WorldWideScience

Sample records for analytical atomic emission

  1. Expressing self-absorption in the analytical function of inductively coupled plasma atomic emission spectrometry

    Science.gov (United States)

    Kántor, Tibor; Bartha, András

    2015-11-01

    The self-absorption of spectral lines was studied with up to date multi-element inductively coupled plasma atomic emission spectrometry (ICP-AES) instrumentation using radial and axial viewing of the plasma, as well, performing line peak height and line peak area measurements. Two resonance atomic and ionic lines of Cd and Mg were studied, the concentration range was extended up to 2000 mg/L. At the varying analyte concentration, constant matrix concentration of 10,000 mg/L Ca was ensured in the pneumatically nebulized solutions. The physical and the phenomenological formulation of the emission analytical function is overviewed and as the continuity of the earlier results the following equation is offered:

  2. New high temperature plasmas and sample introduction systems for analytical atomic emission and mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Montaser, A.

    1992-01-01

    New high temperature plasmas and new sample introduction systems are explored for rapid elemental and isotopic analysis of gases, solutions, and solids using mass spectrometry and atomic emission spectrometry. Emphasis was placed on atmospheric pressure He inductively coupled plasmas (ICP) suitable for atomization, excitation, and ionization of elements; simulation and computer modeling of plasma sources with potential for use in spectrochemical analysis; spectroscopic imaging and diagnostic studies of high temperature plasmas, particularly He ICP discharges; and development of new, low-cost sample introduction systems, and examination of techniques for probing the aerosols over a wide range. Refs., 14 figs. (DLC)

  3. Analytical control of wollastonite for biomedical applications by use of atomic absorption spectrometry and inductively coupled plasma atomic emission spectrometry.

    Science.gov (United States)

    De Aza, P N; Guitián, F; De Aza, S; Valle, F J

    1998-04-01

    Preliminary in vitro experiments revealed that wollastonite (CaSiO3) is a potentially highly bioactive material that forms a hyroxyapatite (HA) surface layer on exposure to simulated body fluid with an ion concentration, pH and temperature virtually identical with those of human blood plasma. The formation of the HA layer is an essential requirement for an artificial material to be used as bioactive bone substitute. This finding opens up a wide field for biomedical applications of wollastonite. Biomaterials used as implants in the human body require strict control of trace elements and of the toxic species specified in American Society for Testing and Materials F-1185-88 (As, Cd, Hg and Pb) in ceramic hydroxyapatite for surgical implantation. In this work, two types of pseudowollastonite, the high temperature form of wollastonite, were analysed by using cold vapour atomic absorption spectrometry and hydride generation atomic absorption spectrometry, in order to determine the elements stated in the above-mentioned norm, and inductively coupled plasma atomic emission spectrometry to establish the SiO2/CaO ratio of the two materials and analyse for all other impurities introduced by the raw materials and by the processes of synthesis, sintering and grinding. Barium and Mg were especially prominent in raw materials, and Zr, Y, Mg, W, Co and Ni come mainly from the processing. PMID:9684401

  4. Prospects in Analytical Atomic Spectrometry

    CERN Document Server

    Bolshakov, A A; Nemets, V M

    2006-01-01

    Tendencies in five main branches of atomic spectrometry (absorption, emission, mass, fluorescence and ionization spectrometry) are considered. The first three techniques are the most widespread and universal, with the best sensitivity attributed to atomic mass spectrometry. In the direct elemental analysis of solid samples, the leading roles are now conquered by laser-induced breakdown and laser ablation mass spectrometry, and the related techniques with transfer of the laser ablation products into inductively-coupled plasma. Advances in design of diode lasers and optical parametric oscillators promote developments in fluorescence and ionization spectrometry and also in absorption techniques where uses of optical cavities for increased effective absorption pathlength are expected to expand. Prospects for analytical instrumentation are seen in higher productivity, portability, miniaturization, incorporation of advanced software, automated sample preparation and transition to the multifunctional modular archite...

  5. Trends of investigations on atomic analytical emission spectrometry (AES) in Lithuania

    Science.gov (United States)

    Salkauskas, Julius

    2003-11-01

    The main trends, results and methods of the investigations in AES are reviewed. The majority of the papers were devoted to the regularities and processes in electric discharges applied as spectra excitation sources. For this task the methods of plasma diagnostics, computer simulation, Fourier analysis of the noises, fluctuation as well as the correlation methods were developed and applied in AES. Lately much attention was paid to the metrological problems in spectrochemistry and analytical chemistry. At present the methods of inductively coupled plasma mass spectroscopy are implemented.

  6. 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., Jr.

    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.

  7. Single atom electrochemical and atomic analytics

    Science.gov (United States)

    Vasudevan, Rama

    In the past decade, advances in electron and scanning-probe based microscopies have led to a wealth of imaging and spectroscopic data with atomic resolution, yielding substantial insight into local physics and chemistry in a diverse range of systems such as oxide catalysts, multiferroics, manganites, and 2D materials. However, typical analysis of atomically resolved images is limited, despite the fact that image intensities and distortions of the atoms from their idealized positions contain unique information on the physical and chemical properties inherent to the system. Here, we present approaches to data mine atomically resolved images in oxides, specifically in the hole-doped manganite La5/8Ca3/8MnO3, on epitaxial films studied by in-situ scanning tunnelling microscopy (STM). Through application of bias to the STM tip, atomic-scale electrochemistry is demonstrated on the manganite surface. STM images are then further analyzed through a suite of algorithms including 2D autocorrelations, sliding window Fourier transforms, and others, and can be combined with basic thermodynamic modelling to reveal relevant physical and chemical descriptors including segregation energies, existence and strength of atomic-scale diffusion barriers, surface energies and sub-surface chemical species identification. These approaches promise to provide tremendous insights from atomically resolved functional imaging, can provide relevant thermodynamic parameters, and auger well for use with first-principles calculations to yield quantitative atomic-level chemical identification and structure-property relations. This research was sponsored by the Division of Materials Sciences and Engineering, BES, DOE. Research was conducted at the Center for Nanophase Materials Sciences, which also provided support and is a DOE Office of Science User Facility.

  8. Analytic Solutions of Three-Level Dressed-Atom Model

    Institute of Scientific and Technical Information of China (English)

    WANG Zheng-Ling; YIN Jian-Ping

    2004-01-01

    On the basis of the dressed-atom model, the general analytic expressions for the eigenenergies, eigenstates and their optical potentials of the A-configuration three-level atom system are derived and analysed. From the calculation of dipole matrix element of different dressed states, we obtain the spontaneous-emission rates in the dressed-atom picture. We find that our general expressions of optical potentials for the three-level dressed atom can be reduced to the same as ones in previous references under the approximation of a small saturation parameter. We also analyse the dependences of the optical potentials of a three-level 85Rb atom on the laser detuning and the dependences of spontaneous-emission rates on the radial position in the dark hollow beam, and discuss the probability (population) evolutions of dressed-atomic eigenstates in three levels in the hollow beam.

  9. An analytical method for hydrogeochemical surveys: Inductively coupled plasma-atomic emission spectrometry after using enrichment coprecipitation with cobalt and ammonium pyrrolidine dithiocarbamate

    Science.gov (United States)

    Hopkins, D.M.

    1991-01-01

    Trace metals that are commonly associated with mineralization were concentrated and separated from natural water by coprecipitation with ammonium pyrollidine dithiocarbamate (APDC) and cobalt and determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The method is useful in hydrogeochemical surveys because it permits preconcentration near the sample sites, and selected metals are preserved shortly after the samples are collected. The procedure is relatively simple: (1) a liter of water is filtered; (2) the pH is adjusted; (3) Co chloride and APDC are added to coprecipitate the trace metals; and (4) later, the precipitate is filtered, dissolved, and diluted to 10 ml for a 100-fold concentration enrichment of the separated metals. Sb(III), As(III), Cd, Cr, Cu, Fe, Pb, Mo, Ni, Ag, V, and Zn can then be determined simultaneously by ICP-AES. In an experiment designed to measure the coprecipitation efficiency, Sb(III), Cd and Ag were recovered at 70 to 75% of their original concentration. The remaining metals were recovered at 85 to 100% of their original concentrations, however. The range for the lower limits of determination for the metals after preconcentration is 0.1 to 3.0 ??g/l. The precision of the method was evaluated by replicate analyses of a Colorado creek water and two simulated water samples. The accuracy of the method was estimated using a water reference standard (SRM 1643a) certified by the U.S. National Bureau of Standards. In addition, the method was evaluated by analyzing groundwater samples collected near a porphyry copper deposit in Arizona and by analyzing meltwater from glacier-covered areas favorable for mineralization in south-central Alaska. The results for the ICP-AES analyses compared favorably with those obtained using the sequential technique of GFAAS on the acidified but unconcentrated water samples. ICP-AES analysis of trace-metal preconcentrates for hydrogeochemical surveys is more efficient than GFAAS because a

  10. New high temperature plasmas and sample introduction systems for analytical atomic emission and mass spectrometry. Progress report, January 1, 1990--December 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Montaser, A.

    1992-09-01

    New high temperature plasmas and new sample introduction systems are explored for rapid elemental and isotopic analysis of gases, solutions, and solids using mass spectrometry and atomic emission spectrometry. Emphasis was placed on atmospheric pressure He inductively coupled plasmas (ICP) suitable for atomization, excitation, and ionization of elements; simulation and computer modeling of plasma sources with potential for use in spectrochemical analysis; spectroscopic imaging and diagnostic studies of high temperature plasmas, particularly He ICP discharges; and development of new, low-cost sample introduction systems, and examination of techniques for probing the aerosols over a wide range. Refs., 14 figs. (DLC)

  11. Emissivity: A Program for Atomic Emissivity Calculations

    OpenAIRE

    Sochi, Taha

    2009-01-01

    In this article we report the release of a new program for calculating the emissivity of atomic transitions. The program, which can be obtained with its documentation from our website www.scienceware.net, passed various rigorous tests and was used by the author to generate theoretical data and analyze observational data. It is particularly useful for investigating atomic transition lines in astronomical context as the program is capable of generating a huge amount of theoretical data and comp...

  12. An effective analytical system based on a pulsed direct current microplasma source for ultra-trace mercury determination using gold amalgamation cold vapor atomic emission spectrometry

    International Nuclear Information System (INIS)

    A novel analysis system based on a low power atmospheric pressure pulsed direct current (Pdc) microplasma is described for the determination of ultra-trace mercury in natural water by cold vapor generation atomic emission spectrometry (CV-AES). The plasma was generated with a miniaturized home-built high-voltage Pdc power supply which decreased the volume and weight of the whole experiment setup. The CV-Pdc-AES system is based on the preconcentration of mercury vapor on a gold filament trapping micro-column prior to detection that provides fast, reproducible absorption and desorption of mercury. The micro-column is produced by winding 30 μm diameter 100 m long gold filament to a small ball and then insert it into a quartz tube of 6 mm i.d, 8 mm o.d. Under the optimized experimental conditions, the new system provides high sensitivity (detection limit: 0.08 pg mL−1) and good reproducibility (RSD 3.0%, [Hg] = 20 pg mL−1, n = 11). The calibration curve is linear at levels near the detection limit up to at least 200 pg mL−1 and the accuracy is on the order of 1–4%. The proposed method was applied to 5 real water samples for mercury ultra-trace analysis. The advantages and features of the newly developed system include high sensitivity, simple structure, low cost, and compact volume with field portable potential. - Highlights: • A novel system based on a low power pulsed dc microplasma for mercury detection. • A small home-built pulsed dc power supply was used to ignite the microplasma. • A gold filament preconcentrator followed by thermal desorption was used. • A detection limit of 0.08 pg mL−1 was achieved for sensitive mercury detection. • The system is compact, low power, and has potential for field portable application

  13. Analytical evaluation of atomic form factors: application to Rayleigh scattering

    CERN Document Server

    Safari, L; Amaro, P; Jänkälä, K; Fratini, F

    2014-01-01

    Atomic form factors are widely used for the characterization of targets and specimens, from crystallography to biology. By using recent mathematical results, here we derive an analytical expression for the atomic form factor within the independent particle model constructed from nonrelativistic screened hydrogenic wavefunctions. The range of validity of this analytical expression is checked by comparing the analytically obtained form factors with the ones obtained within the Hartee-Fock method. As an example, we apply our analytical expression for the atomic form factor to evaluate the differential cross section for Rayleigh scattering off neutral atoms.

  14. Analytical evaluation of atomic form factors: Application to Rayleigh scattering

    Energy Technology Data Exchange (ETDEWEB)

    Safari, L., E-mail: laleh.safari@ist.ac.at [IST Austria (Institute of Science and Technology Austria), Am Campus 1, 3400 Klosterneuburg (Austria); Department of Physics, University of Oulu, Box 3000, FI-90014 Oulu (Finland); Santos, J. P. [Laboratório de Instrumentação, Engenharia Biomédica e Física da Radiação (LIBPhys-UNL), Departamento de Física, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Amaro, P. [Laboratório de Instrumentação, Engenharia Biomédica e Física da Radiação (LIBPhys-UNL), Departamento de Física, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Physikalisches Institut, Universität Heidelberg, D-69120 Heidelberg (Germany); Jänkälä, K. [Department of Physics, University of Oulu, Box 3000, FI-90014 Oulu (Finland); Fratini, F. [Department of Physics, University of Oulu, Box 3000, FI-90014 Oulu (Finland); Institute of Atomic and Subatomic Physics, TU Wien, Stadionallee 2, 1020 Wien (Austria); Departamento de Física, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG (Brazil)

    2015-05-15

    Atomic form factors are widely used for the characterization of targets and specimens, from crystallography to biology. By using recent mathematical results, here we derive an analytical expression for the atomic form factor within the independent particle model constructed from nonrelativistic screened hydrogenic wave functions. The range of validity of this analytical expression is checked by comparing the analytically obtained form factors with the ones obtained within the Hartee-Fock method. As an example, we apply our analytical expression for the atomic form factor to evaluate the differential cross section for Rayleigh scattering off neutral atoms.

  15. The Study on Analytical Method of Lead, Cadmium and Chromium in Copper Metal by Matrix Matching Method of Inductively Coupled Plasma Atomic Emission Spectrometer

    International Nuclear Information System (INIS)

    Analytical results of a fixed concentration of Pb, Cd and Cr in the synthetic copper standard solution (RMs) for using the matrix no matched standard calibration curve at various wavelength by ICP showed that accuracy (140 ∼ 1,070% in case of Pb) is very poor at all wavelengths because of the Cu matrix effect. Analytical results of a fixed concentration of Pb, Cd and Cr in the different concentration solutions of Cu showed that found values were on the increase or decrease as the rate of a regular equation as the concentration of Cu was increased. Accuracies by the Cu matching method in the analysis of Pb, Cd and Cr in the synthetic copper standard solution (RMs) were higher than 99.9%

  16. Analytical relativistic self-consistent-field calculations for atoms

    International Nuclear Information System (INIS)

    A new second-order representation of the Dirac equation is presented. This representation which is exact for a hydrogen atom is applied to approximate analytical self-consistent-field calculations for atoms. Results are given for the rare-gas atoms from helium to radon and for lead. The results compare favorably with numerical Dirac-Hartree-Fock solutions

  17. A Thermo-Chemical Reactor for analytical atomic spectrometry

    International Nuclear Information System (INIS)

    A novel atomization/vaporization system for analytical atomic spectrometry is developed. It consists of two electrically and thermally separated parts that can be heated separately. Unlike conventional electrothermal atomizers in which atomization occurs immediately above the vaporization site and at the same instant of time, the proposed system allows analyte atomization via an intermediate stage of fractional condensation as a two stage process: Vaporization → Condensation → Atomization. The condensation step is selective since vaporized matrix constituents are mainly non-condensable gases and leave the system by diffusion while analyte species are trapped on the cold surface of a condenser. This kind of sample distillation keeps all the advantages of traditional electrothermal atomization and allows significant reduction of matrix interferences. Integration into one design a vaporizer, condenser and atomizer gives much more flexibility for in situ sample treatment and thus the system is called a Thermo-Chemical Reactor (TCR). Details of the design, temperature measurements, vaporization-condensation-atomization mechanisms of various elements in variety of matrices are investigated in the TCR with spectral, temporal and spatial resolution. The ability of the TCR to significantly reduce interferences and to conduct sample pyrolysis at much higher temperatures as compared to conventional electrothermal atomizers is demonstrated. The analytical potential of the system is shown when atomic absorption determination of Cd and Pb in citrus leaves and milk powder without the use of any chemical modification

  18. A Thermo-Chemical Reactor for analytical atomic spectrometry

    Science.gov (United States)

    Gilmutdinov, A. Kh.; Nagulin, K. Yu.

    2009-01-01

    A novel atomization/vaporization system for analytical atomic spectrometry is developed. It consists of two electrically and thermally separated parts that can be heated separately. Unlike conventional electrothermal atomizers in which atomization occurs immediately above the vaporization site and at the same instant of time, the proposed system allows analyte atomization via an intermediate stage of fractional condensation as a two stage process: Vaporization → Condensation → Atomization. The condensation step is selective since vaporized matrix constituents are mainly non-condensable gases and leave the system by diffusion while analyte species are trapped on the cold surface of a condenser. This kind of sample distillation keeps all the advantages of traditional electrothermal atomization and allows significant reduction of matrix interferences. Integration into one design a vaporizer, condenser and atomizer gives much more flexibility for in situ sample treatment and thus the system is called a Thermo-Chemical Reactor (TCR). Details of the design, temperature measurements, vaporization-condensation-atomization mechanisms of various elements in variety of matrices are investigated in the TCR with spectral, temporal and spatial resolution. The ability of the TCR to significantly reduce interferences and to conduct sample pyrolysis at much higher temperatures as compared to conventional electrothermal atomizers is demonstrated. The analytical potential of the system is shown when atomic absorption determination of Cd and Pb in citrus leaves and milk powder without the use of any chemical modification.

  19. Analytical estimate for low-altitude ENA emissivity

    Science.gov (United States)

    Goldstein, J.; Bisikalo, D. V.; Shematovich, V. I.; Gérard, J.-C.; Søraas, F.; McComas, D. J.; Valek, P. W.; LLera, K.; Redfern, J.

    2016-02-01

    We formulate the first analytical model for energetic neutral atom (ENA) emissivity that partially corrects for the global viewing geometry dependence of low-altitude emissions (LAEs) observed by Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS). The emissivity correction requires the pitch angle distribution (PAD) and geophysical location of low-altitude ENAs. To estimate PAD, we create an energy-dependent analytical model, based on a Monte Carlo simulation. We account for energy binning by integrating model PAD over each energy bin. We account for finite angular pixels by computing emissivity as an integral over the pitch angle range sampled by the pixel. We investigate location uncertainty in TWINS pixels by performing nine variations of the emissivity calculation. Using TWINS 2 ENA imaging data from 1131 to 1145 UT on 6 April 2010, we derive emissivity-corrected ion fluxes for two angular pixel sizes: 4° and 1°. To evaluate the method, we compare TWINS-derived ion fluxes to simultaneous in situ data from the National Oceanic and Atmospheric Administration (NOAA) 17 satellite. The TWINS-NOAA agreement for emissivity-corrected flux is improved by up to a factor of 7, compared to uncorrected flux. The highest 1° pixel fluxes are a factor of 2 higher than for 4° pixels, consistent with pixel-derived fluxes that are artificially low because subpixel structures are smoothed out, and indicating a possible slight advantage to oversampling the instrument-measured LAE signal. Both TWINS and NOAA ion fluxes decrease westward of 2000 magnetic local time. The TWINS-NOAA comparison indicates that the global ion precipitation oval comprises multiple smaller-scale (3-5° of latitude) structures.

  20. Analytical and quantitative concentration of gunshot residues (Pb, Sb, Ba) to estimate entrance hole and shooting-distance using confocal laser microscopy and inductively coupled plasma atomic emission spectrometer analysis: an experimental study.

    Science.gov (United States)

    Turillazzi, Emanuela; Di Peri, Giovanni Paolo; Nieddu, Antonio; Bello, Stefania; Monaci, Fabrizio; Neri, Margherita; Pomara, Cristoforo; Rabozzi, Roberto; Riezzo, Irene; Fineschi, Vittorio

    2013-09-10

    The identification of gunshot residues (GSRs) on human body in firearm related fatalities may be essential for the evaluation of gunshot wounds and for the analysis of the shooting distance. The present study introduces the elemental analysis of the GSRs by inductively coupled plasma atomic emission spectrometer analysis (ICP-AES) performed on skin samples. ICP-AES was used to increase the accuracy of the analysis in gunshots fired from long and medium distance. In this experimental study, a series of 50 test shots have been performed in an open space with lateral wind protection. As target we used pig skin cut into 20 cm × 20 cm squares. The firing distances were 0.2, 5, 50, 100 and 150 cm. To exclude environmental contamination, each skin sample was carefully washed with deionized water and dried at room temperature in a closed box before the shooting test. We choose 9×21 and the 7.65 mm calibers handguns, loaded with different ammunitions. At ICP-AES analysis a clearly decreasing trend in the quantity and the concentration of the different elements of GSR by increasing the firing distance for both the guns used in the test was evident for every portion of skin samples analyzed. The analytical results obtained by ICP-AES confirmed very high concentrations of Pb, Sb, and Ba in the close-range shots and low concentrations of these particles in the intermediate and distant shots. In particular, the concentration of Sb, Ba, and Pb was significantly different from loose values when the firing distance was 100-150 cm for both the 9×21 and the 7.65 mm calibers. PMID:23890629

  1. High-voltage spark atomic emission detector for gas chromatography

    Science.gov (United States)

    Calkin, C. L.; Koeplin, S. M.; Crouch, S. R.

    1982-01-01

    A dc-powered, double-gap, miniature nanosecond spark source for emission spectrochemical analysis of gas chromatographic effluents is described. The spark is formed between two thoriated tungsten electrodes by the discharge of a coaxial capacitor. The spark detector is coupled to the gas chromatograph by a heated transfer line. The gas chromatographic effluent is introduced into the heated spark chamber where atomization and excitation of the effluent occurs upon breakdown of the analytical gap. A microcomputer-controlled data acquisition system allows the implementation of time-resolution techniques to distinguish between the analyte emission and the background continuum produced by the spark discharge. Multiple sparks are computer averaged to improve the signal-to-noise ratio. The application of the spark detector for element-selective detection of metals and nonmetals is reported.

  2. [Determination of potassium in sodium by flame atomic emission spectroscopy].

    Science.gov (United States)

    Xie, C; Wen, X; Jia, Y; Sun, S

    2001-06-01

    Sodium is used as a coolant in China experiment fast reactor (CEFR). Potassium in sodium has an influence on heat property of reactor. A analytical method has been developed to determinate potassium in sodium by flame atomic emission spectroscopy. Sodium sample is dissolved by ultrasonic humidifier. The working conditions of the instrument and inTerferences from matrix sodium, acid effect and concomitant elements have been studied. Standard addition experiments are carried out with potassium chloride. The percentage recoveries are 94.7%-109.8%. The relative standard deviation is 4.2%. The analytical range accords with sodium quality control standard of CFFR. The precision corresponds to the international analytical method in sodium coolant reactor. PMID:12947670

  3. Atomic emission spectroscopy in high electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, J.E.; Filuk, A.B.; Carlson, A.L. [and others

    1995-12-31

    Pulsed-power driven ion diodes generating quasi-static, {approximately}10 MV/cm, 1-cm scale-length electric fields are used to accelerate lithium ion beams for inertial confinement fusion applications. Atomic emission spectroscopy measurements contribute to understanding the acceleration gap physics, in particular by combining time- and space-resolved measurements of the electric field with the Poisson equation to determine the charged particle distributions. This unique high-field configuration also offers the possibility to advance basic atomic physics, for example by testing calculations of the Stark-shifted emission pattern, by measuring field ionization rates for tightly-bound low-principal-quantum-number levels, and by measuring transition-probability quenching.

  4. Atomic emission spectroscopy in high electric fields

    International Nuclear Information System (INIS)

    Pulsed-power driven ion diodes generating quasi-static, ∼10 MV/cm, 1-cm scale-length electric fields are used to accelerate lithium ion beams for inertial confinement fusion applications. Atomic emission spectroscopy measurements contribute to understanding the acceleration gap physics, in particular by combining time- and space-resolved measurements of the electric field with the Poisson equation to determine the charged particle distributions. This unique high-field configuration also offers the possibility to advance basic atomic physics, for example by testing calculations of the Stark-shifted emission pattern, by measuring field ionization rates for tightly-bound low-principal-quantum-number levels, and by measuring transition-probability quenching

  5. Electric focusing preconcentration device for element composition monitoring of air aerosols by atomic emission spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Dočekal, Bohumil; Mikuška, Pavel; Šikola, T.; Večeřa, Zbyněk; Zlámal, J.

    Hamburg : University of Hamburg, 2006 - (Broekaert, J.). B56 [ISEAC34. International Symposium on Environmental Analytical Chemistry /34./. 04.06.2006-08.06.2006, Hamburg] R&D Projects: GA AV ČR IAA400310505 Keywords : electrostatic pre-concentration * airborne particles * atomic emission spectrometric detection Subject RIV: CB - Analytical Chemistry, Separation

  6. Theory of atomic spectral emission intensity

    International Nuclear Information System (INIS)

    The theoretical derivation of a new spectral line intensity formula for atomic radiative emission is presented. The theory is based on first principles of quantum physics and statistical physics. It is argued that the formulation of the theory provides a very good example of the manner in which quantum logic transforms into common sense logic. The theory is strongly supported by experimental evidence. (author) (16 refs.)

  7. Formulating analytic expressions for atomic collision cross sections

    International Nuclear Information System (INIS)

    Methods to formulate analytic expression for atomic collision cross sections as a function of projectile energy are described on the basis of the experiences of the data compilation work for more than 20 years. Topics considered are the choice of appropriate functional forms for the expressions and optimization of adjustable parameters. To make extrapolation possible, functions to be used should have the form with reasonable asymptotic behavior. In this respect, modified Green-McNeal formulas have been found useful for various atomic collision cross sections. For ionization processes, a modified Lotz formula has often given a good fit. The ALESQ code for least-squares fits has been convenient to optimize adjustable parameters in analytic expressions. (author)

  8. Spontaneous emission of two interacting atoms near an interface

    Institute of Scientific and Technical Information of China (English)

    Dehua Wang

    2009-01-01

    The spontaneous emission rate of two interacting excited atoms near a dielectric interface is studied using the photon closed-orbit theory and the dipole image method.The total emission rate of one atom during the emission process is calculated as a function of the distance between the atom and the interface.The results suggest that the spontaneous emission rate depends not only on the atomic-interface distances,but also on the orientation of the two atomic dipoles and the initial distance between the two atoms.The oscillation in the spontaneous emission rate is caused by the interference between the outgoing electromagnetic wave emitted from one atom and other waves arriving at this atom after traveling along various classical orbits.Each peak in the Fourier transformed spontaneous emission rate corresponds with one action of photon classical orbit.

  9. Emission Probability of the Cascade Three-Level-Atom Mazer with Injected Atomic Coherence

    Institute of Scientific and Technical Information of China (English)

    熊锦; 张智明

    2002-01-01

    We investigate the effects of the injected atomic coherence on the atomic emission probability of the micromaser injected with ultracold cascade three-level atoms by considering that the atoms are initially in the coherent superposition states of the two upper levels. We show that there is no interference between the transitions from the two upper levels to the lowest level. In the large atom-field-detuning case, the atomic emission probability decreases as the coherent parameter increases. In the zero atom-field-detuning case, the atomic emission probability has three sets of resonance peaks. The reason for these results has been explained.

  10. X-ray Emission of Hollow Atoms

    Institute of Scientific and Technical Information of China (English)

    ZhaoYongtao; XiaoGuoqing; ZhangXiaoan; YangZhihu; ChenXimeng; ZhangYanping

    2003-01-01

    We have systematically investigated the X-rays emission of hollow atoms (HA) which formed in the interaction of highly charged ions with a variety of solid surfaces at the atomic physics experimental setup of IMP. The X-ray spectra were measured by Si(Li) detectors with effective energy ranging from 1 keV to 60 keV. The results show that, the X-ray emission from the formed HA is closely correlated with the charge state of the projectile ions, and weakly correlated with the velocity of the projectile ions. For example, it was found that when Ar18+ ions interact with Be-target, the yield of K X-ray with character energy of 3.0 keV is 7.2×10-3 per ion, which is two times and 5 order of magnitude higher than those in the interactions of Ar17+ and Ar16+ ions respectively. When Ar15+ ions interact with the same targets, the Argon K X-ray would be too feeble to be detected. The X-ray yield with single ion in this experiment can be represented by the following equation,

  11. Experimental and theoretical comparison of the precision of flame atomic absorption, fluorescence, and emission measurements

    International Nuclear Information System (INIS)

    Theoretical equations and experimental evaluation procedures for the determination of the precision of flame atomic absorption, emission, and fluorescence measurements are presented. These procedures and noise power spectra are used to evaluate the precision and noise characteristics of atomic copper measurements with all three techniques under the same experimental conditions in a H2-air flame. At the detection limit, emission and fluorescence measurements are limited by background emission shot and flicker noise whereas absorption measurements are limited by flame transmission lamp flicker noise. Analyte flicker noise limits precision at higher analyte concentrations for all three techniques. Fluctutations in self-absorption and the inner filter effect are shown to contribute to the noise in atomic emission and fluorescence measurements

  12. Analytical optimization for field emission of carbon nanotube array

    Institute of Scientific and Technical Information of China (English)

    WANG XinQing; LI Liang; CHEN Min; JIN HongXiao; JIN DingFeng; PENG Min; GE HongLiang

    2009-01-01

    To optimize field emission (FE) property of carbon nanotube (CNT) array on a planar cathode surface,the Fowler-Nordheim formula has been used to discuss the maximum of the emission current density with the floating sphere model in this paper. The emission current density is dominating as the ane-lytical Fowler-Nordheim function of the intertube distance, and the maximum of the emission current density is deduced and discussed. The results indicate that the intertube distance in CNT array criti-cally affects the field enhancement factor and the emission current density, whose maximum occurs at the intertube distance approximating a tenth of the tube height. Considering the emission current den-sity and the field enhancement factor, the FE can be optimized analytically when the intertube distance is about a tenth of the tube height.

  13. Analytical calculations of scattering lengths in atomic physics

    International Nuclear Information System (INIS)

    We describe a method for evaluating analytical long-range contributions to scattering lengths for some potentials used in atomic physics. We assume that an interaction potential between colliding particles consists of two parts. The form of a short-range component, vanishing beyond some distance from the origin (a core radius), need not be given. Instead, we assume that a set of short-range scattering lengths due to that part of the interaction is known. A long-range tail of the potential is chosen to be an inverse power potential, a superposition of two inverse power potentials with suitably chosen exponents or the Lent potential. For these three classes of long-range interactions a radial Schrodinger equation at zero energy may be solved analytically with solutions expressed in terms of the Bessel, Whittaker and Legendre functions, respectively. We utilize this fact and derive exact analytical formulae for the scattering lengths. The expressions depend on the short-range scattering lengths, the core radius and parameters characterizing the long-range part of the interaction. Cases when the long-range potential (or its part) may be treated as a perturbation are also discussed and formulae for scattering lengths linear in strengths of the perturbing potentials are given. It is shown that for some combination of the orbital angular momentum quantum number and an exponent of the leading term of the potential the derived formulae, exact or approximate, take very simple forms and contain only polynomial and trigonometric functions. The expressions obtained in this paper are applicable to scattering of charged particles by neutral targets and to collisions between neutrals. The results are illustrated by accelerating convergence of scattering lengths computed for e--Xe and Cs-Cs systems. (author)

  14. Inductively coupled plasma-atomic emission spectroscopy: The determination of trace impurities in uranium hexafluoride

    Science.gov (United States)

    Floyd, M. A.; Morrow, R. W.; Farrar, R. B.

    An analytical method has been developed for the determination of trace impurities in high-purity uranium hexafluoride using liquid-liquid extraction of the uranium from the trace impurities followed by analysis with inductively coupled plasma-atomic emission spectroscopy. Detection limits, accuracy, and precision data are presented.

  15. Entanglement of unstable atoms: modifications of the emission properties

    Energy Technology Data Exchange (ETDEWEB)

    Sancho, P [Delegacion de AEMET en Castilla y Leon. Orion 1, 47014, Valladolid (Spain); Plaja, L [Area de Optica. Departamento de Fisica Aplicada. Universidad de Salamanca. Pl. de la Merced s/n, 37008, Salamanca (Spain)

    2009-08-28

    We analyse the influence of entanglement on the emission properties of atoms. To this end, we firstly propose a scheme for the preparation of a pair of entangled helium atoms, one in the ortho- and the other in the para-spin configuration. We discuss a realistic scenario for this process, based on the double ionization of He by intense laser fields. These states are used to analyse disentanglement and the role of entanglement in the spontaneous emission from the pair. In particular, we show that the decaying rate of an entangled atom is different from that in a product state, modifying the temporal emission distribution and lifetime of the atoms.

  16. Entanglement of unstable atoms: modifications of the emission properties

    CERN Document Server

    Sancho, Pedro

    2009-01-01

    We analyse the influence of entanglement on the emission properties of atoms. To this end, first, we propose a scheme for the preparation of a pair of entangled Helium atoms, one in the ortho and the other in the para spin configuration. We discuss a realistic scenario for this process, based in the double ionization of He by intense laser fields. These states are used to analyse disentanglement and the role of entanglement in the spontaneous emission from the pair. In particular, we show that the decaying rate of an entangled atom is different from that in a product state, modifying the temporal emission distribution and lifetime of the atoms.

  17. Directional emission of single photons from small atomic samples

    DEFF Research Database (Denmark)

    Miroshnychenko, Yevhen; V. Poulsen, Uffe; Mølmer, Klaus

    2013-01-01

    We provide a formalism to describe deterministic emission of single photons with tailored spatial and temporal profiles from a regular array of multi-level atoms. We assume that a single collective excitation is initially shared by all the atoms in a metastable atomic state, and that this state i...... coupled by a classical laser field to an optically excited state which rapidly decays to the ground atomic state. Our model accounts for the different field polarization components via re-absorption and emission of light by the Zeeman manifold of optically excited states.......We provide a formalism to describe deterministic emission of single photons with tailored spatial and temporal profiles from a regular array of multi-level atoms. We assume that a single collective excitation is initially shared by all the atoms in a metastable atomic state, and that this state is...

  18. The emission properties of an atom inside a cavity when manipulating the atoms outside the cavity

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wen; YE Liu; XIONG Kuang-wei; ZHANG Jin

    2003-01-01

    Considering three two-level atoms initially in the GHZ state, then one atom of them is put into an initially empty cavity and made resonant interaction. It is shown that the emission properties of the atom inside the cavity can be affected only when both of the atoms outside the cavity have been manipulated. This conclusion can also be generalized to n two-level atoms.

  19. Using simple instrumentation to solve complex analytical problems: advanced AAS atomizers for volatile compounds and analyte trapping techniques

    Czech Academy of Sciences Publication Activity Database

    Dědina, Jiří; de Moraes, D. P.; Dessuy, M. B.; Kratzer, Jan; Řezáčová, Olga; Svoboda, Milan; Matoušek, Tomáš; de Moraes Flores, E. M.; Vale, M. G. R.

    2010. s. 59. [Rio Symposium on Atomic Spectrometry /11./. 24.10.2010-29.10.2010, Mar del Plata] R&D Projects: GA ČR GA203/09/1783 Institutional research plan: CEZ:AV0Z40310501 Keywords : AAS * volatile compounds * analyte trapping techniques Subject RIV: CB - Analytical Chemistry, Separation http://www.11thriosymposium.com.ar/index.htm

  20. Photoionization of Endohedral Atoms: Collective, Reflective and Collateral Emissions

    International Nuclear Information System (INIS)

    The photoionization properties of a fullerene-confined atom differ dramatically from that of an isolated atom. In the low energy region, where the fullerene plasmons are active, the electrons of the confined atom emerge through a collective channel carrying a significant chunk of plasmon with it. The photoelectron angular distribution of the confined atom however shows far lesser impact of the effect. At higher energies, the interference between two single-electron ionization channels, one directly from the atom and another reflected off the fullerene cage, producuces oscillatory cross sections. But for the outermost atomic level, which transfers some electrons to the cage, oscillations are further modulated by the collateral emission from the part of the atomic charge density transferred to the cage. These various modes of emissions are studied for the photoionization of Ar endohedrally confined in C60.

  1. Emission Spectra of a Moving Atom in an Electromagnetic Field

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jing-Tao; FENG Xun-Li; XU Zhi-Zhan

    2000-01-01

    The emission spectra of a two-level atom moving in an electromafneric fiekd are studied We find that there that there is a shift in the peak position and that each peak splits into double peaks The shit is duble peaks The shift is duc to the detuning indced by the atomic mition and the splitting is casused by the atomic energy change due of photons

  2. A simple analytical model for electronic conductance in a one dimensional atomic chain across a defect

    Energy Technology Data Exchange (ETDEWEB)

    Khater, Antoine; Szczesniak, Dominik [Laboratoire de Physique de l' Etat Condense UMR 6087, Universite du Maine, 72085 Le Mans (France)

    2011-04-01

    An analytical model is presented for the electronic conductance in a one dimensional atomic chain across an isolated defect. The model system consists of two semi infinite lead atomic chains with the defect atom making the junction between the two leads. The calculation is based on a linear combination of atomic orbitals in the tight-binding approximation, with a single atomic one s-like orbital chosen in the present case. The matching method is used to derive analytical expressions for the scattering cross sections for the reflection and transmission processes across the defect, in the Landauer-Buttiker representation. These analytical results verify the known limits for an infinite atomic chain with no defects. The model can be applied numerically for one dimensional atomic systems supported by appropriate templates. It is also of interest since it would help establish efficient procedures for ensemble averages over a field of impurity configurations in real physical systems.

  3. Atomic and Nuclear Analytical Methods XRF, Mössbauer, XPS, NAA and Ion-Beam Spectroscopic Techniques

    CERN Document Server

    Verma, H R

    2007-01-01

    This book is a blend of analytical methods based on the phenomenon of atomic and nuclear physics. It comprises comprehensive presentations about X-ray Fluorescence (XRF), Mössbauer Spectroscopy (MS), X-ray Photoelectron Spectroscopy (XPS), Neutron- Activation Analysis (NAA), Particle Induced X-ray Emission Analysis (PIXE), Rutherford Backscattering Analysis (RBS), Elastic Recoil Detection (ERD), Nuclear Reaction Analysis (NRA), Particle Induced Gamma-ray Emission Analysis (PIGE), and Accelerator Mass Spectrometry (AMS). These techniques are commonly applied in the fields of medicine, biology, environmental studies, archaeology or geology et al. and pursued in major international research laboratories.

  4. Theory of analytical curves in atomic fluorescence flame spectrometry

    NARCIS (Netherlands)

    Hooymayers, H.P.

    1968-01-01

    An explicit expression for the intensity of atomic resonance fluorescence as a function of atomic concentration in a flame is derived under certain idealized conditions. The expression is generally valid for a pure Doppler absorption line profile as well as for a combined Doppler and collisional bro

  5. Analytical theory for the nuclear level shift of hadronic atoms

    International Nuclear Information System (INIS)

    The spectrum problem in the Coulomb potential distorted at small distances is considered. Nuclear shifts of 3-levels in p anti p and Σ-p atoms are calculated. The probabilities of radiative transitions from p-states to the shifted s-states in hadronic atom are also given. It is shown that the reconstruction of atomic levels switches to oscillation regime when absorption increases. The limits of applicability of the perturbation theory in terms of the scattering length for different values of absorption is discussed. An exactly solvable model, Coulomb plus Yamaguchi potential, is considered

  6. Effect of discharge parameters on emission yields in a radio-frequency glow-discharge atomic-emission source

    Science.gov (United States)

    Parker, Mark; Hartenstein, Matthew L.; Marcus, R. Kenneth

    1997-05-01

    A study is performed on a radio-frequency glow-discharge atomic-emission (rf-GD-AES) source to determine the factors effecting the emission yields for both metallic and nonconductive sample types. Specifically, these studies focus on determining how the operating parameters (power and pressure) influence emission yields. The results follow predicted patterns as determined by Langmuir probe diagnostic studies of a similar source. In particular, discharge gas pressure is the key operating parameter as slight changes in pressure may significantly affect the emission yield of the analyte species. RF power is less important and is shown to produce only relatively small changes in the emission yield over the ranges typically used in rf-GD analyses. These studies indicate that the quantitative analysis of layered materials, depth-profiling, may be adversely affected if the data collection scheme, i.e. the quantitative algorithm, requires changing the pressure during an analysis to keep the operating current and voltage constant. A direct relationship is shown to exist between the Ar (discharge gas) emission intensity and that of sputtered species for nonconductors. This observance is used to compensate for differences in emission intensities observed in the analysis of various thickness nonconductive samples. The sputtered element emission signals are corrected based on the emission intensity of an Ar (1) transition, implying that quantitative analysis of nonconductive samples is not severely limited by the availability of matrix matched standards.

  7. Emissivity measurements with an Atomic Force Microscope

    OpenAIRE

    van Zwol, Pieter Jan; Ranno, Laurent; Chevrier, Joel

    2011-01-01

    We show that functionalized micromechanical bilayer levers can be used as sensitive probes to accurately measure radiative heat flux in vacuum between two materials at the micro scale. By means of calibration to one material these measurements can be made quantitative for radiative heat flux or for either temperature or material emissivity. We discuss issues and opportunities for our method and provide ample technical details regarding its implementation and demonstrate good correspondence wi...

  8. Extracting Oscillation Frequencies in Spontaneous Emission Rate of an Atom Between Two Mirrors

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hai-Jun; DU Meng-Li

    2007-01-01

    For an atom in a medium with refractive index n sandwiched between two parallel mirrors, we derive an analytical formula for the spontaneous emission rate based on Fermi's golden rule. The oscillations are not transparent in this formula. By performing Fourier transform on scaling variable measuring system size while holding system configuration fixed, we extracted the frequencies of many oscillations in this system. We show that these oscillations correspond to emitted photon closed-orbits going away from and returning to the emitting atom.

  9. Modelling the position of analyte emission maxima in low temperature direct current arc plasma using statistical procedures

    International Nuclear Information System (INIS)

    In low temperature argon arc plasma, emission spectral lines of different analytes have characteristic radial distributions with emission maxima distributed over a wide plasma region, from the arc axis toward the arc periphery. It was assumed that the occurrence of emission maxima is a result of collective action of factors that control vaporization, dissociation, excitation, ionization and analyte transport. A statistical analysis was used to reveal a correlation between these various factors and a radial position of maximum emission. A regression analysis was used both for predictive and explanatory purposes: a model was built that successfully predicted analyte spatial emission characteristics, based on their physical properties and local plasma parameters, and a relative importance of proposed predictors was estimated. - Highlights: ► PCR analysis was used to model radial emission profiles in DC arc plasma. ► The main factors governing the radial distribution of atomic emission were analyzed. ► A model was built based on local plasma parameters and analyte physical properties.

  10. Generation of Volatile Compounds for Analytical Atomic Spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Dědina, Jiří

    Chichester: John Wiley & Sons Ltd, 2011 - (Meyers, R.), s. 897-936 ISBN 978-0-470-97333-2 R&D Projects: GA ČR GA203/09/1783 Institutional research plan: CEZ:AV0Z40310501 Keywords : VCs * AAS * AES * AFS Subject RIV: CB - Analytical Chemistry, Separation

  11. Demonstration of Weak Measurement Based on Atomic Spontaneous Emission

    OpenAIRE

    Shomroni, Itay; Bechler, Orel; Rosenblum, Serge; Dayan, Barak

    2013-01-01

    We demonstrate a new type of weak measurement based on the dynamics of spontaneous emission. The pointer in our scheme is given by the Lorentzian distribution characterizing atomic exponential decay via emission of a single photon. We thus introduce weak measurement, so far demonstrated nearly exclusively with laser beams and Gaussian statistics, into the quantum regime of single emitters and single quanta, enabling the exploitation of a wide class of sources that are abundant in nature. We d...

  12. Emission spectrum of the atomic chain excited by channeled particle

    CERN Document Server

    Epp, V

    2014-01-01

    Basic properties of radiation of the atomic chains excited by a channeled particle are considered. Using a very simple two-dimensional model of a crystal lattice we have shown that the main part of this radiation is generated on the frequency of oscillations of a channeled particle between the crystal planes, shifted by the Doppler effect. Spectral and angular distribution and spectral distribution of the radiation of the atomic chain excited by channeled particle were calculated. Emission spectrum of the atomic chain excited by channeled particle was plotted.

  13. Analytical model of carbon dioxide emission with energy payback effect

    International Nuclear Information System (INIS)

    An analytical model is proposed to account for carbon emission behaviour during replacement of power source from fossil fuel to renewable energy in which sustainability of energy supply is stressed. Logistic function of time is assumed for producing renewable power sources. Analyses show that energy payback time (EPT) should be much shorter than the doubling time of manufacturing cycle to secure adequate available energy during, as well as after, the replacement. A nuclear plant, small hydropower plant, wind power plant and photovoltaic cell are taken as representative candidates and investigated as options to replace fossil power until toward the end of this century. Nuclear or small hydropower plants are promising candidates but the photovoltaic cell needs further development efforts to reduce EPT and avoid energy expense after the replacement. (author)

  14. Atomic Coherence in the Micromaser Injected with Slow V-type Three-State Atoms: Emission Probability

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-Ming; LIANG Wen-Qing; XIE Sheng-Wu

    2001-01-01

    The effects of atomic coherence on the single-mode two-photon rnicromaser injected with slow V-type three-state atoms are studied for the first time. It is shown that the atomic coherence can modify the atomic emission probability. The effects of the atomic centre-of-mass momentum, the cavity length and other parameters are also studied.

  15. Atomic emission and atomic absorption spectrometric analysis of high-purity powders for the production of ceramics

    International Nuclear Information System (INIS)

    Direct analysis methods and multistage combined analytical procedures for the determination of impurities at the μg/g level and the upper ng/g level in high-purity powders of Al2O3, AlN, Si3N4 and SiC are described. Results obtained with a novel direct slurry-atomization technique using a Babington nebulizer and inductively coupled plasma optical emission spectrometry (ICP-OES) are presented. A comparison of analysis results of combined analytical procedures including wet chemical decomposition and determinations with graphite furnace atomic absorption spectrometry (ETAAS) or ICP-OES with those of slurry-atomization ICP-OES show the capabilities of this technique for routine analysis in production control. Detection limits for Al, B, Ca, Co, Cu, Fe, Mg, Mn, Si, Ti, W, V, and Zn in the matrices mentioned are between 0.03 and 2.5 μg/g. For elemental concentrations ≥10 μg/g relative standard deviations of the measurements are generally below 10%. The technique is shown to be a powerful tool for trace determinations in powder samples. This is shown by its use for analysis of a series of the ceramic powders mentioned and comparative results of other direct techniques such as total reflection X-ray fluorescence spectrometry and instrumental neutron activation analysis. (orig.)

  16. 0.5 to 6 MeV Ar ion induced X-ray emission in view to analytical application

    International Nuclear Information System (INIS)

    A study of the X-ray emission induced by 0.5 to 6 MeV Ar ions has been realized in view of multielemental analytical applications. The historical development of the use of heavy ion induced X-ray emission in analysis and the theoretical background of inner-shell ionization in heavy ion-atom collisions are described. The emission of non characteristic X-rays and the effects related to the penetration of heavy ions in matter are also related. The experimental part contains a description of the experimental devices and of the X-ray spectra fitting method. Thick target yields as a function of the target Z and the Ar ion energy are reported. The analytical possibilities are examined and an application to the analysis of Si and Cl in cadmium telluride crystals is given

  17. 40 CFR 87.64 - Sampling and analytical procedures for measuring gaseous exhaust emissions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Sampling and analytical procedures for measuring gaseous exhaust emissions. 87.64 Section 87.64 Protection of Environment ENVIRONMENTAL PROTECTION....64 Sampling and analytical procedures for measuring gaseous exhaust emissions. (a) The system...

  18. 40 CFR 87.82 - Sampling and analytical procedures for measuring smoke exhaust emissions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Sampling and analytical procedures for measuring smoke exhaust emissions. 87.82 Section 87.82 Protection of Environment ENVIRONMENTAL PROTECTION... analytical procedures for measuring smoke exhaust emissions. The system and procedures for sampling...

  19. Emission spectrum of a harmonically trapped A-type three-level atom

    Institute of Scientific and Technical Information of China (English)

    Guo Hong; Tang Pei

    2013-01-01

    We theoretically investigate the emission spectrum for a ∧-type three-level atom trapped in the node of a standing wave.We show that the atomic center-of-mass motion not only directly affects the peak number,peak position,and peak height in the atomic emission spectrum,but also influences the effects of the cavity field and the atomic initial state on atomic emission spectrum.

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

    OpenAIRE

    DAGMAR GALUSKOVÁ; DUŠAN GALUSEK; PAVOL ŠAJGALÍK

    2014-01-01

    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 spectros...

  1. Analytical Framework to Evaluate Emission Control Systems for Marine Engines

    OpenAIRE

    Jayaram, Varalakshmi

    2010-01-01

    Emissions from marine diesel engines are mainly uncontrolled and affect regional air quality and health of people living near ports. Many emission control strategies are evolving to reduce these emissions and their impacts. This dissertation characterizes the effectiveness of new technologies for reducing NOx and PM2.5 emissions from a range of marine diesel engines. Researchers, regulators and policy makers require these characterizations to develop emission inventories and suitable mitigati...

  2. Analytical Solutions of Temporal Evolution of Populations in Optically-Pumped Atoms with Circularly Polarized Light

    Directory of Open Access Journals (Sweden)

    Heung-Ryoul Noh

    2016-03-01

    Full Text Available We present an analytical calculation of temporal evolution of populations for optically pumped atoms under the influence of weak, circularly polarized light. The differential equations for the populations of magnetic sublevels in the excited state, derived from rate equations, are expressed in the form of inhomogeneous second-order differential equations with constant coefficients. We present a general method of analytically solving these differential equations, and obtain explicit analytical forms of the populations of the ground state at the lowest order in the saturation parameter. The obtained populations can be used to calculate lineshapes in various laser spectroscopies, considering transit time relaxation.

  3. CANAS '01 - Colloquium analytical atomic spectroscopy; CANAS '01 - Colloquium Analytische Atomspektroskopie. Programm. Kurzfassungen der Vortraege und Poster

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The main topics of the meeting on analytical atom spectroscopy were: optical atom spectrometry, x-ray fluorescence analysis, absorption spectroscopy, icp mass spectroscopy, trace analysis, sampling, sample preparation and quality assurance.

  4. Theory of optical near-resonant cone emission in atomic vapor

    International Nuclear Information System (INIS)

    A time-dependent theory for conical emission during near-resonant propagation of laser light in an atomic vapor, which includes full propagation for the laser and frequency sidebands in a nonlinear two-level medium is presented. The density-matrix equations for the dipole moment and population are solved in the dressed atomic frame. The polarization source terms are accurate to order γ/R, where γ is a damping constant and R is the generalized Rabi frequency. Analytical plane-wave solutions and numerical, cylindrically symmetric propagation simulations including diffraction are presented. It is shown that the calculations with cylindrically symmetric fields and atomic excitation profiles are incapable of accounting for the high levels of optical gain that are responsible for the intense conical emission observed in experiments. This result is at first surprising, since the model accounts rigorously for all of the physical phenomena that have been previously proposed as being responsible for generating large gains, and the calculation matches the symmetry of the observations. The lack of large calculated gain seems to imply the existence of higher-order (m>0) radial modes in the field for the experimental conditions that give rise to cone emission. In the simulations, however, the cylindrically symmetric fields do produce weak red-detuned cones with angular-frequency distributions similar to those seen in experiments

  5. Photon Emission Dynamics of a Two-Level Atom in a Cavity

    CERN Document Server

    Lee, Chang Jae

    2015-01-01

    The collapse and revival of quantum states appear in diverse areas of physics. In quantum optics the occurrence of such a phenomena in the evolution of an atomic state, interacting with a light field initially in a coherent state, was predicted by using the Jaynes-Cummings model (JCM), and subsequently demonstrated experimentally. In this paper we revisit the JCM with the Monte-Carlo wave function approach and investigate the time evolution of the photon emission rate of the atom in a cavity. Analytical and numerical quantum trajectory calculations show that the cavity and the initial field statistics strongly influence the photon emission dynamics. A coherent field indeed gives rise to a collapse and revival behavior that mirrors atomic state evolution. However, there are differences between the two. The emission rate for a field in a Fock number state exhibits a sinusoidal oscillation, and there exists a quiescent period for a thermal field. These properties are quite different from those in free space. It ...

  6. An Analytical Model for Adsorption and Diffusion of Atoms/Ions on Graphene Surface

    Directory of Open Access Journals (Sweden)

    Yan-Zi Yu

    2015-01-01

    Full Text Available Theoretical investigations are made on adsorption and diffusion of atoms/ions on graphene surface based on an analytical continuous model. An atom/ion interacts with every carbon atom of graphene through a pairwise potential which can be approximated by the Lennard-Jones (L-J potential. Using the Fourier expansion of the interaction potential, the total interaction energy between the adsorption atom/ion and a monolayer graphene is derived. The energy-distance relationships in the normal and lateral directions for varied atoms/ions, including gold atom (Au, platinum atom (Pt, manganese ion (Mn2+, sodium ion (Na1+, and lithium-ion (Li1+, on monolayer graphene surface are analyzed. The equilibrium position and binding energy of the atoms/ions at three particular adsorption sites (hollow, bridge, and top are calculated, and the adsorption stability is discussed. The results show that H-site is the most stable adsorption site, which is in agreement with the results of other literatures. What is more, the periodic interaction energy and interaction forces of lithium-ion diffusing along specific paths on graphene surface are also obtained and analyzed. The minimum energy barrier for diffusion is calculated. The possible applications of present study include drug delivery system (DDS, atomic scale friction, rechargeable lithium-ion graphene battery, and energy storage in carbon materials.

  7. Spectral shaping of cascade emissions from multiplexed cold atomic ensembles

    Science.gov (United States)

    Jen, H. H.; Chen, Y.-C.

    2016-01-01

    We investigate the spectral properties of the biphoton state from the cascade emissions of cold atomic ensembles, which are composed of a telecommunication photon (signal) followed by an infrared one (idler) via four-wave mixing. With adiabatic conditions for Gaussian driving pulses of width τ , the spectrum of the biphoton state has the form of a Gaussian that conserves signal and idler photon energies within ℏ /τ modulated by a Lorentzian with a superradiant linewidth. Multiplexing the atomic ensembles with frequency-shifted cascade emissions, we may manipulate and shape the spectrum of the biphoton state. The entropy of entanglement is derived from Schmidt decomposition, which can be larger if we multiplex the atomic ensembles in a way that conserves signal and idler photon central energies. The eigenvalues in Schmidt bases are degenerate in pairs for symmetric spectral shaping in which the mode probability densities show interference patterns. We also demonstrate the excess entropy of entanglement that comes from continuous frequency space, which scales up the total entropy. The scheme of the multiplexed cascade-emitted biphoton state provides multimode structures that are useful in long-distance quantum communication and multimode quantum information processing.

  8. Infrared [Fe II] Emission Lines from Radiative Atomic Shocks

    CERN Document Server

    Koo, Bon-Chul; Kim, Hyun-Jeong

    2016-01-01

    [Fe II] emission lines are prominent in the infrared (IR), and they are important diagnostic tools for radiative atomic shocks. We investigate the emission characteristics of [Fe II] lines using a shock code developed by Raymond (1979) with updated atomic parameters. We first review general characteristics of IR [Fe II] emission lines from shocked gas, and derive [Fe II] line fluxes as a function of shock speed and ambient density. We have compiled the available IR [Fe II] line observations of interstellar shocks and compare them to the ratios predicted from our model. The sample includes both young and old supernova remnants in the Galaxy and the Large Magellanic Cloud and several Herbig-Haro objects. We find that the observed ratios of IR [Fe II] lines generally fall on our grid of shock models, but the ratios of some mid-infrared lines, e.g., [Fe II] 35.35 um/[Fe II] 25.99 um, [Fe II] 5.340 um/[Fe II] 25.99 um, and [Fe II] 5.340 um/[Fe II] 17.94 um, are significantly offset from our model grid. We discuss ...

  9. Cooperative analysis of alloying elements in zirconium alloys using inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    The Second Sub-Committee on Zircaloy Analysis, under Committee on Analytical Chemistry of Nuclear Fuels and Reactor Materials, JAERI, carried out a cooperative analysis with the nine laboratories on the determination of tin, iron, nickel and chromium in zirconium alloys to evaluate the practical applicability of inductively coupled plasma (ICP) atomic emission spectrometry. This report describes the sample decomposition procedures, determination conditions and procedures, and analytical results. The results obtained for alloying elements in samples for cooperative analysis (JAERI CRMs Z11 to Z14 and others) were compared with certified values or those obtained by X-ray fluorescence method, and were in good agreement with those values. ICP atomic emission spectrometry were shown to be an effective field method for determining alloying elements (C.V. % 2 to 7 for 0.5 to 1.90 % Sn, C.V. % 2 to 3 for 0.093 to 0.130 % Fe, C.V. % 3 to 6 for 0.095 to 0.110 % Ni and C.V. % 2 to 7 for 0.01 to 0.150 % Cr) in zirconium alloys. (author)

  10. Electron emission from a two-dimensional crystal with atomic thickness

    OpenAIRE

    Xianlong Wei; Qing Chen; Lianmao Peng

    2013-01-01

    Electron emission from a two-dimensional (2D) crystal with atomic thickness is theoretically studied with all the features associated with the low dimensionality and the atomic thickness being well considered. It is shown that, the atomic thickness results in quantum confinement of electrons in the crystal along thickness direction, and consequently two different ways of electron emission from it without and with quantum confinement of electrons normal to emission boundary: edge emission and ...

  11. Analytic solution and pulse area theorem for three-level atoms

    Science.gov (United States)

    Shchedrin, Gavriil; O'Brien, Chris; Rostovtsev, Yuri; Scully, Marlan O.

    2015-12-01

    We report an analytic solution for a three-level atom driven by arbitrary time-dependent electromagnetic pulses. In particular, we consider far-detuned driving pulses and show an excellent match between our analytic result and the numerical simulations. We use our solution to derive a pulse area theorem for three-level V and Λ systems without making the rotating wave approximation. Formulated as an energy conservation law, this pulse area theorem can be used to understand pulse propagation through three-level media.

  12. Three-dimensional time-dependent computer modeling of the electrothermal atomizers for analytical spectrometry

    Science.gov (United States)

    Tsivilskiy, I. V.; Nagulin, K. Yu.; Gilmutdinov, A. Kh.

    2016-02-01

    A full three-dimensional nonstationary numerical model of graphite electrothermal atomizers of various types is developed. The model is based on solution of a heat equation within solid walls of the atomizer with a radiative heat transfer and numerical solution of a full set of Navier-Stokes equations with an energy equation for a gas. Governing equations for the behavior of a discrete phase, i.e., atomic particles suspended in a gas (including gas-phase processes of evaporation and condensation), are derived from the formal equations molecular kinetics by numerical solution of the Hertz-Langmuir equation. The following atomizers test the model: a Varian standard heated electrothermal vaporizer (ETV), a Perkin Elmer standard THGA transversely heated graphite tube with integrated platform (THGA), and the original double-stage tube-helix atomizer (DSTHA). The experimental verification of computer calculations is carried out by a method of shadow spectral visualization of the spatial distributions of atomic and molecular vapors in an analytical space of an atomizer.

  13. Self-interstitial configuration in molybdenum studied by modified analytical embedded atom method

    Indian Academy of Sciences (India)

    Jian-Min Zhang; Zhang Fang Wang; Ke-Wei Xu

    2009-05-01

    The stability of various atomic configurations containing a self-interstitial atom (SIA) in a model representing Mo has been investigated using the modified analytical embedded atom method (MAEAM). The lattice relaxations are treated with the molecular dynamics (MD) simulation at absolute zero of temperature. Six relatively stable self-interstitial configurations and formation energies have been described and calculated. The results indicate that the [1 1 1] dumbbell interstitial S111 has the lowest formation energy, and in ascending order, the sequence of the configurations is predicted to be S111, C, S110, T, S001 and O. From relaxed displacement field up to the fifth-NN atoms of six configurations, we know that the relaxed displacements depend not only on separation distances of the NN atoms from the defect centre but also strongly on the direction of the connected line between the NN atoms and the defect centre. The equilibrium distances between two nearest atoms in the core of the S111, C, S110, T, S001 and O configurations are 0.72a, 0.72a, 0.71a, 0.72a, 0.70a and 0.70a, respectively.

  14. A comparative study of inductively coupled plasma optical emission spectrometry and microwave plasma atomic emission spectrometry for the direct determination of lanthanides in water and environmental samples

    International Nuclear Information System (INIS)

    A new instrumental technique – Microwave Plasma Atomic Emission Spectrometry (MP - AES) is compared to conventional Inductively Coupled Plasma Optical Emission Spectrometry (ICP - OES) for direct determination of lanthanides. Estimation of both methods is done using standard measurement conditions. The present study includes spectral and non- spectral matrix effect evaluation. Tested analytical wavelengths of lanthanides are divided into three groups: 1) relatively free, 2) interfered by other lanthanides and 3) interfered by concomitant elements. Non spectral effect on analytes is examined in two typical real matrices – acidic plant digests and saline water. The capabilities of both plasma methods for quantitative determination of La, Ce, Sm, Eu, Gd and Er are compared. The interference - free emission lines are selected; appropriate background correction is proposed and the corresponding instrumental detection limits are calculated. Key words: lanthanides, ICP -OES, MP -AES, spectral and non-spectral interference

  15. Advances with tungsten coil atomizers: Continuum source atomic absorption and emission spectrometry

    International Nuclear Information System (INIS)

    Two new tungsten coil spectrometers are described: a continuum source tungsten coil atomic absorption spectrometer and a tungsten coil atomic emission spectrometer. Both devices use a 150 W tungsten coil extracted from a slide projector bulb. The power is provided by a computer-controlled, solid state, constant current 0-10 A supply. The heart of the optical system is a high-resolution spectrometer with a multi-channel detector. The continuum source system employs xenon or deuterium lamps, and is capable of multi-element analyses of complex samples like engine oil, urine, and polluted water. Spiked engine oil samples give mean percent recoveries of 98 ± 9, 104 ± 9, and 93 ± 0.8 for Al, V, and Ni, respectively. Copper, Zn, and Cd are determined in urine samples; while Cd, Co, Yb, and Sr are determined in water samples. Detection limits for Cd, Zn, Cu, Yb, Sr, and Co are: 8, 40, 1, 4, 1, and 4 μg l-1. The technique of tungsten coil atomic emission spectrometry using a 150 W commercial projector bulb is reported for the first time. Calcium, Ba, and Sr are determined with detection limits of 0.01, 0.5, and 0.1 μg l-1. Relative standard deviations are lower than 10% in each case, and Sr is determined in two water standard reference materials

  16. Atomic carbon in comet atmospheres. Origin and emission spectra

    International Nuclear Information System (INIS)

    A detailed study of neutral carbon emissions is made, to precise the excitation mechanism nature, to determine the production mechanisms and examine wether information on CO and CO2 molecule abundance could be deduced, or wether another source must be looked for. After an exhaustive study of excitation rates necessary for theoretical intensity calculation, a new effect has been discovered, and which acts on the atom excitation rates, via their distribution on the fundamental hyperfine levels. On the other hand, the strong dependency of the excitation rate ratio with heliocentric velocity and with the hypothesis which is made on the atom population initial distribution has been revealed. The carbon abundance in all the comets of the initial sample has been calculated, then compared to the water one revealing two groups of comets. Then an abundance criterium to remove the CO and CO2 molecules from the carbon potential-parents in the Bradfield comet has been used while CO is the best candicate for C(3P) and C(1D) atom production in the West, Kohoutek and Bennet comets (but to certain conditions). The important conclusion is that, while the relative abundance (C2/OH, CN/OH,...) of the minor carbon compounds were constant, the CO relative abundance varies from an object to the other, probably an effect due to repeated passage of some comets near the sun

  17. Electric focusing preconcentration devices for element in-time monitoring of air aerosols by atomic emission spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Večeřa, Zbyněk; Mikuška, Pavel; Dočekal, Bohumil; Šikola, T.; Zlámal, J.

    Pardubice : Univerzita Pardubice a Spektroskopická společnost JMM, 2005 - (Černohorský, T.; Krejčová, A.; Šrámková, J.; Matěcha, J.). s. 207 [International Conference on Inorganic Environmental Analysis /4./. 19.09.2005-22.09.2005, Pardubice] R&D Projects: GA AV ČR IAA400310505 Keywords : electrostatic pre-concentration * airborne particles * atomic emission spectrometric detection Subject RIV: CB - Analytical Chemistry, Separation

  18. 14 CFR 34.64 - Sampling and analytical procedures for measuring gaseous exhaust emissions.

    Science.gov (United States)

    2010-01-01

    ... Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. This document can be obtained from the... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Sampling and analytical procedures for... Turbine Engines) § 34.64 Sampling and analytical procedures for measuring gaseous exhaust emissions....

  19. 14 CFR 34.82 - Sampling and analytical procedures for measuring smoke exhaust emissions.

    Science.gov (United States)

    2010-01-01

    ... Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. This document can be... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Sampling and analytical procedures for... Sampling and analytical procedures for measuring smoke exhaust emissions. The system and procedures...

  20. Atomic Oscillator Strengths by Emission Spectroscopy and Lifetime Measurements

    Science.gov (United States)

    Wiese, W. L.; Griesmann, U.; Kling, R.; Musielok, J.

    2002-11-01

    Over the last seven years, we have carried out numerous oscillator strength measurements for some light and medium heavy elements (Musielok et al. 1995, 1996, 1997, 1999, 2000; Veres & Wiese 1996; Griesmann et al. 1997; Bridges & Wiese 1998; Kling et al. 2001; Kling & Gries- mann 2000; Bridges & Wiese to be published). Most recently we have determined numerous transitions of Mu II (Kling et al. 2001; Kling & Griesmann 2000) and are now working on Cl I (Bridges & Wiese to be published). See the summary statement at the end of the text. For the emission measurements, we have applied either a high-current wall-stabilized arc (described for example, in Musielok et al. (1999)), or a high-current hollow cathode, or a Penning discharge. The latter two sources were used for branching ratio measurements from common upper 1ev- els, while the wall-stabilized arc was operated at atmospheric pressure under the condition of partial local thermodynamic equilibrium, which allows the measurement of relative transition probabilities. Absolute data were obtained by combining the emission results with lifetime data measured by other research groups, especially the University of Hannover, with which we have closely collaborated. This group uses the laser induced fluorescence (LIF) technique. Our emission spectra were recorded for the light elements with a 2 m grating spectrometer, or, for Mu II, with an FT 700 vacuum ultraviolet Fourier transform spectrometer. The radiometric calibration was carried out with a tungsten strip lamp for the visible part of the spectrum and with a deuterium lamp for the ultraviolet. All measurements were made under optically thin conditions, which was checked by doubling the path length with a focusing mirror setup. Typical uncertainties of the measured oscillator strengths are estimated to be in the range 15%-20% (one-standard deviation). However, discrepancies with advanced atomic structure theories are sometimes much larger. In Tables 1-3 and Fig. 1, we

  1. Phonon dispersion on Ag (100) surface: A modified analytic embedded atom method study

    Science.gov (United States)

    Xiao-Jun, Zhang; Chang-Le, Chen

    2016-01-01

    Within the harmonic approximation, the analytic expression of the dynamical matrix is derived based on the modified analytic embedded atom method (MAEAM) and the dynamics theory of surface lattice. The surface phonon dispersions along three major symmetry directions , and X¯M¯ are calculated for the clean Ag (100) surface by using our derived formulas. We then discuss the polarization and localization of surface modes at points X¯ and M¯ by plotting the squared polarization vectors as a function of the layer index. The phonon frequencies of the surface modes calculated by MAEAM are compared with the available experimental and other theoretical data. It is found that the present results are generally in agreement with the referenced experimental or theoretical results, with a maximum deviation of 10.4%. The agreement shows that the modified analytic embedded atom method is a reasonable many-body potential model to quickly describe the surface lattice vibration. It also lays a significant foundation for studying the surface lattice vibration in other metals. Project supported by the National Natural Science Foundation of China (Grant Nos. 61471301 and 61078057), the Scientific Research Program Funded by Shaanxi Provincial Education Department, China (Grant No. 14JK1301), and the Specialized Research Fund for the Doctoral Program of Higher Education, China (Grant No. 20126102110045).

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

    Science.gov (United States)

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

    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.

  3. Determination of trace impurities in uranium hexafluoride using inductively coupled plasma-atomic emission spectroscopy

    International Nuclear Information System (INIS)

    A procedure has been developed to determine 30 trace elements in high-purity uranium hexafluoride (UF6) using inductively coupled plasma-atomic emission spectroscopy. The analytical method consists of a liquid-liquid extraction of the uranium from the trace impurities with a tri-(2-ethyl-hexyl)-phosphate (TEHP)-hexane mixture. A computer-controlled scanning monochromator system interfaced to an inductively coupled plasma (ICP) is then used to determine the levels of 30 trace elements present in the UF6. A single sample dissolution procedure is used for all elements investigated. This preliminary report details experimental work done to date as part of a countinuing program to determine metallic impurities in uranium by ICP

  4. Analytical estimation of the gravitational constant with atomic and nuclear physical constants

    International Nuclear Information System (INIS)

    If NA represents the Avogadro's number, gravitational constant associated with atomic electromagnetic interaction can be expressed as GE ≅ N2AG. With GE and with the assumed two new pseudo numbers x ≈ 38.725 and y ≈ 47.415, value of G can be fixed for 10 digits in a verifiable approach. (x, y) can be called as the back ground analytical numbers using by which micro-macro physical constants can be interlinked qualitatively and quantitatively

  5. Design of electric focusing preconcentration devices for in-time monitoring of element composition of air aerosols by atomic emission spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Dočekal, Bohumil; Večeřa, Zbyněk; Mikuška, Pavel; Šikola, T.; Zlámal, J.

    Antverp : University of Antwerp, 2005 - (Van Grieken, R.). s. 393 [Colloquium Spectroscopicum Internationale /34./. 04.09.2005-09.09.2005, Antwerp] R&D Projects: GA AV ČR IAA400310505 Keywords : electrostatic pre-concentration * airborne particles * atomic emission spectrometric detection Subject RIV: CB - Analytical Chemistry, Separation

  6. High-precision three-dimensional atom localization via spontaneous emission in a four-level atomic system

    Science.gov (United States)

    Wang, Zhiping; Yu, Benli

    2016-06-01

    We investigate the three-dimensional atom localization via spontaneous emission in a four-level atomic system. It is found that the detecting probability and precision of atom localization can be significantly improved due to the interference effects induced by the vacuum radiation field and the two laser fields. More importantly, the almost 100% probability of finding an atom within a certain range can be reached when corresponding conditions are satisfied. As a result, our scheme may be helpful in a spatially selective single-qubit phase gate, entangling gates, and quantum error correction for quantum information processing.

  7. Analytical use of proton-induced x-ray emission

    International Nuclear Information System (INIS)

    Proton-induced X-ray emission is capable of simultaneous quantitative determination of 10-15 elements. An introduction to the physical properties of the method is given and detection limits are shown for a routine analysis of a thin aerosol sample. Examples of applications to both thick and thin samples are presented. Human tooth dentine is analysed for lead, with simple sample preparation, indicating lead values of a few ppm for Swedish children. Quantitative analyses of several other elements are obtained simultaneously. Cascade impactors are used for sampling aerosols in work environment during welding operations giving information of size distribution and concentrations of the elements present. The aerosol dominated by particle sizes between 0.5 and 2 μm as measured by the impactor, but the size distributions are different for different elements and welding techniques and depend on the distance from the welding source. The relative abundance of the elements found in the aerosol indicates the presence of fractionation mechanisms. (author)

  8. Characterization of helium/argon working gas systems in a radiofrequency glow discharge atomic emission source. Part I: Optical emission, sputtering and electrical characteristics

    Science.gov (United States)

    Christopher, Steven J.; Hartenstein, Matthew L.; Marcus, R. Kenneth; Belkin, Mikhail; Caruso, Joseph A.

    1998-08-01

    Studies are performed to determine the influence of discharge gas composition (helium/argon working gas mixtures) on the analyte emission signal intensities, sputtering rates, and DC-bias characteristics of an analytical radiofrequency glow discharge atomic emission spectroscopy (RF-GD-AES) source. As the partial pressure of He is increased from 0 to 15 torr, increased emission intensity is observed for a range of bulk and trace elements in NIST 1250 SRM (low alloy steel), regardless of the base pressure of Ar in the source (5 and 9 torr). In contrast to increases in analyte emission intensity of up to 300%, counterindicative decreases in the sputtering rates on the order of about 30-50% are observed. The magnitude of these effects depends on both the partial pressure of helium introduced to the source and the total pressure of the He and Ar gases. Use of relative emission yield (REY) to normalize changes in emission intensity to sputtering rates indicates that excitation efficiencies increase under these conditions. Increases in average electron energy and temperature appear to control this response. Decreases in both analyte emission intensities and sputter rates occur with increasing He partial pressure when the total pressure in the cell remains fixed (11 torr in these studies). Emission yields for the fixed pressure, mixed gas plasmas decrease as the partial pressure of He (He/Ar ratio) in the RF-GD source increases. In this case, decreases in electron number densities appear to dictate the lower REYs. Measurement of DC-bias values at the sample surface provide understanding with respect to the observed changes in sputtering rates as well as suggest the origins of changes in plasma electron energetics. Use of a diamond stylus profilometer provides both the quantitative sputter rate information as well as qualitative insights into the use of mixed gas plasmas for enhanced depth profiling capabilities. The analyte emission characteristics of these mixed gas

  9. Determination of daily intake of elements from Philippine total diet samples using inductively coupled plasma-atomic emission spectrometry

    International Nuclear Information System (INIS)

    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

  10. Three-phase plasma arc atomic-emission spectrometric analysis of environmental samples using an ultrasonic nebulizer

    Energy Technology Data Exchange (ETDEWEB)

    Ghatass, Zekry F. [Institute of Graduate Studies and Research, Alexandria University, 163 El-Horreya Avenue, P.O. Box 832, Chatby 21526, Alexandria (Egypt); Roston, Gamal D. [Department of Physics, Faculty of Science, Alexandria University, Alexandria (Egypt); Mohamed, Moustafa M. [Medical Research Institute, Alexandria University, Alexandria (Egypt)

    2003-06-01

    Combination of an ultrasonic nebulizer and plasma excitation sources for spectrochemical analysis offers desirable features of low detection limits, high sample throughput, wide dynamic range of operation, acceptable precision and accuracy, and simultaneous quantitative analytical capabilities. Moreover, the ultrasonic nebulizer does not require sample preconcentration. Recently we have developed a three-phase plasma arc (TPPA) for atomic emission spectrochemical analysis. In the present work, to increase the analytical utility of the three-phase plasma system, an ultrasonic nebulizer was used for sample introduction. The effects of the argon gas flow rate, current, excitation temperature have been studied. The analytical calibration curves are obtained for Ca, Cr, Fe, Mg and Mn, and detection limits have been calculated. The present technique is used to determine the concentration of the elements Ca, Cr, Fe, Mg and Mn in airborne samples. (orig.)

  11. Spontaneous Emission from a Driven Atom Embedded in a Photonic Crystal

    Institute of Scientific and Technical Information of China (English)

    XIE Shuang-Yuan; YANG Ya-Ping; CHENG Hong; ZHU Shi-Yao; WU Xiang

    2000-01-01

    The properties of the spontaneous emission from a three-level atom with an external driving field in a photonic crystal are studied. The population in the two upper levels displays complete decay or oscillatory behavior,depending on the initial atomic state and the relative position of the two upper levels from the forbidden gap.The intensity and the phase of the external field can also affect spontaneous emission from the atom.

  12. Mass and emission spectrometry in the Analytical Chemistry Division of Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    The capabilities of the Mass and Emission Spectrometry Section of the Analytical Chemistry Division of Oak Ridge National Laboratory are described. Many different areas of mass spectrometric expertise are represented in the section: gas analysis, high abundance sensitivity measurements, high- and low-resolution organic analyses, spark source trace constituent analysis, and ion microprobe analysis of surfaces. These capabilities are complemented by emission spectrometry. The instruments are described along with a few applications, some of which are unique

  13. Palladium emissions in the environment. Analytical methods, environmental assessment and health effects

    Energy Technology Data Exchange (ETDEWEB)

    Zereini, F. [Frankfurt Univ., Frankfurt am Main (Germany). Inst. for Atmosphere and Environment; Alt, F. (eds.)

    2006-07-01

    To date the investigations of metal emissions from automotive catalysts has focused mainly on platinum. Since 1993, however, platinum has been increasingly replaced by palladium as the predominant substance in pollution-control catalysts. Now the release of palladium in automotive catalysts is becoming just a critical problem as that of platinum. The editors present the latest research results related to all aspects of palladium emissions in the environment, as well as an assessment of their effects on the environment and health. The book focuses on the following topics: analytical methods; sources of palladium emissions; occurrence, chemical behaviour and fate in the environment; bioavailability and biomonitoring; and health-risk potential. (orig.)

  14. 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.

  15. Microwave plasma atomic emission spectrometric determination of Ca, K and Mg in various cheese varieties.

    Science.gov (United States)

    Ozbek, Nil; Akman, Suleyman

    2016-02-01

    Microwave plasma-atomic emission spectrometry (MP-AES) was used to determine calcium, magnesium and potassium in various Turkish cheese samples. Cheese samples were dried at 100 °C for 2 days and then digested in a mixture of nitric acid/hydrogen peroxide (3:1). Good linearities (R(2) > 0.999) were obtained up to 10 μg mL(-1) of Ca, Mg and K at 445.478 nm, 285.213 nm and 766.491 nm, respectively. The analytes in a certified reference milk powder sample were determined within the uncertainty limits. Moreover, the analytes added to the cheese samples were recovered quantitatively (>90%). All determinations were performed using aqueous standards for calibration. The LOD values for Ca, Mg and K were 0.036 μg mL(-1), 0.012 μg mL(-1) and 0.190 μg mL(-1), respectively. Concentrations of Ca, K and Mg in various types of cheese samples produced in different regions of Turkey were found between 1.03-3.70, 0.242-0.784 and 0.081-0.303 g kg(-1), respectively. PMID:26304350

  16. An analytic study of applying miller cycle to reduce nox emission from petrol engine

    OpenAIRE

    Wang, Yaodong; Lin, Lin; Roskilly, Antony P.; Zeng, Shengchuo; Huang, Jincheng; He, Yunxin; Huang, Xiaodong; Huang, Huilan; Wei, Haiyan; Li, Shangping; Yang, J

    2007-01-01

    An analytic study of applying miller cycle to reduce nox emission from petrol engine correspondence: Corresponding author. Tel.: +0044 191 2223522; fax: +0044 191 2225491. (Wang, Yaodong) (Wang, Yaodong) School of Marine Science and Technology, Newcastle University - Newcastle upon Tyne--> , NE1 7RU--> - UNITED KINGDOM (Wang, Yaodong) Mechanical Engineering College, Guangxi University - Nanning--...

  17. The emission of atoms and molecules accompanying fracture of single-crystal MgO

    Science.gov (United States)

    Dickinson, J. T.; Jensen, L. C.; Mckay, M. R.; Freund, F.

    1986-01-01

    The emission of particles due to deformation and fracture of materials has been investigated. The emission of electrons (exoelectron emission), ions, neutral species, photons (triboluminescence), as well as long wavelength electromagnetic radiation was observed; collectively these emissions are referred to as fractoemission. This paper describes measurements of the neutral emission accompanying the fracture of single-crystal MgO. Masses detected are tentatively assigned to the emission of H2, CH4, H2O, CO, O2, CO2, and atomic Mg. Other hydrocarbons are also observed. The time dependencies of some of these emissions relative to fracture are presented for two different loading conditions.

  18. An analytic study of applying Miller cycle to reduce NOx emission from petrol engine

    International Nuclear Information System (INIS)

    An analytic investigation of applying Miller cycle to reduce nitrogen oxides (NOx) emissions from a petrol engine is carried out. The Miller cycle used in the investigation is a late intake valve closing version. A detailed thermodynamic analysis of the cycle is presented. A comparison of the characters of Miller cycle with Otto cycle is presented. From the results of thermodynamic analyses, it can be seen that the application of Miller cycle is able to reduce the compression pressure and temperature in the cylinder at the end of compression stroke. Therefore, it lowers down the combustion temperature and NOx formation in engine cylinder. These results in a lower exhaust temperature and less NOx emissions compared with that of Otto cycle. The analytic results also show that Miller cycle ratio is a main factor to influence the combustion temperature, and then the NOx emissions and the exhaust temperature. The results from the analytic study are used to analyse and to compare with the previous experimental results. An empirical formula from the previous experimental results that showed the relation of NOx emissions with the exhaust temperature at different engine speed is presented. The results from the study showed that the application of Miller cycle may reduce NOx emissions from petrol engine

  19. Treatment of the emission and absorption spectra of a general formalism Λ-type three-level atom driven by a two-mode field with nonlinearities

    International Nuclear Information System (INIS)

    An analytical expression of the emission and absorption spectra, for a Λ-type three-level cavity-bound atom interacting with a two-mode cavity field, is given using the dressed states of the system. We take explicitly into account the existence of forms of nonlinearities of both the field and the intensity-dependent atom-field coupling. The characteristics of the emission and absorption spectra for binomial and squeezed coherent states of the modes are exhibited. The effects of the mean number of photons, detuning and the nonlinearity forms on the spectra are analysed

  20. Analytic Evaluation of some 2-, 3- and 4- Electron Atomic Integrals Containing Exponentially Correlated Functions of $r_{ij}$

    CERN Document Server

    Padhy, Bholanath

    2016-01-01

    A simple method is outlined for analytic evaluation of the basic 2-electron atomic integral with integrand containing products of atomic s-type Slater orbitals and exponentially correlated function of the form $r_{ij} exp(-\\lambda_{ij}r_{ij})$, by employing the Fourier representation of $exp(-\\lambda_{ij}r_{ij})/r_{ij}$ without the use of either the spherical harmonic addition theorem or the Feynman technique. This method is applied to obtain closed-form expressions, in a simple manner, for certain other 2-,3- and 4-electron atomic integrals with integrands which are products of exponentially correlated functions and atomic s-type Slater orbitals.

  1. Analytical method for parameterizing the random profile components of nanosurfaces imaged by atomic force microscopy

    CERN Document Server

    Mirsaidov, Utkur; Polyakov, Yuriy S; Misurkin, Pavel I; Musaev, Ibrahim; Polyakov, Sergey V

    2010-01-01

    The functional properties of many technological surfaces in biotechnology, electronics, and mechanical engineering depend to a large degree on the individual features of their nanoscale surface texture, which in turn are a function of the surface manufacturing process. Among these features, the surface irregularities and self-similarity structures at different spatial scales, especially in the range of 1 to 100 nm, are of high importance because they greatly affect the surface interaction forces acting at a nanoscale distance. An analytical method for parameterizing the surface irregularities and their correlations in nanosurfaces imaged by atomic force microscopy (AFM) is proposed. In this method, flicker noise spectroscopy - a statistical physics approach - is used to develop six nanometrological parameters characterizing the high-frequency contributions of jump- and spike-like irregularities into the surface texture. These contributions reflect the stochastic processes of anomalous diffusion and inertial e...

  2. Contribution to the study of X-ray emission induced by accelerated bromine and krypton ions and possibilities of analytical applications

    International Nuclear Information System (INIS)

    In view of analytical applications the X-ray emission induced by 3 to 85 MeV Br and Kr ions has been studied. Thick target yields have been measured and ionization cross section for K and L shells have been calculated. The X-ray emission rates and energy shifts have also been determined. The results are discussed in the frame of the actually existing models for inner shell ionization in atomic collisions. As a practical application azteque ceramics have been analyzed. The possibilities and the difficulties of the technic are emphasized

  3. Flagging and correcting non-spectral matrix interferences with spatial emission profiles and gradient dilution in inductively coupled plasma-atomic emission spectrometry

    International Nuclear Information System (INIS)

    Matrix interference remains one of the most daunting challenges commonly encountered in inductively coupled plasma-atomic emission spectrometry (ICP-AES). In the present study, a method is described that enables identification and correction of matrix interferences in axial-viewed ICP-AES through a combination of spatial mapping and on-line gradient dilution. Cross-sectional emission maps of the plasma are used to indicate the presence of non-spectral (plasma-related and sample-introduction-related) matrix interferences. In particular, apparent concentrations of an analyte species determined at various radial locations in the plasma differ in the presence of a matrix interference, which allows the interference to be flagged. To correct for the interference, progressive, on-line dilution of the sample, performed by a gradient high-performance liquid-chromatograph pump, is utilized. The spatially dependent intensities of analyte emission are monitored at different levels of sample dilution. As the dilution proceeds, the matrix-induced signal variation is reduced. At a dilution where the determined concentrations become independent of location in the plasma, the matrix interference is minimized. - Highlights: • Non-spectral matrix interference in ICP-AES is flagged and minimized. • Emission from different locations of the plasma are collected simultaneously. • Spatially dependent determined concentrations indicate the presence of interference. • Gradient dilution is performed on both calibration standards and sample. • Optimal dilution factor to minimize interference is found as dilution increases

  4. Chromatographic separation and inductively coupled plasma atomic emission spectrometric determination of the rare earth metals contained in terbium

    International Nuclear Information System (INIS)

    The chromatographic separation of rare earth elements (REEs), prior to inductively coupled plasma atomic emission spectrometric (ICP-AES) measurements, using a column packed with 2-ethylexyl hydrogen 2-ethyl-hexylphosphonate (PC-88A)-loaded polymer resin in order to exclude spectral interferences was examined. A favourable separation of trace amounts of metals (La, Nd and Sm) from a large amount of terbium was achieved simply by elution with dilute hydrochloric acid. Trace lanthanum and neodymium in metallic terbium were determined by separation of the analyte ions from the matrix element followed by ICP-AES analysis. (author). 16 refs.; 5 figs.; 2 tabs

  5. An Analytical Solution for Acoustic Emission Source Location for Known P Wave Velocity System

    Directory of Open Access Journals (Sweden)

    Longjun Dong

    2014-01-01

    Full Text Available This paper presents a three-dimensional analytical solution for acoustic emission source location using time difference of arrival (TDOA measurements from N receivers, N⩾5. The nonlinear location equations for TDOA are simplified to linear equations, and the direct analytical solution is obtained by solving the linear equations. There are not calculations of square roots in solution equations. The method solved the problems of the existence and multiplicity of solutions induced by the calculations of square roots in existed close-form methods. Simulations are included to study the algorithms' performance and compare with the existing technique.

  6. Experimental estimation of oxidation-induced Si atoms emission on Si(001) surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Shuichi, E-mail: ogasyu@tagen.tohoku.ac.jp; Tang, Jiayi; Takakuwa, Yuji [Institute Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan)

    2015-08-15

    Kinetics of Si atoms emission during the oxidation of Si(001) surfaces have been investigated using reflection high energy electron diffraction combined with Auger electron spectroscopy. The area ratio of the 1 × 2 and the 2 × 1 domains on a clean Si(001) surface changed with the oxidation of the surface by Langmuir-type adsorption. This change in the domain ratio is attributed to the emission of Si atoms. We can describe the changes in the domain ratio using the Si emission kinetics model, which states that (1) the emission rate is proportional to the oxide coverage, and (2) the emitted Si atoms migrate on the surface and are trapped at S{sub B} steps. Based on our model, we find experimentally that up to 0.4 ML of Si atoms are emitted during the oxidation of a Si(001) surface at 576 °C.

  7. Experimental estimation of oxidation-induced Si atoms emission on Si(001) surfaces

    International Nuclear Information System (INIS)

    Kinetics of Si atoms emission during the oxidation of Si(001) surfaces have been investigated using reflection high energy electron diffraction combined with Auger electron spectroscopy. The area ratio of the 1 × 2 and the 2 × 1 domains on a clean Si(001) surface changed with the oxidation of the surface by Langmuir-type adsorption. This change in the domain ratio is attributed to the emission of Si atoms. We can describe the changes in the domain ratio using the Si emission kinetics model, which states that (1) the emission rate is proportional to the oxide coverage, and (2) the emitted Si atoms migrate on the surface and are trapped at SB steps. Based on our model, we find experimentally that up to 0.4 ML of Si atoms are emitted during the oxidation of a Si(001) surface at 576 °C

  8. Contribution of nitrogen atoms and ions to the luminescence emission during femotosecond filamentation in air

    Science.gov (United States)

    Li, Su-Yu; Li, Shu-Chang; Sui, Lai-Zhi; Jiang, Yuan-Fei; Chen, An-Min; Jin, Ming-Xing

    2016-01-01

    During femtosecond filamentation in air, nitrogen molecules and corresponding molecular ions undergo dissociation due to the high intensity of laser pulses, generating nitrogen atoms and atomic ions. The generated atoms and atomic ions emit luminescence in the UV range, which superposes on those emissions for the neutral and ionic nitrogen molecules. Here we report on a significant difference between the emission behavior of the 391-nm line and the other spectral lines under different pump laser polarizations. We attribute this difference to the contribution of the atomic ions to the luminescence emission around 391 nm. The difference becomes more evident in tightly focusing cases, providing an indirect but effective evidence for the dissociation of nitrogen molecular ions.

  9. Hooke's Atom in an Arbitrary External Electric Field: Analytical Solutions of Two-Electron Problem by Path Integral Approach

    Institute of Scientific and Technical Information of China (English)

    CAI Liang; ZHANG Ping; YANG Tao; PAN Xiao-Yin

    2011-01-01

    By using the path integral approach, we investigate the problem of Hooke's atom (two electrons interacting with Coulomb potential in an external harmonic-oscillator potential) in an arbitrary time-dependent electric field. For a certain infinite set of discrete oscillator frequencies, we obtain the analytical solutions. The ground state polarization of the atom is then calculated. The same result is also obtained through linear response theory.

  10. Spontaneous emission of a photon: wave packet structures and atom-photon entanglement

    OpenAIRE

    Fedorov, M. V.; Efremov, M. A.; Kazakov, A. E.; Chan, K W; Law, C. K.; Eberly, J. H.

    2004-01-01

    Spontaneous emission of a photon by an atom is described theoretically in three dimensions with the initial wave function of a finite-mass atom taken in the form of a finite-size wave packet. Recoil and wave-packet spreading are taken into account. The total atom-photon wave function is found in the momentum and coordinate representations as the solution of an initial-value problem. The atom-photon entanglement arising in such a process is shown to be closely related to the structure of atom ...

  11. Spontaneous Emission of an Excited Atom in a Dusty Unmagnetized Plasma Medium

    OpenAIRE

    Naser Alinejad; Noushin Pishbin

    2014-01-01

    Investigation of spontaneous decay of an excited atom in dusty unmagnetized plasma is presented in this paper. The transverse contribution to the decay rate is normally associated with spontaneous emission. The rate of spontaneous emission can be obtained by Fermi’s golden rule. In this calculation, the transverse contribution to dielectric permittivity and Green function technique are used. Calculation of the decay rate of atoms is applicable to understand the particular structure of the vac...

  12. Evaluation of the temporal profiles and the analytical features of a laser ablation - Pulsed glow discharge coupling for optical emission spectrometry

    Science.gov (United States)

    González de Vega, Claudia; Bordel, Nerea; Pereiro, Rosario; Sanz-Medel, Alfredo

    2016-07-01

    The coupling of a glow discharge (GD) in pulsed mode (PGD) as secondary source for excitation/ionization of the material provided by laser ablation (LA) has been investigated using optical emission spectrometry (OES). The variation of the laser pulse delay with respect to the GD pulse allows to producing the ablation process during prepeak, plateau or afterglow GD regions. Emission properties of the LA-PGD plasma in each temporal region of the GD pulse have been evaluated for analytical lines of different elements. Resonant atomic lines have shown higher emission intensity in the prepeak region compared to non-resonant lines. Non-resonant lines showed higher enhancement of the emission intensity in the afterglow region. Moreover, the coupled LA-PGD system offered better linear correlation coefficients using a set of glass standards for calibration as well as lower detection limits (by at least a factor of two) when compared to laser induced breakdown spectroscopy.

  13. Methane Oxidation to Methanol without CO2 Emission: Catalysis by Atomic Negative Ions

    OpenAIRE

    Tesfamichael, Aron; Suggs, Kelvin; Felfli, Zineb; Msezane, Alfred Z

    2014-01-01

    The catalytic activities of the atomic Y-, Ru-, At-, In-, Pd-, Ag-, Pt-, and Os- ions have been investigated theoretically using the atomic Au- ion as the benchmark for the selective partial oxidation of methane to methanol without CO2 emission. Dispersion-corrected density-functional theory has been used for the investigation. From the energy barrier calculations and the thermodynamics of the reactions, we conclude that the catalytic effect of the atomic Ag-, At-, Ru-, and Os- ions is higher...

  14. Double-pulse laser ablation sampling: Enhancement of analyte emission by a second laser pulse at 213 nm

    International Nuclear Information System (INIS)

    For the purpose of devising methods for minimally destructive multi-element analysis, we compare the performance of a 266 nm–213 nm double-pulse scheme against that of the single 266 nm pulse scheme. The first laser pulse at 266 nm ablates a mica sample. Ten ns later, the second pulse at 213 nm and 64 mJ cm−2 orthogonally intercepts the gas plume to enhance the analyte signal. Emissions from aluminum, silicon, magnesium and sodium are simultaneously observed. At low 266 nm laser fluence when only sub-ng of sample mass is removed, the signal enhancement by the 213 nm pulse is especially apparent. The minimum detectable amount of aluminum is about 24 fmol; it will be a hundred times higher if the sample is analyzed by the 266 nm pulse alone. The minimum detectable mass for the other analytes is also reduced by about two orders of magnitude when the second pulse at 213 nm is introduced. The spectral and temporal properties of the enhanced signal are consistent with the mechanism of ultra-violet laser excited atomic fluorescence of dense plumes. - Highlights: • We devise a two-laser-pulse scheme to analyze the elemental composition of mica as test samples. • We compare the analytical performance of the single 266 nm pulse scheme against the 266 nm – 213 nm two pulse scheme. • The two pulse scheme improves the absolute LODs of the analytes by about a hundred times. • The spectral and temporal properties of the enhanced signal are consistent with the mechanism

  15. Double-pulse laser ablation sampling: Enhancement of analyte emission by a second laser pulse at 213 nm

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Bruno Yue [Laser Technologies Group, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Department of Physics, Hong Kong Baptist University, Kowloon Tong, Hong Kong (China); Mao, Xianglei [Laser Technologies Group, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Hou, Huaming [Laser Technologies Group, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Ocean University of China, Qingdao (China); Zorba, Vassilia; Russo, Richard E. [Laser Technologies Group, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Cheung, Nai-Ho, E-mail: nhcheung@hkbu.edu.hk [Department of Physics, Hong Kong Baptist University, Kowloon Tong, Hong Kong (China)

    2015-08-01

    For the purpose of devising methods for minimally destructive multi-element analysis, we compare the performance of a 266 nm–213 nm double-pulse scheme against that of the single 266 nm pulse scheme. The first laser pulse at 266 nm ablates a mica sample. Ten ns later, the second pulse at 213 nm and 64 mJ cm{sup −2} orthogonally intercepts the gas plume to enhance the analyte signal. Emissions from aluminum, silicon, magnesium and sodium are simultaneously observed. At low 266 nm laser fluence when only sub-ng of sample mass is removed, the signal enhancement by the 213 nm pulse is especially apparent. The minimum detectable amount of aluminum is about 24 fmol; it will be a hundred times higher if the sample is analyzed by the 266 nm pulse alone. The minimum detectable mass for the other analytes is also reduced by about two orders of magnitude when the second pulse at 213 nm is introduced. The spectral and temporal properties of the enhanced signal are consistent with the mechanism of ultra-violet laser excited atomic fluorescence of dense plumes. - Highlights: • We devise a two-laser-pulse scheme to analyze the elemental composition of mica as test samples. • We compare the analytical performance of the single 266 nm pulse scheme against the 266 nm – 213 nm two pulse scheme. • The two pulse scheme improves the absolute LODs of the analytes by about a hundred times. • The spectral and temporal properties of the enhanced signal are consistent with the mechanism.

  16. Visible Light Emission from Atomic Scale Patterns Fabricated by the Scanning Tunneling Microscope

    DEFF Research Database (Denmark)

    Thirstrup, C.; Sakurai, M.; Stokbro, Kurt; Aono, M.

    1999-01-01

    Scanning tunneling microscope (STM) induced light emission from artificial atomic scale structures comprising silicon dangling bonds on hydrogen-terminated Si(001) surfaces has been mapped spatially and analyzed spectroscopically in the visible spectral range. The light emission is based on a novel...

  17. X-ray emission from charge exchange of highly-charged ions in atoms and molecules

    Science.gov (United States)

    Greenwood, J. B.; Williams, I. D.; Smith, S. J.; Chutjian, A.

    2000-01-01

    Charge exchange followed by radiative stabilization are the main processes responsible for the recent observations of X-ray emission from comets in their approach to the Sun. A new apparatus was constructed to measure, in collisions of HCIs with atoms and molecules, (a) absolute cross sections for single and multiple charge exchange, and (b) normalized X-ray emission cross sections.

  18. Electron and X-ray emission in collisions of multiply charged ions and atoms

    International Nuclear Information System (INIS)

    The author presents experimental results of electron and X-ray emission following slow collisions of multiply charged ions and atoms. The aim of the investigation was to study the mechanisms which are responsible for the emission. (G.T.H.)

  19. Development of an axially viewed inductively coupled plasma for atomic emission spectrometry and comparison between the detection limits of lead

    International Nuclear Information System (INIS)

    An ICP(Inductively Coupled plasma) emission spectrometer was developed with an axially viewed ICP source incorporated by a 5-turned induction coil and a torch, outer quartz tube of which was 50 mm longer than that used in conventional ICP/AES(Inductively Coupled Plasma Atomic Emission Spectrometry). The optimization of the system has been performed in terms of the determination of signal-to-noise ratio and background intensity at various rf powers, sample flow rates, argon gas flow rates and cut-off gas flow rates. The spectro-analytical characteristics of the spectrum obtained between 200 and 500 nm was revealed to be similar compared with a vertically viewed ICP source. The detection limit of Pb(II) at 220.35 nm was 11 ppb which was 5 times lower than that obtained with a vertically viewed ICP source. (author)

  20. Calculation of spontaneous emission from a V-type three-level atom in photonic crystals using fractional calculus

    International Nuclear Information System (INIS)

    Fractional time derivative, an abstract mathematical operator of fractional calculus, is used to describe the real optical system of a V-type three-level atom embedded in a photonic crystal. A fractional kinetic equation governing the dynamics of the spontaneous emission from this optical system is obtained as a fractional Langevin equation. Solving this fractional kinetic equation by fractional calculus leads to the analytical solutions expressed in terms of fractional exponential functions. The accuracy of the obtained solutions is verified through reducing the system into the special cases whose results are consistent with the experimental observation. With accurate physical results and avoiding the complex integration for solving this optical system, we propose fractional calculus with fractional time derivative as a better mathematical method to study spontaneous emission dynamics from the optical system with non-Markovian dynamics.

  1. Atomic spatial coherence with spontaneous emission in a strong coupling cavity

    CERN Document Server

    Fang, Zhen; Zhou, Xiaoji; Chen, Xuzong

    2010-01-01

    The role of spontaneous emission in the interaction between a two-level atom and a pumped micro-cavity in the strong coupling regime is discussed in this paper. Especially, using a quantum Monte-Carlo simulation, we investigate atomic spatial coherence. It is found that atomic spontaneous emission destroys the coherence between neighboring lattice sites, while the cavity decay does not. Furthermore, our computation of the spatial coherence function shows that the in-site locality is little affected by the cavity decay, but greatly depends on the cavity pump amplitude.

  2. Radiative emission of neutrino pair from nucleus and inner core electrons in heavy atoms

    CERN Document Server

    Yoshimura, M

    2013-01-01

    Radiative emission of neutrino pair (RENP) from atomic states is a new tool to experimentally investigate undetermined neutrino parameters such as the smallest neutrino mass, the nature of neutrino masses (Majorana vs Dirac), and their CP properties. We study effects of neutrino pair emission either from nucleus or from inner core electrons in which the zero-th component of quark or electron vector current gives rise to large coupling. Both the overall rate and the spectral shape of photon energy are given for a few cases of interesting target atoms. Calculated rates exceed those of previously considered target atoms by many orders of magnitudes.

  3. Forbidden line emission from highly ionized atoms in tokamak plasmas

    Science.gov (United States)

    Feldman, U.; Doschek, G. A.; Bhatia, A. K.

    1982-01-01

    Considerable interest in the observation of forbidden spectral lines from highly ionized atoms in tokamak plasmas is related to the significance of such observations for plasma diagnostic applications. Atomic data for the elements Ti Cr, Mn, Fe, Ni, and Kr have been published by Feldman et al. (1980) and Bhatia et al. (1980). The present investigation is concerned with collisional excitation rate coefficients and radiative decay rates, which are interpolated for ions of elements between calcium, and krypton and for levels of the 2s2 2pk, 2s 2p(k+1), and 2p(k+2) configurations, and for the O I, N I, C I, B I, and Be I isoelectronic sequences. The provided interpolated atomic data can be employed to calculate level populations and relative line intensities for ions of the considered sequences, taking into account levels of the stated configurations. Important plasma diagnostic information provided by the forbidden lines includes the ion temperature

  4. Master equation for collective spontaneous emission with quantized atomic motion

    OpenAIRE

    Damanet, François; Braun, Daniel; Martin, John

    2015-01-01

    We derive a markovian master equation for the internal dynamics of an ensemble of two-level atoms including the quantization of their motion. Our equation provides a unifying picture of the effects of recoil and indistinguishability of atoms beyond the Lamb-Dicke regime on both their dissipative and conservative dynamics. We give general expressions for the decay rates and the dipole-dipole shifts for any motional states, generalizing those in Ref. [1]. We find closed-form formulas for a numb...

  5. Transient Emission of Three-Level Atoms in a Photonic Crystal with a Pseudogap

    Institute of Scientific and Technical Information of China (English)

    XU Xing-Sheng; CHEN Hong-Da

    2006-01-01

    @@ We study the transient behaviour of an external field induced transient emission of three-level atomic systems embedded in a photonic crystal with a pseudogap. The expressions for fluorescence spectra and emission dynamics for luminescent materials in the pseudogap are obtained. The properties of the transient gain in the pseudogap are discussed. It shows that the transient emission in the pseudogap can be effectively controlled.

  6. Spatial oscillations in the spontaneous emission rate of an atom inside a metallic wedge

    CERN Document Server

    Zhao, H J

    2010-01-01

    A method of images is applied to study the spontaneous emission of an atom inside a metallic wedge with an opening angle of $\\pi/N$, where N is an arbitrary positive integer. We show the method of images gives a rate formula consistent with that from Quantum Electrodynamics. Using the method of images, we show the correspondence between the oscillations in the spontaneous emission rate and the closed-orbits of emitted photon going away and returning to the atom inside the wedge. The closed-orbits can be readily constructed using the method of images and they are also extracted from the spontaneous emission rate.

  7. Frequency lock of a dye laser emission on iron atomic line top

    International Nuclear Information System (INIS)

    The aim of this thesis is to realize a frequency lock of a dye laser emission on iron atomic line top. To reach that goal, the author first presents the calculation of atomic vapour density by means of laser absorption ratio measure and studies the dye laser working. It is then necessary to find a device giving the required precision on the frequency of the absorption line choosen. It is obtained thanks to the atomic line reconstitution by optogalvanic effect which gives the reference. Besides, the author presents the necessity of a laser emission power regulation which is obtained thanks to a device including an acoustic and optic modulator. A reliable and accurate captor is choosen and adjusted testing various hollow cathode lamps. The method to obtain the frequency lock of laser emission on iron atomic line top is described. (TEC). 18 refs., 64 figs

  8. Capillary gas chromatography with atomic emission detection for determining chlorophenols in water and soil samples

    Energy Technology Data Exchange (ETDEWEB)

    Campillo, Natalia [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, E-30071 Murcia (Spain); Aguinaga, Nerea [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, E-30071 Murcia (Spain); Vinas, Pilar [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, E-30071 Murcia (Spain); Lopez-Garcia, Ignacio [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, E-30071 Murcia (Spain); Hernandez-Cordoba, Manuel [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, E-30071 Murcia (Spain)]. E-mail: hcordoba@um.es

    2005-11-03

    A purge-and-trap preconcentration system coupled to a GC equipped with a microwave-induced atomic emission detector was used to determine 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP) and 2,4,6-trichlorophenol (2,4,6-TCP) in water and soil samples. The analytes were previously leached from the solid matrices into a 5% (w/v) sodium carbonate solution using an ultrasonic probe. It was necessary to acetylate the compounds before purging them from the aqueous medium, which, at the same time, improved their chromatographic separation. After selecting the optimal experimental conditions, the performance of the system was evaluated. Each chromatographic run took 26 min, including the purge time. Detection limits for 5 ml water samples ranged from 23 to 150 ng l{sup -1}, which is lower than the limits reached using the methods proposed by the US Environmental Pollution Agency (EPA) for chlorophenols in water. For soil samples, detection limits were calculated for 7 g samples, the resulting values ranging between 80 and 540 pg g{sup -1} for 2,4,6-TCP and 2-CP, respectively. The accuracy of the method was checked by analysing a certified reference soil, as well as fortified water and soil samples.

  9. 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.

  10. Emission Channeling Studies of the Lattice Site of Oversized Alkali Atoms Implanted in Metals

    CERN Multimedia

    2002-01-01

    % IS340 \\\\ \\\\ As alkali atoms have the largest atomic radius of all elements, the determination of their lattice configuration following implantation into metals forms a critical test for the various models predicting the lattice site of implanted impurity atoms. The site determination of these large atoms will especially be a crucial check for the most recent model that relates the substitutional fraction of oversized elements to their solution enthalpy. Recent exploratory $^{213}$Fr and $^{221}$Fr $\\alpha$-emission channeling experiments at ISOLDE-CERN and hyperfine interaction measurements on Fr implanted in Fe gave an indication for anomalously large substitutional fractions. To investigate further the behaviour of Fr and other alkali atoms like Cs and Rb thoroughly, more on-line emission channeling experiments are needed. We propose a number of shifts for each element, where the temperature of the implanted metals will be varied between 50$^\\circ$ and 700$^\\circ$~K. Temperature dependent measurements wi...

  11. Development of desolvation system for single-cell analysis using droplet injection inductively coupled plasma atomic emission spectroscopy

    International Nuclear Information System (INIS)

    With a view to enhance the sensitivity of analytical instruments used in the measurement of trace elements contained in a single cell, we have now equipped the previously reported micro-droplet injection system (M-DIS) with a desolvation system. This modified M-DIS was coupled to inductively coupled plasma atomic emission spectroscopy (ICP-AES) and evaluated for its ability to measure trace elements. A flow rate of 100 mL/min for the additional gas and a measurement point –7.5 mm above the load coil (ALC) have been determined to be the optimal parameters for recording the emission intensity of the Ca(II) spectral lines. To evaluate the influence of the desolvation system, we recorded the emission intensities of the Ca(I), Ca(II), and H-β spectral lines with and without inclusion of the desolvation system. The emission intensity of the H-β spectral line reduces and the magnitude of the Ca(II)/Ca(I) emission intensity ratio increases four-fold with inclusion of the desolvation system. Finally, the elements Ca, Mg, and Fe present in a single cell of Pseudococcomyxa simplex are simultaneously determined by coupling the M-DIS equipped with the desolvation system to ICP-AES. (author)

  12. Teleporting the one-qubit state via two-level atoms with spontaneous emission

    Energy Technology Data Exchange (ETDEWEB)

    Hu Mingliang, E-mail: mingliang0301@xupt.edu.cn, E-mail: mingliang0301@163.com [School of Science, Xi' an University of Posts and Telecommunications, Xi' an 710061 (China)

    2011-05-14

    We study quantum teleportation via two two-level atoms coupled collectively to a multimode vacuum field and prepared initially in different atomic states. We concentrated on the influence of the spontaneous emission, collective damping and dipole-dipole interaction of the atoms on fidelity dynamics of quantum teleportation and obtained the region of spatial distance between the two atoms over which the state can be teleported nonclassically. Moreover, we showed through concrete examples that entanglement of the channel state is the prerequisite but not the only essential quantity for predicting the teleportation fidelity.

  13. In-situ determination of cross-over point for overcoming plasma-related matrix effects in inductively coupled plasma-atomic emission spectrometry

    International Nuclear Information System (INIS)

    A novel method is described for overcoming plasma-related matrix effects in inductively coupled plasma-atomic emission spectrometry (ICP-AES). The method is based on measurement of the vertically resolved atomic emission of analyte within the plasma and therefore requires the addition of no reagents to the sample solution or to the plasma. Plasma-related matrix effects enhance analyte emission intensity low in the plasma but depress the same emission signal at higher positions. Such bipolar behavior is true for all emission lines and matrices that induce plasma-related interferences. The transition where the enhancement is balanced by the depression (the so-called cross-over point) results in a spatial region with no apparent matrix effects. Although it would be desirable always to perform determinations at this cross-over point, its location varies between analytes and from matrix to matrix, so it would have to be found separately for every analyte and for every sample. Here, a novel approach is developed for the in-situ determination of the location of this cross-over point. It was found that the location of the cross-over point is practically invariant for a particular analyte emission line when the concentration of the matrix was varied. As a result, it is possible to determine in-situ the location of the cross-over point for all analyte emission lines in a sample by means of a simple one-step sample dilution. When the original sample is diluted by a factor of 2 and the diluted sample is analyzed again, the extent of the matrix effect is identical (zero) between the original sample and the diluted sample at one and only one location - the cross-over point. This novel method was verified with several single-element matrices (0.05 M Na, Ca, Ba and La) and some mixed-element matrices (mixtures of Na-Ca, Ca-Ba, and a plant-sample digest). The inaccuracy in emission intensity due to the matrix effect could be as large as - 30% for conventional measurements in the

  14. In-situ determination of cross-over point for overcoming plasma-related matrix effects in inductively coupled plasma-atomic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Chan, George C.-Y. [Department of Chemistry, Indiana University, 800 E Kirkwood Avenue, Bloomington, IN 47405 (United States); Hieftje, Gary M. [Department of Chemistry, Indiana University, 800 E Kirkwood Avenue, Bloomington, IN 47405 (United States)], E-mail: hieftje@indiana.edu

    2008-03-15

    A novel method is described for overcoming plasma-related matrix effects in inductively coupled plasma-atomic emission spectrometry (ICP-AES). The method is based on measurement of the vertically resolved atomic emission of analyte within the plasma and therefore requires the addition of no reagents to the sample solution or to the plasma. Plasma-related matrix effects enhance analyte emission intensity low in the plasma but depress the same emission signal at higher positions. Such bipolar behavior is true for all emission lines and matrices that induce plasma-related interferences. The transition where the enhancement is balanced by the depression (the so-called cross-over point) results in a spatial region with no apparent matrix effects. Although it would be desirable always to perform determinations at this cross-over point, its location varies between analytes and from matrix to matrix, so it would have to be found separately for every analyte and for every sample. Here, a novel approach is developed for the in-situ determination of the location of this cross-over point. It was found that the location of the cross-over point is practically invariant for a particular analyte emission line when the concentration of the matrix was varied. As a result, it is possible to determine in-situ the location of the cross-over point for all analyte emission lines in a sample by means of a simple one-step sample dilution. When the original sample is diluted by a factor of 2 and the diluted sample is analyzed again, the extent of the matrix effect is identical (zero) between the original sample and the diluted sample at one and only one location - the cross-over point. This novel method was verified with several single-element matrices (0.05 M Na, Ca, Ba and La) and some mixed-element matrices (mixtures of Na-Ca, Ca-Ba, and a plant-sample digest). The inaccuracy in emission intensity due to the matrix effect could be as large as - 30% for conventional measurements in the

  15. Evaluation of the effect of wavelength poisitioning errors on Kalman filtering results in inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    This work evaluates the effect of wavelength positioning errors in spectral scans on analytical results when the Kalman filtering technique is used for the correction of line interferences in inductively coupled plasma atomic emission spectrometry (ICP-AES). The results show that a positioning accuracy of 0.1 pm is required in order to obtain accurate and precise estimates for analyte concentrations. The positioning error in sample scans is more crucial than that in model scans. The relative bias in measured analyte concentration originating from a positioning error in a sample scan increases linearly with an increase in the magnitude of the error and the peak distance of the overlapping lines, but is inversely proportional to the signal-to-background ratio. By the use of an optimization procedure for the positions of scans with the innovations number as the criterion, the wavelength positioning error can be reduced and, correspondingly, the accuracy and precision of analytical results improved. 19 refs., 4 figs., 2 tabs

  16. Electron emission in collisions of intermediate energy ions with atoms

    International Nuclear Information System (INIS)

    The aim of this work, is the analysis of the processes of electronic emission produced in the collisions of small ions (H+, He++) of intermediate energy (50 a 200 KeV/amu) with light gaseous targets. (A.C.A.G.)

  17. Line emission processes in atomic and molecular shocks

    International Nuclear Information System (INIS)

    The review discusses the observations and theoretical models of interstellar shock waves in diffuse and molecular clouds. After summarizing the relevant gas dynamics, atomic, molecular and grain processes, and physics of radiative and magnetic precursors, the author describes observational diagnostics of shocks. This paper concludes with a discussion of two topics: unstable or non-steady shocks and thermal conduction in metal-rich shocks

  18. Photon emission spectroscopy of ion-atom collisions

    Energy Technology Data Exchange (ETDEWEB)

    Nystroem, B.

    1995-10-01

    Emission cross sections for the 1snp{sup 1}P{sub 1}-levels have been measured by photon emission spectroscopy for the collision systems He{sup +} + He at 10 keV and He{sup 2+} + He at 10-35 keV. Photon spectra of Krypton (Kr VIII) and Xenon (Xe V - IX) have also been obtained using 10q keV beams of Kr{sup q+} (q=7-9) and Xe{sup q+} (q=5-9) colliding with Helium and Argon. The Lifetimes of 3p{sup 2}P-levels in Na-like Nb are reported together with lifetime for the 3s3p{sup 3}P{sub 1}-level in Mg-like Ni, Kr, Y, Zr and Nb where this level has an intercombination transition to the ground state. 45 refs, 20 figs.

  19. Photon emission spectroscopy of ion-atom collisions

    International Nuclear Information System (INIS)

    Emission cross sections for the 1snp1P1-levels have been measured by photon emission spectroscopy for the collision systems He+ + He at 10 keV and He2+ + He at 10-35 keV. Photon spectra of Krypton (Kr VIII) and Xenon (Xe V - IX) have also been obtained using 10q keV beams of Krq+ (q=7-9) and Xeq+ (q=5-9) colliding with Helium and Argon. The Lifetimes of 3p2P-levels in Na-like Nb are reported together with lifetime for the 3s3p3P1-level in Mg-like Ni, Kr, Y, Zr and Nb where this level has an intercombination transition to the ground state. 45 refs, 20 figs

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

    International Nuclear Information System (INIS)

    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

  1. Evaluating emission levels of polycyclic aromatic hydrocarbons from organic materials by analytical pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Fabbri, Daniele; Vassura, Ivano [Laboratory of Chemistry, C.I.R.S.A., University of Bologna, via S. Alberto 163, I-48100 Ravenna (Italy)

    2006-03-01

    A procedure in off-line analytical pyrolysis was investigated for the rapid determination of polycyclic aromatic hydrocarbons (PAHs) evolved from thermal degradation of organic materials. Samples spiked with perdeuterated PAHs were pyrolysed at 1000{sup o}C for 60s by means of a resistively heated filament pyrolyser inserted into a glass chamber connected to a cartridge with a sorbent (XAD-2 resin). PAHs trapped onto the resin were extracted with dichloromethane and analysed by gas chromatography-mass spectrometry (GC-MS). The analytical performance of the overall procedure (precision, recovery, effect of experimental parameters) was evaluated by pyrolysing a bituminous coal certified reference material (CRM). Emission levels of naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, acenaphtylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene were determined for bituminous and anthracite coals, tyre, and cellulose. Despite some limitations, the method was adequate to the purpose of quantitatively measuring the tendency of various materials to release volatile PAHs upon heating. (author)

  2. Determination of atomic hydrogen density in non-thermal hydrogen plasmas via emission actinometry

    Energy Technology Data Exchange (ETDEWEB)

    Wang Weiguo [Laboratory of Plasmas Physical Chemistry, PO Box 288, Dalian University of Technology, Dalian 116024 (China); Xu Yong [Laboratory of Plasmas Physical Chemistry, PO Box 288, Dalian University of Technology, Dalian 116024 (China); Geng Zicai [Laboratory of Plasmas Physical Chemistry, PO Box 288, Dalian University of Technology, Dalian 116024 (China); Liu Zhongwei [Laboratory of Plasmas Physical Chemistry, PO Box 288, Dalian University of Technology, Dalian 116024 (China); Zhu Aimin [Laboratory of Plasmas Physical Chemistry, PO Box 288, Dalian University of Technology, Dalian 116024 (China)

    2007-07-21

    Atomic hydrogen plays an important role in the chemical vapour deposition of diamond and other functional materials. This paper reports the experimental determinations of atomic hydrogen density in dielectric barrier discharge hydrogen plasmas via optical emission spectrometry using Ar as an actinometer. At certain discharge conditions (ac 24 kHz, 28 kV of peak-to-peak voltage), the approximate hydrogen dissociation fractions calculated from the emission intensities with respect to electron temperatures obtained with the Langmuir probe, are decreased from 0.099 to 0.01 as the gas pressure increases from 2 to 4 Torr. The relative H atom mole fractions as a function of discharge parameters (spatial position and gas flow rate) have been investigated. It is shown that the discharge characteristics strongly depend on the spatial position but not on the gas flow rate. The influences of the above operating parameters on the emission intensities have been discussed.

  3. Determination of atomic hydrogen density in non-thermal hydrogen plasmas via emission actinometry

    International Nuclear Information System (INIS)

    Atomic hydrogen plays an important role in the chemical vapour deposition of diamond and other functional materials. This paper reports the experimental determinations of atomic hydrogen density in dielectric barrier discharge hydrogen plasmas via optical emission spectrometry using Ar as an actinometer. At certain discharge conditions (ac 24 kHz, 28 kV of peak-to-peak voltage), the approximate hydrogen dissociation fractions calculated from the emission intensities with respect to electron temperatures obtained with the Langmuir probe, are decreased from 0.099 to 0.01 as the gas pressure increases from 2 to 4 Torr. The relative H atom mole fractions as a function of discharge parameters (spatial position and gas flow rate) have been investigated. It is shown that the discharge characteristics strongly depend on the spatial position but not on the gas flow rate. The influences of the above operating parameters on the emission intensities have been discussed

  4. Methane Oxidation to Methanol without CO2 Emission: Catalysis by Atomic Negative Ions

    CERN Document Server

    Tesfamichael, Aron; Felfli, Zineb; Msezane, Alfred Z

    2014-01-01

    The catalytic activities of the atomic Y-, Ru-, At-, In-, Pd-, Ag-, Pt-, and Os- ions have been investigated theoretically using the atomic Au- ion as the benchmark for the selective partial oxidation of methane to methanol without CO2 emission. Dispersion-corrected density-functional theory has been used for the investigation. From the energy barrier calculations and the thermodynamics of the reactions, we conclude that the catalytic effect of the atomic Ag-, At-, Ru-, and Os- ions is higher than that of the atomic Au- ion catalysis of CH4 conversion to methanol. By controlling the temperature around 290K (Os-), 300K (Ag-), 310K (At-), 320K (Ru-) and 325K (Au-) methane can be completely oxidized to methanol without the emission of CO2. We conclude by recommending the investigation of the catalytic activities of combinations of the above negative ions for significant enhancement of the selective partial oxidation of methane to methanol.

  5. Directional spontaneous emission and lateral Casimir-Polder force on an atom close to a nanofiber

    Science.gov (United States)

    Scheel, Stefan; Buhmann, Stefan Yoshi; Clausen, Christoph; Schneeweiss, Philipp

    2015-10-01

    We study the spontaneous emission of an excited atom close to an optical nanofiber and the resulting scattering forces. For a suitably chosen orientation of the atomic dipole, the spontaneous emission pattern becomes asymmetric and a resonant Casimir-Polder force parallel to the fiber axis arises. For a simple model case, we show that such a lateral force is due to the interaction of the circularly oscillating atomic dipole moment with its image inside the material. With the Casimir-Polder energy being constant in the lateral direction, the predicted lateral force does not derive from a potential in the usual way. Our results have implications for optical force measurements on a substrate as well as for laser cooling of atoms in nanophotonic traps.

  6. Determination of the elemental composition of cyanobacteria cells and cell fractions by atomic emission and atomic absorption spectrometry

    International Nuclear Information System (INIS)

    An approach to studying the elemental composition of cyanobacteria Spirulina platensis and Nostoc commune using a set of complementary analytical methods (ICP-AES, PAAS, and ETAAS) was proposed . The procedures were adapted for the determination of macro- and microelements (Na, K, Mg, Ca, Fe, Mn, Cu, Mo, Zn, B, and Se) in the biomass of cyanobacteria and separated cell fractions (chloroform and water-methanol extracts and precipitates). The conditions for the mineralization of biological materials were optimized for autoclave and microwave sample preparation procedures. The evaporation and atomization of Se and Mo in a graphite furnace in the presence of chloroform and methanol were studied

  7. Towards broadening thermospray flame furnace atomic absorption spectrometry: Influence of organic solvents on the analytical signal of magnesium

    OpenAIRE

    Ezequiel Morzan; Jorge Stripeikis; Mabel Tudino

    2015-01-01

    This study demonstrates the influence of the solvent when thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) is employed for the determination of elements of low volatility, taking magnesium (Mg) as leading case. Several organic solvents/water solutions of different characteristics (density, surface tension, viscosity, etc.) and proportions were employed for the TS-FF-AAS analytical determination. To this end, solutions containing methanol, ethanol and isopropanol in water w...

  8. Direct determination of sodium, potassium, chromium and vanadium in biodiesel fuel by tungsten coil atomic emission spectrometry

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •Direct analysis of biodiesel on a tungsten coil atomizer. •Determination of Na, K, Cr and V by tungsten coil atomic emission spectrometry. •Sample dilution with methanol or ethanol. •Ten-microliter sample aliquots and limits of detection between 20 and 90 μg kg−1. •Low consumption of reagents, samples and gases in a 140 s per run procedure. -- Abstract: High levels of sodium and potassium can be present in biodiesel fuel and contribute to corrosion, reduced performance and shorter engine lifetime. On the other hand, trace amounts of chromium and vanadium can increase the emission of pollutants during biodiesel combustion. Sample viscosity, immiscibility with aqueous solutions and high carbon content can compromise biodiesel analyzes. In this work, tungsten filaments extracted from microscope light bulbs are used to successively decompose biodiesel's organic matrix, and atomize and excite the analytes to determine sodium, potassium, chromium and vanadium by tungsten coil atomic emission spectrometry (WCAES). No sample preparation other than simple dilution in methanol or ethanol is required. Direct analysis of 10-μL sample aliquots using heating cycles with less than 150 s results in limits of detection (LOD) as low as 20, 70, 70 and 90 μg kg−1 for Na, K, Cr and V, respectively. The procedure's accuracy is checked by determining Na and K in a biodiesel reference sample and carrying out spike experiments for Cr and V. No statistically significant differences were observed between reference and determined values for all analytes at a 95% confidence level. The procedure was applied to three different biodiesel samples and concentrations between 6.08 and 95.6 mg kg−1 for Na and K, and between 0.22 and 0.43 mg kg−1 for V were obtained. The procedure is simple, fast and environmentally friendly. Small volumes of reagents, samples and gases are used and no residues are generated. Powers of detection are comparable to

  9. Characterization of laser - induced plasmas by atomic emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Pace, Diego M; Bertuccelli, Graciela; D' Angelo, Cristian A, E-mail: ddiaz@exa.unicen.edu.ar, E-mail: gbertucc@exa.unicen.edu.ar, E-mail: cdangelo@exa.unicen.edu.ar [Instituto de Fisica ' Arroyo Seco' , Facultad de Ciencias Exactas, U.N.C.P.B.A., Campus Universitario, Paraje Arroyo Seco, (B7000GHG) Tandil, Buenos Aires (Argentina)

    2011-01-01

    In this work, Laser-induced breakdown spectroscopy (LIBS) has been applied to characterization of plasmas generated in air at atmospheric pressure from a calcium hydroxide sample with a known concentration of Mg by using an infrared Nd:YAG laser. The influence of laser irradiance on plasma morphology and emission intensity was studied. Spatially-integrated intensities of Mg I-II lines along the line-of-sight were measured for different laser energies and delay times. The plasma temperature and the electron density were determined in each case by using and algorithm that calculates the optical thickness of the spectral lines and reproduces their experimental profiles in a framework of an homogeneous plasma in LTE that takes into account the effects of self-absorption. The results obtained showed the usefulness of this approach to provide additional information retrieved from the optical thickness of spectral lines for plasma characterization in LIBS experiments.

  10. Cadmium, copper, lead, and zinc determination in precipitation: A comparison of inductively coupled plasma atomic emission spectrometry and graphite furnace atomization atomic absorption spectrometry

    Science.gov (United States)

    Reddy, M.M.; Benefiel, M.A.; Claassen, H.C.

    1987-01-01

    Selected trace element analysis for cadmium, copper, lead, and zinc in precipitation samples by inductively coupled plasma atomic emission Spectrometry (ICP) and by atomic absorption spectrometry with graphite furnace atomization (AAGF) have been evaluated. This task was conducted in conjunction with a longterm study of precipitation chemistry at high altitude sites located in remote areas of the southwestern United States. Coefficients of variation and recovery values were determined for a standard reference water sample for all metals examined for both techniques. At concentration levels less than 10 micrograms per liter AAGF analyses exhibited better precision and accuracy than ICP. Both methods appear to offer the potential for cost-effective analysis of trace metal ions in precipitation. ?? 1987 Springer-Verlag.

  11. Using a squeezed field to protect two-atom entanglement against spontaneous emissions

    International Nuclear Information System (INIS)

    Tunable interaction between two atoms in a cavity is realized by interacting the two atoms with an extra controllable single-mode squeezed field. Such a controllable interaction can be further used to control entanglement between the two atoms against amplitude damping decoherence caused by spontaneous emissions. For the independent amplitude damping decoherence channel, entanglement will be lost completely without controls, while it can be partially preserved by the proposed strategy. For the collective amplitude damping decoherence channel, our strategy can enhance the entanglement compared with the uncontrolled case when the entanglement of the uncontrolled stationary state is not too large

  12. [Study of emission spectra of N atom generated in multi-needle-to-plate corona discharge].

    Science.gov (United States)

    Ge, Hui; Yu, Ran; Zhang, Lu; Mi, Dong; Zhu, Yi-Min

    2012-06-01

    The emission spectra of nitrogen (N) atom produced by multi-needle-to-plate negative corona discharge in air were detected successfully at one atmosphere, and the excited transition spectral line at 674.5 nm with maximum value of relative intensity was selected to investigate the influences of air and electrical parameters on N atom relative density. The results indicate that N atom relative density in ionization region increases with the increase in power; decreases with increasing discharge gap and relative humidity; and with the increase in N2 content, the relative density of N active atom firstly increases and then decreases. Under present experimental conditions, the maximum value of N atom relative density appears at the axial distance from needle point r = 1 mm. PMID:22870624

  13. Analytical computation of prompt gamma ray emission and detection for proton range verification

    International Nuclear Information System (INIS)

    A prompt gamma (PG) slit camera prototype recently demonstrated that Bragg Peak position in a clinical proton scanned beam could be measured with 1–2 mm accuracy by comparing an expected PG detection profile to a measured one. The computation of the expected PG detection profile in the context of a clinical framework is challenging but must be solved before clinical implementation. Obviously, Monte Carlo methods (MC) can simulate the expected PG profile but at prohibitively long calculation times. We implemented a much faster method that is based on analytical processing of precomputed MC data that would allow practical evaluation of this range monitoring approach in clinical conditions.Reference PG emission profiles were generated with MC simulations (PENH) in targets consisting of either 12C, 14N, 16O, 31P or 40Ca, with 10% of 1H. In a given geometry, the local PG emission can then be derived by adding the contribution of each element, according to the local energy of the proton obtained by continuous slowing down approximation and the local composition. The actual incident spot size is taken into account using an optical model fitted to measurements and by super sampling the spot with several rays (up to 113). PG transport in the patient/camera geometries and the detector response are modelled by convolving the PG production profile with a transfer function. The latter is interpolated from a database of transfer functions fitted to MC data (PENELOPE) generated for a photon source in a cylindrical phantom with various radiuses and a camera placed at various positions.As a benchmark, the analytical model was compared to MC and experiments in homogeneous and heterogeneous phantoms. Comparisons with MC were also performed in a thoracic CT. For all cases, the analytical model reproduced the prediction of the position of the Bragg peak computed with MC within 1 mm for the camera in nominal configuration. When compared to measurements, the shape of the profiles

  14. Analytical computation of prompt gamma ray emission and detection for proton range verification

    Science.gov (United States)

    Sterpin, E.; Janssens, G.; Smeets, J.; Vander Stappen, François; Prieels, D.; Priegnitz, Marlen; Perali, Irene; Vynckier, S.

    2015-06-01

    A prompt gamma (PG) slit camera prototype recently demonstrated that Bragg Peak position in a clinical proton scanned beam could be measured with 1-2 mm accuracy by comparing an expected PG detection profile to a measured one. The computation of the expected PG detection profile in the context of a clinical framework is challenging but must be solved before clinical implementation. Obviously, Monte Carlo methods (MC) can simulate the expected PG profile but at prohibitively long calculation times. We implemented a much faster method that is based on analytical processing of precomputed MC data that would allow practical evaluation of this range monitoring approach in clinical conditions. Reference PG emission profiles were generated with MC simulations (PENH) in targets consisting of either 12C, 14N, 16O, 31P or 40Ca, with 10% of 1H. In a given geometry, the local PG emission can then be derived by adding the contribution of each element, according to the local energy of the proton obtained by continuous slowing down approximation and the local composition. The actual incident spot size is taken into account using an optical model fitted to measurements and by super sampling the spot with several rays (up to 113). PG transport in the patient/camera geometries and the detector response are modelled by convolving the PG production profile with a transfer function. The latter is interpolated from a database of transfer functions fitted to MC data (PENELOPE) generated for a photon source in a cylindrical phantom with various radiuses and a camera placed at various positions. As a benchmark, the analytical model was compared to MC and experiments in homogeneous and heterogeneous phantoms. Comparisons with MC were also performed in a thoracic CT. For all cases, the analytical model reproduced the prediction of the position of the Bragg peak computed with MC within 1 mm for the camera in nominal configuration. When compared to measurements, the shape of the profiles

  15. Analytical computation of prompt gamma ray emission and detection for proton range verification.

    Science.gov (United States)

    Sterpin, E; Janssens, G; Smeets, J; Vander Stappen, François; Prieels, D; Priegnitz, Marlen; Perali, Irene; Vynckier, S

    2015-06-21

    A prompt gamma (PG) slit camera prototype recently demonstrated that Bragg Peak position in a clinical proton scanned beam could be measured with 1-2 mm accuracy by comparing an expected PG detection profile to a measured one. The computation of the expected PG detection profile in the context of a clinical framework is challenging but must be solved before clinical implementation. Obviously, Monte Carlo methods (MC) can simulate the expected PG profile but at prohibitively long calculation times. We implemented a much faster method that is based on analytical processing of precomputed MC data that would allow practical evaluation of this range monitoring approach in clinical conditions. Reference PG emission profiles were generated with MC simulations (PENH) in targets consisting of either (12)C, (14)N, (16)O, (31)P or (40)Ca, with 10% of (1)H. In a given geometry, the local PG emission can then be derived by adding the contribution of each element, according to the local energy of the proton obtained by continuous slowing down approximation and the local composition. The actual incident spot size is taken into account using an optical model fitted to measurements and by super sampling the spot with several rays (up to 113). PG transport in the patient/camera geometries and the detector response are modelled by convolving the PG production profile with a transfer function. The latter is interpolated from a database of transfer functions fitted to MC data (PENELOPE) generated for a photon source in a cylindrical phantom with various radiuses and a camera placed at various positions. As a benchmark, the analytical model was compared to MC and experiments in homogeneous and heterogeneous phantoms. Comparisons with MC were also performed in a thoracic CT. For all cases, the analytical model reproduced the prediction of the position of the Bragg peak computed with MC within 1 mm for the camera in nominal configuration. When compared to measurements, the shape of the

  16. Ultratrace determination of lead by hydride generation in-atomizer trapping atomic absorption spectrometry: Optimization of plumbane generation and analyte preconcentration in a quartz trap-and-atomizer device

    Czech Academy of Sciences Publication Activity Database

    Kratzer, Jan

    71-72, MAY-JUN (2012), s. 40-47. ISSN 0584-8547 R&D Projects: GA ČR(CZ) GPP206/11/P002 Institutional support: RVO:68081715 Keywords : hydride generation AAS * lead determination * trap-and-atomizer device Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.141, year: 2012

  17. Analytical Model of the Nonlinear Dynamics of Cantilever Tip-Sample Surface Interactions for Various Acoustic-Atomic Force Microscopies

    Science.gov (United States)

    Cantrell, John H., Jr.; Cantrell, Sean A.

    2008-01-01

    A comprehensive analytical model of the interaction of the cantilever tip of the atomic force microscope (AFM) with the sample surface is developed that accounts for the nonlinearity of the tip-surface interaction force. The interaction is modeled as a nonlinear spring coupled at opposite ends to linear springs representing cantilever and sample surface oscillators. The model leads to a pair of coupled nonlinear differential equations that are solved analytically using a standard iteration procedure. Solutions are obtained for the phase and amplitude signals generated by various acoustic-atomic force microscope (A-AFM) techniques including force modulation microscopy, atomic force acoustic microscopy, ultrasonic force microscopy, heterodyne force microscopy, resonant difference-frequency atomic force ultrasonic microscopy (RDF-AFUM), and the commonly used intermittent contact mode (TappingMode) generally available on AFMs. The solutions are used to obtain a quantitative measure of image contrast resulting from variations in the Young modulus of the sample for the amplitude and phase images generated by the A-AFM techniques. Application of the model to RDF-AFUM and intermittent soft contact phase images of LaRC-cp2 polyimide polymer is discussed. The model predicts variations in the Young modulus of the material of 24 percent from the RDF-AFUM image and 18 percent from the intermittent soft contact image. Both predictions are in good agreement with the literature value of 21 percent obtained from independent, macroscopic measurements of sheet polymer material.

  18. Mercury determination in non- and biodegradable materials by cold vapor capacitively coupled plasma microtorch atomic emission spectrometry

    International Nuclear Information System (INIS)

    Highlights: → Use of a miniaturized analytical system with microtorch plasma for Hg determination. → Determination of Hg in non- and biodegradable materials using cold vapor generation. → Figures of merit and advantages of the miniaturized system for Hg determination. - Abstract: A new analytical system consisting of a low power capacitively coupled plasma microtorch (20 W, 13.56 MHz, 150 ml min-1 Ar) and a microspectrometer was investigated for the Hg determination in non- and biodegradable materials by cold-vapor generation, using SnCl2 reductant, and atomic emission spectrometry. The investigated miniaturized system was used for Hg determination in recyclable plastics from electronic equipments and biodegradable materials (shopping bags of 98% biodegradable polyethylene and corn starch) with the advantages of easy operation and low analysis costs. Samples were mineralized in HNO3-H2SO4 mixture in a high-pressure microwave system. The detection limits of 0.05 ng ml-1 or 0.08 μg g-1 in solid sample were compared with those reported for other analytical systems. The method precision was 1.5-9.4% for Hg levels of 1.37-13.9 mg kg-1, while recovery in two polyethylene certified reference materials in the range 98.7 ± 4.5% (95% confidence level).

  19. Solid phase microextraction capillary gas chromatography combined with furnace atomization plasma emission spectrometry for speciation of mercury in fish tissues

    International Nuclear Information System (INIS)

    The use of solid phase microextraction in conjunction with tandem gas chromatography-furnace atomization plasma emission spectrometry (SPME-GC-FAPES) was evaluated for the determination of methylmercury and inorganic mercury in fish tissue. Samples were digested with methanolic potassium hydroxide, derivatized with sodium tetraethylborate and extracted by SPME. After the SPME extraction, species were separated by GC and detected by FAPES. All experimental parameters were optimized for best separation and analytical response. A repeatability precision of typically 2% can be achieved with long-term (3 months) reproducibility precision of 4.3%. Certified Reference Materials DORM-2, DOLT-2 and TORT-2 from the National Research Council of Canada were analyzed to verify the accuracy of this technique. Detection limits of 1.5 ng g-1 for methylmercury and 0.7 ng g-1 for inorganic mercury in biological tissues were obtained

  20. Fourier transform infrared emission spectra of atomic rubidium: g- and h-states

    Czech Academy of Sciences Publication Activity Database

    Civiš, Svatopluk; Ferus, Martin; Kubelík, Petr; Chernov, Vladislav E.; Zanozina, Ekaterina M.

    2012-01-01

    Roč. 45, č. 17 (2012), s. 175002. ISSN 0953-4075 R&D Projects: GA AV ČR IAAX00100903 Institutional support: RVO:61388955 Keywords : Fourier transform infrared emission spectra * atomic rubidium * physical chemistry Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.031, year: 2012

  1. Determination of serum lithium: comparison between atomic emission and absorption spectrometry methods

    Directory of Open Access Journals (Sweden)

    Carlos Elielton do Espírito Santo

    2014-02-01

    Full Text Available Introduction: The therapeutic monitoring of lithium, through concentration measurements, is important for individual dose adjustment, as a marker of treatment adherence and to prevent poisoning and side effects. Objectives: Validate and compare two methods - atomic emission and atomic absorption - for the determination of lithium in serum samples. Methodology: Parameters such as specificity, precision, accuracy, limit of detection (LOD and linearity were considered. The atomic absorption spectrometer was used, operating in either emission or absorption mode. For the quantitative comparison of 30 serum samples from patients with mood disorder treated with lithium, the results were submitted to Student's t-test, F-test and Pearson's correlation. Results: The limit of quantification (LOQ was established as 0.05 mEq/l of lithium, and calibration curves were constructed in the range of 0.05-2 mEq/l of lithium, using aqueous standards. Sample preparation time was reduced, what is important in medical laboratory. Conclusion: Both methods were considered satisfactory, precise and accurate and can be adopted for lithium quantification. In the comparison of quantitative results in lithium-treated patients through statistical tests, no significant differences were observed. Therefore the methods for lithium quantification by flame atomic absorption spectrometry (FAAS and flame atomic emission spectrometry (FAES may be considered similar.

  2. Parity violating radiative emission of neutrino pair in heavy alkaline earth atoms of even isotopes

    CERN Document Server

    Yoshimura, M; Uetake, S

    2014-01-01

    Metastable excited states ${}^3P_2, {}^3P_0$ of heavy alkaline earth atoms of even isotopes are studied for parity violating (PV) effects in radiative emission of neutrino pair (RENP). PV terms arise from interference between two diagrams containing neutrino pair emission of valence spin current and nuclear electroweak charge density proportional to the number of neutrons in nucleus. This mechanism gives large PV effects, since it does not suffer from the suppression of 1/(electron mass) usually present for non-relativistic atomic electrons. A controllable magnetic field is crucial to identify RENP process by measuring PV observables. Results of PV asymmetries under the magnetic field reversal and the photon circular polarization reversal are presented for an example of Yb atom.

  3. Determination of noble metals by Inductively Coupled Plasma Atomic Emission Spectrometry

    International Nuclear Information System (INIS)

    Full text: It is well known that significant quantities of soluble fission products such as La, Ce, Pr, Eu, Gd, Sm and noble metals such as Ag, Pt, Au, Ru, Rh, Pd are produced in the spent fuel dissolver solutions, in nuclear reactors. The recovery of noble metals from generated high level waste assumes importance in view of their usage in chemical and electronic industries. In the present work, Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) technique has been explored to determine six noble metals in aqueous solutions. Synthetic solution standards containing individually Ag, Au, Pt, Pd, Rh and Ru in the range of 1-500 μg/mL were prepared. Individual elemental solutions at 100μg/mL were fed in to the plasma. The instrumental parameters were obtained for positioning of the analytical line with appropriate sensitivity on the photomultiplier tube. The prominent ICP lines reported in literature in decreasing order of sensitivities for Au are 242.745, 267.895, 197.819, 208.219 nm; Ru are 240.272, 245.657, 267.876 nm; for Rh are 233.477, 249.077, 343.419, 252.053 nm and for Pt are 214.423, 203.646, 214.937 nm respectively. Of these the lines shown in bold are only accessible with the axial ICP unit used in these studies. In addition less sensitive lines in the polyscan mode were chosen, where one can access an elemental line 2.2 nm on either side of the analytical channel provided in polychromator of the instrument. The lines chosen in the polyscan are: Pt 306.471, Ru 249.877 and Rh at 343.489 nm. For Ag and Pd the lines at 328.068 nm and 340.458 nm available with the polychromator of the ICP unit were used. A three point standardization containing the analytes in the concentration range of 0.1 to 200 μg/mL was used. The detection limits determined as per the IUPAC convention for these elements are given. The analytical range for Ag and Pd were 0.05-200 μg/mL while for other elements viz: Au, Pt, Rh and Ru it was 0.5-500 μg/mL . Synthetic samples

  4. Emission of energetic neutral atoms from water ice under Ganymede surface-like conditions

    Science.gov (United States)

    Wieser, Martin; Futaana, Yoshifumi; Barabash, Stas; Wurz, Peter

    2016-05-01

    The co-rotating plasma around Jupiter precipitates on the surfaces of the jovian moons, where it is not hindered by a local magnetic field. Precipitating ions lead to the emission of energetic neutral atoms, which are produced via backscattering and sputtering processes, from the surface. The European Space Agency's JUICE mission to Jupiter carries as part of the Particle Environment Package experiment an imaging energetic neutral atom spectrometer called the jovian Neutrals Analyzer (JNA). When it is in orbit around Ganymede, JNA will measure the energetic neutral atom flux emitted from the surface of Ganymede in the energy range from 10 eV to 3300 eV. The surface of Ganymede consists of a large fraction of water ice. To characterize the expected energetic neutral atom fluxes from water ice due to precipitating jovian plasma, we impacted protons and singly charged oxygen ions with energies up to 33 keV on a salty water ice target kept at Ganymede surface conditions. Emitted energetic atoms were measured energy- and mass-resolved using the JNA prototype instrument. The data show high yields for energetic neutral atoms per incident ion in the JNA energy range. For incident protons, energetic neutral atom yields between 0.28 at 1 keV and ∼40 at 33 keV were observed. For incident singly charged oxygen ions, the observed energetic neutral atom yield ranged from 0.8 for at 3 keV to ∼170 at 23 keV.

  5. Model for Atomic Oxygen Visible Line Emissions in Comet C/1995 O1 Hale-Bopp

    CERN Document Server

    Raghuram, Susarla

    2012-01-01

    We have recently developed a coupled chemistry-emission model for the green and red-doublet emissions of atomic oxygen on comet Hyakutake. In the present work we applied our model to comet Hale-Bopp, which had an order of magnitude higher H2O production rate than comet Hyakutake, to evaluate the photochemistry associated with the production and loss of O(1S) and O(1D) atoms and emission processes of green and red-doublet lines. We present the wavelength-dependent photo-attenuation rates for different photodissociation processes forming O(1S) and O(1D). The calculated radiative efficiency profiles of O(1S) and O(1D) atoms show that in comet Hale-Bopp the green and red-doublet emissions are emitted mostly above radial distances of 10^3 and 10^4 km, respectively. The model calculated [OI] 6300 A emission surface brightness and average intensity over the Fabry-P{\\'e}rot spectrometer field of view are consistent with the observation of Morgenthaler et al. (2001), while the intensity ratio of green to red-doublet e...

  6. On the deviation from the sech2 superradiant emission law in a two-level atomic system

    International Nuclear Information System (INIS)

    The atomic superradiant emission is treated in the single particle mean field approximation. A single particle Hamiltonian, which represents a dressed two-level atom in a radiation field, can be obtained and it is verified that it describes the transient regime of the emission process. While the line shape emission for a bare atom follows the sech2 law, for the dressed atom the line shape deviates appreciably from this law and it is verified that the deviation depends crucially on the ratio of the dynamic frequency shift to the transition frequency. This kind of deviation is observed in experimental results. (Author)

  7. Control of spontaneous emission from a microwave-field-driven four-level atom in an anisotropic photonic crystal

    International Nuclear Information System (INIS)

    The spontaneous emission properties of a microwave-field-driven four-level atom embedded in anisotropic double-band photonic crystals (PCs) are investigated. We discuss the influences of the band-edge positions, Rabi frequency and detuning of the microwave field on the emission spectrum. It is found that several interesting features such as spectral-line enhancement, spectral-line suppression, spectral-line overlap, and multi-peak structures can be observed in the spectra. The proposed scheme can be achieved by use of a microwave-coupled field into hyperfine levels in rubidium atom confined in a photonic crystal. These theoretical investigations may provide more degrees of freedom to manipulate the atomic spontaneous emission. -- Highlights: ► Spontaneous emission properties of an atom embedded in PCs are investigated. ► Spectral-line enhancement, suppression and overlapping are observed. ► The results provide more degrees of freedom to control atomic spontaneous emission.

  8. Angle-resolved 2D imaging of electron emission processes in atoms and molecules

    International Nuclear Information System (INIS)

    A variety of electron emission processes have been studied in detail for both atomic and molecular systems, using a highly efficient experimental system comprising two time-of-flight (TOF) rotatable electron energy analyzers and a 3rd generation synchrotron light source. Two examples are used here to illustrate the obtained results. Firstly, electron emissions in the HCL molecule have been mapped over a 14 eV wide photon energy range over the Cl 2p ionization threshold. Particular attention is paid to the dissociative core-excited states, for which the Auger electron emission shows photon energy dependent features. Also, the evolution of resonant Auger to the normal Auger decay distorted by post-collision interaction has been observed and the resonating behavior of the valence photoelectron lines studied. Secondly, an atomic system, neon, in which excitation of doubly excited states and their subsequent decay to various accessible ionic states has been studied. Since these processes only occurs via inter-electron correlations, the many body dynamics of an atom can be probed, revealing relativistic effects, surprising in such a light atom. Angular distribution of the decay of the resonances to the parity unfavored continuum exhibits significant deviation from the LS coupling predictions

  9. Spontaneous emission spectrum of a three-level atom embedded in photonic crystal

    Institute of Scientific and Technical Information of China (English)

    刘国强; 王健; 张汉壮

    2005-01-01

    The two models of three-level (one upper level and two lower levels, or two upper levels and one lower level) atom embedded in a double-band photonic crystal are adopted. The atomic transitions from the upper levels to the lower levels are assumed to be coupled by the same reservoir which are respectively the isotropic photonic band gap (PBG)modes, the anisotropic PBG modes and the free vacuum modes. The effects of the fine structure of the atomic ground state levels in the model with one upper level and two lower levels, and the quantum interferences in the model with two upper levels and one lower level on the spontaneous emission spectrum of an atom are investigated in detail. Most interestingly, it is shown that new spontaneous emission lines are produced from the fine splitting of atomic ground state levels in the isotropic PBG case. The quantum interferences induce additional narrow spontaneous lines near the transition from the empty upper level to the lower level.

  10. Charging Induced Emission of Neutral Atoms from NaCl Nanocube Corners

    OpenAIRE

    Ceresoli, Davide; Zykova-Timan, Tatyana; Tosatti, Erio

    2008-01-01

    Detachment of neutral cations/anions from solid alkali halides can in principle be provoked by donating/subtracting electrons to the surface of alkali halide crystals, but generally constitutes a very endothermic process. However, the amount of energy required for emission is smaller for atoms located in less favorable positions, such as surface steps and kinks. For a corner ion in an alkali halide cube the binding is the weakest, so it should be easier to remove that atom, once it is neutral...

  11. Ultra fast atomic process in X-ray emission by inner-shell ionization

    Energy Technology Data Exchange (ETDEWEB)

    Moribayashi, Kengo; Sasaki, Akira [Japan Atomic Energy Research Inst., Neyagawa, Osaka (Japan). Kansai Research Establishment; Tajima, T.

    1998-03-01

    An ultra-fast atomic process together with X-ray emission by inner-shell ionization using high intensity (10{sup 18} W/cm{sup 2}) short pulse (20fs) X-ray is studied. A new class of experiment is proposed and a useful pumping source is suggested. In this method, it is found that the gain value of X-ray laser amounts to larger than 1000(1/cm) with use of the density of 10{sup 22}/cm{sup 3} of carbon atom. Electron impact ionization effect and initial density effect as well as intensity of pumping source effect are also discussed. (author)

  12. Determination of Mercury in Milk by Cold Vapor Atomic Fluorescence: A Green Analytical Chemistry Laboratory Experiment

    Science.gov (United States)

    Armenta, Sergio; de la Guardia, Miguel

    2011-01-01

    Green analytical chemistry principles were introduced to undergraduate students in a laboratory experiment focused on determining the mercury concentration in cow and goat milk. In addition to traditional goals, such as accuracy, precision, sensitivity, and limits of detection in method selection and development, attention was paid to the…

  13. Photochemistry of atomic oxygen green and red-doublet emissions in comets at larger heliocentric distances

    CERN Document Server

    Raghuram, Susarla

    2014-01-01

    In comets the atomic oxygen green to red-doublet emission intensity ratio (G/R ratio) of 0.1 has been used to confirm H$_2$O as the parent species producing oxygen emission lines. The larger ($>$0.1) value of G/R ratio observed in a few comets is ascribed to the presence of higher CO$_2$ and CO relative abundances in the cometary coma. We aim to study the effect of CO$_2$ and CO relative abundances on the observed G/R ratio in comets observed at large ($>$2 au) heliocentric distances by accounting for important production and loss processes of O($^1$S) and O($^1$D) in the cometary coma. Recently we have developed a coupled chemistry-emission model to study photochemistry of O($^1$S) and O($^1$D) atoms and the production of green and red-doublet emissions in comets Hyakutake and Hale-Bopp. In the present work we applied the model to six comets where green and red-doublet emissions are observed when they are beyond 2 au from the Sun. In a water-dominated cometary coma and with significant ($>$10%) CO$_2$ relati...

  14. Determination of heavy metals in solid emission and immission samples using atomic absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fara, M.; Novak, F. [EGU Prague, PLC, Bichovice, Prague (Czechoslovakia)

    1995-12-01

    Both flame and electrothermal methods of atomic absorption spectroscopy (AAS) have been applied to the determination of Al, As, Be, Ca, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, TI, Se, V and Zn in emission and emission (deposition) samples decomposed in open PTFE test-tubes by individual fuming-off hydrofluoric, perchloroic and nitric acid. An alternative hydride technique was also used for As and Se determination and Hg was determined using a self-contained AAS analyzer. A graphite platform proved good to overcome non-spectral interferences in AAS-ETA. Methods developed were verified by reference materials (inc. NBS 1633a).

  15. Flow Injection and Atomic Absorption Spectrometry - An Effective and Attractive Analytical Chemical Combination

    DEFF Research Database (Denmark)

    Hansen, Elo Harald; Nielsen, Steffen

    1998-01-01

    One of the advantages of the flow injection (FI) concept is that it is compatible with virtually all detection techniques. Being a versatile vehicle for enhancing the performance of the individual detection devices, the most spectacular results have possibly been obtained in conjunction with atomic...

  16. Secondary electron emission from Au by medium energy atomic and molecular ions

    CERN Document Server

    Itoh, A; Obata, F; Hamamoto, Y; Yogo, A

    2002-01-01

    Number distributions of secondary electrons emitted from a Au metal surface have been measured for atomic and molecular ions of H sup + , He sup + , C sup + , N sup + , O sup + , H sup + sub 2 , H sup + sub 3 , HeH sup + , CO sup + and O sup + sub 2 in the energy range 0.3-2.0 MeV. The emission statistics obtained are described fairly well by a Polya function. The Polya parameter b, determining the distribution shape, is found to decrease monotonously with increasing emission yield gamma, revealing a surprising relationship of b gamma approx 1 over the different projectile species and impact energies. This finding supports certainly the electron cascading model. Also we find a strong negative molecular effect for heavier molecular ions, showing a significant reduction of gamma compared to the estimated values using constituent atomic projectile data.

  17. X-ray emission simulation from hollow atoms produced by high intensity laser irradiation

    International Nuclear Information System (INIS)

    We theoretically study the x-ray emission from hollow atoms produced by collisions of multiply charged ions accelerated by a short pulse laser with a solid or foil. By using the multistep-capture-and-loss (MSCL) model a high conversion efficiency to x-rays in an ultrafast atomic process is obtained. It is also proposed to apply this x-ray emission process to the x-ray source. For a few keV x-rays this x-ray source has a clear advantage. The number of x-ray photons increases as the laser energy becomes larger. For a laser energy of 10 J, the number of x-ray photons of 3x1011 is estimated. (author)

  18. In-situ vaporization and matrix removal for the determination of rare earth impurities in zirconium dioxide by electrothermal vaporization inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    A novel method for the determination of trace rare earth impurities in ZrO2 powder has been developed based on electrothermal vaporization inductively coupled plasma atomic emission spectrometry. A polytetrafluoroethylene slurry was used as a fluorinating reagent to convert both the matrix (Zr) and the analytes (rare earth elements) into fluorides with different volatilities at a high temperature in a graphite furnace. The more volatile ZrF4 was removed in-situ by selective vaporization prior to the determination of the analytes, removing matrix spectral interferences. Under optimum operating conditions, the absolute detection limits of the analytes varied from 0.04 ng (Yb) to 0.50 ng (Pr) with relative standard deviations less than 5%. The recommended approach has been successfully applied to the determination of trace rare earth impurities (La, Pr, Eu, Gd, Ho and Yb) in ZrO2 powder and the results were in good agreement with those obtained by pneumatic nebulization inductively coupled plasma atomic emission spectrometry after the separation of the matrix using a solvent extraction procedure

  19. A Radiative Cycle with Stimulated Emission from Atoms (Ions) in an astrophysical Plasma

    OpenAIRE

    Johansson, S.; Letokhov, V. S.

    2002-01-01

    We propose that a radiative cycle operates in atoms (ions) located in a rarefied gas in the vicinity of a hot star. Besides spontaneous transitions the cycle includes a stimulated transition in one very weak intermediate channel. This radiative "bottle neck" creates a population inversion, which for an appropriate column density results in amplification and stimulated radiation in the weak transition. The stimulated emission opens a fast decay channel leading to a fast radiative cycle in the ...

  20. Analytical investigation of the feasibility of sacrificial microchannel sealing for Chip-Scale Atomic Magnetometers

    OpenAIRE

    Tsujimoto, Kazuya; Hirai, Yoshikazu; Sugano, Koji; Tsuchiya, Toshiyuki; TABATA, Osamu

    2014-01-01

    An alkali metal vapor cell is a crucial component of the highly sensitive Chip Scale Atomic Magnetometers (CSAMs) that are increasingly deployed in a variety of electronic devices. Herein, we propose a novel microfabrication technique utilizing an array of microchannels at a bonded interface, to enable gas feedthrough for evacuation of unwanted gases from a vapor cell and subsequent introduction of an inert gas, followed by permanent sealing of the microchannels by reflow of a glass frit. The...

  1. Sputtering of copper atoms by keV atomic and molecular ions A comparison of experiment with analytical and computer based models

    CERN Document Server

    Gillen, D R; Goelich,

    2002-01-01

    Non-resonant multiphoton ionisation combined with quadrupole and time-of-flight analysis has been used to measure energy distributions of sputtered copper atoms. The sputtering of a polycrystalline copper target by 3.6 keV Ar sup + , N sup + and CF sub 2 sup + and 1.8 keV N sup + and CF sub 2 sup + ion bombardment at 45 deg. has been investigated. The linear collision model in the isotropic limit fails to describe the high energy tail of the energy distributions. However the TRIM.SP computer simulation has been shown to provide a good description. The results indicate that an accurate description of sputtering by low energy, molecular ions requires the use of computer simulation rather than analytical approaches. This is particularly important when considering plasma-surface interactions in plasma etching and deposition systems.

  2. Optimization and development of the instrumental parameters for a method of multielemental analysis through atomic spectroscopy emission, for the determination of My, Fe Mn and Cr

    International Nuclear Information System (INIS)

    This study optimized the instrumental parameters of a method of multielemental (sequential) analysis, through atomic emission, for the determination of My, Fe,Mn and Cr. It used the factorial design at two levels and the method of Simplex optimization, that permitted the determination of the four cations under the same instrumental conditions. The author studied an analytic system, in which the conditions were not lineal between instrumental answers and the concentration, having to make adjustment of the calibration curves in homocedastic and heterocedastic conditions. (S. Grainger)

  3. International Atomic Energy Agency consultants' meeting on Analytical Quality Control Services, Vienna, 17-19 September 1990

    International Nuclear Information System (INIS)

    An International Atomic Energy Agency Consultants' Meeting on Analytical Quality Control Services was held at the Vienna International Center 17-19 September 1990. The Consultants generally conclude that the current methods of the preparation of the materials for intercomparison studies and facilities are adequate for the current Agency mission for trace element and radionuclide materials, but it is suggested that freeze-drying facilities for biological materials are needed. This is critically important for many of the collected materials uniquely important to the Agency mission. Also new equipment for automated sieving analysis be acquired for some applications. Homogeneity testing performed by AQCS includes the determination of several trace elements (radionuclides) of different concentrations of several sub-samples taken from one bottle and the results are compared with those obtained for sub-samples taken from various bottles chosen at random using one way analysis of variance. This procedure is found to be appropriate and could be used further. TC and CRP should be promoted in relation to the development of reliable analytical methods for the determination of so called ''difficult elements'' like: Mo, Al, I, F, Li, Co, Cd and Ni as well as 237Np, 226Ra, 228Ra. Intercomparison runs should stay open to the whole international community although it would be desirable to consult ''reference labs'' for the certification of selected (''difficult'') analytes. The presently employed programme for intercomparison studies for data evaluation are valuable and suitable. Refs, figs and tabs

  4. Atoms

    Institute of Scientific and Technical Information of China (English)

    刘洪毓

    2007-01-01

    Atoms(原子)are all around us.They are something like the bricks (砖块)of which everything is made. The size of an atom is very,very small.In just one grain of salt are held millions of atoms. Atoms are very important.The way one object acts depends on what

  5. Spectral profile of atomic emission lines and effects of pulse duration on laser ablation in liquid

    International Nuclear Information System (INIS)

    The emission spectra of laser-ablated Cu atoms in water were examined, focusing on the irradiation-pulse duration effects. Spectral line profile was observed for the pulse duration of 19, 90, and 150 ns at various delay times. The line width as narrow as instrumental width was obtained by 150-ns pulse at the delay time of 800 ns. Also, long pulses result in high intensity of the emission. The spectral feature obtained by long pulses looks similar to that obtained in a gas phase. The absorption of the later part of the long pulse directly by the plume having been formed by the earlier part of the pulse may be the cause of this gas-phase-like emission. Whether the pulse heats directly the surface or the plume was investigated by the measurements of the removal volume of the ablation pit obtained by laser confocal scanning microscopy and the maximum bubble expansion size observed by shadowgraphy.

  6. Relativistic theory for radiative forward electron emission in heavy ion-atom encounters

    Science.gov (United States)

    Jakubaßa-Amundsen, Doris; Müller, Robert; Surzhykov, Andrey; Yerokhin, Vladimir

    2014-12-01

    The forward electron emission with simultaneous photon production during the scattering of relativistic, highly stripped projectiles from light target atoms is calculated within the Dirac theory. The method of calculation is a simplification of the impulse approximation and is based on the relation of the cross section for radiative capture to continuum of loosely bound electrons to the frame-transformed electron bremsstrahlung cross section. It is demonstrated that such an approximation is well justified in a large region of energies and photon emission angles, with the exception of the extreme forward and backward emission and the soft-photon energy limit. The cusp spectrum and the corresponding angular distribution are compared to recent experimental data for the collision system 90.38 MeV/amu U88+ + N2.

  7. Fusion plasma diagnostics by means of atomic emissions in X-ray range

    International Nuclear Information System (INIS)

    ITER, a fusion reactor will also provide an ample opportunity for advance atomic physic data and understanding. The fusion plasma interactions with the internal machine components will release particles. These impurity elements of low to high atomic numbers, once enter into the plasma boundary and as transport towards the core will undergo numerous atomic processes like excitation, relaxation, recombination, or ionization; and will result in line and continuum emissions from the impurity atoms or ions. Currently application of Tungsten as diverter material is foreseen for ITER. So, there is a need of advancement in atomic modelling for Tungsten as enabling optical and spectroscopy diagnostic designs require extensive simulation data from the emission modelling. India is responsible for delivering two X-ray Crystal Spectrometers to ITER which are based on X-ray spectroscopy (XRCS) of Hydrogen or Helium like ions of low or high Z impurities in the plasmas. The XRCS-Survey, a broad-band X-ray spectrometer, is one of the important diagnostic systems which will be put in the first set of diagnostics on ITER helping the start-up of the plasma operations. The primary function of this spectrometer will be to accurately measure plasma impurity concentration and their in-flux at fast enough rates in order to protect and/or control the machine during all phases of the ITER operations. The XRCS-Edge, a modified Johann spectrometer, is dedicated to measure profiles of ion temperature and poloidal rotation velocity in the plasma edge regions. Edge spectrometer is mainly required for advanced plasma control and will provide valuable data for edge pedestal physics. These systems will have to reliably function in the high neutron environment of the ITER. Preliminary design of the spectrometers is currently on-going and performance has been simulated with the impurity emission data modelled with ADAS atomic database and SANCO impurity transport code. This presentation will focus on

  8. Optical Emission Spectroscopic Measurement of Hydroxyl Radicals in Air Discharge with Atomized Water%Optical Emission Spectroscopic Measurement of Hydroxyl Radicals in Air Discharge with Atomized Water

    Institute of Scientific and Technical Information of China (English)

    孙明; 陈维刚; 张颖

    2011-01-01

    Effects of discharge mode, voltage applied, size of the nozzle discharge electrode and flow rate of water on the generation of hydroxyl radical were investigated in air discharge with atomized water, by using optical emission spectroscopy (OES). Water was injected into the discharge region through the discharge nozzle electrode, and a large amount of fine water drops, formed and distributed in the discharge region, corona discharge was more effective to generate were observed. It was found that negative DC the hydroxyl radicals in comparison to positive DC corona discharge or negative pulsed discharge. A larger outer diameter of the nozzle electrode or a stronger electric field is beneficial for hydroxyl-radical generation. Moreover, there is a critical value in the flow rate of atomized water against the discharge voltage. Below this critical value, hydroxyl-radical generation increases with the increase in flow rate of the water, while above this value, it decreases. In addition, it is observed that OES from the discharge is mainly in the ultraviolet domain. The results are helpful in the study of the mechanism and application of plasma in pollution-control in either air or water.

  9. 7th Czechoslovak spectroscopic conference and VIIIth CANAS (Conference on analytical atomic spectroscopy). Abstracts. Vol. 2

    International Nuclear Information System (INIS)

    The conference on spectroscopy held in Ceske Budejovice on June 18-22, 1984, proceeded in three sessions: atomic spectroscopy, molecular spectroscopy and special spectroscopic techniques. In the molecular spectroscopy session, 81 papers were read of which 12 were inputted in INIS. The subject of inputted papers was the use of NMR for the analysis of organic compounds and for the study of radiation defects in semiconductors, and the use of infrared spectroscopy for the analysis of nuclear and irradiated materials. (J.P.)

  10. Analytical modelling of acoustic emission from buried or surface-breaking cracks under stress

    International Nuclear Information System (INIS)

    Acoustic emission (AE) is a non-destructive testing method used in various industries (aerospace, petrochemical and pressure-vessel industries in general, power generation, civil engineering, mechanical engineering, etc...) for the examination of large structures subjected to various stresses (e.g. mechanical loading).The energy released by a defect under stress (the AE phenomenon) can propagate as guided waves in thin structures or as surface Rayleigh waves in thick ones. Sensors (possibly permanently) are positioned at various locations on the structure under examination and are assumed to be sensitive to these waves. Then, post-processing tools typically based on signal processing and triangulation algorithms can be used to inverse these data, allowing one to estimate the position of the defect from which emanates the waves measured. The French Atomic Energy Commission is engaged in the development of tools for simulating AE examinations. These tools are based on specific models for the AE sources, for the propagation of guided or Rayleigh waves and for the behaviour of AE sensors. Here, the coupling of a fracture mechanics based model for AE source and surface/guided wave propagation models is achieved through an integral formulation relying on the elastodynamic reciprocity principle. As a first approximation, a simple piston-like model is used to predict the sensitivity of AE sensors. Predictions computed by our simulation tool are compared to results from the literature for validation purpose.

  11. Atoms

    International Nuclear Information System (INIS)

    Completed by recent contributions on various topics (atoms and the Brownian motion, the career of Jean Perrin, the evolution of atomic physics since Jean Perrin, relationship between scientific atomism and philosophical atomism), this book is a reprint of a book published at the beginning of the twentieth century in which the author addressed the relationship between atomic theory and chemistry (molecules, atoms, the Avogadro hypothesis, molecule structures, solutes, upper limits of molecular quantities), molecular agitation (molecule velocity, molecule rotation or vibration, molecular free range), the Brownian motion and emulsions (history and general features, statistical equilibrium of emulsions), the laws of the Brownian motion (Einstein's theory, experimental control), fluctuations (the theory of Smoluchowski), light and quanta (black body, extension of quantum theory), the electricity atom, the atom genesis and destruction (transmutations, atom counting)

  12. Study of emission episodes of urban aerosol by ion beam analytical techniques

    International Nuclear Information System (INIS)

    Complete text of publication follows. Aerosol pollution has impact on the climate and on human health. Thus investigation of atmospheric aerosol is important in urban environment such as Debrecen. One of the main goals of our study was to define the sources of the particles. The hourly evolution of atmospheric aerosol concentration was used to identify sources of fine (aerodynamic diameter < 2,5 μm) and coarse (10 μm ≥ aerodynamic diameter ≥ 2.5 μm) urban particulate matter in Debrecen. In both size fractions sources were found which were characterized by high heavy metal content. In this study we provide accurate information of the sources of coarse mode heavy metals by using nuclear and scanning electron microscopy. Single particle analysis of chosen samples was carried out on the ATOMKI Scanning Nuclear Microprobe Facility. Elemental composition for Z ≥ 6, morphology and size of around 500 coarse mode particles were determined by Scanning Transmission Ion Microscopy, light-element PIXE and PIXE analytical methods. Furthermore Scanning Electron Microscopy (SEM) was used to investigate particles morphology. The main components of the particles were Na, K, Ca, S, P and Fe with traces of Ti, V, Cr, Mn, Ni, Cu, Zn, Co, Pb. S-rich particles were enriched in one or more of the following elements: Na, Ca, K, Fe, Zn. Trace metals (Mn, Cu, Zn, Cr) occurred together Fe supposedly originated from industrial emission or traffic. P appeared in the Ca-rich particles. Particles with high concentration of Ni were rich in V, Fe and S. Thus this source was identified as residual combustion. V-rich particles occurred together with Fe, Mn and Cr. Their possible source was industry. Pb was attached to Ca, Fe, S containing particles. As result of the SEM study the following particle types (Figure 1.) were identified: semitransparent material (S-K-rich, S-Zn-rich, PCa-rich), spherical (FeO, Fe-Ni-Cr-V-rich), cubic (KCl, CaCl) and crystalline (S-Ca-rich). The main sources of

  13. A device for automatic photoelectric control of the analytical gap for emission spectrographs

    Science.gov (United States)

    Dietrich, John A.; Cooley, Elmo F.; Curry, Kenneth J.

    1977-01-01

    A photoelectric device has been built that automatically controls the analytical gap between electrodes during excitation period. The control device allows for precise control of the analytical gap during the arcing process of samples, resulting in better precision of analysis.

  14. Two-photon ionization rates of atomic hydrogen: comparison of numerical and analytical techniques

    International Nuclear Information System (INIS)

    The photoionization rate and emitted electron angular distribution were computed for ground-state atomic hydrogen, in the two-photon regime (6.80--13.6 eV), for laser irradiances between 1013 and 1015 W/cm2, and for linear polarization. A direct numerical solution of the time-dependent Schroedinger equation (TDSE) was performed by a standard method and with slow laser turnon and turnoff pulse-envelope switching functions incorporated. Comparison is made with the predictions of a two-photon ionization rate formula, as described by Klarsfeld [Lett. Nuovo Cimemto 3, 395 (1970)] in second-order perturbation theory, into which a resonance width and threshold shift were inserted. Under the conditions of this problem the width was dominated by the one-photon Rabi rate, and the threshold shift by the ponderomotive energy. Photoionization rates and angular distributions determined from the TDSE agreed well with the values obtained from the extended Klarsfeld formula

  15. Consistent Analytic Embedded Atom Potential for Face-Centered Cubic Metals and Alloys

    Institute of Scientific and Technical Information of China (English)

    Iyad A. Hijazi; Young Ho Park

    2009-01-01

    A consistent empirical embedded-atom potential that includes a long range force was developed for fcc (face-centered cubic) metals and alloys. The proposed potential for pure metals does not require modification of the initial function form when being applied to alloy systems. The potential parameters of this model were determined by fitting lattice constant, three elastic constants, cohesive energy, and vacancy formation energies of the pure metals and the heats of solution of the binary alloys via an optimization technique. Parameters for Ag, Al, Au, Cu, Ni, Pd and Pt were obtained. The obtained parameters were used to calculate the bulk modulus, divacancy formation energy, crystal stability, stacking fault energy, vacancy migration energy, and melting point for each pure metal and the heats of formation and lattice constants for binary alloys. The predicted values were in good agreement with experimental results.

  16. Halogenated salicylaldehyde azines: The heavy atom effect on aggregation-induced emission enhancement properties

    International Nuclear Information System (INIS)

    This study investigates the heavy-atom effect (HAE) on aggregation-induced emission enhancement (AIEE) properties of salicylaldehyde azines. For this purpose, a series of halogenated salicylaldehyde azine derivatives, namely, chloro-salicylaldehyde azine (1), bromo-salicylaldehyde azine (2) and iodo-salicylaldehyde azine (3) are synthesized. 1 and 2 display typical AIEE characteristics of salicylaldehyde azine compounds; whereas for the iodo-substituent in 3, is found to be effective “external” heavy atom quenchers to salicylaldehyde azine fluorescence in aggregated state. Based on its weak fluorescence in aggregated state and relative strong fluorescence in dispersed state, 3 can also be applied as a turn-on fluorescence probe for egg albumin detection attributed to hydrophobic interaction. -- Highlights: • This study investigates the heavy-atom effect (HAE) on aggregation-induced emission enhancement (AIEE) properties of salicylaldehyde azines. • Chloro- and bromo-salicylaldehyde display typical AIEE properties of salicylaldehyde azine, whereas the iodo-substitute quenches AIEE in aggregated state. • Iodo-salicylaldehyde can be applied as a turn-on fluorescence probe for egg albumin detection attributed to hydrophobic interaction

  17. Halogenated salicylaldehyde azines: The heavy atom effect on aggregation-induced emission enhancement properties

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiao-tong, E-mail: chenxiaotong@tsinghua.edu.cn [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Tong, Ai-jun [Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084 (China)

    2014-01-15

    This study investigates the heavy-atom effect (HAE) on aggregation-induced emission enhancement (AIEE) properties of salicylaldehyde azines. For this purpose, a series of halogenated salicylaldehyde azine derivatives, namely, chloro-salicylaldehyde azine (1), bromo-salicylaldehyde azine (2) and iodo-salicylaldehyde azine (3) are synthesized. 1 and 2 display typical AIEE characteristics of salicylaldehyde azine compounds; whereas for the iodo-substituent in 3, is found to be effective “external” heavy atom quenchers to salicylaldehyde azine fluorescence in aggregated state. Based on its weak fluorescence in aggregated state and relative strong fluorescence in dispersed state, 3 can also be applied as a turn-on fluorescence probe for egg albumin detection attributed to hydrophobic interaction. -- Highlights: • This study investigates the heavy-atom effect (HAE) on aggregation-induced emission enhancement (AIEE) properties of salicylaldehyde azines. • Chloro- and bromo-salicylaldehyde display typical AIEE properties of salicylaldehyde azine, whereas the iodo-substitute quenches AIEE in aggregated state. • Iodo-salicylaldehyde can be applied as a turn-on fluorescence probe for egg albumin detection attributed to hydrophobic interaction.

  18. Nonthermal Optical Emission Spectrometry: Direct Atomization and Excitation of Cadmium for Highly Sensitive Determination.

    Science.gov (United States)

    Cai, Yi; Zhang, Ya-Jie; Wu, De-Fu; Yu, Yong-Liang; Wang, Jian-Hua

    2016-04-19

    The low atomization and excitation capability of nonthermal microplasma, e.g., dielectric barrier discharge (DBD), has greatly hampered its potential applications for the determination of metals in solution. In the present work, an inspiring development is reported for direct atomization and excitation of cadmium in aqueous solution by DBD and facilitates highly sensitive determination. A DBD microplasma is generated on the nozzle of a pneumatic micronebulizer to focus the DBD energy on a confined space and atomize/excite metals in the spray. Meanwhile, an appropriate sample matrix and nebulization in helium further improves the atomization and excitation capability of DBD. With cadmium as a model, its emission is recorded by a CCD spectrometer at 228.8 nm. By using an 80 μL sample solution nebulized at 3 μL s(-1), a linear range of 5-1000 μg L(-1) along with a detection limit of 1.5 μg L(-1) is achieved, which is comparable to those obtained by commercial bulky inductively coupled plasma (ICP)-based instrumentations. PMID:27030025

  19. Ozone-stimulated emission due to atomic oxygen population inversions in an argon microwave plasma torch

    International Nuclear Information System (INIS)

    It is shown that, in a microwave torch discharge in an argon jet injected into an oxygen atmosphere at normal pressure, quasi-resonant energy transfer from metastable argon atoms to molecules of oxygen and ozone generated in the torch shell and, then, to oxygen atoms produced via the dissociation of molecular oxygen and ozone leads to the inverse population of metastable levels of atomic oxygen. As a result, the excited atomic oxygen with population inversions becomes a gain medium for lasing at wavelengths of 844.6 and 777.3 nm (the 33P-33S and 35P-35S transitions). It is shown that an increase in the ozone density is accompanied by an increase in both the lasing efficiency at these wavelength and the emission intensity of the plasma-forming argon at a wavelength of 811.15 nm (the 2P04s-2P04p transition). When the torch operates unstably, the production of singlet oxygen suppresses ozone generation; as a result, the lasing effect at these wavelengths disappears.

  20. CHIANTI—AN ATOMIC DATABASE FOR EMISSION LINES. XII. VERSION 7 OF THE DATABASE

    International Nuclear Information System (INIS)

    The CHIANTI spectral code consists of an atomic database and a suite of computer programs to calculate the optically thin spectrum of astrophysical objects and carry out spectroscopic plasma diagnostics. The database includes atomic energy levels, wavelengths, radiative transition probabilities, collision excitation rate coefficients, and ionization and recombination rate coefficients, as well as data to calculate free-free, free-bound, and two-photon continuum emission. Version 7 has been released, which includes several new ions, significant updates to existing ions, as well as Chianti-Py, the implementation of CHIANTI software in the Python programming language. All data and programs are freely available at http://www.chiantidatabase.org, while the Python interface to CHIANTI can be found at http://chiantipy.sourceforge.net.

  1. CHIANTI-AN ATOMIC DATABASE FOR EMISSION LINES. XII. VERSION 7 OF THE DATABASE

    Energy Technology Data Exchange (ETDEWEB)

    Landi, E. [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Del Zanna, G.; Mason, H. E. [Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Young, P. R. [College of Science, George Mason University, 4400 University Drive, Fairfax, VA, 22030 (United States); Dere, K. P. [School of Physics, Astronomy and Computational Sciences, MS 6A2, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States)

    2012-01-10

    The CHIANTI spectral code consists of an atomic database and a suite of computer programs to calculate the optically thin spectrum of astrophysical objects and carry out spectroscopic plasma diagnostics. The database includes atomic energy levels, wavelengths, radiative transition probabilities, collision excitation rate coefficients, and ionization and recombination rate coefficients, as well as data to calculate free-free, free-bound, and two-photon continuum emission. Version 7 has been released, which includes several new ions, significant updates to existing ions, as well as Chianti-Py, the implementation of CHIANTI software in the Python programming language. All data and programs are freely available at http://www.chiantidatabase.org, while the Python interface to CHIANTI can be found at http://chiantipy.sourceforge.net.

  2. Plasmon Enhanced Electron and Atom Emission from a Spherical Sodium Cluster: Na91-

    International Nuclear Information System (INIS)

    The photoabsorption cross section of the negatively charged, spherical Na91- cluster shows a broad collective resonance at ℎω=2.65 eV, the decay of which can lead to two final channels: atom and electron emission. The branching ratio between the two channels was measured to increase linearly with photon energy over the unexpectedly broad energy range of 1.2 eV, which is attributed to the cluster close-quote s incipient valence band width. The femtosecond time scales of the processes involved are discussed. copyright 1996 The American Physical Society

  3. Measurement of visible and UV emission from Energetic Neutral Atom Precipitation (ENAP), on Spacelab

    Science.gov (United States)

    Tinsley, B. A.

    1980-10-01

    The charge exchange of plasmaspheric ions and exospheric H and O and of solar wind ions with exospheric and interplanetary H are sources of precipitating neutrals whose faint emission may be observed by the imaging spectrometric observatory during dark periods of the SL-1 orbit. Measurements of the interactions of these precipitating atoms with the thermosphere are needed to evaluate the heating and ionization effects on the atmosphere as well as the selective loss of i energetic ions from the sources (predominantly the ring current).

  4. Inductively coupled plasma-atomic emission spectrometry (ICP-AES) in support of nuclear waste management

    International Nuclear Information System (INIS)

    Simulated complex nuclear waste solutions are characterized by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AEC). The system uses and ICP source focused on both a polychromator and a computer-controlled scanning monochromator for intensity measurements. This instrumentation allows for simultaneous and sequential measurements of liquid extraction distribution coefficients needed in the development of process flow sheets for component separations. A large number of elements are determined rapidly with adequate sensitivity and accuracy. The focus of this investigation centers on the analysis of nuclear fission products. 13 references, 13 tables

  5. A Complete Model Helium Atom: Theoretical Emissivities, the Case B Approximation, and the Primordial Helium Abundance

    Science.gov (United States)

    Porter, R. L.; Bauman, R. P.; MacAdam, K. B.; Ferland, G. J.

    2004-12-01

    We have completed the development of a new model helium atom for the spectra simulation code Cloudy. All relevant astrophysically significant processes are included, and the spectrum is solved self-consistently with the thermal and ionization structure of the simulated system. We present here an overview of the differences that distinguish our model from those by previous authors. We also compare predicted case B emissivities with those from previous works. The differences will have significant consequences for the interpretation of spectra of a wide variety of systems. We also explore deviations from the case B approximation and present an estimate of the primordial helium abundance.

  6. Two-photon emission spectrum of a two-level atom in a cavity

    International Nuclear Information System (INIS)

    We have studied the two-photon emission spectrum (TPES) of a two-level atom interaction with a single mode of radiation field in an ideal cavity. By means of the two-photon Jaynes-Cummings model and Heisenberg equation, we have obtained the expressions of system operators and TPES. We find that the structures of TPES depend on the photon statistics distribution of initial field and the pass-band width of detector Γ. When Γ < λ (coupling constant), TPES exhibits the multi-peaked structure. (author). 18 refs, 12 figs, 2 tabs

  7. Analysis of atmospheric aerosols by atomic emission spectrometry with electrical discharge sampling

    International Nuclear Information System (INIS)

    A procedure is developed for the determination of the concentration of heavy metals (Pb, Mn, Cu, Ni, Zn, and Cd) in atmospheric air by atomic emission spectrometry with gas-discharge sampling onto the end of a standard carbon electrode. A design of a two-section sampler is proposed; the sampler provides the rapid determination of deposition factors for the deposition of heavy metals contained in aerosol particles onto the end of a carbon electrode. Examples of determining metal concentrations in a model sample of air and in atmospheric air and determination limits of metals deposited onto the end of a carbon electrode are given

  8. Projectile X-ray emission in relativistic ion-atom collisions

    OpenAIRE

    Salem, Shadi

    2010-01-01

    This work reports on the study of the projectile x-ray emission in relativistic ion-atom collisions. Excitation of K-shell in He-like uranium ions, electron capture into H-like uranium ions and Simultaneous ionization and excitation of initially He-like uranium ions have been studied using the experimental storage ring at GSI. Information about the population of the excited states for the H- and He-like uranium ions, can be obtained by measuring the angular distribution of the decay radiation...

  9. Energetic Neutral Atom Emissions From Venus: VEX Observations and Theoretical Modeling

    Science.gov (United States)

    Fok, M.-C.; Galli, A.; Tanaka, T.; Moore, T. E.; Wurz, P.; Holmstrom, M.

    2007-01-01

    Venus has almost no intrinsic magnetic field to shield itself from its surrounding environment. The solar wind thus directly interacts with the planetary ionosphere and atmosphere. One of the by-products of this close encounter is the production of energetic neutral atom (ENA) emissions. Theoretical studies have shown that significant amount of ENAs are emanated from the planet. The launch of the Venus Express (VEX) in 2005 provided the first light ever of the Venus ENA emissions. The observed ENA flux level and structure are in pretty good agreement with the theoretical studies. In this paper, we present VEX ENA data and the comparison with numerical simulations. We seek to understand the solar wind interaction with the planet and the impacts on its atmospheres.

  10. Directional `superradiant' collisions: bosonic amplification of atom pairs emitted from an elongated Bose-Einstein condensate

    OpenAIRE

    Vardi, A.; Moore, M. G.

    2002-01-01

    We study spontaneous directionality in the bosonic amplification of atom pairs emitted from an elongated Bose-Einstein condensate (BEC), an effect analogous to `superradiant' emission of atom-photon pairs. Using a simplified model, we make analytic predictions regarding directional effects for both atom-atom and atom-photon emission. These are confirmed by numerical mean-field simulations, demonstrating the the feasibility of nearly perfect directional emission along the condensate axis. The ...

  11. Correspondence Between Oscillations and Emitted Photon Closed-Orbits in Spontaneous Emission Rate of an Atom Near a Dielectric Slab

    International Nuclear Information System (INIS)

    We study the oscillations in the spontaneous emission rate of an atom near a dielectric slab. The emission rate is calculated as a function of system size using quantum electrodynamics. It exhibits multi-periodic oscillations. Four frequencies of the oscillations are extracted by Fourier transforms. They agree with actions of photon closed-orbits going away and returning to the atom. These oscillations are explained as manifestations of quantum interference effects between the emitted photon wave near the atom and the returning photon waves travelling along various closed-orbits.

  12. Correspondence Between Oscillations and Emitted Photon Closed-Orbits in Spontaneous Emission Rate of an Atom Near a Dielectric Slab

    Institute of Scientific and Technical Information of China (English)

    YUN Su-Jun; WANG Fu-He; ZHOU Yun-Song; DU Meng-Li

    2007-01-01

    We study the oscillations in the spontaneous emission rate of an atom near a dielectric slab. The emission rate is calculated as a function of system size using quantum electrodynamics. It exhibits multi-periodic oscillations.Four frequencies of the oscillations are extracted by Fourier transforms. They agree with actions of photon closed-orbits going away and returning to the atom. These oscillations are explained as manifestations of quantum interference effects between the emitted photon wave near the atom and the returning photon waves travelling along various closed-orbits.

  13. Experimental study of conversion from atomic high—order harmonics to x—ray emissions

    Institute of Scientific and Technical Information of China (English)

    WangQi; ChenJian-Xin; XiaYuan-Qin; ChenDe-Ying

    2003-01-01

    There are two physical phenomena in a strong laser intensity. One is the high-order harmonic emission; the other is x-ray emission from optical-field ionized plasmas. The experiment of conversion from high-order harmonics to x-ray emissions was given with a 105fs Ti:sapphire laser by adjusting laser intensities. The ingredient in plasma was investigated by the numerical simulations.Our experimental results suggested that the free electrons have detrimental effects on harmonic generation but are favourable for x-ray emission from optical-field ionized plasmas. If we want to obtain more intense harmonic signals as a coherent light source in the soft x-ray region, we must avoid the production of free electrons in plasmas. At the same time, if we want to observe x-rays for the development of high-repetition-rate table-top soft x-ray lasers, we should strip all atoms in the plasmas to a necessary ionized stage by the optical-field-ionization in the field of a high-intensity laser pulse.

  14. Experimental study of conversion from atomic high-order harmonics to x-ray emissions

    Institute of Scientific and Technical Information of China (English)

    王骐; 陈建新; 夏元钦; 陈德应

    2003-01-01

    There are two physical phenomena in a strong laser intensity. One is the high-order harmonic emission; the other is x-ray emission from optical-field ionized plasmas. The experiment of conversion from high-order harmonics to x-ray emissions was given with a 105fs Ti:sapphire laser by adjusting laser intensities. The ingredient in plasma was investigated by the numerical simulations. Our experimental results suggested that the free electrons have detrimental effects on harmonic generation but are favourable for x-ray emission from optical-field ionized plasmas. If we want to obtain more intense harmonic signals as a coherent light source in the soft x-ray region, we must avoid the production of free electrons in plasmas. At the same time, if we want to observe x-rays for the development of high-repetition-rate table-top soft x-ray lasers, we should strip all atoms in the plasmas to a necessary ionized stage by the optical-fieldionization in the field of a high-intensity laser pulse.

  15. Mineral elements in dental composites by atomic and nuclear analytical methods. II. Improved analysis by PIXE

    International Nuclear Information System (INIS)

    In the corrosive environment of the mouth, a diversity of interactions take place at the solid-solid and solid-liquid interfaces of a tooth's filling. Moreover, the mineral elements of the restorative material may induce a complex response of the organism. The approach of these problems requires sensitive surface elemental analysis of the composite and of the dental enamel and dentine. Particle-induced X-ray emission (PIXE) is such a method and has been applied in investigations of hard dental tissues; however, it was not used so far in the study of dental composites. We continue our study by evaluating the potential of PIXE for analysis of these materials. Three types of composites with two color shades each have been studied. The measurements were performed with 3 MeV protons, using a hyperpure Ge detector in a spectroscopic chain connected to a computer. The spectra were processed with the dedicated program Leone. PIXE without additional Al absorbent foil allowed the detection of Z > 14 elements in composites. In two glass- and ceramics-based materials we found: Ca, Zr, Ba, Yb and traces of Sr and In in Tetric Ceram (Vivadent); and Ca, Zr, Ba, Hf, possibly Mn, and traces of Ni, Ho, Ti, Fe, Cr in Valux Plus (3M Dental), after elimination of the escape peaks. In quartz-based Evicrol (Spofa), Si, Ca, Ti, Fe and traces of K, Cr, Ni, Cu, Zn were seen. Materials with different color shades showed variations of Ti, Cr, Fe, Ni and Cu in Evicrol, as contrasted to Tetric Ceram and Valux Plus whose spectra were color-invariant. By its sensitivity and low background, PIXE enables the detection of many trace elements in dental composites; it could serve also in new materials' development and forensic expertise. (authors)

  16. Fingerprinting of complex mixtures with the use of high performance liquid chromatography, inductively coupled plasma atomic emission spectroscopy and chemometrics

    International Nuclear Information System (INIS)

    The molecular and metal profile fingerprints were obtained from a complex substance, Atractylis chinensis DC-a traditional Chinese medicine (TCM), with the use of the high performance liquid chromatography (HPLC) and inductively coupled plasma atomic emission spectroscopy (ICP-AES) techniques. This substance was used in this work as an example of a complex biological material, which has found application as a TCM. Such TCM samples are traditionally processed by the Bran, Cut, Fried and Swill methods, and were collected from five provinces in China. The data matrices obtained from the two types of analysis produced two principal component biplots, which showed that the HPLC fingerprint data were discriminated on the basis of the methods for processing the raw TCM, while the metal analysis grouped according to the geographical origin. When the two data matrices were combined into a one two-way matrix, the resulting biplot showed a clear separation on the basis of the HPLC fingerprints. Importantly, within each different grouping the objects separated according to their geographical origin, and they ranked approximately in the same order in each group. This result suggested that by using such an approach, it is possible to derive improved characterisation of the complex TCM materials on the basis of the two kinds of analytical data. In addition, two supervised pattern recognition methods, K-nearest neighbors (KNNs) method, and linear discriminant analysis (LDA), were successfully applied to the individual data matrices-thus, supporting the PCA approach

  17. Determination of rare-earth elements in geological materials by inductively coupled argon plasma atomic emission spectrometry (ICAP-AES)

    International Nuclear Information System (INIS)

    The determination of 12 rare earth elements viz Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Y and Yb in geological materials, particularly in silicate rocks by ICAP-AES method is descried. Here, the stepwise chemical separation of major elements (Si, Al, Fe, Mg) followed by precipitation of rare earth with fluoride-hydroxide cycles is carried out. This precipitate which is mainly rare earths, is dissolved in HNO3 to get final clear solution. Synthetic aqueous standards are prepared containing rare earths only in the concentration range 0.01 μg/ml to 0.2 μg/ml. JY 1 m Czerny-Turner scanning monochromator is used to measure intensities of rare earth analytical lines selected. The mean relative standard deviation lies between 0.8% to 4.0% for all the elements determined. The mica schist samples are dissolved in HNO3 in combination with diluted HF (1:100) and few drops of perchloric acid. The end sample is taken in 5% nitric acid. Clear solution is obtained which is evaporated to near dry and finally made to a known volume with water. JY -2000 ICP- AES sequential atomic emission spectrometer is used to measure intensities of rare earth elements. Single rare earth element standard solutions are used in the concentration range of 0.l ppm to 10 ppm. (author)

  18. Fingerprinting of complex mixtures with the use of high performance liquid chromatography, inductively coupled plasma atomic emission spectroscopy and chemometrics

    Energy Technology Data Exchange (ETDEWEB)

    Ni Yongnian [Department of Chemistry, Nanchang University, Nanchang, Jiangxi 330047 (China)], E-mail: ynni@ncu.edu.cn; Peng Yunyan [Department of Chemistry, Nanchang University, Nanchang, Jiangxi 330047 (China); Kokot, Serge [Inorganic Materials Program, School of Physical and Chemical Sciences, Queensland University of Technology, Brisbane, Queensland 4001 (Australia)

    2008-05-26

    The molecular and metal profile fingerprints were obtained from a complex substance, Atractylis chinensis DC-a traditional Chinese medicine (TCM), with the use of the high performance liquid chromatography (HPLC) and inductively coupled plasma atomic emission spectroscopy (ICP-AES) techniques. This substance was used in this work as an example of a complex biological material, which has found application as a TCM. Such TCM samples are traditionally processed by the Bran, Cut, Fried and Swill methods, and were collected from five provinces in China. The data matrices obtained from the two types of analysis produced two principal component biplots, which showed that the HPLC fingerprint data were discriminated on the basis of the methods for processing the raw TCM, while the metal analysis grouped according to the geographical origin. When the two data matrices were combined into a one two-way matrix, the resulting biplot showed a clear separation on the basis of the HPLC fingerprints. Importantly, within each different grouping the objects separated according to their geographical origin, and they ranked approximately in the same order in each group. This result suggested that by using such an approach, it is possible to derive improved characterisation of the complex TCM materials on the basis of the two kinds of analytical data. In addition, two supervised pattern recognition methods, K-nearest neighbors (KNNs) method, and linear discriminant analysis (LDA), were successfully applied to the individual data matrices-thus, supporting the PCA approach.

  19. Elemental Content in Brown Rice by Inductively Coupled Plasma Atomic Emission Spectroscopy Reveals the Evolution of Asian Cultivated Rice

    Institute of Scientific and Technical Information of China (English)

    Yawen Zeng; Luxiang Wang; Juan Du; Jiafu Liu; Shuming Yang; Xiaoying Pu; Fenghui Xiao

    2009-01-01

    The phylogenetic relationship for classification traits and eight mineral elements in brown rice (Oryza sativa L.) from Yunnan Province in China was carried out using microwave assisted digestion followed by inductively coupled plasma atomic emission spectroscopy, and the analytical procedures were carefully controlled and validated. In general, the results show that the mean levels of K, Ca, Mg, Fe and Cu in brown rice for 789 accessions of rice landraces was distinctly lower than that of improved cultivars. They further demonstrate that Ca plays an important role in the differentiation of subspecies indica-japonica, especially to enhance adaptation of cold stress, and that five mineral elements in brown rice enhance the eurytopicity from landrace to improved cultivar. Hierarchical cluster analysis, using average linkage from SPSS software based on eight mineral elements in brown rice, showed that Yunnan rice could be grouped into rice landrace and improved cultivar, with the rice landrace being further clustered into five subgroups, and that, interestingly, purple rice does not cluster with either of the groups. Our present data confirm that indica is the closest relative of late rice and white rice, and that they constitute rice landraces together, whereas japonica is the closest relatives of non-nuda, early-mid and glutinous rice. It is further shown that japonica, non-nuda, early-mid, glutinous, white and red rice might be more primitive than indica, nuda, late, non-glutinous and purple rice, respectively.

  20. Microwave digestion of sludge, soil and sediment samples for metal analysis by inductively coupled plasma-atomic emission spectrometry

    International Nuclear Information System (INIS)

    Three digestion programs for the Anton Paar multiwave microwave were investigated to obtain a simple, rapid method for the determination of metals in sludge, soil and sediment samples. The digests were subsequently analysed for metal content by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The trace metals determined were Mn, Ni, Zn, Pb, Cr, Cd, Cu and V, and the major elements determined were Mg, Ca, Fe and Al. In addition to the heating programs used, different combinations and volumes of hydrofluoric, nitric and hydrochloric acids were evaluated for digestion efficiency. Three standard reference materials (SRMs) were used in the comparison. From the results obtained, the fastest microwave program (36 min) provided the most consistent recovery data for all three SRMs. Six millilitres of HNO3 was the optimum acid mixture for the digestion of LGC6136 sewage sludge (with the exception of Al) and for LGC6138 coal carbonisation site soil. For PACS-1 marine sediment (and for the determination of Al in LGC6136), a mixture of 3 ml of HNO3+2 ml of HF produced the best analytical results. The experimental results were in agreement with the certified values and demonstrated that the proposed method was precise and accurate

  1. A Radiative Cycle with Stimulated Emission from Atoms (Ions) in an astrophysical Plasma

    CERN Document Server

    Johansson, S

    2003-01-01

    We propose that a radiative cycle operates in atoms (ions) located in a rarefied gas in the vicinity of a hot star. Besides spontaneous transitions the cycle includes a stimulated transition in one very weak intermediate channel. This radiative "bottle neck" creates a population inversion, which for an appropriate column density results in amplification and stimulated radiation in the weak transition. The stimulated emission opens a fast decay channel leading to a fast radiative cycle in the atom (or ion). We apply this model by explaining two unusually bright Fe II lines at 250.7 and 250.9 nm in the UV spectrum of gas blobs close to h Carinae, one of the most massive and luminous stars in the Galaxy. The gas blobs are spatially resolved from the central star by the Hubble Space Telescope (HST). We also suggest that in the frame of a radiative cycle stimulated emission is a key phenomenon behind many spectral lines showing anomalous intensities in spectra of gas blobs outside eruptive stars.

  2. Two-photon-excited stimulated emission from atomic oxygen in flames and cold gases

    International Nuclear Information System (INIS)

    The authors describe their observation of stimulated emission (SE) from the atomic oxygen 33P - 33 transition at 845 nm following two-photon excitation of the 23P - 33 transition using 226-nm laser radiation. They studied this SE process in flames and room temperature flows of O2 and N2O, comparing its behavior to fluorescence (FL) signals acquired simultaneously. Rapid depletion of the laser-excited state by the SE process may impact the use of diagnostic techniques based on multiphoton excitation in oxygen and other species. The strength of the SE signal suggests that it may have applications as a diagnostic technique. To prove that the signal observed in the direction of the laser beam as in fact SE, they measured the relative strengths of the forward direction signal and the FL collected at right angles. Because FL and SE have distinctly different dependences on the density of excited atoms or molecules responsible for their emission, their signals should behave differently as the excited state density is varied through changes is excitation conditions. The difference in the behavior of the signals, especially evident at the lower intensities is shown

  3. Discovery of K-Shell Emission Lines of Neutral Atoms in the Galactic Center Region

    CERN Document Server

    Nobukawa, Masayoshi; Tsuru, Takeshi Go; Ryu, Syukyo G; Tatischeff, Vincent

    2010-01-01

    The K-shell emission line of neutral irons from the Galactic center (GC) region is one of the key for the structure and activity of the GC. The origin is still open question, but possibly due either to X-ray radiation or to electron bombarding to neutral atoms. To address this issue, we analyzed the Suzaku X-ray spectrum from the GC region of intense neutral iron line emission, and report on the discovery of Kalpha lines of neutral argon, calcium, chrome, and manganese atoms. The equivalent widths of these Kalpha lines indicate that the metal abundances in the GC region should be ~1.6 and ~4 of solar value, depending on the X-ray and the electron origins, respectively. On the other hand, the metal abundances in the hot plasma in the GC region are found to be ~1-2 solar. These results favor that the origin of the neutral Kalpha lines are due to X-ray irradiation.

  4. Lifetime distribution of spontaneous emission from an assembly of atoms in a dielectric slab

    International Nuclear Information System (INIS)

    Spontaneous decay behavior from an assembly of atoms (or molecules) in a dielectric slab sandwiched by two dielectric semi-infinite spaces with arbitrary refractive indices is investigated. We introduce a lifetime distribution function to describe decay kinetics. The zero-point fluctuations of the electromagnetic field are calculated as a function of the position of atom in the slab. They display a symmetric profile with respect to the central plane of the slab in symmetric structure sample and the contributions of the guided modes and the radiation modes components both exhibit cosinelike variation with a base but with a phase difference of π. With the increase of the thickness of the slab, the oscillations become dense. In contrast, for the asymmetric structure case, the related curves are asymmetric with respect to the middle plane of slab and exhibit considerably distorted cosinelike oscillations. The dependence of the spontaneous emission rate of atoms on the thickness of the slab and the refractive indices of substrate also is surveyed. Our calculations show that quite wide or narrow lifetime distribution can occur for different thicknesses of the slab. The coexistence of both accelerated and inhibited decay processes appears. The calculated results are in good agreement with experimental results

  5. Electron emission in collisions of fast highly charged bare ions with helium atoms

    Science.gov (United States)

    Mondal, Abhoy; Mandal, Chittranjan; Purkait, Malay

    2016-01-01

    We have studied the electron emission from ground state helium atom in collision with fast bare heavy ions at intermediate and high incident energies. In the present study, we have applied the present three-body formalism of the three Coulomb wave (3C-3B) model and the previously adopted four-body formalism of the three Coulomb wave (3C-4B). To represent the active electron in the helium atom in the 3C-3B model, the initial bound state wavefunction is chosen to be hydrogenic with an effective nuclear charge. The wavefunction for the ejected electron in the exit channel has been approximated to be a Coulomb continuum wavefunction with same effective nuclear charge. Effectively the continuum-continuum correlation effect has been considered in the present investigation. Here we have calculated the energy and angular distribution of double differential cross sections (DDCS) at low and high energy electron emission from helium atom. The large forward-backward asymmetry is observed in the angular distribution which is explained in terms of the two-center effect (TCE). Our theoretical results are compared with available experimental results as well as other theoretical calculations based on the plain wave Born approximation (PWBA), continuum-distorted wave (CDW) approximation, continuum-distorted wave eikonal-initial state (CDW-EIS) approximation, and the corresponding values obtained from the 3C-4B model [S. Jana, R. Samanta, M. Purkait, Phys. Scr. 88, 055301 (2013)] respectively. It is observed that the four-body version of the present investigation produces results which are in better agreement with experimental observations for all cases.

  6. An analytical inversion method for determining regional and global emissions of greenhouse gases: Sensitivity studies and application to halocarbons

    Directory of Open Access Journals (Sweden)

    A. Stohl

    2009-03-01

    Full Text Available A new analytical inversion method has been developed to determine the regional and global emissions of long-lived atmospheric trace gases. It exploits in situ measurement data from three global networks and builds on backward simulations with a Lagrangian particle dispersion model. The emission information is extracted from the observed concentration increases over a baseline that is itself objectively determined by the inversion algorithm. The method was applied to two hydrofluorocarbons (HFC-134a, HFC-152a and a hydrochlorofluorocarbon (HCFC-22 for the period January 2005 until March 2007. Detailed sensitivity studies with synthetic as well as with real measurement data were done to quantify the influence on the results of the a priori emissions and their uncertainties as well as of the observation and model errors. It was found that the global a posteriori emissions of HFC-134a, HFC-152a and HCFC-22 all increased from 2005 to 2006. Large increases (21%, 16%, 18%, respectively from 2005 to 2006 were found for China, whereas the emission changes in North America (−9%, 23%, 17%, respectively and Europe (11%, 11%, −4%, respectively were mostly smaller and less systematic. For Europe, the a posteriori emissions of HFC-134a and HFC-152a were slightly higher than the a priori emissions reported to the United Nations Framework Convention on Climate Change (UNFCCC. For HCFC-22, the a posteriori emissions for Europe were substantially (by almost a factor 2 higher than the a priori emissions used, which were based on HCFC consumption data reported to the United Nations Environment Programme (UNEP. Combined with the reported strongly decreasing HCFC consumption in Europe, this suggests a substantial time lag between the reported time of the HCFC-22 consumption and the actual time of the HCFC-22 emission. Conversely, in China where HCFC consumption is increasing rapidly according to the UNEP data, the a posteriori emissions are only about 40% of the a

  7. A new analytical inversion method for determining regional and global emissions of greenhouse gases: sensitivity studies and application to halocarbons

    Directory of Open Access Journals (Sweden)

    A. Stohl

    2008-11-01

    Full Text Available A new analytical inversion method has been developed to determine the regional and global emissions of long-lived atmospheric trace gases. It exploits in situ measurement data from a global network and builds on backward simulations with a Lagrangian particle dispersion model. The emission information is extracted from the observed concentration increases over a baseline that is itself objectively determined by the inversion algorithm. The method was applied to two hydrofluorocarbons (HFC-134a, HFC-152a and a hydrochlorofluorocarbon (HCFC-22 for the period January 2005 until March 2007. Detailed sensitivity studies with synthetic as well as with real measurement data were done to quantify the influence on the results of the a priori emissions and their uncertainties as well as of the observation and model errors. It was found that the global a posteriori emissions of HFC-134a, HFC-152a and HCFC-22 all increased from 2005 to 2006. Large increases (21%, 16%, 18%, respectively from 2005 to 2006 were found for China, whereas the emission changes in North America and Europe were modest. For Europe, the a posteriori emissions of HFC-134a and HFC-152a were slightly higher than the a priori emissions reported to the United Nations Framework Convention on Climate Change (UNFCCC. For HCFC-22, the a posteriori emissions for Europe were substantially (by almost a factor 2 higher than the a priori emissions used, which were based on HCFC consumption data reported to the United Nations Environment Programme (UNEP. Combined with the reported strongly decreasing HCFC consumption in Europe, this suggests a substantial time lag between the reported timing of the HCFC-22 consumption and the actual timing of the HCFC-22 emission. Conversely, in China where HCFC consumption is increasing rapidly according to the UNEP data, the a posteriori emissions are only about 40% of the a priori emissions. This reveals a substantial storage of HCFC-22 and potential for future

  8. Optimization of conditions for the determination of Eu, Gd and Sm by atomic absorption spectrometry (AAS) and atomic emission spectrometry (AES)

    International Nuclear Information System (INIS)

    The possibilities of the determination of Sm, Eu and Gd by atomic absorption and emission spectrometry were investigated. Measurement parameters on a Varian atomic absorption spectrometer were optimized (the height of the measurement above the nozzle of the burner, stoichiometry of the dinitrogen oxide-acetylene flame by statistical evaluation of the signals). The following optimal conditions were found for the Sm, Eu and Gd determinations: Samarium - measurement under the emission arrangement at 476.1 nm wavelength, slit width 0.05 nm, in reduction flame close to the outlet slit of the flame (at the lowest part of the flame). Europium - measurement under the absorption arrangement at 459.4 nm wavelength, slit width 1 nm, in reduction flame at the lowest part of the flame. Gadolinium - measurement under the emission arrangement at 461.7 nm wavelength, slit width 0.05 nm, at the lowest part of the flame. (author). 2 figs., 3 tabs., 2 refs

  9. Mineral distribution in rice: Measurement by Microwave Plasma Atomic Emission Spectroscopy (MP-AES)

    International Nuclear Information System (INIS)

    Microwave Plasma Atomic Emission Spectroscopy (MP-AES) is a new technology with comparable performance and sensitivity to Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Both instrument use plasma as the energy source that produces atomic and ionic emission lines. However, MP-AES uses nitrogen as the plasma gas instead of argon which is an additional expense for ICP-OES. Thus, MP-AES is more economical. This study quantified six essential minerals (Se, Zn, Fe, Cu, Mn and K) in rice using MP-AES. Hot plate digestion was used for sample extraction and the detection limit for each instrument was compared with respect to the requirement for routine analysis in rice. Black, red and non-pigmented rice samples were polished in various intervals to determine the concentration loss of minerals. The polishing time corresponds to the structure of the rice grains such as outer bran layer (0 to 15), inner bran layer (15 to 30), outer endosperm layer (30 to 45), and middle endosperm layer (45 to 60). Results of MP-AES analysis showed that black rice had all essential materials (except K) in high concentration at the outer bran layer. The red and non-pigmented rice samples on the other hand, contained high levels of Se, Zn, Fe, and Mn in the whole bran portion. After 25 seconds, the mineral concentrations remained constant. The concentration of Cu however, gave consistent value in all polishing intervals, hence Cu might be located in the inner endosperm layer. Results also showed that K was uniformly distributed in all samples where 5% loss was consistently observed for every polishing interval. Therefore, the concentration of K was also affected by polishing time. Thus, the new MP-AES technology with comparable performance to ICP-OES is a promising tool for routine analysis in rice. (author)

  10. Determination of manganese in thermoluminescent materials by inductively coupled plasma atomic emission spectrometry and spectrophotometry

    International Nuclear Information System (INIS)

    The content of manganese in the mixed fluorides CaF2: MnF2 and CaF2: Mn thermoluminophors was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) and spectrophotometry. The various Mn emission lines were compared and the manganese emission line at 257.610 nm was used for ICP-AES analysis. For the spectrophotometric determination the manganese(II) ions were oxidized to intensively coloured permanganate ions using potassium periodate. No statistically significant differences were found between the results of ICP-AES and spectrophotometric methods of analysis. The thermoluminophors were synthesized by coprecipitation of manganese with CaF2, varying the concentration of manganese in the initial solutions in the range of 0.01 - 2.0 % (m/m). The coprecipitated mixed fluorides CaF2: MnF2 were heated at 1423 K. The glow curves of synthesized CaF2: Mn thermoluminophors were measured. (author)

  11. The emission of oxygen green line and density of O atom determined by using ISUAL and SABER measurements

    Directory of Open Access Journals (Sweden)

    J.-B. Nee

    2012-04-01

    Full Text Available Emissions of the 557.7 nm green line airglow observed by the ISUAL (Imager of Sprites and Upper Atmospheric Lightning instrument on board the FORMOSAT-2 satellite in May and November 2008 are studied here to derive the density distributions of the atomic oxygen by using atmospheric parameters from MSISE-00 model and TIMED (Thermosphere Ionosphere Mesosphere Energetics and Dynamics/SABER (Sounding of the Atmosphere using Broadband Emission Radiometry measurements. The May observations were made in 10 days from a fixed orbit of longitude (100° E with the results showing emission rate and O atom density both peaked at heights of about 90 km over 10° to 20° latitudes in the Northern Hemisphere (NH. In the Southern Hemisphere (SH, the emission rate and density of O atom are both low compared with those in NH. In November, the observations were made as the satellite traveled over all 14 orbits around the earth, covering all longitudes and latitudes of 25° S–45° N. Strong peaks of emission rates and O atoms are found at heights of about 95 km in the mid-latitudes in both hemispheres. In the equator, the airglow layer has a weaker emission rate but with higher altitude compared with those of mid-latitudes. In the lower and upper mesosphere at heights below 85 km and above 105 km, there are more O atoms in the equatorial regions than in the mid-latitudes. And there is a good correlation between the O atom and the temperature structure. A comparison with O atom distribution derived from OH airglow observed by TIMED/SABER at about the same time shows similar results.

  12. Determination of bismuth by dielectric barrier discharge atomic absorption spectrometry coupled with hydride generation: Method optimization and evaluation of analytical performance

    Czech Academy of Sciences Publication Activity Database

    Kratzer, Jan; Boušek, J.; Sturgeon, R. E.; Mester, Z.; Dědina, Jiří

    2014-01-01

    Roč. 86, č. 19 (2014), s. 9620-9625. ISSN 0003-2700 Grant ostatní: GA AV ČR(CZ) M200311202 Institutional support: RVO:68081715 Keywords : dielectric barrier discharge * hydride generation * atomic absorption spectrometry Subject RIV: CB - Analytical Chemistry , Separation Impact factor: 5.636, year: 2014

  13. Nondestructive atomic compositional analysis of BeMgZnO quaternary alloys using ion beam analytical techniques

    Energy Technology Data Exchange (ETDEWEB)

    Zolnai, Z., E-mail: zolnai.zsolt@ttk.mta.hu [Research Centre for Natural Sciences, Institute of Technical Physics and Materials Science (MFA), Konkoly-Thege M. út 29-33, H-1121 Budapest (Hungary); Toporkov, M. [Department of Electrical and Computer Engineering, Virginia Commonwealth University, 601W Main St, Richmond, VA 23284 (United States); Volk, J. [Research Centre for Natural Sciences, Institute of Technical Physics and Materials Science (MFA), Konkoly-Thege M. út 29-33, H-1121 Budapest (Hungary); Department of Electrical and Computer Engineering, Virginia Commonwealth University, 601W Main St, Richmond, VA 23284 (United States); Demchenko, D.O. [Department of Physics, Virginia Commonwealth University, 701W. Grace St., Richmond, VA 23284 (United States); Okur, S. [Department of Electrical and Computer Engineering, Virginia Commonwealth University, 601W Main St, Richmond, VA 23284 (United States); Szabó, Z. [Research Centre for Natural Sciences, Institute of Technical Physics and Materials Science (MFA), Konkoly-Thege M. út 29-33, H-1121 Budapest (Hungary); Özgür, Ü.; Morkoç, H.; Avrutin, V. [Department of Electrical and Computer Engineering, Virginia Commonwealth University, 601W Main St, Richmond, VA 23284 (United States); Kótai, E. [Wigner Research Centre for Physics, Institute for Particle and Nuclear Physics, Konkoly-Thege M. út 29-33, H-1121 Budapest (Hungary)

    2015-02-01

    Highlights: • BeMgZnO thin layers were grown with plasma-assisted molecular beam epitaxy (MBE). • The Be contents were accurately measured with RBS and proton elastic backscattering. • The Tauc bandgap was measured from optical transmittance experiments. • The bandgap has been varied between 3.26 eV and 4.62 eV via the Be and Mg content. • Experimental and density functional theory calculated bandgaps were in good agreement. - Abstract: The atomic composition with less than 1–2 atom% uncertainty was measured in ternary BeZnO and quaternary BeMgZnO alloys using a combination of nondestructive Rutherford backscattering spectrometry with 1 MeV He{sup +} analyzing ion beam and non-Rutherford elastic backscattering experiments with 2.53 MeV energy protons. An enhancement factor of 60 in the cross-section of Be for protons has been achieved to monitor Be atomic concentrations. Usually the quantitative analysis of BeZnO and BeMgZnO systems is challenging due to difficulties with appropriate experimental tools for the detection of the light Be element with satisfactory accuracy. As it is shown, our applied ion beam technique, supported with the detailed simulation of ion stopping, backscattering, and detection processes allows of quantitative depth profiling and compositional analysis of wurtzite BeZnO/ZnO/sapphire and BeMgZnO/ZnO/sapphire layer structures with low uncertainty for both Be and Mg. In addition, the excitonic bandgaps of the layers were deduced from optical transmittance measurements. To augment the measured compositions and bandgaps of BeO and MgO co-alloyed ZnO layers, hybrid density functional bandgap calculations were performed with varying the Be and Mg contents. The theoretical vs. experimental bandgaps show linear correlation in the entire bandgap range studied from 3.26 eV to 4.62 eV. The analytical method employed should help facilitate bandgap engineering for potential applications, such as solar blind UV photodetectors and

  14. Nondestructive atomic compositional analysis of BeMgZnO quaternary alloys using ion beam analytical techniques

    International Nuclear Information System (INIS)

    Highlights: • BeMgZnO thin layers were grown with plasma-assisted molecular beam epitaxy (MBE). • The Be contents were accurately measured with RBS and proton elastic backscattering. • The Tauc bandgap was measured from optical transmittance experiments. • The bandgap has been varied between 3.26 eV and 4.62 eV via the Be and Mg content. • Experimental and density functional theory calculated bandgaps were in good agreement. - Abstract: The atomic composition with less than 1–2 atom% uncertainty was measured in ternary BeZnO and quaternary BeMgZnO alloys using a combination of nondestructive Rutherford backscattering spectrometry with 1 MeV He+ analyzing ion beam and non-Rutherford elastic backscattering experiments with 2.53 MeV energy protons. An enhancement factor of 60 in the cross-section of Be for protons has been achieved to monitor Be atomic concentrations. Usually the quantitative analysis of BeZnO and BeMgZnO systems is challenging due to difficulties with appropriate experimental tools for the detection of the light Be element with satisfactory accuracy. As it is shown, our applied ion beam technique, supported with the detailed simulation of ion stopping, backscattering, and detection processes allows of quantitative depth profiling and compositional analysis of wurtzite BeZnO/ZnO/sapphire and BeMgZnO/ZnO/sapphire layer structures with low uncertainty for both Be and Mg. In addition, the excitonic bandgaps of the layers were deduced from optical transmittance measurements. To augment the measured compositions and bandgaps of BeO and MgO co-alloyed ZnO layers, hybrid density functional bandgap calculations were performed with varying the Be and Mg contents. The theoretical vs. experimental bandgaps show linear correlation in the entire bandgap range studied from 3.26 eV to 4.62 eV. The analytical method employed should help facilitate bandgap engineering for potential applications, such as solar blind UV photodetectors and heterostructures

  15. Development of an analytical method for antimony speciation in vegetables by HPLC-hydride generation-atomic fluorescence spectrometry.

    Science.gov (United States)

    Olivares, David; Bravo, Manuel; Feldmann, Jorg; Raab, Andrea; Neaman, Alexander; Quiroz, Waldo

    2012-01-01

    A new method for antimony speciation in terrestrial edible vegetables (spinach, onions, and carrots) was developed using HPLC with hydride generation-atomic fluorescence spectrometry. Mechanical agitation and ultrasound were tested as extraction techniques. Different extraction reagents were evaluated and optimal conditions were determined using experimental design methodology, where EDTA (10 mmol/L, pH 2.5) was selected because this chelate solution produced the highest extraction yield and exhibited the best compatibility with the mobile phase. The results demonstrated that EDTA prevents oxidation of Sb(III) to Sb(V) and maintains the stability of antimony species during the entire analytical process. The LOD and precision (RSD values obtained) for Sb(V), Sb(III), and trimethyl Sb(V) were 0.08, 0.07, and 0.9 microg/L and 5.0, 5.2, and 4.7%, respectively, for a 100 microL sample volume. The application of this method to real samples allowed extraction of 50% of total antimony content from spinach, while antimony extracted from carrots and onion samples ranged between 50 and 60 and 54 and 70%, respectively. Only Sb(V) was detected in three roots (onion and spinach) that represented 60-70% of the total antimony in the extracts. PMID:22970588

  16. Analysis of non-conducting powders by glow-discharge atomic emission spectrography

    International Nuclear Information System (INIS)

    An analytical method for control of the impurity levels of non-conducting powders during their preparation (particularly milling processes) is proposed. Impurity concentrations between some hundredths and a few percent as well as admixtures concentrations higher than 10% are determined. The glow discharge emission spectrography is applied after briquetting the samples with an excess of copper powder using a Grimm-type glow discharge lamp and a grating plan spectrograph with photographic detection. Difficulties arise from the band spectra due to non-metallic elements in the sample and from insufficient grain sizes, mixture homogeneity and compactness of the briquettes. The efficiency and detection limits in determination of SiO2 and ZrO2 in Al2O3 and of SiO2 in Bi2Ru2O7 are described. (author)

  17. On the emission of the fast $\\delta-$electrons during nuclear $\\beta^{-}$-decay in few-electron atoms

    CERN Document Server

    Frolov, Alexei M

    2016-01-01

    We discuss a possibility to observe fast secondary electrons ($\\delta-$electrons) during nuclear $\\beta^{-}$-decay in few-electron atoms and ions. Formulas for the corresponding probabilities and explicit expression for the energy spectrum of $\\delta-$electrons are derived in the closed analytical forms.

  18. Extraction concentration and atomic emission determination of controlled elements in acid mine waters

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, B.I.; Oshchepkova, A.P. (Permskij Gosudarstvennyj Univ. (USSR))

    1984-09-01

    Exchange reactions between metal (Cd, Zn, Co, Hg, etc.) dithizonates and diantipyrylmethane (DAM) salts in non-aqueous solutions have been examined. Metal ions forming stable thiocyanate or iodide complexes (Cd(SCN)/sub 4//sup 2 -/, CdI/sub 4//sup 2 -/) pass from the dithizonates to form anionic complexes and then ion pairs with protonated DAM. Addition of DAM salts to organic extracts is an effective method of decomposition of dithizonates and preconcentration of elements in a microphase formed due to extract separation into two phases. A combination of preconcentration of microelements in a three-phase system with atomic emission analysis makes it possible to determine a group of controlled micro elements in complex acid mine waters.

  19. Intra- and intercycle interference of electron emission in laser assisted XUV atomic ionization

    CERN Document Server

    Gramajo, Ana Alicia; Garibotti, Carlos Roberto; Arbó, Diego

    2016-01-01

    We study the ionization of atomic hydrogen in the direction of polarization due to a linearly polarized XUV pulse in the presence a strong field IR. We describe the photoelectron spectra as an interference problem in the time domain. Electron trajectories steming from different optical laser cycles give rise to intercycle interference energy peaks known as sidebands. These sidebands are modulated by a grosser structure coming from the intracycle interference of the two electron trajectories born during the same optical cycle. We make use of a simple semiclassical model which offers the possibility to establish a connection between emission times and the photoelectron kinetic energy. We compare the semiclassical predictions with the continuum-distorted wave strong field approximation and the ab initio solution of the time dependent Schr\\"odinger equation. We analyze such interference pattern as a function of the time delay between the IR and XUV pulse and also as a function of the laser intensity.

  20. Some metals determination in beers by atomic emission spectrometry of induced argon plasma

    International Nuclear Information System (INIS)

    It was made the identification and determination of metals in brazilian bottled and canned beer, using atomic emission spectrometry with d.c. are and argon coupled plasma excitation sources. The elements Co, Cr, Cu, Fe, Pb and Zn were determined in beer samples, after treatment with HNO sub(3) conc. /H sub(2) O sub(2) (30%). In the determination of Co, Cr, Cu, Pb and Zn and alternative method using HNO sub(3) conc. /O sub(3) was proved be useful. The results obtained for Co, Cr, Cu, Fe, Pb and Zn were below the limits established by brazilian legislation, showing the good quality of the beer concerning the metals. The results of this work were requested by the previous Ministerio do Meio Ambiente e Urbanismo in order to contribute to review the brazilian legislation in foods and beverages about metals contents. (author)

  1. Extraction concentration and atomic emission determination of controlled elements in acid mine waters

    International Nuclear Information System (INIS)

    Exchange reactions between metal (Cd, Zn, Co, Hg, etc.) dithizonates and diantipyrylmethane (DAM) salts in non-aqueoUs solutions have been examined. Metal ions forming stable thiocyanate or iodide complexes (Cd(SCN)42-, CdI42-) pass from the dithizonates to form anionic complexes and then ion pairs with protonated DAM. Addition of DAM salts to organic extracts is an effective method of decomposition of dithizonates and preconcentration of elements in a microphase formed due to extract separation into two phases. A combination of preconcentration of microelements in a three-phase system with atomic emission analysis makes it possible to determine a group of controlled micro elements in complex acid mine waters

  2. Radiative emission of neutrino pairs in atoms and light sterile neutrinos

    Directory of Open Access Journals (Sweden)

    D.N. Dinh

    2015-03-01

    Full Text Available The process of Radiative Emission of Neutrino Pair (RENP in atoms is sensitive to the absolute neutrino mass scale, the type of spectrum neutrino masses obey and the nature – Dirac or Majorana – of massive neutrinos. We analyse the possibility to test the hypothesis of existence of neutrinos with masses at the eV scale coupled to the electron in the weak charged lepton current in an RENP experiment. The presence of eV scale neutrinos in the neutrino mixing is associated with the existence of sterile neutrinos which mix with the active flavour neutrinos. At present there are a number of hints for active–sterile neutrino oscillations driven by Δm2∼1 eV2. We perform a detailed analysis of the RENP phenomenology within the “3+1” scheme with one sterile neutrino.

  3. An analytical model for estimating the reduction of methane emission through landfill cover soils by methane oxidation.

    Science.gov (United States)

    Yao, Yijun; Su, Yao; Wu, Yun; Liu, Weiping; He, Ruo

    2015-01-01

    Landfill is an important source of atmospheric methane (CH4). In this study, the development and partial validation are presented for an analytical model for predicting the reduction of CH4 emission in landfill cover soils by CH4 oxidation. The model combines an analytic solution of a coupled oxygen (O2) and CH4 soil gas transport in landfill covers with a piecewise first-order aerobic biodegradation, including the influences of environmental factors such as cover soil thickness, CH4 oxidation and CH4 production rate. Comparison of soil gas concentration profiles with a soil column experiment is provided for a partial validation, and then this model is applied to predict the reduction of CH4 emission through landfill covers in several other cases. A discussion is provided to illustrate the roles of soil layer thickness, reaction rate constant for CH4 oxidation and CH4 production rate in determining CH4 emissions. The results suggest that the increase of cover soil thickness cannot always increase CH4 oxidation rates or removal efficiency, which becomes constant if the thickness of landfill cover soil is larger than a limit. PMID:25464331

  4. 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.)

  5. Transition rates and transition rate diagrams in atomic emission spectroscopy: A review

    International Nuclear Information System (INIS)

    In low pressure plasmas with low electron densities, such as glow discharges, radiative de-excitation is a major de-excitation process of most excited states. Their relative de-excitation rates can be determined by emission spectroscopy, making it possible to study excitation processes in these discharges. This is in contrast to denser plasmas, in which such considerations are usually based on relative populations of excited states and concepts related to thermodynamic equilibrium. In the approach using reaction rates rather than populations, a convenient tool is the recently introduced formalism of transition rate diagrams. This formalism is reviewed, its relevance to different plasmas is discussed and some recent results on glow discharge excitation of manganese, copper and iron ions are presented. The prospects for the use of this formalism for the comparison of rate constants and cross sections for charge transfer reactions with argon ions of elements of interest in analytical glow discharge spectroscopy are discussed. - Highlights: • Radiative deexcitation is a major deexcitation process in some plasmas. • Rates of radiative transitions can be presented in transition rate diagrams. • Transition rate diagrams can be calculated based on emission spectra. • Transition rate diagrams can indicate collisional excitation processes. • Transition rate diagrams of Fe II, Cu II, Mn II in a glow discharge plasma are reviewed

  6. Applied Analytical Combustion/emissions Research at the NASA Lewis Research Center - a Progress Report

    Science.gov (United States)

    Deur, J. M.; Kundu, K. P.; Nguyen, H. L.

    1992-01-01

    Emissions of pollutants from future commercial transports are a significant concern. As a result, the Lewis Research Center (LeRC) is investigating various low emission combustor technologies. As part of this effort, a combustor analysis code development program was pursued to guide the combustor design process, to identify concepts having the greatest promise, and to optimize them at the lowest cost in the minimum time.

  7. Applied analytical combustion/emissions research at the NASA Lewis Research Center

    Science.gov (United States)

    Deur, J. M.; Kundu, K. P.; Nguyen, H. L.

    1992-01-01

    Emissions of pollutants from future commercial transports are a significant concern. As a result, the Lewis Research Center (LeRC) is investigating various low emission combustor technologies. As part of this effort, a combustor analysis code development program was pursued to guide the combustor design process, to identify concepts having the greatest promise, and to optimize them at the lowest cost in the minimum time.

  8. Analytic Solution of Charge Density of Single Wall Carbon Nanotube under Conditions of Field Electron Emission

    Institute of Scientific and Technical Information of China (English)

    LI Zhi-Bing; WANG Wei-Liang

    2006-01-01

    We derive the analytic solution of induced electrostatic potential along single wall carbon nanotubes. Under the hypothesis of constant density of states in the charge-neutral level, we are able to obtain the linear density of excess charge in an external Geld parallel to the tube axis.

  9. Analytic solution of charge density of single wall carbon nanotube in conditions of field electron emission

    OpenAIRE

    Li, Zhibing; Wang, Weiliang

    2006-01-01

    We derived the analytic solution of induced electrostatic potential along single wall carbon nanotubes. Under the hypothesis of constant density of states in the charge-neutral level, we are able to obtain the linear density of excess charge in an external field parallel to the tube axis.

  10. Method development for the determination of calcium, copper, magnesium, manganese, iron, potassium, phosphorus and zinc in different types of breads by microwave induced plasma-atomic emission spectrometry.

    Science.gov (United States)

    Ozbek, Nil; Akman, Suleyman

    2016-06-01

    A novel method was developed for the determination of calcium, magnesium, potassium, iron, copper, zinc, and manganese and phosphorous in various kinds of breads samples sold in Turkey by microwave plasma-atomic emission spectrometry (MIP-AES). Breads were dried at 100 °C for one day, ground thoroughly and then digested using nitric acid/hydrogen per oxide (3:1). The analytes in certified reference wheat flour and maize flour samples were determined in the uncertainty limits of the certified values as well as the analytes added to the mixture of ground bread and acid mixture prior to digestion were recovered quantitatively (>90%). Therefore, all determinations were made by linear calibration technique using aqueous standards. The LOD values for Ca, Cu, Fe, K, Mg, Mn, P and Zn were 13.1, 0.28, 4.47, 118, 1.10, 0.41, 7550 and 3.00 ng mL(-1), respectively. No spectral interference was detected at the working wavelengths of the analytes. PMID:26830585

  11. Identifying Student and Teacher Difficulties in Interpreting Atomic Spectra Using a Quantum Model of Emission and Absorption of Radiation

    Science.gov (United States)

    Savall-Alemany, Francisco; Domènech-Blanco, Josep Lluís; Guisasola, Jenaro; Martínez-Torregrosa, Joaquín

    2016-01-01

    Our study sets out to identify the difficulties that high school students, teachers, and university students encounter when trying to explain atomic spectra. To do so, we identify the key concepts that any quantum model for the emission and absorption of electromagnetic radiation must include to account for the gas spectra and we then design two…

  12. Continuous-flow determination of aqueous sulfur by atmospheric-pressure helium microwave-induced plasma atomic emission spectrometry with gas-phase sample introduction

    Science.gov (United States)

    Nakahara, Taketoshi; Mori, Toshio; Morimoto, Satoru; Ishikawa, Hiroshi

    1995-06-01

    A simple continuous-flow generation of volatile hydrogen sulfide and sulfur dioxide by acidification of aqueous sulfide and sulfite ions, respectively, is described for the determination of low concentrations of sulfur by atmospheric-pressure helium microwave-induced plasma atomic emission spectrometry (MIP-AES) in the normal ultraviolet (UV) and vacuum ultraviolet (VUV) regions of the spectrum. For measuring spectral lines in the VUV region, the monochromator and the enclosed external optical path between the MIP source and the entrance slit of the monochromator have both been purged with nitrogen to minimize oxygen absorption below 190 nm. Sulfur atomic emission lines at 180.73, 182.04 and 217.05 nm have been selected as the analytical lines. Of the various acids examined, 1.0 M hydrochloric acid is the most favorable for both the generation of hydrogen sulfide from sulfide ions and sulfur dioxide from sulfite ions. Either generated hydrogen sulfide or sulfur dioxide is separated from the solution in a simple gas-liquid separator and swept into the helium stream of a microwave-induced plasma for analysis. The best attainable detection limits (3 σ criterion) for sulfur at 180.73 nm were 0.13 and 1.28 ng ml -1 for the generation of hydrogen sulfide and sulfur dioxide, respectively, with the corresponding background equivalent concentrations of 20.9 and 62.2 ng ml -1 in sulfur concentration. The typical analytical working graphs obtained under the optimized experimental conditions were rectilinear over approximately four orders of magnitude in sulfur concentration. The present method has been successfully applied to the recovery test of the sulfide spiked to waste water samples and to the determination of sulfite in some samples of commercially available wine.

  13. Control of spontaneous emission from a microwave-field-coupled three-levelΛ-type atom in photonic crystals

    International Nuclear Information System (INIS)

    The spontaneous emission spectrum of a three-level Λ-type atom driven by a microwave field was studied. For the two transitions coupled to the same modified reservoir, we discussed the influence of photonic band gap and Rabi frequency of the microwave field on the emission spectrum. The emission spectrum is given for different locations of the upper band-edge frequency. With the transition frequencies moving from outside the band gap to inside, the number of peaks decreases in the emission spectrum and the multipeak structure of spectral line is finally replaced by a strong non-Lorentzian shape. With increase of the Rabi frequency of the microwave field, we find the spectral line changes from a multipeak structure to a two-peak structure, originating from the inhibition of spontaneous emission for the corresponding decay channel.

  14. Atom-specific look at the surface chemical bond using x-ray emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, A.; Wassdahl, N.; Weinelt, M. [Uppsala Univ. (Sweden)] [and others

    1997-04-01

    CO and N{sub 2} adsorbed on the late transition metals have become prototype systems regarding the general understanding of molecular adsorption. It is in general assumed that the bonding of molecules to transition metals can be explained in terms of the interaction of the frontier HOMO and LUMO molecular orbitals with the d-orbitals. In such a picture the other molecular orbitals should remain essentially the same as in the free molecule. For the adsorption of the isoelectronic molecules CO and N{sub 2} this has led to the so called Blyholder model i.e., a synergetic {sigma} (HOMO) donor and {pi} (LUMO) backdonation bond. The authors results at the ALS show that such a picture is oversimplified. The direct observation and identification of the states related to the surface chemical bond is an experimental challenge. For noble and transition metal surfaces, the adsorption induced states overlap with the metal d valence band. Their signature is therefore often obscured by bulk substrate states. This complication has made it difficult for techniques such as photoemission and inverse photoemission to provide reliable information on the energy of chemisorption induced states and has left questions unanswered regarding the validity of the frontier orbitals concept. Here the authors show how x-ray emission spectroscopy (XES), in spite of its inherent bulk sensitivity, can be used to investigate adsorbed molecules. Due to the localization of the core-excited intermediate state, XE spectroscopy allows an atomic specific separation of the valence electronic states. Thus the molecular contributions to the surface measurements make it possible to determine the symmetry of the molecular states, i.e., the separation of {pi} and {sigma} type states. In all the authors can obtain an atomic view of the electronic states involved in the formation of the chemical bond to the surface.

  15. Use of gradient dilution to flag and overcome matrix interferences in axial-viewing inductively coupled plasma-atomic emission spectrometry

    International Nuclear Information System (INIS)

    Despite the undisputed power of inductively coupled plasma-atomic emission spectrometry (ICP-AES), its users still face serious challenges in obtaining accurate analytical results. Matrix interference is perhaps the most important challenge. Dilution of a matrix-containing sample is a common practice to reduce matrix interference. However, determining the optimal dilution factor requires tedious and time-consuming offline sample preparation, since emission lines and the effect of matrix interferences are affected differently by the dilution. The current study exploits this difference by employing a high-performance liquid chromatography gradient pump prior to the nebulizer to perform on-line mixing of a sample solution and diluent. Linear gradient dilution is performed on both the calibration standard and the matrix-containing sample. By ratioing the signals from two emission lines (from the same or different elements) as a function of dilution factor, the analyst can not only identify the presence of a matrix interference, but also determine the optimal dilution factor needed to overcome the interference. A ratio that does not change with dilution signals the absence of a matrix interference, whereas a changing ratio indicates the presence of an interference. The point on the dilution profile where the ratio stabilizes indicates the optimal dilution factor to correct the interference. The current study was performed on axial-viewing ICP-AES with o-xylene as the solvent

  16. A Molecular Dynamics Study of the Static Structure, Thermodynamic and Transport Properties of Liquid Iron Using the Modified Analytic Embedded Atom Method

    OpenAIRE

    DALGIÇ, Serap Şentürk; KOÇOĞLU, İbrahim

    2006-01-01

    Using the modified analytic embedded atom method (MAEAM), we have carried out molecular dynamics (MD) simulation to compute structure,thermodynamic and transport properties of liquid iron. The Foiles type effective pair potential based on the MAEAM potential functions proposed by Quyang and co-workers are shown to predict the pair distribution function well near its melting. The calculated thermodynamic properties such as, the internal energy, Helmholtz free energy and entropy are in...

  17. [Study of characteristics of excited O atom generated in multi-needle-to-plate corona discharge by emission spectroscopy].

    Science.gov (United States)

    Ge, Hui; Yan, Ling; Mi, Dong; Zhu, Yi-min; Zhang, Lu

    2012-04-01

    The emission spectra of O(3p 5 P --> 3s 5 S2(0) 777.4 nm) produced by multi-needle-to-plate negative corona discharge and positive streamer discharge in air were successfully recorded at one atmosphere. The influences of discharge power, electrode gap, content of N2 and relative humidity on the excited O atom production were investigated in negative corona discharge. Meanwhile, the distribution of relative density of excited O atom in discharge space was also studied in positive streamer discharge. The results indicate that, for negative corona discharge, the amount of O active atom increases with the increase in power, decreases with increased discharge gap. And with the increase in relative humidity and N2 content, its amount firstly increases and then decreases; whereas for positive corona discharge, the relative density of O active atom from needlepoint to plate firstly increases and then decreases. PMID:22715745

  18. An analytical study of nitrogen oxides and carbon monoxide emissions in hydrocarbon combustion with added nitrogen, preliminary results

    Science.gov (United States)

    Bittker, D. A.

    1979-01-01

    The effect of combustor operating conditions on the conversion of fuel-bound nitrogen (FBN) to nitrogen oxides NO sub x was analytically determined. The effect of FBN and of operating conditions on carbon monoxide (CO) formation was also studied. For these computations, the combustor was assumed to be a two stage, adiabatic, perfectly-stirred reactor. Propane-air was used as the combustible mixture and fuel-bound nitrogen was simulated by adding nitrogen atoms to the mixture. The oxidation of propane and formation of NO sub x and CO were modeled by a fifty-seven reaction chemical mechanism. The results for NO sub x and CO formation are given as functions of primary and secondary stage equivalence ratios and residence times.

  19. Determination of eight trace elements in doped crystal ALN by inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    Complete text of publication follows. In this paper, an accurate and simple method has been developed for the determination of trace Cr, Co, Cu, Fe, Mg, Mn ,Ni and Zn in doped AlN crystal using inductively coupled plasma atomic emission spectrometry (ICP-AES). AlN crystal becomes ideal substrate for the epitaxial growth of GaN, AlGaN with high Al ingredient and AlN which are used to fabricate ultraviolet LEDs, blue- ultraviolet solid state LDs, lasers, ultraviolet detectors. At present, It is a very important aspect for scientific workers to promote in the transition metals elements doped AlN showing ferromagne. Owing its low detection limits and multi-element capability, ICP-AES has been used in many fields.The optimum instrument working conditions are selected .AlN crystal was fused with KOH and the fusion product was dissolved in dilute aqua regia. Matrix effect from KOH and interference to the spectral lines of the elements to be determined were investigated and corrected by matrix matching and background correction method. Detection limits of elements were 0.01% to 0.0002% The recoveries for elements were 98% to 104%. The relative standard deviation was 0.5% to 4.0%.

  20. Direct solid soil analysis by laser ablation inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    Determination of heavy metals in soils by inductively coupled plasma atomic emission spectrometry (ICP-AES) usually involves the time-consuming step of preparing a solution of the solid that is then nebulized into the plasma. According to regulations, digestion by aqua regia(hydrochloric acid + nitric acid, 3 + 1) should be carried out although it is known that this method is incomplete for silicate soils. The problem can be eliminated by introducing the solid directly into the plasma using the laser ablation technique for sampling. Results are described for a study of laser ablation using a Q-switched Nd: YAG laser coupled with a new échelle spectrometer which has a multichannel solid-state detector. The laser pulses were focused onto the solid surface of pressed soil samples to generate an aerosol which is entrained in a flowing Ar stream, transported through a tube and then introduced directly into the inductively coupled plasma. Some characteristics of the preparation technique, the selection of an internal standard and homogeneity tests of the elemental distribution are reported along with a comparison and evaluation of three methods of calibration. The criteria used to measure the performance of laser ablation ICP-AES are the relative standard deviations obtained of 4.9–12.7% and the accuracy, 0.3–12.4% for Fe, Mn, Cu, Pb, Cr, Zn and Ni

  1. Combination of the ionic-to-atomic line intensity ratios from two test elements for the diagnostic of plasma temperature and electron number density in Inductively Coupled Plasma Atomic Emission Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tognoni, E. [Istituto per i Processi Chimico-Fisici, Area della Ricerca del Consiglio Nazionale delle Ricerche Via Moruzzi 1, 56124 Pisa (Italy)], E-mail: tognoni@ipcf.cnr.it; Hidalgo, M.; Canals, A. [Departamento de Quimica Analitica, Nutricion y Bromatologia. Universidad de Alicante. Apdo. 99, 03080, Alicante (Spain); Cristoforetti, G.; Legnaioli, S.; Salvetti, A.; Palleschi, V. [Istituto per i Processi Chimico-Fisici, Area della Ricerca del Consiglio Nazionale delle Ricerche Via Moruzzi 1, 56124 Pisa (Italy)

    2007-05-15

    In Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) spectrochemical analysis, the MgII(280.270 nm)/MgI(285.213 nm) ionic to atomic line intensity ratio is commonly used as a monitor of the robustness of operating conditions. This approach is based on the univocal relationship existing between intensity ratio and plasma temperature, for a pure argon atmospheric ICP in thermodynamic equilibrium. In a multi-elemental plasma in the lower temperature range, the measurement of the intensity ratio may not be sufficient to characterize temperature and electron density. In such a range, the correct relationship between intensity ratio and plasma temperature can be calculated only when the complete plasma composition is known. We propose the combination of the line intensity ratios of two test elements (double ratio) as an effective diagnostic tool for a multi-elemental low temperature LTE plasma of unknown composition. In particular, the variation of the double ratio allows us discriminating changes in the plasma temperature from changes in the electron density. Thus, the effects on plasma excitation and ionization possibly caused by introduction of different samples and matrices in non-robust conditions can be more accurately interpreted. The method is illustrated by the measurement of plasma temperature and electron density in a specific analytic case.

  2. Combination of the ionic-to-atomic line intensity ratios from two test elements for the diagnostic of plasma temperature and electron number density in Inductively Coupled Plasma Atomic Emission Spectroscopy

    International Nuclear Information System (INIS)

    In Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) spectrochemical analysis, the MgII(280.270 nm)/MgI(285.213 nm) ionic to atomic line intensity ratio is commonly used as a monitor of the robustness of operating conditions. This approach is based on the univocal relationship existing between intensity ratio and plasma temperature, for a pure argon atmospheric ICP in thermodynamic equilibrium. In a multi-elemental plasma in the lower temperature range, the measurement of the intensity ratio may not be sufficient to characterize temperature and electron density. In such a range, the correct relationship between intensity ratio and plasma temperature can be calculated only when the complete plasma composition is known. We propose the combination of the line intensity ratios of two test elements (double ratio) as an effective diagnostic tool for a multi-elemental low temperature LTE plasma of unknown composition. In particular, the variation of the double ratio allows us discriminating changes in the plasma temperature from changes in the electron density. Thus, the effects on plasma excitation and ionization possibly caused by introduction of different samples and matrices in non-robust conditions can be more accurately interpreted. The method is illustrated by the measurement of plasma temperature and electron density in a specific analytic case

  3. Effect of early injection strategy on spray atomization and emission reduction characteristics in bioethanol blended diesel fueled engine

    International Nuclear Information System (INIS)

    This study is to investigate the emission reduction characteristics of bioethanol blended diesel fuel at early injection condition including spray, atomization and evaporation characteristics. The spray atomization and evaporation characteristics were investigated using spray visualization system and KIVA-3V code, respectively. In this work, the effect of ethanol blending on the spray behavior is more evident at early injection condition. In the calculation results, the droplet size of bioethanol blended fuel was smaller than that of diesel, and bioethanol blended diesel droplets firstly evaporated by its volatility and superior atomization characteristics. In early injection condition, the bioethanol blending caused an increase in indicated mean effective pressure with an extension of the ignition delay. The cooling effect of the bioethanol fuel reduced NOx. The HC emission increased and the CO emission decreased because of the ethanol blending. The geometry mean diameter and total number density increased as a result of ethanol blending, the particle number in the nuclei mode decreased, and the particle number in the accumulation mode increased in early injection condition. -- Highlights: ► The overall spray, combustion and emission characteristics of bioethanol-blended diesel fuel are measured. ► Experimental results are compared in the early injection- and the conventional injection cases. ► Atomization and evaporation characteristics of diesel-bioethanol blended fuel were numerically analyzed using KIVA-3V. ► In the early injection cases, the cooling effect of bioethanol fuel is clearer compared to the conventional injection. ► By the early injection strategy with bioethanol blended diesel fuel, the exhaust emissions can be significantly reduced.

  4. Determination of trace elements in Egyptian cane sugar (Deshna Factories) by neutron activation, atomic absorption spectrophotometric and inductively coupled plasma-atomic emission spectrometric analysis

    International Nuclear Information System (INIS)

    Multielement instrumental neutron activation (INAA), inductively coupled plasma-atomic emission spectrometric (ICP-AES) and atomic absorption spectrophotometric (AAS) analyses were utilized for the determination of Ag, Al, As, Au, Ba, Be, Br, Ca, Cd, Ce, Cl, Co, Cr, Cu, Eu, Fe, Ga, Hf, K, La, Li, Lu, Mg, Mn, Na, Nb, Ni, P, Pb, Sb, Sc, Se, Sm, Sn, Sr, Ta, Th, Ti, U, V, W and Zn in sugar cane plant, raw juice, juice in different stages, syrup, deposits, molasses, A, B and C sugar, refinery 1 and 2 sugar, and in soil samples picked up from the immediate vicinity of the cane plant roots at surface, 30 and 60 cm depth, respectively. (author)

  5. An analytical continuation approach for evaluating emission lineshapes of molecular aggregates and the adequacy of multichromophoric F\\"orster theory

    CERN Document Server

    Banchi, Leonardo; Ishizaki, Akihito; Giorda, Paolo

    2013-01-01

    In large photosynthetic chromophore-protein complexes not all chromophores are coupled strongly, and thus the situation is well described by formation of delocalized states in certain domains of strongly coupled chromophores. In order to describe excitation energy transfer among different domains without performing extensive numerical calculations,one of the most popular techniques is a generalization of Forster theory to multichromophoric aggregates (generalized Forster theory) proposed by Sumi [J.Phys.Chem.B,103,252(1999)] and Scholes and Fleming [J.Phys.Chem.B 104,1854(2000)]. The aim of this paper is twofold. In the first place, by means of analytic continuation and a time convolutionless quantum master equation approach, a theory of emission lineshape of multichromophoric systems or molecular aggregates is proposed. In the second place,a comprehensive framework that allows for a clear,compact and effective study of the multichromophoric approach in the full general version proposed by Jang, Newton and Si...

  6. Utilization of synchrotron radiation in analytical chemistry. Soft X-ray emission and absorption spectroscopy

    International Nuclear Information System (INIS)

    Synchrotron soft X-ray spectroscopy includes three major types of spectroscopy such as X-ray absorption spectroscopy (XAS), X-ray emission spectroscopy (XES), and X-ray photoelectron spectroscopy (XPS). This paper takes up XAS and XES of soft X-rays, and briefly describes the principle. XAS is roughly classified into XANES (X-ray absorption near-edge structure) and EXAFS (extended X-ray absorption fine structure), and XANES is mainly used in the analysis based on XAS of soft X-rays. As the examples of the latest soft X-ray analyses, the following are introduced: (1) bandgap of boron implantation diamond and the local structure of boron, (2) catalytic sites in solid fuel cell carbon electrode, and (3) soft X-ray analysis under atmospheric pressure. (A.O.)

  7. Excitation of O(1D) atoms in aurorae and emission of the forbidden OI 6300-A line

    Science.gov (United States)

    Rees, M. H.; Roble, R. G.

    1986-01-01

    The electron aurora leads to six processes capable of exciting the O(1D2) metastable state of the atomic-oxygen ground-state configuration, the parent state of the 6300-A red line. Altitude profiles of the volume emission rate resulting from each process are computed for Maxwellian electron spectra with characteristic energies between 0.1 and 2.0 keV. Since each process peaks at a different altitude, the sum or total volume emission rate extends over a wide altitude range. Measurements of 6300-A emission obtained by rocket and satellite-borne instruments are summarized, and it is shown that the chemical reaction of N(2D) with O2 is the major source of O(1D) atoms in the electron aurora. New calculations of the 6300-A:4728-A column emission-rate ratio are presented for a range of characteristic energies in an assumed Maxwellian electron spectrum. An approximate equation for the red-line emission per unit energy input is given as a function of electron-spectrum characteristic energy.

  8. INVESTIGATIONS OF SUPERCONDUCTING AND NON-SUPERCONDUCTING YBa2 Cu3 O7-x BY FIELD ION MICROSCOPY, ATOM-PROBE MASS SPECTROSCOPY AND FIELD ELECTRON EMISSION

    OpenAIRE

    Kellogg, G.; Brenner, S

    1988-01-01

    The structure and composition of superconducting and non-superconducting samples of YBa2Cu3O7-x were examined by field ion microscopy, atom-probe mass spectroscopy and field-electron emission techniques. Field ion microscope images from both types of material exhibited ring structures associated with atomic or multiatomic layers and uniform, layer-by-layer field evaporation was possible. Atom-probe mass spectra contained signals corresponding to atomic and molecular oxygen, all three metals, ...

  9. Preconcentration of uranium, thorium, zirconium, titanium, molybdenum and vanadium with oxine supported on microcrystalline naphthalene and their determinations by inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    A sensitive and rapid method for the determination of uranium, thorium, zirconium, titanium, molybdenum and vanadium by inductively coupled plasma atomic emission spectrometry (ICP-AES) after solid-liquid extraction with microcrystalline naphthalene is developed. Analytes were quantitatively adsorbed as their oxinate complexes on naphthalene and determined by ICP-AES after stripping with 2 M HCl. The effect of various experimental parameters such as pH, reagent amounts, naphthalene amount and stripping conditions on the determination of these elements was investigated in detail. Under the optimized experimental conditions, the detection limits of this method for U (VI), Th (IV), Zr (IV), Ti (IV), Mo (VI) and V (V) were 20.0 ng mL-1 and the relative standard deviations obtained for three replicate determinations at a concentration of 1.0 µg mL-1 were 1.5-3.0%. The proposed method has been applied in the analysis of SY-2, SY-3 and pre-analysed samples for U, Th, Zr, Ti, Mo and V the analytical results are in good agreement with recommended values. (author)

  10. Determination of rare earth elements, thorium, and uranium in mussel, ark shell, and coral by inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    The determination of rare earth elements, thorium, and uranium in mussel, ark shell, and coral was made by inductively coupled plasma atomic emission spectrometry(ICP-AES). Four samples of mussels, original mussles, and mussels powdered by the original standard method, were dissolved with a mixture of HNO3 and HClO4. For one part of the sample solution, coprecipitation by ferric hydroxide was applied. Analytical values obtained with and without coprecipitation showed good agreement. The sample solutions for shells and coral were prepared by acid decomposition, and the elements to be determined were separated from calcium by coprecipitation to eliminate spectral interference by calcium. Analytical values were obtained from the calibration curves made with standard solutions containing matrix components at concentrations similar to those for real samples solutions. The concentrations of rare earth elements, Th and U in sample solutions of mussel ranged from 0.001 μg/g to 0.2 μg/g. The concentrations of rare earth elements and Th in mussel, shells, and coral are 2000 -- 15000 times higher than those in sea water. (author)

  11. Gunshot residue testing in suicides: Part II: Analysis by inductive coupled plasma-atomic emission spectrometry.

    Science.gov (United States)

    Molina, D Kimberley; Castorena, Joe L; Martinez, Michael; Garcia, James; DiMaio, Vincent J M

    2007-09-01

    Several different methods can be employed to test for gunshot residue (GSR) on a decedent's hands, including scanning electron microscopy with energy dispersive x-ray (SEM/EDX) and inductive coupled plasma-atomic emission spectrometry (ICP-AES). In part I of this 2-part series, GSR results performed by SEM/EDX in undisputed cases of suicidal handgun wounds were studied. In part II, the same population was studied, deceased persons with undisputed suicidal handgun wounds, but GSR testing was performed using ICP-AES. A total of 102 cases were studied and analyzed for caliber of weapon, proximity of wound, and the results of the GSR testing. This study found that 50% of cases where the deceased was known to have fired a handgun immediately prior to death had positive GSR results by ICP/AES, which did not differ from the results of GSR testing by SEM/EDX. Since only 50% of cases where the person is known to have fired a weapon were positive for GSR by either method, this test should not be relied upon to determine whether someone has discharged a firearm and is not useful as a determining factor of whether or not a wound is self-inflicted or non-self-inflicted. While a positive GSR result may be of use, a negative result is not helpful in the medical examiner setting as a negative result indicates that either a person fired a weapon prior to death or a person did not fire a weapon prior to death. PMID:17721164

  12. Identifying student and teacher difficulties in interpreting atomic spectra using a quantum model of emission and absorption of radiation

    Science.gov (United States)

    Savall-Alemany, Francisco; Domènech-Blanco, Josep Lluís; Guisasola, Jenaro; Martínez-Torregrosa, Joaquín

    2016-06-01

    Our study sets out to identify the difficulties that high school students, teachers, and university students encounter when trying to explain atomic spectra. To do so, we identify the key concepts that any quantum model for the emission and absorption of electromagnetic radiation must include to account for the gas spectra and we then design two questionnaires, one for teachers and the other for students. By analyzing the responses, we conclude that (i) teachers lack a quantum model for the emission and absorption of electromagnetic radiation capable of explaining the spectra, (ii) teachers and students share the same difficulties, and (iii) these difficulties concern the model of the atom, the model of radiation, and the model of the interaction between them.

  13. Analytical validation of near-zero emissions from coal-fired plants and how to enable compliance with regulations

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Kenneth; Bossoutrot, Valerie; Mauvais, Patrick; Carre, Martine; Jacksier, Tracey [Air Liquide Delaware Reserach and Technology Center, Newark, DE (United States); Riviere, Morgane; Missault, Daniel

    2011-11-15

    Coal accounts for a significant percentage of the worldwide electricity generation. However, coal is one of the most impure fuels. The impurities include Al, Fe, S and Hg. These impurities, which are generated during combustion, can be adsorbed onto particles which result from the combustion process and can be emitted into the atmosphere. Oxycombustion along with purification is a leading technology to create a near-zero emissions plant by eliminating almost all of the mercury, SOx, NOx, and particulate pollutants from plant emissions. This technology provides a > 90 % CO{sub 2} stream which is suitable for safe and permanent storage (carbon capture and sequestration). The decreased generation of impurities in the CO{sub 2} stream will prevent release of these impurities into the environment. The capability of this solution is based on analytical validation of the impurities in the process stream(s). The complexity of NOx and SOx measurements in CO{sub 2}-rich streams, which will enable compliance to both existing and emerging regulations, is discussed in this contribution. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Yong Sam; Choi, Kwang Soon; Moon, Jong Hwa; Kim, Sun Ha; Lim, Jong Myoung; Kim, Young Jin [KAERI, Taejon (Korea, Republic of); Quraishi, Shamshad Begum [Bangladesh Atomic Energy Commission, Dhaka (Bangladesh)

    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)

  15. Estimation of zirconium in Zr-C-Nb alloy by Inductively Coupled Plasma-Atomic Emission Spectrometry technique

    International Nuclear Information System (INIS)

    The present paper discusses a new method developed for estimation of Zirconium (Zr) in Niobium alloy by Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES). The present procedure involves dissolution of Niobium alloy in a mixture of Sulfuric acid, Nitric acid and Hydro Fluoric acid and subsequent analysis of Zr in Niobium alloy by sequential ICP-AES (Model: JY Ultima 2C HR). A Relative Standard Deviation of less than ± 5% has been achieved in this method. (author)

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

    International Nuclear Information System (INIS)

    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)

  17. Projectile X-ray emission in relativistic ion-atom collisions

    Energy Technology Data Exchange (ETDEWEB)

    Salem, Shadi Mohammad Ibrahim

    2010-03-16

    This work reports on the study of the projectile X-ray emission in relativistic ion-atom collisions. Excitation of K-shell in He-like uranium ions, electron capture into H-like uranium ions and Simultaneous ionization and excitation of initially He-like uranium ions have been studied using the experimental storage ring at GSI. For the K{sub {alpha}}{sub 1} and K{sub {alpha}}{sub 2} transitions originating from the excitation of the He-like uranium ions, no alignment was observed. In contrast, the Ly{sub {alpha}}{sub 1} radiation from the simultaneous ionization-excitation process of the He-like uranium ions shows a clear alignment. The experimental value leads to the inclusion of a magnetic term in the interaction potential. The capture process of target electrons into the highly-charged heavy ions was studied using H-like uranium ions at an incident energy of 220 MeV/u, impinging on N{sub 2} gas-target. It was shown that, the strongly aligned electrons captured in 2p{sub 3/2} level couple with the available 1s{sub 1/2} electron which shows no initial directional preference. The magnetic sub-state population of the 2p{sub 3/2} electron is redistributed according to the coupling rules to the magnetic sub-states of the relevant two-electron states. This leads to the large anisotropy in the corresponding individual ground state transitions contributing to the K{sub {alpha}}{sub 1} emission. From the K{sub {alpha}}{sub 1}/K{sub {alpha}}{sub 2} ratio, the current results show that the incoherent addition of the E1 and M2 transition components yield to an almost isotropic emission of the total K{sub {alpha}}{sub 1}. In contrast to the radiative electron capture, the experimental results for the K-shell single excitation of He-like uranium ions indicate that only the {sup 1}P{sub 1} level contributes to the K{sub {alpha}}{sub 1} transition. For this case, the anisotropy parameter {beta}{sub 20} was found to be -0.20{+-}0.03. This work also reports on the study of a two

  18. Activation of extended red emission photoluminescence in carbon solids by exposure to atomic hydrogen and UV radiation

    Science.gov (United States)

    Furton, Douglas G.; Witt, Adolf N.

    1993-01-01

    We report on new laboratory results which relate directly to the observation of strongly enhanced extended red emission (ERE) by interstellar dust in H2 photodissociation zones. The ERE has been attributed to photoluminescence by hydrogenated amorphous carbon (HAC). We are demonstrating that exposure to thermally dissociated atomic hydrogen will restore the photoluminescence efficiency of previously annealed HAC. Also, pure amorphous carbon (AC), not previously photoluminescent, can be induced to photoluminesce by exposure to atomic hydrogen. This conversion of AC into HAC is greatly enhanced by the presence of UV irradiation. The presence of dense, warm atomic hydrogen and a strong UV radiation field are characteristic environmental properties of H2 dissociation zones. Our results lend strong support to the HAC photoluminescence explanation for ERE.

  19. Analysis of Si3N4 ultra fine powder using high-pressure acid digestion and slurry injection in inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    Si3N4 powder has been analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES). The sample was dissolved by high-pressure acid digestion with HF, H2SO4 (1+1), and HNO3 mixture. This technique is well suited for the impurity analysis of Si3N4 because the matrix interference is eliminated. A round robin samples trace elements, such as Ca, W, Co, Al, Fe, Mg, and Na, were determined. For the direct analysis, slurry nebulization of 0.96 mm Si3N4 powder also has been studied by ICP-AES. Emission intensities of Fe were measure as ICP operational conditions were changed. Significant signal difference between slurry particles and aqueous solution was observed in the present experiment. Analytical results of slurry injection and high-pressure acid digestion were compared. For the use of aqueous standard solution for calibration, k-factor was determined to be 1.71 for further application

  20. Zeeman effects in the hyperfine structure of atomic iodine photodissociation laser emission.

    Science.gov (United States)

    Hwang, W. C.; Kasper, J. V. V.

    1972-01-01

    Observation of hyperfine structure in laser emission from CF3I and C2F5I photodissociation lasers. Constant magnetic fields affect the time behavior of the emission by changing the relative gains of the hyperfine transitions. Time-varying fields usually present in photodissociation lasers further complicate the emission.

  1. Daily and hourly sourcing of metallic and mineral dust in urban air contaminated by traffic and coal-burning emissions

    NARCIS (Netherlands)

    Moreno, T.; Karanasiou, A.; Amato, F.; Lucarelli, F.; Nava, S.; Calzolai, G.; Chiari, M.; Coz, E.; Artíñano, B.; Lumbreras, J.; Borge, R.; Boldo, E.; Linares, C.; Alastuey, A.; Querol, X.; Gibbons, W.

    2013-01-01

    A multi-analytical approach to chemical analysis of inhalable urban atmospheric particulate matter (PM), integrating particle induced X-ray emission, inductively coupled plasma mass spectrometry/atomic emission spectroscopy, chromatography and thermal-optical transmission methods, allows comparison

  2. Coupled Chemistry-Emission Model for Atomic Oxygen Green and Red-doublet Emissions in Comet C/1996 B2 Hyakutake

    CERN Document Server

    Bhardwaj, Anil

    2012-01-01

    The green (5577 \\AA) and red-doublet (6300, 6364 \\AA) lines are prompt emissions of metastable oxygen atoms in the $^1$S and $^1$D states, respectively, that have been observed in several comets. The value of intensity ratio of green to red-doublet (G/R ratio) of 0.1 has been used as a benchmark to identify the parent molecule of oxygen lines as H$_2$O. A coupled chemistry-emission model is developed to study the production and loss mechanisms of O($^1$S) and O($^1$D) atoms and the generation of red and green lines in the coma of C/1996 B2 Hyakutake. The G/R ratio depends not only on photochemistry, but also on the projected area observed for cometary coma, which is a function of the dimension of the slit used and geocentric distance of the comet. Calculations show that the contribution of photodissociation of H$_2$O to the green (red) line emission is 30 to 70% (60 to 90%), while CO$_2$ and CO are the next potential sources contributing 25 to 50% ($<$5%). The ratio of the photo-production rate of O($^1$S)...

  3. Analytic Evaluation of Three Different Five-Electron Atomic Integrals Involving Exponentially Correlated Functions of $r_{ij}$ With $r_{ij}$'s Not Forming A Closed Loop

    CERN Document Server

    Padhy, B

    2016-01-01

    The simple method outlined in our earlier paper [B.Padhy, Orissa Journal of Physics, vol.19, No.1, p.1, February 2012] has been utilized here for analytic evaluation of three different five-electron atomic integrals with integrands involving products of s Slater-type orbitals and exponentially correlated functions of the form $r_{ij} exp(-\\lambda_{ij} r_{ij})$. Only products of those $r_{ij}$'s which do not form a closed loop by themselves, are considered.

  4. A novel analytical system involving hydride generation and gold-coated W-coil trapping atomic absorption spectrometry for selenium determination at ng l-1 level

    International Nuclear Information System (INIS)

    A novel analytical technique was developed where gaseous hydrogen selenide formed by sodium tetrahydroborate reduction is transported to and trapped on a resistively heated gold-coated W-coil atom trap for in situ preconcentration. Gold coating on W-coil was prepared by using an organic solution of Au. The atom trap is held at 165 oC during the collection stage and is heated up to 675 deg. C for revolatilization; analyte species formed are transported to an externally heated quartz T-tube where the atomization takes place and the transient signal is obtained. The carrier gas consisted of 112.5 ml min-1 Ar with 75 ml min-1 H2 during the collection step and 112.5 ml min-1 Ar with 450 ml min-1 H2 in the revolatilization step. The half width of the transient signal obtained is less than 0.5 s. The RSD for the measurements was found to be 3.9% (n = 11) for 0.10 μg l-1 Se using peak height measurements. The calibration plot for 27.0 ml of sample collected in 4.0 min using a flow rate of 6.75 ml min-1 was linear between 0.13 and 2.0 μg l-1 of Se. The limit of detection (3 s) is 39 ng l-1. The enhancement factor for the characteristic concentration (Co) was found to be 20.1 when compared to conventional hydride generation atomic absorption spectrometry system without trap. In order to check the accuracy of the method, standard reference material, natural water NIST 1640 was employed; the result was found to be in good agreement with the certified value at the 95% confidence level

  5. Electron-Stimulated Emission of Na Atoms from NaCl Nanocube Corners

    OpenAIRE

    Ceresoli, D.; Zykova-Timan, T.; Tosatti, E.

    2006-01-01

    We performed first principles density functional calculations and simulations of magic-size neutral NaCl nanocubes, and computed the the extraction of a Na neutral corner atom after donating an electron. The atomic structure of the resulting Na corner vacancy is presented.

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

    International Nuclear Information System (INIS)

    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

  7. Dephasing dynamics of Rydberg atom spin waves

    CERN Document Server

    Bariani, F; Kennedy, T A B

    2012-01-01

    A theory of Rydberg atom interactions is used to derive analytical forms for the spin wave pair correlation function in laser-excited cold-atom vapors. This function controls the quantum statistics of light emission from dense, inhomogeneous clouds of cold atoms of various spatial dimensionalities. The results yield distinctive scaling behaviors on the microsecond timescale, including generalized exponential decay. A detailed comparison is presented with a recent experiment on a cigar-shaped atomic ensemble [Y. Dudin and A. Kuzmich, Science 336, 887 (2012)], in which Rb atoms are excited to a set of Rydberg levels.

  8. An Approach to the Control Management of Gaseous Pollutants Emissions from Power Plants Using Analytic Hierarchy Process (AHP

    Directory of Open Access Journals (Sweden)

    FATEMEH TANHA

    2015-10-01

    Full Text Available Population growth, industrial pollution and high-energy consumption, cause the release of significant amounts of pollutants in the environment. Power plants play an important role in the release of pollutants such as sulfur dioxide, nitrogen oxides, and carbon dioxide. If the necessary measures in the field of prevention and control do not be implemented, human health and other living creatures would be at risk. The aim of this study was to control management of gaseous pollutants emissions from power plants using Analytic Hierarchy Process (AHP. In this study, first, the emission rate of power plant pollutants from existing monitors was directly examined. In order to determine priority control from a variety of pollutants, SO2, NOX, and CO2 gases were selected using the AHP method. Assessment criteria were determined using previous studies. To specify the priority control first the weight matrix of criteria determination and then the relative weight of each of the pollutants was identified. Finally, the ultimate weight of each pollutant was identified using the calculation of the arithmetic mean in the AHP method. Among the trio-selected pollutants determined for priority control, the NOX  with the final weight of 0.577 was regarded as the first priority, SO2  with the final weight of 0.32 considered as the second priority and the third priority was specified to CO2  with the final weight of 0.093. The present study is a new approach to identify and prioritize pollutants. It has provided the ability to plan and carry out the appropriate control design for power plant pollutants.

  9. Use of stirred tanks for studying matrix effects caused by inorganic acids, easily ionized elements and organic solvents in inductively coupled plasma atomic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Paredes, Eduardo [Departamento de Quimica Analitica, Nutricion y Bromatologia, University of Alicante, 03080 Alicante (Spain); Maestre, Salvador E. [Departamento de Quimica Analitica, Nutricion y Bromatologia, University of Alicante, 03080 Alicante (Spain); Todoli, Jose L. [Departamento de Quimica Analitica, Nutricion y Bromatologia, University of Alicante, 03080 Alicante (Spain)]. E-mail: jose.todoli@ua.es

    2006-03-15

    A stirred tank was used for the first time to elucidate the mechanism responsible for inductively coupled plasma atomic emission spectroscopy (ICP-AES) matrix effects caused by inorganic, acids and easily ionized elements (EIEs), as well as organic, ethanol and acetic acid, compounds. In order to gradually increase the matrix concentration, a matrix solution was introduced inside a stirred container (tank) initially filled with an aqueous multielement standard. PolyTetraFluoroEthylene (PTFE) tubing was used to deliver the resulting solution to the liquid sample introduction system. Matrix concentration ranged from 0 to 2 mol l{sup -1} in the case of inorganic acids (i.e., nitric, sulfuric, hydrochloric and a mixture of them), from 0 to about 2500 mg l{sup -1} for EIEs (i.e., sodium, calcium and mixtures of both) and from 0% to 15%, w/w for organic compounds. Up to 40-50 different solutions were prepared and measured in a period of time shorter than 6-7 min. This investigation was carried out in terms of emission intensity and tertiary aerosols characteristics. The experimental setup used in the present work allowed to thoroughly study the effect of matrix concentration on analytical signal. Generally speaking, the experiments concerning tertiary aerosol characterization revealed that, in the case of inorganic acids and EIEs, the mechanism responsible for changes in aerosol characteristics was the droplet fission. In contrast, for organic matrices it was found that the interference was caused by a change in both aerosol transport and plasma thermal characteristics. The extent of the interferences caused by organic as well as inorganic compounds was compared for a set of 14 emission lines through a wide range of matrix concentrations. With a stirred tank, it is possible to choose an efficient internal standard for any given matrix composition. The time required to complete this procedure was shorter than 7 min.

  10. Use of stirred tanks for studying matrix effects caused by inorganic acids, easily ionized elements and organic solvents in inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    A stirred tank was used for the first time to elucidate the mechanism responsible for inductively coupled plasma atomic emission spectroscopy (ICP-AES) matrix effects caused by inorganic, acids and easily ionized elements (EIEs), as well as organic, ethanol and acetic acid, compounds. In order to gradually increase the matrix concentration, a matrix solution was introduced inside a stirred container (tank) initially filled with an aqueous multielement standard. PolyTetraFluoroEthylene (PTFE) tubing was used to deliver the resulting solution to the liquid sample introduction system. Matrix concentration ranged from 0 to 2 mol l-1 in the case of inorganic acids (i.e., nitric, sulfuric, hydrochloric and a mixture of them), from 0 to about 2500 mg l-1 for EIEs (i.e., sodium, calcium and mixtures of both) and from 0% to 15%, w/w for organic compounds. Up to 40-50 different solutions were prepared and measured in a period of time shorter than 6-7 min. This investigation was carried out in terms of emission intensity and tertiary aerosols characteristics. The experimental setup used in the present work allowed to thoroughly study the effect of matrix concentration on analytical signal. Generally speaking, the experiments concerning tertiary aerosol characterization revealed that, in the case of inorganic acids and EIEs, the mechanism responsible for changes in aerosol characteristics was the droplet fission. In contrast, for organic matrices it was found that the interference was caused by a change in both aerosol transport and plasma thermal characteristics. The extent of the interferences caused by organic as well as inorganic compounds was compared for a set of 14 emission lines through a wide range of matrix concentrations. With a stirred tank, it is possible to choose an efficient internal standard for any given matrix composition. The time required to complete this procedure was shorter than 7 min

  11. Emission, optical--optical double resonance, and excited state absorption spectroscopy of matrix isolated chromium and molybdenum atoms

    International Nuclear Information System (INIS)

    Making use of a combination of time-resolved emission, optical--optical double resonance, and excited state absorption spectroscopy, it has been possible to assign virtually all spectral features with energies below the z7P0 state of matrix isolated Cr atoms. The a5S state located at 7593 cm-1 in the free gaseous Cr atom has lifetimes of 6.32 and 5.1 s in Ar and Kr matrices, respectively. Matrix perturbations on Cr emission lines are small (-1). The dependence of nonradiative decay rates on the local density of states is elucidated. The magnitude of matrix shifts for a particular transition is correlated with the electronic configurations of ground and excited states and it is pointed out that states having only ''s'' electrons in addition to ''d'' electrons maintain their gas phase energy relationships in the matrix environment. Direct fluorescence is observed from the z7P0 level of Mo to the 7s ground state. The spin-orbit splitting of the ''relaxed'' z7P0 state is 690 cm-1, slightly lower than the 707 cm-1 splitting of the free gaseous Mo atom

  12. Comment on "Effect of entanglement on the decay dynamics of a pair of H(2p) atoms due to spontaneous emission"

    OpenAIRE

    Sancho, Pedro; Plaja, Luis

    2011-01-01

    Tanabe et al (Phys. Rev. A {\\bf 82} 040101(R) 2010) have experimentally demonstrated that the emission properties of unstable atoms in entangled and product states are different. The authors define an apparent decay time as a fitting parameter which falls below the lifetime of the single atom for entangled pairs. We argue that their results about coincidence time spectra are correct, but those concerning lifetimes cannot be considered conclusive because they assume the emission of photons by ...

  13. Analytical Study of the Effect of the System Geometry on Photon Sensitivity and Depth of Interaction of Positron Emission Mammography

    Directory of Open Access Journals (Sweden)

    Pablo Aguiar

    2012-01-01

    Full Text Available Positron emission mammography (PEM cameras are novel-dedicated PET systems optimized to image the breast. For these cameras it is essential to achieve an optimum trade-off between sensitivity and spatial resolution and therefore the main challenge for the novel cameras is to improve the sensitivity without degrading the spatial resolution. We carry out an analytical study of the effect of the different detector geometries on the photon sensitivity and the angle of incidence of the detected photons which is related to the DOI effect and therefore to the intrinsic spatial resolution. To this end, dual head detectors were compared to box and different polygon-detector configurations. Our results showed that higher sensitivity and uniformity were found for box and polygon-detector configurations compared to dual-head cameras. Thus, the optimal configuration in terms of sensitivity is a PEM scanner based on a polygon of twelve (dodecagon or more detectors. We have shown that this configuration is clearly superior to dual-head detectors and slightly higher than box, octagon, and hexagon detectors. Nevertheless, DOI effects are increased for this configuration compared to dual head and box scanners and therefore an accurate compensation for this effect is required.

  14. PIXE in 1980: Summary of the second international conference on particle induced x-ray emission and its analytical applications

    International Nuclear Information System (INIS)

    The Second International Conference on Particle Induced X-ray Emission (PIXE) and its analytical applications was held in Lund, Sweden, June 9-12, 1980. About a hundred papers were presented, including seven invited talks (PIXE and particle scattering, microbeam analysis, applications to aerosols and biological samples). The main impression left by the conference was that both the PIXE method and its applications are in a phase of fast development. Considerable effort has successfully been devoted to optimizing the basic PIXE technique. Also the great advantage of simultaneously getting information about lighter elements and sample mass was reported to have been successfully employed in routine analyses. PIXE, which was initially considered to be a method mainly for thin samples, has also been shown to be competitive for a variety of thick samples. Data from aerosol studies was presented. With the PIXE-method, it is feasible to perform series of measurements over a long period of time, many samples in parallel and/or samples from sites of poor accessibility. However, the advantages of PIXE may be further exploited in aerosol investigations and some promising lines of sampler development were reported. Sample preparation techniques are crucial for applications to biological samples and several laboratories are engaged in such developmental work. However, it was also evident that PIXE is already giving significant contributions to research in biology and medicine

  15. Atomic Processes in Emission Characteristics of a Lithium Plasma Plume Formed by Double-Pulse Laser Ablation

    International Nuclear Information System (INIS)

    High resolution spectral analysis of lithium plasma formed by single and double laser ablation has been undertaken to understand the plume-laser interaction, especially at the early stages of the plasma plume. In order to identify different atomic processes in evolving plasma, time resolved spectral emission studies at different inter-pulse delays have been performed for ionic and neutral lithium lines emitting from different levels. Along with the enhancement in emission intensity, a large line broadening and spectral shift, especially in the case of excited state transition Li I 610.3 nm have been observed in the presence of the second pulse. This broadening and shift gradually decrease with increasing time delay. Another interesting feature is the appearance of a multi-component structure in the ionic line at 548.4 nm and these components change conversely into a single structure at the later stages of the plasma. The multi-component structures are correlated with the presence of different velocity (temperature) distributions in non-LTE conditions. Atomic analyses by computing photon emissivity coefficients with an ADAS code have been used to identify the above processes.

  16. Atomic Processes in Emission Characteristics of a Lithium Plasma Plume Formed by Double-Pulse Laser Ablation

    Science.gov (United States)

    Sivakumaran, V.; Ajai, Kumar; K. Singh, R.; Prahlad, V.; C. Joshi, H.

    2013-03-01

    High resolution spectral analysis of lithium plasma formed by single and double laser ablation has been undertaken to understand the plume-laser interaction, especially at the early stages of the plasma plume. In order to identify different atomic processes in evolving plasma, time resolved spectral emission studies at different inter-pulse delays have been performed for ionic and neutral lithium lines emitting from different levels. Along with the enhancement in emission intensity, a large line broadening and spectral shift, especially in the case of excited state transition Li I 610.3 nm have been observed in the presence of the second pulse. This broadening and shift gradually decrease with increasing time delay. Another interesting feature is the appearance of a multi-component structure in the ionic line at 548.4 nm and these components change conversely into a single structure at the later stages of the plasma. The multi-component structures are correlated with the presence of different velocity (temperature) distributions in non-LTE conditions. Atomic analyses by computing photon emissivity coefficients with an ADAS code have been used to identify the above processes.

  17. X-ray emission from heavy atomic collisions : couplings of inner shells in superheavy quasimolecules

    OpenAIRE

    Verma, Punita

    2010-01-01

    Overcritical electromagnetic fields with a coupling strength of ZUA greater than or equal to 1/alpha (=137, with alpha being the fine structure constant) can be experienced in superheavy quasimolecules (atomic number ZUA = Z1+Z2) formed transiently in close collisions of two very heavy atomic partners (Z1, Z2) at velocities (vion) smaller compared to the orbital velocity of the innermost electrons of concern (ve-). The inner shell processes in these collisions are governed approximately by th...

  18. Data correlation in on-line solid-phase extraction-gas chromatography-atomic emission/mass spectrometric detection of unknown microcontaminants

    NARCIS (Netherlands)

    Hankemeier, Th.; Rozenbrand, J.; Abhadur, M.; Vreuls, J.J.; Brinkman, U.A.Th.

    1998-01-01

    A procedure is described for the (non-target) screening of hetero-atom-containing compounds in tap and waste water by correlating data obtained by gas chromatography (GC) using atomic emission (AED) and mass selective (MS) detection. Solid-phase extraction (SPE) was coupled on-line to both GC system

  19. Atomic parity violation in heavy alkalis: detection by stimulated emission for cesium and traps for cold francium

    International Nuclear Information System (INIS)

    The present work deals with the recent advances of atomic spectroscopy experiments on cesium and francium, which aim at precise parity violation (PV) measurements in these atoms. Within the framework of a 'double-badged thesis', the candidate devoted himself on the one hand to the preliminary PV measurement (8% accuracy) of the present Cs experiment at the Kastler-Brossel laboratory in Paris and on the other hand to the preparation of a Fr radioactive atomic sample (production and trapping) at the LNL (INFN) in Italy. The two experiments are at very different stages. The measurements reported for cesium were actually made possible thanks to the work initiated in 1991, for the PV detection by stimulated emission. The Italian experiment is instead in a beginning stage: in order to probe the properties of francium, which is unstable, a number of atoms large enough has to be first produced and collected. The PV schemes which proved to be well suited for cesium are a solid starting point for the case of francium. (author)

  20. Atomic parity violation in heavy alkalis: detection by stimulated emission for cesium and traps for cold francium

    Energy Technology Data Exchange (ETDEWEB)

    Sanguinetti, St

    2004-07-01

    The present work deals with the recent advances of atomic spectroscopy experiments on cesium and francium, which aim at precise parity violation (PV) measurements in these atoms. Within the framework of a 'double-badged thesis', the candidate devoted himself on the one hand to the preliminary PV measurement (8% accuracy) of the present Cs experiment at the Kastler-Brossel laboratory in Paris and on the other hand to the preparation of a Fr radioactive atomic sample (production and trapping) at the LNL (INFN) in Italy. The two experiments are at very different stages. The measurements reported for cesium were actually made possible thanks to the work initiated in 1991, for the PV detection by stimulated emission. The Italian experiment is instead in a beginning stage: in order to probe the properties of francium, which is unstable, a number of atoms large enough has to be first produced and collected. The PV schemes which proved to be well suited for cesium are a solid starting point for the case of francium. (author)

  1. Noise-immune cavity-enhanced analytical atomic spectrometry — NICE-AAS — A technique for detection of elements down to zeptogram amounts

    International Nuclear Information System (INIS)

    Noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS) is a powerful technique for detection of molecular compounds in gas phase that is based on a combination of two important concepts: frequency modulation spectroscopy (FMS) for reduction of noise, and cavity enhancement, for prolongation of the interaction length between the light and the sample. Due to its unique properties, it has demonstrated unparalleled detection sensitivity when it comes to detection of molecular constituents in the gas phase. However, despite these, it has so far not been used for detection of atoms, i.e. for elemental analysis. The present work presents an assessment of the expected performance of Doppler-broadened (Db) NICE-OHMS for analytical atomic spectrometry, then referred to as noise-immune cavity-enhanced analytical atomic spectrometry (NICE-AAS). After a description of the basic principles of Db-NICE-OHMS, the modulation and detection conditions for optimum performance are identified. Based on a previous demonstrated detection sensitivity of Db-NICE-OHMS of 5 × 10−12 cm−1 Hz−1∕2 (corresponding to a single-pass absorbance of 7 × 10−11 over 10 s), the expected limits of detection (LODs) of Hg and Na by NICE-AAS are estimated. Hg is assumed to be detected in gas phase directly while Na is considered to be atomized in a graphite furnace (GF) prior to detection. It is shown that in the absence of spectral interferences, contaminated sample compartments, and optical saturation, it should be feasible to detect Hg down to 10 zg/cm3 (10 fg/m3 or 10−5 ng/m3), which corresponds to 25 atoms/cm3, and Na down to 0.5 zg (zg = zeptogram = 10−21 g), representing 50 zg/mL (parts-per-sextillion, pps, 1:1021) in liquid solution (assuming a sample of 10 μL) or solely 15 atoms injected into the GF, respectively. These LODs are several orders of magnitude lower (better) than any previous laser-based absorption technique previously demonstrated under

  2. Determination of some inorganic metals in edible vegetable oils by inductively coupled plasma atomic emission spectroscopy (ICP-AES)

    OpenAIRE

    Musa Özcan, M.; Altun, Turkan; Gode, Fethiye; Arslan, Gulsin; Pehlivan, Erol

    2008-01-01

    Seventeen edible vegetable oils were analyzed spectrometrically for their metal (Cu, Fe, Mn, Co, Cr, Pb, Cd, Ni, and Zn) contents. Toxic metals in edible vegetable oils were determined by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The highest metal concentrations were measured as 0.0850, 0.0352, 0.0220, 0.0040, 0.0010, 0.0074, 0.0045, 0.0254 and 0.2870 mg/kg for copper in almond oil, for iron in corn oil-(c), for manganese in soybean oil, for cobalt in sunflower oil-(b...

  3. Dislocation emission at the Silicon/Silicon nitride interface: A million atom molecular dynamics simulation on parallel computers

    Science.gov (United States)

    Bachlechner; Omeltchenko; Nakano; Kalia; Vashishta; Ebbsjo; Madhukar

    2000-01-10

    Mechanical behavior of the Si(111)/Si(3)N4(0001) interface is studied using million atom molecular dynamics simulations. At a critical value of applied strain parallel to the interface, a crack forms on the silicon nitride surface and moves toward the interface. The crack does not propagate into the silicon substrate; instead, dislocations are emitted when the crack reaches the interface. The dislocation loop propagates in the (1; 1;1) plane of the silicon substrate with a speed of 500 (+/-100) m/s. Time evolution of the dislocation emission and nature of defects is studied. PMID:11015901

  4. Dislocation Emission at the Silicon/Silicon Nitride Interface: A Million Atom Molecular Dynamics Simulation on Parallel Computers

    International Nuclear Information System (INIS)

    Mechanical behavior of the Si(111)/Si3N4 (0001) interface is studied using million atom molecular dynamics simulations. At a critical value of applied strain parallel to the interface, a crack forms on the silicon nitride surface and moves toward the interface. The crack does not propagate into the silicon substrate; instead, dislocations are emitted when the crack reaches the interface. The dislocation loop propagates in the (1 11) plane of the silicon substrate with a speed of 500 (±100) m/s . Time evolution of the dislocation emission and nature of defects is studied. (c) 2000 The American Physical Society

  5. Shape-dependent localized surface plasmon enhanced UV-emission from ZnO grown by atomic layer deposition

    Science.gov (United States)

    Lin, Ying; Liu, Xing Qiang; Wang, Ti; Chen, Chao; Wu, Hao; Liao, Lei; Liu, Chang

    2013-03-01

    Two-dimensional arrays of Al nanoparticles (NPs) were used to demonstrate the localized surface plasmon resonance (LSPR) enhanced UV light emission from ZnO grown by atomic layer deposition. Well defined NP arrays with different shapes were fabricated on the surface of ZnO by electron-beam lithography. A theoretical analysis based on the finite-difference time-domain method was carried out to show the shape dependence of the LSPR wavelength. Time resolved photoluminescence and temperature-dependent photoluminescence measurements suggested that the Al NPs arrays increase the radiative recombination rate by the resonance coupling between the localized surface plasmons and the excitons of the ZnO. By top excitation of the Al NP arrays coupled with ZnO, a 2.6-fold enhancement in peak photoluminescence intensity was measured. The enhancement strongly depended on the NP’s shape, revealing an important way of geometrical tuning the UV-emission.

  6. Acid dissolution of soils and rocks for the determination of boron by inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    The boron concentration in rocks, soils and standard reference materials was determined using hydrofluoric acid-aqua regia dissolution followed by inductively coupled plasma atomic emission spectrometry (ICP-AES) using the B 1 249.773 -nm line, corrected for spectral interference by iron. An excess of fluoride was complexed with aluminium to release boron from the stable fluoroborate ion and to protect the borosilicate and quartz components of the instrument. Boron was not lost by volatilisation during volume reduction. Soil and rock boron values determined using the recommended dissolution procedures were comparable to those obtained using the accepted sodium carbonate fusion procedure and by d.c. arc emission spectrophotometry, and those for standard reference materials showed good agreement and precision with the literature values. (author)

  7. Rapid determination of major and minor elements in rare earth-cobalt magnets by inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    Major and minor constituents, Sm, Ce, Y, Co, Fe, Mn, Cu, Zr and Hf, in typical rare earth-cobalt magnets were determined sequentially by inductively coupled plasma atomic emission spectrometry. Sample solutions were prepared by dissolving the magnets with aqua regia followed by dilution with 1.2 M HCl to suitable concentration. Beryllium was added as an internal standard in order to improved experimental accuracy and precision, and the emission intensity of Be was measured by using an additional small monochromator attached to the original instrument system. Cobalt, Fe, Cu and Zr in the magnets were also determined by conventional spectrophotometry. The results obtained by both methods were in good agreement with each other. (author)

  8. A COUPLED CHEMISTRY-EMISSION MODEL FOR ATOMIC OXYGEN GREEN AND RED-DOUBLET EMISSIONS IN THE COMET C/1996 B2 HYAKUTAKE

    Energy Technology Data Exchange (ETDEWEB)

    Bhardwaj, Anil; Raghuram, Susarla, E-mail: bhardwaj_spl@yahoo.com, E-mail: anil_bhardwaj@vssc.gov.in, E-mail: raghuramsusarla@gmail.com [Space Physics Laboratory, Vikram Sarabhai Space Centre, Trivandrum 695022 (India)

    2012-03-20

    The green (5577 Angstrom-Sign ) and red-doublet (6300, 6364 Angstrom-Sign ) lines are prompt emissions of metastable oxygen atoms in the {sup 1}S and {sup 1}D states, respectively, that have been observed in several comets. The value of the intensity ratio of green to red-doublet (G/R ratio) of 0.1 has been used as a benchmark to identify the parent molecule of oxygen lines as H{sub 2}O. A coupled chemistry-emission model is developed to study the production and loss mechanisms of the O({sup 1}S) and O({sup 1}D) atoms and the generation of red and green lines in the coma of C/1996 B2 Hyakutake. The G/R ratio depends not only on photochemistry, but also on the projected area observed for cometary coma, which is a function of the dimension of the slit used and the geocentric distance of the comet. Calculations show that the contribution of photodissociation of H{sub 2}O to the green (red) line emission is 30%-70% (60%-90%), while CO{sub 2} and CO are the next potential sources contributing 25%-50% (<5%). The ratio of the photoproduction rate of O({sup 1} S) to O({sup 1} D) would be around 0.03 ({+-}0.01) if H{sub 2}O is the main source of oxygen lines, whereas it is {approx}0.6 if the parent is CO{sub 2}. Our calculations suggest that the yield of O({sup 1} S) production in the photodissociation of H{sub 2}O cannot be larger than 1%. The model-calculated radial brightness profiles of the red and green lines and G/R ratios are in good agreement with the observations made on the comet Hyakutake in 1996 March.

  9. Comment on "Effect of entanglement on the decay dynamics of a pair of H(2p) atoms due to spontaneous emission"

    CERN Document Server

    Sancho, Pedro

    2011-01-01

    Tanabe et al (Phys. Rev. A {\\bf 82} 040101(R) 2010) have experimentally demonstrated that the emission properties of unstable atoms in entangled and product states are different. The authors define an apparent decay time as a fitting parameter which falls below the lifetime of the single atom for entangled pairs. We argue that their results about coincidence time spectra are correct, but those concerning lifetimes cannot be considered conclusive because they assume the emission of photons by the two atoms to be independent processes, a doubtful hypothesis for entangled states. We suggest an improved evaluation of the lifetimes based on a rigorous approach, which demands some modifications of the experimental procedure.

  10. Acoustic emission and magnification of atomic lines resolution for laser breakdown of salt water in ultrasound field

    Energy Technology Data Exchange (ETDEWEB)

    Bulanov, Alexey V., E-mail: a-bulanov@me.com [Far Eastern Federal University, Vladivostok, Russia 690950 (Russian Federation); V.I. Il’ichev Pacific Oceanological Institute, Vladivostok, Russia 690041 (Russian Federation); Nagorny, Ivan G., E-mail: ngrn@mail.ru [Far Eastern Federal University, Vladivostok, Russia 690950 (Russian Federation); Institute for automation and control processes, Vladivostok, Russia 690041 (Russian Federation)

    2015-10-28

    Researches of the acoustic effects accompanying optical breakdown in a water, generated by the focused laser radiation with power ultrasound have been carried out. Experiments were performed by using 532 nm pulses from Brilliant B Nd:YAG laser. Acoustic radiation was produced by acoustic focusing systems in the form hemisphere and ring by various resonance frequencies of 10.7 kHz and 60 kHz. The experimental results are obtained, that show the sharply strengthens effects of acoustic emission from a breakdown zone by the joint influence of a laser and ultrasonic irradiation. Essentially various thresholds of breakdown and character of acoustic emission in fresh and sea water are found out. The experimental result is established, testifying that acoustic emission of optical breakdown of sea water at presence and at absence of ultrasound essentially exceeds acoustic emission in fresh water. Atomic lines of some chemical elements like a Sodium, Magnesium and so on were investigated for laser breakdown of water with ultrasound field. The effect of magnification of this lines resolution for salt water in ultrasound field was obtained.

  11. Acoustic emission and magnification of atomic lines resolution for laser breakdown of salt water in ultrasound field

    International Nuclear Information System (INIS)

    Researches of the acoustic effects accompanying optical breakdown in a water, generated by the focused laser radiation with power ultrasound have been carried out. Experiments were performed by using 532 nm pulses from Brilliant B Nd:YAG laser. Acoustic radiation was produced by acoustic focusing systems in the form hemisphere and ring by various resonance frequencies of 10.7 kHz and 60 kHz. The experimental results are obtained, that show the sharply strengthens effects of acoustic emission from a breakdown zone by the joint influence of a laser and ultrasonic irradiation. Essentially various thresholds of breakdown and character of acoustic emission in fresh and sea water are found out. The experimental result is established, testifying that acoustic emission of optical breakdown of sea water at presence and at absence of ultrasound essentially exceeds acoustic emission in fresh water. Atomic lines of some chemical elements like a Sodium, Magnesium and so on were investigated for laser breakdown of water with ultrasound field. The effect of magnification of this lines resolution for salt water in ultrasound field was obtained

  12. X-ray emission from a high-atomic-number z-pinch plasma created from compact wire arrays

    International Nuclear Information System (INIS)

    Thermal and nonthermal x-ray emission from the implosion of compact tungsten wire arrays in 5-MA Saturn discharges is reported. The timing of multiple implosions and the thermal x-ray spectra (1 to 10 keV) agree with 2D radiation-hydrocode simulations. Nonthermal x-ray emission (10 to 100 keV) correlates with pinch spots distributed along the z-axis. The similarities of the measured nonthermal spectrum, yield, and pinch-spot emission with those of 0.8-MA, single-exploded-wire discharges on Gamble-II suggest a common nonthermal-production mechanism. Nonthermal x-ray yields are lower than expected from current scaling of Gamble II results, suggesting that implosion geometries are not as efficient as single-wire geometries for nonthermal x-ray production. The instabilities, azimuthal asymmetries, and inferred multiple implosions that accompany the implosion geometry lead to larger, more irregular pinch spots, a likely reason for reduced nonthermal efficiency. A model for nonthermal-electron acceleration across magnetic fields in highly-collisional, high-atomic-number plasmas combined with 1D hydrocode simulations of Saturn compact loads predicts weak nonthermal x-ray emission. (author). 3 figs., 10 refs

  13. X-ray emission from a high-atomic-number z-pinch plasma created from compact wire arrays

    International Nuclear Information System (INIS)

    Thermal and nonthermal x-ray emission from the implosion of compact tungsten wire arrays in 5-MA Saturn discharges is reported. The timing of multiple implosions and the thermal x-ray spectra (1 to 10 keV) agree with 2D radiation-hydrocode simulations. Nonthermal x-ray emission (10 to 100 keV) correlates with pinch spots distributed along the z-axis. The similarities of the measured nonthermal spectrum, yield, and pinch-spot emission with those of 0.8-MA, single- exploded-wire discharges on Gamble-II suggest a common nonthermal- production mechanism. Nonthermal x-ray yields are lower than expected from current scaling of Gamble II results, suggesting that implosion geometries are not as efficient as single-wire geometries for nonthermal x-ray production. The instabilities, azimuthal asymmetries, and inferred multiple implosions that accompany the implosion geometry lead to larger, more irregular pinch spots, a likely reason for reduced nonthermal efficiency. A model for nonthermal-electron acceleration across magnetic fields in highly- collisional, high-atomic-number plasmas combined with 1D hydrocode simulations of Saturn compact loads predicts weak nonthermal x-ray emission

  14. An analytical continuation approach for evaluating emission lineshapes of molecular aggregates and the adequacy of multichromophoric Förster theory

    Science.gov (United States)

    Banchi, Leonardo; Costagliola, Gianluca; Ishizaki, Akihito; Giorda, Paolo

    2013-05-01

    In large photosynthetic chromophore-protein complexes not all chromophores are coupled strongly, and thus the situation is well described by formation of delocalized states in certain domains of strongly coupled chromophores. In order to describe excitation energy transfer among different domains without performing extensive numerical calculations, one of the most popular techniques is a generalization of Förster theory to multichromophoric aggregates (generalized Förster theory) proposed by Sumi [J. Phys. Chem. B 103, 252 (1999), 10.1021/jp983477u] and Scholes and Fleming [J. Phys. Chem. B 104, 1854 (2000), 10.1021/jp993435l]. The aim of this paper is twofold. In the first place, by means of analytic continuation and a time convolutionless quantum master equation approach, a theory of emission lineshape of multichromophoric systems or molecular aggregates is proposed. In the second place, a comprehensive framework that allows for a clear, compact, and effective study of the multichromophoric approach in the full general version proposed by Jang, Newton, and Silbey [Phys. Rev. Lett. 92, 218301 (2004), 10.1103/PhysRevLett.92.218301] is developed. We apply the present theory to simple paradigmatic systems and we show on one hand the effectiveness of time-convolutionless techniques in deriving lineshape operators and on the other hand we show how the multichromophoric approach can give significant improvements in the determination of energy transfer rates in particular when the systems under study are not the purely Förster regime. The presented scheme allows for an effective implementation of the multichromophoric Förster approach which may be of use for simulating energy transfer dynamics in large photosynthetic aggregates, for which massive computational resources are usually required. Furthermore, our method allows for a systematic comparison of multichromophoric Föster and generalized Förster theories and for a clear understanding of their respective limits

  15. Effect of surfactant addition on ultrasonic leaching of trace elements from plant samples in inductively coupled plasma-atomic emission spectrometry

    Science.gov (United States)

    Borkowska-Burnecka, Jolanta; Jankowiak, Urszula; Zyrnicki, Wieslaw; Anna Wilk, Kazimiera

    2004-04-01

    The applicability of surfactants in sample preparation of plant materials followed by analysis by inductively coupled plasma atomic emission spectrometry has been examined. Reference materials (INCT-MPH-2-Mixed Polish Herbs, INCT-TL-1 black tea leaves and CTA-VTL-2 -Virginia tobacco leaves) and commercially available tea leaves were analyzed. Effects of addition surfactants (Triton X-100, didodecyldimethylammonium bromide and cetyltrimethylammonium bromide) on efficiency of ultrasonic leaching of elements from the plant samples and on plasma parameters were investigated. Low concentrations of the surfactants in solutions did not affect, in practice, analytical line intensities and the nebulization process. Quantitative recovery of some elements could be obtained by ultrasonic diluted acid leaching with the aid of surfactants. However, the element recovery depended on type of surfactant, as well as element and sample material. Plasma parameters, i.e. the excitation temperatures of Ar I, Fe II and Ca II as well as the electron number density and the Mg II/Mg I intensity ratio did not vary significantly due to the surfactants in solutions.

  16. Effect of surfactant addition on ultrasonic leaching of trace elements from plant samples in inductively coupled plasma-atomic emission spectrometry

    International Nuclear Information System (INIS)

    The applicability of surfactants in sample preparation of plant materials followed by analysis by inductively coupled plasma atomic emission spectrometry has been examined. Reference materials (INCT-MPH-2-Mixed Polish Herbs, INCT-TL-1 black tea leaves and CTA-VTL-2 -Virginia tobacco leaves) and commercially available tea leaves were analyzed. Effects of addition surfactants (Triton X-100, didodecyldimethylammonium bromide and cetyltrimethylammonium bromide) on efficiency of ultrasonic leaching of elements from the plant samples and on plasma parameters were investigated. Low concentrations of the surfactants in solutions did not affect, in practice, analytical line intensities and the nebulization process. Quantitative recovery of some elements could be obtained by ultrasonic diluted acid leaching with the aid of surfactants. However, the element recovery depended on type of surfactant, as well as element and sample material. Plasma parameters, i.e. the excitation temperatures of Ar I, Fe II and Ca II as well as the electron number density and the Mg II/Mg I intensity ratio did not vary significantly due to the surfactants in solutions

  17. Improved Statistical Determination of Absolute Neutrino Masses via Radiative Emission of Neutrino Pairs from Atoms

    CERN Document Server

    Zhang, Jue

    2016-01-01

    The atomic transition from an excited state $|{\\rm e}\\rangle$ to the ground state $|{\\rm g}\\rangle$ by emitting a neutrino pair and a photon, i.e., $|{\\rm e}\\rangle \\to |{\\rm g}\\rangle + |\\gamma\\rangle + |\

  18. Determination of lithium and potassium in uranium oxide powders and pellets by Flame Atomic Emission Spectrometric method

    International Nuclear Information System (INIS)

    The present paper describes a method developed at Control Laboratory, NFC which includes prior separation of lithium and potassium from uranium matrix before their measurements. Solvent extraction, using Tri-n-Butyl Phosphate (TBP) in CCI4 followed by Tri-n-Octyl Phosphine Oxide (TOPO) in CCI4, is employed for prior separation of Li and K. The resultant aqueous solution was analyzed by Flame-Atomic Emission Spectrometric (AES) method. Solvent extraction conditions are optimized for measurement of Li and K in the same aliquot. Experimental conditions such as instrument calibration, flame condition, fuel flow, sample flow rate through nebulizer, burner height etc. are also optimized. Under the optimal condition the detection limits achieved for lithium is 0.02 ppm and 0.2 ppm for potassium. A RSD of ± 3 % for Li at 0.05 ppm and ± 4% for K at 1 ppm level has been achieved in this method. The results of lithium in the sample are compared with the values obtained by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). Similarly, values of potassium are compared with Flame-Atomic Absorption Spectrometry (Flame-AAS) technique. The comparisons are in good agreement. The above method is simple, sensitive, reproducible and can be used for measurement of lithium and potassium in UO2 powder and pellets on regular basis

  19. CHIANTI—AN ATOMIC DATABASE FOR EMISSION LINES. XIII. SOFT X-RAY IMPROVEMENTS AND OTHER CHANGES

    International Nuclear Information System (INIS)

    The CHIANTI spectral code consists of two parts: an atomic database and a suite of computer programs in Python and IDL. Together, they allow the calculation of the optically thin spectrum of astrophysical objects and provide spectroscopic plasma diagnostics for the analysis of astrophysical spectra. The database includes atomic energy levels, wavelengths, radiative transition probabilities, collision excitation rate coefficients, ionization, and recombination rate coefficients, as well as data to calculate free-free, free-bound, and two-photon continuum emission. Version 7.1 has been released, which includes improved data for several ions, recombination rates, and element abundances. In particular, it provides a large expansion of the CHIANTI models for key Fe ions from Fe VIII to Fe XIV to improve the predicted emission in the 50-170 Å wavelength range. All data and programs are freely available at http://www.chiantidatabase.org and in SolarSoft, while the Python interface to CHIANTI can be found at http://chiantipy.sourceforge.net.

  20. CHIANTI-AN ATOMIC DATABASE FOR EMISSION LINES. XIII. SOFT X-RAY IMPROVEMENTS AND OTHER CHANGES

    Energy Technology Data Exchange (ETDEWEB)

    Landi, E. [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Young, P. R. [College of Science, George Mason University, 4400 University Drive, Fairfax, VA, 22030 (United States); Dere, K. P. [School of Physics, Astronomy and Computational Sciences, MS 6A2, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); Del Zanna, G.; Mason, H. E. [Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)

    2013-02-15

    The CHIANTI spectral code consists of two parts: an atomic database and a suite of computer programs in Python and IDL. Together, they allow the calculation of the optically thin spectrum of astrophysical objects and provide spectroscopic plasma diagnostics for the analysis of astrophysical spectra. The database includes atomic energy levels, wavelengths, radiative transition probabilities, collision excitation rate coefficients, ionization, and recombination rate coefficients, as well as data to calculate free-free, free-bound, and two-photon continuum emission. Version 7.1 has been released, which includes improved data for several ions, recombination rates, and element abundances. In particular, it provides a large expansion of the CHIANTI models for key Fe ions from Fe VIII to Fe XIV to improve the predicted emission in the 50-170 A wavelength range. All data and programs are freely available at http://www.chiantidatabase.org and in SolarSoft, while the Python interface to CHIANTI can be found at http://chiantipy.sourceforge.net.

  1. Effects of nozzle lip geometry on spray atomization and emissions advanced gas turbine combustors

    Science.gov (United States)

    Micklow, Gerald J.; Roychoudhury, Subir; Nguyen, H. L.

    1991-01-01

    A parametric study is conducted to investigate the effect of nozzle lip geometry on nozzle fuel distribution, emissions and temperature distribution for a rich burn section of a rich burn/quick quench/lean burn combustor. It is seen that the nozzle lip geometry greatly affects the fuel distribution, emissions and temperature distribution. It is determined that at an equivalence ratio of 1.6 the NO concentration could be lowered by a factor greater than three by changing the nozzle lip geometry.

  2. Research as a guide for curriculum development: An example from introductory spectroscopy. I. Identifying student difficulties with atomic emission spectra

    Science.gov (United States)

    Ivanjek, L.; Shaffer, P. S.; McDermott, L. C.; Planinic, M.; Veza, D.

    2015-01-01

    This is the first of two closely related articles (Paper I and Paper II) that together illustrate how research in physics education has helped guide the design of instruction that has proved effective in improving student understanding of atomic spectroscopy. Most of the more than 1000 students who participated in this four-year investigation were science majors enrolled in the introductory calculus-based physics course at the University of Washington (UW) in Seattle, WA, USA. The others included graduate and undergraduate teaching assistants at UW and physics majors in introductory and advanced physics courses at the University of Zagreb, Zagreb, Croatia. About half of the latter group were preservice high school physics teachers. This article (Paper I) describes how several serious conceptual and reasoning difficulties were identified among students as they tried to relate a discrete line spectrum to the energy levels of atoms in a light source. Paper II illustrates how findings from this research informed the development of a tutorial that led to significant improvement in student understanding of atomic emission spectra.

  3. Research as a guide for curriculum development: An example from introductory spectroscopy. II. Addressing student difficulties with atomic emission spectra

    Science.gov (United States)

    Ivanjek, L.; Shaffer, P. S.; McDermott, L. C.; Planinic, M.; Veza, D.

    2015-02-01

    This is the second of two closely related articles (Paper I and Paper II) that together illustrate how research in physics education has helped guide the design of instruction that has proved effective in improving student understanding of atomic spectroscopy. Most of the more than 1000 students who participated in this four-year investigation were science majors enrolled in the introductory calculus-based physics course at the University of Washington (UW) in Seattle, WA, USA. The others included graduate and undergraduate teaching assistants at UW and physics majors in introductory and advanced physics courses at the University of Zagreb, Zagreb, Croatia. About half of the latter group were preservice high school physics teachers. Paper I describes how several conceptual and reasoning difficulties were identified among university students as they tried to relate a discrete line spectrum to the energy levels of atoms in a light source. This second article (Paper II) illustrates how findings from this research informed the development of a tutorial that led to improvement in student understanding of atomic emission spectra.

  4. Cu determination in crude oil distillation products by atomic absorption and inductively coupled plasma mass spectrometry after analyte transfer to aqueous solution

    International Nuclear Information System (INIS)

    Cu was determined in a wide range of petroleum products from crude oil distillation using flame atomic absorption spectrometry (FAAS), electrothermal atomic absorption spectrometry (ETAAS) and inductively coupled plasma mass spectrometry (ICP-MS). Different procedures of sample preparation were evaluated: (i) mineralization with sulfuric acid in an open system (ii) mineralization in a closed microwave system (iii) combustion in hydrogen-oxygen flame in the Wickbold's apparatus (iv) matrix evaporation followed by acid dissolution, and (v) acidic extraction. All the above procedures led to the transfer of the analyte into an aqueous solution for the analytical measurement step. It was found that application of FAAS was limited to the analysis of the heaviest petroleum products of high Cu content. In ICP-MS, the use of internal reference method (with Rh or In as internal reference element) was required to eliminate the matrix effects in the analysis of extracts and the concentrated solutions of mineralized heavy petroleum products. The detection limits (in original samples) were equal to, respectively, 10, 86, 3.3, 0.9 and 0.4 ng g-1 in procedures i-v with ETAAS detection and 10, 78, 1.1 and 0.5 ng g-1 in procedures i-iii and v with ICP-MS detection. The procedures recommended here were validated by recovery experiments, certified reference materials analysis and comparison of results, obtained for a given sample, in different ways. The Cu content in the analyzed samples was: 50-110 ng g-1 in crude oil, -1 in gasoline, -1 in atmospheric oil, -1 in heavy vacuum oil and 140-300 ng g-1 in distillation residue

  5. Characterization of petroleum distillates by GC-AED (coupling with gas chromatography and atomic emission detection); Caracterisation des distillats petroliers par couplage chromatographie en phase gazeuse et detection par emission atomique

    Energy Technology Data Exchange (ETDEWEB)

    Baco, F.

    1997-05-21

    This thesis describes the characterization of atmospheric petroleum distillates (kerosenes and gas-oils) and vacuum distillates by hyphenated technic of Gas Chromatography and Atomic Emission Detector (GC-AED). A gas chromatographic simulated distillation, which gives the weight % of sample as a function of the petroleum cut temperature, was adapted to the GC-AED to obtain an original information about the elemental composition profile. After generalities, historic of the development of the instrument and the first petroleum applications are described. In the experimental part, analytical conditions used, different technics of characterisation of distillates and the base of samples analyzed are exposed. After a study of the GC-AED`s performances for the target elements (C, H, S, N), a quantitative method for the elemental analysis of distillates was developed and validated at three levels: total elemental analysis, simulated distillation and elemental composition as a function of the distillation profile. Finally, different ways for the applications of the GC-AED in order to characterize the distillates were explored, in particular to classify products and predict some petroleum properties (cetane number, density,...). The more interesting outlook seems to be the prediction of some properties as a function of the distillation profile. (author) 155 refs.

  6. Determination of trace elements in heroin by inductively coupled plasma atomic emission spectrometry using ultrasonic nebulization

    Science.gov (United States)

    Budič, Bojan; Klemenc, Sonja

    2000-06-01

    A method for the determination of Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, Ni, P, S, Sr and Zn in heroin samples by ICP-AES using ultrasonic nebulization is described. The samples were microwave digested with HNO 3. To improve the detection limits and minimise the matrix interferences the experimental parameters were optimised by variation of the operating power, carrier gas flow rate and observation height above the load coil. Optimum operating conditions for most of the analytes were at operating power 1550 W, carrier gas flow rate between 0.8 and 1.0 l min -1 and observation height between 10 and 12 mm above load coil. The limits of detection were below 0.5 μg g -1 (dry mass) for most of the elements investigated. The analytical recoveries of spiked samples were in the range between 94 and 103% and precision was on average better than 6%. The analysis of heroin samples shows that the method is simple, rapid and capable of providing accurate results for all the analytes investigated with the exception of nickel which was below the limit of detection in the analyzed samples.

  7. An Investigation on the Extraction and Quantitation of a Hexavalent Chromium in Acrylonitrile Butadiene Styrene Copolymer (ABS) and Printed Circuit Board (PCB) by Ion Chromatography Coupled with Inductively Coupled Plasma Atomic Emission Spectrometry

    International Nuclear Information System (INIS)

    A hexavalent chromium (Cr (VI)) is one of the hazardous substances regulated by the RoHS. The determination of Cr (VI) in various polymers and printed circuit board (PCB) has been very important. In this study, the three different analytical methods were investigated for the determination of a hexavalent chromium in Acrylonitrile Butadiene Styrene copolymer (ABS) and PCB. The results by three analytical methods were obtained and compared. An analytical method by UV-Visible spectrometer has been generally used for the determination of Cr (VI) in a sample, but a hexavalent chromium should complex with diphenylcarbazide for the detection in the method. The complexation did make an adverse effect on the quantitative analysis of Cr (VI) in ABS. The analytical method using diphenylcarbazide was also not applicable to printed circuit board (PCB) because PCB contained lots of irons. The irons interfered with the analysis of hexavalent chromium because those also could complex with diphenylcarbazide. In this study, hexavalent chromiums in PCB have been separated by ion chromatography (IC), then directly and selectively detected by inductively coupled plasma atomic emission spectrometry (ICP-AES). The quantity of Cr (VI) in PCB was 0.1 mg/kg

  8. COMPARISON OF AIR POLLUTANT EMISSIONS FROM VAPORIZING AND AIR ATOMIZING WASTE OIL HEATERS

    Science.gov (United States)

    The paper gives results of a characterization of gaseous and particulate emissions and vaporizing pot solid residues resulting from the combustion of waste crankcase oil in space heaters. Two types of waste oil burners were tested: a vaporizing oil burner rated at 35.2 kW, and an...

  9. Energy absorption, ionization, and harmonic emission in laser-irradiated atomic clusters

    OpenAIRE

    Kundu, M.

    2007-01-01

    The excellent coupling of laser light to atomic clusters is a known, experimentally established fact. However, the physical mechanism of laser absorption is still controversially discussed. Linear resonance (LR) absorption occurs for sufficiently long laser pulses of optical or longer wavelengths. Here the Mie-plasma frequency initially rises above the laser frequency, then drops due to cluster expansion and therefore meets the laser frequency at some point. Instead, in few-cycle laser pulses...

  10. Improved statistical determination of absolute neutrino masses via radiative emission of neutrino pairs from atoms

    Science.gov (United States)

    Zhang, Jue; Zhou, Shun

    2016-06-01

    The atomic transition from an excited state |e ⟩ to the ground state |g ⟩ by emitting a neutrino pair and a photon, i.e., |e ⟩→|g ⟩+|γ ⟩+|νi⟩+|ν¯j⟩ with i , j =1 , 2, 3, has been proposed by Yoshimura and his collaborators as an alternative way to determine the absolute scale m0 of neutrino masses. More recently, a statistical analysis of the fine structure of the photon spectrum from this atomic process has been performed [N. Song et al. Phys. Rev. D 93, 013020 (2016)] to quantitatively examine the experimental requirements for a realistic determination of absolute neutrino masses. In this paper, we show how to improve the statistical analysis and demonstrate that the previously required detection time can be reduced by one order of magnitude for the case of a 3 σ determination of m0˜0.01 eV with an accuracy better than 10%. Such an improvement is very encouraging for further investigations on measuring absolute neutrino masses through atomic processes.

  11. Solar-energy conversion and light emission in an atomic monolayer p-n diode

    Science.gov (United States)

    Pospischil, Andreas; Furchi, Marco M.; Mueller, Thomas

    2014-04-01

    The limitations of the bulk semiconductors currently used in electronic devices--rigidity, heavy weight and high costs--have recently shifted the research efforts to two-dimensional atomic crystals such as graphene and atomically thin transition-metal dichalcogenides. These materials have the potential to be produced at low cost and in large areas, while maintaining high material quality. These properties, as well as their flexibility, make two-dimensional atomic crystals attractive for applications such as solar cells or display panels. The basic building blocks of optoelectronic devices are p-n junction diodes, but they have not yet been demonstrated in a two-dimensional material. Here, we report a p-n junction diode based on an electrostatically doped tungsten diselenide (WSe2) monolayer. We present applications as a photovoltaic solar cell, a photodiode and a light-emitting diode, and obtain light-power conversion and electroluminescence efficiencies of ~0.5% and ~0.1%, respectively. Given recent advances in the large-scale production of two-dimensional crystals, we expect them to profoundly impact future developments in solar, lighting and display technologies.

  12. Heavy metal adsorptivity of calcium-alginate-modified diethylenetriamine-silica gel and its application to a flow analytical system using flame atomic absorption spectrometry.

    Science.gov (United States)

    Mori, Masanobu; Suzuki, Toshinobu; Sugita, Tsuyoshi; Nagai, Daisuke; Hirayama, Kazuo; Onozato, Makoto; Itabashi, Hideyuki

    2014-08-20

    This study aimed to evaluate the heavy metal adsorptivity of calcium-alginate-modified diethylenetriamine-silica gel (CaAD) and incorporate this biosorbent into a flow analytical system for heavy metal ions using flame atomic absorption spectrometry (FAAS). The biosorbent was synthesized by electrostatically coating calcium alginate onto diethylenetriamine (dien)-silica gel. Copper ion adsorption tests by a batch method showed that CaAD exhibited a higher adsorption rate compared with other biosorbents despite its low maximum adsorption capacity. Next, CaAD was packed into a 1mL microcolumn, which was connected to a flow analytical system equipped with an FAAS instrument. The flow system quantitatively adsorbed heavy metals and enriched their concentrations. This quantitative adsorption was achieved for pH 3-4 solutions containing 1.0×10(-6) M of heavy metal ions at a flow rate of 5.0 mL min(-1). Furthermore, the metal ions were successfully desorbed from CaAD at low nitric acid concentrations (0.05-0.15 M) than from the polyaminecarboxylic acid chelating resin (Chelex 100). Therefore, CaAD may be considered as a biosorbent that quickly adsorbs and easily desorbs analyte metal ions. In addition, the flow system enhanced the concentrations of heavy metals such as Cu(2+), Zn(2+), and Pb(2+) by 50-fold. This new enrichment system successfully performed the separation and determination of Cu(2+) (5.0×10(-8)M) and Zn(2+) (5.7×10(-8) M) in a river water sample and Pb(2+) (3.8×10(-9) M) in a ground water sample. PMID:25086892

  13. Heavy metal adsorptivity of calcium-alginate-modified diethylenetriamine-silica gel and its application to a flow analytical system using flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Highlights: • Calcium-alginate-modified dien-silica gel adsorbed multivalent metal ions. • Metal ions adsorbed on CaAD were eluted using low acidic concentrations. • Flow system with CaAD-packed column enriched metal concentrations up to 50-fold. - Abstract: This study aimed to evaluate the heavy metal adsorptivity of calcium-alginate-modified diethylenetriamine-silica gel (CaAD) and incorporate this biosorbent into a flow analytical system for heavy metal ions using flame atomic absorption spectrometry (FAAS). The biosorbent was synthesized by electrostatically coating calcium alginate onto diethylenetriamine (dien)-silica gel. Copper ion adsorption tests by a batch method showed that CaAD exhibited a higher adsorption rate compared with other biosorbents despite its low maximum adsorption capacity. Next, CaAD was packed into a 1 mL microcolumn, which was connected to a flow analytical system equipped with an FAAS instrument. The flow system quantitatively adsorbed heavy metals and enriched their concentrations. This quantitative adsorption was achieved for pH 3–4 solutions containing 1.0 × 10−6 M of heavy metal ions at a flow rate of 5.0 mL min−1. Furthermore, the metal ions were successfully desorbed from CaAD at low nitric acid concentrations (0.05–0.15 M) than from the polyaminecarboxylic acid chelating resin (Chelex 100). Therefore, CaAD may be considered as a biosorbent that quickly adsorbs and easily desorbs analyte metal ions. In addition, the flow system enhanced the concentrations of heavy metals such as Cu2+, Zn2+, and Pb2+ by 50-fold. This new enrichment system successfully performed the separation and determination of Cu2+ (5.0 × 10−8 M) and Zn2+ (5.7 × 10−8 M) in a river water sample and Pb2+ (3.8 × 10−9 M) in a ground water sample

  14. A general analytical model for formaldehyde and VOC emission/sorption in single-layer building materials and its application in determining the characteristic parameters

    Science.gov (United States)

    Xiong, Jianyin; Liu, Cong; Zhang, Yinping

    2012-02-01

    A general analytical model for characterizing emission and sorption of formaldehyde and volatile organic compounds (VOCs) in single-layer building materials is developed. Compared with traditional models, the present model can be applicable for four kinds of typical physical processes, i.e., emission in ventilated and airtight chambers, and sorption in these two types of chambers. Based on the general analytical model, a novel method is proposed to determine the characteristic parameters (the diffusion coefficient, Dm, and the material/air partition coefficient, K) of formaldehyde and VOC sorption in ventilated and airtight chambers. It establishes a linear relationship between the logarithm of dimensionless excess concentration and sorption time, and the Dm and K can be conveniently obtained from the slope and intercept of the regression line. The results of applying the present model are compared with the experimental data in the literature. The good agreement between them not only validates the model but also demonstrates that the measured characteristic parameters are accurate and reliable. The general analytical model should prove useful for unified characterization and prediction of emission/sorption in building materials as well as for parameter measurement.

  15. Efficient field emission from α-Fe2O3 nanoflakes on an atomic force microscope tip

    Science.gov (United States)

    Zhu, Y. W.; Yu, T.; Sow, C. H.; Liu, Y. J.; Wee, A. T. S.; Xu, X. J.; Lim, C. T.; Thong, J. T. L.

    2005-07-01

    Aligned arrays of flake-shaped hematite (α-Fe2O3) nanostructure have been fabricated on an atomic force microscope (AFM) tip. They are created by simply heating an iron-coated AFM tip in ambience on a hot plate. These nanoflakes are characterized as α-Fe2O3 single crystalline structures with tip radii as small as several nanometers and are highly effective as electron field emitters. With a vacuum gap of about 150μm, field emission measurements of α-Fe2O3 nanoflakes on AFM tips show a low turn-on voltage of about 400-600V and a high current density of 1.6Acm-2 under 900V. Such high emission current density is attributed to the nanoscale sharp tips of the as-grown nanoflakes. Based on the Fowler-Nordheim theory, it is demonstrated the enhancement factor of α-Fe2O3 nanoflakes on AFM tips is comparable to that of carbon nanotubes. Our findings suggest that α-Fe2O3 nanoflakes are potentially useful as candidates for future electron field emission devices.

  16. Transition probabilities for lines of Cr II, Na II and Sb I by laser produced plasma atomic emission spectroscopy

    International Nuclear Information System (INIS)

    Absolute transition probabilities for lines of Cr II, Na II and Sb I were determined by emission spectroscopy of laser induced plasmas. The plasma was produced focusing the emission of a pulsed Nd-Yag laser on solid samples containing the atom in study. The light arising from the plasma region was collected by and spectrometer. the detector used was a time-resolved optical multichannel analyzer (OMA III EG and G). The wavelengths of the measured transitions range from 2000 to 4100 A. The spectral resolution of the system was 0.2 A. The method can be used in insulators materials as Cl Na crystals and in metallic samples as Al-Cr and Sn-Sb alloys. To avoid self-absorption effects the alloys were made with low Sb or Cr content. Relative transition probabilities have been determined from measurements of emission-line intensities and were placed on an absolute scale by using, where possible, accurate experimental lifetime values form the literature or theoretical data. From these measurements, values for plasma temperature (8000-24000K), electron densities (approx 10 ''16 cm''-3) and self-absorption coefficients have been obtained

  17. Transition probabilities for lines of Cr II, Na II and Sb I by laser produced plasma atomic emission spectroscopy

    International Nuclear Information System (INIS)

    Absolute transition probabilities for lines of CR II, Na II and Sb I were determined by emission spectroscopy of laser induced plasmas. the plasma was produced focusing the emission of a pulsed Nd-Yag laser on solid samples containing the atom in study. the light arising from the plasma region was collected by and spectrometer. the detector used was a time-resolved optical multichannel analyzer (OMA III EG and G). The wavelengths of the measured transitions range from 2000 sto 4100 A. The spectral resolution of the system was 0. 2 A. The method can be used in insulators materials as Cl Na crystals and in metallic samples as Al-Cr and Sn-Sn alloys. to avoid self-absorption effects the alloys were made with low Sb or Cr content. Relative transition probabilities have been determined from measurements of emission-line intensities and were placed on an absolute scale by using, where possible, accurate experimental lifetime values form the literature or theoretical data. From these measurements, values for plasma temperature (8000-24000 K), electron densities (∼∼ 10''16 cm ''-3) and self-absorption coefficients have been obtained. (Author) 56 refs

  18. Comparison of analytical and Monte Carlo calculations of multi-photon effects in bremsstrahlung emission by high-energy electrons

    DEFF Research Database (Denmark)

    Mangiarotti, Alessio; Sona, Pietro; Ballestrero, Sergio;

    2012-01-01

    Approximate analytical calculations of multi-photon effects in the spectrum of total radiated energy by high-energy electrons crossing thin targets are compared to the results of Monte Carlo type simulations. The limits of validity of the analytical expressions found in the literature are establi...

  19. Building and analyzing models from data by stirred tank experiments for investigation of matrix effects caused by inorganic matrices and selection of internal standards in Inductively Coupled Plasma-Atomic Emission Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Grotti, Marco [Dipartimento di Chimica e Chimica Industriale, Via Dodecaneso 31, 16146 Genova (Italy)], E-mail: grotti@chimica.unige.it; Paredes, Eduardo; Maestre, Salvador; Todoli, Jose Luis [Departamento de Quimica Analitica, Nutricion y Bromatologia, Universidad de Alicante, 03080, Alicante (Spain)

    2008-05-15

    Interfering effects caused by inorganic matrices (inorganic acids as well as easily ionized elements) in inductively coupled plasma-atomic emission spectroscopy have been modeled by regression analysis of experimental data obtained using the 'stirred tank method'. The main components of the experimental set-up were a magnetically-stirred container and two peristaltic pumps. In this way the matrix composition was gradually and automatically varied, while the analyte concentration remained unchanged throughout the experiment. An inductively coupled plasma spectrometer with multichannel detection based on coupled charge device was used to simultaneously measure the emission signal at several wavelengths when the matrix concentration was modified. Up to 50 different concentrations were evaluated in a period of time of 10 min. Both single interfering species (nitric, hydrochloric and sulphuric acids, sodium and calcium) and different mixtures (aqua regia, sulfonitric mixture, sodium-calcium mixture and sodium-nitric acid mixture) were investigated. The dependence of the emission signal on acid concentration was well-fitted by logarithmic models. Conversely, for the easily ionized elements, 3-order polynomial models were more suitable to describe the trends. Then, the coefficients of these models were used as 'signatures' of the matrix-related signal variations and analyzed by principal component analysis. Similarities and differences among the emission lines were highlighted and discussed, providing a new insight into the interference phenomena, mainly with regards to the combined effect of concomitants. The combination of the huge amount of data obtained by the stirred tank method in a short period of time and the speed of analysis of principal component analysis provided a judicious means for the selection of the optimal internal standard in inductively coupled plasma-atomic emission spectroscopy.

  20. Building and analyzing models from data by stirred tank experiments for investigation of matrix effects caused by inorganic matrices and selection of internal standards in Inductively Coupled Plasma-Atomic Emission Spectroscopy

    International Nuclear Information System (INIS)

    Interfering effects caused by inorganic matrices (inorganic acids as well as easily ionized elements) in inductively coupled plasma-atomic emission spectroscopy have been modeled by regression analysis of experimental data obtained using the 'stirred tank method'. The main components of the experimental set-up were a magnetically-stirred container and two peristaltic pumps. In this way the matrix composition was gradually and automatically varied, while the analyte concentration remained unchanged throughout the experiment. An inductively coupled plasma spectrometer with multichannel detection based on coupled charge device was used to simultaneously measure the emission signal at several wavelengths when the matrix concentration was modified. Up to 50 different concentrations were evaluated in a period of time of 10 min. Both single interfering species (nitric, hydrochloric and sulphuric acids, sodium and calcium) and different mixtures (aqua regia, sulfonitric mixture, sodium-calcium mixture and sodium-nitric acid mixture) were investigated. The dependence of the emission signal on acid concentration was well-fitted by logarithmic models. Conversely, for the easily ionized elements, 3-order polynomial models were more suitable to describe the trends. Then, the coefficients of these models were used as 'signatures' of the matrix-related signal variations and analyzed by principal component analysis. Similarities and differences among the emission lines were highlighted and discussed, providing a new insight into the interference phenomena, mainly with regards to the combined effect of concomitants. The combination of the huge amount of data obtained by the stirred tank method in a short period of time and the speed of analysis of principal component analysis provided a judicious means for the selection of the optimal internal standard in inductively coupled plasma-atomic emission spectroscopy

  1. X-ray emission from a high-atomic-number z-pinch plasma created from compact wire arrays

    International Nuclear Information System (INIS)

    Thermal and nonthermal x-ray emission from the implosion of compact tungsten wire arrays, driven by 5 MA from the Saturn accelerator, are measured and compared with LLNL Radiation-Hydro-Code (RHC) and SNL Hydro-Code (HC) numerical models. Multiple implosions, due to sequential compressions and expansions of the plasma, are inferred from the measured multiple x-radiation bursts. Timing of the multiple implosions and the thermal x-ray spectra measured between 1 and 10 keV are consistent with the RHC simulations. The magnitude of the nonthermal x-ray emission measured from 10 to 100 keV ranges from 0.02 to 0.08% of the total energy radiated and is correlated with bright-spot emission along the z-axis, as observed in earlier Gamble-11 single exploding-wire experiments. The similarities of the measured nonthermal spectrum and bright-spot emission with those measured at 0.8 MA on Gamble-II suggest a common production mechanism for this process. A model of electron acceleration across magnetic fields in highly-collisional, high-atomic-number plasmas is developed, which shows the existence of a critical electric field, Ec, below which strong nonthermal electron creation (and the associated nonthermal x rays) do not occur. HC simulations show that significant nonthermal electrons are not expected in this experiment (as observed) because the calculated electric fields are at least one to two orders-of-magnitude below Ec. These negative nonthermal results are confirmed by RHC simulations using a nonthermal model based on a Fokker-Plank analysis. Lastly, the lower production efficiency and the larger, more irregular pinch spots formed in this experiment relative to those measured on Gamble II suggest that implosion geometries are not as efficient as single exploding-wire geometries for warm x-ray production

  2. Analytical chemistry

    International Nuclear Information System (INIS)

    This book is comprised of nineteen chapters, which describes introduction of analytical chemistry, experimental error and statistics, chemistry equilibrium and solubility, gravimetric analysis with mechanism of precipitation, range and calculation of the result, volume analysis on general principle, sedimentation method on types and titration curve, acid base balance, acid base titration curve, complex and firing reaction, introduction of chemical electro analysis, acid-base titration curve, electrode and potentiometry, electrolysis and conductometry, voltammetry and polarographic spectrophotometry, atomic spectrometry, solvent extraction, chromatograph and experiments.

  3. Emission Channeling Studies on the Behaviour of Light Alkali Atoms in Wide-Band-Gap Semiconductors

    CERN Multimedia

    Recknagel, E; Quintel, H

    2002-01-01

    % IS342 \\\\ \\\\ A major problem in the development of electronic devices based on diamond and wide-band-gap II-VI compound semiconductors, like ZnSe, is the extreme difficulty of either n- or p-type doping. The only reports of successful n-type doping of diamond involves ion implanted Li, which was found to be an intersititial donor. Recent theoretical calculations suggest that Na, P and N dopant atoms are also good candidates for n-type doping of diamond. No experimental evidence has been obtained up to now, mainly because of the complex and partly unresolved defect situation created during ion implantation, which is necessary to incorporate potential donor atoms into diamond. \\\\ \\\\In the case of ZnSe, considerable effort has been invested in trying to fabricate pn-junctions in order to make efficient, blue-light emitting diodes. However, it has proved to be very difficult to obtain p-type ZnSe, mainly because of electrical compensation related to background donor impurities. Li and Na are believed to be ampho...

  4. Study of the fission dynamics of hot atomic nuclei by means of the neutron emission

    International Nuclear Information System (INIS)

    In the framework of the present thesis fusion processes with subsequent fission are studied in the heavy ion reactions 141Pr+40Ar and 175Lu+12C. The aim of the studies is the determination of the hitherto not precisely known lifetimes of excited composite systems before these separate into two fission fragments. In order to study such effects the reactions 141Pr+40Ar at 316 MeV argon as well as 175Lu+12C at 192 MeV carbon projectile energy were measured. The evaluation of the measured angular distribution of the fission fragments and the evaporation residual nuclei yielded the angular momentum ranges which lead to the fusion with subsequent fission respectively to evaporation residual nuclei. A large critical angular momentum of 109± ℎ in the reaction Pr+Ar and an essentially smaller value of 62±6 ℎ for the system Lu+C result regarding the uncomplete fusion. The analysis of the neutron emission measured in coincidence with fission fragments allowed the determination of the neutron multiplicities for the composite system before the scission as well as for each single fission fragment. Large multiplicities before the scission of 3.6±0.6 and 6.3±0.8 in the reactions Pr+Ar and Lu+C were observed. In the study of the pre-equilibrium neutron emission in the incompletely fusioning system Lu+C for the first time a strong concentration of the emitted neutrons in the plane defined by the direction of flight of the fission fragments and the ion beam was shown. This anisotropy can be interpreted as anisotrope neutron emission relative to the angular momentum direction of the composite system. A corresponding anisotropy was not observed for the neutron evaporation from the completely equilibrated system. (orig./HSI)

  5. 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 %.

  6. Zinc, lead and copper in human teeth measured by induced coupled argon plasma atomic emission spectroscopy (ICP-AES)

    International Nuclear Information System (INIS)

    Inductively Coupled Argon Plasma Atomic Emission Spectroscopy (ICP-AES) has been used to determine Pb, Zn and Cu levels in 47 exfoliated human teeth (all of which required extraction for orthodontic reasons). Lead concentrations for the group were 1.7 μg (g tooth mass)-1 to 40.5 μg (g tooth mass)-1, with a median of 9.8 (g (g tooth mass)-1. A median lead level in excess of the group value was found for the teeth of six lorry drivers who were included in the study. A more significant enhancement was found for the seven subjects whose age was in excess of 60 years. The median values for Zn and Cu were 123.0 and 0.6 μg (g tooth mass)-1 respectively. Present values for tooth-Zn are lower than published data for other ethnic groups

  7. Analysis of neodymium oxide for rare earth impurities by inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    A procedure for the determination of the rare earths elements in neodymium oxide with purity grade above 99% by inductively coupled plasma optical emission spectrometry is described. Determination limits were 0,005% for the elements Eu, Dy, Gd, Tb, Ho and Y and 0,01% for Sm and La. The precision of the method was evaluated through the relative standard deviation (RSD) for individual rare earth elements. The values lies in the range of 3 -7% for most of them but lanthanum, has shown 13% RSD. (author)

  8. Study of matrix effects produced by inorganic species in inductively coupled plasma atomic emission spectrometry with several spray chambers

    International Nuclear Information System (INIS)

    In the present work, the influence of the spray chamber design on the matrix effects was investigated in Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The study was carried out in terms of aerosol drop size distribution and emission signal. Solutions of two inorganic acids and salts were employed to characterize the extent of the matrix effects throughout this work. Several spray chambers. a double-pass (Scott - type), a conventional cyclonic, and two low-volume cyclonic - type spray chambers (i.e., Cinnabar, and Genie) were used in order to evaluate the matrix effects produced by nitric and sulphuric acid solutions. A glass concentric pneumatic micro nebulizer (Atom Mist) was used in conjunction with all four chambers. When nitric or sulphuric acid solutions were nebulized, the double pass spray chamber registered noticeable changes in the drop size distribution. The low-volume spray chambers, in turn, afforded changes in the aerosol drop size distributions similar to the conventional cyclonic one. The matrix effects on the signal were reduced with all three cyclonic spray chambers with respect to the double pass one. Concerning the effect of inorganic salts, the results obtained with a High Efficiency Nebulizer (HEN) coupled to a double pass spray chamber and to a cyclonic type one revealed several issues: (i) the matrix effects were more severe at low liquid and gas flow rates; (ii) as for inorganic acids, the use of a cyclonic spray chamber led to a mitigation of the matrix effects with respect to a double pass spray chamber. (author)

  9. Present status for the determination of metallic impurities in nuclear fuels by atomic emission spectroscopy (review report)

    International Nuclear Information System (INIS)

    Present status for the determination of metallic impurities in nuclear fuels by atomic emission spectroscopy (AES) is reviewed. In the first chapter of introduction, brief progress of the developments of AES is described. In the second chapter, emission spectrograph with direct current arc (DCA) or inductively coupled plasma (ICP) source is shown with the emphasis on the confinement of plutonium. In the third chapter, impurity elements and maximum concentration limits in various nuclear fuels and equivalent boron content factors are given on the base of ASTM (American Society for Testing and Materials) standards in 1987. In the fourth chapter, examples of the analyses of nuclear fuels by DCA-AES and carrier distillation method, and the results of standard uranium oxide analysis conducted by 15 AEC-connected laboratories in U.S.A. are presented. In the fifth chapter, the determination of rare earth elements by DCA-AES after the chemical separation of U and Pu by solvent extraction, ion-exchange and so on. In the sixth and seventh chapters, the determination of U and Pu, and metallic impurities in U and Pu fuels by ICP-AES are described, respectively. In the eighth chapter, the determination of Am by ICP-AES is explained. In the ninth chapter, a comparison of the detection limits in aqueous solutions for various spectrometric techniques including recently developed laser-induced atomic fluorescence spectroscopy (LIF) and laser-enhaned ionization spectroscopy (LEI) are given. In the last chapter, experimental plan using DCA-AES and ICP-AES installed this time at Plutonium Fuel Research Laboratory of Oarai Research Establishment is introduced. (author)

  10. Abstracts of the 2. Brazilian Meeting on Analytical Chemistry

    International Nuclear Information System (INIS)

    Abstracts of theoretical and experimental works on Qualitative and Quantitative Analytical Chemistry are presented. Among the various analytical techniques used, emphasis is given to: neutron activation analysis, crystal doping and annealing, isotopic tracing, fission tracks detection, atomic absorption spectrophotometry, emission spectroscopy with induced coupled plasma, X-ray diffraction, nuclear magnetic resonance, mass spectrometry, polarography, ion exchange and/or thin-layer chromatography, electrodeposition, potentiometric titration and others. (C.L.B)

  11. Determination of selenium in blood serum by inductively coupled plasma atomic emission spectrometry with pneumatic nebulization

    Energy Technology Data Exchange (ETDEWEB)

    Machat, Jiri; Kanicky, Viktor; Otruba, Vitezslav [Laboratory of Plasma Sources for Chemical Analysis-Laboratory of Atomic Spectrochemistry, Faculty of Science, Masaryk University Brno (Czech Republic)

    2002-02-01

    The possibility of determining selenium in blood serum using inductively coupled plasma emission spectrometry with conventional pneumatic nebulization was studied. A high-resolution spectrometer (SBW=6 pm) with laterally viewed ICP was employed. Analysis with conventional pneumatic nebulization could overcome laborious and demanding digestion, which is necessary for hydride generation. A pressure digestion with nitric acid at 160 C was sufficient to decrease the carbon content in the serum sample to 5%-10% of its original value. Spectral interference of the CN band was observed and mathematically corrected. It was found that the carbon-induced selenium line emission enhancement occurred even under ICP optimized conditions. A method of determination was developed and applied to the analysis of blood serum. True limit of detection in real samples is 0.01-0.02 mg/L and the limit of quantification (RSD 10%) is 0.03-0.07 mg/L using Se I 196.090 nm line at an integration time of 10-2 s. The method was tested by analysis of porcine blood serum and the serum reference material Seronorm MI 0181. (orig.)

  12. Tracing the Milky Way Nuclear Wind with 21cm Atomic Hydrogen Emission

    CERN Document Server

    Lockman, Felix J

    2016-01-01

    There is evidence in 21cm HI emission for voids several kpc in size centered approximately on the Galactic centre, both above and below the Galactic plane. These appear to map the boundaries of the Galactic nuclear wind. An analysis of HI at the tangent points, where the distance to the gas can be estimated with reasonable accuracy, shows a sharp transition at Galactic radii $R\\lesssim 2.4$ kpc from the extended neutral gas layer characteristic of much of the Galactic disk, to a thin Gaussian layer with FWHM $\\sim 125$ pc. An anti-correlation between HI and $\\gamma$-ray emission at latitudes $10^{\\circ} \\leq |b| \\leq 20^{\\circ}$ suggests that the boundary of the extended HI layer marks the walls of the Fermi Bubbles. With HI we are able to trace the edges of the voids from $|z| > 2$ kpc down to $z\\approx0$, where they have a radius $\\sim 2$ kpc. The extended HI layer likely results from star formation in the disk, which is limited largely to $R \\gtrsim 3$ kpc, so the wind may be expanding into an area of rela...

  13. Atomic data of Ti II from laser produced Ti plasmas by optical emission spectroscopy

    International Nuclear Information System (INIS)

    In the present study, the emission spectrum of titanium produced from laser induced plasma has been measured at different distances from the target. The Titanium target is irradiated by using the high power Q-switched Nd:YAG laser (λ=1064 nm) that generates energy 750 mJ/pulse of duration rate 6 ns and repetition rate 10 Hz in vacuum and at different distances. The variation of the distance from the target affects the measured plasma parameters, i.e. the electron density, the ion temperature and the velocity distribution. The electron density increases with the increase of the distance from the target. At a distance 0.6 mm from the target it decreases to 2.28·1016 cm-3. The temperature increases with the distance from the get until a distance of 1 mm, after that it decreases. It is found that the plasma velocity increases with the distance then it decreases again. Then, Energy levels and transition probabilities for 3d2 4p →(3d2 4s + 3d3) lines have been determined by measurement of emission line intensities from an optically thin laser produced plasma of Ti II in vacuum. Calculations with intermediate coupling using Hartree-Fock wave functions have been carried out in order to place the experimental data on an absolute scale and also to evaluate the lifetimes. The plasma parameters in different regions of the plasma plume have been measured and used to obtain further transition probabilities. (author)

  14. Atomic scale properties of magnetic Mn-based alloys probed by Emission Mössbauer spectroscopy

    CERN Multimedia

    Mn-based alloys are characterized by a wealth of properties, which are of interest both from fundamental physics point of view and particularly attractive for different applications in modern technology: from magnetic storage to sensing and spin-based electronics. The possibility to tune their magnetic properties through post-growth thermal processes and/or stoichiometry engineering is highly important in order to target different applications (i.e. Mn$_{x}$Ga) or to increase their Curie temperature above room temperature (i.e. off-stoichiometric MnSi). In this project, the Mössbauer effect will be applied at $^{57}$Fe sites following implantation of radioactive $^{57}$Mn, to probe the micro-structure and magnetism of Mn-based alloys at the most atomic-scale. The proposed experimental plan is devoted to establish a direct correlation between the local structure and bulk magnetism (and other physical properties) of Mn-based alloys.

  15. Filling of double vacancy in the K atomic shell with emission of one single photon

    International Nuclear Information System (INIS)

    A method was developed to calculate the transition rate for two-electron one-photon K(sub αα) transition (2s 2p → 1s2). The method was tested for Ni with two K-shell vacancies in the initial state. The (sub αα) rate is calculated within the framework of a single system formed by the atom and the radiation. The transition is originated in the interactiion between the parts of that system. In the dipole approximation, the transition rate is obtained from the second order term of the time dependente perturbation theory. Hartree-Fock-Slater wave functions were used in the calculations for Ni. The results are compared with the available theoretical and experimental information. (Author)

  16. Thermal Diffusion of Si Atoms at the Interface of Mo/Si Bilayers Studied with a Soft X-ray Emission Microscope

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Thermal diffusion of Si atoms at the interface in Mo/Si multilayers was observed with an imaging-type soft-X-ray emission microscope developed by us. It was possible to observe the diffusion with 0.2nm depth resolution in the direction normal to the interface by comparing the emission intensity for exactly the same position. The diffusion coefficient of Si atoms in Mo at 600℃ was roughly estimated to be 6.0×10-17cm2/s.

  17. Abstracts of the 1. Brazilian Meeting on Analytical Chemistry

    International Nuclear Information System (INIS)

    Abstracts from experimental studies on analytical chemistry are presented. Several techniques have been used, such as: neutron activation analysis, potentiometry, optical emission spectroscopy, alpha and gamma spectroscopy, atomic absorption spectrophotometry, radiometric analysis, fission track detection, complexometry and others. Samples analysed are of various kinds: environmental materials (soil, water, air), rocks, coal, lanthanide complexes, polycarbonates and synthetic quartz. (C.L.B.)

  18. An atomic orbital-based formulation of analytical gradients and nonadiabatic coupling vector elements for the state-averaged complete active space self-consistent field method on graphical processing units

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, James W.; Hohenstein, Edward G.; Luehr, Nathan; Martínez, Todd J., E-mail: toddjmartinez@gmail.com [Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305 (United States); SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States)

    2015-10-21

    We recently presented an algorithm for state-averaged complete active space self-consistent field (SA-CASSCF) orbital optimization that capitalizes on sparsity in the atomic orbital basis set to reduce the scaling of computational effort with respect to molecular size. Here, we extend those algorithms to calculate the analytic gradient and nonadiabatic coupling vectors for SA-CASSCF. Combining the low computational scaling with acceleration from graphical processing units allows us to perform SA-CASSCF geometry optimizations for molecules with more than 1000 atoms. The new approach will make minimal energy conical intersection searches and nonadiabatic dynamics routine for molecular systems with O(10{sup 2}) atoms.

  19. An atomic orbital-based formulation of analytical gradients and nonadiabatic coupling vector elements for the state-averaged complete active space self-consistent field method on graphical processing units

    International Nuclear Information System (INIS)

    We recently presented an algorithm for state-averaged complete active space self-consistent field (SA-CASSCF) orbital optimization that capitalizes on sparsity in the atomic orbital basis set to reduce the scaling of computational effort with respect to molecular size. Here, we extend those algorithms to calculate the analytic gradient and nonadiabatic coupling vectors for SA-CASSCF. Combining the low computational scaling with acceleration from graphical processing units allows us to perform SA-CASSCF geometry optimizations for molecules with more than 1000 atoms. The new approach will make minimal energy conical intersection searches and nonadiabatic dynamics routine for molecular systems with O(102) atoms

  20. An atomic orbital-based formulation of analytical gradients and nonadiabatic coupling vector elements for the state-averaged complete active space self-consistent field method on graphical processing units

    Science.gov (United States)

    Snyder, James W.; Hohenstein, Edward G.; Luehr, Nathan; Martínez, Todd J.

    2015-10-01

    We recently presented an algorithm for state-averaged complete active space self-consistent field (SA-CASSCF) orbital optimization that capitalizes on sparsity in the atomic orbital basis set to reduce the scaling of computational effort with respect to molecular size. Here, we extend those algorithms to calculate the analytic gradient and nonadiabatic coupling vectors for SA-CASSCF. Combining the low computational scaling with acceleration from graphical processing units allows us to perform SA-CASSCF geometry optimizations for molecules with more than 1000 atoms. The new approach will make minimal energy conical intersection searches and nonadiabatic dynamics routine for molecular systems with O(102) atoms.

  1. Determination of micro yttrium in an ytterbium matrix by inductively coupled plasma atomic emission spectrometry and wavelet transform

    Institute of Scientific and Technical Information of China (English)

    MA Xiaoguo

    2005-01-01

    In the determination of trace yttrium (Y) in an ytterbium (Yb) matrix by inductively coupled plasma atomic emission spectrometry (ICP-AES), the most prominent line of yttrium, Y 371.030 nm line, suffers from strong interference due to an emission line of ytterbium. In this work, a method based on wavelet transform was proposed for the spectral interference correction. Haar wavelet was selected as the mother wavelet. The discrete detail after the third decomposition, D3,was chosen for quantitative analysis based on the consideration of both separation degree and peak height. The linear correlation coefficient between the height of the left positive peak in D3 and the concentration of Y was calculated to be 0.9926.Six synthetic samples were analyzed, and the recovery for yttrium varied from 96.3% to 110.0%. The amounts of yttrium in three ytterbium metal samples were determined by the proposed approach with an average relative standard deviation (RSD)of 2.5%, and the detection limit for yttrium was 0.016%. This novel correction technique is fast and convenient, since neither complicated model assumption nor time-consuming iteration is required. Furthermore, it is not affected by the wavelength drift inherent in monochromators that will severely reduce the accuracy of results obtained by some chemometric methods.

  2. Solid-phase microextraction and gas chromatography with atomic emission detection for multiresidue determination of pesticides in honey

    International Nuclear Information System (INIS)

    A method based on solid-phase microextraction (SPME) followed by gas chromatography with microwave-induced plasma atomic emission detection for determining 16 pesticides of different chemical families (organochlorines, organophosphorus compounds and pyrethrins) in honey is proposed. Parameters affecting the sample enrichment step, such as sample mass, ionic strength, absorption and desorption times and temperatures, were carefully optimized in the direct immersion mode. Element-specific detection and quantification was carried out by monitoring the chlorine (479 nm), bromine (478 nm) and sulphur (181 nm) emission lines, which provided nearly specific chromatograms. The matrix effect was evaluated for samples of different floral origin, it being concluded that standard addition calibration was required for quantification purposes. The detection limits ranged from 0.02 to 10 ng g-1, depending on the compound and the honey sample under analysis. The method is reliable and can be considered useful for routine monitoring. None of the honey samples analyzed contained the studied compounds at concentrations above the corresponding detection limits

  3. Rapid coal analysis. Part II: Slurry atomization DCP emission analysis of NBS coal

    Energy Technology Data Exchange (ETDEWEB)

    McCurdy, D.L.; Wichman, M.D.; Fry, R.C.

    1985-11-01

    A McCrone Micronising Mills is used to wet grind NBS bituminous coal to a median particle diameter of 5.7 m within 10 min. The finely divided coal slurry is immediately nebulized without sieving into a three-electrode DCP for accurate trace element determinations within 15 min overall lapsed time. Three important parameters contribute to near-quantitative elemental recovery without the use of wet or dry ashing, matrix matching, standard additions, as correction factors. These parameters are: (1) extremely small coal particle size, (2) spray chamber conditions favoring unusually efficient characteristic of the hot DCP. Near-unity response factors are observed for the rapid DCP emission determination of trace metals in finely divided coal slurry. Calibration may therefore be performed simply with aqueous standards. The slurry method gives near quantitative agreement between experimental and certified values for Cr, Cu, Mg, Mn, Ni, and Pb in NBS bituminous coal.

  4. Wafer-Size and Single-Crystal MoSe2 Atomically Thin Films Grown on GaN Substrate for Light Emission and Harvesting.

    Science.gov (United States)

    Chen, Zuxin; Liu, Huiqiang; Chen, Xuechen; Chu, Guang; Chu, Sheng; Zhang, Hang

    2016-08-10

    Two-dimensional (2D) atomic-layered semiconductors are important for next-generation electronics and optoelectronics. Here, we designed the growth of an MoSe2 atomic layer on a lattice-matched GaN semiconductor substrate. The results demonstrated that the MoSe2 films were less than three atomic layers thick and were single crystalline of MoSe2 over the entire GaN substrate. The ultrathin MoSe2/GaN heterojunction diode demonstrated ∼850 nm light emission and could also be used in photovoltaic applications. PMID:27409977

  5. Characteristic X-ray emission in close collisions between heavy ions and atoms

    International Nuclear Information System (INIS)

    In this paper an attempt is given to answer the question of how far the inner-shell vacancy production in very heavy ion-atom collisions is influenced by the electronic configuration of the projectile prepared prior to the collision producing the observed vacancy. The variation of this configuration has been induced by changing the primary charge state of the projectile, the target density and thickness or by inverting the collision system. It turns out from the performed analysis of the experimental data that the excitation of even most strongly bound MO's can be easily dependent on these factors which have been ignored until now, especially in discussions of the 1sσ or 2pσ vacancy production at ZUA > 130. Experiments performed for the first time with gaseous targets for such heavy systems show very convincingly the influence of the outer-shell configuration on the vacancy production in inner shells. The analysis of the data has been performed in terms of electronic transitions among MO's transiently formed during the collision. In many cases a satisfactory agreement between theoretical predictions and experiment has been achieved. (orig./HSI)

  6. International congress on analytical science for advanced material processing and environmental impact assessment

    International Nuclear Information System (INIS)

    The topics covered in the proceedings of the International Congress on Analytical Science 2010 include sampling and sample treatment pre-concentration (including solid phase extraction) organic analytical reagents, chemometrics, quality assurance/quality control, chromatography (GC, HPLC, IC, TLC etc.) and related techniques, hyphenated methods atomic spectroscopy (absorption, emission, fluorescence, XRF, XRD, lasers), molecular spectroscopy (IR, Raman), separation methods in analytical chemistry, sensors. Mass spectrometry, nuclear analytical methods, electroanalytical methods, geoanalytical chemistry, thermal analysis, process analytical chemistry, molecular probes for analyte sensing and imaging, express test methods, surface analytical methods, analytical microscopy, bioanalytical chemistry, environmental analysis, characterization of nano materials, analysis of new materials (including high-purity materials), analysis of food and agricultural products, clinical/forensic analysis, online analysis/process analytical chemistry, novel analytical techniques, lab on chips, LIMS, trace metal analysis and speciation. Papers relevant to INIS are indexed separately

  7. Comparison of a portable micro-X-ray fluorescence spectrometry with inductively coupled plasma atomic emission spectrometry for the ancient ceramics analysis

    International Nuclear Information System (INIS)

    Two multielement instrumental methods of analysis, micro X-ray fluorescence spectrometry (micro-XRF) and inductively coupled plasma atomic emission spectrometry (ICP-AES) were applied for the analysis of 7th and 5th century B.C. ancient ceramic sherds in order to evaluate the above two methods and to assess the potential to use the current compact and portable micro-XRF instrument for the in situ analysis of ancient ceramics. The distinguishing factor of interest is that micro-XRF spectrometry offers the possibility of a nondestructive analysis, an aspect of primary importance in the compositional analysis of cultural objects. Micro-XRF measurements were performed firstly directly on the ceramic sherds with no special pretreatment apart from surface cleaning (micro-XRF on sherds) and secondly on pressed pellet disks which were prepared for each ceramic sherd (micro-XRF on pellet). For the ICP-AES determination of elements, test solutions were prepared by the application of a microwave-assisted decomposition procedure in closed high-pressure PFA vessels. Also, the standard reference material SARM 69 was used for the efficiency calibration of the micro-XRF instrument and was analysed by both methods. In order to verify the calibration, the standard reference materials NCS DC 73332 and SRM620 as well as the reference materials AWI-1 and PRI-1 were analysed by micro-XRF. Elemental concentrations determined by the three analytical procedures (ICP-AES, micro-XRF on sherds and micro-XRF on pellets) were statistically treated by correlation analysis and Student's t-test (at the 95% confidence level)

  8. Atomic Emission, Absorption and Fluorescence in the Laser-induced Plasma

    International Nuclear Information System (INIS)

    The main result of our efforts is the development and successful application of the theoretical model of laser induced plasma (LIP) that allows a back-calculation of the composition of the plasma (and the condensed phase) based on the observable plasma spectrum. The model has an immediate experimental input in the form of LIP spectra and a few other experimentally determined parameters. The model is also sufficiently simple and, therefore, practical. It is conveniently interfaced in a graphical user-friendly form for using by students and any laboratory personnel with only minimal training. In our view, the model opens up the possibility for absolute analysis, i.e. the analysis which requires no standards and tedious calibration. The other parts of this proposal (including plasma diagnostics) were somewhat subordinate to this main goal. Plasma diagnostics provided the model with the necessary experimental input and led to better understanding of plasma processes. Another fruitful direction we pursued was the use of the correlation analysis for material identification and plasma diagnostics. Through a number of computer simulations we achieved a clear understanding of how, where and why this approach works being applied to emission spectra from a laser plasma. This understanding will certainly improve the quality of forensic and industrial analyses where fast and reliable material identification and sorting are required

  9. Determination of Vanadium, Tin and Mercury in Atmospheric Particulate Matter and Cement Dust Samples by Direct Current Plasma Atomic Emission Spectrometry.

    Science.gov (United States)

    Hindy, Kamal T.; And Others

    1992-01-01

    An atmospheric pollution study applies direct current plasma atomic emission spectrometry (DCP-AES) to samples of total suspended particulate matter collected in two industrial areas and one residential area, and cement dust collected near major cement factories. These samples were analyzed for vanadium, tin, and mercury. The results indicate the…

  10. Quantum Interference in Spontaneous Emission from a V-Type Three-Level Atom in a Two-Band Photonic Crystal

    Institute of Scientific and Technical Information of China (English)

    YANG Ya-Ping; Chen Hong; ZHU Shi-Yao

    2000-01-01

    The spontaneous emission from a V-type three-level atom embedded in a two-band photonic crystal is studied.Due to the quantum interference between the two transitions and existence of two bands, the populations in the upper levels display some novel behavior: anti-trapping, population oscillation, and population inversion.

  11. TH-C-BRD-01: Analytical Computation of Prompt Gamma Ray Emission and Detection for Proton Range Verification

    International Nuclear Information System (INIS)

    Purpose: A prompt gamma (PG) slit camera prototype demonstrated that on-line range monitoring within 1–2 mm could be performed by comparing expected and measured PG detection profiles. Monte Carlo (MC) can simulate the expected PG profile but this would result in prohibitive computation time for a complete pencil beam treatment plan. We implemented a much faster method that is based on analytical processing of pre-computed MC data. Methods: The formation of the PG detection signal can be separated into: 1) production of PGs and 2) detection by the camera detectors after PG transport in geometry. For proton energies from 40 to 230 MeV, PG productions in depth were pre-computed by MC (PENH) for 12C, 14N, 16O, 31P and 40Ca. The PG production was then modeled analytically by adding the PG production for each element according to local proton energy and tissue composition.PG transport in the patient/camera geometries and the detector response were modeled by convolving the PG production profile with a transfer function. The latter is interpolated from a database of transfer functions fitted to pre-computed MC data (PENELOPE). The database was generated for a photon source in a cylindrical phantom with various radiuses and a camera placed at various positions.As a benchmark, the analytical model was compared to PENH for a water phantom, a phantom with different slabs (adipose, muscle, lung) and a thoracic CT. Results: Good agreement (within 5%) was observed between the analytical model and PENH for the PG production. Similar accuracy for detecting range shifts was also observed. Speed of around 250 ms per profile was achieved (single CPU) using a non-optimized MatLab implementation. Conclusion: We devised a fast analytical model for generating PG detection profiles. In the test cases considered in this study, similar accuracy than MC was achieved for detecting range shifts. This research is supported by IBA

  12. Comment on ``Effect of entanglement on the decay dynamics of a pair of H(2p) atoms due to spontaneous emission''

    Science.gov (United States)

    Sancho, Pedro; Plaja, Luis

    2011-06-01

    T. Tanabe [Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.82.040101 82, 040101(R) (2010)] have experimentally demonstrated that the emission properties of unstable atoms in entangled and product states are different. The authors define an apparent decay time as a fitting parameter which falls below the lifetime of the single atom for entangled pairs. We argue that their results about coincidence time spectra are correct, but those concerning lifetimes cannot be considered conclusive because they assume the emission of photons by the two atoms to be independent processes, a doubtful hypothesis for entangled states. We suggest an improved evaluation of the lifetimes based on a rigorous approach, which demands some modifications of the experimental procedure.

  13. Analytical formulae for total cross sections for electron scattering by atoms (N, O, F, Ne, P, S, Cl, Ar, As, Se, Br, Kr) between 0.5-10 keV

    Energy Technology Data Exchange (ETDEWEB)

    Williart, A. [Univ. Nacional de Educacion a Distancia, Madrid (Spain). Dept. de Fisica de los Materiales; Garcia, G. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Madrid (Spain)

    2001-10-01

    Analytical formulae for total cross sections for electron scattering by atoms which are close to the noble gases (Ne, Ar and Kr), for electron energies ranging from 0.5 to 10 keV, have been obtained in this study. We have shown, previously, that molecular total cross sections, at these energies, depend on target polarizability and the number of target electrons. A similar behaviour has been supposed for total cross sections of some atoms (N, O, F, P, S, Cl, As, Se and Br). The obtained expression depends on atomic parameters and it is based in some correlation derived from noble gases. The applicability of the formula has been checked by comparison with available data for atomic oxygen. (orig.)

  14. Low-Altitude Emission of Energetic Neutral Atoms from Precipitating Magnetospheric Ions: IMAGE/HENA Mission-Long Survey

    Science.gov (United States)

    Vievering, J. T.; Roelof, E. C.; Nair, H.; Sotirelis, T.

    2012-12-01

    Remote sensing of ring current losses should be of considerable utility to the RBSP mission. Low-altitude emission (LAE) of energetic neutral atoms (ENAs) yields a sensitive measurement of the precipitation of magnetospheric energetic ions into the dense monatomic oxygen (O) exosphere at altitudes ˜350 km. LAE is the brightest source of ENAs with energies 1two correlations emerged. Order-of-magnitude increases in 52-180 keV ENA O occurred during only the largest geomagnetic storms, while abrupt order-of-magnitude decreases in the ENA H (some lasting only a day or two) showed a nearly 1:1 correlation with isolated days of near-zero AE-40 nT) was restricted to ring current invariant latitudes 60-65 deg, well below the auroral zone. The next stage of our HENA mission-long study* will examine the latitude range of in situ ion precipitation measured on DMSP passes at ˜800 km altitude, above the reduced-intensity HENA LAE during days of near-zero AE. *Supported by NASA Grant NNX12AJ59G.

  15. Optical emission spectroscopy as a tool for studying, optimizing, and monitoring plasma-assisted atomic layer deposition processes

    International Nuclear Information System (INIS)

    In this note it is demonstrated that optical emission spectroscopy (OES) is an easy-to-implement and valuable tool to study, optimize, and monitor thin film growth by plasma-assisted atomic layer deposition (ALD). The species in the plasma can be identified through the analysis of the light emitted by the plasma. OES provides therefore information on the reactant species delivered to the surface by the plasma but it also yields unique insight into the surface reaction products and, as a consequence, on the reaction mechanisms of the deposition process. Time-resolved measurements reveal information about the amount of precursor dosing and length of plasma exposure needed to saturate the self-limiting half reactions, which is useful for the optimization of the ALD process. Furthermore, time-resolved OES can also be used as an easy-to-implement process monitoring tool for plasma-assisted ALD processes on production equipment; for example, to monitor reactor wall conditions or to detect process faults in real time.

  16. 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...

  17. Correlation between Soft X-ray Absorption and Emission Spectra of the Nitrogen Atoms within Imidazolium-Based Ionic Liquids.

    Science.gov (United States)

    Horikawa, Yuka; Tokushima, Takashi; Takahashi, Osamu; Hoke, Hiroshi; Takamuku, Toshiyuki

    2016-08-01

    Soft X-ray absorption spectroscopy (XAS) has been performed on the N K-edge of two imidazolium-based ionic liquids (ILs), 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([C2mim][TFSA]) and 1-ethyl-3-methylimidazolium bromide ([C2mim][Br]), to clarify the electronic structures of the ILs. Soft X-ray emission spectroscopy (XES) has also been applied to the ILs by excitation at various X-ray energies according to the XAS spectra. It was possible to fully associate the XAS peaks with the XES peaks. Additionally, both XAS and XES spectra of the ILs were well reproduced by the theoretical spectra for a single-molecule model on [C2mim](+) and [TFSA](-) using density functional theory. The assignments for the XAS and XES peaks of the ILs were accomplished from both experimental and theoretical approaches. The theoretical XAS and XES spectra of [C2mim](+) and [TFSA](-) did not significantly depend on the conformations of the ions. The reproducibility of the theoretical spectra for the single-molecule model suggested that the interactions between the cations and anions are very weak in the ILs, thus scarcely influencing the electronic structures of the nitrogen atoms. PMID:27388151

  18. Multielement analysis of Pakistan coal by X-ray fluorescence spectrometry and inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    Major, minor and trace element concentration levels are determined for 21 tertiary lignites and sub-bituminous coal samples collected from seven major coal field in Pakistan. Samples are collected as channel samples and/or run of mine samples. All samples are analysed by the x-ray fluorescence spectrometry (XRFS) technique whereas samples from Cherat coal field and the Katha-Pale coal field are analysed by the inductively coupled plasma atomic emission spectrometry (ICP-AES). Significant concentrations of toxic elements such as S, Ce, Cd, Cr, Cu, Mn, Ni, P, Pb, U and V are found in these coal samples. Thus, continuous exposure to dust of these coals (by the mine workers and inhabitants of the nearby settlements) and their extensive use of domestic purpose (cooking/heating), or in brick kilns and in combustion chambers of thermal power plants may cause significant environmental pollution problems as well as health problems. Their use in the industrial and energy sectors will further pose engineering/operational problems in items of requirements of preventive measures against corrosion of the combustion units. (author) 8 tabs

  19. 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...

  20. Participation of the public in licensing procedures under the Atomic Energy Act and the Federal Emission Control Act

    International Nuclear Information System (INIS)

    Section 7 of the Atomic Energy Act (AtG), section 4 of the Federal Emission Control Act (BImSchG), the Nuclear Installations Licensing Ordinance (AtVfV), and the Ninth Ordinance on the Implementation of the BImSchG (Principles of the licensing procedure) require participation of the public in the procedure before administrative provisions or decisions are issued. The book presents the legally prescribed steps at which participation of the public is mandatory, for the simple case (only one license on the agenda), and for the multi-stage licensing procedure: preliminary negotiations / filling of applications for a license and filing of documents / public announcement of projects / access to files / objections / preclusion of delayed objections / public hearing and other expert discussions / termination of procedure, decision-making by the authorities / decisions on subdivision of procedure into defined stages / modification of the procedure. The analysis of the functions of participation of the public examines the following goals: information / representation of interests / reconciliation of interests / legitimation / control / protection of rights / support. Finally, the book explains the principles of the Constitution demanding participation of the public: human dignity / democracy / rule of law / anticipated effects of the right to have recourse to the courts / civil rights. (orig./HP)

  1. Development of an analytical method for the determination of arsenic in gasoline samples by hydride generation–graphite furnace atomic absorption spectrometry

    International Nuclear Information System (INIS)

    The purpose of the present work was to optimize the conditions for the determination of arsenic in gasoline with hydride generation–graphite furnace atomic absorption spectrometry after acid digestion using a full two-level factorial design with center point. The arsine was generated in a batch system and collected in a graphite tube coated with 150 μg Ir as a permanent modifier. The sample volume, the pre-reduction conditions, the temperature program and modifier mass were kept fixed for all experiments. The estimated main effects were: reducing agent concentration (negative effect), acid concentration (negative effect) and trapping temperature (positive effect). It was observed that there were interactions between the variables. Moreover, the curvature was significant, indicating that the best conditions were at the center point. The optimized parameters for arsine generation were 2.7 mol L−1 hydrochloric acid and 1.6% (w/v) sodium tetrahydroborate. The optimized conditions to collect arsine in the graphite furnace were a trapping temperature of 250 °C and a collection time of 30 s. The limit of detection was 6.4 ng L−1 and the characteristic mass was 24 pg. Two different systems for acid digestion were used: a digester block with cold finger and a microwave oven. The concentration of arsenic found with the proposed method was compared with that obtained using a detergentless microemulsion and direct graphite furnace determination. The results showed that the factorial design is a simple tool that allowed establishing the appropriate conditions for sample preparation and also helped in evaluating the interaction between the factors investigated. - Highlights: ► We determined As in gasoline using hydride generation–graphite furnace AAS. ► We compared three sample preparation procedures. ► A multivariate approach was used to optimize the conditions. ► Analytical performance was best for semi-open digestion.

  2. Development of an analytical method for the determination of arsenic in gasoline samples by hydride generation-graphite furnace atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Emilene M. [Universidade Federal do Pampa, Bage, RS (Brazil); Universidade Federal de Pelotas, Pelotas, RS (Brazil); Dessuy, Morgana B.; Boschetti, Wiliam [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves, 9500, 91501-970 Porto Alegre, RS (Brazil); Vale, Maria Goreti R., E-mail: mgrvale@ufrgs.br [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves, 9500, 91501-970 Porto Alegre, RS (Brazil); Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Ferreira, Sergio L.C. [Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Instituto de Quimica, Universidade Federal da Bahia, Salvador, BA (Brazil); Welz, Bernhard [Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900 Florianopolis, SC (Brazil)

    2012-05-15

    The purpose of the present work was to optimize the conditions for the determination of arsenic in gasoline with hydride generation-graphite furnace atomic absorption spectrometry after acid digestion using a full two-level factorial design with center point. The arsine was generated in a batch system and collected in a graphite tube coated with 150 {mu}g Ir as a permanent modifier. The sample volume, the pre-reduction conditions, the temperature program and modifier mass were kept fixed for all experiments. The estimated main effects were: reducing agent concentration (negative effect), acid concentration (negative effect) and trapping temperature (positive effect). It was observed that there were interactions between the variables. Moreover, the curvature was significant, indicating that the best conditions were at the center point. The optimized parameters for arsine generation were 2.7 mol L{sup -1} hydrochloric acid and 1.6% (w/v) sodium tetrahydroborate. The optimized conditions to collect arsine in the graphite furnace were a trapping temperature of 250 Degree-Sign C and a collection time of 30 s. The limit of detection was 6.4 ng L{sup -1} and the characteristic mass was 24 pg. Two different systems for acid digestion were used: a digester block with cold finger and a microwave oven. The concentration of arsenic found with the proposed method was compared with that obtained using a detergentless microemulsion and direct graphite furnace determination. The results showed that the factorial design is a simple tool that allowed establishing the appropriate conditions for sample preparation and also helped in evaluating the interaction between the factors investigated. - Highlights: Black-Right-Pointing-Pointer We determined As in gasoline using hydride generation-graphite furnace AAS. Black-Right-Pointing-Pointer We compared three sample preparation procedures. Black-Right-Pointing-Pointer A multivariate approach was used to optimize the conditions. Black

  3. Quantum beat spectroscopy: stimulated emission probe of hyperfine quantum beats in the atomic Cs 8p $^{2}P_{3/2}$ level

    CERN Document Server

    Bayram, S B; Popov, O I; Guney, C; Havey, M D; Boyle, W P

    2014-01-01

    Measurements of hyperfine polarization quantum beats are used determine the magnetic dipole (A) and electric quadrupole (B) coupling constants in the excited atomic Cs 8p level. The experimental approach is a novel combination of pulsed optical pumping and time-delayed stimulated emission probing of the excited level. From the measured evolution of the atomic linear polarization degree as a function of probe delay time, we determine the hyperfine coupling constants A = 7.42(6) MHz and B = 0.14(29) MHz.

  4. The chemical speciation and analysis of trace elements in sediment with Neutron Activation Analytical method(NAA) and atomic mass spectrometry

    International Nuclear Information System (INIS)

    In this research, first of all, the analytical methods for the determination of major elements in sediment have been developed with ICP-MS (Inductively Coupled Plasma Mass Spectrometry). The analytical results of major elements (Al, Ca, K, Fe, Mg) with Cool ICP-MS were much better than those with normal ICP-MS. The analytical results were compared with those of NAA (Neutron Activation Analysis). NAA were a little superior to ICP-MS for the determination of major elements in sediment as a non-destructive trace analytical trace analytical method. The analytical methods for the determination of minor elements (Cr, Ce, U, Co, Pb, As, Se) have been also developed with ICP-MS. The analytical results by standard calibration curve with ICP-MS were not accurate due to the matrix interferences. Thus, the internal standard method was applied, then the analytical results for minor elements with ICP-MS were greatly improved. The analytical results obtained by ICP-MS were compared with those obtained by NAA. It showed that the two analytical methods have great capabilities for the determination of minor elements in sediments. Accordingly, the NAA will plan an important role in analysis of environment sample with complex matrix. ICP-MS also will play an important role because it has a great capability for the determination of Pb that could not be determined by NAA

  5. Easily ionizable element (EIE) interferences in inductively coupled plasma atomic emission spectrometry. II. Minimization of EIE effects by choice of observation volume

    Science.gov (United States)

    Galley, Paul J.; Hieftje, Gary M.

    1994-07-01

    Measurements by inductively coupled plasma atomic emission spectrometry (ICP-AES) are expected to be immune to interferences caused by easily ionizable elements. This article demonstrates how observation width, viewing height and viewing volume can be chosen to minimize such interferences and to optimize emission-signal collection in either side-on or end-on configurations. At this time, results must be viewed as a confirmation of previous findings rather than a practical means of performing routine plasma optimizations. Volume data were computed from high-resolution two-dimensional laterally and radially resolved images of Ca I and Ca II emission in the presence and absence of a lithium concomitant. For side-on observation of calcium atomic emission, the customary arrangement, the optimal balance between signal-to-background ( S/B) ratio and interference effects arises from use of a 0.5 mm observation width. The optimal position for measurement and the ideal height of the observation volume were dependent on applied r.f. power. More extended contiguous regions of high S/B ratio became available with the proper spatial averaging, which is inherent in viewing an extended volume. Side-on observation of Ca II emission in the presence of a Li concomitant was best with a 5 mm viewing width at low r.f. power (500 and 1000 W) and a narrow width (< 1 mm) at higher power (1500 W). End-on observation of Ca atomic emission was optimal for a 1000 W plasma viewed within 1.5 mm of the central axis with an observation width of less than 6 mm. For end-on Ca II viewing, a 1500 W plasma minimized the lithium interference while maximizing the S/B ratio when the midpoint of the viewing position was within 1 mm of the central channel and the observation width was less than 2.5 mm.

  6. Schroedinger atom

    International Nuclear Information System (INIS)

    Features of an electrodynamical interpretation suggested by Schroedinger for the wave function are discribed. According to this conception electron charges are continuously distributed all over the volume of an atomic system. The proof is given that classical electrodynamics keeps its action inside atom. Schroedinger's atom has been shown to be the only model in which electrones do not lose their energy for emission when they move around nucleus. A significance of the distributed electron charge self-field is estimated. Practical applications of this conception have been noted including the new trend in quantum electrodynamics. Experimental and theoretical corroborations of the atom model with a continuous electron charge are adduced

  7. Studying the R-branch and the Q-branch emission spectral lines of diatomic molecules using improved analytical formula

    Science.gov (United States)

    Jiang, Yonghong; Sun, Weiguo; Zhang, Yi; Fu, Jia; Fan, Qunchao; Li, Huidong; Feng, Hao

    2016-06-01

    The difference converging method (DCM) used to predict the R-branch and the Q-branch high-lying rotational lines for diatomic systems is improved in this study. The key analytical formulae of the DCM method are modified by adding a higher order spectral term Hυ, and adding a physical converging criterion to improve the accuracy of predictions. Applications of the improved DCM method to the R-branch of the TiF molecule and the Q-branch of the 193IrN molecule show that the accuracy of the R-branch and the Q-branch rotational lines is about one order of magnitude better than the results obtained using the previous formulae, which demonstrate the necessity of the added small term Hυ and the physical converging criterion. The DCM results are also shown to be better than the extrapolated rotational lines using the least-squares method.

  8. An `Analytic Dynamical Magnetosphere' formalism for X-ray and optical emission from slowly rotating magnetic massive stars

    CERN Document Server

    Owocki, Stanley P; Sundqvist, Jon O; Petit, Veronique; Cohen, David H; Townsend, Richard H D

    2016-01-01

    Slowly rotating magnetic massive stars develop "dynamical magnetospheres" (DM's), characterized by trapping of stellar wind outflow in closed magnetic loops, shock heating from collision of the upflow from opposite loop footpoints, and subsequent gravitational infall of radiatively cooled material. In 2D and 3D magnetohydrodynamic (MHD) simulations the interplay among these three components is spatially complex and temporally variable, making it difficult to derive observational signatures and discern their overall scaling trends.Within a simplified, steady-state analysis based on overall conservation principles, we present here an "analytic dynamical magnetosphere" (ADM) model that provides explicit formulae for density, temperature and flow speed in each of these three components -- wind outflow, hot post-shock gas, and cooled inflow -- as a function of colatitude and radius within the closed (presumed dipole) field lines of the magnetosphere. We compare these scalings with time-averaged results from MHD si...

  9. Studying the R-branch and the Q-branch emission spectral lines of diatomic molecules using improved analytical formula.

    Science.gov (United States)

    Jiang, Yonghong; Sun, Weiguo; Zhang, Yi; Fu, Jia; Fan, Qunchao; Li, Huidong; Feng, Hao

    2016-06-01

    The difference converging method (DCM) used to predict the R-branch and the Q-branch high-lying rotational lines for diatomic systems is improved in this study. The key analytical formulae of the DCM method are modified by adding a higher order spectral term Hυ, and adding a physical converging criterion to improve the accuracy of predictions. Applications of the improved DCM method to the R-branch of the TiF molecule and the Q-branch of the (193)IrN molecule show that the accuracy of the R-branch and the Q-branch rotational lines is about one order of magnitude better than the results obtained using the previous formulae, which demonstrate the necessity of the added small term Hυ and the physical converging criterion. The DCM results are also shown to be better than the extrapolated rotational lines using the least-squares method. PMID:26974473

  10. Study on sodium viewing technique applying sodium gamma-rays emission tomography. Verification of basic principle by analytical investigation

    International Nuclear Information System (INIS)

    To confirm structural integrity of a primary cooling system and in-vessel components in a sodium-cooled fast breeder reactor, monitoring and inspection technique applying Gamma-rays emitted from sodium are proposed. The basic principle is as follows. As radioisotope 24Na decays, photons are emitted and a fraction of these photons penetrate materials. If the number of these photons is counted by radiation detectors, an image of gamma-rays source is reconstructed by a computed tomography technique. In this report, Applicability and problems concerned with the technique are investigated. Main results are as follows: (1) To verify applicability, the technique was analytically investigated based on gamma-rays emitted from sodium coolant in a typical pipe of a primary cooling system. As a result, it was confirmed that the image of gamma-rays source could be reconstructed. (2) A required time to measure in a spatial resolution of about 1mm was investigated in the detection efficiency of 20%. The time was about 4 minutes per section by a thousand detectors in the typical pipe of a primary cooling system. And in a typical steam generator, the time was about 2 days per section by ten thousand detectors. (3) To realize a fluoroscopic inspection system, it is necessary that the principle should be verified by experimental researches. Main equipments of the system are a collimator, radiation detector, scanner, signal processing device and image processing device. As a spatial resolution is decide by the collimator, the shape must be evaluated by experimental researches and analytical investigation. (author)

  11. The use of ion chromatography-dc plasma atomic emission spectrometry for the speciation of trace metals

    Energy Technology Data Exchange (ETDEWEB)

    Urasa, I.T.

    1991-09-20

    The original objects of this research program were: to interface d.c. plasma atomic emission spectrometer with an ion chromatograph; to characterize and optimize the combined systems for application in the speciation of metals in aqueous solutions; to use this system in the study of the solution chemistry of various metals; and to find ways in which the measurement sensitivity of the method can be enhanced, thereby allowing the detection of metal species at low ppb concentration levels. This approach has been used to study the chemistry of and speciate several elements in solution including: arsenic, chromium, iron, manganese, nickel phosphorus, platinum, selenium, and vanadium. During the course of this research, we have found that the solution chemistry of the elements studied and the speciation data obtained can vary considerably depending on the solution, and the chromatographic conditions employed. The speciation of chromium, iron, and vanadium was found to be highly influenced by the acidity of the sample. The element selective nature of the d.c. plasma detector allows these changes to be monitored, thereby providing quantitative information on the new moieties formed. New approaches are being developed including the use of chelating ligands as preconcentration agents for purposes of reducing further the detection limits of the elements of interest and to improve the overall element speciation scheme. New thrusts are being directed towards the employment of post-column derivatization method coupled with colorimetric measurements to detect and quantify metal species eluting from the chromatographic column. The influence of sample acidity on these investigations will be carefully evaluated. These new thrusts are described in the accompanying Project Renewal Proposal.

  12. X-ray emission spectroscopy applied to glycine adsorbed on Cu(110): An atom and symmetry projected view

    Energy Technology Data Exchange (ETDEWEB)

    Hasselstroem, J.; Karis, O.; Weinelt, M. [Uppsala Univ. (Sweden)] [and others

    1997-04-01

    When a molecule is adsorbed on a metal surface by chemical bonding new electronic states are formed. For noble and transition metals these adsorption-induced states overlap with the much more intense metal d-valence band, making them difficult to probe by for instance direct photoemission. However, it has recently been shown that X-ray emission spectroscopy (XES) can be applied to adsorbate systems. Since the intermediate state involves a core hole, this technique has the power to project out the partial density of states around each atomic site. Both the excitation and deexcitation processes are in general governed by the dipole selection rules. For oriented system, it is hence possible to obtain a complete separation into 2p{sub x}, 2p{sub y} and 2p{sub z} contributions using angular resolved measurements. The authors have applied XES together with other core level spectroscopies to glycine adsorption on Cu(110). Glycine (NH{sub 2}CH{sub 2}COOH) is the smallest amino acid and very suitable to study by core level spectroscopy since it has several functional groups, all well separated in energy by chemical shifts. Its properties are futhermore of biological interest. In summary, the authors have shown that it is possible to apply XES to more complicated molecular adsorbates. The assignment of different electronic states is however not as straight forward as for simple diatomic molecules. For a complete understanding of the redistribution and formation of new electronic states associated with the surface chemical bond, experimental data must be compared to theoretical calculations.

  13. Spectral evolution of energetic neutral atom emissions at the heliospheric poles as measured by IBEX during its first three years

    Energy Technology Data Exchange (ETDEWEB)

    Dayeh, M. A.; Allegrini, F.; Desai, M. I.; Ebert, R. W.; Fuselier, S. A.; Livadiotis, G.; McComas, D. J.; Schwadron, N. A. [Southwest Research Institute, San Antonio, TX 78228 (United States); DeMajistre, R. [Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723 (United States); Janzen, P.; Reisenfeld, D. [University of Montana, Missoula, MT 59812 (United States); Siewert, M., E-mail: maldayeh@swri.edu [Institut für Astronomie der Universität Bonn, Abteilung f. Astrophysik und Extraterrestrische Forschung, Auf dem Hügel 71, D-53121 Bonn (Germany)

    2014-12-10

    The Interstellar Boundary Explorer (IBEX) mission continues to measure energetic neutral atom (ENA) emissions produced by charge exchange between solar wind (SW) protons and interstellar neutrals at the edge of our heliosphere. Using the first 3 yr of IBEX-Hi ENA measurements (2009-2011), we examined the spectral evolution of ∼0.5-6 keV ENAs at the polar regions (above 60°). We found the following: (1) pixels with a characteristic 'ankle' spectra (lower spectral index at higher energies) increase by ∼5% in 2010 and ∼10% in 2011 compared to 2009. (2) The averaged spectral index in 2011 is smaller than that of 2009. (3) The slope of the ENA spectrum above ∼1.7 keV is more variable than the slope below ∼1.7 keV. The lower spectral index at higher energies of the spectrum does not appear to be caused by an increase of the ENA production at these energies, but rather from a consistent decrease at lower energies. (4) The decrease in polar ENA fluxes does not correlate significantly with the averaged SW dynamic pressure, back-traced in time to 1 AU along the flow streamlines (originating between 10° and 30° for slow SW, and 60° and 80° for fast SW), assuming these are the respective conditions of ENA progenitors back in time. These results provide insights into the complexity of relating the slow and fast SW contributions to polar ENAs and shed light on how the solar output and the resulting change in the global heliospheric structure possibly affect the heliosheath (HS) populations.

  14. Measurement of Urinary Cadmium in Glazers Using Solid Phase Extraction Followed by Inductively Coupled Plasma Atomic Emission Spectroscopy

    Directory of Open Access Journals (Sweden)

    Seyed Jamaleddin Shahtaheri

    2012-07-01

    Full Text Available Glazers are exposed to a variety of heavy metals in the ceramic industry, causing adverse effect on the body systems. Cadmium is one of the major raw materials for production of colored glazes. To evaluate occupational exposure to cadmium, spot urine samples were collected from 49 tile and pottery glazers in Yazd City in 2010 at the beginning and end of the work shift (98 samples. Totally, 55 office workers were also evaluated as control group. Samples were prepared using solid phase extraction followed by Inductively Coupled Plasma Atomic Emission Spectroscopy. All the participants filled out a self administered questionnaire comprises questions about work shift, kind of job, use of mask, ventilation,work history, overtime work, age, weight, and height. The lung function tests were performed in a standing position according to the American Thoracic Society recommendation on both control andcadmium exposed individuals. Analysis of covariance (ANCOVA was used to evaluate the data. The mean values of cadmium levels before and after shift in study group was 3.88 and 10.85 μg/gcreatinine,respectively. The mean values of cadmium levels at the end of the work shift in the glazers urine samples was almost 3.53 times higher than the control group and 2.17 times higher than the ACGIHbiological exposure indices (5 μg/g creatinine. In addition the lung functions of glazers was significantly lower than the office workers (p<0.001. Exposure to cadmium in ceramic industry can lead to the reduction of respiratory capacity. Hygienic behaviors such as using protective mask and working in efficient ventilated workplaces can decrease the rate of occupational exposure to cadmium.

  15. Volatile organo-selenium speciation in biological matter by solid phase microextraction–moderate temperature multicapillary gas chromatography with microwave induced plasma atomic emission spectrometry detection

    OpenAIRE

    Dietz, Christian; Sanz Landaluze, Jon; Ximenez Embun, Pilar; Madrid Albarrán, Yolanda; Cámara, Carmen

    2004-01-01

    Microwave induced plasma atomic emission spectrometry (MIP-AES) in combination with multicapillary (MC) gas chromatography could be proven to be useful for element specific detection of volatile species. Solid phase microextraction (SPME) was used for preconcentration and sample-matrix separation. The fiber desorption unit as well as the heating control for the MCcolumn were in-house developed and multicapillary column was operated at moderate temperatures (30–100 ◦C). The method was...

  16. Trace enrichment with activated carbon and determination of Ni, Hg, Sn and Cd using diethyldithiocarbamate as complexant by atomic emission spectrography (AES)

    International Nuclear Information System (INIS)

    A methods has been developed for the preconcentration and determination of trace amounts of Hg, Ni, Sn and Cd in aqueous solutions. The complexes of these elements with sodium diethyl dithiocarbamate were adsorbed on activated charcoal and determined by atomic emission spectrography d-c arc technique. Factors which affect the quantitative recovery of the microamounts of the elements were optimised. Pd was used as an internal standard. The detection limits ranged from 0.01 to 0.05 ppm. (author)

  17. Quantitation of motexafin lutetium in human plasma by liquid chromatography-tandem mass spectrometry and inductively coupled plasma-atomic emission spectroscopy

    OpenAIRE

    Miles, Dale; Mody, Tarak D.; Hatcher, Lori I.; Fiene, John; Stiles, Mark; Patrick P. Lin; Lee, J.W.

    2003-01-01

    Liquid chromatography-tandem mass spectrometry (LC-MS/MS) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) methods were developed and validated for the evaluation of motexafin lutetium (MLu, lutetium texaphyrin, PCI-0123) pharmacokinetics in human plasma. The LC-MS/MS method was specific for MLu, whereas the ICP-AES method measured total elemental lutetium. Both methods were fast, simple, precise, and accurate. For the LC-MS/MS method, a closely related analogue (PCI-0353...

  18. Alcohol and metal determination in alcoholic beverages through high-temperature liquid-chromatography coupled to an inductively coupled plasma atomic emission spectrometer.

    Science.gov (United States)

    Terol, Amanda; Paredes, Eduardo; Maestre, Salvador E; Prats, Soledad; Todolí, José L

    2011-06-01

    In the present work, an inductively coupled plasma atomic emission spectrometry (ICP-AES) system was used as a high temperature liquid chromatography (HTLC) detector for the determination of alcohols and metals in beverages. For the sake of comparison, a refractive index (RI) detector was also employed for the first time to detect alcohols with HTLC. The organic compounds studied were methanol, ethanol, propan-1-ol and butan-1-ol (in the 10-125 mg/L concentration range) and the elements tested were magnesium, aluminum, copper, manganese and barium at concentrations included between roughly 0.01 and 80 mg/L. Column heating temperatures ranged from 80 to 175 °C and the optimum ones in terms of peak resolution, sensitivity and column lifetime were 125 and 100 °C for the HTLC-RI and HTLC-ICP-AES couplings, respectively. The HTLC-ICP-AES interface design (i.e., spray chamber design and nebulizer type used) was studied and it was found that a single pass spray chamber provided about 2 times higher sensitivities than a cyclonic conventional design. Comparatively speaking, limits of detection for alcohols were of the same order for the two evaluated detection systems (from 5 to 25 mg/L). In contrast, unlike RI, ICP-AES provided information about the content of both organic and inorganic species. Furthermore, temperature programming was applied to shorten the analysis time and it was verified that ICP-AES was less sensitive to temperature changes and modifications in the analyte chemical nature than the RI detector. Both detectors were successfully applied to the determination of short chain alcohols in several beverages such as muscatel, pacharan, punch, vermouth and two different brands of whiskeys (from 10 to 40 g of ethanol/100 g of sample). The results of the inorganic elements studied by HTLC-ICP-AES were compared with those obtained using inductively coupled plasma mass spectrometry (ICP-MS) obtaining good agreement between them. Recoveries found for spiked samples

  19. Tungsten coil atomic emission spectrometry combined with dispersive liquid-liquid microextraction: A synergistic association for chromium determination in water samples.

    Science.gov (United States)

    Vidal, Lorena; Silva, Sidnei G; Canals, Antonio; Nóbrega, Joaquim A

    2016-02-01

    A novel and environment friendly analytical method is reported for total chromium determination and chromium speciation in water samples, whereby tungsten coil atomic emission spectrometry (WCAES) is combined with in situ ionic liquid formation dispersive liquid-liquid microextraction (in situ IL-DLLME). A two stage multivariate optimization approach has been developed employing a Plackett-Burman design for screening and selection of the significant factor involved in the in situ IL-DLLME procedure, which was later optimized by means of a circumscribed central composite design. The optimum conditions were complexant concentration: 0.5% (or 0.1%); complexant type: DDTC; IL anion: PF6(-); [Hmim][Cl] IL amount: 60 mg; ionic strength: 0% NaCl; pH: 5 (or 2); centrifugation time: 10 min; and centrifugation speed: 1000 rpm. Under the optimized experimental conditions the method was evaluated and proper linearity was obtained with a correlation coefficient of 0.991 (5 calibration standards). Limits of detection and quantification for both chromium species were 3 and 10 µg L(-1), respectively. This is a 233-fold improvement when compared with chromium determination by WCAES without using preconcentration. The repeatability of the proposed method was evaluated at two different spiking levels (10 and 50 µg L(-1)) obtaining coefficients of variation of 11.4% and 3.6% (n=3), respectively. A certified reference material (SRM-1643e NIST) was analyzed in order to determine the accuracy of the method for total chromium determination and 112.3% and 2.5 µg L(-1) were the recovery (trueness) and standard deviation values, respectively. Tap, bottled mineral and natural mineral water samples were analyzed at 60 µg L(-1) spiking level of total Cr content at two Cr(VI)/Cr(III) ratios, and relative recovery values ranged between 88% and 112% showing that the matrix has a negligible effect. To our knowledge, this is the first time that combines in situ IL-DLLME and WCAES. PMID:26653490

  20. An analytical study of nitrogen oxides and carbon monoxide emissions in hydrocarbon combustion with added nitrogen - Preliminary results

    Science.gov (United States)

    Bittker, D. A.

    1980-01-01

    The influence of ground-based gas turbine combustor operating conditions and fuel-bound nitrogen (FBN) found in coal-derived liquid fuels on the formation of nitrogen oxides and carbon monoxide is investigated. Analytical predictions of NOx and CO concentrations are obtained for a two-stage, adiabatic, perfectly-stirred reactor operating on a propane-air mixture, with primary equivalence ratios from 0.5 to 1.7, secondary equivalence ratios of 0.5 or 0.7, primary stage residence times from 12 to 20 msec, secondary stage residence times of 1, 2 and 3 msec and fuel nitrogen contents of 0.5, 1.0 and 2.0 wt %. Minimum nitrogen oxide but maximum carbon monoxide formation is obtained at primary zone equivalence ratios between 1.4 and 1.5, with percentage conversion of FBN to NOx decreasing with increased fuel nitrogen content. Additional secondary dilution is observed to reduce final pollutant concentrations, with NOx concentration independent of secondary residence time and CO decreasing with secondary residence time; primary zone residence time is not observed to affect final NOx and CO concentrations significantly. Finally, comparison of computed results with experimental values shows a good semiquantitative agreement.

  1. Laboratory-scale evaluation of various sampling and analytical methods for determining mercury emissions from coal-fired power plants

    Energy Technology Data Exchange (ETDEWEB)

    Agbede, R.O.; Bochan, A.J.; Clements, J.L. [Advanced Technology Systems, Inc., Monroeville, PA (United States)] [and others

    1995-11-01

    Comparative bench-scale mercury sampling method tests were performed at the Advanced Technology Systems, Inc. (ATS) laboratories for EPA Method 101A, EPA Method 29 and the Ontario Hydro Method. Both blank and impinger spiking experiments were performed. The experimental results show that the ambient level of mercury in the ATS laboratory is at or below the detection limit (10 ng Hg) as measured by a cold vapor atomic absorption spectrophotometer (CVAAS) which was used to analyze the mercury samples. From the mercury spike studies, the following observations and findings were made. (a) The recovery of mercury spikes using EPA Method 101A was 104%. (b) The Ontario Hydro Method retains about 90% of mercury spikes in the first absorbing solution but has a total spike retention of 106%. As a result, the test data shows possible migration of spiked mercury from the first impinger solution (KCI) to the permanganate impingers. (c) For the EPA Method 29 solutions, when only the peroxide impingers were spiked, mercury recoveries were 65.6% for the peroxide impingers, 0.1% for the knockout impinger and 32.8% for the permanganate impingers with an average total mercury recovery of 98.4%. At press time, data was still being obtained for both the peroxide and permanganate impinger solution spikes. This and other data will be available at the presentation.

  2. Characterization of polycyclic aromatic hydrocarbon emissions in the particulate and gas phase from smoldering mosquito coils containing various atomic hydrogen/carbon ratios

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Tzu-Ting, E-mail: d89844001@ntu.edu.tw [Department of Environmental Engineering and Health, Yuanpei University, No. 306, Yuanpei St., Hsin Chu 30015, Taiwan (China); Lin, Shaw-Tao [Department of Applied Chemistry, Providence University, No. 200 Chung-Chi Rd., Salu Dist., Taichung City 43301, Taiwan (China); Lin, Tser-Sheng [Department of Safety, Health, and Environmental Engineering, National United University, 2 Lien Da, Maioli 360, Taiwan (China); Chung, Hua-Yi [Department of Environmental Engineering and Health, Yuanpei University, No. 306, Yuanpei St., Hsin Chu 30015, Taiwan (China)

    2015-02-15

    The polycyclic aromatic hydrocarbon emissions in particulate and gas phases generated from smoldering mosquito coils containing various atomic H/C ratios were examined. Five types of mosquito coils were burned in a test chamber with a total airflow rate of 8.0 L/min at a constant relative humidity and temperature. The concentrations of individual PAHs were determined using the GC/MS technique. Among the used mosquito coils, the atomic H/C ratio ranged from 1.23 to 1.57, yielding total mass, gaseous, and particulate PAH emission factors of 28.17–78.72 mg/g, 26,139.80–35,932.98 and 5735.22–13,431.51 ng/g, respectively. The various partitions of PAHs in the gaseous and particulate phases were in the ranges, 70.26–83.70% and 16.30–29.74% for the utilized mosquito coils. The carcinogenic potency of PAH emissions in the particulate phase (203.82–797.76 ng/g) was approximately 6.92–25.08 times higher than that of the gaseous phase (26.27–36.07 ng/g). Based on the analyses of PAH emissions, mosquito coils containing the lowest H/C ratio, a low oxygen level, and additional additives (i.e., CaCO{sub 3}) are recommended for minimizing the production of total PAH emission factors and carcinogenic potency. - Highlights: • PAHs emissions are influenced by mosquito coils containing various atomic H/C ratios. • The PAHs generated by burning mosquito coils mainly occur in the gaseous phase. • Total TEQ emission factors of PAHs mainly consisted of the particulate phase (> 87%). • The BaP and BaA accounted for 71.13–77.28% of the total TEQ emission factors. • Special PAH ratios were regarded as characteristic ratios for burning mosquito coil.

  3. Secondary electron emission of thin carbon foils under the impact of hydrogen atoms, ions and molecular ions, under energies within the MeV range

    International Nuclear Information System (INIS)

    This work focuses on the study of the emission statistics of secondary electrons from thin carbon foils bombarded with H0, H2+ and H3+ projectiles in the 0.25-2.2 MeV energy range. The phenomenon of secondary electron emission from solids under the impact of swift ions is mainly due to inelastic interactions with target electrons. The phenomenological and theoretical descriptions, as well as a summary of the main theoretical models are the subject of the first chapter. The experimental set-up used to measure event by event the electron emission of the two faces of a thin carbon foil traversed by an energetic projectile is described in the chapter two. In this chapter are also presented the method and algorithms used to process experimental spectra in order to obtain the statistical distribution of the emitted electrons. Chapter three presents the measurements of secondary electron emission induced by H atoms passing through thin carbon foils. The secondary electron yields are studied in correlation with the emergent projectile charge state. We show the peculiar role of the projectile electron, whether it remains or not bound to the incident proton. The fourth chapter is dedicated to the secondary electron emission induced by H2+ and H3+ polyatomic ions. The results are interpreted in terms of collective effects in the interactions of these ions with solids. The role of the proximity of the protons, molecular ion fragments, upon the amplitude of these collective effects is evidenced from the study of the statistics of forward emission. These experiences allowed us to shed light on various aspects of atom and polyatomic ion inter-actions with solid surfaces. (author)

  4. Analysis of the CCRMP Oka-2 rare-earth reference mineral of the britholite-apatite series by electrothermal atomic-absorption and inductively-coupled plasma atomic-emission spectrometry

    International Nuclear Information System (INIS)

    The lanthanides and yttrium in the Canadian Certified Reference Materials Project (CCRMP) new rare-earth mineral reference material, Oka-2, were determined by electrothermal atomic-absorption and inductively-coupled plasma atomic-emission spectrometry (ICPAES) after sample decomposition with acids and separation of the rare-earth metals from phosphate and other matrix elements by precipitation as fluorides and oxalates. Thorium, yttrium and the common major and minor elements were determined by ICPAES after sample decomposition by fusion with lithium meta- and tetraborates and dissolution of the melt in a mixture of dilute nitric acid and ethylenediaminetetra-acetic acid solution. For comparison purposes, silicon, phosphorus, calcium, magnesium and iron were also determined by other methods. The results obtained are compared with other CCRMP values and with those obtained previously for a similar rare-earth mineral from the same geographical area. Oka-2 is considered to be a thorian intermediate member of the britholite-apatite series. (author)

  5. Use of GSR particle analysis program on an analytical SEM to identify sources of emission of airborne particles

    International Nuclear Information System (INIS)

    Full text: High concentrations of airborne particles, in particular PM10 (particulate matter 10, but has been little used in Australia for airborne particulates. Two sets of 15 mm PM10 samples were collected in March and April 2000 from two sites in Brisbane, one within a suburb and one next to an arterial road. The particles were collected directly onto double-sided carbon tapes with a cascade impactor attached to a high-volume PM10 sampler. The carbon tapes were analysed in a JEOL 840 SEM equipped with a Be-window energy-dispersive X-ray detector and Moran Scientific microanalysis system. An automated Gun Shot Residue (GSR) program was used together with backscattered electron imaging to characterise and analyse individual particulates. About 6,000 particles in total were analysed for each set of impactor samples. Due to limitations of useful pixel size, only particles larger than about 0.5 μm could be analysed. The size, shape and estimated elemental composition (from Na to Pb) of the particles were subjected to non-hierarchical cluster analysis and the characteristics of the clusters were related to their possible sources of emission. Both samples resulted in similar particle clusters. The particles could be classified into three main categories non-spherical (58% of the total number of analysed particles, shape factor >1 1), spherical (15%) and 'carbonaceous' (27%, ie with unexplained % of elemental mass >75%). Non-spherical particles were mainly sea salt and soil particles, and a small amount of iron, lead and mineral dust. The spherical particles were mainly sea salt particles and flyash, and a small amount of iron, lead and secondary sulphate dust. The carbonaceous particles included carbon material mixed with secondary aerosols, roadside dust, sea salt or industrial dust. The arterial road sample also contained more roadside dust and less secondary aerosols than the suburb sample. Current limitations with this method are the minimum particle size

  6. The determination of traces of rare earths in other rare earths by atomic absorption with electrothermal atomization and by d.c. arc emission spectrography

    International Nuclear Information System (INIS)

    The determination of traces of some rare earth elements (Yb, Eu, Tm, Sm, Dy, Ho, Er) in matrices of other rare earths by a.a.s. with electrothermal atomization (tantalum ribbon), and of traces of Tm and Dy by a.e.s. with d.c. arc excitation is described. The influence of the boiling points of the traces and matrices on the possibility and the sensitivity of the a.a.s. determinations is discussed. The results of the methods are compared. Better absolute, and in most cases also relative, detection limits can be achieved by a.a.s

  7. Non-constant relative atomic masses due to varying isotopic abundance of polynuclidic elements and their effect on the accuracy of analytical results

    International Nuclear Information System (INIS)

    Alterations of actual relative atomic masses occur in natural samples by natural isotope ratio shifts of polynuclidic elements. Therefore, using nuclear properties for gaining a measuring signal, isotopic shifts of certain elements may lead to significant measuring errors

  8. A new nebulization device with exchangeable aerosol generation mode as a useful tool to investigate sample introduction processes in inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    A new sample introduction device has been designed in order to differentiate between the effects of the aerosol production and its following desolvation on analytical performances of an inductively coupled plasma optical spectrometer. This research tool allows to easily switch between the pneumatic and ultrasonic aerosol generation mode and to use a joint desolvation chamber. In this way, a real comparison between aerosol production systems may be attained and the influence of aerosol generation process on analytical figures clearly distinguished from that of the desolvation process. In this work, the separate effects of the aerosol generation and desolvation processes on analytical sensitivity and tolerance towards matrix effects have been investigated. Concerning sensitivity, it was found that both the processes play an important role in determining emission intensities, being the increase in sensitivity due to desolvation higher than that due to the improved aerosol generation efficiency. Concerning the matrix effects, a predominant role of the desolvation system was found, while the influence of the aerosol generation mode was much less important. For nitric acid, the decreasing effect was mitigated by the presence of a desolvation system, due to partial removal of the acid. On the contrary, the depressive effect of sulfuric acid was enhanced by the presence of a desolvation system, due to degradation of the solvent removal efficiency and to further decrease in the analyte transport rate caused by clustering phenomena. Concerning the interferences due to sodium and calcium, a depressive effect was observed, which is enhanced by desolvation

  9. Analytical techniques

    International Nuclear Information System (INIS)

    The paper concerns the physical principles behind the analytical techniques employing high energy ion microbeams, with special attention to features that affect their use with microbeams. Particle-induced x-ray emission (PIXIE) is discussed with respect to X-ray production, thick-target PIXIE, a microbeam PIXIE system, sensitivity, and microbeam PIXIE applications. An explanation of nuclear reaction analysis (NRA) is given for NRA with charged particle detection, NRA with neutron detection and NRA with gamma detection. The essentials of Rutherford back scattering (RBS) are given, along with the elastic recoil detection analysis, which has very close connections with RBS but was introduced much more recently. Finally a comparison of the microbeam's capability with those of its main competitors is presented. (UK)

  10. Native defects affecting the Li atom distribution tune the optical emission of ZnO:Li epitaxial thin film

    International Nuclear Information System (INIS)

    It is found that the oxygen vacancy (VO) defect concentration affecting the separation between individual species in LiZn-Lii complex influences the optical emission property of Li0.06Zn0.94O epitaxial thin film grown by pulsed laser deposition. The film grown under low oxygen partial pressure (n-type conductivity)/higher partial pressure (resistive-type) has broad emission at ∼2.99 eV/∼2.1 eV and a narrower emission at 3.63 eV/3.56 eV, respectively. First principle based mBJLDA electronic structure calculation suggests that the emission at 2.99 eV is due to the LiZn-Lii pair complex and the emission at 2.1 eV is when the component species are away from each other

  11. Native defects affecting the Li atom distribution tune the optical emission of ZnO:Li epitaxial thin film

    Science.gov (United States)

    Sahu, R.; Dileep, K.; Loukya, B.; Datta, R.

    2014-02-01

    It is found that the oxygen vacancy (VO) defect concentration affecting the separation between individual species in LiZn-Lii complex influences the optical emission property of Li0.06Zn0.94O epitaxial thin film grown by pulsed laser deposition. The film grown under low oxygen partial pressure (n-type conductivity)/higher partial pressure (resistive-type) has broad emission at ˜2.99 eV/˜2.1 eV and a narrower emission at 3.63 eV/3.56 eV, respectively. First principle based mBJLDA electronic structure calculation suggests that the emission at 2.99 eV is due to the LiZn-Lii pair complex and the emission at 2.1 eV is when the component species are away from each other.

  12. Analytical data and sample locality map for aqua-regia leachates of stream sediments analyzed by ICP, and emission spectrographic and ICP results for many NURE stream sediments from the Killik River Quadrangle, Alaska

    International Nuclear Information System (INIS)

    A U.S. Geological Survey report is presented giving analytical data and sample locality map for aqua-regia leachates of stream sediments analyzed by ICP, and emission spectrographic and ICP results for many NURE stream sediments from the Killik River Quadrangle, Alaska

  13. Economical Alternatives for High Sensitivity in Atomic Spectrometry Laboratory

    Directory of Open Access Journals (Sweden)

    O. Yavuz Ataman

    2007-12-01

    Full Text Available The most commonly used analytical tools for determination of elements at trace levels are atomic absorption spectrometry (AAS, inductively coupled plasma, optical emission and mass spectrometry (ICP-OES and ICP-MS and atomic fluorescence spectrometry (AFS. Although sensitive plasma techniques are becoming predominant in most of the western laboratories, AAS keeps its importance in developing countries. Simple and inexpensive ways of enhancing sensitivity will be described for laboratories equipped with only a flame AA spectrometer. Although there are many chemical preconcentration procedures to improve sensitivity of flame AAS, only some atom trapping techniques will be included here. One kind of atom trapping device is a slotted quartz tube (SQT used for in situ preconcentration of analyte species followed by a rapid revolatilization cycle to obtain an enhanced signal. These devices provide limits of detection at a level of µg L-1. Another kind of atom trapping involves use of vapor generation technique and quartz or tungsten atom trapping surfaces. The analytical steps consist of the generation of volatile species, usually by hydride formation using NaBH4, trapping these species at the surface of an atom trap held at an optimized temperature and finally re-volatilizing analyte species by rapid heating of trap. These species are transported using a carrier gas to an externally heated quartz tube as commonly used in hydride generation AAS systems; a transient signal is formed and measured. These traps have limits of detection in the order of ng L-1.

  14. Electron-impact studies of atomic oxygen: II. Emission cross section measurements of the O I 3So→3P transition (130.4 nm)

    International Nuclear Information System (INIS)

    The optical excitation function of the O I 3So→3P transition (130.4 nm), produced by electron-impact excitation of atomic oxygen, has been measured over an extended energy range from threshold to 1.0 keV. Measurements were obtained in a crossed-beam experiment using both magnetically confined and electrostatically focused electrons in collision with atomic oxygen produced by a microwave discharge source. A 0.2 m vacuum ultraviolet monochromator system was used to measure the emitted O I radiation at 130.4 nm. The relative O I (130.4 nm) emission intensity corresponding to the 3So→3P transition was then put on the absolute scale by normalization to the O I (130.4 nm) cross section produced by dissociative excitation of O2 at 30 eV (Kanik et al 2000). (author)

  15. Determination of some inorganic metals in edible vegetable oils by inductively coupled plasma atomic emission spectroscopy (ICP-AES

    Directory of Open Access Journals (Sweden)

    Musa Özcan, M.

    2008-09-01

    Full Text Available Seventeen edible vegetable oils were analyzed spectrometrically for their metal (Cu, Fe, Mn, Co, Cr, Pb, Cd, Ni, and Zn contents. Toxic metals in edible vegetable oils were determined by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES. The highest metal concentrations were measured as 0.0850, 0.0352, 0.0220, 0.0040, 0.0010, 0.0074, 0.0045, 0.0254 and 0.2870 mg/kg for copper in almond oil, for iron in corn oil-(c, for manganese in soybean oil, for cobalt in sunflower oil-(b and almond oil, for chromium in almond oil, for lead in virgin olive oil, for cadmium in sunflower oil-(e, for nickel almond oil and for zinc in almond oil respectively. The method for determining toxic metals in edible vegetable oils by using ICP-AES is discussed. The metals were extracted from low quantities of oil (2-3 g with a 10% nitric acid solution. The extracted metal in acid solution can be injected into the ICPAES. The proposed method is simple and allows the metals to be determined in edible vegetable oils with a precision estimated below 10% relative standard deviation (RSD for Cu, 5% for Fe, 15% for Mn, 8% for Co, 10% for Cr, 20% for Pb, 5% for Cd, 16% for Ni and 11% for Zn.En este estudio se analizó espectrométricamente el contenido en metales (Cu, Fe, Mn, Co, Cr, Pb, Cd, Ni, and Zn de 17 aceites vegetales comestibles mediante ICP-AES. Las concentaciones más elevadas se encontraron para el cobre en el aceite de almendra (0.0850 mg/kg, para el hierro en el aceite de maiz(c,(0.0352 mg/kg, para el manganeso en el aceite de soja (0.0220 mg/kg, para el cobalto en el aceite de girasol (b (0.0040 mg/kg, para el cromo en el aceite de almendra (0.0010 mg/kg, para el plomo en el aceite de oliva virgen (0.0074 mg/kg, para el cadmio en el aceite de girasol (e (0.0045 mg/kg, para el niquel en el aceite de almendra (0.0254 mg/kg y para el zincen el aceite de almendra (0.2870 mg/kg. Los metales se extrajeron a partir de bajas cantidades de aceite (2-3 g, con

  16. Quantitative Determination of Density of Ground State Atomic Oxygen from Both TALIF and Emission Spectroscopy in Hot Air Plasma Generated by Microwave Resonant Cavity

    Science.gov (United States)

    Marchal, F.; Yousfi, M.; Merbahi, N.; Wattieaux, G.; Piquemal, A.

    2016-03-01

    Two experimental techniques have been used to quantify the atomic oxygen density in the case of hot air plasma generated by a microwave (MW) resonant cavity. The latter operates at a frequency of 2.45 GHz inside a cell of gas conditioning at a pressure of 600 mbar, an injected air flow of 12 L/min and an input MW power of 1 kW. The first technique is based on the standard two photon absorption laser induced fluorescence (TALIF) using xenon for calibration but applied for the first time in the present post discharge hot air plasma column having a temperature of about 4500 K near the axis of the nozzle. The second diagnostic technique is an actinometry method based on optical emission spectroscopy (OES). In this case, we compared the spectra intensities of a specific atomic oxygen line (844 nm) and the closest wavelength xenon line (823 nm). The two lines need to be collected under absolutely the same spectroscopic parameters. The xenon emission is due to the addition of a small proportion of xenon (1% Xe) of this chemically inert gas inside the air while a further small quantity of H2 (2%) is also added in the mixture in order to collect OH(A-X) and NH(A-X) spectra without noise. The latter molecular spectra are required to estimate gas and excitation temperatures. Optical emission spectroscopy measurements, at for instance the position z=12 mm on the axis plasma column that leads to a gas measured temperature equal to 3500 K, an excitation temperature of about 9500 K and an atomic oxygen density 2.09×1017±0.2×1017 cm-3. This is in very good agreement with the TALIF measurement, which is equal to 2.0×1017 cm-3.

  17. Determination of trace amounts of molybdenum in plant tissue by solvent extraction-atomic-absorption and direct-current plasma emission spectrometry.

    Science.gov (United States)

    Lajunen, L H; Kubin, A

    1986-03-01

    Methods are presented for determination of molybdenum in plant tissue by flame and graphite-furnace atomic-absorption spectrometry and direct-current argon-plasma emission spectrometry. The samples are digested in HNO(3)-H(2)SO(4)-HC1O(4) mixture, and Mo is separated and concentrated by chelation and extraction. Three organic solvents (methyl isobutyl ketone, di-isobutyl ketone and isoamyl alcohol) and two ligands (8-hydroxyquinoline and toluene-3,4-dithiol) were studied. The procedure were tested on pine needle and birch leaf samples. PMID:18964076

  18. Emissive properties of xenon ions from a laser-produced plasma in the 100-140 Å spectral range: Atomic-physics analysis of the experimental data

    Science.gov (United States)

    Gilleron, F.; Poirier, M.; Blenski, T.; Schmidt, M.; Ceccotti, T.

    2003-08-01

    In order to design extreme ultraviolet (EUV) sources for nanolithography, xenon EUV emission has been experimentally studied in a plasma generated by the interaction of a high-power laser with a droplet jet. A theoretical model assuming that the resulting plasma is optically thick allows one to find the distribution of the relevant ions and transitions involved in the emission process. Atomic physics computations are performed using the HULLAC code to give a detailed account of the transitions involved. The importance of 4p-4d, 4d-4f, and 4d-5p transitions is stressed, as well as the need for configuration-interaction treatment of the Δn=0 transitions. Comparisons of a modeled local thermodynamical equilibrium spectrum with experiment provides qualitative agreement and permits an estimate of the plasma temperature, density, and dimensions.

  19. Characterization and mutual comparison of new electrolytic cell designs for hydride generation-atomic absorption spectrometry with a quartz tube atomizer using Se as a model analyte and Se-75 as a radioactive indicator

    Czech Academy of Sciences Publication Activity Database

    Hraníček, J.; Červený, V.; Kratzer, Jan; Vobecký, Miloslav; Rychlovský, P.

    2012-01-01

    Roč. 27, č. 10 (2012), s. 1761-1771. ISSN 0267-9477 R&D Projects: GA ČR GA203/09/1783 Institutional support: RVO:68081715 Keywords : electrochemical hydride generation AAS * selenium hydride * radiotracer study Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.155, year: 2012

  20. 40 CFR Appendix C to Part 136 - Inductively Coupled Plasma-Atomic Emission Spectrometric Method for Trace Element Analysis of...

    Science.gov (United States)

    2010-07-01

    ... absorption spectrometry, or other approved methodology. 5.2.4Wavelength scanning of analyte line region. If..., Publication No. 77-206, August 1977. 14.8“OSHA Safety and Health Standards, General Industry,” (29 CFR part... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Inductively Coupled...

  1. Simultaneous determination of sub μg·g-1 levels of nine impurities in high purity iron by horizontal cation exchange resin mini-column and ICP-atomic emission spectrometry

    International Nuclear Information System (INIS)

    Inductively coupled plasma-atomic emission spectrometry (ICP-AES) has been applied to the simultaneous determination of trace impurities in high purity iron after simultaneous separation. Sub μg·g-1 levels of Ca, Cd, Co, Cu, Mg, Mn, Ni, Pb and Zn in high purity iron which had been dissolved in hydrofluoric acid and hydrogen peroxide were separated from the iron matrix using a horizontal cation exchange resin mini-column. Flow rates and flow directions of solutions through the mini-column were controlled by a peristaltic pump. Adsorbed elements on the resin mini-column were rapidly eluted using a reverse flow of the eluant against the flow for the adsorption. The eluted elements were determined by ICP-AES using an internal standard method and good results were obtained. A 100-fold enrichment of analytes was obtained with this preconcentration system using 1 g of the sample in comparison with an ordinary sample solution in which 0.5 g of the sample was dissolved in 100 cm3 without separation. (author)

  2. Improvement of AOAC Official Method 984.27 for the determination of nine nutritional elements in food products by Inductively coupled plasma-atomic emission spectroscopy after microwave digestion: single-laboratory validation and ring trial.

    Science.gov (United States)

    Poitevin, Eric; Nicolas, Marine; Graveleau, Laetitia; Richoz, Janique; Andrey, Daniel; Monard, Florence

    2009-01-01

    A single-laboratory validation (SLV) and a ring trial (RT) were undertaken to determine nine nutritional elements in food products by inductively coupled plasma-atomic emission spectroscopy in order to improve and update AOAC Official Method 984.27. The improvements involved optimized microwave digestion, selected analytical lines, internal standardization, and ion buffering. Simultaneous determination of nine elements (calcium, copper, iron, potassium, magnesium, manganese, sodium, phosphorus, and zinc) was made in food products. Sample digestion was performed through wet digestion of food samples by microwave technology with either closed or open vessel systems. Validation was performed to characterize the method for selectivity, sensitivity, linearity, accuracy, precision, recovery, ruggedness, and uncertainty. The robustness and efficiency of this method was proved through a successful internal RT using experienced food industry laboratories. Performance characteristics are reported for 13 certified and in-house reference materials, populating the AOAC triangle food sectors, which fulfilled AOAC criteria and recommendations for accuracy (trueness, recovery, and z-scores) and precision (repeatability and reproducibility RSD and HorRat values) regarding SLV and RT. This multielemental method is cost-efficient, time-saving, accurate, and fit-for-purpose according to ISO 17025 Norm and AOAC acceptability criteria, and is proposed as an improved version of AOAC Official Method 984.27 for fortified food products, including infant formula. PMID:19916387

  3. Chemometric evaluation of Cd, Co, Cr, Cu, Ni (inductively coupled plasma optical emission spectrometry) and Pb (graphite furnace atomic absorption spectrometry) concentrations in lipstick samples intended to be used by adults and children.

    Science.gov (United States)

    Batista, Érica Ferreira; Augusto, Amanda dos Santos; Pereira-Filho, Edenir Rodrigues

    2016-04-01

    A method was developed for determining the concentrations of Cd, Co, Cr, Cu, Ni and Pb in lipstick samples intended to be used by adults and children using inductively coupled plasma optical emission spectrometry (ICP OES) and graphite furnace atomic absorption spectrometry (GF AAS) after treatment with dilute HNO3 and hot block. The combination of fractional factorial design and Desirability function was used to evaluate the ICP OES operational parameters and the regression models using Central Composite and Doehlert designs were calculated to stablish the best working condition for all analytes. Seventeen lipstick samples manufactured in different countries with different colors and brands were analyzed. Some samples contained high concentrations of toxic elements, such as Cr and Pb, which are carcinogenic and cause allergic and eczematous dermatitis. The maximum concentration detected was higher than the permissible safe limits for human use, and the samples containing these high metal concentrations were intended for use by children. Principal component analysis (PCA) was used as a chemometrics tool for exploratory analysis to observe the similarities between samples relative to the metal concentrations (a correlation between Cd and Pb was observed). PMID:26838401

  4. On the multiphoton emission during U.V. and X-ray absorption by atoms in intense laser fields

    International Nuclear Information System (INIS)

    A discussion of the u.v. and x-ray absorption cross section by a hydrogen atom in the presence of an intense i.r. laser field is presented, taking into account the influence of laser field on the electronic states. (Author)

  5. Sounding of the Atmosphere using Broadband Emission Radiometry observations of daytime mesospheric O2(1Δ) 1.27 μm emission and derivation of ozone, atomic oxygen, and solar and chemical energy deposition rates

    Science.gov (United States)

    Mlynczak, Martin G.; Marshall, B. Thomas; Martin-Torres, F. Javier; Russell, James M.; Thompson, R. Earl; Remsberg, Ellis E.; Gordley, Larry L.

    2007-08-01

    We report observations of the daytime O2(1Δ) airglow emission at 1.27 μm recorded by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the NASA Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) satellite. The measured limb radiances are inverted to yield vertical profiles of the volume emission rate of energy from the O2 molecule. From these emission rates we subsequently derive the mesospheric ozone concentrations using a nonlocal thermodynamic equilibrium (non-LTE) radiative and kinetic model. Rates of energy deposition due to absorption of ultraviolet radiation in the Hartley band of ozone are also derived, independent of knowledge of the ozone abundance and solar irradiances. Atomic oxygen concentrations are obtained from the ozone abundance using photochemical steady state assumptions. Rates of energy deposition due to exothermic chemical reactions are also derived. The data products illustrated here are from a test day (4 July 2002) of SABER Version 1.07 data which are now becoming publicly available. This test day illustrates the high quality of the SABER O2(1Δ) airglow and ozone data and the variety of fundamental science questions to which they can be applied.

  6. Investigation of trialkoxysilane hydrolysis kinetics using liquid chromatography with inductively coupled plasma atomic emission spectrometric detection and non-linear regression modeling

    International Nuclear Information System (INIS)

    A novel approach is demonstrated for measuring rates of the consecutive acid-base catalyzed hydrolysis reactions of (3-glycidoxypropyl)trimethoxysilane (GPTMS) and (3-aminopropyl)triethoxysilane (APTES) in dilute aqueous solution using liquid chromatography with inductively coupled plasma atomic emission spectrometric (ICP-AES) detection. The hydrolysis reactions are monitored by sampling kinetic solutions in a timewise manner and performing liquid chromatographic separations of the parent silane and organosilicon hydrolysis products. The column effluent is fed into the ICP through a direct injection nebulizer for online monitoring of silicon atomic emission at 251.611 nm, producing a series of silicon chromatograms for each kinetic run. Reversed phase separations are effected using acetonitrile-water gradients and are complete in 6 min or less. The systematic changes in peak areas provide information from which the rate constants of the consecutive hydrolysis reactions (k1, k2, and k3) are obtained by non-linear regression modeling. Using a quenching scheme, hydrolysis half-lives as brief as 3 min for the parent silane can be monitored. For each compound, a series of rate constants are obtained over a range of pH and buffer concentration, permitting estimation of the catalytic constants kH3O+ and kOH- for the consecutive acid-base catalyzed hydrolysis reactions by multiple regression analysis

  7. Coherently controlled emissions |4P3/2,1/2> ↔ |4S1/2> from a femtosecond Λ-type excitation scheme in potassium atom

    Science.gov (United States)

    Pentaris, D.; Damianos, D.; Papademetriou, G.; Lyras, A.; Steponkevičius, K.; Vaičaitis, V.; Efthimiopoulos, T.

    2016-07-01

    The combined excitation of high density potassium (K) vapour by 100 fs pump-coupling pulses is experimentally studied. The intense pump pulse excites the two-photon ? transition and internally generated emissions are initiated along the atomic paths: ? (path-1) and, ? (path-2). The temporally delayed coupling pulse coherently drives the ? transitions, in a Λ-type excitation scheme. The competing axial and conical emission components of the well-resolved ? transitions (D2 and D1 lines of K) are substantially enhanced and controlled, for appropriate detunings and pump-coupling temporal delays. The coherence relaxation time (CRT) of the two-photon excited ? state is determined by exploiting the temporal delay in the pulse sequence. The effect of the pulse delay and the fs pulse bandwidth on the system dynamics is discussed as well as the role of dephasing collisions between K and buffer gas atoms. The proposed scheme can be employed in radiative multi-level systems, for the direct estimation of coherence relaxation rates of various states.

  8. Collective mechanisms for atomic processes in plasmas

    International Nuclear Information System (INIS)

    New mechanisms for atomic processes in plasmas induced by the collective behavior of the system are proposed, the collective behavior being a consequence of the long range of the Coulomb forces between the (charged) particles. These new mechanisms are hydrogen recombination with plasmon emission, ionization by plasmon absorption, and bound-bound and free-free atomic transitions with emission or absorption of plasmons. The Bohm-Pines Fock-Tani Hamiltonian for a proton at rest immersed in a finite temperature plasma (in the electron gas model), is obtained from first principles by a sequence of canonical transformations. This Hamiltonian shows explicitly the new proposed reaction and scattering mechanisms, in which, the emission or absorption of plasmons allow the process to occur. Expressions for plasmonic recombination matrix elements in the orthogonalized Born approximation (OBA) and the distorted wave Born approximation (DWBA) are given in terms of 6- or 12-dimensional integrals which are reduced analytically to 2-dimensional integrals. Explicit evaluations of the cross section for the plasmonic and radiative recombination in the (OBA) are obtained. The results indicate that the radiative mechanism is negligible compared to the plasmonic mode for the value of the parameters and quantum numbers indicated above. Finally by using a generalized Schroedinger equation for composite particles in a medium he recalculates the energy shift of a hydrogen atom produced by the exchange between a free electron and the bound atomic electron. The result shows that the shifts are important for the highly excited states of atoms in plasmas

  9. E(A+M)PEC - An OpenCL Atomic & Molecular Plasma Emission Code For Interstellar Medium Simulations

    CERN Document Server

    de Avillez, Miguel A; Breitschwerdt, Dieter

    2011-01-01

    E(A+M)PEC traces the ionization structure, cooling and emission spectra of plasmas. It is written in OpenCL, runs in NVIDIA Graphics Processor Units and can be coupled to any HD or MHD code to follow the dynamical and thermal evolution of any plasma in, e.g., the interstellar medium (ISM).

  10. Electron emission and exciton production of LiF surfaces by grazing impact of hydrogen neutral atoms

    International Nuclear Information System (INIS)

    We put forward an alternative mechanism to understand the physics underlying the electron emission and exciton formation occurring during grazing collision of neutral hydrogen on LiF(001) surfaces. Instead of visualizing the negative ion formation as the precursor, we propose the formation of excited H(n=2) as a catalyzer to produce excitons and electrons

  11. Influence of easily ionised elements on the delayed responses of the emission intensities of an analyte in a power modulated U-shaped argon stabilised DC arc plasma with an aerosol supply

    Directory of Open Access Journals (Sweden)

    MIROSLAV KUZMANOVIC

    2005-09-01

    Full Text Available The current of a U-shaped argon stabilised DC arc was square modulated with a 40 Hz repetition frequency between 6 and 3 A. The delayed line intensity responses to the modulation of the arc current were investigated using calcium as a representative analyte. The intensities of both the atomic and ionic lines were monitored at different distances from the arc axis in the presence of various concentrations of the easily ionised element. Temporal evolutions were monitored on a millisecond time scale. It was found that the responses of the line intesity to the arc current change strongly depended on the observed radial position, especially in the vicinity of the arc axis. The obtained results showed a significant influence of even small amounts of the easily ionised element on the excitation and transport of the analyte and indicated a way of possibly improving the analytical capabilities of the excitation source.

  12. Atomic layer deposition of TiO2 and Al2O3 on nanographite films: structure and field emission properties

    Science.gov (United States)

    Kleshch, Victor I.; Ismagilov, Rinat R.; Smolnikova, Elena A.; Obraztsova, Ekaterina A.; Tuyakova, Feruza; Obraztsov, Alexander N.

    2016-03-01

    Atomic layer deposition (ALD) of metal oxides (MO) was used to modify the properties of nanographite (NG) films produced by direct current plasma-enhanced chemical vapor deposition technique. NG films consist of a few layers of graphene flakes (nanowalls) and nanoscrolls homogeneously distributed over a silicon substrate with a predominantly vertical orientation of graphene sheets to the substrate surface. TiO2 and Al2O3 layers, with thicknesses in the range of 50 to 250 nm, were deposited on NG films by ALD. The obtained NG-MO composite materials were characterized by scanning electron microscopy, energy dispersive x-ray analysis, and Raman spectroscopy. It was found that ALD forms a uniform coating on graphene flakes, while on the surface of needle-like nanoscrolls it forms spherical nanoparticles. Field emission properties of the films were measured in a flat vacuum diode configuration. Analysis based on obtained current-voltage characteristics and electrostatic calculations show that emission from NG-TiO2 films is determined by the nanoscrolls protruding from the TiO2 coverage. The TiO2 layers with thicknesses of <200 nm almost do not affect the overall field emission characteristics of the films. At the same time, these layers are able to stabilize the NG films' surface and can lead to an improvement of the NG cold cathode performance in vacuum electronics.

  13. Development of novel and sensitive methods for the determination of sulfide in aqueous samples by hydrogen sulfide generation-inductively coupled plasma-atomic emission spectroscopy

    International Nuclear Information System (INIS)

    Two new, simple and accurate methods for the determination of sulfide (S2-) at low levels (μg L-1) in aqueous samples were developed. The generation of hydrogen sulfide (H2S) took place in a coil where sulfide reacted with hydrochloric acid. The resulting H2S was then introduced as a vapor into an inductively coupled plasma-atomic emission spectrometer (ICP-AES) and sulfur emission intensity was measured at 180.669 nm. In comparison to when aqueous sulfide was introduced, the introduction of sulfur as H2S enhanced the sulfur signal emission. By setting a gas separator at the end of the reaction coil, reduced sulfur species in the form of H2S were removed from the water matrix, thus, interferences could be avoided. Alternatively, the gas separator was replaced by a nebulizer/spray chamber combination to introduce the sample matrix and reagents into the plasma. This methodology allowed the determination of both sulfide and sulfate in aqueous samples. For both methods the linear response was found to range from 5 μg L-1 to 25 mg L-1 of sulfide. Detection limits of 5 μg L-1 and 6 μg L-1 were obtained with and without the gas separator, respectively. These new methods were evaluated by comparison to the standard potentiometric method and were successfully applied to the analysis of reduced sulfur species in environmental waters

  14. Scaling properties of cavity-enhanced atom cooling

    CERN Document Server

    Horak, P; Horak, Peter; Ritsch, Helmut

    2001-01-01

    We extend an earlier semiclassical model to describe the dissipative motion of N atoms coupled to M modes inside a coherently driven high-finesse cavity. The description includes momentum diffusion via spontaneous emission and cavity decay. Simple analytical formulas for the steady-state temperature and the cooling time for a single atom are derived and show surprisingly good agreement with direct stochastic simulations of the semiclassical equations for N atoms with properly scaled parameters. A thorough comparison with standard free-space Doppler cooling is performed and yields a lower temperature and a cooling time enhancement by a factor of M times the square of the ratio of the atom-field coupling constant to the cavity decay rate. Finally it is shown that laser cooling with negligible spontaneous emission should indeed be possible, especially for relatively light particles in a strongly coupled field configuration.

  15. Flame-in-gas-shield and miniature diffusion flame hydride atomizers for atomic fluorescence spectrometry: optimization and comparison

    International Nuclear Information System (INIS)

    A detailed optimization of relevant experimental parameters of two hydride atomizers for atomic fluorescence spectrometry: flame-in-gas-shield atomizer with a two-channel shielding unit and a standard atomizer for atomic fluorescence spectrometry, miniature diffusion flame, was performed. Arsine, generated by the reaction with NaBH4 in a flow injection arrangement, was chosen as the model hydride. Analytical characteristics of both the atomizers (sensitivity, noise, limits of detection) were compared. Under optimum conditions sensitivity obtained with flame-in-gas-shield atomizer was approximately twice higher than with miniature diffusion flame. The additional advantage of flame-in-gas-shield atomizer is significantly lower flame emission resulting in a better signal to noise ratio. The resulting arsenic limits of detection for miniature diffusion flame and flame-in-gas-shield atomizer were 3.8 ng l−1 and 1.0 ng l−1, respectively. - Highlights: • We optimized and compared two hydride atomizers for atomic fluorescence spectrometry. • Miniature diffusion flame and flame-in-gas-shield atomizer were optimized. • The limit of detection for arsenic was 1.0 ng l−1

  16. Tracking and uncertainty in absorption spectrometry and atomic emission; Trazabilidad e incertidumbre en espectrometria de absorcion y emision atomica

    Energy Technology Data Exchange (ETDEWEB)

    Arvizu Torres, Maria del Rocio; Ramirez Cruz, Pedro [Centro Nacional de Metrologia (CENAM), Division de Materiales Metalicos, Area de Metrologia de Materiales, Departamento de Educacion Continua, El Marquez, Queretaro (Mexico)

    2008-04-18

    In this course it is described what methodology is, the measuring instruments and the importance of its calibration. The history of the International System of Units is described and what the meaning of tracking is. Also the general concepts of uncertainty in analytical measurements are shown, such as the measurements of central tendency and the variability measurements. [Spanish] En este curso se describe que es metodologia, los instrumentos de medicion y la importancia de calibrarlos. Se describe la historia del Sistema Internacional de Unidades y que es la trazabilidad. Tambien se presentan conceptos generales de incertidumbre en mediciones analiticas, como las medidas de tendencia central y las medidas de variabilidad.

  17. Resonant nonstationary amplification of polychromatic laser pulses and conical emission in an optically dense ensemble of neon metastable atoms

    OpenAIRE

    Bagayev, S. N.; Egorov, V. S.; Mekhov, I. B.; Moroshkin, P. V.; Chekhonin, I. A.; Davliatchine, E. M.; Kindel, E.

    2003-01-01

    Experimental and numerical investigation of single-beam and pump-probe interaction with a resonantly absorbing dense extended medium under strong and weak field-matter coupling is presented. Significant probe beam amplification and conical emission were observed. Under relatively weak pumping and high medium density, when the condition of strong coupling between field and resonant matter is fulfilled, the probe amplification spectrum has a form of spectral doublet. Stronger pumping leads to t...

  18. MID-INFRARED ATOMIC FINE-STRUCTURE EMISSION-LINE SPECTRA OF LUMINOUS INFRARED GALAXIES: SPITZER/IRS SPECTRA OF THE GOALS SAMPLE

    International Nuclear Information System (INIS)

    We present the data and our analysis of mid-infrared atomic fine-structure emission lines detected in Spitzer/Infrared Spectrograph high-resolution spectra of 202 local Luminous Infrared Galaxies (LIRGs) observed as part of the Great Observatories All-sky LIRG Survey (GOALS). We readily detect emission lines of [S IV], [Ne II], [Ne V], [Ne III], [S III]18.7μm, [O IV], [Fe II], [S III]33.5μm, and [Si II]. More than 75% of these galaxies are classified as starburst-dominated sources in the mid-infrared, based on the [Ne V]/[Ne II] line flux ratios and equivalent width of the 6.2 μm polycyclic aromatic hydrocarbon feature. We compare ratios of the emission-line fluxes to those predicted from stellar photo-ionization and shock-ionization models to constrain the physical and chemical properties of the gas in the starburst LIRG nuclei. Comparing the [S IV]/[Ne II] and [Ne III]/[Ne II] line ratios to the Starburst99-Mappings III models with an instantaneous burst history, the emission-line ratios suggest that the nuclear starbursts in our LIRGs have ages of 1-4.5 Myr, metallicities of 1-2 Z☉, and ionization parameters of 2-8 × 107 cm s–1. Based on the [S III]33.5μm/[S III]18.7μm ratios, the electron density in LIRG nuclei is typically one to a few hundred cm–3, with a median electron density of ∼300 cm–3, for those sources above the low density limit for these lines. We also find that strong shocks are likely present in 10 starburst-dominated sources of our sample. A significant fraction of the GOALS sources (80) have resolved neon emission-line profiles (FWHM ≥600 km s–1) and five show clear differences in the velocities of the [Ne III] or [Ne V] emission lines, relative to [Ne II], of more than 200 km s–1. Furthermore, six starburst and five active galactic nucleus dominated LIRGs show a clear trend of increasing line width with ionization potential, suggesting the possibility of a compact energy source and stratified interstellar medium in their

  19. Alternativas analíticas para determinação de ferro e titânio em cimento Portland Comparative study of analytical methods for iron and titanium determination in Portland cement

    OpenAIRE

    Jorge de O. Franco Jr.; Maria das Graças A. Korn; Antonio Celso S. Costa; Anibal de Freitas Santos Jr.; Leonardo S. G. Teixeira

    2001-01-01

    In the present work four different analytical methodologies were studied for the determination of iron and titanium in Portland cement. The cement samples were dissolved with hot HCl and HF, being compared Fe and Ti concentrations through four analytical methods: molecular absorption spectrophotometry using the reagents 1,2-hydroxybenzene-3,5-disulfonic acid (Tiron) and the 5-chloro-salicylic acid (CSA), inductively coupled plasma atomic emission spectrometry (ICP-AES) and flame atomic absorp...

  20. Uncertainties in Atomic Data and Their Propagation Through Spectral Models. I.

    Science.gov (United States)

    Bautista, M. A.; Fivet, V.; Quinet, P.; Dunn, J.; Gull, T. R.; Kallman, T. R.; Mendoza, C.

    2013-01-01

    We present a method for computing uncertainties in spectral models, i.e., level populations, line emissivities, and emission line ratios, based upon the propagation of uncertainties originating from atomic data.We provide analytic expressions, in the form of linear sets of algebraic equations, for the coupled uncertainties among all levels. These equations can be solved efficiently for any set of physical conditions and uncertainties in the atomic data. We illustrate our method applied to spectral models of Oiii and Fe ii and discuss the impact of the uncertainties on atomic systems under different physical conditions. As to intrinsic uncertainties in theoretical atomic data, we propose that these uncertainties can be estimated from the dispersion in the results from various independent calculations. This technique provides excellent results for the uncertainties in A-values of forbidden transitions in [Fe ii]. Key words: atomic data - atomic processes - line: formation - methods: data analysis - molecular data - molecular processes - techniques: spectroscopic

  1. Excimer laser-ablated plasma atomic spectrometry

    International Nuclear Information System (INIS)

    The characterization and evaluation of a new kind of excimer laser-ablated plasma and applications for direct spectrochemical analysis were investigated through time- and space-resolved spectroscopy. The shape, size, emission spectra, and excitation temperatures of the plasma are largely department on the atmospheric surroundings, the ambient gas composition, the pressure, and laser energy. Spatial discrimination may be desirable to increase the line-to-background (L/B) ratio in atomic emission spectroscopy. A direct spectrochemical analytical method for solid samples with good linearity was developed using the excimer laser-AES. The sensitivity of the analytical signal varied depending on the chemical matrix of the solid samples. A typical detection limit for potassium in a glass matrix was 0.13 μg/g.

  2. Speciation of mercury compounds by gas chromatography with atomic emission detection. Simultaneous optimization of a headspace solid-phase microextraction and derivatization procedure by use of chemometric techniques

    Energy Technology Data Exchange (ETDEWEB)

    Carro, A.M.; Neira, I.; Rodil, R.; Lorenzo, R. A. [Univ. Santiago de Compostela (Spain). Dpto. Quimica Analitica, Nutricion y Bromatologia

    2003-06-01

    A method is proposed for the extraction and determination of organomercury compounds and Hg(II) in seawater samples by headspace solid-phase microextraction (HS-SPME) combined with capillary gas chromatography-microwave-induced plasma atomic emission spectrometry. The mercury species were derivatized with sodium tetraphenylborate, sorbed on a polydimethylsiloxane-coated fused-silica fibre, and desorbed in the injection port of the GC, in splitless mode. Experimental design methodology was used to evaluate the effect of six HS-SPME-derivatization variables: sample volume, NaBPh{sub 4} volume, pH, sorption time, extraction-derivatization temperature, and rate of stirring. Use of a multicriterion decision-making approach, with the desirability function, enabled determination of the optimum working conditions of the procedure for simultaneous analysis of three mercury species. (orig.)

  3. Determination of trace zirconium and hafnium in high-purity scandium oxide by inductively coupled plasma atomic emission spectrometry and extraction chromatography

    International Nuclear Information System (INIS)

    Inductively coupled plasma atomic emission spectrometry in combination with extraction chromatography was applied to the determination of trace amounts of zirconium and hafnium in high-purity scandium oxide. The chromatographic column separation procedure was carried out with 1-phenyl-3-methyl-4-benzoylpyrazol-5-one as the stationary phase and hydrochloride acid as the mobile phase. Optimum column operating conditions were established. The enrichment factor based on 0.1 g of scandium oxide was over 2000. The results obtained agreed well with those obtained by spark-source mass spectrometry without the separation of scandium. For a sample mass of 0.3 g, the detection limits for zirconium and hafnium were 0.14 and 0.17 μg g-1, respectively. The proposed method could be applied to the analysis of scandium oxide of laser grade and 99.9995% purity

  4. Determination of Cu, Zn, Pb and Cd by atomic emission spectrometry with inductively coupled plasma in waters and sediments from San Juan Ecosystem, Santiago de Cuba

    International Nuclear Information System (INIS)

    In this paper the levels of concentration of copper, zinc, lead and cadmium in waters and sediments from the ecosystem San Juan in the Santiago of Cuba province were evaluated. Two sampling of the ecosystem in two stations belonging to the high and middle part of the river, in rainy and little rainy periods were carried out. The conservation and treatment of the samples were developed according to established standards and the determinations of the elements were realized using atomic emission spectrometry with inductively coupled plasma. The concentrations intervals of the studied elements were established so much in the superficial waters like in the sediments and it was demonstrated that exists statistical significant differences for the factors station, period and type of sample, being the middle part of the river, the little rainy period and the sediments, where the grater concentrations of the pollutants appear

  5. Pattern recognition of Inductively Coupled Plasma Atomic Emission Spectroscopy of human scalp hair for discriminating between healthy and Hepatitis C patients

    Energy Technology Data Exchange (ETDEWEB)

    Lloyd, Gavin R. [Centre for Chemometrics, School of Chemistry, University of Bristol, Cantocks Close, Bristol BS2 8DF (United Kingdom); Ahmad, Sajjad [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Wasim, Mohammad [Chemistry Division, Pakistan Institute of Nuclear Science and Technology, P.O. Nilore, Islamabad (Pakistan); Brereton, Richard G., E-mail: r.g.brereton@bris.ac.uk [Centre for Chemometrics, School of Chemistry, University of Bristol, Cantocks Close, Bristol BS2 8DF (United Kingdom)

    2009-09-01

    Inductively Coupled Plasma Atomic Emission Spectroscopy measurements of six trace elements were performed on the scalp hair of 155 donors, 73 of which have been diagnosed with Hepatitis C and 82 Controls. Principal Components Analysis (PCA) was employed to visualise the separation between groups and show the relationship between the elements and the diseased state. Pattern recognition methods for classification involving Quadratic Discriminant Analysis and Partial Least Squares Discriminant Analysis (PLS-DA) were applied to the data. The number of significant components for both PCA and PLS were determined using the bootstrap. The stability of training set models were determined by repeatedly splitting the data into training and test sets and employing visualisation for two components models: the percent classification ability (CC), predictive ability (PA) and model stability (MS) were computed for test and training sets.

  6. Pattern recognition of Inductively Coupled Plasma Atomic Emission Spectroscopy of human scalp hair for discriminating between healthy and Hepatitis C patients

    International Nuclear Information System (INIS)

    Inductively Coupled Plasma Atomic Emission Spectroscopy measurements of six trace elements were performed on the scalp hair of 155 donors, 73 of which have been diagnosed with Hepatitis C and 82 Controls. Principal Components Analysis (PCA) was employed to visualise the separation between groups and show the relationship between the elements and the diseased state. Pattern recognition methods for classification involving Quadratic Discriminant Analysis and Partial Least Squares Discriminant Analysis (PLS-DA) were applied to the data. The number of significant components for both PCA and PLS were determined using the bootstrap. The stability of training set models were determined by repeatedly splitting the data into training and test sets and employing visualisation for two components models: the percent classification ability (CC), predictive ability (PA) and model stability (MS) were computed for test and training sets.

  7. Preparation of immission dust samples for the analysis of toxic substances in dust by atomic emission spectroscopy with inductively coupled plasma

    International Nuclear Information System (INIS)

    Samples of air-dust-concentration- and air-dust-deposit measurements were digested by a standardized wet digestion procedure and the amounts of substances in the dust according to class I TA Luft by Atomic Emission Spectroscopy with Inductively Coupled Plasma (AES-ICP). The characteristic values for procedures according to VDI 2449, sheet 1, were determined for lead, vanadium, cadmium, chromium, copper, nickel and zinc. By partial automatic control of the digestion procedure the personel expenditure of work could be reduced by a factor 13. Dust filter samples were analysed without sample preparation by evaporating the material with a solid state laser. The absolute detection limit was between 1 and 100 ng/cm2 for the elements arsenic, cadmium, cobalt, chromium, mercury, antimony, selen and thallium. For sampling by means of the Beta-Staubmeter the relative detection limits for the laser-ICP were 10-fold lower than by use of a nebulizer. (orig.)

  8. Laser based analysis using a passively Q-switched laser employing analysis electronics and a means for detecting atomic optical emission of the laser media

    Science.gov (United States)

    Woodruff, Steven D.; Mcintyre, Dustin L.

    2016-03-29

    A device for Laser based Analysis using a Passively Q-Switched Laser comprising an optical pumping source optically connected to a laser media. The laser media and a Q-switch are positioned between and optically connected to a high reflectivity mirror (HR) and an output coupler (OC) along an optical axis. The output coupler (OC) is optically connected to the output lens along the optical axis. A means for detecting atomic optical emission comprises a filter and a light detector. The optical filter is optically connected to the laser media and the optical detector. A control system is connected to the optical detector and the analysis electronics. The analysis electronics are optically connected to the output lens. The detection of the large scale laser output production triggers the control system to initiate the precise timing and data collection from the detector and analysis.

  9. Dipole Emission In Finite Photonic Band-Gap Structures an Exactly Solvable One-Dimensional Model

    CERN Document Server

    Dowling, J P

    1999-01-01

    I consider an exact model of atomic spontaneous dipole emission and classical dipole radiation in a finite photonic band-gap structure. The full 3D or 2D problem is reduced to a finite 1D model, and then this is solved for analytically using algebraic matrix transfer techniques. The results give insight to the electromagnetic emission process in periodic dielectrics, quantitative predictions for emission in 1D dielectric stacks, and qualitative formulas for the 2D and 3D problem.

  10. Elastic collisions between Si and D atoms at low temperatures and accurate analytic potential energy function and molecular constants of the SiD(X2∏) radical

    Institute of Scientific and Technical Information of China (English)

    Shi De-Heng; Zhang Jin-Ping; Sun Jin-Feng; Zhu Zun-Lue

    2009-01-01

    Interaction potential of the SiD(X2∏) radical is constructed by using the CCSD(T) theory in combination with the largest correlation-consistent quintuple basis set augmented with the diffuse functions in the valence range. Using the interaction potential, the spectroscopic parameters are accurately determined. The present D0, De, Re, ωe, αe and Be values are of 3.0956 eV, 3.1863 eV, 0.15223 nm, 1472.894 cm-1, 0.07799 cm-1 and 3.8717 cm-1, respectively,which are in excellent agreement with the measurements. A total of 26 vibrational states is predicted when J = 0 by solving the radial Schr(o)dinger equation of nuclear motion. The complete vibrational levels, classical turning points,initial rotation and centrifugal distortion constants when J = 0 are reported for the first time, which are in good accord with the available experiments. The total and various partial-wave cross sections are calculated for the elastic collisions between Si and D atoms in their ground states at 1.0×10-11-1.0×10-3 a.u. when the two atoms approach each other along the SiD(X2∏) potential energy curve. Four shape resonances are found in the total elastic cross sections, and their resonant energies are of 1.73×10-5, 4.0×10-5, 6.45×10-5 and 5.5×10-4 a.u., respectively. Each shape resonance in the total elastic cross sections is carefully investigated. The results show that the shape of the total elastic cross sections is mainly dominated by the s partial wave at very low temperatures. Because of the weakness of the shape resonances coming from the higher partial waves, most of them are passed into oblivion by the strong s partial-wave elastic cross sections.

  11. Thermospheric atomic oxygen concentrations from WINDII O+(2P→2D) 732 nm emission: Comparisons with the NRLMSISE-00 and C-IAM models and with GUVI observations

    Science.gov (United States)

    Shepherd, Gordon G.; Cho, Young-Min; Fomichev, Victor I.; Martynenko, Oleg V.

    2016-09-01

    Thermospheric atomic oxygen concentrations have been retrieved from observations by the Wind Imaging Interferometer (WINDII) O+(2P→2D) 732 and 733 nm emissions and are compared with results obtained by the Global Ultraviolet Imager (GUVI). Although the observations compared were taken ten years apart, the periods were selected on the basis of solar activity, using the Canadian Ionosphere and Atmosphere Model (C-IAM) to bridge the time gap. Results from all of these were compared with those from the Naval Research Laboratory Mass Spectrometer and Incoherent Scatter (NRLMSISE-00) model. Comparisons were made on the basis of F10.7 solar flux, day of year, local time, season, latitude and longitude. The WINDII local time variations showed enhanced values for the Northern spring season. Latitude and longitude plots showed smooth variations for NRLMSISE-00 and large variations for both WINDII and GUVI observations; in particular a depression in atomic oxygen concentration around 40 °S latitude and 100 °E longitude that is tentatively identified with a longitudinal wave 1 that does not propagate in local time but has an annual variation. The averaged values showed the WINDII values to be 0.75 that of NRLMSISE-00 compared with 0.80 for GUVI. Thus the WINDII values agreed with those of GUVI to within 6%, although taken 10 years apart.

  12. An integrated analytical framework for quantifying the LCOE of waste-to-energy facilities for a range of greenhouse gas emissions policy and technical factors

    International Nuclear Information System (INIS)

    This study presents a novel integrated method for considering the economics of waste-to-energy (WTE) facilities with priced greenhouse gas (GHG) emissions based upon technical and economic characteristics of the WTE facility, MSW stream, landfill alternative, and GHG emissions policy. The study demonstrates use of the formulation for six different policy scenarios and explores sensitivity of the results to ranges of certain technical parameters as found in existing literature. The study shows that details of the GHG emissions regulations have large impact on the levelized cost of energy (LCOE) of WTE and that GHG regulations can either increase or decrease the LCOE of WTE depending on policy choices regarding biogenic fractions from combusted waste and emissions from landfills. Important policy considerations are the fraction of the carbon emissions that are priced (i.e. all emissions versus only non-biogenic emissions), whether emissions credits are allowed due to reducing fugitive landfill gas emissions, whether biogenic carbon sequestration in landfills is credited against landfill emissions, and the effectiveness of the landfill gas recovery system where waste would otherwise have been buried. The default landfill gas recovery system effectiveness assumed by much of the industry yields GHG offsets that are very close to the direct non-biogenic GHG emissions from a WTE facility, meaning that small changes in the recovery effectiveness cause relatively larger changes in the emissions factor of the WTE facility. Finally, the economics of WTE are dependent on the MSW stream composition, with paper and wood being advantageous, metal and glass being disadvantageous, and plastics, food, and yard waste being either advantageous or disadvantageous depending upon the avoided tipping fee and the GHG emissions price.

  13. An integrated analytical framework for quantifying the LCOE of waste-to-energy facilities for a range of greenhouse gas emissions policy and technical factors.

    Science.gov (United States)

    Townsend, Aaron K; Webber, Michael E

    2012-07-01

    This study presents a novel integrated method for considering the economics of waste-to-energy (WTE) facilities with priced greenhouse gas (GHG) emissions based upon technical and economic characteristics of the WTE facility, MSW stream, landfill alternative, and GHG emissions policy. The study demonstrates use of the formulation for six different policy scenarios and explores sensitivity of the results to ranges of certain technical parameters as found in existing literature. The study shows that details of the GHG emissions regulations have large impact on the levelized cost of energy (LCOE) of WTE and that GHG regulations can either increase or decrease the LCOE of WTE depending on policy choices regarding biogenic fractions from combusted waste and emissions from landfills. Important policy considerations are the fraction of the carbon emissions that are priced (i.e. all emissions versus only non-biogenic emissions), whether emissions credits are allowed due to reducing fugitive landfill gas emissions, whether biogenic carbon sequestration in landfills is credited against landfill emissions, and the effectiveness of the landfill gas recovery system where waste would otherwise have been buried. The default landfill gas recovery system effectiveness assumed by much of the industry yields GHG offsets that are very close to the direct non-biogenic GHG emissions from a WTE facility, meaning that small changes in the recovery effectiveness cause relatively larger changes in the emissions factor of the WTE facility. Finally, the economics of WTE are dependent on the MSW stream composition, with paper and wood being advantageous, metal and glass being disadvantageous, and plastics, food, and yard waste being either advantageous or disadvantageous depending upon the avoided tipping fee and the GHG emissions price. PMID:22425189

  14. Measurements of plasma temperature and electron density in laser-induced copper plasma by time-resolved spectroscopy of neutral atom and ion emissions

    Indian Academy of Sciences (India)

    V K Unnikrishnan; Kamlesh Alti; V B Kartha; C Santhosh; G P Gupta; B M Suri

    2010-06-01

    Plasma produced by a 355 nm pulsed Nd:YAG laser with a pulse duration of 6 ns focussed onto a copper solid sample in air at atmospheric pressure is studied spectroscopically. The temperature and electron density characterizing the plasma are measured by time-resolved spectroscopy of neutral atom and ion line emissions in the time window of 300–2000 ns. An echelle spectrograph coupled with a gated intensified charge coupled detector is used to record the plasma emissions. The temperature is obtained using the Boltzmann plot method and the electron density is determined using the Saha– Boltzmann equation method. Both parameters are studied as a function of delay time with respect to the onset of the laser pulse. The results are discussed. The time window where the plasma is optically thin and is also in local thermodynamic equilibrium (LTE), necessary for the laser-induced breakdown spectroscopy (LIBS) analysis of samples, is deduced from the temporal evolution of the intensity ratio of two Cu I lines. It is found to be 700–1000 ns.

  15. Comparison of a neural network with multiple linear regression for quantitative analysis in ICP-atomic emission spectroscopy

    International Nuclear Information System (INIS)

    A two layer perceptron with backpropagation of error is used for quantitative analysis in ICP-AES. The network was trained by emission spectra of two interfering lines of Cd and As and the concentrations of both elements were subsequently estimated from mixture spectra. The spectra of the Cd and As lines were also used to perform multiple linear regression (MLR) via the calculation of the pseudoinverse S+ of the sensitivity matrix S. In the present paper it is shown that there exist close relations between the operation of the perceptron and the MLR procedure. These are most clearly apparent in the correlation between the weights of the backpropagation network and the elements of the pseudoinverse. Using MLR, the confidence intervals over the predictions are exploited to correct for the optical device of the wavelength shift. (orig.)

  16. Resonant nonstationary amplification of polychromatic laser pulses and conical emission in an optically dense ensemble of neon metastable atoms

    CERN Document Server

    Bagayev, S N; Mekhov, I B; Moroshkin, P V; Chekhonin, I A; Davliatchine, E M; Kindel, E

    2003-01-01

    Experimental and numerical investigation of single beam and pump-probe interaction with a resonantly absorbing dense extended medium under strong and weak field-matter coupling is presented. Significant probe beam amplification and conical emission were observed. Under relatively weak pumping and high medium density, when the condition of strong coupling between field and resonant matter is fulfilled, the probe amplification spectrum has a form of spectral doublet. Stronger pumping leads to the appearance of a single peak of the probe beam amplification at the transition frequency. The greater probe intensity results in an asymmetrical transmission spectrum with amplification at the blue wing of the absorption line and attenuation at the red one. Under high medium density, a broad band of amplification appears. Theoretical model is based on the solution of the Maxwell-Bloch equations for a two-level system. Different types of probe transmission spectra obtained are attributed to complex dynamics of a coherent...

  17. Major constituent quantitative determination in uranium alloys by coupled plasma atomic emission spectrometry and X ray fluorescence wavelength dispersive spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Luis Claudio de; Silva, Adriana Mascarenhas Martins da; Gomide, Ricardo Goncalves; Silva, Ieda de Souza, E-mail: luis.claudio@ctmsp.mar.mil.br, E-mail: adriana@ctmsp.mar.mil.br, E-mail: gomide@ctmsp.mar.mil.br, E-mail: ieda@ctmsp.mar.mil.br [Centro Tecnologico da Marinha em Sao Paulo (CEA/CTMSP), Ipero, SP (Brazil). Centro Experimental Aramar

    2013-07-01

    A wavelength-dispersive X-ray fluorescence (WD-XRF) spectrometric method for determination of major constituents elements (Zr, Nb, Mo) in Uranium/Zirconium/Niobium and Uranium/Molybdenum alloy samples were developed. The methods use samples taken in the form of chips that were dissolved in hot nitric acid and precipitate particles melted with lithium tetraborate and dissolved in hot nitric acid and finally analyzed as a solution. Studies on the determination by inductively coupled plasma optic emission spectrometry (ICP OES) using matched matrix in calibration curve were developed. The same samples solution were analyzed in both methods. The limits of detection (LOD), linearity of the calibrations curves, recovery study, accuracy and precision of the both techniques were carried out. The results were compared. (author)

  18. Major constituent quantitative determination in uranium alloys by coupled plasma atomic emission spectrometry and X ray fluorescence wavelength dispersive spectrometry

    International Nuclear Information System (INIS)

    A wavelength-dispersive X-ray fluorescence (WD-XRF) spectrometric method for determination of major constituents elements (Zr, Nb, Mo) in Uranium/Zirconium/Niobium and Uranium/Molybdenum alloy samples were developed. The methods use samples taken in the form of chips that were dissolved in hot nitric acid and precipitate particles melted with lithium tetraborate and dissolved in hot nitric acid and finally analyzed as a solution. Studies on the determination by inductively coupled plasma optic emission spectrometry (ICP OES) using matched matrix in calibration curve were developed. The same samples solution were analyzed in both methods. The limits of detection (LOD), linearity of the calibrations curves, recovery study, accuracy and precision of the both techniques were carried out. The results were compared. (author)

  19. Analytical spectroscopy. Analytical Chemistry Symposia Series, Volume 19

    International Nuclear Information System (INIS)

    This book contains papers covering several fields in analytical chemistry including lasers, mass spectrometry, inductively coupled plasma, activation analysis and emission spectroscopy. Separate abstracting and indexing was done for 64 papers in this book

  20. Development of novel and sensitive methods for the determination of sulfide in aqueous samples by hydrogen sulfide generation-inductively coupled plasma-atomic emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Colon, M. [Department of Chemistry, University of Girona, Campus Montilivi, 17071 Girona (Spain); Departamento de Quimica Analitica, Nutricion y Bromatologia, University of Alicante, 03080 Alicante (Spain); Todoli, J.L. [Departamento de Quimica Analitica, Nutricion y Bromatologia, University of Alicante, 03080 Alicante (Spain); Hidalgo, M. [Department of Chemistry, University of Girona, Campus Montilivi, 17071 Girona (Spain); Iglesias, M. [Department of Chemistry, University of Girona, Campus Montilivi, 17071 Girona (Spain)], E-mail: monica.iglesias@udg.es

    2008-02-25

    Two new, simple and accurate methods for the determination of sulfide (S{sup 2-}) at low levels ({mu}g L{sup -1}) in aqueous samples were developed. The generation of hydrogen sulfide (H{sub 2}S) took place in a coil where sulfide reacted with hydrochloric acid. The resulting H{sub 2}S was then introduced as a vapor into an inductively coupled plasma-atomic emission spectrometer (ICP-AES) and sulfur emission intensity was measured at 180.669 nm. In comparison to when aqueous sulfide was introduced, the introduction of sulfur as H{sub 2}S enhanced the sulfur signal emission. By setting a gas separator at the end of the reaction coil, reduced sulfur species in the form of H{sub 2}S were removed from the water matrix, thus, interferences could be avoided. Alternatively, the gas separator was replaced by a nebulizer/spray chamber combination to introduce the sample matrix and reagents into the plasma. This methodology allowed the determination of both sulfide and sulfate in aqueous samples. For both methods the linear response was found to range from 5 {mu}g L{sup -1} to 25 mg L{sup -1} of sulfide. Detection limits of 5 {mu}g L{sup -1} and 6 {mu}g L{sup -1} were obtained with and without the gas separator, respectively. These new methods were evaluated by comparison to the standard potentiometric method and were successfully applied to the analysis of reduced sulfur species in environmental waters.

  1. Validation of an analytical method for the determination of total mercury in urine samples using cold vapor atomic absorption spectrometry (CV-AAS)

    International Nuclear Information System (INIS)

    Mercury (Hg) is a toxic metal applied to a variety of products and processes, representing a risk to the health of occupationally or accidentally exposed subjects. Dental amalgam is a restorative material composed of metallic mercury, which use has been widely debated in the last decades. Due to the dubiety of the studies concerning dental amalgam, many efforts concerning this issue have been conducted. The Tropical Medicine Foundation (Tocantins, Brazil) has recently initiated a study to evaluate the environmental and occupational levels of exposure to mercury in dentistry attendants at public consulting rooms in the city of Araguaina (TO). In collaboration with this study, the laboratory of analysis at IPEN's Chemistry and Environment Center is undertaking the analysis of mercury levels in exposed subjects' urine samples using cold vapor atomic absorption spectrometry. This analysis requires the definition of a methodology capable of generating reliable results. Such methodology can only be implemented after a rigorous validation procedure. As part of this work, a series of tests were conducted in order to confirm the suitability of the selected methodology and to assert that the laboratory addresses all requirements needed for a successful implementation of the methodology. The following parameters were considered in order to test the method's performance: detection and quantitation limits, selectivity, sensitivity, linearity, accuracy and precision. The assays were carried out with certified reference material, which assures the traceability of the results. Taking into account the estimated parameters, the method can be considered suitable for the afore mentioned purpose. The mercury concentration found for the reference material was of (95,12 +- 11,70)mug.L-1 with a recovery rate of 97%. The method was also applied to 39 urine samples, six of which (15%) showing urinary mercury levels above the normal limit of 10μg.L-1. The obtained results fall into a range

  2. Lead determinations in human bone by particle induced x-ray emission (PIXE) and graphite furnace atomic absorption spectrometry (GFAAS)

    International Nuclear Information System (INIS)

    Chronic lead (Pb) intoxication has been linked to Alzheimer's disease (AD). Lead, like many heavy elements, tends to accumulate in bone. Pixe is a powerful analytical tool which permits the determination of Pb at the μg/g level without requiring sample digestion. GFAAS is one of the most sensitive methods for the determination of Pb and is capable of determining ng/g levels is solution. For bone analyses by GFAAS, sample dissolution and a matrix modifier are required. Rib bone samples were analyzed for Pb by PIXE and GFAAS. IAEA Animal Bone (H-5) was used as a secondary standard for Pb with both methods to ensure accuracy. The range of Pb concentrations in human rib bone was 1.4-11.5 μ/g for the trabecular surface by PIXE, 1.3-45 μg/g for the cortical surface by PIXE, and 1.54-11.75 μg/g for whole bone by GFAAS. No significant difference (p.<0.05 was found for AD versus control for either surface or for whole bone. (author). 17 refs., 2 figs., 3 tabs

  3. The closed orbit theoretical calculation of the spontaneous emission rate of atom near the interface%原子在界面附近自发辐射率的闭合轨道理论计算

    Institute of Scientific and Technical Information of China (English)

    王丽林; 徐强; 隗莲

    2013-01-01

    利用闭合轨道理论,对原子在界面附近的自发辐射率的计算公式进行了推导,并对界面附近原子自发辐射率的多周期振荡现象进行了系统的研究。首先,根据光子的闭合轨道理论,把原子的自发辐射用经典的偶极天线辐射来模拟,推导出原子在一个金属界面旁的自发辐射率的计算公式,然后再推广到两个金属界面旁的原子自发辐射情况,并对原子自发辐射率的多周期振荡进行了分析。%We derived the formula of the spontaneous emission rate of atoms near the interfaces and discussed the multi-periodic oscillating phenomenon of the atoms near the interfaces .First of all ,according to the photon closed-orbit theory ,we simulated the spontaneous emission of atom near interface as the radiation of the classic dipole antenna ,then we derived the calculation for-mula of the spontaneous emission of atom near a metal surface .Next ,we developed this case to the spontaneous emission of atom near two metal surfaces ,and analyzed the multi-periodic oscil-lating phenomenon appeared in the spontaneous emission rate of atom near two metal surfaces .

  4. 40 CFR 86.1310-2007 - Exhaust gas sampling and analytical system for gaseous emissions from heavy-duty diesel-fueled...

    Science.gov (United States)

    2010-07-01

    ... mass of particulate emissions is determined from a proportional mass sample collected on a filter and from the sample flow and total flow over the test period. As an option, the measurement of total fuel..., Volume 1: Materials, Fuels, Emissions, and Noise, Section 13, Page 13.170), which is incorporated...

  5. On atomization of europium and dysprosium in U-Pu matrix after chemical separation using GF-AAS technique

    International Nuclear Information System (INIS)

    Direct analysis of U-Pu bearing material by atomic emission spectrometry (AES) is not possible for determination of Eu and Dy at trace level, because of their rich emission line spectra, which can cause severe spectral interference. Atomic absorption spectrometry (AAS) is the alternate method for determination of these elements. Though the direct determination of Dy and Eu is possible by AAS, the atomization of these elements in U-Pu matrix is the result of analyte-matrix-carbon type of interactions. During the method development for Dy and Eu by AAS, absorbance signal was significantly suppressed in presence of U-Pu as compared to matrix free solution

  6. Resonant nonstationary amplification of polychromatic laser pulses and conical emission in an optically dense ensemble of neon metastable atoms

    International Nuclear Information System (INIS)

    Experimental and numerical investigation of single-beam and pump-probe interaction with a resonantly absorbing dense extended medium under strong and weak field-matter coupling is presented. Significant probe beam amplification and conical emission were observed. Under relatively weak pumping and high medium density, when the condition of strong coupling between field and resonant matter is fulfilled, the probe amplification spectrum has a form of spectral doublet. Stronger pumping leads to the appearance of a single peak of the probe beam amplification at the transition frequency. The greater probe intensity results in an asymmetrical transmission spectrum with amplification at the blue wing of the absorption line and attenuation at the red one. Under high medium density, a broadband of amplification appears. The theoretical model is based on the solution of the Maxwell-Bloch equations for a two-level system. Different types of probe transmission spectra obtained are attributed to complex dynamics of a coherent medium response to broadband polychromatic radiation of a multimode dye laser

  7. The impact of molecular emission in compositional depth profiling using Glow Discharge-Optical Emission Spectroscopy

    International Nuclear Information System (INIS)

    The scope of this paper is to investigate and discuss how molecular emission can affect elemental analysis in glow discharge optical emission (GD-OES), particularly in compositional depth profiling (CDP) applications. Older work on molecular emission in glow discharges is briefly reviewed, and the nature of molecular emission spectra described. Work on the influence of hydrogen in the plasma, in particular elevated background due to a continuum spectrum, is discussed. More recent work from sputtering of polymers and other materials with a large content of light elements in a Grimm type source is reviewed, where substantial emission has been observed from several light diatomic molecules (CO, CH, OH, NH, C2). It is discussed how the elevated backgrounds from such molecular emission can lead to significant analytical errors in the form of 'false' depth profile signals of several atomic analytical lines. Results from a recent investigation of molecular emission spectra from mixed gases in a Grimm type glow discharge are presented. An important observation is that dissociation and subsequent recombination processes occur, leading to formation of molecular species not present in the original plasma gas. Experimental work on depth profiling of a polymer coating and a thin silicate film, using a spectrometer equipped with channels for molecular emission lines, is presented. The results confirm that molecular emission gives rise to apparent depth profiles of elements not present in the sample. The possibilities to make adequate corrections for such molecular emission in CDP of organic coatings and very thin films are discussed

  8. Analytic trigonometry

    CERN Document Server

    Bruce, William J; Maxwell, E A; Sneddon, I N

    1963-01-01

    Analytic Trigonometry details the fundamental concepts and underlying principle of analytic geometry. The title aims to address the shortcomings in the instruction of trigonometry by considering basic theories of learning and pedagogy. The text first covers the essential elements from elementary algebra, plane geometry, and analytic geometry. Next, the selection tackles the trigonometric functions of angles in general, basic identities, and solutions of equations. The text also deals with the trigonometric functions of real numbers. The fifth chapter details the inverse trigonometric functions

  9. Theory of light-matter interactions in cascade and diamond type atomic ensembles

    CERN Document Server

    Jen, Hsiang-Hua

    2011-01-01

    In this thesis, we investigate the quantum mechanical interaction of light with matter in the form of a gas of ultracold atoms: the atomic ensemble. We present a theoretical analysis of two problems, which involve the interaction of quantized electromagnetic fields (called signal and idler) with the atomic ensemble (i) cascade two-photon emission in an atomic ladder configuration, and (ii) photon frequency conversion in an atomic diamond configuration. The motivation of these studies comes from potential applications in long-distance quantum communication where it is desirable to generate quantum correlations between telecommunication wavelength light fields and ground level atomic coherences. We develop a theory of correlated signal-idler pair correlation. The analysis is complicated by the possible generation of multiple excitations in the atomic ensemble. An analytical treatment is given in the limit of a single excitation assuming adiabatic laser excitations. The analysis predicts superradiant timescales ...

  10. Determination of scandium in geological materials, rare earth minerals and niobate/tantalate-type of samples by inductively coupled plasma atomic emission spectrometry after solvent extraction/acid hydrolysis separation

    International Nuclear Information System (INIS)

    Solvent extraction of scandium from 1.5 M HCl medium using di(2-ethyl hexyl) phosphoric acid in hexane or benzene selectively separates Sc from the accompanying elements in rare-earth minerals (like monazite, xenotime, gadolinite) and also in geological materials. Acid hydrolysis separation of Nb/Ta-type samples separates Sc from the major matrix elements and the remaining elements do not influence the Sc signal in inductively coupled plasma atomic emission spectrometry or flame atomic absorption spectrometry. To avoid the matrix effect due to sodium that accompanies the analyte using the reported backstripping of Sc from the organic extract by 2 M NaOH, the organic extract was evaporated off leaving the Sc in the residue which in turn was treated with a mixture of HNO3-HClO4, dissolved in HCl (10%, v/v) and made up to a known volume before aspiration in the plasma for estimation. The silica-rich geological materials were dissolved by HF-HCl-H2SO4 treatment and the rare-earth minerals (monazite/xenotime) were digested by H2SO4-HCl followed by dissolution in 1.5 M HCl before applying the solvent extraction procedure. In Nb/Ta-type of samples, Sc was separated from Nb and Ta by acid hydrolysis, involving fusion with Na2O2, dissolution in HCl followed by NH3 precipitation and hydrolysis in HCl. The oxychloride precipitates of Nb and Ta are filtered off and the filtrates assayed for Sc. The proposed methods have been applied to some international geological reference standards (SY-2, SY-3, MRG-1, Mica-Fe, G-2, GH and ASK-2), rare-earth minerals like monazite, xenotime and gadolinite and also to some Nb/Ta-type samples including reference standards IGS-33 and IGS-34, and the results are compared. Both methods are simple, rapid and accurate, showing a relative standard deviation of less than 1% at the 55 μg g-1 level and 9.0% (at the 1.0 μg g-1). (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  11. Analytical methods used at model facility

    International Nuclear Information System (INIS)

    A description of analytical methods used at the model LEU Fuel Fabrication Facility is presented. The methods include gravimetric uranium analysis, isotopic analysis, fluorimetric analysis, and emission spectroscopy

  12. Analyticity of the density of electronic wavefunctions

    DEFF Research Database (Denmark)

    Sørensen, Thomas Østergaard; Fournais, S.; Hoffmann-Ostenhof, M.;

    2004-01-01

    We prove that the electronic densities of atomic and molecular eigenfunctions are real analytic in R^3 away from the nuclei.......We prove that the electronic densities of atomic and molecular eigenfunctions are real analytic in R^3 away from the nuclei....

  13. The effect of phenomenological modeling of z-pinch implosions on the scaling of k-shell emission with atomic number and mass

    International Nuclear Information System (INIS)

    Recent 1-D phenomenological modeling of plasma turbulence by enhancing transport coefficients has shown that it is possible to achieve good agreement with experimental plasma conditions at stagnation, especially when compared to previous laminar flow calculations. Since this original phenomenological study focused upon only a single Physics International Inc. argon experiment, it is important to build a stronger foundation for this modeling. This is accomplished by: (1) including turbulence effects phenomenologically in the 1-D, radiation, MHD average fluid description of the turbulent flow by enhancing the resistivity Ω, viscosity υ, and heat conductivity κ transport coefficients; (2) finding a set of (κ,υ,Ω) coefficients that reasonably produces the stagnation temperatures and densities of a Physics International Inc. aluminum experiment; (3) this choice of transport coefficients is then tested for dependence on mass loading m and atomic number Z by comparing calculated implosion conditions with those found in a variety of PI aluminum and argon experiments. The authors find that the choice of enhanced transport coefficients that produces good agreement with the stagnation temperatures and densities of the single PI aluminum experiment also gives acceptable agreement for the other aluminum and argon experiments. Based on the presumption that a better representation of plasma conditions at stagnation also gives rise to more realistic K-shell yield scaling with atomic number, the minimum load mass and kinetic energy (machine energy) requirements needed to efficiently produce K-shell emission are calculated for aluminum and argon using enhanced transport calculations. These results are then extrapolated to other Z materials and compared with predictions of the original laminar flow scaling study. Implications of this work for large current machines will be presented

  14. Position-dependent oscillated decay of a two-level atom immersed in a two-dimensional photon fluid

    Science.gov (United States)

    Zhang, Xiongfeng; Yin, Miao; Liang, Wenyao

    2016-01-01

    A Weisskopf-Wigner theory has been used to investigate the spontaneous emission of a two-level atom placed in a photon superfluid. It is found that the atom decays exponentially. However, the atomic decay rate changes periodically with the position of the atom and it is minimal when the atom is located at the wave nodes. The largest decay rate of the atom in photon superfluid has the same order of magnitude as it is in vacuum of free space. Moreover, the analytical result shows that the decay of an atom in photon superfluid, compared with that in planar cavity without photon superfluid, will be inhibited. The physical origin of atomic decay inhibition is also discussed.

  15. Qualitative criterion for atom sputtering angle distributions

    International Nuclear Information System (INIS)

    A model is introduced to explain the shape of atom polar emission angle distributions for monocomponent targets sputtered by normally incident keV - energy ions. Analytical expressions are obtained from the model which make it possible to identify three known kinds of the angle distributions - subcosinus, isotropic and supracosinus, for given ion energies and target-ion pairs. Furthermore the fourth, hybrid false-isotropic distribution is found, which is superposition of supracosinus and subcosinus distributions. The theoretical predictions of the angle distributions shape agree with the numerical modeling for sputtering of carbon and platinum by 0.1-10 keV Ar+ ions

  16. Continuous Determination of 12 Elements in Geochemical Samples by Inductively Coupled Plasma-Atomic Emission Spectrometry and Flame Atomic Absorption Spectrometry%电感耦合等离子体发射光谱法和火焰原子吸收光谱法连续测定化探样品中12个元素

    Institute of Scientific and Technical Information of China (English)

    于阗; 张连起; 陈小迪

    2011-01-01

    The continuous determination of 12 elements in geochemical samples by inductive coupled plasma-atomic emission spectrometry (ICP-AES) and flame atomic absorption spectrometry ( FAAS) was reported in this paper. Samples were digested with mixed acid of HCI-HF-HNO3-HC1O4 and Cu, Pb, Zn, Co, Ni, Cr, Sr, Ba, V, Mn in the sample solution were determined directly by ICP-AES. Then, Ag and Cd in the same sample solution were enriched by extraction with potassium iodide-methyl isobutyl ketone ( KI-MIBK) and determined by FAAS. The precision of FAAS method for Ag and Cd was 6. 5% and 4. 7% RSD ( n = 12) , respectively. In comparison with the common analytical method, the proposed method provides the higher sensitivity, good accuracy and precision, high economy, high efficiency and is suitable for routine analysis of these elements in geochemical samples.%建立了地质化探样品中不同含量和检出限要求的12个元素的连续测定方法.样品经一次取样,用盐酸-氢氟酸-硝酸-高氯酸溶样,电感耦合等离子体发射光谱法测定铜、铅、锌、钴、镍、镉、锶、钡、钒、锰后,加碘化钾-甲基异丁基甲酮萃取分离,火焰原子吸收光谱法测定银、镉.银、镉的相对标准偏差(RSD,n=12)分别为6.5%、4.7%.与现行分析方法相比,建立的方法灵敏度和精密度高、准确度好,降低了生产成本,缩短了检测时间,尤其适合大量化探样品的测定.

  17. Determination of trace levels of dissolved vanadium in seawater by use of synthetic complexing agents and inductively coupled plasma-atomic emission spectroscopy (ICP-AES)

    Energy Technology Data Exchange (ETDEWEB)

    Abbasse, G.; Ouddane, B.; Fischer, J.C. [Univ. des Sciences et Technologies et Lille, Lab. de Chimie Analytique et Marine (ELICO), UPRESA CNRS 8013, Villeneuve d' Ascq (France)

    2002-11-01

    In the determination of traces of dissolved vanadium in complex matrices such as seawater, separation and enrichment from the matrix is of special importance. A wide variety of methods has been proposed for preconcentration, depending to the nature of samples and the methods to be used for measurement. Among these methods separation techniques based on sorption on to chelating resins seem convenient, rapid, and capable of achieving a high concentration factor. The methods proposed in this paper are based on the transformation of all dissolved vanadium species in seawater into organic complexes by use of synthetic complexing agents such as dithizone, luminol, or 8-hydroxyquinoline; the resulting vanadium-organic complexes were sorbed on to a C{sub 18} column at a flow rate of 5 mL min{sup -1}. The vanadium sorbed on the C{sub 18} columns was then stripped by use of nitric acid (2 mol L{sup -1}) and analysed by inductively coupled plasma-atomic emission spectroscopy, ICP-AES. This method was optimised and use of other chelating resins, such as chelamine, chelex-100, and immobilised 8-hydroxyquinoline and was compared by passing seawater samples directly over the resins. The experimental conditions (pH, acid used for elution, and contact time between the liquid sample and the resin) were optimised. The results were compared for all the resins used and were indicative of excellent and coherent reproducibility. (orig.)

  18. Leaching of heavy metals from contaminated soils using inductively coupled plasma optical emission spectrometer (ICP-OES) and atomic absorption spectrometer (AAS)

    International Nuclear Information System (INIS)

    The clean-up of soils contaminated with heavy metals is one of the most difficult tasks for environmental engineering. Heavy metals are highly persistent in soil and a number of techniques have been developed that aim to remove heavy metals from contaminated soil. A method has been adopted to evaluate dynamic leaching of metal contaminants from industrial soil samples obtained from textile industrial sites in Lahore, Pakistan. In the extraction procedures employed five different leaching liquors were used: 0.01 M CaCl/sub 2/, 1 M HNO/sub 3/, a 1:1 mixture of 0.1M HCl and 0.1M NaCl, 0.01 M EDTA and pH controlled 0.5 M acetic acid. The qualitative and quantitative analyses were carried out by Atomic Absorption Spectroscopy (AAS) and Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES). The results indicate that Cu, Zn, Cd, Ni, Pb, Fe and As were extracted in the soil samples in varying concentration when using the different leach liquors. The predominant metals which were leached were As 78.7 ng/ml in 0.01 M EDTA; Zn 1.81 mu g/ml and Fe 898.96 macro g/ml in HNO/sub 3/. (author)

  19. Evaluation of flow injection-solution cathode glow discharge-atomic emission spectrometry for the determination of major elements in brines.

    Science.gov (United States)

    Yang, Chun; Wang, Lin; Zhu, Zhenli; Jin, Lanlan; Zheng, Hongtao; Belshaw, Nicholas Stanley; Hu, Shenghong

    2016-08-01

    A new method for the determination of major metal elements in high salinity brines was developed by solution cathode glow discharge (SCGD) with flow injection analysis (FIA). The matrix interferences of major cations and anions in brines have been evaluated. It was found that high concentration of Na(+) and K(+) could interfere each other, K(+) at a concentration of 400mgL(-1) enhanced the signal intensity of Na(+) more than 20%. The effect of the anions was observed and it was noted that the signal intensity of both Ca(2+) and Mg(2+) were suppressed significantly when the SO4(2-) reached 100mgL(-1). It was demonstrated that some low molecular weight organic substances such as formic acid, glycerol and ascorbic acid could eliminate interference of SO4(2-) even with volume percentages of 0.5%. Under the optimized condition, the proposed FIA-SCGD can determine K, Na, Ca and Mg with the limits of detection of 0.49 (K), 0.14 (Na), 11 (Ca) and 5.5 (Mg) ngmL(-1). The proposed method has been successfully applied to the analysis of 5 salt lake samples and compared with those obtained with inductively coupled plasma atomic emission spectrometry (ICP-AES). The advantages of small size, low energy consumption, good stability and repeatability indicated that the SCGD is promising for the determination of major ions in brine samples. PMID:27216688

  20. Ultrasound-assisted extraction in the determination of arsenic, cadmium, copper, lead, and silver in contaminated soil samples by inductively coupled plasma atomic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Vaeisaenen, A.; Suontamo, R.; Silvonen, J. [Univ. of Jyvaeskylae, Dept. of Chemistry, Jyvaeskylae (Finland); Rintala, J. [Univ. of Jyvaeskylae, Dept. of Biological and Environmental Science, Jyvaeskylae (Finland)

    2002-05-01

    An extraction method was developed for the determination of toxic elements in contaminated soil samples by inductively coupled plasma atomic emission spectrometry (ICP-AES). The determination of arsenic, cadmium, lead, and silver in ultrasound-assisted extracts of SRM 2710 and SRM 2711 by ICP-AES was carried out with high accuracy and precision (RSD<3.7%). The certified concentrations of the SRMs were obtained for arsenic, cadmium, lead, and silver by using an ultrasound-assisted extraction method with a digestion solution of (1+1)-diluted aqua regia. The determination of copper in SRMs by the ultrasound-assisted extraction method and analysis by ICP-AES failed to obtain the certified concentrations at the 95% level of confidence using ({+-}2 s) as confidence limits of the mean. However, the same results were observed with the use of the microwave digestion method and reflux, which is the ISO 11466 standard method. The analysis of the SRMs showed that the ultrasound-assisted extraction method is highly comparable with the other methods used for such purposes. The major advantages of the ultrasound-assisted extraction method compared to the microwave and reflux methods are the high treatment rate (50 samples simultaneously in nine minutes) and low reagent usage, the main benefit of which are the low chloride and nitrate concentrations in the extracts. (orig.)

  1. Microporous polytetrafluoroethylene tube separator for the determination of beryllium by flow injection - or suction-flow -solvent extraction followed by inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    A dual-tube separator was constructed for the purpose of flow injection - or suction-flow-solvent extraction followed by inductively coupled plasma atomic emission spectrometry. It consisted of an inner microporous polytetrafluoroethylene (PTFE) tube (1 mm i.d., 10 cm long, porosity 70%) and an outer PTFE tube (3 mm i.d.). This system was used for the determination of beryllium in alloys by extraction as the acetylacetonate into carbon tetrachloride. The phase separation was complete at an organic flow-rate of 0.2-6.2 ml min-1 and an aqueous flow-rate of up to 6.2 ml min-1. With a sample volume of 0.5 ml (50 p.p.b. Be) and sample and organic flow-rates of 1.2 and 0.7 ml min-1, respectively, the relative standard deviation (n = 10) was 1.3% and the sampling rate was 25 h-1. The sensitivity was enhanced about 2.6-fold compared with that obtained by the direct nebulisation of an aqueous solution. (author)

  2. Volatile organo-selenium speciation in biological matter by solid phase microextraction-moderate temperature multicapillary gas chromatography with microwave induced plasma atomic emission spectrometry detection

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, C.; Sanz Landaluze, J.; Ximenez-Embun, P.; Madrid-Albarran, Y.; Camara, C

    2004-01-16

    Microwave induced plasma atomic emission spectrometry (MIP-AES) in combination with multicapillary (MC) gas chromatography could be proven to be useful for element specific detection of volatile species. Solid phase microextraction (SPME) was used for preconcentration and sample-matrix separation. The fiber desorption unit as well as the heating control for the MC column were in-house developed and multicapillary column was operated at moderate temperatures (30-100 deg. C). The method was optimized for organo-selenium species (dimethylselenide (DMSe), diethylselenide (DEtSe) and dimethyldiselenide (DMDSe)), using a chemometric approach. Stationary phases for the separation column were optimized using a conventional GC and contrasted with the results obtained with the MC. Application was focussed on selenium accumulating biological matter, such as lupine, yeast, Indian mustard and garlic. These samples were grown in hydroponic solution containing inorganic selenium (Na{sub 2}SeO{sub 3} and Na{sub 2}SeO{sub 4}). SPME sampling was carried out in fixed volume flow boxes in headspace above the living plants and in vials using treated samples. Results demonstrate inorganic selenium transformation into volatile organic species during metabolism. Separation is fast, a chromatogram can be obtained in less than 3 min and detection limits were at sub-ppb level for all investigated species. The system is independent from the use of a conventional gas chromatographic oven and can be used as a versatile alternative to highly cost intensive methods such as GC-ICP-MS.

  3. Volatile organo-selenium speciation in biological matter by solid phase microextraction-moderate temperature multicapillary gas chromatography with microwave induced plasma atomic emission spectrometry detection

    International Nuclear Information System (INIS)

    Microwave induced plasma atomic emission spectrometry (MIP-AES) in combination with multicapillary (MC) gas chromatography could be proven to be useful for element specific detection of volatile species. Solid phase microextraction (SPME) was used for preconcentration and sample-matrix separation. The fiber desorption unit as well as the heating control for the MC column were in-house developed and multicapillary column was operated at moderate temperatures (30-100 deg. C). The method was optimized for organo-selenium species (dimethylselenide (DMSe), diethylselenide (DEtSe) and dimethyldiselenide (DMDSe)), using a chemometric approach. Stationary phases for the separation column were optimized using a conventional GC and contrasted with the results obtained with the MC. Application was focussed on selenium accumulating biological matter, such as lupine, yeast, Indian mustard and garlic. These samples were grown in hydroponic solution containing inorganic selenium (Na2SeO3 and Na2SeO4). SPME sampling was carried out in fixed volume flow boxes in headspace above the living plants and in vials using treated samples. Results demonstrate inorganic selenium transformation into volatile organic species during metabolism. Separation is fast, a chromatogram can be obtained in less than 3 min and detection limits were at sub-ppb level for all investigated species. The system is independent from the use of a conventional gas chromatographic oven and can be used as a versatile alternative to highly cost intensive methods such as GC-ICP-MS

  4. Development of pyrolysis-GC with selective detection. Coupling of pyrolysis-GC to atomic emission detection (py-GC-AED)

    Energy Technology Data Exchange (ETDEWEB)

    Ross, A.B.; Jones, J.M.; Williams, A. [Department of Fuel and Energy, University of Leeds, Woodhouse Lane, LS2 9JT Leeds (United Kingdom); Junyapoon, S.; Bartle, K.D. [School of Chemistry, University of Leeds, Woodhouse Lane, LS2 9JT Leeds (United Kingdom)

    2001-04-01

    Atomic emission detection (AED) is one of the most powerful detectors available for GC due to its unique selectivity and sensitivity to a wide range of elements. The coupling of py-GC to AED should therefore have many applications in fuel, forensic and polymer sciences. In this study on-line py-GC-AED has been developed for the analysis of volatile organic compounds (VOC) (C{sub 1}-C{sub 8}), evolved from a range of samples including coal, biomass, waste tyres, and plastics. An off-line py-GC-AED system, using an intermediate trapping and focussing method with a programmed temperature vaporisation (PTV) injector has also been developed for the selective trapping of VOC. The positive identification of sulphur and oxygen containing compounds in coal, biomass and tyre pyrolysis products has been demonstrated. The technique is very sensitive for sulphur, but less sensitive to oxygen and nitrogen compounds. The development of a 'closed' injection system using a sequence of valves significantly improved sensitivity for all elements. The operation of the two techniques is discussed in terms of both instrument constraints and detector breakthrough.

  5. Application of gas chromatography with atomic emission detection to the geochemical investigation of polycyclic aromatic sulfur heterocycles in Egyptian crude oils

    Energy Technology Data Exchange (ETDEWEB)

    Hegazi, A.H.; Andersson, J.T. [Institute of Inorganic and Analytical Chemistry, University of Munster, Wilhelm-Klemm Strasse 8, 48149 Munster (Germany); El-Gayar, M.Sh. [Department of Chemistry, Faculty of Science, Alexandria University, P.O. Box 426, Alexandria 21321 (Egypt)

    2004-01-15

    Twelve crude oils from a number of producing wells in the Gulf of Suez and Western Desert, Egypt were characterized by a variety of saturate biomarker compositions. The biomarker distribution clearly grouped the Gulf of Suez oils into two source-related types but revealed significant differences among the Western Desert oils. The oils were fractionated into saturates, mono- and polyaromatics; and the distribution of polycyclic aromatic sulfur heterocycles (PASH) in the polyaromatics fraction was investigated by gas chromatography (GC) with atomic emission detector (AED) in the carbon- and sulfur-selective modes. This makes possible the evaluation of the distribution patterns of PASHs even in cases where their relative abundance is low. The thiophenic distribution fingerprints were utilized for oil/oil correlations. Significant differences in the relative abundance of benzothiophenes and dibenzothiophenes were obvious between the Gulf of Suez and Western Desert oils. Moreover, the PASH pattern distinguished between oils derived from carbonate and siliciclastic source rocks. Maturity parameters based upon methyldibenzothiophene isomers were found consistent with other maturity-dependent saturate biomarkers.

  6. Multi-element analysis using inductively coupled plasma mass spectrometry and inductively coupled plasma atomic emission spectroscopy for provenancing of animals at the continental scale.

    Science.gov (United States)

    Kreitals, Natasha M; Watling, R John

    2014-11-01

    Chemical signatures within the environment vary between regions as a result of climatological, geochemical and anthropogenic influences. These variations are incorporated into the region's geology, soils, water and vegetation; ultimately making their way through the food chain to higher level organisms. Because the variation in chemical signatures between areas is significant, a specific knowledge of differences in elemental distribution patterns between, and within populations, could prove beneficial for provenancing animals or animal related products when applied to indigenous and feral faunal populations. The domestic pig (Sus scrofa domestica) was used as an investigative model to determine the feasibility of using a chemical traceability method for the provenance determination of animal tissue. Samples of pig muscle, tongue, stomach, heart, liver and kidney were collected from known farming areas around Australia. Samples were digested in 1:3 H2O2:HNO3 and their elemental composition determined using solution based Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Pigs from different growing regions in Australia could be distinguished based on the chemical signature of each individual tissue type. Discrimination was possible at a region, state and population level. This investigation demonstrates the potential for multi-element analysis of low genetic variation native and feral species of forensic relevance. PMID:25240220

  7. Exotic atoms

    International Nuclear Information System (INIS)

    The experiments use a solid hydrogen layer to form muonic hydrogen isotopes that escape into vacuum. The method relies on transfer of the muon from protium to either a deuteron or a triton. The resulting muonic deuterium or muonic tritium will not immediately thermalize because of the very low elastic cross sections, and may be emitted from the surface of the layer. Measurements which detect decay electrons, muonic x-rays, and fusion products have been used to study the processes. A target has been constructed which exploits muonic atom emission in order to learn more about the energy dependence of transfer and muon molecular formation

  8. Analytical Laboratories

    Data.gov (United States)

    Federal Laboratory Consortium — NETL’s analytical laboratories in Pittsburgh, PA, and Albany, OR, give researchers access to the equipment they need to thoroughly study the properties of materials...

  9. Analytical testing

    Science.gov (United States)

    Flannelly, W. G.; Fabunmi, J. A.; Nagy, E. J.

    1981-01-01

    Analytical methods for combining flight acceleration and strain data with shake test mobility data to predict the effects of structural changes on flight vibrations and strains are presented. This integration of structural dynamic analysis with flight performance is referred to as analytical testing. The objective of this methodology is to analytically estimate the results of flight testing contemplated structural changes with minimum flying and change trials. The category of changes to the aircraft includes mass, stiffness, absorbers, isolators, and active suppressors. Examples of applying the analytical testing methodology using flight test and shake test data measured on an AH-1G helicopter are included. The techniques and procedures for vibration testing and modal analysis are also described.

  10. Analytical performance of glow discharge optical emission spectrometry with neon-argon mixed gases in determination of aluminum in steel samples%氖氩混合气体辉光放电发射光谱法测定钢样中铝的分析特性

    Institute of Scientific and Technical Information of China (English)

    WAGATSUMA; Kazuaki; HYUNKOOK; Park

    2007-01-01

    The emission characteristics of several atomic and ionic line of Al emitted from a Ne-Ar mixed gas glow discharge plasma were investigated. In comparison with pure Ar and pure Ne plasmas, the relative intensities of the Al emission lines are much different among these plasma gases. The Al Ⅱ lines which are identified to the 4f-3d transitions, such as Al Ⅱ 358. 71 nm and Al Ⅱ 358.66 nm, give intense emission when Ne is employed as the plasma gas, whereas these Al Ⅱ lines cannot be emitted from the pure Ar plasma. The reason for this effect is that the 4f excited levels are highly and selectively populated through resonance charge transfer collision between Al atom and Ne ion. The addition of small amounts of Ar to the Ne plasma increases the population of gas ions as well as the number density of electrons in the plasma because Ar ions are predominantly produced through Penning ionization collision between Ne metastable and Ar atom. This change occurring in the Ne-Ar mixed gas plasma results in enhancement in the emission intensities of Al lines. Among the atomic and ionic Al lines, the Al Ⅱ 358. 641 nm line can be employed as an analytical line for determination of trace-level Al, since the intensity is large and the background equivalent concentration is small in the Ne-Ar plasma.%研究了在Ne-Ar混合气体辉光等离子体中铝的原子及离子发射光谱线,并与纯Ar和纯Ne辉光等离子体进行了比较.在不同的放电气体环境下,Al发射线的相对强度不同.在Ne为放电气体时,可以观察到由4f→3d跃迁而产生的Al Ⅱ 358.71 nm和Al Ⅱ 358.66 nm两条发射线,而这两条线在以Ar为放电气体时不会产生.这种现象的原因是由于4f激发态是由Al原子和Ne离子的共振电荷转移碰撞而选择性高几率的产生的.由于亚稳态的Ne与Ar原子的彭宁碰撞会产生大量的Ar离子,因此在Ne等离子体中加入少量的Ar气时,会增加等离子体中气体离子的数量和电子

  11. Spectra of alkali atoms

    International Nuclear Information System (INIS)

    Emission spectra of alkali atoms has been determined by using spectrometer at the ultraviolet to infra red waves range. The spectra emission can be obtained by absorption spectrophotometric analysis. Comparative evaluations between experimental data and data handbook obtained by spark method were also presented. (author tr.)

  12. Deviation from Boltzmann distribution in excited energy levels of singly-ionized iron in an argon glow discharge plasma for atomic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lei; Kashiwakura, Shunsuke; Wagatsuma, Kazuaki, E-mail: wagatuma@imr.tohoku.ac.jp

    2012-01-15

    A Boltzmann plot for many iron ionic lines having excitation energies of 4.7-9.1 eV was investigated in an argon glow discharge plasma when the discharge parameters, such as the voltage/current and the gas pressure, were varied. A Grimm-style radiation source was employed in a DC voltage range of 400-800 V at argon pressures of 400-930 Pa. The plot did not follow a linear relationship over a wide range of the excitation energy, but it yielded a normal Boltzmann distribution in the range of 4.7-5.8 eV and a large overpopulation in higher-lying excitation levels of iron ion. A probable reason for this phenomenon is that excitations for higher excited energy levels of iron ion would be predominantly caused by non-thermal collisions with argon species, the internal energy of which is received by iron atoms for the ionization. Particular intense ionic lines, which gave a maximum peak of the Boltzmann plot, were observed at an excitation energy of ca. 7.7 eV. They were the Fe II 257.297-nm and the Fe II 258.111-nm lines, derived from the 3d{sup 5}4s4p {sup 6}P excited levels. The 3d{sup 5}4s4p {sup 6}P excited levels can be highly populated through a resonance charge transfer from the ground state of argon ion, because of good matching in the excitation energy as well as the conservation of the total spin before and after the collision. An enhancement factor of the emission intensity for various Fe II lines could be obtained from a deviation from the normal Boltzmann plot, which comprised the emission lines of 4.7-5.8 eV. It would roughly correspond to a contribution of the charge transfer excitation to the excited levels of iron ion, suggesting that the charge-transfer collision could elevate the number density of the corresponding excited levels by a factor of ca.10{sup 4}. The Boltzmann plots give important information on the reason why a variety of iron ionic lines can be emitted from glow discharge plasmas.

  13. Deviation from Boltzmann distribution in excited energy levels of singly-ionized iron in an argon glow discharge plasma for atomic emission spectrometry

    International Nuclear Information System (INIS)

    A Boltzmann plot for many iron ionic lines having excitation energies of 4.7–9.1 eV was investigated in an argon glow discharge plasma when the discharge parameters, such as the voltage/current and the gas pressure, were varied. A Grimm-style radiation source was employed in a DC voltage range of 400–800 V at argon pressures of 400–930 Pa. The plot did not follow a linear relationship over a wide range of the excitation energy, but it yielded a normal Boltzmann distribution in the range of 4.7–5.8 eV and a large overpopulation in higher-lying excitation levels of iron ion. A probable reason for this phenomenon is that excitations for higher excited energy levels of iron ion would be predominantly caused by non-thermal collisions with argon species, the internal energy of which is received by iron atoms for the ionization. Particular intense ionic lines, which gave a maximum peak of the Boltzmann plot, were observed at an excitation energy of ca. 7.7 eV. They were the Fe II 257.297-nm and the Fe II 258.111-nm lines, derived from the 3d54s4p 6P excited levels. The 3d54s4p 6P excited levels can be highly populated through a resonance charge transfer from the ground state of argon ion, because of good matching in the excitation energy as well as the conservation of the total spin before and after the collision. An enhancement factor of the emission intensity for various Fe II lines could be obtained from a deviation from the normal Boltzmann plot, which comprised the emission lines of 4.7–5.8 eV. It would roughly correspond to a contribution of the charge transfer excitation to the excited levels of iron ion, suggesting that the charge-transfer collision could elevate the number density of the corresponding excited levels by a factor of ca.104. The Boltzmann plots give important information on the reason why a variety of iron ionic lines can be emitted from glow discharge plasmas.

  14. The CHIANTI atomic database

    CERN Document Server

    Young, Peter R; Landi, Enrico; Del Zanna, Giulio; Mason, Helen

    2015-01-01

    The CHIANTI atomic database was first released in 1996 and has had a huge impact on the analysis and modeling of emissions from astrophysical plasmas. The database has continued to be updated, with version 8 released in 2015. Atomic data for modeling the emissivities of 246 ions and neutrals are contained in CHIANTI, together with data for deriving the ionization fractions of all elements up to zinc. The different types of atomic data are summarized here and their formats discussed. Statistics on the impact of CHIANTI to the astrophysical community are given and examples of the diverse range of applications are presented.

  15. Graphite filter atomizer in atomic absorption spectrometry

    Science.gov (United States)

    Katskov, Dmitri A.

    2007-09-01

    Graphite filter atomizers (GFA) for electrothermal atomic absorption spectrometry (ETAAS) show substantial advantages over commonly employed electrothermal vaporizers and atomizers, tube and platform furnaces, for direct determination of high and medium volatility elements in matrices associated with strong spectral and chemical interferences. Two factors provide lower limits of detection and shorter determination cycles with the GFA: the vaporization area in the GFA is separated from the absorption volume by a porous graphite partition; the sample is distributed over a large surface of a collector in the vaporization area. These factors convert the GFA into an efficient chemical reactor. The research concerning the GFA concept, technique and analytical methodology, carried out mainly in the author's laboratory in Russia and South Africa, is reviewed. Examples of analytical applications of the GFA in AAS for analysis of organic liquids and slurries, bio-samples and food products are given. Future prospects for the GFA are discussed in connection with analyses by fast multi-element AAS.

  16. Use of Atomic Absorption Technique in Environmental Studies

    International Nuclear Information System (INIS)

    This chapter consists of some points including the process of atomic absorption, historical hint, key basics, the atom ionization and formation of plasma, applications in the device of atomic absorption, quantum analysis with atomic absorption, components of the device of atomic absorption, standardization of this device, atomic absorption in the the graphite furnace, supervising the analytical interventions, spectral interventions, non-spectral interventions, the utmost electric energy for atomization, preparation of standards and samples, the system of acidic digestion, similar analytical techniques.

  17. Method development for the determination of manganese, cobalt and copper in green coffee comparing direct solid sampling electrothermal atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry.

    Science.gov (United States)

    Oleszczuk, Nédio; Castro, Jacira T; da Silva, Márcia M; Korn, Maria das Graças A; Welz, Bernhard; Vale, Maria Goreti R

    2007-10-31

    A method has been developed for the determination of cobalt, copper and manganese in green coffee using direct solid sampling electrothermal atomic absorption spectrometry (SS-ET AAS). The motivation for the study was that only a few elements might be suitable to determine the origin of green coffee so that the multi-element techniques usually applied for this purpose might not be necessary. The three elements have been chosen as test elements as they were found to be significant in previous investigations. A number of botanical certified reference materials (CRM) and pre-analyzed samples of green coffee have been used for method validation, and inductively coupled plasma optical emission spectrometry (ICP OES) after microwave-assisted acid digestion of the samples as reference method. Calibration against aqueous standards could be used for the determination of Mn and Co by SS-ET AAS, but calibration against solid CRM was necessary for the determination of Cu. No significant difference was found between the results obtained with the proposed method and certified or independently determined values. The limits of detection for Mn, Cu and Co were 0.012, 0.006 and 0.004mugg(-1) using SS-ET AAS and 0.015, 0.13 and 0.10mugg(-1) using ICP OES. Seven samples of Brazilian green coffee have been analyzed, and there was no significant difference between the values obtained with SS-ET AAS and ICP OES for Mn and Cu. ICP OES could not be used as a reference method for Co, as essentially all values were below the limit of quantification of this technique. PMID:19073113

  18. The use of ion chromatography-dc plasma atomic emission spectrometry for the speciation of trace metals. Annual performance report, February 1, 1989--January 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Urasa, I.T.

    1991-09-20

    The original objects of this research program were: to interface d.c. plasma atomic emission spectrometer with an ion chromatograph; to characterize and optimize the combined systems for application in the speciation of metals in aqueous solutions; to use this system in the study of the solution chemistry of various metals; and to find ways in which the measurement sensitivity of the method can be enhanced, thereby allowing the detection of metal species at low ppb concentration levels. This approach has been used to study the chemistry of and speciate several elements in solution including: arsenic, chromium, iron, manganese, nickel phosphorus, platinum, selenium, and vanadium. During the course of this research, we have found that the solution chemistry of the elements studied and the speciation data obtained can vary considerably depending on the solution, and the chromatographic conditions employed. The speciation of chromium, iron, and vanadium was found to be highly influenced by the acidity of the sample. The element selective nature of the d.c. plasma detector allows these changes to be monitored, thereby providing quantitative information on the new moieties formed. New approaches are being developed including the use of chelating ligands as preconcentration agents for purposes of reducing further the detection limits of the elements of interest and to improve the overall element speciation scheme. New thrusts are being directed towards the employment of post-column derivatization method coupled with colorimetric measurements to detect and quantify metal species eluting from the chromatographic column. The influence of sample acidity on these investigations will be carefully evaluated. These new thrusts are described in the accompanying Project Renewal Proposal.

  19. Determination of Hg{sup 2+} by on-line separation and pre-concentration with atmospheric-pressure solution-cathode glow discharge atomic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qing [Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050 (China); Zhang, Zhen [Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050 (China); School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Wang, Zheng, E-mail: wangzheng@mail.sic.ac.cn [Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050 (China)

    2014-10-03

    Highlights: • A modified SBA-15 mesoporous silica (SH-SBA-15) was synthesized as a sorbent. • On-line SPE combined with SCGD-AES based on FIA was used to detect Hg{sup 2+} firstly. • A simple, low-cost Hg{sup 2+} analysis in a complex matrix was established. • The sensitive detection of Hg{sup 2+} was achieved with a detection limit of 0.75 μg L{sup −1}. - Abstract: A simple and sensitive method to determine Hg{sup 2+} was developed by combining solution-cathode glow discharge atomic emission spectrometry (SCGD-AES) with flow injection (FI) based on on-line solid-phase extraction (SPE). We synthesized L-cysteine-modified mesoporous silica and packed it in an SPE microcolumn, which was experimentally determined to possess a good mercury adsorption capacity. An enrichment factor of 42 was achieved under optimized Hg{sup 2+} elution conditions, namely, an FI flow rate of 2.0 mL min{sup −1} and an eluent comprised of 10% thiourea in 0.2 mol L{sup −1} HNO{sub 3}. The detection limit of FI–SCGD-AES was determined to be 0.75 μg L{sup −1}, and the precision of the 11 replicate Hg{sup 2+} measurements was 0.86% at a concentration of 100 μg L{sup −1}. The proposed method was validated by determining Hg{sup 2+} in certified reference materials such as human hair (GBW09101b) and stream sediment (GBW07310)

  20. Game Analytics

    DEFF Research Database (Denmark)

    Seif El-Nasr, Magy; Drachen, Anders; Canossa, Alessandro

    2013-01-01

    Game Analytics has gained a tremendous amount of attention in game development and game research in recent years. The widespread adoption of data-driven business intelligence practices at operational, tactical and strategic levels in the game industry, combined with the integration of quantitative...... measures in user-oriented game research, has caused a paradigm shift. Historically, game development has not been data-driven, but this is changing as the benefits of adopting and adapting analytics to inform decision making across all levels of the industry are becoming generally known and accepted....