements. The measurement of sulfur by ICP-OES and IC (as sulfate) using the “high performance” methodology could be useful for characterizing primary calibration standards and certified reference materials with low uncertainties. The relative expanded uncertainties (% U) expressed at 95% confidence interval for ICP-OES analyses varied from 0.1% to 0.3%, while in the case of IC, they were between 0.2% and 1.2%. The described methods are more suitable for characterizing primary calibration standards and certifying reference materials of GSH, than for routine measurements. PMID:29403814

  10. Comparison method for uranium determination in ore sample by inductively coupled plasma optical emission spectrometry (ICP-OES).

    Science.gov (United States)

    Sert, Şenol

    2013-07-01

    A comparison method for the determination (without sample pre-concentration) of uranium in ore by inductively coupled plasma optical emission spectrometry (ICP-OES) has been performed. The experiments were conducted using three procedures: matrix matching, plasma optimization, and internal standardization for three emission lines of uranium. Three wavelengths of Sm were tested as internal standard for the internal standardization method. The robust conditions were evaluated using applied radiofrequency power, nebulizer argon gas flow rate, and sample uptake flow rate by considering the intensity ratio of the Mg(II) 280.270 nm and Mg(I) 285.213 nm lines. Analytical characterization of method was assessed by limit of detection and relative standard deviation values. The certificated reference soil sample IAEA S-8 was analyzed, and the uranium determination at 367.007 nm with internal standardization using Sm at 359.260 nm has been shown to improve accuracy compared with other methods. The developed method was used for real uranium ore sample analysis.

  11. Evaluation of power transfer efficiency for a high power inductively coupled radio-frequency hydrogen ion source

    Science.gov (United States)

    Jain, P.; Recchia, M.; Cavenago, M.; Fantz, U.; Gaio, E.; Kraus, W.; Maistrello, A.; Veltri, P.

    2018-04-01

    Neutral beam injection (NBI) for plasma heating and current drive is necessary for International Thermonuclear Experimental reactor (ITER) tokamak. Due to its various advantages, a radio frequency (RF) driven plasma source type was selected as a reference ion source for the ITER heating NBI. The ITER relevant RF negative ion sources are inductively coupled (IC) devices whose operational working frequency has been chosen to be 1 MHz and are characterized by high RF power density (˜9.4 W cm-3) and low operational pressure (around 0.3 Pa). The RF field is produced by a coil in a cylindrical chamber leading to a plasma generation followed by its expansion inside the chamber. This paper recalls different concepts based on which a methodology is developed to evaluate the efficiency of the RF power transfer to hydrogen plasma. This efficiency is then analyzed as a function of the working frequency and in dependence of other operating source and plasma parameters. The study is applied to a high power IC RF hydrogen ion source which is similar to one simplified driver of the ELISE source (half the size of the ITER NBI source).

  12. Preconcentration and determination of some lanthanide elements with immobilized bacteria by flow injection inductively coupled plasma atomic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Maquieira, A.; Elmahadi, H.; Puchades, R. [Universidad Politecnica de Valencia (Spain)

    1996-02-01

    The on-line combination of flow injection column preconcentration with sequential inductively coupled plasma atomic emission spectrometry is shown to provide an enrichment factor of 36 for La{sup 3+}, 34 for Ce{sup 3+} and 51 for Nd{sup 3+}, at 1 {mu}g ml{sup -1} for 5 ml of sample. The significant improvement in the (3s) detection limit by preconcentration compared with that without preconcentration demonstrates the efficiency of preconcentration with the bacterium Spirulina platensis immobilized on controlled-pore glass. Recovery of all the lanthanide cations is quantitative and the capacity was calculated. Practical application of the method was demonstrated by the determination of La{sup 3+} and Nd{sup 3+} impurities in a cerium(III) nitrate reagent. Adsorption isotherm studies were used to describe the mechanisms and the nature of the column binding sites. Isotherm plots showed a Langmuirian shape for La{sup 3+} and an anti-Lanmuirian shape for Ce{sup 3+} and Nd{sup 3+}. Equilibrium constants were also calculated. (Author).

  13. Tin Content Determination in Canned Fruits and Vegetables by Hydride Generation Inductively Coupled Plasma Optical Emission Spectrometry

    Directory of Open Access Journals (Sweden)

    Sanda Rončević

    2012-01-01

    Full Text Available Tin content in samples of canned fruits and vegetables was determined by hydride generation inductively coupled plasma atomic emission spectrometry (HG-ICP-OES, and it was compared with results obtained by standard method of flame atomic absorption spectrometry (AAS. Selected tin emission lines intensity was measured in prepared samples after addition of tartaric acid and followed by hydride generation with sodium borohydride solution. The most favorable line at 189.991 nm showed the best detection limit (1.9 μg L−1 and limit of quantification (6.4 μg kg−1. Good linearity and sensitivity were established from time resolved analysis and calibration tests. Analytical accuracy of 98–102% was obtained by recovery study of spiked samples. Method of standard addition was applied for tin determination in samples from fully protected tinplate. Tin presence at low-concentration range was successfully determined. It was shown that tenth times less concentrations of Sn were present in protected cans than in nonprotected or partially protected tinplate.

  14. Self-Powered Random Number Generator Based on Coupled Triboelectric and Electrostatic Induction Effects at the Liquid-Dielectric Interface.

    Science.gov (United States)

    Yu, Aifang; Chen, Xiangyu; Cui, Haotian; Chen, Libo; Luo, Jianjun; Tang, Wei; Peng, Mingzeng; Zhang, Yang; Zhai, Junyi; Wang, Zhong Lin

    2016-12-27

    Modern cryptography increasingly employs random numbers generated from physical sources in lieu of conventional software-based pseudorandom numbers, primarily owing to the great demand of unpredictable, indecipherable cryptographic keys from true random numbers for information security. Thus, far, the sole demonstration of true random numbers has been generated through thermal noise and/or quantum effects, which suffers from expensive and complex equipment. In this paper, we demonstrate a method for self-powered creation of true random numbers by using triboelectric technology to collect random signals from nature. This random number generator based on coupled triboelectric and electrostatic induction effects at the liquid-dielectric interface includes an elaborately designed triboelectric generator (TENG) with an irregular grating structure, an electronic-optical device, and an optical-electronic device. The random characteristics of raindrops are harvested through TENG and consequently transformed and converted by electronic-optical device and an optical-electronic device with a nonlinear characteristic. The cooperation of the mechanical, electrical, and optical signals ensures that the generator possesses complex nonlinear input-output behavior and contributes to increased randomness. The random number sequences are deduced from final electrical signals received by an optical-electronic device using a familiar algorithm. These obtained random number sequences exhibit good statistical characteristics, unpredictability, and unrepeatability. Our study supplies a simple, practical, and effective method to generate true random numbers, which can be widely used in cryptographic protocols, digital signatures, authentication, identification, and other information security fields.

  15. Standard test method for determining elements in waste Streams by inductively coupled plasma-atomic emission spectroscopy

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This test method covers the determination of trace, minor, and major elements in waste streams by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) following an acid digestion of the sample. Waste streams from manufacturing processes of nuclear and non-nuclear materials can be analyzed. This test method is applicable to the determination of total metals. Results from this test method can be used to characterize waste received by treatment facilities and to formulate appropriate treatment recipes. The results are also usable in process control within waste treatment facilities. 1.2 This test method is applicable only to waste streams that contain radioactivity levels that do not require special personnel or environmental protection. 1.3 A list of the elements determined in waste streams and the corresponding lower reporting limit is found in Table 1. 1.4 This test method has been used successfully for treatment of a large variety of waste solutions and industrial process liquids. The com...

  16. RAPID DETERMINATION OF 237 NP AND PU ISOTOPES IN WATER BY INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY AND ALPHA SPECTROMETRY

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, S.; Jones, V.; Culligan, B.; Nichols, S.; Noyes, G.

    2010-06-23

    A new method that allows rapid preconcentration and separation of plutonium and neptunium in water samples was developed for the measurement of {sup 237}Np and Pu isotopes by inductively-coupled plasma mass spectrometry (ICP-MS) and alpha spectrometry; a hybrid approach. {sup 238}U can interfere with {sup 239}Pu measurement by ICP-MS as {sup 238}UH{sup +} mass overlap and {sup 237}Np via peak tailing. The method provide enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then moving Pu to DGA resin for additional removal of uranium. The decontamination factor for uranium from Pu is almost 100,000 and the decontamination factor for U from Np is greater than 10,000. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration is performed using a streamlined calcium phosphate precipitation method. Purified solutions are split between ICP-MS and alpha spectrometry so that long and short-lived Pu isotopes can be measured successfully. The method allows for simultaneous extraction of 20 samples (including QC samples) in 4 to 6 hours, and can also be used for emergency response. {sup 239}Pu, {sup 242}Pu and {sup 237}Np were measured by ICP-MS, while {sup 236}Pu, {sup 238}Pu, and {sup 239}Pu were measured by alpha spectrometry.

  17. Use of inductively coupled plasma-mass spectrometry in boron-10 stable isotope experiments with plants, rats, and humans.

    Science.gov (United States)

    Vanderpool, R A; Hoff, D; Johnson, P E

    1994-11-01

    The commercial availability of inductively coupled plasma-mass spectrometry technology (ICP-MS) has presented the opportunity to measure the boron concentrations and isotope ratios in a large number of samples with minimal sample preparation. A typical analytical sequence for fecal samples consists of 25 acid blanks, 1 digestion blank, 5 calibration solutions, 4 standard reference material solutions, 10 samples, and 4 natural abundance bias standards. Boron detection limits (3 x 1 sigma) for acid blanks are 0.11 ppb for 10B, and 0.40 ppb for 11B. Isotope ratios were measured in fecal samples with 20 to 50 ppb boron with sample had a 1.0 ppb boron memory after a 6-min washout. Boron isotope ratios in geological materials are highly variable; apparently this variability is reflected in plants of a fixed natural abundance value for boron requires that a natural abundance ratio be determined for each sample or related data set. The natural abundance variability also prevents quantitation and calculation of isotope dilution by instrument-supplied software. To measure boron transport in animal systems, 20 micrograms of 10B were fed to a fasted rat. During the 3 days after a 10B oral dose, 95% of the 10B was recovered from the urine and 4% from the feces. Urinary isotope ratios, 11B/10B, changed from a natural abundance of 4.1140 to an enriched value of 0.95077, a 77% change.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Frequency-tuning radiofrequency plasma source operated in inductively-coupled mode under a low magnetic field

    Science.gov (United States)

    Takahashi, Kazunori; Nakano, Yudai; Ando, Akira

    2017-07-01

    A radiofrequency (rf) inductively-coupled plasma source is operated with a frequency-tuning impedance matching system, where the rf frequency is variable in the range of 20-50 MHz and the maximum power is 100 W. The source consists of a 45 mm-diameter pyrex glass tube wound by an rf antenna and a solenoid providing a magnetic field strength in the range of 0-200 Gauss. A reflected rf power for no plasma case is minimized at the frequency of ˜25 MHz, whereas the frequency giving the minimum reflection with the high density plasma is about 28 MHz, where the density jump is observed when minimizing the reflection. A high density argon plasma above 1× {{10}12} cm-3 is successfully obtained in the source for the rf power of 50-100 W, where it is observed that an external magnetic field of a few tens of Gauss yields the highest plasma density in the present configuration. The frequency-tuning plasma source is applied to a compact and high-speed silicon etcher in an Ar-SF6 plasma; then the etching rate of 8~μ m min-1 is obtained for no bias voltage to the silicon wafer, i.e. for the case that a physical ion etching process is eliminated.

  19. [Determination of iodine and its species in plant samples using ion chromatography-inductively coupled plasma mass spectrometry].

    Science.gov (United States)

    Lin, Li; Chen, Guang; Chen, Yuhong

    2011-07-01

    A method was established for the determination of iodine and its species in plant samples using ion chromatography-inductively coupled plasma mass spectrometry (IC-ICP/ MS). Alkaline extraction and IC-ICP/MS were applied as the sample pre-treatment method and the detection technique respectively, for iodate and iodide determination. Moreover, high-temperature pyrolysis absorption was adopted as the pre-treatment method for total iodine analysis, which finally converted all the iodine species into iodide and measured the iodide by IC-ICP/MS. The recoveries of iodine for alkaline extraction and high-temperature pyrolysis absorption were 89.6%-97.5% and 95.2%-111.2%, respectively. The results were satisfactory. The detection limit of iodine was 0.010 mg/kg. The iodine and its speciation contents in several kinds of plant samples such as seaweeds, kelp, cabbage, tea leaf and spinach were investigated. It was shown that the iodine in seaweeds mainly existed as organic iodine; while the ones in kelp, cabbage, tea leaf and spinach mainly existed as inorganic iodine.

  20. Time-resolved spatial distribution measurements of pulse-modulated argon plasmas in an inductively coupled plasma reactor

    Science.gov (United States)

    Park, Ji-Hwan; Kim, Dong-Hwan; Kim, Yu-Sin; Chung, Chin-Wook

    2017-05-01

    The time variation of the plasma parameters along with their spatial distributions were measured in pulse-modulated (PM) inductively coupled argon plasma via the phase delay harmonic analysis method (PDHAM). During the initial active-glow, the distributions of both the ion flux and the electron temperature in the plasma bulk have M-shaped profiles due to the antenna geometry. Then, while the plasma is approaching a steady state, the spatial distribution evolves into a profile with a convex shape. The effects of the antenna geometry and the time evolution on the distribution profile are lesser under low gas pressure, and diminish at the wafer level. The diffusion of the charged particles and the nonlocal electron kinetics account for these characteristics. It is observed that the initial distribution of the electron temperature is affected by the electron density distribution of the previous after-glow at the wafer level. The distribution profiles at different pulse frequencies were also measured. At higher pulse frequencies, the distribution profile is more frequently smoothed by diffusion during the after-glow, leading to higher uniformity.

  1. On-line double isotope dilution laser ablation inductively coupled plasma mass spectrometry for the quantitative analysis of solid materials.

    Science.gov (United States)

    Fernández, Beatriz; Rodríguez-González, Pablo; García Alonso, J Ignacio; Malherbe, Julien; García-Fonseca, Sergio; Pereiro, Rosario; Sanz-Medel, Alfredo

    2014-12-03

    We report on the determination of trace elements in solid samples by the combination of on-line double isotope dilution and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The proposed method requires the sequential analysis of the sample and a certified natural abundance standard by on-line IDMS using the same isotopically-enriched spike solution. In this way, the mass fraction of the analyte in the sample can be directly referred to the certified standard so the previous characterization of the spike solution is not required. To validate the procedure, Sr, Rb and Pb were determined in certified reference materials with different matrices, including silicate glasses (SRM 610, 612 and 614) and powdered samples (PACS-2, SRM 2710a, SRM 1944, SRM 2702 and SRM 2780). The analysis of powdered samples was carried out both by the preparation of pressed pellets and by lithium borate fusion. Experimental results for the analysis of powdered samples were in agreement with the certified values for all materials. Relative standard deviations in the range of 6-21% for pressed pellets and 3-21% for fused solids were obtained from n=3 independent measurements. Minimal sample preparation, data treatment and consumption of the isotopically-enriched isotopes are the main advantages of the method over previously reported approaches. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Induction of colonic regulatory T cells by indigenous Clostridium species.

    Science.gov (United States)

    Atarashi, Koji; Tanoue, Takeshi; Shima, Tatsuichiro; Imaoka, Akemi; Kuwahara, Tomomi; Momose, Yoshika; Cheng, Genhong; Yamasaki, Sho; Saito, Takashi; Ohba, Yusuke; Taniguchi, Tadatsugu; Takeda, Kiyoshi; Hori, Shohei; Ivanov, Ivaylo I; Umesaki, Yoshinori; Itoh, Kikuji; Honda, Kenya

    2011-01-21

    CD4(+) T regulatory cells (T(regs)), which express the Foxp3 transcription factor, play a critical role in the maintenance of immune homeostasis. Here, we show that in mice, T(regs) were most abundant in the colonic mucosa. The spore-forming component of indigenous intestinal microbiota, particularly clusters IV and XIVa of the genus Clostridium, promoted T(reg) cell accumulation. Colonization of mice by a defined mix of Clostridium strains provided an environment rich in transforming growth factor-β and affected Foxp3(+) T(reg) number and function in the colon. Oral inoculation of Clostridium during the early life of conventionally reared mice resulted in resistance to colitis and systemic immunoglobulin E responses in adult mice, suggesting a new therapeutic approach to autoimmunity and allergy.

  3. Induction of mesenchymal stem cell chondrogenesis by polyacrylate substrates

    OpenAIRE

    Glennon-Alty, Laurence; Williams, Rachel; Dixon, Simon; Murray, Patricia

    2013-01-01

    Mesenchymal stem cells (MSCs) can generate chondrocytes in vitro, but typically need to be cultured as aggregates in the presence of transforming growth factor beta (TGF-?), which makes scale-up difficult. Here we investigated if polyacrylate substrates modelled on the functional group composition and distribution of the Arg-Gly-Asp (RGD) integrin-binding site could induce MSCs to undergo chondrogenesis in the absence of exogenous TGF-?. Within a few days of culture on the biomimetic polyacry...

  4. Induction of apoptosis and cell proliferation inhibition by paclitaxel in ...

    African Journals Online (AJOL)

    In this study, anti-proliferative and apoptotic effects of paclitaxel, which is itself an antichemotherapeutic agent, to FM3A cell line originated from Mouse mammary carcinoma at 7 different doses were examined. Seven different doses of paclitaxel (P1 = 3 nM, P2 = 7.5 nM, P3 = 15 nM, P4 = 30 nM, P5 = 60 nM, P6 = 120 nM, ...

  5. Biophysical induction of vascular smooth muscle cell podosomes.

    Directory of Open Access Journals (Sweden)

    Na Young Kim

    Full Text Available Vascular smooth muscle cell (VSMC migration and matrix degradation occurs with intimal hyperplasia associated with atherosclerosis, vascular injury, and restenosis. One proposed mechanism by which VSMCs degrade matrix is through the use of podosomes, transient actin-based structures that are thought to play a role in extracellular matrix degradation by creating localized sites of matrix metalloproteinase (MMP secretion. To date, podosomes in VSMCs have largely been studied by stimulating cells with phorbol esters, such as phorbol 12,13-dibutyrate (PDBu, however little is known about the physiological cues that drive podosome formation. We present the first evidence that physiological, physical stimuli mimicking cues present within the microenvironment of diseased arteries can induce podosome formation in VSMCs. Both microtopographical cues and imposed pressure mimicking stage II hypertension induce podosome formation in A7R5 rat aortic smooth muscle cells. Moreover, wounding using a scratch assay induces podosomes at the leading edge of VSMCs. Notably the effect of each of these biophysical stimuli on podosome stimulation can be inhibited using a Src inhibitor. Together, these data indicate that physical cues can induce podosome formation in VSMCs.

  6. Asymmetric flow field-flow fractionation coupled to inductively coupled plasma mass spectrometry for the quantification of quantum dots bioconjugation efficiency.

    Science.gov (United States)

    Menéndez-Miranda, Mario; Encinar, Jorge Ruiz; Costa-Fernández, José M; Sanz-Medel, Alfredo

    2015-11-27

    Hyphenation of asymmetric flow field-flow fractionation (AF4) to an on-line elemental detection (inductively coupled plasma-mass spectrometry, ICP-MS) is proposed as a powerful diagnostic tool for quantum dots bioconjugation studies. In particular, conjugation effectiveness between a "model" monoclonal IgG antibody (Ab) and CdSe/ZnS core-shell Quantum Dots (QDs), surface-coated with an amphiphilic polymer, has been monitored here by such hybrid AF4-ICP-MS technique. Experimental conditions have been optimized searching for a proper separation between the sought bioconjugates from the eventual free reagents excesses employed during the bioconjugation (QDs and antibodies). Composition and pH of the carrier have been found to be critical parameters to ensure an efficient separation while ensuring high species recovery from the AF4 channel. An ICP-MS equipped with a triple quadropole was selected as elemental detector to enable sensitive and reliable simultaneous quantification of the elemental constituents, including sulfur, of the nanoparticulated species and the antibody. The hyphenated technique used provided nanoparticle size-based separation, elemental detection, and composition analysis capabilities that turned out to be instrumental in order to investigate in depth the Ab-QDs bioconjugation process. Moreover, the analytical strategy here proposed allowed us not only to clearly identify the bioconjugation reaction products but also to quantify nanoparticle:antibodies bioconjugation efficiency. This is a key issue in future development of analytical and bioanalytical photoluminescent QDs applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Magnetic immunoassay coupled with inductively coupled plasma mass spectrometry for simultaneous quantification of alpha-fetoprotein and carcinoembryonic antigen in human serum

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xing; Chen, Beibei; He, Man; Zhang, Yiwen; Xiao, Guangyang; Hu, Bin, E-mail: binhu@whu.edu.cn

    2015-04-01

    The absolute quantification of glycoproteins in complex biological samples is a challenge and of great significance. Herein, 4-mercaptophenylboronic acid functionalized magnetic beads were prepared to selectively capture glycoproteins, while antibody conjugated gold and silver nanoparticles were synthesized as element tags to label two different glycoproteins. Based on that, a new approach of magnetic immunoassay-inductively coupled plasma mass spectrometry (ICP-MS) was established for simultaneous quantitative analysis of glycoproteins. Taking biomarkers of alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) as two model glycoproteins, experimental parameters involved in the immunoassay procedure were carefully optimized and analytical performance of the proposed method was evaluated. The limits of detection (LODs) for AFP and CEA were 0.086 μg L{sup −1} and 0.054 μg L{sup −1} with the relative standard deviations (RSDs, n = 7, c = 5 μg L{sup −1}) of 6.5% and 6.2% for AFP and CEA, respectively. Linear range for both AFP and CEA was 0.2–50 μg L{sup −1}. To validate the applicability of the proposed method, human serum samples were analyzed, and the obtained results were in good agreement with that obtained by the clinical chemiluminescence immunoassay. The developed method exhibited good selectivity and sensitivity for the simultaneous determination of AFP and CEA, and extended the applicability of metal nanoparticle tags based on ICP-MS methodology in multiple glycoprotein quantifications. - Highlights: • 4-Mercaptophenylboronic acid functionalized magnetic beads were prepared and characterized. • ICP-MS based magnetic immunoassay approach was developed for quantification of glycoproteins. • AFP and CEA were quantified simultaneously with Au and Ag NPs as element tags. • The developed method exhibited good selectivity and sensitivity for target glycoproteins.

  8. Magnetic solid phase extraction coupled with inductively coupled plasma mass spectrometry for the speciation of mercury in environmental water and human hair samples.

    Science.gov (United States)

    Ma, Shishuai; He, Man; Chen, Beibei; Deng, Wenchao; Zheng, Qi; Hu, Bin

    2016-01-01

    In this work, γ-mercaptopropyltrimethoxysilane (γ-MPTS) modified Fe3O4@SiO2 magnetic nanoparticles (MNPs) was successfully prepared, and characterized by Fourier transform infrared spectrometer (FT-IR), Transmission electron microscope (TEM) and Vibrating sample magnetometer (VSM). The sorption performance of the prepared Fe3O4@SiO2@γ-MPTS MNPs towards methylmercury (CH3Hg(+)) and inorganic mercury (Hg(2+)) was investigated. It was found that CH3Hg(+) and Hg(2+) could be simultaneously retained on the prepared Fe3O4@SiO2@γ-MPTS MNPs, and the quantitative elution of CH3Hg(+) and total mercury (THg) was achieved by using 1.5 mol L(-1) HCl containing 0.01% and 3% thiourea (m/v), respectively. And the levels of Hg(2+) were obtained by subtracting CH3Hg(+) from THg. Based on the above facts, a method of magnetic solid phase extraction (MSPE) combined with inductively coupled plasma mass spectrometry (ICP-MS) was developed for the speciation of CH3Hg(+) and Hg(2+). Various experimental parameters affecting MSPE of CH3Hg(+) and Hg(2+) such as pH, eluent, sample volume, and co-existing ions have been studied. Under the optimized conditions, the limits of detection (LODs) for CH3Hg(+) and THg were 1.6 and 1.9 ng L(-1), respectively. The accuracy of the proposed method was validated by analysis of a Certified Reference Material NRCC DORM-2 dogfish muscle, and the determined values are in good agreement with the certified values. The proposed method has also been successfully applied for the speciation of CH3Hg(+) and Hg(2+) in environmental water and human hair samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Coupling of an electrodialyzer with inductively coupled plasma mass spectrometry for the on-line determination of trace impurities in silicon wafers after surface metal extraction.

    Science.gov (United States)

    Chang, I-long; Hsu, I-hsiang; Yang, Mo-hsiung; Sun, Yun-chang

    2010-02-19

    Understanding the properties that determine the distribution and behavior of trace impurities in Si wafers is critical to defining and controlling the performance, reliability, and yields of integrated microelectronic devices. It remains, however, an intrinsically difficult task to determine trace impurities in Si because of the minute concentrations and extremely high levels of matrix involved. In this study, we used an electrodialyzer for the simultaneous on-line removal of the silicate and acid matrices through the neutralization of the excessive hydrogen ion and selectively separation of acid and silicate ions by the combination of electrode reaction as a source of hydroxide ions with the anion exchange membrane separation. To retain the analyte ions in the sample stream, we found that the presence of moderate amounts of nitric acid and hydrazine were necessary to improve the retention efficiency, not only for Zn(2+), Ni(2+), Cu(2+), and Co(2+) ions but also for CrO(4)(2-) ion. Under the optimized conditions, the interference that resulted from the sample matrix was suppressed significantly to provide satisfactory analytical signals. The precision of this method was ca. 5% when we used an electrodialyzer equipped with an anion exchange membrane to remove the sample matrix prior to performing inductively coupled plasma mass spectrometry (ICP-MS); the good agreement between the data obtained using our proposed method and those obtained using a batchwise wet chemical technique confirmed its accuracy. Our method permits the determination of Zn, Ni, Cu, Co, and Cr in Si wafers at detection limits within the range from 2.2 x 10(15) to 9.0 x 10(15) atoms cm(-3). Copyright 2009 Elsevier B.V. All rights reserved.

  10. Induction of primordial germ cell-like cells from mouse embryonic stem cells by ERK signal inhibition.

    Science.gov (United States)

    Kimura, Tohru; Kaga, Yoshiaki; Ohta, Hiroshi; Odamoto, Mika; Sekita, Yoichi; Li, Kunpeng; Yamano, Noriko; Fujikawa, Keita; Isotani, Ayako; Sasaki, Norihiko; Toyoda, Masashi; Hayashi, Katsuhiko; Okabe, Masaru; Shinohara, Takashi; Saitou, Mitinori; Nakano, Toru

    2014-10-01

    Primordial germ cells (PGCs) are embryonic germ cell precursors. Specification of PGCs occurs under the influence of mesodermal induction signaling during in vivo gastrulation. Although bone morphogenetic proteins and Wnt signaling play pivotal roles in both mesodermal and PGC specification, the signal regulating PGC specification remains unknown. Coculture of mouse embryonic stem cells (ESCs) with OP9 feeder cells induces mesodermal differentiation in vitro. Using this mesodermal differentiation system, we demonstrated that PGC-like cells were efficiently induced from mouse ESCs by extracellular signal-regulated kinase (ERK) signaling inhibition. Inhibition of ERK signaling by a MAPK/ERK kinase (MEK) inhibitor upregulated germ cell marker genes but downregulated mesodermal genes. In addition, the PGC-like cells showed downregulation of DNA methylation and formed pluripotent stem cell colonies upon treatment with retinoic acid. These results show that inhibition of ERK signaling suppresses mesodermal differentiation but activates germline differentiation program in this mesodermal differentiation system. Our findings provide a new insight into the signaling networks regulating PGC specification. © 2014 AlphaMed Press.

  11. Influence of binders on infrared laser ablation of powdered tungsten carbide pressed pellets in comparison with sintered tungsten carbide hardmetals studied by inductively coupled plasma atomic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Hola, Marketa [Research Centre for Environmental Chemistry and Ecotoxicology and Laboratory of Atomic Spectrochemistry, Faculty of Science, Masaryk University in Brno, Kotlarska 2, CZ 611 37 Brno (Czech Republic); Otruba, Vitezslav [Research Centre for Environmental Chemistry and Ecotoxicology and Laboratory of Atomic Spectrochemistry, Faculty of Science, Masaryk University in Brno, Kotlarska 2, CZ 611 37 Brno (Czech Republic); Kanicky, Viktor [Research Centre for Environmental Chemistry and Ecotoxicology and Laboratory of Atomic Spectrochemistry, Faculty of Science, Masaryk University in Brno, Kotlarska 2, CZ 611 37 Brno (Czech Republic)]. E-mail: viktork@chemi.muni.cz

    2006-05-15

    Laser ablation (LA) was studied as a sample introduction technique for the analysis of powdered and sintered tungsten carbides (WC/Co) by inductively coupled plasma optical emission spectrometry (ICP-OES). The possibility to work with powdered and compact materials with close chemical composition provided the opportunity to compare LA sampling of similar substances in different forms that require different preparation procedures. Powdered WC/Co precursors of sintered hardmetals were prepared for the ablation as pressed pellets with and without powdered silver as a binder, while sintered hardmetal blocks were embedded into a resin to obtain discs, which were then smoothed and polished. A Q-switched Nd:YAG laser operated at its fundamental wavelength of 1064 nm with a pulse frequency of 10 Hz and maximum pulse energy of 220 mJ was used. A single lens was used for the laser beam focusing. An ablation cell (14 cm{sup 3}) mounted on a PC-controlled XY-translator was connected to an ICP spectrometer Jobin Yvon 170 Ultrace (laterally viewed ICP, mono- and polychromator) using a 1.5-m tubing (4 mm i.d.). Ablation was performed in a circular motion (2 mm diameter). Close attention was paid to the study of the crater parametres depending on hardness, cohesion and Ag binder presence in WC/Co samples. The influence of the Co content on the depth and structure of the ablation craters of the binderless pellets was also studied. Linear calibration plots of Nb, Ta and Ti were obtained for cemented WC/Co samples, binderless and binder-containing pellets. Relative widths of uncertainty intervals about the centroids vary between {+-} 3% and {+-} 7%, and exceptionally reach a value above 10%. The lowest determinable quantities (LDQ) of Nb, Ta and Ti calculated from the calibration lines were less than 0.5% (m/m). To evaluate the possibility of quantitative elemental analysis by LA-ICP-OES, two real sintered WC/Co samples and two real samples of powdered WC/Co materials were analysed

  12. Induction of tumor necrosis factor expression and resistance in a human breast tumor cell line.

    OpenAIRE

    Spriggs, D; Imamura, K; Rodriguez, C; Horiguchi, J; Kufe, D W

    1987-01-01

    Tumor necrosis factor (TNF) is a polypeptide cytokine that is cytotoxic to some but not all tumor cells. The basis for resistance to the cytotoxic effects of this agent remains unclear. We have studied the development of TNF resistance in human ZR-75-1 breast carcinoma cells. ZR-75-1 cells have undetectable levels of TNF RNA and protein. However, TNF transcripts are transiently induced in these cells by exposure to recombinant human TNF. This induction of TNF RNA is associated with production...

  13. Induction of mesenchymal stem cell chondrogenesis by polyacrylate substrates.

    Science.gov (United States)

    Glennon-Alty, Laurence; Williams, Rachel; Dixon, Simon; Murray, Patricia

    2013-04-01

    Mesenchymal stem cells (MSCs) can generate chondrocytes in vitro, but typically need to be cultured as aggregates in the presence of transforming growth factor beta (TGF-β), which makes scale-up difficult. Here we investigated if polyacrylate substrates modelled on the functional group composition and distribution of the Arg-Gly-Asp (RGD) integrin-binding site could induce MSCs to undergo chondrogenesis in the absence of exogenous TGF-β. Within a few days of culture on the biomimetic polyacrylates, both mouse and human MSCs, and a mesenchymal-like mouse-kidney-derived stem cell line, began to form multi-layered aggregates and started to express the chondrocyte-specific markers, Sox9, collagen II and aggrecan. Moreover, collagen II tended to be expressed in the centre of the aggregates, similarly to developing limb buds in vivo. Surface analysis of the substrates indicated that those with the highest surface amine content were most effective at promoting MSC chondrogenesis. These results highlight the importance of surface group functionality and the distribution of those groups in the design of substrates to induce MSC chondrogenesis. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  14. Determination of major, minor and trace elements in rock samples by laser ablation inductively coupled plasma mass spectrometry: Progress in the utilization of borate glasses as targets

    International Nuclear Information System (INIS)

    Leite, Tacito Dantas F.; Escalfoni, Rainerio; Fonseca, Teresa Cristina O. da; Miekeley, Norbert

    2011-01-01

    The present work is a continuation of a research study performed at our laboratory aiming at the multielement analysis of rock samples (basalts and shale) by inductively coupled plasma mass spectrometry in combination with laser ablation using borate glasses as analytical targets. Argon, nitrogen-argon mixtures and helium were evaluated as cell gases, the latter confirming its better performance. Different operational parameters of the laser, such as gas flow, energy, focus, scanning speed and sampling frequency were optimized. External calibration was made with standards prepared by fusion of geological reference materials (basalts 688 and BCR-2, obsidian SRM 278, and shale SGR-1) of different mass fractions in the meta-tetra borate matrix. Coefficients of determination (R 2 ) were > 0.99 for 30 elements from o total of 40 determined. Method validation was then performed using additional certified reference materials (BHVO-2, BIR-1, SCo-1) produced as borate targets in a similar way. Accuracies were better than 10% for most of the elements studied and analytical precisions, calculated from the residual standard deviations of calibration curves were, typically, between 6% and 10%. Additionally, the semiquantitative TotalQuant (registered) technique was applied, which gave, within the expected uncertainty for this calibration technique, concordant results when compared to the quantitative external calibration procedure. Both methods were then used for the analysis of marine shale samples, which are of great geological interest in petroleum prospecting.

  15. Specific determination of intact cisplatin and monohydrated cisplatin in human plasma and culture medium ultrafiltrates using HPLC on-line with inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Bell, Deanna N; Liu, Johnson J; Tingle, Malcolm D; McKeage, Mark J

    2006-06-06

    We have developed a specific assay for cisplatin in human plasma ultrafiltrate (PUF) and cell culture medium ultrafiltrate (MUF) using HPLC on-line with inductively coupled plasma mass spectrometry (ICP-MS). Separation of cisplatin (6 min) and monohydrated cisplatin (12 min) was achieved using a muBondapak C(18) column (Waters) and a mobile phase (0.075 mM sodium dodecyl sulfate and 3% methanol, adjusted to pH 2.5 with triflic acid) pumped at a flow rate of 0.5 mL/min. The analytes were detected with little background interference by ICP-MS monitoring of platinum masses (m/z 194/195). Calibration curves were linear over three orders of magnitude (0.05-8 microM) and the limit of quantitation was 0.1 microM. Intra- and inter-assay accuracy (range 91.6-113%) and precision (range 1.00-12.3%) were acceptable for PUF and MUF. The method was applied to determining cisplatin during ex vivo incubation of the drug in whole human blood at 37 degrees C. In conclusion, a specific, sensitive and reliable HPLC-ICP-MS assay has been established for determining intact cisplatin in PUF and MUF.

  16. Beta-lactamase induction and cell wall metabolism in Gram-negative bacteria

    Science.gov (United States)

    Zeng, Ximin; Lin, Jun

    2013-01-01

    Production of beta-lactamases, the enzymes that degrade beta-lactam antibiotics, is the most widespread and threatening mechanism of antibiotic resistance. In the past, extensive research has focused on the structure, function, and ecology of beta-lactamases while limited efforts were placed on the regulatory mechanisms of beta-lactamases. Recently, increasing evidence demonstrate a direct link between beta-lactamase induction and cell wall metabolism in Gram-negative bacteria. Specifically, expression of beta-lactamase could be induced by the liberated murein fragments, such as muropeptides. This article summarizes current knowledge on cell wall metabolism, beta-lactam antibiotics, and beta-lactamases. In particular, we comprehensively reviewed recent studies on the beta-lactamase induction by muropeptides via two major molecular mechanisms (the AmpG–AmpR–AmpC pathway and BlrAB-like two-component regulatory system) in Gram-negative bacteria. The signaling pathways for beta-lactamase induction offer a broad array of promising targets for the discovery of new antibacterial drugs used for combination therapies. Therefore, to develop effective mitigation strategies against the widespread beta-lactam resistance, examination of the molecular basis of beta-lactamase induction by cell wall fragment is highly warranted. PMID:23734147

  17. M27 Expressed by Cytomegalovirus Counteracts Effective Type I Interferon Induction of Myeloid Cells but Not of Plasmacytoid Dendritic Cells

    Science.gov (United States)

    Döring, Marius; Lessin, Irina; Frenz, Theresa; Spanier, Julia; Kessler, Annett; Tegtmeyer, Pia; Dağ, Franziska; Thiel, Nadine; Trilling, Mirko; Lienenklaus, Stefan; Weiss, Siegfried; Scheu, Stefanie; Messerle, Martin; Cicin-Sain, Luka; Hengel, Hartmut

    2014-01-01

    ABSTRACT In healthy individuals, the functional immune system effectively confines human cytomegalovirus (CMV) replication, while viral immune evasion and persistence preclude sterile immunity. Mouse CMV (MCMV) is a well-established model to study the delicate CMV-host balance. Effective control of MCMV infection depends on the induction of protective type I interferon (IFN-I) responses. Nevertheless, it is unclear whether in professional antigen-presenting cell subsets MCMV-encoded evasins inhibit the induction of IFN-I responses. Upon MCMV treatment, enhanced expression of MCMV immediate-early and early proteins was detected in bone marrow cultures of macrophages and myeloid dendritic cells compared with plasmacytoid dendritic cell cultures, whereas plasmacytoid dendritic cells mounted more vigorous IFN-I responses. Experiments with Toll-like receptor (TLR)- and/or RIG-I like helicase (RLH)-deficient cell subsets revealed that upon MCMV treatment of myeloid cells, IFN-I responses were triggered independently of TLR and RLH signaling, whereas in plasmacytoid dendritic cells, IFN-I induction was strict