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Sample records for atomic emission determination

  1. [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

  2. 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.

  3. 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.

  4. 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

  5. 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).

  6. 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.

  7. 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

  8. 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

  9. 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)

  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. 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)

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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%.

  17. 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.

  18. 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

  19. 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

  20. 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.

  1. 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

  2. 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.)

  3. 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)

  4. 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)

  5. 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.)

  6. 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

  7. 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

  8. 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...

  9. 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 %.

  10. 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)

  11. 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

  12. 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)

  13. 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 + |\

  14. 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.

  15. 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).

  16. 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.

  17. Improving the accuracy of atomic emission determination of europium isotope ratio without reference samples

    International Nuclear Information System (INIS)

    A method has been developed of determining the isotopic composition of europium without standard reference samples. The estimation of the analysis accuracy has shown a statistically negligible systematic error. The confidence level of single determination (P0.95) is ± 0.3 at.% at 151Eu levels from 47.47 to 98.2 at.%

  18. 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

  19. 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...

  20. Determination of Ca, Mg, and Mn in Tea Samples with Microwave Plasma Atomic Emission Spectrometry

    OpenAIRE

    Akbıyık, Dilek; Özbek, Nil; Akman, Süleyman

    2014-01-01

    Tea is one of the oldest and the most common beverages and its elements are quite rich. Studies show that tea and infusion herbal tea samples may have lots of contamination. It is determined that these contaminations may result from the production phase, the soil it grows, fertilizeds used, and from gases emitted to the atmosphere [1]. Depending on the concentrations, these kinds of contaminations may affect human health.  In this study, more than 30 tea samples were solubilized with microwav...

  1. 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)

  2. 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.

  3. 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...

  4. 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)

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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)

  10. 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

  11. 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

  12. 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)

  13. 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)

  14. 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

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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)

  3. 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.

  4. 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

  5. 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.)

  6. 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

  7. 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

  8. 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…

  9. 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

  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. 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)

  12. 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.)

  13. 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)

  14. 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

  15. 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

  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. 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

  18. 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.)

  19. Method of trivalent chromium concentration determination by atomic spectrometry

    Science.gov (United States)

    Reheulishvili, Aleksandre N.; Tsibakhashvili, Neli Ya.

    2006-12-12

    A method is disclosed for determining the concentration of trivalent chromium Cr(III) in a sample. The addition of perchloric acid has been found to increase the atomic chromium spectrometric signal due to Cr(III), while leaving the signal due to hexavalent chromium Cr(VI) unchanged. This enables determination of the Cr(III) concentration without pre-concentration or pre-separation from chromium of other valences. The Cr(III) concentration may be measured using atomic absorption spectrometry, atomic emission spectrometry or atomic fluorescence spectrometry.

  20. 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.

  1. 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.

  2. 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,

  3. Flotation separation of Cd, Co, Cr, Cu, Ni and Tl from calcium minerals and their determination by inductively coupled plasma-atomic emission spectrometry

    International Nuclear Information System (INIS)

    The method of inductively coupled plasma-atomic spectrometry (ICP-AES), is developed for determination of Cd, Co, Cr, Cu, Ni and Tl in traces in calcite and gypsum. The interferences of Ca as matrix element on Co, Cr, Cu, Ni and Tl intensities during their ICP-AES determination are investigated. The results reveal that Ca does not interfere on intensities of Cr, but tends to decrease the intensity of the other elements. To eliminate those matrix interferences of Ca on trace elements intensities a flotation separation method is proposed. Lead(II) hexamethylenedithiocarbamate, Pb(HMDTC)2, is applied as a collector for flotation of trace elements from acidic solutions of mineral samples. The most suitable concentrations of calcite and gypsum solutions for flotation are ascertained. The detection limits of ICP-AES method following flotation of elements present in calcite and gypsum as impurities are determined: 0.022 and 0.061 μg·g-1 for Cd, 0.071 and 0.042 μg·g-1 for Co, 0.026 and 0.132 μg·g-1 for Cr, 0.164 and 0.149 μg·g-1 for Cu, 0.289 and 0.095 μg·g-1 for Ni and 0.645 and 0.7666 μg·g-1 for Tl, respectively. (Original)

  4. 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

  5. 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.

  6. 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.

  7. Determination of the mineral compositions of some selected oil-bearing seeds and kernels using Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES

    Directory of Open Access Journals (Sweden)

    Musa Özcan, M.

    2006-06-01

    Full Text Available The aim of this paper was to establish the mineral contents of oil-bearing seeds and kernels such as peanut, turpentine, walnut, hazelnut, sesame, corn, poppy, almond, sunflower etc., using Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES. Significant differences in mineral composition were observed among crops. All seeds and kernels contained high amounts of Al, Ca, Fe, K, Mg, Na, P and Zn. B, Cr, Cu, Li, Ni, Sr, Ti while V contents of the crops were found to be very low. The levels of K and P of all crops in this study were found to be higher than those of other seeds and kernels. The results obtained from analyses of the crops showed that the mean levels of potassiumcontent ranged from 1701.08 mg/kg (corn to 20895.8 mg/kg (soybean, the average content of phosphorus ranged from 3076.9 mg/kg (turpentine to 12006,5 mg/kg to 2617.4 mg/kg (cotton seed, and Ca from 68.4 mg/kg (corn to 13195.7 mg/kg (poppy seed. The results show that these values may  be useful for the evaluation of dietary information. Particularly the obtained results provide evidence that soybean, pinestone and poppy seed are a good source of K, P and Ca, respectively. Whereas pinestone is a good source of zinc.La finalidad del trabajo es establecer el contenido en elementos minerales de semillas oleaginosas tales como cacahuetes, trementina, avellana, sesamo, maiz, almendras, girasol, utilizando ICP-AES. Se han observado diferencias significativas en la composición de minerales entre cosechas. Todas las semillas contienen cantidades elevadas de Al, Ca, Fe, K, Mg, Na, P y Zn. Los contenidos de B, Cr, Cu, Li, Ni, Sr, Ti y V, sin embargo, fueron bajos. Los contenidos de K y P en todas las semillas estudiadas fueron superiores a las de otras semillas. El contenido medio de K osciló entre 1.701,1 mg/kg (maiz a 20.895,8 mg/kg (soja, el P entre 3.076.9 mg/kg (trementina a 12.006.5 mg/kg o 2.617,4 mg/kg (semilla de algodón, y Ca de 68,4 mg/kg (maiz a 13.195,7 mg

  8. 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...

  9. 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.

  10. 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.

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

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •We worked out ICP-MS method of Hf determination in Zr and Zr compounds. •We used NAA method as reference one. •We obtained pure zirconium matrix by ion exchange (Diphonix® resin). •These permit to determine ≥1 × 10−4% Hf in Zr sample by ICP MS with good precision and accuracy. -- Abstract: Hafnium at the very low level of 1–8 ppm (in relation to zirconium) was determined in zirconium sulfate solutions (originating from investigations of the separation of ca. 44 ppm Hf from zirconium by means of the ion exchange method) by using three independent methods: inductively coupled plasma mass spectrometry (ICP MS), neutron activation analysis (NAA) and inductively coupled plasma atomic emission spectrometry (ICP-AES). The results of NAA and ICP MS determinations were consistent with each other across the entire investigated range (the RSD of both methods did not exceed 38%). The results of ICP-AES determination were more diverse, particularly at less than 5 ppm Hf (RSD was significantly higher: 29–253%). The ion exchange method exploiting Diphonix® resin proved sufficient efficiency in Zr–Hf separation when the initial concentration ratio of the elements ([Zr]0/[Hf]0) ranged from 1200 to ca. 143,000

  12. 火焰原子发射光谱法测定电解质饮料中钾钠的含量%Determination of Potassium and Sodium in Electrolyte Drink by Flame Atomic Emission Spectrometry Method

    Institute of Scientific and Technical Information of China (English)

    黄冬兰; 潘丽君

    2015-01-01

    A method was established for determination of potassium and sodium contents in electrolyte drink by flame atomic emission spectrometry (FAES). The detection limits of K and Na were 0.004 22μg/mL and 0.002 16μg/mL respectively. And the relative standard devitation (RSD) were 91.1%~100.9% and 93.0%~102.8%respectively. The method is simple, rapid, accurate, reproducible, and without using extra light source. Its experimental results are as closely as that of the flame atomic absorption spectrometry (FAAS).%建立了火焰原子发射光谱法测定电解质饮料中钾和钠含量的方法.钾、钠的方法检出限分别为0.00422μg/mL和0.00216μg/mL,钾、钠的加标回收率分别为91.1%~100.9%和93.0%~102.8%.该方法操作简单、快速、准确度高、重现性好、无需使用附加光源,测定结果与火焰原子吸收光谱法无显著性差异.

  13. A novel method for simultaneous determination of selected elements in dolomite and magnesia by Inductively Coupled Plasma Atomic Emission Spectroscopy with slurry sample introduction

    Science.gov (United States)

    Bok-Badura, Joanna; Jakóbik-Kolon, Agata; Turek, Marian; Szczerba, Jacek; Lemanowicz, Marcin; Karoń, Krzysztof

    2015-11-01

    The slurry nebulization ICP-AES method for simultaneous determination of selected elements in dolomite and magnesia was proposed. Based on the investigation results the optimal conditions for this analysis were as follows: particle size CRM 782-1 and High Purity Magnesia BCS-CRM 389/1 were analyzed. Student's t-test proved that there were no statistically significant differences between determined values and the certified ones. This proves that the slurry sample introduction into plasma in ICP-AES technique can be applied for simultaneous determination of elements in dolomite and magnesia.

  14. Method of determining radioactive atom valence

    International Nuclear Information System (INIS)

    The valency state of radionuclides emitting low-energy conversion electrons is determined from the measured change in kinetic energies of conversion electrons which is determined by electron spectroscopy. The determined changes in kinetic energies correspond to changes in binding energies of electrons in the atomic shell which are related to the valency state of the radionuclides. The advantage of the method is the possibility of determining valency states in trace amounts of radioactive substances, its nondestructive character and high sensitivity (10-11g). (E.S.)

  15. 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

  16. 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

  17. Applicability of solid-phase microextraction combined with gas chromatography atomic emission detection (GC-MIP AED) for the determination of butyltin compounds in sediment samples

    Energy Technology Data Exchange (ETDEWEB)

    Carpinteiro, J.; Rodriguez, I.; Cela, R. [Universidad de Santiago de Compostela, Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Santiago de Compostela 15782 (Spain)

    2004-11-01

    The performance of solid-phase microextraction (SPME) applied to the determination of butyltin compounds in sediment samples is systematically evaluated. Matrix effects and influence of blank signals on the detection limits of the method are studied in detail. The interval of linear response is also evaluated in order to assess the applicability of the method to sediments polluted with butyltin compounds over a large range of concentrations. Advantages and drawbacks of including an SPME step, instead of the classic liquid-liquid extraction of the derivatized analytes, in the determination of butyltin compounds in sediment samples are considered in terms of achieved detection limits and experimental effort. Analytes were extracted from the samples by sonication using glacial acetic acid. An aliquot of the centrifuged extract was placed on a vial where compounds were ethylated and concentrated on a PDMS fiber using the headspace mode. Determinations were carried out using GC-MIP AED. (orig.)

  18. Determination of barium, strontium and nine minor and trace elements in impure barite and strontianite by inductively-coupled plasma atomic-emission spectrometry after dissolution in disodium ethylenediaminetetraacetate.

    Science.gov (United States)

    Gupta, J G

    1991-10-01

    A new method has been developed for the determination of barium, strontium, silicon and nine minor and trace elements of barite and strontianite associated with gangue materials. It involves dissolution of the sample by boiling under reflux with a concentrated solution of disodium ethylenedi-aminetetraacetate (EDTA-2Na) in the presence of ammonium hydroxide. Barite and strontianite dissolve quantitatively under this condition, and any associated silicate and sulphide mineral impurities, remaining insoluble, are filtered off and ignited to constant weight in a platinum crucible. Silica is determined gravimetrically by heating the residue with concentrated sulphuric and hydrofluoric acids, followed by ignition to oxides. The residue is fused with sodium bisulphate and dissolved in dilute sulphuric acid. After suitable dilution of the EDTA-2Na solution, Ba, Sr, Be, Co, Cr, Cu, La, Ni, V, Yb and Zn are determined by inductively-coupled plasma atomic-emission spectrometry (ICP-AES). The bisulphate fusion product is separately analysed by ICP-AES, and the elements found are combined with those obtained from the EDTA-2Na solution. The replicate values of this work compare well with each other and with other values obtained by independent methods. PMID:18965264

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

    International Nuclear Information System (INIS)

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

  20. Simultaneous preconcentration of copper and mercury in water samples by cloud point extraction and their determination by inductively coupled plasma atomic emission spectrometry

    Science.gov (United States)

    Shoaee, Hamta; Roshdi, Mina; Khanlarzadeh, Nasibeh; Beiraghi, Asadollah

    2012-12-01

    A cloud-point extraction process coupled to ICP-OES by using 3-nitro benzaldehyde thiosemicarbazone (3-NBT) as complexing agent was developed for the simultaneous preconcentration and determination of copper and mercury in water samples. The variables affecting the complexation and extraction steps were optimized. Under the optimum conditions (i.e. 1.5 × 10-5 mol L-1 ligand, 0.3% (v/v) Triton X-114, 55 °C equilibrium temperature, incubation time of 30 min) the calibration graphs were linear in the range of 5-120 and 10-100 ng mL-1 with enhancement factor of 82.7 and 51.3 for Cu2+ and Hg2+, respectively. The preconcentration factors were 28.6 in both cases and detection limits were obtained 0.48 for Cu and 1.1 ng mL-1 for Hg. The precisions (R.S.D.%) for five replicate determinations at 50 ng mL-1 of copper and mercury were better than 1.8% and 3.2%, respectively. The accuracy of the proposed method is validated by analyzing a certified reference material of water (RTC-QCI-049) with satisfactory results. Finally, the proposed method was utilized successfully for the determination of copper and mercury in surface water (river), tap water and bottled mineral water samples.

  1. A study on the determination of major, minor and trace constituents in meteorites by Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES)

    Science.gov (United States)

    Zhang, Z.; Bear, B. R.; Fassel, V. A.

    A study on the ICP-AES determination of 42 major and trace elements in meteorites was described. The sample was dissolved in a mixture of aqua regia and HF in a sealed Teflon bomb and boric acid is added after dissolution to complex the excess HF. The final solution is transformed into an aerosol via ultrasonic nebulization. The reference solutions employed for calibrating the spectrometers contained only the HF-aqua regia-HS3BO3 matrix. A polychromator and a programmable scanning monochromator interfaced to the same plasma excitation source provided the spectroscopic data. The accuracy of the determination was assessed by: (1) comparing our results with those obtained by neutron activation and X-ray fluorescence; and (2) by analyzing several geological references samples (US Geological Survey and Canadian Certified Reference Materials). The analytical results showed good agreement. The relative standard deviation of the determination of the major elements ranged from 0.5 to 2%, and of the minor and trace elements from 0.5 to 8%.

  2. Uranium determination using atomic spectrometric techniques: An overview

    International Nuclear Information System (INIS)

    This review focuses on the determination of uranium using spectroanalytical techniques that are aimed at total determination such as flame atomic absorption spectrometry (FAAS), electrothermal atomic absorption spectrometry (ETAAS), inductively coupled plasma optical emission spectrometry (ICP-OES); and inductively coupled plasma mass spectrometry (ICP-MS) that also enables the determination of uranium isotopes. The advantages and shortcomings related to interferences, precision, accuracy, sample type and equipment employed in the analysis are taken into account, as well as the complexity and costs (i.e., acquisition, operation and maintenance) associated with each of the techniques. Strategies to improve their performance that employ separation and/or preconcentration steps are considered, with an emphasis given to solid-phase extraction because of its advantages compared to other preconcentration procedures.

  3. 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)

  4. 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

  5. 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...

  6. 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...

  7. Determination of trace amounts of thorium and uranium in coal ash by inductively coupled plasma atomic emission spectrometry after extraction with 2-thenoyltrifluoroacetone and back-extraction with dilute nitric acid

    International Nuclear Information System (INIS)

    A method of sample preparation is described that can be used for the determination of trace amounts of thorium and uranium in coal ash by inductively coupled plasma atomic emission spectrometry. After acid digestion of the samples, the elements are separated independently from the matrix by 2-thenoyltrifluoroacetone (TTA)-benzene extraction procedures. Thorium is extracted with 0.25 M TTA at pH 1.2 in the presence of ascorbic acid. Uranium(VI) is extracted with 0.16 M TTA at pH 3.5 in the presence of EDTA. The amount of EDTA to be added to the sample solutions must be properly controlled because an excess reduces the recovery of uranium. Thorium and uranium are finally measured in the back-extract in 2 M nitric acid. The detection limits were 11 μg l-1 for Th and 29 μg l-1 for U and the relative standard deviations ranged from 3.0 to 8.6% for Th and 3.9 to 4.3% for U. (author)

  8. 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

  9. 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...

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. Quantitative determination of impurities in nuclear grade aluminum by Flame-Atomic Absorption Spectrometry

    International Nuclear Information System (INIS)

    The paper deals with quantitative determination of impurity elements in nuclear grade aluminum, used as fin tubes in research reactors, by Flame-Atomic Absorption Spectrometry (F-AAS). The results have been compared with those obtained by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) method. Experimental conditions used in both the methods are given in the paper. (author)

  15. In situ determination of Zeeman content of collective atomic memories

    International Nuclear Information System (INIS)

    Knowledge and control of atomic Zeeman populations is necessary for the realization of useful, long-lived quantum memories. We propose and implement a method to determine atomic state population distributions for atomic spin waves. Zeeman composition of single atomic spin waves of a cold atomic gas, confined in a one-dimensional optical lattice, is inferred with high precision by measurements of signal–idler polarization correlations as a function of spin-wave storage time. (paper)

  16. 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.

  17. Determination of Atomic Data Pertinent to the Fusion Energy Program

    Energy Technology Data Exchange (ETDEWEB)

    Reader, J.

    2013-06-11

    We summarize progress that has been made on the determination of atomic data pertinent to the fusion energy program. Work is reported on the identification of spectral lines of impurity ions, spectroscopic data assessment and compilations, expansion and upgrade of the NIST atomic databases, collision and spectroscopy experiments with highly charged ions on EBIT, and atomic structure calculations and modeling of plasma spectra.

  18. 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.

  19. 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 ...

  20. Miniaturized Corona Discharge-Atomic Emission Spectrometer for Determination of Trace Mercury%小型化电晕放电-原子发射光谱仪检测痕量汞

    Institute of Scientific and Technical Information of China (English)

    罗虹; 侯贤灯; 龙舟

    2015-01-01

    A miniaturized atomic emission spectrometer composed of a corona discharge source and a handheld charge-coupled device detector was constructed for the sensitive determination of trace mercury, with photochemical vapor generation for sample introduction. By using formic acid, mercury vapor was generated under the irradiation of UV light, and then the vapor was introduced into the corona discharge area with the carrier gas flow of argon. The optical signals were captured and analyzed by the charge-coupled device detector at 253. 7 nm. Under the optimized conditions including 4% formic acid, discharge voltage of 90 V, and carrier gas flow rate of 200 mL/min, the stable detection signals were obtained ( RSD=2. 5%). The calibration curves were plotted with the concentration of mercury ranging from 0. 5 to 1000 ng/mL, with a correlation coefficient >0. 99 and the limit of detection of 0. 03 ng/mL. Two certified reference materials were analyzed, and a t-test demonstrated that the determined results by the proposed method had no significant difference with the certified values at the confidence level of 95%. Water samples collected from both Funan River in Chengdu and the Lotus Pond on campus of Sichuan University were analyzed as well, with the recoveries of standard addition between 93 . 8% and 103%. The miniaturized instrumentation demonstrated several advantages including easy construction, low power consumption, high sensitivity, and portability for field analysis.%采用电晕放电激发源和手持式电荷耦合检测器组装了小型化原子发射光谱仪,将其用于检测痕量汞。以光化学蒸气发生技术作为进样手段,在甲酸辅助下用紫外光照射样品溶液产生汞蒸气,并由氩气带入电晕放电光源中,激发后产生汞原子发射光谱信号,用电荷耦合检测器在253.7 nm处检测。经优化得到的最佳实验条件为甲酸浓度4%,电晕放电电压90 V,载气流速200 mL/min;检测信号

  1. 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

  2. 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.

  3. 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.

  4. Determination of atomic cluster structure with cluster fusion algorithm

    DEFF Research Database (Denmark)

    Obolensky, Oleg I.; Solov'yov, Ilia; Solov'yov, Andrey V.; Greiner, Walter

    We report an efficient scheme of global optimization, called cluster fusion algorithm, which has proved its reliability and high efficiency in determination of the structure of various atomic clusters.......We report an efficient scheme of global optimization, called cluster fusion algorithm, which has proved its reliability and high efficiency in determination of the structure of various atomic clusters....

  5. 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 ...

  6. First AID (Atom counting for Isotopic Determination).

    Energy Technology Data Exchange (ETDEWEB)

    Roach, J. L. (Jeffrey L.); Israel, K. M. (Kimberly M.); Steiner, R. E. (Robert E.); Duffy, C. J. (Clarence J.); Roench, F. R. (Fred R.)

    2002-01-01

    Los Alamos National Laboratory (LANL) has established an in vitro bioassay monitoring program in compliance with the requirements in the Code of Federal Regulations, 10 CFR 835, Occupational Radiation Protection. One aspect of this program involves monitoring plutonium levels in at-risk workers. High-risk workers are monitored using the ultra-sensitive Therrnal Ionization Mass Spectrometry (TIMS) technique to ensure compliance with DOE standards. TIMS is used to measure atom ratios of 239Pua nd 240Puw ith respect to a tracer isotope ('Pu). These ratios are then used to calculate the amount of 239Pu and 240Pup resent. This low-level atom counting technique allows the calculation of the concentration levels of 239Pu and 240Pu in urine for at risk workers. From these concentration levels, dose assessments can be made and worker exposure levels can be monitored. Detection limits for TIMS analysis are on the order of millions of atoms, which translates to activity levels of 150 aCi 239Pua nd 500 aCi for 240Pu. pCi for Our poster presentation will discuss the ultra-sensitive, low-level analytical technique used to measure plutonium isotopes and the data verification methods used for validating isotopic measurements.

  7. 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.)

  8. Evaluation on the methodology of blood manganese determination by inductively coupled plasma atomic emission spectrometry%ICP-AES法测定全血锰的方法学评价

    Institute of Scientific and Technical Information of China (English)

    郁飞; 李萌; 曹波

    2012-01-01

    Objective To evaluate the methodology of determining blood manganese by inductively coupled plasma atomic emission spectrometry (ICP-AES) , and apply the method in daily detection work. Methods The whole blood samples were treated with nitric acid, and the concentration of the nitric acid was 1 mol/L. The supernatant fluid was collected. The concentrations of the whole blood manganese were determined by ICP-AES under the condition of 279.544 nm in 1 027 healthy children. The precision, recovery rate, sensitivity and anti-interference ability were evaluated, and the normal reference range was definited. Results The within-run coefficient of variation (CV) was 6. 2%-6. 6% , the between-run CV was 7. L%-7. 6% , and the total CV was 7. 2%-7. 8%. The relative standard deviation (RSD) was 1. 66%-2. 36%. The standardized recovery rate was 95. 0%-96. 9%. The linear equation was Y = 7 035. 6X +759. 02, and the correlation coefficient of the whole blood manganese was r =0. 999 7. The interference elements, K, Na, Cl, Ca and Mg (1 : 1 , 25 mg/L) and Fe (2 mg/L) were added into the blank solution and the standard reserve liquid of 100 μg/L manganese. The concentration of manganese had no obvious change. The normal reference range of whole blood manganese in 1 027 healthy children was (4. 89 ±2. 67) μg/L. Conclusions ICP-AES for determining whole blood manganese has no obvious system error. This method is accurate and reliable, and can be applied as a conventional way to detect whole blood manganese.%目的 对电感耦合等离子体发射光谱法(ICP-AES)测定血锰进行方法学评价,并应用于日常检测工作.方法 全血样本经1 mol/L硝酸处理后吸取上清液,采用ICP-AES在279.544 nm处测定样本,评价其精密度、回收率、灵敏度及抗干扰能力;同时采用ICP-AES测定1 027名健康体检儿童的全血锰浓度,确定正常参考范围.结果 ICP-AES测定血锰的批内变异系数(CV)为6.2% ~6.6%,批间CV为7.1%~7.6

  9. Determining peak stress history using acoustic emissions

    International Nuclear Information System (INIS)

    As part of the test program at the Nevada Test Site, there is a need for determining the peak stress induced by explosions in tuff. Standard techniques make use of various gages grouted into the tuff prior to the test. These are difficulties in interpreting the output of these gages and there is always the chance that the gage will not survive long enough to allow a stress determination to be made. As an alternative, we have been testing a passive technique for determining peak stress as a function of distance from a test. Using core samples retrieved from the vicinity of an explosion, we have tested for the existence of a threshold stress for the onset of acoustic emissions, the Kaiser effect (Kaiser 1950). From laboratory results it is known that for many rock types, the previously applied peak stress can be detected by restressing a sample while monitoring acoustic emissions. An abrupt onset for acoustic emission activity typically occurs at a stress state close to the previous peak. The point of this work was to determine if the Kaiser effect occurred in tuff and, if so, whether it could be used to determine the peak stresses induced by an explosion. On the basis of four tests it is only possible to draw tentative conclusions. There does seem to be enough evidence of the existence and stress dependence of the Kaiser effect in the tuff to allow hope for the use of this technique in studying past stress states. In future tests the saturation state of the samples should be carefully controlled. Tests should be done on variously oriented subcores from a main core to determine the other components of the in situ stress tensor. If the components are indeed decoupled, as these few tests indicate, then a complete stress determination can be made this way. It would be interesting to use the same technique to try and determine in situ stresses in tuff. 7 refs., 6 figs

  10. 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.

  11. 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.)

  12. Hall Determination of Atomic Radii of Alkali Metals

    Science.gov (United States)

    Houari, Ahmed

    2008-01-01

    I will propose here an alternative method for determining atomic radii of alkali metals based on the Hall measurements of their free electron densities and the knowledge of their crystal structure. (Contains 2 figures.)

  13. 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

  14. Electrothermal atomization atomic absorption spectrometric determination of trace metals in uranium-plutomium fuel materials

    International Nuclear Information System (INIS)

    Atomic absorption spectrometric methods using the electrothermal mode of atomization developed for the determination of Ag, Be, Ca, Cd, Cr, Co, Cu, Fe, Li, Mn, Na, Ni, Sn and Zn in (U, Pu) solution with 4% plutonium have been described. The carbon rod atomizer has been adapted for glove box operation to enable handling of plutonium containing solution samples. Multielement solution standards with graded concentrations of the analytes and fixed concentration of the matrix are used in the standardization process. Nanogram to sub-nanogram quantities of the analytes have been determined with a precision of better than 9% RSD using 5 μl of the sample aliquots. (orig.)

  15. 电感耦合等离子体原子发射光谱法测定电解钴中杂质元素%Inductively coupled plasma atomic emission spectrometric determination of impurity elements in electrolytic cobalt

    Institute of Scientific and Technical Information of China (English)

    王凌; 冉文生; 张辽生; 刘立新

    2011-01-01

    Cobalt metal sample after with acid digestion,directly without matrix with the full spectrum of separation direct-read inductively coupled plasmaa tomic emission of impurity element determination.To determine the best working conditions of instrument,choose a suitable analytical spectral lines,adopt yttrium as internal standard material,compensation matrix effect.Method for determining the detect limit the elements in 0.0006% ~0.001% between.,Methods used for sample,the relative standard deviation is determined1.5%~ 7.5%,recovery of 94.0 ~104.0%,the result obtained were in consistency with thoses found by methods of the national standards.%金属钴试样经酸消解后,未经基体分离直接以全谱直读电感耦合等离子发射光谱仪测定其中杂质元素。确定了仪器的最佳工作条件,选择了合适的分析谱线,采用钇作为内标物质,补偿基体效应。方法测定各元素的检出限在0.0001~0.02mg.L-1范围内。方法用于样品的测定,相对标准偏差为1.5%~7.5%,回收率为94.0~104.0%,各元素的测定值与国家标准方法的测定值相符合。

  16. Adsorption Geometry Determination of Single Molecules by Atomic Force Microscopy

    OpenAIRE

    Schuler, Bruno; Liu, Wei; Tkatchenko, Alexandre; Moll, Nikolaj; Meyer, Gerhard; Mistry, Anish; Fox, David; GROSS, Leo

    2013-01-01

    We measured the adsorption geometry of single molecules with intramolecular resolution using noncontact atomic force microscopy with functionalized tips. The lateral adsorption position was determined with atomic resolution, adsorption height differences with a precision of 3 pm, and tilts of the molecular plane within 0.2 degrees. The method was applied to five pi-conjugated molecules, including three molecules from the olympicene family, adsorbed on Cu(111). For the olympicenes, we found th...

  17. Determination of trace amounts of scandium by atomic absorption spectroscopy.

    Science.gov (United States)

    Chau, Y K

    1968-05-01

    Optimum instrumental conditions were investigated for the determination of trace quantities of scandium by atomic-absorption spectroscopy. Enhancement effects by organic solvents and by complex extractions were also studied. (46)Sc was used to establish the optimum extraction conditions. A sensitivity of 0.06 ppm of Sc was observed when using extraction into oxine-butanol and atomic absorption was measured with an acetylene-nitrous oxide flame. PMID:18960315

  18. 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.

  19. Organic solvents as interferents in arsenic determination by hydride generation atomic absorption spectrometry with flame atomization

    Science.gov (United States)

    Karadjova, Irina B.; Lampugnani, Leonardo; Dědina, Jiri; D'Ulivo, Alessandro; Onor, Massimo; Tsalev, Dimiter L.

    2006-05-01

    Interference effects of various organic solvents miscible with water on arsenic determination by hydride generation atomic absorption spectrometry have been studied. Arsine was chemically generated in continuous flow hydride generation system and atomized by using a flame atomizer able to operate in two modes: miniature diffusion flame and flame-in-flame. The effects of experimental variables and atomization mode were investigated: tetrahydroborate and hydrochloric acid concentrations, argon, hydrogen and oxygen supply rates for the microflame, and the distance from the atomization region to the observation zone. The nature of the species formed in the flame due to the pyrolysis of organic solvent vapors entering the flame volume together with arsine is discussed. The observed signal depression in the presence of organic solvents has been mainly attributed to the atomization interference due to heterogeneous gas-solid reaction between the free arsenic atoms and finely dispersed carbon particles formed by carbon radicals recombination. The best tolerance to interferences was obtained by using flame-in-flame atomization (5-10 ml min - 1 of oxygen flow rate), together with higher argon and hydrogen supply rates and elevated observation heights.

  20. 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

  1. 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.

  2. 电感耦合等离子体原子发射光谱法测定人造金刚石中铁、钴、锰、镍%Determination of Fe, Co, Mn and Ni in Synthetic Diamonds by Inductively Coupled Plasma Atomic Emission Spectrometry

    Institute of Scientific and Technical Information of China (English)

    高光洁子; 李艳萍; 冯圣雅; 谢琰军; 况春江; 曹枨

    2014-01-01

    A method for the determination of Fe, Co, Mn and Ni in synthetic diamonds by inductively coupled plasma atomic emission spectrometry ( ICP-AES) was proposed. The synthetic diamond sample was decomposed completely, while the sample was burned in air at 1000 ℃ for 10 h, and then a mixed acid of H2 SO4 , aqua regia and HClO4 was used for the dissolving the residue of the sample. In this method, the limits of detection of Fe, Co, Mn and Ni were 0. 0147, 0. 0018, 0. 0006 and 0. 0027 mg/L, respectively. Under the optimum condition, Fe, Co, Mn and Ni in synthetic diamond sample were determined. The values of RSDs (n=7) were less than 0. 5%. The recoveries of added standard were 94. 0%-105. 0%.

  3. 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)

  4. Simultaneous determination of gold and silver in blister copper by inductively coupled plasma atomic emission spectrometry%电感耦合等离子体发射光谱法同时测定粗铜中金和银

    Institute of Scientific and Technical Information of China (English)

    刘益锋; 冯俊汉; 李展江; 史亚晓

    2012-01-01

    Blister copper sample were dissolved in mixed acid of hydrochloric acid and nitric acid. Gold and silver content was determined directly by inductively coupled plasma optical emission spectrometry (ICPOES) by using 242. 794 nm and 328. 068 nm as analyzing spectral line. Investigation of the effects of matrix and co-existing ions were studied. It was shown that copper had certain effect on the determination, but can be removed by matrix-matching, while other impurity elements had no influence. The method has been applied to the blister copper and the results are consistent with the results by the method of YS/T521. 2-2009, with the relative standard deviations of gold and silver (RSD, n = 12) smaller than 1. 9 % and 1.1% respectively. In addition, the recoveries of testing elements were between 95 % and 105 %.%粗铜样品用盐酸和硝酸混合酸溶解,选择242.794 nm和328.068 nm的光谱线分别作为金和银的分析线,直接用电感耦合等离子体发射光谱法(ICP-AES)同时测定了粗铜中金和银含量.考察了基体效应和共存离子等因素对测定的影响.实验表明,铜存在基体效应对测定有影响,但可以采用基体匹配的方法消除,粗铜中的其他杂质元素对测定没有影响.用本法测定了粗铜中的金和银含量,测定值与行业标准方法(YS/T521.2- 2009)的测定值相符,金、银测定结果的相对标准偏差分别小于1.9%和1.1%(n=12),加标回收率在95%~105%之间.

  5. 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.

  6. 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.

  7. Spectrofluorimetric, Atomic Absorption Spectrometric and Spectrophotometric Determination of Some Fluoroquinolones

    OpenAIRE

    Hesham Salem

    2005-01-01

    Simple, accurate, sensitive and selective spectrofluorimetric, atomic absorption spectrometric and spectrophotometric methods are described for the quantitative determination of ten fluoroquinolones (amifloxacin, ciprofloxacin hydrochloride, difloxacin hydrochloride, enoxacin, enrofloxacin, lomefloxacin hydrochloride, levofloxacin, norfloxacin, ofloxacin and pefloxacin mesylate). The first method was a spectrofluorimetric method in which samples of the studied drugs in 0.1 N H2SO4 showed nati...

  8. The determination of zirconium by atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    The interference of iron in the determination of zirconium by atomic absorption spectrophotometry was studied. Attempts were made to emininate this interference by complexing the iron with EDTA, ascorbic acid and hydrazine; also by the addition of ammonium fluoride to the solution. Some experiments were carried out in order to explain the results obtained

  9. Determination of Trace Metals in Lutetium-Yttrium Orthosilicate by Solution-Cathode Glow Discharge-Atomic Emission Spectrometry%液体阴极辉光放电原子发射光谱法分析硅酸钇镥中痕量杂质元素

    Institute of Scientific and Technical Information of China (English)

    盖荣银; 汪正; 贺岩峰; 李青; 邹慧君; 张国霞

    2014-01-01

    TheLutetium-YttriumOrthosilicate(LYSO)isakindofscintillatingcrystalmaterialwiththebest comprehensive properties. In this work, the trace elements Ca, Fe, K, Li, Mg and Na in LYSO were determined by solution-cathode glow discharge-atomic emission spectrometry ( SCGS-AES ) . The optimal conditions included 0. 1 mol/L HNO3 sample solutions and operation at a voltage at 1080 V with a flow rate of 2. 0 mL/min. The LYSO matrix concentration tolerance of the SCGD source was determined to be 10 g/L. Sample solutions dissolving from several LYSO samples with HF, HNO3 and HClO4 were examined by SCGD-AES. For LYSO samples, the values obtained by SCGD-AES agree well with those obtained by axial inductively coupled plasma-atomic emission spectroscopy ( ICP-AES ) and inductively coupled plasma-mass spectroscopy (ICP-MS). The emissions of Lu and Y were not observed, so that the determination of trace elements in LYSO matrices could be conducted with little interference. The detection limits of Ca, Fe, K, Li, Mg and Na in LYSO were 1. 0, 3. 0, 0. 02, 0. 01, 0. 02 and 1. 0 mg/kg, respectively.%采用液体阴极辉光放电原子发射光谱( Solution-cathode glow discharge-atomic emission spectrometry, SCGD-AES)法测定了硅酸钇镥(Lutetium-Yttrium Orthosilicate, LYSO)闪烁晶体材料中痕量元素 Ca,Fe, K, Li, Mg和Na。最佳实验条件是溶液pH为1的HNO3,直流电压为1080 V,溶液流速为2.0 mL/min。本方法对LYSO基体的耐盐量为10 g/L。硅酸钇镥晶体使用HNO3, HF, HClO4溶解后经SCGD-AES分析测定,结果同电感耦合等离子体发射光谱( Inductively coupled plasma-atomic emission spectroscopy, ICP-AES)和电感耦合等离子体质谱( Inductively coupled plasma-mass spectroscopy, ICP-MS)分析结果比对,具有较好的一致性。在运用SCGD-AES对LYSO的测定中,未观察到Lu、Y元素的激发谱线,因此测定LYSO中痕量元素时测定的光谱干扰少,Ca, Fe, K, Li, Mg和Na的检出限分别为:1.0,3.0,0.02,0.01,0.02和1

  10. Determination of atomic number and composition of human enamel

    International Nuclear Information System (INIS)

    The teeth are organs of complicated structure that consist, partly, of hard tissue containing in its interior the dental pulp, rich in vases and nerves. The main mass of the tooth is constituted by the dentine, which is covered with hard tissues and of epithelial origin called enamel. The dentine of the human teeth used in this work were completely removed and the teeth were cut with a device with a diamond disc. In this work the chemical composition of the human enamel was determined, which showed a high percentage of Ca and P, in agreement with the results found in the literature. The effective atomic number of the material and the half-value layer in the energy range of diagnostic X-ray beams were determined. Teeth could be used to evaluated the public's individual doses as well as for retrospective dosimetry what confirms the importance of their effective atomic number and composition determination. (author)

  11. 电感耦合等离子体原子发射光谱法同时测定饮用水的硬度和碱度%Simultaneous determination of the hardness and alkalinity in drinking water by inductively coupled plasma atomic emission spectrometry

    Institute of Scientific and Technical Information of China (English)

    霍建中; 段旭川

    2013-01-01

    The feasibility of simultaneous determination of hardness and alkalinity of drinking water by inductively coupled plasma atomic emission spectrometry (ICP-AES) was studied.the water sample was acidified off-line with diluted hydrochloric acid.The bicarbonates in water sample were in-situ converted into carbon dioxide,which was also dissolved in original water.Then,the solution was sampled by conventional single tube of inductively coupled plasma atomic emission spectrometer.The simultaneous sampling of CO2,Ca and Mg was realized at relatively low atomizer pressure.Among them,CO2 was sampled in gas state,while Ca and Mg were sampled in atomizing state.In this study,the bicarbonates with low sampling efficiency in atomizing method were converted into gas carbon dioxide,which had high sampling efficiency,thus the determination sensitivity of carbon was increased,realizing the accurate determination.The measured content of inorganic carbon was converted to the content of bicarbonates,so the alkalinity of drinking water was obtained.Meanwhile,the content of Ca and Mg was converted to the content of calcium carbonate to calculate the hardness of water.Under the optimal experimental conditions,i.e.,atomizer pressure of 241.3 kPa and dilution ratio of 5for water sample,the hardness and alkalinity of drinking water were simultaneously determined by this method.The found results were consistent with those obtained by titration method.%研究了使用电感耦合等离子体原子发射光谱法(ICP-AES)同时测定饮用水的硬度和碱度可行性.通过用稀盐酸离线酸化水样,使水样中的碳酸氢根原位转化为二氧化碳并继续溶解在原水中,然后使用ICP-AES仪器上常规的单管吸取溶液,在比较低的雾化器压力下实现了CO2、Ca、Mg的同时进样.其中CO2属于气态进样,而钙、镁属于雾化进样.由于方法将雾化法进样效率低的碳酸氢根转化成进样效率高的二氧化碳气态,因此碳的测定灵敏

  12. Determinants and predictability of global wildfire emissions

    Directory of Open Access Journals (Sweden)

    W. Knorr

    2012-08-01

    Full Text Available Biomass burning is one of the largest sources of atmospheric trace gases and aerosols globally. These emissions have a major impact on the radiative balance of the atmosphere and on air quality, and are thus of significant scientific and societal interest. Several datasets have been developed that quantify those emissions on a global grid and offered to the atmospheric modelling community. However, no study has yet attempted to systematically quantify the dependence of the inferred pyrogenic emissions on underlying assumptions and input data. Such a sensitivity study is needed for understanding how well we can currently model those emissions and what the factors are that contribute to uncertainties in those emission estimates.

    Here, we combine various satellite-derived burned area products, a terrestrial ecosystem model to simulate fuel loads and the effect of fire on ecosystem dynamics, a model of fuel combustion, and various emission models that relate combusted biomass to the emission of various trace gases and aerosols. We carry out simulations with varying parameters for combustion completeness and fuel decomposition rates within published estimates, four different emissions models and three different global burned-area products. We find that variations in combustion completeness and simulated fuel loads have the largest impact on simulated global emissions for most species, except for some with highly uncertain emission factors. Variation in burned-area estimates also contribute considerably to emission uncertainties. We conclude that global models urgently need more field-based data for better parameterisation of combustion completeness and validation of simulated fuel loads, and that further validation and improvement of burned area information is necessary for accurately modelling global wildfire emissions. The results are important for chemical transport modelling studies, and for simulations of biomass burning impacts on the

  13. 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.

  14. 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

  15. 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.

  16. Extraction-atomic-absorption determination of vanadium in salt liquors

    International Nuclear Information System (INIS)

    An extraction-atomic-absorption method to determine 0.1-0.8 mg/l vanadium in salt liquors containing 300 g/l NaCl is developed. To separate the basis extraction concentrating with hydroxyquinoline solution in chloroform with subsequent reextraction of vanadium at pH 9.4 is used. Results of vanadium determination in the salt liquer are as follows: vanadium determined x=0.22 mg/l, n=10, ssub(x)=0.045 mg/l, confidence range (at α=0.95)-(0.22+-0.03) mg/l, relative standard deviation is 0.20

  17. Determination of cadmium in aluminium by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    A direct method for the determination of cadmium in elemental aluminium is described. Metal samples are dissolved in diluted hydrochloric acid and cadmium is determined by atomic absorption spectrometry in an air-acetylene flame. Interference by non-specific absorption observed at the analytical wavelength incorrected for by means of a non-absorbing line emitted by the hollow-cathode lamp. Relatively large amounts of arsenic do not interfere. The minimun determinable concentration of cadmium for this procedure is 2-3 ppm, expressed on aluminium basis. (author)

  18. 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 ...

  19. 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...

  20. Determination of lead traces in water and liqueurs by derivative atom trapping flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Sun, H. [Department of Chemistry, Hebei University, Baoding, 071002 (China); Yang Lili [Department of Chemistry, Hebei University, Baoding, 071002 (China); Zhang Deqiang [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing (China); Wang Weixiao [Department of Chemistry, Hebei University, Baoding, 071002 (China); Sun Jianmin [Department of Chemistry, Hebei University, Baoding, 071002 (China)

    1997-07-01

    A new method for the direct determination of lead traces using derivative atom trapping flame atomic absorption spectrometry (DAT-FAAS) with an improved water-cooled stainless steel trapping equipment in an air-acetylene flame was investigated. The optimum conditions concerning the sensitivity were studied. For a 1 min collection, the characteristic concentration (given as derivative absorbance of 0.0044) and the detection limit (3s) were 1.4 ng/mL and 0.27 ng/mL, respectively. This is 361 and 74-fold better than those of the conventional flame atomic absorption spectrometry (FAAS) and comparable to those of graphite furnace atomic absorption spectrometry (GFAAS). The detection limit and sensitivity of DAT-FAAS for a 3 min collection time were 2 and 3 orders of magnitude higher than those of conventional FAAS. The present method was applied to the determination of lead in water and liqueur samples with a recovery range of 94-108% and a relative standard deviation of 3.5-5.6%. (orig.). With 5 figs., 5 tabs.

  1. Flame atomic absorption determination of ultra trace zinc after preconcentration

    International Nuclear Information System (INIS)

    Complete text of publication follows. The determination of toxic metal ions is becoming increasingly important because of the increased interest in environmental samples including water, soil, plant, etc. Although flame atomic absorption spectrometry is widely used because of its low cost, its sensitivity is usually insufficient for the low concentrations found in environmental samples. Matrix interferences are another problem in atomic absorption spectrometric determinations of trace elements. Solving these problems requires a preconcentration and a matrix elimination step (A. Uzun et al., Talanta, 54, (2001)197). Zinc is a biologically essential micronutrient, and coordinates with macromolecules as a cofactor to confer catalytic function of structural integrity. Such metalloproteins have been implicated in diverse functions ranging from protein, nucleic acid, carbohydrate, and lipid metabolism, to gene transcription (B.L. Vallee et al., Physio. Revs, 73:1 (1993) 99). Zinc is frequently present at trace level in cadmium and their compounds. Numerous methods have been published for such determination. However, they are not simple and usually require extensive and laborious steps for separation of zinc from cadmium (C.W. McDonald et al., Anal. Chem., 46 (1974) 300). In this work a simple, reliable and rapid method for determination of ultra trace zinc by flame atomic absorption spectrometry is presented. The limit of detection (LOD), of the proposed method for the determination of Zn2+ ion was studied under the optimal experimental conditions. The LOD obtained from CLOD=KbSbm-1 (J.D. Ingle et al., Spectrochemical Analysis, Prentice Hall, Englewood Cliffs, NJ, 1988) for a numerical factor Kb=3 is 120 ng.L-1.The method was successfully applied for the determination of zinc ion in different samples, especially determination of ultra trace amount of zinc in waters and plants.

  2. Determination of trace elements in paints by direct sampling graphite furnace atomic absorption spectrometry

    International Nuclear Information System (INIS)

    A direct sampling graphite furnace atomic absorption spectrometric (DS-GFAAS) method for the determination of Cd, Pb, Cr, Ni, Co and Cu in paints has been developed. Serigraphy, acrylic and tattoo paints were analysed. Approaches like pyrolysis and atomization temperatures, modifiers and sample mass introduced in the atomizer were studied. Quantification was performed using calibration curves measured with aqueous standard solutions pipetted onto the platform. The sample mass introduced in the graphite tube ranged from 0.02 to 8.0 mg. Palladium was used as modifier for Cd, Pb and Cu, while Mg(NO3)2 was used for Co. For Ni determination, the graphite platform was covered with carbon powder. The characteristic masses of Cd, Pb, Cr, Ni, Co and Cu were 1.4, 22.5, 7.9, 11.0, 9.6 and 12.5 pg, while the limits of detection were 0.0004, 0.001, 0.03, 0.22, 0.11 and 0.05 μg g-1 of Cd, Pb, Cr, Ni, Co and Cu, respectively. The accuracy was determined by comparison of the results with those obtained by inductively coupled plasma mass spectrometry (ICP-MS) and graphite furnace atomic absorption spectrometry (GFAAS), using liquid sampling of digests. For matrix characterization, major and minor elements (Al, Mg, Ba, Ca, Cr, Cu, Pb, Sr, Ti and Mg) were determined by inductively coupled plasma optical emission spectrometry (ICP OES)

  3. Direct atomic absorption determination of cadmium in solid foodstuffs

    International Nuclear Information System (INIS)

    A procedure is proposed for the direct rapid determination of cadmium in solid foodstuff samples by atomic absorption analysis using a modified Lvov furnace equipped with a graphite partition filter. The use of this furnace eliminates the step of transferring a solid sample to solution, allows calibration solutions to be employed properly in the direct analysis of solid samples, suppresses unselective absorption, and substantially shortens the time of analysis. 12 refs., 3 figs., 2 tabs

  4. 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...

  5. Hydrogen atom density in narrow-gap microwave hydrogen plasma determined by calorimetry

    Science.gov (United States)

    Yamada, Takahiro; Ohmi, Hiromasa; Kakiuchi, Hiroaki; Yasutake, Kiyoshi

    2016-02-01

    The density of hydrogen (H) atoms in the narrow-gap microwave hydrogen plasma generated under high-pressure conditions is expected to be very high because of the high input power density of the order of 104 W/cm3. For measuring the H atom density in such a high-pressure and high-density plasma, power-balance calorimetry is suited since a sufficient signal to noise ratio is expected. In this study, H atom density in the narrow-gap microwave hydrogen plasma has been determined by the power-balance calorimetry. The effective input power to the plasma is balanced with the sum of the powers related to the out-going energy per unit time from the plasma region via heat conduction, outflow of high-energy particles, and radiation. These powers can be estimated by simple temperature measurements using thermocouples and optical emission spectroscopy. From the power-balance data, the dissociation fraction of H2 molecules is determined, and the obtained maximum H atom density is (1.3 ± 0.2) × 1018 cm-3. It is found that the H atom density increases monotonically with increasing the energy invested per one H2 molecule within a constant plasma volume.

  6. Determination of gold by chemical hydride generation atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Complete text of publication follows. The chemical vapour generation (CVG) of transition and noble metals opens a novel route for introduction of these elements into atomic spectrometric sources. It can be accomplished by merging an acidic sample with tetrahydroborate reductant solution (Y. L. Feng et al., J. of Anal. At. Spectrom., 20 (2005) 255-265). There have been some studies for determination of Au; however, only mg L-1 levels of gold have been determined by CVG - Atomic Absorption Spectrometry (AAS) (G. Ertas et al., Applied Spectroscopy, 60 (2006) 423-429). Volatile Au species were generated in flow injection arrangement from acid environment in presence of surfactants. The core of the system is a mixing manifold based on 3 concentric capillaries (T. Matousek et al., J. of Anal. At. Spectrom., 18 (2003) 487-494) protruding into the glass gas-liquid separator (glass, volume 3 ml). Optimum flow rate of Ar as a carrier gas was found at 240 mL/min. The study of generation parameters as well as the use of reaction modifiers-surfactants and dithiocarbamate- will be presented. Quartz tube multiatomizer for AAS was employed for atomization. Atomization conditions including composition of carrier gases and their flow rates and atomization temperature were optimized. 900 deg C was found as the optimum atomization temperature; over 900 deg C, peak area of Au signal decreased; in addition, peak shape was altered. A sharp maximum of 6 mL/min oxygen as the outer gas was observed. Another important point was that hydrogen-rich atmosphere caused signal depression. Analytical performance of this approach to generation and atomization will be discussed and perspectives of its future will be outlined. This work was supported by the GA ASCR (grant No. A400310507 and IAA400310704) and Institute of Analytical Chemistry of the ASCR, v.v.i. (project no. AV0Z40310501). This work also was supported from OYP (Faculty Development Program) from the Middle East Technical University

  7. 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...

  8. 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.

  9. 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.)

  10. Direct experimental determination of the atomic structure at internal interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Browning, N.D. [Oak Ridge National Lab., TN (United States)]|[Illinois Univ., Chicago, IL (United States); Pennycook, S.J. [Oak Ridge National Lab., TN (United States)

    1995-07-01

    A crucial first step in understanding the effect that internal interfaces have on the properties of materials is the ability to determine the atomic structure at the interface. As interfaces can contain atomic disorder, dislocations, segregated impurities and interphases, sensitivity to all of these features is essential for complete experimental characterization. By combining Z-contrast imaging and electron energy loss spectroscopy (EELS) in a dedicated scanning transmission electron microscope (STEM), the ability to probe the structure, bonding and composition at interfaces with the necessary atomic resolution has been obtained. Experimental conditions can be controlled to provide, simultaneously, both incoherent imaging and spectroscopy. This enables interface structures observed in the image to be interpreted intuitively and the bonding in a specified atomic column to be probed directly by EELS. The bonding and structure information can then be correlated using bond-valence sum analysis to produce structural models. This technique is demonstrated for 25{degrees}, 36{degrees} and 67{degrees} symmetric and 45{degrees} and 25{degrees} asymmetric [001] tilt grain boundaries in SrTiO{sub 3} The structures of both types of boundary were found to contain partially occupied columns in the boundary plane. From these experimental results, a series of structural units were identified which could be combined, using continuity of gain boundary structure principles, to construct all [001] tilt boundaries in SrTiO{sub 3}. Using these models, the ability of this technique to address the issues of vacancies and dopant segregation at grain boundaries in electroceramics is discussed.

  11. Atomic absorption determination of yttrium in matallurgic materials

    International Nuclear Information System (INIS)

    Atomic absorption spectroscopy techniques have been developed for Y determination in Mg-, Cr-, Ni-, Ti base alloys. The lower limit of Y determination is 0.01%. The Sr amount equals 0.07 and 0.035 for the 0.01-0.1 and 0.1-1.0 mas.% ranges of Y concentration, respectively. The presence in solution of 0.5-5 M HCl, H2SO4 and HNO3 as well as of up to 1 mg/ml Fe, Co, Zr, Ce, Sn, Zn, Cu, Mo doesn't affect the analysis results

  12. Determinants and predictability of global wildfire emissions

    OpenAIRE

    Knorr, W.; V. Lehsten; A. Arneth

    2012-01-01

    Biomass burning is one of the largest sources of atmospheric trace gases and aerosols globally. These emissions have a major impact on the radiative balance of the atmosphere and on air quality, and are thus of significant scientific and societal interest. Several datasets have been developed that quantify those emissions on a global grid and offered to the atmospheric modelling community. However, no study has yet attempted to systematically quantify the dependence of the inferred pyrogenic ...

  13. Determination of lithium in coloured alcoholic beverages by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Complete text of publication follows. Lithium was first found in ashes from wine in 1878, and its presence was later confirmed by spectroscopy, but its determination in wine and beverages is not well documented, unlike the extensive research reported on other metals. Several methods can be implemented for determination of lithium, involving the use of atomic spectroscopy techniques. This paper reports on an analytical optimization to determine lithium by atomic absorption spectrometry (AAS). Good results in reproducibility, accuracy and precision were obtained. No significant interference was found. The method was applied for determination of lithium in six rum samples, eight brandy samples, four vermouth samples, eight whisky samples and two bourbon samples. The value of lithium content in samples ranges from 0,33 to 1,48 μg/ml. Recovery experiments were carried out in order to evaluate the accuracy of the method in samples determination. The values obtained ranges from 95,71% to 98%. The precision of the method in that samples determination was evaluated through variation coefficients. The values obtained ranges from 7,2% to 2,5%. The results have been statistically compared with those obtained using the Inductively Coupled Plasma Atomic Emission Spectrometry (ICP/AES) and reaches a 95% level of significance.

  14. 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.

  15. 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.

  16. 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

  17. 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)

  18. 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...

  19. Microwave digestion-inductively coupled plasma atomic emission spectrometry (ICP-AES) for the determination of Pb, As, Cd, Cu, Mg and other heavy metal elements in edible oil%微波消解-电感耦合等离子体法测定食用油中微量Pb、AS、Cd、Cu、等多种重金属元素

    Institute of Scientific and Technical Information of China (English)

    杨小媛; 范柯; 蔡羽嘉

    2013-01-01

    Objective:To establish microwave digestion plus inductively coupled plasma atomic emission spectrometric (ICP-AES) method for the simultaneous online determination of Pb,As,Cd,Cu,Mg and other heavy metal elements in edible oil.Methods:The edible oil sample was pretreated by direct microwave digestion and acid digestion respectively,then ICP-AES instrument was used for the determination of sensitivity,precision and accuracy of Pb,As,Cd,Cu,Mg and other heavy metal elements in both groups.Then the resulis of the two groups were compared.Results:The minimum detectable concentration is not statistically significant between microwave digestion group and acid digestion group.The correlation coefficient is 0.9998.The relative standard deviation is from 0.61% to 2.2% and the recovery rate is between 93% and 102%.Conclusion:The method of microwave digestionplus inductively coupled plasma atomic emission spectrometric (ICP-AES) can simultaneously determine multi heavy metals concentrations in edible oil rapidly and sensitively with high accuracy and precision.It is applicable for the determination of large quantities of edible oil.%目的:建立一种用微波消解-电感耦合等离子体法(ICP-AES)同时在线测定食用油中Pb、As、Cd、Cu、Mg等多种重金属元素方法.方法:食用油类样品直接经微波消解前处理后用ICP-AES仪测定其中Pb、As、Cd、Cu、Mg等多元素含量,并与酸消解前处理法进行测定结果的灵敏度、精密度及准确度比较.结果:本方法测定最低检出浓度与酸消解处理法无显著性差异,相关系数r可达0.9998,相对标准偏差0.61%~2.2%,加标回收率93%~102%.结论:该方法能同时测定食用油中多种重金属元素含量,方法快速,灵敏,准确度高,精密度好,适用于大批量食用油实际样品的检测需求.

  20. Spectrofluorimetric, Atomic Absorption Spectrometric and Spectrophotometric Determination of Some Fluoroquinolones

    Directory of Open Access Journals (Sweden)

    Hesham Salem

    2005-01-01

    Full Text Available Simple, accurate, sensitive and selective spectrofluorimetric, atomic absorption spectrometric and spectrophotometric methods are described for the quantitative determination of ten fluoroquinolones (amifloxacin, ciprofloxacin hydrochloride, difloxacin hydrochloride, enoxacin, enrofloxacin, lomefloxacin hydrochloride, levofloxacin, norfloxacin, ofloxacin and pefloxacin mesylate. The first method was a spectrofluorimetric method in which samples of the studied drugs in 0.1 N H2SO4 showed native fluorescence at 450 nm when excitation was at 290 nm. The calibration graph was rectilinear from 0.3-1.4 μg mL-1 (method I. Cobalt sulphate was used for precipitation of the ion associates formed from the reaction with the cited drugs. The formation and solubility of the solid complexes at the optimum conditions of pH and ionic strength values have been studied. The method depends on direct determination of the ions in the precipitate or indirect determination of the ions in the filtrate by atomic absorption spectroscopy. The optimum conditions for precipitation were carefully studied. Rectilinear calibration graphs were obtained in the range of 3-30 μg mL-1 for each of the investigated drugs. The molar ratios of the formed chelats were determined by Job's method and their association constants were also calculated (method II. Ammonium vanadate was used for the spectrophotometric determination of the selected fluoroquinolones by oxidation in sulphuric acid medium resulting in the development of a greenish blue colour measured at 766 nm which was attributed to the vanadium (IV produced by reduction of vanadium (V by the selected drugs. The optimum conditions for heating time, reagent concentration and sulphuric acid concentration were carefully studied. The accuracy and precision of the proposed method was confirmed by estimating five or six replicates within Beer's law limits were obtained in the range 10-40 μg mL-1 for each of the investigated drugs

  1. 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.

  2. 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.

  3. Atomic spectroscopy and highly accurate measurement: determination of fundamental constants

    International Nuclear Information System (INIS)

    This document reviews the theoretical and experimental achievements of the author concerning highly accurate atomic spectroscopy applied for the determination of fundamental constants. A pure optical frequency measurement of the 2S-12D 2-photon transitions in atomic hydrogen and deuterium has been performed. The experimental setting-up is described as well as the data analysis. Optimized values for the Rydberg constant and Lamb shifts have been deduced (R = 109737.31568516 (84) cm-1). An experiment devoted to the determination of the fine structure constant with an aimed relative uncertainty of 10-9 began in 1999. This experiment is based on the fact that Bloch oscillations in a frequency chirped optical lattice are a powerful tool to transfer coherently many photon momenta to the atoms. We have used this method to measure accurately the ratio h/m(Rb). The measured value of the fine structure constant is α-1 = 137.03599884 (91) with a relative uncertainty of 6.7*10-9. The future and perspectives of this experiment are presented. This document presented before an academic board will allow his author to manage research work and particularly to tutor thesis students. (A.C.)

  4. 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

  5. ICP-AES法测定螺旋藻中的杂质元素铝%Determination of impurity element aluminum in spirulina by inductively coupled plasma atomic emission spectrometry

    Institute of Scientific and Technical Information of China (English)

    林易晨

    2015-01-01

    探讨用ICP-AES技术测定螺旋藻中杂质元素铝,并对共存元素光谱干扰及其消除进行研究,所建立的分析方法,快速、结果准确,有较好的精密度和准确度,适用于螺旋藻中铝的测定.%The determination of impurity element aluminum in spirulina by ICP-AES was studied. The spectral interference and elimination of coexisting elements was investigated. The established analytical method is fast ,precise and accurate. The method is applicable to the determination of aluminum content in spirulina.

  6. 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.

  7. Determination of forty trace impurity elements in uranium compounds using inductively coupled plasma atomic emission spectrography with end-on viewing of the ICP and a medium-size spectrograph

    International Nuclear Information System (INIS)

    A unified spectral analytical method is outlined which can determine up to 40 trace impurities elements in uranium compounds. This can be used to analyse nuclear fuels. The method uses a reversed-phase partition chromatographic technique to separate the impurities from the uranium matrix and end-on viewing of an inductively coupled plasma (ICP) using a medium-sized quartz spectrograph. The experimental method, calibration and results of recovery tests are given. The method uses a smaller sample (approx. 1/40) than the ASTM specified analytical procedure. (UK)

  8. 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.)

  9. 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

  10. Determination of metals in atmospheric particulates using atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Nineteen trace metals in atmospheric samples have been determined by atomic absorption spectrometry, using a graphite furnace for most elements. Paper filters have been used to collect air samples. The sample preparation procedure involves the removal of organic matter and the conversion of the metals to soluble salts by ashing the filters in an oxygen plasma at 125 deg C for 6 h. and by subsequent dissolution in HN03HCl solution. The sensitivities achieved are in the range of 2,5.10-5 and 6,3.10-3 μg/m3, for an air volume of 2000 m3. (author)

  11. Impurities determination of uranium metal flame spectrophotometry and atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    The atomic absorption flame spectrophotometry has been applied to the determination of chromium, copper, iron, lead, manganese and nickel in the metal of uranium. The first step to be done is to dissolve the uranium sample in nitric acid and then the uranium is extracted by a tributylphosphate-carbon tetrachloride solution. The aqueous phase which contains the chromium, copper, iron, lead, manganese and nickel is aspirated into an airacetylene flame. The results of this method are compared with the results of emission spectrographic method. It is found that this technique is competative to other methods in the sense that it is quite fast and accurate. (author)

  12. 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.

  13. 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

  14. Atomic absorption spectrometric determination of mineral elements in mammalian bones

    International Nuclear Information System (INIS)

    The phosphorus content of the major bones of male and female selected mammals was determined using the yellow vanadomolybdate colorimetric method. For each animal, the bone with the highest phosphorus content was used as pilot sample. Varying concentrations of strontium were added to solutions of the ashed pilot samples to minimize phosphorus interference in the determination of calcium and magnesium using flame atomic absorption spectrophotometry operated on the air-acetylene mode. At least 6,000 ppm (0.6%) of strontium was required to give optimum results for calcium. The amount of magnesium obtained from the analysis was not affected by the addition of strontium. With the incorporation of strontium in the sample solution, all elements of interest can be determined in the same sample solution. Based on this, a procedure is proposed for the determination of calcium and other elements in bones. Average recoveries of spiked calcium and magnesium were 97.85% and 98.16%, respectively at the 95% confidence level. The coefficients of variation obtained for replicate determinations using one of the samples were 0.00% for calcium, lead and sodium, 2.93% for magnesium, 3.27% for iron and 3.92% for zinc at the concentration levels found in that sample. Results from the proposed procedure compared well with those from classical chemical methods at the 95% confidence level. It is evident that calcium phosphorus, magnesium and sodium which are the most abundant elements in the bones are distributed in varying amounts both in the different types of bones and different animal species, although the general trend is Ca > P > Na > Mg for each bone considered. The calcium - phosphorus ratio is generally 3:1. The work set out to propose an atomic absorption spectrometric method for the multi-element analysis of mammalian bones with a single sample preparation and to study the distribution pattern of these elements in the bones. (Author)

  15. 直读光谱法测定超低碳钢板的碳含量%Determination of Carbon in Steel Sheets of Ultra-Low Carbon Content by Direct-Reading Atomic Emission Spectrography

    Institute of Scientific and Technical Information of China (English)

    李吉; 牟正明; 包雪鹏; 孙国燕

    2014-01-01

    用一系列含碳量(wC )在0.002%~0.03%范围内的标准物质在直读光谱仪上按选定的工作条件测定各样品的碳量。根据所得每一样品的一系列测定值以及各项统计量,分析并判断了直读光谱法在测定钢板中超低碳含量的准确度和精密度水平。试验结果表明:①测定结果的准确度受样品的基体背景及仪器标准化条件的影响,引入了系统误差;据此建议选择与待测样品基体匹配的标准物质校准仪器并选择合理的仪器标准化条件。②在上述含碳量范围内,所得测定值的S%值(包括10次测定和5次测定的计算值)差异较小,其极值之差为3×10-4%,但对相对标准偏差有显著影响,其最低值在2%左右,而最高值达21%。③在所选定的测定条件下,对碳含量在10-5数量级的样品而言,准确度或系统误差的波动范围在±1×10-4%范围内。%A set of CRM′s with values of wC% ranged from 0.002% to 0.03% was analyzed for their carbon contents with a direct reading AES under the specified working conditions.A statistical study was made based on data obtained,i.e.,the values ofwC% of each of the CRM′s and their statistics and levels of accuracy and precision of the method for determination of ultra-low carbon in steel sheets were assessed.It was shown that:① accuracy of the analytical results was affected by the matrix background of individual sample and standardization condition of the instrument,it is advised to choose CRM′s having similar composition with the sample for calibration of instrument and rational condition of standardization;② in the range of carbon content concerned,only small differences among values of S% (either for n=5 or 10)were obtained with difference of extreme values of 3×10-4 %,but significant differences of values of RSD% were observed with min.and max.values of 2% and 21% respectively;and ③ range of fluctuation of systematic

  16. 直读光谱法测定超低碳钢板的碳含量%Determination of Carbon in Steel Sheets of Ultra-Low Carbon Content by Direct-Reading Atomic Emission Spectrography

    Institute of Scientific and Technical Information of China (English)

    李吉; 牟正明; 包雪鹏; 孙国燕

    2014-01-01

    A set of CRM′s with values of wC% ranged from 0.002% to 0.03% was analyzed for their carbon contents with a direct reading AES under the specified working conditions.A statistical study was made based on data obtained,i.e.,the values ofwC% of each of the CRM′s and their statistics and levels of accuracy and precision of the method for determination of ultra-low carbon in steel sheets were assessed.It was shown that:① accuracy of the analytical results was affected by the matrix background of individual sample and standardization condition of the instrument,it is advised to choose CRM′s having similar composition with the sample for calibration of instrument and rational condition of standardization;② in the range of carbon content concerned,only small differences among values of S% (either for n=5 or 10)were obtained with difference of extreme values of 3×10-4 %,but significant differences of values of RSD% were observed with min.and max.values of 2% and 21% respectively;and ③ range of fluctuation of systematic error (or of accuracy)for determination of carbon content at the magnitude of 10-5 attained to values ranged in ±1×10-4 %.%用一系列含碳量(wC )在0.002%~0.03%范围内的标准物质在直读光谱仪上按选定的工作条件测定各样品的碳量。根据所得每一样品的一系列测定值以及各项统计量,分析并判断了直读光谱法在测定钢板中超低碳含量的准确度和精密度水平。试验结果表明:①测定结果的准确度受样品的基体背景及仪器标准化条件的影响,引入了系统误差;据此建议选择与待测样品基体匹配的标准物质校准仪器并选择合理的仪器标准化条件。②在上述含碳量范围内,所得测定值的S%值(包括10次测定和5次测定的计算值)差异较小,其极值之差为3×10-4%,但对相对标准偏差有显著影响,其最低值在2%左右,而最高值达21%。③在所选定的测

  17. Micro-determination of ytterbium with electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    This communication reports the use of a pyrolytic graphite coated tube, lined with tantalum-tungsten, and a local made atomic absorption spectrometer (Model WFD-Y3) for the determination of small amount Yb in pure Y2O3 and mixed rare earth oxides. It is found that the method proposed is sensitive, reproducible and simple in manipulation. Even as low as 0.2 μg Yb in one gram sample (n x 10-7) can be determined directly without pre-concentration. It is found experimentally that the optimum condition for drying is at 150 deg C. for 20 sec, ashing at 1000 deg C. for 20 sec and atomization at 2770 deg C. for 12 sec. Within the range 1.0-18ng Yb/ml the calibration curve of Yb is linear. Before injecting into the tube, the acidity of the sample solution should be ajusted to 0.1 to 2 M with nitric or hydrochloric acid. For 5ng Yb/ml, Al(III), Ca(II) and La(III) interference, when their amount present is 50 μg/ml or more. On the other hand, Cu(II), Fe(III), Mg(II), K(I) and Y(III) in amount up to 1 mg/ml do not interfere

  18. Inverse Mapping of Polarised Optical Emission from Pulsars : Basic Formulation and Determination of Emission Altitude

    OpenAIRE

    Donald, John Mc; Connor, Padraig O'; de Burca, Dairmaid; Golden, Aaron; Shearer, Andy

    2011-01-01

    We present an inverse mapping approach to determining the emission height of the optical photons from pulsars, which is directly constrained by empirical data. The model discussed is for the case of the Crab pulsar. Our method, using the optical Stokes parameters, determines the most likely geometry for emission including magnetic field inclination angle ($\\alpha$), observers line of sight angle ($\\chi$) and emission height. We discuss the computational implementation of the approach, along w...

  19. 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.

  20. 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.

  1. Determination of soluble lead in paint coating on wood furniture by inductively coupled plasma atomic emission spectrometry%电感耦合等离子体原子发射光谱法测定木家具油漆涂层中的可溶性铅

    Institute of Scientific and Technical Information of China (English)

    司银平; 海凌超; 杨建华

    2011-01-01

    涂料中的重金属Pb会损害人体骨髓造血系统和神经系统,并对儿童的生长发育产生不利影响.目前大部分标准指定采用原子吸收法测定涂料中的重金属;但该方法操作繁琐、检测周期长.为此,采用电感耦合等离子体原子发射光谱法(ICP-AES;具有分析速度快、准确度高、可同时检测多种元素等优点)测定木家具油漆涂层中可溶性Pb的含量,探讨了温度、震荡时间及酸度对可溶性Pb含量测量结果的影响.结果表明,随着温度的升高,可溶性Pb含量明显升高;震荡时间超过0.5h后对可溶性Pb含量测定的影响较小;当盐酸浓度为0.14mol/L 时,油漆涂层中的可溶性Pb几乎能被完全溶解.%Heavy metal Pb in paint coatings causes damage to bone marrow hematopoietic system and nervous system of human and has unfavorable effect on the growth and development of children. Currently, atomic absorption spectrometric method is adopted in a majority of standards as the appointed method for determining heavy metals in paints, but it is tedious and requires a long test cycle. Thus inductively coupled plasma atomic emission spectrometric method (ICP-AES; having advantages such as rapid analysis, high accuracy and ability to simultaneously detect multiple elements) was adopted to determine soluble Pb in furniture made of wood. The factors affecting the determination of soluble Pb content, such as temperature, shock time and acidity, were investigated. Results show that the content of soluble Pb tends to significantly increase with increasing temperature. At a level of above 0. 5 h, shock time had little influence on the determination of soluble Pb content. When the concentration of HC1 was 0.14 mol/L, Pb in the paint coatings was almost completely dissolved.

  2. Determination of polarization relaxation times of atomic levels

    International Nuclear Information System (INIS)

    Probe signal polarization plane rotation in the field of an advanced in time intensive pulse is investigated taking into account optical pumping of atoms in a resonant medium. It is shown that the polarization plane modification is due to two processes: atoms radiation relaxation and collisions induced by atom magnetic sublevels redistribution. This method enables to measure large times of atoms collisions on the background of short times of the atom radiation decay

  3. Temperature and emissivity determination of liquid steel S235

    International Nuclear Information System (INIS)

    Temperature determination of liquid metals is difficult but a necessary tool for improving materials and processes such as arc welding in the metal-working industry. A method to determine the surface temperature of the weld pool is described. A TIG welding process and absolute calibrated optical emission spectroscopy are used. This method is combined with high-speed photography. 2D temperature profiles are obtained. The emissivity of the radiating surface has an important influence on the temperature determination. A temperature dependent emissivity for liquid steel is given for the spectral region between 650 and 850 nm. (paper)

  4. Determination of Trace Elements in Pomegranate Peel and Pomegranate Seed by Inductively Coupled Plasma-Atomic Emission Spectrometry with Microwave Digestion%微波消解-等离子体原子发射光谱法测定石榴皮和石榴籽中微量元素

    Institute of Scientific and Technical Information of China (English)

    吴佳; 解成喜

    2012-01-01

    采用微波消解样品,电感耦合等离子体原子发射光谱法(ICP-AES)测定了石榴皮和石榴籽中K、Ca、Mg、Fe、A1、Cu、Zn、Mn、Na、Li、P、S12种微量元素的含量.在最佳仪器工作条件下,各元素的加标回收率为91.8%~103.1%,相对标准偏差(RSD)为0.70%~2.68%.实验结果可为石榴皮和石榴籽中微量元素与其药效的相关性提供科学依据.%The trace elements of K,Ca,Mg,Fe, Al,Cu,Zn,Mn,Na,Li,P and S in the pomegranate peel and pomegranate seed were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) with microwave digestion. Under the optimal working conditions of the equipment, the element recoveries of standard addition are 91. 8% ~ 103. l%,and the relative standard deviations (RSDs) are 0. 70%~2. 68%.

  5. 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

  6. Determination of antimony by using tungsten trap atomic absorption spectrometry

    International Nuclear Information System (INIS)

    An electrically heated tungsten coil was used as a trap in the determination of antimony. The technique consists of three steps. Initially, SbH3 is formed by hydride generation procedure; then the analyte species in vapor form are transported to W-coil trap heated at 370 deg. C. Following the preconcentration step, the trap is heated to 895 deg. C; analyte species are revolatilized and transported to the flame-heated quartz atom cell where atomization and the formation of signal take place. The experimental parameters were optimized both for trap and no-trap studies. The most important experimental parameters are concentrations of HCl and NaBH4 solutions, H2 and Ar gas flow rates, and collection and revolatilization temperatures of W-coil. Accuracy was tested using a certified reference material, waste water EU-L-1. Limit of detection for the system is 16 ng l-1 using a sample of 36 ml collected in 4.0 min. Enhancement factor in sensitivity was 17

  7. Determination of molybdenum in flotation concentrates by atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    Molybdenum was determined by atomic absorption spectrophotometry in 0.05 N ammoniacal solution after the decomposition of the concentrate with aqua regia. Negros ore from Philippines was used as a flotation feed, which contained chalcopyrites and calcium-magnesium minerals. Among the metals tested copper, iron and the alkaline earths interfered. Less than 50 ppm of copper yielded lower results for molybdenum. Higher results came out with more than 50 ppm of copper. In the presence of iron and citric acid (0.4 g/100 ml) which is a suppressor for hydroxide formation, a lower estimation resulted for molybdenum. Calcium interfered, lower results by 2 and >10% being obtained with respective 2.5 and 20 ppm of calcium. More than 20 ppm of magnesium behaved similarly. Sodium sulfate (0.5 g/100 ml) served as the suppressor for copper, iron and citric acid; 100 ppm each of copper and iron did not interfere in this way. Interferences due to calcium and magnesium (less than 60 ppm) was able to be masked by the addition of sodium silicate (200 ppm as silica). The analysis of flotation products and synthetic samples consisting of molybdenite, chalcopyrite, calcium chloride and magnesium sulfate revealed that the atomic absorption method can be applied to the analysis of the concentrates for molybdenum with an error of about 2%. (auth.)

  8. Cinchocaine hydrochloride determination by atomic absorption spectrometry and spectrophotometry.

    Science.gov (United States)

    Abdel-Ghani, Nour T; Youssef, Ahmed F A; Awady, Mohamed A

    2005-05-01

    Two sensitive spectrophotometric and atomic absorption spectrometric procedures have been developed for determination of cinchocaine hydrochloride (Cin.Cl) in pure form and in pharmaceutical formulation. The spectrophotometric method was based on formation of an insoluble colored ion-associate between the cited drug and tetrathiocyanatocobaltate (CoTC) or hexathiocyanatochromate (CrTC) which dissolved and extracted in an organic solvent. The optimal experimental conditions for quantitative extraction such as pH, concentration of the reagents and solvent were studied. Toluene and iso-butyl alcohol proved to be the most suitable solvents for quantitative extraction of Cin-CoTC and Cin-CrTC ion-associates with maximum absorbance at 620 and 555 nm, respectively. The optimum concentration ranges, molar absorptivities, Ringbom ranges and Sandell sensitivities were also evaluated. The atomic absorption spectrometric method is based on measuring of the excess cobalt or chromium in the aqueous solution, after precipitation of the drug, at 240.7 and 357.9 nm, respectively. Linear application ranges, characteristic masses and detection limits were 57.99-361.9, 50.40 and 4.22 microg ml(-1) of Cin.Cl, in case of CoTC, while 37.99-379.9, 18.94 and 0.81 microg ml(-1) in case of CrTC. PMID:15910814

  9. [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

  10. Ionization potential of neutral atomic plutonium determined by laser spectroscopy

    International Nuclear Information System (INIS)

    The ionization potential of the neutral plutonium atom, Pu i, has been determined by two- and three-step resonance photoionization observation of the threshold of ionization and of the Rydberg series. The Rydberg series were observed by field ionization as series that converge to the first ionization limit and as autoionizing series the converge to the second and to several higher convergence limits. The threshold and Rydberg series were obtained through a number of two- and three-step pathways. The photoionization threshold value for the 239Pu i ionization potential is 48 582(30) cm-1, and the more accurate value from the Rydberg series is 48 604(1) cm-1 or 6.0262(1) eV

  11. Determining Absorption, Emissivity Reduction, and Local Suppression Coefficients inside Sunspots

    OpenAIRE

    Ilonidis, Stathis; Zhao, Junwei

    2010-01-01

    The power of solar acoustic waves is reduced inside sunspots mainly due to absorption, emissivity reduction, and local suppression. The coefficients of these power-reduction mechanisms can be determined by comparing time-distance cross-covariances obtained from sunspots and from the quiet Sun. By analyzing 47 active regions observed by SOHO/MDI without using signal filters, we have determined the coefficients of surface absorption, deep absorption, emissivity reduction, and local suppression....

  12. 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

  13. 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

  14. 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

  15. Determination of metallic impurities in uranium compounds of nuclear purity by atomic absorption spectrophotometry with electrothermal atomization

    International Nuclear Information System (INIS)

    Atomic absorption spectrometry, with electrothermal atomization, has been used for the determination of Al, Cd, Cr, Fe, Mn and Ni in uranium oxide standards. The analysis were performed without sample dissolution and without uranium chemical separation. This technique is adequate for the qualification of uranium of nuclear purity according to the standard specifications. (Author)

  16. 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.

  17. 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.

  18. Determination of cadmium in biodiesel using microemulsion and electrothermal atomization atomic absorption spectrometry.

    Science.gov (United States)

    Lima, Adriana S; Silva, Deise G; Teixeira, Leonardo S G

    2015-01-01

    This work aimed to prepare biodiesel microemulsions for the subsequent quantification of cadmium via graphite furnace atomic absorption spectrometry (GFAAS). The biodiesel samples were prepared using n-propanol as an emulsifier, 10% (v/v) nitric acid as the aqueous phase, and biodiesel. Pseudoternary phase diagrams were constructed to determine the microemulsion region with the specified components. The optimized conditions for microemulsion formation were 57.6% (v/v) n-propanol, 21.2% (v/v) biodiesel, and 21.2% (v/v) nitric acid solution. The stability of the microemulsified system was investigated using aqueous and organic standards, and the system was found to be stable for at least 240 min. The applied pyrolysis and atomization temperatures were 800 and 2000 °C, respectively, and 5 μg of aluminum was used as the chemical modifier. The obtained limits of detection and quantification were 0.2 and 0.5 μg kg(-1), respectively, and the characteristic mass was 1.6 pg. The precision, expressed as the relative standard deviation (% R.S.D., n = 10), was 2.5% for a sample with a cadmium concentration of 6.5 μg kg(-1). The accuracy was determined from addition and recovery experiments, with results varying from 93 to 108% recovery. This study demonstrates that the proposed method based on the use of a microemulsion formation in sample preparation can be applied as an efficient alternative for the determination of cadmium in biodiesel by GFAAS. Cadmium determination in biodiesel samples of different origins (soybean, corn, cotton, and sunflower) was evaluated after acid digestion using the inductively coupled plasma-mass spectrometry (ICP-MS) technique, and the obtained results were compared to the results obtained using the proposed method. The paired t test (95% confidence level) did not show significant differences. The concentrations of cadmium found ranged from 5.3 to 8.0 μg kg(-1). PMID:25381584

  19. 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...

  20. 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)

  1. Determination of hydration film thickness using atomic force microscopy

    Institute of Scientific and Technical Information of China (English)

    PENG Changsheng; SONG Shaoxian; GU Qingbao

    2005-01-01

    Dispersion of a solid particle in water may lead to the formation of hydration film on the particle surface, which can strongly increase the repulsive force between the particles and thus strongly affect the stability of dispersions. The hydration film thickness, which varies with the variation of property of suspension particles, is one of the most important parameters of hydration film, and is also one of the most difficult parameters that can be measured accurately. In this paper, a method, based on force-distance curve of atomic force microscopy, for determining the hydration film thickness of particles is developed. The method utilizes the difference of cantilever deflection before, between and after penetrating the hydration films between tip and sample, which reflect the difference of slope on the force-distance curve. 3 samples, mica, glass and stainless steel, were used for hydration thickness determination, and the results show that the hydration film thickness between silicon tip and mica, glass and stainless steel are 30.0(2.0, 29.0(1.0 and 32.5(2.5 nm, respectively.

  2. 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)

  3. 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.

  4. 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.

  5. The determinants of CO2 emissions: empirical evidence from Italy

    OpenAIRE

    Cerdeira Bento, João Paulo

    2014-01-01

    This paper investigates major determinants of CO2 emissions in a small open economy such as Italy over the period 1960-2012 using Granger causality and cointegration methods to ascertain short-run and long-run relationships between emissions, trade openness and energy consumption. The research findings do not support a possible decoupling between economic growth and energy consumption, so that energy conservation policies are expected to have a negative impact on economic growth. Therefore, t...

  6. Molybdenum work function determined by electron emission microscopy.

    Science.gov (United States)

    Jacobson, D. L.; Campbell, A. E.

    1971-01-01

    A polycrystalline molybdenum sample was recrystallized and thermally stabilized. Quantitative measurements of the emission from each individual grain were obtained with an electron emission microscope. The effective work function for each grain was then calculated. The crystallographic orientation of each grain was determined by Laue back-reflection techniques. A polar plot of effective work function vs crystallographic orientation for the sample was constructed to provide a correlation between effective work function and crystallographic orientation.

  7. 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

  8. Studies in atomic-fluorescence spectroscopy-V The fluorescence characteristics and determination of antimony.

    Science.gov (United States)

    Dagnall, R M; Thompson, K C; West, T S

    1967-10-01

    Atomic-fluorescence of antimony may be generated in an air-propane flame by nebulizing aqueous solutions of antimony salts whilst irradiating the flame by means of a microwave-excited electrode-less discharge tube operating at 30 W. The strongest fluorescence is exhibited by the (4)S(11 2 ) --> (4)P(1 3 ) 2311 A resonance line and weaker signals are observed at the 2068 and 2176 A resonance lines and at four intercombination lines, at 2598, 2671, 2770 and 2878 A. A process of thermally assisted direct-line fluorescence is postulated to account for the otherwise inexplicable intensity of the 2598 A line emission. Atomic-fluorescence spectroscopy at 2176 A permits the determination of antimony in the range 0.1-120 ppm with a detection limit of 0.05 ppm. With the same equipment and source, the range of measurement for atomic-absorption was 6-120 ppm and the detection limit was 1 ppm. No interferences were observed from 100-fold molar amounts of Cd, Co, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, NH(4), Pb and Zn or from arsenate, chloride, nitrate, phosphate and sulphate. PMID:18960212

  9. Determinants of carbon dioxide emissions: Empirical evidence from 69 countries

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Susan Sunila [School of Accounting, Economics and Finance, Deakin University, 70 Elgar Road, Melbourne, Victoria (Australia)

    2011-01-15

    This study investigates the determinants of carbon dioxide emissions (CO{sub 2}) for a global panel consisting of 69 countries using a dynamic panel data model. To make the panel data analysis more homogenous, we also investigate the determinants of CO{sub 2} emissions for a number of sub-panels. These sub-panels are constructed based on the income level of countries. In this way, we end up with three income panels; namely, high income, middle income, and low income panels. The time component of our dataset is 1985-2005 inclusive. Our main findings are that trade openness, per capita GDP, and energy consumption, proxied by per capita electric power consumption and per capita total primary energy consumption, have positive effects on CO{sub 2} emissions. Urbanisation is found to have a negative impact on CO{sub 2} emissions in high income, middle income, and low income panels. For the global panel, only GDP per capita and per capita total primary energy consumption are found to be statistically significant determinants of CO{sub 2} emission, while urbanisation, trade openness, and per capita electric power consumption have negative effects on the CO{sub 2} emissions. (author)

  10. 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

  11. 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.

  12. MAGIA - using atom interferometry to determine the Newtonian gravitational constant

    International Nuclear Information System (INIS)

    We describe our experiment MAGIA (misura accurata di G mediante interferometria atomica), in which we will use atom interferometry to perform a high precision measurement of the Newtonian gravitational constant G. Free-falling laser-cooled atoms in a vertical atomic fountain will be accelerated due to the gravitational potential of nearby source masses (SMs). Detecting this acceleration with techniques of Raman atom interferometry will enable us to assign a value to G. To suppress systematic effects we will implement a double-differential measurement. This includes launching two atom clouds in a gradiometer configuration and moving the SMs to different vertical positions. We briefly summarize the general idea of the MAGIA experiment and put it in the context of other high precision G-measurements. We present the current status of the experiment and report on analyses of the expected measurement accuracy

  13. THE ATOMIC WEIGHTS COMMISSION AND ISOTOPIC ABUNDANCE RATIO DETERMINATIONS.

    Energy Technology Data Exchange (ETDEWEB)

    HOLDEN, N.E.

    2005-08-07

    Following Thomson's discovery of stable isotopes in non-radioactive chemical elements, the derivation of atomic weight values from mass spectrometric measurements of isotopic abundance ratios moved very slowly. Forty years later, only 3 1/2 % of the recommended values were based on mass spectrometric measurements and only 38% in the first half century. It might be noted that two chemical elements (tellurium and mercury) are still based on chemical measurements, where the atomic weight value calculated from the relative isotopic abundance measurement either agrees with the value from the chemical measurement or the atomic weight value calculated from the relative isotopic abundance measurement falls within the uncertainty of the chemical measurement of the atomic weight. Of the 19 chemical elements, whose atomic weight is based on non-corrected relative isotopic abundance measurements, five of these are two isotope systems (indium, iridium, lanthanum, lutetium and tantalum) and one is a three-isotope system (oxygen).

  14. 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...

  15. 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)

  16. 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.

  17. 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)

  18. Determination of trace sulfur and phosphorus in wolframite concentrate by inductively coupled plasma atomic emission spectrometry%电感耦合等离子体原子发射光谱法测定黑钨精矿中痕量硫磷

    Institute of Scientific and Technical Information of China (English)

    高小飞; 倪文山; 姚明星; 李贤珍

    2012-01-01

    以过氧化钠为熔剂在高温下熔融矿样,用酒石酸提取,在最佳的实验条件下,选用紫外区的180.669 nm和178.221 nm光谱线分别作为硫和磷的分析线,用电感耦合等离子体原子 发射光谱法(ICP-AES)同时测定了黑钨精矿中硫和磷.为了避免在酸性条件下产生的大量钨酸沉淀对硫、磷的吸附,加入了酒石酸络合钨.钨、铁、硅、锰、钙产生的基体效应通过选择较低的观测高度和基体匹配的方法克服.硫、磷的检出限分别为0.0070 mg/L和0.0048 mg/L,线性范围均为0.01~100 μg/mL.建立的方法用于标准样品的测定,测定结果与认定值吻合.样品分析结果的相对标准偏差(RSD)为1.7%~2.8%.%Under the optical experiment conditions,the spectral line of 178. 221nm and 180. 669 nm in ultraviolet band were selected as analytical lines of sulfur and phosphorus respectively, and sulfur and phosphorus in wolframite concentrate were determined simultaneously by inductively coupled plasma atomic emission spectrometry with sodium peroside as flux for melting mining sample at high temperature and tartaric acid as extractant. Tartaric acid was added for the complexation of tungsten in order to avoid the adsorption of sulfur and phosphors by large amount of tungstic acid precipitates which generated in acid condition. The matrix effect produced by tungsten, iron, silicon, manganese and calcium were overcome by selection of relatively low observation height and matrix matching method. The detection limit of sulfur and phosphorous was 0. 007 0 mg/L and 0. 004 8 mg/L,respectively, and the linear range was the same as 0. 01-100 μg/mL. The proposed method was applied for the determination of certified reference materials, and the determination results were consistent with the certified value. The relative standard deviations (RSDs) for sample analysis results were 1. 7%-2. 8%.

  19. 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...

  20. Determining the Leaf Emissivity of Three Crops by Infrared Thermometry

    Directory of Open Access Journals (Sweden)

    Chiachung Chen

    2015-05-01

    Full Text Available Plant temperature can provide important physiological information for crop management. Non-contact measurement with an infrared thermometer is useful for detecting leaf temperatures. In this study, a novel technique was developed to measure leaf emissivity using an infrared thermometer with an infrared sensor and a thermocouple wire. The measured values were transformed into true temperatures by calibration equations to improve the measurement accuracy. The relationship between two kinds of measurement temperatures and setting emissivities was derived as a model for calculating of true emissivity. The emissivities of leaves of three crops were calculated by the mathematical equation developed in this study. The mean emissivities were 0.9809, 0.9783, 0.981 and 0.9848 for Phalaenopsis mature and new leaves and Paphiopedilum and Malabar chestnut leaves, respectively. Emissivity differed significantly between leaves of Malabar chestnut and the two orchids. The range of emissivities determined in this study was similar to that in the literature. The precision of the measurement is acceptable. The method developed in this study is a real-time, in situ technique and could be used for agricultural and forestry plants.

  1. 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)

  2. 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:

  3. 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)

  4. Emission spectrographic determination of volatile trace elements in geologic materials by a carrier distillation technique

    Science.gov (United States)

    Barton, H.N.

    1986-01-01

    Trace levels of chalcophile elements that form volatile sulfide minerals are determined in stream sediments and in the nonmagnetic fraction of a heavy-mineral concentrate of stream sediments by a carrier distillation emission spectrographic method. Photographically recorded spectra of samples are visually compared with those of synthetic standards for the two sample types. Rock and soil samples may also be analyzed by comparison with the stream-sediment standards. A gallium oxide spectrochemical carrier/buffer enhances the early emission of the volatile elements. Detection limits in parts per million attained are: Sb 5, As 20, Bi 0.1, Cd 1, Cu 1, Pb 2, Ag 0.1, Zn 2, and Sn 0.1. A comparison with other methods of analysis, total-burn emission and atomic absorption spectroscopy, shows good correlation for standard reference for materials and samples from a variety of geologic terranes. ?? 1986.

  5. Inductively coupled plasma atomic emission spectrometric determination of acid-soluble metal elements chromium,manganese, zinc and copper in talcum powder%电感耦合等离子体原子发射光谱法测定滑石粉中酸溶金属元素铬锰锌铜

    Institute of Scientific and Technical Information of China (English)

    胡晓静; 曾泽; 王长文; 仇薪越; 牟明仁; 富瑶; 沈桂玲; 刘向宽

    2011-01-01

    After digestion by aqua regia with microwave and selection of corresponding spectral lines at 267. 7, 257. 6, 213. 8 and 324. 7 nm as analytical lines, the acid-dissoluble metal elements including chromium, manganese, zinc and copper in talcum powder were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) under optimized conditions with radio frequency power of 1 250 W, auxiliary air flow rate of 0. 60 L/min and atomizer pressure of 26 psi. When the concentration of each testing element was 2. 0 μg/mL, the interferences caused by 20. 0 μg/mL of I-ron, magnesium, calcium, aluminum, zinc, nickel and copper were all less than 5 %. Since the contents of these elements in talcum powder were less than 1 %, their influence on the determination could be ignored. The detection limits of chromium, manganese, zinc and copper were 0. 004 8, 0. 003 8, 0. 001 and 0. 002 6 μg/mL, respectively. This proposed method was applied in actual samples, and the determination results were consistent with those obtained by inductively coupled plasma mass spectrometry (ICP-MS) with relative standard deviations (RSD, n = 8) of 1.1%-4. 2% and recoveries of 93 %-107 %.%以王水作溶剂,微波消解法消解样品,选择267.7、257.6、213.8和324.7 nm波长的光谱线分别作为铬、锰、锌和铜的分析线,在发射功率为1 250 W、辅助气流量为0.60 L/min、雾化器压力为26 psi的优化条件下以电感耦合等离子体原子发射光谱法(ICP-AES)测定了滑石粉中酸溶金属元素铬、锰、锌、铜含量.样品中的基体组分硅酸镁在王水中的溶解量很少,对测定没有影响.当测定待测元素浓度均为2.0μg/mL的溶液时,20.0 μg/mL的铁、镁、钙、铝、锌、镍、铜对待测元素的干扰均小于5%.由于滑石粉中这些元素含量小于1%,因此它们对测定的影响可以忽略.铬、锰、锌、铜的检出限分别为0.004 8、0.003 8、0.001、0.002 6μg/mL.滑石粉样品分析

  6. Atomic-spectrometric determination of lithium, sodium, potassium and strontium in high-pure scandium

    International Nuclear Information System (INIS)

    Determination of lithium, sodium and potassium in strontium by flame photometry with atomic-absorption spectrophotometer is described. Scandium effect on value of Li, K. Na analytical signal in flame is studied. It is shown, that the base understates analytical signals. Determination of strontium by flame photometry is impossible. Determination of strontium (1x10-13 kg/ml) by atomic-absorption method with electrothermal atomization is possible

  7. Crystal structure solution from experimentally determined atomic pair distribution functions

    OpenAIRE

    Juhas, Pavol; Granlund, Luke; Gujarathi, Saurabh R.; Duxbury, Phillip M.; Billinge, Simon J. L.

    2010-01-01

    The paper describes an extension of the Liga algorithm for structure solution from atomic pair distribution function (PDF), to handle periodic crystal structures with multiple elements in the unit cell. The procedure is performed in 2 separate steps - at first the Liga algorithm is used to find unit cell sites consistent with pair distances extracted from the experimental PDF. In the second step the assignment of atom species over cell sites is solved by minimizing the overlap of their empiri...

  8. 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 ...

  9. Wall loss of atomic nitrogen determined by ionization threshold mass spectrometry

    International Nuclear Information System (INIS)

    In the afterglow of an inductively coupled N2 plasma, relative N atom densities are measured by ionization threshold mass spectrometry as a function of time in order to determine the wall loss time twN from the exponential decay curves. The procedure is performed with two mass spectrometers on different positions in the plasma chamber. twN is determined for various pressures, i.e., for 3.0, 5.0, 7.5, and 10 Pa. For this conditions also the internal plasma parameters electron density ne and electron temperature Te are determined with the Langmuir probe and the rotational temperature TrotN2 of N2 is determined with the optical emission spectroscopy. For TrotN2, a procedure is presented to evaluate the spectrum of the transition υ′=0→υ″=2 of the second positive system (C3Πu→B3Πg) of N2. With this method, a gas temperature of 610 K is determined. For both mass spectrometers, an increase of the wall loss times of atomic nitrogen with increasing pressure is observed. The wall loss time measured with the first mass spectrometer in the radial center of the cylindrical plasma vessel increases linearly from 0.31 ms for 3 Pa to 0.82 ms for 10 Pa. The wall loss time measured with the second mass spectrometer (further away from the discharge) is about 4 times higher. A model is applied to describe the measured twN. The main loss mechanism of atomic nitrogen for the considered pressure is diffusion to the wall. The surface loss probability βN of atomic nitrogen on stainless steel was derived from twN and is found to be 1 for the present conditions. The difference in wall loss times measured with the mass spectrometers on different positions in the plasma chamber is attributed to the different diffusion lengths

  10. Experimental parameters of vanadium determination by atomic-absorption spectroscopy with graphite-furnace atomization

    International Nuclear Information System (INIS)

    It was found that impregnation of a graphite cuvette (HGA-72) with salts of elements which form stable carbides (Ta, Si, Nb, Zr, W, La) decreases the absorbance signal for vanadium. The slope of the atomization curves indicates that formation of vanadium atoms is inhibited, probably by formation of a ternary compound between the impregnating element, vanadium and graphite. On the contrary bigger signals and better repeatability of results may be achieved when the cuvette is coated with pyrolytic graphite and methane is added to the sheath gas. The presence of methane increases the atomization efficiency and compensates for the disadvantageous influence of any air present in the sheath gas. (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. Simultaneous Atomic Absorption Spectrometry for Cadmium and Lead Determination in Wastewater: A Laboratory Exercise

    Science.gov (United States)

    Correia, Paulo R. M.; Oliveira, Pedro V.

    2004-01-01

    The simultaneous determination of cadmium and lead by multi-element atomic absorption spectrometry with electrochemical atomization is proposed by employing a problem-based approach. The reports indicate that the students assimilated the principles of the simultaneous atomic absorption spectrometry (SIMAAS), the role of the chemical modifier, the…

  13. 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

  14. 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 ...

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. 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)

  3. 电感耦合等离子体发射光谱法测定载金炭中铜铁钙镁%Determination of Copper, Iron, Calcium and Magnesium in Gold-Loaded Carbon by Inductively Coupled Plasma-Atomic Emission Spectrometry

    Institute of Scientific and Technical Information of China (English)

    夏珍珠

    2012-01-01

    This article introduces a method of Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) for the determination of copper, iron, calcium and magnesium in gold-loaded carbon. After incineration, the residua of the sample were dissolved by HC1 and HNO3, and then the solution in diluted aqua regia was determined by ICP-AES. Factors such as sample drying temperature, the material of the crucible, incineration temperature, incineration time, and media for testing and the interference of the coexisting elements was studied in detail on how they influence the result. The results show that the proper sample drying temperature for the gold-loaded carbon was 150t. The inoxidability of the quartz pot is higher than that of ceramic crucible, and it also has a lower blank, and stable results. Through an interference test, the coexisting elements in the gold-loaded carbon did not interfere with the determination of copper, iron, calcium and magnesium. This method was applied to the analysis of samples with the relative standard deviations ( RSDs) for Cu, Fe, Ca and Mg in the range of 0.84% -1.45%, 0.80% -1.44%, 0.78% -2.69% and 0.96% -2.61%, respectively. Standard addition recoveries for Cu, Fe, Ca and Mg were in the range of 98.5% - 100.9% , 99.4% -102.0% , 97. 1% - 102.5% and 100. 7% - 104.5%, repectively. The method was simple, and suitable for simultaneous determination of multiple elements.%样品经灼烧灰化后,用盐酸、硝酸溶解残渣,在稀王水介质中用电感耦合等离子体发射光谱法测定载金炭中的铜、铁、钙和镁.试验了烘样温度、灼烧坩埚的材质、温度和时间、测定介质及共存元素干扰等因素的影响.结果表明,载金炭的烘样温度宜选择150℃,石英材质的坩埚耐侵蚀性高于瓷坩埚,且空白值低、结果稳定,载金炭中共存元素不干扰铜、铁、钙和镁的测定.该方法用于样品的分析,相对标准偏差(RSD)为0.78%~2.69%,加标回收率为97.1

  4. 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

  5. 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

  6. Use of electrothermal atomization for determining metallic impurities in nuclearly pure uranium compounds

    International Nuclear Information System (INIS)

    Atomic absorption spectrometry with electrothermal atomization was used for the determination of Al, Cd, Cr, Fe, Mn, Mo and Ni as impurities in uranium oxide samples. The determinations were performed in solubilized samples both with and without uranium separation as well as in solid samples. (Author)

  7. 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

  8. 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.

  9. Determination of As,Sb,S,Cu,Pb,Zn in Arsenic Ore and Stibium Ore by Inductively Coupled Plasma-Atomic Emission Spectrometry With Aqua Regia Digestion%王水溶矿-等离子体光谱法测定砷矿石和锑矿石中砷锑硫铜铅锌

    Institute of Scientific and Technical Information of China (English)

    马新荣; 马生凤; 王蕾; 温宏利; 巩爱华; 许俊玉

    2011-01-01

    建立了王水溶矿-电感耦合等离子体发射光谱法测定砷矿石和锑矿石中主、次量元素砷、锑、硫及含量范围在100μg/g以上的铜、铅、锌等元素的方法.研究了放置时间、溶液酸度、氧化剂与络合剂对砷、锑、硫及其他元素测定的影响.不同王水浓度酸度对可同时测定的其他元素的影响不明显;当溶液酸度较小时,不能放置,应及时测定;如需放置,应在溶液定容前加入酒石酸防止水解.样品中砷、锑、硫的含量在0.74%~39.7%时,相对误差(RE)在-0.17%~7.74%,5次独立测定的相对标准偏差(RSD)均小于2%;含量在100~500 μg/g以下的Sb,RE在-2.5%~4.79%,5次独立测定的RSD均小于2%.由于稀释倍数较大(DF=1000),不能准确测定含量在100 μg/g以下的铜、铅、锌;含量在100μg/g以上的铜、铅、锌的RE在-10.3%~10.3%,5次独立测定的RSD基本小于5%.经标准物质验证获得满意结果.方法也可应用于砷、锑含量较高的硫化矿的测定.%The method for determining concentrations of As, Sb, S, and Cu, Pb , Zn which are above 100 μg/g, within arsenic ore and stibium ore by inductively coupled plasma-atomic emission spectrometry (ICP-AES) with aqua regia digestion is reported in this paper. The experimental conditions such as placement time, solution acidity, and the influence of oxidant and complexing agents on As, Sb, S and the other elements were studied. The relative error ( RE) was determined to be between -0.17% and 7.74% with a RSD (n=5) of <2% if the concentrations of As, Sb, S in the samples were in the range of 0.74-39.7%. However, the RE was from -2.5% to 4.79% and RSD(n =5) was < 2% if the Sb concentration is lower than 100-500 μg/g. The RE was determined to be between - 10.3% and 10.3% with a RSD(n=5) of generally less than 5% if the Cu, Pb and Zn concentrations were more than 100 μg/g. No accurate data were obtained for Cu, Pb and Zn if the concentrations

  10. 电感耦合等离子体光谱法测定黄铁矿和黄铜矿中的铁铜硫%Determination of Fe, Cu and S in Pyrite and Chalcopyrite Samples by Inductively Coupled Plasma-Atomic Emission Spectrometry

    Institute of Scientific and Technical Information of China (English)

    马新荣; 王蕾; 温宏利; 巩爱华

    2011-01-01

    The methods of water bath dissolution by aqua regia to open dissolution by acid mixing HC1-HNO3 -HF-HC104 and determine Fe, Cu and S in pyrite and chalcopyrite by Inductively Coupled Plasma-Atomic Emission Spectrometry ( ICP-AES ) are discussed in this paper. By applying a weighting method to prepare standard solutions, the error caused by scale reading can be greatly reduced during the dilution step. The advantages of using the water bath dissolution by aqua regia method include reduced digestion time, reduced amount of reagent addition and simple analytical processing. When Fe combines with Si in sulfide ore, it cannot be dissolved by aqua regia, yet it can when using open dissolution by acid mixing. The optimal spectrum lines were selected to determine high concentration of Fe, Cu and S ( x%-xx% ) with dilution factor of 1000. Both sample preparation methods are simple to operate and attain good accuracy and precision. The method was validated by the national standard materials of GBW 07267 ( pyrite ) and GBW 07268 ( chalcopyrite ). The accuracy ( RE ) and precision ( RSD, n =5 ) of Fe and Cu were less than 2%. However, accuracy and precision for S was lower when using the method of open dissolution by acid mixing, yielding a RE and RSD of -9.48% and - 18% , respectively. The short period stability of GBW 07267 and GBW 07268 was tested by 10 continuous determinations using the method of water bath dissolution with aqua regia; the RSD being less than 2.%样品用王水水浴和HCl-HNO3-HF-HClO4敞开酸溶两种溶矿方式分解,电感耦合等离子体发射光谱法(ICP-AES)测定黄铜矿和黄铁矿中铁、铜、硫.应用称重法配制标准溶液,明显地降低了在标准溶液在逐级稀释过程中由于体积读数等原因产生的误差.样品用王水水浴分解,消解时间短,试剂加入量少,分析步骤简单;由于硫化矿石中Fe的一部分可能与Si结合,王水无法将其全部溶解,对于Fe的测定采用混合酸敞开酸溶.

  11. Bound trace element content of bovine retinal disk membranes as determined by particle-induced x-ray emission.

    OpenAIRE

    McCormick, L D

    1985-01-01

    Particle-induced x-ray emission (PIXE) was used to determine the trace element content of bovine retinal disk membranes. PIXE is a multielemental analytical technique capable of the simultaneous detection and quantization of all elements from sodium and above in atomic number. The multielemental capability of PIXE allows the analysis time per element to be very low if a number of elements are detected in each sample. In addition, the multielemental capability of PIXE can be used to determine ...

  12. Neutron emission from primary fragments and mass determination

    International Nuclear Information System (INIS)

    In the frame of statistical model with preequilibrium contribution a probability of prompt neutron emission from primary fission fragments has been calculated. The calculation of yields of primary f.f. from experimental values of relevant yields has been performed using these probabilities. An influence of using post-neutron experimental yield of f.f.'s on the determination of mass distribution of primary f.f.'s has been discussed. (orig.)

  13. A comparison of simultaneous plasma, atomic absorption, and iron colorimetric determinations of major and trace constituents in acid mine waters

    Science.gov (United States)

    Ball, J.W.; Nordstrom, D.K.

    1994-01-01

    Sixty-three water samples collected during June to October 1982 from the Leviathan/Bryant Creek drainage basin were originally analyzed by simultaneous multielement direct-current plasma (DCP) atomic-emission spectrometry, flame atomic-absorption spectrometry, graphite-furnace atomic-absorption spectrometry (GFAAS) (thallium only), ultraviolet-visible spectrometry, and hydride-generation atomic-absorption spectrometry.Determinations were made for the following metallic and semi-metallic constituents: AI, As, B, Ba, Be, Bi, Cd, Ca, Cr, Co, Cu, Fe(11), Fe(total), Li, Pb, Mg, Mn, Mo, Ni, K, Sb, Se, Si, Na, Sr, TI, V, and Zn. These samples were re-analyzed later by simultaneous multielement inductively coupled plasma (ICP) atomic-emission spectrometry and Zeeman-corrected GFAAS to determine the concentrations of many of the same constituents with improved accuracy, precision, and sensitivity. The result of this analysis has been the generation of comparative concentration values for a significant subset of the solute constituents. Many of the more recently determined values replace less-than-detection values for the trace metals; others constitute duplicate analyses for the major constituents. The multiple determinations have yielded a more complete, accurate, and precise set of analytical data. They also have resulted in an opportunity to compare the performance of the plasma-emission instruments operated in their respective simultaneous multielement modes. Flame atomic-absorption spectrometry was judged best for Na and K and hydride-generation atomic-absorption spectrometry was judged best for As because of their lower detection limit and relative freedom from interelement spectral effects. Colorimetric determination using ferrozine as the color agent was judged most accurate, precise, and sensitive for Fe. Cadmium, lead, and vanadium concentrations were too low in this set of samples to enable a determination of whether ICP or DCP is a more suitable technique. Of

  14. 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.

  15. 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.

  16. 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.

  17. 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...

  18. 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

  19. 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).

  20. 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.

  1. 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

  2. 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...

  3. 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.

  4. 浊点萃取-流动注射电感耦合等离子体原子发射光谱法同时测定水中镉钴铜镍锌%Simultaneous Determination of Cadmium, Cobalt,Copper, Nickel and Zinc in Water Samples by Flow Injection-Inductively Coupled Plasma-Atomic Emission Spectrometry after Cloud Point Extraction

    Institute of Scientific and Technical Information of China (English)

    陈建国; 陈恒武; 金献忠; 陈海婷

    2009-01-01

    A cloud point extraction procedure was developed for pre-concentration of trace amount of Cd2+, Co2+,Cu2+, Ni2+ and Zn2+ in water samples prior to inductively coupled plasma atomic emission spectrometric determination. 5-Br-PADAP was used to transform the metal ions into water in-soluble chelates, and the chelates were extracted into a surfactant-rich phase of Triton X-114. After being diluted with ethanol-nitric acid solution, the surfactant-rich phase containing the concentrated metal ions was introduced into the ICP with flow injection technique. Various experimental conditions such as sampling volume, integration time, extraction acidity and concentrations of 5-Br-PADAP and Triton X-114 were examined. Under the optimized conditions, enhancement factors of 18, 10, 16, 10, 8 and detection limits of 0.7, 1.6, 1.3, 5.7, and 3.2 g/L were obtained for Cd2+, Co2+,Cu2+, Ni2+ and Zn2+, respectively. The developed method was successfully applied to the determination of Cd2+, Co2+,Cu2+, Ni2+ and Zn2+ in tap water, river water and sea water samples. Recoveries for the spiked samples were in the range of 80% and 118%.%本文提出了浊点萃取-流动注射电感耦合等离子体原子发射光谱(FI-ICP-AES)法同时测定水中镉、钴、铜、镍、锌的新方法.利用5-Br-PADAP将待测金属离子转化为水不溶性的螯合物,并萃取到表面活性剂Triton X-114的浓缩相,以乙醇-硝酸溶液稀释含富集离子的浓缩相,并以FI-ICP-AES法测定.考察了流动注射进样体积、积分时间、萃取体系介质酸度、螯合剂和表面活性剂用量等实验条件的影响.在折衷条件下,镉、钴、铜、镍和锌的浓缩倍率可达18、10、16、10和8,检出限分别为0.7 μg/L、1.6 μg/L、1.3 μg/L、5.7 μg/L、3.2 μg/L.方法成功应用于自来水、河水和海水中痕量镉、钴、铜、镍和锌的分析.在0.02 mg/L 和0.10 mg/L二个水平进行加入回收试验,回收率在80%与118%之间.

  5. Determination of Cr, V and P in Ilmenite by Inductively Coupled Plasma-Atomic Emission Spectrometry with Sodium Peroxide Fusion%过氧化钠碱熔-电感耦合等离子体发射光谱法测定钛铁矿中铬磷钒

    Institute of Scientific and Technical Information of China (English)

    王卿; 赵伟; 张会堂; 周长祥; 回寒星

    2012-01-01

    An analytical method for the determination of trace elements of Cr, P and V in ilmenite with sodium peroxide by Inductively Coupled Plasma-Atomic Emission Spectrometry ( ICP-AES ) is proposed. The sample was digested by sodium peroxide fusion following which, the clear top solution was acidized to measure Cr, P and V by ICP-AES. The optimum instrumental conditions and selection of spectral lines for the elemental analysis were studied. The large dilution of 1000 and calibration standard solution by adding sodium as the matrix were conducted to eliminate the matrix effect. 2 mL HC1 was loaded to acidize the sample solution in order to avoid eroding the machines sampling system by the strong basicity of the solution by sodium peroxide fusion. The detection limit of this method was 4.46 -23.55 fig/g. According to the validation by national standard materials, the accuracy of the method (relative error) was less than 10% , and precision (RSD, n = 12) was 0.68% to 9. 90%. Compared with the spectrophotometer method for single element determination, this method showed many advantages, such as a low detection limit, high sensitivity, a wide measuring range, convenient operation, and was suitable for batch samples.%样品经过氧化钠碱熔,溶解后的上层清液直接酸化,用电感耦合等离子体发射光谱测定钛铁矿中铬、磷、钒的含量.确定了钛铁矿石中Cr、P、V的分析谱线、光谱级次;为了消除钠盐基体的影响,确定稀释因子为1000,标准曲线基体与样品基体保持一致;为避免过氧化钠熔矿后溶液碱性较大对选样系统造成腐蚀,加入2.00 mL盐酸对溶液进行酸化.方法检出限为4.46 ~23.55μg/g,采用国家一级标准物质进行验证,方法准确度小于10%,精密度为0.68%~9.90%.本法与分光光度法单一元素测定相比较,具有测量范围宽、结果准确、操作简便、省时省力、适合大批量样品测定等突出的优点.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Carbon nanotubes as solid-phase extraction sorbents prior to atomic spectrometric determination of metal species: A review

    International Nuclear Information System (INIS)

    Highlights: ► The use of CNTs as sorbent for metal species in solid phase extraction has been described. ► Physical and chemical strategies for functionalization of carbon nanotubes have been discussed. ► Published analytical methods concerning solid phase extraction and atomic spectrometric determination have been reviewed. - Abstract: New materials have significant impact on the development of new methods and instrumentation for chemical analysis. From the discovery of carbon nanotubes in 1991, single and multi-walled carbon nanotubes – due to their high adsorption and desorption capacities – have been employed as sorption substrates in solid-phase extraction for the preconcentration of metal species from diverse matrices. Looking for successive improvements in sensitivity and selectivity, in the past few years, carbon nanotubes have been utilized as sorbents for solid phase extraction in three different ways: like as-grown, oxidized and functionalized nanotubes. In the present paper, an overview of the recent trends in the use of carbon nanotubes for solid phase extraction of metal species in environmental, biological and food samples is presented. The determination procedures involved the adsorption of metals on the nanotube surface, their quantitative desorption and subsequent measurement by means of atomic spectrometric techniques such as flame atomic absorption spectrometry, electrothermal atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry/mass spectrometry, among others. Synthesis, purification and types of carbon nanotubes, as well as the diverse chemical and physical strategies for their functionalization are described. Based on 140 references, the performance and general properties of the applications of solid phase extraction based on carbon nanotubes for metal species atomic spectrometric determination are discussed.

  12. Carbon nanotubes as solid-phase extraction sorbents prior to atomic spectrometric determination of metal species: A review

    Energy Technology Data Exchange (ETDEWEB)

    Herrero Latorre, C., E-mail: carlos.herrero@usc.es [Universidad de Santiago de Compostela, Dpto. Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Alfonso X el Sabio s/n, 27002 Lugo (Spain); Alvarez Mendez, J.; Barciela Garcia, J.; Garcia Martin, S.; Pena Crecente, R.M. [Universidad de Santiago de Compostela, Dpto. Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Alfonso X el Sabio s/n, 27002 Lugo (Spain)

    2012-10-24

    Highlights: Black-Right-Pointing-Pointer The use of CNTs as sorbent for metal species in solid phase extraction has been described. Black-Right-Pointing-Pointer Physical and chemical strategies for functionalization of carbon nanotubes have been discussed. Black-Right-Pointing-Pointer Published analytical methods concerning solid phase extraction and atomic spectrometric determination have been reviewed. - Abstract: New materials have significant impact on the development of new methods and instrumentation for chemical analysis. From the discovery of carbon nanotubes in 1991, single and multi-walled carbon nanotubes - due to their high adsorption and desorption capacities - have been employed as sorption substrates in solid-phase extraction for the preconcentration of metal species from diverse matrices. Looking for successive improvements in sensitivity and selectivity, in the past few years, carbon nanotubes have been utilized as sorbents for solid phase extraction in three different ways: like as-grown, oxidized and functionalized nanotubes. In the present paper, an overview of the recent trends in the use of carbon nanotubes for solid phase extraction of metal species in environmental, biological and food samples is presented. The determination procedures involved the adsorption of metals on the nanotube surface, their quantitative desorption and subsequent measurement by means of atomic spectrometric techniques such as flame atomic absorption spectrometry, electrothermal atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry/mass spectrometry, among others. Synthesis, purification and types of carbon nanotubes, as well as the diverse chemical and physical strategies for their functionalization are described. Based on 140 references, the performance and general properties of the applications of solid phase extraction based on carbon nanotubes for metal species atomic spectrometric determination are discussed.

  13. On the opportunity of spectroscopic determination of absolute atomic densities in non-equilibrium plasmas from measured relative intensities within resonance multiplets distorted by self-absorption

    CERN Document Server

    Lavrov, B P

    2007-01-01

    The opportunities of the application of the recently proposed approach in optical emission spectroscopy of non-equilibrium plasmas have been studied. The approach consists of several methods of the determination of {\\em absolute} particle densities of atoms from measured {\\em relative} intensities within resonance multiplets distorted by self-absorption. All available spectroscopic data concerning resonance spectral lines of atoms having multiplet ground states from boron up to gallium were analyzed. It is found that in the case of C, O, F, S and Cl atoms an application of the methods needs VUV technique, while densities of B, Al, Si, Sc, Ti, V, Co, Ni, Ga atoms may be obtained by means of the intensity measurements in UV and visible parts of emission spectra suitable for ordinary spectrometers used for optical diagnostics and monitoring of non-equilibrium plasmas including industrial plasma technologies.

  14. Determination of electric field-dependent effective secondary emission coefficients for He/Xe ions on brass

    International Nuclear Information System (INIS)

    Effective secondary emission coefficients, γeff, for He+ and Xe+ ions are determined from the experimental Paschen curves of Postel and Cappelli [Appl. Phys. Lett. 76, 544 (2000)] through Townsend's condition for a self-sustained discharge. The γeff dependence on the reduced electric field E/p, where p is the gas pressure, is obtained using the calculated dependence of the reduced Townsend's ionization coefficient α(E/p)/p on the reduced electric field. Average values of the secondary emission coefficients are also estimated for brass and atomic and molecular ions as well as excited atoms and molecules of He and Xe, through a best fit of the simulated Paschen curves to the experimental ones. The found average values of the secondary emission coefficients are 0.1 for He and 0.0016 for Xe. Comparison is made with the limited available experimental results

  15. Pre-Harvest Sugarcane Burning: Determination of emission factors through laboratory measurements and quantification of emissions

    Science.gov (United States)

    de Azeredo Franca, D.; Maria Longo, K.; Gomes Soares Neto, T.; Carlos dos Santos, J.; Rudorf, B. F.; Alves de Aguiar, D.; Freitas, S.; Vieira Cortez, E.; Stockler S. Lima, R.; S. Gacita, M.; Anselmo, E.; A. Carvalho, J., Jr.

    2011-12-01

    Sugarcane is a relevant crop to Brazilian economy and roughly 50% of its production is used to produce ethanol. São Paulo state is the largest producer of sugarcane in Brazil being responsible for almost 60% of its production in a cultivated area of 4.5 Mha in 2010. Sugarcane harvest practice can be performed either with green harvest or with pre-harvest burning. A "Green Ethanol" Protocol is underway to eliminate the pre-harvest burning practice by 2014 in most of the sugarcane cultivated land in São Paulo state. During the last five years close to 2 Mha were annually harvested with the pre-harvest burning practice. This practice emits particulate material, greenhouse gases, and tropospheric ozone precursors to the atmosphere. Even with policies to eliminate the burning practice in the near future there is still a significant environmental damage due to the pre-harvest burning practice of sugarcane. Thus the generation of reliable inventories of emissions due to this activity is crucial in order to assess the environmental impact. Presently the official Brazilian emissions inventories do not include the sugarcane pre-harvest burning contribution. Therefore, this work aims to estimate the annual emissions (from 2006 to 2010) associated with pre-harvest sugarcane burning practice in São Paulo state, including the determination of emission factors for some trace gases and particulate material smaller than 2.5 μm. Annual remote sensing based mappings of burned sugarcane fields throughout the harvest season in each crop year made in the context of Canasat Project (http://www.dsr.inpe.br/laf/canasat/en/) were added to the Brazilian Biomass Burning Emission Model (3BEM) in order to estimate trace gases and aerosols emissions. Two laboratory combustion experiments were carried out to determine the emission factors estimation. Samples of different varieties of sugarcane were harvested in dry weather conditions and in distinct sites in the state of São Paulo to assure

  16. Determination of gold in geologic materials by solvent extraction and atomic-absorption spectrometry

    Science.gov (United States)

    Huffman, Claude; Mensik, J.D.; Riley, L.B.

    1967-01-01

    The two methods presented for the determination of traces of gold in geologic materials are the cyanide atomic-absorption method and the fire-assay atomic-absorption method. In the cyanide method gold is leached with a sodium-cyanide solution. The monovalent gold is then oxidized to the trivalent state and concentrated by extracting into methyl isobutyl ketone prior to estimation by atomic absorption. In the fire-assay atomic-absorption method, the gold-silver bead obtained from fire assay is dissolved in nitric and hydrochloric acids. Gold is then concentrated by extracting into methyl isobutyl ketone prior to determination by atomic absorption. By either method concentrations as low as 50 parts per billion of gold can be determined in a 15-gram sample.

  17. 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.)

  18. 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

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. Selenium determination in biological material by atomic absorption spectrophotometry in graphite furnace and using vapor generation

    International Nuclear Information System (INIS)

    The applicability of the atomic absorption spectrophotometry to the determination of selenium in biological material using vapor generation and electrothermal atomization in the graphite furnace was investigated. Instrumental parameters and the analytical conditions of the methods were studied. Decomposition methods for the samples were tested, and the combustion in the Wickbold apparatus was chosen. (author)

  4. A laboratory manual for the determination of metals in water and wastewater by atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    This guide presents, in addition to a brief discussion of the basic principles and practical aspects of atomic absorption spectrophotometry, a scheme of analysis for the determination of 19 metals in water and wastewater, 16 by flame atomic absorption and 3 by vapour generation techniques. Simplicity, speed and accuracy were the main criteria considered in the selection of the various methods

  5. Determination of Chlorine in Marine Sediment by Inductively Coupled Plasma-Atomic Emission Spectrometry with Ammonia Extraction%氨水提取-电感耦合等离子体发射光谱法测定海洋沉积物中的氯

    Institute of Scientific and Technical Information of China (English)

    马生凤; 温宏利; 赵怀颖; 孙红宾; 巩爱华

    2013-01-01

    氯的电离能高,在等离子体中难于解离,通常的电感耦合等离子体发射光谱(ICP-AES)光路不能彻底地将空气排出,使得氯的光波被强烈吸收,很难找出相应的特征谱线因而无法准确测定地质样品中的氯.本文对海洋沉积物样品用10%的氨水在超声振荡器中振荡30 min,即可完全提取其中的氯,用ICP-AES测定,选择分析谱线为725.670 nm,方法检出限为50μg/g(10σ,稀释因子=100).用海洋沉积物标准物质GBW07313、GBW07315、GBW07316验证,方法精密度(RSD,n=7)为4.3% ~8.6%,测定值与标准值的相对误差为2.9% ~4.9%.方法简单快速,准确度高,实现了地质样品中氯的准确测定,能够满足海洋地球化学研究的需要.%It is difficult to dissociate Cl by plasma because of the high ionization energy. Since the optical path of Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) cannot produce a low enough vacuum, the light wave of Cl is absorbed intensively causing difficulty in identifying the characteristic spectrum and subsequently in obtaining an accurate measurement of Cl in geology samples. In this article, a method is described here for completely extracting Cl in marine sediment samples by 10% ammonia with 30 minutes ultrasound bath. The Cl was measured by TCP-AES with an analysis spectrum of 725. 670 nm. The detection limit of this method, which was based on ten standard deviations of the blank ( 10σ, dilution factor = 100) , was 50 μg/g for Cl. The accuracy and precision of the method were verified by analyzing different geological certified reference materials GBW 07313, GBW 07315 and GBW 07316. The relative standard deviations (RSD, n = 7) of the results of independent determination GBW 07316 were 4. 3% -8. 6% , and relative error (n = 7) were 2. 9% -7. 5% . Compared with traditional methods, this method is simple, fast, easy to perform, and its precision and accuracy are suitable for marine geochemistry.

  6. 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

  7. 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.

  8. Determination of various extracted Al species and their fractions by atomic spectrometry techniques

    International Nuclear Information System (INIS)

    Complete text of publication follows. During the last few decades aluminium and its distribution in the environment has attracted much attention because of Al toxic effects to the plants, animals and humans. Its concentration in different environmental samples varies widely. While determination of high Al concentrations can be realized with no serious problem, reliable determination of its trace and ultratrace concentrations requires the development of enrichment techniques capable of improving both, the selectivity and also sensitivity for this analyte. Two extraction methods were used for selective separation and preconcentration of aluminium trace concentrations from model solutions. Solid phase extraction (SPE) using nanometer-sized titanium dioxide as a solid sorbent and cloud point extraction (CPE) using nonionic surfactant octylphenoxypolyethoxyethanol (Triton X-114) were utilized. Spectrometry techniques such as flame (F AAS) and electrothermal (ET AAS) atomic absorption spectrometry, inductively coupled plasma optical emission spectrometry (ICP OES) or inductively coupled plasma mass spectrometry (ICP MS) were applied for the determination of aluminium. Direct TiO2-slurry sampling was used for sample injection into the graphite furnace of ET AAS in SPE. Optimized procedures were used for the determination of trace and ultratrace amounts of total aluminium and various aluminium species and their fractions in speciation analysis and fractionation studies using environmental samples such as natural waters, soils and sediments. The work was supported by Slovak Research and Development Agency under the contracts No. APVT-20-010204, LPP-0038-06, LPP-0146-09 and SK-CZ-0044-07, by Scientific Grant Agency of Ministry of Education of Slovak Republic and the Slovak Academy of Sciences under the contracts No. VEGA 1/4464/07 and VEGA 1/0272/08 and by Ministry of Education, Youth and Sports of Czech Republic under the contract No. MEB 080813.

  9. Evaluation of quartz tubes as atomization cells for gold determination by thermospray flame furnace atomic absorption spectrometry

    International Nuclear Information System (INIS)

    This work describes the development of a new analytical procedure able to determine gold by thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) using nickel tubes (NiT) and quartz tubes (QT) as atomization cells. Experiments involving changes in the flow injection operational parameters, reagent concentrations and sizes of the QT were performed in order to optimize sensitivity. Under the same operational conditions, it was observed that the employment of QT increases the sensitivity of gold determination when compared to the nickel tube. Since solutions of highly concentrated hydrochloric acid showed the best performance as carriers, quartz tubes were also preferred due to its greater tolerance to corrosion by mineral acids in comparison to NiT. In addition, changes in the internal diameter of the QT revealed an important improvement in sensitivity for smaller tubes. Under optimized conditions the main figures of merit showed values close to that of graphite furnace atomic absorption spectrometry with the addition of an excellent improvement of the sample throughput. They are: LOD (3 s): 0.004 μg mL−1, sensitivity: 0.306 (μg mL−1)−1, RSD% (n = 10, 1 μg mL−1): 2.5, linear range: 0.01–4 μg mL−1 and sample throughput: 72 h−1. This new method was employed for the determination of gold in homeopathic medicines with no need of sample digestion. Validation of the analytical results will be shown. A full discussion of the most relevant findings regarding the role of the atomization cell as a strategic key for improving sensitivity will be also provided. - Highlights: ► Quartz tubes as furnaces in TS-FFAAS. ► Small tubes for controlling radial dispersion. ► Improved figures of merit for gold determination. ► Analysis of homeopathic medicines.

  10. 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)

  11. Photometric and emission-spectrometric determination of boron in steels

    International Nuclear Information System (INIS)

    A method for the photometric determination of boron in unalloyed and alloyed steels is described, in which Curcumine is used as reagent. A separation of boron is not necessary. Limit of detection: 0.0003% B. The decomposition of boron nitride in the steel is achieved by heating the whole sample in fuming sulphuric acid/phosphoric acid. For the emission spectrometric investigation of solid steel samples and for the spectrochemical analysis of solutions with plasma excitation working parameters are given and possibilities of interferences are demonstrated. (orig.)

  12. Photometric and emission-spectrometric determination of boron in steels

    Energy Technology Data Exchange (ETDEWEB)

    Thierig, D.

    1982-01-01

    A method for the photometric determination of boron in unalloyed and alloyed steels is described, in which Curcumine is used as reagent. A separation of boron is not necessary. Limit of detection: 0.0003% B. The decomposition of boron nitride in the steel is achieved by heating the whole sample in fuming sulphuric acid/phosphoric acid. For the emission spectrometric investigation of solid steel samples and for the spectrochemical analysis of solutions with plasma excitation working parameters are given and possibilities of interferences are demonstrated.

  13. Determinants of Nitrous Oxide Emission from Agricultural Drainage Waters

    International Nuclear Information System (INIS)

    Emissions of the powerful greenhouse gas nitrous oxide (N2O) from agricultural drainage waters are poorly quantified and its determinants are not fully understood. Nitrous oxide formation in agricultural soils is known to increase in response to N fertiliser application, but the response of N2O in field drainage waters is unknown. This investigation combined an intensive study of the direct flux of N2O from the surface of a fertilised barley field with measurement of dissolved N2O and nitrate (NO3) concentrations in the same field's drainage waters. Dissolved N2O in drainage waters showed a clear response to field N fertilisation, following an identical pattern to direct N2O flux from the field surface. The range in N2O concentrations between individual field drains sampled on the same day was large, indicating considerable spatial variability exists at the farm scale. A consistent pattern of very rapid outgassing of the dissolved N2O in open drainage ditches was accentuated at a weir, where increased turbulence led to a clear drop in dissolved N2O concentration. This study underlines the need for carefully planned sampling campaigns wherever whole farm or catchment N2O emission budgets are attempted. It adds weight to the argument for the downward revision of the IPCC emission factor (EF5-g) for NO3 in drainage waters

  14. Determinants of nitrous oxide emission from agricultural drainage waters

    International Nuclear Information System (INIS)

    Emissions of the powerful greenhouse gas nitrous oxide (N2O) from agricultural drainage waters are poorly quantified and its determinants are not fully understood. Nitrous oxide formation in agricultural soils is known to increase in response to N fertiliser application, but the response of N2O in field drainage waters is unknown. This investigation combined an intensive study of the direct flux of N2O from the surface of a fertilised barley field with measurement of dissolved N2O and nitrate (NO3) concentrations in the same field's drainage waters. Dissolved N2O in drainage waters showed a clear response to field N fertilisation, following an identical pattern to direct N2O flux from the field surface. The range in N2O concentrations between individual field drains sampled on the same day was large, indicating considerable spatial variability exists at the farm scale. A consistent pattern of very rapid outgassing of the dissolved N2O in open drainage ditches was accentuated at a weir, where increased turbulence led to a clear drop in dissolved N2O concentration. This study underlines the need for carefully planned sampling campaigns wherever whole farm or catchment N2O emission budgets are attempted. It adds weight to the argument for the downward revision of the IPCC emission factor (EF5-g) for NO3 in drainage waters

  15. 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.

  16. Determination of three-dimensional atomic positions from tomographic reconstruction using ensemble empirical mode decomposition

    Science.gov (United States)

    Li, Po-Nan; Wu, Zong-Han; Hsiao, Chien-Nan; Lee, Ting-Kuo; Chen, Chien-Chun

    2016-08-01

    Tomographic reconstruction from a tilt series of electron micrographs has raised great interest in materials, chemical, and condensed matters science because of its capability of revealing 3D local atomic structures within nanomaterials. Previous breakthroughs have demonstrated that the positions of individual atoms can not only be visualized but also determined by combining a scanning transmission electron microscope with a high-angle annular dark-field detector, equally sloped tomography, and the filtering/denoising method. However, the filtering/denoising approach—whether imposed on 2D projections or 3D reconstruction—raises concerns regarding the robustness of image processing, the accuracy of atomic positions, and the artificial atoms introduced during filtering. In this article, we report a general method that overcomes these limitations. By removing unphysical oscillations in 2D projections through ensemble empirical mode decomposition and applying a standard Wiener filter to the 3D reconstruction, we are able to determine atomic structures with higher accuracy.

  17. Evaluation of a method for the determination of chromium in urine by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    A method for the determination of chromium in urine by atomic absorption spectrometry, using electrothermic atomization with pyrolytic graphite tubes, is proposed. The determinations are performed by standard addition. The method is applicable to biologic monitoring of populations with different degrees of exposition. It is also used in the analysis of chromium in sediments. Results of chromium in urine of a population group non-exposed to the metal are presented. 11 refs

  18. Determination of vanadium in food and traditional Chinese medicine by graphite furnace atomic absorption spectroscopy

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Various experimental conditions were described for the vanadium determination by graphite furnace atomic ab-sorption spectroscopy (GFAAS). The experiments showed that when atomization took place under the conditions where thecombination of a pyrolytic coating graphite tube and fast raising temperature were used and the temperature was stable, thesignal peak shapes could be improved, the sensitivity was enhanced, and the memory effect was removed. The vanadium infood and traditional Chinese medicinal herbs can be accurately determined using the standard curve method.

  19. Determination of semi-empirical correlation between hydrogen and manganese atomic ratio and manganese sulphate concentration in aqueous solution

    International Nuclear Information System (INIS)

    The Manganese Bath (MB) is a widely used technique for measuring the emission rate of the neutrons source. In a measurement the source is placed in the center of an aqueous solution of manganese sulfate (MnSO4), large enough to ensure that only a very small fraction of neutrons emitted by the source escape of the system. Why not be the only single core manganese to absorb the neutrons from the source and any other losses, the MB uses several parameters arranged in the form of four key terms that make algebraic form of the final value neutron emission from a source: saturation activity A(t), the sensitivity (ε) of Standardization System, the fraction of thermal neutrons (F) caught by 55Mn which in particular the ratio between hydrogen atoms and manganese, and the correction parameter K related to the escape of neutrons from the solution, the capture of neutrons by the source material and the capture of fast neutrons in the solution is determined by mathematical simulation of MB. The purpose of this study is to establish a functional relationship, using the gravimetric method, between the physical density, concentration and atoms ratio of hydrogen and manganese in the solution of the MB and with forecasts that do stop these values so that different concentrations for MB may be held, with the objective to reduce uncertainties in the parameters of the correction of K and F, therefore reducing the uncertainty in the emission rate source. (author)

  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. Determining Original Inventory Amount of Radioactive Substances from Unmonitored Radionuclide Emissions

    International Nuclear Information System (INIS)

    The purpose of this document is to determine the air emissions inventory of the Savannah River Site. To satisfy regulatory requirements, a new equation has been developed to determine original inventory amounts from unmonitored radionuclide emissions

  2. 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.

  3. 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.

  4. 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)

  5. Determination of the attenuation map in emission tomography

    CERN Document Server

    Zaidi, H

    2002-01-01

    Reliable attenuation correction methods for quantitative emission computed tomography (ECT) require accurate delineation of the body contour and often necessitate knowledge of internal anatomical structure. Two broad classes of methods have been used to calculate the attenuation map referred to as "transmissionless" and transmission-based attenuation correction techniques. While calculated attenuation correction belonging to the first class of methods is appropriate for brain studies, more adequate methods must be performed in clinical applications where the attenuation coefficient distribution is not known a priori, and for areas of inhomogeneous attenuation such as the chest. Measured attenuation correction overcomes this problem and utilizes different approaches to determine this map including transmission scanning, segmented magnetic resonance images or appropriately scaled X-ray CT scans acquired either independently on separate or simultaneously on multimodality imaging systems. Combination of data acqu...

  6. Determination of traces of cadmium in zinc by flameless atomic absorption spectrophotometry after extraction

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, A.; Willmann, K.H.; Simon, F.J.

    1985-01-01

    The suitability of dithizone, diethyldithiocarbamate and tetramethylendithiocarbamate as chelating agents for the extraction-photometric cadmium determination by flameless atomic absorption spectrophotometry in the presence of zinc was investigated. It has been found that the extraction of the dithizone chelate by carbon tetrachloride permits an uninfluenced determination of cadmium in the presence of a zinc excess up to 10/sup 5/. Therefore the use of flameless atomic absorption spectrophotometry raises the selectivity as compared to photometry, because photometry only permits a 1000-fold excess of zinc. With this method 2x10/sup -4/% of cadmium in zinc can be determined without further corrections of matrix effects.

  7. Determination of $\\pi\\pi$ scattering lengths from measurement of $\\pi^+\\pi^-$ atom lifetime

    CERN Document Server

    Adeva, B; Benayoun, M; Benelli, A; Berka, Z; Brekhovskikh, V; Caragheorgheopol, G; Cechak, T; Chiba, M; Chliapnikov, P V; Ciocarlan, C; Constantinescu, S; Costantini, S; Curceanu, C; Doskarova, P; Dreossi, D; Drijard, D; Dudarev, A; Ferro-Luzzi, M; Fungueiriño Pazos, J L; Gallas Torreira, M; Gerndt, J; Gianotti, P; Goldin, D; Gomez, F; Gorin, A; Gorchakov, O; Guaraldo, C; Gugiu, M; Hansroul, M; Hons, Z; Hosek, R; Iliescu, M; Karpukhin, V; Kluson, J; Kobayashi, M; Kokkas, P; Komarov, V; Kruglov, V; Kruglova, L; Kulikov, A; Kuptsov, A; Kuroda, K I; Lamberto, A; Lanaro, A; Lapshin, V; Lednicky, R; Leruste, P; Levi Sandri, P; Lopez Aguera, A; Lucherini, V; Maki, T; Manuilov, I; Marin, J; Narjoux, J L; Nemenov, L; Nikitin, M; Nunez Pardo, T; Okada, K; Olchevskii, V; Pazos, A; Pentia, M; Penzo, A; Perreau, J M; Plo, M; Ponta, T; Rappazzo, G F; Riazantsev, A; Rodriguez, J M; Rodriguez Fernandez, A; Romero Vidal, A; Ronjin, V.M.; Rykalin, V; Saborido, J; Santamarina, C; Schacher, J; Schuetz, C; Sidorov, A; Smolik, J; Takeutchi, F; Tarasov, A; Tauscher, L; Tobar, M J; Trojek, T; Trusov, S; Utkin, V; Vazquez Doce, O; Vlachos, S; Voskresenskaya, O; Vrba, T; Willmott, C; Yazkov, V; Yoshimura, Y; Zhabitsky, M; Zrelov, P

    2011-01-01

    The DIRAC experiment at CERN has achieved a sizeable production of $\\pi^+\\pi^-$ atoms and has significantly improved the precision on its lifetime determination. From a sample of 21227 atomic pairs, a 4% measurement of the S-wave $\\pi\\pi$ scattering length difference $|a_0-a_2| = (.0.2533^{+0.0080}_{-0.0078}|_\\mathrm{stat}.{}^{+0.0078}_{-0.0073}|_\\mathrm{syst})M_{\\pi^+}^{-1}$ has been attained, providing an important test of Chiral Perturbation Theory.

  8. Determination of the Relative Atomic Masses of Metals by Liberation of Molecular Hydrogen

    Science.gov (United States)

    Waghorne, W. Earle; Rous, Andrew J.

    2009-01-01

    Students determine the relative atomic masses of calcium, magnesium, and aluminum by reaction with hydrochloric acid and measurement of the volume of hydrogen gas liberated. The experiment demonstrates stoichiometry and illustrates clearly that mass of the reagent is not the determinant of the amounts in chemical reactions. The experiment is…

  9. 40 CFR 63.325 - Determination of equivalent emission control technology.

    Science.gov (United States)

    2010-07-01

    ... Determination of equivalent emission control technology. (a) Any person requesting that the use of certain... equivalent emission reductions: (1) Diagrams, as appropriate, illustrating the emission control technology...) during each portion of the dry cleaning cycle with and without the use of the candidate emission...

  10. Some problems connected with boron determination by atomic absorption spectroscopy and the sensitivity improvement

    Directory of Open Access Journals (Sweden)

    JELENA J. SAVOVIC

    2001-08-01

    Full Text Available Two atomizers were compared: an N2O–C2H2 flame and a stabilized U-shaped DC arc with aerosol supply. Both the high plasma temperature and the reducing atmosphere obtained by acetylene addition to the argon stream substantially increase the sensitivity of boron determination by atomic absorption spectroscopy (AAS when the arc atomizer is used. The results were compared with those for silicon as a control element. The experimental characteristic concentrations for both elements were compared with the computed values. The experimentally obtained characteristic concentration for boron when using the arc atomizer was in better agreement with the calculated value. It was estimated that the influence of stable monoxide formation on the sensitivity for both elements was about the same, but reduction of analyte and formation of non-volatile carbide particles was more important for boron, which is the main reason for the low sensitivity of boron determination using a flame atomizer. The use of an arc atomizer suppresses this interference and significantly improves the sensitivity of the determination.

  11. Cerebral perfusion reserve indexes determined by fluoromethane positron emission scanning

    International Nuclear Information System (INIS)

    An index of cerebral perfusion reserve (RES%), defined as the percent change of regional cerebral blood flow over baseline per mm Hg of end-tidal CO2 tension, was determined for each middle cerebral artery (MCA) territory in patients with unilateral carotid distribution transient ischemic attacks or minor cerebrovascular accidents and was compared with that of age-matched, neurologically normal volunteers. Vasodilator responses to induced hypercapnia were tested during inhalation of 5% CO2 in 95% O2 while regional cerebral blood flow was measured by fluoromethane inhalation positron emission tomography. Mean RES% for 24 normal MCA territories was 5.2 +/- 0.8%. Mean RES% for 15 patient nonischemic MCA territories was 3.8 +/- 1.3% and for 15 ischemic MCA territories was 2.8 +/- 1.9% (both p less than 0.001). Individual RES% values and symmetry ratios between ischemic and nonischemic regions were also determined and compared with angiographic data. Areas of diminished, asymmetric, or paradoxical (two patients) CO2 reactivity appear to correspond to areas of compensatory vasodilation. We found this technique to be a safe and reproducible method for defining and recording localized areas of cerebral tissue at apparent risk for hemodynamically related damage

  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

    2016-01-01

    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…

  13. 40 CFR Appendix G to Part 75 - Determination of CO2 Emissions

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Determination of CO2 Emissions G... (CONTINUED) CONTINUOUS EMISSION MONITORING Pt. 75, App. G Appendix G to Part 75—Determination of CO2 Emissions 1.Applicability The procedures in this appendix may be used to estimate CO2 mass...

  14. Different platform and tube geometries and atomization temperatures in graphite furnace atomic absorption spectrometry: Cadmium determination in whole blood as a case study

    International Nuclear Information System (INIS)

    In the present work the performance of different platform and tube geometries and atomization temperatures in graphite furnace atomic absorption spectrometry was investigated, using the determination of Cd in whole blood as an example. Grooved, integrated and fork platforms as well as atomization temperatures between 1200 deg. C and 2200 deg. C were investigated in a longitudinally heated graphite atomizer and compared with the performance of a transversely heated furnace. In the longitudinally heated furnace the increase of the atomization temperature in the studied range resulted in an increase of matrix effects for all platform geometries. The integrated platform exhibited slightly lower sensitivity and increased multiplicative interferences in comparison to the other two platform designs. Interference-free Cd determination was possible with all types of platforms and 1200 deg. C as the atomization temperature as well as with grooved and fork platforms at 1700 deg. C. On the other hand, lower atomization temperatures resulted in poorer limits of detection, due to the longer integration time needed. No matrix effect was observed at any atomization temperature using the transversely heated atomizer; in addition, limits of detection were better than those observed with the longitudinally heated atomizer. Best values were around 0.02 μg L-1 with the latter atomizer compared to values around 0.02 μg L-1 with the former one

  15. The EU Emission Trading Scheme. Sectoral Allocation Patterns and Factors Determining Emission Changes

    OpenAIRE

    Kettner, Claudia; Kletzan-Slamanig, Daniela; Köppl, Angela

    2013-01-01

    The EU Emission Trading Scheme (EU ETS) that covers emitters from industry and energy supply representing 40 percent of the EU's greenhouse gas emissions is the biggest implementation of a cap-and-trade scheme worldwide. In this paper, we analyse sectoral allocation caps focusing on three emission intensive sectors ("power and heat", "cement and lime", "pulp and paper"), assess the development of emissions and discuss the main drivers for emissions in these sectors since the start of the EU E...

  16. 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.

  17. Determination of tellurium by hydride generation with in situ trapping flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Matusiewicz, H.; Krawczyk, M. [Politechn Poznanska, Poznan (Poland)

    2007-03-15

    The analytical performance of coupled hydride generation - integrated atom trap (HG-IAT) atomizer flame atomic absorption spectrometry (FAAS) system was evaluated for determination of Te in reference material (GBW 07302 Stream Sediment), coal fly ash and garlic. Tellurium, using formation of H{sub 2}Te vapors, is atomized in air-acetylene flame-heated IAT. A new design HG-IAT-FAAS hyphenated technique that would exceed the operational capabilities of existing arrangernents (a water-cooled single silica tube, double-slotted quartz tube or an 'integrated trap') was investigated. An improvement in detection limit was achieved compared with using either of the above atom trapping techniques separately. The concentration detection limit, defined as 3 times the blank standard deviation (3{sigma}), was 0.9 ng mL{sup -1} for Te. For a 2 min in situ preconcentration time (sample volume of 2 mL), sensitivity enhancement compared to flame AAS, was 222 fold, using the hydride generation atom trapping technique. The sensitivity can be further improved by increasing the collection time. The precision, expressed as RSD, was 7.0% (n = 6) for Te. The accuracy of the method was verified using a certified reference material (GBW 07302 Stream Sediment) by aqueous standard calibration curves. The measured Te contents of the reference material was in agreement with the information value. The method was successfully applied to the determination of tellurium in coal fly ash and garlic.

  18. Direct determination of selenoproteins in polyvinylidene difluoride membranes by electrothermal atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Sidenius, U; Gammelgaard, Bente

    2000-01-01

    A method for the direct determination of selenoproteins in plastic membranes after protein separation by gel electrophoresis was developed. Quantification was based on the determination of the selenium content of the proteins by electrothermal atomic absorption spectrometry (ET-AAS) after manual...... were excised and chemical modifier was added on top of the excised membrane prior to atomic absorption measurement. Acceptable linearity was achieved in the range 2-10 ng Se, corresponding to selenium concentrations close to 1 mg/L, when aqueous solutions of selenomethionine standard as well as...

  19. The Abundances of Light Neutron-Capture Elements in Planetary Nebulae III. The Impact of New Atomic Data on Nebular Selenium and Krypton Abundance Determinations

    CERN Document Server

    Sterling, N C; Dinerstein, H L

    2015-01-01

    The detection of neutron(n)-capture elements in several planetary nebulae (PNe) has provided a new means of investigating s-process nucleosynthesis in low-mass stars. However, a lack of atomic data has inhibited accurate trans-iron element abundance determinations in astrophysical nebulae. Recently, photoionization and recombination data were determined for Se and Kr, the two most widely detected n-capture elements in nebular spectra. We have incorporated these new data into the photoionization code Cloudy. To test the atomic data, numerical models were computed for 15 PNe that exhibit emission lines from multiple Kr ions. We found systematic discrepancies between the predicted and observed emission lines that are most likely caused by inaccurate photoionization and recombination data. These discrepancies were removed by adjusting the Kr$^+$--Kr$^{3+}$ photoionization cross sections within their cited uncertainties and the dielectronic recombination rate coefficients by slightly larger amounts. From grids of ...

  20. Transmission electron microscopy studies of atomic ordering and crystal size determination on the nanometer scale

    International Nuclear Information System (INIS)

    Atomic ordering and site determination have been studied em areas of progressively smaller scale. In paper I we studied how AI and Si arc ordered in a π-AlFeMgSi matrix. Single crystal investigations were carried out using CBED for site-symmetry and refinement of atomic positions. Electron channelling was used to determine how Al and Si were arranged on atomic sites within the crystal. In paper III and IV, we studied MnO2 crystallites. The crystallites were of' nanometer size and therefore, in contrast to paper I and II, single crystal analysis could not be carried out. Instead, SAD was used to determine the arrangement of Mn atoms on the octahedral sites between oxygen hcp layers and also used to obtain information on how crystal and unit cell sizes vary within the film. The small size of nanocrystals generally limits the use of single crystal analysis techniques. However, electron channelling (or ALCHEMI) can be used to study the site arrangement of atoms in nanometer sized thin films if the film and substrate are coherent and if studied in plane view. This is explored m paper V. (Author)

  1. [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

  2. 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.)

  3. Determination of atomized concentration by β-ray method during flood discharge from high dam

    International Nuclear Information System (INIS)

    The principle of determining the atomized concentration by β-ray transmission measurement is described. The laboratory calibration was carried out with the wet filter paper to simulate water content in the air, from which the quantitative relation between the β-ray count rate and water content in the air was derived. Therefore, the atomized concentration can be determined by using the β-ray count rate measured in situ and the calibration curve. The tests in situ show that the β-ray transmission method used to measure the atomized concentration during the period of flood discharge from the high dam in hydro-power stations is precise, rapid and has a higher sensitivity than the γ-ray transmission method

  4. Electrochemical preconcentration and hydride generation methods for trace determination of selenium by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    The use of atomic absorption spectrometry in combination with two different preconcentration/separation techniques for the determination of trace concentrations of selenium is described. Electrochemical preconcentration onto a platinum electrode with a subsequent atomization of selenium is discussed briefly. Several parameters are considered such as the presence of depolarizers, and the temperature of the electrolyzed solutions. Special attention is payed to the efficiency of the atomization step, and a method to improve this is proposed. Applications of the technique to real samples are also reported. Secondly, the separation of the selenium as the volatile selenium hydride from the sample solution is considered. Several papers in this thesis deal with commonly occurring interferants as nickel and copper and with ways of minimizing or avoiding the interferring effects, whereas other papers relate to more theoretical aspects of the hydride generation process. New methods for the determination of selenium in technical samples with high contents of nickel and copper are also presented

  5. 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)

  6. 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.

  7. 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.

  8. 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)

  9. 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.

  10. 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.

  11. Structure determination in 55-atom Li-Na and Na-K nanoalloys.

    Science.gov (United States)

    Aguado, Andrés; López, José M

    2010-09-01

    The structure of 55-atom Li-Na and Na-K nanoalloys is determined through combined empirical potential (EP) and density functional theory (DFT) calculations. The potential energy surface generated by the EP model is extensively sampled by using the basin hopping technique, and a wide diversity of structural motifs is reoptimized at the DFT level. A composition comparison technique is applied at the DFT level in order to make a final refinement of the global minimum structures. For dilute concentrations of one of the alkali atoms, the structure of the pure metal cluster, namely, a perfect Mackay icosahedron, remains stable, with the minority component atoms entering the host cluster as substitutional impurities. At intermediate concentrations, the nanoalloys adopt instead a core-shell polyicosahedral (p-Ih) packing, where the element with smaller atomic size and larger cohesive energy segregates to the cluster core. The p-Ih structures show a marked prolate deformation, in agreement with the predictions of jelliumlike models. The electronic preference for a prolate cluster shape, which is frustrated in the 55-atom pure clusters due to the icosahedral geometrical shell closing, is therefore realized only in the 55-atom nanoalloys. An analysis of the electronic densities of states suggests that photoelectron spectroscopy would be a sufficiently sensitive technique to assess the structures of nanoalloys with fixed size and varying compositions. PMID:20831313

  12. Determining the emissivity of pig skin for accurate infrared thermography

    DEFF Research Database (Denmark)

    Sørensen, Dennis D.; Clausen, Sønnik; Mercer, James B.;

    2014-01-01

    significantly lower than for the ear base (p <0.001) and the udder (p <0.005). Emissivity of the three skin areas with no blood perfusion (after euthanasia) tended to be lower (p = 0.06) compared with the emissivity of the skin areas when perfused with blood. The results of this study confirm that it is valid...

  13. DETERMINATION OF COPPER AND ZINC IN MINERAL WATERS BY ATOMIC ABSORPTION SPECTROPHOTOMETRY

    Directory of Open Access Journals (Sweden)

    Tatiana Mitina

    2011-12-01

    Full Text Available The content of copper and zinc in mineral waters were determined by atomic spectroscopy with preliminary extraction of metals. Validation of the technique was carried out by the method of standard additions and proved the reliability of analytical data.

  14. Direct microcomputer controlled determination of zinc in human serum by flow injection atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Simonsen, Kirsten Wiese; Nielsen, Bent; Jensen, Arne;

    1986-01-01

    A procedure is described for the direct determination of zinc in human serum by fully automated, microcomputer controlled flow injection atomic absorption spectrometry (Fl-AAS). The Fl system is pumpless, using the negative pressure created by the nebuliser. It only consists of a three-way valve...

  15. Chemical modifiers in electrothermal atomic absorption determination of Platinum and Palladium containing preparations in blood serum

    Directory of Open Access Journals (Sweden)

    Аntonina Alemasova

    2012-11-01

    Full Text Available The biological liquids matrixes influence on the characteristic masses and repeatability of Pt and Pd electrothermal atomic absorption spectroscopy (ETAAS determination was studied. The chemical modifiers dimethylglyoxime and ascorbic acid for matrix interferences elimination and ETAAS results repeatability improvement were proposed while bioliquids ETAAS analysis, and their action mechanism was discussed.

  16. Determination of trace and minor elements in alloys by atomic-absorption spectroscopy using an induction-heated graphite-well furnace as atom source-II.

    Science.gov (United States)

    Ashy, M A; Headridge, J B; Sowerbutts, A

    1974-06-01

    Results are presented for the atomic-absorption spectrophotometric determination of zinc in aluminium and aluminium-silicon alloys, and aluminium, antimony and tin in steels, by means of solid samples dropped into an induction-heated graphite-well furnace to produce the atomic vapour. PMID:18961510

  17. Determination of iodine in seaweed and table salt by an indirect atomic absorption method

    International Nuclear Information System (INIS)

    Decomposition methods based on fusion with alkali are discussed, with respect to the determination of iodine in biological material. It is shown that sodium hydroxide can be used for the decomposition of seaweed without loss of iodine. In spite of the oxidizing conditions, the iodine will be present as iodide in the final ash. The iodide can be determined by an indirect atomic-absorption method, based on the reaction between iodide and mercury(II), with determination of mercury by cold vapour atomic-absorption spectrometry. The basis of the method is discussed, and it is shown that the use of tin(II) as reductant is essential. The effect of the oxidation state of the iodine on the sensitivity of the method is pointed out. High concentrations of chloride interfere, but it is still possible to determine iodide in iodinated table salt. (author)

  18. Synthesis and atomic structure determination of Al8V5 gamma-brass

    International Nuclear Information System (INIS)

    Many structurally complex compounds like quasicrystals and their approximants are known to be stabilized at a particular electron per atom ratio e/a, regardless of constituent elements involved. This has been often referred to as the Hume-Rothery electron concentration rule. We consider the understanding of the Hume-Rothery stabilization mechanism to be best deepened by performing both ab initio LMTO-ASA and FLAPW band calculations for the complex compound whose atomic structure is experimentally determined. Admittedly, however, a computing time increases rapidly beyond practical level with increasing the number of atoms in a unit cell. Among various candidates, we chose a series of gamma-brasses containing 52 atoms in a unit cell by taking a full advantage of the facts that it exists in as many as 24 binary alloy systems and that its unit cell is just in size to be handled even in more time-consuming FLAPW method. We have so far studied the stability mechanism of Cu5Zn8 and Cu9Al4, both being regarded as its prototype, and TM2Zn11 gamma-brasses containing late transition elements TM=Fe, Co, Ni and Pd. In the present work, we chose the gamma-brass consisting of early transition metal element V and trivalent element Al. An almost single phase Al8V5 gamma-brass was ultimately synthesized by overcoming metallurgical difficulties encountered. Its atomic structure was determined by using the Brandon model as a starting structure in the Rietveld structure analysis for powdered diffraction spectra taken at the beam line BL02B2 of 8 GeV synchrotron radiation facility, SPring-8, Japan. The atomic structure suitable for band calculations was then proposed by eliminating quenched-in chemical disorder, i.e., partial mixing of Al and V atoms at given sites with minimum sacrifice. (author)

  19. 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

  20. 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...

  1. Analytical performance of a low-gas-flow torch optimized for inductively coupled plasma atomic emission spectrometry

    Science.gov (United States)

    Montaser, A.; Huse, G.R.; Wax, R.A.; Chan, S.-K.; Golightly, D.W.; Kane, J.S.; Dorrzapf, A.F., 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.

  2. 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.

  3. Atomic absorption determination of platinum and rhenium in deactivated catalysts based on γ-alumina

    International Nuclear Information System (INIS)

    A flame atomic absorption method has been developed for the determination of Pt and Re in deactivated catalysts based on γ-Al2O3. Hydrofluoric acid is used for catalyst dissolution. The lower determination limits are 1 μg/ml for Pt and 5 μg/ml for Re, RSD are 0.01-0.15 and 0.03-0.25 respectively

  4. Atomic Absorption and Spectrophotometeric Determinations of Salicylhydroxamic Acid in Its Pure and Pharmaceutical Dosage Forms

    OpenAIRE

    SALEM, Alaa-Eldin AbdelAziz

    2003-01-01

    A new method for the indirect determination of salicylhydroxamic acid (SHAM) using atomic absorption spectrometry (AAS) was proposed. The method is based on precipitating the ion associate complex of SHAM with [Cu (NH3)4]2+. The excess, unreacted, Cu2+ ions were determined using AAS. Another spectrophotometric method based on measuring the absorbance of the formed [Cu (NH3)4]-SHAM complex in dioxane was proposed. The green color of the complex formed was measured at 330 nm. The two...

  5. Determination of cadmium as pollutant in tobaccos using atomic absorption analysis

    International Nuclear Information System (INIS)

    Atomic absorption spectroscopy has been used for the determination of cadmium in non-aqueous media. It was found that the determination of cadmium in methanol is more accurate and more precise. In this case a concentration of 0.1 ppm was accurately determined with a relative deviation not exceeding 3.2%. Using this technique, the amount of cadmium in Syrian as well as in imported tobacco was determined and found to be in the range 0.64-1.11 ppm. It was also established that the cadmium concentration in imported tobacco is higher than that in Syrian tobacco. (author)

  6. Site specific incorporation of heavy atom-containing unnatural amino acids into proteins for structure determination

    Science.gov (United States)

    Xie, Jianming; Wang, Lei; Wu, Ning; Schultz, Peter G.

    2008-07-15

    Translation systems and other compositions including orthogonal aminoacyl tRNA-synthetases that preferentially charge an orthogonal tRNA with an iodinated or brominated amino acid are provided. Nucleic acids encoding such synthetases are also described, as are methods and kits for producing proteins including heavy atom-containing amino acids, e.g., brominated or iodinated amino acids. Methods of determining the structure of a protein, e.g., a protein into which a heavy atom has been site-specifically incorporated through use of an orthogonal tRNA/aminoacyl tRNA-synthetase pair, are also described.

  7. Determination of atomic steps at argon ion bombarded Ge(100) surfaces

    International Nuclear Information System (INIS)

    The step atom density has been determined quantitatively on argon ion bombarded Ge(100) surfaces. The density has been derived from half width of LEED spots at characteristic energies. Ar+ bombardment produces random oriented step arrays with various terrace widths on Ge(100) surfaces with an edge atom density up to 40% which decreases on heat treatment. Only the non primitive lattice occurs on Ge(100) faces even after various heat treatments. The measuring and evaluation technique may be used for all kinds of surfaces on single crystals. (Auth.)

  8. Exploiting flow Injection and sequential injection schemes for trace metal determinations by electrothermal atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    Determination of low or trace-level amounts of metals by electrothermal atomic absorption spectrometry (ETAAS) often requires the use of suitable preconcentration and/or separation procedures in order to attain the necessary sensitivity and selectivity. Such schemes are advantageously executed in...... compensated by superior performance and versatility. In fact, two approaches are conceivable: The analyte-loaded ion-exchange beads might either be transported directly into the graphite tube where they are pyrolized and the measurand is atomized and quantified; or the loaded beads can be eluted and the...

  9. Determination of {pi}{pi} scattering lengths from measurement of {pi}{sup +{pi}-} atom lifetime

    Energy Technology Data Exchange (ETDEWEB)

    Adeva, B. [Santiago de Compostela University (Spain); Afanasyev, L. [JINR Dubna (Russian Federation); Benayoun, M. [LPNHE des Universites Paris VI/VII, IN2P3-CNRS (France); Benelli, A. [Zurich University (Switzerland); Berka, Z. [Czech Technical University in Prague, Prague (Czech Republic); Brekhovskikh, V. [IHEP Protvino (Russian Federation); Caragheorgheopol, G. [IFIN-HH, National Institute for Physics and Nuclear Engineering, Bucharest (Romania); Cechak, T. [Czech Technical University in Prague, Prague (Czech Republic); Chiba, M. [Tokyo Metropolitan University (Japan); Chliapnikov, P.V. [IHEP Protvino (Russian Federation); Ciocarlan, C.; Constantinescu, S. [IFIN-HH, National Institute for Physics and Nuclear Engineering, Bucharest (Romania); Costantini, S. [Basel University (Switzerland); Curceanu, C. [IFIN-HH, National Institute for Physics and Nuclear Engineering, Bucharest (Romania); Doskarova, P. [Czech Technical University in Prague, Prague (Czech Republic); Dreossi, D. [INFN, Sezione di Trieste and Trieste University, Trieste (Italy); Drijard, D., E-mail: Daniel.Drijard@cern.ch [CERN, Geneva (Switzerland); Dudarev, A. [JINR Dubna (Russian Federation); Ferro-Luzzi, M. [CERN, Geneva (Switzerland); Fungueirino Pazos, J.L. [Santiago de Compostela University (Spain)

    2011-10-05

    The DIRAC experiment at CERN has achieved a sizeable production of {pi}{sup +{pi}-} atoms and has significantly improved the precision on its lifetime determination. From a sample of 21 227 atomic pairs, a 4% measurement of the S-wave {pi}{pi} scattering length difference |a{sub 0}-a{sub 2}|=(0.2533{sub -0.0078}{sup +0.0080}|{sub stat}{sup +0.0078}{sub -0.0073}|{sub syst})M{sub {pi}}{sup +-1} has been attained, providing an important test of Chiral Perturbation Theory.

  10. Relative quasar luminosities determined from emission line strengths

    International Nuclear Information System (INIS)

    It is stated that observations of flat radio spectrum QSOs confirm the strong correlation between continuum luminosity and emission line equivalent width. The data indicate that the luminosities of QSO emission lines increase as the 1/3 power of the continuum luminosity. Unless the zero point of the relationship between emission line equivalent width and continuum luminosity depends on redshift, both the local hypothesis and zero pressure models of the Universe in which the deceleration parameter q0approximately equals 0 are ruled out by the data at about the 99% confidence level. (author)

  11. 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.

  12. 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

  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. 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, ...

  15. An accurate determination of the Avogadro constant by counting the atoms in a 28Si crystal

    CERN Document Server

    Andreas, B; Bartl, G; Becker, P; Bettin, H; Borys, M; Busch, I; Gray, M; Fuchs, P; Fujii, K; Fujimoto, H; Kessler, E; Krumrey, M; Kuetgens, U; Kuramoto, N; Mana, G; Manson, P; Massa, E; Mizushima, S; Nicolaus, A; Picard, A; Pramann, A; Rienitz, O; Schiel, D; Valkiers, S; Waseda, A

    2010-01-01

    The Avogadro constant links the atomic and the macroscopic properties of matter. Since the molar Planck constant is well known via the measurement of the Rydberg constant, it is also closely related to the Planck constant. In addition, its accurate determination is of paramount importance for a definition of the kilogram in terms of a fundamental constant. We describe a new approach for its determination by "counting" the atoms in 1 kg single-crystal spheres, which are highly enriched with the 28Si isotope. It enabled isotope dilution mass spectroscopy to determine the molar mass of the silicon crystal with unprecedented accuracy. The value obtained, 6.02214084(18) x 10^23 mol^-1, is the most accurate input datum for a new definition of the kilogram.

  16. Determination of the sites of Fe atoms in Fe-substituted Mn12

    Institute of Scientific and Technical Information of China (English)

    Cao Hui-Bo; Chen Dong-Liang; He Lun-Hua; Zhang Jun-Rong; Wang Fang-Wei; Wu Zi-Yu; Yan Qi-Wei

    2007-01-01

    In this paper neutron difiraction experiments were performed for Fe-substituted Mn12 in order to determine the sites of Fe atoms.The results of structure refinements for the sample with our accessed highest Fe content showed that all Fe atoms occupied Mn(3) sites in the Mn12 skeleton.The x-ray absorption fine structure experiments as well as multiple scattering simulations gave the same result.Thus we concluded that Fe atoms only occupied Mn(3) sites.This conclusion also means that Fe-substituted Mn12 series only includes the four single-molecule magnets of [Mn12-xFexO12(CH3COO)16(H2O)4]·4H2O(x-1,2,3,and 4), denoted by Mn11Fe1,Mn10Fe2,Mn9Fe3,and Mn8Fe4,respectively.

  17. Apparent directional spectral emissivity determination of semitransparent materials

    Science.gov (United States)

    Chun-Yang, Niu; Hong, Qi; Ya-Tao, Ren; Li-Ming, Ruan

    2016-04-01

    An inverse estimation method and corresponding measurement system are developed to measure the apparent spectral directional emissivities of semitransparent materials. The normal spectral emissivity and transmissivity serve as input for the inverse analysis. Consequently, the refractive index and absorption coefficient of the semitransparent material could be retrieved by using the pseudo source adding method as the forward method and the stochastic particle swarm optimization algorithm as the inverse method. Finally, the arbitrary apparent spectral directional emissivity of semitransparent material is estimated by using the pseudo source adding method given the retrieval refractive index and absorption coefficient. The present system has the advantage of a simple experimental structure, high accuracy, and excellent capability to measure the emissivity in an arbitrary direction. Furthermore, the apparent spectral directional emissivity of sapphire at 773 K is measured by using this system in a spectral range of 3 μm–12 μm and a viewing range of 0°–90°. The present method paves the way for a new directional spectral emissivity measurement strategy. Project supported by the National Natural Science Foundation of China (Grant Nos. 51476043 and 51576053) and the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (Grant No. 51421063).

  18. 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.

  19. Determination of dopant atomic positions with kinematical X-ray standing waves

    International Nuclear Information System (INIS)

    Recent advances in the kinematic X-ray standing wave technique (KXSW) for the determination of the atomic coordinates and displacement parameters in nonperfect crystalline materials are described in this thesis. The methodology has been improved by considering three significant aspects: - the inclusion of weak multiple beam contributions - the excitation of secondary fluorescence in multiple-element samples - the influence of the crystal mosaicity on the fluorescence yield. The improvements allowed to successfully apply the method to investigate complex oxide materials of current interest for potential device applications. The thermally-induced interdiffusion of cobalt and manganese thin films on zinc oxide single crystals has been studied to determine which lattice sites are occupied preferentially. The data analysis revealed that after thermal diffusion the adsorbed atoms occupied zinc sites in the host lattice. The mean deviation of the cobalt atomic position from the zinc lattice site was comparable to the thermal displacement parameter of the zinc atoms. In the case of manganese a secondary phase was found on the surface. Measurements performed on LaSrMnO4 provided new insight concerning the rotation of the oxygen octahedron around the manganese atoms and the concomitant displacements of the strontium and lanthanum atoms. It was found that the oxygen octahedra are rotated around the [100]-direction by 4,5 . The measurements in transmission geometry performed on titanium dioxide (rutile) demonstrated that KXSW measurements in the Laue geometry is a viable technique. By performing KXSW under grazing-incidence conditions it is possible to achieve depth resolution. The results clearly show that the extended KXSW technique is a versatile method for characterizing complex material systems. (orig.)

  20. 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

  1. 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)

  2. 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)

  3. 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)

  4. Can UK fossil fuel emissions be determined by radiocarbon measurements?

    Science.gov (United States)

    Wenger, Angelina; O'Doherty, Simon; Rigby, Matthew; Manning, Alistair; Palmer, Paul

    2016-04-01

    The GAUGE project evaluates different methods to estimate UK emissions. However, estimating carbon dioxide emissions as a result of fossil fuel burning is challenging as natural fluxes in and out of the atmosphere are very large. Radiocarbon (14C) measurements offer a way to specifically measure the amount of recently added carbon dioxide from fossil fuel burning. This is possible as, due to their age, all the radiocarbon in fossil fuels has decayed. Hence the amount of recently added CO2 from fossil fuel burning can be measured as a depletion of the 14C content in air. While this method has been successfully applied by several groups on a city or a regional scale, this is the first attempt at using the technique for a national emission estimate. Geographically the UK, being an island, is a good location for such an experiment. But are 14CO2 measurements the ideal solution for estimating fossil fuel emissions as they are heralded to be? Previous studies have shown that 14CO2emissions from the nuclear industry mask the 14C depletion caused by fossil fuel burning and result in an underestimation of the fossil fuel CO2. While this might not be a problem in certain regions around the world, many countries like the UK have a substantial nuclear industry. A correction for this enhancement from the nuclear industry can be applied but are invariably difficult as 14CO2emissions from nuclear power plants have a high temporal variability. We will explain how our sampling strategy was chosen to minimize the influence form the nuclear industry and why this proved to be challenging. In addition we present the results from our ground based measurements to show why trying to estimate national emissions using radiocarbon measurements was overambitious, and how practical the technique is for the UK in general.

  5. The determination, by atomic-absorption spectrophotometry, of trace elements in sulphide concentrates

    International Nuclear Information System (INIS)

    The separation, concentration, and determination of trace elements in base-metal and sulphide concentrates are described. After the sample has been dissolved, the trace elements that form insoluble hydroxides are precipitated with lanthanum as the coprecipitant and are separated from those elements that form soluble amines with ammonia. The precipitate is dissolved, and the trace elements selenium, tellurium, arsenic, antimony, bismuth, tin, vanadium, chromium, manganese, and aluminium are determined by atomic-absorption spectrophotometry. Coefficients of variation between 1 and 10 per cent, depending on the amount of the element, were obtained, with limits of determination ranging from 0,1 to 50 p.p.m

  6. Determination of Trace Hg in Underground Water by Inductively Coupled Plasma-Atomic Emission Spectrometry with Cu-DDTC Separation and Enrichment%铜-铜试剂分离富集-电感耦合等离子体发射光谱法测定地下水中痕量汞

    Institute of Scientific and Technical Information of China (English)

    崔德松

    2011-01-01

    利用铜(Ⅱ)与铜试剂反应生成鳌合物沉淀的同时,能将痕量汞(Ⅱ)共同沉淀出来的特性,将汞(Ⅱ)分离富集,电感耦合等离子体发射光谱法测定地下水中汞的含量.在汞标准溶液中,加入不同量的铜和铜试剂测定汞的真实含量,最终确定铜和铜试剂最佳加入量.通过优选分析线、背景恰当扣除处理,水溶液体积由200mL浓缩至5 mL,富集40倍后汞的检出限可达0.1μg/L.方法用于测定国家标准物质GBW(E)080006和实际样品,测定值与标准值、国家标准方法测定值一致,均在允许误差范围内.方法精密度(RSD,n=12)小于10%,可满足地下水中痕量汞的测定要求.%A method for the determination of Hg in underground water by inductively coupled plasma-optical emission spectrometry (ICP-AES) has been developed. Hg( Ⅱ ) was separated and enriched according to the coprecipitation of Hg( Ⅱ ) by Cu( Ⅱ ) and DDTC chelate compound in water. In order to detect the accurate value of Hg, different amount of Cu and DDTC was loaded into Hg standard solution to optimize the added amounts of Cu and DDTC. The lowest detecting concentration of Hg was 0. 1μg/L after selecting optimal analyzing line, correcting background reasonably, and condensing the volume of water from 200 mL to 5 mL with enrichment factor of 40. Certified Reference Materials and practical samples were analyzed and the results were in good agreement with the certified values obtained following national standard methods. The relative standard deviation ( RSD, n = 12) is less than 10%, Therefore, the proposed method meets the requirements for determination of trace Hg in underground water.

  7. 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.

  8. Determination of Cr(VI) and Cr(III) in urine and dextrose by inductively coupled plasma emission spectroscopy

    Science.gov (United States)

    Mianzhi, Zhuang; Barnes, Ramon M.

    The determination of Cr(VI) and Cr(III) in human urine and in commercial dextrose solution is performed by induclively coupled plasma-atomic emission spectroscopy after selective preconcentration of the chromium species at different pH values by poly(dithiocarbamate) and poly(acrylamidoxime) chelating resins. The chelating properties of these resins with chromium, including the kinetics of uptake and removal of Cr(III), and the influence of matrix concentrations were evaluated. Chromium in human urine was found to exist exclusively as Cr(III).

  9. Determination of PM10 emission rates from street sweepers.

    Science.gov (United States)

    Fitz, D R; Bumiller, K

    2000-02-01

    The use of street sweepers to clean paved roads, particularly after high-wind events, has been proposed as a PM10 control method. Using an artificial tunnel, the emission rates for several street sweepers were quantified under actual operating conditions. The tunnel was a tent enclosure, 6.1 x 4.3 x 73 m, open on both ends. PM10 concentrations were measured at the inlet and outlet while a sweeper removed sand deposited along the length. Measurements were made using a specialized low-volume filter sampler and an integrating nephelometer. The volume of air passing through the tunnel was measured by releasing an inert tracer, sulfur hexafluoride, at the inlet and measuring its concentration at the outlet. A large difference in emission rates between vacuum-type sweepers was observed, with rates varying from 5 to 100 mg m-1 swept. For the cleanest sweepers, the background rates (collected by sweeping clean pavement) were about half of the total PM10 emission rate. These background emission rates likely were from diesel exhaust; background rates for the single gasoline-powered sweeper were below detection. Particle light scattering data confirmed the filter collection results. The artificial tunnel approach would be useful in measuring total emissions from other mobile and stationary sources. PMID:10680347

  10. Determination of biomass burning emission factors. Methods and results

    International Nuclear Information System (INIS)

    Biomass burning, in a broad sense, encompasses different burning practices, including open and confined burnings, and different types of vegetation. Emission factors of gaseous or particulate trace compounds are directly dependent both on the fuel type and the combustion process. Emission factors are generally calculated by stoichiometric considerations using the carbon mass balance method, applied either to combustion chamber experiments or to field experiments based on ground-level measurements or aircraft sampling in smoke plumes. There have been a number of experimental studies in the last 10 years to investigate wildfires in tropical, temperate, or boreal regions. This article presents an overview of measurement methods and experimental data on emission factors of reactive or radiatively active trace compounds, including trace gases and particles. It focuses on fires in tropical regions, that is, forest and savanna fires, agricultural burns, charcoal production, use of fuel wood and charcoal combustion. 6 figs., 8 tabs., 65 refs

  11. 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.

  12. Experiments on studying beryllium - steam interaction, determination of oxidated beryllium emissivity factor

    International Nuclear Information System (INIS)

    The report presents results of beryllium emissivity factor measurements within 700-1300 K temperature range. The tests were conducted at Institute of Atomic Energy of the National Nuclear Center of the Republic of Kazakhstan to receive experimental data for verification of calculation programs describing an accident involving water coolant discharge into ITER reactor vacuum cavity. (author)

  13. Origin of monoterpene emissions from boreal tree species: Determination of de novo and pool emissions by 13CO2 labeling

    Science.gov (United States)

    Rinne, J.; Ghirardo, A.; Koch, K.; Taipale, R.; Zimmer, I.; Schnitzler, J.

    2009-12-01

    Boreal forests emit a large amount of monoterpenes into the atmosphere. Traditionally these emissions are assumed to originate as evaporation from large storage pools. Thus their diurnal cycle would depend mostly on temperature. However, there is indication that a significant part of the monoterpene emission would originate directly from de novo synthesis. By applying 13CO2 fumigation and analyzing the isotope fractions with proton transfer reaction mass spectrometry (PTR-MS) and classical GC-MS we studied the origin of monoterpene emissions from some major Eurasian boreal and alpine tree species. We determined the fractions originating from de novo biosynthesis and from large internal monoterpene storages for three coniferous tree species with specialized monoterpene storage structures and one dicotyledon species without such structures. The emission from dicotyledon species Betula pendula originated solely from the de novo synthesis. The origin of the emissions from coniferous species was mixed with varying fraction originating from de novo synthesis (Pinus sylvestris 58%, Picea abies 33.5%, Larix decidua 9.8%) and the rest from large internal monoterpene storage pools. Application of the observed fractions of emission originating from de novo synthesis and large storage pools in a hybrid emission algorithm resulted in a better description of ecosystem scale monoterpene emissions from a boreal Scots pine forest stand.

  14. Optimization of trace molybdenum content determination in human nails by graphite furnace atomic absorption spectrometry

    International Nuclear Information System (INIS)

    The accurate determination of molybdenum (Mo) in biological materials is of considerable importance in medical science because of the essential role played by this element in human metabolism. Molybdenum is a component of enzymes responsible for the initial stages of nitrogen, carbon and sulfur metabolism of plants, animals and humans. This element is usually determined by neutron activation analysis (NAA) in variety of samples, but direct measurement of low levels of molybdenum in biological samples by NAA is difficult. Recently instrumental analysis procedures such as atomic absorption spectrometry (AAS) have been used in clinical measurements for determination of many trace elements in the biological samples. These techniques are much simpler and cheaper than NAA. In this paper we are reporting a method of sample preparation for determining molybdenum by using graphite furnace atomic absorption spectrometry (GF-AAS). This method is the most readily available technique for determination of molybdenum at the ng/g level in biological samples. It can be used for the routine hospital laboratory determination of molybdenum and has appropriate sensitivity and simplicity. The best and reliable results for molybdenum analysis was achieved by digestion of nails in HNO3 2 N and was determined in the range from 0.11 to 5.10 μg/g

  15. Determination of vanadium in mussels by electrothermal atomic absorption spectrometry without chemical modifiers

    Energy Technology Data Exchange (ETDEWEB)

    Saavedra, Y.; Fernandez, P. [Centro de Control do Medio Marino, Peirao de Vilaxoan s/n, Vilagarcia de Arousa, 36611 Pontevedra (Spain); Gonzalez, A. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Quimica, 15706, Santiago de Compostela (Spain)

    2004-05-01

    A method was developed for the quantitative determination of total vanadium concentration in mussels via electrothermal atomic absorption spectrometry (ETAAS). After the microwave digestion of the samples, a program using temperatures of 1600 C and 2600 C for ashing and atomization respectively, without any matrix modifiers, allowed us to obtain results that were satisfactory since they agreed closely with certified reference material values. The detection limit was 0.03 mg kg{sup -1} (dry weight), indicating that the method is suitable for the analysis of mussel samples. This determination was compared with matrix modifiers that have been reported previously. The method was applied to various cultivated and wild mussels from the Galician coast, yielding levels below 1 mg kg{sup -1} (wet weight). (orig.)

  16. Determination of the anomalous scattering factors of high-Z atoms using bremsstrahlung radiation

    International Nuclear Information System (INIS)

    The anomalous scattering factors (f' and f'') of tungsten, gold and lead atoms have been determined using external bremsstrahlung (EB) photons. The EB photons are produced by the interaction of a beta particle from a beta source with a nickel target. These photons are allowed to pass through thin targets of tungsten, gold and lead. The transmitted photons have been measured by using a GMX-type HPGe detector coupled to an 8K multichannel analyser. The transmitted spectra show a sharp decrease in intensity at the K shell binding energies of the target atoms. The regions around the decreased portion have been used to determine the anomalous scattering factors. The experimentally measured values are compared with the available theoretical values.

  17. Determination of the anomalous scattering factors of high-Z atoms using bremsstrahlung radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hosur, Savita B; Naik, L R; Badiger, N M [Department of Physics, Karnatak University, Dharwad 580003 (India)], E-mail: nagappa123@yahoo.co.in

    2009-02-14

    The anomalous scattering factors (f' and f'') of tungsten, gold and lead atoms have been determined using external bremsstrahlung (EB) photons. The EB photons are produced by the interaction of a beta particle from a beta source with a nickel target. These photons are allowed to pass through thin targets of tungsten, gold and lead. The transmitted photons have been measured by using a GMX-type HPGe detector coupled to an 8K multichannel analyser. The transmitted spectra show a sharp decrease in intensity at the K shell binding energies of the target atoms. The regions around the decreased portion have been used to determine the anomalous scattering factors. The experimentally measured values are compared with the available theoretical values.

  18. Tin Content Determination in Canned Fruits and Vegetables by Hydride Generation Inductively Coupled Plasma Optical Emission Spectrometry

    Directory of Open Access Journals (Sweden)

    Sanda Rončević

    2012-01-01

    Full Text Available Tin content in samples of canned fruits and vegetables was determined by hydride generation inductively coupled plasma atomic emission spectrometry (HG-ICP-OES, and it was compared with results obtained by standard method of flame atomic absorption spectrometry (AAS. Selected tin emission lines intensity was measured in prepared samples after addition of tartaric acid and followed by hydride generation with sodium borohydride solution. The most favorable line at 189.991 nm showed the best detection limit (1.9 μg L−1 and limit of quantification (6.4 μg kg−1. Good linearity and sensitivity were established from time resolved analysis and calibration tests. Analytical accuracy of 98–102% was obtained by recovery study of spiked samples. Method of standard addition was applied for tin determination in samples from fully protected tinplate. Tin presence at low-concentration range was successfully determined. It was shown that tenth times less concentrations of Sn were present in protected cans than in nonprotected or partially protected tinplate.

  19. 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)...

  20. Atomic absorbtion spectrometric determination of platinum, palladium and rhodium in catalysts for automotive exhaust

    International Nuclear Information System (INIS)

    Analytical parameters of the electrothermal atomic absorption spectrometry method have been optimized for determination of platinum, palladium and rhodium in ceramic-supported catalysts for automobile exhaust gas treatment. Two chemical sample preparation methods have been proposed. In order to simplify the sample preparation procedure and to prevent the possible losses of platinum group metals the treatment of the previously ground sample with a mixture of mineral acids is recommended. (authors)

  1. Atomic-absorption spectrometric determination of trace metals in zirconium and zircaloy by discrete sample nebulization

    International Nuclear Information System (INIS)

    A discrete sample nebulization technique was employed to determine trace metals in nuclear grade zirconium and Zircaloy by flame atomic-absorption spectrometry. With 10% (w/v) sample solutions, detection limits for Cd, Cu, Mn, Ni and Pb were 0.6, 2, 1, 3, and 10 μg/g. Micro standard-addition procedures and background correction were employed to minimize matrix interferences produced by the high salt content of the aspirated solutions. (author)

  2. Using Xe as a heavy atom for phase determination of protein trichosanthin structure

    International Nuclear Information System (INIS)

    Under gas pressures of 1-3 MPa, xenon can be bound to discrete sites in hydrophobic cavities of protein, so as to use Xe as a heavy atom for determining phases in protein crystallography. Using single anomalous scattering diffraction method, we demonstrate that an interpretable electron density map can be obtained for protein trichosanthin from a single xenon derivative. We found, for the first time, a pre-existing hydrophobic cavity just under the protein surface of trichosanthin. (authors)

  3. Experimental determination of conduction channels in atomic scale conductors based on shot noise measurements

    OpenAIRE

    Vardimon, Ran; Klionsky, Marina; Tal, Oren

    2013-01-01

    We present an experimental procedure for obtaining the conduction channels of low-dimensional conductors based on shot noise measurements. The transmission coefficient for each channel is determined numerically from the measured conductance and Fano factor. The channel analysis is demonstrated for atomic contacts of Ag, Au, Al and Pt, showing their channel evolution as a function of conductance and mechanical elongation. This approach can be readily applied to map the conduction channels in a...

  4. Atomic-absorption determination of tantalum and niobium in ore concentrates

    International Nuclear Information System (INIS)

    A flame atom-absorption method was developed for determining tantalum and niobium at their level greater than 5% in Ta-Nb ore concentrates. Flame was produced by a nitrous oxide-acetylene mixture. The optimal composition of a buffer (3 mg/ml) of iron was determined by the method of factorial planning of the experiment and steep ascention by gradient. The optimizing parameter in factorial planning was obtained from the difference of optical densities of Ta and Nb, by taking the average value for two solutions which had dissimilar total composition and which imitated the real composition of the ore concentrates, i.e., the value of (ΔD/Dsub(av))sub(Ta) or (ΔD/Dsub(av))sub(Nb). The optimization of analytical conditions corresponded to the condition (ΔD/Dsub(av))→ 0, which indicated that the chosen optimizing parameter also facilitated the attainment of maximum D values. The variation coefficient in the determination of Ta and Nb was respectively 0.8 and 1.4%. There was a good agreement between the results obtained in Ta analysis by the atom-absorption and the extraction-gravimetric methods, and in Nb analysis by the atom-absorption, differential spectrophotometric and x-ray fluorescence methods

  5. Optimal Fluorescence Waveband Determination for Detecting Defective Cherry Tomatoes Using a Fluorescence Excitation-Emission Matrix

    Directory of Open Access Journals (Sweden)

    In-Suck Baek

    2014-11-01

    Full Text Available A multi-spectral fluorescence imaging technique was used to detect defective cherry tomatoes. The fluorescence excitation and emission matrix was used to measure for defects, sound surface and stem areas to determine the optimal fluorescence excitation and emission wavelengths for discrimination. Two-way ANOVA revealed the optimal excitation wavelength for detecting defect areas was 410 nm. Principal component analysis (PCA was applied to the fluorescence emission spectra of all regions at 410 nm excitation to determine the emission wavelengths for defect detection. The major emission wavelengths were 688 nm and 506 nm for the detection. Fluorescence images combined with the determined emission wavebands demonstrated the feasibility of detecting defective cherry tomatoes with >98% accuracy. Multi-spectral fluorescence imaging has potential utility in non-destructive quality sorting of cherry tomatoes.

  6. 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.

  7. 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

  8. 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

  9. 电感耦合等离子体发射光谱法测定红土镍矿石中镍铬镁铝钴%Determination of Ni, Cr, Mg, Al and Co in Nickel-Bearing Laterite by Inductively Coupled Plasma-Atomic Emission Spectrometry

    Institute of Scientific and Technical Information of China (English)

    胡顺峰; 王霞; 郭合颜; 金伟

    2011-01-01

    选用王水、氢氟酸、高氯酸、盐酸对红土镍矿石样品进行溶样试验,结果表明采用王水溶解,氢氟酸助溶,高氯酸冒烟除去氢氟酸的溶样方法较好;用盐酸溶解盐类,电感耦合等离子体发射光谱法测定溶液中镍、铬、镁、铝、钴元素,对目标元素进行了光谱干扰考察,选择了合适的分析谱线,结果表明铁会使目标元素谱线背景强度增高,采用在混合标准溶液中加入与样品中含量相当的铁可以消除基体干扰;除铬元素外其他目标元素加标回收率在96.83% ~ 105.23%,相对标准偏差小于3.3%.建立的方法应用于标准样品分析,除铬元素外的其他元素测定值与标准值吻合较好.铬元素回收率较低,有待进一步研究.%The different acid systems of aqua regia, HF + HC104 and HC1 were chosen for dissolving tests for Ni-bearing laterite samples. Results indicated that using aqua regia to dissolve samples with the support of HF acid and adding HC104 acid to remove HF, is an ideal method for Ni-bearing laterite. The sample solution was dissolved by HC1 before loading to determine Ni, Cr, Mg, Al and Co by inductively coupled plasma emission spectrometry (ICP-MS). The right analytical spectral lines were chosen after studying the spectral interferences for the selected elements. Test results demonstrated that Fe can increased the background intensity of the selected elements' spectral lines. The addition of the same amount of Fe with samples in mixed standard solution can eliminate matrix interference. Experimental results show that the recovery factors of Ni, Mg, Al and Co were 96. 83% - 105. 23% with a relative standard deviation( RSD) of less than 3. 3% , except Cr. The element determination results (except Cr) were in good agreement with certified values of standard materials. A further study is necessary for the low recovery of Cr.

  10. Concept of effective states of atoms in compounds to describe properties determined by the densities of valence electrons in atomic cores

    CERN Document Server

    Titov, Anatoly V; Skripnikov, Leonid V

    2014-01-01

    A new approach for describing the effective electronic states of "atoms in compounds" to study the properties of molecules and condensed matter which are circumscribed by the operators heavily concentrated in atomic cores is proposed. Among the properties are hyperfine structure, space parity (P) and time reversal invariance (T) nonconservation effects, chemical shifts of x-ray emission lines (XES), M\\"{o}ssbauer effect, etc. Advantage of the approach is that a good quantitative agreement of predicted and experimental data can be attained even for such difficult cases as XES chemical shifts providing correct quantum-mechanical interpretation of the experimental data. From computational point of view the method can be quite efficient being implemented in the framework of the relativistic pseudopotential theory [Int.J. Quantum Chem. 71, 359 (1999)] and procedures of recovering the wave functions in heavy-atom cores [Int.J. Quantum Chem. 104, 223 (2005)] after a molecular, cluster or periodic structure calculati...

  11. Determination of Ca, Cu, Fe and Pb in sugarcane raw spirits by atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    The determination of Ca, Cu, Fe and Pb in sugarcane raw spirits by atomic absorption spectrophotometry was carried out. For 20 μL injected sample, calibration within the 0,5-25,0 mg. L-1 Ca; 0,25-5,0 mg. L-1 Cu, Pb and Cu intervals were established using the ratios Cu, Ca, Fe and Pb absorbance versus analyte concentration, respectively. Typical linear correlations of r = 0,999 were obtained. The proposed method was applied for the direct determination of Ca, Cu, Fe and Pb in sugar cane spirits, and in samples. The results obtained were in accordance to those obtained at 95% confidence level

  12. Sensitivity enhancement of beryllium determination in graphite furnace-atomic absorption spectrometry by use of atomization under pressure

    International Nuclear Information System (INIS)

    Using pressurized atomization both peak height and area sensitivity of beryllium is considerably improved. The enhancement may probably be explained by the fact that the Lorentz broadening and shift is more than compensated for by the lower diffusion rate of atoms with increasing pressures. The alteration of peak shapes and parameters should result in a diminishment of vapor phase interferences with increasing pressure. The relative time resolution of the detection system also improves with increasing pressures, with a consequent improvement of precision and accuracy. In the absorbance domain calibration curves are more linear with pressurized atomization than at atmospheric pressure. (Author)

  13. 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

  14. Determining the Leaf Emissivity of Three Crops by Infrared Thermometry

    OpenAIRE

    Chiachung Chen

    2015-01-01

    Plant temperature can provide important physiological information for crop management. Non-contact measurement with an infrared thermometer is useful for detecting leaf temperatures. In this study, a novel technique was developed to measure leaf emissivity using an infrared thermometer with an infrared sensor and a thermocouple wire. The measured values were transformed into true temperatures by calibration equations to improve the measurement accuracy. The relationship between two kinds of m...

  15. The determination, by atomic-absorption spectrophotometry, of impurities in manganese dioxide

    International Nuclear Information System (INIS)

    This report describes various methods for the determination of impurities in electrolytic manganese dioxide by atomic-absorption spectrophotometry (AAS). The sample is dissolved in a mixture of acids, any residue being ignited and retreated with acid. Several AAS methods were applied so that the analysis required to meet the specifications could be attained. These involved conventional flame AAS, AAS with electrothermal atomization (ETA), hydride generation coupled with AAS, and cold-vapour AAS. Of the elements examined, copper, iron, zinc, and lead can be determined direct with confidence with or without corrections based on recoveries obtained from spiked solutions. Nickel can be determined direct by use of the method of standard additions, and copper, nickel, and lead by ETA with the method of standard additions. Arsenic and antimony are determined by hydride generation coupled with AAS, and mercury by cold-vapour AAS. The precision of analysis (relative standard deviation) is generally less than 0,050. Values were obtained for aluminium, molybdenum, magnesium, sodium, copper, chromium, and cadmium, but the accuracy of these determinations has not been fully established

  16. 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

  17. 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.)

  18. 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.

  19. 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.

  20. An instantaneous approach for determining the infrared emissivity of swine surface and the influencing factors.

    Science.gov (United States)

    Zhang, Kun; Jiao, Leizi; Zhao, Xiande; Dong, Daming

    2016-04-01

    Infrared thermal imaging technology has been widely employed in temperature measurements of human and animals and its accuracy relies on the determination process of the emissivity of the target to a large extent. However, common used methods were unable to determine the emissivity of the surface of living animals and thus lower the accuracy. In this paper, we suggested a new approach to acquire the infrared emissivity of living swine in real time. In the approach, the surface temperature of swine and reference body were measured to compute the emissivity and the measurement process was completed in a non-contact and non-invasive manner. We changed the surface reflection energy of animals and reference body by changing the ambient radiant energy and obtain the surface emissivity in real time without confirming the actual temperature of animal surface. In this way, the infrared emissivity of the animal surface can be determined instantaneously and without knowing the real temperature. Both swine specimen and a living swine were used in this study. Using this method, we measured the emissivity of different body sites of the swine. The results showed that the emissivity values at different body sites show the significant differences. The emissivity values at trotter and eye were respectively 0.895 and 0.930 and the emissivity on swine surface varied from 0.945 to 0.978. More important, the distribution of the infrared emissivity on a living swine was explored and the detailed differences of the emissivity on a swine surface can be cleanly seen. Furthermore, we studied the influencing factors on the emissivity of animal surface, through measuring the emissivity distribution on swine surface when pig specimens were sprayed with water on the surface or heated using this method. This study is of great significance for the accurate measurement of swine surface temperature. PMID:27033042

  1. Determination of Elemental Ratio in an Atomic Column by Electron Energy Loss Spectroscopy.

    Science.gov (United States)

    Haruta, Mitsutaka; Hosaka, Yoshiteru; Ichikawa, Noriya; Saito, Takashi; Shimakawa, Yuichi; Kurata, Hiroki

    2016-07-26

    Atomic-resolution quantification of the elemental ratio of Fe to Mn at the octahedral and tetrahedral sites in brownmillerite Ca2Fe1.07Mn0.93O5 was determined using electron energy-loss spectroscopy combined with aberration-corrected scanning transmission electron microscopy. The combined techniques revealed that oversampling of the spectral imaging data yielded a spatially resolved area that very nearly reflects atomic resolution (∼1.2 Å radius). The average experimental ratios of Fe to Mn within this region were 17.5:82.5 for the octahedral sites and 81.6:18.4 for the tetrahedral sites. The elemental ratio in an octahedral atomic column was successfully extracted by estimating the mixing of signals from nearest neighbor columns. The results indicated that the ratio of Fe to Mn was 13:87 at the octahedral site, which is in good agreement with the results of neutron diffraction analysis. In addition, the uncertainty of experimental results obtained by using an average 1.2 Å radius was less than 10% at octahedral sites, depending on the sample thickness. In contrast, the experimental error due to dechanneling of incident electrons was larger at the tetrahedral sites. This experimental procedure has wide application for determining the spatially resolved composition ratio of elements in perovskite-like compounds. PMID:27341006

  2. The structure determination of Al20Cu2Mn3 by near atomic resolution chemical mapping

    International Nuclear Information System (INIS)

    Highlights: • The structure of Al20Cu2Mn3 with a space group of Bbmm is completely determined. • The actual formula of Al20Cu2Mn3 is Al31Cu3Mn5. • Al20Cu2Mn3 is formed by a parallel tessellation of hexagon subunits. • Al20Cu2Mn3 is prone to twinning by an alternate tessellation of hexagon subunits. • The Al20Cu2Mn3 is coherent with α-Al along its longitudinal axis. - Abstract: Al20Cu2Mn3 phase is one kind of common dispersoids in aluminum alloys; however, the atomic arrangement of Al20Cu2Mn3 has not yet been clearly identified. Combining the atomic resolution high angle annular dark field and chemical composition quantitative results, three structure models of Al20Cu2Mn3 were derived basing on the isostructural Mn11Ni4Al60. The formation enthalpies and total energy were calculated using the first-principles approach. The structure of the Al20Cu2Mn3 phase with the minimal energy was identified, giving a fully relaxed structure with lattice parameters of a = 23.98 Å, b = 12.54 Å, c = 7.66 Å, which belongs to a space group of Bbmm. The determined structure is in excellent agreement with the near atomic resolution chemical mapping results

  3. Self-consistent determination of line-width and probe shape using atomic force microscopy

    International Nuclear Information System (INIS)

    A self-consistent method for determining line-width and probe shape using an atomic force microscope (AFM) has been developed. Through acquisition of three images in which one tip images the other, and each tip images the sample a least-squares determination of the shapes of both tips, and the parameters that define the line-width standard can be determined. Application of the self-consistent method produces measurements that can be made traceable to the definition of the metre through appropriate calibration of the AFM. A comparison between the line-width determined by the method and a calibrated line-width standard shows good agreement. Sources of uncertainty specific to the self-consistent method are discussed. (paper)

  4. 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

  5. Direct determination of lead in sweet fruit-flavored powder drinks by electrothermal atomic absorption spectrometry

    Science.gov (United States)

    Lima, Éder C.; Krug, Francisco José; Arruda, Marco A. Z.

    1998-04-01

    A simplified method for direct determination of lead in sweet fruit-flavored powder drinks, syrups and honeys by electrothermal atomic absorption spectrometry without sample digestion is proposed. Samples were dissolved in water, acidified to 0.2% (v/v) HNO 3, and directly injected into an end-capped transversely heated graphite atomizer (THGA). Building up of carbonaceous residue inside the atomizer was effectively precluded for sugar solutions not exceeding 8.0% (m/v) when a heating program with two pyrolysis steps (600 and 1000°C) was carried out without air-ashing. Under these conditions one atomizer supported about 250 firings. Among various chemical modifiers tested, better recovery and repeatability results were obtained with a 5 μg Pd + 3 μg Mg(NO 3) 2 mixture. Tests carried out with individual concomitants containing up to 1.0 μg Na, K, Ca or Cl, and up to 10.0 μg phosphate or sulphate, and several mixtures of these six concomitants, did not reveal significant interferences on lead atomization. Characteristic mass and detection limit based on integrated absorbance were 15 and 11 pg Pb, respectively. The relative standard deviation based on 10 measurements for typical samples (20-60 ng g -1 Pb) was always lower than 5.5%. The detection limit of 7.0 ng g -1 Pb attained the Codex recommendation for the maximum allowed lead contents in the sugar samples. Application of t-test to the results obtained by the proposed direct analysis, and the official method adopted by Food Chemical Codex, demonstrated that there were no significant differences at the 5% probability level.

  6. 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 ...

  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. Determination of lithium isotopes at natural abundance levels by atomic absorption spectrometry

    Science.gov (United States)

    Meier, A.L.

    1982-01-01

    The relationships of the absorption of 6Li and 7Li hollow cathode lamp emissions are used to determine lithium isotopic composition in the natural abundance range of geologic materials. Absorption was found to have a nonlinear dependence upon total lithium concentration and isotopic composition. A method using nonlinear equations to describe the relationship of the absorption of 6Li and 7Li lamp radiation is proposed as a means of calculating isotopic composition that is independent of total lithium concentration.

  9. Determination of metallic impurities in raw materials for radioisotope production by atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    Atomic absorption spectrometry has been used for the determination of traces of calcium in scandium oxide, copper in zinc, iron in cobalt oxide, manganese In ferric oxide, nickel in copper and zinc in gallium oxide. The influences on the sensitivities arising from the hollow cathode currents, the gas pressures and the acid concentrations have been considered. A study of the interferences from the metallic matrices has also been performed, the interference due to the absorption of the manganese radiation by the atoms of iron being the most outstanding . In order to remove the interfering elements and increase sensitivity, pre-concentration methods have been tested. The addition methods has also been used. (Author) 14 refs

  10. Determination of tetraalkyllead compounds in gasoline by liquid chromatography-atomic absorption spectrometry

    Science.gov (United States)

    Messman, J.D.; Rains, T.C.

    1981-01-01

    A liquid chromatography-atomic absorption spectrometry (LC-AAS) hybrid analytical technique is presented for metal speciation measurements on complex liquid samples. The versatility and inherent metal selectivity of the technique are Illustrated by the rapid determination of five tetraalkyllead compounds in commercial gasoline. Separation of the individual tetraalkyllead species is achieved by reversed-phase liquid chromatography using an acetonitrile/water mobile phase. The effluent from the liquid Chromatograph Is introduced directly into the aspiration uptake capillary of the nebulizer of an air/acetylene flame atomic absorption spectrometer. Spectral interferences due to coeluting hydrocarbon matrix constituents were not observed at the 283.3-nm resonance line of lead used for analysis. Detection limits of this LC-AAS hydrid analytical technique, based on a 20-??L injection, are approximately 10 ng Pb for each tetraalkyllead compound.

  11. 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.

  12. 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.

  13. Methods of Temperature and Emission Measure Determination of Coronal Loops

    Science.gov (United States)

    Cirtain, J. W.; Schmelz, J. T.; Martens, P. C. H.

    2002-05-01

    Recent observational results from both SOHO-EIT and TRACE indicate that coronal loops are isothermal along their length (axially). These results are obtained from a narrowband filter ratio method that assumes that the plasma is isothermal along the line of sight (radially). However, these temperatures vary greatly from those derived from differential emission measure (DEM) curves produced from spectral lines recorded by SOHO-CDS. The DEM results indicate that the loops are neither axially nor radially isothermal. This discrepancy was investigated by Schmelz et al. (2001). They chose pairs of iron lines from the same CDS data set to mimic the EIT and TRACE loop results. Ratios of different lines gave different temperatures, indicating that the plasma was not radially isothermal. In addition the results indicated that the loop was axially isothermal, even though the DEM analysis of the same data showed this result to be false. Here we have analyzed the EIT data for the CDS loop published by Schmelz et al. (2001). We took the ratios of the 171-to-195 and 195-to-284 filter data, and made temperature maps of the loop. The results indicate that the loop is axially isothermal, but different temperatures were found for each pair of filters. Both ratio techniques force the resultant temperature to lie within the range where the response functions (for filters) or the emissivity functions (for lines) overlap; isothermal loops are therefore a byproduct of the analysis. This conclusion strengthens support for the idea that temperature and emission measure results from filter ratio methods may be misleading or even drastically wrong. This research was funded in part by the NASA/TRACE MODA grant for Montana State University. Solar physics research at the University of Memphis is supported by NASA grant NAG5-9783.

  14. Determination of Elements by Atomic Absorption Spectrometry in Medicinal Plants Employed to Alleviate Common Cold Symptoms

    Institute of Scientific and Technical Information of China (English)

    F Zehra Küçükbay; Ebru Kuyumcu

    2014-01-01

    Eleven important medicinal plants generally used by the people of Turkey for the treatment of com-mon cold have been studied for their mineral contents .Eleven minor and major elements (essential ,non-essen-tial and toxic) were identified in the Asplenium adiantum-nigrum L .,Althaea of ficinalis L .,Verbascum phlomoides L .,Euphorbiachamaesyce L .,Zizyphus jujube Miller ,Peganum harmala L .,Arum dioscori-dis Sm .,Sambucus nigra L .,Piper longum L .,Tussilago farfara L .and Elettariacardamomum Maton by employing flame atomic absorption and emission spectrometry and electro-thermal atomic absorption spectrom-etry .Microwave digestion procedure for total concentration was applied under optimized conditions for dissolu-tion of medicinal plants .Plant based biological certified reference materials (CRMs) served as standards for quantification .These elements are found to be present in varying concentrations in the studied plants .The baseline data presented in this work can be used in understanding the role of essential ,non-essential and toxic elements in nutritive ,preventive and therapeutic properties of medicinal plants .

  15. Determination of Se in soil samples using the proton induced X-ray emission technique

    International Nuclear Information System (INIS)

    An alternative method for the direct determination of total Se in soil samples is presented. A large number of trace elements is present in soil at concentration values in the range of part per billion and tenths of parts of million. The most common are the trace elements of Al, Si, K, Ca, Ti, V, Cr, Fe, Cu, Zn, Br, Rb, Mo, Cd, and Pb. As for biological samples many of these elements are of great importance for the nutrition of plants, while others are toxic, and others have an unknown role. Selenium is an essential micronutrient for humans and animals but it is also known that in certain areas Se deficiency or toxicity has caused endemic disease to livestock and humans through the soil-plant-animal linkage. In this work the suitability of the proton induced X-ray emission (PIXE) technique as a fast and nondestructive technique useful to measure total the Se content in soil samples is demonstrated. To validate the results a comparison of data collected using the conventional atomic absorption spectrophotometry (AAS) method was performed. (orig.)

  16. Improved in-situ methods for determining land surface emissivity

    Science.gov (United States)

    Göttsche, Frank; Olesen, Folke; Hulley, Glynn

    2014-05-01

    The accurate validation of LST satellite products, such as the operational LST retrieved by the Land Surface Analysis - Satellite Application Facility (LSA-SAF), requires accurate knowledge of emissivity for the areas observed by the ground radiometers as well as for the area observed by the satellite sensor. Especially over arid regions, the relatively high uncertainty in land surface emissivity (LSE) limits the accuracy with which land surface temperature (LST) can be retrieved from thermal infrared (TIR) radiance measurements. LSE uncertainty affects LST obtained from satellite measurements and in-situ radiance measurements alike. Furthermore, direct comparisons between satellite sensors and ground based sensors are complicated by spatial scale mismatch: ground radiometers usually observe some 10 m2, whereas satellite sensors typically observe between 1 km2 and 100 km2. Therefore, validation sites have to be carefully selected and need to be characterised on the scale of the ground radiometer as well as on the scale of the satellite pixel. The permanent stations near Gobabeb (Namibia; hyper-arid desert climate) and Dahra (Senegal; hot-arid steppe-prairie climate) are two of KIT's four dedicated LST validation stations. Gobabeb station is located on vast and flat gravel plains (several 100 km2), which are mainly covered by coarse gravel, sand, and desiccated grass. The gravel plains are highly homogeneous in space and time, which makes them ideal for validating a broad range of satellite-derived products. Dahra station is located in so called 'tiger bush' and is covered by strongly seasonal grass (95%) and sparse, evergreen trees (dominantly acacia trees) with a background of reddish sand. The strong seasonality is caused by a pronounced rainy season, during which LST retrieval is highly challenging. Outside the rainy season, both sites have relatively large fractions of bare ground and desiccated vegetation: therefore, they are particularly prone to be

  17. Determination of the time evolution of fission from particle emission

    International Nuclear Information System (INIS)

    Recently measured properties of the prescission particle emission from heavy-ion induced fission of systems with A∼200 were analyzed using the statistical model. Simultaneous fits to prescission neutron, proton, and α-particle multiplicities and mean kinetic energies can be obtained when the deformation dependence of both the particle transmission coefficients and particle binding energies are taken into account. The experimental data are consistent with a total fission time scale of (30±10)x10-21 s, with more than half of this time being spent beyond the saddle point

  18. 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...

  19. 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

  20. Methane emission from naturally ventilated livestock buildings can be determined from gas concentration measurements

    DEFF Research Database (Denmark)

    Bjerg, Bjarne; Zhang, Guoqiang; Madsen, Jørgen; Rom, Hans Benny

    2012-01-01

    Determination of emission of contaminant gases as ammonia, methane, or laughing gas from natural ventilated livestock buildings with large opening is a challenge due to the large variations in gas concentration and air velocity in the openings. The close relation between calculated animal heat...... feasible to investigate the influence of feed composition on methane emission in a relative large number of operating cattle buildings and consequently it can support a development towards reduced greenhouse gas emission from cattle production....

  1. Determination of radioactive emission origins based on analyses of isotopic composition

    International Nuclear Information System (INIS)

    The nature of radioactivity emissions can be determined through gamma spectroscopy of air samples with good precision, which means that the type of source of the emission may be found, e.g. nuclear weapons test, of nuclear power plant accident. Combined with information on wind trajectories it is normally possible to recognize time and area for the emission. In this preliminary study, the knowledge of and preparedness for such measurements are described. (L.E.)

  2. Optimal Fluorescence Waveband Determination for Detecting Defective Cherry Tomatoes Using a Fluorescence Excitation-Emission Matrix

    OpenAIRE

    In-Suck Baek; Kim, Moon S.; Hoosoo Lee; Wang-Hee Lee; Byoung-Kwan Cho

    2014-01-01

    A multi-spectral fluorescence imaging technique was used to detect defective cherry tomatoes. The fluorescence excitation and emission matrix was used to measure for defects, sound surface and stem areas to determine the optimal fluorescence excitation and emission wavelengths for discrimination. Two-way ANOVA revealed the optimal excitation wavelength for detecting defect areas was 410 nm. Principal component analysis (PCA) was applied to the fluorescence emission spectra of all regions at 4...

  3. 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)

  4. 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)

  5. Determination of Trace Selenium in Electrolytic Manganese by Graphite Furnace Atomic Absorption Spectrometry

    Institute of Scientific and Technical Information of China (English)

    YAO Jun; ZHOU Fang-qin; MA Cheng-jin; TUO Yong; LIU Jian-ben; WU Zhu-qin; TAN Zhu-zhong

    2003-01-01

    The effects of four types of graphite tube and five matrix modifiers on the determination of selenium by graphite furnace atomic absorption spectrometry were compared.The results show that platform thermolysis coat graphite tube and magnesium nitrate and cobaltco as matrix modifer can get a high sensitivity and a good recovery.The optimized working conditions and interference in the determination were invesigated.This result is consistent with that of XRF.The recovery is from 100.8 % to102.2 %,the relative standard deviation is from 3.47% to 5.56 % (n=9),and the detection limit of selenium is 378 pg (C=44.5μg/g to 97.3μg/g.).The proposed method can be applied to the rapid determination of selenium in electrolytic manganese.

  6. An atomic-absorption method for the determination of gold in large samples of geologic materials

    Science.gov (United States)

    VanSickle, Gordon H.; Lakin, Hubert William

    1968-01-01

    A laboratory method for the determination of gold in large (100-gram) samples has been developed for use in the study of the gold content of placer deposits and of trace amounts of gold in other geologic materials. In this method the sample is digested with bromine and ethyl ether, the gold is extracted into methyl isobutyl ketone, and the determination is made by atomicabsorption spectrophotometry. The lower limit of detection is 0.005 part per million in the sample. The few data obtained so far by this method agree favorably with those obtained by assay and by other atomic-absorption methods. About 25 determinations can be made per man-day.

  7. Preconcentration of Vanadium(Ⅴ) on Crosslinked Chitosan and Determination by Graphite Furnace Atomic Absorption Spectrometry

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new method is proposed for the preconcentration of vanadium(Ⅴ) with crosslinked chitosan (CCTS) and determination by graphite furnace atomic absorption spectrometry (GFAAS). The adsorption rate of vanadium(Ⅴ) by CCTS was 97% at pH 4.0, and vanadium(Ⅴ) was eluted from crosslinked chitosan with 2 mL 2.0 mol*L-1 chlorhydric acid and determined by GFAAS. The detection limit (3σ,n=7) for vanadium(Ⅴ) was 4.8×1 0-12g and the relative standard deviation (R.S.D) at concentration level of 2.6 μg*L-1 is less than 3.6%. The method shows a good selectivity and high sensitivity, and it was applied to determination of vanadium(Ⅴ) in oyster and water samples. The analytic recoveries are (97±5)%.

  8. Determination of fleet hourly emission and on-road vehicle emission factor using integrated monitoring and modeling approach

    Science.gov (United States)

    Kim Oanh, N. T.; Martel, M.; Pongkiatkul, P.; Berkowicz, R.

    Roadside air quality and vehicle emission are important and challenging issues in urban air quality management which need to be adequately characterized. This study involves designing a monitoring program that produces suitable data to determine the on-road hourly fleet emission and emission factors of individual vehicles in a street canyon. Simultaneous hourly monitoring of roadside gaseous pollutants (both windward and leeward sides), traffic volume and speed, and wind in a busy street of Bangkok was conducted in the rainy season when traffic emission was predominant in the city. Higher pollutant concentrations often occurred at midday (11:00 to 14:00h) when higher traffic density (3700-3800vehicles h - 1, weekdays) was observed. The levels of toluene and xylenes found in this study are higher than the roadside levels reported in other Asian cities. Hourly maximum concentrations reached 258ppb for toluene, 51ppb for m, p-xylenes, 15ppb for o-xylene, 526ppb for NO x, and 10.5ppm for CO. Hourly monitoring data during the periods when the street canyon effects were pronounced were selected for determination of the fleet hourly emission and vehicle emission factors by back calculation using a street canyon model (Operational Street Pollution Model). The average fleet hourly emission at daytime of NO x (6.2kg km - 1 h - 1), CO (54kg km - 1 h - 1), toluene (2.1kg km - 1 h - 1), m, p-xylenes (0.73kg km - 1 h - 1) and o-xylene (0.27kg km - 1 h - 1) did not vary much. However, the emission rates were substantially reduced at nighttime following the traffic pattern. The obtained pollutant emission factors varied within each group of vehicles with the average values agreed reasonably with the chassis dynamometer results for NO x but somewhat higher for CO and TX. The model estimated results are, however, considered to better represent the real driving conditions in the street at the average vehicle travel speed of around 20km h - 1. A statistical sampling design is proposed

  9. 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

  10. 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

  11. Emissions of the city of Augsburg determined using the mass balance method

    Energy Technology Data Exchange (ETDEWEB)

    Kalthoff, N.; Corsmeier, U.; Schmidt, K.; Kottmeier, C.; Fiedler, F. [Universitaet Karlsruhe (Germany). Institut fuer Meteorologie und Klimaforschung; Habram, M.; Slemr, F. [Fraunhofer Institut fuer Atmospharische Umweltforschung, Garmisch (Germany)

    2002-07-01

    Air quality models require emission data of air pollutants with high temporal and spatial resolution. The highly resolved emissions are calculated by complex emission models and may thus be subject to considerable uncertainties. To assess the uncertainty of the emission model calculations, emissions of the city of Augsburg in southern Germany were determined experimentally on several days in October 1998 using the technique of mass balance. Two algorithms were used to estimate the CO and NO{sub x} emissions from the data measured by two research aircraft, two tethered balloons, and an airship on the lateral surface enclosing the area of investigation. The two algorithms provided results which agree within the calculated uncertainties. The differences can be attributed mainly to the different interpolation methods applied to the layer between the lowest flight level and the ground. The measurements show that on the different weekdays both CO and NO{sub x} emissions varied by about a factor of two which is much larger than the variability predicted by the emission model. Higher than predicted CO emissions were observed on Saturday, 10 October 1998, whereas NO{sub x} emissions on 10 October were substantially smaller than predicted by the emission model. (author)

  12. 40 CFR 75.72 - Determination of NOX mass emissions for common stack and multiple stack configurations.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Determination of NOX mass emissions... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING NOX Mass Emissions Provisions § 75.72 Determination of NOX mass emissions for common stack and multiple...

  13. 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.

  14. 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.

  15. Methylmercury determination in biological samples using electrothermal atomic absorption spectrometry after acid leaching extraction

    Energy Technology Data Exchange (ETDEWEB)

    Saber-Tehrani, Mohammad; Hashemi-Moghaddam, Hamid; Givianrad, Mohammad Hadi; Abroomand-Azar, Parviz [Islamic Azad University, Department of Chemistry, Science and Research Branch, Tehran (Iran)

    2006-11-15

    An efficient and sensitive method for the determination of methylmercury in biological samples was developed based on acid leaching extraction of methylmercury into toluene. Methylmercury in the organic phase was determined by electrothermal atomic absorption spectrometry (ETAAS). The methylmercury signal was enhanced and the reproducibility increased by formation of certain complexes and addition of Pd-DDC modifier. The complex of methylmercury with DDC produced the optimum analytical signal in terms of sensitivity and reproducibility compared to complexes with dithizone, cysteine, 1,10-phenanthroline, and diethyldithiocarbamate. Method performance was optimized by modifying parameters such as temperature of mineralization, atomization, and gas flow rate. The limit of detection for methylmercury determination was 0.015 {mu}g g{sup -1} and the RSD of the whole procedure was 12% for human teeth samples (n=5) and 15.8% for hair samples (n=5). The method's accuracy was investigated by using NIES-13 and by spiking the samples with different amounts of methylmercury. The results were in good agreement with the certified values and the recoveries were 88-95%. (orig.)

  16. Atomic absorption spectroscopic, conductometric and colorimetric methods for determination of some fluoroquinolone antibacterials using ammonium reineckate

    Science.gov (United States)

    Al-Ghannam, Sheikha M.

    2008-04-01

    Three accurate, rapid and simple atomic absorption spectrometric (AAS), conductometric and colorimetric methods were developed for the determination of gatifloxacin (GTF), moxifloxacin (MXF) and sparfloxacin (SPF). The proposed methods depend upon the reaction of ammonium reineckate with the studied drugs to form stable precipitate of ion-pair complexes, which was dissolved in acetone. The pink coloured complexes were determined either by AAS or colorimetrically at λmax 525 nm directly using the dissolved complex. Using conductometric titration, the studied drugs could be evaluated in 50% (v/v) acetone. The optimizations of various experimental conditions were described. Optimum concentration ranges for the determination of GTF, MXF and SPF were 5.0-150, 40-440 μg mL -1 and 0.10-1.5 mg mL -1 using atomic absorption (AAS), conductometric and colorimetric methods, respectively. Detection and quantification limits are ranges from 1.5 to 2.3 μg mL -1 using AAS method or 30-45 μg mL -1 using colorimetric method. The proposed procedures have been applied successfully to the analysis of these drugs in pharmaceutical formulations and the results are favourably comparable to the reference methods.

  17. Influence and determinative factors of ion-to-atom arrival ratio in unbalanced magnetron sputtering systems

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Low pressure sputtering with a controlled ratio of ion flux to deposited atom flux at the condensing surface is one of the main directions of development of magnetron sputtering methods.Unbalanced magnetron sputtering,by producing dense secondary plasma around the substrate,provides a high ion current density.The closed-field unbalanced magnetron sputtering system (CFUBMS) has been established as a versatile technique for high-rate deposition high-quality metal,alloy,and ceramic thin films.The key factor in the CFUBMS system is the ability to transport high ion currents to the substrate,which can enhance the formation of full dense coatings at relatively low value homologous temperature.The investigation shows that the energy of ions incidenced at the substrate and the ratio of the flux of these ions to the flux of condensing atoms are the fundamental parameters in determining the structure and properties of films produced by ion-assisted deposition processes.Increasing ion bombardment during deposition combined with increasing mobility of the condensing atoms favors the formation of a dense microstructure and a smooth surface.

  18. Determination of heavy metals in imported food for Libyan marketing by using Atomic Absorption Spectrometer (AAS)

    International Nuclear Information System (INIS)

    Nowadays, it becomes difficult to differentiate between essential and toxic elements, since all elements are toxic if their concentration is exceeded the permissible level recommended by the world health organization (WHO). In some instances the recommended and toxicity levels are close, therefore; it is necessary to differentiate between these essential and toxic levels even in very low concentrations. Several thousands of imported food samples (5877), including: canned soft drinks and juices, biscuits, baking powder, canned tomato past, canned hot spice, canned infant milk, canned concentrated milk, chocolates, canned tuna, and canned oil, were collected randomly from different markets around the country. The samples were analyzed for heavy metals: Cu, Zn, Fe, Sn, As, Pb, and Hg, by atomic absorption spectrometer (AAS), using flame atomization for Cu, Zn, and Fe, hydride generation (HG) for Sn and As, cold vapor for Hg and electrothermal atomization for Pb determination. The obtained AAS results were compared with the Libyan and international food specifications. Most of the samples analyzed were within the specification range and only a little have higher heavy metals level. (Authors)

  19. 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.

  20. Direct determination of sodium and potassium in blood serum by flow injection and atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    A simple and reliable method for the measurement of sodium and potassium in blood serum without any sample dilution by using flow injection and atomic absorption spectrophotometry is described. A sample throughout of 100 measurements per hour is possible. The coefficient of variation for within-run determination was about 1,14 and 2,36% for sodium and potassium, respectively, in serum samples (n=10). The method is easily adaptable to pediatric research, because of the low required sample volume of 5ul. (Author)

  1. 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.

  2. Atomic absorption spectrometric determination of some metal ions after preconcentration by solid phase extraction using amberlite XAD 16 resin loaded with thenoyltrifluoroacetone

    International Nuclear Information System (INIS)

    Complete text of publication follows. The direct determination of extremely low concentrations of trace elements by modern atomic spectroscopic methods, such as atomic absorption spectrometry and inductively coupled plasma atomic emission spectrometry is often difficult because of insufficient sensitivity and selectivity of the methods used. For this reason, the preliminary separation and preconcentration of trace elements from the matrix are often required. Solid phase extraction shows several major advantages such as simplicity, rapidity and high enrichment factor, the ability of combination with different detection techniques in the form of on-line or off-line mode and finally cost saving (Tokalioglu et al., Microchim Acta 164 (2009) 471-477.). A new solid phase extraction method for the separation and preconcentration of Cu(II), Pb(II), Ni(II), Co(II), Mn(II) and Fe(III) ions was developed. As solid phase material, Amberlite XAD-16 resin loaded with thenoyltrifluoroacetone (TTA) was used. For this purpose, 0.5 g of the resin was saturated with 10 mL of 0.5% (w/v) TTA solution. After preconcentrating, the metals retained on the resin were eluted with 10 mL of 2 mol L-1 HCl and then determined by flame atomic absorption spectrometry. The effect of some parameters for the preconcentration of the metal ions was investigated. The optimum pH was found as 6. Eluent for quantitative elution was 10 mL of 2 mol L-1 HCl.

  3. 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.

  4. 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

  5. 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

  6. 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

  7. 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.

  8. Trace levels of metallic corrosion in water determined by emission spectrography

    Science.gov (United States)

    Snell, H. H.

    1966-01-01

    Emission spectrographic method determines trace amounts of inorganic impurities in potable water. The capability of this innovation should arouse considerable interest among plant biologists, chemists working in organic synthesis, and pathologists.

  9. Determination of lead in dolomite by Zeeman electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    The mineral lorandite (TlAsS2), present in the Alshar deposit (Republic of Macedonia), is a possible solar neutrino detector (Freedman et al., 1976). As a result of nuclear reaction between the isotopes of thallium 205Tl and the solar neutrino, 205 Pb is produced. The aim of the idea is to determine the content of Pb in the lorandite, that could give information for the value of solar neutrino flux over extended time (Pavicevic, 1994). A method for the lead determination in dolomite by Zeeman electrothermal atomic absorption spectrometry, is presented. After the dissolution of samples, lead was extracted with sodium diethyldithio-carbamate. The lead-diethyldithiocarbamate complex was extracted into methylisobutyl ketone from a medium of pH 6.0-10.0. The procedure was verified by method of standard additions and by analyzing referent standard samples. A calibration curve (for organic solutions containing up to 1 ng Pb) was made using the proposed extraction procedure for standard solutions of lead. The standard deviation (SD) for 0.5 ng Pb is 0.01 ng and the relative standard deviation ranges from 2.5 to 3.5%. The detection limit of the method, calculated as 3 SD of the blank, was found to be 1.5 ng.g-1. The operation conditions in electrothermal atomic absorption measurements (temperature and time) were: drying - 90oC, 20 s; charring - 400oC, 20 s; atomizing - 1900oC, 3 s; cleaning - 2650oC, 3 s (Author)

  10. Method 200.12 - Determination of Trace Elements in Marine Waters by StabilizedTemperature Graphite Furnace Atomic Absorption

    Science.gov (United States)

    This method provides procedures for the determination of total recoverable elements by graphite furnace atomic absorption (GFAA) in marine waters, including estuarine, ocean and brines with salinities of up to 35 ppt.

  11. Gold in natural water: A method of determination by solvent extraction and electrothermal atomization

    Science.gov (United States)

    McHugh, J.B.

    1984-01-01

    A method has been developed using electrothermal atomization to effectively determine the amount of gold in natural water within the nanogram range. The method has four basic steps: (1) evaporating a 1-L sample; (2) putting it in hydrobromic acid-bromine solution; (3) extracting the sample with methyl-isobutyl-ketone; and (4) determining the amount of gold using an atomic absorption spectrophotometer. The limit of detection is 0.001 ??g gold per liter. Results from three studies indicate, respectively, that the method is precise, effective, and free of interference. Specifically, a precision study indicates that the method has a relative standard deviation of 16-18%; a recovery study indicates that the method recovers gold at an average of 93%; and an interference study indicates that the interference effects are eliminated with solvent extraction and background correction techniques. Application of the method to water samples collected from 41 sites throughout the Western United States and Alaska shows a gold concentration range of < 0.001 to 0.036 ??g gold per liter, with an average of 0.005 ??g/L. ?? 1984.

  12. Determination of tellurium in indium antimonide semiconductor material by electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Shiue, M Y; Sun, Y C; Yang, M H

    2001-08-01

    A method for the determination of the dopant concentration of tellurium in dissolved indium antimonide semiconductor material by electrothermal atomic absorption spectrometry (ETAAS) was developed. Efforts were made to investigate the optimal conditions of the furnace heating program and the effect of palladium modifier on the variation of tellurium and the background absorbance. According to the results obtained, the presence of palladium chemical modifier in the analysis of indium antimonide allowed the successful retention of tellurium in the graphite tube, and the optimum mass of palladium modifier was found to be dependent on the sample matrix concentration. The absorbance profile of tellurium and the background level were significantly improved when a pyrolysis temperature of 1100 degrees C and an atomization temperature of 2200 degrees C were employed in the optimized heating program. With the use of this method, a detection limit of 0.8 microg g(-1) tellurium in indium antimonide could be achieved. The applicability of the proposed method was evaluated by comparison with two independent methods, i.e. slurry sampling-ETAAS and ICP-MS. From the good agreement between the results, it was demonstrated that the proposed method is suitable for the determination of typical dopant concentrations of tellurium in indium antimonide. PMID:11534624

  13. 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.)

  14. 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.

  15. 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.

  16. Determination of atom percent deuterium in deuterium gas using a vibrating-probe density meter

    International Nuclear Information System (INIS)

    Atom percent deuterium may be effectively analyzed in a mixture of hydrogen and deuterium gases from the density determination of the mixture of water-heavy water which is formed after the gas sample is converted to an oxide and condensed. The density can be accurately measured by using a vibrating-tube density meter which is standardized with air and pure water or other density standards. This deuterium determination requires no empirical standardization against known deuterium standards. The sample gas in a helium carrier is passed through a hot copper oxide tube; the hydrogen and deuterium oxides are condensed in a liquid-nitrogen cooled collection bulb, which was designed for effective entrapment and prevention of sample exposure to the atmosphere

  17. Indirect determination of trace phenol in water by atomic-absorption spectrophotometry.

    Science.gov (United States)

    Bo-Xing, X; Tong-Ming, X; Ming-Neng, S; Yu-Zhi, F

    1985-03-01

    An indirect method for determination of trace phenol in water by atomic-absorption spectrophotometry (AAS) is described. The phenol is brominated in acidic solution with KBrO(3)-KBr solution at room temperature. The excess of bromine is reacted with KI and the I(2) produced is extracted into cyclohexane and then reduced back to I(-) with ascorbic acid. The I(-) is then complexed with Cd(2+) in sulphuric acid medium and the complex extracted into MIBK. The extract is analysed by flame AAS for Cd (and hence indirectly for phenol). The linear concentration range for determination of phenol is 6 x 10(-7)-0.9 x 10(-5)M in aqueous solution. Several foreign ions and organic substances do not interfere. PMID:18963829

  18. Levels of trace elements in different varieties of wheat determined by Atomic Absorption Spectroscopy

    International Nuclear Information System (INIS)

    Trace elements Ag, Au, Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sr and Zn were determined in six wheat samples purchased from the open market in different localities (Egypt, Saudi Arabia, Yemen, Oman, Dubai and Australia). The dried powdered samples were decomposed in HNO3-HClO4 acids mixtures and elements were determined using recording atomic absorption spectrophotometer. The results were within the safety baseline of all the assayed elements. Certified biological standards, Brown's Kale (BK), Orchard Leaves (OL) and tomato leaves (TOML) were used to assure the accuracy of results. However, Co, Pb and Sr were absent from samples except the Egyptian samples. The obtained databases were statistically treated. Several significant and strong positive correlation coefficients (r=0.506-1.00) between the groups of elements were observed. On the other hand, strong negative correlations (r=0.492-0.873) between another group of elements were also shown. (author)

  19. Determination of molybdenum in silicates through atomic absorption spectrometry using pre-concentration by active carbon

    International Nuclear Information System (INIS)

    An analytical procedure for molybdenum determination in geological materials through Atomic Absorption Spectrometry, after pre-concentration of the Mo-APDC complex in activated carbon, has been developed, which is needed in order to reduce the dilution effect in the sample decomposition. During the development of this method the influence of pH, the amount of APDC for complexation of Mo and the interference of Fe, Ca, Mn, Al, K, Na, Mg and Ti were tested. It was shown that none of these causes any significant effect on the Mo determination proposed. The results of the analysis at the international geochemical reference samples JB-1 (basalt) and GH (granite) were very accurate and showed that the detection limit in rocks (1,00g) is 0,6 ppm, when using sample dilution of 1 ml and microinjection techniques. (author)

  20. The direct determination of HgS by thermal desorption coupled with atomic absorption spectrometry

    Science.gov (United States)

    Coufalík, Pavel; Zvěřina, Ondřej; Komárek, Josef

    2016-04-01

    This research was aimed at the direct determination of HgS in environmental samples by means of thermal desorption coupled with atomic absorption spectrometry. Operating parameters of the apparatus used for thermal desorption (including a prototype desorption unit) are described in this work, as well as the procedure for measuring mercury release curves together with an evaluation of the analytical signal including two methods of peak integration. The results of thermal desorption were compared with HgS contents obtained by sequential extraction. The limits of quantification of the proposed method for the selective determination of the black and red forms of HgS were 4 μg kg- 1 and 5 μg kg- 1, respectively. The limit of quantification of red HgS in soils was 35 μg kg- 1. The developed analytical procedure was applied to soil and sediment samples from historical mining areas.

  1. Absolute number densities of helium metastable atoms determined by atomic absorption spectroscopy in helium plasma-based discharges used as ambient desorption/ionization sources for mass spectrometry

    International Nuclear Information System (INIS)

    The absolute number densities of helium atoms in the 2s 3S1 metastable state were determined in four plasma-based ambient desorption/ionization sources by atomic absorption spectroscopy. The plasmas included a high-frequency dielectric barrier discharge (HF-DBD), a low temperature plasma (LTP), and two atmospheric-pressure glow discharges, one with AC excitation and the other with DC excitation. Peak densities in the luminous plumes downstream from the discharge capillaries of the HF-DBD and the LTP were 1.39 × 1012 cm−3 and 0.011 × 1012 cm−3, respectively. Neither glow discharge produced a visible afterglow, and no metastable atoms were detected downstream from the capillary exits. However, densities of 0.58 × 1012 cm−3 and 0.97 × 1012 cm−3 were measured in the interelectrode regions of the AC and DC glow discharges, respectively. Time-resolved measurements of metastable atom densities revealed significant random variations in the timing of pulsed absorption signals with respect to the voltage waveforms applied to the discharges. - Highlights: • We determine He metastable number densities for four plasma types • The highest number densities were observed in a dielectric barrier discharge • No helium metastable atoms were observed downstream from the exits of glow discharges

  2. Determination of halogens by flame emission of metal halogenides

    International Nuclear Information System (INIS)

    The A-B systems InF, InCl, InBr, and InI have been excited by laminar H2-N2 flames in order to dermine individual halogens or their mixtures qualitatively or quantitatively. In optimizing the fuel gas composition two different behavior patterns have been found for band intensities, which are correlated with binding energies of InX (X = halogen). The low temperature of the flame leads to complicated matrix effects which first of all result from effects on excitation and from competitive reactions. In general, cations cause a decreased intensity. Therefore, salts have to be converted into hydrohalide acids by ion exchange. Qualitative determinations of individual halogens are possible at a 500 to 50,000fold excess of the others, whereas quantitative determinations can be performed at a 100 to 5,000fold excess in 10-4 molar solutions with errors of 2 to 10 per cent. (author)

  3. Alternative approaches to correct interferences in the determination of boron in shrimps by electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    The aim of this study is to propose alternative techniques and methods in combination with the classical chemical modification to correct the major matrix interferences in the determination of boron in shrimps. The performance of an internal standard (Ge) for the determination of boron by the simultaneous multi-element atomic absorption spectrometry was tested. The use of internal standardization increased the recovery from 85.9% to 101% and allowed a simple correction of errors during sampling preparation and heating process. Furthermore, a new preparation procedure based on the use of citric acid during digestion and dilution steps improved the sensitivity of the method and decreased the limit of detection. Finally, a comparative study between the simultaneous multi-element atomic absorption spectrometry with a longitudinal Zeeman-effect background correction system, equipped with a transversely-heated graphite atomizer and the single element atomic absorption spectrometry with a D2 background correction system, equipped with an end-heated graphite atomizer was undertaken to investigate the different behavior of boron in both techniques. Different chemical modifiers for the determination of boron were tested with both techniques. Ni-citric acid and Ca were the optimal chemical modifiers when simultaneous multi-element atomic absorption spectrometry and single-element atomic absorption spectrometry were used, respectively. By using the single-element atomic absorption spectrometry, the calculated characteristic mass was 220 pg and the calculated limit of detection was 370 μg/kg. On the contrary, with simultaneous multi-element atomic absorption spectrometry, the characteristic mass was 2200 pg and the limit of detection was 5.5 mg/kg. - Highlights: • New approaches were developed to cope with interferences of B determination by ETAAS • Ge was used as internal standard for the determination of B by simultaneous ETAAS • Citric acid was used during digestion

  4. 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

  5. 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.

  6. 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.

  7. Simultaneous determination of cadmium and lead in wine by electrothermal atomic absorption spectrometry

    Science.gov (United States)

    Freschi, Gian P. G.; Dakuzaku, Carolina S.; de Moraes, Mercedes; Nóbrega, Joaquim A.; Gomes Neto, José A.

    2001-10-01

    A method has been developed for the direct simultaneous determination of Cd and Pb in white and red wine by electrothermal atomic absorption spectrometry (ET-AAS) using a transversely heated graphite tube atomizer (THGA) with longitudinal Zeeman-effect background correction. The thermal behavior of both analytes during pyrolysis and atomization stages were investigated in 0.028 mol l -1 HNO 3 and in 1+1 v/v diluted wine using mixtures of Pd(NO 3) 2+Mg(NO 3) 2 and NH 4H 2PO 4+Mg(NO 3) 2 as chemical modifiers. With 5 μg Pd+3 μg Mg as the modifiers and a two-step pyrolysis (10 s at 400°C and 10 s at 600°C), the formation of carbonaceous residues inside the atomizer was avoided. For 20 μl of sample (wine+0.056 mol l -1 HNO 3, 1+1, v/v) dispensed into the graphite tube, analytical curves in the 0.10-1.0 μg l -1 Cd and 5.0-50 μg l -1 Pb ranges were established. The characteristic mass was approximately 0.6 pg for Cd and 33 pg for Pb, and the lifetime of the tube was approximately 400 firings. The limits of detection (LOD) based on integrated absorbance (0.03 μg l -1 for Cd, 0.8 μg l -1 for Pb) exceeded the requirements of Brazilian Food Regulations (decree #55871 from Health Department), which establish the maximum permissible level for Cd at 200 μg l -1 and for Pb at 500 μg l -1. The relative standard deviations ( n=12) were typically <8% for Cd and <6% for Pb. The recoveries of Cd and Pb added to wine samples varied from 88 to 107% and 93 to 103%, respectively. The accuracy of the direct determination of Cd and Pb was checked for 10 table wines by comparing the results with those obtained for digested wine using single-element ET-AAS, which were in agreement at the 95% confidence level.

  8. Continuous flow hydride generation-atomic fluorescence spectrometric determination and speciation of arsenic in wine

    International Nuclear Information System (INIS)

    Methods for the atomic fluorescence spectrometric (AFS) determination of total arsenic and arsenic species in wines based on continuous flow hydride generation (HG) with atomization in miniature diffusion flame (MDF) are described. For hydride-forming arsenic, L-cysteine is used as reagent for pre-reduction and complexation of arsenite, arsenate, monomethylarsonate and dimethylarsinate. Concentrations of hydrochloric acid and tetrahydroborate are optimized in order to minimize interference by ethanol. Procedure permits determination of the sum of these four species in 5-10-fold diluted samples with limit of detection (LOD) 0.3 and 0.6 μg l-1 As in white and red wines, respectively, with precision between 2% and 8% RSD at As levels within 0.5-10 μg l-1. Selective arsine generation from different reaction media is used for non-chromatographic determination of arsenic species in wines: citrate buffer at pH 5.1 for As(III); 0.2 mol l-1 acetic acid for arsenite + dimethylarsinate (DMA); 8 mol l-1 HCl for total inorganic arsenic [As(III) + As(V)]; and monomethylarsonate (MMA) calculated by difference. Calibration with aqueous and ethanol-matched standard solutions of As(III) is used for 10- and 5-fold diluted samples, respectively. The LODs are 0.4 μg l-1 for As(III) and 0.3 μg l-1 for the other three As species and precision is within 4-8% RSDs. Arsenic species in wine were also determined by coupling of ion chromatographic separation on an anion exchange column and HG-flame AFS detection. Methods were validated by means of recovery studies and comparative analyses by HG-AFS and electrothermal atomic absorption spectrometry after microwave digestion. The LODs were 0.12, 0.27, 0.15 and 0.13 μg l-1 (as As) and RSDs were 2-6%, 5-9%, 3-7% and 2-5% for As(III), As(V), MMA and DMA arsenic species, respectively. Bottled red and white wines from Bulgaria, Republic of Macedonia and Italy were analyzed by non-chromatographic and chromatographic procedures and the As

  9. Mesoporous Silica Nanoparticles as an Adsorbent for Preconcentration and Determination of Trace Amount of Nickel in Environmental Samples by Atom Trap Flame Atomic Absorption Spectrometry

    Science.gov (United States)

    Shirkhanloo, H.; Falahnejad, M.; Zavvar Mousavi, H.

    2016-01-01

    A rapid enrichment method based on solid-phase extraction (SPE) has been established for preconcentration and separation of trace Ni(II) ions in water samples prior to their determination by atom trap flame atomic absorption spectrometry. A column filled with bulky NH2-UVM7 was used as the novel adsorbent. Under optimal conditions, the linear range, limit of detection (LOD), and preconcentration factor (PF) were 3-92 μg/L, 0.8 μg/L, and 100, respectively. The validity of the method was checked by the standard reference material.

  10. 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...

  11. 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...

  12. Study of the roles of chemical modifiers in determining boron using graphite furnace atomic absorption spectrometry and optimization of the temperature profile during atomization

    International Nuclear Information System (INIS)

    The measurement conditions for determining boron using graphite furnace–atomic absorption spectrometry (GF-AAS) were investigated. Differences in the boron absorbance profiles were found using three different commercially available GF-AAS instruments when the graphite atomizers in them were not tuned. The boron absorbances found with and without adjusting the graphite atomizers suggested that achieving an adequate absorbance for the determination of boron requires a sharp temperature profile that overshoots the target temperature during the atomization process. Chemical modifiers that could improve the boron absorbance without the need for using coating agents were tested. Calcium carbonate improved the boron absorbance but did not suppress variability in the peak height. Improvement of boron absorbance was comparatively less using iron nitrate or copper nitrate than using calcium carbonate, but variability in the peak height was clearly suppressed using iron nitrate or copper nitrate. The limit of detection was 0.0026 mg L−1 when iron nitrate was used. It appears that iron nitrate is a useful new chemical modifier for the quick and simple determination of boron using GF-AAS. (author)

  13. 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.

  14. Matrix elimination method for the determination of precious metals in ores using electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Salih, Bekir; Celikbiçak, Omür; Döker, Serhat; Doğan, Mehmet

    2007-03-28

    Poly(N-(hydroxymethyl)methacrylamide)-1-allyl-2-thiourea) hydrogels, poly(NHMMA-ATU), were synthesized by gamma radiation using (60)Co gamma source in the ternary mixture of NHMMA-ATU-H(2)O. These hydrogels were used for the specific gold, silver, platinum and palladium recovery, pre-concentration and matrix elimination from the solutions containing trace amounts of precious metal ions. Elimination of inorganic matrices such as different transition and heavy metal ions, and anions was performed by adjusting the solution pH to 0.5 that was the selective adsorption pH of the precious metal ions. Desorption of the precious metal ions was performed by using 0.8 M thiourea in 3M HCl as the most efficient desorbing agent with recovery values more than 95%. In the desorption medium, thiourea effect on the atomic signal was eliminated by selecting proper pyrolysis and atomization temperatures for all precious metal ions. Precision and the accuracy of the results were improved in the graphite furnace-atomic absorption spectrometer (GFAAS) measurements by applying the developed matrix elimination method performing the adsorption at pH 0.5. Pre-concentration factors of the studied precious metal ions were found to be at least 1000-fold. Detection limits of the precious metal ions were found to be less than 10 ng L(-1) of the all studied precious metal ions by using the proposed pre-concentration method. Determination of trace levels of the precious metals in the sea-water, anode slime, geological samples and photographic fixer solutions were performed using GFAAS clearly after applying the adsorption-desorption cycle onto the poly(NHMMA-UTU) hydrogels. PMID:17386783

  15. Matrix elimination method for the determination of precious metals in ores using electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Poly(N-(hydroxymethyl)methacrylamide)-1-allyl-2-thiourea) hydrogels, poly(NHMMA-ATU), were synthesized by gamma radiation using 60Co γ source in the ternary mixture of NHMMA-ATU-H2O. These hydrogels were used for the specific gold, silver, platinum and palladium recovery, pre-concentration and matrix elimination from the solutions containing trace amounts of precious metal ions. Elimination of inorganic matrices such as different transition and heavy metal ions, and anions was performed by adjusting the solution pH to 0.5 that was the selective adsorption pH of the precious metal ions. Desorption of the precious metal ions was performed by using 0.8 M thiourea in 3 M HCl as the most efficient desorbing agent with recovery values more than 95%. In the desorption medium, thiourea effect on the atomic signal was eliminated by selecting proper pyrolysis and atomization temperatures for all precious metal ions. Precision and the accuracy of the results were improved in the graphite furnace-atomic absorption spectrometer (GFAAS) measurements by applying the developed matrix elimination method performing the adsorption at pH 0.5. Pre-concentration factors of the studied precious metal ions were found to be at least 1000-fold. Detection limits of the precious metal ions were found to be less than 10 ng L-1 of the all studied precious metal ions by using the proposed pre-concentration method. Determination of trace levels of the precious metals in the sea-water, anode slime, geological samples and photographic fixer solutions were performed using GFAAS clearly after applying the adsorption-desorption cycle onto the poly(NHMMA-UTU) hydrogels

  16. 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.

  17. Determination of nickel in active pharmaceutical ingredients by electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Bubnič, Zoran; Urleb, Uroš; Kreft, Katjuša; Veber, Marjan

    2010-03-01

    An electrothermal atomic absorption spectrometric procedure for the determination of nickel in active pharmaceutical ingredients was developed. Since the recoveries of nickel by the direct dissolution of samples in diluted nitric acid were low and caused errors in the determination of Ni in pharmaceutical samples, different approaches for sample pre-treatment were examined. It was found that the microwave digestion was the most suitable way for sample preparation. Various combinations of digestion agents and different microwave conditions were tested. The combination of nitric acid and hydrogen peroxide was found to be the most appropriate. The validity of the method was evaluated by recovery studies of spiked samples and by the comparison of the results obtained by inductively coupled plasma mass spectrometry (ICP-MS). The recovery ranged from 87.5 to 104.0% and a good agreement was achieved between both methods. The detection limit and the limit of quantification were 0.6 and 2.1 µg g-1 respectively. The precision of the method was confirmed by the determination of Ni in the spiked samples and was below 4%, expressed in terms of a relative standard deviation. The method was applied to the determination of nickel in production samples of active pharmaceutical ingredients and intermediates. PMID:24061653

  18. Determination of iron in natural and mineral waters by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    ROLANDAS KAZLAUSKAS

    2004-05-01

    Full Text Available Simple methods for the determination of Fe in natural and mineral waters by flame atomic absorption spectrometry (AAS are suggested. The results of the investigation of selectivity of the proposed AAS method proved that this procedure is not affected by high concentrations of other metals. The calibration graph for iron was linear at levels near the detection limit up to at least 0.10 mg ml-1. For the determination of microamounts of iron in mineral waters, an extraction AAS technique was developed. Iron was retained as Fe-8-oxyquinoline complex and extracted into chloroform. The optimal conditions for the extraction of the iron complex were determined. The AAS method was applied to the determination of Fe in mineral waters and natural waters from different areas of Lithuania. The accuracy of the developed method was sufficient and evaluated in comparison with a photometric method. The obtained results demonstrated that the procedure could be successfully applied for the analysis of water samples with satisfactory accuracy.

  19. Atomic absorption determination, in metal sulphide concentrates, of the elements that form gaseous hydrides

    International Nuclear Information System (INIS)

    An account is given of the investigational work on the determination of trace amounts of arsenic, antimony, bismuth, germanium, selenium, and tellurium by the technique using hydride generation and atomic-absorption spectrophotometry. The gaseous hydride is generated by reduction with sodium borohydride, and is subsequently swept by a flow of nitrogen into an air-entrained hydrogen-nitrogen flame. The generation equipment used is simple and inexpensive, and can be readily assembled in most laboratories. The optimum parameters were determined for each element. The effects of 31 probable interfering elements were investigated, and it was found that, although the majority did not interfere, severe interference was encountered when copper, nickel, and the noble metals were present. Methods for the elimination of copper and nickel were developed to allow the determination of arsenic, antimony, bismuth, selenium, and tellurium at the lower parts-per-million level in metal sulphide concentrates with an acceptable accuracy and precision. The determination of microgram amounts of germanium was found to be unsatisfactory

  20. Sulfur hexafluoride (SF6) emissions in East Asia determined by inverse modeling

    Science.gov (United States)

    Fang, X.; Thompson, R. L.; Saito, T.; Yokouchi, Y.; Kim, J.; Li, S.; Kim, K. R.; Park, S.; Graziosi, F.; Stohl, A.

    2014-05-01

    Sulfur hexafluoride (SF6) has a global warming potential of around 22 800 over a 100-year time horizon and is one of the greenhouse gases regulated under the Kyoto Protocol. Around the year 2000 there was a reversal in the global SF6 emission trend, from a decreasing to an increasing trend, which was likely caused by increasing emissions in countries that are not obligated to report their annual emissions to the United Nations Framework Convention on Climate Change. In this study, SF6 emissions during the period 2006-2012 for all East Asian countries - including Mongolia, China, Taiwan, North Korea, South Korea and Japan - were determined by using inverse modeling and in situ atmospheric measurements. We found that the most important sources of uncertainty associated with these inversions are related to the choice of a priori emissions and their assumed uncertainty, the station network as well as the meteorological input data. Much lower uncertainties are due to seasonal variability in the emissions, inversion geometry and resolution, and the measurement calibration scale. Based on the results of these sensitivity tests, we estimate that the total SF6 emission in East Asia increased rapidly from 2404 ± 325 Mg yr-1 in 2006 to 3787 ± 512 Mg yr-1 in 2009 and stabilized thereafter. China contributed 60-72% to the total East Asian emission for the different years, followed by South Korea (8-16%), Japan (5-16%) and Taiwan (4-7%), while the contributions from North Korea and Mongolia together were less than 3% of the total. The per capita SF6 emissions are highest in South Korea and Taiwan, while the per capita emissions for China, North Korea and Japan are close to global average. During the period 2006-2012, emissions from China and from South Korea increased, while emissions from Taiwan and Japan decreased overall.