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Sample records for ambient ionization source

  1. Comparison of Three Plasma Sources for Ambient Desorption/Ionization Mass Spectrometry

    Science.gov (United States)

    McKay, Kirsty; Salter, Tara L.; Bowfield, Andrew; Walsh, James L.; Gilmore, Ian S.; Bradley, James W.

    2014-09-01

    Plasma-based desorption/ionization sources are an important ionization technique for ambient surface analysis mass spectrometry. In this paper, we compare and contrast three competing plasma based desorption/ionization sources: a radio-frequency (rf) plasma needle, a dielectric barrier plasma jet, and a low-temperature plasma probe. The ambient composition of the three sources and their effectiveness at analyzing a range of pharmaceuticals and polymers were assessed. Results show that the background mass spectrum of each source was dominated by air species, with the rf needle producing a richer ion spectrum consisting mainly of ionized water clusters. It was also seen that each source produced different ion fragments of the analytes under investigation: this is thought to be due to different substrate heating, different ion transport mechanisms, and different electric field orientations. The rf needle was found to fragment the analytes least and as a result it was able to detect larger polymer ions than the other sources.

  2. Ambient desorption/ionization mass spectrometry using a liquid sampling-atmospheric glow discharge (LS-APGD) ionization source.

    Science.gov (United States)

    Marcus, R Kenneth; Burdette, Carolyn Q; Manard, Benjamin T; Zhang, Lynn X

    2013-10-01

    A novel approach to ambient desorption/ionization mass spectrometry (ADI-MS) is described, based on a recently developed liquid sampling-atmospheric pressure glow discharge (LS-APGD) ionization source. The device is essentially unmodified relative to its implementation in elemental mass spectrometry, where the operational space is characterized by low operation power (LS-APGD source is mounted onto the source interface of a Thermo Finnigan LCQ Advantage Max quadrupole ion trap mass spectrometer without modifications to the instrument faceplate or ion optics. Described here is the initial evaluation of the roles of source geometry and working parameters, including electrolytic solution composition and plasma current, on the response of caffeine residues, with preliminary limits of detection based on the relative standard deviation of the spectral background suggested to be on the 10-pg level. Demonstrative spectra are presented for green tea extracts and raw leaves, coffee beans, a dried (raw) tobacco leaf, an analgesic tablet, and paper currency. Versatility is further revealed through the determination of components in common cigarette smoke. In each case, the spectra are characterized by (M + H)(+) species of the expected constituents. The capacity for a single source to perform both in solution and particulate elemental analysis (as shown previously) and ADI of molecular species is unique in the realm of mass spectrometry.

  3. Ionization mechanism of the ambient pressure pyroelectric ion source (APPIS) and its applications to chemical nerve agent detection.

    Science.gov (United States)

    Neidholdt, Evan L; Beauchamp, J L

    2009-11-01

    We present studies of the ionization mechanism operative in the ambient pressure pyroelectric ionization source (APPIS), along with applications that include detection of simulants for chemical nerve agents. It is found that ionization by APPIS occurs in the gas-phase. As the crystal is thermally cycled over a narrow temperature range, electrical discharges near the surface of the crystal produce energetic species which, through reactions with atmospheric molecules, result in reactant ions such as protonated water clusters or clusters of hydroxide and water. Reactant ions can be observed directly in the mass spectrometer. These go on to react with trace neutrals via proton transfer reactions to produce the ions observed in mass spectra, which are usually singly protonated or deprotonated species. Further implicating gas-phase ionization, observed product distributions are highly dependent on the composition of ambient gases, especially the concentration of water vapor and oxygen surrounding the source. For example, basic species such as triethylamine are observed as singly protonated cations at a water partial pressure of 10 torr. At a water pressure of 4 torr, reactive oxygen species are formed and lead to observation of protonated amine oxides. The ability of the APPIS source to detect basic molecules with high proton affinities makes it highly suited for the detection of chemical nerve agents. We demonstrate this application using simulants corresponding to VX and GA (Tabun). With the present source configuration pyridine is detected readily at a concentration of 4 ppm, indicating ultimate sensitivity in the high ppb range. PMID:19682922

  4. Direct and Convenient Mass Spectrometry Sampling with Ambient Flame Ionization

    OpenAIRE

    Xiao-Pan Liu; Hao-Yang Wang; Jun-Ting Zhang; Meng-Xi Wu; Wan-Shu Qi; Hui Zhu; Yin-Long Guo

    2015-01-01

    Recent innovations in ambient ionization technology for the direct analysis of various samples in their native environment facilitate the development and applications of mass spectrometry in natural science. Presented here is a novel, convenient and flame-based ambient ionization method for mass spectrometric analysis of organic compounds, termed as the ambient flame ionization (AFI) ion source. The key features of AFI ion source were no requirement of (high) voltages, laser beams and spray g...

  5. Chemometric optimization of a low-temperature plasma source design for ambient desorption/ionization mass spectrometry

    International Nuclear Information System (INIS)

    Low-temperature plasmas (LTPs) are attractive sources for atomic and molecular mass spectrometry (MS). In the past, the LTP probe, which was first described by Harper et al., was used successfully for direct molecular mass spectrometric analysis with minimal sample pretreatment in a variety of applications. Unfortunately, the desorption/ionization source itself is commercially not available and custom-built LTP set-ups with varying geometry and operational configurations were utilized in the past. In the present study, a rapid chemometrics approach based on systematic experiments and multivariate data analysis was used to optimize the LTP probe geometry and positioning relative to the atmospheric-pressure inlet of a mass spectrometer. Several parameters were studied including the probe geometry, electrode configuration, quartz tube dimensions, probe positioning and operating conditions. It was found that the plasma-to-MS-inlet distance, the plasma-to-sample-plate distance, and the angle between the latter are very important. Additional effects on the analytical performance were found for the outer electrode width, the positioning of the electrodes, the inner diameter of the quartz tube, the quartz wall thickness, and the gas flow. All experiments were performed using additional heating of the sample to enhance thermal desorption and maximize the signal (T = 150 °C). After software-assisted optimization, attractive detection limits were achieved (e.g., 1.8 × 10−7 mol/L for 4-acetamidothiophenol). Moreover, relative standard deviation (RSD) improved from values of up to 30% before optimization to < 15% RSD after the procedure was completed. This chemometrics approach for method optimization is not limited to LTP-MS and considered to be attractive for other plasma-based instrumentation as well. - Highlights: • Plasmas are useful in ambient desorption/ionization mass spectrometry. • Rapid and direct analysis is performed without sample preparation.

  6. Chemometric optimization of a low-temperature plasma source design for ambient desorption/ionization mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Albert, Anastasia [University of Muenster, Institute of Inorganic and Analytical Chemistry, Corrensstraße 30, 48149 Muenster (Germany); Engelhard, Carsten, E-mail: engelhard@chemie.uni-siegen.de [University of Siegen, Department of Chemistry and Biology, Adolf-Reichwein-Straße 2, 57076 Siegen (Germany)

    2015-03-01

    Low-temperature plasmas (LTPs) are attractive sources for atomic and molecular mass spectrometry (MS). In the past, the LTP probe, which was first described by Harper et al., was used successfully for direct molecular mass spectrometric analysis with minimal sample pretreatment in a variety of applications. Unfortunately, the desorption/ionization source itself is commercially not available and custom-built LTP set-ups with varying geometry and operational configurations were utilized in the past. In the present study, a rapid chemometrics approach based on systematic experiments and multivariate data analysis was used to optimize the LTP probe geometry and positioning relative to the atmospheric-pressure inlet of a mass spectrometer. Several parameters were studied including the probe geometry, electrode configuration, quartz tube dimensions, probe positioning and operating conditions. It was found that the plasma-to-MS-inlet distance, the plasma-to-sample-plate distance, and the angle between the latter are very important. Additional effects on the analytical performance were found for the outer electrode width, the positioning of the electrodes, the inner diameter of the quartz tube, the quartz wall thickness, and the gas flow. All experiments were performed using additional heating of the sample to enhance thermal desorption and maximize the signal (T = 150 °C). After software-assisted optimization, attractive detection limits were achieved (e.g., 1.8 × 10{sup −7} mol/L for 4-acetamidothiophenol). Moreover, relative standard deviation (RSD) improved from values of up to 30% before optimization to < 15% RSD after the procedure was completed. This chemometrics approach for method optimization is not limited to LTP-MS and considered to be attractive for other plasma-based instrumentation as well. - Highlights: • Plasmas are useful in ambient desorption/ionization mass spectrometry. • Rapid and direct analysis is performed without sample preparation.

  7. Ambient ionization mass spectrometry: A tutorial

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Min-Zong; Cheng, Sy-Chi; Cho, Yi-Tzu [Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Shiea, Jentaie, E-mail: jetea@fac.nsysu.edu.tw [Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Cancer Center, Kaohsiung Medical University, Kaohsiung, Taiwan (China)

    2011-09-19

    Highlights: {yields} Ambient ionization technique allows the direct analysis of sample surfaces with little or no sample pretreatment. {yields} We sort ambient ionization techniques into three main analytical strategies, direct ionization, direct desorption/ionization, and two-step ionization. {yields} The underlying principles of operation, ionization processes, detecting mass ranges, sensitivity, and representative applications of these techniques are described and compared. - Abstract: Ambient ionization is a set of mass spectrometric ionization techniques performed under ambient conditions that allows the direct analysis of sample surfaces with little or no sample pretreatment. Using combinations of different types of sample introduction systems and ionization methods, several novel techniques have been developed over the last few years with many applications (e.g., food safety screening; detection of pharmaceuticals and drug abuse; monitoring of environmental pollutants; detection of explosives for antiterrorism and forensics; characterization of biological compounds for proteomics and metabolomics; molecular imaging analysis; and monitoring chemical and biochemical reactions). Electrospray ionization and atmospheric pressure chemical ionization are the two main ionization principles most commonly used in ambient ionization mass spectrometry. This tutorial paper provides a review of the publications related to ambient ionization techniques. We describe and compare the underlying principles of operation, ionization processes, detecting mass ranges, sensitivity, and representative applications of these techniques.

  8. The Effects of Added Hydrogen on Noble Gas Discharges Used as Ambient Desorption/Ionization Sources for Mass Spectrometry

    Science.gov (United States)

    Ellis, Wade C.; Lewis, Charlotte R.; Openshaw, Anna P.; Farnsworth, Paul B.

    2016-07-01

    We demonstrate the effectiveness of using hydrogen-doped argon as the support gas for the dielectric barrier discharge (DBD) ambient desorption/ionization (ADI) source in mass spectrometry. Also, we explore the chemistry responsible for the signal enhancement observed when using both hydrogen-doped argon and hydrogen-doped helium. The hydrogen-doped argon was tested for five analytes representing different classes of molecules. Addition of hydrogen to the argon plasma gas enhanced signals for gas-phase analytes and for analytes coated onto glass slides in positive and negative ion mode. The enhancements ranged from factors of 4 to 5 for gas-phase analytes and factors of 2 to 40 for coated slides. There was no significant increase in the background. The limit of detection for caffeine was lowered by a factor of 79 using H2/Ar and 2 using H2/He. Results are shown that help explain the fundamental differences between the pure-gas discharges and those that are hydrogen-doped for both argon and helium. Experiments with different discharge geometries and grounding schemes indicate that observed signal enhancements are strongly dependent on discharge configuration.

  9. The Effects of Added Hydrogen on Noble Gas Discharges Used as Ambient Desorption/Ionization Sources for Mass Spectrometry

    Science.gov (United States)

    Ellis, Wade C.; Lewis, Charlotte R.; Openshaw, Anna P.; Farnsworth, Paul B.

    2016-09-01

    We demonstrate the effectiveness of using hydrogen-doped argon as the support gas for the dielectric barrier discharge (DBD) ambient desorption/ionization (ADI) source in mass spectrometry. Also, we explore the chemistry responsible for the signal enhancement observed when using both hydrogen-doped argon and hydrogen-doped helium. The hydrogen-doped argon was tested for five analytes representing different classes of molecules. Addition of hydrogen to the argon plasma gas enhanced signals for gas-phase analytes and for analytes coated onto glass slides in positive and negative ion mode. The enhancements ranged from factors of 4 to 5 for gas-phase analytes and factors of 2 to 40 for coated slides. There was no significant increase in the background. The limit of detection for caffeine was lowered by a factor of 79 using H2/Ar and 2 using H2/He. Results are shown that help explain the fundamental differences between the pure-gas discharges and those that are hydrogen-doped for both argon and helium. Experiments with different discharge geometries and grounding schemes indicate that observed signal enhancements are strongly dependent on discharge configuration.

  10. Direct and Convenient Mass Spectrometry Sampling with Ambient Flame Ionization

    Science.gov (United States)

    Liu, Xiao-Pan; Wang, Hao-Yang; Zhang, Jun-Ting; Wu, Meng-Xi; Qi, Wan-Shu; Zhu, Hui; Guo, Yin-Long

    2015-11-01

    Recent innovations in ambient ionization technology for the direct analysis of various samples in their native environment facilitate the development and applications of mass spectrometry in natural science. Presented here is a novel, convenient and flame-based ambient ionization method for mass spectrometric analysis of organic compounds, termed as the ambient flame ionization (AFI) ion source. The key features of AFI ion source were no requirement of (high) voltages, laser beams and spray gases, but just using small size of n-butane flame (height approximately 1 cm, about 500 oC) to accomplish the rapid desorption and ionization for direct analysis of gaseous-, liquid- and solid-phase organic compounds, as well as real-world samples. This method has high sensitivity with a limit of detection of 1 picogram for propyphenazone, which allows consuming trace amount of samples. Compared to previous ionization methods, this ion source device is extremely simple, maintain-free, low-cost, user-friendly so that even an ordinary lighter (with n-butane as fuel) can achieve efficient ionization. A new orientation to mass spectrometry ion source exploitation might emerge from such a convenient, easy and inexpensive AFI ion source.

  11. Chemometric optimization of a low-temperature plasma source design for ambient desorption/ionization mass spectrometry

    Science.gov (United States)

    Albert, Anastasia; Engelhard, Carsten

    2015-03-01

    Low-temperature plasmas (LTPs) are attractive sources for atomic and molecular mass spectrometry (MS). In the past, the LTP probe, which was first described by Harper et al., was used successfully for direct molecular mass spectrometric analysis with minimal sample pretreatment in a variety of applications. Unfortunately, the desorption/ionization source itself is commercially not available and custom-built LTP set-ups with varying geometry and operational configurations were utilized in the past. In the present study, a rapid chemometrics approach based on systematic experiments and multivariate data analysis was used to optimize the LTP probe geometry and positioning relative to the atmospheric-pressure inlet of a mass spectrometer. Several parameters were studied including the probe geometry, electrode configuration, quartz tube dimensions, probe positioning and operating conditions. It was found that the plasma-to-MS-inlet distance, the plasma-to-sample-plate distance, and the angle between the latter are very important. Additional effects on the analytical performance were found for the outer electrode width, the positioning of the electrodes, the inner diameter of the quartz tube, the quartz wall thickness, and the gas flow. All experiments were performed using additional heating of the sample to enhance thermal desorption and maximize the signal (T = 150 °C). After software-assisted optimization, attractive detection limits were achieved (e.g., 1.8 × 10- 7 mol/L for 4-acetamidothiophenol). Moreover, relative standard deviation (RSD) improved from values of up to 30% before optimization to < 15% RSD after the procedure was completed. This chemometrics approach for method optimization is not limited to LTP-MS and considered to be attractive for other plasma-based instrumentation as well.

  12. Mass spectrometry of solid samples in open air using combined laser ionization and ambient metastable ionization

    Science.gov (United States)

    He, X. N.; Xie, Z. Q.; Gao, Y.; Hu, W.; Guo, L. B.; Jiang, L.; Lu, Y. F.

    2012-01-01

    Mass spectrometry of solid samples in open air was carried out using combined laser ionization and metastable ionization time-of-flight mass spectrometry (LI-MI-TOFMS) in ambient environment for qualitative and semiquantitative (relative analyte information, not absolute information) analysis. Ambient metastable ionization using a direct analysis in realtime (DART) ion source was combined with laser ionization time-of-flight mass spectrometry (LI-TOFMS) to study the effects of combining metastable and laser ionization. A series of metallic samples from the National Institute of Standards and Technology (NIST 494, 495, 498, 499, and 500) and a pure carbon target were characterized using LI-TOFMS in open air. LI-MI-TOFMS was found to be superior to laser-induced breakdown spectroscopy (LIBS). Laser pulse energies between 10 and 200 mJ at the second harmonic (532 nm) of an Nd:YAG laser were applied in the experiment to obtain a high degree of ionization in plasmas. Higher laser pulse energy improves signal intensities of trace elements (such as Fe, Cr, Mn, Ni, Ca, Al, and Ag). Data were analyzed by numerically calculating relative sensitivity coefficients (RSCs) and limit of detections (LODs) from mass spectrometry (MS) and LIBS spectra. Different parameters, such as boiling point, ionization potential, RSC, LOD, and atomic weight, were shown to analyze the ionization and MS detection processes in open air.

  13. 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

  14. Plasma ionization under simulated ambient Mars conditions for quantification of methane by mass spectrometry.

    Science.gov (United States)

    Taghioskoui, Mazdak; Zaghloul, Mona

    2016-04-01

    Ambient ionization techniques enable ion production in the native sample environment for mass spectrometry, without a need for sample preparation or separation. These techniques provide superior advantages over conventional ionization methods and are well developed and investigated for various analytical applications. However, employing ambient ionization techniques for in situ extra-terrestrial chemical analysis requires these techniques to be designed and developed according to the ambient conditions of extra-terrestrial environments, which substantially differ from the ambient conditions of Earth. Here, we report a plasma ionization source produced under simulated ambient Mars conditions for mass spectrometry. The plasma ionization source was coupled to a quadrupole mass spectrometer, and quantitative and qualitative analyses of trace amounts of methane, as an analyte of interest in Mars discovery missions, were demonstrated. The miniature plasma source was operational at a net power as low as ∼1.7 W in the pressure range of 4-16 Torr. A detection limit as low as ∼0.15 ppm (v/v) at 16 Torr for methane was demonstrated. PMID:26947458

  15. Effect of gas pressure on ionization of ambient gas

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An Nd: YAG pulsed laser (145 mJ) was used to ablate aluminum target and Ar was used as protecting gas. Time-and space-resolved spectra of the plasmas under pressure 100 Pa, 1 kPa, 10 kPa and 100 kPa were acquired with time- and space-resolved technique. The characteristics of the plasma radiating under each pressure were briefly described, and the laws of Ar characteristical radiaton were analyzed in detail. Based on the profile of Ar characteristical radiation under these pressure, the relation between protecting gas pressure and its ionization was briefly discussed, and explained with quantum theory. Farther more, the mechanism of ambient gas ionization was investigated. As the result, it was suggested that the main mechanism inducing protecting gas to ionize should be the absorption of the plasma continuum radiation by the gas.

  16. Prediction of acrylamide formation in biscuits based on fingerprint data generated by ambient ionization mass spectrometry employing direct analysis in real time (DART) ion source.

    Science.gov (United States)

    Vaclavik, Lukas; Capuano, Edoardo; Gökmen, Vural; Hajslova, Jana

    2015-04-15

    The objective of this study is the evaluation of the potential of high-throughput direct analysis in real time-high resolution mass spectrometry (DART-HRMS) fingerprinting and multivariate regression analysis in prediction of the extent of acrylamide formation in biscuit samples prepared by various recipes and baking conditions. Information-rich mass spectral fingerprints were obtained by analysis of biscuit extracts for preparation of which aqueous methanol was used. The principal component analysis (PCA) of the acquired data revealed an apparent clustering of samples according to the extent of heat-treatment applied during the baking of the biscuits. The regression model for prediction of acrylamide in biscuits was obtained by partial least square regression (PLSR) analysis of the data matrix representing combined positive and negative ionization mode fingerprints. The model provided a least root mean square error of cross validation (RMSECV) equal to an acrylamide concentration of 5.4 μg kg(-1) and standard error of prediction (SEP) of 14.8 μg kg(-1). The results obtained indicate that this strategy can be used to accurately predict the amounts of acrylamide formed during baking of biscuits. Such rapid estimation of acrylamide concentration can become a useful tool in evaluation of the effectivity of processes aiming at mitigation of this food processing contaminant. However, the robustness this approach with respect to variability in the chemical composition of ingredients used for preparation of biscuits should be tested further.

  17. Development of Thermal Dissociation Atmospheric Chemical Ionization Source for Rapid Mass Spectrometric Analysis of Ambient Samples%常压热解离化学电离源的研制及表征

    Institute of Scientific and Technical Information of China (English)

    韩京; 李建强; 张燮; 胡斌; 罗明标; 陈焕文

    2011-01-01

    A novel thermal dissociation atmospheric chemical ionization source (TDCI) was developed for rapid chemical ionization of ambient analytes in complex matrices. By coupling the TDCI source to a commercial LTQ XL mass spectrometer, the dissociation of chemical reagents such as ionic liquids was systematically investigated using multiple-stage mass spectrometric experiments. The primary ions generated through the thermal dissociation process of the ionic liquids were accelerated by the high voltage applied on the repelling electrode of the TDCI source, and then reacted with the analytes present in the matrices of the raw samples to produce ions of analytes, which were then guided to the LTQ instrument for mass analysis. The construction of the TDCI source was detailed in the text. The effects of the experimental parameters such as the pyrolysis temperature, the distance, and the angles formed between the electrodes were experimentally studied using the signals of characteristic fragments of the ionic liquid. Under the optimal experimental parameters, TDCI was able to directly ionize a wide variety of compounds, including the poplar (e.g., amino acids, doping compounds) and non-polar chemicals (e.g, naphthalene) for sensitive detection using LTQ-MS, without any sample pretreatment. The average time for a single sample analysis was less than 30 s, and the relative standard deviation of the method was in the range of 5.9%- 11.1 %; the LOD for naphthalene was estimated to be 2.93 × 10-7 g/L.%自行研制了常压热解离化学电离源(TDCI),与商品化LTQ XL质谱仪成功联用,进一步考察了TDCI的性能,并对其应用领域进行了初步探索.TDCI-MS/MS谱图表明,离子液体可在现有实验条件下产生特征离子碎片;升高TDCI源偏置电压和温度,可以提高离子液体的信号强度.基于优化后的实验参数,常压热解离化学电离质谱方法(TDCI-MS)可以有效检测沙丁胺醇和萘等极性与非极性物质.本方法

  18. Coupling corona discharge for ambient extractive ionization mass spectrometry.

    Science.gov (United States)

    Hu, Bin; Zhang, Xinglei; Li, Ming; Peng, Xuejiao; Han, Jing; Yang, Shuiping; Ouyang, Yongzhong; Chen, Huanwen

    2011-12-01

    Unlike the extractive electrospray ionization (EESI) technique described elsewhere, a corona discharge instead of electrospray ionization has been utilized to charge a neutral solvent spray under ambient conditions for the generation of highly charged microdroplets, which impact a neutral sample plume for the extractive ionization of the analytes in raw samples without any sample pretreatment. Using the positive ion mode, molecular radical cations were easily generated for the detection of non-polar compounds (e.g., benzene, cyclohexane, etc.), while protonated molecular ions of polar compounds (e.g., acetonitrile, acetic ether) were readily produced for the detection. By dispensing the matrix in a relatively large space, this method tolerates highly complex matrices. For a given sample such as lily fragrances, more compounds were detected by the method established here than the EESI technique. An acceptable relative standard deviation (RSD 8.9%, n = 11) was obtained for the direct measurement of explosives (10 ppb) in waste water samples. The experimental data demonstrate that this method could simultaneously detect both polar and non-polar analytes with high sensitivity, showing promising applications for the rapid detection of a wide variety of compounds present in complex matrices. PMID:21971289

  19. Data-Independent Microbial Metabolomics with Ambient Ionization Mass Spectrometry

    Science.gov (United States)

    Rath, Christopher M.; Yang, Jane Y.; Alexandrov, Theodore; Dorrestein, Pieter C.

    2013-08-01

    Atmospheric ionization methods are ideally suited for prolonged MS/MS analysis. Data-independent MS/MS is a complementary technique for analysis of biological samples as compared to data-dependent analysis. Here, we pair data-independent MS/MS with the ambient ionization method nanospray desorption electrospray ionization (nanoDESI) for untargeted analysis of bacterial metabolites. Proof-of-principle data and analysis are illustrated by sampling Bacillus subtilis and Pseudomonas aeruginosa directly from Petri dishes. We found that this technique enables facile comparisons between strains via MS and MS/MS plots which can be translated to chemically informative molecular maps through MS/MS networking. The development of novel techniques to characterize microbial metabolites allows rapid and efficient analysis of metabolic exchange factors. This is motivated by our desire to develop novel techniques to explore the role of interspecies interactions in the environment, health, and disease. This is a contribution to honor Professor Catherine C. Fenselau in receiving the prestigious ASMS Award for a Distinguished Contribution in Mass Spectrometry for her pioneering work on microbial mass spectrometry.

  20. Ambient diode laser desorption dielectric barrier discharge ionization mass spectrometry of nonvolatile chemicals.

    Science.gov (United States)

    Gilbert-López, Bienvenida; Schilling, Michael; Ahlmann, Norman; Michels, Antje; Hayen, Heiko; Molina-Díaz, Antonio; García-Reyes, Juan F; Franzke, Joachim

    2013-03-19

    In this work, the combined use of desorption by a continuous wave near-infrared diode laser and ionization by a dielectric barrier discharge-based probe (laser desorption dielectric barrier discharge ionization mass spectrometry (LD-DBDI-MS)) is presented as an ambient ionization method for the mass spectrometric detection of nonvolatile chemicals on surfaces. A separation of desorption and ionization processes could be verified. The use of the diode laser is motivated by its low cost, ease of use, and small size. To achieve an efficient desorption, the glass substrates are coated at the back side with a black point (target point, where the sample is deposited) in order to absorb the energy offered by the diode laser radiation. Subsequent ionization is accomplished by a helium plasmajet generated in the dielectric barrier discharge source. Examples on the application of this approach are shown in both positive and negative ionization modes. A wide variety of multiclass species with low vapor pressure were tested including pesticides, pharmaceuticals and explosives (reserpine, roxithromycin, propazine, prochloraz, spinosad, ampicillin, dicloxacillin, enrofloxacin, tetracycline, oxytetracycline, erythromycin, spinosad, cyclo-1,3,5,7-tetramethylene tetranitrate (HMX), and cyclo-1,3,5-trimethylene trinitramine (RDX)). A comparative evaluation revealed that the use of the laser is advantageous, compared to just heating the substrate surface. PMID:23419061

  1. Chemical ionization mass spectrometer (CIMS for ambient measurements of ammonia

    Directory of Open Access Journals (Sweden)

    D. R. Benson

    2010-03-01

    Full Text Available This study describes a chemical ionization mass spectrometer (CIMS for fast response, in-situ measurements for gas phase ammonia. Protonated ethanol ions were used as the ion-molecule reaction reagent. The CIMS sensitivity was estimated to be between 4–25 Hz/pptv with 30% uncertainty. The instrument background was below 1 ppbv and at lowest was 300 pptv. The uncertainty associated with the instrumental background was less than 30 pptv under the optimized experimental conditions. The time response was less than 30 s, and the detection limit was approximately 60 pptv. This CIMS was used to measure the ambient NH3 in Kent, Ohio, for several weeks throughout three seasons. The measured ammonia mixing ratios were usually at the sub-ppbv level, and higher during the spring (200±120 pptv than in the winter (60±75 pptv and fall (150±80 pptv.

  2. Revealing source signatures in ambient BTEX concentrations

    International Nuclear Information System (INIS)

    Management of ambient concentrations of Volatile Organic Compounds (VOCs) is essential for maintaining low ozone levels in urban areas where its formation is under a VOC-limited regime. The significant decrease in traffic-induced VOC emissions in many developed countries resulted in relatively comparable shares of traffic and non-traffic VOC emissions in urban airsheds. A key step for urban air quality management is allocating ambient VOC concentrations to their pertinent sources. This study presents an approach that can aid in identifying sources that contribute to observed BTEX concentrations in areas characterized by low BTEX concentrations, where traditional source apportionment techniques are not useful. Analysis of seasonal and diurnal variations of ambient BTEX concentrations from two monitoring stations located in distinct areas reveal the possibility to identify source categories. Specifically, the varying oxidation rates of airborne BTEX compounds are used to allocate contributions of traffic emissions and evaporative sources to observed BTEX concentrations. - BTEX sources are identified from temporal variations of ambient concentration

  3. A Chemical Ionization Mass Spectrometer for ambient measurements of Ammonia

    Directory of Open Access Journals (Sweden)

    D. R. Benson

    2010-08-01

    Full Text Available This study presents a chemical ionization mass spectrometer (CIMS for fast response, in-situ measurements of gas phase ammonia (NH3. The NH3 background level detected with the CIMS ranged between 0.3–1 ppbv, with an uncertainty of 30 pptv under optimized conditions. The instrument sensitivity varied from 4–25 Hz/pptv for >1 MHz of reagent ion signals (protonated ethanol ions, with a 30% uncertainty estimated based on variability in calibration signals. The CIMS detection limit for NH3 was ~60 pptv at a 1 min integration time (3 sigma. The CIMS time response was <30 s. This new NH3-CIMS has been used for ambient measurements in Kent, Ohio, for several weeks throughout three seasons. The measured NH3 mixing ratios were usually at the sub-ppbv level and higher in spring (200 ± 120 pptv than in winter (60 ± 75 pptv and fall (150 ± 80 pptv. High emissions of SO2 from power plants in this region, and thus possible high acidity of aerosol particles, may explain these low NH3 mixing ratios in general.

  4. Electric Power From Ambient Energy Sources

    Energy Technology Data Exchange (ETDEWEB)

    DeSteese, John G.; Hammerstrom, Donald J.; Schienbein, Lawrence A.

    2000-10-03

    This report summarizes research on opportunities to produce electric power from ambient sources as an alternative to using portable battery packs or hydrocarbon-fueled systems in remote areas. The work was an activity in the Advanced Concepts Project conducted by Pacific Northwest National Laboratory (PNNL) for the Office of Research and Development in the U.S. Department of Energy Office of Nonproliferation and National Security.

  5. Ambient Mass Spectrometry Imaging with Picosecond Infrared Laser Ablation Electrospray Ionization (PIR-LAESI).

    Science.gov (United States)

    Zou, Jing; Talbot, Francis; Tata, Alessandra; Ermini, Leonardo; Franjic, Kresimir; Ventura, Manuela; Zheng, Jinzi; Ginsberg, Howard; Post, Martin; Ifa, Demian R; Jaffray, David; Miller, R J Dwayne; Zarrine-Afsar, Arash

    2015-12-15

    A picosecond infrared laser (PIRL) is capable of cutting through biological tissues in the absence of significant thermal damage. As such, PIRL is a standalone surgical scalpel with the added bonus of minimal postoperative scar tissue formation. In this work, a tandem of PIRL ablation with electrospray ionization (PIR-LAESI) mass spectrometry is demonstrated and characterized for tissue molecular imaging, with a limit of detection in the range of 100 nM for reserpine or better than 5 nM for verapamil in aqueous solution. We characterized PIRL crater size using agar films containing Rhodamine. PIR-LAESI offers a 20-30 μm vertical resolution (∼3 μm removal per pulse) and a lateral resolution of ∼100 μm. We were able to detect 25 fmol of Rhodamine in agar ablation experiments. PIR-LAESI was used to map the distribution of endogenous methoxykaempferol glucoronide in zebra plant (Aphelandra squarrosa) leaves producing a localization map that is corroborated by the literature. PIR-LAESI was further used to image the distribution inside mouse kidneys of gadoteridol, an exogenous magnetic resonance contrast agent intravenously injected. Parallel mass spectrometry imaging (MSI) using desorption electrospray ionization (DESI) and matrix assisted laser desorption ionization (MALDI) were performed to corroborate PIR-LAESI images of the exogenous agent. We further show that PIR-LAESI is capable of desorption ionization of proteins as well as phospholipids. This comparative study illustrates that PIR-LAESI is an ion source for ambient mass spectrometry applications. As such, a future PIRL scalpel combined with secondary ionization such as ESI and mass spectrometry has the potential to provide molecular feedback to guide PIRL surgery.

  6. Chemical Aspects of the Extractive Methods of Ambient Ionization Mass Spectrometry

    Science.gov (United States)

    Badu-Tawiah, Abraham K.; Eberlin, Livia S.; Ouyang, Zheng; Cooks, R. Graham

    2013-04-01

    Ambient ionization techniques allow complex chemical samples to be analyzed in their native state with minimal sample preparation. This brings the obvious advantages of simplicity, speed, and versatility to mass spectrometry: Desorption electrospray ionization (DESI), for example, is used in chemical imaging for tumor margin diagnosis. This review on the extractive methods of ambient ionization focuses on chemical aspects, mechanistic considerations, and the accelerated chemical reactions occurring in charged liquid droplets generated in the spray process. DESI uses high-velocity solvent droplets to extract analytes from surfaces. Nano-DESI employs liquid microjunctions for analyte dissolution, whereas paper-spray ionization uses DC potentials applied to wet porous material such as paper or biological tissue to field emit charged analyte-containing solvent droplets. These methods also operate in a reactive mode in which added reagents allow derivatization during ionization. The accelerated reaction rates seen in charged microdroplets are useful in small-scale rapid chemical synthesis.

  7. Monitoring Enzymatic Reactions in Real Time Using Venturi Easy Ambient Sonic-Spray Ionization Mass Spectrometry.

    Science.gov (United States)

    Jansson, Erik T; Dulay, Maria T; Zare, Richard N

    2016-06-21

    We developed a technique to monitor spatially confined surface reactions with mass spectrometry under ambient conditions, without the need for voltage or organic solvents. Fused-silica capillaries immersed in an aqueous solution, positioned in close proximity to each other and the functionalized surface, created a laminar flow junction with a resulting reaction volume of ∼5 pL. The setup was operated with a syringe pump, delivering reagents to the surface through a fused-silica capillary. The other fused-silica capillary was connected to a Venturi easy ambient sonic-spray ionization source, sampling the resulting analytes at a slightly higher flow rate compared to the feeding capillary. The combined effects of the inflow and outflow maintains a chemical microenvironment, where the rate of advective transport overcomes diffusion. We show proof-of-concept where acetylcholinesterase was immobilized on an organosiloxane polymer through electrostatic interactions. The hydrolysis of acetylcholine by acetylcholinesterase into choline was monitored in real-time for a range of acetylcholine concentrations, fused-silica capillary geometries, and operating flow rates. Higher reaction rates and conversion yields were observed with increasing acetylcholine concentrations, as would be expected. PMID:27249533

  8. Air flow assisted ionization for remote sampling of ambient mass spectrometry and its application.

    Science.gov (United States)

    He, Jiuming; Tang, Fei; Luo, Zhigang; Chen, Yi; Xu, Jing; Zhang, Ruiping; Wang, Xiaohao; Abliz, Zeper

    2011-04-15

    Ambient ionization methods are an important research area in mass spectrometry (MS) analysis. Under ambient conditions, the gas flow and atmospheric pressure significantly affect the transfer and focusing of ions. The design and implementation of air flow assisted ionization (AFAI) as a novel and effective, remote sampling method for ambient mass spectrometry are described herein. AFAI benefits from a high extracting air flow rate. A systematic investigation of the extracting air flow in the AFAI system has been carried out, and it has been demonstrated not only that it plays a role in the effective capture and remote transport of charged droplets, but also that it promotes desolvation and ion formation, and even prevents ion fragmentation during the ionization process. Moreover, the sensitivity of remote sampling ambient MS analysis was improved significantly by the AFAI method. Highly polar and nonpolar molecules, including dyes, pharmaceutical samples, explosives, drugs of abuse, protein and volatile compounds, have been successfully analyzed using AFAI-MS. The successful application of the technique to residue detection on fingers, large object analysis and remote monitoring in real time indicates its potential for the analysis of a variety of samples, especially large objects. The ability to couple this technique with most commercially available MS instruments with an API interface further enhances its broad applicability.

  9. A combined desorption ionization by charge exchange (DICE) and desorption electrospray ionization (DESI) source for mass spectrometry.

    Science.gov (United States)

    Chan, Chang-Ching; Bolgar, Mark S; Miller, Scott A; Attygalle, Athula B

    2011-01-01

    A source that couples the desorption ionization by charge exchange (DICE) and desorption electrospray ionization (DESI) techniques together was demonstrated to broaden the range of compounds that can be analyzed in a single mass spectrometric experiment under ambient conditions. A tee union was used to mix the spray reagents into a partially immiscible blend before this mixture was passed through a conventional electrospray (ES) probe capillary. Using this technique, compounds that are ionized more efficiently by the DICE method and those that are ionized better with the DESI procedure could be analyzed simultaneously. For example, hydroquinone, which is not detected when subjected to DESI-MS in the positive-ion generation mode, or the sodium adduct of guaifenesin, which is not detected when examined by DICE-MS, could both be detected in one experiment when the two techniques were combined. The combined technique was able to generate the molecular ion, proton and metal adduct from the same compound. When coupled to a tandem mass spectrometer, the combined source enabled the generation of product ion spectra from the molecular ion and the [M + H](+) or [M + metal](+) ions of the same compound without the need to physically change the source from DICE to DESI. The ability to record CID spectra of both the molecular ion and adduct ions in a single mass spectrometric experiment adds a new dimension to the array of mass spectrometric methods available for structural studies. PMID:21472555

  10. A Combined Desorption Ionization by Charge Exchange (DICE) and Desorption Electrospray Ionization (DESI) Source for Mass Spectrometry

    Science.gov (United States)

    Chan, Chang-Ching; Bolgar, Mark S.; Miller, Scott A.; Attygalle, Athula B.

    2011-01-01

    A source that couples the desorption ionization by charge exchange (DICE) and desorption electrospray ionization (DESI) techniques together was demonstrated to broaden the range of compounds that can be analyzed in a single mass spectrometric experiment under ambient conditions. A tee union was used to mix the spray reagents into a partially immiscible blend before this mixture was passed through a conventional electrospray (ES) probe capillary. Using this technique, compounds that are ionized more efficiently by the DICE method and those that are ionized better with the DESI procedure could be analyzed simultaneously. For example, hydroquinone, which is not detected when subjected to DESI-MS in the positive-ion generation mode, or the sodium adduct of guaifenesin, which is not detected when examined by DICE-MS, could both be detected in one experiment when the two techniques were combined. The combined technique was able to generate the molecular ion, proton and metal adduct from the same compound. When coupled to a tandem mass spectrometer, the combined source enabled the generation of product ion spectra from the molecular ion and the [M + H]+ or [M + metal]+ ions of the same compound without the need to physically change the source from DICE to DESI. The ability to record CID spectra of both the molecular ion and adduct ions in a single mass spectrometric experiment adds a new dimension to the array of mass spectrometric methods available for structural studies.

  11. Food quality and authenticity screening via easy ambient sonic-spray ionization mass spectrometry.

    Science.gov (United States)

    Porcari, Andreia M; Fernandes, Gabriel D; Barrera-Arellano, Daniel; Eberlin, Marcos N; Alberici, Rosana M

    2016-02-21

    This review is the first to summarize a decade of studies testing the use of easy ambient sonic-spray ionization mass spectrometry (EASI-MS) and its several sister techniques, Venturi (V-EASI), thermal imprinting (TI-EASI) and Spartan (S-EASI) mass spectrometry in food quality control and authentication. Since minimal or no sample preparation is required, such ambient desorption/ionization techniques have been shown to provide direct, fast and selective fingerprinting characterization at the molecular level based on the pools of the most typical components. They have also been found to be applicable on intact, undisturbed samples or on simple solvent extracts. Fundamentals of EASI-MS and its sister techniques, including mechanisms, devices, parameters and strategies, as well as the many applications reported for food analysis, are summarized and discussed. PMID:26820190

  12. Food quality and authenticity screening via easy ambient sonic-spray ionization mass spectrometry.

    Science.gov (United States)

    Porcari, Andreia M; Fernandes, Gabriel D; Barrera-Arellano, Daniel; Eberlin, Marcos N; Alberici, Rosana M

    2016-02-21

    This review is the first to summarize a decade of studies testing the use of easy ambient sonic-spray ionization mass spectrometry (EASI-MS) and its several sister techniques, Venturi (V-EASI), thermal imprinting (TI-EASI) and Spartan (S-EASI) mass spectrometry in food quality control and authentication. Since minimal or no sample preparation is required, such ambient desorption/ionization techniques have been shown to provide direct, fast and selective fingerprinting characterization at the molecular level based on the pools of the most typical components. They have also been found to be applicable on intact, undisturbed samples or on simple solvent extracts. Fundamentals of EASI-MS and its sister techniques, including mechanisms, devices, parameters and strategies, as well as the many applications reported for food analysis, are summarized and discussed.

  13. Design and experiment of a laser ionization source for ion mobility spectrometer

    Institute of Scientific and Technical Information of China (English)

    JI Ren-dong; KONG Xiang-he; LIU Xian-yun; ZHANG Shu-dong

    2006-01-01

    @@ The fabrication and characterization of a laser ionization source for ion mobility spectrometer (IMS) is described with the calculated parameter of the drift tube.Ions are created in air at ambient pressure using laser ionization (λ=248 nm) with air as the drift gas.Mobility spectra for positive ions at different electric fields are obtained with the length of drift tube of 25 and 50 mm,respectively.The distribution of the electric field in the drift tube (50 mm) has also been investigated by SIMION simulation with the ion shutter closed and open respectively.

  14. Electrospray-assisted laser desorption/ionization mass spectrometry for direct ambient analysis of solids.

    Science.gov (United States)

    Shiea, Jentaie; Huang, Min-Zon; Hsu, Hsiu-Jung; Lee, Chi-Yang; Yuan, Cheng-Hui; Beech, Iwona; Sunner, Jan

    2005-01-01

    A new method of electrospray-assisted laser desorption/ionization (ELDI) mass spectrometry, which combines laser desorption with post-ionization by electrospray, was applied to rapid analysis of solid materials under ambient conditions. Analytes were desorbed from solid metallic and insulating substrata using a pulsed nitrogen laser. Post-ionization produced high-quality mass spectra characteristic of electrospray, including protein multiple charging. For the first time, mass spectra of intact proteins were obtained using laser desorption without adding a matrix. Bovine cytochrome c and an illicit drug containing methaqualone were chosen in this study to demonstrate the applicability of ELDI to the analysis of proteins and synthetic organic compounds. PMID:16299699

  15. Ambient Femtosecond Laser Vaporization and Nanosecond Laser Desorption Electrospray Ionization Mass Spectrometry

    Science.gov (United States)

    Flanigan, Paul; Levis, Robert

    2014-06-01

    Recent investigations of ambient laser-based transfer of molecules into the gas phase for subsequent mass spectral analysis have undergone a renaissance resulting from the separation of vaporization and ionization events. Here, we seek to provide a snapshot of recent femtosecond (fs) duration laser vaporization and nanosecond (ns) duration laser desorption electrospray ionization mass spectrometry experiments. The former employs pulse durations of electrospray ionization, femtosecond laser vaporization provides a universal, rapid mass spectral analysis method requiring no sample workup. Remarkably, laser pulses with intensities exceeding 1013 W cm-2 desorb intact macromolecules, such as proteins, and even preserve the condensed phase of folded or unfolded protein structures according to the mass spectral charge state distribution, as demonstrated for cytochrome c and lysozyme. Because of the ability to vaporize and ionize multiple components from complex mixtures for subsequent analysis, near perfect classification of explosive formulations, plant tissue phenotypes, and even the identity of the manufacturer of smokeless powders can be determined by multivariate statistics. We also review the more mature field of nanosecond laser desorption for ambient mass spectrometry, covering the wide range of systems analyzed, the need for resonant absorption, and the spatial imaging of complex systems like tissue samples.

  16. Rules and regulations on ionizing radiations sources installations

    International Nuclear Information System (INIS)

    The finality of this legislative text is to establish the standards and procedures for site, design, building, operation and decommissioning of nuclear installations, radioactive installations and ionizing radiations sources. This text include the commercialization of radioactive substances and equipment fabrication

  17. Real Time Monitoring of Containerless Microreactions in Acoustically Levitated Droplets via Ambient Ionization Mass Spectrometry.

    Science.gov (United States)

    Crawford, Elizabeth A; Esen, Cemal; Volmer, Dietrich A

    2016-09-01

    Direct in-droplet (in stillo) microreaction monitoring using acoustically levitated micro droplets has been achieved by combining acoustic (ultrasonic) levitation for the first time with real time ambient tandem mass spectrometry (MS/MS). The acoustic levitation and inherent mixing of microliter volumes of reactants (3 μL droplets), yielding total reaction volumes of 6 μL, supported monitoring the acid-catalyzed degradation reaction of erythromycin A. This reaction was chosen to demonstrate the proof-of-principle of directly monitoring in stillo microreactions via hyphenated acoustic levitation and ambient ionization mass spectrometry. The microreactions took place completely in stillo over 30, 60, and 120 s within the containerless stable central pressure node of an acoustic levitator, thus readily promoting reaction miniaturization. For the evaluation of the miniaturized in stillo reactions, the degradation reactions were also carried out in vials (in vitro) with a total reaction volume of 400 μL. The reacted in vitro mixtures (6 μL total) were similarly introduced into the acoustic levitator prior to ambient ionization MS/MS analysis. The in stillo miniaturized reactions provided immediate real-time snap-shots of the degradation process for more accurate reaction monitoring and used a fraction of the reactants, while the larger scale in vitro reactions only yielded general reaction information. PMID:27505037

  18. [Use of ionizing radiation sources in metallurgy: risk assessment].

    Science.gov (United States)

    Giugni, U

    2012-01-01

    Use of ionizing radiation sources in the metallurgical industry: risk assessment. Radioactive sources and fixed or mobile X-ray equipment are used for both process and quality control. The use of ionizing radiation sources requires careful risk assessment. The text lists the characteristics of the sources and the legal requirements, and contains a description of the documentation required and the methods used for risk assessment. It describes how to estimate the doses to operators and the relevant classification criteria used for the purpose of radiation protection. Training programs must be organized in close collaboration between the radiation protection expert and the occupational physician.

  19. Detection of Cellulose-Derived Chromophores by Ambient Ionization-MS.

    Science.gov (United States)

    Schedl, Andreas; Korntner, Philipp; Zweckmair, Thomas; Henniges, Ute; Rosenau, Thomas; Potthast, Antje

    2016-01-19

    The detection of individual chromophores that contribute to the overall discoloration of paper ("yellowing") is a challenge because those substances are only present in very small amounts. In this research, two analytical approaches based on ambient ionization techniques, namely, desorption electrospray ionization and paper spray, both coupled to mass spectrometry, are compared to each other with regard to their suitability for detecting acetylated cellulosic key chromophores. The paper spray approach proved to be the more sensitive and versatile method. Subsequently, paper spray (PS)-mass spectrometry was applied to model papers and historical papers in which the acetylated chromophores were detected successfully. Independent accurate mass measurements confirmed the results obtained from reference compounds, model samples, and real-world specimens. PMID:26691171

  20. Ambient mass spectrometry imaging: plasma assisted laser desorption ionization mass spectrometry imaging and its applications.

    Science.gov (United States)

    Feng, Baosheng; Zhang, Jialing; Chang, Cuilan; Li, Liping; Li, Min; Xiong, Xingchuang; Guo, Chengan; Tang, Fei; Bai, Yu; Liu, Huwei

    2014-05-01

    Mass spectrometry imaging (MSI) has been widely used in many research areas for the advantages of providing informative molecular distribution with high specificity. Among the recent progress, ambient MSI has attracted increasing interests owing to its characteristics of ambient, in situ, and nonpretreatment analysis. Here, we are presenting the ambient MSI for traditional Chinese medicines (TCMs) and authentication of work of art and documents using plasma assisted laser desorption ionization mass spectrometry (PALDI-MS). Compared with current ambient MSI methods, an excellent average resolution of 60 μm × 60 μm pixel size was achieved using this system. The feasibility of PALDI-based MSI was confirmed by seal imaging, and its authentication applications were demonstrated by imaging of printed Chinese characters. Imaging of the Radix Scutellariae slice showed that the two active components, baicalein and wogonin, mainly were distributed in the epidermis of the root, which proposed an approach for distinguishing TCMs' origins and the distribution of active components of TCMs and exploring the environmental effects of plant growth. PALDI-MS imaging provides a strong complement for the MSI strategy with the enhanced spatial resolution, which is promising in many research fields, such as artwork identification, TCMs' and botanic research, pharmaceutical applications, etc. PMID:24670045

  1. In-Source Laser Resonance Ionization at ISOL Facilities

    CERN Document Server

    Marsh, Bruce; Feddosseev, Valentin

    Resonance ionization laser ion source development has been carried out at two radioactive ion beam facilities: ISOLDE (CERN, Switzerland) and the IGISOL facility (Jyvaskyla, Finland). The scope of the Resonance Ionization Laser Ion Source has been extended to 27 elements with the development of new three-step ionization schemes for Sb, Sc, Dy, Y and Au. The efficiencies were determined to be in the range of 2 - 20 %. Additionally, a new two-step ionization scheme has been developed for bismuth in an off-line atomic beam unit. The scheme relies on ionization via a strong and broad auto-ionizing resonance at an energy of 63196.79 cm$^{−1}$. This scheme may offer an improvement over the existing RILIS efficiency and will be more convenient for use during resonance ionization spectroscopy of Bi isotopes. The RILIS can be used as a spectroscopic tool to probe features such as the hyperfine structures and the isotope-shifts of radioisotopes with low production rates. By coupling a laser scanning process that dire...

  2. Characterization of selenium in ambient aerosols and primary emission sources.

    Science.gov (United States)

    De Santiago, Arlette; Longo, Amelia F; Ingall, Ellery D; Diaz, Julia M; King, Laura E; Lai, Barry; Weber, Rodney J; Russell, Armistead G; Oakes, Michelle

    2014-08-19

    Atmospheric selenium (Se) in aerosols was investigated using X-ray absorption near-edge structure (XANES) spectroscopy and X-ray fluorescence (XRF) microscopy. These techniques were used to determine the oxidation state and elemental associations of Se in common primary emission sources and ambient aerosols collected from the greater Atlanta area. In the majority of ambient aerosol and primary emission source samples, the spectroscopic patterns as well as the absence of elemental correlations suggest Se is in an elemental, organic, or oxide form. XRF microscopy revealed numerous Se-rich particles, or hotspots, accounting on average for ∼16% of the total Se in ambient aerosols. Hotspots contained primarily Se(0)/Se(-II). However, larger, bulk spectroscopic characterizations revealed Se(IV) as the dominant oxidation state in ambient aerosol, followed by Se(0)/Se(-II) and Se(VI). Se(IV) was the only observed oxidation state in gasoline, diesel, and coal fly ash, while biomass burning contained a combination of Se(0)/Se(-II) and Se(IV). Although the majority of Se in aerosols was in the most toxic form, the Se concentration is well below the California Environmental Protection Agency chronic exposure limit (∼20000 ng/m(3)). PMID:25075640

  3. State Register of Sources of Ionizing Radiation and Occupational exposure

    CERN Document Server

    2002-01-01

    One of main tasks of Radiation Protection Centre is to collect, process, systematize, store and provide the data on sources of ionizing radiation and occupational exposures. The number of sources in 2002 is provided and compared with previous year. Distribution of workers according to the type of practice is compared with previous year. Distribution of sealed sources and x-ray machines according their use is presented.

  4. Progress of resonant ionization laser ion source development at GANIL

    International Nuclear Information System (INIS)

    SPIRAL2 (Système de Production d’Ions Radioactifs Accélérés en Ligne) is a research facility under construction at GANIL (Grand Accélérateur National d’Ions Lourds) for the production of radioactive ion beams by isotope separation on-line methods and low-energy in-flight techniques. A resonant ionization laser ion source will be one of the main techniques to produce the radioactive ion beams. GISELE (GANIL Ion Source using Electron Laser Excitation) is a test bench developed to study a fully operational laser ion source available for Day 1 operations at SPIRAL2 Phase 2. The aim of this project is to find the best technical solution which combines high selectivity and ionization efficiency with small ion beam emittance and stable long term operation. Latest results about the new ion source geometry will be presented

  5. A high efficiency thermal ionization source adapted to mass spectrometers

    International Nuclear Information System (INIS)

    A tungsten crucible thermal ionization source mounted on a quadrupole mass spectrometer is described. The crucible is a disposable rod with a fine hole bored in one end; it is heated by electron bombardment. The schematic design of the assembly, including water cooling, is described and depicted. Historically, the design is derived from that of ion sources used on ion separators at Los Alamos and Dubna, but the crucible is made smaller and simplified. 10 refs., 4 figs

  6. A compact neutron generator using a field ionization source

    Energy Technology Data Exchange (ETDEWEB)

    Persaud, Arun [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Waldmann, Ole [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kapadia, Rehan [Univ. of California, Berkeley, CA (United States); Takei, Kuniharu [Univ. of California, Berkeley, CA (United States); Javey, Ali [Univ. of California, Berkeley, CA (United States); Schenkel, Thomas [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-02-15

    We study field ionization as a means to create ions for compact and rugged neutron source. Arrays of carbon nano-fibers promise the high field-enhancement factors required for efficient field ionization. We report on the fabrication of arrays of field emitters with a density up to 106 tips/cm2 and measure their performance characteristics using electron field emission. Lastly, the critical issue of uniformity is discussed, as are efforts towards coating the nano-fibers to enhance their lifetime and surface properties.

  7. A compact neutron generator using a field ionization source

    Energy Technology Data Exchange (ETDEWEB)

    Persaud, Arun; Waldmann, Ole; Schenkel, Thomas [E.O. Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Kapadia, Rehan; Takei, Kuniharu; Javey, Ali [Department of Electrical Engineering and Computer Sciences, University of California at Berkeley, Berkeley, California 94720 (United States)

    2012-02-15

    Field ionization as a means to create ions for compact and rugged neutron sources is pursued. Arrays of carbon nano-fibers promise the high field-enhancement factors required for efficient field ionization. We report on the fabrication of arrays of field emitters with a density up to 10{sup 6} tips/cm{sup 2} and measure their performance characteristics using electron field emission. The critical issue of uniformity is discussed, as are efforts towards coating the nano-fibers to enhance their lifetime and surface properties.

  8. A Tubular Ionizer as an Efficient Negative Fluorine Ion Source

    International Nuclear Information System (INIS)

    In order to establish the optimal conditions of F- ion production by the tubular ionizer extensive studies of SF6 ionization using the mass separator were performed. The SF6, SF5, SF4, SF3 and F negative ions were observed, and the F- yields as a function of the source temperature, gas pressure and an amount of alkaline metal vapors (K, Na, Ca, Sr, Ba) were measured. The efficiency of F- production of about 40 obtained for the optimal conditions. The delay time and adsorption enthalpy of fluorine on the tantalum surface has been measured for the first time. (author)

  9. Ambient Mass Spectrometry Imaging: A Comparison of Desorption Ionization by Sonic Spray and Electrospray

    Science.gov (United States)

    Janfelt, Christian; Nørgaard, Asger W.

    2012-10-01

    Easy ambient sonic spray ionization (EASI) and desorption electrospray ionization (DESI) were used for imaging of a number of samples, including sections of rat brain and imprints of plant material on porous Teflon. A novel approach termed Displaced Dual-mode Imaging was utilized for the direct comparison of the two methods: Images were recorded with the individual rows alternating between EASI and DESI, yielding a separate image for each technique recorded under perfectly similar conditions on the same sample. EASI works reliably for imaging of all samples, but the choice of spray solvent and flow rate is more critical in tissue imaging with EASI than with DESI. The overall sensitivity of EASI is, in general, slightly lower than that of DESI, and the representation of the dynamic range is different in images of the two techniques for some samples. However, for abundant compounds, EASI works well, resulting in images of similar quality as DESI. EASI can thus be used in imaging experiments where the application of high voltage is impractical or undesirable. The present study is in its nature also a comparison of the characteristics of the two techniques, showing results also applicable for non-imaging work, with regards to sensitivity and experimental conditions.

  10. Anion formation in sputter ion sources by neutral resonant ionization

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, J. S., E-mail: johnsvogel@yahoo.com [University of California, 8300 Feliz Creek Dr., Ukiah, California 95482 (United States)

    2016-02-15

    Focused Cs{sup +} beams in sputter ion sources create mm-diameter pits supporting small plasmas that control anionization efficiencies. Sputtering produces overwhelmingly neutral products that the plasma can ionize as in a charge-change vapor. Electron capture between neutral atoms rises as the inverse square of the difference between the ionization potential of the Cs state and the electron affinity of the sputtered atom, allowing resonant ionization at very low energies. A plasma collision-radiation model followed electronic excitation up to Cs(7d). High modeled Cs(7d) in a 0.5 mm recess explains the 80 μA/mm{sup 2} C{sup −} current density compared to the 20 μA/mm{sup 2} from a 1 mm recess.

  11. Anion formation in sputter ion sources by neutral resonant ionization

    International Nuclear Information System (INIS)

    Focused Cs+ beams in sputter ion sources create mm-diameter pits supporting small plasmas that control anionization efficiencies. Sputtering produces overwhelmingly neutral products that the plasma can ionize as in a charge-change vapor. Electron capture between neutral atoms rises as the inverse square of the difference between the ionization potential of the Cs state and the electron affinity of the sputtered atom, allowing resonant ionization at very low energies. A plasma collision-radiation model followed electronic excitation up to Cs(7d). High modeled Cs(7d) in a 0.5 mm recess explains the 80 μA/mm2 C− current density compared to the 20 μA/mm2 from a 1 mm recess

  12. Ionization efficiency estimations for the SPES surface ion source

    Science.gov (United States)

    Manzolaro, M.; Andrighetto, A.; Meneghetti, G.; Rossignoli, M.; Corradetti, S.; Biasetto, L.; Scarpa, D.; Monetti, A.; Carturan, S.; Maggioni, G.

    2013-12-01

    Ion sources play a crucial role in ISOL (Isotope Separation On Line) facilities determining, with the target production system, the ion beam types available for experiments. In the framework of the SPES (Selective Production of Exotic Species) INFN (Istituto Nazionale di Fisica Nucleare) project, a preliminary study of the alkali metal isotopes ionization process was performed, by means of a surface ion source prototype. In particular, taking into consideration the specific SPES in-target isotope production, Cs and Rb ion beams were produced, using a dedicated test bench at LNL (Laboratori Nazionali di Legnaro). In this work the ionization efficiency test results for the SPES Ta surface ion source prototype are presented and discussed.

  13. The regulatory control of ionizing radiation sources in Lithuania

    International Nuclear Information System (INIS)

    The Radiation Protection Centre of the Ministry of Health is the regulatory authority responsible for radiation protection of the public and of workers using sources of ionizing radiation in Lithuania. One of its responsibilities is the control of radioactive sources, which includes keeping the registry, investigating persons arrested while illegally carrying or in possession of radioactive material, decision making and control of users of radioactive sources. The computer based registry contains a directory of more than 24,000 sources and some 800 users in research, medicine and industry. Most of these sources are found in smoke detectors and X ray equipment. The potentially most dangerous sources for therapy and industry (sealed and unsealed) are also listed in this registry. Problems connected with the regulatory control of radioactive sources in Lithuania are presented and their solution is discussed. (author)

  14. Laser desorption lamp ionization source for ion trap mass spectrometry.

    Science.gov (United States)

    Wu, Qinghao; Zare, Richard N

    2015-01-01

    A two-step laser desorption lamp ionization source coupled to an ion trap mass spectrometer (LDLI-ITMS) has been constructed and characterized. The pulsed infrared (IR) output of an Nd:YAG laser (1064 nm) is directed to a target inside a chamber evacuated to ~15 Pa causing desorption of molecules from the target's surface. The desorbed molecules are ionized by a vacuum ultraviolet (VUV) lamp (filled with xenon, major wavelength at 148 nm). The resulting ions are stored and detected in a three-dimensional quadrupole ion trap modified from a Finnigan Mat LCQ mass spectrometer operated at a pressure of ≥ 0.004 Pa. The limit of detection for desorbed coronene molecules is 1.5 pmol, which is about two orders of magnitude more sensitive than laser desorption laser ionization mass spectrometry using a fluorine excimer laser (157 nm) as the ionization source. The mass spectrum of four standard aromatic compounds (pyrene, coronene, rubrene and 1,4,8,11,15,18,22,25-octabutoxy-29H,31H-phthalocyanine (OPC)) shows that parent ions dominate. By increasing the infrared laser power, this instrument is capable of detecting inorganic compounds. PMID:25601688

  15. Analysis of 3-panel and 4-panel microscale ionization sources

    International Nuclear Information System (INIS)

    Two designs of a microscale electron ionization (EI) source are analyzed herein: a 3-panel design and a 4-panel design. Devices were fabricated using microelectromechanical systems technology. Field emission from carbon nanotube provided the electrons for the EI source. Ion currents were measured for helium, nitrogen, and xenon at pressures ranging from 10-4 to 0.1 Torr. A comparison of the performance of both designs is presented. The 4-panel microion source showed a 10x improvement in performance compared to the 3-panel device. An analysis of the various factors affecting the performance of the microion sources is also presented. SIMION, an electron and ion optics software, was coupled with experimental measurements to analyze the ion current results. The electron current contributing to ionization and the ion collection efficiency are believed to be the primary factors responsible for the higher efficiency of the 4-panel microion source. Other improvements in device design that could lead to higher ion source efficiency in the future are also discussed. These microscale ion sources are expected to find application as stand alone ion sources as well as in miniature mass spectrometers.

  16. Cumulation in the exposure to sources of ionizing radiation

    International Nuclear Information System (INIS)

    The Dutch National Institute of Public health and Environmental protection (RIVM) has investigated if the maximum permissible risk of 10-6 a-1 for a single source and 10-5a-1 for all sources of ionizing radiation, as defined in the framework of BNS (policy notice regarding the regulation of ionizing radiation), are exceeded in the Dutch population due to the exposure by one single source or all sources respectively. The following sources were considered: radionuclide laboratories, nuclear installations, nuclear waste, sources and devices, conventional energy plants, phosphate fertilizer plants, other non-nuclear industries, transport of radioactive sources and consumer goods. A distinction was made between 'critical' groups due to geographical factors and due to behaviour, such as consumption of special food-stuffs. For risk assessment a uniform risk factor of 0.025 Sv-1 was used, as proposed in BNS. This factor is based on the life-time risk of women and includes the higher risk factors for children. (author). 15 refs.; 4 figs.; 9 tabs

  17. A resonant ionization laser ion source at ORNL

    Science.gov (United States)

    Liu, Y.; Stracener, D. W.

    2016-06-01

    Multi-step resonance laser ionization has become an essential tool for the production of isobarically pure radioactive ion beams at the isotope separator on-line (ISOL) facilities around the world. A resonant ionization laser ion source (RILIS) has been developed for the former Holifield Radioactive Ion Beam Facility (HRIBF) of Oak Ridge National Laboratory. The RILIS employs a hot-cavity ion source and a laser system featuring three grating-tuned and individually pumped Ti:Sapphire lasers, especially designed for stable and simple operation. The RILIS has been installed at the second ISOL production platform of former HRIBF and has successfully provided beams of exotic neutron-rich Ga isotopes for beta decay studies. This paper reports the features, advantages, limitations, and on-line and off-line performance of the RILIS.

  18. Negative Corona Discharge Ion Source Under Ambient Conditions with Mini Line-cylinder Electrodes

    Institute of Scientific and Technical Information of China (English)

    Kun Liu; Fei Tang; Xiao-hao Wang; Liang Zhang; Xue-ye Wei

    2009-01-01

    A novel ambient negative corona discharge ion source with mini line-cylinder electrodes is designed. The diameters of inner and outer electrode are 0.16 and 4 mm respectively. With a special assembly method, a perfect coaxiality of the two electrodes is obtained. An injection system utilizing a temperature control technique, achieves a constant and stable concentra-tion of the sample, which is critical to the experiment. The formulas of the corona onset voltage of line-cylinder electrodes are also introduced. The experiment results show that negative substances such as formic acid and acetic acid can be ionized under ambient con-ditions. When combined with micro electrical mechanical system fabrication process, the volume of the ion source can be reduced dramatically, but there is an undesirable surface discharge. To solve the surface discharge problem, an improved structure was designed and tested. The simplicity of the interface of the ion source makes it suitable for mass spec-trometer, micro mass spectrometer, ion mobility spectrometer, and high-field asymmetric waveform ion mobility spectrometer applications.

  19. Towards a Carbon Nanotube Ionization Source for Planetary Atmosphere Exploration

    Science.gov (United States)

    Oza, A. V.; Leblanc, F.; Berthelier, J. J.; Becker, J.; Coulomb, R.; Gilbert, P.; Hong, N. T.; Lee, S.; Vettier, L.

    2015-12-01

    The characterization of planetary exospheres today, relies on the development of a highly efficient ionization source, due to the scant neutral molecules (n atmospheres provide insight on to physical processes known to occur such as: space weathering, magneto-atmosphere interactions, as well as atmospheric escape mechanisms, all of which are being heavily investigated via current 3D Monte Carlo simulations (Turc et al. 2014, Leblanc et al. 2016 in prep) at LATMOS. Validation of these studies will rely on in-situ observations in the coming decades. Neutral detection strongly depends on electron-impact ionization which via conventional cathode-sources, such as thermal filaments (heated up to 2000 K), may only produce the target ionization essential for energy-measurements with large power consumption. Carbon nanotubes (CNTs) however are ideal low-power, cold cathodes, when subject to moderate electric fields (E ~ 1 MV / m). We present our current device, a small CNT chip, of emission area 15 mm2, emitting electrons that pass through an anode grid and subsequent electrostatic analyzer. The device currently extracts hundreds of µAmperes with applied external voltages ~ -150 Volts, approaching minimum power consumption plasma sputtering the icy regolith with heavy ions and electrons (keV < E < MeV), producing predominately molecular oxygen (Johnson et al. 2002).

  20. Health risk assessment of jobs involving ionizing radiation sources

    Directory of Open Access Journals (Sweden)

    Spasojević-Tišma Vera D.

    2011-01-01

    Full Text Available The study included 75 subjects exposed to low doses of external ionizing radiation and 25 subjects from the control group, all male. The first group (A consisted of 25 subjects employed in the production of technetium, with an average job experience of 15 years. The second group (B consisted of 25 subjects exposed to ionizing radiation from enclosed sources, working in jobs involving the control of X-ray devices and americium smoke detectors, their average work experience being 18.5 years. The third group (C consisted of 25 subjects involved in the decontamination of the terrain at Borovac from radioactive rounds with depleted uranium left over after the NATO bombing of Serbia in 1999, their average job experience being 18.5 years. The control group (K consisted of 25 subjects who have not been in contact with sources of ionizing radiation and who hold administrative positions. Frequencies of chromosome aberrations were determined in lymphocytes of peripheral blood and compared to the control group. The average annual absorbed dose determined by thermoluminescent dosimeters for all three groups did not exceed 2 mSv. In the present study, the largest number of observed changes are acentric fragments and chromosome breaks. The highest occupational risk appears to involve subjects working in manufacturing of the radio-isotope technetium.

  1. Ionizing radiation sources used in medical applications in Brazil

    International Nuclear Information System (INIS)

    Preliminary data about ionizing radiation sources used in medical applications and obtained through a national programme by IRD/CNEN together with Brazilian health authorities are presented. The data presentation follows, as close as possible, recommendations given by the United Nations Scientific Committee on Effects of Atomic Radiation (UNSCEAR). This programme has two main aims: First: to contribute for research in the field of ionizing radiation effects and risks including information about equipment quality control and procedures adopted by professionals working in Radiation Medicine. Second: to investigate the radiation protection status in Brazil, in order to give assistance to Brazilian health authorities for planning regional radiation programmes and training programmes for medical staffs. (F.E.). 13 refs, 19 figs, 34 tabs

  2. Identification of the ionizing source of NGC 2024

    CERN Document Server

    Bik, A; Kaper, L; Comeron, F; Waters, L B F M; De Koter, A; Hanson, M M

    2003-01-01

    We propose the late-O, early-B star IRS2b as the ionizing source of the Flame Nebula (NGC 2024). It has been clear that such a hot, massive star must be present in this heavily obscured region, and now it has been identified. New near-infrared photometry shows that IRS2b is the most luminous and hottest star in the young star cluster embedded in the center of NGC 2024. The near-infrared observations (5' x 5') cover ~90 % of the HII region detected in radio continuum radiation, making the probability very low that the ionizing star is not present in the field. A K-band spectrum of IRS2b obtained with ISAAC on the Very Large Telescope indicates that the spectral type of IRS2b is in the range O8V - B2V. Additional arguments indicate that its spectral type is likely closer to O8 than to B2. The corresponding amount of ionizing radiation is consistent with published radio continuum and recombination line observations.

  3. A Carbon Nanotube Electron Source Based Ionization Vacuum Gauge

    Energy Technology Data Exchange (ETDEWEB)

    Changkun Dong; Ganapati Myneni

    2003-10-01

    The results of fabrication and performance of an ionization vacuum gauge using a carbon nanotube (CNT) electron source are presented. The electron source was constructed with multi-wall nanotubes (MWNT), which were grown using thermal chemical vapor deposition (CVD) process. The electron emission of the source was stable in vacuum pressure up to 10-7 Torr, which is better than the metal field emitters. The measurement linearity of the gauge was better than {+-}10% from 10-6 to 10-10 Torr. The gauge sensitivity of 4 Torr-1 was achieved under 50 {micro}A electron emission in nitrogen. The gauge is expected to find applications in vacuum measurements from 10-7 Torr to below 10-11 Torr.

  4. Direct identification of prohibited substances in cosmetics and foodstuffs using ambient ionization on a miniature mass spectrometry system.

    Science.gov (United States)

    Ma, Qiang; Bai, Hua; Li, Wentao; Wang, Chao; Li, Xinshi; Cooks, R Graham; Ouyang, Zheng

    2016-03-17

    Significantly simplified work flows were developed for rapid analysis of various types of cosmetic and foodstuff samples by employing a miniature mass spectrometry system and ambient ionization methods. A desktop Mini 12 ion trap mass spectrometer was coupled with paper spray ionization, extraction spray ionization and slug-flow microextraction for direct analysis of Sudan Reds, parabens, antibiotics, steroids, bisphenol and plasticizer from raw samples with complex matrices. Limits of detection as low as 5 μg/kg were obtained for target analytes. On-line derivatization was also implemented for analysis of steroid in cosmetics. The developed methods provide potential analytical possibility for outside-the-lab screening of cosmetics and foodstuff products for the presence of illegal substances.

  5. New Types of Ionization Sources for Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    None

    2008-12-01

    The purpose of this Cooperative Research and Development Agreement (CRADA) between UT-Battelle (Contractor) and MDS Sciex (Participant) and ESA, Inc. (Participant) is to research, develop and apply new types of ionization sources and sampling/inlet systems for analytical mass spectrometry making use of the Participants state-of-the-art atmospheric sampling mass spectrometry electrochemical cell technology instrumentation and ancillary equipment. The two overriding goals of this research project are: to understand the relationship among the various instrumental components and operational parameters of the various ion sources and inlet systems under study, the chemical nature of the gases, solvents, and analytes in use, and the nature and abundances of the ions ultimately observed in the mass spectrometer; and to develop new and better analytical and fundamental applications of these ion sources and inlet systems or alternative sources and inlets coupled with mass spectrometry on the basis of the fundamental understanding obtained in Goal 1. The end results of this work are expected to be: (1) an expanded utility for the ion sources and inlet systems under study (such as the analysis of new types of analytes) and the control or alteration of the ionic species observed in the gas-phase; (2) enhanced instrument performance as judged by operational figures-of-merit such as dynamic range, detection limits, susceptibility to matrix signal suppression and sensitivity; and (3) novel applications (such as surface sampling with electrospray) in both applied and fundamental studies. The research projects outlined herein build upon work initiated under the previous CRADA between the Contractor and MDS Sciex on ion sources and inlet systems for mass spectrometry. Specific ion source and inlet systems for exploration of the fundamental properties and practical implementation of these principles are given.

  6. Real-Time Metabolomics on Living Microorganisms Using Ambient Electrospray Ionization Flow-Probe

    DEFF Research Database (Denmark)

    Hsu, Cheng-Chih; ElNaggar, Mariam S.; Peng, Yao;

    2013-01-01

    sampling probe for electrospray ionization-mass spectrometry to extract and ionize metabolite mixtures directly from living microbial colonies grown on soft nutrient agar in Petri-dishes without any sample pretreatment. To demonstrate the robustness of the method, this technique was applied to observe...

  7. [The glow discharge as an atomization and ionization source

    International Nuclear Information System (INIS)

    This is to summarize the research progress in this project at the University of Florida over the past 13 months. In keeping with the directions of the Federal Demonstration Project, the report will be brief, presenting an overview of the major findings. We have continued the study of the glow discharge, primarily as an ionization source for elemental analysis. Glow discharge interest continues to grow in the analytical chemistry community as evidenced by the number of special symposia at major conferences, by the new researchers entering the field, and by the introduction of new instrumentation. There is little doubt that glow discharge mass spectrometry, for example, is now a major technique in the elemental analysis of solids

  8. A rapid ambient ionization-mass spectrometry approach to monitoring the relative abundance of isomeric glycerophospholipids

    Science.gov (United States)

    Kozlowski, Rachel L.; Mitchell, Todd W.; Blanksby, Stephen J.

    2015-04-01

    Glycerophospholipids with two, non-equivalent fatty acyl chains can adopt one of two isomeric forms depending on the relative position of substitutions on the glycerol backbone. These so-called sn-positional isomers can have distinct biophysical and biochemical behaviors making it desirable to uniquely assign their regiochemistries. Unambiguous assignment of such similar molecular structures in complex biological extracts is a significant challenge to current analytical technologies. We have recently reported a novel mass spectrometric method that combines collision- and ozone-induced dissociation in series (CID/OzID) to yield product ions characteristic of acyl chain substitution patterns in glycerophospholipids. Here phosphatidylcholines are examined using the CID/OzID protocol combined with desorption electrospray ionization (DESI) to facilitate the rapid exploration of sample arrays comprised of a wide variety of synthetic and biological sources. Comparison of the spectra acquired from different extracts reveals that the sn-positional isomers PC 16:0/18:1 and PC 18:1/16:0 (where the 18:1 chain is present at the sn-2 and sn-1 position of the glycerol backbone, respectively) are most often found together in lipids of either natural or synthetic origin. Moreover, the proportions of the two isomers vary significantly between extracts from different organisms or even between adjacent tissues from the same organism.

  9. Perfume fingerprinting by easy ambient sonic-spray ionization mass spectrometry: nearly instantaneous typification and counterfeit detection.

    Science.gov (United States)

    Haddad, Renato; Catharino, Rodrigo Ramos; Marques, Lygia Azevedo; Eberlin, Marcos Nogueira

    2008-11-01

    Perfume counterfeiting is an illegal worldwide practice that involves huge economic losses and potential consumer risk. EASI is a simple, easily performed and rapidly implemented desorption/ionization technique for ambient mass spectrometry (MS). Herein we demonstrate that EASI-MS allows nearly instantaneous perfume typification and counterfeit detection. Samples are simply sprayed onto a glass rod or paper surface and, after a few seconds of ambient drying, a profile of the most polar components of the perfume is acquired. These components provide unique and reproducible chemical signatures for authentic perfume samples. Counterfeiting is readily recognized since the exact set and relative proportions of the more polar chemicals, sometimes at low concentrations, are unknown or hard to reproduce by the counterfeiters and hence very distinct and variable EASI-MS profiles are observed for the counterfeit samples.

  10. A Liquid Injection Field Desorption/Ionization-Electrospray Ionization Combination Source for a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer

    Science.gov (United States)

    Linden, H. Bernhard; Gross, Jürgen H.

    2011-12-01

    A new type of combination ion source has been devised. It unites two complementary ionization methods, i.e., liquid injection field desorption/ionization (LIFDI) and electrospray ionization (ESI). This LIFDI-ESI combination ion source has been constructed for a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. The LIFDI-ESI combination ion source can be switched between the LIFDI and ESI modes of operation within 15 min without breaking the vacuum. The source design and its operation are described. LIFDI-FT-ICR spectra of the ionic liquid trihexyl(tetradecyl)-phosphonium tris(pentafluoroethyl)-trifluorophosphate, polyethylene glycol 600, 2,3,4-tridodecyloxy-benzaldehyde, and [60]fullerene are described.

  11. ambiental

    Directory of Open Access Journals (Sweden)

    Roque Leal Salcedo

    2008-01-01

    Full Text Available El derecho internacional ambiental es un conocimiento de carácter transversal, que entre otras consideraciones refleja las preocupaciones de la sociedad por la implementación de un modelo de desarrollo sustentable para el respeto a las reglas del medio natural que garantizan la integridad y renovación de los sistemas naturales. El presente artículo enfoca esta visión a través del análisis de material documental revisado, entre ellos tratados internacionales que permiten distinguir el desarrollo del derecho internacional ambiental y el papel de Organización de las Naciones Unidas (ONU, en el propósito común del derecho individual y colectivo de disfrutar de una vida, un ambiente seguro, sano y ecológicamente equilibrado. En función a estas disertaciones las consideraciones finales exponen parte de la visión que ha estructurado la ONU y que representan un aporte considerable en el fomento de la conciencia mundial sobre la necesidad de establecer vínculos entre las naciones para el continuo desarrollo de esta rama del derecho.

  12. Potential Ambient Energy-Harvesting Sources and Techniques

    Science.gov (United States)

    Yildiz, Faruk

    2009-01-01

    Ambient energy harvesting is also known as energy scavenging or power harvesting, and it is the process where energy is obtained from the environment. A variety of techniques are available for energy scavenging, including solar and wind powers, ocean waves, piezoelectricity, thermoelectricity, and physical motions. For example, some systems…

  13. Noble-gas ionization in the ion source with Penning effect

    International Nuclear Information System (INIS)

    By additional use of that the ion source efficiency can be increased the Penning ionization. The results of estimates of certain coefficients for the processes taking place in the plasma ion sources are presented

  14. Critical comparison of mass analyzers for forensic hair analysis by ambient ionizations mass spectrometry

    NARCIS (Netherlands)

    Duvivier, W.F.; Beek, van T.A.; Nielen, M.W.F.

    2016-01-01

    Rationale
    Recently, several direct and/or ambient mass spectrometry (MS) approaches have been suggested for drugs of abuse imaging in hair. The use of mass spectrometers with insufficient selectivity could result in false-positive measurements due to isobaric interferences. Different mass analyz

  15. Direct analysis of steviol glycosides from Stevia leaves by ambient ionization mass spectrometry performed on whole leaves.

    Science.gov (United States)

    Zhang, J Isabella; Li, Xin; Ouyang, Zheng; Cooks, R Graham

    2012-07-01

    Leaf spray mass spectrometry is explored as a fast and simple way for direct analysis of sweet glycosides in fresh untreated Stevia leaves without sample pretreatment. In this technique, a fresh triangular piece of Stevia leaf serves as both sample and substrate. Application of a butanol : methanol : water mixture and a high voltage to intact leaf material produces a high electric field at the tip of the leaf. This results in field emission of charged droplets containing the glycosides. The resulting dry ions are detected by mass spectrometry and confirmed by tandem mass spectrometry and exact mass measurements. A comparison between leaf spray and other ambient ionization methods which are successful for screening glycosides in Stevia leaves--desorption electrospray ionization, low temperature plasma and paper spray--shows that leaf spray produces the highest quality spectra. It is also extremely easy to implement with no need for nebulizing gas or sample preparation and is suited to semi-quantitative determinations. The potential for the application of leaf spray mass spectrometry to direct and rapid screening of plant materials is here realized in the case of Stevia sweet glycosides. PMID:22606683

  16. Air flow-assisted ionization imaging mass spectrometry method for easy whole-body molecular imaging under ambient conditions.

    Science.gov (United States)

    Luo, Zhigang; He, Jiuming; Chen, Yi; He, Jingjing; Gong, Tao; Tang, Fei; Wang, Xiaohao; Zhang, Ruiping; Huang, Lan; Zhang, Lianfeng; Lv, Haining; Ma, Shuanggang; Fu, Zhaodi; Chen, Xiaoguang; Yu, Shishan; Abliz, Zeper

    2013-03-01

    Whole-body molecular imaging is able to directly map spatial distribution of molecules and monitor its biotransformation in intact biological tissue sections. Imaging mass spectrometry (IMS), a label-free molecular imaging method, can be used to image multiple molecules in a single measurement with high specificity. Herein, a novel easy-to-implement, whole-body IMS method was developed with air flow-assisted ionization in a desorption electrospray ionization mode. The developed IMS method can effectively image molecules in a large whole-body section in open air without sample pretreatment, such as chemical labeling, section division, or matrix deposition. Moreover, the signal levels were improved, and the spatial assignment errors were eliminated; thus, high-quality whole-body images were obtained. With this novel IMS method, in situ mapping analysis of molecules was performed in adult rat sections with picomolar sensitivity under ambient conditions, and the dynamic information of molecule distribution and its biotransformation was provided to uncover molecular events at the whole-animal level. A global view of the differential distribution of an anticancer agent and its metabolites was simultaneously acquired in whole-body rat and model mouse bearing neuroglioma along the administration time. The obtained drug distribution provided rich information for identifying the targeted organs and predicting possible tumor spectrum, pharmacological activity, and potential toxicity of drug candidates.

  17. Performance, at ambient temperature, of ionization chambers filled with a liquid dielectric

    International Nuclear Information System (INIS)

    The authors describe the performance characteristics of ionization chambers filled with carefully purified normal hexane. A detailed study of the background of a detector of this type enabled them to define the conditions in which it is possible to stabilize this background and to reduce it to about 10-14 A/cm2, for a uniform electric field of 8000 V/cm. Under irradiation with alpha or gamma rays, and at laboratory temperature, the current which passes through the chamber is a linear function of the applied electric field, up to a critical field value which is a function of the degree of purity of the liquid. Above that critical value, a process of ion-multiplication takes place, somewhat, similar to that which takes place in gases. The change in the ionization current then becomes exponential. In that area of multiplication the authors detected impulses created by the passage of individual alpha particles. The low mobility of the ions in the hexane and their extensive recombination considerably limits the amplitude of the impulses, which can easily be confused with the amplifier's background if a certain number of precautions are not taken. Impulses were recorded with amplitudes varying between 2.5 x 10-5 and 25 x 10-5 V, and with growth-times between 2 and 20 μs in electric fields of 21600 to 65600 V/cm. A number of preliminary results for other liquid fillings are given. (author)

  18. Development of a surface ionization source for the production of radioactive alkali ion beams in SPIRAL

    Energy Technology Data Exchange (ETDEWEB)

    Eleon, C. [GANIL, CEA/DSM CNRS/IN2P3, Bd H. Becquerel, BP 55027, 14076 CAEN cedex 5 (France)], E-mail: sceleon@triumf.ca; Jardin, P.; Gaubert, G.; Saint-Laurent, M.-G.; Alcantara-Nunez, J.; Alves Conde, R.; Barue, C.; Boilley, D.; Cornell, J. [GANIL, CEA/DSM CNRS/IN2P3, Bd H. Becquerel, BP 55027, 14076 CAEN cedex 5 (France); Delahaye, P. [3 CERN ISOLDE, 1211 Geneva 23 (Switzerland); Dubois, M.; Jacquot, B.; Leherissier, P.; Leroy, R.; Lhersonneau, G. [GANIL, CEA/DSM CNRS/IN2P3, Bd H. Becquerel, BP 55027, 14076 CAEN cedex 5 (France); Marie-Jeanne, M. [3 CERN ISOLDE, 1211 Geneva 23 (Switzerland); Maunoury, L. [CIRIL, Bd H. Becquerel, BP 55027, 14076 CAEN cedex 5 (France); Pacquet, J.Y.; Pellemoine, F. [GANIL, CEA/DSM CNRS/IN2P3, Bd H. Becquerel, BP 55027, 14076 CAEN cedex 5 (France); Pierret, C. [CIRIL, Bd H. Becquerel, BP 55027, 14076 CAEN cedex 5 (France)] (and others)

    2008-10-15

    In the framework of the production of radioactive alkali ion beams by the isotope separation on-line (ISOL) method in SPIRAL I, a surface ionization source has been developed at GANIL to produce singly-charged ions of Li, Na and K. This new source has been designed to work in the hostile environment whilst having a long lifetime. This new system of production has two ohmic heating components: the first for the target oven and the second for the ionizer. The latter, being in carbon, offers high reliability and competitive ionization efficiency. This surface ionization source has been tested on-line using a {sup 48}Ca primary beam at 60.3 A MeV with an intensity of 0.14 pA. The ionization efficiencies obtained for Li, Na and K are significantly better than the theoretical values of the ionization probability per contact. The enhanced efficiency, due to the polarization of the ionizer, is shown to be very important also for short-lived isotopes. In the future, this source will be associated with the multicharged electron-cyclotron-resonance (ECR) ion source NANOGAN III for production of multicharged alkali ions in SPIRAL. The preliminary tests of the set up are also presented in this contribution.

  19. In-source photocatalytic reduction of disulfide bonds during laser desorption ionization

    OpenAIRE

    Qiao, L.; Bi, H.; Busnel, J M; B. Liu; Girault, H. H.

    2008-01-01

    A photosensitive plate based on sintered TiO2 nanoparticles has been developed to carry out in-source photo-induced reductions for cleavage of disulfide bridges using glucose as a hole scavenger during laser desorption ionization.

  20. Ambient ionization mass spectrometric analysis of human surgical specimens to distinguish renal cell carcinoma from healthy renal tissue.

    Science.gov (United States)

    Alfaro, Clint M; Jarmusch, Alan K; Pirro, Valentina; Kerian, Kevin S; Masterson, Timothy A; Cheng, Liang; Cooks, R Graham

    2016-08-01

    Touch spray-mass spectrometry (TS-MS) is an ambient ionization technique (ionization of unprocessed samples in the open air) that may find intraoperative applications in quickly identifying the disease state of cancerous tissues and in defining surgical margins. In this study, TS-MS was performed on fresh kidney tissue (∼1-5 cm(3)), within 1 h of resection, from 21 human subjects afflicted by renal cell carcinoma (RCC). The preliminary diagnostic value of TS-MS data taken from freshly resected tissue was evaluated. Principal component analysis (PCA) of the negative ion mode (m/z 700-1000) data provided the separation between RCC (16 samples) and healthy renal tissue (13 samples). Linear discriminant analysis (LDA) on the PCA-compressed data estimated sensitivity (true positive rate) and specificity (true negative rate) of 98 and 95 %, respectively, based on histopathological evaluation. The results indicate that TS-MS might provide rapid diagnostic information in spite of the complexity of unprocessed kidney tissue and the presence of interferences such as urine and blood. Desorption electrospray ionization-MS imaging (DESI-MSI) in the negative ionization mode was performed on the tissue specimens after TS-MS analysis as a reference method. The DESI imaging experiments provided phospholipid profiles (m/z 700-1000) that also separated RCC and healthy tissue in the PCA space, with PCA-LDA sensitivity and specificity of 100 and 89 %, respectively. The TS and DESI loading plots indicated that different ions contributed most to the separation of RCC from healthy renal tissue (m/z 794 [PC 34:1 + Cl](-) and 844 [PC 38:4 + Cl](-) for TS vs. m/z 788 [PS 36:1 - H](-) and 810 [PS 38:4 - H](-) for DESI), while m/z 885 ([PI 38:4 - H](-)) was important in both TS and DESI. The prospect, remaining hurdles, and future work required for translating TS-MS into a method of intraoperative tissue diagnosis are discussed. Graphical abstract Touch spray-mass spectrometry used for

  1. Ionization detection system for aerosols

    Science.gov (United States)

    Jacobs, Martin E.

    1977-01-01

    This invention relates to an improved smoke-detection system of the ionization-chamber type. In the preferred embodiment, the system utilizes a conventional detector head comprising a measuring ionization chamber, a reference ionization chamber, and a normally non-conductive gas triode for discharging when a threshold concentration of airborne particulates is present in the measuring chamber. The improved system utilizes a measuring ionization chamber which is modified to minimize false alarms and reductions in sensitivity resulting from changes in ambient temperature. In the preferred form of the modification, an annular radiation shield is mounted about the usual radiation source provided to effect ionization in the measuring chamber. The shield is supported by a bimetallic strip which flexes in response to changes in ambient temperature, moving the shield relative to the source so as to vary the radiative area of the source in a manner offsetting temperature-induced variations in the sensitivity of the chamber.

  2. Ionization cross sections and ionic yield in an ion source with confined electron beam

    International Nuclear Information System (INIS)

    A new ion source for fully stripped ion production and polarized particles storage is studied. Ionization cross sections are simulated by the semi-empirical Loetz formula revised by Donets. The ionic yield of the ion source is calculated per pulse and second in the case of this source being used for a synchrocyclotron, a linear accelerator or a cyclotron

  3. Optimization of a hot-cavity type resonant ionization laser ion source

    Energy Technology Data Exchange (ETDEWEB)

    Henares, J. L., E-mail: henares@ganil.fr; Lecesne, N.; Hijazi, L.; Bastin, B.; Leroy, R.; Osmond, B.; Vignet, J. L. [GANIL, BP 55027, 14076 Caen Cedex 5 (France); Kron, T.; Naubereit, P.; Wendt, K. [Johannes Gutenberg-Universität Mainz, Staudinger Weg 7, 55099 Mainz (Germany); Lassen, J. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3 (Canada); Le Blanc, F. [IPN Orsay, BP 1-91406 Orsay (France)

    2016-02-15

    Resonant Ionization Laser Ion Source (RILIS) is nowadays an important technique in many Radioactive Ion Beam (RIB) facilities for its reliability and ability to ionize efficiently and element selectively. Grand Accélérateur National d’Ions Lourds (GANIL) Ion Source using Electron Laser Excitation (GISELE) is an off-line test bench for RILIS developed to study a fully operational resonant laser ion source at GANIL facility. The ion source body has been designed as a modular system to investigate different experimental approaches by varying the design parameters, to develop the future on-line laser ion source. The aim of this project is to determine the best technical solution which combines high selectivity and ionization efficiency with small ion beam emittance and stable long term operation. Latest results concerning emittance and time profile development as a function of the temperature for different ion source versions will be presented.

  4. Optimization of a hot-cavity type resonant ionization laser ion source

    International Nuclear Information System (INIS)

    Resonant Ionization Laser Ion Source (RILIS) is nowadays an important technique in many Radioactive Ion Beam (RIB) facilities for its reliability and ability to ionize efficiently and element selectively. Grand Accélérateur National d’Ions Lourds (GANIL) Ion Source using Electron Laser Excitation (GISELE) is an off-line test bench for RILIS developed to study a fully operational resonant laser ion source at GANIL facility. The ion source body has been designed as a modular system to investigate different experimental approaches by varying the design parameters, to develop the future on-line laser ion source. The aim of this project is to determine the best technical solution which combines high selectivity and ionization efficiency with small ion beam emittance and stable long term operation. Latest results concerning emittance and time profile development as a function of the temperature for different ion source versions will be presented

  5. Protein Analysis by Ambient Ionization Mass Spectrometry Using Trypsin-Immobilized Organosiloxane Polymer Surfaces.

    Science.gov (United States)

    Dulay, Maria T; Eberlin, Livia S; Zare, Richard N

    2015-12-15

    In the growing field of proteomic research, rapid and simple protein analysis is a crucial component of protein identification. We report the use of immobilized trypsin on hybrid organic-inorganic organosiloxane (T-OSX) polymers for the on-surface, in situ digestion of four model proteins: melittin, cytochrome c, myoglobin, and bovine serum albumin. Tryptic digestion products were sampled, detected, and identified using desorption electrospray ionization mass spectrometry (DESI-MS) and nanoDESI-MS. These novel, reusable T-OSX arrays on glass slides allow for protein digestion in methanol:water solvents (1:1, v/v) and analysis directly from the same polymer surface without the need for sample preparation, high temperature, and pH conditions typically required for in-solution trypsin digestions. Digestion reactions were conducted with 2 μL protein sample droplets (0.35 mM) at incubation temperatures of 4, 25, 37, and 65 °C and digestion reaction times between 2 and 24 h. Sequence coverages were dependent on the hydrophobicity of the OSX polymer support and varied by temperature and digestion time. Under the best conditions, the sequence coverages, determined by DESI-MS, were 100% for melittin, 100% for cytochrome c, 90% for myoglobin, and 65% for bovine serum albumin. PMID:26567450

  6. Development of a surface ionization source for the SPIRAL 2 project

    Energy Technology Data Exchange (ETDEWEB)

    Pichard, A.; Jardin, P.; Saint-Laurent, M.-G.; Frigot, R.; Bajeat, O.; Delahaye, P.; Dubois, M.; Fraanberg-Delahaye, H.; Lecomte, P.; Leherissier, P.; Leroy, R.; Lecesne, N.; Maunoury, L.; Mery, A.; Pacquet, J. Y. [GANIL, Bd Henri Becquerel, BP 55027, 14076 Caen Cedex 5 (France); Collaboration: GANISOL Team

    2010-02-15

    Development of new radioactive beams, and thus of new target ion sources (TISs) for isotope-separator-on-line production systems are in progress at GANIL for the SPIRAL 2 project. The efficiency and time response measurements of each step in the production process are crucial to predict and maximize the available yields, in particular, for short lived isotopes. This paper presents a method for measuring these quantities that makes use of a stable alkali chopped beam of controlled intensity. This method was applied to surface ionization source test for high efficiency. Results of recent experiments are presented that include ionization efficiency measurements for Cs, Rb, K, Na, and Li with a graphite and rhenium ionizer and dwell time of these alkalis on graphite. The results enabled to design a first surface ionization source prototype which will be installed in the SPIRAL 2 TIS.

  7. Medium Vacuum Electron Emitter as Soft Atmospheric Pressure Chemical Ionization Source for Organic Molecules.

    Science.gov (United States)

    Liedtke, Sascha; Ahlmann, Norman; Marggraf, Ulrich; Schütz, Alexander; Vautz, Wolfgang; Franzke, Joachim

    2016-05-01

    An electron emitter as a soft atmospheric pressure chemical ionization source is presented, which operates at inner pressures of the device in the medium vacuum range (>10(-3) hPa). Conventional nonradioactive electron emitters require high vacuum (pump-by 2% compared to high-vacuum conditions. This can be compensated with an increase of the electron source output. The functionality of this ion source is demonstrated with mass spectrometric and ion mobility measurements of acetone, eucalyptol, and diisopropyl methanephosphonate. Additional mass spectrometric measurements of 20 different organic compounds demonstrate the soft characteristics of this ionization source. PMID:27046293

  8. Diffuse gas in retired galaxies: nebular emission templates and constraints on the sources of ionization

    Science.gov (United States)

    Johansson, Jonas; Woods, Tyrone E.; Gilfanov, Marat; Sarzi, Marc; Chen, Yan-Mei; Oh, Kyuseok

    2016-10-01

    We present emission-line templates for passively-evolving (`retired') galaxies, useful for investigation of the evolution of the interstellar medium in these galaxies, and characterization of their high-temperature source populations. The templates are based on high signal-to-noise (>800) co-added spectra (3700-6800 Å) of ˜11 500 gas-rich Sloan Digital Sky Survey galaxies devoid of star formation and active galactic nuclei. Stacked spectra are provided for the entire sample and sub-samples binned by mean stellar age. In our previous paper, Johansson et al., these spectra provided the first measurements of the He II 4686 Å line in passively-evolving galaxies, and the observed He II/Hβ ratio constrained the contribution of accreting white dwarfs (the `single-degenerate' scenario) to the Type Ia supernova rate. In this paper, the full range of unambiguously detected emission lines are presented. Comparison of the observed [O I] 6300 Å/Hα ratio with photoionization models further constrains any high-temperature single-degenerate scenario for Type Ia supernovae (with 1.5 ≲ T/105 K ≲ 10) to ≲3-6 per cent of the observed rate in the youngest age bin (i.e. highest SN Ia rate). Hence, for the same temperatures, in the presence of an ambient population of post-asymptotic giant branch stars, we exclude additional high-temperature sources with a combined ionizing luminosity of ≈1.35 × 1030 L⊙/M⊙,* for stellar populations with mean ages of 1-4 Gyr. Furthermore, we investigate the extinction affecting both the stellar and nebular continuum. The latter shows about five times higher values. This contradicts isotropically distributed dust and gas that renders similar extinction values for both cases.

  9. Schottky Tunneling Source Impact Ionization Mosfet (STS-IMOS with Enhanced Device Performance

    Directory of Open Access Journals (Sweden)

    Sangeeta Singh

    2015-06-01

    Full Text Available In this paper, we propose and investigate a schottky tunneling source impact ionization MOSFET (STSIMOS with enhanced device performance. STS-IMOS has silicide (NiSi source to lower the breakdown voltage of conventional impact ionization MOS (IMOS. There is cumulative effect of both impact ionization and source induced tunneling for the current gating mechanism of the device. The silicide source offers immensely low parasitic resistance subsequently there is an increment in voltage drop across intrinsic region. This leads to appreciable lowering of breakdown and threshold voltage for STS-IMOS. Hence, it demonstrates enhanced device performance over conventional IMOS. Besides this for STS-IMOS the location of maximum electric field has shifted towards the source and now it is quite away from gate oxide. Hence, it shows high immunity against Vth fluctuations due to hot electron damage. Consequently, it is found that device reliability is also improved significantly.

  10. Improving the selectivity of the ISOLDE resonance ionization laser ion source and in-source laser spectroscopy of polonium

    International Nuclear Information System (INIS)

    Exotic atomic nuclei far away from stability are fascinating objects to be studied in many scientific fields such as atomic-, nuclear-, and astrophysics. Since these are often short-lived isotopes, it is necessary to couple their production with immediate extraction and delivery to an experiment. This is the purpose of the on-line isotope separator facility, ISOLDE, at CERN. An essential aspect of this laboratory is the Resonance Ionization Laser Ion Source (RILIS) because it provides a fast and highly selective means of ionizing the reaction products. This technique is also a sensitive laser-spectroscopy tool for the development and improvement of electron excitation schemes for the resonant laser photoionization and the study of the nuclear structure or fundamental atomic physics. Each of these aspects of the RILIS applications are subjects of this thesis work: a new device for the suppression of unwanted surface ionized contaminants in RILIS ion beams, known as the Laser Ion Source and Trap (LIST), was implemented into the ISOLDE framework, further developed and characterized; a new electron-excitation scheme for the laser ionization of calcium was developed; the ionization energy of polonium was determined by high-precision Rydberg spectroscopy; and finally, the first ever on-line physics operation of the highly selective LIST enabled the study of nuclear structure properties of 217Po by in-source resonance ionization spectroscopy.

  11. Source apportionment of ambient VOCS in Mumbai city

    Science.gov (United States)

    Srivastava, Anjali

    Air pollution kills almost half a million Asians every year. Most of this pollution is emitted from buses, trucks, motorcycles and other forms of transport. As Asia's cities continue to expand, the rising number of vehicles has resulted in even greater pollution. Amongst the measures available to control, vehicular emission was engine modification, catalytic converters and fuel modifications. Some of these have led to emissions of some hazardous air pollutants (HAP) like volatile organic compounds (VOCs). VOC emission is an area needing attention in air quality management. This paper discusses a study on VOC concentration at major sources like traffic junction, residential area, commercial areas, industrial areas and petrol pumps in Mumbai city. CMB8 Model has been used to apportion VOCs in Mumbai city. It was observed that evaporative emissions dominate in Mumbai. In order to control VOCs in air the management strategy should thus focus on cost effective vapor recovery systems at refueling stations and in vehicles. Effective inspection and maintenance programme can reduce evaporative and exhaust VOC emissions. Modifying certain fuel parameters, like reducing benzene content in petrol will as well reduce VOC content in air. The benzene content in petrol was 3% in the year 2001 in Mumbai. Adulteration also results in high levels of VOCs in air.

  12. Conceptual Demonstration of Ambient Desorption-Optical Emission Spectroscopy Using a Liquid Sampling-Atmospheric Pressure Glow Discharge Microplasma Source.

    Science.gov (United States)

    Marcus, R Kenneth; Paing, Htoo W; Zhang, Lynn X

    2016-06-01

    The concept of ambient desorption-optical emission spectroscopy (AD-OES) is demonstrated using a liquid sampling-atmospheric pressure glow discharge (LS-APGD) microplasma as the desorption/excitation source. The LS-APGD has previously been employed for elemental analysis of solution samples and particulates introduced via laser ablation in both the optical emission and mass spectrometries (OES, MS) modes. In addition, the device has been shown to be effective for the analysis of elemental and molecular species operating in an ambient desorption/ionization mass spectrometry (ADI-MS) mode. Proof-of-concept is presented here in the use of the LS-APGD to volatilize three very diverse sample forms (metallic thin films, dry solution residues, and bulk materials), with the liberated material excited within the microplasma and detected via OES, i.e., AD-OES. While the demonstration is principally qualitative at this point, it is believed that the basic approach may find application across a broad spectrum of analytical challenges requiring elemental analysis, including metals, soils, and volume-limited solutions, analogous to what has been seen in the development of the field of ADI-MS for molecular species determinations. PMID:27175512

  13. A compact 3D-printed interface for coupling open digital microchips with Venturi easy ambient sonic-spray ionization mass spectrometry.

    Science.gov (United States)

    Hu, Jie-Bi; Chen, Ting-Ru; Chang, Chia-Hsien; Cheng, Ji-Yen; Chen, Yu-Chie; Urban, Pawel L

    2015-03-01

    Digital microfluidics (DMF) based on the electrowetting-on-dielectric phenomenon is a convenient way of handling microlitre-volume aliquots of solutions prior to analysis. Although it was shown to be compatible with on-line mass spectrometric detection, due to numerous technical obstacles, the implementation of DMF in conjunction with MS is still beyond the reach of many analytical laboratories. Here we present a facile method for coupling open DMF microchips to mass spectrometers using Venturi easy ambient sonic-spray ionization operated at atmospheric pressure. The proposed interface comprises a 3D-printed body that can easily be "clipped" at the inlet of a standard mass spectrometer. The accessory features all the necessary connections for an open-architecture DMF microchip with T-shaped electrode arrangement, thermostatting of the microchip, purification of air (to prevent accidental contamination of the microchip), a Venturi pump, and two microfluidic pumps to facilitate transfer of samples and reagents onto the microchip. The system also incorporates a touch-screen panel and remote control for user-friendly operation. It is based on the use of popular open-source electronic modules, and can readily be assembled at low expense.

  14. In-source resonance ionization spectroscopy of high lying energy levels in atomic uranium

    International Nuclear Information System (INIS)

    In-source resonance ionization spectroscopy of uranium has been carried out as preparation for the analysis of low contaminations of nuclear material in environmental samples via laser mass spectrometry. Using three-step resonance ionization spectroscopy, 86 levels of odd parity in the energy range from 37,200-38,650 cm-1 were studied, 51 of these levels were previously unknown. Suitable excitation schemes for analytic applications are discussed.

  15. In-source resonance ionization spectroscopy of high lying energy levels in atomic uranium

    Science.gov (United States)

    Raeder, Sebastian; Fies, Silke; Gottwald, Tina; Mattolat, Christoph; Rothe, Sebastian; Wendt, Klaus

    2010-02-01

    In-source resonance ionization spectroscopy of uranium has been carried out as preparation for the analysis of low contaminations of nuclear material in environmental samples via laser mass spectrometry. Using three-step resonance ionization spectroscopy, 86 levels of odd parity in the energy range from 37,200-38,650 cm - 1 were studied, 51 of these levels were previously unknown. Suitable excitation schemes for analytic applications are discussed.

  16. In-source resonance ionization spectroscopy of high lying energy levels in atomic uranium

    Energy Technology Data Exchange (ETDEWEB)

    Raeder, Sebastian, E-mail: raeder@uni-mainz.de; Fies, Silke; Gottwald, Tina; Mattolat, Christoph [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik (Germany); Rothe, Sebastian [CERN, Engineering Department (Switzerland); Wendt, Klaus [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik (Germany)

    2010-02-15

    In-source resonance ionization spectroscopy of uranium has been carried out as preparation for the analysis of low contaminations of nuclear material in environmental samples via laser mass spectrometry. Using three-step resonance ionization spectroscopy, 86 levels of odd parity in the energy range from 37,200-38,650 cm{sup -1} were studied, 51 of these levels were previously unknown. Suitable excitation schemes for analytic applications are discussed.

  17. Resonant Ionization Laser Ion Source (RILIS) off-line developments on Ga, Al and Ca

    International Nuclear Information System (INIS)

    The Resonant Ionization Laser Ion Source (RILIS) is an element selective, highly efficient and versatile tool for generation of radioactive ion beams at on-line mass separator facilities. Parallel to TRIUMF’s on-line RILIS at the Isotope Separator and ACcelerator (ISAC) facility, an off-line Laser Ion Source test stand (LIS STAND) is operated for systematic laser resonance ionization spectroscopy, ionization scheme and ion source development. Three titanium sapphire (Ti:Sa) lasers optionally equipped with harmonic frequency generation units are used to resonantly step-wise excite and ionize elements of interest. A grating tuned Ti:Sa laser allows continuous laser wavelength scans of up to Δ≈200nm. With this laser inventory and the LIS STAND, atomic Rydberg series and auto-ionizing levels can systematically be studied. The LIS STAND has been in use since 2009 and so far the spectroscopy on Ga, Al and Ca has been performed. The development of efficient laser resonant ionization schemes, their investigation and comparison using the LIS STAND are discussed

  18. Low power energy harvesting and storage techniques from ambient human powered energy sources

    Science.gov (United States)

    Yildiz, Faruk

    Conventional electrochemical batteries power most of the portable and wireless electronic devices that are operated by electric power. In the past few years, electrochemical batteries and energy storage devices have improved significantly. However, this progress has not been able to keep up with the development of microprocessors, memory storage, and sensors of electronic applications. Battery weight, lifespan and reliability often limit the abilities and the range of such applications of battery powered devices. These conventional devices were designed to be powered with batteries as required, but did not allow scavenging of ambient energy as a power source. In contrast, development in wireless technology and other electronic components are constantly reducing the power and energy needed by many applications. If energy requirements of electronic components decline reasonably, then ambient energy scavenging and conversion could become a viable source of power for many applications. Ambient energy sources can be then considered and used to replace batteries in some electronic applications, to minimize product maintenance and operating cost. The potential ability to satisfy overall power and energy requirements of an application using ambient energy can eliminate some constraints related to conventional power supplies. Also power scavenging may enable electronic devices to be completely self-sustaining so that battery maintenance can eventually be eliminated. Furthermore, ambient energy scavenging could extend the performance and the lifetime of the MEMS (Micro electromechanical systems) and portable electronic devices. These possibilities show that it is important to examine the effectiveness of ambient energy as a source of power. Until recently, only little use has been made of ambient energy resources, especially for wireless networks and portable power devices. Recently, researchers have performed several studies in alternative energy sources that could provide

  19. Evolution process and sources of ambient volatile organic compounds during a severe haze event in Beijing, China.

    Science.gov (United States)

    Wu, Rongrong; Li, Jing; Hao, Yufang; Li, Yaqi; Zeng, Limin; Xie, Shaodong

    2016-08-01

    108 ambient volatile organic compounds (VOCs) were measured continuously at a time resolution of an hour using an online gas chromatography-frame ionization detector/mass spectrometry (GC-FID/MS) in October 2014 in Beijing, and positive matrix factorization (PMF) was performed with online data. The evolution process and causes for high levels of VOCs during a haze event were investigated through comprehensive analysis. Results show that mixing ratios of VOCs during the haze event (89.29 ppbv) were 2 to 5 times as that in non-haze days, There was a distinct accumulation process of VOCs at the beginning of the haze event, and the mixing ratios of VOCs maintained at the high levels until to the end of pollution when the mixing ratios of ambient VOCs recovered to the normal concentration levels in a few hours. Some reactive and toxic species increased remarkably as well, which indicates a potential health risk to the public in terms of VOCs. Eight sources were resolved by PMF, and results revealed gasoline exhaust was the largest contributor (32-46%) to the ambient VOCs in Beijing. Emissions of gasoline exhaust surged from 13.46 to 40.36 ppbv, with a similar variation pattern to total VOCs, indicating that high levels of VOCs were largely driven to by expanded vehicular emissions. Emissions of biomass burning also increased noticeably (from 2.32 to 11.12 ppbv), and backward trajectories analysis indicated regional transport of biomass burning emissions. Our findings suggested that extremely high levels of VOCs during the haze event was primarily attributed to vehicular emissions, biomass burning and regional transport, as well as stationary synoptic conditions. PMID:27093124

  20. Evolution process and sources of ambient volatile organic compounds during a severe haze event in Beijing, China.

    Science.gov (United States)

    Wu, Rongrong; Li, Jing; Hao, Yufang; Li, Yaqi; Zeng, Limin; Xie, Shaodong

    2016-08-01

    108 ambient volatile organic compounds (VOCs) were measured continuously at a time resolution of an hour using an online gas chromatography-frame ionization detector/mass spectrometry (GC-FID/MS) in October 2014 in Beijing, and positive matrix factorization (PMF) was performed with online data. The evolution process and causes for high levels of VOCs during a haze event were investigated through comprehensive analysis. Results show that mixing ratios of VOCs during the haze event (89.29 ppbv) were 2 to 5 times as that in non-haze days, There was a distinct accumulation process of VOCs at the beginning of the haze event, and the mixing ratios of VOCs maintained at the high levels until to the end of pollution when the mixing ratios of ambient VOCs recovered to the normal concentration levels in a few hours. Some reactive and toxic species increased remarkably as well, which indicates a potential health risk to the public in terms of VOCs. Eight sources were resolved by PMF, and results revealed gasoline exhaust was the largest contributor (32-46%) to the ambient VOCs in Beijing. Emissions of gasoline exhaust surged from 13.46 to 40.36 ppbv, with a similar variation pattern to total VOCs, indicating that high levels of VOCs were largely driven to by expanded vehicular emissions. Emissions of biomass burning also increased noticeably (from 2.32 to 11.12 ppbv), and backward trajectories analysis indicated regional transport of biomass burning emissions. Our findings suggested that extremely high levels of VOCs during the haze event was primarily attributed to vehicular emissions, biomass burning and regional transport, as well as stationary synoptic conditions.

  1. Hot-cavity studies for the Resonance Ionization Laser Ion Source

    Science.gov (United States)

    Henares, J. L.; Lecesne, N.; Hijazi, L.; Bastin, B.; Kron, T.; Lassen, J.; Le Blanc, F.; Leroy, R.; Osmond, B.; Raeder, S.; Schneider, F.; Wendt, K.

    2016-09-01

    The Resonance Ionization Laser Ion Source (RILIS) has emerged as an important technique in many Radioactive Ion Beam (RIB) facilities for its reliability, and ability to ionize target elements efficiently and element selectively. GISELE is an off-line RILIS test bench to study the implementation of an on-line laser ion source at the GANIL separator facility. The aim of this project is to determine the best technical solution which combines high selectivity and ionization efficiency with small ion beam emittance and stable long term operation. The ion source geometry was tested in several configurations in order to find a solution with optimal ionization efficiency and beam emittance. Furthermore, a low work function material was tested to reduce the contaminants and molecular sidebands generated inside the ion source. First results with ZrC ionizer tubes will be presented. Furthermore, a method to measure the energy distribution of the ion beam as a function of the time of flight will be discussed.

  2. Resonance ionization laser ion sources for on-line isotope separators (invited).

    Science.gov (United States)

    Marsh, B A

    2014-02-01

    A Resonance Ionization Laser Ion Source (RILIS) is today considered an essential component of the majority of Isotope Separator On Line (ISOL) facilities; there are seven laser ion sources currently operational at ISOL facilities worldwide and several more are under development. The ionization mechanism is a highly element selective multi-step resonance photo-absorption process that requires a specifically tailored laser configuration for each chemical element. For some isotopes, isomer selective ionization may even be achieved by exploiting the differences in hyperfine structures of an atomic transition for different nuclear spin states. For many radioactive ion beam experiments, laser resonance ionization is the only means of achieving an acceptable level of beam purity without compromising isotope yield. Furthermore, by performing element selection at the location of the ion source, the propagation of unwanted radioactivity downstream of the target assembly is reduced. Whilst advances in laser technology have improved the performance and reliability of laser ion sources and broadened the range of suitable commercially available laser systems, many recent developments have focused rather on the laser/atom interaction region in the quest for increased selectivity and/or improved spectral resolution. Much of the progress in this area has been achieved by decoupling the laser ionization from competing ionization processes through the use of a laser/atom interaction region that is physically separated from the target chamber. A new application of gas catcher laser ion source technology promises to expand the capabilities of projectile fragmentation facilities through the conversion of otherwise discarded reaction fragments into high-purity low-energy ion beams. A summary of recent RILIS developments and the current status of laser ion sources worldwide is presented.

  3. Resonance ionization laser ion sources for on-line isotope separators (invited)

    International Nuclear Information System (INIS)

    A Resonance Ionization Laser Ion Source (RILIS) is today considered an essential component of the majority of Isotope Separator On Line (ISOL) facilities; there are seven laser ion sources currently operational at ISOL facilities worldwide and several more are under development. The ionization mechanism is a highly element selective multi-step resonance photo-absorption process that requires a specifically tailored laser configuration for each chemical element. For some isotopes, isomer selective ionization may even be achieved by exploiting the differences in hyperfine structures of an atomic transition for different nuclear spin states. For many radioactive ion beam experiments, laser resonance ionization is the only means of achieving an acceptable level of beam purity without compromising isotope yield. Furthermore, by performing element selection at the location of the ion source, the propagation of unwanted radioactivity downstream of the target assembly is reduced. Whilst advances in laser technology have improved the performance and reliability of laser ion sources and broadened the range of suitable commercially available laser systems, many recent developments have focused rather on the laser/atom interaction region in the quest for increased selectivity and/or improved spectral resolution. Much of the progress in this area has been achieved by decoupling the laser ionization from competing ionization processes through the use of a laser/atom interaction region that is physically separated from the target chamber. A new application of gas catcher laser ion source technology promises to expand the capabilities of projectile fragmentation facilities through the conversion of otherwise discarded reaction fragments into high-purity low-energy ion beams. A summary of recent RILIS developments and the current status of laser ion sources worldwide is presented

  4. Study of low work function materials for hot cavity resonance ionization laser ion sources

    CERN Document Server

    Schwellnus, F; Crepieux, B; Fedosseev, V N; Marsh, B A; Mattolat, Ch; Menna, M; Österdahl, F K; Raeder, S; Stora, T; Wendta, K

    2009-01-01

    The selectivity of a hot cavity resonance ionization laser ion source (RILIS) is most often limited by contributions from competing surface ionization of the hot walls of the ionization cavity. In this article we present investigations on the properties of designated high temperature, low work function materials regarding their performance and suitability as cavity material for RILIS. Tungsten test cavities, impregnated with a mixture of barium oxide and strontium oxide (BaOSrO on W), or alternatively gadolinium hexaboride (GdB6) were studied in comparison to a standard tungsten RILIS cavity as being routinely used for hot cavity laser ionization at ISOLDE. Measurement campaigns took place at the off-line mass separators at ISOLDE/CERN, Geneva and RISIKO/University of Mainz.

  5. Study of Low Work Function Materials for Hot Cavity Resonance Ionization Laser Ion Sources

    CERN Document Server

    Catherall, R; Fedosseev, V; Marsh, B; Mattolat, C; Menna, Mariano; Österdahl, F; Raeder, S; Schwellnus, F; Stora, T; Wendt, K; CERN. Geneva. AB Department

    2008-01-01

    The selectivity of a hot cavity resonance ionization laser ion source (RILIS) is most often limited by contributions from competing surface ionization on the hot walls of the ionization cavity. In this article we present investigations on the properties of designated high-temperature, low-work function materials regarding their performance and suitability as cavity material for RILIS. Tungsten test cavities, impregnated with a mixture of barium oxide and strontium oxide (BaOSrO on W), or alternatively gadolinium hexaboride (GdB6) were studied in comparison to a standard tungsten RILIS cavity as being routinely used for hot cavity laser ionization at ISOLDE. Measurement campaigns took place at the off-line mass separators at ISOLDE / CERN, Geneva and RISIKO / University of Mainz.

  6. Reduction of PM emissions from specific sources reflected on key components concentrations of ambient PM10

    Science.gov (United States)

    Minguillon, M. C.; Querol, X.; Monfort, E.; Alastuey, A.; Escrig, A.; Celades, I.; Miro, J. V.

    2009-04-01

    The relationship between specific particulate emission control and ambient levels of some PM10 components (Zn, As, Pb, Cs, Tl) was evaluated. To this end, the industrial area of Castellón (Eastern Spain) was selected, where around 40% of the EU glazed ceramic tiles and a high proportion of EU ceramic frits (middle product for the manufacture of ceramic glaze) are produced. The PM10 emissions from the ceramic processes were calculated over the period 2000 to 2007 taking into account the degree of implementation of corrective measures throughout the study period. Abatement systems (mainly bag filters) were implemented in the majority of the fusion kilns for frit manufacture in the area as a result of the application of the Directive 1996/61/CE, leading to a marked decrease in PM10 emissions. On the other hand, ambient PM10 sampling was carried out from April 2002 to July 2008 at three urban sites and one suburban site of the area and a complete chemical analysis was made for about 35 % of the collected samples, by means of different techniques (ICP-AES, ICP-MS, Ion Chromatography, selective electrode and elemental analyser). The series of chemical composition of PM10 allowed us to apply a source contribution model (Principal Component Analysis), followed by a multilinear regression analysis, so that PM10 sources were identified and their contribution to bulk ambient PM10 was quantified on a daily basis, as well as the contribution to bulk ambient concentrations of the identified key components (Zn, As, Pb, Cs, Tl). The contribution of the sources identified as the manufacture and use of ceramic glaze components, including the manufacture of ceramic frits, accounted for more than 65, 75, 58, 53, and 53% of ambient Zn, As, Pb, Cs and Tl levels, respectively (with the exception of Tl contribution at one of the sites). The important emission reductions of these sources during the study period had an impact on ambient key components levels, such that there was a high

  7. Source geometry factors for HDR 192Ir brachytherapy secondary standard well-type ionization chamber calibrations

    Science.gov (United States)

    Shipley, D. R.; Sander, T.; Nutbrown, R. F.

    2015-03-01

    Well-type ionization chambers are used for measuring the source strength of radioactive brachytherapy sources before clinical use. Initially, the well chambers are calibrated against a suitable national standard. For high dose rate (HDR) 192Ir, this calibration is usually a two-step process. Firstly, the calibration source is traceably calibrated against an air kerma primary standard in terms of either reference air kerma rate or air kerma strength. The calibrated 192Ir source is then used to calibrate the secondary standard well-type ionization chamber. Calibration laboratories are usually only equipped with one type of HDR 192Ir source. If the clinical source type is different from that used for the calibration of the well chamber at the standards laboratory, a source geometry factor, ksg, is required to correct the calibration coefficient for any change of the well chamber response due to geometric differences between the sources. In this work we present source geometry factors for six different HDR 192Ir brachytherapy sources which have been determined using Monte Carlo techniques for a specific ionization chamber, the Standard Imaging HDR 1000 Plus well chamber with a type 70010 HDR iridium source holder. The calculated correction factors were normalized to the old and new type of calibration source used at the National Physical Laboratory. With the old Nucletron microSelectron-v1 (classic) HDR 192Ir calibration source, ksg was found to be in the range 0.983 to 0.999 and with the new Isodose Control HDR 192Ir Flexisource ksg was found to be in the range 0.987 to 1.004 with a relative uncertainty of 0.4% (k = 2). Source geometry factors for different combinations of calibration sources, clinical sources, well chambers and associated source holders, can be calculated with the formalism discussed in this paper.

  8. Influence of the radioactive source position inside the well-type ionization chamber

    Energy Technology Data Exchange (ETDEWEB)

    Kuahara, L.T.; Correa, E.L.; Potiens, M.P.A., E-mail: liliankuahara@usp.br [Instituto de Pesquisas Energeticas e Nucleres (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    The activimeter, instrument used in radionuclide activity measurement, consists primarily of a well type ionization chamber coupled to a special electronic device. Its response, after calibration, is shown in activity units (Becquerel or Curie). The goal of this study is to verify radioactive source position influence over activity measured by this instrument. Radioactive sources measurements were made at different depths inside the ionization chamber well. Results showed maximum variation of -23 %, -28 % and -15 % for {sup 57}Co, {sup 133}Ba and {sup 137}Cs, respectively. (author)

  9. Source formulation for electron-impact ionization for fluid plasma simulations

    DEFF Research Database (Denmark)

    Müller, S.H.; Holland, C.; Tynan, G.R.;

    2009-01-01

    The derivation of the correct functional form of source terms in plasma fluid theory is revisited. The relation between the fluid source terms and atomic physics differential cross sections is established for particle-impact ionization. It is shown that the interface between atomic and plasma...... physics is completely described by three scalar functions of the incident particle energy. These are the total cross section and the newly introduced forward momentum and energy functions, which are properties of the differential cross sections only. For electron-impact ionization, the binary...

  10. REQUIEREMENTS TO THE LIMITATION OF POPULATION EXPOSURE FROM NATURAL IONIZING SOURCES IN UTILITY CONDITIONS

    Directory of Open Access Journals (Sweden)

    I. P. Stamat

    2010-01-01

    Full Text Available The article presents conceptually new requirements to the limitation of population exposure from natural ionizing sources in the industry conditions, introduced to the Main Sanitary Rules for Radiation Safety -99/2010 (OSPORB-99/2010 in development of requirements of the Radiation Safety Norms-99/2009 (NRB-99/2009. It is shown that introduction of these requirements is, first of all, aimed at resolution of some existing earlier serious contradictions in the management of radiation safety control and supervision for the impact from natural ionizing sources to population in the utility conditions.

  11. Mass spectrometric characterization of a pyrolytic radical source using femtosecond ionization

    Energy Technology Data Exchange (ETDEWEB)

    Frey, H.M.; Beaud, P.; Mischler, B.; Radi, P.P.; Tzannis, A.P.; Gerber, T. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    Radicals play, as reactive species, an important role in the chemistry of combustion. In contrast to atmospheric flames where spectra are congested due to high vibrational and rotational excitation, experiments in the cold environment of a molecular beam (MB) yield clean spectra that can be easily attributed to one species by Resonantly Enhanced Multi Photon Ionization (REMP). A pyrolytic radical source has been set up. To characterize the efficiency of the source `soft` ionization with femto second pulses is applied which results in less fragmentation, simplifying the interpretation of the mass spectrum. (author) figs., tabs., refs.

  12. Resonant Ionization Laser Ion Source Project at TRIUMF

    Energy Technology Data Exchange (ETDEWEB)

    Lassen, J., E-mail: lassen@triumf.ca; Bricault, P.; Dombsky, M.; Lavoie, J. P. [TRIUMF (Canada); Geppert, Ch.; Wendt, K. [Johannes Gutenberg-Universitaet Mainz (Germany)

    2005-04-15

    Resonant laser excitation and ionisation is one of the most successful tools for the selective production of radioactive ion beams (RIB) at on-line mass separator facilities. TRIUMF plans to augment the current ion sources with a resonant ionisation laser ion source (RILIS), to use the high production yields from the target, as shown by the delivery of 3*10{sup 4}/s {sup 11}Li ions from a standard target ion source with surface ionisation. The development and installation of TRIUMF's RILIS (TRILIS) is necessary to provide beams of short lived isotopes that conventional ion sources could not produce in sufficient intensity and purity for nuclear-, and nuclear astrophysics- experiments. A laser system consisting of three tunable titanium-sapphire (TiSa) lasers with frequency doubling and tripling was employed to demonstrate first off-line resonance ionisation of Ga, and is being installed for first on-line test and a run on {sup 62}Ga in December 2004.

  13. Insurance of Radioisotopes and Ionizing Radiation Sources in France

    International Nuclear Information System (INIS)

    Since the early sixties, Assuratome has amassed quite a long experience in the insurance of radioisotopes and more generally of ionising radiation sources when they are used transported or stored outside a nuclear installation. Aware of the specific dangers of such devices, and having no experience in this domain French insurers were looking for a pragmatic solution which would permit to continue to provide cover for users or fabricants of small radioactive sources and in the meantime to keep a rigorous control on the claims and on the loss ratio which would be achieved over the years. Hence the decision was taken by the French Insurance market to entrust the French Nuclear Insurance Pool, Assuratome, as the recommended body for delivering specific 'nuclear policies' as an expert for this category of business. The next step was to make sure that the 'conventional policies' would not provide the same cover. Therefore, an appropriate exclusion clause was introduced in all the general conditions of the TPL Policies of the conventional market and consequently in the majority, if not all, the reinsurance treaties. Besides the obvious advantage resulting in the management of this category of business in a centralised body, a major benefit of this situation is based on the strict control by the insurer of the compulsory authorisation delivered by the authorities to the owner of the radioactive source. Unofficial sources having in principal no insurance possibilities in France their use would be virtually impossible.(author)

  14. The Ionization Source in the Nucleus of M84

    Science.gov (United States)

    Bower, G. A.; Green, R. F.; Quillen, A. C.; Danks, A.; Malumuth, E. M.; Gull, T.; Woodgate, B.; Hutchings, J.; Joseph, C.; Kaiser, M. E.

    2000-01-01

    We have obtained new Hubble Space Telescope (HST) observations of M84, a nearby massive elliptical galaxy whose nucleus contains a approximately 1.5 X 10(exp 9) solar mass dark compact object, which presumably is a supermassive black hole. Our Space Telescope Imaging Spectrograph (STIS) spectrum provides the first clear detection of emission lines in the blue (e.g., [0 II] lambda 3727, HBeta and [0 III] lambda lambda4959,5007), which arise from a compact region approximately 0".28 across centered on the nucleus. Our Near Infrared Camera and MultiObject Spectrometer (NICMOS) images exhibit the best view through the prominent dust lanes evident at optical wavelengths and provide a more accurate correction for the internal extinction. The relative fluxes of the emission lines we have detected in the blue together with those detected in the wavelength range 6295 - 6867 A by Bower et al. indicate that the gas at the nucleus is photoionized by a nonstellar process, instead of hot stars. Stellar absorption features from cool stars at the nucleus are very weak. We update the spectral energy distribution of the nuclear point source and find that although it is roughly flat in most bands, the optical to UV continuum is very red, similar to the spectral energy distribution of BL Lac. Thus, the nuclear point source seen in high-resolution optical images is not a star cluster but is instead a nonstellar source. Assuming isotropic emission from this source, we estimate that the ratio of bolometric luminosity to Eddington luminosity is about 5 x 10(exp -7). However, this could be underestimated if this source is a misaligned BL Lac object, which is a possibility suggested by the spectral energy distribution and the evidence of optical variability we describe.

  15. Analytical modeling of Schottky tunneling source impact ionization MOSFET with reduced breakdown voltage

    Directory of Open Access Journals (Sweden)

    Sangeeta Singh

    2016-03-01

    Full Text Available In this paper, we have investigated a novel Schottky tunneling source impact ionization MOSFET (STS-IMOS to lower the breakdown voltage of conventional impact ionization MOS (IMOS and developed an analytical model for the same. In STS-IMOS there is an accumulative effect of both impact ionization and source induced barrier tunneling. The silicide source offers very low parasitic resistance, the outcome of which is an increment in voltage drop across the intrinsic region for the same applied bias. This reduces operating voltage and hence, it exhibits a significant reduction in both breakdown and threshold voltage. STS-IMOS shows high immunity against hot electron damage. As a result of this the device reliability increases magnificently. The analytical model for impact ionization current (Iii is developed based on the integration of ionization integral (M. Similarly, to get Schottky tunneling current (ITun expression, Wentzel–Kramers–Brillouin (WKB approximation is employed. Analytical models for threshold voltage and subthreshold slope is optimized against Schottky barrier height (ϕB variation. The expression for the drain current is computed as a function of gate-to-drain bias via integral expression. It is validated by comparing it with the technology computer-aided design (TCAD simulation results as well. In essence, this analytical framework provides the physical background for better understanding of STS-IMOS and its performance estimation.

  16. Coupling an electrospray source and a solids probe/chemical ionization source to a selected ion flow tube apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Melko, Joshua J.; Ard, Shaun G.; Shuman, Nicholas S.; Viggiano, Albert A., E-mail: afrl.rvborgmailbox@kirtland.af.mil [Air Force Research Laboratory, Space Vehicles Directorate, Kirtland AFB, New Mexico 87117-5776 (United States); Pedder, Randall E.; Taormina, Christopher R. [Ardara Technologies L.P., 12941 Route 993, Ardara, Pennsylvania 15615 (United States)

    2015-08-15

    A new ion source region has been constructed and attached to a variable temperature selected ion flow tube. The source features the capabilities of electron impact, chemical ionization, a solids probe, and electrospray ionization. The performance of the instrument is demonstrated through a series of reactions from ions created in each of the new source regions. The chemical ionization source is able to create H{sub 3}O{sup +}, but not as efficiently as similar sources with larger apertures. The ability of this source to support a solids probe, however, greatly expands our capabilities. A variety of rhenium cations and dications are created from the solids probe in sufficient abundance to study in the flow tube. The reaction of Re{sup +} with O{sub 2} proceeds with a rate constant that agrees with the literature measurements, while the reaction of Re{sub 2}{sup 2+} is found to charge transfer with O{sub 2} at about 60% of the collision rate; we have also performed calculations that support the charge transfer pathway. The electrospray source is used to create Ba{sup +}, which is reacted with N{sub 2}O to create BaO{sup +}, and we find a rate constant that agrees with the literature.

  17. Coupling an electrospray source and a solids probe/chemical ionization source to a selected ion flow tube apparatus

    Science.gov (United States)

    Melko, Joshua J.; Ard, Shaun G.; Shuman, Nicholas S.; Pedder, Randall E.; Taormina, Christopher R.; Viggiano, Albert A.

    2015-08-01

    A new ion source region has been constructed and attached to a variable temperature selected ion flow tube. The source features the capabilities of electron impact, chemical ionization, a solids probe, and electrospray ionization. The performance of the instrument is demonstrated through a series of reactions from ions created in each of the new source regions. The chemical ionization source is able to create H3O+, but not as efficiently as similar sources with larger apertures. The ability of this source to support a solids probe, however, greatly expands our capabilities. A variety of rhenium cations and dications are created from the solids probe in sufficient abundance to study in the flow tube. The reaction of Re+ with O2 proceeds with a rate constant that agrees with the literature measurements, while the reaction of Re22+ is found to charge transfer with O2 at about 60% of the collision rate; we have also performed calculations that support the charge transfer pathway. The electrospray source is used to create Ba+, which is reacted with N2O to create BaO+, and we find a rate constant that agrees with the literature.

  18. High-Pressure Photon Ionization Source for TOFMS and Its Application for Online Breath Analysis.

    Science.gov (United States)

    Wang, Yan; Jiang, Jichun; Hua, Lei; Hou, Keyong; Xie, Yuanyuan; Chen, Ping; Liu, Wei; Li, Qingyun; Wang, Shuang; Li, Haiyang

    2016-09-20

    Photon ionization mass spectrometry (PI-MS) is a widely used technique for the online detection of trace substances in complex matrices. In this work, a new high-pressure photon ionization (HPPI) ion source based on a vacuum ultraviolet (VUV) Kr lamp was developed for time-of-flight mass spectrometry (TOFMS). The detection sensitivity was improved by elevating the ion source pressure to about 700 Pa. A radio frequency (RF)-only quadrupole was employed as the ion guide system following the HPPI source to achieve high ion transmission efficiency. In-source collision induced dissociation (CID) was conducted for accurate chemical identification by varying the voltage between the ion source and the ion guide. The high humidity of the breath air can promote the detection of some compounds with higher ionization potentials (IPs) that could not be well detected by single photon ionization (SPI) at low pressure. Under 100% relative humidity (37 °C), the limits of detection down to 0.015 ppbv (parts per billion by volume) for aliphatic and aromatic hydrocarbons were obtained. This HPPI-TOFMS system was preliminarily applied for online investigations of the exhaled breath from both healthy nonsmoker and smoker subjects, demonstrating its analytical capacity for complicated gases analysis. Subsequently, several frequently reported VOCs in the breath of healthy volunteers, i.e., acetone, isoprene, 2-butanone, ethanol, acetic acid, and isopropanol, were successfully identified and quantified. PMID:27574033

  19. Atmospheric Pressure Chemical Ionization Sources Used in The Detection of Explosives by Ion Mobility Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Waltman, Melanie J. [New Mexico Inst. of Mining and Technology, Socorro, NM (United States)

    2010-05-01

    Explosives detection is a necessary and wide spread field of research. From large shipping containers to airline luggage, numerous items are tested for explosives every day. In the area of trace explosives detection, ion mobility spectrometry (IMS) is the technique employed most often because it is a quick, simple, and accurate way to test many items in a short amount of time. Detection by IMS is based on the difference in drift times of product ions through the drift region of an IMS instrument. The product ions are created when the explosive compounds, introduced to the instrument, are chemically ionized through interactions with the reactant ions. The identity of the reactant ions determines the outcomes of the ionization process. This research investigated the reactant ions created by various ionization sources and looked into ways to manipulate the chemistry occurring in the sources.

  20. Oxidative potential and inflammatory impacts of source apportioned ambient air pollution in Beijing.

    Science.gov (United States)

    Liu, Qingyang; Baumgartner, Jill; Zhang, Yuanxun; Liu, Yanju; Sun, Yongjun; Zhang, Meigen

    2014-11-01

    Air pollution exposure is associated with a range of adverse health impacts. Knowledge of the chemical components and sources of air pollution most responsible for these health effects could lead to an improved understanding of the mechanisms of such effects and more targeted risk reduction strategies. We measured daily ambient fine particulate matter (Beijing, and assessed the contribution of its chemical components to the oxidative potential of ambient air pollution using the dithiothreitol (DTT) assay. The composition data were applied to a multivariate source apportionment model to determine the PM contributions of six sources or factors: a zinc factor, an aluminum factor, a lead point factor, a secondary source (e.g., SO4(2-), NO3(2-)), an iron source, and a soil dust source. Finally, we assessed the relationship between reactive oxygen species (ROS) activity-related PM sources and inflammatory responses in human bronchial epithelial cells. In peri-urban Beijing, the soil dust source accounted for the largest fraction (47%) of measured ROS variability. In central Beijing, a secondary source explained the greatest fraction (29%) of measured ROS variability. The ROS activities of PM collected in central Beijing were exponentially associated with in vivo inflammatory responses in epithelial cells (R2=0.65-0.89). We also observed a high correlation between three ROS-related PM sources (a lead point factor, a zinc factor, and a secondary source) and expression of an inflammatory marker (r=0.45-0.80). Our results suggest large differences in the contribution of different PM sources to ROS variability at the central versus peri-urban study sites in Beijing and that secondary sources may play an important role in PM2.5-related oxidative potential and inflammatory health impacts.

  1. Major reactive species of ambient volatile organic compounds (VOCs) and their sources in Beijing

    Institute of Scientific and Technical Information of China (English)

    SHAO; Min; FU; Linlin; LIU; Ying; LU; Sihua; ZHANG; Yuanhan

    2005-01-01

    Volatile organic compounds (VOCs) are important precursors of atmospheric chemical processes. As a whole mixture, the ambient VOCs show very strong chemical reactivity. Based on OH radical loss rates in the air, the chemical reactivity of VOCs in Beijing was calculated. The results revealed that alkenes, accounting for only about 15% in the mixing ratio of VOCs, provide nearly 75% of the reactivity of ambient VOCs and the C4 to C5 alkenes were the major reactive species among the alkenes. The study of emission characteristics of various VOCs sources indicated that these alkenes are mainly from vehicle exhaust and gasoline evaporation. The reduction of alkene species in these two sources will be effective in photochemical pollution control in Beijing.

  2. Guide for prepare the plan for radiological emergency by the users of ionizing radiation sources

    International Nuclear Information System (INIS)

    The Radiological Emergency Plan foresees all the possible radiological accidents with the ionizing sources the entity is using. The measures should be adopted by every factor is supped to take part in the emergencies created. The effectiveness of the guaranteed. THis guide establishes the model for elaborating the radiological Emergency Plans

  3. SOLAR HARD X-RAY SOURCE SIZES IN A BEAM-HEATED AND IONIZED CHROMOSPHERE

    International Nuclear Information System (INIS)

    Solar flare hard X-rays (HXRs) are produced as bremsstrahlung when an accelerated population of electrons interacts with the dense chromospheric plasma. HXR observations presented by Kontar et al. using the Ramaty High-Energy Solar Spectroscopic Imager have shown that HXR source sizes are three to six times more extended in height than those predicted by the standard collisional thick target model (CTTM). Several possible explanations have been put forward including the multi-threaded nature of flare loops, pitch-angle scattering, and magnetic mirroring. However, the nonuniform ionization (NUI) structure along the path of the electron beam has not been fully explored as a solution to this problem. Ionized plasma is known to be less effective at producing nonthermal bremsstrahlung HXRs when compared to neutral plasma. If the peak HXR emission was produced in a locally ionized region within the chromosphere, the intensity of emission will be preferentially reduced around this peak, resulting in a more extended source. Due to this effect, along with the associated density enhancement in the upper chromosphere, injection of a beam of electrons into a partially ionized plasma should result in an HXR source that is substantially more vertically extended relative to that for a neutral target. Here we present the results of a modification to the CTTM, which takes into account both a localized form of chromospheric NUI and an increased target density. We find 50 keV HXR source widths, with and without the inclusion of a locally ionized region, of ∼3 Mm and ∼0.7 Mm, respectively. This helps to provide a theoretical solution to the currently open question of overly extended HXR sources

  4. SOLAR HARD X-RAY SOURCE SIZES IN A BEAM-HEATED AND IONIZED CHROMOSPHERE

    Energy Technology Data Exchange (ETDEWEB)

    O' Flannagain, Aidan M.; Gallagher, Peter T. [Astrophysics Research Group, School of Physics, Trinity College Dublin, Dublin 2 (Ireland); Brown, John C. [Astronomy and Astrophysics Group, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

    2015-02-01

    Solar flare hard X-rays (HXRs) are produced as bremsstrahlung when an accelerated population of electrons interacts with the dense chromospheric plasma. HXR observations presented by Kontar et al. using the Ramaty High-Energy Solar Spectroscopic Imager have shown that HXR source sizes are three to six times more extended in height than those predicted by the standard collisional thick target model (CTTM). Several possible explanations have been put forward including the multi-threaded nature of flare loops, pitch-angle scattering, and magnetic mirroring. However, the nonuniform ionization (NUI) structure along the path of the electron beam has not been fully explored as a solution to this problem. Ionized plasma is known to be less effective at producing nonthermal bremsstrahlung HXRs when compared to neutral plasma. If the peak HXR emission was produced in a locally ionized region within the chromosphere, the intensity of emission will be preferentially reduced around this peak, resulting in a more extended source. Due to this effect, along with the associated density enhancement in the upper chromosphere, injection of a beam of electrons into a partially ionized plasma should result in an HXR source that is substantially more vertically extended relative to that for a neutral target. Here we present the results of a modification to the CTTM, which takes into account both a localized form of chromospheric NUI and an increased target density. We find 50 keV HXR source widths, with and without the inclusion of a locally ionized region, of ∼3 Mm and ∼0.7 Mm, respectively. This helps to provide a theoretical solution to the currently open question of overly extended HXR sources.

  5. Update of NIST half-life results corrected for ionization chamber source-holder instability.

    Science.gov (United States)

    Unterweger, M P; Fitzgerald, R

    2014-05-01

    As reported at the ICRM 2011, it was discovered that the source holder used for calibrations in the NIST 4πγ ionization chamber (IC) was not stable. This has affected a large number of half-life measurement results previously reported and used in compilations of nuclear data. Corrections have been made on all of the half-life data based on the assumption that the changes to the ionization chamber response were gradual. The corrections are energy dependent and therefore radionuclide specific. This presentation will review our results and present the recommended changes in half-life values and/or uncertainties.

  6. Un tool Open Source per la ricerca dispersi in ambiente montano

    OpenAIRE

    Tiziano Cosso; Roberto Marzocchi; Danilo Repetto

    2013-01-01

    G4MoRe, Gter-for Mountain Rescue, è un tool interamente sviluppato con prodotti Open Source e pensato come supporto alle attività di ricerca dispersi in ambiente montano, prodotto e supportato da Gter srl.G4MoRe, Gter-for Mountain Rescue, is a tool developed entirely with Open Source products and designed as support to research activitiesof missing people in the mountains, manufactured and supported by Gter srl.

  7. Connection between ambient density fluctuations and clumpy Langmuir waves in type III radio sources

    Science.gov (United States)

    Robinson, P. A.; Cairns, I. H.; Gurnett, D. A.

    1992-01-01

    A recent stochastic-growth theory of clumpy Langmuir waves in type III sources is shown to imply that the clumps will have the same size distribution as the ambient low-frequency density fluctuations in the solar wind. Spectral analysis of Langmuir-wave time series from the ISEE 3 plasma wave instrument confirms this prediction to within the uncertainties in the spectra. The smallest Langmuir clump size is inferred to be in the range 0.4-30 km in general, and 2-30 km for beam-resonant waves, and it is concluded that the diffusion of waves in the source is anomalous.

  8. Pulsed plasma sources for the production of intense ion beams based on catalytic resonance ionization

    International Nuclear Information System (INIS)

    In this paper we describe a technique to produce planar and volumetric ion sources of nearly every element. This technique is based on a generalization of the LIBORS-process (Laser Ionization Based On Resonant Saturation) which because of its similarity to chemical catalytic reactions has been called CATRION (CATalytic Resonance IONization). A vapor containing the desired atomic species is doped with a suitable element processing resonance transitions that can be pumped ro saturation with a laser. By superelastic collisions with the excited atoms and by simulated bremsstrahlung absorption seed electrons are heated. It is the heated electron component which then by collisional processes ionizes the desired atomic species and are multiplied. 41 refs.; 4 figs.; 3 tabs

  9. Source self-attenuation in ionization chamber measurements of (57)Co solutions.

    Science.gov (United States)

    Cessna, Jeffrey T; Golas, Daniel B; Bergeron, Denis E

    2016-03-01

    Source self-attenuation for solutions of (57)Co of varying density and carrier concentration was measured in nine re-entrant ionization chambers maintained at NIST. The magnitude of the attenuation must be investigated to determine whether a correction is necessary in the determination of the activity of a source that differs in composition from the source used to calibrate the ionization chamber. At our institute, corrections are currently made in the measurement of (144)Ce, (109)Cd, (67)Ga, (195)Au, (166)Ho, (177)Lu, and (153)Sm. This work presents the methods used as recently applied to (57)Co. A range of corrections up to 1% were calculated for dilute to concentrated HCl at routinely used carrier concentrations.

  10. Field ionization characteristics of an ion source array for neutron generators

    Energy Technology Data Exchange (ETDEWEB)

    B. Bargsten Johnson; P. R. Schwoebel; P. J. Resnick; C. E. Holland; L. Hertz; D. L. Chichester

    2013-11-01

    A new deuterium ion source is being developed to improve the performance of existing compact neutron generators. The ion source is a microfabricated array of metal tips with an integrated gate (i.e., grid) and produces deuterium ions by field ionizing (or field desorbing) a supply of deuterium gas. Deuterium field ion currents from arrays at source temperatures of 77?K and 293?K are studied. Ion currents from single etched-wire tips operating under the same conditions are used to help understand array results. I-F characteristics of the arrays were found to follow trends similar to those of the better understood single etched-wire tip results; however, the fields achieved by the arrays are limited by electrical breakdown of the structure. Neutron production by field ionization at 293?K was demonstrated for the first time from microfabricated array structures with integrated gates.

  11. Field ionization characteristics of an ion source array for neutron generators

    Energy Technology Data Exchange (ETDEWEB)

    Bargsten Johnson, B.; Schwoebel, P. R. [University of New Mexico, Albuquerque, New Mexico 87131 (United States); Resnick, P. J. [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States); Holland, C. E. [SRI International, Menlo Park, California 94025 (United States); Hertz, K. L. [Sandia National Laboratories, Livermore, California 94551 (United States); Chichester, D. L. [Idaho National Laboratory, Idaho Falls, Idaho 83415 (United States)

    2013-11-07

    A new deuterium ion source is being developed to improve the performance of existing compact neutron generators. The ion source is a microfabricated array of metal tips with an integrated gate (i.e., grid) and produces deuterium ions by field ionizing (or field desorbing) a supply of deuterium gas. Deuterium field ion currents from arrays at source temperatures of 77 K and 293 K are studied. Ion currents from single etched-wire tips operating under the same conditions are used to help understand array results. I-F characteristics of the arrays were found to follow trends similar to those of the better understood single etched-wire tip results; however, the fields achieved by the arrays are limited by electrical breakdown of the structure. Neutron production by field ionization at 293 K was demonstrated for the first time from microfabricated array structures with integrated gates.

  12. Direct detection of fungal siderophores on bats with white-nose syndrome via fluorescence microscopy-guided ambient ionization mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Samantha J Mascuch

    Full Text Available White-nose syndrome (WNS caused by the pathogenic fungus Pseudogymnoascus destructans is decimating the populations of several hibernating North American bat species. Little is known about the molecular interplay between pathogen and host in this disease. Fluorescence microscopy ambient ionization mass spectrometry was used to generate metabolic profiles from the wings of both healthy and diseased bats of the genus Myotis. Fungal siderophores, molecules that scavenge iron from the environment, were detected on the wings of bats with WNS, but not on healthy bats. This work is among the first examples in which microbial molecules are directly detected from an infected host and highlights the ability of atmospheric ionization methodologies to provide direct molecular insight into infection.

  13. Direct detection of fungal siderophores on bats with white-nose syndrome via fluorescence microscopy-guided ambient ionization mass spectrometry

    Science.gov (United States)

    Mascuch, Samantha J.; Moree, Wilna J.; Cheng-Chih Hsu, Cheng-Chih; Turner, Gregory G.; Cheng, Tina L.; Blehert, David S.; Kilpatrick, A. Marm; Frick, Winifred F.; Meehan, Michael J.; Dorrestein, Pieter C.; Gerwick, Lena

    2015-01-01

    White-nose syndrome (WNS) caused by the pathogenic fungus Pseudogymnoascus destructans is decimating the populations of several hibernating North American bat species. Little is known about the molecular interplay between pathogen and host in this disease. Fluorescence microscopy ambient ionization mass spectrometry was used to generate metabolic profiles from the wings of both healthy and diseased bats of the genus Myotis. Fungal siderophores, molecules that scavenge iron from the environment, were detected on the wings of bats with WNS, but not on healthy bats. This work is among the first examples in which microbial molecules are directly detected from an infected host and highlights the ability of atmospheric ionization methodologies to provide direct molecular insight into infection.

  14. Improving the Selectivity of the ISOLDE Resonance Ionization Laser Ion Source and In-Source Laser Spectroscopy of Polonium

    OpenAIRE

    Fink, D.

    2014-01-01

    Exotic atomic nuclei far away from stability are fascinating objects to be studied in many scientic elds such as atomic-, nuclear-, and astrophysics. Since these are often short-lived isotopes, it is necessary to couple their production with immediate extraction and delivery to an experiment. This is the purpose of the on-line isotope separator facility, ISOLDE, at CERN. An essential aspect of this laboratory is the Resonance Ionization Laser Ion Source (RILIS) because it provides a fast and ...

  15. Single window for issuing licenses for export and import of ionizing radiation sources and transit of radioactive sources

    International Nuclear Information System (INIS)

    In this paper we present the electronic system for application and issuing licenses for export, import and transit of goods (EXIM), particularly for ionizing radiation sources, in the Republic of Macedonia. This system is a modern and helpful tool for simple issuing licenses, for establishing a unique database and it represents a harmonized system for exchanging information between the governmental, public and private legal persons in the Republic of Macedonia. (author)

  16. Sources of Particular Pollutants in Ambient Air at a Petrochemical Enterprise

    Institute of Scientific and Technical Information of China (English)

    Xue Jianliang; Zhao Dongfeng; ChengJianguang; Chen Lu; Liu Wei

    2013-01-01

    The study on source apportionment of particular pollutants in ambient air at a petrochemical enterprise is the ba-sis of the control over air pollution. Through analyzing particular pollutants in the samples collected from one petrochemi-cal enterprise in northwestern China, the sources of particular pollutants were discussed. The test results showed that con-centrations of particular pollutants in different sites were remarkably different. Results showed that the sampling sites with higher concentrations of particular pollutants, including toluene, xylenes, NH3 and H2S, were located at the boundary of the petrochemical enterprise. Instead, the concentrations of NMHC in the ambient air sampling sites were higher than those at the boundary of the petrochemical enterprise. The sampling sites with higher concentrations of particular pollutants were located in the area that was close to the petrochemical enterprise. The results obtained from the Pearson correlation co-efifcients analyses, the factor analyses, andχ2-tests of the particular pollutants had revealed that NH3, H2S, toluene and xylenes at all sampling sites came from the same source, while NMHC might come from some other sources besides the petrochemical enterprise.

  17. A method to measure the activity of sealed gamma sources by means of ionization chambers

    International Nuclear Information System (INIS)

    The paper contains a recommendation concerning the propagation of the activity unit for sealed gamma sources from the normals of the national metrological authorities of the USSR (VNIM) and the GDR (ASMW) to normals of lower order. Propagation of the activity unit is provided by comparative measurements with ionization chambers. The recommendation implies cases in which the source contains impurities as well as cases in which the design of the sources to be compared is different. Furthermore, the recommendation includes the method of error evaluation. (author)

  18. Dependence with air density of the response of the PTW SourceCheck ionization chamber for low energy brachytherapy sources

    Energy Technology Data Exchange (ETDEWEB)

    Tornero-López, Ana M.; Guirado, Damián; Ruiz-Arrebola, Samuel [Servicio de Radiofísica y Protección Radiológica, Hospital Universitario San Cecilio, E-18012 Granada (Spain); Perez-Calatayud, Jose [Servicio de Radioterapia, Unidad de Radiofísica, Hospital Universitario y Politécnico La Fe, E-46026 Valencia (Spain); Simancas, Fernando; Lallena, Antonio M. [Departamento de Física Atómica, Molecular y Nuclear, Universidad de Granada, E-18071 Granada (Spain); Gazdic-Santic, Maja [Department of Medical Physics and Radiation Safety, Clinical Centre of Sarajevo University, 71000 Sarajevo (Bosnia and Herzegovina)

    2013-12-15

    Purpose: Air-communicating well ionization chambers are commonly used to assess air kerma strength of sources used in brachytherapy. The signal produced is supposed to be proportional to the air density within the chamber and, therefore, a density-independent air kerma strength is obtained when the measurement is corrected to standard atmospheric conditions using the usual temperature and pressure correction factor. Nevertheless, when assessing low energy sources, the ionization chambers may not fulfill that condition and a residual density dependence still remains after correction. In this work, the authors examined the behavior of the PTW 34051 SourceCheck ionization chamber when measuring the air kerma strength of {sup 125}I seeds.Methods: Four different SourceCheck chambers were analyzed. With each one of them, two series of measurements of the air kerma strength for {sup 125}I selectSeed{sup TM} brachytherapy sources were performed inside a pressure chamber and varying the pressure in a range from 747 to 1040 hPa (560 to 780 mm Hg). The temperature and relative humidity were kept basically constant. An analogous experiment was performed by taking measurements at different altitudes above sea level.Results: Contrary to other well-known ionization chambers, like the HDR1000 PLUS, in which the temperature-pressure correction factor overcorrects the measurements, in the SourceCheck ionization chamber they are undercorrected. At a typical atmospheric situation of 933 hPa (700 mm Hg) and 20 °C, this undercorrection turns out to be 1.5%. Corrected measurements show a residual linear dependence on the density and, as a consequence, an additional density dependent correction must be applied. The slope of this residual linear density dependence is different for each SourceCheck chamber investigated. The results obtained by taking measurements at different altitudes are compatible with those obtained with the pressure chamber.Conclusions: Variations of the altitude and

  19. Management of ionizing radiation sources in university, medical and industrial environments

    International Nuclear Information System (INIS)

    This conference treats several subjects relative to the use of radioactive sources. The first session comprises three articles about ionizing sources and regulation. The second session, with three articles, tackles the question of radiation protection in the use of sources in industrial field. The third session, four articles, treats the same question but in the medicine and university media. The fourth session (three articles) is devoted to the organisation of radiation protection in the case of accidents. The fifth session concerns the management of spent sources (three articles). The sixth session studies the radiation protection of sources in Europe. The seventh and final session ends with the part and coordination of actors in radiation protection in the sources management (three articles). (N.C.)

  20. Direct determination of trace amounts of acetic acid using a novel ambient glow discharge ion source

    Institute of Scientific and Technical Information of China (English)

    Xiao Hao Wang; Kun Liu; Fei Tang; Jiu Ming He; Xue Ye Wei; Zeper Abliz

    2010-01-01

    A novel ambient glow discharge ion source with improved line-cylinder electrodes is put forward and designed in this paper.The diameters of inner and outer electrodes are 0.16 and 4 mm respectively.With a special assembly method,a perfect coaxiality of the two electrodes is obtained.From the gas discharge experiment,it can be seen that the discharge can stably work in normal glow discharge mode.The operating currents of the ion source are in an order of milliamperes and can generate a much larger number and wider variety of reagent ions.The MS experiment shows that the ion source has higher detection sensitivity.

  1. Infrared Matrix-Assisted Laser Desorption Electrospray Ionization (IR-MALDESI) Imaging Source Coupled to a FT-ICR Mass Spectrometer

    Science.gov (United States)

    Robichaud, Guillaume; Barry, Jeremy A.; Garrard, Kenneth P.; Muddiman, David C.

    2013-01-01

    Mass spectrometry imaging (MSI) allows for the direct monitoring of the abundance and spatial distribution of chemical compounds over the surface of a tissue sample. This technology has opened the field of mass spectrometry to numerous innovative applications over the past 15 years. First used with SIMS and MALDI MS that operate under vacuum, interest has grown for mass spectrometry ionization sources that allow for effective imaging but where the analysis can be performed at ambient pressure with minimal or no sample preparation. We introduce here a versatile source for MALDESI imaging analysis coupled to a hybrid LTQ-FT-ICR mass spectrometer. The imaging source offers single shot or multi-shot capability per pixel with full control over the laser repetition rate and mass spectrometer scanning cycle. Scanning rates can be as fast as 1 pixel/second and a spatial resolution of 45 μm was achieved with oversampling.

  2. Experimental research on benzene detection using ion mobility spectrometer with a laser ionization source

    Institute of Scientific and Technical Information of China (English)

    LIU Xian-yun; KONG Xiang-he; JI Ren-dong; ZHANG Shu-dong

    2006-01-01

    An ion mobility spectrometer equipped with a laser ionization source is used for the sensitive detection of benzene.Mobility spectra of the benzene are presented.We also discussed the mobility spectra at various concentrations and drift voltages.Detection limits are determined to be in the upper ppbv range.In the end,the advantages and possibilities of this technique are briefly discussed.

  3. A trapped ion source with improved ionizing efficiency for the production of multiply charged ions

    International Nuclear Information System (INIS)

    An ultrahigh vacuum 'trapped ion source' has been developed following closely Redhead's basic design. Positive ions have been trapped within the space charge of a magnetically confined electron beam with potential barriers at either end of the ionization region, resulting in the production of multiply charged ions. These highly stripped ions are formed by the successive collisions with low energy (0 mass spectrometer. The results obtained in the production of multiply charged ions of Au are presented. (auth.)

  4. Sources and levels of ambient ocean sound near the Antarctic Peninsula.

    Science.gov (United States)

    Dziak, Robert P; Bohnenstiehl, DelWayne R; Stafford, Kathleen M; Matsumoto, Haruyoshi; Park, Minkyu; Lee, Won Sang; Fowler, Matt J; Lau, Tai-Kwan; Haxel, Joseph H; Mellinger, David K

    2015-01-01

    Arrays of hydrophones were deployed within the Bransfield Strait and Scotia Sea (Antarctic Peninsula region) from 2005 to 2009 to record ambient ocean sound at frequencies of up to 125 and 500 Hz. Icequakes, which are broadband, short duration signals derived from fracturing of large free-floating icebergs, are a prominent feature of the ocean soundscape. Icequake activity peaks during austral summer and is minimum during winter, likely following freeze-thaw cycles. Iceberg grounding and rapid disintegration also releases significant acoustic energy, equivalent to large-scale geophysical events. Overall ambient sound levels can be as much as ~10-20 dB higher in the open, deep ocean of the Scotia Sea compared to the relatively shallow Bransfield Strait. Noise levels become lowest during the austral winter, as sea-ice cover suppresses wind and wave noise. Ambient noise levels are highest during austral spring and summer, as surface noise, ice cracking and biological activity intensifies. Vocalizations of blue (Balaenoptera musculus) and fin (B. physalus) whales also dominate the long-term spectra records in the 15-28 and 89 Hz bands. Blue whale call energy is a maximum during austral summer-fall in the Drake Passage and Bransfield Strait when ambient noise levels are a maximum and sea-ice cover is a minimum. Fin whale vocalizations were also most common during austral summer-early fall months in both the Bransfield Strait and Scotia Sea. The hydrophone data overall do not show sustained anthropogenic sources (ships and airguns), likely due to low coastal traffic and the typically rough weather and sea conditions of the Southern Ocean. PMID:25875205

  5. Sources and levels of ambient ocean sound near the Antarctic Peninsula.

    Directory of Open Access Journals (Sweden)

    Robert P Dziak

    Full Text Available Arrays of hydrophones were deployed within the Bransfield Strait and Scotia Sea (Antarctic Peninsula region from 2005 to 2009 to record ambient ocean sound at frequencies of up to 125 and 500 Hz. Icequakes, which are broadband, short duration signals derived from fracturing of large free-floating icebergs, are a prominent feature of the ocean soundscape. Icequake activity peaks during austral summer and is minimum during winter, likely following freeze-thaw cycles. Iceberg grounding and rapid disintegration also releases significant acoustic energy, equivalent to large-scale geophysical events. Overall ambient sound levels can be as much as ~10-20 dB higher in the open, deep ocean of the Scotia Sea compared to the relatively shallow Bransfield Strait. Noise levels become lowest during the austral winter, as sea-ice cover suppresses wind and wave noise. Ambient noise levels are highest during austral spring and summer, as surface noise, ice cracking and biological activity intensifies. Vocalizations of blue (Balaenoptera musculus and fin (B. physalus whales also dominate the long-term spectra records in the 15-28 and 89 Hz bands. Blue whale call energy is a maximum during austral summer-fall in the Drake Passage and Bransfield Strait when ambient noise levels are a maximum and sea-ice cover is a minimum. Fin whale vocalizations were also most common during austral summer-early fall months in both the Bransfield Strait and Scotia Sea. The hydrophone data overall do not show sustained anthropogenic sources (ships and airguns, likely due to low coastal traffic and the typically rough weather and sea conditions of the Southern Ocean.

  6. Target-ion source unit ionization efficiency measurement by method of stable ion beam implantation

    CERN Document Server

    Panteleev, V.N; Fedorov, D.V; Moroz, F.V; Orlov, S.Yu; Volkov, Yu.M

    The ionization efficiency is one of the most important parameters of an on-line used target-ion source system exploited for production of exotic radioactive beams. The ionization efficiency value determination as a characteristic of a target-ion source unit in the stage of its normalizing before on-line use is a very important step in the course of the preparation for an on-line experiment. At the IRIS facility (Petersburg Nuclear Physics Institute, Gatchina) a reliable and rather precise method of the target-ion source unit ionization efficiency measurement by the method of stable beam implantation has been developed. The method worked out exploits an off-line mass-separator for the implantation of the ion beams of selected stable isotopes of different elements into a tantalum foil placed inside the Faraday cup in the focal plane of the mass-separator. The amount of implanted ions has been measured with a high accuracy by the current integrator connected to the Faraday cup. After the implantation of needed a...

  7. Status of the future SPIRAL2 resonance ionization laser ion source GISELE

    International Nuclear Information System (INIS)

    Resonance Ionization Spectroscopy is a most powerful tool for efficient and selective production of ion beams in particular useful at on-line isotope breeders. For this purpose the future upgrade S3 (Super Separator Spectrometer) of the SPIRAL2 accelerator at GANIL (Caen, France) includes a gas cell at its fission target. Therein high resolution RIS on short lived isotopes will be performed, addressing either the in-cell or in-jet technology. The corresponding Resonance Ionization Laser Ion Source project GISELE is furthermore designed to produce strong and pure radioisotope beams for experiments at the future hot cavity unit of SPIRAL2. Its laser system will combine sets of tunable high-repetition rate pulsed dye as well as titanium:sapphire lasers. Currently, off-line preparation studies are performed with the titanium:sapphire lasers for the day 1 requested beams of Zinc and Tin. A suitable excitation scheme was developed for Zinc and the ionization efficiency was determined. For Tin three known ionization schemes, a 3-step and two widely identical 2-step schemes, were tested and compared with published results from other facilities.

  8. Sources and effects of ionizing radiation. UNSCEAR 2000 report to the General Assembly, with scientific annexes. Volume I: Sources

    International Nuclear Information System (INIS)

    Over the past few years the United Nations Scientific Committee on the effects of Atomic Radiation has undertaken a broad review of the sources and effects of ionizing radiation. In the present report, the Committee, drawing on the main conclusions of its scientific assessment summarizes the developments in radiation science in the years leading up to the next millennium. It covers the following: the effects of radiation exposure; levels of radiation exposure; radiological consequences of the Chernobyl accident; sources of radiation exposure including natural exposures, man-made environmental exposures, medical and occupational exposures; radiation associated cancer. This volume includes five Annexes covering: dose assessment methodologies; exposure from natural sources; exposures to the public from man-made sources of radiation and occupational radiation exposures

  9. GISELE: A resonant ionization laser ion source for the production of radioactive ions at GANIL

    CERN Document Server

    Lecesne, N; Wendt, K; Mattolat, C; Rothe, S; Pichard, A; Pacquet, J Y; Dubois, M; Coterreau, E; Franberg, H; Leroy, R; Gottwald, T; Alves-Conde, R; Flambard, J L; De Oliveira, F; Le Blanc, F; Jardin, P; Olivier, A; Lassen, J

    2010-01-01

    SPIRAL2 is the new project under construction at GANIL to produce radioactive ion beams and in particular neutron rich ion beams. For the past 10 yr SPIRAL1 at GANIL has been delivering accelerated radioactive ion beams of gases. Both facilities now need to extend the range of radioactive ion beams produced to condensable elements. For that purpose, a resonant ionization laser ion source, funded by the French Research National Agency, is under development at GANIL, in collaboration with IPN Orsay, University of Mainz (Germany) and TRIUMF, Vancouver (Canada). A description of this project called GISELE (GANIL Ion Source using Electron Laser Excitation) is presented.

  10. GISELE: A resonant ionization laser ion source for the production of radioactive ions at GANIL

    Energy Technology Data Exchange (ETDEWEB)

    Lecesne, N.; Alves-Conde, R.; De Oliveira, F.; Dubois, M.; Flambard, J. L.; Franberg, H.; Jardin, P.; Leroy, R.; Pacquet, J. Y.; Pichard, A.; Saint-Laurent, M. G. [GANIL, BP 55027, 14076 Caen Cedex 5 (France); Coterreau, E.; Le Blanc, F.; Olivier, A. [IPN Orsay, BP 1-91406 Orsay (France); Gottwald, T.; Mattolat, C.; Wendt, K. [Johannes Gutenberg-Universitaet Mainz, Staudinger Weg 7, 55099 Mainz (Germany); Lassen, J. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3 (Canada); Rothe, S. [Department of Engineering, CERN, CH-1211 Geneva 23 (Switzerland)

    2010-02-15

    SPIRAL2 is the new project under construction at GANIL to produce radioactive ion beams and in particular neutron rich ion beams. For the past 10 yr SPIRAL1 at GANIL has been delivering accelerated radioactive ion beams of gases. Both facilities now need to extend the range of radioactive ion beams produced to condensable elements. For that purpose, a resonant ionization laser ion source, funded by the French Research National Agency, is under development at GANIL, in collaboration with IPN Orsay, University of Mainz (Germany) and TRIUMF, Vancouver (Canada). A description of this project called GISELE (GANIL Ion Source using Electron Laser Excitation) is presented.

  11. Ionization source utilizing a multi-capillary inlet and method of operation

    Science.gov (United States)

    Smith, Richard D.; Kim, Taeman; Udseth, Harold R.

    2004-10-12

    A multi-capillary inlet to focus ions and other charged particles generated at or near atmospheric pressure into a relatively low pressure region, which allows increased conductance of ions and other charged particles. The multi-capillary inlet is juxtaposed between an ion source and the interior of an instrument maintained at near atmospheric pressure, it finds particular advantages when deployed to improve the ion transmission between an electrospray ionization source and the first vacuum stage of a mass spectrometer, and finds its greatest advantages when deployed in conjunction with an electrodynamic (RF) ion funnel deployed within the interior of the mass spectrometer, particularly an ion funnel equipped with a jet disturber.

  12. On the comparison of energy sources: feasibility of radio frequency and ambient light harvesting

    CERN Document Server

    Korotkevich, Alexander O; Lavrova, Olga; Coutsias, Evangelos

    2015-01-01

    With growing interest in multi source energy harvesting including integrated microchips we propose a comparison of radio frequency (RF) and solar energy sources in a typical city. Harvesting devices for RF and solar energy will be competing for space of a compact micro or nano device as well as for orientation with respect to the energy source. This is why it is important to investigate importance of every source of energy and make a decision whether it will be worthwhile to include such harvesters. We considered theoretically possible irradiance by RF signal in different situations, typical for the modern urban environment and compared it with ambient solar energy sources available through the night, including moon light. Our estimations show that solar light energy dominates by far margin practically all the time, even during the night, if there is a full moon in the absence of clouds. At the same time, in the closed compartments or at the new moon RF harvesting can be beneficial as a source of "free" energ...

  13. Sources and effects of ionizing radiation. UNSCEAR 1996 report to the General Assembly, with scientific annex

    International Nuclear Information System (INIS)

    During the last few years the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has undertaken a broad review of the sources and effects of ionizing radiation. The results of this work have been issued in a series of publications: the UNSCEAR 1993 Report with nine scientific annexes, the UNSCEAR 1994 Report with two scientific annexes and the present UNSCEAR 1996 Report with one scientific annex, ''Effects of radiation on the environment''. These three publications from a series of reports entitled Sources and Effects of Ionizing Radiation, which together inform the General Assembly and the scientific and world community of the Committee's latest findings and evaluations. The Committee considers in this report the effects of ionizing radiation on plants and animals in the environment. These effects have not previously been addressed directly by the Committee. The emphasis of past assessments has been on determining the effects of radiation on human health. With the increasing interest around the world in nurturing the environment and concerns about possible detrimental effects of radiation, the time is appropriate for the Committee to provide a summary of the effects of radiation on the environment. Refs, figs, tabs

  14. The impact of information on behavior under an ambient-based policy for regulating nonpoint source pollution

    Science.gov (United States)

    Miao, Haoran; Fooks, Jacob R.; Guilfoos, Todd; Messer, Kent D.; Pradhanang, Soni M.; Suter, Jordan F.; Trandafir, Simona; Uchida, Emi

    2016-05-01

    Stemming from Segerson [1988], literature on nonpoint source pollution shows that ambient-based regulatory policies can induce polluters in a common watershed to comply with an exogenously determined pollution standard. This study uses laboratory economic experiments in a spatially heterogeneous setting to test the effectiveness of an ambient tax/subsidy policy in a setting with realistic in-stream nutrient transport dynamics when varying levels of sensor information on ambient pollution are available to the agents and the regulator. We find that increasing the frequency of ambient monitoring improves the spatial allocation of emissions reductions. In particular, with more frequent monitoring, the ambient-based policy induces firms further from the monitoring point to reduce emissions significantly more than downstream firms. Overall, the results suggest that enhanced temporal resolution of monitoring leads to efficiency gains.

  15. Detection of plutonium isotopes at lowest quantities using in-source resonance ionization mass spectrometry.

    Science.gov (United States)

    Raeder, S; Hakimi, A; Stöbener, N; Trautmann, N; Wendt, K

    2012-11-01

    The in-source resonance ionization mass spectrometry technique was applied for quantification of ultratrace amounts of plutonium isotopes as a proof of principle study. In addition to an overall detection limit of 10(4) to 10(5) atoms, this method enables the unambiguous identification and individual quantification of the plutonium isotopes (238)Pu and (241)Pu which are of relevance for dating of radiogenic samples. Due to the element-selective ionization process, these isotopes can be measured even under a high surplus of isobaric contaminations from (238)U or (241)Am, which considerably simplifies chemical preparation. The technique was developed, tested, and characterized on a variety of synthetic and calibration samples and is presently applied to analyze environmental samples.

  16. Rapid analysis of Delta-9-tetrahydrocannabinol in hair using direct analysis in real time ambient ionization orbitrap mass spectrometry

    NARCIS (Netherlands)

    Duvivier, W.F.; Beek, van T.A.; Pennings, E.J.M.; Nielen, M.W.F.

    2014-01-01

    RATIONALE - Forensic hair analysis methods are laborious, time-consuming and provide only a rough retrospective estimate of the time of drug intake. Recently, hair imaging methods using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) were reported, but these methods require

  17. POPULATION RADIATION PROTECTION PROVIDING UNDER THE INFLUENCE OF NATURAL IONIZING IRRADIATION SOURCES

    Directory of Open Access Journals (Sweden)

    E. G. Stepanov

    2015-01-01

    Full Text Available An article presents the modern problems of population radiation protection inBashkortostanRepublic. The main natural ionizing irradiation sources are identified and their contribution to the total exposure dose of the BashkortostanRepublicpopulation is analyzed. The types of the main natural ionizing irradiation sources are identified, as well as the ways of their intake and the methods of their influence. The results of laboratory studies are presented for the radon equivalent equilibrium volumetric activity, for the average gamma radiation dose rate in dwellings, for the investigations of gross alpha and gross beta activity in drinking water and open water sourcesBashkortostanRepublic. The article underlines the main problems of the radiation situation in the new construction. The main preventive measures are pointed out for the radiation protection of the buildings under construction improving. The article also presents an analysis of the results of activities of the Administration of Rospotrebnadzor in theBashkortostanRepublicfor the reducing of the levels of the Republican population exposure from the natural irradiation sources.

  18. Sources of ambient fine particulate matter at two community sites in Detroit, Michigan

    Science.gov (United States)

    Hammond, Davyda M.; Dvonch, J. Timothy; Keeler, Gerald J.; Parker, Edith A.; Kamal, Ali S.; Barres, James A.; Yip, Fuyuen Y.; Brakefield-Caldwell, Wilma

    Detroit, Michigan is a non-attainment area of the annual PM 2.5 (particles ⩽2.5 μm in diameter) National Ambient Air Quality Standard (NAAQS), and contains a host of local pollution contributors including high diesel traffic from a nearby international border crossing. A source apportionment analysis was conducted using PM 2.5 data collected from 1999 to 2002 by the Community Action Against Asthma (CAAA) project in Detroit, Michigan. CAAA used a community-based participatory research approach to identify and address the environmental triggers for asthma among children residing in southwest and east Detroit. The data used for the study included 24-h measurements of PM 2.5 mass, elemental and organic carbon, and a suite of trace element species, along with hourly measurements of PM 2.5 mass and black carbon. Positive matrix factorization (PMF2) was used to quantitatively apportion the sources of ambient PM 2.5 at each of two Detroit community sites. Results showed that southwest Detroit PM 2.5 levels can be apportioned to seven source categories: secondary sulfate/coal combustion, gasoline vehicles, diesel vehicles, refinery/oil combustion, iron-steel manufacturing/waste incineration, automotive electroplating, and sewage sludge incineration that includes crustal material from runoff. The PMF2 model apportioned the east Detroit PM 2.5 data into five source categories: secondary sulfate/coal combustion, motor vehicles/combustion, refinery/oil combustion, iron-steel manufacturing/waste incineration, and automotive electroplating. For both locations, approximately over 60% of the PM 2.5 mass was attributed to secondary sulfate/coal combustion sources, approximately 30% to vehicular sources, and 1-5% to local industrial sources. The unexplained mass accounted for <2% of the measured PM 2.5 mass. This study illustrates that regional secondary sulfate/coal combustion and local motor vehicle emissions alone are enough for this mid-western US city to be in non

  19. REQUIREMENTS TO THE LIMITATION OF POPULATION EXPO-SURE FROM THE NATIRAL IONIZING IRRADIATION SOURCES IN INDUSTRIAL CONDITIONS

    Directory of Open Access Journals (Sweden)

    I. P. Stamat

    2010-01-01

    Full Text Available The paper presents conceptually new requirements to the limitation of population exposure from the natural ionizing irradiation sources in industrial conditions, introduced into Basic Sanitary Rules of Radiation Safety (OSPORB-99/2010. It is shown that, first of all, introduction of these requirements is aimed at the resolution of variety of previously existing serious contradictions in organization of radiation safety control and supervision for the impact of natural ionizing irradiation sources in industry.

  20. Molecular Characterization of S- and N-containing Organic Constituents in Ambient Aerosols by negative ion mode High-Resolution Nanospray Desorption Electrospray Ionization Mass Spectrometry: CalNex 2010 field study

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, Rachel E.; Laskin, Alexander; Laskin, Julia; Rubitschun, Caitlin L.; Surratt, Jason D.; Goldstein, Allen H.

    2014-11-27

    Samples of ambient aerosols from the 2010 California Research at the Nexus of Air Quality and Climate Change (CalNex) field study were analyzed using Nanospray Desorption Electrospray Ionization High Resolution Mass Spectrometry (nano-DESI/MS). Four samples per day were collected in Bakersfield, CA on June 20-24 with a collection time of 6 hours per sample. Four characteristic groups of organic constituents were identified in the samples: compounds containing carbon, hydrogen, and oxygen only (CHO), sulfur- (CHOS), nitrogen-(CHON), and both nitrogen- and sulfur-containing organics (CHONS). Within the groups, organonitrates, organosulfates, and nitroxy organosulfates were assigned based on accurate mass measurements and elemental ratio comparisons. Changes in the chemical composition of the aerosol samples were observed throughout the day. The number of observed CHO compounds increased in the afternoon samples, suggesting regional photochemical processing as a source. The average number of CHOS compounds had the smallest changes throughout the day, consistent with a more broadly distributed source. Both of the nitrogen-containing groups (CHON and CHONS) had greater numbers of compounds in the night and morning samples, indicating that nitrate radical chemistry was likely a source for those compounds. Most of the compounds were found in submicron particles. The size distribution of CHON compounds was bimodal. We conclude that the majority of the compounds observed were secondary in nature with both biogenic and anthropogenic sources.

  1. Properties and cellular effects of particulate matter from direct emissions and ambient sources.

    Science.gov (United States)

    Jin, Wenjie; Su, Shu; Wang, Bin; Zhu, Xi; Chen, Yilin; Shen, Guofeng; Liu, Junfeng; Cheng, Hefa; Wang, Xilong; Wu, Shuiping; Zeng, Eddy; Xing, Baoshan; Tao, Shu

    2016-10-14

    The pollution of particulate matter (PM) is of great concern in China and many other developing countries. It is generally recognized that the toxicity of PM is source and property dependent. However, the relationship between PM properties and toxicity is still not well understood. In this study, PM samples from direct emissions of wood, straw, coal, diesel combustion, cigarette smoking and ambient air were collected and characterized for their physicochemical properties. Their expression of intracellular reactive oxygen species (ROS) and levels of inflammatory cytokines (i.e., tumor necrosis factor-α (TNF-α)) was measured using a RAW264.7 cell model. Our results demonstrated that the properties of the samples from different origins exhibited remarkable differences. Significant increases in ROS were observed when the cells were exposed to PMs from biomass origins, including wood, straw and cigarettes, while increases in TNF-α were found for all the samples, particularly those from ambient air. The most important factor associated with ROS generation was the presence of water-soluble organic carbon, which was extremely abundant in the samples that directly resulted from biomass combustion. Metals, endotoxins and PM size were the most important properties associated with increases in TNF-α expression levels. The association of the origins of PM particles and physicochemical properties with cytotoxic properties is illustrated using a cluster analysis. PMID:27409416

  2. Properties and cellular effects of particulate matter from direct emissions and ambient sources.

    Science.gov (United States)

    Jin, Wenjie; Su, Shu; Wang, Bin; Zhu, Xi; Chen, Yilin; Shen, Guofeng; Liu, Junfeng; Cheng, Hefa; Wang, Xilong; Wu, Shuiping; Zeng, Eddy; Xing, Baoshan; Tao, Shu

    2016-10-14

    The pollution of particulate matter (PM) is of great concern in China and many other developing countries. It is generally recognized that the toxicity of PM is source and property dependent. However, the relationship between PM properties and toxicity is still not well understood. In this study, PM samples from direct emissions of wood, straw, coal, diesel combustion, cigarette smoking and ambient air were collected and characterized for their physicochemical properties. Their expression of intracellular reactive oxygen species (ROS) and levels of inflammatory cytokines (i.e., tumor necrosis factor-α (TNF-α)) was measured using a RAW264.7 cell model. Our results demonstrated that the properties of the samples from different origins exhibited remarkable differences. Significant increases in ROS were observed when the cells were exposed to PMs from biomass origins, including wood, straw and cigarettes, while increases in TNF-α were found for all the samples, particularly those from ambient air. The most important factor associated with ROS generation was the presence of water-soluble organic carbon, which was extremely abundant in the samples that directly resulted from biomass combustion. Metals, endotoxins and PM size were the most important properties associated with increases in TNF-α expression levels. The association of the origins of PM particles and physicochemical properties with cytotoxic properties is illustrated using a cluster analysis.

  3. Development of dielectric-barrier-discharge ionization.

    Science.gov (United States)

    Guo, Cheng'an; Tang, Fei; Chen, Jin; Wang, Xiaohao; Zhang, Sichun; Zhang, Xinrong

    2015-03-01

    Dielectric-barrier-discharge ionization is an ambient-ionization technique. Since its first description in 2007, it has attracted much attention in such fields as biological analysis, food safety, mass-spectrometry imaging, forensic identification, and reaction monitoring for its advantages, e.g., low energy consumption, solvent-free method, and easy miniaturization. In this review a brief introduction to dielectric barrier discharge is provided, and then a detailed introduction to the dielectric-barrier-discharge-ionization technique is given, including instrumentation, applications, and mechanistic studies. Based on the summary of reported work, possible future uses of this type of ionization source are discussed at the end. PMID:25510973

  4. Chemical ionization mass spectrometry using carbon nanotube field emission electron sources.

    Science.gov (United States)

    Radauscher, Erich J; Keil, Adam D; Wells, Mitch; Amsden, Jason J; Piascik, Jeffrey R; Parker, Charles B; Stoner, Brian R; Glass, Jeffrey T

    2015-11-01

    A novel chemical ionization (CI) source has been developed based on a carbon nanotube (CNT) field emission electron source. The CNT-based electron source was evaluated and compared with a standard filament thermionic electron source in a commercial explosives trace detection desktop mass spectrometer. This work demonstrates the first reported use of a CNT-based ion source capable of collecting CI mass spectra. Both positive and negative modes were investigated. Spectra were collected for a standard mass spectrometer calibration compound, perfluorotributylamine (PFTBA), as well as trace explosives including trinitrotoluene (TNT), Research Department explosive (RDX), and pentaerythritol tetranitrate (PETN). The electrical characteristics, lifetime at operating pressure, and power requirements of the CNT-based electron source are reported. The CNT field emission electron sources demonstrated an average lifetime of 320 h when operated in constant emission mode under elevated CI pressures. The ability of the CNT field emission source to cycle on and off can provide enhanced lifetime and reduced power consumption without sacrificing performance and detection capabilities. Graphical Abstract ᅟ. PMID:26133527

  5. Negative ion beam formation using thermal contact ionization type plasma source

    Energy Technology Data Exchange (ETDEWEB)

    Fukuura, Yoshiyuki; Murakami, Kazutugu; Masuoka, Toshio; Katsumata, Itsuo [Osaka City Univ. (Japan). Faculty of Engineering

    1997-02-01

    The small ion sources utilizing thermal ionization have been already developed, and at present, in order to increase ion yield, that being developed to the cylindrical plasma prototype having the inner surface of a Re foil cylinder as the ionization surface, and stably functioning at 3,000 K has been developed, and by using this plasma source, the research on the formation of various ions has been carried out. At present, the research on the formation of Li negative ion beam is carried out. The separation of negative ions from electrons is performed with the locally limited magnetic field using a small iron core electromagnet placed behind the electrostatic accelerating lens system. So for, the formation of about 2 {mu}A at maximum of negative ions was confirmed. It was decided to identify the kinds of ions by time of flight (TOF) process, and the various improvements for this purpose were carried out. The experimental setup, the structure of the plasma source, the circuits for TOF measurement and so on are explained. The experimental results are reported. The problems are the possibility of the formation of alkali metals, the resolution of the time axis of the TOF system and so on. (K.I.)

  6. Functional group composition of ambient and source organic aerosols determined by tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    J. Dron

    2010-04-01

    Full Text Available The functional group composition of various organic aerosols (OA is being investigated using a recently developed analytical approach based on atmospheric pressure chemical ionisation-tandem mass spectrometry (APCI-MS/MS. The determinations of the three functional groups' contents are performed quantitatively by neutral loss (carboxylic and carbonyl groups and precursor ion (nitro groups scanning modes of a tandem mass spectrometer. Major organic aerosol sources are studied: vehicular emission and wood combustion for primary aerosol sources; and a secondary organic aerosol (SOA produced through photo-oxidation of o-xylene. The results reveal significant differences in the functional group contents of these source aerosols. The laboratory generated SOA is dominated by carbonyls while carboxylics are preponderate in the wood combustion particles. On the other hand, vehicular emissions are characterised by a strong nitro content. The total amount of the three functional groups accounted for 1.7% (vehicular to 13.5% (o-xylene photo-oxidation of the organic carbon. The diagnostic functional group ratios are then used to tentatively differentiate sources of particles collected in an urban background environment located in an Alpine valley (Chamonix, France during a strong winter pollution event. The three functional groups under study account for a total functionalisation rate of 2.2 to 3.8% of the organic carbon in this ambient aerosol, which is also dominated by carboxylic moieties. In this particular case study of a deep alpine valley during winter, we show that the nitro- and carbonyl-to-carboxylic diagnostic ratios can be a useful tool to distinguish the sources. In these conditions, the total OA concentrations are highly dominated by wood combustion OA. This result is confirmed by an organic markers source apportionment approach which assesses a wood burning organic carbon contribution of about 60%. Finally, examples of functional group mass

  7. On the Ionization of Luminous WMAP Sources in the Galaxy : Constraints from He Recombination Line Observations with the GBT

    CERN Document Server

    Roshi, D Anish; Rosero, Viviana; Vaddi, Sravani

    2012-01-01

    The Wilkinson Microwave Anisotropy Probe (WMAP) free-free foreground emission map is used to identify diffuse ionized regions (DIR) in the Galaxy (Rahman & Murray 2010). It has been found that the 18 most luminous WMAP sources produce more than half of the total ionizing luminosity of the Galaxy. We observed radio recombination lines (RRLs) toward the luminous WMAP source G49.75-0.45 with the Green Bank Telescope near 1.4 GHz. Hydrogen RRL is detected toward the source but no helium line is detected, implying that n_He+/n_H+ ~10 times to explain the observations. If selective absorption of He- ionizing photons by dust is causing this additional attenuation, then the ratio of dust absorption cross sections for He- and H- ionizing photons should be > ~6.

  8. Ion-ion reactions for charge reduction of biopolymer at atmospheric pressure ambient

    Institute of Scientific and Technical Information of China (English)

    Yue Ming Zhou; Jian Hua Ding; Xie Zhang; Huan Wen Chen

    2007-01-01

    Extractive electrospray ionization source (EESI) was adapted for ion-ion reaction, which was demonstrated by using a linear quadrupole ion trap mass spectrometer for the first ion-ion reaction of biopolymers in the atmospheric pressure ambient.

  9. Order n.02-059 /P-RM of 05 juin 2002 setting up radioprotection et safety of ionizing radiation sources

    International Nuclear Information System (INIS)

    This order establishes the legal framework of radioprotection and safety of ionizing radiation sources in Mali. The scope as well as the definition of some main terms are given. The basis principles of radioprotection against ionizing radiation sources are defined. Instructions in uses of ionizing radiations, penal provisions are outlined

  10. New ambient pressure photoemission endstation at Advanced Light Source beamline 9.3.2

    KAUST Repository

    Grass, Michael E.

    2010-01-01

    During the past decade, the application of ambient pressure photoemission spectroscopy (APPES) has been recognized as an important in situ tool to study environmental and materials science, energy related science, and many other fields. Several APPES endstations are currently under planning or development at the USA and international light sources, which will lead to a rapid expansion of this technique. The present work describes the design and performance of a new APPES instrument at the Advanced Light Source beamline 9.3.2 at Lawrence Berkeley National Laboratory. This new instrument, Scienta R4000 HiPP, is a result of collaboration between Advanced Light Source and its industrial partner VG-Scienta. The R4000 HiPP provides superior electron transmission as well as spectromicroscopy modes with 16 μm spatial resolution in one dimension and angle-resolved modes with simulated 0.5° angular resolution at 24° acceptance. Under maximum transmission mode, the electron detection efficiency is more than an order of magnitude better than the previous endstation at beamline 9.3.2. Herein we describe the design and performance of the system, which has been utilized to record spectra above 2 mbar. © 2010 American Institute of Physics.

  11. Size, source and chemical composition as determinants of toxicity attributable to ambient particulate matter

    Science.gov (United States)

    Kelly, Frank J.; Fussell, Julia C.

    2012-12-01

    Particulate matter (PM) is a complex, heterogeneous mixture that changes in time and space. It encompasses many different chemical components and physical characteristics, many of which have been cited as potential contributors to toxicity. Each component has multiple sources, and each source generates multiple components. Identifying and quantifying the influences of specific components or source-related mixtures on measures of health-related impacts, especially when particles interact with other co-pollutants, therefore represents one of the most challenging areas of environmental health research. Current knowledge does not allow precise quantification or definitive ranking of the health effects of PM emissions from different sources or of individual PM components and indeed, associations may be the result of multiple components acting on different physiological mechanisms. Some results do suggest a degree of differential toxicity, namely more consistent associations with traffic-related PM emissions, fine and ultrafine particles, specific metals and elemental carbon and a range of serious health effects, including increased morbidity and mortality from cardiovascular and respiratory conditions. A carefully targeted programme of contemporary toxicological and epidemiological research, incorporating more refined approaches (e.g. greater speciation data, more refined modelling techniques, accurate exposure assessment and better definition of individual susceptibility) and optimal collaboration amongst multidisciplinary teams, is now needed to advance our understanding of the relative toxicity of particles from various sources, especially the components and reactions products of traffic. This will facilitate targeted abatement policies, more effective pollution control measures and ultimately, a reduction in the burden of disease attributable to ambient PM pollution.

  12. Contributions to cities' ambient particulate matter (PM): A systematic review of local source contributions at global level

    Science.gov (United States)

    Karagulian, Federico; Belis, Claudio A.; Dora, Carlos Francisco C.; Prüss-Ustün, Annette M.; Bonjour, Sophie; Adair-Rohani, Heather; Amann, Markus

    2015-11-01

    For reducing health impacts from air pollution, it is important to know the sources contributing to human exposure. This study systematically reviewed and analysed available source apportionment studies on particulate matter (of diameter of 10 and 2.5 microns, PM10 and PM2.5) performed in cities to estimate typical shares of the sources of pollution by country and by region. A database with city source apportionment records, estimated with the use of receptor models, was also developed and available at the website of the World Health Organization. Systematic Scopus and Google searches were performed to retrieve city studies of source apportionment for particulate matter. Six source categories were defined. Country and regional averages of source apportionment were estimated based on city population weighting. A total of 419 source apportionment records from studies conducted in cities of 51 countries were used to calculate regional averages of sources of ambient particulate matter. Based on the available information, globally 25% of urban ambient air pollution from PM2.5 is contributed by traffic, 15% by industrial activities, 20% by domestic fuel burning, 22% from unspecified sources of human origin, and 18% from natural dust and salt. The available source apportionment records exhibit, however, important heterogeneities in assessed source categories and incompleteness in certain countries/regions. Traffic is one important contributor to ambient PM in cities. To reduce air pollution in cities and the substantial disease burden it causes, solutions to sustainably reduce ambient PM from traffic, industrial activities and biomass burning should urgently be sought. However, further efforts are required to improve data availability and evaluation, and possibly to combine with other types of information in view of increasing usefulness for policy making.

  13. Molecular Ionization-Desorption Analysis Source (MIDAS) for Mass Spectrometry: Thin-Layer Chromatography

    Science.gov (United States)

    Winter, Gregory T.; Wilhide, Joshua A.; LaCourse, William R.

    2016-02-01

    Molecular ionization-desorption analysis source (MIDAS), which is a desorption atmospheric pressure chemical ionization (DAPCI) type source, for mass spectrometry has been developed as a multi-functional platform for the direct sampling of surfaces. In this article, its utility for the analysis of thin-layer chromatography (TLC) plates is highlighted. Amino acids, which are difficult to visualize without staining reagents or charring, were detected and identified directly from a TLC plate. To demonstrate the full potential of MIDAS, all active ingredients from an analgesic tablet, separated on a TLC plate, were successfully detected using both positive and negative ion modes. The identity of each of the compounds was confirmed from their mass spectra and compared against standards. Post separation, the chemical signal (blue permanent marker) as reference marks placed at the origin and solvent front were used to calculate retention factor (Rf) values from the resulting ion chromatogram. The quantitative capabilities of the device were exhibited by scanning caffeine spots on a TLC plate of increasing sample amount. A linear curve based on peak are, R2 = 0.994, was generated for seven spots ranging from 50 to 1000 ng of caffeine per spot.

  14. Micro Corona Ionizer as an Ozone Source for Bacterial Cell Lysis

    Science.gov (United States)

    Lee, Eun-Hee; Lim, Hyun Jeong; Chua, Beelee; Son, Ahjeong

    2015-04-01

    DNA extraction is a critical process of DNA assays including polymerase chain reaction (PCR), microarrays, molecular cloning, and DNA hybridization which has been well established and can be implemented by commercial kits. DNA extraction involves cell lysis, precipitation, and purification through the combination of physical and chemical processes. Cell lysis is essential to high DNA recovery yield which can be achieved via a variety of physical, chemical, and enzymatic methods. However, these methods were originally developed for bioassays that were labor intensive, time consuming, and vulnerable to contamination and inhibition. Here, we proposed to employ a micro corona ionizer as an ozone source to lyse bacterial cells. Ozone has been well known and used as a disinfectant which allows cell lysis and DNA extraction. Previously, we have shown that a micro corona ionizer is capable of generating a significant amount of ozone. In this study, we employed the micro corona ionizer for the bacterial cell lysis which consists of a 50 μm diameter cantilever wire as the discharge cathode and a 50 μm thick copper foil as anode. Applied voltages varied from 1900 to 2200 V with corresponding corona currents from 16 to 28 μA. The resultant ozone (concentration > 0.14 ppm) generated from the micro corona ionizer was bubbled into the sample via a miniature pump. We demonstrated the cell lysis of Pseudomonas putida as the target bacterium using the micro corona ionizer. At a flow rate of 38 ml/min and applied corona voltage of 2000 V, 98.5 ± 0.2% lysis (normalized to sonication result) was achieved after 10 min. In comparison, untreated and air-treated samples showed normalized % lysis of 11.9 ± 2.4 and 36.1 ± 1.7%, respectively. We also showed that the cell lysis efficiency could be significantly increased by increasing the flow rate and the applied corona voltage. By comparing the experimental results for continuous and pulsed treatment, we verified that the percentage of

  15. Calibration of the KRISS reference ionization chamber for certification of ²²²Rn gaseous sources.

    Science.gov (United States)

    Lee, J M; Lee, K B; Lee, S H; Oh, P J; Park, T S; Kim, B C; Lee, M S

    2013-11-01

    A primary measurement system for gaseous (222)Rn based on the defined solid angle counting method has recently been constructed at KRISS and the reference ionization chamber used to measure the activities of gamma-emitting single radionuclides was adopted as a secondary standard for gaseous (222)Rn. A 20 mL flame-sealed glass ampoule source from the primary measurement system was used to calibrate the ionization chamber for (222)Rn. The (222)Rn efficiency of the ionization chamber was compared with that calculated by using a photon energy-dependent efficiency curve and that measured by using a standard (226)Ra solution. From the comparisons we draw the conclusion that the reference ionization chamber for gamma-emitting radionuclides can be a suitable secondary measurement system for gaseous (222)Rn sources.

  16. Atomic data for integrated tokamak modelling – Fermi-shuttle type ionization as a possible source of high energy electrons

    Directory of Open Access Journals (Sweden)

    Tőkési K.

    2014-01-01

    Full Text Available The ionization of Ar by 15 keV N+ ion is studied theoretically. The energy distributions of the ejected electrons as a function of the scattering angle were calculated using the classical trajectory Monte Carlo method. We identify the signature of the Fermi-shuttle type ionization in the double differential cross sections which should be a possible source of the high energy electrons in the plasma. Our classical calculation also describes the previously measured data with high accuracy.

  17. Nuclear law: nuclear matter and ionizing radiation sources. Wastes; Droit nucleaire: matieres nucleaires et sources de rayonnements ionisants. Dechets

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-15

    The object of this work is since its first edition in 1983 under the title 'Collection of nuclear activities legislation and regulation ' to realize an ordered collection of texts constituting the juridical and institutional frame of nuclear activities, gathering the legislative, regulatory and technical texts; the international, European and national texts. Aiming to include the whole of the atom applications, this collection tackles various themes, in ten chapters.The volume number two includes the following chapters: nuclear matters and ionizing radiations sources; wastes. Previously edited by the Cea, that realizes it it is now published in the collection 'Legislation and regulation' of officials journals editions. (N.C.)

  18. Functional group composition of ambient and source organic aerosols determined by tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Dron, J.; El Haddad, I.; Temime-Roussel, B.; Wortham, H.; Marchand, N. [Univ Aix Marseille, CNRS, Lab Chim Provence, Equipe Instrumentat and React Atmospher, UMR 6264, F-13331 Marseille 3 (France); Jaffrezo, J.L. [Univ Grenoble 1, CNRS, UMR 5183, Lab Glaciol and Geophys Environm, F-38402 St Martin Dheres (France)

    2010-07-01

    The functional group composition of various organic aerosols (OA) is investigated using a recently developed analytical approach based on atmospheric pressure chemical ionisation-tandem mass spectrometry (APCIMS/MS). The determinations of three functional groups contents are performed quantitatively by neutral loss (carboxylic and carbonyl groups, R-COOH and R-CO-R' respectively) and precursor ion (nitro groups, R-NO{sub 2}) scanning modes of a tandem mass spectrometer. Major organic aerosol sources are studied: vehicular emission and wood combustion for primary aerosol sources; and a secondary organic aerosol (SOA) produced through photooxidation of o-xylene. The results reveal significant differences in the functional group contents of these source aerosols. The laboratory generated SOA is dominated by carbonyls while carboxylics are preponderate in the wood combustion particles. On the other hand, vehicular emissions are characterised by a strong nitro content. The total amount of the three functional groups accounts for 1.7% (vehicular) to 13.5% (o-xylene photooxidation) of the organic carbon. Diagnostic functional group ratios are then used to tentatively discriminate sources of particles collected in an urban background environment located in an Alpine valley (Chamonix, France) during a strong winter pollution event. The three functional groups under study account for a total functionalization rate of 2.2 to 3.8% of the organic carbon in this ambient aerosol, which is also dominated by carboxylic moieties. In this particular case study of a deep alpine valley during winter, we show that the nitro- and carbonyl-to-carboxylic diagnostic ratios can be a useful tool to discriminate sources. In these conditions, the total OA concentrations are highly dominated by wood combustion OA. This result is confirmed by an organic markers source apportionment approach which assess a wood burning organic carbon contribution of about 60%. Finally, examples of functional

  19. Functional group composition of ambient and source organic aerosols determined by tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    J. Dron

    2010-08-01

    Full Text Available The functional group composition of various organic aerosols (OA is investigated using a recently developed analytical approach based on atmospheric pressure chemical ionisation-tandem mass spectrometry (APCI-MS/MS. The determinations of three functional groups contents are performed quantitatively by neutral loss (carboxylic and carbonyl groups, R-COOH and R-CO-R´ respectively and precursor ion (nitro groups, R-NO2 scanning modes of a tandem mass spectrometer. Major organic aerosol sources are studied: vehicular emission and wood combustion for primary aerosol sources; and a secondary organic aerosol (SOA produced through photooxidation of o-xylene. The results reveal significant differences in the functional group contents of these source aerosols. The laboratory generated SOA is dominated by carbonyls while carboxylics are preponderate in the wood combustion particles. On the other hand, vehicular emissions are characterised by a strong nitro content. The total amount of the three functional groups accounts for 1.7% (vehicular to 13.5% (o-xylene photooxidation of the organic carbon. Diagnostic functional group ratios are then used to tentatively discriminate sources of particles collected in an urban background environment located in an Alpine valley (Chamonix, France during a strong winter pollution event. The three functional groups under study account for a total functionalisation rate of 2.2 to 3.8% of the organic carbon in this ambient aerosol, which is also dominated by carboxylic moieties. In this particular case study of a deep alpine valley during winter, we show that the nitro- and carbonyl-to-carboxylic diagnostic ratios can be a useful tool to discriminate sources. In these conditions, the total OA concentrations are highly dominated by wood combustion OA. This result is confirmed by an organic markers source apportionment approach which assess a wood burning organic carbon contribution of about 60

  20. Functional group composition of ambient and source organic aerosols determined by tandem mass spectrometry

    International Nuclear Information System (INIS)

    The functional group composition of various organic aerosols (OA) is investigated using a recently developed analytical approach based on atmospheric pressure chemical ionisation-tandem mass spectrometry (APCIMS/MS). The determinations of three functional groups contents are performed quantitatively by neutral loss (carboxylic and carbonyl groups, R-COOH and R-CO-R' respectively) and precursor ion (nitro groups, R-NO2) scanning modes of a tandem mass spectrometer. Major organic aerosol sources are studied: vehicular emission and wood combustion for primary aerosol sources; and a secondary organic aerosol (SOA) produced through photooxidation of o-xylene. The results reveal significant differences in the functional group contents of these source aerosols. The laboratory generated SOA is dominated by carbonyls while carboxylics are preponderate in the wood combustion particles. On the other hand, vehicular emissions are characterised by a strong nitro content. The total amount of the three functional groups accounts for 1.7% (vehicular) to 13.5% (o-xylene photooxidation) of the organic carbon. Diagnostic functional group ratios are then used to tentatively discriminate sources of particles collected in an urban background environment located in an Alpine valley (Chamonix, France) during a strong winter pollution event. The three functional groups under study account for a total functionalization rate of 2.2 to 3.8% of the organic carbon in this ambient aerosol, which is also dominated by carboxylic moieties. In this particular case study of a deep alpine valley during winter, we show that the nitro- and carbonyl-to-carboxylic diagnostic ratios can be a useful tool to discriminate sources. In these conditions, the total OA concentrations are highly dominated by wood combustion OA. This result is confirmed by an organic markers source apportionment approach which assess a wood burning organic carbon contribution of about 60%. Finally, examples of functional group mass

  1. Ambient gas/particle partitioning. 3. Estimating partition coefficients of apolar, polar, and ionizable organic compounds by their molecular structure.

    Science.gov (United States)

    Arp, Hans Peter H; Gosses, Kai-Uwe

    2009-03-15

    Equilibrium gas/particle partitioning coefficients of terrestrial aerosols, Kip, are dependent on various intermolecular interactions that can be quantified by experimentally determined compound-specific descriptors. For many compounds of environmental interest, such as emerging contaminants and atmospheric phototransformation products, these compound-specific descriptors are unknown or immeasurable. Often, only the molecular structure is known. Here we present the ability of two computer programs to predict equilibrium partitioning to terrestrial aerosols solely on the basis of molecular structure: COSMOtherm and SPARC. The greatest hurdle with designing such an approach is to identify suitable molecular surrogates to represent the dominating sorbing phases, which for ambient terrestrial aerosols are the water insoluble organic matter (WIOM) phase and the mixed-aqueous phase. For the WI0M phase, hypothetical urban secondary organic aerosol structural units from Kalberer et al. Science 2004, 303, 1659-1662 were investigated as input surrogates, and for the mixed-aqueous phase mildly acidic water was used as a surrogate. Using a validation data set of more than 1400 experimentally determined Kip values for polar, apolar, and ionic compounds ranging over 9 orders of magnitude (including semivolatile compounds such as PCDD/Fs, pesticides, and PBDEs), SPARC and COSMOtherm were generally able to predict Kip values well within an order of magnitude over an ambient range of temperature and relative humidity. This is remarkable as these two models were not fitted or calibrated to any experimental data. As these models can be used for potentially any organic molecule, they are particularly recommended for environmental screening purposes and for use when experimental compound descriptor data are not available. PMID:19368193

  2. Where are all of the nebulae ionized by supersoft X-ray sources?

    Science.gov (United States)

    Woods, T. E.; Gilfanov, M.

    2016-01-01

    Accreting, steadily nuclear-burning white dwarfs are associated with so-called close-binary supersoft X-ray sources (SSSs), observed to have temperatures of a few × 105 K and luminosities on the order of 1038 erg s-1. These and other types of SSSs are expected to be capable of ionizing their surrounding circumstellar medium; however, to date only one such nebula was detected in the Large Magellanic Cloud (of its six known close-binary SSSs), surrounding the accreting, nuclear-burning WD CAL 83. This has led to the conclusion that most SSSs cannot have been both luminous (≳1037 erg s-1) and hot (≳few × 104 K) for the majority of their past accretion history, unless the density of the interstellar medium (ISM) surrounding most sources is much less than that inferred for the CAL 83 nebula (4-10 cm- 3). Here, we demonstrate that most SSSs must lie in much lower density media than CAL 83. Past efforts to detect such nebulae have not accounted for the structure of the ISM in star-forming galaxies and, in particular, for the fact that most of the volume is occupied by low density warm and hot ISM. CAL 83 appears to lie in a region of ISM which is at least ˜40-fold overdense. We compute the probability of such an event to be ≈18 per cent, in good agreement with observed statistics. We provide a revised model for the `typical' SSS nebula, and outline the requirements of a survey of the Magellanic Clouds which could detect the majority of such objects. We then briefly discuss some of the possible implications, should there prove to be a large population of previously undiscovered ionizing sources.

  3. Sources and effects of ionizing radiation. UNSCEAR 1994 report to the General Assembly, with scientific annexes

    International Nuclear Information System (INIS)

    During the last few years the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has undertaken a broad review of the sources and effects of ionizing radiation. Nine scientific annexes on particular subjects were issued in the UNSCEAR 1993 Report. Two further annexes have been completed, and these comprise the UNSCEAR 1994 Report. This is the twelfth substantive Report of the Committee, informing the General Assembly and the scientific and world community of its latest assessments. The two reports, 1993 and 1994, are complementary and provide a coherent summary of the Committee's findings and programme of work. The Committee considers in this report the effects of ionizing radiation on plants and animals in the environment. These effects have not previously been addressed directly by the Committee. The emphasis of past assessments has been on determining the effects of radiation on human health. With the increasing interest around the world in nurturing the environment and concerns about possible detrimental effects of radiation, the time is appropriate for the Committee to provide a summary of the effects of radiation on the environment. Refs, figs, tabs

  4. The wall correction factor for a spherical ionization chamber used in brachytherapy source calibration

    Energy Technology Data Exchange (ETDEWEB)

    Piermattei, A [Istituto di Fisica, Universita Cattolica S Cuore, Rome (Italy); Azario, L [Istituto di Fisica, Universita Cattolica S Cuore, Rome (Italy); Fidanzio, A [Istituto di Fisica, Universita Cattolica S Cuore, Rome (Italy); Viola, P [Istituto di Fisica, Universita Cattolica S Cuore, Rome (Italy); Dell' Omo, C [Istituto di Fisica, Universita Cattolica S Cuore, Rome (Italy); Iadanza, L [Centro di Riferimento Oncologico della Basilicata-Rionero in Vulture, Pz (Italy); Fusco, V [Centro di Riferimento Oncologico della Basilicata-Rionero in Vulture, Pz (Italy); Lagares, J I [Universidad de Sevilla, Facultad de Medicina, Dpto Fisiologia Medica y Biofisica, Sevilla (Spain); Capote, R [Universidad de Sevilla, Facultad de Medicina, Dpto Fisiologia Medica y Biofisica, Sevilla (Spain)

    2003-12-21

    The effect of wall chamber attenuation and scattering is one of the most important corrections that must be determined when the linear interpolation method between two calibration factors of an ionization chamber is used. For spherical ionization chambers the corresponding correction factors A{sub w} have to be determined by a non-linear trend of the response as a function of the wall thickness. The Monte Carlo and experimental data here reported show that the A{sub w} factors obtained for an Exradin A4 chamber, used in the brachytherapy source calibration, in terms of reference air kerma rate, are up to 1.2% greater than the values obtained by the linear extrapolation method for the studied beam qualities. Using the A{sub w} factors derived from Monte Carlo calculations, the accuracy of the calibration factor N{sub K,Ir} for the Exradin A4, obtained by the interpolation between two calibration factors, improves about 0.6%. The discrepancy between the new calculated factor and that obtained using the complete calibration curve of the ion-chamber and the {sup 192}Ir spectrum is only 0.1%.

  5. Molecular characterization of S- and N-containing organic constituents in ambient aerosols by negative ion mode high-resolution Nanospray Desorption Electrospray Ionization Mass Spectrometry: CalNex 2010 field study

    Science.gov (United States)

    O'Brien, Rachel E.; Laskin, Alexander; Laskin, Julia; Rubitschun, Caitlin L.; Surratt, Jason D.; Goldstein, Allen H.

    2014-11-01

    Samples of ambient aerosols from the 2010 California Research at the Nexus of Air Quality and Climate Change (CalNex) field study were analyzed using negative ion mode Nanospray Desorption Electrospray Ionization High-Resolution Mass Spectrometry (nano-DESI/MS). Four samples per day (6 h each) were collected in Bakersfield, CA on 20-24 June. Four characteristic groups were identified: molecules composed of carbon, hydrogen, and oxygen only (CHO), sulfur- (CHOS), nitrogen- (CHON), and both nitrogen- and sulfur-containing organics (CHONS). The chemical formula and elemental ratios were consistent with the presence of organonitrates, organosulfate, and nitroxy organosulfates in the negative ion mode mass spectra. The number of observed CHO compounds increased in the afternoon samples, suggesting photochemical processing as a source. The average number of CHOS compounds had the smallest changes during the day, consistent with a more broadly distributed source. Both of the nitrogen-containing groups (CHONS and CHON) had greater numbers of compounds in the early morning (midnight to 6 A.M.) and night (6 P.M. to midnight) samples, respectively, consistent with nitrate radical chemistry as a likely source for those compounds. Most of the compounds were found in submicron particles. The size distribution of the number of CHON compounds was bimodal, potentially indicating two types of sources. We conclude that the majority of the compounds observed were secondary in nature with both biogenic and anthropogenic sources. These data are complementary to previous results from positive ion mode nano-DESI/MS analysis of a subset of the same samples providing a more complete view of aerosol chemical composition at Bakersfield.

  6. Radiological impact of natural and artificial sources of ionizing radiation. Report UNSCEAR 2000

    International Nuclear Information System (INIS)

    The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) was established by the General Assembly in 1995. It has the mandate to assess the levels and effects of ionizing radiation. During the last years UNSCEAR has undertaken a broad review of the natural and artificial sources of ionizing radiation. The results of these evaluations have been presented in a Report to the General Assembly with Scientific Annexes including extensive data for the world community (Report UNSCEAR 2000). The greatest contribution to radiation exposure comes from natural background sources. There are considerable variation in the exposures of the population depending on the altitude and latitude, characteristics of the soil and diet and the construction and ventilation features of houses. The global annual average per caput is 2.4 mSv with typical range 1 to 10 mSv. The next largest component comes from medical radiation examinations and treatments with an annual average of 0.4 mSv ranging from 0.04 to 1.0 mSv depending on the level o f medical care. The man-made practices, activities, and events in which radionuclides are released to the environment are always of much concern, but usually they contribute quite low to radiation exposure to humans. Atmospheric testing caused the greatest releases but nowadays very low residual annual levels of exposures persist (0.005 mSv). Nuclear Power production is responsible for only very low exposure and may reach in the future an average annual level of 0.0002 mSv. (Author)

  7. Ionizing radiation sources: very diversified means, multiple applications and a changing regulatory environment. Conference proceedings

    International Nuclear Information System (INIS)

    This document brings together the available presentations given at the conference organised by the French society of radiation protection about ionizing radiation source means, applications and regulatory environment. Twenty eight presentations (slides) are compiled in this document and deal with: 1 - Overview of sources - some quantitative data from the national inventory of ionizing radiation sources (Yann Billarand, IRSN); 2 - Overview of sources (Jerome Fradin, ASN); 3 - Regulatory framework (Sylvie Rodde, ASN); 4 - Alternatives to Iridium radiography - the case of pressure devices at the manufacturing stage (Henri Walaszek, Cetim; Bruno Kowalski, Welding Institute); 5 - Dosimetric stakes of medical scanner examinations (Jean-Louis Greffe, Charleroi hospital of Medical University); 6 - The removal of ionic smoke detectors (Bruno Charpentier, ASN); 7 - Joint-activity and reciprocal liabilities - Organisation of labour risk prevention in case of companies joint-activity (Paulo Pinto, DGT); 8 - Consideration of gamma-graphic testing in the organization of a unit outage activities (Jean-Gabriel Leonard, EDF); 9 - Radiological risk control at a closed and independent work field (Stephane Sartelet, Areva); 10 - Incidents and accidents status and typology (Pascale Scanff, IRSN); 11 - Regional overview of radiation protection significant events (Philippe Menechal, ASN); 12 - Incident leading to a tritium contamination in and urban area - consequences and experience feedback (Laurence Fusil, CEA); 13 - Experience feedback - loss of sealing of a calibration source (Philippe Mougnard, Areva); 14 - Blocking incident of a 60Co source (Bruno Delille, Salvarem); 15 - Triggering of gantry's alarm: status of findings (Philippe Prat, Syctom); 16 - Non-medical electric devices: regulatory changes (Sophie Dagois, IRSN; Jerome Fradin, ASN); 17 - Evaluation of the dose equivalent rate in pulsed fields: method proposed by the IRSN and implementation test (Laurent Donadille, IRSN); 18

  8. Source apportionment of ambient aerosol applying PMF on AMS mobile and stationary data

    Science.gov (United States)

    Mohr, C.; Weimer, S.; Richter, R.; Decarlo, P. F.; Chirico, R.; Heringa, M. F.; Prévôt, A. S. H.; Baltensperger, U.

    2009-04-01

    Ambient aerosols are divided into the categories "primary" and "secondary", referring to particles directly emitted into the air, or formed out of precursor species such as volatile organic compounds, respectively. Main sources for primary urban aerosol and precursor species are traffic emissions, but also wood burning for domestic heating purposes especially in winter time (Alfarra et al., 2007). The quantification of various types of aerosol components is important for source identification which in turn is the basis of all mitigation activities. Positive Matrix Factorization (PMF) is a statistical based source apportionment tool that uses constrained, weighted least squares estimation to determine source profiles and strengths. PMF has been applied recently for the first time on highly time resolved organic mass spectra (Lanz et al., 2007) measured by an Aerodyne aerosol mass spectrometer (AMS) (Canagaratna et al., 2007). For the data presented here, two AMS were deployed together with additional instrumentation in the metropolitan area of Zurich in winter 2007/2008. The high-resolution time-of-flight AMS was stationed at an urban background site in the center, 30 meters from and shielded against direct traffic emissions. The quadrupole-based AMS was deployed in a mobile van allowing for on-road submicron aerosol composition measurements, and investigations into the spatial variability of aerosol concentration and composition. Results indicate that traffic emissions are the main contributor to submicron aerosol concentrations measured on-road. Hydrocarbon-like organic aerosol (HOA), a marker for traffic emissions (Lanz et al. 2007), dominates the primary aerosol mass, together with black carbon (BC). BC was monitored with the MAAP (multi angle absorption photometer). Another significant contributor to primary organic aerosol mass in downtown Zurich is domestic wood burning for heating purposes. Traffic and wood burning emissions make up roughly 50% of the total

  9. Source geometry factors for HDR ¹⁹²Ir brachytherapy secondary standard well-type ionization chamber calibrations.

    Science.gov (United States)

    Shipley, D R; Sander, T; Nutbrown, R F

    2015-03-21

    Well-type ionization chambers are used for measuring the source strength of radioactive brachytherapy sources before clinical use. Initially, the well chambers are calibrated against a suitable national standard. For high dose rate (HDR) (192)Ir, this calibration is usually a two-step process. Firstly, the calibration source is traceably calibrated against an air kerma primary standard in terms of either reference air kerma rate or air kerma strength. The calibrated (192)Ir source is then used to calibrate the secondary standard well-type ionization chamber. Calibration laboratories are usually only equipped with one type of HDR (192)Ir source. If the clinical source type is different from that used for the calibration of the well chamber at the standards laboratory, a source geometry factor, k(sg), is required to correct the calibration coefficient for any change of the well chamber response due to geometric differences between the sources. In this work we present source geometry factors for six different HDR (192)Ir brachytherapy sources which have been determined using Monte Carlo techniques for a specific ionization chamber, the Standard Imaging HDR 1000 Plus well chamber with a type 70010 HDR iridium source holder. The calculated correction factors were normalized to the old and new type of calibration source used at the National Physical Laboratory. With the old Nucletron microSelectron-v1 (classic) HDR (192)Ir calibration source, ksg was found to be in the range 0.983 to 0.999 and with the new Isodose Control HDR (192)Ir Flexisource k(sg) was found to be in the range 0.987 to 1.004 with a relative uncertainty of 0.4% (k = 2). Source geometry factors for different combinations of calibration sources, clinical sources, well chambers and associated source holders, can be calculated with the formalism discussed in this paper.

  10. The ionizing sources of luminous compact HII regions in the RCW106 and RCW122 clouds

    CERN Document Server

    Grave, J M C; Ojha, D K; Teixeira, G; Pace, G

    2013-01-01

    Given the rarity of young O star candidates, compact HII regions embedded in dense molecular cores continue to serve as potential sites to peer into the details of high-mass star formation. To uncover the ionizing sources of the most luminous and compact HII regions embedded in the RCW106 and RCW122 giant molecular clouds, known to be relatively nearby (2-4 kpc) and isolated, thus providing an opportunity to examine spatial scales of a few hundred to a thousand AU in size. High spatial resolution (0.3"), mid-infrared spectra (R=350), including the fine structure lines [ArIII] and [NeII], are obtained for four luminous compact HII regions, embedded inside the dense cores within the RCW106 and RCW122 molecular cloud complexes. At this resolution, these targets reveal point-like sources surrounded by nebulosity of different morphologies, uncovering details at spatial dimensions of <1000AU. The point-like sources display [ArIII] and [NeII] lines - the ratios of which are used to estimate the temperature of the...

  11. Development of an Ionization Scheme for Gold using the Selective Laser Ion Source at the On-Line Isotope Separator ISOLDE

    CERN Document Server

    Fedosseev, V; Marsh, B A; CERN. Geneva. AB Department

    2006-01-01

    At the ISOLDE on-line isotope separation facility, the resonance ionization laser ion source (RILIS) can be used to ionize reaction products as they effuse from the target. The RILIS process of laser step-wise resonance ionization of atoms in a hot metal cavity provides a highly element selective stage in the preparation of the radioactive ion beam. As a result, the ISOLDE mass separators can provide beams of a chosen isotope with greatly reduced isobaric contamination. The number of elements available at RILIS has been extended to 26, with the addition of a new three-step ionization scheme for gold. The optimal ionization scheme was determined during an extensive study of the atomic energy levels and auto-ionizing states of gold, carried out by means of in-source resonance ionization spectroscopy. Details of the ionization scheme and a summary of the spectroscopy study are presented.

  12. Laboratory and Ambient Measurements of Oxidized Organic Compounds in the Gas Phase Using Nitrate Ion Chemical Ionization Coupled with High Resolution Time-of-Flight Mass Spectrometry

    Science.gov (United States)

    Massoli, P.; Stark, H.; Canagaratna, M. R.; Krechmer, J.; Lambe, A. T.; Isaacman-VanWertz, G. A.; Nowak, J. B.; Kimmel, J.; Kroll, J. H.; Jayne, J. T.; Worsnop, D. R.

    2015-12-01

    Chemical Ionization Mass Spectrometry (CIMS) is a widely used technique for molecular level characterization of inorganic and organic gas phase species. Here we present laboratory and ambient measurements of gaseous organic compounds by means of a High Resolution Time-of-Flight Chemical Ionization Mass Spectrometry (HR-ToF-CIMS) using nitrate ion (NO3-) chemistry, which recently has proven capable of selectively detecting oxidized organic molecules in the gas-phase via clustering with NO3- and its high order clusters. Such low and extremely low volatility organic compounds (LVOC, ELVOC) have an important role in particulate phase chemistry and formation of secondary organic aerosol (SOA). The HR-ToF-CIMS was deployed during the Southern Oxidant and Aerosol Study (SOAS) at the forest site in Centreville, AL (June 1 - July 15, 2013), where emissions were dominated by biogenic volatile organic compounds (BVOC), occasionally mixing with anthropogenic emissions. During SOAS, the HR-ToF-CIMS detected oxidation products of both isoprene (typically C5 LVOC) and terpenes (typically C10 ELVOC). The isoprene-related LVOC showed a diurnal cycle with a day time peak, while two groups of terpene ELVOC were identified, one peaking at night and one peaking during the day. Positive Matrix Factorization (PMF) analyses are applied to the dataset to further interpret these observations. The effect of anthropogenic pollution on the biogenic-dominated environment was also investigated during periods of elevated nitrous and sulfur dioxide levels. To further aid in interpretation of the SOAS dataset, oxidized organic molecules were produced via OH and O3 initiated oxidation of biogenic gas-phase precursors in targeted laboratory studies and detected using the HR-ToF-CIMS. Spectra were obtained in these studies over a range of simulated atmospheric conditions.

  13. Direct and non-destructive proof of authenticity for the 2nd generation of Brazilian real banknotes via easy ambient sonic spray ionization mass spectrometry.

    Science.gov (United States)

    Schmidt, Eduardo Morgado; Franco, Marcos Fernando; Regino, Karen Gomes; Lehmann, Eraldo Luiz; Arruda, Marco Aurélio Zezzi; de Carvalho Rocha, Werickson Fortunato; Borges, Rodrigo; de Souza, Wanderley; Eberlin, Marcos Nogueira; Correa, Deleon Nascimento

    2014-12-01

    Using a desorption/ionization technique, easy ambient sonic-spray ionization coupled to mass spectrometry (EASI-MS), documents related to the 2nd generation of Brazilian Real currency (R$) were screened in the positive ion mode for authenticity based on chemical profiles obtained directly from the banknote surface. Characteristic profiles were observed for authentic, seized suspect counterfeit and counterfeited homemade banknotes from inkjet and laserjet printers. The chemicals in the authentic banknotes' surface were detected via a few minor sets of ions, namely from the plasticizers bis(2-ethylhexyl)phthalate (DEHP) and dibutyl phthalate (DBP), most likely related to the official offset printing process, and other common quaternary ammonium cations, presenting a similar chemical profile to 1st-generation R$. The seized suspect counterfeit banknotes, however, displayed abundant diagnostic ions in the m/z 400-800 range due to the presence of oligomers. High-accuracy FT-ICR MS analysis enabled molecular formula assignment for each ion. The ions were separated by 44 m/z, which enabled their characterization as Surfynol® 4XX (S4XX, XX=40, 65, and 85), wherein increasing XX values indicate increasing amounts of ethoxylation on a backbone of 2,4,7,9-tetramethyl-5-decyne-4,7-diol (Surfynol® 104). Sodiated triethylene glycol monobutyl ether (TBG) of m/z 229 (C10H22O4Na) was also identified in the seized counterfeit banknotes via EASI(+) FT-ICR MS. Surfynol® and TBG are constituents of inks used for inkjet printing.

  14. Portable, Battery Operated Capillary Electrophoresis with Optical Isomer Resolution Integrated with Ionization Source for Mass Spectrometry

    Science.gov (United States)

    Moini, Mehdi; Rollman, Christopher M.

    2016-03-01

    We introduce a battery operated capillary electrophoresis electrospray ionization (CE/ESI) source for mass spectrometry with optical isomer separation capability. The source fits in front of low or high resolution mass spectrometers similar to a nanospray source with about the same weight and size. The source has two high voltage power supplies (±25 kV HVPS) capable of operating in forward or reverse polarity modes and powered by a 12 V rechargeable lithium ion battery with operation time of ~10 h. In ultrafast CE mode, in which short narrow capillaries (≤15 μm i.d., 15-25 cm long) and field gradients ≥1000 V/cm are used, peak widths at the base are <1 s wide. Under these conditions, the source provides high resolution separation, including optical isomer resolution in ~1 min. Using a low resolution mass spectrometer (LTQ Velos) with a scan time of 0.07 s/scan, baseline separation of amino acids and their optical isomers were achieved in ~1 min. Moreover, bovine serum albumin (BSA) was analyzed in ~1 min with 56% coverage using the data-dependent MS/MS. Using a high resolution mass spectrometer (Thermo Orbitrap Elite) with 15,000 resolution, the fastest scan time achieved was 0.15 s, which was adequate for CE-MS analysis when optical isomer separation is not required or when the optical isomers were well separated. Figures of merit including a detection limit of 2 fmol and linear dynamic range of two orders of magnitude were achieved for amino acids.

  15. A perspective on 30 years of progress in ambient noise: Source mechanisms and the characteristics of the sound field

    Science.gov (United States)

    Cato, Douglas H.

    2012-11-01

    The last 30 years has seen substantial progress in ocean ambient noise research, particularly in understanding the mechanisms of sound generation by the sources of ambient noise, the way in which the noise field is affected by sound propagation, and improvements in quantifying the relationship between noise and environmental parameters. This has led to significant improvements in noise prediction. Activity was probably strongest in the 1980s and 1990s, as evident, for example, in the Sea Surface Sound conferences and their published proceedings (four over 10 years). Although much of the application has been to sonar, there has also been interest in using ambient noise to measure properties of the environment and in its significance to marine life. There have been significant changes in the ambient noise itself over the last 30 years. The contribution from human activities appears to have increased, particularly that due to increases in shipping numbers. Biological noise has also increased with the significant increases in populations of some whale species following the cessation of broad scale whaling in the 1960s and early 1970s. Concern about the effects of noise on marine animals as well as the way they exploit the noise has led to renewed interest in ambient noise.

  16. A proposal for a novel H ion source based on electron cyclotron resonance heating and surface ionization

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, Ollie A [Los Alamos National Laboratory; Kurennoy, Sergey [Los Alamos National Laboratory

    2008-01-01

    A design for a novel H{sup -} ion source based on electron cyclotron resonance plasma heating and surface ionization is presented. The plasma chamber of the source is an rf-cavity designed for TE{sub 111} eigenmode at 2.45 GHz. The desired mode is excited with a loop antenna. The ionization process takes place on a cesiated surface of a biased converter electrode. The H{sup -} ion beam is further 'self-extracted' through the plasma region. The magnetic field of the source is optimized for plasma generation by electron cyclotron resonance heating, and beam extraction. The design features of the source are discussed in detail and the attainable H{sup -} ion current, beam emittance and duty factor of the novel source are estimated.

  17. A Proposal for a Novel H- Ion Source Based on Electron Cyclotron Resonance Plasma Heating and Surface Ionization

    Science.gov (United States)

    Tarvainen, O.; Kurennoy, S.

    2009-03-01

    A design for a novel H- ion source based on electron cyclotron resonance plasma heating and surface ionization is presented. The plasma chamber of the source is an rf-cavity designed for TE111 eigenmode at 2.45 GHz. The desired mode is excited with a loop antenna. The ionization process takes place on a cesiated surface of a biased converter electrode. The H- ion beam is further "self-extracted" through the plasma region. The magnetic field of the source is optimized for plasma generation by electron cyclotron resonance heating, and beam extraction. The design features of the source are discussed in detail and the attainable H- ion current, beam emittance and duty factor of the novel source are estimated.

  18. Study on variation of lipids during different growth phases of living cyanobacteria using easy ambient sonic-spray ionization mass spectrometry.

    Science.gov (United States)

    Liu, Yiqun; Zhang, Jialing; Nie, Honggang; Dong, Chunxia; Li, Ze; Zheng, Zhenggao; Bai, Yu; Liu, Huwei; Zhao, Jindong

    2014-07-15

    Lipids are important components of cell membranes and thylakoids in cyanobacteria, and they play vital roles in various biological activities. Real-time tracing of the variation of membrane lipids can provide insights of the physiological status of cyanobacterial cells. In this work, easy ambient sonic-spray ionization mass spectrometry (EASI-MS) was utilized to investigate the changes of acidic lipids in unicellular (Synechocystis 6803, Synechococcus 7002) and filamentous (Anabaena 7120) cyanobacteria during different growth phases. A sqdX mutant with a reduced synthesis of sulfoquinovosyl diacylglycerol (SQDG) was constructed to verify the acquired data of EASI-MS. Principal component analysis (PCA) was performed to compare the acquired data, enabling the discrimination of different species of cyanobacteria in day-to-day analysis. The results showed that the three representative cyanobacteria and their growth status can be easily determined on the basis of the lipids components detected by EASI-MS. Very interestingly, significant decreases of the ratios of SQDG/PG and dramatic changes of the unsaturation level of lipids were observed in different culture times in these cyanobacteria, and these two unique characters can be used describe the aging of cyanobacteria.

  19. Dynamic nonpoint-source pollution control policy: ambient transfers and uncertainty

    OpenAIRE

    Athanassoglou, Stergios

    2009-01-01

    When a regulator cannot observe or infer individual emissions, corrective policy must rely on ambient pollution data. Assuming this kind of environment, we study a class of differential games of pollution control with profit functions that are polynomial in the global pollution stock. Given an open-loop emissions strategy satisfying mild regularity conditions, an ambient transfer scheme is exhibited that induces it in Markov-perfect equilibrium (MPE). Proposed transfers are a polynomial fu...

  20. Atmospheric pressure chemical ionization of explosives using alternating current corona discharge ion source.

    Science.gov (United States)

    Usmanov, D T; Chen, L C; Yu, Z; Yamabe, S; Sakaki, S; Hiraoka, K

    2015-04-01

    The high-sensitive detection of explosives is of great importance for social security and safety. In this work, the ion source for atmospheric pressure chemical ionization/mass spectrometry using alternating current corona discharge was newly designed for the analysis of explosives. An electromolded fine capillary with 115 µm inner diameter and 12 mm long was used for the inlet of the mass spectrometer. The flow rate of air through this capillary was 41 ml/min. Stable corona discharge could be maintained with the position of the discharge needle tip as close as 1 mm to the inlet capillary without causing the arc discharge. Explosives dissolved in 0.5 µl methanol were injected to the ion source. The limits of detection for five explosives with 50 pg or lower were achieved. In the ion/molecule reactions of trinitrotoluene (TNT), the discharge products of NOx (-) (x = 2,3), O3 and HNO3 originating from plasma-excited air were suggested to contribute to the formation of [TNT - H](-) (m/z 226), [TNT - NO](-) (m/z 197) and [TNT - NO + HNO3 ](-) (m/z 260), respectively. Formation processes of these ions were traced by density functional theory calculations. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26149109

  1. Evidence for an Additional Heat Source in the Warm Ionized Medium of Galaxies

    CERN Document Server

    Reynolds, R J; Tufte, S L

    1999-01-01

    Spatial variations of the [S II]/H-Alpha and [N II]/H-Alpha line intensity ratios observed in the gaseous halo of the Milky Way and other galaxies are inconsistent with pure photoionization models. They appear to require a supplemental heating mechanism that increases the electron temperature at low densities n_e. This would imply that in addition to photoionization, which has a heating rate per unit volume proportional to n_e^2, there is another source of heat with a rate per unit volume proportional to a lower power of n_e. One possible mechanism is the dissipation of interstellar plasma turbulence, which according to Minter & Spangler (1997) heats the ionized interstellar medium in the Milky Way at a rate ~ 1x10^-25 n_e ergs cm^-3 s^-1. If such a source were present, it would dominate over photoionization heating in regions where n_e < 0.1 cm^-3, producing the observed increases in the [S II]/H-Alpha and [N II]/H-Alpha intensity ratios at large distances from the galactic midplane, as well as accoun...

  2. Ionization Source of a Minor-axis Cloud in the Outer Halo of M82

    CERN Document Server

    Matsubayashi, K; Shimono, A; Hattori, T; Ozaki, S; Yoshikawa, T; Taniguchi, Y; Nagao, T; Kajisawa, M; Shioya, Y; Bland-Hawthorn, J

    2012-01-01

    The M82 `cap' is a gas cloud at a projected radius of 11.6 kpc along the minor axis of this well known superwind source. The cap has been detected in optical line emission and X-ray emission and therefore provides an important probe of the wind energetics. In order to investigate the ionization source of the cap, we observed it with the Kyoto3DII Fabry-Perot instrument mounted on the Subaru Telescope. Deep continuum, Ha, [NII]6583/Ha, and [SII]6716,6731/Ha maps were obtained with sub-arcsecond resolution. The superior spatial resolution compared to earlier studies reveals a number of bright Ha emitting clouds within the cap. The emission line widths ( 60%), i.e., an order of magnitude higher than observed in dwarf galaxies to date. Using these results, we discuss the evolutionary history of the M82 superwind. Future UV/X-ray surveys are expected to confirm that the temperature of the gas is consistent with our moderate shock model.

  3. Design and performance of a high-flux electrospray ionization source for ion soft landing.

    Science.gov (United States)

    Gunaratne, K Don D; Prabhakaran, Venkateshkumar; Ibrahim, Yehia M; Norheim, Randolph V; Johnson, Grant E; Laskin, Julia

    2015-05-01

    We report the design and evaluation of a new high-intensity electrospray ionization source for ion soft-landing experiments. The source incorporates a dual ion funnel, which enables operation with a higher gas load through an expanded diameter heated inlet into the additional first region of differential pumping. This capability allowed us to examine the effect of the inner diameter (ID) of the heated stainless steel inlet on the total ion current transmitted through the dual funnel interface and, more importantly, the mass-selected ion current delivered to the deposition target. The ion transmission of the dual funnel is similar to the transmission of the single funnel used in our previous soft landing studies. However, substantially higher ion currents were obtained using larger ID heated inlets and an orthogonal inlet geometry, in which the heated inlet was positioned perpendicular to the direction of ion propagation through the instrument. The highest ion currents were obtained using the orthogonal geometry and a 1.4 mm ID heated inlet. The corresponding stable deposition rate of ∼1 μg of mass-selected ions per day will facilitate future studies focused on the controlled deposition of complex molecules on substrates for studies in catalysis, energy storage, and self-assembly.

  4. Where are all of the nebulae ionized by supersoft X-ray sources?

    CERN Document Server

    Woods, T E

    2015-01-01

    Accreting, steadily nuclear-burning white dwarfs are associated with so-called close-binary supersoft X-ray sources (SSSs), observed to have temperatures of a few$\\times 10^{5}$K and luminosities on the order of $10^{38}$erg/s. These and other types of SSSs are expected to be capable of ionizing their surrounding circumstellar medium, however, to date only one such nebula was detected in the Large Magellanic Cloud (of its 6 known close-binary SSSs), surrounding the accreting, nuclear-burning WD CAL 83. This has led to the conclusion that most SSSs cannot have been both luminous ($\\gtrsim 10^{37}$erg/s) and hot ($\\gtrsim$ few $\\times 10^{4}$K) for the majority of their past accretion history, unless the density of the ISM surrounding most sources is much less than that inferred for the CAL 83 nebula (4--10$\\rm{cm}^{-3}$). Here we demonstrate that most SSSs must lie in much lower density media than CAL 83. Past efforts to detect such nebulae have not accounted for the structure of the ISM in star-forming galaxi...

  5. Design of 1+ Ion Source Coupling First Design of the Resonant Ionization Laser Ion Source For the Multi-Mega Watt Target Station

    CERN Document Server

    A. Olivier, F. Le Blanc, C. Lau

    The realisation of next-generation ion sources suitable for the EURISOL multi-mega-watt (MMW) target station needs exhaustive studies and developments. An exhaustive review was carried out to evaluate the capability of the ion-sources to operate under the irradiation conditions of the MMW target station. In addition, selectivity must be taken into account to avoid the spread of unwanted radioactivity out of the target-ion-source system (TIS).These studies led to consider RILIS (Resonance Ionization Laser Ion Source) as the reference ion source for this target station.

  6. Calculation of Ambient (H*(10)) and Personal (Hp(10)) Dose Equivalent from a 252Cf Neutron Source

    Energy Technology Data Exchange (ETDEWEB)

    Traub, Richard J.

    2010-03-26

    The purpose of this calculation is to calculate the neutron dose factors for the Sr-Cf-3000 neutron source that is located in the 318 low scatter room (LSR). The dose factors were based on the dose conversion factors published in ICRP-21 Appendix 6, and the Ambient dose equivalent (H*(10)) and Personal dose equivalent (Hp(10)) dose factors published in ICRP Publication 74.

  7. Effects of noise from non-traffic-related ambient sources on sleep: Review of the literature of 1990-2010

    OpenAIRE

    Sarah Omlin; Bauer, Georg F.; Mark Brink

    2011-01-01

    This article reviews the literature about the effects of specific non-traffic-related ambient noise sources on sleep that appeared in the last two decades. Although everybody is faced with noise of non-traffic and non-industry origin (e.g. sounds made by neighbors, talk, laughter, music, slamming doors, structural equipment, ventilation, heat pumps, noise from animals, barking dogs, outdoor events etc.), little scientific knowledge exists about its effects on sleep. The findings of the presen...

  8. Model of ionization equilibrium for a source of multiply charged ions of E.C.R. type

    International Nuclear Information System (INIS)

    An attempt is made to find a theoretical model which would describe the mecahnism inherent to a multiply charged heavy ion source with continuous extraction. The processes of radiative recombination are negligible and it thus results an ionization equilibrium governed by ionization and diffusion not very far from the 'coronal' equilibrium. We propose to put into evidence that the lifetime tausub(Z) of an ion of charge Z varies as Z3. The theoretical ion charge distributions will be compared with those obtained experimentally in the case of an Argon beam

  9. Strong Orientation Effects in Ionization of H$_2^+$ by Short, Intense, High-Frequency Light Sources

    OpenAIRE

    Selsto, S.; Forre, M.; Hansen, J. P.; Madsen, L. B.

    2005-01-01

    We present three dimensional time-dependent calculations of ionization of arbitrarily spatially oriented H$_2^+$ by attosecond, intense, high-frequency laser fields. The ionization probability shows a strong dependence on both the internuclear distance and the relative orientation between the laser field and the internuclear axis.

  10. A New Diagnostic Diagram of Ionization Source for High Redshift Emission Line Galaxies

    CERN Document Server

    Zhang, Kai

    2016-01-01

    We propose a new diagram, the Kinematic-Excitation diagram (KEx diagram), which uses the [OIII]/H\\beta\\ line ratio and the [OIII]5007 emission line width (\\sigma_{[OIII]}) to diagnose the ionization source and physical properties of the Active Galactic Nuclei (AGNs) and the star-forming galaxies (SFGs). The KEx diagram is a suitable tool to classify emission-line galaxies (ELGs) at intermediate redshift because it uses only the [OIII]5007 and H\\beta\\ emission lines. We use the SDSS DR7 main galaxy sample and the Baldwin-Phillips-Terlevich (BPT) diagnostic to calibrate the diagram at low redshift. We find that the diagram can be divided into 3 regions: one occupied mainly by the pure AGNs (KEx-AGN region), one dominated by composite galaxies (KEx-composite region), and one contains mostly SFGs (KEx-SFG region). AGNs are separated from SFGs in this diagram mainly because they preferentially reside in luminous and massive galaxies and have high [OIII]/H\\beta. The separation of AGN from star-forming galaxies is e...

  11. Dust particle charge screening in the dry-air plasma produced by an external ionization source

    Energy Technology Data Exchange (ETDEWEB)

    Derbenev, I. N.; Filippov, A. V., E-mail: fav@triniti.ru [State Research Center of the Russian Federation Troitsk Institute for Innovation and Fusion Research (Russian Federation)

    2015-08-15

    The ionic composition of the plasma produced by an external ionization source in dry air at atmospheric pressure and room temperature and the screening of the electric field of a dust particle in such a plasma have been investigated. The point sink model based on the diffusion-drift approximation has been used to solve the screening problem. We have established that the main species of ions in the plasma under consideration are O{sub 4}{sup +}, O{sub 2}{sup -}, and O{sub 4}{sup -} and that the dust particle potential distribution is described by a superposition of four exponentials with four different constants. We show that the first constant coincides with the inverse Debye length, the second is described by the inverse ambipolar diffusion length of the positive and negative plasma components in the characteristic time of their recombination, the third is determined by the conversion of negative ions, and the fourth is determined by the attachment and recombination of electrons and diatomic ions.

  12. Development of a short pulsed corona discharge ionization source for ion mobility spectrometry

    International Nuclear Information System (INIS)

    The development of a pulsed corona discharge ionization source and its use in ion mobility spectrometry (IMS) is presented. In a point-plane electrode geometry, an electrical pulse up to 12 kV, 150 ns rise time and 500 ns pulse width was used to generate a corona discharge in air. A single positive high voltage pulse was able to generate about 1.6x1010 ions at energy consumption of 22 μJ. Since the temporal distribution of ions is in a pulsed form, the possibility of removal the ion gate has been investigated. By purposely arranging the interface between discharge field and drift field, nearly 107 positive ions were drawn into the drift region with absence of the ion gate after every single discharge. The positive spectrum of acetone dimer (working at room temperature) was obtained with a resolving power of 20 by using this configuration. The advantages of this new scheme are the low power consumption compared with the dc method as well as the simplicity of the IMS cell structure

  13. Long term response stability of a well-type ionization chamber used in calibration of high dose rate brachytherapy sources

    Directory of Open Access Journals (Sweden)

    Vandana S

    2010-01-01

    Full Text Available Well-type ionization chamber is often used to measure strength of brachytherapy sources. This study aims to check long term response stability of High Dose Rate (HDR -1000 Plus well-type ionization chamber in terms of reference air kerma rate (RAKR of a reference 137 Cs brachytherapy source and recommend an optimum frequency of recalibration. An HDR-1000 Plus well-type ionization chamber, a reference 137 Cs brachytherapy source (CDCSJ5, and a MAX-4000 electrometer were used in this study. The HDR-1000 Plus well-type chamber was calibrated in terms of reference air kerma rate by the Standards Laboratory of the International Atomic Energy Agency (IAEA, Vienna. The response of the chamber was verified at regular intervals over a period of eight years using the reference 137 Cs source. All required correction factors were applied in the calculation of the RAKR of the 137 Cs source. This study reveals that the response of the HDR-1000 Plus well-type chamber was well within ±0.5% for about three years after calibration/recalibration. However, it shows deviations larger than ±0.5% after three years of calibration/recalibration and the maximum variation in response of the chamber during an eight year period was 1.71%. The optimum frequency of recalibration of a high dose rate well-type chamber should be three years.

  14. Long term response stability of a well-type ionization chamber used in calibration of high dose rate brachytherapy sources.

    Science.gov (United States)

    Vandana, S; Sharma, S D

    2010-04-01

    Well-type ionization chamber is often used to measure strength of brachytherapy sources. This study aims to check long term response stability of High Dose Rate (HDR)-1000 Plus well-type ionization chamber in terms of reference air kerma rate (RAKR) of a reference (137)Cs brachytherapy source and recommend an optimum frequency of recalibration. An HDR-1000 Plus well-type ionization chamber, a reference (137)Cs brachytherapy source (CDCSJ5), and a MAX-4000 electrometer were used in this study. The HDR-1000 Plus well-type chamber was calibrated in terms of reference air kerma rate by the Standards Laboratory of the International Atomic Energy Agency (IAEA), Vienna. The response of the chamber was verified at regular intervals over a period of eight years using the reference (137)Cs source. All required correction factors were applied in the calculation of the RAKR of the (137)Cs source. This study reveals that the response of the HDR-1000 Plus well-type chamber was well within +/-0.5% for about three years after calibration/recalibration. However, it shows deviations larger than +/-0.5% after three years of calibration/recalibration and the maximum variation in response of the chamber during an eight year period was 1.71%. The optimum frequency of recalibration of a high dose rate well-type chamber should be three years.

  15. Ion mobility spectrometric analysis of vaporous chemical warfare agents by the instrument with corona discharge ionization ammonia dopant ambient temperature operation.

    Science.gov (United States)

    Satoh, Takafumi; Kishi, Shintaro; Nagashima, Hisayuki; Tachikawa, Masumi; Kanamori-Kataoka, Mieko; Nakagawa, Takao; Kitagawa, Nobuyoshi; Tokita, Kenichi; Yamamoto, Soichiro; Seto, Yasuo

    2015-03-20

    The ion mobility behavior of nineteen chemical warfare agents (7 nerve gases, 5 blister agents, 2 lachrymators, 2 blood agents, 3 choking agents) and related compounds including simulants (8 agents) and organic solvents (39) was comparably investigated by the ion mobility spectrometry instrument utilizing weak electric field linear drift tube with corona discharge ionization, ammonia doping, purified inner air drift flow circulation operated at ambient temperature and pressure. Three alkyl methylphosphonofluoridates, tabun, and four organophosphorus simulants gave the intense characteristic positive monomer-derived ion peaks and small dimer-derived ion peaks, and the later ion peaks were increased with the vapor concentrations. VX, RVX and tabun gave both characteristic positive monomer-derived ions and degradation product ions. Nitrogen mustards gave the intense characteristic positive ion peaks, and in addition distinctive negative ion peak appeared from HN3. Mustard gas, lewisite 1, o-chlorobenzylidenemalononitrile and 2-mercaptoethanol gave the characteristic negative ion peaks. Methylphosphonyl difluoride, 2-chloroacetophenone and 1,4-thioxane gave the characteristic ion peaks both in the positive and negative ion mode. 2-Chloroethylethylsulfide and allylisothiocyanate gave weak ion peaks. The marker ion peaks derived from two blood agents and three choking agents were very close to the reactant ion peak in negative ion mode and the respective reduced ion mobility was fluctuated. The reduced ion mobility of the CWA monomer-derived peaks were positively correlated with molecular masses among structurally similar agents such as G-type nerve gases and organophosphorus simulants; V-type nerve gases and nitrogen mustards. The slope values of the calibration plots of the peak heights of the characteristic marker ions versus the vapor concentrations are related to the detection sensitivity, and within chemical warfare agents examined the slope values for sarin, soman

  16. Characterization and source apportionment of health risks from ambient PM10 in Hong Kong over 2000-2011

    Science.gov (United States)

    Li, Zhiyuan; Yuan, Zibing; Li, Ying; Lau, Alexis K. H.; Louie, Peter K. K.

    2015-12-01

    Atmospheric particulate matter (PM) pollution is a major public health concern in Hong Kong. In this study, the spatiotemporal variations of health risks from ambient PM10 from seven air quality monitoring stations between 2000 and 2011 were analyzed. Positive matrix factorization (PMF) was adopted to identify major source categories of ambient PM10 and quantify their contributions. Afterwards, a point-estimated risk model was used to identify the inhalation cancer and non-cancer risks of PM10 sources. The long-term trends of the health risks from classified local and non-local sources were explored. Furthermore, the reason for the increase of health risks during high PM10 days was discussed. Results show that vehicle exhaust source was the dominant inhalation cancer risk (ICR) contributor (72%), whereas trace metals and vehicle exhaust sources contributed approximately 27% and 21% of PM10 inhalation non-cancer risk (INCR), respectively. The identified local sources accounted for approximately 80% of the ICR in Hong Kong, while contribution percentages of the non-local and local sources for INCR are comparable. The clear increase of ICR at high PM days was mainly attributed to the increase of contributions from coal combustion/biomass burning and secondary sulfate, while the increase of INCR at high PM days was attributed to the increase of contributions from the sources coal combustion/biomass burning, secondary nitrate, and trace metals. This study highlights the importance of health risk-based source apportionment in air quality management with protecting human health as the ultimate target.

  17. Declaration and authorization forms for the fabrication, distribution or use of radioactive sources or electric generators of ionizing radiation

    International Nuclear Information System (INIS)

    This document gathers all the forms to be completed when declaring or when asking for an authorization for the fabrication, retailing or use of radioactive sources or electric equipment generating ionizing radiation. These forms can concern all domains (use of sealed radioactive sources, possession and use of a particle accelerator or of radionuclides, import or export of radionuclides or of products containing radionuclides), or the use of such materials or equipment in the medical sector, or the fabrication and use in industry or research, or in user's guides for radioactive sources

  18. Effects of noise from non-traffic-related ambient sources on sleep: Review of the literature of 1990-2010

    Directory of Open Access Journals (Sweden)

    Sarah Omlin

    2011-01-01

    Full Text Available This article reviews the literature about the effects of specific non-traffic-related ambient noise sources on sleep that appeared in the last two decades. Although everybody is faced with noise of non-traffic and non-industry origin (e.g. sounds made by neighbors, talk, laughter, music, slamming doors, structural equipment, ventilation, heat pumps, noise from animals, barking dogs, outdoor events etc., little scientific knowledge exists about its effects on sleep. The findings of the present extensive literature search and review are as follows: Only a small number of surveys, laboratory and field studies about mainly neighborhood, leisure and animal noise have been carried out. Most of them indicate that ambient noise has some effect on human sleep. However, a quantitative meta-analysis and comparison is not possible due to the small number of studies available and at times large differences in quality.

  19. Effects of noise from non-traffic-related ambient sources on sleep: review of the literature of 1990-2010.

    Science.gov (United States)

    Omlin, Sarah; Bauer, Georg F; Brink, Mark

    2011-01-01

    This article reviews the literature about the effects of specific non-traffic-related ambient noise sources on sleep that appeared in the last two decades. Although everybody is faced with noise of non-traffic and non-industry origin (e.g. sounds made by neighbors, talk, laughter, music, slamming doors, structural equipment, ventilation, heat pumps, noise from animals, barking dogs, outdoor events etc.), little scientific knowledge exists about its effects on sleep. The findings of the present extensive literature search and review are as follows: Only a small number of surveys, laboratory and field studies about mainly neighborhood, leisure and animal noise have been carried out. Most of them indicate that ambient noise has some effect on human sleep. However, a quantitative meta-analysis and comparison is not possible due to the small number of studies available and at times large differences in quality. PMID:21768734

  20. Visualization of Ambient Mass Spectrometry with the Use of Schlieren Photography.

    Science.gov (United States)

    Winter, Gregory T; Wilhide, Joshua A; LaCourse, William R

    2016-01-01

    This manuscript outlines how to visualize mass spectrometry ambient ionization sources using schlieren photography. In order to properly optimize the mass spectrometer, it is necessary to characterize and understand the physical principles of the source. Most commercial ambient ionization sources utilize jets of nitrogen, helium, or atmospheric air to facilitate the ionization of the analyte. As a consequence, schlieren photography can be used to visualize the gas streams by exploiting the differences in refractive index between the streams and ambient air for visualization in real time. The basic setup requires a camera, mirror, flashlight, and razor blade. When properly configured, a real time image of the source is observed by watching its reflection. This allows for insight into the mechanism of action in the source, and pathways to its optimization can be elucidated. Light is shed on an otherwise invisible situation. PMID:27404400

  1. Sources and Levels of Ambient Ocean Sound near the Antarctic Peninsula

    OpenAIRE

    Dziak, Robert P.; Bohnenstiehl, DelWayne R.; Stafford, Kathleen M.; Haruyoshi Matsumoto; Minkyu Park; Won Sang Lee; Fowler, Matt J.; Tai-Kwan Lau; Haxel, Joseph H.; Mellinger, David K.

    2015-01-01

    Arrays of hydrophones were deployed within the Bransfield Strait and Scotia Sea (Antarctic Peninsula region) from 2005 to 2009 to record ambient ocean sound at frequencies of up to 125 and 500 Hz. Icequakes, which are broadband, short duration signals derived from fracturing of large free-floating icebergs, are a prominent feature of the ocean soundscape. Icequake activity peaks during austral summer and is minimum during winter, likely following freeze-thaw cycles. Iceberg grounding and rapi...

  2. The non-uniformity correction factor for the cylindrical ionization chambers in dosimetry of an HDR 192Ir brachytherapy source

    Directory of Open Access Journals (Sweden)

    Majumdar Bishnu

    2006-01-01

    Full Text Available The aim of this study is to derive the non-uniformity correction factor for the two therapy ionization chambers for the dose measurement near the brachytherapy source. The two ionization chambers of 0.6 cc and 0.1 cc volume were used. The measurement in air was performed for distances between 0.8 cm and 20 cm from the source in specially designed measurement jig. The non-uniformity correction factors were derived from the measured values. The experimentally derived factors were compared with the theoretically calculated non-uniformity correction factors and a close agreement was found between these two studies. The experimentally derived non-uniformity correction factor supports the anisotropic theory.

  3. Critical review and meta-analysis of ambient particulate matter source apportionment using receptor models in Europe

    Science.gov (United States)

    Belis, C. A.; Karagulian, F.; Larsen, B. R.; Hopke, P. K.

    2013-04-01

    A review was conducted of the published literature on source apportionment of ambient particulate matter (PM) in Europe using receptor models (RMs). Consistent records were identified for source contribution estimates of PM mass concentrations for 272 records and of organic carbon (OC) in PM for 60 records. Over the period 2000-2012, a shift was observed in the use of RMs from principal component analysis, enrichment factors, and classical factor analysis to Positive Matrix Factorization while Chemical Mass Balance is still topical. Following a meta-analysis of the published results, six major source categories for PM were defined that comprise almost all individual sources apportioned in Europe: atmospheric formation of secondary inorganic aerosol (SIA), traffic, re-suspension of crustal/mineral dust, biomass burning, (industrial) point sources, and sea/road salt. For the OC fraction, the three main source categories were: atmospheric formation of secondary organic aerosol, biomass burning, and fossil fuel combustion. The geographical and seasonal variations of these sources are mapped and discussed. A special analysis of PM concentrations that exceed the current European air quality limits indicated SIA and traffic as the most important source categories to target for abatement throughout the year together with biomass burning during the cold season.

  4. Plasma diagnosis as a tool for the determination of the parameters of electron beam evaporation and sources of ionization

    Science.gov (United States)

    Mukherjee, Jaya; Dileep Kumar, V.; Yadav, S. P.; Barnwal, Tripti A.; Dikshit, Biswaranjan

    2016-07-01

    The atomic vapor generated by electron beam heating is partially ionized due to atom-atom collisions (Saha ionization) and electron impact ionization, which depend upon the source temperature and area of evaporation as compared to the area of electron beam bombardment on the target. When electron beam evaporation is carried out by inserting the target inside an insulating liner to reduce conductive heat loss, it is expected that the area of evaporation becomes significantly more than the area of electron beam bombardment on the target, resulting in reduced electron impact ionization. To assess this effect and to quantify the parameters of evaporation, such as temperature and area of evaporation, we have carried out experiments using zirconium, tin and aluminum as a target. By measuring the ion content using a Langmuir probe, in addition to measuring the atomic vapor flux at a specific height, and by combining the experimental data with theoretical expressions, we have established a method for simultaneously inferring the source temperature, evaporation area and ion fraction. This assumes significance because the temperature cannot be reliably measured by an optical pyrometer due to the wavelength dependent source emissivity and reflectivity of thin film mirrors. In addition, it also cannot be inferred from only the atomic flux data at a certain height as the area of evaporation is unknown (it can be much more than the area of electron bombardment, especially when the target is placed in a liner). Finally, the reason for the lower observed electron temperatures of the plasma for all the three cases is found to be the energy loss due to electron impact excitation of the atomic vapor during its expansion from the source.

  5. The fingerprints of photoionization and shock-ionization in two CSS sources

    Science.gov (United States)

    Reynaldi, Victoria; Feinstein, Carlos

    2016-01-01

    We investigate the ionization state of the extended emission-line regions (EELRs) around two compact steep-spectrum (CSS) radio galaxies, 3C 268.3 and 3C 303.1, in order to identify the contribution of photoionization and shock-ionization. We perform a new spectroscopical (long-slit) analysis with GMOS/Gemini with the slit oriented in the radio-jet direction, where outflows are known to exist. The [Ne V] λ3426 emission is the most interesting feature of the spectra and the one key to breaking the degeneracy between the models: since this emission-line is more extended than He II, it challenges the ionization structure proposed by any photoionization model, also its intensity relative to H β does not behave as expected with respect to the ionization parameter U in the same scenario. On the contrary, when it is compared to the intensity of [O II] λ3727/H β and all these results are joined, the whole scenario is plausible to be explained as emission coming from the hot, compressed, shocked gas in shock-ionization models. Although the model fitting is strongly sensitive to the chosen line ratios, it argues for the presence of external and strong ionizing fields, such as the precursor field created by the shock or/and the AGN radiation field. In this paper, we show how AGN photoionization and shock-ionization triggered by jet-cloud interaction work together in these EELRs in order to explain the observed trends and line-ratio behaviours in a kinematically acceptable way.

  6. Management of ionizing radiation sources in university, medical and industrial environments; Gestion des sources ionisantes en milieux universitaire, medical et industriel

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    This conference treats several subjects relative to the use of radioactive sources. The first session comprises three articles about ionizing sources and regulation. The second session, with three articles, tackles the question of radiation protection in the use of sources in industrial field. The third session, four articles, treats the same question but in the medicine and university media. The fourth session (three articles) is devoted to the organisation of radiation protection in the case of accidents. The fifth session concerns the management of spent sources (three articles). The sixth session studies the radiation protection of sources in Europe. The seventh and final session ends with the part and coordination of actors in radiation protection in the sources management (three articles). (N.C.)

  7. Trends in selected ambient volatile organic compound (VOC) concentrations and a comparison to mobile source emission trends in California's South Coast Air Basin

    Science.gov (United States)

    Pang, Yanbo; Fuentes, Mark; Rieger, Paul

    2015-12-01

    Trends in ambient concentrations of Volatile Organic Compounds (VOC) in the South Coast Air Basin (SoCAB) are compared to trends in VOC emissions from Light-Duty Gasoline Vehicles (LDGV) tested on chassis dynamometers and to trends observed in tunnel studies during the same period to understand the impacts of gasoline vehicle emissions on ambient VOC concentrations from 1999 to 2009. Annual median concentrations for most ambient VOCs decreased 40% from 1999 to 2009 in the SoCAB, based on data from the Photochemical Assessment Monitoring Stations (PAMS). Annual concentration decreases of most compounds, except 2,2,4-trimethylpentane, are highly correlated with the decrease of acetylene, a marker for tailpipe emissions from LDGV. This indicates that ambient VOC concentration decreases were likely due to tailpipe emission reductions from gasoline vehicles. Air Toxics Monitoring Network data also support this conclusion. Benzene concentration-normalized ratios for most compounds except ethane, propane, isoprene, and 2,2,4-trimethylpentane were stable even as these compound concentrations decreased significantly from 1999 to 2009. Such stability suggests that the main sources of ambient VOC were still the same from 1999 to 2009. The comparison of trends in dynamometer testing and tunnel studies also shows that tailpipe emissions remained the dominant source of tunnel LDGV emissions. The pronounced changes in 2,2,4-trimethylpentane ratios due to the introduction of Phase 3 gasoline also confirm the substantial impact of LDGV emissions on ambient VOCs. Diurnal ambient VOC data also suggest that LDGV tailpipe emissions remained the dominant source of ambient VOCs in the SoCAB in 2009. Our conclusion, which is that current inventory models underestimate VOC emissions from mobile sources, is consistent with that of several recent studies of ambient trends in the SoCAB. Our study showed that tailpipe emissions remained a bigger contributor to ambient VOCs than evaporative

  8. Characterization and Application of Microplasma Devices for Ambient Mass Spectrometry and Surface Analysis

    Science.gov (United States)

    Symonds, Joshua; Gann, Reuben; Fernández, Facundo; Orlando, Thomas

    2012-10-01

    In ambient mass spectrometry, ionization sources with broad chemical compatibility, low fragmentation, and high reliability are one of the keys necessary to enable effective and rapid analysis of unknown samples. One such approach, employing a variety of ambient-pressure microplasma discharges, has demonstrated itself to be a promising technique with a variety of successful applications and results. This class of devices holds a competitive edge over alternative ambient ionization methods when cost and portability are a concern: microplasmas typically require only modest electrical power and minimal gas flows to operate. We have developed our own such devices and methods, and look more closely into the physical nature of what makes particular designs successful. We focus on the development of these devices to perform mass spectrometry imaging in tandem with optical microscope imaging of samples at ambient pressure. Additionally, we investigate the use of microplasma devices for production of VUV photons, another highly effective ionization source.

  9. Effects of Ionizing Radiations on the Haematopoietic Tissue. Proceedings of a Panel on the Effects of Various Types of Ionizing Radiations from Different Sources on Haematopoietic Tissue

    International Nuclear Information System (INIS)

    The atomic energy industry and the medical sciences are making increasing use of gamma and X-irradiation as well as neutron, proton and mixed irradiation of high-energy particles from reactors, both in research work and in the treatment of patients. For this reason the need for a more detailed investigation of the influence of different sources of irradiation on the haematopoietic tissue becomes more urgent from day to day. This task should no longer be considered as a purely scientific one, but rather as a matter of practical application, since an understanding of the radiosensitivity of haematopoietic tissue is essential in treating patients by X-ray or other radioactive therapies, as well as in treating persons involved in radiation accidents, particularly where bone-marrow or organ transplantation is necessary. A panel of experts on ''The Effects of Various Types of Ionizing Radiations from Different Sources on Haematopoietic Tissue'' was convened by the International Atomic Energy Agency at its headquarters in Vienna from 17 to 20 May, 1966. The meeting was attended by 22 experts from 13 countries. The object was to discuss (1) the facts and concepts of normal haematopoiesis and its regulation, (2) the qualitative and quantitative aspects of the effects of conventional radiation sources on haematopoiesis, and (3) the comparative reactions of haematopoietic tissue from different animals after irradiation. The meeting produced a stimulating exchange of ideas, as is witnessed by this publication, which contains all the papers and discussions

  10. Source apportionment of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in ambient air of an industrial region in Turkey

    Science.gov (United States)

    Aydin, Yagmur Meltem; Kara, Melik; Dumanoglu, Yetkin; Odabasi, Mustafa; Elbir, Tolga

    2014-11-01

    Source apportionment is generally applied to a time series of data collected at a single site. However, in a complex airshed containing several different sources, it may be helpful to collect samples from multiple sites to ensure that some of them have low contributions from specific sources, thus the boundaries can be properly defined. Ambient air polycyclic aromatic hydrocarbon (PAH) and polychlorinated biphenyls (PCB) samples (n = 160) were collected at 40 sites during four seasons (summer, fall, winter, and spring) between July 2009 and April 2010 in the heavily industrialized Aliaga region in Turkey to investigate their spatial, seasonal variations and to identify possible PAH and PCB sources. The newest version of EPA PMF (V5.0) having the capability of handling multiple site data was used for source apportionment. Five PAH sources were identified as biomass and coal combustion, iron-steel production, unburned crude oil and petroleum products, and diesel and gasoline exhaust emissions with contributions of 40, 27, 27, 3, and 3%, respectively. The sources of PCBs were identified as iron-steel production (consisting of steel-making and ship breaking activities), coal and wood combustion, and evaporative emissions from technical PCB mixtures with contributions of 57, 31, and 12%, respectively.

  11. Thermoelectric power source utilizing ambient energy harvesting for remote sensing and transmitting

    Science.gov (United States)

    DeSteese, John G

    2010-11-16

    A method and apparatus for providing electrical energy to an electrical device wherein the electrical energy is originally generated from temperature differences in an environment having a first and a second temperature region. A thermoelectric device having a first side and a second side wherein the first side is in communication with a means for transmitting ambient thermal energy collected or rejected in the first temperature region and the second side is in communication with the second temperature region thereby producing a temperature gradient across the thermoelectric device and in turn generating an electrical current.

  12. Accurate mass fragment library for rapid analysis of pesticides on produce using ambient pressure desorption ionization with high-resolution mass spectrometry.

    Science.gov (United States)

    Kern, Sara E; Lin, Lora A; Fricke, Frederick L

    2014-08-01

    U.S. food imports have been increasing steadily for decades, intensifying the need for a rapid and sensitive screening technique. A method has been developed that uses foam disks to sample the surface of incoming produce. This work provides complimentary information to the extensive amount of published pesticide fragmentation data collected using LCMS systems (Sack et al. Journal of Agricultural and Food Chemistry, 59, 6383-6411, 2011; Mol et al. Analytical and Bioanalytical Chemistry, 403, 2891-2908, 2012). The disks are directly analyzed using transmission-mode direct analysis in real time (DART) ambient pressure desorption ionization coupled to a high resolution accurate mass-mass spectrometer (HRAM-MS). In order to provide more certainty in the identification of the pesticides detected, a library of accurate mass fragments and isotopes of the protonated parent molecular ion (the [M+H]⁺) has been developed. The HRAM-MS is equipped with a quadrupole mass filter, providing the capability of "data-dependent" fragmentation, as opposed to "all -ion" fragmentation (where all of the ions enter a collision chamber and are fragmented at once). A temperature gradient for the DART helium stream and multiple collision energies were employed to detect and fragment 164 pesticides of varying chemical classes, sizes, and polarities. The accurate mass information of precursor ([M+H]⁺ ion) and fragment ions is essential in correctly identifying chemical contaminants on the surface of imported produce. Additionally, the inclusion of isotopes of the [M+H]⁺ in the database adds another metric to the confirmation process. The fragmentation data were collected using a Q-Exactive mass spectrometer and were added to a database used to process data collected with an Exactive mass spectrometer, an instrument that is more readily available for this screening application. The commodities investigated range from smooth-skinned produce such as apples to rougher surfaces like broccoli

  13. Accurate Mass Fragment Library for Rapid Analysis of Pesticides on Produce Using Ambient Pressure Desorption Ionization with High-Resolution Mass Spectrometry

    Science.gov (United States)

    Kern, Sara E.; Lin, Lora A.; Fricke, Frederick L.

    2014-08-01

    U.S. food imports have been increasing steadily for decades, intensifying the need for a rapid and sensitive screening technique. A method has been developed that uses foam disks to sample the surface of incoming produce. This work provides complimentary information to the extensive amount of published pesticide fragmentation data collected using LCMS systems (Sack et al. Journal of Agricultural and Food Chemistry, 59, 6383-6411, 2011; Mol et al. Analytical and Bioanalytical Chemistry, 403, 2891-2908, 2012). The disks are directly analyzed using transmission-mode direct analysis in real time (DART) ambient pressure desorption ionization coupled to a high resolution accurate mass-mass spectrometer (HRAM-MS). In order to provide more certainty in the identification of the pesticides detected, a library of accurate mass fragments and isotopes of the protonated parent molecular ion (the [M+H]+) has been developed. The HRAM-MS is equipped with a quadrupole mass filter, providing the capability of "data-dependent" fragmentation, as opposed to "all -ion" fragmentation (where all of the ions enter a collision chamber and are fragmented at once). A temperature gradient for the DART helium stream and multiple collision energies were employed to detect and fragment 164 pesticides of varying chemical classes, sizes, and polarities. The accurate mass information of precursor ([M+H]+ ion) and fragment ions is essential in correctly identifying chemical contaminants on the surface of imported produce. Additionally, the inclusion of isotopes of the [M+H]+ in the database adds another metric to the confirmation process. The fragmentation data were collected using a Q-Exactive mass spectrometer and were added to a database used to process data collected with an Exactive mass spectrometer, an instrument that is more readily available for this screening application. The commodities investigated range from smooth-skinned produce such as apples to rougher surfaces like broccoli. The

  14. Group and phase velocities from deterministic and ambient sources measured during the AlpArray-EASI experiment

    Science.gov (United States)

    Kolínský, Petr; Zigone, Dimitri; Fuchs, Florian; Bianchi, Irene; Qorbani, Ehsan; Apoloner, Maria-Theresia; Bokelmann, Götz; AlpArray-EASI Working Group

    2016-04-01

    The Eastern Alpine Seismic Investigation (EASI) was a complementary experiment to the AlpArray project. EASI was composed of 55 broadband seismic stations deployed in a winding swath of 540 km length along longitude 13.350 E from the Czech-German border to the Adriatic Sea. Average north-south inter-station distance was 10 km, the distance of each station to either side of the central line was 6 km. Such a dense linear network allows for surface wave dispersion measurements by both deterministic and ambient noise sources along the same paths. During the experiment (July 2014 - August 2015), three earthquakes ML = 2.6, 2.9 and 4.2 occurred in Austria and Northern Italy only several kilometers off the swath. We measure Rayleigh and Love wave group velocities between the source and a single station for the recorded earthquakes, as well as phase velocities between selected pairs of stations using the standard two-station method. We also calculate cross-correlations of ambient noise between selected pairs of stations and we determine the corresponding group velocity dispersion curves. We propose a comparison of phase velocities between two stations measured from earthquakes with group velocities obtained from cross-correlations for the same station pairs. We also compare group velocities measured at single station using earthquakes, which occurred along the swath, with group velocities measured from cross-correlations. That way we analyze velocities of both deterministic and ambient noise reconstructed surface waves propagating along the same path. We invert the resulting dispersion curves for 1D shear wave velocity profiles with depth and we compile a quasi-2D velocity model along the EASI swath.

  15. A corona discharge atmospheric pressure chemical ionization source with selective NO(+) formation and its application for monoaromatic VOC detection.

    Science.gov (United States)

    Sabo, Martin; Matejčík, Štefan

    2013-11-21

    We have developed a new type of corona discharge (CD) for atmospheric pressure chemical ionization (APCI) for application in ion mobility spectrometry (IMS) as well as in mass spectrometry (MS). While the other CD-APCI sources are able to generate H3O(+)·(H2O)n as the major reactant ions in N2 or in zero air, the present CD-APCI source has the ability to generate up to 84% NO(+)·(H2O)n reactant ions in zero air. The change of the working gas from zero air to N2 allows us to change the major reactant ions from NO(+)·(H2O)n to H3O(+)·(H2O)n. In this paper we present the description of the new CD-APCI and discuss the processes associated with the NO(+) formation. The selective formation of NO(+)·(H2O)n reactant ions offers chemical ionization based on these ions which can be of great advantage for some classes of chemicals. We demonstrate here a significant increase in the sensitivity of the IMS-MS instrument for monoaromatic volatile organic compound (VOC) detection upon NO(+)·(H2O)n chemical ionization. PMID:24081306

  16. The fingerprints of Photoionization and Shock-Ionization in two CSS sources

    CERN Document Server

    Reynaldi, V

    2015-01-01

    We investigate the ionization state of the Extended Emission-Line Regions (EELRs) around two compact steep-spectrum (CSS) radio galaxies, 3C~268.3 and 3C~303.1, in order to identify the contribution of photoionization and shock-ionization. We perform a new spectroscopical (long-slit) analysis with GMOS/Gemini with the slit oriented in the radio-jet direction, where outflows are known to exist. The [Ne V]$\\lambda 3426$ emission is the most interesting feature of the spectra and the key to breaking the degeneracy between the models: since this emission-line is more extended than HeII, it challenges the ionization structure proposed by any photoionization model, also its intensity relative to H$\\beta$ does not behave as expected with respect to the ionization parameter U in the same scenario. On the contrary, when it is compared to the intensity of [OII]$\\lambda3727$/H$\\beta$ and all these results are joined, the whole scenario is plausible to be explained as emission coming from the hot, compressed, shocked gas...

  17. The effect of intergalactic helium on hydrogen reionization: implications for the sources of ionizing photons at z>6

    Science.gov (United States)

    Ciardi, B.; Bolton, J. S.; Maselli, A.; Graziani, L.

    2012-06-01

    We investigate the effect of primordial helium on hydrogen reionization using a hydrodynamical simulation combined with the cosmological radiative transfer code CRASH. The radiative transfer simulations are performed in a 35.12 h-1 comoving Mpc box using a variety of assumptions for the amplitude and power-law extreme-ultraviolet (EUV) spectral index of the ionizing emissivity at z > 6. We use an empirically motivated prescription for ionizing sources which, by design, ensures all of the models are consistent with constraints on the Thomson scattering optical depth and the metagalactic hydrogen photoionization rate at z˜ 6. The inclusion of helium slightly delays reionization due to the small number of ionizing photons which reionize neutral helium instead of hydrogen. However, helium has a significant impact on the thermal state of the intergalactic medium (IGM) during hydrogen reionization. Models with a soft EUV spectral index, α= 3, produce IGM temperatures at the mean density at z˜ 6, T0≃ 10 500 K, which are ˜20 per cent higher compared to models in which helium photoheating is excluded. Harder EUV indices produce even larger IGM temperature boosts by the end of hydrogen reionization. A comparison of these simulations to recent observational estimates of the IGM temperature at z˜ 5-6 suggests that hydrogen reionization was primarily driven by Population II stellar sources with a soft EUV index, ?. We also find that faint, as yet undetected galaxies, characterized by a luminosity function with a steepening faint-end slope (αLF≤-2) and an increasing Lyman continuum escape fraction (fesc˜ 0.5), are required to reproduce the ionizing emissivity used in our simulations at z > 6. Finally, we note there is some tension between recent observational constraints which indicate the IGM is >10 per cent neutral by volume z˜ 7, and estimates of the ionizing emissivity at z= 6 which indicate only 1-3 ionizing photons are emitted per hydrogen atom over a Hubble

  18. Ambient mass spectrometry employing direct analysis in real time (DART) ion source for olive oil quality and authenticity assessment

    International Nuclear Information System (INIS)

    A novel approach for the authentication of olive oil samples representing different quality grades has been developed. A new type of ion source, direct analysis in real time (DART), coupled to a high-resolution time-of-flight mass spectrometer (TOFMS) was employed for the comprehensive profiling of triacylglycerols (TAGs) and/or polar compounds extracted with a methanol-water mixture. The main parameters influencing the ionization efficiency of TAGs were the type of sample solvent, degree of sample dilution, ion beam temperature, and presence of a dopant (ammonia vapors). The ionization yield of polar compounds depended mainly on a content of water in the extract and ion beam temperature. Using DART-TOFMS, not only differentiation among extra virgin olive oil (EVOO), olive pomace oil (OPO) and olive oil (OO) could be easily achieved, but also EVOO adulteration with commonly used adulterant, hazelnut oil (HO), was feasible. Based on the linear discriminant analysis (LDA), the introduced method allowed detection of HO addition of 6 and 15% (v/v) when assessing DART-TOFMS mass profiles of polar compounds and TAGs, respectively.

  19. Ambient mass spectrometry employing direct analysis in real time (DART) ion source for olive oil quality and authenticity assessment

    Energy Technology Data Exchange (ETDEWEB)

    Vaclavik, Lukas; Cajka, Tomas; Hrbek, Vojtech [Institute of Chemical Technology Prague, Faculty of Food and Biochemical Technology, Department of Food Chemistry and Analysis, Technicka 5, 166 28 Prague 6 (Czech Republic); Hajslova, Jana, E-mail: jana.hajslova@vscht.cz [Institute of Chemical Technology Prague, Faculty of Food and Biochemical Technology, Department of Food Chemistry and Analysis, Technicka 5, 166 28 Prague 6 (Czech Republic)

    2009-07-10

    A novel approach for the authentication of olive oil samples representing different quality grades has been developed. A new type of ion source, direct analysis in real time (DART), coupled to a high-resolution time-of-flight mass spectrometer (TOFMS) was employed for the comprehensive profiling of triacylglycerols (TAGs) and/or polar compounds extracted with a methanol-water mixture. The main parameters influencing the ionization efficiency of TAGs were the type of sample solvent, degree of sample dilution, ion beam temperature, and presence of a dopant (ammonia vapors). The ionization yield of polar compounds depended mainly on a content of water in the extract and ion beam temperature. Using DART-TOFMS, not only differentiation among extra virgin olive oil (EVOO), olive pomace oil (OPO) and olive oil (OO) could be easily achieved, but also EVOO adulteration with commonly used adulterant, hazelnut oil (HO), was feasible. Based on the linear discriminant analysis (LDA), the introduced method allowed detection of HO addition of 6 and 15% (v/v) when assessing DART-TOFMS mass profiles of polar compounds and TAGs, respectively.

  20. Radiation fields by intermediate-age stellar populations with binaries as ionizing sources of H II regions

    CERN Document Server

    Zhang, F; Cheng, L; Wang, L; Kang, X; Zhuang, Y; Han, Z

    2014-01-01

    Radiation fields emitted by O, B-type stars or young stellar populations (SPs) are generally considered as significant central ionizing sources (CISs) of classic H II regions. In our previous studies, we show that the inclusion of binary interactions in stellar population synthesis models can significantly increase the ultraviolet spectrum hardness and the number of ionizing photons of intermediate-age (IA, 7<~log(t/yr)<~8) SPs. In this work, we present photoionization models of H II regions ionized by radiation fields emitted by IA SPs, and show that radiation fields of IA SPs, including binary systems, are in theory possible candidates of significant CISs of classic H II regions. When radiation fields of IA SPs comprising binary systems are used as the CISs of classic H II regions, the theoretical strengths of a number of lines (such as [O III]4959', [S II]6716', etc.), weaker than observations, are raised; the border /selection-criterion lines, between star-forming galaxies and AGNs in the diagnostic...

  1. Boosting the Detection Potential of Liquid Chromatography-Electron Ionization Mass Spectrometry Using a Ceramic Coated Ion Source

    Science.gov (United States)

    Magrini, Laura; Famiglini, Giorgio; Palma, Pierangela; Termopoli, Veronica; Cappiello, Achille

    2016-01-01

    Detection of target and non-target substances and their characterization in complex samples is a challenging task. Here we demonstrate that coating the electron ionization (EI) ion source of an LC-MS system with a sol-gel ceramic film can drastically improve the detection of high-molecular weight and high-boiling analytes. A new ion source coated with a ceramic material was developed and tested with a mixture of polycyclic aromatic hydrocarbons (PAH) with an increasing number of rings. Comparison of the results obtained with those for an uncoated stainless steel (SS) ion source shows a dramatic improvement in the MS signals, with a nearly 40-fold increase of the signal-to-noise ratio. We also demonstrate the ability of the new system to produce excellent chromatographic profiles for hard-to-detect hormones.

  2. Ionized gas clouds and the nature of apparent variability of a compact radio source in the galactic center

    Energy Technology Data Exchange (ETDEWEB)

    Ozernoj, L.M.; Shishov, V.I. (AN SSSR, Moscow. Fizicheskij Inst.)

    1982-05-01

    Clouds of ionized gas recently discovered at the center of our Galaxy are proposed to be responsible for the observed ''halo- core'' structure of the ''point'' radio source (which is explained as a result of scattering on inhomogeneities of substantially scales). This hypothesis implies that the core flux is probably variable, which resolves a contradiction between observations made by Kellermann et al. (1977) and Lo et al. (1981). It is capable also to explain both the origin and variability of the 0.511 MeV annihilation line observed in the direction of the Galactic center.

  3. Ionized gas clouds and the origin of the apparent variability of the compact galactic-center radio source

    International Nuclear Information System (INIS)

    The ionized gas clouds recently discovered at the center of the Galaxy could be responsible for the core--halo structure observed in the compact radio source there. The apparent structure would result from scattering by irregularities of widely differing scale. On this hypothesis the core radio flux would probably be variable, resolving the conflict between the VLBI measurements by Kellermann et al. and Lo et al. The origin and variability of the 0.511-MeV annihilation line observed toward the galactic center could be explained as well

  4. Ionized gas clouds and the origin of the apparent variability of the compact galactic-center radio source

    Energy Technology Data Exchange (ETDEWEB)

    Ozernoi, L.M.; Shishov, V.I.

    1982-05-01

    The ionized gas clouds recently discovered at the center of the Galaxy could be responsible for the core--halo structure observed in the compact radio source there. The apparent structure would result from scattering by irregularities of widely differing scale. On this hypothesis the core radio flux would probably be variable, resolving the conflict between the VLBI measurements by Kellermann et al. and Lo et al. The origin and variability of the 0.511-MeV annihilation line observed toward the galactic center could be explained as well.

  5. Ionized gas clouds and the nature of apparent variability of a compact radio source in the galactic center

    International Nuclear Information System (INIS)

    Clouds of ionized gas recently discovered at the center of our Galaxy are proposed to be responsible for the observed ''halo- core'' structure of the ''point'' radio source (which is explained as a result of scattering on inhomogeneities of substantially scales). This hypothesis implies that the core flux is probably variable, which resolves a contradiction between observations made by Kellermann et al. (1977) and Lo et al. (1981). It is capable also to explain both the origin and variability of the 0.511 MeV annihilation line observed in the direction of the Galactic center

  6. Ambient particle source apportionment and daily hospital admissions among children and elderly in Copenhagen

    DEFF Research Database (Denmark)

    Andersen, Zorana Jovanovic; Wahlin, P.; Raaschou-Nielsen, Ole;

    2007-01-01

    An association between particulate air pollution and morbidity and mortality is well established. However, little is known about which sources of particulate matter contribute most to the adverse health effects. Identification of responsible sources would merit more efficient control. For a 6-year...... period (01 January 1999 to 31 December 2004), we examined associations between urban background PM(10) in the presence of gaseous pollutants (CO, NO(2)) and hospital admissions due to cardiovascular and respiratory disease in the elderly (age>/=65), and asthma in children (age 5-18) in Copenhagen......, Denmark. We further studied associations between fractions of PM(10) assigned to six sources (biomass, secondary, oil, crustal, sea salt, and vehicle) and admissions during a 1(1/2) -year campaign. We used Poisson generalized additive time-series model adjusted for season, day of the week, public holidays...

  7. Characterization of concentration, particle size distribution, and contributing factors to ambient hexavalent chromium in an area with multiple emission sources

    Science.gov (United States)

    Yu, Chang Ho; Huang, Lihui; Shin, Jin Young; Artigas, Francisco; Fan, Zhi-hua (Tina)

    2014-09-01

    Airborne hexavalent chromium (Cr(VI)) is a known pulmonary carcinogen and can be emitted from both natural and anthropogenic sources, including diesel emissions. However, there is limited knowledge about ambient Cr(VI) concentration levels and its particle size distribution. This pilot study characterized ambient Cr(VI) concentrations in the New Jersey Meadowlands (NJ ML) district, which is close to the heavily trafficked New Jersey Turnpike (NJTPK) as well as Chromium Ore Processing Residue (COPR) waste sites. Monitoring was simultaneously conducted at two sites, William site (∼50 m from NJTPK) and MERI site (∼700 m from NJTPK). The distance between the two sites is approximately 6.2 km. Ambient Cr(VI) concentrations and PM2.5 mass concentrations were concurrently measured at both sites during summer and winter. The summer concentrations (mean ± S.D. [median]), 0.13 ± 0.06 [0.12] ng/m3 at the MERI site and 0.08 ± 0.05 [0.07] ng/m3 at the William site, were all significantly higher than the winter concentrations, 0.02 ± 0.01 [0.02] ng/m3 and 0.03 ± 0.01 [0.03] ng/m3 at the MERI and William sites, respectively. The site difference (i.e., MERI > William) was observed for summer Cr(VI) concentrations; however, no differences for winter and pooled datasets. These results suggest higher Cr(VI) concentrations may be attributed from stronger atmospheric reactions such as photo-oxidation of Cr(III) to Cr(VI) in the summer. The Cr(VI) distribution as a function of particle size, ranging from 0.18 to 18 μm, was determined at the William site. It was found that Cr(VI) was enriched in the particles less than 2.5 μm in diameter (PM2.5). This finding suggested potential health concerns, because PM2.5 are easily inhaled and deposited in the alveoli. A multiple linear regression analysis confirmed ambient Cr(VI) concentrations were significantly affected by meteorological factors (i.e., temperature and humidity) and reactive gases/particles (i.e., O3, Fe and Mn).

  8. Neutral resonant ionization in a H− plasma source: Potential of doubly excited **H−

    International Nuclear Information System (INIS)

    Hydrogen plasmas are optically dense to Lyman-α radiation, maintaining *H(n = 2) neutral atoms that may undergo neutral resonant ionization to **H−. One state, **H−(2p2 3Pe), is thought bound at 9.7 meV with a several nanosecond lifetime while all others are unbound resonances. Collision dynamics of two *H(2s) shows that an ionic pair of (p, **H−) resolves at least three long-standing collision experiments. The doubly excited anion also has a path to the unexcited ion pair whose only physical distinction is that both (p, H−) have energy of 3.7 eV

  9. Development of a compact neutron source based on field ionization processes

    Energy Technology Data Exchange (ETDEWEB)

    Persaud, Arun; Allen, Ian; Dickinson, Michael R.; Schenkel, Thomas; Kapadia, Rehan; Takei, Kuniharu; Javey, Ali

    2010-11-25

    The authors report on the use of carbon nanofiber nanoemitters to ionize deuterium atoms for the generation of neutrons in a deuterium-deuterium reaction in a preloaded target. Acceleration voltages in the range of 50-80 kV are used. Field emission of electrons is investigated to characterize the emitters. The experimental setup and sample preparation are described and first data of neutron production are presented. Ongoing experiments to increase neutron production yields by optimizing the field emitter geometry and surface conditions are discussed.

  10. Development of a Compact Neutron Source based on Field Ionization Processes

    CERN Document Server

    Persaud, Arun; Dickinson, Michael R; Kapadia, Rehan; Takei, Kuniharu; Javey, Ali; Schenkel, Thomas

    2010-01-01

    We report on the use of nano-emitters, here carbon nano-fibers(CNFs), to ionize deuterium atoms and the creation of neutrons in a deuterium-deuterium reaction in a pre-loaded target. Acceleration voltages in the range of 50-80 kV are used. Field emission of electrons is investigated to characterize the emitters. Experimental setup and sample preparation are discussed and preliminary data of first neutron production is shown. We further discuss ongoing experiments to increase neutron production yields by optimizing the field emitter geometry and surface conditions.

  11. Sources and effects of ionizing radiation. UNSCEAR 2000 report to the General Assembly, with scientific annexes. Volume II: Effects

    International Nuclear Information System (INIS)

    Over the past few years the United Nations Scientific Committee on the effects of Atomic Radiation has undertaken a broad review of the sources and effects of ionizing radiation. In the present report, the Committee, drawing on the main conclusions of its scientific assessment summarizes the developments in radiation science in the years leading up to the next millennium. It covers the following: the effects of radiation exposure; levels of radiation exposure; radiological consequences of the Chernobyl accident; sources of radiation exposure including natural exposures, man-made environmental exposures, medical and occupational exposures; radiation associated cancer. This volume includes five Annexes covering: DNA repair and mutagenesis; biological effects at low radiation doses; combined effects of radiation and other agents; epidemiological evaluation of radiation-induced cancer and exposure effects of the Chernobyl accident

  12. Occurrence and sources of particulate nitro-polycyclic aromatic hydrocarbons in ambient air in Denmark

    DEFF Research Database (Denmark)

    Feilberg, A.; Poulsen, M.W.B.; Nielsen, T.;

    2001-01-01

    The occurrence of selected nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) associated with atmospheric particulate matter has been investigated at an urban site and at a semi-rural site. For this purpose an analysis method based on gas chromatography and tandem ion trap mass spectrometry has...... been developed and applied. The nitro-PAK levels have been compared with levels of other air pollutants including unsubstituted PAHs, inorganic gases and particulate matter, as well as with meteorological parameters. Correlations and concentration ratios suggest that the dominant source of 9...

  13. CO2 laser experiments using nuclear reactions as the ionization source.

    Science.gov (United States)

    Rhoads, H. S.; Schneider, R. T.; Allario, F.

    1971-01-01

    Experimental studies show that the output of a CO2 laser is significantly increased by products of the nuclear reaction He-3 (n,p)T. Helium-3 was used in lieu of the natural helium normally present in the 1:1:8 CO2:N2:He laser gas mixture (pressure = 6 torr). The laser assembly was then exposed to a reactor thermal neutron flux of about 100 million neutrons/sq cm/sec. Power output of the laser doubled while the electrical power input decreased; electrical efficiency was thus more than doubled. Results indicate that additional ionization by the energetic charged particles may be responsible for the improved laser performance.

  14. Methane bubble ascent within muddy aquatic sediments under different ambient methane source strengths

    Science.gov (United States)

    Tarboush Sirhan, Shahrazad; Katsman, Regina; Ten Brink, Uri

    2016-04-01

    Methane (CH4) is the simplest and, the most common hydrocarbon in nature. It is considered as one of the most adverse greenhouse gases, at least 25 times more potent than carbon dioxide. When concentration of the dissolved methane in pore waters exceeds the solubility of the gas (affected in turn by temperature, pressure, salinity and by other factors) methane bubbles nucleate. Gas migration in fine-grained cohesive muddy aquatic sediments is accompanied by sediment fracturing. When gas pressure is high enough to overcome compression, friction, and cohesion at grain contacts, gas migrates by pushing the grains apart. These sub-vertical fractures provide lowered-resistance conduits for migration of other bubbles that can destabilize sediment structure resulting even in slope failure. Therefore, understanding the processes governing bubble propagation within fine-grained aquatic sediment is important. Previous models showed that bubbles propagation within fine-grained muddy aquatic sediments can be modeled using principles of linear elastic fracture mechanics. Mass transfer between the bubble rising with high velocity and the surrounding sediments was mostly ignored. We use a coupled macroscopic mechanical/reaction-transport numerical model under a variable source strength profile associated with bio-chemical processes of methane production and consumption within the sediment, as it occurs in nature. The model shows that changes in the dissolved methane concentrations strongly affect bubble ascent velocity, sometimes leading to its retardation below the sediment-water interface

  15. Air pollutant emissions from Chinese households: A major and underappreciated ambient pollution source.

    Science.gov (United States)

    Liu, Jun; Mauzerall, Denise L; Chen, Qi; Zhang, Qiang; Song, Yu; Peng, Wei; Klimont, Zbigniew; Qiu, Xinghua; Zhang, Shiqiu; Hu, Min; Lin, Weili; Smith, Kirk R; Zhu, Tong

    2016-07-12

    As part of the 12th Five-Year Plan, the Chinese government has developed air pollution prevention and control plans for key regions with a focus on the power, transport, and industrial sectors. Here, we investigate the contribution of residential emissions to regional air pollution in highly polluted eastern China during the heating season, and find that dramatic improvements in air quality would also result from reduction in residential emissions. We use the Weather Research and Forecasting model coupled with Chemistry to evaluate potential residential emission controls in Beijing and in the Beijing, Tianjin, and Hebei (BTH) region. In January and February 2010, relative to the base case, eliminating residential emissions in Beijing reduced daily average surface PM2.5 (particulate mater with aerodynamic diameter equal or smaller than 2.5 micrometer) concentrations by 14 ± 7 μg⋅m(-3) (22 ± 6% of a baseline concentration of 67 ± 41 μg⋅m(-3); mean ± SD). Eliminating residential emissions in the BTH region reduced concentrations by 28 ± 19 μg⋅m(-3) (40 ± 9% of 67 ± 41 μg⋅m(-3)), 44 ± 27 μg⋅m(-3) (43 ± 10% of 99 ± 54 μg⋅m(-3)), and 25 ± 14 μg⋅m(-3) (35 ± 8% of 70 ± 35 μg⋅m(-3)) in Beijing, Tianjin, and Hebei provinces, respectively. Annually, elimination of residential sources in the BTH region reduced emissions of primary PM2.5 by 32%, compared with 5%, 6%, and 58% achieved by eliminating emissions from the transportation, power, and industry sectors, respectively. We also find air quality in Beijing would benefit substantially from reductions in residential emissions from regional controls in Tianjin and Hebei, indicating the value of policies at the regional level.

  16. Air pollutant emissions from Chinese households: A major and underappreciated ambient pollution source.

    Science.gov (United States)

    Liu, Jun; Mauzerall, Denise L; Chen, Qi; Zhang, Qiang; Song, Yu; Peng, Wei; Klimont, Zbigniew; Qiu, Xinghua; Zhang, Shiqiu; Hu, Min; Lin, Weili; Smith, Kirk R; Zhu, Tong

    2016-07-12

    As part of the 12th Five-Year Plan, the Chinese government has developed air pollution prevention and control plans for key regions with a focus on the power, transport, and industrial sectors. Here, we investigate the contribution of residential emissions to regional air pollution in highly polluted eastern China during the heating season, and find that dramatic improvements in air quality would also result from reduction in residential emissions. We use the Weather Research and Forecasting model coupled with Chemistry to evaluate potential residential emission controls in Beijing and in the Beijing, Tianjin, and Hebei (BTH) region. In January and February 2010, relative to the base case, eliminating residential emissions in Beijing reduced daily average surface PM2.5 (particulate mater with aerodynamic diameter equal or smaller than 2.5 micrometer) concentrations by 14 ± 7 μg⋅m(-3) (22 ± 6% of a baseline concentration of 67 ± 41 μg⋅m(-3); mean ± SD). Eliminating residential emissions in the BTH region reduced concentrations by 28 ± 19 μg⋅m(-3) (40 ± 9% of 67 ± 41 μg⋅m(-3)), 44 ± 27 μg⋅m(-3) (43 ± 10% of 99 ± 54 μg⋅m(-3)), and 25 ± 14 μg⋅m(-3) (35 ± 8% of 70 ± 35 μg⋅m(-3)) in Beijing, Tianjin, and Hebei provinces, respectively. Annually, elimination of residential sources in the BTH region reduced emissions of primary PM2.5 by 32%, compared with 5%, 6%, and 58% achieved by eliminating emissions from the transportation, power, and industry sectors, respectively. We also find air quality in Beijing would benefit substantially from reductions in residential emissions from regional controls in Tianjin and Hebei, indicating the value of policies at the regional level. PMID:27354524

  17. Isomer separation of $^{70g}Cu$ and $^{70m}Cu$ with a resonance ionization laser ion source

    CERN Document Server

    Köster, U; Mishin, V I; Weissman, L; Huyse, M; Kruglov, K; Müller, W F; Van Duppen, P; Van Roosbroeck, J; Thirolf, P G; Thomas, H C; Weisshaar, D W; Schulze, W; Borcea, R; La Commara, M; Schatz, H; Schmidt, K; Röttger, S; Huber, G; Sebastian, V; Kratz, K L; Catherall, R; Georg, U; Lettry, Jacques; Oinonen, M; Ravn, H L; Simon, H

    2000-01-01

    Radioactive copper isotopes were ionized with the resonance ionization laser ion source at the on-line isotope separator ISOLDE (CERN). Using the different hyperfine structure in the 3d/sup 10/ 4s /sup 2/S/sub 1/2/-3d/sup 10/ 4p /sup 2/P/sub 1/2//sup 0/ transition the low- and high-spin isomers of /sup 70/Cu were selectively enhanced by tuning the laser wavelength. The light was provided by a narrow-bandwidth dye laser pumped by copper vapor lasers and frequency doubled in a BBO crystal. The ground state to isomeric state intensity ratio could be varied by a factor of 30, allowing to assign gamma transitions unambiguously to the decay of the individual isomers. It is shown that the method can also be used to determine magnetic moments. In a first experiment for the 1/sup +/ ground state of /sup 70/Cu a magnetic moment of (+)1.8(3) mu /sub N/ and for the high-spin isomer of /sup 70/Cu a magnetic moment of (+or-)1.2(3) mu /sub N/ could be deduced. (20 refs).

  18. Comparison of reactant and analyte ions for ⁶³Nickel, corona discharge, and secondary electrospray ionization sources with ion mobility-mass spectrometry.

    Science.gov (United States)

    Crawford, C L; Hill, H H

    2013-03-30

    (63)Nickel radioactive ionization ((63)Ni) is the most common and widely used ion source for ion mobility spectrometry (IMS). Regulatory, financial, and operational concerns with this source have promoted recent development of non-radioactive sources, such as corona discharge ionization (CD), for stand-alone IMS systems. However, there has been no comparison of the negative ion species produced by all three sources in the literature. This study compares the negative reactant and analyte ions produced by three sources on an ion mobility-mass spectrometer: conventional (63)Ni, CD, and secondary electrospray ionization (SESI). Results showed that (63)Ni and SESI produced the same reactant ion species while CD produced only the nitrate monomer and dimer ions. The analyte ions produced by each ion source were the same except for the CD source which produced a different ion species for the explosive RDX than either the (63)Ni or SESI source. Accurate and reproducible reduced mobility (K0) values, including several values reported here for the first time, were found for each explosive with each ion source. Overall, the SESI source most closely reproduced the reactant ion species and analyte ion species profiles for (63)Ni. This source may serve as a non-radioactive, robust, and flexible alternative for (63)Ni. PMID:23598216

  19. Sources of ambient concentrations and chemical composition of PM 2.5-0.1 in Cork Harbour, Ireland

    Science.gov (United States)

    Hellebust, S.; Allanic, A.; O'Connor, I. P.; Jourdan, C.; Healy, D.; Sodeau, J. R.

    2010-02-01

    Particulate matter (PM 10-2.5 and PM 2.5-0.1) has been collected over a period of one year in Cork Harbour, Ireland, using a high-volume cascade impactor and polyurethane foam collection substrate. Collected PM 2.5-0.1 was analysed for water-soluble inorganic ions and metal content using ion chromatography and inductively coupled plasma-optical emission spectroscopy. On average approximately 50% by mass of the chemical content of PM was identified. The motivation for the study was to assess the potential impact of shipping emissions on air quality in Cork Harbour and City, with a view to informing public health impacts. The average ambient concentration of PM 10 between May 2007 and April 2008 was 4.6 µgm - 3 and the maximum concentration measured in one sample, representing a 4 day collection period, was 16 µgm - 3 . The major inorganic constituents identified in PM collected in Haulbowline Island in Cork Harbour were sulfate, ammonium, nitrate, chloride and sodium ions, which were mainly attributable to sea salt and secondary inorganic aerosols from regional sources. The results were analysed by principal component analysis for the purpose of source apportionment. Four factors were identified explaining over 80% of the data set variance. The factors were: shipping, sea salt, crustal material and secondary inorganic aerosols (SIA). The smaller size fraction was frequently observed to dominate, as the average concentration was 2.77 µgm - 3 for PM 2.5-0.1 compared to 1.9 µgm - 3 for PM 10-2.5. Fresh ship plumes were not found to make a significant contribution to primary PM 2.5-0.1 concentrations adjacent to the shipping channel. However, this was partially attributed to the ultrafine nature of ship emissions and the majority of the toxic metal content was attributed to emissions associated with heavy oil combustion sources, which include ship engines.

  20. Response of the modern lactating sow and progeny to source and level of supplemental dietary fat during high ambient temperatures.

    Science.gov (United States)

    Rosero, D S; van Heugten, E; Odle, J; Arellano, C; Boyd, R D

    2012-08-01

    The objective of this study was to determine the response to increments of 2 sources of dietary fat on lactating sow and progeny performance during high ambient temperatures. Data were collected from 391 sows (PIC Camborough) from June to September in a 2,600-sow commercial unit in Oklahoma. Sows were randomly assigned to a 2 × 3 factorial arrangement of treatments and a control diet. Factors included 1) fat sources, animal-vegetable blend (A-V) and choice white grease (CWG), and 2) fat levels (2%, 4%, and 6%). The A-V blend contained 14.5% FFA with an iodine value of 89, peroxide value of 4.2 mEq/kg, and anisidine value of 23, whereas CWG contained 3.7% FFA with an iodine value of 62, peroxide value of 9.8 mEq/kg, and anisidine value of 5. Diets were corn-soybean meal based, with 8.0% distillers dried grains with solubles and 6.0% wheat middlings, and contained 3.56-g standardized ileal digestible Lys/Mcal ME. Sows were balanced by parity, with 192 and 199 sows representing parity 1 and parity 3 to 5, respectively. Feed refusal increased linearly (P feed and energy intake increased linearly (P Sows fed CWG diets had reduced (linear, P sow and litter gain relative to feed intake) compared with the G:F of sows fed the control diet or the diets containing the A-V blend (0.50, 0.43, and 0.44, respectively; P feed efficiency than CWG. Subsequent litter size and reproductive performance was improved by inclusion of both sources of fat in diets fed to lactating sows.

  1. Measurement of the ambient gamma dose equivalent and kerma from the small 252Cf source at 1 meter and the small 60Co source at 2 meters

    Energy Technology Data Exchange (ETDEWEB)

    Carl, W. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-07-30

    NASA Langley Research Center requested a measurement and determination of the ambient gamma dose equivalent rate and kerma at 100 cm from the 252Cf source and determination of the ambient gamma dose equivalent rate and kerma at 200 cm from the 60Co source for the Radiation Budget Instrument Experiment (Rad-X). An Exradin A6 ion chamber with Shonka air-equivalent plastic walls in combination with a Supermax electrometer were used to measure the exposure rate and free-in-air kerma rate of the two sources at the requested distances. The measured gamma exposure, kerma, and dose equivalent rates are tabulated.

  2. Assessment of fast and thermal neutron ambient dose equivalents around the KFUPM neutron source storage area using nuclear track detectors

    Energy Technology Data Exchange (ETDEWEB)

    Fazal-ur-Rehman [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)]. E-mail: fazalr@kfupm.edu.sa; Al-Jarallah, M.I. [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Abu-Jarad, F. [Radiation Protection Unit, Environmental Protection Department, Saudi Aramco, P. O. Box 13027, Dhahran 31311 (Saudi Arabia); Qureshi, M.A. [Center for Applied Physical Sciences, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

    2005-11-15

    A set of five {sup 241}Am-Be neutron sources are utilized in research and teaching at King Fahd University of Petroleum and Minerals (KFUPM). Three of these sources have an activity of 16Ci each and the other two are of 5Ci each. A well-shielded storage area was designed for these sources. The aim of the study is to check the effectiveness of shielding of the KFUPM neutron source storage area. Poly allyl diglycol carbonate (PADC) Nuclear track detectors (NTDs) based fast and thermal neutron area passive dosimeters have been utilized side by side for 33 days to assess accumulated low ambient dose equivalents of fast and thermal neutrons at 30 different locations around the source storage area and adjacent rooms. Fast neutron measurements have been carried out using bare NTDs, which register fast neutrons through recoils of protons, in the detector material. NTDs were mounted with lithium tetra borate (Li{sub 2}B{sub 4}O{sub 7}) converters on their surfaces for thermal neutron detection via B10(n,{alpha})Li6 and Li6(n,{alpha})H3 nuclear reactions. The calibration factors of NTD both for fast and thermal neutron area passive dosimeters were determined using thermoluminescent dosimeters (TLD) with and without a polyethylene moderator. The calibration factors for fast and thermal neutron area passive dosimeters were found to be 1.33 proton tracks cm{sup -2}{mu}Sv{sup -1} and 31.5 alpha tracks cm{sup -2}{mu}Sv{sup -1}, respectively. The results show variations of accumulated dose with the locations around the storage area. The fast neutron dose equivalents rates varied from as low as 182nSvh{sup -1} up to 10.4{mu}Svh{sup -1} whereas those for thermal neutron ranged from as low as 7nSvh{sup -1} up to 9.3{mu}Svh{sup -1}. The study indicates that the area passive neutron dosimeter was able to detect dose rates as low as 7 and 182nSvh{sup -1} from accumulated dose for thermal and fast neutrons, respectively, which were not possible to detect with the available active neutron

  3. Development of a He/CdI$_2$ gas-jet system coupled to a surface-ionization type ion-source in JAEA-ISOL: towards determination of the first ionization potential of Lr (Z = 103)

    CERN Document Server

    Sato, T K; Sato, N; Tsukada, K; Toyoshima, A; Ooe, K; Miyashita, S; Kaneya, Y; Osa, A; Schädel, M; Nagame, Y; Ichikawa, S; Stora, T; Kratz, J V

    2015-01-01

    We report on development of a gas-jet transport system coupled to a surface ionization ion-source in the JAEA-ISOL (Isotope Separator On-Line) system. As a new aerosol material for the gas-jet system, CdI2, which has a low boiling point of 713 °C, is exploited to prevent deposition of the aerosol material on the surface of the ion-source. An additional filament is newly installed in the previous ion-source to provide uniform heating of an ionizer. The present system is applied to the measurement of absolute efficiencies of various short-lived lanthanide isotopes produced in nuclear reactions.

  4. Measurement of the neutron spectrum and ambient neutron dose rate equivalent from the small 252Cf source at 1 meter

    Energy Technology Data Exchange (ETDEWEB)

    Radev, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-07-07

    NASA Langley Research Center requested a measurement of the neutron spectral distribution and fluence from the 252Cf source (model NS-120, LLNL serial # 7001677, referred as the SMALL Cf source) and determination of the ambient neutron dose rate equivalent and kerma at 100 cm for the Radiation Budget Instrument Experiment (Rad-X). The dosimetric quantities should be based on the neutron spectrum and the current neutron-to-dose conversion coefficients.

  5. A bremsstrahlung gamma-ray source based on stable ionization injection of electrons into a laser wakefield accelerator

    Science.gov (United States)

    Döpp, A.; Guillaume, E.; Thaury, C.; Lifschitz, A.; Sylla, F.; Goddet, J.-P.; Tafzi, A.; Iaquanello, G.; Lefrou, T.; Rousseau, P.; Conejero, E.; Ruiz, C.; Ta Phuoc, K.; Malka, V.

    2016-09-01

    Laser wakefield acceleration permits the generation of ultra-short, high-brightness relativistic electron beams on a millimeter scale. While those features are of interest for many applications, the source remains constraint by the poor stability of the electron injection process. Here we present results on injection and acceleration of electrons in pure nitrogen and argon. We observe stable, continuous ionization-induced injection of electrons into the wakefield for laser powers exceeding a threshold of 7 TW. The beam charge scales approximately with the laser energy and is limited by beam loading. For 40 TW laser pulses we measure a maximum charge of almost 1 nC per shot, originating mostly from electrons of less than 10 MeV energy. The relatively low energy, the high charge and its stability make this source well-suited for applications such as non-destructive testing. Hence, we demonstrate the production of energetic radiation via bremsstrahlung conversion at 1 Hz repetition rate. In accordance with GEANT4 Monte-Carlo simulations, we measure a γ-ray source size of less than 100 μm for a 0.5 mm tantalum converter placed at 2 mm from the accelerator exit. Furthermore we present radiographs of image quality indicators.

  6. Source Apportionment of Ambient PM10 in the Urban Area of Longyan City, China: a Comparative Study Based on Chemical Mass Balance Model and Factor Analysis Method

    Institute of Scientific and Technical Information of China (English)

    QIU Li-min; LIU Miao; WANG Ju; ZHANG Sheng-nan; FANG Chun-sheng

    2012-01-01

    In order to identify the day and night pollution sources of PM10 in ambient air in Longyan City,the authors analyzed the elemental composition of respirable particulate matters in the day and night ambient air samples and various pollution sources which were collected in January 2010 in Longyan with inductivity coupled plasma-mass spectrometry(ICP-MS).Then chemical mass balance(CMB)model and factor analysis(FA)method were applied to comparatively study the inorganic components in the sources and receptor samples.The results of factor analysis show that the major sources were road dust,waste incineration and mixed sources which contained automobile exhaust,soil dust/secondary dust and coal dust during the daytime in Longyan City,China.There are two major sources of pollution which are soil dust and mixture sources of automobile exhaust and secondary dust during the night in Longyan.The results of CMB show that the major sources are secondary dust,automobile exhaust and road dust during the daytime in Longyan.The major sources are secondary dust,soil dust and automobile exhaust during the night in Longyan.The results of the two methods are similar to each other and the results will guide us to plan to control the PM10 pollution sources in Longyan.

  7. Direct Coupling of Solid-Phase Microextraction with Mass Spectrometry: Sub-pg/g Sensitivity Achieved Using a Dielectric Barrier Discharge Ionization Source.

    Science.gov (United States)

    Mirabelli, Mario F; Wolf, Jan-Christoph; Zenobi, Renato

    2016-07-19

    We report a new strategy for the direct coupling of Solid-Phase Microextraction (SPME) with mass spectrometry, based on thermal desorption of analytes extracted on the fibers, followed by ionization by a dielectric barrier discharge ionization (DBDI) source. Limits of detection as low as 0.3 pg/mL and a linear dynamic range of ≥3 orders of magnitude were achieved, with a very simple and reproducible approach. Different from direct analysis in real time (DART), desorption electrospray ionization (DESI), or low-temperature plasma (LTP), the desorption of the analytes from the SPME devices in our setup is completely separated from the ionization event. This enhances the reproducibility of the method and minimizes ion suppression phenomena. The analytes were quantitatively transferred from the SPME to the DBDI source, and the use of an active capillary ionization embodiment of the DBDI source greatly enhanced the ion transmission to the MS. This, together with the extraordinary sensitivity of DBDI, allowed subpg/mL sensitivities to be reached and to skip conventional and time-consuming chromatographic separation. PMID:27332082

  8. Non ionizing radiations: Sources, fields of application, problem issues and normatives

    International Nuclear Information System (INIS)

    The purpose of this paper is briefly to review radiation sources, in work and life places, and national standards, proposed or enforced in different countries, with particular reference to ELF. RF and MW electromagnetic fields. It is aimed to give a help to qualitative valutation on the work we can carry out for the development of an effective health protection of workers and general public. (author)

  9. Non ionizing radiations Sources, fields of application, problem issues and normatives

    CERN Document Server

    Raganella, L

    1988-01-01

    The purpose of this paper is briefly to review radiation sources, in work and life places, and national standards, proposed or enforced in different countries, with particular reference to ELF. RF and MW electromagnetic fields. It is aimed to give a help to qualitative valutation on the work we can carry out for the development of an effective health protection of workers and general public.

  10. Novel matching lens and spherical ionizer for a cesium sputter ion source

    Indian Academy of Sciences (India)

    D C Weisser; N R Lobanov; P A Hausladen; L K Fifield; H J Wallace; S G Tims; E G Apushkinsky

    2002-12-01

    The beam optics of a multi-sample sputter ion source, based on the NEC MCSNICS, has been modified to accommodate cathode voltages higher than 5 kV and dispenses with the nominal extractor. The cathode voltage in Cs sputter sources plays the role of the classical extractor accomplishing the acceleration of beam particles from eV to keV energy, minimizing space charge effects and interactions between the beam and residual gas. The higher the cathode voltage, the smaller are these contributions to the emittance growth. The higher cathode voltage also raises the Child’s law limit on the Cs current resulting in substantially increased output. The incidental focusing role of the extractor is reallocated to a deceleration Einzel lens and the velocity change needed to match to the pre-acceleration tube goes to a new electrode at the tube entrance. All electrodes are large enough to ensure that the beam fills less than 30% of the aperture to minimize aberrations. The improvements are applicable to sputter sources generally.

  11. Legacy ionizing radiation sources: implications for a university in the 21st century

    International Nuclear Information System (INIS)

    Legacy radiological materials are often possessed by universities that may date back many years. These materials have often been left behind by researchers and are rediscovered after the retirement of an academic or renovation works. The University of Melbourne has materials dating from the 19th and 20th centuries. As times change the requirements for the use, possession, security and storage of these items change requiring the commitment of resources to their management. A major project was undertaken by the University of Melbourne to identify and categorize a series of unknown sources. This paper will outline the challenges associated with this programme and the resources that were required for its implementation.

  12. Detection of polychlorinated biphenyls in transformer oils in Vietnam by multiphoton ionization mass spectrometry using a far-ultraviolet femtosecond laser as an ionization source.

    Science.gov (United States)

    Vu, Thi Thuy Duong; Vu, Duong; Nghiem, Thi Ha Lien; Imasaka, Tomoko; Tang, Yuanyuan; Shibuta, Shinpei; Hamachi, Akifumi; Do, Quang Hoa; Imasaka, Totaro

    2016-03-01

    Polychlorinated biphenyls (PCBs) in transformer and food oils were measured using gas chromatography combined with multiphoton ionization mass spectroscopy. An ultrashort laser pulse emitting in the far-ultraviolet region was utilized for efficient ionization of the analytes. Numerous signal peaks were clearly observed for a standard sample mixture of PCBs when the third and fourth harmonic emissions (267 and 200nm) of a femtosecond Ti:sapphire laser (800nm) were employed. The signal intensities were found to be greater when measured at 200nm compared with those measured at 267nm, providing lower detection limits especially for highly chlorinated PCBs at shorter wavelengths. After simple pretreatment using disposable columns, PCB congeners were measured and found to be present in the transformer oils used in Vietnam. PMID:26717841

  13. Detection of polychlorinated biphenyls in transformer oils in Vietnam by multiphoton ionization mass spectrometry using a far-ultraviolet femtosecond laser as an ionization source.

    Science.gov (United States)

    Vu, Thi Thuy Duong; Vu, Duong; Nghiem, Thi Ha Lien; Imasaka, Tomoko; Tang, Yuanyuan; Shibuta, Shinpei; Hamachi, Akifumi; Do, Quang Hoa; Imasaka, Totaro

    2016-03-01

    Polychlorinated biphenyls (PCBs) in transformer and food oils were measured using gas chromatography combined with multiphoton ionization mass spectroscopy. An ultrashort laser pulse emitting in the far-ultraviolet region was utilized for efficient ionization of the analytes. Numerous signal peaks were clearly observed for a standard sample mixture of PCBs when the third and fourth harmonic emissions (267 and 200nm) of a femtosecond Ti:sapphire laser (800nm) were employed. The signal intensities were found to be greater when measured at 200nm compared with those measured at 267nm, providing lower detection limits especially for highly chlorinated PCBs at shorter wavelengths. After simple pretreatment using disposable columns, PCB congeners were measured and found to be present in the transformer oils used in Vietnam.

  14. A bremsstrahlung gamma-ray source based on stable ionization injection of electrons into a laser wakefield accelerator

    CERN Document Server

    Döpp, A; Thaury, C; Lifschitz, A; Sylla, F; Goddet, J-P; Tafzi, A; Iaquanello, G; Lefrou, T; Rousseau, P; Conejero, E; Ruiz, C; Phuoc, K Ta; Malka, V

    2016-01-01

    Laser wakefield acceleration permits the generation of ultra-short, high-brightness relativistic electron beams on a millimeter scale. While those features are of interest for many applications, the source remains constraint by the poor stability of the electron injection process. Here we present results on injection and acceleration of electrons in pure nitrogen and argon. We observe stable, continuous ionization-induced injection of electrons into the wakefield for laser powers exceeding a threshold of 7 TW. The beam charge scales approximately linear with the laser energy and is limited by beam loading. For 40 TW laser pulses we measure a maximum charge of almost 1 nC per shot, originating mostly from electrons of less than 10 MeV energy. The relatively low energy, the high charge and its stability make this source well-suited for applications such as non-destructive testing. Hence, we demonstrate the production of energetic radiation via bremsstrahlung conversion at 1 Hz repetition rate. In accordance wit...

  15. The Ionized Circumstellar Envelopes of Orion Source I and the Becklin Neugebauer Object

    CERN Document Server

    Plambeck, R L; Carpenter, J M; Eisner, J A; Lamb, J W; Leitch, E M; Marrone, D P; Muchovej, S J; Perez, L M; Pound, M W; Teuben, P J; Volgenau, N H; Woody, D P; Wright, M C H; Zauderer, B A

    2012-01-01

    The 229 GHz (lambda 1.3mm) radio emission from Orion-KL was mapped with up to 0.14'' angular resolution with CARMA, allowing measurements of the flux densities of Source I ('SrcI') and the Becklin-Neugebauer Object (BN), the 2 most massive stars in this region. We find integrated flux densities of 310 +/- 45 mJy for SrcI and 240 +/- 35 mJy for BN. SrcI is optically thick even at 229 GHz. No trace of the H30alpha recombination line is seen in its spectrum, although the v_2=1, 5(5,0)-6(4,3) transition of H2O, 3450 K above the ground state, is prominent. SrcI is elongated at position angle 140 degrees, as in 43 GHz images. These results are most easily reconciled with models in which the radio emission from SrcI arises via the H- free-free opacity in a T < 4500 K disk, as considered by Reid et al. (2007). By contrast, the radio spectrum of BN is consistent with p+/e- free-free emission from a dense (n_e ~ 5x10^7 cm^{-3}), but otherwise conventional, hypercompact HII region. The source is becoming optically th...

  16. Organic Materials Ionizing Radiation Susceptibility for the Outer Planet/Solar Probe Radioisotope Power Source

    Science.gov (United States)

    Golliher, Eric L.; Pepper, Stephen V.

    2001-01-01

    The Department of Energy is considering the current Stirling Technology Corporation 55 We Stirling Technology Demonstration Convertor as a baseline option for an advanced radioisotope power source for the Outer Planets/Solar Probe project of Jet Propulsion Laboratory and other missions. However, since the Technology Demonstration Convertor contains organic materials chosen without any special consideration of flight readiness, and without any consideration of the extremely high radiation environment of Europa, a preliminary investigation was performed to address the radiation susceptibility of the current organic materials used in the Technology Demonstration Convertor. This report documents the results of the investigation. The results of the investigation show that candidate replacement materials have been identified to be acceptable in the harsh Europa radiation environment.

  17. The in-gas-jet laser ion source: resonance ionization spectroscopy of radioactive atoms in supersonic gas jets

    OpenAIRE

    Kudryavtsev, Yu; Ferrer, R; Huyse, M.; Van den Bergh, P.; Van Duppen, P.(KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, Leuven, 3001, Belgium)

    2012-01-01

    New approaches to perform efficient and selective step-wise Resonance Ionization Spectroscopy (RIS) of radioactive atoms in different types of supersonic gas jets are proposed. This novel application results in a major expansion of the In-Gas Laser Ionization and Spectroscopy (IGLIS) method developed at KU Leuven. Implementation of resonance ionization in the supersonic gas jet allows to increase the spectral resolution by one order of magnitude in comparison with the currently performed in-g...

  18. Three-photon resonance ionization of atomic Mn in a hot-cavity laser ion source using Ti:sapphire lasers

    Science.gov (United States)

    Liu, Y.; Gottwald, T.; Mattolat, C.; Wendt, K.

    2015-06-01

    Three-photon resonance ionization of atomic manganese (Mn) in a hot-cavity ion source using Ti:sapphire lasers has been demonstrated. Three-step ionization schemes employing different intermediate levels and Rydberg or autoionizing (AI) states in the final ionization step are established. Strong AI resonances were observed via the 3d54s5s f 6S5/2 level at 49 415.35 cm-1, while Rydberg transitions were reached from the 3d54s4d e 6D9/2,7/2,5/2 levels at around 47 210 cm-1. Analyses of the strong Rydberg transitions associated with the 3d54s4d e 6D7/2 lower level indicate that they belong to the dipole-allowed 4d → nf 6F°9/2,7/2,5/2 series converging to the 3d54s 7S3 ground state of Mn II. From this series, an ionization potential of 59 959.56 ± 0.01 cm-1 is obtained for Mn. At high ion source temperatures the semi-forbidden 4d → nf 8F°9/2,7/2,5/2 series was also observed. The overall ionization efficiency for Mn has been measured to be about 0.9% when using the strong AI transition in the third excitation step and 0.3% when employing an intense Rydberg transition. Experimental data indicate that the ionization efficiency was limited by the interaction of Mn atoms with ion source materials at high temperatures.

  19. Astrophysical Ionizing Radiation and the Earth: A Brief Review and Census of Intermittent Intense Sources

    CERN Document Server

    Melott, Adrian L

    2011-01-01

    Cosmic radiation backgrounds are a constraint on life, and their distribution will affect the Galactic Habitable Zone. Life on Earth has developed in the context of these backgrounds, and characterizing event rates will elaborate the important influences. This in turn can be a base for comparison with other potential life-bearing planets. In this review we estimate the intensities and rates of occurrence of many kinds of strong radiation bursts by astrophysical entities ranging from gamma-ray bursts at cosmological distances to the Sun itself. Many of these present potential hazards to the biosphere: on timescales long compared with human history, the probability of an event intense enough to disrupt life on the land surface or in the oceans becomes large. We enumerate the known sources of radiation and characterize their intensities at the Earth and rates or upper limits on these quantities. When possible, we estimate a "lethal interval", our best estimate of how often a major extinction-level event is proba...

  20. Diffuse Gas in Retired Galaxies: Nebular Emission Templates and Constraints on the Sources of Ionization

    CERN Document Server

    Johansson, Jonas; Gilfanov, Marat; Sarzi, Marc; Chen, Yan-Mei; Oh, Kyuseok

    2016-01-01

    We present emission line templates for passively evolving ("retired") galaxies, useful for investigation of the evolution of the ISM in these galaxies, and characterization of their high-temperature source populations. The templates are based on high signal-to-noise ($>800$) co-added spectra ($3700-6800$\\AA) of $\\sim11500$ gas-rich Sloan Digital Sky Survey galaxies devoid of star-formation and active galactic nuclei. Stacked spectra are provided for the entire sample and sub-samples binned by mean stellar age. In Johansson~et al (2014), these spectra provided the first measurements of the He II 4686\\AA\\ line in passively-evolving galaxies, and the observed He II/H$\\beta$ ratio constrained the contribution of accreting white dwarfs (the "single-degenerate" scenario) to the type Ia supernova rate. In this paper, the full range of unambiguously detected emission lines are presented. Comparison of the observed [O I] 6300\\AA/H$\\alpha$ ratio with photoionization models further constrains any high-temperature single...

  1. Liquid sampling-atmospheric pressure glow discharge (LS-APGD) ionization source for elemental mass spectrometry: preliminary parametric evaluation and figures of merit.

    Science.gov (United States)

    Quarles, C Derrick; Carado, Anthony J; Barinaga, Charles J; Koppenaal, David W; Marcus, R Kenneth

    2012-01-01

    A new, low-power ionization source for the elemental analysis of aqueous solutions has recently been described. The liquid sampling-atmospheric pressure glow discharge (LS-APGD) source operates at relatively low currents (LS-APGD has been interfaced to what is otherwise an organic, LC-MS mass analyzer, the Thermo Scientific Exactive Orbitrap without any modifications, other than removing the electrospray ionization source supplied with that instrument. A glow discharge is initiated between the surface of the test solution exiting a glass capillary and a metallic counter electrode mounted at a 90° angle and separated by a distance of ~5 mm. As with any plasma-based ionization source, there are key discharge operation and ion sampling parameters that affect the intensity and composition of the derived mass spectra, including signal-to-background ratios. We describe here a preliminary parametric evaluation of the roles of discharge current, solution flow rate, argon sheath gas flow rate, and ion sampling distance as they apply on this mass analyzer system. A cursive evaluation of potential matrix effects due to the presence of easily ionized elements indicate that sodium concentrations of up to 50 μg mL(-1) generally cause suppressions of less than 50%, dependant upon the analyte species. Based on the results of this series of studies, preliminary limits of detection (LOD) have been established through the generation of calibration functions. While solution-based concentration LOD levels of 0.02-2 μg mL(-1) are not impressive on the surface, the fact that they are determined via discrete 5 μL injections leads to mass-based detection limits at picogram to single-nanogram levels. The overhead costs associated with source operation (10 W d.c. power, solution flow rates of LS-APGD ion source may present a practical alternative to inductively coupled plasma sources typically employed in elemental mass spectrometry.

  2. Correction of phase velocity bias caused by strong directional noise sources in high-frequency ambient noise tomography: a case study in Karamay, China

    Science.gov (United States)

    Wang, Kai; Luo, Yinhe; Yang, Yingjie

    2016-05-01

    We collect two months of ambient noise data recorded by 35 broad-band seismic stations in a 9 × 11 km area (1-3 km station interval) near Karamay, China, and do cross-correlation of noise data between all station pairs. Array beamforming analysis of the ambient noise data shows that ambient noise sources are unevenly distributed and the most energetic ambient noise mainly comes from azimuths of 40°-70°. As a consequence of the strong directional noise sources, surface wave components of the cross-correlations at 1-5 Hz show clearly azimuthal dependence, and direct dispersion measurements from cross-correlations are strongly biased by the dominant noise energy. This bias renders that the dispersion measurements from cross-correlations do not accurately reflect the interstation velocities of surface waves propagating directly from one station to the other, that is, the cross-correlation functions do not retrieve empirical Green's functions accurately. To correct the bias caused by unevenly distributed noise sources, we adopt an iterative inversion procedure. The iterative inversion procedure, based on plane-wave modeling, includes three steps: (1) surface wave tomography, (2) estimation of ambient noise energy and biases and (3) phase velocities correction. First, we use synthesized data to test the efficiency and stability of the iterative procedure for both homogeneous and heterogeneous media. The testing results show that: (1) the amplitudes of phase velocity bias caused by directional noise sources are significant, reaching ˜2 and ˜10 per cent for homogeneous and heterogeneous media, respectively; (2) phase velocity bias can be corrected by the iterative inversion procedure and the convergence of inversion depends on the starting phase velocity map and the complexity of the media. By applying the iterative approach to the real data in Karamay, we further show that phase velocity maps converge after 10 iterations and the phase velocity maps obtained using

  3. Permissible dose from external sources of ionizing radiation. Recommendations of the National Committee on Radiation Protection. Handbook 59

    International Nuclear Information System (INIS)

    The Advisory Committee on X-ray and Radium Protection was formed in 1929 upon the recommendation of the International Commission on Radiological Protection, under the sponsorship of the National Bureau of Standards, and with the cooperation of the leading radiological organizations. The small committee functioned effectively until the advent of atomic energy, which introduced a large number of new and serious problems in the field of radiation protection. The present report deals primarily with the protection of persons occupationally exposed to ionizing radiation from external sources. An attempt has been made to cover most of the situations encountered in practice. However, it has not always been possible to make recommendations in quantitative terms. In such cases the recommendations are intended to serve as practical guides. The recommendations are based on presently available information and cannot be regarded as permanent. For this reason and on general grounds it is strongly recommended that exposure to radiation be kept at the lowest practicable level in all cases

  4. Self-Aspirated Atmospheric Pressure Chemical Ionization Source for Direct Sampling of Analytes on Surfaces and in Liquid Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Asano, Keiji G [ORNL; Ford, Michael J [ORNL; Tomkins, Bruce A [ORNL; Van Berkel, Gary J [ORNL

    2005-01-01

    A self-aspirating heated nebulizer probe is described and demonstrated for use in the direct analysis of analytes on surfaces and in liquid samples by atmospheric pressure chemical ionization (APCI) mass spectrometry. Functionality and performance of the probe as a self-aspirating APCI source is demonstrated using reserpine and progesterone as test compounds. The utility of the probe to sample analytes directly from surfaces was demonstrated first by scanning development lanes of a reversed-phase thin-layer chromatography plate in which a three-component dye mixture, viz., Fat Red 7B, Solvent Green 3, and Solvent Blue 35, was spotted and the components were separated. Development lanes were scanned by the sampling probe operated under computer control (x, y plane) while full-scan mass spectra were recorded using a quadrupole ion trap mass spectrometer. In addition, the ability to sample the surface of pharmaceutical tablets (viz., Extra Strength Tylenol(reg. sign) and Evista(reg. sign) tablets) and to detect the active ingredients (acetaminophen and raloxifene, respectively) selectively was demonstrated using tandem mass spectrometry (MS/MS). Finally, the capability to sample analyte solutions from the wells of a 384-well microtiter plate and to perform quantitative analyses using MS/MS detection was illustrated with cotinine standards spiked with cotinine-d{sub 3} as an internal standard.

  5. Self-aspirating atmospheric pressure chemical ionization source for direct sampling of analytes on surfaces and in liquid solutions.

    Science.gov (United States)

    Asano, Keiji G; Ford, Michael J; Tomkins, Bruce A; Van Berkel, Gary J

    2005-01-01

    A self-aspirating heated nebulizer probe is described and demonstrated for use in the direct analysis of analytes on surfaces and in liquid samples by atmospheric pressure chemical ionization (APCI) mass spectrometry. Functionality and performance of the probe as a self-aspirating APCI source is demonstrated using reserpine and progesterone as test compounds. The utility of the probe to sample analytes directly from surfaces was demonstrated first by scanning development lanes of a reversed-phase thin-layer chromatography plate in which a three-component dye mixture, viz., Fat Red 7B, Solvent Green 3, and Solvent Blue 35, was spotted and the components were separated. Development lanes were scanned by the sampling probe operated under computer control (x, y plane) while full-scan mass spectra were recorded using a quadrupole ion trap mass spectrometer. In addition, the ability to sample the surface of pharmaceutical tablets (viz., Extra Strength Tylenol and Evista tablets) and to detect the active ingredients (acetaminophen and raloxifene, respectively) selectively was demonstrated using tandem mass spectrometry (MS/MS). Finally, the capability to sample analyte solutions from the wells of a 384-well microtiter plate and to perform quantitative analyses using MS/MS detection was illustrated with cotinine standards spiked with cotinine-d3 as an internal standard.

  6. Characterization of the PTW SourceCheck ionization chamber with the Valencia lodgment for (125)I seed verification.

    Science.gov (United States)

    Tornero-López, Ana M; Torres Del Río, Julia; Ruiz, Carmen; Perez-Calatayud, Jose; Guirado, Damián; Lallena, Antonio M

    2015-12-01

    In brachytherapy using (125)I seed implants, a verification of the air kerma strength of the sources used is required. Typically, between 40 and 100 seeds are implanted. Checking all of them is unaffordable, especially when seeds are disposed in sterile cartridges. Recently, a new procedure allowing the accomplishment of the international recommendations has been proposed for the seedSelectron system of Elekta Brachytherapy. In this procedure, the SourceCheck ionization chamber is used with a special lodgment (Valencia lodgment) that allows to measure up to 10 seeds simultaneously. In this work we analyze this procedure, showing the feasibility of the approximations required for its application, as well as the effect of the additional dependence with the air density that shows the chamber model used. Uncertainty calculations and the verification of the approximation needed to obtain a calibration factor for the Valencia lodgment are carried out. The results of the present work show that the chamber dependence with the air density is the same whether the Valencia lodgment is used or not. On the contrary, the chamber response profile is influenced by the presence of the lodgment. The determination of this profile requires various measurements due to the nonnegligible variability found between different experiments. If it is considered, the uncertainty in the determination of the air-kerma strength increases from 0.5% to 1%. Otherwise, a systematic additional uncertainty of 1% would occur. This could be relevant for the comparison between user and manufacturer measurements that is mandatory in the case studied here.

  7. Gas-phase naphthalene concentration data recovery in ambient air and its relevance as a tracer of sources of volatile organic compounds

    Science.gov (United States)

    Uria-Tellaetxe, Iratxe; Navazo, Marino; de Blas, Maite; Durana, Nieves; Alonso, Lucio; Iza, Jon

    2016-04-01

    Despite the toxicity of naphthalene and the fact that it is a precursor of atmospheric photooxidants and secondary aerosol, studies on ambient gas-phase naphthalene are generally scarce. Moreover, as far as we are concerned, this is the first published one using long-term hourly ambient gas-phase naphthalene concentrations. In this work, it has been also demonstrated the usefulness of ambient gas-phase naphthalene to identify major sources of volatile organic compounds (VOC) in complex scenarios. Initially, in order to identify main benzene emission sources, hourly ambient measurements of 60 VOC were taken during a complete year together with meteorological data in an urban/industrial area. Later, due to the observed co-linearity of some of the emissions, a procedure was developed to recover naphthalene concentration data from recorded chromatograms to use it as a tracer of the combustion and distillation of petroleum products. The characteristic retention time of this compound was determined comparing previous GC-MS and GC-FID simultaneous analysis by means of relative retention times, and its concentration was calculated by using relative response factors. The obtained naphthalene concentrations correlated fairly well with ethene (r = 0.86) and benzene (r = 0.92). Besides, the analysis of daily time series showed that these compounds followed a similar pattern, very different from that of other VOC, with minimum concentrations at day-time. This, together with the results from the assessment of the meteorological dependence pointed out a coke oven as the major naphthalene and benzene emitting sources in the study area.

  8. Ambient noise tomography with non-uniform noise sources and low aperture networks: case study of deep geothermal reservoirs in northern Alsace, France

    Science.gov (United States)

    Lehujeur, Maximilien; Vergne, Jérôme; Maggi, Alessia; Schmittbuhl, Jean

    2016-10-01

    We developed and applied a method for ambient noise surface wave tomography that can deal with noise cross-correlation functions governed to first order by a non-uniform distribution of the ambient seismic noise sources. The method inverts the azimuthal distribution of noise sources that are assumed to be far from the network, together with the spatial variations of the phase and group velocities on an optimized irregular grid. Direct modeling of the two-sided noise correlation functions avoids dispersion curve picking on every station pair and minimizes analyst intervention. The method involves station pairs spaced by distances down to a fraction of a wavelength, thereby bringing additional information for tomography. After validating the method on synthetic data, we applied it to a set of long-term continuous waveforms acquired around the geothermal sites at Soultz-sous-Forêts and Rittershoffen (Northern Alsace, France). For networks with limited aperture, we show that taking the azimuthal variations of the noise energy into account has significant impact on the surface wave dispersion maps. We obtained regional phase and group velocity models in the 1-7 s period range, which is sensitive to the structures encompassing the geothermal reservoirs. The ambient noise in our dataset originates from two main directions, the northern Atlantic Ocean and the Mediterranean Sea, and is dominated by the first Rayleigh wave overtone in the 2 - 5 s period range.

  9. IAEA-USA-Russian Federation cooperation in the field of enhancing the security and protectability of ionizing radiation sources

    International Nuclear Information System (INIS)

    In the Russian Federation, issues relating to the safe operation of nuclear power facilities are coordinated by the Federal Atomic Energy Agency (FAEA). Rosatom is responsible for the provision of nuclear, radiological, technical, industrial, fire and environmental safety; labour protection; protection of personnel, the population and the environment in the vicinity of the facilities; prevention and mitigation of emergency situations; accounting and control of radioactive materials and radioactive waste; and the safe handling of nuclear and radioactive materials, radioactive waste and spent nuclear fuel, taking into account the international scientific and technical cooperation in this field. All these issues are also related to the management of ionizing radiation sources (IRSs). The legal basis of IRS use in Russia is reported. FAEA implemented the following IRS management: methodical supervision, organization and conduct of work on licensing, certification and preparation of decisions on recognition of the organizations reported to Rosatom as being capable of operating nuclear power facilities, including handling of IRSs and prolongation of their lifetime; issue of certificates for transport of nuclear and radiological materials; organization of the State system of accounting and control of radioactive materials (RM) and radioactive waste (RW); and prevention and mitigation of emergency situations at the organizations reported to Rosatom. The organizational structure of the State system of accounting and control of radioactive materials and radioactive waste is discussed. Increasing the security of IRS management is becoming more and more important in the wake of the threat of unauthorized use of IRSs in terrorist acts. Several activities directed at increasing the safety and security of IRS management are being carried out in the framework of international cooperation. This work is being most actively performed in the framework of the cooperation between

  10. New constraints on the magmatic system beneath Newberry Volcano from the analysis of active and passive source seismic data and ambient noise

    Science.gov (United States)

    Heath, Benjamin Allen

    Using joint P-wave seismic tomography, receiver functions, and ambient noise we image the magmatic structure beneath Newberry Volcano, located near Bend, Oregon. Use of active source and teleseismic events in a joint tomographic inversion provides the ray crossings necessary to resolve a low velocity body around 4 km depth. Receiver functions show large lateral heterogeneity and are consistent with the location of a low velocity body derived from the tomography but require a larger low velocity anomaly. Ambient noise autocorrelations are used to image a low velocity reflector, located at ~3 km depth, shallower than the imaged low velocity body recovered using tomography and receiver functions. Ultimately, our results reveal a magma chamber at 3-4 km depth beneath Newberry caldera, with an overlying partially molten sill at ~3 km depth. These results show the usefulness of dense seismometer deployments over volcanoes.

  11. Negative Ion In-Source Decay Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry for Sequencing Acidic Peptides

    Science.gov (United States)

    McMillen, Chelsea L.; Wright, Patience M.; Cassady, Carolyn J.

    2016-05-01

    Matrix-assisted laser desorption/ionization (MALDI) in-source decay was studied in the negative ion mode on deprotonated peptides to determine its usefulness for obtaining extensive sequence information for acidic peptides. Eight biological acidic peptides, ranging in size from 11 to 33 residues, were studied by negative ion mode ISD (nISD). The matrices 2,5-dihydroxybenzoic acid, 2-aminobenzoic acid, 2-aminobenzamide, 1,5-diaminonaphthalene, 5-amino-1-naphthol, 3-aminoquinoline, and 9-aminoacridine were used with each peptide. Optimal fragmentation was produced with 1,5-diaminonphthalene (DAN), and extensive sequence informative fragmentation was observed for every peptide except hirudin(54-65). Cleavage at the N-Cα bond of the peptide backbone, producing c' and z' ions, was dominant for all peptides. Cleavage of the N-Cα bond N-terminal to proline residues was not observed. The formation of c and z ions is also found in electron transfer dissociation (ETD), electron capture dissociation (ECD), and positive ion mode ISD, which are considered to be radical-driven techniques. Oxidized insulin chain A, which has four highly acidic oxidized cysteine residues, had less extensive fragmentation. This peptide also exhibited the only charged localized fragmentation, with more pronounced product ion formation adjacent to the highly acidic residues. In addition, spectra were obtained by positive ion mode ISD for each protonated peptide; more sequence informative fragmentation was observed via nISD for all peptides. Three of the peptides studied had no product ion formation in ISD, but extensive sequence informative fragmentation was found in their nISD spectra. The results of this study indicate that nISD can be used to readily obtain sequence information for acidic peptides.

  12. In Situ Electrostatic Separation of Ambient PM2.5 into Source-Specific Fractions During Collection in a FRM Sampler

    Energy Technology Data Exchange (ETDEWEB)

    Naresh Shah; Frank E. Huggins; Gerald P. Huffman

    2006-07-31

    Coal combustion is generally viewed as a major source of PM2.5 emissions into the atmosphere. For some time, toxicologists have been asking for an exposure environment enriched with the coal combustion source specific PM{sub 2.5} to conduct meaningful exposure studies to better understand the mechanisms of the adverse health effects of coal combustion specific PM2.5 in the ambient environment. There are several unique characteristics of primary PM generated from coal combustion. In this research project, an attempt has been made to exploit some of the unique properties of PM generated from coal fired power plants to preferentially separate them out from the rest of the primary and secondary PM in the ambient environment. An existing FRM sampler used for monitoring amount of PM{sub 2.5} in the ambient air is modified to incorporate an electrostatic field. A DC corona charging device is also installed at the ambient air inlet to impart positive or negative charge to the PM. Visual Basic software has been written to simulate the lateral movement of PM as it passes through the electrostatic separator under varying operating conditions. The PM samples collected on polycarbonate filters under varying operating conditions were extensively observed for clustering and/or separation of PM in the direction parallel to the electric field. No systematic PM separation was observed under any of the operating conditions. A solution to overcome this kind of turbulence caused remixing has been offered. However, due to major programmatic changes in the DOE UCR program, there are no venues available to further pursue this research.

  13. Measurements and source apportionment of particle-associated polycyclic aromatic hydrocarbons in ambient air in Riyadh, Saudi Arabia

    Science.gov (United States)

    Bian, Qijing; Alharbi, Badr; Collett, Jeffrey; Kreidenweis, Sonia; Pasha, Mohammad J.

    2016-07-01

    Ambient air samples were obtained in Riyadh, the capital and largest city of Saudi Arabia, during two measurement campaigns spanning September 2011 to September 2012. Sixteen particle-phase polycyclic aromatic hydrocarbons (PAH) were quantified in 167 samples. Pyrene and fluoranthene were the most abundant PAH, with average of 3.37 ± 14.01 ng m-3 and 8.00 ± 44.09 ng m-3, respectively. A dominant contribution from low molecular weight (LMW) PAH (MW oil combustion emissions dominated total PAH concentrations, accounting for on average 96%, likely due to widespread use of oil fuels in energy production (power plants and industries). Our results demonstrate the significant influence of petroleum product production and consumption on particulate-phase PAH concentrations in Riyadh, but also point to the importance of traffic and solid fuel burning, including coke burning and seasonal biomass burning, especially as they contribute to the ambient levels of HMW PAH.

  14. Phenolic Compounds of Pinus brutia Ten.: Chemical Investigation and Quantitative Analysis Using an Ultra-Performance Liquid Chromatography Tandem Mass Spectrometry with Electrospray Ionization Source

    OpenAIRE

    İbrahim Kıvrak; Şeyda Kıvrak; Mansur Harmandar; Yunus Çetintaş

    2013-01-01

    In this study, phenolic content of Pinus brutia ’s bark was examined using an ultra-performance liquid chromatography tandem mass spectrometry with electrospray ionization source (UPLC-ESI-MS/MS) working in multiple reaction monitoring mode. U ltrasonic extraction method with 50% ethanol solution was used for the extraction of bark. The bark of Pinus brutia consisted of 15 compounds: gallic acid, gentisic acid, protocatechuic acid, 4-hydroxy benzoic acid, catechin hydrate, vanillic acid, caff...

  15. Activity measurements of radioactive solutions by liquid scintillation counting and pressurized ionization chambers and Monte Carlo simulations of source-detector systems for metrology

    International Nuclear Information System (INIS)

    The research works 'Activity measurements of radioactive solutions by liquid scintillation and pressurized ionization chambers and Monte Carlo simulations of source-detector systems' was presented for the graduation: 'Habilitation a diriger des recherches'. The common thread of both themes liquid scintillation counting and pressurized ionization chambers lies in the improvement of the techniques of radionuclide activity measurement. Metrology of ionization radiation intervenes in numerous domains, in the research, in the industry including the environment and the health, which are subjects of constant concern for the world population these last years. In this big variety of applications answers a large number of radionuclides of diverse disintegration scheme and under varied physical forms. The presented works realized within the National Laboratory Henri Becquerel have for objective to assure detector calibration traceability and to improve the methods of activity measurements within the framework of research projects and development. The improvement of the primary and secondary activity measurement methods consists in perfecting the accuracy of the measurements in particular by a better knowledge of the parameters influencing the detector yield. The works of development dealing with liquid scintillation counting concern mainly the study of the response of liquid scintillators to low energy electrons as well as their linear absorption coefficients using synchrotron radiation. The research works on pressurized ionization chambers consist of the study of their response to photons and electrons by experimental measurements compared to the simulation of the source-detector system using Monte Carlo codes. Besides, the design of a new type of ionization chamber with variable pressure is presented. This new project was developed to guarantee the precision of the amount of activity injected into the patient within the framework of diagnosis examination

  16. Scheduling and Power Management Facilities in Linux/RTAI for Real-time Systems powered by Ambient Energy Source

    OpenAIRE

    Chetto, Maryline; Queudet, Audrey

    2011-01-01

    National audience; In this paper, we present a component-based development project dedicated to real-time embedded harvesting systems. Energy harvesting consists in converting the ambient energy into electricity to power electronic devices, making them self-sufficient. Instead of minimizing its energy consumption, such a system must operate in a so-called energy neutral mode by consuming only as much energy as harvested in the environment. Consequently, our objective is to develop and integra...

  17. Ionization gage

    International Nuclear Information System (INIS)

    An ionization manometer is proposed which contains a transducer consisting of an anode, a directly heated cathode and a collector, a power source, a cathode emission current stabilizer, an ionic current amplifier connected to a recorder, and a cathode emission current modulator. To increase the accuracy of measurements under conditions of vacuum evaporation of materials, the modulator has been designed to comprise a source of controlling electric unipolar pulses of a specified duration and frequency and a blocking device connected to the collector. The output of the source of controlling electric unipolar pulses is connected to the emission current stabilizer and to the second input of the blocking device whose output is connected to the ionic current amplifier. The amount of pressure exerted in the vacuum chamber is estimated from the magnitude of the variable constituent of the collector signal

  18. Performance of a high repetition pulse rate laser system for in-gas-jet laser ionization studies with the Leuven laser ion source LISOL

    Energy Technology Data Exchange (ETDEWEB)

    Ferrer, R., E-mail: Rafael.Ferrer@fys.kuleuven.be [Instituut voor Kern- en Stralingsfysica, KU Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Sonnenschein, V.T. [Department of Physics, University of Jyvaeskylae, P.O. Box 35 (YFL), FI-40014 Jyvaeskylae (Finland); Bastin, B. [GANIL, CEA/DSM-CNRS/IN2P3, B.P. 55027, 14076 Caen (France); Franchoo, S. [Institut de Physique Nucleaire (IPN) d' Orsay, 91406 Orsay, Cedex (France); Huyse, M.; Kudryavtsev, Yu. [Instituut voor Kern- en Stralingsfysica, KU Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Kron, T. [Institut fuer Physik, Universitaet Mainz, D-55128 Mainz (Germany); Lecesne, N. [GANIL, CEA/DSM-CNRS/IN2P3, B.P. 55027, 14076 Caen (France); Moore, I.D. [Department of Physics, University of Jyvaeskylae, P.O. Box 35 (YFL), FI-40014 Jyvaeskylae (Finland); Osmond, B. [GANIL, CEA/DSM-CNRS/IN2P3, B.P. 55027, 14076 Caen (France); Pauwels, D. [SCK-CEN, Belgian Nuclear Research Center, Boeretang 200, 2400 Mol (Belgium); Radulov, D. [Instituut voor Kern- en Stralingsfysica, KU Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Raeder, S. [Institut fuer Physik, Universitaet Mainz, D-55128 Mainz (Germany); Rens, L. [Instituut voor Kern- en Stralingsfysica, KU Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium); and others

    2012-11-15

    The laser ionization efficiency of the Leuven gas cell-based laser ion source was investigated under on- and off-line conditions using two distinctly different laser setups: a low-repetition rate dye laser system and a high-repetition rate Ti:sapphire laser system. A systematic study of the ion signal dependence on repetition rate and laser pulse energy was performed in off-line tests using stable cobalt and copper isotopes. These studies also included in-gas-jet laser spectroscopy measurements on the hyperfine structure of {sup 63}Cu. A final run under on-line conditions in which the radioactive isotope {sup 59}Cu (T{sub 1/2} = 81.5 s) was produced, showed a comparable yield of the two laser systems for in-gas-cell ionization. However, a significantly improved time overlap by using the high-repetition rate laser system for in-gas-jet ionization was demonstrated by an increase of the overall duty cycle, and at the same time, pointed to the need for a better shaped atomic jet to reach higher ionization efficiencies.

  19. Liquid Sampling-Atmospheric Pressure Glow Discharge (LS-APGD) Ionization Source for Elemental Mass Spectrometry: Preliminary Parametric Evaluation and Figures of Merit

    Energy Technology Data Exchange (ETDEWEB)

    Quarles, C. Derrick; Carado, Anthony J.; Barinaga, Charles J.; Koppenaal, David W.; Marcus, R. Kenneth

    2012-01-01

    A new, low power ionization source for the elemental analysis of aqueous solutions has recently been described. The liquid sampling-atmospheric pressure glow discharge (LS-APGD) source operates at relatively low currents (<20 mA) and solution flow rates (<50 μL min-1), yielding a relatively simple alternative for atomic mass spectrometry applications. The LS-APGD has been interfaced to what is otherwise an organic, LC-MS mass analyzer, the Thermo Scientific Exactive Orbitrap without any modifications; other than removing the electrospray ionization (ESI) source supplied with that instrument. A glow discharge is initiated between the surface of the test solution exiting a glass capillary and a metallic counter electrode mounted at a 90° angle and separated by a distance of ~5 mm. As with any plasma-based ionization source, there are key discharge operation and ion sampling parameters that affect the intensity and composition of the derived mass spectra; including signal-to-background ratios. We describe here a preliminary parametric evaluation of the roles of discharge current, solution flow rate, argon sheath gas flow rate, and ion sampling distance as they apply on this mass analyzer system. A cursive evaluation of potential matrix effects due to the presence of easily ionized elements (EIEs) indicate that sodium concentrations of up to 500 μg mL-1 generally cause suppressions of less than 50%, dependant upon the analyte species. Based on the results of this series of studies, preliminary limits of detection (LOD) have been established through the generation of calibration functions. Whilst solution-based concentrations LOD levels of 0.02 – 2 μg mL-1 3 are not impressive on the surface, the fact that they are determined via discrete 5 μL injections leads to mass-based detection limits at picogram to singlenanogram levels. The overhead costs associated with source operation (10 W d.c. power, solution flow rates of <50 μL min-1, and gas flow rates <10 mL min

  20. Estimating source-attributable health impacts of ambient fine particulate matter exposure: global premature mortality from surface transportation emissions in 2005

    International Nuclear Information System (INIS)

    Exposure to ambient fine particular matter (PM2.5) was responsible for 3.2 million premature deaths in 2010 and is among the top ten leading risk factors for early death. Surface transportation is a significant global source of PM2.5 emissions and a target for new actions. The objective of this study is to estimate the global and national health burden of ambient PM2.5 exposure attributable to surface transportation emissions. This share of health burden is called the transportation attributable fraction (TAF), and is assumed equal to the proportional decrease in modeled ambient particulate matter concentrations when surface transportation emissions are removed. National population-weighted TAFs for 190 countries are modeled for 2005 using the MOZART-4 global chemical transport model. Changes in annual average concentration of PM2.5 at 0.5 × 0.67 degree horizontal resolution are based on a global emissions inventory and removal of all surface transportation emissions. Global population-weighted average TAF was 8.5 percent or 1.75 μg m−3 in 2005. Approximately 242 000 annual premature deaths were attributable to surface transportation emissions, dominated by China, the United States, the European Union and India. This application of TAF allows future Global Burden of Disease studies to estimate the sector-specific burden of ambient PM2.5 exposure. Additional research is needed to capture intraurban variations in emissions and exposure, and to broaden the range of health effects considered, including the effects of other pollutants. (letter)

  1. Ambient Space and Ambient Sensation

    DEFF Research Database (Denmark)

    Schmidt, Ulrik

    The ambient is the aesthetic production of the sensation of being surrounded. As a concept, 'ambient' is mostly used in relation to the music genre 'ambient music' and Brian Eno's idea of environmental background music. However, the production of ambient sensations must be regarded as a central...... aspect of the aesthetization of modern culture in general, from architecture, transport and urbanized lifeforms to film, sound art, installation art and digital environments. This presentation will discuss the key aspects of ambient aesthetization, including issues such as objectlessness...

  2. Preliminary exploration of energy transfer about sample ionization process in electrospray ionization source%电喷雾离子源中样品离子化能量转移理论的初探

    Institute of Scientific and Technical Information of China (English)

    张维冰; 高方园; 关亚风; 张玉奎

    2014-01-01

    电喷雾离子源(electrospray ionization,ESI)不仅可以用于小分子的检测,也能够用于蛋白质、多肽等大分子的研究。本文通过对离子化过程的系统分析,提出了基于能量最低原理的离子化过程能量转移理论。样品分子在由液相转移到气相形成离子化气体的过程中受到静电力、分子间的范德华力等多种力的作用。样品的离子化是多种力共同作用的结果,在不同的离子化阶段,不同形式的力的作用也不尽相同。电荷在样品表面蒸发和多电荷离子的形成之间存在竞争。对不同结构的分子,分子形态、构象改变导致的两相间转移 Gibbs 自由能变化不同,可能导致离子蒸发、大分子形成多电荷离子、产生链弹射等行为。离子化能量转移理论不仅能够对已有的3种理论加以简化统一,也可以说明溶剂、电解质离子等在离子化过程中的作用,为优化不同结构与形态样品的质谱检测、了解离子化的真实过程提供了一种可能的依据。%Electrospray ionization source(ESI)can be used not only for the detection of small molecules,but also for large molecules such as proteins and peptides. This article proposes energy transfer theory based on the lowest energy principle by systematically analyzing ioniza-tion processes. The transference of the analyte from liquid phase to gas phase can be influenced by multiple forces during the ionization and vaporization processes,such as electrostatics force and van der Waals’force. The ionization of samples is the result of the interactions among mul-tiple forces. During different stages of the ionization process,different forces lead to different effects. There are competition between evaporation and formation of multi-charge ions for char-ges. For molecules with different structures,Gibbs free energy between two phases from the changes of molecule shape or conformation may lead to ion evaporation

  3. Spatially resolved protein hydrogen exchange measured by matrix-assisted laser desorption ionization in-source decay

    DEFF Research Database (Denmark)

    Rand, Kasper D; Bache, Nicolai; Nedertoft, Morten M;

    2011-01-01

    Mass spectrometry has become a powerful tool for measuring protein hydrogen exchange and thereby reveal the structural dynamics of proteins in solution. Here we describe the successful application of a matrix-assisted laser desorption ionization (MALDI) mass spectrometry approach based on in...

  4. Global optimization of the infrared matrix-assisted laser desorption electrospray ionization (IR MALDESI) source for mass spectrometry using statistical design of experiments.

    Science.gov (United States)

    Barry, Jeremy A; Muddiman, David C

    2011-12-15

    Design of experiments (DOE) is a systematic and cost-effective approach to system optimization by which the effects of multiple parameters and parameter interactions on a given response can be measured in few experiments. Herein, we describe the use of statistical DOE to improve a few of the analytical figures of merit of the infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) source for mass spectrometry. In a typical experiment, bovine cytochrome c was ionized via electrospray, and equine cytochrome c was desorbed and ionized by IR-MALDESI such that the ratio of equine:bovine was used as a measure of the ionization efficiency of IR-MALDESI. This response was used to rank the importance of seven source parameters including flow rate, laser fluence, laser repetition rate, ESI emitter to mass spectrometer inlet distance, sample stage height, sample plate voltage, and the sample to mass spectrometer inlet distance. A screening fractional factorial DOE was conducted to designate which of the seven parameters induced the greatest amount of change in the response. These important parameters (flow rate, stage height, sample to mass spectrometer inlet distance, and laser fluence) were then studied at higher resolution using a full factorial DOE to obtain the globally optimized combination of parameter settings. The optimum combination of settings was then compared with our previously determined settings to quantify the degree of improvement in detection limit. The limit of detection for the optimized conditions was approximately 10 attomoles compared with 100 femtomoles for the previous settings, which corresponds to a four orders of magnitude improvement in the detection limit of equine cytochrome c.

  5. A simplified analytical approach to estimate the parameters required for strength determination of HDR 192Ir brachytherapy sources using a Farmer-type ionization chamber

    International Nuclear Information System (INIS)

    Measuring the strength of high dose rate (HDR) 192Ir brachytherapy sources on receipt from the vendor is an important component of a quality assurance program. Owing to their ready availability in radiotherapy departments, the Farmer-type ionization chambers are also used to determine the strength of HDR 192Ir brachytherapy sources. The use of a Farmer-type ionization chamber requires the estimation of the scatter correction factor along with positioning error (c) and the constant of proportionality (f) to determine the strength of HDR 192Ir brachytherapy sources. A simplified approach based on a least squares method was developed for estimating the values of f and Ms. The seven distance method was followed to record the ionization chamber readings for parameterization of f and Ms. Analytically calculated values of Ms were used to determine the room scatter correction factor (Ksc). The Monte Carlo simulations were also carried out to calculate f and Ksc to verify the magnitude of the parameters determined by the proposed analytical approach. The value of f determined using the simplified analytical approach was found to be in excellent agreement with the Monte Carlo simulated value (within 0.7%). Analytically derived values of Ksc were also found to be in good agreement with the Monte Carlo calculated values (within 1.47%). Being far simpler than the presently available methods of evaluating f, the proposed analytical approach can be adopted for routine use by clinical medical physicists to estimate f by hand calculations. - Highlights: ► RAKR measurement of a brachytherapy source by 7 distance method requires the evaluation of ‘f’. ► A simplified analytical approach based on least square method to evaluate ‘f’ and ‘Ms’ was developed. ► Parameter ‘f’ calculated by proposed analytical approach was verified using the Monte Carlo method. ► Proposed analytical approach can be adopted for routine use to estimate ‘f’.

  6. Source apportionment of the ambient PM2.5 across St. Louis using constrained positive matrix factorization

    NARCIS (Netherlands)

    Amato, F.; Hopke, P.K.

    2012-01-01

    In most cases, receptor models are applied to data from a single monitoring site even if there are multiple sampling locations in a given urban area. When it can be reasonably expected that the sites are affected by the same set of sources, it is possible to use the spatial variability of the source

  7. The ionizing treatment of food

    International Nuclear Information System (INIS)

    This book of proceedings contains the talks given by the members of the Society of chemical experts of France (SECF) and by various specialists of the ionizing treatment during the scientific days of September 25-26, 1997. The aim of this meeting was to reconsider the effects of ionization from a scientific point of view and apart from the polemics generated by this domain. The following topics were discussed successively: source and characterization of a ionizing treatment, biological effects of ionization on food and the expected consequences, the ionizing treatment and the reduction of the vitamin C content of fruits and vegetables, is it safe to eat irradiated food?, the organoleptic modifications of food after ionization, quality assurance of dosimetry measurements in an industrial installation of food ionization, the French and European regulations in food ionization, the detection of irradiated foodstuffs, processed food and complex lipid matrices, sterilization of dishes for immuno-depressed patients using ionization. (J.S.)

  8. Comparison of sources of urban ambient particle bound PAHs between non-heating seasons 2009 and 2012 in Belgrade, Serbia

    Directory of Open Access Journals (Sweden)

    Cvetković Anka

    2015-01-01

    Full Text Available Exposure to increased cconcentrations of polycyclic aromatic hydrocarbons (PAHs is associated with adverse health problems and specifically with carcinogenic and mutagenic effects. The major PAH sources outdoors are: stationary sources from industry (power plants, incineration, local industry and domestic sources as the residential heating, burning and pyrolysis of coal, oil, gas, garbage, wood, or other organic substances mobile emissions (diesel and petrol engines, biomass burning and agricultural activities (e.g., open burning of brushwood, straw, stubble. The aim of this study was to assess potential differences in particle-bound PAH levels and source contribution between summer 2009 and 2012 sampling campaigns done at same location in Belgrade urban area. The sampling location is considered representative for a mix of residential, business and industrial areas of New Belgrade, an urban area that has been under rapid development. The average concentrations of PM10 are slightly higher in summer 2012 than in 2009. PM-bound PAH follow the same trend as the PM indicating an increasing strength of PAH sources relative to all PM sources. Appling Positive Matrix Factorization, three potential sources of PAHs in the atmosphere were distinguished: (1 stationary sources, (2 traffic (diesel and gasoline vehicle exhaust and (3 local open burning sources (OBS. The analysis confirmed higher contribution of traffic and lower of OBS in summer 2012 than in 2009, reflecting higher traffic volumes and absence of or lower local OBS emissions due to burning wood, grass and domestic waste in 2012. [Projekat Ministarstva nauke Republike Srbije, br. III41028

  9. Ambient Sensors

    NARCIS (Netherlands)

    Börner, Dirk; Specht, Marcus

    2014-01-01

    This software sketches comprise two custom-built ambient sensors, i.e. a noise and a movement sensor. Both sensors measure an ambient value and process the values to a color gradient (green > yellow > red). The sensors were built using the Processing 1.5.1 development environment. Available under th

  10. Det ambiente

    DEFF Research Database (Denmark)

    Schmidt, Ulrik

    Om begrebet "det ambiente", der beskriver, hvad der sker, når vi fornemmer baggrundsmusikkens diskrete beats, betragter udsigten gennem panoramavinduet eller tager 3D-brillerne på og læner os tilbage i biografsædet. Bogen analyserer, hvorfan ambiente oplevelser skabes, og hvilke konsekvenser det...

  11. Effect of Electrospray Ionization Source Conditions on the Tautomer Distribution of Deprotonated p-Hydroxybenzoic Acid in the Gas Phase.

    Science.gov (United States)

    Xia, Hanxue; Attygalle, Athula B

    2016-06-01

    The deprotonation site of p-hydroxybenzoic acid upon electrospray ionization has been a subject of fervent debate in several articles in the Journal of the American Chemical Society and elsewhere. General consensus is that electrospray ionization mass spectrometry (ESI-MS) experimental results reflect the situation in solution to a considerable extent. Our research, using ion-mobility mass spectrometry, challenges the notion that ESI-MS results directly reflect solution-phase structures and demonstrates that the relative populations of the thermodynamically less favored gaseous carboxylate tautomer or the thermodynamically more favored gaseous phenoxide tautomer, generated from the same aqueous solution of p-hydroxybenzoic acid by ESI, can be varied back and forth by changing the probe position, capillary voltage, desolvation-gas temperature, sample infusion flow rate, and cone voltage. In other words, solvent effects are not the primary criteria that determine the relative population distributions of tautomeric carboxylate (C(-)) and phenoxide (P(-)) ions (m/z 137) generated by electrospray ionization of p-hydroxybenzoic acid. In addition, we propose that the observed ratio of the P(-) and C(-) forms indirectly reflects the relative contribution of the charge-residue or ion-evaporation process that occurs during the electrospray ion generation process. PMID:27164186

  12. Supercritical fluid chromatography coupled with in-source atmospheric pressure ionization hydrogen/deuterium exchange mass spectrometry for compound speciation.

    Science.gov (United States)

    Cho, Yunju; Choi, Man-Ho; Kim, Byungjoo; Kim, Sunghwan

    2016-04-29

    An experimental setup for the speciation of compounds by hydrogen/deuterium exchange (HDX) with atmospheric pressure ionization while performing chromatographic separation is presented. The proposed experimental setup combines the high performance supercritical fluid chromatography (SFC) system that can be readily used as an inlet for mass spectrometry (MS) and atmospheric pressure photo ionization (APPI) or atmospheric pressure chemical ionization (APCI) HDX. This combination overcomes the limitation of an approach using conventional liquid chromatography (LC) by minimizing the amount of deuterium solvents used for separation. In the SFC separation, supercritical CO2 was used as a major component of the mobile phase, and methanol was used as a minor co-solvent. By using deuterated methanol (CH3OD), AP HDX was achieved during SFC separation. To prove the concept, thirty one nitrogen- and/or oxygen-containing standard compounds were analyzed by SFC-AP HDX MS. The compounds were successfully speciated from the obtained SFC-MS spectra. The exchange ions were observed with as low as 1% of CH3OD in the mobile phase, and separation could be performed within approximately 20min using approximately 0.24 mL of CH3OD. The results showed that SFC separation and APPI/APCI HDX could be successfully performed using the suggested method.

  13. Reduction of plasma density in the Helicity Injected Torus with Steady Inductance experiment by using a helicon pre-ionization source.

    Science.gov (United States)

    Hossack, Aaron C; Firman, Taylor; Jarboe, Thomas R; Prager, James R; Victor, Brian S; Wrobel, Jonathan S; Ziemba, Timothy

    2013-10-01

    A helicon based pre-ionization source has been developed and installed on the Helicity Injected Torus with Steady Inductance (HIT-SI) spheromak. The source initiates plasma breakdown by injecting impurity-free, unmagnetized plasma into the HIT-SI confinement volume. Typical helium spheromaks have electron density reduced from (2-3) × 10(19) m(-3) to 1 × 10(19) m(-3). Deuterium spheromak formation is possible with density as low as 2 × 10(18) m(-3). The source also enables HIT-SI to be operated with only one helicity injector at injector frequencies above 14.5 kHz. A theory explaining the physical mechanism driving the reduction of breakdown density is presented.

  14. Liquid sampling-atmospheric pressure glow discharge (LS-APGD) ionization source for elemental mass spectrometry: preliminary parametric evaluation and figures of merit.

    Science.gov (United States)

    Quarles, C Derrick; Carado, Anthony J; Barinaga, Charles J; Koppenaal, David W; Marcus, R Kenneth

    2012-01-01

    A new, low-power ionization source for the elemental analysis of aqueous solutions has recently been described. The liquid sampling-atmospheric pressure glow discharge (LS-APGD) source operates at relatively low currents (elements indicate that sodium concentrations of up to 50 μg mL(-1) generally cause suppressions of less than 50%, dependant upon the analyte species. Based on the results of this series of studies, preliminary limits of detection (LOD) have been established through the generation of calibration functions. While solution-based concentration LOD levels of 0.02-2 μg mL(-1) are not impressive on the surface, the fact that they are determined via discrete 5 μL injections leads to mass-based detection limits at picogram to single-nanogram levels. The overhead costs associated with source operation (10 W d.c. power, solution flow rates of elemental mass spectrometry. PMID:21910014

  15. A simplified analytical approach to estimate the parameters required for strength determination of HDR 192Ir brachytherapy sources using a Farmer-type ionization chamber.

    Science.gov (United States)

    Kumar, Sudhir; Srinivasan, P; Sharma, S D; Mayya, Y S

    2012-01-01

    Measuring the strength of high dose rate (HDR) (192)Ir brachytherapy sources on receipt from the vendor is an important component of a quality assurance program. Owing to their ready availability in radiotherapy departments, the Farmer-type ionization chambers are also used to determine the strength of HDR (192)Ir brachytherapy sources. The use of a Farmer-type ionization chamber requires the estimation of the scatter correction factor along with positioning error (c) and the constant of proportionality (f) to determine the strength of HDR (192)Ir brachytherapy sources. A simplified approach based on a least squares method was developed for estimating the values of f and M(s). The seven distance method was followed to record the ionization chamber readings for parameterization of f and M(s). Analytically calculated values of M(s) were used to determine the room scatter correction factor (K(sc)). The Monte Carlo simulations were also carried out to calculate f and K(sc) to verify the magnitude of the parameters determined by the proposed analytical approach. The value of f determined using the simplified analytical approach was found to be in excellent agreement with the Monte Carlo simulated value (within 0.7%). Analytically derived values of K(sc) were also found to be in good agreement with the Monte Carlo calculated values (within 1.47%). Being far simpler than the presently available methods of evaluating f, the proposed analytical approach can be adopted for routine use by clinical medical physicists to estimate f by hand calculations.

  16. Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE): Emissions of particulate matter from wood and dung cooking fires, brick kilns, generators, trash and crop residue burning

    Science.gov (United States)

    Stone, Elizabeth; Jayarathne, Thilina; Stockwell, Chelsea; Christian, Ted; Bhave, Prakash; Siva Praveen, Puppala; Panday, Arnico; Adhikari, Sagar; Maharjan, Rashmi; Goetz, Doug; DeCarlo, Peter; Saikawa, Eri; Yokelson, Robert

    2016-04-01

    The Nepal Ambient Monitoring and Source Testing Experiment (NAMASTE) field campaign targeted the in situ characterization of widespread and under-sampled combustion sources. In Kathmandu and the Terai, southern Nepal's flat plains, samples of fine particulate matter (PM2.5) were collected from wood and dung cooking fires (n = 22), generators (n = 2), groundwater pumps (n = 2), clamp kilns (n = 3), zig-zag kilns (n = 3), trash burning (n = 4), one heating fire, and one crop residue fire. Co-located measurements of carbon dioxide, carbon monoxide, and volatile organic compounds allowed for the application of the carbon mass balance approach to estimate emission factors for PM2.5, elemental carbon, organic carbon, and water-soluble inorganic ions. Organic matter was chemically speciated using gas chromatography - mass spectrometry for polycyclic aromatic hydrocarbons, sterols, n-alkanes, hopanes, steranes, and levoglucosan, which accounted for 2-8% of the measured organic carbon. These data were used to develop molecular-marker based profiles for use in source apportionment modeling. This study provides quantitative emission factors for particulate matter and its constituents for many important combustion sources in Nepal and South Asia.

  17. Ambient mass spectrometry imaging

    DEFF Research Database (Denmark)

    Janfelt, Christian; Nørgaard, Asger W

    2012-01-01

    Easy ambient sonic spray ionization (EASI) and desorption electrospray ionization (DESI) were used for imaging of a number of samples, including sections of rat brain and imprints of plant material on porous Teflon. A novel approach termed Displaced Dual-mode Imaging was utilized for the direct...... comparison of the two methods: Images were recorded with the individual rows alternating between EASI and DESI, yielding a separate image for each technique recorded under perfectly similar conditions on the same sample. EASI works reliably for imaging of all samples, but the choice of spray solvent and flow...... rate is more critical in tissue imaging with EASI than with DESI. The overall sensitivity of EASI is, in general, slightly lower than that of DESI, and the representation of the dynamic range is different in images of the two techniques for some samples. However, for abundant compounds, EASI works well...

  18. Det Ambiente

    DEFF Research Database (Denmark)

    Schmidt, Ulrik

    Det ambiente er iscenesættelsen af en karakteristisk sanseoplevelse, der er kendetegnet ved fornemmelsen af at være omgivet. I dag bliver begrebet om det ambiente mest anvendt i forbindelse med musikgenren ’ambient musik’. Det ambiente er dog ikke essentielt knyttet til det musikalske, men må...... forstås som et betydeligt bredere fænomen i den moderne æstetiske kultur, der spiller en væsentlig rolle i oplevelsen af moderne transportformer, arkitektur, film, lydkunst, installationskunst og digitale multimedieiscenesættelser. En forståelse af det ambiente er derfor centralt for forståelsen af en...... moderne æstetiseret oplevelseskultur i almindelighed. Da det ambiente ikke hidtil har været gjort til genstand for en mere indgående teoretisk behandling, er der dog stor usikkerhed omkring, hvad fænomenet overhovedet indebærer. Hovedformålet med Det ambiente – Sansning, medialisering, omgivelse er derfor...

  19. Potential of atmospheric pressure chemical ionization source in gas chromatography tandem mass spectrometry for the screening of urinary exogenous androgenic anabolic steroids.

    Science.gov (United States)

    Raro, M; Portolés, T; Pitarch, E; Sancho, J V; Hernández, F; Garrostas, L; Marcos, J; Ventura, R; Segura, J; Pozo, O J

    2016-02-01

    The atmospheric pressure chemical ionization (APCI) source for gas chromatography-mass spectrometry analysis has been evaluated for the screening of 16 exogenous androgenic anabolic steroids (AAS) in urine. The sample treatment is based on the strategy currently applied in doping control laboratories i.e. enzymatic hydrolysis, liquid-liquid extraction (LLE) and derivatization to form the trimethylsilyl ether-trimethylsilyl enol ether (TMS) derivatives. These TMS derivatives are then analyzed by gas chromatography tandem mass spectrometry using a triple quadrupole instrument (GC-QqQ MS/MS) under selected reaction monitoring (SRM) mode. The APCI promotes soft ionization with very little fragmentation resulting, in most cases, in abundant [M + H](+) or [M + H-2TMSOH](+) ions, which can be chosen as precursor ions for the SRM transitions, improving in this way the selectivity and sensitivity of the method. Specificity of the transitions is also of great relevance, as the presence of endogenous compounds can affect the measurements when using the most abundant ions. The method has been qualitatively validated by spiking six different urine samples at two concentration levels each. Precision was generally satisfactory with RSD values below 25 and 15% at the low and high concentration level, respectively. Most the limits of detection (LOD) were below 0.5 ng mL(-1). Validation results were compared with the commonly used method based on the electron ionization (EI) source. EI analysis was found to be slightly more repeatable whereas lower LODs were found for APCI. In addition, the applicability of the developed method has been tested in samples collected after the administration of 4-chloromethandienone. The highest sensitivity of the APCI method for this compound, allowed to increase the period in which its administration can be detected. PMID:26772132

  20. Potential of atmospheric pressure chemical ionization source in gas chromatography tandem mass spectrometry for the screening of urinary exogenous androgenic anabolic steroids.

    Science.gov (United States)

    Raro, M; Portolés, T; Pitarch, E; Sancho, J V; Hernández, F; Garrostas, L; Marcos, J; Ventura, R; Segura, J; Pozo, O J

    2016-02-01

    The atmospheric pressure chemical ionization (APCI) source for gas chromatography-mass spectrometry analysis has been evaluated for the screening of 16 exogenous androgenic anabolic steroids (AAS) in urine. The sample treatment is based on the strategy currently applied in doping control laboratories i.e. enzymatic hydrolysis, liquid-liquid extraction (LLE) and derivatization to form the trimethylsilyl ether-trimethylsilyl enol ether (TMS) derivatives. These TMS derivatives are then analyzed by gas chromatography tandem mass spectrometry using a triple quadrupole instrument (GC-QqQ MS/MS) under selected reaction monitoring (SRM) mode. The APCI promotes soft ionization with very little fragmentation resulting, in most cases, in abundant [M + H](+) or [M + H-2TMSOH](+) ions, which can be chosen as precursor ions for the SRM transitions, improving in this way the selectivity and sensitivity of the method. Specificity of the transitions is also of great relevance, as the presence of endogenous compounds can affect the measurements when using the most abundant ions. The method has been qualitatively validated by spiking six different urine samples at two concentration levels each. Precision was generally satisfactory with RSD values below 25 and 15% at the low and high concentration level, respectively. Most the limits of detection (LOD) were below 0.5 ng mL(-1). Validation results were compared with the commonly used method based on the electron ionization (EI) source. EI analysis was found to be slightly more repeatable whereas lower LODs were found for APCI. In addition, the applicability of the developed method has been tested in samples collected after the administration of 4-chloromethandienone. The highest sensitivity of the APCI method for this compound, allowed to increase the period in which its administration can be detected.

  1. Ambient Gestures

    OpenAIRE

    Karam, Maria; Hare, Jonathon; Lewis, Paul; schraefel, m.c.

    2006-01-01

    We present Ambient Gestures, a novel gesture-based system designed to support ubiquitous ‘in the environment’ interactions with everyday computing technology. Hand gestures and audio feedback allow users to control computer applications without reliance on a graphical user interface, and without having to switch from the context of a non-computer task to the context of the computer. The Ambient Gestures system is composed of a vision recognition software application, a set of gestures to be p...

  2. Waste water treatment plants as sources of polyfluorinated compounds, polybrominated diphenyl ethers and musk fragrances to ambient air

    International Nuclear Information System (INIS)

    To investigate waste water treatment plants (WWTPs) as sources of polyfluorinated compounds (PFCs), polybrominated diphenyl ethers (PBDEs) and synthetic musk fragrances to the atmosphere, air samples were simultaneously taken at two WWTPs and two reference sites using high volume samplers. Contaminants were accumulated on glass fiber filters and PUF/XAD-2/PUF cartridges, extracted compound-dependent by MTBE/acetone, methanol, or hexane/acetone and detected by GC-MS or HPLC-MS/MS. Total (gas + particle phase) concentrations ranged from 97 to 1004 pg m-3 (neutral PFCs), -3 (ionic PFCs), 5781 to 482,163 pg m-3 (musk fragrances) and -3 (PBDEs) and were usually higher at WWTPs than at corresponding reference sites, revealing that WWTPs can be regarded as sources of musk fragrances, PFCs and probably PBDEs to the atmosphere. Different concentrations at the two WWTPs indicated an influence of WWTP size or waste water origin on emitted contaminant amounts. - Waste water treatment plants can be regarded as sources of musk fragrances, polyfluorinated compounds (PFCs) and polybrominated diphenyl ethers (PBDEs) to the atmosphere

  3. Waste water treatment plants as sources of polyfluorinated compounds, polybrominated diphenyl ethers and musk fragrances to ambient air

    Energy Technology Data Exchange (ETDEWEB)

    Weinberg, Ingo, E-mail: ingoweinberg@web.d [GKSS Research Centre Geesthacht, Max Planck Str. 1, 21502 Geesthacht (Germany); Leuphana University Lueneburg, Institute for Ecology and Environmental Chemistry, Scharnhorststr. 1, 21335 Lueneburg (Germany); Dreyer, Annekatrin; Ebinghaus, Ralf [GKSS Research Centre Geesthacht, Max Planck Str. 1, 21502 Geesthacht (Germany)

    2011-01-15

    To investigate waste water treatment plants (WWTPs) as sources of polyfluorinated compounds (PFCs), polybrominated diphenyl ethers (PBDEs) and synthetic musk fragrances to the atmosphere, air samples were simultaneously taken at two WWTPs and two reference sites using high volume samplers. Contaminants were accumulated on glass fiber filters and PUF/XAD-2/PUF cartridges, extracted compound-dependent by MTBE/acetone, methanol, or hexane/acetone and detected by GC-MS or HPLC-MS/MS. Total (gas + particle phase) concentrations ranged from 97 to 1004 pg m{sup -3} (neutral PFCs), sources of musk fragrances, PFCs and probably PBDEs to the atmosphere. Different concentrations at the two WWTPs indicated an influence of WWTP size or waste water origin on emitted contaminant amounts. - Waste water treatment plants can be regarded as sources of musk fragrances, polyfluorinated compounds (PFCs) and polybrominated diphenyl ethers (PBDEs) to the atmosphere

  4. High-field asymmetric waveform ion mobility spectrometry for determining the location of in-source collision-induced dissociation in electrospray ionization mass spectrometry.

    Science.gov (United States)

    Xia, Yuan-Qing; Jemal, Mohammed

    2009-09-15

    The understanding and control of the in-source collision-induced dissociation (CID) of analytes is important for the accurate LC-MS/MS quantitation of drugs and metabolites in biological samples. Accordingly, it was of interest to us to establish whether such in-source CID takes place after and/or before the orifice of an electrospray ionization (ESI) mass spectrometer. A high-field asymmetric waveform ion mobility spectrometry (FAIMS) system that is physically located between the sprayer and the orifice of a mass spectrometer can serve as an ion filter to control ions entering the orifice of the mass spectrometer. In such a configuration, FAIMS could conceivably be used to determine if the in-source CID of an analyte occurs after and/or before the mass spectrometer orifice. We demonstrated this capability of FAIMS using ifetroban acylglucuronide metabolite as a model compound. Under the conditions used, the results showed that the in-source CID conversion of the acylglucuronide metabolite to its parent drug ifetroban occurred almost entirely after the orifice of the mass spectrometer, with the conversion upstream of the orifice accounting for only 5.6% of the conversion. Under the circumstance, the term "post-orifice CID" rather than "in-source CID" may be more appropriate in describing such a dissociation occurring in the front end of a mass spectrometer.

  5. A simplified analytical approach to estimate the parameters required for strength determination of HDR {sup 192}Ir brachytherapy sources using a Farmer-type ionization chamber

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Sudhir [Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, CTCRS, Anushaktinagar, Mumbai 400094 (India); Srinivasan, P. [Radiation Safety Systems Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Sharma, S.D., E-mail: sdsharma_barc@rediffmail.com [Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, CTCRS, Anushaktinagar, Mumbai 400094 (India); Mayya, Y.S. [Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, CTCRS, Anushaktinagar, Mumbai 400094 (India)

    2012-01-15

    Measuring the strength of high dose rate (HDR) {sup 192}Ir brachytherapy sources on receipt from the vendor is an important component of a quality assurance program. Owing to their ready availability in radiotherapy departments, the Farmer-type ionization chambers are also used to determine the strength of HDR {sup 192}Ir brachytherapy sources. The use of a Farmer-type ionization chamber requires the estimation of the scatter correction factor along with positioning error (c) and the constant of proportionality (f) to determine the strength of HDR {sup 192}Ir brachytherapy sources. A simplified approach based on a least squares method was developed for estimating the values of f and M{sub s}. The seven distance method was followed to record the ionization chamber readings for parameterization of f and M{sub s}. Analytically calculated values of M{sub s} were used to determine the room scatter correction factor (K{sub sc}). The Monte Carlo simulations were also carried out to calculate f and K{sub sc} to verify the magnitude of the parameters determined by the proposed analytical approach. The value of f determined using the simplified analytical approach was found to be in excellent agreement with the Monte Carlo simulated value (within 0.7%). Analytically derived values of K{sub sc} were also found to be in good agreement with the Monte Carlo calculated values (within 1.47%). Being far simpler than the presently available methods of evaluating f, the proposed analytical approach can be adopted for routine use by clinical medical physicists to estimate f by hand calculations. - Highlights: Black-Right-Pointing-Pointer RAKR measurement of a brachytherapy source by 7 distance method requires the evaluation of 'f'. Black-Right-Pointing-Pointer A simplified analytical approach based on least square method to evaluate 'f' and 'M{sub s}' was developed. Black-Right-Pointing-Pointer Parameter 'f' calculated by proposed analytical

  6. CONTAINMENT VESSEL TEMPERATURE FOR PU-238 HEAT SOURCE CONTAINER UNDER AMBIENT, FREE CONVECTION AND LOW EMISSIVITY COOLING CONDITIONS

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, N.; Smith, A.

    2011-02-14

    The EP-61 primary containment vessel of the 5320 shipping package has been used for storage and transportation of Pu-238 plutonium oxide heat source material. For storage, the material in its convenience canister called EP-60 is placed in the EP-61 and sealed by two threaded caps with elastomer O-ring seals. When the package is shipped, the outer cap is seal welded to the body. While stored, the EP-61s are placed in a cooling water bath. In preparation for welding, several containers are removed from storage and staged to the welding booth. The significant heat generation of the contents, and resulting rapid rise in component temperature necessitates special handling practices. The test described here was performed to determine the temperature rise with time and peak temperature attained for an EP-61 with 203 watts of internal heat generation, upon its removal from the cooling water bath.

  7. Control of Strobilurin Fungicides in Wheat Using Direct Analysis in Real Time Accurate Time-of-Flight and Desorption Electrospray Ionization Linear Ion Trap Mass Spectrometry

    NARCIS (Netherlands)

    Schurek, J.; Vaclavik, L.; Hooijerink, H.; Lacina, O.; Poustka, J.; Sharman, M.; Caldow, M.; Nielen, M.W.F.; Hajslova, J.

    2008-01-01

    Ambient mass spectrometry has been used for the analysis of strobilurin residues in wheat. The use of this novel, challenging technique, employing a direct analysis in a real time (DART) ion-source coupled with a time-of-flight mass spectrometer (TOF MS) and a desorption electrospray ionization (DES

  8. Preliminary Assessment of Potential for Metal-Ligand Speciation in Aqueous Solution via the Liquid Sampling-Atmospheric Pressure Glow Discharge (LS-APGD) Ionization Source: Uranyl Acetate.

    Science.gov (United States)

    Zhang, Lynn X; Manard, Benjamin T; Powell, Brian A; Marcus, R Kenneth

    2015-07-21

    The determination of metals, including the generation of metal-ligand speciation information, is essential across a myriad of biochemical, environmental, and industrial systems. Metal speciation is generally affected by the combination of some form of chromatographic separation (reflective of the metal-ligand chemistry) with element-specific detection for the quantification of the metal composing the chromatographic eluent. Thus, the identity of the metal-ligand is assigned by inference. Presented here, the liquid sampling-atmospheric pressure glow discharge (LS-APGD) is assessed as an ionization source for metal speciation, with the uranyl ion-acetate system used as a test system. Molecular mass spectra can be obtained from the same source by simple modification of the sustaining electrolyte solution. Specifically, chemical information pertaining to the degree of acetate complexation of uranyl ion (UO2(2+)) is assessed as a function of pH in the spectral abundance of three metallic species: inorganic (nonligated) uranyl, UO2Ac(H2O)n(MeOH)m(+), and UO2Ac2(H2O)n(MeOH)(m)H(+) (n = 1, 2, 3, ...; m = 1, 2, 3, ...). The product mass spectra are different from what are obtained from electrospray ionization sources that have been applied to this system. The resulting relationships between the speciation and pH values have been compared to calculated concentrations of the corresponding uranyl species: UO2(2+), UO2Ac(+), UO2Ac2. The capacity for the LS-APGD to affect both atomic mass spectra and structurally significant spectra for organometallic complexes is a unique and potentially powerful combination.

  9. Congener Profiles and Source-Wise Phase Partitioning Analysis of PCDDs/Fs and PCBs in Gyeonggi-Do Ambient Air, South Korea

    Directory of Open Access Journals (Sweden)

    Jongwon Heo

    2014-10-01

    Full Text Available The atmospheric concentrations and gas–particle partitioning of polychlorinated dibenzo-p-dioxins and furans (PCDDs/Fs and polychlorinated biphenyls (PCBs were investigated at two sites (Suwon and Ansan in Gyeonggi-do, a heavily industrialized area of Korea, during the year 2010. The sum level (Σ17 of PCDDs/Fs and dioxin-like PCBs (dl-PCBs in the ambient air at Suwon and Ansan ranged from 0.04 to 0.30 pg-TEQ·m−3 (geometric mean: 0.09 pg-TEQ·m−3 and 0.17 to 0.63 pg-TEQ·m−3 (geometric mean: 0.36 pg-TEQ·m−3, respectively. Moreover, the geometric mean concentrations of Σ180 PCBs at Suwon and Ansan were 233.6 pg·m−3 and 274.2 pg·m−3, respectively, and di-chlorinated biphenyls and tri-chlorinated biphenyls were the predominant homologs. Among the PCB congeners, 3,3'-dichlorobiphenyl (PCB-11 was the dominant species at both sites during all sampling periods, comprising up to 15.1% of Σ180 PCBs at Ansan and 24.6% at Suwon. We evaluated their gas-to-particle equilibriums by conducting regression between the particle–gas partition coefficient Kp (m3·ug−1 and the corresponding subcooled liquid vapor pressure (PL°. The slope (m values for log–log plots of Kp vs. PL° were steeper in industrial areas owing to local source proximity. Moreover, owing to enhanced emissions from combustion-related sources at low temperatures, PCDD/Fs exhibited the largest deviation from the regression line of the particle–gas partition coefficient. Incinerators were found to be the primary emission source of atmospheric PCDDs/Fs, whereas re-evaporation from pre-existing environmental loads (e.g., storage areas or spilled soil and water bodies was the dominant source for PCBs.

  10. Source apportionment of mass concentration and inhalation risk with long-term ambient PCDD/Fs measurements in an urban area.

    Science.gov (United States)

    Ho, Chi-Chang; Chan, Chang-Chuan; Chio, Chia-Pin; Lai, Yi-Chieh; Chang-Chien, Guo-Ping; Chow, Judith C; Watson, John G; Chen, Lung-Wen A; Chen, Pau-Chung; Wu, Chang-Fu

    2016-11-01

    This study applies a receptor model to quantify source contributions to ambient concentration of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and inhalation cancer risk in Taipei from 2003 through 2009. Seventeen PCDD/F congeners were used in the effective variance solution to the Chemical Mass Balance equations to estimate source-specific mass contributions and inhalation risks. The average total PCDD/F concentration was 0.611pg/Nm(3) (0.036pg I-TEQ/Nm(3)). Traffic emissions contributed the most to the PCDD/F concentration (55.7%), followed by waste incinerators (18.6%) and joss stick burning (9.6%). For the inhalation cancer risk, the average was 1.1×10(-6) with traffic, waste incinerators, and joss paper burning as the main contributors (67.3%, 19.4%, and 6.3%, respectively). The mass and risk contributions of waste incinerators decreased significantly from 2003 to 2009 and were higher at downwind sites than at upwind sites. Reducing PCDD/F emissions from traffic and waste incinerators would provide the greatest health benefit. Policies that reduce the uncontrolled burning of joss stick and joss paper also need to be implemented. PMID:27267692

  11. Star-forming Galactic Contrails at z=3.2 as a Source of Metal Enrichment and Ionizing Radiation

    CERN Document Server

    Rauch, Michael; Haehnelt, Martin G; Gauthier, Jean-Rene

    2013-01-01

    A spectroscopically detected Lyman alpha emitting halo at redshift 3.216 in the GOODS-N field is found to reside at the convergence of several Lyman alpha filaments. HST images show that some of the filaments are inhabited by galaxies. Several of the galaxies in the field have pronounced head-tail structures, which are partly aligned with each other. The blue colors of most tails suggest the presence of young stars, with the emission from at least one of the galaxies apparently dominated by high equivalent width Lyman alpha. Faint, more diffuse, and similarly elongated, apparently stellar features, can be seen over an area with a linear extent of at least 90 kpc. The region within several arcseconds of the brightest galaxy exhibits spatially extended emission by HeII, NV and various lower ionization metal lines. The gas-dynamical features present are strongly reminiscent of ram-pressure stripped galaxies, including evidence for recent star formation in the stripped contrails. Spatial gradients in the appearan...

  12. An instrument combining an electrospray ionization source and a velocity-map imaging spectrometer for studying delayed electron emission of polyanions

    Science.gov (United States)

    Concina, Bruno; Papalazarou, Evangelos; Barbaire, Marc; Clavier, Christian; Maurelli, Jacques; Lépine, Franck; Bordas, Christian

    2016-03-01

    An instrument combining an electrospray ionization source and a velocity-map imaging (VMI) spectrometer has been developed in order to study the delayed electron emission of molecular anions and especially of polyanions. It operates at a high repetition rate (kHz) in order to increase the acquisition speed. The VMI spectrometer has been upgraded for nanosecond time resolution by gating the voltages applied on the position-sensitive detector. Kinetic energy release distribution of thermionic emission (without any contribution from direct detachment) can be recorded for well-defined delays after the nanosecond laser excitation. The capability of the instrument is demonstrated by recording photodetachment spectra of the benchmark C60- anion and C842- dianion.

  13. Phenolic Compounds of Pinus brutia Ten.: Chemical Investigation and Quantitative Analysis Using an Ultra-Performance Liquid Chromatography Tandem Mass Spectrometry with Electrospray Ionization Source

    Directory of Open Access Journals (Sweden)

    İbrahim Kıvrak

    2013-08-01

    Full Text Available In this study, phenolic content of Pinus brutia ’s bark was examined using an ultra-performance liquid chromatography tandem mass spectrometry with electrospray ionization source (UPLC-ESI-MS/MS working in multiple reaction monitoring mode. U ltrasonic extraction method with 50% ethanol solution was used for the extraction of bark. The bark of Pinus brutia consisted of 15 compounds: gallic acid, gentisic acid, protocatechuic acid, 4-hydroxy benzoic acid, catechin hydrate, vanillic acid, caffeic acid, vanillin, p-coumaric acid, ferulic acid, myricetin, resveratrol, luteolin, naringenin, kaempferol. Major compound detected was catechin hydrate (28.305 mg 100 g -1 extract. The phenolic compounds of Pinus brutia extract and pycnogenol were compared, and it is shown that both of them consisted of considerable amount of phenolic compounds.

  14. Tissue Imaging Using Nanospray Desorption Electrospray Ionization Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Laskin, Julia; Heath, Brandi S.; Roach, Patrick J.; Cazares, Lisa H.; Semmes, O. John

    2012-01-03

    We present the first results showing the ambient imaging of biological samples in their native environment using nanospray desorption ionization (nanoDESI) mass spectrometry. NanoDESI is an ambient pressure ionization technique that enables precise control of ionization of molecules from substrates. We demonstrate highly sensitive and robust analysis of tissue samples with high spatial resolution (<12 {mu}m) without sample preparation, which will be essential for applications in clinical diagnostics, drug discovery, molecular biology, and biochemistry.

  15. Sources of ionizing radiation, radioactive or nuclear materials out of control. National system of response in Slovakia

    International Nuclear Information System (INIS)

    In this paper authors deals with the Customs inspection of radioactive materials - present situation as well as with situation after accession of the Slovak Republic process to European Union (EU). he actual response system to incidents with orphan sources or radioactive material occurring in metal scrap, illicit trafficking and disused sources out of control is laid down on the following scheme. The national strategy is aimed to establish a more effective responding system preventing further illegal trafficking with regard to the acceding process which will require for new member states joining EU proper arrangements in improving the safety of radiation sources over the life-cycle to ensure the effective functioning in the conditions of the Slovak Republic's membership in the European Union

  16. Detection of Amines and Ammonia with an Ambient Pressure Mass Spectrometer using a Corona Discharge Ion Source, in an Urban Atmosphere and in a Teflon Film Chamber

    Science.gov (United States)

    Alves, M.; Hanson, D. R.; Grieves, C.; Ortega, J. V.

    2015-12-01

    Amines and ammonia are an important group of molecules that can greatly affect atmospheric particle formation that can go on to impact cloud formation and their scattering of thermal and solar radiation, and as a result human health and ecosystems. In this study, an Ambient Pressure Mass Spectrometer (AmPMS) that is selective and sensitive to molecules with a high proton affinity, such as amines, was coupled with a newly built corona discharge ion source. AmPMS was used to monitor many different nitrogenous compound that are found in an urban atmosphere (July 2015, Minneapolis), down to the single digit pmol/mol level. Simultaneous to this, a proton transfer mass spectrometer also sampled the atmosphere through an inlet within 20 m of the AmPMS inlet. In another set of studies, a similar AmPMS was attached to a large Teflon film chamber at the Atmospheric Chemistry Division at NCAR (August 2015, Boulder). Exploratory studies are planned on the sticking of amines to the chamber walls as well as oxidizing the amine and monitoring products. Depending on the success of these studies, results will be presented on the reversability of amine partitioning and mass balance for these species in the chamber.

  17. Geographic variations of childhood asthma hospitalization and outpatient visits and proximity to ambient pollution sources at a U.S.-Canada border crossing

    Directory of Open Access Journals (Sweden)

    Rivers Patrick A

    2005-06-01

    Full Text Available Abstract Background Childhood asthma is a significant public health problem in the United States and evidence is accumulating regarding the contribution from traffic and ambient air pollution. This study is a companion piece of a related Buffalo asthma study in adults recently published in the July 2004 issue of American Journal of Public Health. This study focuses on children under 18 years of age diagnosed with asthma during a three-year period (2000–2002. In order to determine the effects of particulate air pollution on public health, we conducted an ecologic study of childhood asthma and point-source respirable particulate air pollution in patients diagnosed with asthma (n = 6,425. Patients diagnosed with gastroenteritis (n = 5,132 were used as controls. Results Although the results of this study show spatial patterns similar to the ones observed in the adult study, a multiple-comparison test shows that EPA-designated focus sites located in Buffalo's east side are statistically (p Conclusion Findings of this study can be useful in geographic targeting and in the design of optimal and preventive measures.

  18. Effect of feeding whole linseed as a source of polyunsaturated fatty acids on performance and egg characteristics of laying hens kept at high ambient temperature

    Directory of Open Access Journals (Sweden)

    S Ahmad

    2013-03-01

    Full Text Available The present study was conducted to evaluate the effects of feeding whole linseed on the laying performance and egg characteristics in laying hens kept at high ambient environmental temperatures (average 34 ºC; the diurnal temperature range 26 ºC to 41 ºC. Two hundred and forty 38-wk-old white Leghorn laying hens were fed diets containing 0, 5, 10 or 15% whole linseed (as a source of n-3 polyunsaturated fatty acids for a period of 12 weeks. Egg production was recorded daily, while feed intake and egg characteristics were monitored on weekly basis. The results of the study demonstrated that egg production and feed intake decreased, while feed conversion ratio (FCR per dozen of eggs increased (p 0.05 by linseed levels in the diets offered to the laying hens. The results of the present trial suggest that feeding linseed to the laying hens in hot climates has no detrimental effects on egg characteristics, but has suppressive effects on egg production, feed intake and feed efficiency of laying hens.

  19. Determination of primary combustion source organic carbon-to-elemental carbon (OC / EC) ratio using ambient OC and EC measurements: secondary OC-EC correlation minimization method

    Science.gov (United States)

    Wu, Cheng; Zhen Yu, Jian

    2016-05-01

    Elemental carbon (EC) has been widely used as a tracer to track the portion of co-emitted primary organic carbon (OC) and, by extension, to estimate secondary OC (SOC) from ambient observations of EC and OC. Key to this EC tracer method is to determine an appropriate OC / EC ratio that represents primary combustion emission sources (i.e., (OC / EC)pri) at the observation site. The conventional approaches include regressing OC against EC within a fixed percentile of the lowest (OC / EC) ratio data (usually 5-20 %) or relying on a subset of sampling days with low photochemical activity and dominated by local emissions. The drawback of these approaches is rooted in its empirical nature, i.e., a lack of clear quantitative criteria in the selection of data subsets for the (OC / EC)pri determination. We examine here a method that derives (OC / EC)pri through calculating a hypothetical set of (OC / EC)pri and SOC followed by seeking the minimum of the coefficient of correlation (R2) between SOC and EC. The hypothetical (OC / EC)pri that generates the minimum R2(SOC,EC) then represents the actual (OC / EC)pri ratio if variations of EC and SOC are independent and (OC / EC)pri is relatively constant in the study period. This Minimum R Squared (MRS) method has a clear quantitative criterion for the (OC / EC)pri calculation. This work uses numerically simulated data to evaluate the accuracy of SOC estimation by the MRS method and to compare with two commonly used methods: minimum OC / EC (OC / ECmin) and OC / EC percentile (OC / EC10 %). Log-normally distributed EC and OC concentrations with known proportion of SOC are numerically produced through a pseudorandom number generator. Three scenarios are considered, including a single primary source, two independent primary sources, and two correlated primary sources. The MRS method consistently yields the most accurate SOC estimation. Unbiased SOC estimation by OC / ECmin and OC / EC10 % only occurs when the left tail of OC / EC

  20. Multi-chamber ionization detector

    International Nuclear Information System (INIS)

    For the detector a single beta ionization source and a double- or three-chamber set-up is used, the chambers being designed in the shape of a truncated cone and facing each other with their bases. The source can be positioned with respect to the common center or modal electrode, the adjustment of the ionization in each chamber this becoming easier. The center or modal electrode also can be adjusted with respect to the source. (DG)

  1. Assaying multiple 125I seeds with the well-ionization chamber SourceCheck4π 33005 and a new insert

    Science.gov (United States)

    Ballester, Facundo; Perez-Calatayud, Jose; Vijande, Javier

    2015-01-01

    Purpose To provide a practical solution that can be adopted in clinical routine to fulfill the AAPM-ESTRO recommendations regarding quality assurance of seeds used in prostate permanent brachytherapy. The aim is to design a new insert for the well-ionization chamber SourceCheck4π 33005 (PTW, Germany) that allows evaluating the mean air-kerma strength of up to ten 125I seeds with one single measurement instead of measuring each seed individually. Material and methods The material required is: a) the SourceCheck4π 33005 well-ionization chamber provided with a PTW insert to measure the air-kerma strength S K of one single seed at a time; b) a newly designed insert that accommodates ten seeds in one column, which allows measuring the mean S K of the ten seeds in one single measurement; and c) a container with ten seeds from the same batch and class of the seeds used for the patient implant, and a set of nine non-radioactive seeds. The new insert is characterized by determining its calibration coefficient, used to convert the reading of the well-chamber when ten seeds are measured to their mean S K. The proposed method is validated by comparing the mean S K of the ten seeds obtained from the new insert with the individual measurement of S K of each seed, evaluated with the PTW insert. Results The ratio between the calibration coefficient of the new insert and the calibration coefficient of the PTW insert for the SourceCheck4π 33005 is 1.135 ± 0.007 (k = 1). The mean S K of a set of ten seeds evaluated with this new system is in agreement with the mean value obtained from measuring independently the S K of each seed. Conclusions The new insert and procedure allow evaluating the mean S K of ten seeds prior to the implant in a single measurement. The method is faster and more efficient from radiation protection point of view than measuring the individual S K of each seed. PMID:26816507

  2. Organization and implementation of a national regulatory infrastructure governing protection against ionizing radiation and the safety of radiation sources. Interim report for comment

    International Nuclear Information System (INIS)

    A number of IAEA Member States are undertaking to strengthen their radiation protection and safety infrastructures in order to facilitate the adoption of the requirements established in the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (the Standards). In this connection, the IAEA has developed a technical co-operation programme (Model Project on Upgrading Radiation Protection Infrastructure) to improve radiation protection and safety infrastructures in 51 Member States, taking into account national profiles and needs of the individual participating, countries. The present report deals with the elements of a regulatory infrastructure for radiation protection and safety and intends to facilitate the, implementation of the Basic Safety Standards in practice. It takes into account the proposals in an earlier report, IAEA-TECDOC-663, but it has been expanded to include enabling legislation and modified to be more attuned to infrastructure issues related to implementation of the Standards. The orientation is toward infrastructures concerned with protection and safety for radiation sources used in medicine, agriculture, research, industry and education rather than infrastructures for protection and safety for complex nuclear facilities. It also discusses options for enhancing the effectiveness and efficiency of the infrastructure in accordance with the size and scope of radiation practices and available regulatory resources within a country

  3. Applications of ionizing radiations

    International Nuclear Information System (INIS)

    The R and D activities of the application of Ionizing Radiations Program is comprised to four subprograms: Food and Agricultural Productions Irradiation; Radiation and Radioisotopes Applications in Industry and Environment; Radioactive Sources and Radiation Applications in Human Health; and Radioactive Facilities and Equipment for Nuclear Techniques Applications

  4. Effusive molecular beam-sampled Knudsen flow reactor coupled to vacuum ultraviolet single photon ionization mass spectrometry using an external free radical source

    International Nuclear Information System (INIS)

    A new apparatus using vacuum ultraviolet single photon ionization mass spectrometry (VUV SPIMS) of an effusive molecular beam emanating from a Knudsen flow reactor is described. It was designed to study free radical-molecule kinetics over a significant temperature range (300–630 K). Its salient features are: (1) external free radical source, (2) counterpropagating molecular beam and diffuse VUV photon beam meeting in a crossed-beam ion source of a quadrupole mass spectrometer with perpendicular ion extraction, (3) analog detection of the photocurrent of the free radical molecular cation, and (4) possibility of detecting both free radicals and closed shell species in the same apparatus and under identical reaction conditions owing to the presence of photoelectrons generated by the photoelectric effect of the used VUV-photons. The measured thermal molecular beam-to-background ratio was 6.35 ± 0.39 for Ar and 10.86 ± 1.59 for i-C4H10 at 300 K, a factor of 2.52 and 1.50 smaller, respectively, than predicted from basic gas-dynamic considerations. Operating parameters as well as the performance of key elements of the instrument are presented and discussed. Coupled to an external free radical source a steady-state specific exit flow of 1.6 × 1011 and 5.0 × 1011 molecule s−1 cm−3 of C2H5• (ethyl) and t-C4H9• (t-butyl) free radicals have been detected using VUV SPIMS at their molecular ion m/z 29 and 57, respectively, at 300 K

  5. Effusive molecular beam-sampled Knudsen flow reactor coupled to vacuum ultraviolet single photon ionization mass spectrometry using an external free radical source.

    Science.gov (United States)

    Leplat, N; Rossi, M J

    2013-11-01

    A new apparatus using vacuum ultraviolet single photon ionization mass spectrometry (VUV SPIMS) of an effusive molecular beam emanating from a Knudsen flow reactor is described. It was designed to study free radical-molecule kinetics over a significant temperature range (300-630 K). Its salient features are: (1) external free radical source, (2) counterpropagating molecular beam and diffuse VUV photon beam meeting in a crossed-beam ion source of a quadrupole mass spectrometer with perpendicular ion extraction, (3) analog detection of the photocurrent of the free radical molecular cation, and (4) possibility of detecting both free radicals and closed shell species in the same apparatus and under identical reaction conditions owing to the presence of photoelectrons generated by the photoelectric effect of the used VUV-photons. The measured thermal molecular beam-to-background ratio was 6.35 ± 0.39 for Ar and 10.86 ± 1.59 for i-C4H10 at 300 K, a factor of 2.52 and 1.50 smaller, respectively, than predicted from basic gas-dynamic considerations. Operating parameters as well as the performance of key elements of the instrument are presented and discussed. Coupled to an external free radical source a steady-state specific exit flow of 1.6 × 10(11) and 5.0 × 10(11) molecule s(-1) cm(-3) of C2H5(●) (ethyl) and t-C4H9(●) (t-butyl) free radicals have been detected using VUV SPIMS at their molecular ion m/z 29 and 57, respectively, at 300 K. PMID:24289411

  6. Sequencing of phosphopeptides sulfonated by 4-sulfophenyl isothiocyanate using post-source decay matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    TANG Jianguang; WANG Yongjun; ZHANG Hainan; WANG Chunyu; HU Zhiping; XUE Zhigang; XIA Kun; SHI Xiaoliu

    2006-01-01

    Phosphorylation/dephosphorylation is probably the most common and important reversible post-translational modificaion of proteins. Analyzing the functional effects of phosphorylation is helpful for understanding the biological functions of proteins. Identification of the phosphorylation sites of phosphorylated protein is a prerequisite for research on phosphorylation. In this work, an effective and simple method of identification of protein phosphorylation sites has been developed. Phosphopeptides were selectively enriched with immobilized metal affinity chromatography (IMAC) and subsequently chemically modified by 4-sulfophenyl isothiocyanate, and then the chemically modified phosphopeptides were sequenced with post-source decay (PSD) matrix-assisted laser desorption/ionization (MALDI)time-of-flight mass spectrometry for detecting phosphorylation sites. The charge of derivatization by 4-sulfophenyl isothiocyanate introduces a negative sulfonic acid group at the N-terminus of a peptide, and enables the selective detection of only a single series of C-terminal y-type ions. This chemically assisted method greatly simplifies the extremely complex pattern of PSD fragment ions and makes the PSD spectra more easier to be interpreted. The phosphorylation sites of a synthesized model phosphopeptide and human c-myc protein have been successfully identified by this method.Phosphorylation/dephosphorylation is probably the most common and important reversible post-translational modificaion of proteins. Analyzing the functional effects of phosphorylation is helpful for understanding the biological functions of proteins. Identification of the phosphorylation sites of phosphorylated protein is a prerequisite for research on phosphorylation. In this work, an effective and simple method of identification of protein phosphorylation sites has been developed. Phosphopeptides were selectively enriched with immobilized metal affinity chromatography (IMAC) and subsequently chemically

  7. Ionizing radiation sources: very diversified means, multiple applications and a changing regulatory environment. Conference proceedings; Les sources de rayonnements ionisants: des moyens tres diversifies, des applications multiples et une reglementation en evolution. Recueil des presentations

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-11-15

    This document brings together the available presentations given at the conference organised by the French society of radiation protection about ionizing radiation source means, applications and regulatory environment. Twenty eight presentations (slides) are compiled in this document and deal with: 1 - Overview of sources - some quantitative data from the national inventory of ionizing radiation sources (Yann Billarand, IRSN); 2 - Overview of sources (Jerome Fradin, ASN); 3 - Regulatory framework (Sylvie Rodde, ASN); 4 - Alternatives to Iridium radiography - the case of pressure devices at the manufacturing stage (Henri Walaszek, Cetim; Bruno Kowalski, Welding Institute); 5 - Dosimetric stakes of medical scanner examinations (Jean-Louis Greffe, Charleroi hospital of Medical University); 6 - The removal of ionic smoke detectors (Bruno Charpentier, ASN); 7 - Joint-activity and reciprocal liabilities - Organisation of labour risk prevention in case of companies joint-activity (Paulo Pinto, DGT); 8 - Consideration of gamma-graphic testing in the organization of a unit outage activities (Jean-Gabriel Leonard, EDF); 9 - Radiological risk control at a closed and independent work field (Stephane Sartelet, Areva); 10 - Incidents and accidents status and typology (Pascale Scanff, IRSN); 11 - Regional overview of radiation protection significant events (Philippe Menechal, ASN); 12 - Incident leading to a tritium contamination in and urban area - consequences and experience feedback (Laurence Fusil, CEA); 13 - Experience feedback - loss of sealing of a calibration source (Philippe Mougnard, Areva); 14 - Blocking incident of a {sup 60}Co source (Bruno Delille, Salvarem); 15 - Triggering of gantry's alarm: status of findings (Philippe Prat, Syctom); 16 - Non-medical electric devices: regulatory changes (Sophie Dagois, IRSN; Jerome Fradin, ASN); 17 - Evaluation of the dose equivalent rate in pulsed fields: method proposed by the IRSN and implementation test (Laurent Donadille

  8. Dual electrospray ionization source for confident generation of accurate mass tags using liquid chromatography Fourier transform ion cyclotron resonance mass spectrometry.

    Science.gov (United States)

    Nepomuceno, Angelito I; Muddiman, David C; Bergen, H Robert; Craighead, James R; Burke, Michael J; Caskey, Patrick E; Allan, Jonathan A

    2003-07-15

    Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) has rapidly established a prominent role in proteomics because of its unparalleled resolving power, sensitivity and ability to achieve high mass measurement accuracy (MMA) simultaneously. However, space-charge effects must be quantitatively, routinely, and confidently corrected because they are known to profoundly influence MMA. We argue that the most effective way to account for space-charge effects is to introduce an internal mass calibrant (IMC) using a dual electrospray ionization (ESI) source where the IMC is added from a separate ESI emitter. The major disadvantage of our initial dual ESI source to achieve high MMA, and arguably the only one, was the time required to switch between the analyte emitter and IMC emitter (i.e., >300 ms). While this "switching time" was acceptable for direct infusion experiments, it did not lend itself to high-throughput applications or when conducting on-line liquid separations. In this report, we completely redesigned the dual ESI source and demonstrate several key attributes. First, the new design allows for facile alignment of ESI emitters, undetectable vibration, and the ability to extend to multiple emitters. Second, the switching time was reduced to IMC to be accumulated "simultaneously" in the external ion reservoir and injected as a single ion packet into the ion cyclotron resonance cell, eliminating the need for a separate accumulation and ion injection event for the IMC. Third, by using a high concentration of the IMC, the residence time on this emitter could be reduced to approximately 80 ms, allowing for more time spent accumulating analyte ions of significantly lower concentration. Fourth, multiplexed on-line separations can be carried out providing increased throughput. Specifically, the new dual ESI source has demonstrated its ability to produce a stable ion current over a 45-min time period at 7 T resulting in mass accuracies of 1.08 ppm +/- 0

  9. Flexible xxx-asp/asn and gly-xxx residues of equine cytochrome C in matrix-assisted laser desorption/ionization in-source decay mass spectrometry.

    Science.gov (United States)

    Takayama, Mitsuo

    2012-01-01

    The backbone flexibility of a protein has been studied from the standpoint of the susceptibility of amino acid residues to in-source decay (ISD) in matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). Residues more susceptible to MALDI-ISD, namely Xxx-Asp/Asn and Gly-Xxx, were identified from the discontinuous intense peak of c'-ions originating from specific cleavage at N-Cα bonds of the backbone of equine cytochrome c. The identity of the residues susceptible to ISD was consistent with the known flexible backbone amides as estimated by hydrogen/deuterium exchange (HDX) experiments. The identity of these flexible amino acid residues (Asp, Asn, and Gly) is consistent with the fact that these residues are preferred in flexible secondary structure free from intramolecular hydrogen-bonded structures such as α-helix and β-sheet. The MALDI-ISD spectrum of equine cytochrome c gave not only intense N-terminal side c'-ions originating from N-Cα bond cleavage at Xxx-Asp/Asn and Gly-Xxx residues, but also C-terminal side complement z'-ions originating from the same cleavage sites. The present study implies that MALDI-ISD can give information about backbone flexibility of proteins, comparable with the protection factors estimated by HDX.

  10. Effect of different ionizing radiation doses and dose rates, using Cobalt-60 and electrons beam sources, on the staphylococcal enterotoxin inoculated in mechanically deboned chicken meat

    Energy Technology Data Exchange (ETDEWEB)

    Pomarico Neto, Walter; Brito, Poliana de Paula; Azevedo, Heliana de; Roque, Claudio Vitor; Fukuma, Henrique Takuji, E-mail: pbrito@cnen.gov.br, E-mail: hazevedo@cnen.gov.br, E-mail: cvroque@cnen.gov.br, E-mail: htfukuma@cnen.gov.br [Brazilian Nuclear Energy Commission (LAPOC/CNEN), Pocos de Caldas, MG (Brazil); Kodama, Yasko, E-mail: ykodama@ipen.br [Nuclear and Energy Research Institute (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Miya, Norma Terugo Nago; Pereira, Jose Luiz, E-mail: miya@fea.unicamp.br, E-mail: pereira@fea.unicamp.br [Campinas State University (UNICAMP), SP (Brazil). Dept. of Food Sciences

    2011-07-01

    The purpose of food irradiation is the destruction of present pathogenic microorganisms and the increase of shelf life of foods. To achieve this process, the source of cobalt-60 and the electron accelerator can be used. The mechanically deboned chicken meat (MDCM) is used for the production of traditional meat products, and it may come to present pathogenic microorganisms such as staphylococcus aureus, a bacterium that produces enterotoxin, which causes food poisoning. The objective of this study is to analyze the effect of ionizing irradiation with different doses and dose rates, deriving from different radiation sources, on staphylococcal enterotoxin type B (SEB) in the MDCM. 50 g samples of MDCM were prepared in a batch of 6 kg of MDCM. The samples were contaminated, with the exception of the control, with SEB in amounts of about 100 ng. Then they were conditioned in a transparent bag made of low density polyethylene, frozen at -18{+-}1 deg C overnight and irradiated in these conditions with doses of 0.0 kGy (control), 1.5 kGy and 3.0 kGy, and with three different dose rates, both in the Cobalt-60 and the electron accelerator. The experiments were conducted in quintuplicate. The SEB extraction from the MDCM was performed according to the protocol recommended by the manufacturer of the kit VIDAS Staph Enterotoxin II (bioMerrieux). The principle of mass balance was used to determine the actual amount of SEB removed by irradiation. The treatment that presented the best results was the one with a dose of 1.5 kGy, high dose rate of the electron accelerator. (author)

  11. Evaluation of the operating parameters of the liquid sampling-atmospheric pressure glow discharge (LS-APGD) ionization source for elemental mass spectrometry.

    Science.gov (United States)

    Zhang, Lynn X; Manard, Benjamin T; Konegger-Kappel, Stefanie; Kappel, Stefanie Konegger; Marcus, R Kenneth

    2014-11-01

    The liquid sampling-atmospheric pressure glow discharge (LS-APGD) has been assessed as an ionization source for elemental analysis with an interdependent, parametric evaluation regarding sheath/cooling gas flow rate, discharge current, liquid flow rate, and the distance between the plasma and the sampling cone of the mass spectrometer. In order to better understand plasma processes (and different from previous reports), no form of collision/reaction processing was performed to remove molecular interferents. The evaluation was performed employing five test elements: cesium, silver, lead, lanthanum and nickel (10(-4) mol L(-1) in 1 mol L(-1) HNO3). The intensity of the atomic ions, levels of spectral background, the signal-to-background ratios, and the atomic-to-oxide/hydroxide adduct ratios were monitored in order to obtain fundamental understanding with regards to not only how each parameter effects the performance of this LS-APGD source, but also the inter-parametric effects. The results indicate that the discharge current and the liquid sampling flow rates are the key aspects that control the spectral composition. A compromise set of operating conditions was determined: sheath gas flow rate = 0.9 L min(-1), discharge current = 10 mA, solution flow rate = 10 μL min(-1), and sampling distance = 1 cm. Limits of detection (LODs) were calculated using the SBR-RSDB (signal-to-background ratio/relative standard deviation of the background) approach under the optimized condition. The LODs for the test elementals ranged from 15 to 400 ng mL(-1) for 10 μL injections, with absolute mass values from 0.2 to 4 ng.

  12. Ionizing radiations

    International Nuclear Information System (INIS)

    The purpose of this article is to simplify some of the relevant points of legislation, biological effects and protection for the benefit of the occupational health nurse not familiar with the nuclear industries. The subject is dealt with under the following headings; Understanding atoms. What is meant by ionizing radiation. Types of ionizing radiation. Effects of radiation: long and short term somatic effects, genetic effects. Control of radiation: occupational exposure, women of reproductive age, medical aspects, principles of control. The occupational health nurse's role. Emergency arrangements: national arrangements for incidents involving radiation, action to be taken by the nurse. Decontamination procedures: external and internal contamination. (U.K.)

  13. III. Penning ionization, associative ionization and chemi-ionization processes

    International Nuclear Information System (INIS)

    Physical mechanisms of three important ionization processes in a cold plasma and the methods of their experimental study are discussed. An apparatus for the investigation of the Penning ionization using ionization processes of long lived metastable rare gas atoms is described. Methods of determining interaction energies and ionization rates from the measured energy spectra of the originating electrons are described and illustrated by several examples. Typical associative ionization processes are listed and the ionization rates are compared with those of the Penning ionization. Interactions with short-lived excited particles and the transfer of excitation without ionization are discussed. (J.U.)

  14. Sub-nanosecond time-resolved ambient-pressure X-ray photoelectron spectroscopy setup for pulsed and constant wave X-ray light sources

    Energy Technology Data Exchange (ETDEWEB)

    Shavorskiy, Andrey; Slaughter, Daniel S.; Zegkinoglou, Ioannis; Rude, Bruce S.; Bluhm, Hendrik [Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Neppl, Stefan; Cryan, James P.; Siefermann, Katrin R.; Weise, Fabian; Lin, Ming-Fu; Bacellar, Camila; Ziemkiewicz, Michael P.; Fraund, Matthew W.; Khurmi, Champak; Wright, Travis W.; Schoenlein, Robert W.; Gessner, Oliver, E-mail: ogessner@lbl.gov [Ultrafast X-ray Science Laboratory, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Hertlein, Marcus P.; Tyliszczak, Tolek [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Huse, Nils [Ultrafast X-ray Science Laboratory, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Physics Department, University of Hamburg and Max-Planck Institute for Structure and Dynamics of Matter, 22761 Hamburg (Germany); and others

    2014-09-15

    An apparatus for sub-nanosecond time-resolved ambient-pressure X-ray photoelectron spectroscopy studies with pulsed and constant wave X-ray light sources is presented. A differentially pumped hemispherical electron analyzer is equipped with a delay-line detector that simultaneously records the position and arrival time of every single electron at the exit aperture of the hemisphere with ∼0.1 mm spatial resolution and ∼150 ps temporal accuracy. The kinetic energies of the photoelectrons are encoded in the hit positions along the dispersive axis of the two-dimensional detector. Pump-probe time-delays are provided by the electron arrival times relative to the pump pulse timing. An average time-resolution of (780 ± 20) ps (FWHM) is demonstrated for a hemisphere pass energy E{sub p} = 150 eV and an electron kinetic energy range KE = 503–508 eV. The time-resolution of the setup is limited by the electron time-of-flight (TOF) spread related to the electron trajectory distribution within the analyzer hemisphere and within the electrostatic lens system that images the interaction volume onto the hemisphere entrance slit. The TOF spread for electrons with KE = 430 eV varies between ∼9 ns at a pass energy of 50 eV and ∼1 ns at pass energies between 200 eV and 400 eV. The correlation between the retarding ratio and the TOF spread is evaluated by means of both analytical descriptions of the electron trajectories within the analyzer hemisphere and computer simulations of the entire trajectories including the electrostatic lens system. In agreement with previous studies, we find that the by far dominant contribution to the TOF spread is acquired within the hemisphere. However, both experiment and computer simulations show that the lens system indirectly affects the time resolution of the setup to a significant extent by inducing a strong dependence of the angular spread of electron trajectories entering the hemisphere on the retarding ratio. The scaling of the angular

  15. Sub-nanosecond time-resolved ambient-pressure X-ray photoelectron spectroscopy setup for pulsed and constant wave X-ray light sources.

    Science.gov (United States)

    Shavorskiy, Andrey; Neppl, Stefan; Slaughter, Daniel S; Cryan, James P; Siefermann, Katrin R; Weise, Fabian; Lin, Ming-Fu; Bacellar, Camila; Ziemkiewicz, Michael P; Zegkinoglou, Ioannis; Fraund, Matthew W; Khurmi, Champak; Hertlein, Marcus P; Wright, Travis W; Huse, Nils; Schoenlein, Robert W; Tyliszczak, Tolek; Coslovich, Giacomo; Robinson, Joseph; Kaindl, Robert A; Rude, Bruce S; Ölsner, Andreas; Mähl, Sven; Bluhm, Hendrik; Gessner, Oliver

    2014-09-01

    An apparatus for sub-nanosecond time-resolved ambient-pressure X-ray photoelectron spectroscopy studies with pulsed and constant wave X-ray light sources is presented. A differentially pumped hemispherical electron analyzer is equipped with a delay-line detector that simultaneously records the position and arrival time of every single electron at the exit aperture of the hemisphere with ~0.1 mm spatial resolution and ~150 ps temporal accuracy. The kinetic energies of the photoelectrons are encoded in the hit positions along the dispersive axis of the two-dimensional detector. Pump-probe time-delays are provided by the electron arrival times relative to the pump pulse timing. An average time-resolution of (780 ± 20) ps (FWHM) is demonstrated for a hemisphere pass energy E(p) = 150 eV and an electron kinetic energy range KE = 503-508 eV. The time-resolution of the setup is limited by the electron time-of-flight (TOF) spread related to the electron trajectory distribution within the analyzer hemisphere and within the electrostatic lens system that images the interaction volume onto the hemisphere entrance slit. The TOF spread for electrons with KE = 430 eV varies between ~9 ns at a pass energy of 50 eV and ~1 ns at pass energies between 200 eV and 400 eV. The correlation between the retarding ratio and the TOF spread is evaluated by means of both analytical descriptions of the electron trajectories within the analyzer hemisphere and computer simulations of the entire trajectories including the electrostatic lens system. In agreement with previous studies, we find that the by far dominant contribution to the TOF spread is acquired within the hemisphere. However, both experiment and computer simulations show that the lens system indirectly affects the time resolution of the setup to a significant extent by inducing a strong dependence of the angular spread of electron trajectories entering the hemisphere on the retarding ratio. The scaling of the angular spread with

  16. Sub-nanosecond time-resolved ambient-pressure X-ray photoelectron spectroscopy setup for pulsed and constant wave X-ray light sources.

    Science.gov (United States)

    Shavorskiy, Andrey; Neppl, Stefan; Slaughter, Daniel S; Cryan, James P; Siefermann, Katrin R; Weise, Fabian; Lin, Ming-Fu; Bacellar, Camila; Ziemkiewicz, Michael P; Zegkinoglou, Ioannis; Fraund, Matthew W; Khurmi, Champak; Hertlein, Marcus P; Wright, Travis W; Huse, Nils; Schoenlein, Robert W; Tyliszczak, Tolek; Coslovich, Giacomo; Robinson, Joseph; Kaindl, Robert A; Rude, Bruce S; Ölsner, Andreas; Mähl, Sven; Bluhm, Hendrik; Gessner, Oliver

    2014-09-01

    An apparatus for sub-nanosecond time-resolved ambient-pressure X-ray photoelectron spectroscopy studies with pulsed and constant wave X-ray light sources is presented. A differentially pumped hemispherical electron analyzer is equipped with a delay-line detector that simultaneously records the position and arrival time of every single electron at the exit aperture of the hemisphere with ~0.1 mm spatial resolution and ~150 ps temporal accuracy. The kinetic energies of the photoelectrons are encoded in the hit positions along the dispersive axis of the two-dimensional detector. Pump-probe time-delays are provided by the electron arrival times relative to the pump pulse timing. An average time-resolution of (780 ± 20) ps (FWHM) is demonstrated for a hemisphere pass energy E(p) = 150 eV and an electron kinetic energy range KE = 503-508 eV. The time-resolution of the setup is limited by the electron time-of-flight (TOF) spread related to the electron trajectory distribution within the analyzer hemisphere and within the electrostatic lens system that images the interaction volume onto the hemisphere entrance slit. The TOF spread for electrons with KE = 430 eV varies between ~9 ns at a pass energy of 50 eV and ~1 ns at pass energies between 200 eV and 400 eV. The correlation between the retarding ratio and the TOF spread is evaluated by means of both analytical descriptions of the electron trajectories within the analyzer hemisphere and computer simulations of the entire trajectories including the electrostatic lens system. In agreement with previous studies, we find that the by far dominant contribution to the TOF spread is acquired within the hemisphere. However, both experiment and computer simulations show that the lens system indirectly affects the time resolution of the setup to a significant extent by inducing a strong dependence of the angular spread of electron trajectories entering the hemisphere on the retarding ratio. The scaling of the angular spread with

  17. Resonant ionization by laser beams: application to ions sources and to study the nuclear structure of radioactive tellurium isotopes; Ionisation resonante par faisceaux laser: application aux sources d'ions et a l'etude de la structure des noyaux radioactifs de tellure

    Energy Technology Data Exchange (ETDEWEB)

    Sifi, R

    2007-07-15

    The radioactive ion beams that are produced through current isotope separators are well separated according to the A mass but not according to the Z parameter. The resonant ionization through laser beams applied to ion sources allows the production of radioactive ion beam in a very selective and efficient way by eliminating the isobaric contamination. The first chapter is dedicated to the resonant ionization by laser beams, we describe the principle, the experimental setting, the lasers used, the ionization schemes and the domain of application. The second chapter deals with the application of resonant ionization to laser ion sources for the production of radioactive ion beams. We present experimental tests performed for getting copper ion beams. Resonant ionization through laser is also used in the spectroscopy experiments performed at the Isolde (isotope separation on-line device) installation in CERN where more than 20 elements are ionized very efficiently. The technique is based on a frequency scanning around the excitation transition of the atoms in order to probe the hyperfine structure. Laser spectroscopy allows the determination of the hyperfine structure as well as the isotopic shift of atoms. In the third chapter the method is applied to the spectroscopy of tellurium atoms. First, we define the 2 parameters on which the extraction is based: charge radius and nuclear moments, then we present several theoretical models that we have used to assess our experimental results. (A.C.)

  18. Decree n.06-488 /P-RM of 23 november 2006 determining the rules related to the protection against ionizing radiation, safety and security of ionizing radiation sources

    International Nuclear Information System (INIS)

    This decree determine the r(ules of protection of workers, public, patients and environment against the risks of ionizing radiation. The scope of these rules is defined as well as the definitions of some terms and concepts used in the field such as raioelement, radiopactive waste, dose, level of intervention, etc. The responsability for Malian Agency for radioprotection and for different stakeholders are clarified and those of workers as well. The condition of declaration, obtaining authorization and exemption are set. Instructions related to radioprotection, safety and security ofn ionizing radiation are stated regarding occupational, madical and public exposure and in case of emergency. instructions related to inventory and inspec tion are also defined

  19. Analysis of x-ray spectra emitted from highly ionized atoms in the vacuum spark and laser-produced high power plasma sources

    International Nuclear Information System (INIS)

    The interest in atomic spectroscopy has greatly been reinforced in the last ten years. This gain of interest is directly related to the developments in different fields of research where hot plasmas are created. These fields include in particular controlled thermonuclear fusion research by means of inertial or magnetic confinement approaches and also the most recent efforts to achieve lasers in the XUV region. The present work is based on the specific contribution of the atomic spectroscopy group at the Hebrew University. The recent development of both theoretical and experimental tools allowed us to progress in the understanding of the highly ionized states of heavy elements. In this work the low-inductance vacuum-spark developed at the Hebrew University was used as the hot plasma source. The spectra were recorded in the 7-300 A range by means of a high-resolution extreme-grazing-incidence spectrometer developed at the Racah Institute by Profs. J.L. Schwob and B.S. Fraenkel. To the extend the spectroscopic studies to higher-Z atoms, the laser-produced plasma facility at Soreq Nuclear Center was used. In this work the spectra of the sixth row elements were recorded in the x-rays by means of a crystal spectrometer. All these experimental systems are briefly described in chapter one. Chapter two deals with the theoretical methods used in the present work for the atomic calculations. Chapter three deals with the spectra of elements of the fifth row emitted from the vacuum-spark in the 30-150 A range. These spectra as experimental data were used in order to test ab-initio computations along the NiI sequence 3d-nl transitions. The results of this work are presented in chapter four. Chapter five is devoted to the measurement and analysis of spectra emitted from the vacuum-spark by rare-earth elements. (author)

  20. Determination of Glucosamine in Human Plasma by High-Performance Liquid Chromatography-Atmospheric Pressure Chemical Ionization Source-Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Xingchen Zhou

    2011-01-01

    Full Text Available A sensitive, specific, and rapid high-performance liquid chromatography-atmospheric pressure chemical ionization source-tandem mass spectrometry (HPLC-APCI-MS/MS method for the determination of glucosamine in human plasma was developed and validated. Plasma samples were processed by protein precipitation with dehydrated ethanol, and the chromatographic separation was performed on an Agilent XDB-C18 column with a mobile phase of methanol—0.2% formic acid solution (70 : 30, v/v. Mass spectrometric quantification was carried out in the multiple reaction monitoring (MRM mode, monitoring ion transitions of m/z 180.1 to m/z 162.1 with collision energy (CE of 2 eV for glucosamine and m/z 181.1 to m/z 163.1 with CE of 2 eV for the internal standard (IS in positive ion mode. The linear calibration curves covered a concentration range of 53.27–3409 ng/mL with a lower limit of quantification (LLOQ of 53.27 ng/mL. The extraction recovery of glucosamine was greater than 101.7%. The intra- and interday precisions for glucosamine were less than 10%, and the accuracies were between 93.7% and 102.6%, determined from quality control (QC samples of three representative concentrations. The method has been successfully applied to determining the plasma concentration of glucosamine in a clinical pharmacokinetic study involving 20 healthy Chinese male volunteers.

  1. Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE): emissions of trace gases and light-absorbing carbon from wood and dung cooking fires, garbage and crop residue burning, brick kilns, and other sources

    Science.gov (United States)

    Stockwell, Chelsea E.; Christian, Ted J.; Goetz, J. Douglas; Jayarathne, Thilina; Bhave, Prakash V.; Praveen, Puppala S.; Adhikari, Sagar; Maharjan, Rashmi; DeCarlo, Peter F.; Stone, Elizabeth A.; Saikawa, Eri; Blake, Donald R.; Simpson, Isobel J.; Yokelson, Robert J.; Panday, Arnico K.

    2016-09-01

    The Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE) campaign took place in and around the Kathmandu Valley and in the Indo-Gangetic Plain (IGP) of southern Nepal during April 2015. The source characterization phase targeted numerous important but undersampled (and often inefficient) combustion sources that are widespread in the developing world such as cooking with a variety of stoves and solid fuels, brick kilns, open burning of municipal solid waste (a.k.a. trash or garbage burning), crop residue burning, generators, irrigation pumps, and motorcycles. NAMaSTE produced the first, or rare, measurements of aerosol optical properties, aerosol mass, and detailed trace gas chemistry for the emissions from many of the sources. This paper reports the trace gas and aerosol measurements obtained by Fourier transform infrared (FTIR) spectroscopy, whole-air sampling (WAS), and photoacoustic extinctiometers (PAX; 405 and 870 nm) based on field work with a moveable lab sampling authentic sources. The primary aerosol optical properties reported include emission factors (EFs) for scattering and absorption coefficients (EF Bscat, EF Babs, in m2 kg-1 fuel burned), single scattering albedos (SSAs), and absorption Ångström exponents (AAEs). From these data we estimate black and brown carbon (BC, BrC) emission factors (g kg-1 fuel burned). The trace gas measurements provide EFs (g kg-1) for CO2, CO, CH4, selected non-methane hydrocarbons up to C10, a large suite of oxygenated organic compounds, NH3, HCN, NOx, SO2, HCl, HF, etc. (up to ˜ 80 gases in all). The emissions varied significantly by source, and light absorption by both BrC and BC was important for many sources. The AAE for dung-fuel cooking fires (4.63 ± 0.68) was significantly higher than for wood-fuel cooking fires (3.01 ± 0.10). Dung-fuel cooking fires also emitted high levels of NH3 (3.00 ± 1.33 g kg-1), organic acids (7.66 ± 6.90 g kg-1), and HCN (2.01 ± 1.25 g kg-1), where the latter could

  2. Application of ionizing radiations

    International Nuclear Information System (INIS)

    The main subject of the application of Ionizing Radiations Program is to disseminate and consolidate techniques leading to the use of the radiation technology and radioisotopes application in Industry, Human Health, Agriculture and Environmental Preservation. This Program is divided into four subprograms: 1) Food and Agricultural Products Irradiation; 2) Radiation and Radioisotopes Applications in Industry and Environment; Radioactive Sources and Radiation Applications in Human Health; Radioactive Facilities and Equipment for Nuclear Techniques Applications

  3. Use of ionizing radiation in the recycling of unserviceable tires of automotive and its adequate environmental disposal; Utilizacao da radiacao ionizante na reciclagem de pneus inserviveis de automovel e sua destinacao ambiental adequada

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Clecia de Moura

    2013-07-01

    The aim of this study was to use ionizing radiation in the recycling of scrap tires of automotive. Samples of rubber unserviceable tires were irradiated with radiation doses 200, 400 and 600kGy in an electron accelerator. Subsequently, they were characterized by thermogravimetry (TG), differential scanning calorimetry (DSC), tensile strength mechanical test, spectrophotometry Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). By thermogravimetry was possible to observe the effects of radiation in the mass loss of material. In the DSC curves were observed exothermic decomposition peaks and associated values of enthalpy variation (ΔH). The mechanical properties of the elastomeric matrix with unserviceable tires powder were studied and its behavior to ionizing radiation was analyzed. FTIR spectra were obtained in the 4000 - 650cm-1 region. It was observed that there was no change in the peaks due irradiation. For SEM the micrographs were enlarged from 32 times up to 1000 times and observed in sizes from 1mm up to 20μm. It was observed at doses of 200 and 400kGy, roughness corresponding to breaks or ruptures possibly caused by radiation. In 600kGy radiation dose was observed cavities caused by radiation. It was observed that at all doses occurred degradation. For samples without powder and with 10, 30 and 50% of unserviceable tires powder it was obtained micrographs of 100μm and 200μm amplification. Also it was possible to observe the incorporation of unserviceable tires powder of automotive in the elastomeric matrix of non-irradiated and irradiated samples. (author)

  4. Association of chemical constituents and pollution sources of ambient fine particulate air pollution and biomarkers of oxidative stress associated with atherosclerosis: A panel study among young adults in Beijing, China.

    Science.gov (United States)

    Wu, Shaowei; Yang, Di; Wei, Hongying; Wang, Bin; Huang, Jing; Li, Hongyu; Shima, Masayuki; Deng, Furong; Guo, Xinbiao

    2015-09-01

    Ambient particulate air pollution has been associated with increased oxidative stress and atherosclerosis, but the chemical constituents and pollution sources behind the association are unclear. We investigated the associations of various chemical constituents and pollution sources of ambient fine particles (PM2.5) with biomarkers of oxidative stress in a panel of 40 healthy university students. Study participants underwent repeated blood collections for 12 times before and after relocating from a suburban campus to an urban campus with high air pollution levels in Beijing, China. Air pollution data were obtained from central air-monitoring stations, and plasma levels of oxidized low-density lipoprotein (Ox-LDL) and soluble CD36 (sCD36) were determined in the laboratory (n=464). Linear mixed-effects models were used to estimate the changes in biomarkers in association with exposure variables. PM2.5 iron and nickel were positively associated with Ox-LDL (ppollution sources, PM2.5 from traffic emissions and coal combustion were suggestively and positively associated with Ox-LDL. Our findings suggest that a subset of metals in airborne particles may be the major air pollution components that contribute to the increased oxidative stress associated with atherosclerosis.

  5. Origin of the chemical noise in ambient mass spectrometry

    International Nuclear Information System (INIS)

    The instrumental background of ambient mass spectrometry, (API-MS) is analyzed and the possible potential origins of the background noise is identified. According to the mass spectra obtained using the API-MS instruments by different manufacturers, the characteristic fragment ions all indicated that the background noise are resulted from the phthalates such as diethyl phthalate (DEP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), bis (2-ethylhexyl) phthalate (DEHP), and silicones such as decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6). These chemicals are probably released from the polymeric materials used in the ionization sources, such as O-type sealing ring etc. In addition, the instrumental background has to be considered especially during the analysis of phthalate and peptide compounds. (authors)

  6. Ionization-chamber smoke detector system

    Science.gov (United States)

    Roe, Robert F.

    1976-10-19

    This invention relates to an improved smoke-detection system of the ionization-chamber type. In the preferred embodiment, the system utilizes a conventional detector head comprising a measuring ionization chamber, a reference ionization chamber, and a normally non-conductive gas triode for discharging when a threshold concentration of airborne particulates is present in the measuring chamber. The improved system is designed to reduce false alarms caused by fluctuations in ambient temperature. Means are provided for periodically firing the gas discharge triode and each time recording the triggering voltage required. A computer compares each triggering voltage with its predecessor. The computer is programmed to energize an alarm if the difference between the two compared voltages is a relatively large value indicative of particulates in the measuring chamber and to disregard smaller differences typically resulting from changes in ambient temperature.

  7. Sample preparation and direct electrospray ionization on a tip column for rapid mass spectrometry analysis of complex samples.

    Science.gov (United States)

    Huang, Yun-Qing; You, Jin-Qing; Yuan, Bi-Feng; Feng, Yu-Qi

    2012-10-01

    A handheld pipette tip column electrospray ionization source (PTC-ESI source) was developed for rapid mass spectrometry analysis at ambient pressure. The PTC-ESI source was made up of three main component parts including a micro DC high voltage (HV) power supply, a micropipette and a disposable micropipette tip filled with a plug of adsorbent. A DC high voltage was applied to the sharp point of the micropipette tip column to induce electrospray ionization. The PTC-ESI source was successfully used for direct analysis of basic organic compounds, organic acids and peptides in a simple matrix. In the case of complex samples, micro-extraction based on the adsorbent phase filled in the pipette tip was used to remove impurities and concentrate target analytes prior to ionization. The eluting solution was not pipetted out, but directly dispersed in the form of electrospray from the pipette tip for ionization. The effectiveness of the PTC-ESI source has been further demonstrated by fast analysis of therapeutic compounds and endogenous bioactive chemicals in complex biological samples. PMID:22898704

  8. Ambient noise near the sea-route

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Ambient noise data measured in an experiment conducted in shallow water near a sea-route were analyzed. It was observed that, at low frequency, the horizontal correlation has an obvious difference from that predicted by the classical ambient noise model. The theoretical analyses show that this phenomenon is caused by wind noise together with the discrete shipping noise nearby. An ambient noise model was proposed to include the effects caused by both the noise sources. Data measured at different times verify that the proposed model can be used to forecast the ambient noise field in shallow water near the sea-route.

  9. Ambient noise near the sea-route

    Institute of Scientific and Technical Information of China (English)

    HE Li; LI ZhengLin; PENG ZhaoHui

    2009-01-01

    Ambient noise data measured in an experiment conducted in shallow water near a sea-route were analyzed. It was observed that, at low frequency, the horizontal correlation has an obvious difference from that predicted by the classical ambient noise model. The theoretical analyses show that this phenomenon is caused by wind noise together with the discrete shipping noise nearby. An ambient noise model was proposed to include the effects caused by both the noise sources. Data measured at different times verify that the proposed model can be used to forecast the ambient noise field in shal-low water near the sea-route.

  10. Ambient cosmology and spacetime singularities

    CERN Document Server

    Antoniadis, Ignatios

    2015-01-01

    We present a new approach to the issues of spacetime singularities and cosmic censorship in general relativity. This is based on the idea that standard 4-dimensional spacetime is the conformal infinity of an ambient metric for the 5-dimensional Einstein equations with fluid sources. We then find that the existence of spacetime singularities in four dimensions is constrained by asymptotic properties of the ambient 5-metric, while the non-degeneracy of the latter crucially depends on cosmic censorship holding on the boundary.

  11. Ambient cosmology and spacetime singularities

    Energy Technology Data Exchange (ETDEWEB)

    Antoniadis, Ignatios [Bern University, Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, Bern (Switzerland); Ecole Polytechnique, Palaiseau (France); Cotsakis, Spiros [CERN, Theory Division, Department of Physics, Geneva 23 (Switzerland); National Technical University, School of Applied Mathematics and Physical Sciences, Athens (Greece)

    2015-01-01

    We present a new approach to the issues of spacetime singularities and cosmic censorship in general relativity. This is based on the idea that standard 4-dimensional spacetime is the conformal infinity of an ambient metric for the 5-dimensional Einstein equations with fluid sources. We then find that the existence of spacetime singularities in four dimensions is constrained by asymptotic properties of the ambient 5-metric, while the non-degeneracy of the latter crucially depends on cosmic censorship holding on the boundary. (orig.)

  12. Effects of rigorous emission controls on reducing ambient volatile organic compounds in Beijing, China.

    Science.gov (United States)

    Li, Jing; Wu, Rongrong; Li, Yaqi; Hao, Yufang; Xie, Shaodong; Zeng, Liming

    2016-07-01

    102 volatile organic compound (VOC) species were measured online using a gas chromatography-mass spectrometry/flame ionization detector (GC-MS/FID) at an urban site in Beijing in 11 August to 3 September 2015, when a series of rigorous air quality control measures were implemented in Beijing city and neighbouring provinces. Positive matrix factorization (PMF) was applied to identify emission sources from 1h averaged values of VOC data. Based on the online VOC data and the PMF analysis results, the effectiveness of different control measures were investigated. The PMF results were compared with an emission inventory data. Results show that the rigorous air quality restrictions implemented were successful. The averaged ambient VOC mixing ratios during the emission control period and non-control period were 27.53 and 45.42ppbv, respectively. The mixing ratios of total VOC during the control period were reduced by 40%. Alkanes were the most abundant chemical group in the two periods, followed by oxygenated volatile organic compounds (OVOCs). Almost all quantified VOC species decreased during the control period. Tracers of industrial sources and vehicle exhaust reduced most, including some halocarbons, esters and aromatics. Eight sources were resolved by online PMF analysis for ambient VOCs in Beijing. Contributions of those sources varied significantly during the control and non-control period. Compared with the values before control, contributions of vehicle-related sources were most reduced, followed by solvent utilization. Reductions of vehicle-related sources, solvent utilization, secondary formation, fuel combustion, and biogenic were responsible for 65%, 19%, 10%, 5%, and 1% of the reductions in ambient VOCs. Both PMF results and emission inventory data indicated that the control measure on traffic was very effective in reducing ambient VOCs in Beijing, with the emission reductions of about 50%. PMID:27039059

  13. Occurrence of gaseous and particulate polycyclic aromatic hydrocarbons in the urban atmosphere: study of sources and ambient temperature effect on the gas/particle concentration and distribution

    Energy Technology Data Exchange (ETDEWEB)

    Tsapakis, Manolis [Environmental Chemical Processes Laboratory (ECPL), Department of Chemistry, University of Crete, EL-71409 Heraklion (Greece); Stephanou, Euripides G. [Environmental Chemical Processes Laboratory (ECPL), Department of Chemistry, University of Crete, EL-71409 Heraklion (Greece)]. E-mail: stephanou@chemistry.uoc.gr

    2005-01-01

    The presence of polycyclic aromatic hydrocarbons (PAHs) in an urban region (Heraklion, Greece) and processes that govern their atmospheric fate were studied from November 2000 until February 2002. Sixteen samples were collected, by using an artifact-free sampling device, on a monthly basis and the concentration of PAHs in gas and particulate phase was determined. The most abundant members (gas + particles) were phenanthrene (20.0 {+-} 7.0 ng m{sup -3}), fluoranthene (6.5 {+-} 1.7 ng m{sup -3}), pyrene (6.6 {+-} 2.4 ng m{sup -3}), and chrysene (3.1 {+-} 1.5 ng m{sup -3}). Total concentration (gas + particulate) of PAH ranged from 44.3 to 129.2 ng m{sup -3}, with a mean concentration of 79.3 ng m{sup -3}. Total concentration of PAHs in gas phase ranged from 31.4 to 84.7 ng m{sup -3} with non-observable seasonal variation. Conversely, maximum PAH concentrations in the particulate phase occurred during winter months. Particulate concentration varied from 11.4 to 44.9 ng m{sup -3}, with an average of 25.2 ng m{sup -3}. PAH distribution between gas and particulate phase was in agreement with the sub-cooled vapor pressure. Shift in gas/particle distribution due to difference in ambient temperature elucidated to some extent the seasonal variation of the concentration of PAHs in particles. - Capsule: Ambient PAH partitioning between gas and particle phases vary between compounds and with environmental conditions.

  14. The Flatness and Sudden Evolution of the Intergalactic Ionizing Background

    CERN Document Server

    Muñoz, Joseph A; Davies, Frederick B; Furlanetto, Steven R

    2014-01-01

    The ionizing background of cosmic hydrogen is an important probe of the sources and absorbers of ionizing radiation, their evolution and relationship, in the post-reionization universe. Previous studies show that the ionization rate should be very sensitive to changes in the source population: as the emissivity rises, absorbers shrink in size, increasing the ionizing mean free path and, hence, the ionizing background. By contrast, observations of the ionizing background find a very flat evolution from z~2-5, before falling precipitously at z~6. We resolve this discrepancy by pointing out that, at z~2-5, neutral absorbers are associated with the same collapsed halos that additionally host ionizing galactic sources. Thus, an increasing abundance of galaxies is compensated for by a corresponding increase in the absorber population, which moderates the instability in the ionizing background. However, by z~5-6, gas outside of halos dominates the absorption, the coupling between sources and absorbers is lost, and t...

  15. Electrospray-assisted laser desorption/ionization and tandem mass spectrometry of peptides and proteins.

    Science.gov (United States)

    Peng, Ivory X; Shiea, Jentaie; Ogorzalek Loo, Rachel R; Loo, Joseph A

    2007-01-01

    We have constructed an electrospray-assisted laser desorption/ionization (ELDI) source which utilizes a nitrogen laser pulse to desorb intact molecules from matrix-containing sample solution droplets, followed by electrospray ionization (ESI) post-ionization. The ELDI source is coupled to a quadrupole ion trap mass spectrometer and allows sampling under ambient conditions. Preliminary data showed that ELDI produces ESI-like multiply charged peptides and proteins up to 29 kDa carbonic anhydrase and 66 kDa bovine albumin from single-protein solutions, as well as from complex digest mixtures. The generated multiply charged polypeptides enable efficient tandem mass spectrometric (MS/MS)-based peptide sequencing. ELDI-MS/MS of protein digests and small intact proteins was performed both by collisionally activated dissociation (CAD) and by nozzle-skimmer dissociation (NSD). ELDI-MS/MS may be a useful tool for protein sequencing analysis and top-down proteomics study, and may complement matrix-assisted laser desorption/ionization (MALDI)-based measurements. PMID:17639579

  16. Fragmentation study of rutin, a naturally occurring flavone glycoside cationized with different alkali metal ions, using post-source decay matrix-assisted laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Kéki, S; Deák, G; Zsuga, M

    2001-12-01

    A post-source decay matrix-assisted laser desorption/ionization mass spectrometric (PSD-MALDI-MS) study of rutin, a naturally occurring flavone glycoside cationized with different alkali metal ions, is reported. The fragmentations of rutin were performed by selecting the [R + Cat]+ peaks for PSD, where R represents a rutin molecule and Cat an alkali metal ion (Li+, Na+, K+). The PSD-MALDI mass spectra showed, depending on Cat, different fragmentation patterns with respect to both the quality and quantity of the fragment ions formed. The intensity of fragmentation decreased in the order Li+ > Na+ > K+. The fragmentation mechanism and an explanation for the observed differences are suggested.

  17. Resonance ionization spectroscopy

    International Nuclear Information System (INIS)

    The subject of resonance ionization spectroscopy (RIS) from its inception to the present is summarized. The uses of RIS are principally analytical, and these uses are classified in several different ways for this report. The classifications are: (1) basic ways of counting atoms; (2) RIS applications according to the type of particle detector; (3) applications according to source preparation; (4) applications in chemical physics and chemistry; and (5) applications involving daughter atom detection. Each classification is discussed in some detail, and examples of specific applications are mentioned under each classification. Some other potential applications not necessarily related to these classifications are also mentioned

  18. Declaration and authorization forms for the fabrication, distribution or use of radioactive sources or electric generators of ionizing radiation; Formulaires de declaration et d'autorisation de fabrication, de distribution ou d'utilisation de sources radioactives ou de generateurs electriques de rayonnements ionisants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    This document gathers all the forms to be completed when declaring or when asking for an authorization for the fabrication, retailing or use of radioactive sources or electric equipment generating ionizing radiation. These forms can concern all domains (use of sealed radioactive sources, possession and use of a particle accelerator or of radionuclides, import or export of radionuclides or of products containing radionuclides), or the use of such materials or equipment in the medical sector, or the fabrication and use in industry or research, or in user's guides for radioactive sources

  19. Development of Soft Ionization for Particulate Organic Detection with the Aerodyne Aerosol Mass Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Trimborn, A; Williams, L R; Jayne, J T; Worsnop, D R

    2008-06-19

    During this DOE SBIR Phase II project, we have successfully developed several soft ionization techniques, i.e., ionization schemes which involve less fragmentation of the ions, for use with the Aerodyne time-of-flight aerosol mass spectrometer (ToF-AMS). Vacuum ultraviolet single photon ionization was demonstrated in the laboratory and deployed in field campaigns. Vacuum ultraviolet single photon ionization allows better identification of organic species in aerosol particles as shown in laboratory experiments on single component particles, and in field measurements on complex multi-component particles. Dissociative electron attachment with lower energy electrons (less than 30 eV) was demonstrated in the measurement of particulate organics in chamber experiments in Switzerland, and is now a routine approach with AMS systems configured for bipolar, negative ion detection. This technique is particularly powerful for detection of acidic and other highly oxygenated secondary organic aerosol (SOA) chemical functionality. Low energy electron ionization (10 to 12 eV) is also a softer ionization approach routinely available to AMS users. Finally, Lithium ion attachment has been shown to be sensitive to more alkyl-like chemical functionality in SOA. Results from Mexico City are particularly exciting in observing changes in SOA molecular composition under different photochemical/meteorological conditions. More recent results detecting biomass burns at the Montana fire lab have demonstrated quantitative and selective detection of levoglucosan. These soft ionization techniques provide the ToF-AMS with better capability for identifying organic species in ambient atmospheric aerosol particles. This, in turn, will allow more detailed study of the sources, transformations and fate of organic-containing aerosol.

  20. Emergency hospital visits in association with volcanic ash, dust storms and other sources of ambient particles: a time-series study in Reykjavík, Iceland.

    Science.gov (United States)

    Carlsen, Hanne Krage; Gislason, Thorarinn; Forsberg, Bertil; Meister, Kadri; Thorsteinsson, Throstur; Jóhannsson, Thorsteinn; Finnbjornsdottir, Ragnhildur; Oudin, Anna

    2015-04-13

    Volcanic ash contributed significantly to particulate matter (PM) in Iceland following the eruptions in Eyjafjallajökull 2010 and Grímsvötn 2011. This study aimed to investigate the association between different PM sources and emergency hospital visits for cardiorespiratory causes from 2007 to 2012. Indicators of PM10 sources; "volcanic ash", "dust storms", or "other sources" (traffic, fireworks, and re-suspension) on days when PM10 exceeded the daily air quality guideline value of 50 µg/m3 were entered into generalized additive models, adjusted for weather, time trend and co-pollutants. The average number of daily emergency hospital visits was 10.5. PM10 exceeded the air quality guideline value 115 out of 2191 days; 20 days due to volcanic ash, 14 due to dust storms (two days had both dust storm and ash contribution) and 83 due to other sources. High PM10 levels from volcanic ash tended to be significantly associated with the emergency hospital visits; estimates ranged from 4.8% (95% Confidence Interval (CI): 0.6, 9.2%) per day of exposure in unadjusted models to 7.3% (95% CI: -0.4, 15.5%) in adjusted models. Dust storms were not consistently associated with daily emergency hospital visits and other sources tended to show a negative association. We found some evidence indicating that volcanic ash particles were more harmful than particles from other sources, but the results were inconclusive and should be interpreted with caution.

  1. GoAmazon 2014/15 Thermal Desorption Chemical Ionization Mass Spectrometer (TDCIMS) Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, JN [Univ. of California, Irvine, CA (United States)

    2016-04-01

    The Thermal Desorption Chemical Ionization Mass Spectrometer (TDCIMS) deployment to the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility T3 site in Manacapuru, Brazil, was motivated by two main scientific objectives of the Green Ocean Amazon (GoAmazon) 2014/15 field campaign. 1) Study the interactions between anthropogenic and biogenic emissions by determining important molecular species in ambient nanoparticles. To address this, TDCIMS data will be combined with coincident measurements such as gas-phase sulfuric acid to determine the contribution of sulfuric acid condensation to nucleation and growth. We can then compare that result to TDCIMS-derived nanoparticle composition to determine the fraction of growth that can be attributed to the uptake of organic compounds. The molecular composition of sampled particles will also be used to attribute specific chemical species and mechanisms to growth, such as the condensation of low-volatility species or the oligomerization of α-dicarbonyl compounds. 2) Determine the source of new ambient nanoparticles in the Amazon. The hypothesis prior to measurements was that potassium salts formed from the evaporation of primary particles emitted by fungal spores can provide a unique and important pathway for new particle production in the Amazon basin. To explore this hypothesis, the TDCIMS recorded the mass spectra of sampled ambient particles using a protonated water cluster Chemical Ionization Mass Spectrometer (CIMS). Laboratory tests performed using potassium salts show that the TDCIMS can detect potassium with high sensitivity with this technique.

  2. Chemical composition and source of fine and nanoparticles from recent direct injection gasoline passenger cars: Effects of fuel and ambient temperature

    Science.gov (United States)

    Fushimi, Akihiro; Kondo, Yoshinori; Kobayashi, Shinji; Fujitani, Yuji; Saitoh, Katsumi; Takami, Akinori; Tanabe, Kiyoshi

    2016-01-01

    Particle number, mass, and chemical compositions (i.e., elemental carbon (EC), organic carbon (OC), elements, ions, and organic species) of fine particles emitted from four of the recent direct injection spark ignition (DISI) gasoline passenger cars and a port fuel injection (PFI) gasoline passenger car were measured under Japanese official transient mode (JC08 mode). Total carbon (TC = EC + OC) dominated the particulate mass (90% on average). EC dominated the TC for both hot and cold start conditions. The EC/TC ratios were 0.72 for PFI and 0.88-1.0 (average = 0.92) for DISI vehicles. A size-resolved chemical analysis of a DISI car revealed that the major organic components were the C20-C28 hydrocarbons for both the accumulation-mode particles and nanoparticles. Contribution of engine oil was estimated to be 10-30% for organics and the sum of the measured elements. The remaining major fraction likely originated from gasoline fuel. Therefore, it is suggested that soot (EC) also mainly originated from the gasoline. In experiments using four fuels at three ambient temperatures, the emission factors of particulate mass were consistently higher with regular gasoline than with premium gasoline. This result suggest that the high content of less-volatile compounds in fuel increase particulate emissions. These results suggest that focusing on reducing fuel-derived EC in the production process of new cars would effectively reduce particulate emission from DISI cars.

  3. Seasonal variations and sources of ambient fossil and biogenic-derived carbonaceous aerosols based on 14C measurements in Lhasa, Tibet

    Science.gov (United States)

    Huang, Jie; Kang, Shichang; Shen, Chengde; Cong, Zhiyuan; Liu, Kexin; Wang, Wei; Liu, Lichao

    2010-06-01

    A total of 30 samples of total suspended particles were collected at an urban site in Lhasa, Tibet from August 2006 to July 2007 for investigating carbonaceous aerosol features. The fractions of contemporary carbon ( fc) in total carbon (TC) of ambient aerosols are presented using radiocarbon ( 14C) measurements. The value of fc represents the biogenic contribution to TC, as the biosphere releases organic compounds with the present 14C/ 12C level ( fc = 1), whereas 14C has become extinct in anthropogenic emissions of fossil carbon ( fc = 0). The fc values in Lhasa ranging from 0.357 to 0.702, are higher than Beijing and Tokyo, but clearly lower than the rural region of Launceston, which indicates a major biogenic influence in Lhasa. Seasonal variations of fc values corresponded well with variations of pollutants concentrations (e.g. NO 2). Higher fc values appeared in winter indicating carbonaceous aerosol is more dominated by wood burning and incineration of agricultural wastes within this season. The lower fc values in summer and autumn may be caused by increased diesel and petroleum emissions related to tourism in Lhasa. δ13C values ranged from - 26.40‰ to - 25.10‰, with relative higher values in spring and summer, reflecting the increment of fossil carbon emissions.

  4. Evaluation of the capabilities of atmospheric pressure chemical ionization source coupled to tandem mass spectrometry for the determination of dioxin-like polychlorobiphenyls in complex-matrix food samples.

    Science.gov (United States)

    Portolés, T; Sales, C; Abalos, M; Sauló, J; Abad, E

    2016-09-21

    The use of the novel atmospheric pressure chemical ionization (APCI) source for gas chromatography (GC) coupled to triple quadrupole using tandem mass spectrometry (MS/MS) and its potential for the simultaneous determination of the 12 dioxin-like polychlorobiphenyls (DL-PCBs) in complex food and feed matrices has been evaluated. In first place, ionization and fragmentation behavior of DL-PCBs on the APCI source under charge transfer conditions has been studied followed by their fragmentation in the collision cell. Linearity, repeatability and sensitivity have been studied obtaining instrumental limits of detection and quantification of 0.0025 and 0.005 pg μL(-1) (2.5 and 5 fg on column) respectively for every DL-PCB. Finally, application to real samples has been carried out and DL-PCB congeners (PCB 77, 81, 105, 114, 118, 123, 126, 156, 157, 167, 169, 189) have been detected in the different samples in the range of 0.40-10000 pg g(-1). GC-(APCI)MS/MS has been proved as a suitable alternative to the traditionally accepted confirmation method based on the use of high resolution mass spectrometry and other triple quadrupole tandem mass spectrometry techniques operating with electron ionization. The development of MS/MS methodologies for the analysis of dioxins and DL-PCBs is nowadays particularly important, since this technique was included as a confirmatory method in the present European Union regulations that establish the requirements for the determination of these compounds in food and feed matrices.

  5. Evaluation of the capabilities of atmospheric pressure chemical ionization source coupled to tandem mass spectrometry for the determination of dioxin-like polychlorobiphenyls in complex-matrix food samples.

    Science.gov (United States)

    Portolés, T; Sales, C; Abalos, M; Sauló, J; Abad, E

    2016-09-21

    The use of the novel atmospheric pressure chemical ionization (APCI) source for gas chromatography (GC) coupled to triple quadrupole using tandem mass spectrometry (MS/MS) and its potential for the simultaneous determination of the 12 dioxin-like polychlorobiphenyls (DL-PCBs) in complex food and feed matrices has been evaluated. In first place, ionization and fragmentation behavior of DL-PCBs on the APCI source under charge transfer conditions has been studied followed by their fragmentation in the collision cell. Linearity, repeatability and sensitivity have been studied obtaining instrumental limits of detection and quantification of 0.0025 and 0.005 pg μL(-1) (2.5 and 5 fg on column) respectively for every DL-PCB. Finally, application to real samples has been carried out and DL-PCB congeners (PCB 77, 81, 105, 114, 118, 123, 126, 156, 157, 167, 169, 189) have been detected in the different samples in the range of 0.40-10000 pg g(-1). GC-(APCI)MS/MS has been proved as a suitable alternative to the traditionally accepted confirmation method based on the use of high resolution mass spectrometry and other triple quadrupole tandem mass spectrometry techniques operating with electron ionization. The development of MS/MS methodologies for the analysis of dioxins and DL-PCBs is nowadays particularly important, since this technique was included as a confirmatory method in the present European Union regulations that establish the requirements for the determination of these compounds in food and feed matrices. PMID:27590550

  6. Liquid chromatography coupled to different atmospheric pressure ionization sources-quadrupole-time-of-flight mass spectrometry and post-column addition of metal salt solutions as a powerful tool for the metabolic profiling of Fusarium oxysporum.

    Science.gov (United States)

    Cirigliano, Adriana M; Rodriguez, M Alejandra; Gagliano, M Laura; Bertinetti, Brenda V; Godeas, Alicia M; Cabrera, Gabriela M

    2016-03-25

    Fusarium oxysporum L11 is a non-pathogenic soil-borne fungal strain that yielded an extract that showed antifungal activity against phytopathogens. In this study, reversed-phase high-performance liquid chromatography (RP-HPLC) coupled to different atmospheric pressure ionization sources-quadrupole-time-of-flight mass spectrometry (API-QTOF-MS) was applied for the comprehensive profiling of the metabolites from the extract. The employed sources were electrospray (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI). Post-column addition of metal solutions of Ca, Cu and Zn(II) was also tested using ESI. A total of 137 compounds were identified or tentatively identified by matching their accurate mass signals, suggested molecular formulae and MS/MS analysis with previously reported data. Some compounds were isolated and identified by NMR. The extract was rich in cyclic peptides like cyclosporins, diketopiperazines and sansalvamides, most of which were new, and are reported here for the first time. The use of post-column addition of metals resulted in a useful strategy for the discrimination of compound classes since specific adducts were observed for the different compound families. This technique also allowed the screening for compounds with metal binding properties. Thus, the applied methodology is a useful choice for the metabolic profiling of extracts and also for the selection of metabolites with potential biological activities related to interactions with metal ions.

  7. Psicologia do Ambiente

    OpenAIRE

    Antunes, Dalila; Bernardo, Fátima; Palma-Oliveira, José-Manuel

    2011-01-01

    Na aplicação da Psicologia à área do AMBIENTE importa em primeiro lugar definir o que se entende, neste contexto, por ambiente. O conceito é entendido como toda a envolvente que rodeia o ser humano. Referimo-nos pois ao espaço físico e aos estímulos que nele existem (som, ar, paisagem…), dirigindo-se a Psicologia do Ambiente ao estudo e intervenção sobre a forma como o ambiente influencia o indivíduo ou grupos, e sobre o modo como o comportamento dos indivíduos e grupos influenciam o ambiente...

  8. Estimates of site response based on spectral ratio between horizontal and vertical components of ambient vibrations in the source zone of 2001 Bhuj earthquake

    Science.gov (United States)

    Natarajan, Thulasiraman; Rajendran, Kusala

    2015-02-01

    We investigated the site response characteristics of Kachchh rift basin over the meizoseismal area of the 2001, Mw 7.6, Bhuj (NW India) earthquake using the spectral ratio of the horizontal and vertical components of ambient vibrations. Using the available knowledge on the regional geology of Kachchh and well documented ground responses from the earthquake, we evaluated the H/V curves pattern across sediment filled valleys and uplifted areas generally characterized by weathered sandstones. Although our H/V curves showed a largely fuzzy nature, we found that the hierarchical clustering method was useful for comparing large numbers of response curves and identifying the areas with similar responses. Broad and plateau shaped peaks of a cluster of curves within the valley region suggests the possibility of basin effects within valley. Fundamental resonance frequencies (f0) are found in the narrow range of 0.1-2.3 Hz and their spatial distribution demarcated the uplifted regions from the valleys. In contrary, low H/V peak amplitudes (A0 = 2-4) were observed on the uplifted areas and varying values (2-9) were found within valleys. Compared to the amplification factors, the liquefaction indices (kg) were able to effectively indicate the areas which experienced severe liquefaction. The amplification ranges obtained in the current study were found to be comparable to those obtained from earthquake data for a limited number of seismic stations located on uplifted areas; however the values on the valley region may not reflect their true amplification potential due to basin effects. Our study highlights the practical usefulness as well as limitations of the H/V method to study complex geological settings as Kachchh.

  9. PROCEEDINGS: NATIONAL SYMPOSIUM ON RECENT ADVANCES IN POLLUTANT MONITORING OF AMBIENT AIR AND STATIONARY SOURCES, HELD AT RADISON PLAZA RALEIGH HOTEL, ON MAY 8-10, 1984

    Science.gov (United States)

    The fourth annual national symposium sponsored by EPA's Environmental Monitoring Systems Laboratory was held May 8-10, 1984 in Raleigh, North Carolina. In seven sessions over three days, papers and discussions focused on state-of-the-art systems for monitoring source emissions, a...

  10. Atmosphere and Ambient Space

    DEFF Research Database (Denmark)

    Schmidt, Ulrik

    Atmosphere and Ambient Space This paper explores the relation between atmosphere and ambient space. Atmosphere and ambient space share many salient properties. They are both ontologically indeterminate, constantly varying and formally diffuse and they are both experienced as a subtle, non......-signifying property of a given space. But from a certain point of view, the two concepts also designate quite dissimilar experiences of space. To be ’ambient’ means to surround. Accordingly, ambient space is that space, which surrounds something or somebody. (Gibson 1987: 65) Since space is essentially...... of a surrounding character, all space can thus be described as having a fundamentally ambient character. So what precisely is an ambient space, then? As I will argue in my presentation, ambient space is a sensory effect of spatiality when a space is experienced as being particularly surrounding: a ‘space effect...

  11. Emergency Hospital Visits in Association with Volcanic Ash, Dust Storms and Other Sources of Ambient Particles: A Time-Series Study in Reykjavík, Iceland

    Directory of Open Access Journals (Sweden)

    Hanne Krage Carlsen

    2015-04-01

    Full Text Available Volcanic ash contributed significantly to particulate matter (PM in Iceland following the eruptions in Eyjafjallajökull 2010 and Grímsvötn 2011. This study aimed to investigate the association between different PM sources and emergency hospital visits for cardiorespiratory causes from 2007 to 2012. Indicators of PM10 sources; “volcanic ash”, “dust storms”, or “other sources” (traffic, fireworks, and re-suspension on days when PM10 exceeded the daily air quality guideline value of 50 µg/m3 were entered into generalized additive models, adjusted for weather, time trend and co-pollutants. The average number of daily emergency hospital visits was 10.5. PM10 exceeded the air quality guideline value 115 out of 2191 days; 20 days due to volcanic ash, 14 due to dust storms (two days had both dust storm and ash contribution and 83 due to other sources. High PM10 levels from volcanic ash tended to be significantly associated with the emergency hospital visits; estimates ranged from 4.8% (95% Confidence Interval (CI: 0.6, 9.2% per day of exposure in unadjusted models to 7.3% (95% CI: −0.4, 15.5% in adjusted models. Dust storms were not consistently associated with daily emergency hospital visits and other sources tended to show a negative association. We found some evidence indicating that volcanic ash particles were more harmful than particles from other sources, but the results were inconclusive and should be interpreted with caution.

  12. Electron impact ionization and multiphoton ionization of doped superfluid helium droplets: A comparison.

    Science.gov (United States)

    He, Yunteng; Zhang, Jie; Kong, Wei

    2016-02-28

    We compare characteristics of electron impact ionization (EI) and multiphoton ionization (MPI) of doped superfluid helium droplets using the same droplet source. Selected dopant ion fragments from the two ionization schemes demonstrate different dependence on the doping pressure, which could be attributed to the different ionization mechanisms. While EI directly ionizes helium atoms in a droplet therefore has higher yields for bigger droplets (within a limited size range), MPI is insensitive to the helium in a droplet and is only dependent on the number of dopant molecules. The optimal timing of the ionization pulse also varies with the doping pressure, implying a velocity slip among different sized droplets. Calculations of the doping statistics and ionization probabilities qualitatively agree with the experimental data. Our results offer a word of caution in interpreting the pressure and timing dependence of superfluid helium droplets, and we also devise a scheme in achieving a high degree of doping while limiting the contribution of dopant clusters. PMID:26931697

  13. Characterizing and sourcing ambient PM2.5 over key emission regions in China I: Water-soluble ions and carbonaceous fractions

    Science.gov (United States)

    Zhou, Jiabin; Xing, Zhenyu; Deng, Junjun; Du, Ke

    2016-06-01

    During the past decade, huge research resources have been devoted into studies of air pollution in China, which generated abundant datasets on emissions and pollution characterization. Due to the complex nature of air pollution as well as the limitations of each individual investigating approach, the published results were sometimes perplexing and even contradicting. This research adopted a multi-method approach to investigate region-specific air pollution characteristics and sources in China, results obtained using different analytical and receptor modeling methods were inter-compared for validation and interpretation. A year-round campaign was completed for comprehensive characterization of PM2.5 over four key emission regions: Beijing-Tianjin-Hebei (BTH), Yangzi River Delta (YRD), Pearl River Delta (PRD), and Sichuan Basin (SB). Atmospheric PM2.5 samples were collected from 10/2012 to 08/2013 at four regional sites, located on the diffusion paths of air masses from their corresponding megacities (i.e., Beijing, Shanghai, Guangzhou, and Chengdu). The annual average PM2.5 mass concentrations showed distinct regional difference, with the highest observed at BTH and lowest at PRD site. Nine water-soluble ions together contributed 33-41% of PM2.5 mass, with three dominant ionic species being SO42-, NO3-, NH4+, and carbonaceous particulate matter contributed 16-23% of PM2.5 mass. This implied that combustion and secondary formation were the main sources for PM2.5 in China. In addition, SO42-, NO3-, NH4+, and carbonaceous components (OC, EC) showed clear seasonal patterns with the highest concentration occurring in winter while the lowest in summer. Principal component analysis performed on aerosol data revealed that vehicular emissions, coal/biomass combustion, industry source, soil dust as well as secondary formation were the main potential sources for the ionic components of PM2.5. The characteristic chemical species combined with back trajectory analysis indicated

  14. Health effects of ionizing radiation

    International Nuclear Information System (INIS)

    Ionizing radiation is energy that travels through space as electromagnetic waves or a stream of fast moving particles. In the workplace, the sources of ionizing radiation are radioactive substances, nuclear power plants, x-ray machines and nuclear devices used in medicine, research and industry. Commonly encountered types of radiation are alpha particles, beta particles and gamma rays. Alpha particles have very little penetrating power and pose a risk only when the radioactive substance is deposited inside the body. Beta particles are more penetrating than alpha particles and can penetrate the outer body tissues causing damage to the skin and the eyes. Gamma rays are highly penetrating and can cause radiation damage to the whole body. The probability of radiation-induced disease depends on the accumulated amount of radiation dose. The main health effects of ionizing radiation are cancers in exposed persons and genetic disorders in the children, grandchildren and subsequent generations of the exposed parents. The fetus is highly sensitive to radiation-induced abnormalities. At high doses, radiation can cause cataracts in the eyes. There is no firm evidence that ionizing radiation causes premature aging. Radiation-induced sterility is highly unlikely for occupational doses. The data on the combined effect of ionizing radiation and other cancer-causing physical and chemical agents are inconclusive

  15. sources

    Directory of Open Access Journals (Sweden)

    Shu-Yin Chiang

    2002-01-01

    Full Text Available In this paper, we study the simplified models of the ATM (Asynchronous Transfer Mode multiplexer network with Bernoulli random traffic sources. Based on the model, the performance measures are analyzed by the different output service schemes.

  16. Ionizing radiation dose control for workers in a nuclear plant working with unsealed sources; Controle da dose de radiacao ionizante para trabalhadores em uma instalacao radiativa com fontes nao seladas

    Energy Technology Data Exchange (ETDEWEB)

    Gerulis, Eduardo

    2006-07-01

    With the liberation of the use of the nuclear energy for peaceful applications, International Commission Radiological Protection, ICRP, founded in 1928, created a system of protection of the undesirable doses of ionizing radiation in 1958. This has been received by workers, members of the public and environment and hence it became possible for the introduction of these applications. This protection system is adopted by the International Agency of Energy Atomic, IAEA, that publishes recommendations in safety series, 88 and by the Comissao Nacional de Energia Nuclear, CNEN, which publishes these regulations. The international recommendations and national regulations were adapted and they need to be applied in this way. The present paper uses recommendations of the publication 75 from ICRP, of the publication 115 from 88 and regulations of the regulation NN 3.01 from CNEN to present, through radiological protection measures, the ionizing radiation dose control for workers in a nuclear plant that works in the research, production, division and packing of unsealed sources to be used in clinical applications. In that way it is possible to prevent appropriately the undesirable doses and to confirm the received doses. (author)

  17. Method development aspects for the quantitation of pharmaceutical compounds in human plasma with a matrix-assisted laser desorption/ionization source in the multiple reaction monitoring mode.

    Science.gov (United States)

    Kovarik, Peter; Grivet, Chantal; Bourgogne, Emmanuel; Hopfgartner, Gérard

    2007-01-01

    The present work investigates various method development aspects for the quantitative analysis of pharmaceutical compounds in human plasma using matrix-assisted laser desorption/ionization and multiple reaction monitoring (MALDI-MRM). Talinolol was selected as a model analyte. Liquid-liquid extraction (LLE) and protein precipitation were evaluated regarding sensitivity and throughput for the MALDI-MRM technique and its applicability without and with chromatographic separation. Compared to classical electrospray liquid chromatography/mass spectrometry (LC/ESI-MS) method development, with MALDI-MRM the tuning of the analyte in single MS mode is more challenging due to interfering matrix background ions. An approach is proposed using background subtraction. With LLE and using a 200 microL human plasma aliquot acceptable precision and accuracy could be obtained in the range of 1 to 1000 ng/mL without any LC separation. Approximately 3 s were required for one analysis. A full calibration curve and its quality control samples (20 samples) can be analyzed within 1 min. Combining LC with the MALDI analysis allowed improving the linearity down to 50 pg/mL, while reducing the throughput potential only by two-fold. Matrix effects are still a significant issue with MALDI but can be monitored in a similar way to that used for LC/ESI-MS analysis. PMID:17295425

  18. Chemical composition and sources of ambient aerosol in an urban environment over Athens, Greece: Case study on the role of wintertime biomass burning

    Science.gov (United States)

    Theodosi, Christina

    2016-04-01

    This study examines the chemical composition of aerosols over the Greater Athens Area (GAA). To achieve this, particulate matter sampling has been conducted on a 6h-24h basis and more than 700 aerosol samples were collected at downtown Athens, in Thissio from January 2013 to December 2015. All samples, after mass quantification, were analyzed for major anions (Cl^-, Br^-, NO{_3^-}, SO{_4-2}, PO{_4-3}, C_2O{_4-2}), cations (NH{_4^+}, K^+, Na^+, Mg+2, Ca+2), trace elements (Al, As, Ca, Cd, Co, Cr, Cu, Fe, V, Zn, Mn, Ni, Pb, P, S, Sb), organic carbon (OC) and elemental carbon (EC). Aerosol chemical mass closure calculations indicated that carbonaceous aerosol constitutes a major component, along with nitrate and sulfate anions, dust, cations and EC. Moreover, during the winter periods of December 2012-January 2013 and December 2013-January 2014, air pollution due to excessive use of biomass for domestic heating has been reported as a major environmental problem in the area. To assess the importance of biomass burning as a source of air pollution over the GAA three main sugars specific biomass burning tracers (levoglucosan, mannosan and galactosan) and Polycyclic aromatic hydrocarbons (PAHs) were also analyzed during the winter period. Acknowledgments This work was supported by the State Scholarship Foundation ("IKY Fellowships of Excellence for Postgraduate Studies in Greece - Siemens Programme") in the framework of the Hellenic Republic-Siemens Settlement Agreement.

  19. LED illuminant on the ambient light

    Science.gov (United States)

    Liu, Anqing; Sandipan, Mishra; Shur, Michael

    2014-09-01

    We develop an approach for combining illuminance and spectral power distribution of the LED and ambient light and apply our technique for developing an LED camera flashlight balancing the illuminance contrast between object and background. Our method uses the closed loop, multiobjective optimization comprising: (1) characterizing the lighting task by illuminance, correlated color temperature (CCT), and statistical color quality indices that include a set of Statistical Color Quality Metrics and the Color Rendition Index (CRI) implemented with indexes of S (saturation) or D (dulling); (2) measuring the illuminance and the spectrum of the ambient light on the target lighting surface, which might depend on all the sources proving illumination and on the reflected light; (3) determining the desired illuminance of the LED source on the target lighting surface; (4) calculating the desired luminous flux of the LED source according to the desired illuminance; (5) constituting the SPD of the LED source; (6) calculating the relative spectra counts of the LED source and the ambient light on the target lighting surface (7) calculating the CCT and statistical color quality indexes of the combined light; (8) repeating the above steps until the resulting SPD is close enough to the expectation. Using the above method, an LED camera flashlight has been designed, which works together with usual fluorescent ambient light and generates working lighting environment with high fidelity and high CCT (6000K). The spectrum and luminous flux of the LED lamp is automatically tunable with a change of the ambient light.

  20. Sources

    OpenAIRE

    2015-01-01

    Sources Fondation Pablo Iglesias. Alcala de Henares. Sections : Archives privées de Manuel ArijaArchives extérieuresArchives FNJS de EspañaPrensa Archives Générales de l’Administration. Alcala de Henares. Sections : Opposition au franquismeSig. 653 Sig TOP 82/68.103-68.602.Índice de las cartas colectivas, Relaciones, Cartas al Ministro de Información de Marzo de 1965. c.662. Sources cinématographiques Filmothèque Nationale d’Espagne.NO.DO. N° 1157C. 08/03/1965.aguirre Javier, Blanco vertical....

  1. Applications of ionizing radiations

    International Nuclear Information System (INIS)

    Developments in standard applications and brand new nuclear technologies, with high impact on the future of the agriculture, medicine, industry and the environmental preservation. The Radiation Technology Center (CTR) mission is to apply the radiation and radioisotope technologies in Industry, Health, Agriculture, and Environmental Protection, expanding the scientific knowledge, improving human power resources, transferring technology, generating products and offering services for the Brazilian society. The CTR main R and D activities are in consonance with the IPEN Director Plan (2011-2013) and the Applications of Ionizing Radiation Program, with four subprograms: Irradiation of Food and Agricultural Products; Radiation and Radioisotopes Applications in Industry and Environment; Radioactive Sources and Radiation Applications in Human Health; and Radioactive Facilities and Equipment for the Applications of Nuclear Techniques

  2. Applications of ionizing radiations

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-07-01

    Developments in standard applications and brand new nuclear technologies, with high impact on the future of the agriculture, medicine, industry and the environmental preservation. The Radiation Technology Center (CTR) mission is to apply the radiation and radioisotope technologies in Industry, Health, Agriculture, and Environmental Protection, expanding the scientific knowledge, improving human power resources, transferring technology, generating products and offering services for the Brazilian society. The CTR main R and D activities are in consonance with the IPEN Director Plan (2011-2013) and the Applications of Ionizing Radiation Program, with four subprograms: Irradiation of Food and Agricultural Products; Radiation and Radioisotopes Applications in Industry and Environment; Radioactive Sources and Radiation Applications in Human Health; and Radioactive Facilities and Equipment for the Applications of Nuclear Techniques.

  3. Foodstuffs preservation by ionization

    International Nuclear Information System (INIS)

    This document contains all the papers presented at the meeting on foodstuffs preservation by ionization. These papers deal especially with the food ionization process, its development and the view of the food industry on ionization. Refs and figs (F.M.)

  4. Ionization Energies of Lanthanides

    Science.gov (United States)

    Lang, Peter F.; Smith, Barry C.

    2010-01-01

    This article describes how data are used to analyze the pattern of ionization energies of the lanthanide elements. Different observed pathways of ionization between different ground states are discussed, and the effects of pairing, exchange, and orbital interactions on ionization energies of the lanthanides are evaluated. When all the above…

  5. Ionization Scheme Development at the ISOLDE RILIS

    Science.gov (United States)

    Fedosseev, V. N.; Marsh, B. A.; Fedorov, D. V.; Köster, U.; Tengborn, E.

    2005-04-01

    The resonance ionization laser ion source (RILIS) of the ISOLDE on-line isotope separation facility is based on the method of laser step-wise resonance ionization of atoms in a hot metal cavity. The atomic selectivity of the RILIS complements the mass selection process of the ISOLDE separator magnets to provide beams of a chosen isotope with greatly reduced isobaric contamination. Using a system of dye lasers pumped by copper vapour lasers, ion beams of 24 elements have been generated at ISOLDE with ionization efficiencies in the range of 0.5-15%. As part of the ongoing RILIS development off-line resonance ionization spectroscopy studies carried out in 2003 and 2004 have determined the optimal three-step ionization schemes for scandium, antimony, dysprosium and yttrium.

  6. Ionization Scheme Development at the ISOLDE RILIS

    International Nuclear Information System (INIS)

    The resonance ionization laser ion source (RILIS) of the ISOLDE on-line isotope separation facility is based on the method of laser step-wise resonance ionization of atoms in a hot metal cavity. The atomic selectivity of the RILIS complements the mass selection process of the ISOLDE separator magnets to provide beams of a chosen isotope with greatly reduced isobaric contamination. Using a system of dye lasers pumped by copper vapour lasers, ion beams of 24 elements have been generated at ISOLDE with ionization efficiencies in the range of 0.5-15%. As part of the ongoing RILIS development off-line resonance ionization spectroscopy studies carried out in 2003 and 2004 have determined the optimal three-step ionization schemes for scandium, antimony, dysprosium and yttrium.

  7. Whole-body Mass Spectrometry Imaging by Infrared Matrix-assisted Laser Desorption Electrospray Ionization (IR-MALDESI).

    Science.gov (United States)

    Nazari, Milad; Bokhart, Mark T; Muddiman, David C

    2016-01-01

    Ambient ionization sources for mass spectrometry (MS) have been the subject of much interest in the past decade. Matrix-assisted laser desorption electrospray ionization (MALDESI) is an example of such methods, where features of matrix-assisted laser desorption/ionization (MALDI) (e.g., pulsed nature of desorption) and electrospray ionization (ESI) (e.g., soft-ionization) are combined. One of the major advantages of MALDESI is its inherent versatility. In MALDESI experiments, an ultraviolet (UV) or infrared (IR) laser can be used to resonantly excite an endogenous or exogenous matrix. The choice of matrix is not analyte dependent, and depends solely on the laser wavelength used for excitation. In IR-MALDESI experiments, a thin layer of ice is deposited on the sample surface as an energy-absorbing matrix. The IR-MALDESI source geometry has been optimized using statistical design of experiments (DOE) for analysis of liquid samples as well as biological tissue specimens. Furthermore, a robust IR-MALDESI imaging source has been developed, where a tunable mid-IR laser is synchronized with a computer controlled XY translational stage and a high resolving power mass spectrometer. A custom graphical user interface (GUI) allows user selection of the repetition rate of the laser, number of shots per voxel, step-size of the sample stage, and the delay between the desorption and scan events for the source. IR-MALDESI has been used in variety of applications such as forensic analysis of fibers and dyes and MSI of biological tissue sections. Distribution of different analytes ranging from endogenous metabolites to exogenous xenobiotics within tissue sections can be measured and quantified using this technique. The protocol presented in this manuscript describes major steps necessary for IR-MALDESI MSI of whole-body tissue sections. PMID:27077488

  8. A study of electron density profiles in relation to ionization sources and ground-based radio wave absorption measurements, part 1

    Science.gov (United States)

    Gnanalingam, S.; Kane, J. A.

    1973-01-01

    An extensive set of ground-based measurements of the diurnal variation of medium frequency radio wave adsorption and virtual height is analyzed in terms of current understanding of the D- and lower E-region ion production and loss process. When this is done a gross discrepancy arises, the source of which is not known.

  9. Study of the Dependence of the Source check ionization chamber with pressure; Estudio de la dependencia de la camara de ionizacion Sourcecheck con la presion

    Energy Technology Data Exchange (ETDEWEB)

    Tornero-Lopez, A. M.; Ruiz-Arrabola, S.; Moreno-Torres, M.; Simancas, F.; Guerrero, R.; Guirado, D.

    2013-07-01

    Because of the importance of accurate measurement of power low-energy photons, such as I-125 seeds used in brachytherapy, and the widespread use of Source Check in Europe, this work is to study whether this camera features any dependence the pressure and shows included in the pressure-temperature factor usual. (Author)

  10. Effect of antioxidants on thiobarbituric acid reactive substances of mechanically de boned chicken meat irradiated with ionizing radiation: cobalt-60 and electron beam sources

    Energy Technology Data Exchange (ETDEWEB)

    Brito, Poliana de Paula; Azevedo, Heliana de; Pomarico Neto, Walter; Roque, Claudio Vitor; Brusqui, Armando Luiz, E-mail: hgomes@cnen.gov.b, E-mail: pbrito@cnen.gov.b, E-mail: cvroque@cnen.gov.b, E-mail: abrusqui@cnen.gov.b [Brazilian Nuclear Energy Commission (LAPOC/CNEN), Pocos de Caldas, MG (Brazil); Haguiwara, Marcia Mayumi Harada; Miyagusku, Luciana, E-mail: marciamh@ital.gov.b, E-mail: lucianam@ital.gov.b [Food Technology Institute (ITAL), SP (Brazil). Meat Technology Center

    2011-07-01

    Samples of MDCM with skin were divided into three groups: control (without antioxidants), Antioxidant 1 - A1 (0.3% Sodium Polyphosphate and Sodium Erythorbate 0.05%) and Antioxidant 2 - A2 (Rosemary Extract 0.02% and {alpha}-Tocopherol 0.01%). The three batches of samples were divided into nine groups: no antioxidant and non-irradiated (Cn/I), with antioxidant A1 and non-irradiated (A1n/I), with antioxidant A2 and non-irradiated (A2n/I) without antioxidant and irradiated in Cobalt-60 source (CCo), with antioxidant A1 irradiated in Cobalt 60 source (A1Co) with antioxidant A2 irradiated in Cobalt-60 source (A2Co) with antioxidant A1 irradiated in Electron beam (A1Eb) and with antioxidant A2 irradiated in Electron beam (A2Eb). Each 100 g sample was conditioned in a transparent, low density polyethylene oxygen permeable bag, frozen overnight at a temperature of -18 +- 1 deg C in a chamber, and irradiated in this state, maintaining the temperature low with dry ice. The samples were irradiated with a dose of 3.0 kGy, used two sources of radiation: Cobalt-60 (3.1 kGy.h{sup -1}) and electron beam (2.9 kGy.s{sup -1}). After this process, the samples were evaluated during the refrigeration period (2 +- 1 deg C) for 11 days for the following analysis: total psychotropic bacteria count, thiobarbituric acid reactive substances (TBARS). The addition of antioxidants was able to reduce lipid oxidation caused by the irradiation. There were no differences between the radiation sources used in the same parameters. The better antioxidants mixture in the TBARS reducing it was rosemary extract and {alpha}-tocopherol (A2). (author)

  11. Effect of antioxidants on thiobarbituric acid reactive substances of mechanically de boned chicken meat irradiated with ionizing radiation: cobalt-60 and electron beam sources

    International Nuclear Information System (INIS)

    Samples of MDCM with skin were divided into three groups: control (without antioxidants), Antioxidant 1 - A1 (0.3% Sodium Polyphosphate and Sodium Erythorbate 0.05%) and Antioxidant 2 - A2 (Rosemary Extract 0.02% and α-Tocopherol 0.01%). The three batches of samples were divided into nine groups: no antioxidant and non-irradiated (Cn/I), with antioxidant A1 and non-irradiated (A1n/I), with antioxidant A2 and non-irradiated (A2n/I) without antioxidant and irradiated in Cobalt-60 source (CCo), with antioxidant A1 irradiated in Cobalt 60 source (A1Co) with antioxidant A2 irradiated in Cobalt-60 source (A2Co) with antioxidant A1 irradiated in Electron beam (A1Eb) and with antioxidant A2 irradiated in Electron beam (A2Eb). Each 100 g sample was conditioned in a transparent, low density polyethylene oxygen permeable bag, frozen overnight at a temperature of -18 +- 1 deg C in a chamber, and irradiated in this state, maintaining the temperature low with dry ice. The samples were irradiated with a dose of 3.0 kGy, used two sources of radiation: Cobalt-60 (3.1 kGy.h-1) and electron beam (2.9 kGy.s-1). After this process, the samples were evaluated during the refrigeration period (2 +- 1 deg C) for 11 days for the following analysis: total psychotropic bacteria count, thiobarbituric acid reactive substances (TBARS). The addition of antioxidants was able to reduce lipid oxidation caused by the irradiation. There were no differences between the radiation sources used in the same parameters. The better antioxidants mixture in the TBARS reducing it was rosemary extract and α-tocopherol (A2). (author)

  12. Oxidative potential of ambient water-soluble PM2.5 measured by Dithiothreitol (DTT) and Ascorbic Acid (AA) assays in the southeastern United States: contrasts in sources and health associations

    Science.gov (United States)

    Fang, T.; Verma, V.; Bates, J. T.; Abrams, J.; Klein, M.; Strickland, M. J.; Sarnat, S. E.; Chang, H. H.; Mulholland, J. A.; Tolbert, P. E.; Russell, A. G.; Weber, R. J.

    2015-11-01

    The ability of certain components of particulate matter to induce oxidative stress through catalytic generation of reactive oxygen species (ROS) in vivo may be one mechanism accounting for observed linkages between ambient aerosols and adverse health outcomes. A variety of assays have been used to measure this so-called aerosol oxidative potential. We developed a semi-automated system to quantify oxidative potential of filter aqueous extracts utilizing the dithiothreitol (DTT) assay and have recently developed a similar semi-automated system using the ascorbic acid (AA) assay. Approximately 500 PM2.5 filter samples collected in contrasting locations in the southeastern US were analyzed using both assays. We found that water-soluble DTT activity on a per air volume basis was more spatially uniform than water-soluble AA activity. DTT activity was higher in winter than in summer/fall, whereas AA activity was higher in summer/fall compared to winter, with highest levels near highly trafficked highways. DTT activity was correlated with organic and metal species, whereas AA activity was correlated with water-soluble metals (especially water-soluble Cu, r=0.70-0.91 at most sites). Source apportionment models, Positive Matrix Factorization (PMF) and a Chemical Mass Balance Method with ensemble-averaged source impact profiles (CMB-E), suggest a strong contribution from secondary processes (e.g., organic aerosol oxidation or metal mobilization by formation of an aqueous particle with secondary acids) and traffic emissions to both DTT and AA activities in urban Atlanta. Biomass burning was a large source for DTT activity, but insignificant for AA. DTT activity was well correlated with PM2.5 mass (r=0.49-0.86 across sites/seasons), while AA activity did not co-vary strongly with mass. A linear model was developed to estimate DTT and AA activities for the central Atlanta Jefferson Street site, based on the CMB-E sources that are statistically significant with positive

  13. Oxidative potential of ambient water-soluble PM2.5 in the southeastern United States: contrasts in sources and health associations between ascorbic acid (AA) and dithiothreitol (DTT) assays

    Science.gov (United States)

    Fang, Ting; Verma, Vishal; Bates, Josephine T.; Abrams, Joseph; Klein, Mitchel; Strickland, Matthew J.; Sarnat, Stefanie E.; Chang, Howard H.; Mulholland, James A.; Tolbert, Paige E.; Russell, Armistead G.; Weber, Rodney J.

    2016-03-01

    The ability of certain components of particulate matter to induce oxidative stress through the generation of reactive oxygen species (ROS) in vivo may be one mechanism accounting for observed linkages between ambient aerosols and adverse health outcomes. A variety of assays have been used to measure this so-called aerosol oxidative potential. We developed a semi-automated system to quantify oxidative potential of filter aqueous extracts utilizing the dithiothreitol (DTT) assay and report here the development of a similar semi-automated system for the ascorbic acid (AA) assay. Approximately 500 PM2.5 filter samples collected in contrasting locations in the southeastern US were analyzed for a host of aerosol species, along with AA and DTT activities. We present a detailed contrast in findings from these two assays. Water-soluble AA activity was higher in summer and fall than in winter, with highest levels near heavily trafficked highways, whereas DTT activity was higher in winter compared to summer and fall and more spatially homogeneous. AA activity was nearly exclusively correlated with water-soluble Cu (r = 0.70-0.94 at most sites), whereas DTT activity was correlated with organic and metal species. Source apportionment models, positive matrix factorization (PMF) and a chemical mass balance method with ensemble-averaged source impact profiles (CMB-E), suggest a strong contribution from traffic emissions and secondary processes (e.g., organic aerosol oxidation or metals mobilization by secondary acids) to both AA and DTT activities in urban Atlanta. In contrast, biomass burning was a large source for DTT activity, but insignificant for AA. AA activity was not correlated with PM2.5 mass, while DTT activity co-varied strongly with mass (r = 0.49-0.86 across sites and seasons). Various linear models were developed to estimate AA and DTT activities for the central Atlanta Jefferson Street site, based on the CMB-E sources. The models were then used to estimate daily

  14. Oxidative potential of ambient water-soluble PM2.5 measured by Dithiothreitol (DTT and Ascorbic Acid (AA assays in the southeastern United States: contrasts in sources and health associations

    Directory of Open Access Journals (Sweden)

    T. Fang

    2015-11-01

    Full Text Available The ability of certain components of particulate matter to induce oxidative stress through catalytic generation of reactive oxygen species (ROS in vivo may be one mechanism accounting for observed linkages between ambient aerosols and adverse health outcomes. A variety of assays have been used to measure this so-called aerosol oxidative potential. We developed a semi-automated system to quantify oxidative potential of filter aqueous extracts utilizing the dithiothreitol (DTT assay and have recently developed a similar semi-automated system using the ascorbic acid (AA assay. Approximately 500 PM2.5 filter samples collected in contrasting locations in the southeastern US were analyzed using both assays. We found that water-soluble DTT activity on a per air volume basis was more spatially uniform than water-soluble AA activity. DTT activity was higher in winter than in summer/fall, whereas AA activity was higher in summer/fall compared to winter, with highest levels near highly trafficked highways. DTT activity was correlated with organic and metal species, whereas AA activity was correlated with water-soluble metals (especially water-soluble Cu, r=0.70–0.91 at most sites. Source apportionment models, Positive Matrix Factorization (PMF and a Chemical Mass Balance Method with ensemble-averaged source impact profiles (CMB-E, suggest a strong contribution from secondary processes (e.g., organic aerosol oxidation or metal mobilization by formation of an aqueous particle with secondary acids and traffic emissions to both DTT and AA activities in urban Atlanta. Biomass burning was a large source for DTT activity, but insignificant for AA. DTT activity was well correlated with PM2.5 mass (r=0.49–0.86 across sites/seasons, while AA activity did not co-vary strongly with mass. A linear model was developed to estimate DTT and AA activities for the central Atlanta Jefferson Street site, based on the CMB-E sources that are statistically significant with

  15. Analysis of Parent/Nitrated Polycyclic Aromatic Hydrocarbons in Particulate Matter 2.5 Based on Femtosecond Ionization Mass Spectrometry.

    Science.gov (United States)

    Itouyama, Noboru; Matsui, Taiki; Yamamoto, Shigekazu; Imasaka, Tomoko; Imasaka, Totaro

    2016-02-01

    Particulate matter 2.5 (PM2.5), collected from ambient air in Fukuoka City, was analyzed by gas chromatography combined with multiphoton ionization mass spectrometry using an ultraviolet femtosecond laser (267 nm) as the ionization source. Numerous parent polycyclic aromatic hydrocarbons (PPAHs) were observed in a sample extracted from PM2.5, and their concentrations were determined to be in the range from 30 to 190 pg/m(3) for heavy PPAHs. Standard samples of nitrated polycyclic aromatic hydrocarbons (NPAHs) were examined, and the limits of detection were determined to be in the picogram range. The concentration of NPAH adsorbed on PM2.5 in the air was less than 900-1300 pg/m(3). Graphical Abstract ᅟ. PMID:26419772

  16. Physics of Partially Ionized Plasmas

    Science.gov (United States)

    Krishan, Vinod

    2016-05-01

    Figures; Preface; 1. Partially ionized plasmas here and everywhere; 2. Multifluid description of partially ionized plasmas; 3. Equilibrium of partially ionized plasmas; 4. Waves in partially ionized plasmas; 5. Advanced topics in partially ionized plasmas; 6. Research problems in partially ionized plasmas; Supplementary matter; Index.

  17. Laser-induced fluorescence from N2(+) ions generated by a corona discharge in ambient air.

    Science.gov (United States)

    Konthasinghe, Kumarasiri; Fitzmorris, Kristin; Peiris, Manoj; Hopkins, Adam J; Petrak, Benjamin; Killinger, Dennis K; Muller, Andreas

    2015-09-01

    In this work, we present the measurement of laser-induced fluorescence from N2(+) ions via the B(2)Σu(+)-X(2)Σg(+) band system in the near-ultraviolet. The ions were generated continuously by a plasma glow discharge in low pressure N2 and by a corona discharge in ambient air. The fluorescence decay time was found to rapidly decrease with increasing pressure leading to an extrapolated decay rate of ≍10(10) s(-1) at atmospheric pressure. In spite of this quenching, we were able to observe laser induced fluorescence in ambient air by means of a time-gated spectral measurement. In the process of comparing the emission signal with that of N2 spontaneous Raman scattering, ion concentrations in ambient air of order 10(8-)10(10) cm(-3) were determined. With moderate increases in laser power and collection efficiency, ion concentrations of less than 10(6) cm(-3) may be measurable, potentially enabling applications in atmospheric standoff detection of ionizing radiation from hazardous radioactive sources. PMID:26414524

  18. Development of a new corona discharge based ion source for high resolution time-of-flight chemical ionization mass spectrometer to measure gaseous H2SO4 and aerosol sulfate

    Science.gov (United States)

    Zheng, Jun; Yang, Dongsen; Ma, Yan; Chen, Mindong; Cheng, Jin; Li, Shizheng; Wang, Ming

    2015-10-01

    A new corona discharge (CD) based ion source was developed for a commercial high-resolution time-of-flight chemical ionization mass spectrometer (HRToF-CIMS) (Aerodyne Research Inc.) to measure both gaseous sulfuric acid (H2SO4) and aerosol sulfate after thermal desorption. Nitrate core ions (NO3-) were used as reagent ions and were generated by a negative discharge in zero air followed by addition of excess nitrogen dioxide (NO2) to convert primary ions and hydroxyl radicals (OH) into NO3- ions and nitric acid (HNO3). The CD-HRToF-CIMS showed no detectable interference from hundreds parts per billion by volume (ppbv) of sulfur dioxide (SO2). Unlike the atmospheric pressure ionization (API) ToF-CIMS, the CD ion source was integrated onto the ion-molecule reaction (IMR) chamber and which made it possible to measure aerosol sulfate by coupling to a filter inlet for gases and aerosols (FIGAERO). Moreover, compared with a quadrupole-based mass spectrometer, the desired HSO4- signal was detected by its exact mass of m/z 96.960, which was well resolved from the potential interferences of HCO3-ṡ(H2O)2 (m/z 97.014) and O-ṡH2OṡHNO3 (m/z 97.002). In this work, using laboratory-generated standards the CD-HRToF-CIMS was demonstrated to be able to detect as low as 3.1 × 105 molecules cm-3 gaseous H2SO4 and 0.5 μg m-3 ammonium sulfate based on 10-s integration time and two times of the baseline noise. The CD ion source had the advantages of low cost and a simple but robust structure. Since the system was non-radioactive and did not require corrosive HNO3 gas, it can be readily field deployed. The CD-HRToF-CIMS can be a powerful tool for both field and laboratory studies of aerosol formation mechanism and the chemical processes that were critical to understand the evolution of aerosols in the atmosphere.

  19. Fingerprinting and source identification of an oil spill in China Bohai Sea by gas chromatography-flame ionization detection and gas chromatography-mass spectrometry coupled with multi-statistical analyses.

    Science.gov (United States)

    Sun, Peiyan; Bao, Mutai; Li, Guangmei; Wang, Xinping; Zhao, Yuhui; Zhou, Qing; Cao, Lixin

    2009-01-30

    This paper describes a case study in which advanced chemical fingerprinting and data interpretation techniques were used to characterize the chemical composition and determine the source of an unknown spilled oil reported on the beach of China Bohai Sea in 2005. The spilled oil was suspected to be released from nearby platforms. In response to this specific site investigation need, a tiered analytical approach using gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC-FID) was applied. A variety of diagnostic ratios of "source-specific marker" compounds, in particular isomers of biomarkers, were determined and compared. Several statistical data correlation analysis methods were applied, including clustering analysis and Student's t-test method. The comparison of the two methods was conducted. The comprehensive analysis results reveal the following: (1) The oil fingerprinting of three spilled oil samples (S1, S2 and S3) positively match each other; (2) The three spilled oil samples have suffered different weathering, dominated by evaporation with decrease of the low-molecular-mass n-alkanes at different degrees; (3) The oil fingerprinting profiles of the three spilled oil samples are positive match with that of the suspected source oil samples C41, C42, C43, C44 and C45; (4) There are significant differences in the oil fingerprinting profiles between the three spilled oil samples and the suspected source oil samples A1, B1, B2, B3, B4, C1, C2, C3, C5 and C6.

  20. Identification of autoionizing states of atomic chromium for resonance photo-ionization at the ISOLDE-RILIS

    OpenAIRE

    Goodacre, T Day; Chrysalidis, K; Fedorovc, D; Fedosseev, V. N.; Marsh, B A; Molkanov, P; Rossel, R.E.; Rothe, S.; Seiffert, C.

    2015-01-01

    The resonance ionization laser ion source (RILIS) is the principal ion source of the ISOLDE radioactive beam facility based at CERN. Using the method of in-source resonance ionization spectroscopy, an optimal three-step, three-resonance photo-ionization scheme has been developed for chromium. The scheme uses an ionizing transition to one of the 14 newly observed autoionizing states. This work increases the range of ISOLDE-RILIS ionized beams to 32 chemical elements. Details of the spectroscop...

  1. ATMOSPHERIC-PRESSURE-IONIZATION MASS-SPECTROMETRY .1. INSTRUMENTATION AND IONIZATION TECHNIQUES

    NARCIS (Netherlands)

    BRUINS, AP

    1994-01-01

    Mass spectrometer ion sources are normally located inside a high-vacuum envelope. Such low-pressure ion sources can make use of a range of different ionization methods and are in routine use in analytical mass spectrometers. An ion source operating at atmospheric pressure is better suited, and may b

  2. Resonance ionization spectroscopy 1986

    International Nuclear Information System (INIS)

    The paper presents the proceedings of the Third International Symposium on Resonance Ionization Spectroscopy and its Applications, held at the University College of Swansea, Wales, 1986. The Symposium is divided into eight main sections entitled: photophysics and spectroscopy, noble gas atom counting, resonance ionization mass spectrometry, materials and surface analysis, small molecules, medical and environmental applications, resonance ionization and materials separation, and elementary particles and nuclear physics. Thirty papers were chosen for INIS and indexed separately. (U.K.)

  3. Ionizing Radiation and Life

    OpenAIRE

    Dartnell, L. R.

    2011-01-01

    Ionizing radiation is a ubiquitous feature of the Cosmos, from exogenous cosmic rays (CR) to the intrinsic mineral radioactivity of a habitable world, and its influences on the emergence and persistence of life are wide-ranging and profound. Much attention has already been focused on the deleterious effects of ionizing radiation on organisms and the complex molecules of life, but ionizing radiation also performs many crucial functions in the generation of habitable planetary environments and ...

  4. Abnormal ionization in sonoluminescence

    Institute of Scientific and Technical Information of China (English)

    张文娟; 安宇

    2015-01-01

    Sonoluminescence is a complex phenomenon, the mechanism of which remains unclear. The present study reveals that an abnormal ionization process is likely to be present in the sonoluminescing bubble. To fit the experimental data of previous studies, we assume that the ionization energies of the molecules and atoms in the bubble decrease as the gas density increases and that the decrease of the ionization energy reaches about 60%–70%as the bubble flashes, which is difficult to explain by using previous models.

  5. Ambient Dried Aerogels

    Science.gov (United States)

    Jones, Steven M.; Paik, Jong-Ah

    2013-01-01

    A method has been developed for creating aerogel using normal pressure and ambient temperatures. All spacecraft, satellites, and landers require the use of thermal insulation due to the extreme environments encountered in space and on extraterrestrial bodies. Ambient dried aerogels introduce the possibility of using aerogel as thermal insulation in a wide variety of instances where supercritically dried aerogels cannot be used. More specifically, thermoelectric devices can use ambient dried aerogel, where the advantages are in situ production using the cast-in ability of an aerogel. Previously, aerogels required supercritical conditions (high temperature and high pressure) to be dried. Ambient dried aerogels can be dried at room temperature and pressure. This allows many materials, such as plastics and certain metal alloys that cannot survive supercritical conditions, to be directly immersed in liquid aerogel precursor and then encapsulated in the final, dried aerogel. Additionally, the metalized Mylar films that could not survive the previous methods of making aerogels can survive the ambient drying technique, thus making multilayer insulation (MLI) materials possible. This results in lighter insulation material as well. Because this innovation does not require high-temperature or high-pressure drying, ambient dried aerogels are much less expensive to produce. The equipment needed to conduct supercritical drying costs many tens of thousands of dollars, and has associated running expenses for power, pressurized gasses, and maintenance. The ambient drying process also expands the size of the pieces of aerogel that can be made because a high-temperature, high-pressure system typically has internal dimensions of up to 30 cm in diameter and 60 cm in height. In the case of this innovation, the only limitation on the size of the aerogels produced would be in the ability of the solvent in the wet gel to escape from the gel network.

  6. Application of In-house Desorption Electrospray Ionization Source in Macromolecule Analysis and Its Exploration for Ionization Mechanism%自建电喷雾解吸电离源(DESI)在大分子分析中的应用及离子化机理探索

    Institute of Scientific and Technical Information of China (English)

    江玮; 喻钢

    2012-01-01

    自建了简易的电喷雾解吸电离源(DESI),优化了DESI源喷口的位置和角度,并将其用于常见多肽和蛋白质的分析.多肽和小质量蛋白质( <20 kDa)可以容易地从表面解吸电离,生成清晰的质谱.而牛血清白蛋白(66.4 kDa)不能产生清晰的多电荷分布的质谱,说明当前DESI源的设计可能存在一个电离的分子量上限.通过比较不同的实验条件并对比ESI - MS,发现溶剂分子的挥发过程对电荷分布以及峰宽均有显著影响,可能是由于ESI更软引起.载样表面的性质对DESI - MS的信号强度有较大影响.金表面的自组装单分子膜( SAM)相对于纯金表面有较好的绝缘性,并有助于产生较强信号,说明来自表面的电子转移(电中和)是电喷雾解吸电离过程中的一个重要因素.该文的研究有助于对DESI - MS的实验条件和载样表面的选择,同时增进了对电喷雾解吸电离机理的了解.%A simple DESI source was built. The experimental conditions were optimized and used in the analysis of a few common peptides and proteins. The results indicated that peptides and small proteins( <20 kDa) can be easily ionized and well-defined mass spectra were generated. However, BSA (66. 4 kDa) generated a poorly defined mass spectrum, which implies that there might be a molecular weight upper limit for the current design of the DESI source. The comparison between DESI and ESI mass spectra reveals that solvent evaporation can significantly affect the charge distribution and peak width, maybe due to the fact that ESI is softer than DESI. Self-assembled monolayer (SAM) on gold surface has a higher insulation than that on bare gold surface, so SAM surface can assist the survival of ions, indicating that the electron transfer(electrical neutralization) from the surface is an important factor in the ionization process of DESI. This study will be helpful for the selections of experimental conditions and sample surfaces for DESI - MS

  7. Modeling Carbon Dioxide, pH and Un-Ionized Ammonia Relationships in Serial Reuse Systems

    Science.gov (United States)

    Watten, Barnaby J.; Rust, Michael; Colt, John

    2009-01-01

    In serial reuse systems, excretion of metabolic carbon dioxide has a significant impact on ambient pH, carbon dioxide, and un-ionized ammonia concentrations. This impact depends strongly on alkalinity, water flow rate, feeding rate, and loss of carbon dioxide to the atmosphere. A reduction in pH from metabolic carbon dioxide can significantly reduce the un-ionized ammonia concentration and increase the carbon dioxide concentrations compared to those parameters computed from influent pH. The ability to accurately predict pH in serial reuse systems is critical to their design and effective operation. A trial and error solution to the alkalinity–pH system was used to estimate important water quality parameters in serial reuse systems. Transfer of oxygen and carbon dioxide across the air–water interface, at overflow weirs, and impacts of substrate-attached algae and suspended bacteria were modeled. Gas transfer at the weirs was much greater than transfer across the air–water boundary. This simulation model can rapidly estimate influent and effluent concentrations of dissolved oxygen, carbon dioxide, and un-ionized ammonia as a function of water temperature, elevation, water flow, and weir type. The accuracy of the estimates strongly depends on assumed pollutional loading rates and gas transfer at the weirs. The current simulation model is based on mean daily loading rates; the impacts of daily variation loading rates are discussed. Copies of the source code and executable program are available free of charge.

  8. Development of Non-proximate Probe Electrospray Ionization for Real-Time Analysis of Living Animal.

    Science.gov (United States)

    Yoshimura, Kentaro; Chen, Lee Chuin; Johno, Hisashi; Nakajima, Mayutaka; Hiraoka, Kenzo; Takeda, Sen

    2014-01-01

    Ambient ionization mass spectrometry is one of the most challenging analytical tools in the field of biomedical research. We previously demonstrated that probe electrospray ionization mass spectrometry (PESI-MS) could potentially be used in the rapid diagnosis of cancer. Although this technique does not require a tedious sample pretreatment process, it was not possible for our previously reported setup to be applied to cases involving the direct sampling of tissues from living animal and large animal subjects, because there would not be enough room to accommodate the larger bodies juxtaposed to the ion inlet. To make PESI-MS more applicable for the real-time analysis of living animals, a long auxiliary ion sampling tube has been connected to the ion inlet of the mass spectrometer to allow for the collection of ions and charged droplets from the PESI source (hereafter, referred to as non-proximate PESI). Furthermore, an additional ion sampling tube was connected to a small diaphragm pump to increase the uptake rate of air carrying the ions and charged droplets to the ion inlet. This modification allows for the extended ion sampling orifice to be positioned closer to the specimens, even when they are too large to be placed inside the ionization chamber. In this study, we have demonstrated the use of non-proximate PESI-MS for the real-time analysis for biological molecules and pharmacokinetic parameters from living animals.

  9. Ambient Mass Spectrometry Imaging Using Direct Liquid Extraction Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Laskin, Julia; Lanekoff, Ingela

    2015-11-13

    Mass spectrometry imaging (MSI) is a powerful analytical technique that enables label-free spatial localization and identification of molecules in complex samples.1-4 MSI applications range from forensics5 to clinical research6 and from understanding microbial communication7-8 to imaging biomolecules in tissues.1, 9-10 Recently, MSI protocols have been reviewed.11 Ambient ionization techniques enable direct analysis of complex samples under atmospheric pressure without special sample pretreatment.3, 12-16 In fact, in ambient ionization mass spectrometry, sample processing (e.g., extraction, dilution, preconcentration, or desorption) occurs during the analysis.17 This substantially speeds up analysis and eliminates any possible effects of sample preparation on the localization of molecules in the sample.3, 8, 12-14, 18-20 Venter and co-workers have classified ambient ionization techniques into three major categories based on the sample processing steps involved: 1) liquid extraction techniques, in which analyte molecules are removed from the sample and extracted into a solvent prior to ionization; 2) desorption techniques capable of generating free ions directly from substrates; and 3) desorption techniques that produce larger particles subsequently captured by an electrospray plume and ionized.17 This review focuses on localized analysis and ambient imaging of complex samples using a subset of ambient ionization methods broadly defined as “liquid extraction techniques” based on the classification introduced by Venter and co-workers.17 Specifically, we include techniques where analyte molecules are desorbed from solid or liquid samples using charged droplet bombardment, liquid extraction, physisorption, chemisorption, mechanical force, laser ablation, or laser capture microdissection. Analyte extraction is followed by soft ionization that generates ions corresponding to intact species. Some of the key advantages of liquid extraction techniques include the ease

  10. Nonsymbolic Gestural Interaction for Ambient Intelligence

    DEFF Research Database (Denmark)

    Rehm, Matthias

    2010-01-01

    the addressee with subtle clues about personality or cultural background. Gestures are an extremly rich source of communication-specific and contextual information for interactions in ambient intelligence environments. This chapter reviews the semantic layers of gestural interaction, focusing on the layer...

  11. Laser resonance ionization scheme development for tellurium and germanium at the dual Ti:Sa-Dye ISOLDE RILIS

    Science.gov (United States)

    Day Goodacre, T.; Fedorov, D.; Fedosseev, V. N.; Forster, L.; Marsh, B. A.; Rossel, R. E.; Rothe, S.; Veinhard, M.

    2016-09-01

    The resonance ionization laser ion source (RILIS) is the principal ion source of the ISOLDE radioactive beam facility based at CERN. Using the method of in-source laser resonance ionization spectroscopy, a transition to a new autoionizing state of tellurium was discovered and applied as part of a three-step, three-resonance, photo-ionization scheme. In a second study, a three-step, two-resonance, photo-ionization scheme for germanium was developed and the ionization efficiency was measured at ISOLDE. This work increases the range of ISOLDE RILIS ionized beams to 31 elements. Details of the spectroscopy studies are described and the new ionization schemes are summarized.

  12. Direct detection and identification of active pharmaceutical ingredients in intact tablets by helium plasma ionization (HePI mass spectrometry

    Directory of Open Access Journals (Sweden)

    Athula B. Attygalle

    2014-06-01

    Full Text Available A simple modification converts an electrospray ion source to an ambient-pressure helium plasma ionization source without the need of additional expensive hardware. Peaks for active ingredients were observed in the spectra recorded from intact pharmaceutical tablets placed in this source. A flow of heated nitrogen was used to thermally desorb analytes to gas phase. The desorption temperatures were sometimes as low as 50 °C. For example, negative-ion spectra recorded from an aspirin tablet showed peaks at m/z 137 (salicylate anion and 179 (acetylsalicylate anion which were absent in the background spectra. The overall ion intensity increased as the desorption gas temperature was elevated. Within the same acquisition experiment, both positive- and negative-ion signals for acetaminophen were recorded from volatiles emanating from Tylenol tablets by switching the polarity of the capillary back and forth. Moreover, different preparations of acetaminophen tablets could be distinguished by their ion-intensity thermograms.

  13. Direct detection and identification of active pharmaceutical ingredients in intact tablets by helium plasma ionization (HePI) mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    Athula B. Attygalle; Freneil B. Jariwala; Julius Pavlov; Zhihua Yang; Jason A. Mahr; Mabel Oviedo

    2014-01-01

    A simple modification converts an electrospray ion source to an ambient-pressure helium plasma ionization source without the need of additional expensive hardware. Peaks for active ingredients were observed in the spectra recorded from intact pharmaceutical tablets placed in this source. A flow of heated nitrogen was used to thermally desorb analytes to gas phase. The desorption temperatures were sometimes as low as 50 1C. For example, negative-ion spectra recorded from an aspirin tablet showed peaks at m/z 137 (salicylate anion) and 179 (acetylsalicylate anion) which were absent in the background spectra. The overall ion intensity increased as the desorption gas temperature was elevated. Within the same acquisition experiment, both positive- and negative-ion signals for acetaminophen were recorded from volatiles emanating from Tylenol tablets by switching the polarity of the capillary back and forth. Moreover, different preparations of acetaminophen tablets could be distinguished by their ion-intensity thermograms.

  14. Thin films deposited by laser ablation for the measurement of the ionizing and non-ionizing radiation

    International Nuclear Information System (INIS)

    In this work the obtained results to synthesize thin films of amorphous carbon with incorporated nitrogen and hydrogen are presented, as well as thin films of aluminium oxide using the laser ablation technique. The thin films were exposed to ionizing radiation (gamma rays of a 60 Co source, beta radiation of a 90 Sr source) and a non-ionizing radiation (UV radiation). The obtained results show that it is possible to obtain materials in thin film form with thickness of hundreds of nanometers, which present thermoluminescent response when being irradiated with ionizing radiation and non-ionizing radiation. (Author)

  15. Ambient oxygen promotes tumorigenesis.

    Directory of Open Access Journals (Sweden)

    Ho Joong Sung

    Full Text Available Oxygen serves as an essential factor for oxidative stress, and it has been shown to be a mutagen in bacteria. While it is well established that ambient oxygen can also cause genomic instability in cultured mammalian cells, its effect on de novo tumorigenesis at the organismal level is unclear. Herein, by decreasing ambient oxygen exposure, we report a ∼50% increase in the median tumor-free survival time of p53-/- mice. In the thymus, reducing oxygen exposure decreased the levels of oxidative DNA damage and RAG recombinase, both of which are known to promote lymphomagenesis in p53-/- mice. Oxygen is further shown to be associated with genomic instability in two additional cancer models involving the APC tumor suppressor gene and chemical carcinogenesis. Together, these observations represent the first report directly testing the effect of ambient oxygen on de novo tumorigenesis and provide important physiologic evidence demonstrating its critical role in increasing genomic instability in vivo.

  16. Expanding metabolite coverage of real-time breath analysis by coupling a universal secondary electrospray ionization source and high resolution mass spectrometry--a pilot study on tobacco smokers.

    Science.gov (United States)

    Gaugg, Martin Thomas; Gomez, Diego Garcia; Barrios-Collado, Cesar; Vidal-de-Miguel, Guillermo; Kohler, Malcolm; Zenobi, Renato; Martinez-Lozano Sinues, Pablo

    2016-03-01

    Online breath analysis is an attractive approach to track exhaled compounds without sample preparation. Current commercially available real-time breath analysis platforms require the purchase of a full mass spectrometer. Here we present an ion source compatible with virtually any preexisting atmospheric pressure ionization mass spectrometer that allows real-time analysis of breath. We illustrate the capabilities of such technological development by upgrading an orbitrap mass spectrometer. As a result, we detected compounds in exhaled breath between 70 and 900 Da, with a mass accuracy of typically  <1 ppm; resolutions between m/Δm 22,000 and 70,000 and fragmentation capabilities. The setup was tested in a pilot study, comparing the breath of smokers (n  =  9) and non-smokers (n  =  10). Exogenous compounds associated to smoking, as well as endogenous metabolites suggesting increased oxidative stress in smokers, were detected and in some cases identified unambiguously. Most of these compounds correlated significantly with smoking frequency and allowed accurate discrimination of smokers and non-smokers. PMID:26866308

  17. Detection, identification, and occurrence of thiotetronic acids in drinking water from underground sources by electrospray ionization-high field asymmetric waveform ion mobility spectrometry-quadrupole time-of-flight-mass spectrometry.

    Science.gov (United States)

    Lyczko, Jadwiga; Beach, Daniel; Gabryelski, Wojciech

    2015-10-01

    This paper demonstrates that electrospray ionization (ESI) with differential ion mobility spectroscopy (FAIMS) and "soft" mass spectrometry (MS) provide unique analytical capabilities that led to the discovery of sulfur-containing polar congeners of thiotetronic acid (TA) in drinking water from underground sources in Canada and the United States. Polar TAs accumulate in underground aquifers and appear to be the most abundant class of organic compounds in bottled water but cannot be detected by conventional mass spectrometry methods. We show that normally stable TAs are converted into very reactive ions in ESI which have to be analyzed using special conditions in ESI-FAIMS-MS to avoid extensive dissociation and ion/molecule reactions. De novo identification of 10 TAs was accomplished by the comparative tandem mass spectrometry analysis of authentic TA derivatives from groundwater samples and synthetic TA analogues prepared for this study. We present highlights of gas phase ion chemistry of polar TAs to explain their unique properties and reactivity. TA derivatives were originally isolated from soil bacteria and are of interest in the pharmaceutical industry due to their potent activity against a broad spectrum of pathogenic bacteria and negligible toxicity to mammals. We suspect that TAs are natural disinfection agents protecting groundwater from bacterial contamination, but these compound undergo modifications or decompose during an ozonation water treatment.

  18. Abattoirs as non-hospital source of extended spectrum beta lactamase producers: confirmed by the double disc synergy test and characterized by matrix-assisted laser desorption/ionization time of flight mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Moses Nkechukwu Ikegbunam

    Full Text Available In this study, the presence of extended spectrum beta lactamase (ESBL producing organisms in abattoirs, a non-hospital community was investigated. The presence of ESBL-producing phenotypes was confirmed by the Double Disc Synergy Test (DDST. Out of the 99 isolates screened for ESBL, 28 (28.3% were confirmed positive. The positive isolates were characterised by using Matrix-Assisted Laser Desorption/Ionization Time of flight Mass Spectrometry. 50% of the isolates were Pseudomonas spp., the rest were different species of Acinetobacter, Stenotrophomonas and Achromobacter. Pseudomonas monteilli and Pseudomonas putida were the most occurring in the intestine. The entire positive ESBL producers were subjected to plasmid curing to ascertain the location of the resistant marker. The result of the plasmid curing indicated that the resistant genes were chromosomally borne. The findings have therefore established the presence of ESBL producing organisms in the gut of animals from abattoirs and the table were the meat are sold, and its rate of occurrence is comparable to hospital ICUs. Abattoir communities could probably be a source of human infection with ESBL expressing pathogens and possible transfer to non-ESBL producers.

  19. Detection, identification, and occurrence of thiotetronic acids in drinking water from underground sources by electrospray ionization-high field asymmetric waveform ion mobility spectrometry-quadrupole time-of-flight-mass spectrometry.

    Science.gov (United States)

    Lyczko, Jadwiga; Beach, Daniel; Gabryelski, Wojciech

    2015-10-01

    This paper demonstrates that electrospray ionization (ESI) with differential ion mobility spectroscopy (FAIMS) and "soft" mass spectrometry (MS) provide unique analytical capabilities that led to the discovery of sulfur-containing polar congeners of thiotetronic acid (TA) in drinking water from underground sources in Canada and the United States. Polar TAs accumulate in underground aquifers and appear to be the most abundant class of organic compounds in bottled water but cannot be detected by conventional mass spectrometry methods. We show that normally stable TAs are converted into very reactive ions in ESI which have to be analyzed using special conditions in ESI-FAIMS-MS to avoid extensive dissociation and ion/molecule reactions. De novo identification of 10 TAs was accomplished by the comparative tandem mass spectrometry analysis of authentic TA derivatives from groundwater samples and synthetic TA analogues prepared for this study. We present highlights of gas phase ion chemistry of polar TAs to explain their unique properties and reactivity. TA derivatives were originally isolated from soil bacteria and are of interest in the pharmaceutical industry due to their potent activity against a broad spectrum of pathogenic bacteria and negligible toxicity to mammals. We suspect that TAs are natural disinfection agents protecting groundwater from bacterial contamination, but these compound undergo modifications or decompose during an ozonation water treatment. PMID:26340067

  20. Mujer y medio ambiente

    OpenAIRE

    Zuluaga Sánchez, Gloria Patricia

    1998-01-01

    El debate sobre mujer y medio ambiente es bastante nuevo y, por lo tanto, aun no hay consenso sobre como abordarlo, ni análisis muy profundos sobre la interacción de estas dos problemáticas tan complejas y que además atraviesan las demás temáticas. Con ello no se quiere negar el importante aporte que se ha hecho en tal sentido, por parte de colectividades y de algunas personas. Selene Herculano y Jacqueline Pitanguy (1993), mencionan que el medio ambiente no es una categoría específica y que ...

  1. Multiphoton ionization of atoms

    International Nuclear Information System (INIS)

    The paper is devoted to the analysis of high intensity effects which result from multiphoton ionization of atoms in a high laser intensity, ranging from 1010 to 1015 W cm-2. Resonant multiphoton ionization of atoms, the production of multiply charged ions, and electron energy spectra, are all discussed. (U.K.)

  2. Application of ionizing radiation

    International Nuclear Information System (INIS)

    Fundamental studies by the Nuclear Research Institute concerning the use of ionizing radiations are reported. The ROZA irradiation plant is used for sterilization in medicine and for historic objects preservation. Ionizing radiation is used in the radiation treatment of cables and drinking water. Radiopharmaceuticals are developed. The Institute is an all-state centre for research and development of semiconductor detectors. (M.S.)

  3. Ambient temperature nanoelectrospray ion mobility detector for high performance liquid chromatography in determining amines.

    Science.gov (United States)

    Chen, Chuang; Hou, Keyong; Wang, Weiguo; Li, Jinghua; Li, Haiyang

    2014-09-01

    A nanoelectrospray ionization ion mobility spectrometer (nanoESI-IMS) working at ambient pressure and ambient temperature was developed as a detector of high performance liquid chromatography (HPLC) to achieve sensitive detection of amines with no derivatization and meanwhile provide another dimension of separation. The easier desolvation property of the charged droplets formed in nanoESI source enabled complete desolvation of the product ions of sixteen amines and drugs using the nanoESI-IMS at ambient temperature. Working at ambient temperature was good for suppressing the dissociation of thermal volatile ions, such as only the proton adducted molecular ions were observed for morphine in the nanoESI-IMS. Besides, the resolving power of the nanoESI-IMS also showed an increasing tendency as lowering the working temperature, an increment of 19 percent and 10 percent was observed for diethylamine and triethylamine as the temperature dropped from 92°C to 32°C. The resolving power of the nanoESI-IMS at 32°C for the 16 tested compounds was amid 33-44. With the nanoESI-IMS coupled to HPLC, a six-compound mixture including isomers was successfully separated and detected without any derivatization. And linear response ranges of 1 to 20, 0.5 to 20, and 0.8 to 20μgml(-1) and limits of detection of 0.25, 0.15, and 0.17μgml(-1) for triethylamine, diethylamine, and butylamine, respectively, were obtained with the hyphenated system. These results showed the excellent performance of the two-dimensional separation and detection method in direct qualitative and quantitative analyses of amines.

  4. Ambient Noise Tomography of the British Isles

    Science.gov (United States)

    Nicolson, H. J.; Curtis, A.; Baptie, B.

    2009-12-01

    In recent years, surface wave tomography using empirical Green’s functions computed via the ambient noise interferometry method has become an established approach to lithospheric imaging problems. To date, ambient noise tomography has been successfully applied to seismometer arrays in the United States, Australia, Iceland, China, South Africa, Europe and the Tibetan Plateau. The basis of the ambient seismic interferometry method is that, by cross-correlating noise data between two seismic stations and stacking over a long enough time period, one can approximate the Green’s Function that would have been recorded at one of the stations if the other had actually been a source. Consequently, one of the main advantages of ambient noise interferometry is that traditional seismic sources such as earthquakes or ballistics are not required; therefore it is ideal for application to seismically quiescent areas such as the British Isles. The British Isles are an archipelago located adjacent to the Eurasian continental shelf in a typically intra-plate setting, formed by a complex amalgamation of several terranes. These range from Laurentian north of the Highland Boundary fault to Avalonian south of the Iapetus Suture and evidence of the regions turbulent geological past can be inferred from its lithospheric structure. Previous studies of the structure of the British Isles considered relatively few seismic stations and/or were limited to using offshore shots, quarry blasts or teleseismic earthquakes as seismic energy sources. We have applied the ambient noise tomography method to noise data recorded on approximately 100 broadband and short period seismometers, including many new stations, in the British Isles and mainland Europe. This dense coverage of the British Isles allows us to image the crust and upper mantle velocity structure with a horizontal resolution in the region of 100km across the North Sea and 30km in the mainland United Kingdom. Here we present the first

  5. Guided ionization waves: Theory and experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lu, X., E-mail: luxinpei@hotmail.com [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430030 (China); Naidis, G.V. [Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412 (Russian Federation); Laroussi, M. [Laser and Plasma Engineering Institute, Old Dominion University, Norfolk, VA 23529 (United States); Ostrikov, K. [CSIRO Materials Science and Engineering, P.O. Box 218, Lindfield, NSW 2070 (Australia); School of Physics, The University of Sydney, Sydney, NSW 2006 (Australia)

    2014-07-01

    This review focuses on one of the fundamental phenomena that occur upon application of sufficiently strong electric fields to gases, namely the formation and propagation of ionization waves–streamers. The dynamics of streamers is controlled by strongly nonlinear coupling, in localized streamer tip regions, between enhanced (due to charge separation) electric field and ionization and transport of charged species in the enhanced field. Streamers appear in nature (as initial stages of sparks and lightning, as huge structures—sprites above thunderclouds), and are also found in numerous technological applications of electrical discharges. Here we discuss the fundamental physics of the guided streamer-like structures—plasma bullets which are produced in cold atmospheric-pressure plasma jets. Plasma bullets are guided ionization waves moving in a thin column of a jet of plasma forming gases (e.g., He or Ar) expanding into ambient air. In contrast to streamers in a free (unbounded) space that propagate in a stochastic manner and often branch, guided ionization waves are repetitive and highly-reproducible and propagate along the same path—the jet axis. This property of guided streamers, in comparison with streamers in a free space, enables many advanced time-resolved experimental studies of ionization waves with nanosecond precision. In particular, experimental studies on manipulation of streamers by external electric fields and streamer interactions are critically examined. This review also introduces the basic theories and recent advances on the experimental and computational studies of guided streamers, in particular related to the propagation dynamics of ionization waves and the various parameters of relevance to plasma streamers. This knowledge is very useful to optimize the efficacy of applications of plasma streamer discharges in various fields ranging from health care and medicine to materials science and nanotechnology.

  6. Guided ionization waves: Theory and experiments

    International Nuclear Information System (INIS)

    This review focuses on one of the fundamental phenomena that occur upon application of sufficiently strong electric fields to gases, namely the formation and propagation of ionization waves–streamers. The dynamics of streamers is controlled by strongly nonlinear coupling, in localized streamer tip regions, between enhanced (due to charge separation) electric field and ionization and transport of charged species in the enhanced field. Streamers appear in nature (as initial stages of sparks and lightning, as huge structures—sprites above thunderclouds), and are also found in numerous technological applications of electrical discharges. Here we discuss the fundamental physics of the guided streamer-like structures—plasma bullets which are produced in cold atmospheric-pressure plasma jets. Plasma bullets are guided ionization waves moving in a thin column of a jet of plasma forming gases (e.g., He or Ar) expanding into ambient air. In contrast to streamers in a free (unbounded) space that propagate in a stochastic manner and often branch, guided ionization waves are repetitive and highly-reproducible and propagate along the same path—the jet axis. This property of guided streamers, in comparison with streamers in a free space, enables many advanced time-resolved experimental studies of ionization waves with nanosecond precision. In particular, experimental studies on manipulation of streamers by external electric fields and streamer interactions are critically examined. This review also introduces the basic theories and recent advances on the experimental and computational studies of guided streamers, in particular related to the propagation dynamics of ionization waves and the various parameters of relevance to plasma streamers. This knowledge is very useful to optimize the efficacy of applications of plasma streamer discharges in various fields ranging from health care and medicine to materials science and nanotechnology

  7. Multiphoton ionization of atoms

    International Nuclear Information System (INIS)

    This article provides an overview of the current understanding of multiphoton ionization of atoms. It begins with an introductory section to explain the background of the subject. Then the article develops the three topics which have been central themes of discussion in multiphoton ionization of atoms these past few years: multiply charged ion production, very high order harmonic generation, and above-threshold ionization, a name given to the absorption of a very large number of photons by an already ionized electron. A large part of the review is devoted to some theoretical aspects of multiphoton ionization of atoms and especially non-perturbative theories. Finally the article considers the very near future prospects of laser-electron interactions and more generally laser-matter interactions at 1018 -1019 W cm-2, an intensity range now within reach due to new short pulse laser technology. (author)

  8. Horizontal Correlation of Ambient Noise near a Sea Route

    Institute of Scientific and Technical Information of China (English)

    HE Li; LI Zheng-Lin; ZHANG Ren-He; PENG Zhao-Hui

    2008-01-01

    Ambient noise data measured in an experiment conducted near the sea route are analysed.It is found that at low frequency,the measured horizontal correlation coeffients at different separations oscillate much larger than that predicted by the classical ambient noise model.The theoretical analyses show that the observed phenomenon is mainly caused by windy noise together with the discrete shipping noise nearby.An ambient noise model is proposed to include the effects caused by both the noise sources and can be used to forecast the ambient noise field neara sea route.

  9. Ionization in Atmospheres of Brown Dwarfs and Extrasolar Planets V: Alfv\\'{e}n Ionization

    CERN Document Server

    Stark, Craig R; Diver, Declan A; Rimmer, Paul B

    2013-01-01

    Observations of continuous radio and sporadic X-ray emission from low-mass objects suggest they harbour localized plasmas in their atmospheric environments. For low-mass objects, the degree of thermal ionization is insufficient to qualify the ionized component as a plasma, posing the question: what ionization processes can efficiently produce the required plasma that is the source of the radiation? We propose Alfv\\'{e}n ionization as a mechanism for producing localized pockets of ionized gas in the atmosphere, having sufficient degrees of ionization ($\\geq10^{-7}$) that they constitute plasmas. We outline the criteria required for Alfv\\'{e}n ionization and demonstrate it's applicability in the atmospheres of low-mass objects such as giant gas planets, brown dwarfs and M-dwarfs for both solar and sub-solar metallicities. We find that Alfv\\'{e}n ionization is most efficient at mid to low atmospheric pressures where a seed plasma is easier to magnetize and the pressure gradients needed to drive the required neut...

  10. Ensinar e aprender em ambientes virtuais tridimensionais

    OpenAIRE

    Gonçalves, Vitor

    2012-01-01

    Os mundos virtuais constituem ambientes simulados, normalmente tridimensionais, mediados através de tecnologias de informação e comunicação e que se destinam a ser frequentados por utilizadores que interagem com outros através de avatares. Estes ambientes virtuais tridimensionais (3D) podem ser desenvolvidos recorrendo a software de desenho 3D em versões comerciais e open source ou criados em servidores de mundos virtuais tridimensionais já existentes, tais como o Second Life ou similares. No...

  11. Resonance ionization mass spectrometry at Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Two approaches to Resonance Ionization Mass Spectrometry (RIMS) at Los Alamos National Laboratory are discussed. The first is the use of continuous-wave dye lasers as the ionization source, and the use of pulse counting detection; and results are presented for lutetium and technetium. The second approach is the use of multiphoton resonances in the pulsed laser excitation of atoms. Experiments with 2 + 1 [photons to resonance plus photons to ionize] RIMS schemes for several elements are discussed. (author)

  12. Matrix Assisted Ionization in Vacuum, a Sensitive and Widely Applicable Ionization Method for Mass Spectrometry

    Science.gov (United States)

    Trimpin, Sarah; Inutan, Ellen D.

    2013-05-01

    An astonishingly simple new method to produce gas-phase ions of small molecules as well as proteins from the solid state under cold vacuum conditions is described. This matrix assisted ionization vacuum (MAIV) mass spectrometry (MS) method produces multiply charged ions similar to those that typify electrospray ionization (ESI) and uses sample preparation methods that are nearly identical to matrix-assisted laser desorption/ionization (MALDI). Unlike these established methods, MAIV does not require a laser or voltage for ionization, and unlike the recently introduced matrix assisted ionization inlet method, does not require added heat. MAIV-MS requires only introduction of a crystalline mixture of the analyte incorporated with a suitable small molecule matrix compound such as 3-nitrobenzonitrile directly to the vacuum of the mass spectrometer. Vacuum intermediate pressure MALDI sources and modified ESI sources successfully produce ions for analysis by MS with this method. As in ESI-MS, ion formation is continuous and, without a laser, little chemical background is observed. MAIV, operating from a surface offers the possibility of significantly improved sensitivity relative to atmospheric pressure ionization because ions are produced in the vacuum region of the mass spectrometer eliminating losses associated with ion transfer from atmospheric pressure to vacuum. Mechanistic aspects and potential applications for this new ionization method are discussed.

  13. La radioactividad ambiental

    Directory of Open Access Journals (Sweden)

    Rafael Núñez-Lagos Roglá

    2011-01-01

    Full Text Available Se explican los conceptos fundamentales relacionados con la radiactividad y se utilizan para describir la radiactividad ambiental. Se explican también los isótopos de largo periodo y las principales familias radioactivas junto con la radiación cósmica y los radionucleidos cosmogénicos.

  14. Biological Effects of Ionizing Radiation

    Science.gov (United States)

    Ingram, M.; Mason, W. B.; Whipple, G. H.; Howland, J. W.

    1952-04-07

    This report presents a review of present knowledge and concepts of the biological effects of ionizing radiations. Among the topics discussed are the physical and chemical effects of ionizing radiation on biological systems, morphological and physiological changes observed in biological systems subjected to ionizing radiations, physiological changes in the intact animal, latent changes following exposure of biological systems to ionizing radiations, factors influencing the biological response to ionizing radiation, relative effects of various ionizing radiations, and biological dosimetry.

  15. Modal Parameter Identification of Offshore Platforms under Ambient Excitation

    Institute of Scientific and Technical Information of China (English)

    Yang Hezhen(杨和振); Li Huajun

    2004-01-01

    This paper intends to identify the modal parameters of an offshore platform under ambient excitation, and to compare the identified results with theoretical solutions. Using ambient sources of excitation to determine the modal characteristics of large civil engineering structures is desirable for several reasons. The forced vibration testing of such structures generally requires a large amount of specialized equipment and makes the tests quite expensive. Also, an automated health monitoring system for a large civil structure will most likely use ambient excitation. The Eigensystem Realization Algorithm (ERA) is applied in conjunctied acceleration information. Finally, offshore platform numerical model gets output response data under ambient excitation. Simulated data from numerical model of an offshore platform under ambient excitation is used for the identification of the system. According to the comparison results, the proposed method is shown to be effective for modal parameter identification under ambient excitation.

  16. Study of Condensable Ion Production by Resonant Laser Ionization

    OpenAIRE

    Henares Gonzalez, Jose Luis

    2016-01-01

    This doctoral thesis describes the implementation, optimization and development of a Resonant Ionization LaserIon Source (RILIS) at the GANIL facility (Caen, France). The RILIS is a selective ion source technique which isbased on a step-wise resonant excitation process where the elements of interest are ionized via atomic resonantexcitation by laser radiation. The off-line RILIS test bench at GANIL consists of three tunable titanium:sapphirelasers and a hot-cavity ion source. In this thesis, ...

  17. A Multistep Algorithm for the Radiation Hydrodynamical Transport of Cosmological Ionization Fronts and Ionized Flows

    OpenAIRE

    Daniel J. Whalen; Norman, Michael L.

    2005-01-01

    Radiation hydrodynamical transport of ionization fronts in the next generation of cosmological reionization simulations holds the promise of predicting UV escape fractions from first principles as well as investigating the role of photoionization in feedback processes and structure formation. We present a multistep integration scheme for radiative transfer and hydrodynamics for accurate propagation of I-fronts and ionized flows from a point source in cosmological simulations. The algorithm is...

  18. XUV ionization of aligned molecules

    Energy Technology Data Exchange (ETDEWEB)

    Kelkensberg, F.; Siu, W.; Gademann, G. [FOM Institute AMOLF, Science Park 104, NL-1098 XG Amsterdam (Netherlands); Rouzee, A.; Vrakking, M. J. J. [FOM Institute AMOLF, Science Park 104, NL-1098 XG Amsterdam (Netherlands); Max-Born-Institut, Max-Born Strasse 2A, D-12489 Berlin (Germany); Johnsson, P. [FOM Institute AMOLF, Science Park 104, NL-1098 XG Amsterdam (Netherlands); Department of Physics, Lund University, Post Office Box 118, SE-221 00 Lund (Sweden); Lucchini, M. [Department of Physics, Politecnico di Milano, Istituto di Fotonica e Nanotecnologie CNR-IFN, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Lucchese, R. R. [Department of Chemistry, Texas A and M University, College Station, Texas 77843-3255 (United States)

    2011-11-15

    New extreme-ultraviolet (XUV) light sources such as high-order-harmonic generation (HHG) and free-electron lasers (FELs), combined with laser-induced alignment techniques, enable novel methods for making molecular movies based on measuring molecular frame photoelectron angular distributions. Experiments are presented where CO{sub 2} molecules were impulsively aligned using a near-infrared laser and ionized using femtosecond XUV pulses obtained by HHG. Measured electron angular distributions reveal contributions from four orbitals and the onset of the influence of the molecular structure.

  19. Weak interaction studies using resonance ionization spectroscopy

    International Nuclear Information System (INIS)

    Important developments in laser sources for the vacuum ultraviolet (VUV) region of the spectrum are making it possible to carry out resonance ionization of some of the noble gases. It has already been shown that xenon can be ionized in a two-photon allowed excitation from the ground state. Recently a new method of generating radiation by four-wave mixing in mercury vapor enables excitation of xenon in a one-photon resonance process. With these new laser sources we expect to have effective ionization volumes of 10-3 to 10-2 cm3 for the cases of argon, krypton, and xenon. This has important consequences in weak interaction physics and environmental research

  20. Abnormal ionization in sonoluminescence

    Science.gov (United States)

    Zhang, Wen-Juan; An, Yu

    2015-04-01

    Sonoluminescence is a complex phenomenon, the mechanism of which remains unclear. The present study reveals that an abnormal ionization process is likely to be present in the sonoluminescing bubble. To fit the experimental data of previous studies, we assume that the ionization energies of the molecules and atoms in the bubble decrease as the gas density increases and that the decrease of the ionization energy reaches about 60%-70% as the bubble flashes, which is difficult to explain by using previous models. Project supported by the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20120002110031) and the National Natural Science Foundation of China (Grant No. 11334005).

  1. Determination of OM/OC ratios and specific attenuation coefficients (SAC in ambient fine PM at a rural site in southern Ontario: implications for emission sources, particle aging, and radiative forcing

    Directory of Open Access Journals (Sweden)

    T. W. Chan

    2009-07-01

    Full Text Available Ambient particulate matter (PM samples were collected on quartz filters at a rural site in southern Ontario during intensive studies in 2005 and 2007. The concentrations of organic carbon (OC, pyrolysis organic carbon (POC, and elemental carbon (EC were determined by thermal analysis. These results were compared to the organic aerosol mass concentration (OM measured by an Aerodyne Aerosol Mass Spectrometer (AMS and to the particle absorption coefficient (b_asp obtained from a Radiance Research Particle Soot Absorption Photometer (PSAP. The total organic mass to organic carbon ratios (OM/OC and specific attenuation coefficients (SAC were also derived. According to the results, the POC mass is proportional to the approximated oxygen mass in the aerosols and OM/OC ratios can be estimated directly from thermal measurements. The study also suggests that the air masses from the south, with relatively low OC/EC ratios, high EC, sulphate contents and OM/OC ratios, were originated from urban and industrial emissions and subsequently experienced photo-oxidations in the atmosphere, implying that the oxygenated organics could come from both primary and secondary sources. Whereas the air masses from the north, with relatively high OC/EC ratios, low EC, sulphate contents and OM/OC ratios, were dominant by the background clean air with relatively larger contributions from biogenic emissions.

    The mean SAC derived from the 2005 and 2007 studies are 4.9 m2 g−1 and 3.8 m2 g−1, respectively. When POC mass approaching zero (i.e. the impact of atmospheric aging is minimized, the SAC for primary emitted soot is estimated to be 5.8 m2 g−1 and 6.3 m2 g−1 for the northern and southern air masses, respectively, supported by the corresponding values when particulate sulphate concentration approaches zero. A decreasing trend in the SAC value with atmospheric aging

  2. III. Artificial sources of ionizing radiation

    International Nuclear Information System (INIS)

    A theoretical explanation is given of obtaining electrons by thermal emission. The Coolidge X-ray tube is described. The spectral composition is presented of X radiation, changes in the spectrum of X radiation bremsstrahlung in dependence on anode potential and on different shapes of the rectifier of the high voltage curve. X-ray spectrography of crystals is presented as an example of the use of X radiation. Linear accelerators (simple and multiple), microtrons, cyclotrons and betatrons are used for obtaining higher energy radiation. The principle is given for each accelerator and examples of acclerators are given such as are used in clinical practice and in radiotherapy. (E.S.)

  3. Colloidal Plasmas : Dynamo transformation of the collisional R-T in a weakly ionized plasma

    Indian Academy of Sciences (India)

    C B Dwivedi

    2000-11-01

    Theoretical prediction of a new kind of normal mode behaviour of electro-mechanical nature was first time reported by Dwivedi and Das in 1992 in the context of mesospheric modeling of observed neutral induced turbulence. Local dynamo action (due to relative neutral flow) governs the basic physical principle for linear excitation of the neutral induced low frequency instability (NILF) in mesospheric plasma, which comprises of weakly ionized inhomogeneous gas confined by the external gravity and ambient magnetic field. The present contribution offers physical explanation in terms of dynamo transformation of neutral drag effect as a source to understand complete suppression of the usual collisional R-T and in turn linear driving of the NILF. It is therefore emphasized, worth calling it as the dynamo instability.

  4. Commercial applications of food ionization in France

    International Nuclear Information System (INIS)

    Due to the long history of nuclear energy in France, French public is not frightened by nuclear applications in its everyday life. The first industrial initiative on food ionization dates back to 1956. In 1980, the Joint Expert Committee on Food Ionization concluded that food ionization up to a certain maximum dose presented neither toxicological nor nutritional hazard. This opened the new era for the industrial development. But in 1988, a draft directive to harmonize national legislations was issued by the Commission of European Communities. This stopped many industrial initiatives due to uncertainty. It is estimated that nearly 14,000 tons of various food items have been ionized in France in 1991. About 40% are spices, followed by dry fruit, vegetables, and deboned poultry meat. Most of the present applications are intended to eliminate microorganisms. In 1992, 8 industrial facilities were in operation, mostly using gamma sources. Local research associations were founded to promote food ionization. Food ionization development in the past 30 years has been rapid and important, but the future of this process depends on the European harmonization of legislations. (K.I.)

  5. New standards for ionizing radiation measurements

    International Nuclear Information System (INIS)

    The Ionizing Radiation Division has developed new national standards for mammographic X rays and for brachytherapy sources, such as iodine-125. The Attix chamber, a variable volume free-air ionization chamber, has been established as the primary national standard for mammographic X rays. The Attix chamber resides in the newly developed NIST Mammography Calibration Range and will be used to perform routine calibrations. The wide-angle free-air ionization chamber utilizes a large volume and a novel electric field configuration in order to circumvent the limitations of conventional free-air chambers. Seventeen beam qualities for X rays from molybdenum (Mo) and rhodium (Rh) anodes have been parameterized for the calibration of mammographic ionization chambers. The beam qualities available include anode/filter combinations of Mo/Mo, Mo/Rh and Rh/Rh. The mammography range was developed in collaborations with the U.S. Food and Drug Administration's (FDA) Center for Devices and Radiological Health, the implementors of the Mammography Quality Standards Act (MQSA) of 1992. The wide-angle free-air ionization chamber has been used to measure the output of two types of iodine-125 seeds, those with resin balls and those with silver wire. Both free-air chambers have been intercompared with the Ritz parallel-plate free-air ionization chamber

  6. Extractive electrospray ionization mass spectrometry toward in situ analysis without sample pretreatment.

    Science.gov (United States)

    Li, Ming; Hu, Bin; Li, Jianqiang; Chen, Rong; Zhang, Xie; Chen, Huanwen

    2009-09-15

    A homemade novel nanoextractive electrospray ionization (nanoEESI) source has been characterized for in situ mass spectrometric analysis of ambient samples without sample pretreatment. The primary ions generated using a nanospray emitter interact with the neutral sample plume created by manually nebulizing liquid samples, allowing production of the analyte ions in the spatial cross section of the nanoEESI source. The performance of nanoEESI is experimentally investigated by coupling the nanoEESI source to a commercial LTQ mass spectrometer for rapid analysis of various ambient samples using positive/negative ion detection modes. Compounds of interest in actual samples such as aerosol drug preparations, beverages, milk suspensions, farmland water, and groundwater were unambiguously detected using tandem nanoEESI ion trap mass spectrometry. The limit of detection was low picogram per milliliter levels for the compounds tested. Acceptable relative standard deviation (RSD) values (5-10%) were obtained for direct measurement of analytes in complex matrixes, providing linear dynamic signal responses using manual sample introduction. A single sample analysis was completed within 1.2 s. Requiring no sheath gas for either primary ion production or neutral sample introduction, the nanoEESI has advantages including readiness for miniaturization and integration, simple maintenance, easy operation, and low cost. The experimental data demonstrate that the nanoEESI is a promising tool for high-throughput, sensitive, quantitative, in situ analysis of ambient complex samples, showing potential applications for in situ analysis in multiple disciplines including but not limited to pharmaceutical analysis, food quality control, pesticides residue detection, and homeland security. PMID:19673501

  7. Interlayer spray ionization mass spectrometry for the simple direct analysis of low amounts of sample.

    Science.gov (United States)

    Chen, Jin; Tang, Fei; Guo, Cheng'an; Huo, Xinming; Zhang, Sichun; Wang, Xiaohao

    2016-07-01

    Interlayer spray is proposed as a convenient ionization source for direct analysis by mass spectrometry. Two slices of non-absorbent substrate hold the liquid sample to form a sandwich structure. By applying a high voltage to the sample, spray is generated at the tip of the substrate. The sampling procedure can be operated easily in an open condition and the spray is processed in a semi-enclosed condition, which leads to a relatively stable process. An ultralow amount (target are maintained. Less influence from the substrate is achieved compared with the spray methods based on porous absorbent materials, which results in a sensitivity enhancement of large molecule samples. It is demonstrated that the interlayer spray is applicable for the analysis of various compounds, including therapeutic drugs, peptides, and proteins. Good linearity can be obtained at a concentration as low as 50 ng/mL in the quantitative analysis for imatinib. We also show the ability to identify the chemical residuals on surfaces with high sensitivity by the "wipe-spray" method, which is useful for the fast screening of illicit substances. Interlayer spray working with mass spectrometry provides a promising method for direct analysis in an ambient environment. Graphical Abstract The schematic of the interlayer spray ionization source. PMID:27173393

  8. Ambient Air Quality Data Inventory

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Office of Air and Radiation's (OAR) Ambient Air Quality Data (Current) contains ambient air pollution data collected by EPA, other federal agencies, as well as...

  9. Ambient Air Quality Data Inventory

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Office of Air and Radiation??s (OAR) Ambient Air Quality Data (Current) contains ambient air pollution data collected by EPA, other federal agencies, as well as...

  10. NIF Ambient Vibration Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Noble, C.R.; Hoehler, M.S., S.C. Sommer

    1999-11-29

    LLNL has an ongoing research and development project that includes developing data acquisition systems with remote wireless communication for monitoring the vibrations of large civil engineering structures. In order to establish the capability of performing remote sensing over an extended period of time, the researchers needed to apply this technology to a real structure. The construction of the National Ignition Facility provided an opportunity to test the data acquisition system on a large structure to monitor whether the facility is remaining within the strict ambient vibration guidelines. This document will briefly discuss the NIF ambient vibration requirements and summarize the vibration measurements performed during the Spring and Summer of 1999. In addition, a brief description of the sensors and the data acquisition systems will be provided in Appendix B.

  11. NIF Ambient Vibration Measurements

    International Nuclear Information System (INIS)

    LLNL has an ongoing research and development project that includes developing data acquisition systems with remote wireless communication for monitoring the vibrations of large civil engineering structures. In order to establish the capability of performing remote sensing over an extended period of time, the researchers needed to apply this technology to a real structure. The construction of the National Ignition Facility provided an opportunity to test the data acquisition system on a large structure to monitor whether the facility is remaining within the strict ambient vibration guidelines. This document will briefly discuss the NIF ambient vibration requirements and summarize the vibration measurements performed during the Spring and Summer of 1999. In addition, a brief description of the sensors and the data acquisition systems will be provided in Appendix B

  12. MULTIPHOTON IONIZATION OF ATOMS

    OpenAIRE

    Mainfray, G.

    1985-01-01

    Multiphoton ionization of one-electron atoms, such as atomic hydrogen and alkaline atoms, is well understood and correctly described by rigorous theoretical models. The present paper will be devoted to collisionless multiphoton ionization of many-electron atoms as rare gases. It induces removal of several electrons and the production of multiply charged ions. Up to Xe5+ ions are produced in Xe atoms. Doubly charged ions can be produced, either by simultaneous excitation of two electrons, or b...

  13. Pressurized ionization chamber detectors for industrial use

    International Nuclear Information System (INIS)

    The measurement of the thickness of the sheets made of different materials, e.g. metal, plastic, paper, cellulose, rubber, etc., is one of many industrial applications of nuclear techniques. The ionizing radiation detectors of ionization chamber type are based on measuring the variations in either exposure rate (for gamma radiation) or absorbed dose rate (for beta radiation) occurring in materials of different thickness, placed between the radiation source and the detector. The variations in exposure rate and absorbed dose rate can be traced by using radiation detectors of the ionization chamber type, which convert the exposure rate, X point, or the absorbed dose rate, D point, into a proportional electric current. The more stable the ionization current of the chambers (keeping a constant exposure rate or absorbed dose rate), the slighter the variations that can be detected in either exposure rate or absorbed dose rate, hence in the absorbing material placed between the radiation source and the detector. Based on these facts, several variants of such detectors, including the ionization chamber CIS-P5M-100Kr, CIS-P2M-1000Kr and CIS-P8M-70Kr, have been made. (author)

  14. Two-step laser ionization schemes for in-gas laser ionization and spectroscopy of radioactive isotopes

    International Nuclear Information System (INIS)

    The in-gas laser ionization and spectroscopy technique has been developed at the Leuven isotope separator on-line facility for the production and in-source laser spectroscopy studies of short-lived radioactive isotopes. In this article, results from a study to identify efficient optical schemes for the two-step resonance laser ionization of 18 elements are presented

  15. Two-step laser ionization schemes for in-gas laser ionization and spectroscopy of radioactive isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Kudryavtsev, Yu., E-mail: yuri.kudryavtsev@fys.kuleuven.be; Ferrer, R.; Huyse, M.; Van den Bergh, P.; Van Duppen, P. [Instituut voor Kern- en Stralingsfysica, KU Leuven, 3001 Leuven (Belgium); Vermeeren, L. [SCK-CEN, Nuclear Research Centre, Boeretang 200, B-2400 Mol (Belgium)

    2014-02-15

    The in-gas laser ionization and spectroscopy technique has been developed at the Leuven isotope separator on-line facility for the production and in-source laser spectroscopy studies of short-lived radioactive isotopes. In this article, results from a study to identify efficient optical schemes for the two-step resonance laser ionization of 18 elements are presented.

  16. "Magic" Ionization Mass Spectrometry.

    Science.gov (United States)

    Trimpin, Sarah

    2016-01-01

    The systematic study of the temperature and pressure dependence of matrix-assisted ionization (MAI) led us to the discovery of the seemingly impossible, initially explained by some reviewers as either sleight of hand or the misinterpretation by an overzealous young scientist of results reported many years before and having little utility. The “magic” that we were attempting to report was that with matrix assistance, molecules, at least as large as bovine serum albumin (66 kDa), are lifted into the gas phase as multiply charged ions simply by exposure of the matrix:analyte sample to the vacuum of a mass spectrometer. Applied heat, a laser, or voltages are not necessary to achieve charge states and ion abundances only previously observed with electrospray ionization (ESI). The fundamentals of how solid phase volatile or nonvolatile compounds are converted to gas-phase ions without added energy currently involves speculation providing a great opportunity to rethink mechanistic understanding of ionization processes used in mass spectrometry. Improved understanding of the mechanism(s) of these processes and their connection to ESI and matrix-assisted laser desorption/ionization may provide opportunities to further develop new ionization strategies for traditional and yet unforeseen applications of mass spectrometry. This Critical Insights article covers developments leading to the discovery of a seemingly magic ionization process that is simple to use, fast, sensitive, robust, and can be directly applied to surface characterization using portable or high performance mass spectrometers. PMID:26486514

  17. "Magic" Ionization Mass Spectrometry

    Science.gov (United States)

    Trimpin, Sarah

    2016-01-01

    The systematic study of the temperature and pressure dependence of matrix-assisted ionization (MAI) led us to the discovery of the seemingly impossible, initially explained by some reviewers as either sleight of hand or the misinterpretation by an overzealous young scientist of results reported many years before and having little utility. The "magic" that we were attempting to report was that with matrix assistance, molecules, at least as large as bovine serum albumin (66 kDa), are lifted into the gas phase as multiply charged ions simply by exposure of the matrix:analyte sample to the vacuum of a mass spectrometer. Applied heat, a laser, or voltages are not necessary to achieve charge states and ion abundances only previously observed with electrospray ionization (ESI). The fundamentals of how solid phase volatile or nonvolatile compounds are converted to gas-phase ions without added energy currently involves speculation providing a great opportunity to rethink mechanistic understanding of ionization processes used in mass spectrometry. Improved understanding of the mechanism(s) of these processes and their connection to ESI and matrix-assisted laser desorption/ionization may provide opportunities to further develop new ionization strategies for traditional and yet unforeseen applications of mass spectrometry. This Critical Insights article covers developments leading to the discovery of a seemingly magic ionization process that is simple to use, fast, sensitive, robust, and can be directly applied to surface characterization using portable or high performance mass spectrometers.

  18. Microplasma Ionization of Volatile Organics for Improving Air/Water Monitoring Systems On-Board the International Space Station.

    Science.gov (United States)

    Bernier, Matthew C; Alberici, Rosana M; Keelor, Joel D; Dwivedi, Prabha; Zambrzycki, Stephen C; Wallace, William T; Gazda, Daniel B; Limero, Thomas F; Symonds, Josh M; Orlando, Thomas M; Macatangay, Ariel; Fernández, Facundo M

    2016-07-01

    Low molecular weight polar organics are commonly observed in spacecraft environments. Increasing concentrations of one or more of these contaminants can negatively impact Environmental Control and Life Support (ECLS) systems and/or the health of crew members, posing potential risks to the success of manned space missions. Ambient plasma ionization mass spectrometry (MS) is finding effective use as part of the analytical methodologies being tested for next-generation space module environmental analysis. However, ambient ionization methods employing atmospheric plasmas typically require relatively high operation voltages and power, thus limiting their applicability in combination with fieldable mass spectrometers. In this work, we investigate the use of a low power microplasma device in the microhollow cathode discharge (MHCD) configuration for the analysis of polar organics encountered in space missions. A metal-insulator-metal (MIM) structure with molybdenum foil disc electrodes and a mica insulator was used to form a 300 μm diameter plasma discharge cavity. We demonstrate the application of these MIM microplasmas as part of a versatile miniature ion source for the analysis of typical volatile contaminants found in the International Space Station (ISS) environment, highlighting their advantages as low cost and simple analytical devices. Graphical Abstract ᅟ.

  19. Microplasma Ionization of Volatile Organics for Improving Air/Water Monitoring Systems On-Board the International Space Station

    Science.gov (United States)

    Bernier, Matthew C.; Alberici, Rosana M.; Keelor, Joel D.; Dwivedi, Prabha; Zambrzycki, Stephen C.; Wallace, William T.; Gazda, Daniel B.; Limero, Thomas F.; Symonds, Josh M.; Orlando, Thomas M.; Macatangay, Ariel; Fernández, Facundo M.

    2016-07-01

    Low molecular weight polar organics are commonly observed in spacecraft environments. Increasing concentrations of one or more of these contaminants can negatively impact Environmental Control and Life Support (ECLS) systems and/or the health of crew members, posing potential risks to the success of manned space missions. Ambient plasma ionization mass spectrometry (MS) is finding effective use as part of the analytical methodologies being tested for next-generation space module environmental analysis. However, ambient ionization methods employing atmospheric plasmas typically require relatively high operation voltages and power, thus limiting their applicability in combination with fieldable mass spectrometers. In this work, we investigate the use of a low power microplasma device in the microhollow cathode discharge (MHCD) configuration for the analysis of polar organics encountered in space missions. A metal-insulator-metal (MIM) structure with molybdenum foil disc electrodes and a mica insulator was used to form a 300 μm diameter plasma discharge cavity. We demonstrate the application of these MIM microplasmas as part of a versatile miniature ion source for the analysis of typical volatile contaminants found in the International Space Station (ISS) environment, highlighting their advantages as low cost and simple analytical devices.

  20. Deconstructing Desorption Electrospray Ionization: Independent Optimization of Desorption and Ionization by Spray Desorption Collection

    Science.gov (United States)

    Douglass, Kevin A.; Jain, Shashank; Brandt, William R.; Venter, Andre R.

    2012-11-01

    Spray desorption collection (SDC) and reflective electrospray ionization (RESI) were used to independently study the desorption and ionization processes that together comprise desorption electrospray ionization (DESI). Both processes depend on several instrumental parameters, including the nebulizing gas flow rate, applied potential, and source geometries. Each of these parameters was optimized for desorption, as represented by the results obtained by SDC, and ionization, as represented by the results obtained by RESI. The optimized conditions were then compared to the optimization results for DESI. Our results confirm that optimal conditions for desorption and ionization are different and that in some cases the optimized DESI conditions are a compromise between both sets. The respective results for DESI, RESI, and SDC for each parameter were compared across the methods to draw conclusions about the contribution of each parameter to desorption and ionization separately and then combined within DESI. Our results indicate that desorption efficiency is (1) independent of the applied potential and (2) the impact zone to inlet distance, and that (3) gas pressure settings and (4) sprayer to impact zone distances above optimal for DESI are detrimental to desorption but beneficial for ionization. In addition, possible interpretations for the observed trends are presented.

  1. Atmospheric pressure thermospray ionization using a heated microchip nebulizer.

    Science.gov (United States)

    Keski-Rahkonen, Pekka; Haapala, Markus; Saarela, Ville; Franssila, Sami; Kotiaho, Tapio; Kostiainen, Risto; Auriola, Seppo

    2009-10-30

    When a standard atmospheric pressure chemical ionization (APCI) or atmospheric pressure photoionization (APPI) ion source is used without applying the corona discharge or photoirradiation, atmospheric pressure thermospray ionization (APTSI) of various compounds can be achieved. Although largely ignored, this phenomenon has recently gained interest as an alternative ionization technique. In this study, this technique is performed for the first time on a miniaturized scale using a microchip nebulizer. Sample ionization with the presented microchip-APTSI (microAPTSI) is achieved by applying only heat and gas flow to a nebulizer chip, without any other methods to promote gas-phase ionization. To evaluate the performance of the described microAPTSI setup, ionization efficiency for a set of test compounds was monitored as the microchip positioning, temperature, nebulizer gas flow rate, sample solution composition, and solvent flow rate were varied. The microAPTSI mass spectra of the test compounds were also compared to those obtained with ESI and APCI. The microAPTSI produces ESI-like spectra with low background noise, favoring the formation of protonated or deprotonated molecules of compounds that are ionizable in solution. Multiple charging of peptides without in-source fragmentation was also observed. Unlike ESI, however, the microAPTSI source can tolerate the presence of mobile phase additives like trifluoroacetic acid (TFA) without significant ion suppression. The microAPTSI source can be used with standard mass spectrometer ion source hardware, being a unique alternative to the present interfacing techniques.

  2. Identification of autoionizing states of atomic chromium for resonance photo-ionization at the ISOLDE-RILIS

    CERN Document Server

    Goodacre, T Day; Fedorovc, D; Fedosseev, V N; Marsh, B A; Molkanov, P; Rossel, R E; Rothe, S; Seiffert, C

    2015-01-01

    The resonance ionization laser ion source (RILIS) is the principal ion source of the ISOLDE radioactive beam facility based at CERN. Using the method of in-source resonance ionization spectroscopy, an optimal three-step, three-resonance photo-ionization scheme has been developed for chromium. The scheme uses an ionizing transition to one of the 14 newly observed autoionizing states. This work increases the range of ISOLDE-RILIS ionized beams to 32 chemical elements. Details of the spectroscopic studies are described and the new ionization scheme is summarized. A link to the complete version of this document will be added here following publication:

  3. Ribonucleotide and Ribonucleoside Determination by Ambient Pressure Ion Mobility Spectrometry (IMS)

    OpenAIRE

    Kanu, Abu B.; Hampikian, Greg; Brandt, Simon D; Hill, Herbert H.

    2009-01-01

    Reduced mobilities, resolving powers and detection limits for 12 ribonucleotides and 4 ribonucleosides were measured by ambient pressure electrospray ionization ion mobility spectrometry (ESI-IMS). With the instrument used in this study it was possible to separate some of these compounds within the mixtures. In addition, the detection limits reported for the ribonucleotides and ribonucleosides ranged from 15 to 300 picomoles whereas resolving power ranged from 41 to 56 suggesting that ambient...

  4. Fuel cell with ionization membrane

    Science.gov (United States)

    Hartley, Frank T. (Inventor)

    2007-01-01

    A fuel cell is disclosed comprising an ionization membrane having at least one area through which gas is passed, and which ionizes the gas passing therethrough, and a cathode for receiving the ions generated by the ionization membrane. The ionization membrane may include one or more openings in the membrane with electrodes that are located closer than a mean free path of molecules within the gas to be ionized. Methods of manufacture are also provided.

  5. A corona discharge initiated electrochemical electrospray ionization technique.

    Science.gov (United States)

    Lloyd, John R; Hess, Sonja

    2009-11-01

    We report here the development of a corona discharge (CD) initiated electrochemical (EC) electrospray ionization (ESI) technique using a standard electrospray ion source. This is a new ionization technique distinct from ESI, electrochemistry inherent to ESI, APCI, and techniques using hydroxyl radicals produced under atmospheric pressure conditions. By maximizing the observable CD at the tip of a stainless steel ESI capillary, efficient electrochemical oxidation of electrochemically active compounds is observed. For electrochemical oxidation to be observed, the ionization potential of the analyte must be lower than Fe. Ferrocene labeled compounds were chosen as the electrochemically active moiety. The electrochemical cell in the ESI source was robust, and generated ions with selectivity according to the ionization potential of the analytes and up to zeptomolar sensitivity. Our results indicate that CD initiated electrochemical ionization has the potential to become a powerful technique to increase the dynamic range, sensitivity, and selectivity of ESI experiments. PMID:19747843

  6. Ionized Outflows in 3-D Insights from Herbig-Haro Objects and Applications to Nearby AGN

    Science.gov (United States)

    Cecil, Gerald

    1999-01-01

    HST shows that the gas distributions of these objects are complex and clump at the limit of resolution. HST spectra have lumpy emission-line profiles, indicating unresolved sub-structure. The advantages of 3D over slits on gas so distributed are: robust flux estimates of various dynamical systems projected along lines of sight, sensitivity to fainter spectral lines that are physical diagnostics (reddening-gas density, T, excitation mechanisms, abundances), and improved prospects for recovery of unobserved dimensions of phase-space. These advantages al- low more confident modeling for more profound inquiry into underlying dynamics. The main complication is the effort required to link multi- frequency datasets that optimally track the energy flow through various phases of the ISM. This tedium has limited the number of objects that have been thoroughly analyzed to the a priori most spectacular systems. For HHO'S, proper-motions constrain the ambient B-field, shock velocity, gas abundances, mass-loss rates, source duty-cycle, and tie-ins with molecular flows. If the shock speed, hence ionization fraction, is indeed small then the ionized gas is a significant part of the flow energetics. For AGN'S, nuclear beaming is a source of ionization ambiguity. Establishing the energetics of the outflow is critical to determining how the accretion disk loses its energy. CXO will provide new constraints (especially spectral) on AGN outflows, and STIS UV-spectroscopy is also constraining cloud properties (although limited by extinction). HHO's show some of the things that we will find around AGN'S. I illustrate these points with results from ground-based and HST programs being pursued with collaborators.

  7. Ambiente il nostro futuro

    OpenAIRE

    Canigiani, Franca

    2016-01-01

    L’ambiente è il quadro di vita, la casa comune, il patrimonio di base delle società umane – scriveva un indimenticabile maestro della geografia italiana: Giuseppe Barbieri. Due gli avvenimenti che nel 2015 hanno segnato il passo dell’umanità sulla strada di una più matura coscienza ambientale, fino a comprendere che è necessario e urgente prendersi cura della Terra: primo, la pubblicazione della lettera enciclica di papa Francesco, Laudato si’ sulla cura della casa comune, straordinario saggi...

  8. AOX y medio ambiente.

    OpenAIRE

    Riva Juan, Mª del Carmen; López Ribas, David

    1996-01-01

    Los productos organohalogenados son muy utilizados por la industria y su presencia en el medio ambiente está siendo controlada. En los últimos años se han desarrollado varias técnicas de detección, siendo desde finales de los 80 los AOX (adsorbable organic halogens) uno de los parámetros sobre los que se han realizado más estudios. En muchos paises de la Unión Europea y en E.E.U.U. de América, la presencia de compuestos organohalogenados en aguas continentales y suelos está legislada indicand...

  9. Arquitectura y medio ambiente

    OpenAIRE

    Saura Carulla, Magdalena

    2003-01-01

    La arquitectura y la planificación son el resultado de una integración ponderada de conocimientos técnicos y una multiplicidad de aspectos relacionados con el conocimiento natural y social. En este trabajo el autor propone, desde el ámbito de las ciencias del medio ambiente, diversos planteamientos teóricos y prácticos relacionados con la arquitectura y el urbanismo. El conocimiento de la naturaleza de los sistemas naturales y de los sistemas ecosociales permite al diseñador aplicar un marco ...

  10. The Phobos neutral and ionized torus

    Science.gov (United States)

    Poppe, A. R.; Curry, S. M.; Fatemi, S.

    2016-05-01

    Charged particle sputtering, micrometeoroid impact vaporization, and photon-stimulated desorption are fundamental processes operating at airless surfaces throughout the solar system. At larger bodies, such as Earth's Moon and several of the outer planet moons, these processes generate tenuous surface-bound exospheres that have been observed by a variety of methods. Phobos and Deimos, in contrast, are too gravitationally weak to keep ejected neutrals bound and, thus, are suspected to generate neutral tori in orbit around Mars. While these tori have not yet been detected, the distribution and density of both the neutral and ionized components are of fundamental interest. We combine a neutral Monte Carlo model and a hybrid plasma model to investigate both the neutral and ionized components of the Phobos torus. We show that the spatial distribution of the neutral torus is highly dependent on each individual species (due to ionization rates that span nearly 4 orders of magnitude) and on the location of Phobos with respect to Mars. Additionally, we present the flux distribution of torus pickup ions throughout the Martian system and estimate typical pickup ion fluxes. We find that the predicted pickup ion fluxes are too low to perturb the ambient plasma, consistent with previous null detections by spacecraft around Mars.

  11. SFC-APLI-(TOF)MS: Hyphenation of Supercritical Fluid Chromatography to Atmospheric Pressure Laser Ionization Mass Spectrometry.

    Science.gov (United States)

    Klink, Dennis; Schmitz, Oliver Johannes

    2016-01-01

    Atmospheric-pressure laser ionization mass spectrometry (APLI-MS) is a powerful method for the analysis of polycyclic aromatic hydrocarbon (PAH) molecules, which are ionized in a selective and highly sensitive way via resonance-enhanced multiphoton ionization. APLI was presented in 2005 and has been hyphenated successfully to chromatographic separation techniques like high performance liquid chromatography (HPLC) and gas chromatography (GC). In order to expand the portfolio of chromatographic couplings to APLI, a new hyphenation setup of APLI and supercritical-fluid chromatography (SFC) was constructed and aim of this work. Here, we demonstrate the first hyphenation of SFC and APLI in a simple designed way with respect to different optimization steps to ensure a sensitive analysis. The new setup permits qualitative and quantitative determination of native and also more polar PAH molecules. As a result of the altered ambient characteristics within the source enclosure, the quantification of 1-hydroxypyrene (1-HP) in human urine is possible without prior derivatization. The limit of detection for 1-HP by SFC-APLI-TOF(MS) was found to be 0.5 μg L(-1), which is lower than the 1-HP concentrations found in exposed persons. PMID:26633261

  12. Ionizing radiation in the food industry

    International Nuclear Information System (INIS)

    The present state of application of ionizing radiation to food irradiation is surveyed. The nature of ionizing radiation, interactions of radiation with matter, dosimetric procedures, and types of radiation sources are outlined. Ionizing radiation is used for sprout inhibition, sterilization, for killing insects, parasites, moulds and fungi, and for enzyme activity inhibition. Sprouting can be stimulated by using low radiation doses. The chemical and biological changes occurring in irradiated foods are discussed. The irradiation of 49 kinds of food is permitted in 36 countries, and is applied on a commercial basis in 20 countries. Examples of large irradiating facilities over the world are given. Attention is also paid to the legislative basis of this approach. (M.D.). 2 tabs., 17 refs

  13. The critical ionization velocity

    International Nuclear Information System (INIS)

    The critical ionization velocity effect was first proposed in the context of space plasmas. This effect occurs for a neutral gas moving through a magnetized plasma and leads to rapid ionization and braking of the relative motion when a marginal velocity, 'the critical velocity', is exceeded. Laboratory experiments have clearly established the significance of the critical velocity and have provided evidence for an underlying mechanism which relies on the combined action of electron impact ionization and a collective plasma interaction heating electrons. There is experimental support for such a mechanism based on the heating of electrons by the modified two-stream instability as part of a feedback process. Several applications to space plasmas have been proposed and the possibility of space experiments has been discussed. (author)

  14. Crisis ambiental y cristianismo

    Directory of Open Access Journals (Sweden)

    Felipe Cárdenas

    2008-01-01

    Full Text Available En el artículo se identifican y reconocen algunas opciones que se pueden desarrollar en el cristianismo en relación con la problemática ambiental. Se aborda el dilema bíblico suscitado por interpretaciones antiecológicas y ecológicas. Con base en una lectura de la Biblia, de testimonios cristianos, y en una rememoria de estructuras institucionales, como la parroquia, se analiza el valor que tiene el mensaje cristiano en lo referido a la mitigación de la crisis ambiental.This article identifies and recognizes some options that can be developed in Christianity in relation to the environmental problem. It starts by analyzing the biblical dilemma provoked by both ecological and antiecological interpretations. Based on a reading of the Bible, testimonies from Christians and with a rememory of institutional structures, like the parish, the valué of the Christian message for mitigating the environmental crisis is analyzed.

  15. Radiation dependent ionization model

    International Nuclear Information System (INIS)

    For laser created plasma simulation, hydrodynamics codes need a non-LTE atomic physics package for both EOS and optical properties (emissivity and opacity). However in XRL targets as in some ICF targets, high Z material can be found. In these cases radiation trapping can induce a significant departure from the optically thin ionization description. The authors present a method to change an existing LTE code into a non-LTE code with coupling of ionization to radiation. This method has very low CPU cost and can be used in 2D simulations

  16. Hydrocarbon analysis using desorption atmospheric pressure chemical ionization

    KAUST Repository

    Jjunju, Fred P M

    2013-07-01

    Characterization of the various petroleum constituents (hydronaphthalenes, thiophenes, alkyl substituted benzenes, pyridines, fluorenes, and polycyclic aromatic hydrocarbons) was achieved under ambient conditions without sample preparation by desorption atmospheric pressure chemical ionization (DAPCI). Conditions were chosen for the DAPCI experiments to control whether ionization was by proton or electron transfer. The protonated molecule [M+H]+ and the hydride abstracted [MH]+ form were observed when using an inert gas, typically nitrogen, to direct a lightly ionized plasma generated by corona discharge onto the sample surface in air. The abundant water cluster ions generated in this experiment react with condensed-phase functionalized hydrocarbon model compounds and their mixtures at or near the sample surface. On the other hand, when naphthalene was doped into the DAPCI gas stream, its radical cation served as a charge exchange reagent, yielding molecular radical cations (M+) of the hydrocarbons. This mode of sample ionization provided mass spectra with better signal/noise ratios and without unwanted side-products. It also extended the applicability of DAPCI to petroleum constituents which could not be analyzed through proton transfer (e.g., higher molecular PAHs such as chrysene). The thermochemistry governing the individual ionization processes is discussed and a desorption/ionization mechanism is inferred. © 2012 Elsevier B.V.

  17. Types for BioAmbients

    Directory of Open Access Journals (Sweden)

    Sara Capecchi

    2010-02-01

    Full Text Available The BioAmbients calculus is a process algebra suitable for representing compartmentalization, molecular localization and movements between compartments. In this paper we enrich this calculus with a static type system classifying each ambient with group types specifying the kind of compartments in which the ambient can stay. The type system ensures that, in a well-typed process, ambients cannot be nested in a way that violates the type hierarchy. Exploiting the information given by the group types, we also extend the operational semantics of BioAmbients with rules signalling errors that may derive from undesired ambients' moves (i.e. merging incompatible tissues. Thus, the signal of errors can help the modeller to detect and locate unwanted situations that may arise in a biological system, and give practical hints on how to avoid the undesired behaviour.

  18. Types for BioAmbients

    CERN Document Server

    Capecchi, Sara; 10.4204/EPTCS.19.7

    2010-01-01

    The BioAmbients calculus is a process algebra suitable for representing compartmentalization, molecular localization and movements between compartments. In this paper we enrich this calculus with a static type system classifying each ambient with group types specifying the kind of compartments in which the ambient can stay. The type system ensures that, in a well-typed process, ambients cannot be nested in a way that violates the type hierarchy. Exploiting the information given by the group types, we also extend the operational semantics of BioAmbients with rules signalling errors that may derive from undesired ambients' moves (i.e. merging incompatible tissues). Thus, the signal of errors can help the modeller to detect and locate unwanted situations that may arise in a biological system, and give practical hints on how to avoid the undesired behaviour.

  19. Direct Analysis of Oil Additives by High-Field Asymmetric Waveform Ion Mobility Spectrometry-Mass Spectrometry Combined with Electrospray Ionization and Desorption Electrospray Ionization.

    Science.gov (United States)

    Da Costa, Caitlyn; Turner, Matthew; Reynolds, James C; Whitmarsh, Samuel; Lynch, Tom; Creaser, Colin S

    2016-02-16

    The analysis of corrosion inhibitors in the presence and absence of an oil matrix is reported using electrospray ionization (ESI) and desorption electrospray ionization (DESI), hyphenated with miniaturized high-field asymmetric waveform ion mobility spectrometry (FAIMS) and mass spectrometry (MS). The target analytes were successfully ionized in solution by ESI and directly from steel surfaces using DESI ambient ionization at levels ≥0.0004% w/w (4 ppm) in oil. Differences in the mass spectral profiles observed for the additive/oil mixture are attributed to differences between the ESI and DESI ionization processes. The use of FAIMS improved selectivity for ESI generated analyte ions through reduction in the chemical noise resulting from the oil matrix. DESI enabled the direct, rapid, native state interrogation of oil samples on steel surfaces without sample pretreatment, and the hyphenation of DESI with the miniaturized FAIMS enhanced the relative analyte responses of the surface-active corrosion inhibitors. PMID:26780580

  20. Ionization chamber smoke detectors

    International Nuclear Information System (INIS)

    One kind of smoke detector, the ionization-type, is regulated by the Atomic Energy Control Board (AECB) because it uses a radioactive substance in its mechanism. Radioactivity and radiation are natural phenomena, but they are not very familiar to the average householder. This has led to a number of questions being asked of the AECB. These questions and AECB responses are outlined