Sample records for major ions volatile

  1. Major odorants released as urinary volatiles by urinary incontinent patients.

    PubMed

    Pandey, Sudhir Kumar; Kim, Ki-Hyun; Choi, Si On; Sa, In Young; Oh, Soo Yeon

    2013-01-01

    In this study, volatile urinary components were collected using three different types of samples from patients suffering from urinary incontinence (UI): (1) urine (A); (2) urine + non-used pad (B); and (3) urine + used pad (C). In addition, urine + non-used pad (D) samples from non-patients were also collected as a reference. The collection of urinary volatiles was conducted with the aid of a glass impinger-based mini-chamber method. Each of the four sample types (A through D) was placed in a glass impinger and incubated for 4 hours at 37 °C. Ultra pure air was then passed through the chamber, and volatile urine gas components were collected into Tedlar bags at the other end. These bag samples were then analyzed for a wide range of VOCs and major offensive odorants (e.g., reduced sulfur compounds (RSCs), carbonyls, trimethylamine (TMA), ammonia, etc.). Among the various odorants, sulfur compounds (methanethiol and hydrogen sulfide) and aldehydes (acetaldehyde, butylaldehyde, and isovaleraldehyde) were detected above odor threshold and predicted to contribute most effectively to odor intensity of urine incontinence. PMID:23823973

  2. Major sources of exposure to benzene and other volatile organic chemicals

    Microsoft Academic Search

    Lance Wallace

    1990-01-01

    The major sources of human exposure to about a dozen volatile organic chemicals (VOCs) have recently been identified. For nearly every chemical, the major sources of exposure are completely different from the major sources of emissions. This finding implies that current environmental regulations and control strategies are misdirected. Important sources of exposure are typically not regulated in any way, whereas

  3. Ion mobility spectrometry for detection of skin volatiles

    PubMed Central

    Ruzsanyi, Veronika; Mochalski, Pawel; Schmid, Alex; Wiesenhofer, Helmut; Klieber, Martin; Hinterhuber, Hartmann; Amann, Anton

    2012-01-01

    Volatile organic compounds (VOCs) released by humans through their skin were investigated in near real time using ion mobility spectrometry after gas chromatographic separation with a short multi-capillary column. VOCs typically found in a small nitrogen flow covering the skin are 3-methyl-2-butenal, 6-methylhept-5-en-2-one, sec-butyl acetate, benzaldehyde, octanal, 2-ethylhexanol, nonanal and decanal at volume fractions in the low part per billion-(ppb) range. The technique presented here may contribute to elucidating some physiological processes occurring in the human skin. PMID:23217311

  4. Effect of packaging materials and storage on major volatile compounds in three Australian native herbs.

    PubMed

    Chaliha, Mridusmita; Cusack, Andrew; Currie, Margaret; Sultanbawa, Yasmina; Smyth, Heather

    2013-06-19

    Lemon myrtle, anise myrtle, and Tasmanian pepper leaf are commercial Australian native herbs with a high volatile or essential oil content. Packaging of the herbs in high- or low-density polyethylene (HDPE and LDPE) has proven to be ineffective in preventing a significant loss of volatile components on storage. This study investigates and compares the effectiveness of alternate high-barrier property packaging materials, namely, polyvinylidene chloride coated polyethylene terephthalate/casted polypropylene (PVDC coated PET/CPP) and polyethylene terephthalate/polyethylene terephthalate/aluminum foil/linear low-density polyethylene (PET/PET/Foil/LLDPE), in prevention of volatile compound loss from the three native herbs stored at ambient temperature for 6 months. Concentrations of major volatiles were monitored using gas chromatography-mass spectrometry (GC-MS) techniques. After 6 months of storage, the greatest loss of volatiles from lemon myrtle was observed in traditional LDPE packaging (87% loss) followed by storage in PVDC coated PET/CPP (58% loss) and PET/PET/Foil/LLDPE (loss of 23%). The volatile loss from anise myrtle and Tasmanian pepper leaf stored in PVDC coated PET/CPP and PET/PET/Foil/LLDPE packaging was <30%. This study clearly indicates the importance of selecting the correct packaging material to retain the quality of herbs with high volatile content. PMID:23682630

  5. Influence of prefermentative treatments to the major volatile compounds of Assyrtiko wines.

    PubMed

    Kechagia, Despina; Paraskevopoulos, Yannis; Symeou, Eleni; Galiotou-Panayotou, Maria; Kotseridis, Yorgos

    2008-06-25

    A study of the volatile fraction of Assyrtiko wines, using gas chromatography coupled with olfactometry, was realized. Twenty-seven volatile compounds were identified as potent odorants, most of them originating from the fermentation process. Quantification of the major volatile compounds was realized developing a rapid analytical method based on fractionation of a 50 mL wine aliquot using C 18-reversed phase adsorbent. After elution of the volatile compounds with pentane-diethyl ether and concentration under nitrogen, the final wine extract was injected in a gas chromatography-flame ionization detection system. The method allows satisfactory determination of more than 15 volatile compounds of wine. The linearity of the method gave a typical r (2) between 0.990 and 0.999, while reproducibility ranged from 5.1 to 12.2% (as relative standard deviation) with 9.5% as the average. The method was applied to wines produced by Assyrtiko grapes (AOC Santorini), for two consecutive years, to compare the effect of skin contact prior to fermentation and the must clarification process. Direct press and skin contact wines were differentiated analytically; however, highly significant differences were not. Inversely, the differences found between direct press/clarified and nonclarified wines were significant. Wines produced by direct press and clarified must presented significantly higher levels of ethylic esters and fusel alcohol acetates but lower fusel alcohol levels, leading probably to more fruity wines. This difference, between clarified and nonclarified grape musts, was not significant in the case of the wines produced by skin contact of Assyrtiko berries. These findings were validated by preference sensory analysis tests. PMID:18500807

  6. Aerosol major ion record at Mount Washington

    NASA Astrophysics Data System (ADS)

    Fischer, E. V.; Ziemba, L. D.; Talbot, R. W.; Dibb, J. E.; Griffin, R. J.; Husain, L.; Grant, A. N.

    2007-01-01

    This study examined the seasonal cycles and regional-scale meteorological controls on the chemical properties of bulk aerosols collected from 1999 to 2004 at Mount Washington, the highest peak in the northeastern United States. The concentrations of NH4+ and SO42- peaked during summer months. The pattern for aerosol NO3- was more complicated with relatively high median concentrations characterizing spring and summer months, but with major elevated events occurring during fall, winter, and spring. The seasonal relationship between NH4+ and SO42- indicated that during warmer months a mixture of (NH4)2SO4 and NH4HSO4 was present, while it was mainly the latter in winter. More acidity and higher concentrations of the major species were generally associated with winds from the southwest and west sectors. The highest (?95th percentile) concentrations of SO42- and NH4+ were associated with air mass transport from major upwind source regions in the Midwest and along the eastern seaboard. The ionic composition and seasonal cycle observed at Mount Washington were similar to those measured at other northeastern sites, but the range and average concentrations were much lower. These differences were exaggerated during wintertime. Included in this paper are several Eulerian case studies of SO2 conversion to SO42- during transit from Whiteface Mountain, New York, to Mount Washington. The calculations suggest a gas-phase SO2 oxidation rate of ˜1-2% per hour and demonstrate the possibility of using these two sites to investigate the chemical evolution of air masses as they move from Midwestern source regions to northern New England.

  7. MAJOR ION CHEMISTRY OF LAKES ON THE KENAI PENINSULA, ALASKA

    EPA Science Inventory

    A probability sample of 59 lakes was conducted in August, 1988 to characterize the major ion chemistry of a population of over 800 lakes on the Kenai Peninsula, AK. here were two groups of lakes: those with alkalinity ...

  8. Major Volatiles from MSL SAM Evolved Gas Analyses: Yellowknife Bay Through Lower Mount Sharp

    NASA Technical Reports Server (NTRS)

    McAdam, A. C.; Archer, P. D., Jr.; Sutter, B.; Franz, H. B.; Eigenbrode, J. L.; Ming, D. W.; Morris, R. V.; Niles, P. B.; Stern, J. C.; Freissinet, C.; Glavin, D. P.; Atreya, S. K.; Bish, D. L.; Blake, D. F.; Mahaffy, P. R.; Navarro-Gonzalez, R.; McKay, C. P.; Wilhelm, M. B.

    2015-01-01

    The Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments on the Mars Science Laboratory (MSL) analysed several subsamples of <150 µm fines from five sites at Gale Crater. Three were in Yellowknife Bay: the Rocknest aeolian bedform ("RN") and drilled Sheepbed mudstone from sites John Klein ("JK") and Cumberland ("CB"). One was drilled from the Windjana ("WJ") site on a sandstone of the Kimberly formation investigated on route to Mount Sharp. Another was drilled from the Confidence Hills ("CH") site on a sandstone of the Murray Formation at the base of Mt. Sharp (Pahrump Hills). Outcrops are sedimentary rocks that are largely of fluvial or lacustrine origin, with minor aeolian deposits.. SAM's evolved gas analysis (EGA) mass spectrometry detected H2O, CO2, O2, H2, SO2, H2S, HCl, NO, and other trace gases, including organic fragments. The identity and evolution temperature (T) of evolved gases can support CheMin mineral detection and place constraints on trace volatile-bearing phases or phases difficult to characterize with XRD (e.g., X-ray amorphous phases). They can also give constraints on sample organic chemistry. Here, we discuss trends in major evolved volatiles from SAM EGA analyses to date.

  9. Comparative study of the pyrolysis of lignocellulose and its major components: characterization and overall distribution of their biochars and volatiles.

    PubMed

    Cao, Xuefei; Zhong, Linxin; Peng, Xinwen; Sun, Shaoni; Li, Shouming; Liu, Shijie; Sun, Runcang

    2014-03-01

    In order to investigate the pyrolysis differences among lignocellulose and its major components, the biochars and volatiles of lignocellulose (bamboo), lignin, hemicellulose and holocellulose (from bamboo), and cellulose (from cotton linter) were studied using elemental analysis, FTIR, XRD, SEM, Py-GC/MS and TGA-FTIR. Result showed that the biochar yield of lignin (48.8%) was much higher than those of hemicellulose (21.1%), cellulose (8.3%), holocellulose (20.4%) and bamboo (15.1%), while no obvious elemental difference among these biochars was found. Results from Py-GC/MS indicated that carbonyl compounds, ethers and alcohols were the major volatiles of polysaccharide component pyrolysis, while aromatic compounds were the major volatiles of lignin pyrolysis. The pyrolysis of polysaccharide component mainly occurred at 200-400°C, while the pyrolysis of lignin happened at 300-700°C. PMID:24413478

  10. A volatile organic analyzer for Space Station: Description and evaluation of a gas chromatography/ ion mobility

    NASA Technical Reports Server (NTRS)

    Limero, Thomas F.; James, John T.

    1994-01-01

    A Volatile Organic Analyzer (VOA) is being developed as an essential component of the Space Station's Environmental Health System (EHS) air quality monitoring strategy to provide warning to the crew and ground personnel if volatile organic compounds exceed established exposure limits. The short duration of most Shuttle flights and the relative simplicity of the contaminant removal mechanism have lessened the concern about crew exposure to air contaminants on the Shuttle. However, the longer missions associated with the Space Station, the complex air revitalization system and the proposed number of experiments have led to a desire for real-time monitoring of the contaminants in the Space Station atmosphere. Achieving the performance requirements established for the VOA within the Space Station resource (e.g., power, weight) allocations led to a novel approach that joined a gas chromatograph (GC) to an ion mobility spectrometer (IMS). The authors of this paper will discuss the rational for selecting the GC/IMS technology as opposed to the more established gas chromatography/mass spectrometry (GC/MS) for the foundation of the VOA. The data presented from preliminary evaluations will demonstrate the versatile capability of the GC/IMS to analyze the major contaminants expected in the Space Station atmosphere. The favorable GC/IMS characteristics illustrated in this paper included excellent sensitivity, dual-mode operation for selective detection, and mobility drift times to distinguish co-eluting GC peaks. Preliminary studies have shown that the GC/IMS technology can meet surpass the performance requirements of the Space Station VOA.

  11. Ion-trap detection of volatile organic compounds in alveolar breath

    SciTech Connect

    Phillips, M.; Greenberg, J. (Department of Medicine, St. Vincent's Medical Center of Richmond, Staten Island, NY (United States))

    1992-01-01

    We describe a method for the collection and microanalysis of the volatile organic compounds in human breath. A transportable apparatus supplies subjects with purified air and samples their alveolar breath; the volatile organic compounds are captured in an adsorptive trap containing activated carbon and molecular sieve. The sample is thermally desorbed from the trap in an automated microprocessor-controlled device, concentrated by two-stage cryofocusing, and assayed by gas chromatography with ion-trap detection. Compounds are identified by reference to a computer-based library of mass spectra with subtraction of the background components present in the inspired air. We used this device to study 10 normal subjects and determined the relative abundance of the volatile organic compounds in their alveolar breath. The breath-collecting apparatus was convenient to operate and was well tolerated by human volunteers.

  12. Potential for ion-induced nucleation of volatile organic compounds by radon decay in indoor environments

    SciTech Connect

    Daisey, J.M.

    1991-11-01

    There is considerable interest in the ``unattached`` fraction of radon progeny in indoor air because of its significance to the estimation of the risks of radon exposure. Because of its high mobility in air, the unattached fraction is more efficiently deposited in the respiratory tract. Variation in the diameter of the ``unattached`` fraction and in its diffusion coefficient can be due to clustering of other atmospheric species around the {sup 218}PoO{sub 2}{sup +} ion. The purpose of this study was to investigate the potential for the formation of clusters of vapor phase organic compounds, found in indoor air, around the {sup 218}PoO{sub 2}{sup +} ion and to determine which were most likely to form clusters. A secondary purpose was to provide a compilation of measurements of indoor organic compounds for future experiments and theoretical calculations by the radon research community. The classical charged liquid droplet theory (Thomson equation) was used to estimate the Gibbs free energy of ion-induced nucleation and to provide an indication of the indoor organic compounds most likely to undergo ion-induced nucleation. Forty-four volatile and semi-volatile organic compounds out of the more than 300 which have been reported in indoor air were investigated. Water vapor was included for comparison. The results indicate that there is a potential for the formation of clusters of organic compounds around the {sup 218}PoO{sub 2}{sup +} ion. The compounds with the greatest potential for cluster formation are the volatile oxidized hydrocarbons (e.g., n-butanol, phenol, hexanal, nonanal, benzaldehyde, the ketones and the acetates) and the semi-volatile organic compounds (pentachlorophenol, nicotine, chlordane, chlorpyrifos).

  13. Potential for ion-induced nucleation of volatile organic compounds by radon decay in indoor environments

    SciTech Connect

    Daisey, J.M.

    1991-11-01

    There is considerable interest in the unattached'' fraction of radon progeny in indoor air because of its significance to the estimation of the risks of radon exposure. Because of its high mobility in air, the unattached fraction is more efficiently deposited in the respiratory tract. Variation in the diameter of the unattached'' fraction and in its diffusion coefficient can be due to clustering of other atmospheric species around the {sup 218}PoO{sub 2}{sup +} ion. The purpose of this study was to investigate the potential for the formation of clusters of vapor phase organic compounds, found in indoor air, around the {sup 218}PoO{sub 2}{sup +} ion and to determine which were most likely to form clusters. A secondary purpose was to provide a compilation of measurements of indoor organic compounds for future experiments and theoretical calculations by the radon research community. The classical charged liquid droplet theory (Thomson equation) was used to estimate the Gibbs free energy of ion-induced nucleation and to provide an indication of the indoor organic compounds most likely to undergo ion-induced nucleation. Forty-four volatile and semi-volatile organic compounds out of the more than 300 which have been reported in indoor air were investigated. Water vapor was included for comparison. The results indicate that there is a potential for the formation of clusters of organic compounds around the {sup 218}PoO{sub 2}{sup +} ion. The compounds with the greatest potential for cluster formation are the volatile oxidized hydrocarbons (e.g., n-butanol, phenol, hexanal, nonanal, benzaldehyde, the ketones and the acetates) and the semi-volatile organic compounds (pentachlorophenol, nicotine, chlordane, chlorpyrifos).

  14. Effects of light and copper ions on volatile aldehydes of milk and milk fractions

    SciTech Connect

    Jeno, W.; Bassette, R.; Crang, R.E.

    1988-09-01

    Raw, laboratory-pasteurized and plant-pasteurized homogenized milks were exposed to copper ions (5 ppm), to sunlight or fluorescent light and the effects determined on the composition of volatile aldehydes. The greatest change due to copper treatment was an increase in n-hexanal; acetaldehyde showed the least response in each of the sources of milk. The responses were similar from all three sources of milk with laboratory-pasteurized milk samples showing the greatest responses for each aldehyde analyzed. Similar milk samples exposed to sunlight also showed an increase in volatile aldehydes from all milk sources but with the greatest response being acetaldehyde and n-pentanal components. The milk fraction most susceptible to changes in the presence of light was neutralized whey, whereas resuspended cream was most susceptible to copper exposure. Overall, dialyzed whey appeared to be influenced more than other milk fractions by both light and copper ions.

  15. [Automatic continuous monitoring of volatile organic compounds using ion mobility spectrometer array].

    PubMed

    Zhou, Qing-Hua; Cang, Huai-Wen; Ju, Bang-Yu; Li, Lin; Du, Yong-Zhai; Chen, Chuang; Hou, Ke-Yong; Li, Jing-Hua; Wang, Wei-Guo; Li, Hai-Yang

    2011-12-01

    An ion mobility spectrometer array was designed, in order to broaden the detection range of ion mobility spectrometer and improve the accuracy of compound identification. This instrument was based on the combination of ionization sources of 63Ni positive ion mode, 63Ni negative ion mode and photoionization mode with vacuum UV lamp, and it can continuously monitor the volatile organic compounds in air. With the automatic system of sampling and injection of this instrument, the positive ion of dimethyl sulfoxide and negative ion of dichloromethane were detected simultaneously. By comprehensive analysis of spectra with ion mobility spectrometer array, acrylonitrile, m-xylene and acetone were identified, which were difficult to be distinguished under the 63Ni positive ion mode. Acetone samples were determined quantitatively within four days continuously, and the results indicated that the linear range of acetone in this instrument was 2 orders of magnitude. The linear correlation coefficient R was higher than 0.995, and the relative standard deviations were controlled in the range of 4.0%-18.3%. Methacrylate leaked in simulation was monitored on-line for 24 h continuously, using the method of dynamic tracking, and the result showed the leaking time and the concentration of methacrylate directly. PMID:22468529

  16. Multi-Capillary Column-Ion Mobility Spectrometry of Volatile Metabolites Emitted by Saccharomyces Cerevisiae

    PubMed Central

    Halbfeld, Christoph; Ebert, Birgitta E.; Blank, Lars M.

    2014-01-01

    Volatile organic compounds (VOCs) produced during microbial fermentations determine the flavor of fermented food and are of interest for the production of fragrances or food additives. However, the microbial synthesis of these compounds from simple carbon sources has not been well investigated so far. Here, we analyzed the headspace over glucose minimal salt medium cultures of Saccharomyces cerevisiae using multi-capillary column-ion mobility spectrometry (MCC-IMS). The high sensitivity and fast data acquisition of the MCC-IMS enabled online analysis of the fermentation off-gas and 19 specific signals were determined. To four of these volatile compounds, we could assign the metabolites ethanol, 2-pentanone, isobutyric acid, and 2,3-hexanedione by MCC-IMS measurements of pure standards and cross validation with thermal desorption–gas chromatography-mass spectrometry measurements. Despite the huge biochemical knowledge of the biochemistry of the model organism S. cerevisiae, only the biosynthetic pathways for ethanol and isobutyric acid are fully understood, demonstrating the considerable lack of research of volatile metabolites. As monitoring of VOCs produced during microbial fermentations can give valuable insight into the metabolic state of the organism, fast and non-invasive MCC-IMS analyses provide valuable data for process control. PMID:25197771

  17. Potential for ion-induced nucleation of volatile organic compounds by radon decay in indoor environments

    SciTech Connect

    Daisey, J.M. (Lawrence Berkeley Lab., CA (United States)); Hopke, P.K. (Clarkson Univ., Potsdam, NY (United States))

    1993-07-01

    The theoretical potential for the formation of clusters of vapor-phase organic compounds found in indoor air around the [sup 218]PoO[sub x][sup +] ion was investigated as well as which compounds were most likely to form clusters. A compilation of measurements of indoor organic compounds has been made for future experiments and theoretical calculations by the radon research community. Forty-four volatile and semivolatile organic compounds out of the more than 300 that have been reported in indoor air were investigated. Water vapor was included for comparison. The results indicate that there is a potential for the formation of clusters of organic compounds around the [sup 218]PoO[sub x][sup +] ion. The compounds with the greatest potential for cluster formation are the volatile oxidized hydrocarbons (e.g., n-butanol, phenol, hexanal, nonanal, benzaldehyde, the ketones, and the acetates) and the semivolatile organic compounds (pentachlorophenol, nicotine, chlordane, chlorpyrifos). Although the estimated diameters are consistent with the measured diameters for the unattached fraction, the state of experimental and theoretical knowledge in this area is not sufficiently developed to judge the quantitative validity of these predictions. 48 refs., 1 fig., 5 tabs.

  18. A Volatile Organic Analyzer for Space Station - Description and evaluation of a gas chromatography/ion mobility spectrometer

    NASA Technical Reports Server (NTRS)

    Limero, Thomas; Brokenshire, John; Cumming, Colin; Overton, ED; Carney, Ken; Cross, Jay; Eiceman, Gary; James, John

    1992-01-01

    An on-board Volatile Organic Analyzer (VOA), an essential component of the Environmental Health System (EHS) air-quality monitoring strategy, is described. The strategy is aimed at warning the crew and ground personnel if volatile compounds exceed safe exposure limits. The VOA uses a combination of gas chromatography (GC) and ion-mobility spectrometry (IMS) for environmental monitoring and analysis. It is concluded that the VOA dual-mode detection capability and the ion mobilities in the drift region are unique features that can assist in the resolution of coeluting GC peaks. The VOA is capable of accurately identifying and quantifying target compounds in a complex mixture.

  19. A study on major inorganic ion composition of atmospheric aerosols.

    PubMed

    Salve, P R; Krupadam, R J; Wate, S R

    2007-04-01

    Atmospheric aerosol samples were collected from Akola and Buldana region covering around 40 sqkm area during October-November 2002 and were analyzed for ten major inorganic ions namely F-, Cl-, NO3-, SO4(2-), PO4(2-), Na+, K+, Ca2+, Mg2+ and NH4+ using ion chromatographic technique. The average mass of aerosols was found to be 225.81 microg/m3 with standard deviation of 31.29 and average total water soluble load of total cations and anions was found to be 4.32 microg/m3. The concentration of ions in samples showed a general pattern as SO4(2-) > NO3- > Cl- > PO4(2-) > F- for anions and Na+ > Ca2+ > NH4+ > Mg2+ > K+ for cations. The overall composition of the aerosols was taken into account to identify the sources. The trend showed higher concentration of sodium followed by calcium, sulfate, nitrate, phosphate and ammoinum and found to be influenced by terrestrial sources. The presence of SO4(2-) and NO3- in aerosols may be due to re-suspension of soil particles. Ca2+, Mg2+ and Cl- are to be derived from soil materials. The presence of NH4+ may be attributed to the reaction of NH3 vapors with acidic gases may react or condense on an acidic particle surface of anthropogenic origin. The atmospheric aerosol is slightly acidic due to neutralization of basicity by SO2 and NO(x). PMID:17915758

  20. Enantiomeric distribution of major chiral volatile organic compounds in juniper-flavored distillates.

    PubMed

    Pažitná, Alexandra; Spánik, Ivan

    2014-02-01

    The enantiomeric ratios of chiral volatile organic compounds in juniper-flavored spirits produced by various processing technologies in different EU countries were determined by multidimensional GC using solid-phase microextraction and liquid-liquid extraction as a sample pretreatment procedure. In total, more than 260 compounds were detected in studied spirits from which linalool, ?-terpineol, 4-terpineol, linalool oxides, ?-pinene, and verbenone were selected for enantiomeric separation. The significant differences in enantiomeric ratio of linalool and cis-linalool oxide allowed us to distinguish between samples produced in Slovakia and the United Kingdom from those produced in Germany, Czech Republic, and Belgium. The pure enantiomer of trans-linalool oxide was found only in samples from Germany. It was shown that the enantiomeric ratio is independent of the sample treatment procedure, and only small differences up to 1% were observed. PMID:24339334

  1. Revalidation of the Volatile Organic Analyzer Following a Major On-Orbit Maintenance Activity

    NASA Technical Reports Server (NTRS)

    Limero, Thomas; James, John T.

    2007-01-01

    The Volatile Organic Analyzer (VOA) contributes to the assessment of air quality aboard the International Space Station (ISS) by identifying and quantifying target airborne volatile organic contaminants in the module air. This on-orbit contaminant monitoring capability becomes particularly important during an air quality degradation event such as a system leak. During several ISS air quality degradations, the VOA has generated near real-time data that was used to make decisions or to better understand the contingency. The VOA was operational from January 2002 through June 2003, during which time it was validated by comparing VOA data to simultaneously acquired grab sample containers (GSCs). In January 2003, one of the two analytical channels of the VOA was shutdown because of a component failure, but a redundant channel continued to supply the necessary analytical data. In June 2003, the sole remaining channel was deactivated. Initial assessments of the channel shutdowns pointed to failed fuses or heaters, but neither was considered repairable on orbit. In 2005, it was determined that failed fuses could be replaced on orbit and the crew conducted a diagnostic procedure to identify the failed component. The crew discovered that both channels incurred failed fuses, which lead to a subsequent on orbit maintenance activity and return of the VOA to operational status in December 2005. The VOA has been providing data on the ISS atmosphere since its reactivation in 2005 and this paper will present the VOA data collected during 2006. Special emphasis will be placed upon the revalidation of the repaired VOA using GSCs as well as a summary of the diagnostic and repair procedures.

  2. Volatile Metabolites

    PubMed Central

    Rowan, Daryl D.

    2011-01-01

    Volatile organic compounds (volatiles) comprise a chemically diverse class of low molecular weight organic compounds having an appreciable vapor pressure under ambient conditions. Volatiles produced by plants attract pollinators and seed dispersers, and provide defense against pests and pathogens. For insects, volatiles may act as pheromones directing social behavior or as cues for finding hosts or prey. For humans, volatiles are important as flavorants and as possible disease biomarkers. The marine environment is also a major source of halogenated and sulfur-containing volatiles which participate in the global cycling of these elements. While volatile analysis commonly measures a rather restricted set of analytes, the diverse and extreme physical properties of volatiles provide unique analytical challenges. Volatiles constitute only a small proportion of the total number of metabolites produced by living organisms, however, because of their roles as signaling molecules (semiochemicals) both within and between organisms, accurately measuring and determining the roles of these compounds is crucial to an integrated understanding of living systems. This review summarizes recent developments in volatile research from a metabolomics perspective with a focus on the role of recent technical innovation in developing new areas of volatile research and expanding the range of ecological interactions which may be mediated by volatile organic metabolites. PMID:24957243

  3. The direct sampling ion trap mass spectrometer for the rapid analysis of volatile organic contaminants in groundwater samples

    Microsoft Academic Search

    C. A. Eddy-Dilek; J. Rossabi; M. A. Keenan

    1993-01-01

    Analytical results of volatile organic contaminant (VOC) concentrations in groundwater samples from A\\/M Area obtained using a direct sampling ion trap mass spectrometer (DSITMS) and a gas chromatograph (GC) with an electron capture detector (ECD) were comparable. Replicate water samples were collected at the Integrated Demonstration Site during four bi-weekly sampling periods and analyzed by both instruments. The calibration curves

  4. Major-ion chemistry of the Rocky Mountain snowpack, USA

    USGS Publications Warehouse

    Turk, J.T.; Taylor, H.E.; Ingersoll, G.P.; Tonnessen, K.A.; Clow, D.W.; Mast, M.A.; Campbell, D.H.; Melack, J.M.

    2001-01-01

    During 1993-97, samples of the full depth of the Rocky Mountain snowpack were collected at 52 sites from northern New Mexico to Montana and analyzed for major-ion concentrations. Concentrations of acidity, sulfate, nitrate, and calcium increased from north to south along the mountain range. In the northern part of the study area, acidity was most correlated (negatively) with calcium. Acidity was strongly correlated (positively) with nitrate and sulfate in the southern part and for the entire network. Acidity in the south exceeded the maximum acidity measured in snowpack of the Sierra Nevada and Cascade Mountains. Principal component analysis indicates three solute associations we characterize as: (1) acid (acidity, sulfate, and nitrate), (2) soil (calcium, magnesium, and potassium), and (3) salt (sodium, chloride, and ammonium). Concentrations of acid solutes in the snowpack are similar to concentrations in nearby wetfall collectors, whereas, concentrations of soil solutes are much higher in the snowpack than in wetfall. Thus, dryfall of acid solutes during the snow season is negligible, as is gypsum from soils. Snowpack sampling offers a cost-effective complement to sampling of wetfall in areas where wetfall is difficult to sample and where the snowpack accumulates throughout the winter. Copyright ?? 2001 .

  5. Major ion toxicity of six produced waters to three freshwater species: Application of ion toxicity models and TIE procedures

    SciTech Connect

    Tietge, J.E.; Hockett, J.R. [ENSR Consulting and Engineering, Fort Collins, CO (United States); Evans, J.M. [Gas Research Inst., Chicago, IL (United States)

    1997-10-01

    Previous research to characterize the acute toxicity of major ions to freshwater organisms resulted in the development of statistical toxicity models for three freshwater species (Ceriodaphnia dubia, Pimephales promelas, and Daphnia magna). These ion toxicity models estimate the toxicity of seven major ions utilizing logistic regression. In this study, the ion toxicity models were used in conjunction with Phase 1 toxicity identification evaluation (TIE) procedures to evaluate the contribution of major ion toxicity to the total toxicity of six produced water samples ranging in total salinity from 1.7 to 58.1 g/L. Initial toxicities of all six samples were compared to the model predictions. Four produced waters were found to have toxicity consistent with toxicity attributable to major ion concentrations only. Two produced waters were found to exhibit more toxicity than expected from ion concentrations alone. These samples were subjected to Phase 1 TIE procedures. Toxicities were reduced by specific Phase 1 TIE manipulations to those predicted by the ion toxicity models. Mock effluents were used to verify the results. The combination of the ion toxicity models with Phase 1 TIE procedures successfully quantified the toxicity due to major ions in six produced water samples.

  6. Influence of extraction methodologies on the analysis of five major volatile aromatic compounds of citronella grass (Cymbopogon nardus) and lemongrass (Cymbopogon citratus) grown in Thailand

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infusions of citronella grass (Cymbopogon nardus) and lemongrass (Cymbopogon citratus) have been commonly used in folk medicine in Thailand and other Asian countries. This study focuses on a systematic comparison of two extraction methods for major volatile aromatic compounds (VACs) of citronella g...

  7. Major ion concentrations and the inorganic carbon chemistry of the Humber rivers

    Microsoft Academic Search

    Helen P. Jarvie; Colin Neal; David V. Leach; Geoffery P. Ryland; W. Alan House; Alice J. Robson

    1997-01-01

    Measurements of major ion concentrations in the main rivers draining into the Humber estuary show two dominant spatial patterns, related to anthropogenic sources from catchments draining urban\\/industrial areas and background weathering sources from the rural catchments. Most major ions exhibit dilution effects with flow, with higher concentrations at baseflow compared with stormflow conditions. This suggests a predominance of point (effluent)

  8. The major-ion composition of Carboniferous seawater

    NASA Astrophysics Data System (ADS)

    Holt, Nora M.; García-Veigas, Javier; Lowenstein, Tim K.; Giles, Peter S.; Williams-Stroud, Sherilyn

    2014-06-01

    The major-ion chemistry (Na+, Mg2+, Ca2+, K+, SO42-, and Cl-) of Carboniferous seawater was determined from chemical analyses of fluid inclusions in marine halites, using the cryo scanning electron microscopy (Cryo-SEM) X-ray energy-dispersive spectrometry (EDS) technique. Fluid inclusions in halite from the Mississippian Windsor and Mabou Groups, Shubenacadie Basin, Nova Scotia, Canada (Asbian and Pendleian Substages, 335.5-330 Ma), and from the Pennsylvanian Paradox Formation, Utah, USA, (Desmoinesian Stage 309-305 Ma) contain Na+-Mg2+-K+-Ca2+-Cl- brines, with no measurable SO42-, which shows that the Carboniferous ocean was a “CaCl2 sea”, relatively enriched in Ca2+ and low in SO42- with equivalents Ca2+ > SO42- + HCO3-. ?34S values from anhydrite in the Mississippian Shubenacadie Basin (13.2-14.0 ‰) and the Pennsylvanian Paradox Formation (11.2-12.6 ‰) support seawater sources. Br in halite from the Shubenacadie Basin (53-111 ppm) and the Paradox Basin (68-147 ppm) also indicate seawater parentages. Carboniferous seawater, modeled from fluid inclusions, contained ?22 mmol Ca2+/kg H2O (Mississippian) and ?24 mmol Ca2+/kg H2O (Pennsylvanian). Estimated sulfate concentrations are ?14 mmol SO42-/kg H2O (Mississippian), and ?12 mmol SO42-/kg H2O (Pennsylvanian). Calculated Mg2+/Ca2+ ratios are 2.5 (Mississippian) and 2.3 (Pennsylvanian), with an estimated range of 2.0-3.2. The fluid inclusion record of seawater chemistry shows a long period of CaCl2 seas in the Paleozoic, from the Early Cambrian through the Carboniferous, when seawater was enriched in Ca2+ and relatively depleted in SO42-. During this ?200 Myr interval, Ca2+ decreased and SO42- increased, but did not cross the Ca2+-SO42- chemical divide to become a MgSO4 sea (when SO42- in seawater became greater than Ca2+) until the latest Pennsylvanian or earliest Permian (?309-295 Ma). Seawater remained a MgSO4 sea during the Permian and Triassic, for ?100 Myr. Fluid inclusions also record a long interval, from the Early Cambrian to the Middle Devonian, when seawater had low Mg2+/Ca2+ ratios (<2) that coincide with calcite seas. The Mg2+/Ca2+ ratio of seawater rose from 0.9 in the Middle Devonian, to 2.5 in the Middle/Late Mississippian, 2.3 in the Middle Pennsylvanian, and 3.5 in the Early Permian. The transition from calcite seas to aragonite seas, established from the mineralogy of oölites and early marine cements, occurred in the Late Mississippian. Fluid inclusions show that seawater Mg2+/Ca2+ ratios rose above 2 by the Middle to Late Mississippian coinciding exactly with the shift to aragonite seas. Aragonite seas existed for ?100 Myr, from the Late Mississippian until the Late Triassic/Early Jurassic.

  9. Major Ion Chemistry of Shark River Slough, Everglades National Park

    NASA Astrophysics Data System (ADS)

    Neira, N. M.; Matthews, F. A.; Lagomasino, D.; Price, R. M.

    2010-12-01

    Shark River Slough (SRS) is the dominant surface water flow way in Everglades National Park and its water chemistry is currently being monitored at 6 sites as part of the Florida Coastal Everglades-Long Term Ecological Research program. In order to determine the sources of water, the interactions between the sources of water as well as to calculate residence times of different water source reservoirs and evaporative enrichment, surface water samples were analyzed for major anion and cation concentrations (i.e., Cl, SO2, Ca, K, Mg, and Na). Surface water samples were collected at each site using an ISCO 6172 autosampler, that was programmed to collect a 250-ml sample every 18 h and to composite four such samples into the same 1-liter bottle. Thus, each 1 liter sample represented a 3-day composite. Autosamplers were serviced monthly, and the collected 1 liter of water was split in the laboratory, with one half analyzed for major cations and anions at FIUs hydrogeology laboratory and the other analyzed for total nutrient concentrations at SERCs Nutrient Laboratory. Prior to being analyzed for major cations and anions, the sample was filtered and split again with one half acidified with 10% HCl for the cations analysis. This poster presents the results of the major cations and anions data collected in 2008 and 2009. Chloride and sulfate concentrations in the surface water of SRS tended to be lower and more variable at the most upstream freshwater site as compared to the downstream freshwater sites. The higher variability of the anion concentrations at the most upstream SRS site may be due to its proximity to the water discharge gates along Tamiami Trail that deliver water from the upstream water conservation areas into SRS. The higher concentration and less variability in chloride and sulfate concentrations at the more downstream freshwater sites may be related to greater exposure of the surface water to evaporation.

  10. ANALYSIS OF AMBIENT POLAR VOLATILE ORGANIC COMPOUNDS USING CHEMICAL IONIZATION -- ION TRAP DETECTOR

    EPA Science Inventory

    The current approach to measuring trace levels of volatile organic compounds (VOCs) in ambient air requires cryogenic trapping of the analytes, followed by thermal desorption and low-temperature refocussing onto a column for analysis by capillary gas chromatography/mass spectrome...

  11. On-site Rapid Detection of Trace Non-volatile Inorganic Explosives by Stand-alone Ion Mobility Spectrometry via Acid-enhanced Evaporization

    PubMed Central

    Peng, Liying; Hua, Lei; Wang, Weiguo; Zhou, Qinghua; Li, Haiyang

    2014-01-01

    New techniques for the field detection of inorganic improvised explosive devices (IEDs) are urgently developed. Although ion mobility spectrometry (IMS) has been proved to be the most effective method for screening organic explosives, it still faces a major challenge to detect inorganic explosives owing to their low volatilities. Herein, we proposed a strategy for detecting trace inorganic explosives by thermal desorption ion mobility spectrometry (TD-IMS) with sample-to-sample analysis time less than 5?s based on in-situ acidification on the sampling swabs. The responses for typical oxidizers in inorganic explosives, such as KNO3, KClO3 and KClO4 were at least enhanced by a factor of 3000 and their limits of detection were found to be subnanogram. The common organic explosives and their mixtures with inorganic oxidizers were detected, indicating that the acidification process did not affect the detection of organic explosives. Moreover, the typical inorganic explosives such as black powders, firecrackers and match head could be sensitively detected as well. These results demonstrated that this method could be easily employed in the current deployed IMS for on-site sensitive detection of either inorganic explosives or organic ones. PMID:25318960

  12. Microbial Volatilization of Arsenic

    Microsoft Academic Search

    Prince Amoako; Danny Aylwin; Sean O'Connor

    Arsenic is a dangerous toxin and can be volatilized by many organisms, of which bacteria is a major source. We evaluated whether three common bacteria can volatilize immobile arsenic as well as evaluated a method used for measuring volatile arsenic in fungi can be used for bacteria. Bacillus cereus, Staphlococcus aureus, and Psuedomonas aeruginosa were incubated in media containing 10ppm,

  13. Product ion distributions for the reactions of NO+ with some physiologically significant volatile organosulfur and organoselenium compounds obtained using a selective reagent ionization time-of-flight mass spectrometer

    PubMed Central

    Mochalski, Pawe?; Unterkofler, Karl; Špan?l, Patrik; Smith, David; Amann, Anton

    2014-01-01

    RATIONALE The reactions of NO+ with volatile organic compounds (VOCs) in Selective Reagent Ionization Time-of-Flight Mass Spectrometry (SRI-TOF-MS) reactors are relatively poorly known, inhibiting their use for trace gas analysis. The rationale for this product ion distribution study was to identify the major product ions of the reactions of NO+ ions with 13 organosulfur compounds and 2 organoselenium compounds in an SRI-TOF-MS instrument and thus to prepare the way for their analysis in exhaled breath, in skin emanations and in the headspace of urine, blood and cell and bacterial cultures. METHODS Product ion distributions have been investigated by a SRI-TOF-MS instrument at an E/N in the drift tube reactor of 130 Td for both dry air and humid air (4.9% absolute humidity) used as the matrix gas. The investigated species were five monosulfides (dimethyl sulfide, ethyl methyl sulfide, methyl propyl sulfide, allyl methyl sulfide and methyl 5-methyl-2-furyl sulfide), dimethyl disulfide, dimethyl trisulfide, thiophene, 2-methylthiophene, 3-methylthiophene, methanethiol, allyl isothiocyanate, dimethyl sulfoxide, and two selenium compounds – dimethyl selenide and dimethyl diselenide. RESULTS Charge transfer was seen to be the dominant reaction mechanism in all reactions under study forming the M+ cations. For methanethiol and allyl isothiocyanate significant fractions were also observed of the stable adduct ions NO+M, formed by ion-molecule association, and [M–H]+ ions, formed by hydride ion transfer. Several other minor product channels are seen for most reactions indicating that the nascent excited intermediate (NOM)+* adduct ions partially fragment along other channels, most commonly by the elimination of neutral CH3, CH4 and/or C2H4 species that are probably bound to an NO molecule. Humidity had little effect on the product ion distributions. CONCLUSIONS The findings of this study are of particular importance for data interpretation in studies of volatile organosulfur and volatile organoselenium compounds employing SRI-TOF-MS in the NO+ mode. © 2014 The Authors. Rapid Communications in Mass Spectrometry published by John Wiley & Sons Ltd. PMID:24975248

  14. Ultrafiltration behavior of major ions (Na, Ca, Mg, F, Cl, and SO4) in natural waters.

    PubMed

    Guo, L; Hunt, B J; Santschi, P H

    2001-04-01

    Aquatic colloids, including macromolecules and microparticles, with sizes ranging between 1 nm to 1 micron, play important roles in the mobility and bioavailability of heavy metals and other contaminants in natural waters. Cross-flow ultrafiltration has become one of the most commonly used techniques for isolating aquatic colloids. However, the ultrafiltration behavior of chemical species remains poorly understood. We report here the permeation behavior of major ions (Na, Ca, Mg, F, Cl, and SO4) in natural waters during ultrafiltration using an Amicon 1 kDa ultrafiltration membrane (S10N1). Water samples across a salinity gradient of 0-20@1000 were collected from the Trinity River and Galveston Bay. The permeation behavior of major ions was well predicted by a permeation model, resulting in a constant permeation coefficient for each ion. The value of the model-derived permeation coefficient (Pc) was 0.99 for Na, 0.97 for Cl, and 0.95 for F, respectively, in Trinity River waters. Values of Pc close to 1 indicate that retention of Na, Cl, and F by the 1 kDa membrane during ultrafiltration was indeed minimal (< 1-5%). In contrast, significant (14-36%) retention was observed for SO4, Ca, and Mg in Trinity River waters, with a Pc value of 0.64, 0.82, and 0.86 for SO4, Ca and Mg, respectively. However, these retained major ions can further permeate through the 1 kDa membrane during diafiltration with ultrapure water. The selective retention of major ions during ultrafiltration may have important implications for the measurement of chemical and physical speciation of trace elements when using cross-flow ultrafiltration membranes to separate colloidal species from natural waters. Our results also demonstrate that the percent retention of major ions during ultrafiltration decreases with increasing salinity or ionic strength. This retention is largely attributed to electrostatic repulsion by the negatively charged cartridge membrane. PMID:11317897

  15. Impact of Heavy-Ion Strikes on Nanocrystal Non Volatile Memory Cell Arrays

    Microsoft Academic Search

    Andrea Cester; Alberto Gasperin; Nicola Wrachien; Alessandro Paccagnella; Valentina Ancarani; Cosimo Gerardi

    2006-01-01

    In this work we focused our attention on heavy ion irradiation effects on nanocrystal memory cell arrays. All cells are fabricated by depositing Si nanocrystal on top of a SiO2 layer. Immediately after irradiation we observed neither charge loss following the ion hit, nor appreciable change of the electrical characteristics of the nanocrystal MOSFETs, such as transconductance and drain current

  16. DATA QUALIFICATION REPORT: MAJOR ION AND PH DATA FOR USE ON THE YUCCA MOUNTAIN PROJECT

    SciTech Connect

    C. WILSON; D.M. JENKINS; T. STEINBORN; R. WEMHEUER

    2000-08-23

    This data qualification report uses technical assessment and corroborating data methods according to Attachment 2 of AP-SIII.2Q, Rev. 0, ICN 2, ''Qualification of Unqualified Data and the Documentation of Rationale for Accepted Data'', to qualify major ion and pH data. This report was prepared in accordance with Data Qualification Plan TDP-NBS-GS-00003 1, Revision 2. Additional reports will be prepared to address isotopic and precipitation-related data. Most of the data considered in this report were acquired and developed by the U.S. Geological Survey (USGS). The data qualification team considers the sampling and analytical protocols employed by the USGS over the time period of data acquisition to be state-of-the-art. The sample collection methodologies have evolved with no significant change that could affect the quality of the data considered in this report into the currently used Hydrologic Procedures that support the Yucca Mountain Project-approved USGS Quality Assurance Program Plan. Consequently, for USGS data, the data collection methods, documentation, and results are reasonable and appropriate in view of standard practice at the time the data were collected. A small number of data sets were collected by organizations other than the USGS and were reviewed along with the other major ion and pH data using corroborating data methods. Hydrochemical studies reviewed in this qualification report indicate that the extent and quality of corroborating data are sufficient to support qualification of both USGS and non-USGS major ion and pH data for generalized hydrochemical studies. The corroborating data included other major ion and pH data, isotope data, and independent hydrological data. Additionally, the analytical adequacy of the major ion data was supported by a study of anion-cation charge balances. Charge balance errors for USGS and non-USGS data were under 10% and acceptable for all data. This qualification report addresses the specific major ion data sets selected to support the hydrochemical studies in Analysis/Model Report (AMR) S0040 and pH data used in AMRs U0100 and U0085. Based on a preponderance of evidence, these data are recommended to be qualified for inclusion in technical products in support of the Site Recommendation for generalized uses as described in this report.

  17. ICRH of JET and LHD Majority Ions at Their Fundamental Cyclotron Frequency

    NASA Astrophysics Data System (ADS)

    Krasilnikov, A. V.; Van Eester, D.; Lerche, E.; Ongena, J.; Mailloux, J.; Stamp, M.; Jachmich, S.; Leggate, H.; Vdovin, V.; Walden, A.; Mayoral, M.-L.; Bonheure, G.; Santala, M.; Kiptily, V.; Popovichev, S.; Biewer, T.; Crombe, K.; Esposito, B.; Marocco, D.; Riva, M.; Kaschuck, Yu. A.; Amosov, V. N.; Ericsson, G.; Giacomelli, L.; Hellesen, C.; Hjalmarsson, A.; Kallne, J.; Isobe, M.; Nishiura, M.; Sasao, M.; Nishimura, H.; Saito, K.; Seki, T.; Mutoh, T.; Kumazawa, R.; Takeiri, Y.; Osakabe, M.; Goto, M.; Murakami, S.; Goncharov, P.

    2007-09-01

    Results of the experimental studies of ICRH at the fundamental cyclotron frequency of the majority deuterons in JET plasmas with near-tangential deuteron neutral beam injection (NBI) are presented. 1D, 2D and 3D ICRH modeling indicated that several ITER relevant mechanisms of heating may occur simultaneously in this heating scheme: fundamental ion cyclotron resonance heating of majority and beam D ions, impurity ion heating and electron heating due to Landau damping and TTMP. These mechanisms were studied in JET experiments with a ˜90% D, 5% H plasma including traces of Be and Ar. Up to 2MW of ICRH power was applied at 25 MHz to NBI heated plasmas. In most of the discharges the toroidal magnetic field strength was 3.3T, but in one it was equal to 3.6T. The E+ component of the electric field governs the ion cyclotron heating of not too fast particles. The Doppler shifted RF absorption of the beam deuterons away from the cold resonance at which E+ is small was exploited to enhance the RF power absorption efficiency. Fundamental ICRH experiments were also carried out in LHD hydrogen plasma with high energy hydrogen NBI. ICRH was performed at 38MHz with injected power <1 MW. The effect of fundamental ICRH was clearly demonstrated in both machines.

  18. Detection of Volatile Vapors Emitted from Explosives with a Hand-held Ion Mobility Spectrometer

    SciTech Connect

    Ewing, Robert Gordon; Miller, Carla Jean

    2001-11-01

    Vapor detection of plastic explosives is difficult because of the low vapor pressures of explosive components (i.e. RDX and PETN) present in the complex elastomeric matrix. To facilitate vapor detection of plastic explosives, detection agents (taggants) with higher vapor pressures can be added to bulk explosives during manufacture. This paper investigates the detection of two of these taggants, ethyleneglycol dinitrate (EGDN) and 2,3-dimethyl-2,3-dinitrobutane (DMNB), using a handheld ion mobility spectrometer. These two taggants were detected both from neat vapor sources as well as from bulk explosives (nitroglycerin (NG)-dynamite and C-4 tagged with DMNB). EGDN was detected from NG-dynamite as EGDN·NO3- at a reduced mobility value of 1.45 cm2 V-1 s-1 with detection limits estimated to be about 10 ppbv. DMNB was identified from tagged C-4 as both negative and positive ions with reduced mobility values of 1.33 cm2 V-1 s-1 for DMNB·NO2- and 1.44 cm2 V-1s-1 for DMNB·NH4+. Positive ions for cyclohexanone were also apparent in the spectra from tagged C-4 producing three additional peaks.

  19. Sources and cycling of major ions and nutrients in Devils Lake, North Dakota

    USGS Publications Warehouse

    Lent, R.M.

    1994-01-01

    Devils Lake is a saline lake in a large, closed drainage basin in northeastern North Dakota. Previous studies determined that major-ion and nutrient concentrations in Devils Lake are strongly affected by microbially mediated sulfate reduction and dissolution of sulfate and carbonate minerals in the bottom sediments. These studies documented substantial spatial variability in the magnitude of calculated benthic fluxes coincident with the horizontal salinity gradient in Devils Lake. The purpose of the present study is to evaluate seasonal variability in benthic-flux rates, and to understand the effect of these fluxes on the major- chemistries in Devils Lake between May and October 1991. During the study period, the water column was well mixed, and specific conductance, pH, and temperature did not vary with depth. Dissolved oxygen was enriched near the lake surface due to photosynthesis. Major-ion concentrations and nutrient concentrations did not vary with depth. Because the water-quality data were obtained during open-water periods, the vertical profiles reflect well-mixed conditions. However, the first and last profiles for the study period did document near-bottom maxima of major cations. Secchi-disk depth varied from 0.82 meter on May 7, 1991, to 2.13 meters on June 5, 1991. The mean Secchi-disk depth during the study period was 1.24 meters. Seasonal variations in Secchi-disk depths were attributed to variations in primary productivity and phytoplankton communities. Nutrient cycles in Devils Lake were evaluated using gross primary productivity rate data, sediment trap data, and major-ion and nutrient benthic-flux rate data. Gross primary productivity rate was smallest in May (0.076 gram of carbon per square meter per day) and largest in September (1.8 grams of carbon per square meter per day). Average gross primary productivity for the study period was 0.87 gram of carbon per square meter per day. Average gross primary productivity is consistent with historic data from Devils Lake and with data from other eutrophic lakes. The average flux of organic carbon for the study period was 12 grams per square meter per day. The calculated carbon to nitrogen to phosphorus ratio (317:25:1) is similar to the Redfield ratio (106:16:1); therefore, most organic matter probably is derived from lacustrine phytoplankton. Calculated benthic-flux rates indicated that bottom sediments are important sources of majorions and nutrients to Devils Lake. Only one of the cores collected during this study indicated a net sulfate flux from the lake into the sediments. Seasonal variations in major-ion and nutrient benthic fluxes generally were small. However, there were important differences between the calculated benthic fluxes for this study and the calculated benthic fluxes for 1990. Calculated benthic fluxes of bicarbonate, ammonia, and phosphorus for this study were smaller than calculated benthic fluxes for 1990. The large differences between fluxes for 1990 and 1991 were attributed to calm, stratified water-column conditions in 1990 and well-mixed water-column conditions in 1991. The role of benthic fluxes in the chemical mass balances in Devils Lake was evaluated by calculating response times for major ions and nutrients in Devils Lake. The calculated response times for major ions in Devils Lake ranged from 6.7 years for bicarbonate to 34 years for sulfur (as S04). The response times for major ions are significantly shorter than previous estimates that did not include benthic fluxes. In addition, the relatively short response times for nitrogen (4.2 years) and phosphorus (0.95 year) indicate that nutrients are recycled rapidly between bottom sediments and the lake. During the study period, benthic fluxes were the dominant source of major ions and nutrients to Devils Lake and greatly reduced the response times of all major ions and nutrients for Devils Lake. As a result, bottom-sediment processes appear to buffer major-ion and nutrient concent

  20. [Major ion chemistry of surface water in the Xilin River Basin and the possible controls].

    PubMed

    Tang, Xi-Wen; Wu, Jin-Kui

    2014-01-01

    Under the increasing pressure of water shortage and steppe degradation, information on the hydrological cycle in the steppe region in Inner Mongolia is urgently needed. Major ions are widely used to identify the hydrological processes in a river basin. Based on the analysis results of 239 river water samples collected in 13 sections along the Xilin River system during 2006 to 2008, combined with data from groundwater and precipitation samples collected in the same period and the meteorological and hydrological data in the Xilin River Basin, hydrochemical characteristics and the chemistry of major ions of the Xilin River water have been studied by means of Piper triangle plots and Gibbs diagrams. The results showed that: (1) the total dissolved solid (TDS) in river water mainly ranged between 136.7 mg x L(-1) and 376.5 mg x L(-1), and (2) it had an increasing trend along the river flow path. (3) The major cations and anions of river water were Ca2+ and HCO3-, respectively, and the chemical type of the river water varied from HCO3- -Ca2+ in the headwater area to HCO(3-)-Ca2+ Mg2+ in the lower part. (4) The variation in the concentration of major irons in surface water was not significant at the temporal scale. Usually, the concentration values of major irons were much higher in May than those in other months during the runoff season, while the values were a bit lower in 2007 than those in 2006 and 2008. Except for SO4(2-), the concentrations of other ions such as Ca2+, Na+, Mg2+, K+, Cl- and HCO3- showed a upward trend along the river flow path. Comparing major ion concentrations of the river water with those of local groundwater and precipitation, the concentration in river water was between those of precipitation and groundwater but was much closer to the concentration of groundwater. This indicated that the surface water was recharged by a mixture of precipitation and groundwater, and groundwater showed a larger impact. The Gibbs plot revealed that the chemical compositions of the river water were mainly affected by rock weathering in the drainage area. PMID:24720196

  1. Ion Channel-Forming Alamethicin Is a Potent Elicitor of Volatile Biosynthesis and Tendril Coiling. Cross Talk between Jasmonate and Salicylate Signaling in Lima Bean

    Microsoft Academic Search

    Jurgen Engelberth; Thomas Koch; Gode Schuler; Nadine Bachmann; Jana Rechtenbach; Wilhelm Boland

    2001-01-01

    Alamethicin (ALA), a voltage-gated, ion channel-forming peptide mixture from Trichoderma viride, is a potent elicitor of the biosynthesis of volatile compounds in lima bean (Phaseolus lunatus). Unlike elicitation with jasmonic acid or herbivore damage, the blend of substances emitted comprises only the two homoterpenes, 4,11-dimethylnona-1,3,7-triene and 4,8,12-trimethyltrideca-1,3,7,11-tetraene, and methyl salicylate. Inhibition of octadecanoid signaling by aristolochic acid and phenidone as

  2. Major Ion concentrations in the new NEEM ice core in Greenland

    NASA Astrophysics Data System (ADS)

    Wegner, A.; Azuma, K. G.; Hirabayashi, M.; Schmidt, K.; Hansson, M.; Twarloh, B.

    2012-12-01

    The drilling of the new deep ice core in NEEM (77.45°N 51.06°W) was terminated in 2010. Using a continuous flow analysis system (CFA), discrete samples were filled and analyzed for major ion concentrations (Na, K, Mg, Ca, Cl, SO_4 and NO_3) using Ion Chromatography (IC). The samples were measured at Alfred Wegener Institute for Polar and Marine Research (Germany) and National Institute of Polar Research (Japan). Here we present preliminary results of the major Ion concentrations. We found highest variations in concentrations of Calcium and Magnesium which are mainly originating from terrestrial sources with concentrations between 5-10 ppb and 4 ppb during the Holocene compared to 800 ppb and 80 ppb during the LGM. This is in line with measurements of particulate dust concentrations. Sulphate concentrations closely follow DO events and vary between 25 ppb during the Holocene and ~400 ppb during the LGM. Sodium concentrations vary between ~ 8 ppb during the Holocene and up to 100 ppb during the LGM. We discuss influences of changes in the source areas and atmospheric transport intensity on the different time scales.

  3. Quantitative analysis of volatile organic compounds using ion mobility spectra and cascade correlation neural networks

    NASA Technical Reports Server (NTRS)

    Harrington, Peter DEB.; Zheng, Peng

    1995-01-01

    Ion Mobility Spectrometry (IMS) is a powerful technique for trace organic analysis in the gas phase. Quantitative measurements are difficult, because IMS has a limited linear range. Factors that may affect the instrument response are pressure, temperature, and humidity. Nonlinear calibration methods, such as neural networks, may be ideally suited for IMS. Neural networks have the capability of modeling complex systems. Many neural networks suffer from long training times and overfitting. Cascade correlation neural networks train at very fast rates. They also build their own topology, that is a number of layers and number of units in each layer. By controlling the decay parameter in training neural networks, reproducible and general models may be obtained.

  4. Volatile budget of Eyjafjallajokull magmas

    NASA Astrophysics Data System (ADS)

    Sigurdsson, H.; Mandeville, C. W.

    2010-12-01

    Volatile elments played a critical role in the style of activity during the 2010 eruptions of the glacier-covered Eyjafjallajokull volcano in Iceland. The alkali basalt flank eruption at Fimmvorduhals was dominated by vigorous fire fountaining that produced dominantly spatter-fed aa lava flows. Production of fine ash during the subsequent summit eruption has been variously attributed to magma fragmentation, either due to water-ice-magma interaction related to the 250 m thick glacier cover over the crater, or juvenile volatile content of the magma. Considering the great impact of the ash dispersal on trans-North Atlantic aviation, knowledge of the fragmentation mechanism and the relative roles of juvenile magmatic gases versus phreatomagmatic fragmentation is of prime significance. To evaluate the potential importance of juvenile components, the concentrations of volatiles in magmas erupted in 2010 from Eyjafjallajokull volcano in Iceland have been measured. Analysis of glass inclusions in olivine Fo 77-85 and plagioclase phenocrysts in the alkali basalt magma erupted at Fimmvorduhals flank eruption contain high total volatiles in the range 0.96 - 2.12 wt.%, and sulfur 0.10 - 0.16 wt.%. These glass inclusions are comparable to major element bulk composition of Fimmvörduháls alkali basalt lavas. In contrast, tephra from the explosive summit crater eruption are trachy-andesitic. This magma contains a rather wide range of olivine and plagioclase phenocrysts of Fo48-79 and An 69-81, with both basaltic and andesitic glass inclusions. This diversity is also reflected in a much wider range of total volatile content from 0.1 - 2.88 wt.% and sulfur 0.1 - 0.24 wt.%. At the basic end, the glass inclusions are comparable to the Fimmvorduhals alkali basalt lava, but some have andesitic composition. The highest volatile content is observed in the andesitic glass inclusions in plagioclase An78. Further analysis of glass inclusions and matrix glass by FTIR and ion probe is in progress.

  5. Crustal Assimilation at Mid-Ocean Ridges Using Major and Trace Elements, Volatiles, Oxygen Isotopes and Petrologic Modeling

    NASA Astrophysics Data System (ADS)

    Wanless, Dorsey; Perfit, Michael; Ridley, W. Ian; Klein, Emily; Wallace, Paul; Valley, John; Grimes, Craig

    2010-05-01

    While the majority of eruptions at spreading centers produce lavas with relatively homogeneous mid-ocean ridge basalt (MORB) compositions, the formation of tholeiitic andesites and dacites at mid-ocean ridges (MOR) remains a petrologic enigma. Andesitic and dacitic lava flows have been observed and sampled at several different locations along the global MOR system; including propagating ridge tips at ridge-transform intersections on the Juan de Fuca Ridge and eastern Galápagos spreading center, and at the 9°N overlapping spreading center on the East Pacific Rise. Despite the formation of these lavas at different ridges, MOR dacites show remarkably similar major element trends, incompatible trace element enrichments, and isotopic signatures suggesting similar processes control their chemistry. Although most geochemical variability in MOR basalts is consistent with low-pressure fractional crystallization of various mantle-derived parental melts, our geochemical data from MOR dacitic glasses suggest that contamination from a seawater-altered component is important in their petrogenesis. MOR dacites are characterized by elevated U, Th, Zr, and Hf and relatively low Nb and Ta, and P. Al2O3 and K2O concentrations in the dacites are higher than expected from fractional crystallization alone. Very high Cl and H2O concentrations and relatively low oxygen isotope ratios (~5.6 vs. expected values ~6.9) in the fresh dacite glasses can be explained by magmatic contamination from a component of ocean crust altered by hydrothermal fluids. Crystallization of silicate phases and Fe-oxides causes an increase in delta18O in the residual magma but assimilation of material altered at high temperatures will result in the lower delta18O values. Additionally, petrologic modeling of MOR dacite compositions suggests that partial melting and assimilation are both integral to their petrogenesis. Extreme fractional crystallization of a MORB parent combined with partial melting and assimilation (AFC) of amphibole-bearing altered crust produces a hybrid magma with geochemical signatures consistent with MOR dacites. Most of the andesitic lavas are the result of mixing between evolved FeTi basalt and a highly evolved dacitic melt. Our data support the hypothesis that crustal assimilation is an important process in the formation of highly evolved MOR lavas and may be significant in the generation of evolved MORB in general. Additionally, these processes are likely to be more common in regions of episodic magma supply and enhanced magma-crust interaction, such as at the ends of ridge segments where MOR andesites and dacites erupt.

  6. Energy spectra of the major ion species in the ring current during geomagnetic storms

    NASA Technical Reports Server (NTRS)

    Kistler, L. M.; Ipavich, F. M.; Hamilton, D. C.; Gloeckler, G.; Wilken, B.

    1989-01-01

    Nearly equatorial storm time energy spectra of the four major magnetospheric ions, H(+), O(+), He(+), and He(2+), obtained for the August 1984-November 1985 period by the charge-energy-mass spectrometer aboard the AMPTE/CCE spacecraft during the main and early recovery phases of all geomagnetic storms with minimum Dst of less than -50 nT were examined. It was found that, in the dawn-to-noon sector, there was a dip in the a spectra of all ions at 5-20 keV/e, while in the noon-to-dusk sector, the proton phase space density dropped off sharply below 5 keV. These spectra were compared with those predicted by a model of ion drift and loss in the magnetosphere. It was found that the spectra are most consistent with a Volland-Stern electric field with gamma = 2 and with a rotation of the nominal dawn-to-dusk electric field eastward by 2 hrs local time.

  7. Mobilization of major inorganic ions during experimental diagenesis of characterized peats

    USGS Publications Warehouse

    Bailey, A.M.; Cohen, A.D.; Orem, W.H.; Blackson, J.H.

    2000-01-01

    Laboratory experiments were undertaken to study changes in concentrations of major inorganic ions during simulated burial of peats to about 1.5 km. Cladium, Rhizophora, and Cyrilla peats were first analyzed to determine cation distributions among fractions of the initial materials and minerals in residues from wet oxidation. Subsamples of the peats (80 g) were then subjected to increasing temperatures and pressures in steps of 5??C and 300 psi at 2-day intervals and produced solutions collected. After six steps, starting from 30??C and 300 psi, a final temperature of 60??C and a final pressure of 2100 psi were achieved. The system was then allowed to stand for an additional 2 weeks at 60??C and 2100 psi. Treatments resulted in highly altered organic solids resembling lignite and expelled solutions of systematically varying compositions. Solutions from each step were analyzed for Na+, Ca2+, Mg2+, total dissolved Si (Si(T)), Cl-, SO42-, and organic acids and anions (OAAs). Some data on total dissolved Al (Al(T)) were also collected. Mobilization of major ions from peats during these experiments is controlled by at least three processes: (1) loss of dissolved ions in original porewater expelled during compaction, (2) loss of adsorbed cations as adsorption sites are lost during modification of organic solids, and (3) increased dissolution of inorganic phases at later steps due to increased temperatures (Si(T)) and increased complexing by OAAs (Al(T)). In general, results provide insight into early post-burial inorganic changes occurring during maturation of terrestrial organic matter. (C) 2000 Elsevier Science B.V. All rights reserved.

  8. Statistical models to predict the toxicity of major ions to Ceriodaphnia dubia, Daphnia magna and Pimephales promelas (fathead minnows)

    Microsoft Academic Search

    David R. Mount; David D. Gulley; J. Russell Hockett; Tyler D. Garrison; James M. Evans

    1997-01-01

    Toxicity of fresh waters with high total dissolved solids has been shown to be dependent on the specific ionic composition of the water. To provide a predictive tool to assess toxicity attributable to major ions, the authors tested the toxicity of over 2,900 ion solutions using the daphnids, Ceriodaphnia dubia and Daphnia magna, and fathead minnows (Pimephales promelas). Multiple logistic

  9. Influence of extraction methodologies on the analysis of five major volatile aromatic compounds of citronella grass (Cymbopogon nardus) and lemongrass (Cymbopogon citratus) grown in Thailand.

    PubMed

    Chanthai, Saksit; Prachakoll, Sujitra; Ruangviriyachai, Chalerm; Luthria, Devanand L

    2012-01-01

    This paper deals with the systematic comparison of extraction of major volatile aromatic compounds (VACs) of citronella grass and lemongrass by classical microhydrodistillation (MHD), as well as modern accelerated solvent extraction (ASE). Sixteen VACs were identified by GC/MS. GC-flame ionization detection was used for the quantification of five VACs (citronellal, citronellol, geraniol, citral, and eugenol) to compare the extraction efficiency of the two different methods. Linear range, LOD, and LOQ were calculated for the five VACs. Intraday and interday precisions for the analysis of VACs were determined for each sample. The extraction recovery, as calculated by a spiking experiment with known standards of VACs, by ASE and MHD ranged from 64.9 to 91.2% and 74.3 to 95.2%, respectively. The extraction efficiency of the VACs was compared for three solvents of varying polarities (hexane, dichloromethane, and methanol), seven different temperatures (ranging from 40 to 160 degrees C, with a gradual increment of 20 degrees C), five time periods (from 1 to 10 min), and three cycles (1, 2, and 3 repeated extractions). Optimum extraction yields of VACs were obtained when extractions were carried out for 7 min with dichloromethane and two extraction cycles at 120 degrees C. The results showed that the ASE technique is more efficient than MHD, as it results in improved yields and significant reduction in extraction time with automated extraction capabilities. PMID:22816268

  10. Determination of the volatile fraction of Polygonum bistorta L. at different growing stages and evaluation of its antimicrobial activity against two major honeybee (Apis mellifera) pathogens.

    PubMed

    Cecotti, Roberto; Carpana, Emanuele; Falchero, Luca; Paoletti, Renato; Tava, Aldo

    2012-02-01

    The composition of the volatile fraction of Polygonum bistorta L. (also known as bistort or snakeroot) was investigated. Fresh aerial parts of this plant species were collected in the Western Italian Alps during the summer at three different phenological stages, namely vegetative, flowering, and fruiting, and steam-distilled in a Clevenger-type apparatus. The oils accounted for 0.004 to 0.010% of the fresh plant material, and their compositions were determined by GC/FID and GC/MS. The composition of the oils during the vegetative period varied both in quantity and quality; several classes of compounds were found with a predominance of alcohols in the vegetative phase, terpenes and linear-chained saturated hydrocarbons in the flowering phase, while saturated aliphatic acids and their methyl esters were predominant in fruiting phase. The most abundant compounds were 3-methylbut-3-en-1-ol in the vegetative phase, linalool in the flowering phase, and dodecanoic acid and its methyl ester in the fruiting phase. The obtained essential oils were then tested against two major bee pathogens, i.e., Paenibacillus larvae and Melissococcus plutonius, and against a reference bacterial species, Bacillus subtilis. Data were compared to those obtained with reference standards used against those pathogens such as the essential oils obtained from leaves and bark of Cinnamomum zeylanicum (cinnamon), and the antibiotic oxytetracyclin. PMID:22344911

  11. Solar Ion Processing of Major Element Surface Compositions of Mature Mare Soils: Insights from Combined XPS and Analytical TEM Observations

    NASA Technical Reports Server (NTRS)

    Christoffersen, R.; Dukes, C.; Keller, L. P.; Baragiola, R.

    2012-01-01

    Solar wind ions are capable of altering the sur-face chemistry of the lunar regolith by a number of mechanisms including preferential sputtering, radiation-enhanced diffusion and sputter erosion of space weathered surfaces containing pre-existing compositional profiles. We have previously reported in-situ ion irradiation experiments supported by X-ray photoelectron spectroscopy (XPS) and analytical TEM that show how solar ions potentially drive Fe and Ti reduction at the monolayer scale as well as the 10-100 nm depth scale in lunar soils [1]. Here we report experimental data on the effect of ion irradiation on the major element surface composition in a mature mare soil.

  12. Major ion chemistry and weathering processes in the Midyan Basin, northwestern Saudi Arabia.

    PubMed

    Ghrefat, Habes A; Batayneh, Awni; Zaman, Haider; Zumlot, Taisser; Elawadi, Eslam; Nazzal, Yousef

    2013-10-01

    Chemical characteristics of 72 groundwater samples collected from Midyan Basin have been studied to evaluate major ion chemistry together with the geochemical and weathering processes controlling the water composition. Water chemistry of the study area is mainly dominated by Na, Ca, SO4, and Cl. The molar ratios of (Ca?+?Mg)/total cations, (Na?+?K)/total cations, (Ca?+?Mg)/(Na?+?K), (Ca?+?Mg)/(HCO3?+?SO4), (Ca?+?Mg)/HCO3, and Na/Cl reveal that water chemistry of the Midyan Basin is controlled by evaporite dissolution (gypsum and/or anhydrite, and halite), silicate weathering, and minor contribution of carbonate weathering. The studied groundwater samples are largely undersaturated with respect to dolomite, gypsum, and anhydrite. These waters are capable of dissolving more of these minerals under suitable physicochemical conditions. PMID:23609922

  13. Detecting volatile compounds from Kraft lignin degradation in the headspace of microbial cultures by selected ion flow tube mass spectrometry (SIFT-MS).

    PubMed

    Gibson, Andrew; Malek, Lada; Dekker, Robert F H; Ross, Brian

    2015-05-01

    Selected Ion Flow Tube Mass Spectrometry (SIFT-MS) was used to quantify methanol and other volatile compounds in the headspace of one bacterial and 12 fungal lignin-degrading microbial cultures. Cultures were grown in 250mL Erlenmeyer flasks capped with aluminum foil containing 40mL of nutrient media using Kraft lignin (0.3% w/v) as the sole carbon source. Analysis was done using SIFT-MS with H3O(+) and NO(+) precursors. Product ions were identified with multiple ion mode (MIM). Full scan (FS) mode was used to identify other compounds of interest. Absidia cylindrospora, Ischnoderma resinosum and Pholiota aurivella increased headspace methanol concentration by 136ppb, 1196ppb and 278ppb, respectively, while Flammulina velutipes and Laetiporus sulphureus decreased concentration below ambient levels. F. velutipes and L. sulphureus were found to produce products of methanol oxidation (formaldehyde and formic acid) and were likely metabolizing methanol. Some additional unidentified compounds generated by the fungal cultures are intriguing and will require further study. SIFT-MS can be used to quantify methanol and other volatile compounds in the headspace of microbial cultures and has the potential to be a rapid, sensitive, non-invasive tool useful in elucidating the mechanisms of lignin degradative pathways. PMID:25771342

  14. Major Ion Chemistry and Mixing Proportions of Nitrate Sources in Urban Groundwater

    NASA Astrophysics Data System (ADS)

    Munster, J.; Hanson, G. N.; Bokuniewicz, H.

    2007-05-01

    Working with Dr. Gilbert Hanson has allowed me to apply general mixing equations to identification of nonpoint sources of groundwater contamination. These methods have not commonly been used in hydrologic studies, as they involve a more classical petrologic approach, one which Dr. Hanson has pioneered. Our drinking water supplies are becoming more susceptible to contamination and knowing the chemistry of contaminate sources will yield precise determination of potential sources to groundwater and allow government agencies to adopt policies to reduce or prevent contamination. The geochemistry of soil water from below fertilized turfgrass sites and of sewage from septic tank/cesspools was used to place constraints on the sources of nitrate in groundwater of an unconsolidated aquifer in Suffolk County, Long Island, New York, USA. Twenty four sewage samples were acquired from Suffolk County Public Works. Soil water samples, from suction lysimeters, were acquired monthly during 2003, totaling 70 samples. We found that soil water concentrations were elevated in Ca, Mg and SO4 relative to sewage and sewage had higher concentrations of Cl, N-NO3, PO4, Na and K. This difference in the major ion chemistry allows identification of the source signatures in groundwater. We then compared the source signatures to 28 groundwater wells on binary ion diagrams of SO4, Cl and N- NO3 and created a cation sorption model for Na, Ca, Mg and K, in order to model cation concentrations on binary ion diagrams. These diagrams allow estimates of the relative contributions of each source to each well. Groundwater wells plotted according to their major land use and show that wells of similar land use have similar geochemistry and similar source contributions. The estimates of source contributions show that the proportions of soil water and sewage increase as residential land use increases. Although volumetric source proportions to groundwater wells are similar for soil water and sewage within a given land use, sewage contributes a greater proportion to the nitrate concentration in groundwater wells. For example, sewage contributes between 86-100% of the nitrate in wells sourced in medium density residential land use, even when accounting for a 50% reduction in nitrate concentrations from the septic tank/cesspool system. Our results indicate that to decrease the nitrate concentrations in groundwater one must reduce the load from septic tank/cesspool systems.

  15. Volatile (sulphur and chlorine), major, and trace element geochemistry of mafic to intermediate tephras from the Chilean Southern Volcanic Zone (33-43°S)

    NASA Astrophysics Data System (ADS)

    Wehrmann, Heidi; Hoernle, Kaj; Jacques, Guillaume; Garbe-Schönberg, Dieter; Schumann, Kai; Mahlke, Julia; Lara, Luis E.

    2014-10-01

    Here we present the first systematic investigation of volatile geochemistry along the Southern Volcanic Zone (SVZ) of Chile. Holocene olivine-hosted melt inclusions in the most mafic tephras sampled from 16 volcanoes along the volcanic front of the SVZ between 33°S and 43°S were analysed for pre-eruptive sulphur, chlorine, and major element contents. These results are combined with trace element compositions of the host whole rocks. The highest fractionation-corrected gas contents occur in the least-degassed melt inclusions from small monogenetic cones of Los Hornitos, Cabeza de Vaca, and Apagado from both the transitional and the southern-central SVZ, reaching ~3,000 ?g/g S and 1,400 ?g/g Cl, while the lowest abundances of ~1,100 ?g/g S and ~600 ?g/g Cl were found in the central SVZ at Volcán Lonquimay, Volcán Llaima, and Volcán Villarrica. Chlorine co-varies with trace element indicators for the degree of melting and/or source enrichment, such that the lowest Cl contents are found in high-degree melts from the most depleted mantle sources. The size of the volcanic edifices correlates inversely with Cl abundances in the melt. This could reflect more extensive degassing during ascent through the complex magma plumbing systems beneath the stratovolcanoes or greater dilution during larger degrees of melting of more depleted sources, or a combination of these factors. Compared to other subduction zones, the SVZ melt inclusions exhibit Cl and S abundances in the same range as most of those from the Central American and those from the Marianas arcs.

  16. Evaluation of environmental factors affecting yields of major dissolved ions of streams in the United States

    USGS Publications Warehouse

    Peters, Norman E.

    1984-01-01

    The seven major dissolved ions in streams-sodium, potassium, magnesium, calcium, chloride, sulfate, and bicarbonate and their sum dissolved solids from 56 basins in the conterminous United States and Hawaii were correlated with bedrock type, annual precipitation, population density, and average stream temperature of their respective basins through multiple linear-regression equations to predict annual yields. The study was restricted to basins underlain by limestone, sandstone, or crystalline rock. Depending on the constituent, yields ranged from about 10 to 100,000 kilograms per square kilometer. Predicted yields were within 1 order of magnitude of measured yields. The most important factor in yield prediction was annual precipitation, which accounted for 58 to 71 percent of all yields. Rock type was second in importance. Yields of magnesium, calcium, bicarbonate, and dissolved solids from limestone basins were 4 to 10 times larger than those from sandstone or crystalline basins as a result of carbonate weathering. Population density was an ineffective indicator of all constituents except sodium and chloride; it accounted for 13 percent of the annual sodium yield and 20 percent of the annual chloride yield. Average stream temperature was significant only for calcium and bicarbonate in limestone basins. Its relationship with yields was consistently negative. Either carbonate dissolution increases at low temperatures, or weathering in northern basins, which contain glacial deposits and have the lowest stream temperatures, is greater than in southern basins. Average ion contributions from atmospheric deposition accounted for 30 percent of the sodium and chloride and 60 percent of the sulfate in annual yields. The amount of sulfate derived from atmospheric contributions was higher in sandstone and crystalline basins (65 and 80 percent, respectively) than limestone basins (38 percent). This disparity is attributed to the lack of available sulfate in crystalline rock and the chemical precipitation of sulfate in the sandstone basins, most of which are in semi-arid or arid areas.

  17. Seasonal changes in the major ion and ?13CDIC geochemistry of Arctic Alaskan rivers

    NASA Astrophysics Data System (ADS)

    Lehn, G. O.; Jacobson, A. D.; Douglas, T. A.; McClelland, J. W.; Khosh, M. S.; Barker, A.

    2010-12-01

    Model predications indicate anthropogenic greenhouse warming will be most severe at high latitudes where permafrost stores large quantities of organic carbon. Permafrost thaw could reintroduce this carbon into the carbon cycle and transform the Arctic into a source of CO2 and possibly, CH4. Thus, tracking the rate and extent of permafrost thaw bears on understanding feedbacks between Arctic climate change and global warming. Downward movement of the seasonally thawed “active” layer into previously frozen soils may yield unique mineral weathering signatures that relate to changes in carbon storage. We present two potential tracking methods, namely seasonal changes in dissolved major ion concentrations and the carbon isotope composition of dissolved inorganic carbon (?13CDIC). We also present a novel method for measuring carbonate alkalinity in organic-rich rivers. Water samples were collected from six watersheds on the North Slope of Alaska. All rivers drain continuous permafrost but three drain tussock tundra-dominated watersheds and three drain bare bedrock catchments with minor tundra influences. Water samples were collected from April until October in 2009 and 2010. In organic-rich rivers, carbonate alkalinity and alkalinity associated with dissolved organic matter may contribute to total alkalinity. Carbonate alkalinity is difficult to measure at the low pH conditions common in organic-rich rivers. Moreover, conventional methods for measuring alkalinity, such as Gran titration, tend to overestimate total alkalinity, presumably because organic matter absorbs more protons than its functional charge equivalent. Thus, we measured dissolved CO2 in-situ using a customized NDIR sensor, and we calculated carbonate alkalinity using carbonate equilibria equations. Initial results suggest this method accurately characterizes the carbonate geochemistry of organic-rich rivers. Major ion and ?13CDIC trends suggest that silicate weathering dominates during the spring melt while carbonate weathering dominates as the summer progresses and the active layer deepens. In tundra streams, early season ?13CDIC values indicate carbonic acid-silicate weathering. Late season ?13CDIC values indicate carbonic acid-carbonate weathering. In both cases, the microbial decomposition of C3 organic matter provides the dissolved CO2 that forms carbonic acid. Bedrock streams display high and nearly constant ?13CDIC values from spring melt to fall base flow. These streams also have high dissolved sulfate concentrations. The ?13CDIC values may originate from sulfuric acid-carbonate weathering, although isotopic equilibration with atmospheric CO2 could be important. The difference between the tundra versus bedrock streams isolates the geochemical signature of active layer weathering processes. Our study indicates how seasonal changes in mineral weathering can track deepening of the active layer.

  18. GC/MS-positive ion chemical ionization and MS/MS study of volatile benzene compounds in five different woods used in barrel making.

    PubMed

    Flamini, Riccardo; Dalla Vedova, Antonio; Cancian, Davide; Panighel, Annarita; De Rosso, Mirko

    2007-05-01

    Extracts from acacia, chestnut, cherry, mulberry, and oak wood, used in making barrels for aging wine and spirits were studied by GC/MS positive ion chemical ionization (PICI). Wood chips were extracted by a 50% water/ethanol solution and a tartrate buffer pH 3.2-12% ethanol (model wine) solution. The principal compounds identified in extracts were guaiacol-containing aldehydes and alcohols, such as benzaldehyde and derivatives, vanillin and syringaldehyde, cinnamaldehyde and coniferaldehyde, eugenol and methoxyeugenol, guaiacol and methoxyguaiacol derivatives. PICI using methane as reagent gas produced a high yield of the protonated molecular ion of volatile phenols, compound identification was confirmed by collision-induced-dissociation (CID) experiments on [M + H](+) species. MS/MS fragmentation patterns were studied with standard compounds: guaiacol-containing molecules were characterized by neutral methyl and methanol losses, benzaldehyde derivatives by CO loss. Acacia wood extracts contained significant syringaldehyde and anisaldehyde, but no eugenol and methoxyeugenol. Significant syringaldehyde, eugenol and methoxyeugenol, and high vanillin were found in chestnut and oak wood extracts; low presence of volatile benzene compounds was found in mulberry wood extracts. Cherry wood extracts were characterized by the presence of several benzaldehyde derivatives and high trimethoxyphenol. PMID:17370248

  19. Wet precipitation of major ions, polonium-210, and organic carbon in a metropolitan city, Seoul, Korea

    NASA Astrophysics Data System (ADS)

    Yan, G.; Kim, G.

    2011-12-01

    An extensive survey of chemical constituents in precipitation including dissolved organic carbon, dissolved nitrogen, major ions, trace elements, and radionuclides was conducted in a representative urban environment of Seoul over one-year period from 2009 to 2010. The sources for these chemical species were apportioned by applying principal component analysis (PCA) in association with commonly acknowledged key tracers, such as Na, K, Ca, and V. The fossil fuel combustion (especially coal) was shown to be the dominant source for most constituents being investigated, with biomass burning being recognized as another significant source. With the aid of air mass backward trajectory analyses, we concluded that the primary fraction of the chemical species in our precipitation samples originated locally in Korea, albeit the frequent long-range transport from the eastern and northeastern China might contribute substantially. Overall, our study suggests the significant role of human activities in altering the atmospheric environment of Seoul and presumably most urban areas around the world, highlighting its profound environmental implications, such as health risks posed by excessive polonium-210, enhanced rainwater acidity from organic acids, and radiative forcing by organic aerosols.

  20. STUDY ABROADFOR InteRnatIOnal RelatIOns & GlObal studIes MaJORs study abroad

    E-print Network

    Johnston, Daniel

    STUDY ABROADFOR InteRnatIOnal RelatIOns & GlObal studIes MaJORs study abroad #12;WHY YOU SHOULD STUDY ABROAD 2 STUDY ABROAD FOR InTeRnATIOnAl RelATIOnS & GlOBAl STUDIeS MAJORS Study abroad programs Consider the real cost of studying abroad: the difference between a semester in Austin and a semester

  1. Major ion chemistry of the Ganga-Brahmaputra river system: Weathering processes and fluxes to the Bay of Bengal

    Microsoft Academic Search

    M. M. Sarin; S. Krishnaswami; K. Dilli; B. L. K. Somayajulu; W. S. Moore

    1989-01-01

    The Ganga-Brahmaputra, one of the world's largest river systems, is first in terms of sediment transport and fourth in terms of water discharge. A detailed and systematic study of the major ion chemistry of these rivers and their tributaries, as well as the clay mineral composition of the bed sediments has been conducted. The chemistry of the highland rivers (upper

  2. Separation of penicillin and its major degradation products by ion-pair reversed-phase high-pressure liquid chromatography.

    PubMed

    Ghebre-Sellassie, I; Hem, S L; Knevel, A M

    1982-03-01

    An ion-pair reversed-phase high-pressure liquid chromatographic technique capable of separating penicillin and its major degradation products within 8 min was developed. The influence of pH, counterion concentration, buffer concentration, and organic modifier content was studied and the observed behavior of the compounds during the chromatographic process was discussed. PMID:6279818

  3. The general description of major ion concentrations in groundwater of Latvia

    NASA Astrophysics Data System (ADS)

    Kalv?ns, A.; Delina, A.

    2012-04-01

    Latvia is situated at the North central part of the Baltic sedimentary basin where the crystalline basement is found in depth between 0.6 to 2 km. Three large aquifer complexes with distinct chemical composition of groundwater are identified: the stagnant water exchange zone where Na-Ca-Cl brine is found; the slow water exchange zone where Na-Ca-Cl-SO4 brackish water is found and active water exchange zone where the freshwater resides. These are separated by distinct regional aquicludes. The composition of the Cl- dominated brines at the base of sedimentary basin is characterised by shift from Na+ towards Ca++ as dominant cation, partially associated with depth of the aquifer and the strength of the brine. The concentration of SO4-- here is inversely linked to the concentration of Ca++ and, according to geochemical modelling, often is close to the solubility limit of the gypsum. The major ion concentrations in the E and W part of the territory are rather different. Therefore two different initial sources of the formation brine were suggested. Alternatively the observations can be explained by different thermal histories of different parts of the basin, affecting the rate of albitization - exchange of the Na for Ca in the solution due to water-rock interaction. The groundwater composition in the slow exchange zone can be nicely explained by the mixing of freshwater and brine residing deeper in the presence of gypsum during some but no all stages of mixing. In some shallow parts of the zone still bound by the Narva regional aquiclude freshwater is found. The question is posted - could this be a paleogroundwater originating from the extensive continental glaciations that override the territory several times during the Pleistocene? Initial isotope studies presented elsewhere seems to give negative answer to this question. The active water exchange zone is characterised by fresh Ca-Mg-HCO3 water with exceptions in cases where gypsum are abundant in sedimentary rocks and sulphate ion prevails. The freshwater composition seems to be mostly controlled by three minerals - calcite, dolomite and gypsum. It is suggested that clay minerals can play a significant role in controlling the relative concentrations of cations, but this is not strictly proven jet. Well documented modern seawater intrusion induced by water abstraction is found in the territory of Liep?ja city. The upwelling of slat water from below can be spotted across the territory as well. These zones are usually associated with tectonic faults, enabling the upwelling of salty water across regional aquicludes. Particularly prominent is the saltwater body in the vicinity of the Riga city. Three major rives are discharging in the sea there making it a natural confluence zone of groundwater as well. The intensive groundwater abstraction in the city probably enhanced the upwelling of saltwater here, but primary it is a natural phenomenon. The interesting question is if there is any paleogroundwater trapped in the active or slow water exchange zone of the sedimentary basin that could be distinguished from modern infiltration water due to particular isotope signal originating in the quaternary cold stages or chemical composition - remains of relict sea water or sedimentation water. This study is supported by the ESF project No. 2009/0212/1DP/1.1.1.2.0/09/APIA/VIAA/060.

  4. DIRECT TRACE ANALYSIS OF VOLATILE ORGANIC COMPOUNDS IN AIR USING ION TRAP MASS SPECTROMETERS WITH FILTERED NOISE FIELDS

    EPA Science Inventory

    Two ion trap mass spectrometers and direct air sampling interfaces are being evaluated in the laboratory for monitoring toxic air pollutants in real time. he mass spectrometers are the large, laboratory-based Finnigan MAT ion trap (ITMS) and the compact, field-deployable Teledyne...

  5. Resection is a major repair pathway of heavy ion-induced DNA lesions

    NASA Astrophysics Data System (ADS)

    Durante, Marco; Averbeck, Nicole; Taucher-Scholz, Gisela

    Space radiation include densely ionizing heavy ions, which can produce clustered DNA damage with high frequency in human cells. Repair of these complex lesions is generally assumed to be more difficult than for simple double-strand breaks. We show here that human cells use break resection with increasing frequency after exposure to heavy ions. Resection can lead to misrepair of the DNA lesion, via microhomology mediated end-joining. Resection can therefore be responsible for the increased effectiveness of heavy ions in the induction of mutations and genetic late effects.

  6. Effect of major ions on the toxicity of copper to Hyalella azteca and implications for the biotic ligand model

    Microsoft Academic Search

    Uwe Borgmann; Monica Nowierski; D. George Dixon

    2005-01-01

    The effect of major ions (Ca, Mg, Na, and K) and pH on Cu toxicity (LC50) to Hyalella azteca was determined in 1 week exposures. The simplest equation for describing Cu toxicity is a linear relationship between the total dissolved Cu LC50 and Ca and Na in water, ignoring pH. This equation would be useful in tier one of a

  7. Assessing the influence of watershed land use patterns on the major ion chemistry of river waters in the Shimousa Upland, Japan

    Microsoft Academic Search

    Masumi Yamamuro

    2008-01-01

    To assess the influence of land use pattern on the major ion chemistry of river water, seasonal changes in major ion concentrations were studied in the Shimousa Upland, Japan where urbanisation is still in progress. Water samples were collected from 24 sites from the Ohori River basin and analysed four times representing four seasons from August 2006 to April 2007

  8. Statistical models to predict the toxicity of major ions to Ceriodaphnia dubia, Daphnia magna and Pimephales promelas (fathead minnows)

    SciTech Connect

    Mount, D.R. [Environmental Protection Agency, Duluth, MN (United States); Gulley, D.D. [Univ. of Wyoming, Laramie, WY (United States); Hockett, J.R.; Garrison, T.D. [ENSR Consulting and Engineering, Fort Collins, CO (United States); Evans, J.M. [Gas Research Inst., Chicago, IL (United States)

    1997-10-01

    Toxicity of fresh waters with high total dissolved solids has been shown to be dependent on the specific ionic composition of the water. To provide a predictive tool to assess toxicity attributable to major ions, the authors tested the toxicity of over 2,900 ion solutions using the daphnids, Ceriodaphnia dubia and Daphnia magna, and fathead minnows (Pimephales promelas). Multiple logistic regression was used to relate ion composition to survival for each of the three test species. In general, relative ion toxicity was K{sup +} > HCO{sub 3}{sup {minus}} {approx} Mg{sup 2+} > Cl{sup {minus}} > SO{sub 4}{sup 2{minus}}; Na{sup +} and Ca{sup 2+} were not significant variables in the regressions, suggesting that the toxicity of Na{sup +} and Ca{sup 2+} salts was primarily attributable to the corresponding anion. For C. dubia and D. magna, toxicity of Cl{sup {minus}}, SO{sub 4}{sup 2{minus}}, and K{sup +} was reduced in solutions enriched with more than one cation. Final regression models showed a good quality of fit to the data (R{sup 2} = 0.767--0.861). Preliminary applications of these models to field-collected samples indicated a high degree of accuracy for the C. dubia model, while the D. magna and fathead minnow models tended to overpredict ion toxicity. Studies of oil and gas produced waters, irrigation drain waters, shale oil leachates, sediment pore waters, and industrial process waters have shown toxicity caused by elevated concentrations of common ions.

  9. Development of an IMS Type System for Volatile Organic Compunds Detection: Simulation and Comparision of the Ion Distributions

    E-print Network

    Ortiz, Guillermo P; Boggio, Norberto G; Vorobioff, Juan; Ortiz, Juan J; Gómez, Sergio; Aucar, Gustavo A; Lamagna, Alberto; Boselli, Alfredo

    2009-01-01

    Ion Mobility Spectrometry (IMS) is a well-known, sensitive and rapid technique to detect dangerous organic compounds. We propose a system in which a crown type discharge generates a ionic flow that is swept towards an array of collectors by a transverse electric field. The ions are separated as they enter the cell according to their mobility. Thus, the distribution of the charge deposited at the detector assembly constitutes a {\\em fingerprint} for each organic compound. Simulations of our cell and experiments were performed for small amounts of acetone, ethanol and toluene. The dependence on the cell parameters of the current and charge versus time of flight was analyzed. Our simulation reproduces only qualitatively the experimental results. However, a PCA statistical analysis of the results obtained by simulation of the proposed design shows that the fingerprint is useful for a clear identification of such compounds.

  10. Electron impact and chemical ionization mass spectral analysis of a volatile uranyl derivative

    SciTech Connect

    Reutter, D.J.; Hardy, D.R.

    1981-01-01

    Quadrupole mass spectral analysis of the volatile uranium ligand complex bis (1,1,1,5,5,5-hexafluoro-2,4-pentanedionato) dioxouranium-di-n-butyl sulfoxide is described utilizing electron impact (EI) and methane chemical ionization (CI) ion sources. All major ions are tentatively identified and the potential usefulness of this complex for determining uranium isotope /sup 235/U//sup 238/U abundance is demonstrated.

  11. Major ion chemistry and hydrochemical studies of groundwater of Bangalore South Taluk, India.

    PubMed

    Ravikumar, P; Venkatesharaju, K; Somashekar, R K

    2010-04-01

    Groundwater is almost globally important for human consumption as well as for the support of habitat and for maintaining the quality of base flow to rivers, while its quality assessment is essential to ensure sustainable safe use of the resources for drinking, agricultural, and industrial purposes. In the current study, 28 groundwater samples were collected around Vrishabhavathi valley region of Bangalore South Taluk to assess water quality and investigate hydrochemical nature by analyzing the major cations (Ca(2+), Mg(2+), Na(+), K(+)) and anions,(HCO(3)(-) Cl( - ), F( - ), SO(4)(2-), NO(3)(-), PO(4)(3),CO(3)(2-)) besides some physical and chemical parameters (pH, electrical conductivity, alkalinity, and total hardness). Also, geographic information system-based groundwater quality mapping in the form of visually communicating contour maps was developed to delineate spatial variation in physico-chemical characteristics of groundwater samples. Piper trilinear diagram was constructed to identify groundwater groups (hydrochemical facies) using major anionic and cationic concentration and it was found that majority of the samples belongs to Ca(2+)-Mg(2+)-Cl(-)-SO(4)(2+) and Ca(2+)-Mg(2+)-HCO(3)(-) hydrochemical facies. Wilcox classification and US Salinity Laboratory hazard diagram suggests that 92.86% of the samples were falling under good to permissible category and C3-S1 groups, respectively, indicating high salinity/low sodium. PMID:19415520

  12. One-year observations of size distribution characteristics of major aerosol constituents at a coastal receptor site in Hong Kong - Part 1: Inorganic ions and oxalate

    NASA Astrophysics Data System (ADS)

    Bian, Q.; Huang, X. H. H.; Yu, J. Z.

    2014-01-01

    Size distribution data of major aerosol constituents are essential in source apportioning of visibility degradation, testing and verification of air quality models incorporating aerosols. We report here one-year observations of mass size distributions of major inorganic ions (sulfate, nitrate, chloride, ammonium, sodium, potassium, magnesium and calcium) and oxalate at a coastal suburban receptor site in Hong Kong, China. A total of 43 sets of size segregated samples in the size range of 0.056-18 ?m were collected from March 2011 to February 2012. The size distributions of sulfate, ammonium, potassium and oxalate were characterized by a dominant droplet mode with a mass mean aerodynamic diameter (MMAD) in the range of ~0.7-0.9 ?m. Oxalate had a slightly larger MMAD than sulfate on days with temperatures above 22 °C as a result of the process of volatilization and repartitioning. Nitrate was mostly dominated by the coarse mode but enhanced presence in fine mode was detected on winter days with lower temperature and lower concentrations of sea salt and soil particles. This data set reveals an inversely proportional relationship between the fraction of nitrate in the fine mode and product of the sum of sodium and calcium in equivalent concentrations and the dissociation constant of ammonium nitrate (i.e., (1/[Na+] + 2[Ca2+]) × (1/Ke')). The seasonal variation observed for sea salt aerosol abundance, with lower values in summer and winter, is possibly linked with the lower marine salinities in these two seasons. Positive matrix factorization was applied to estimate the relative contributions of local formation and transport to the observed ambient sulfate level through the use of the combined datasets of size-segregated sulfate and select gaseous air pollutants. On average, the regional/super-regional transport of air pollutants was the dominant source at this receptor site, especially on high sulfate days, while local formation processes contributed approximately 30% of the total sulfate. This work provides field measurement-based evidence for importance of understanding both local photochemistry and regional/super-regional transport in order to properly simulate sulfate aerosols in air quality models.

  13. One-year observations of size distribution characteristics of major aerosol constituents at a coastal receptor site in Hong Kong - Part 1: Inorganic ions and oxalate

    NASA Astrophysics Data System (ADS)

    Bian, Q.; Huang, X. H. H.; Yu, J. Z.

    2014-09-01

    Size distribution data of major aerosol constituents are essential in source apportioning of visibility degradation, testing and verification of air quality models incorporating aerosols. We report here 1-year observations of mass size distributions of major inorganic ions (sulfate, nitrate, chloride, ammonium, sodium, potassium, magnesium and calcium) and oxalate at a coastal suburban receptor site in Hong Kong, China. A total of 43 sets of size-segregated samples in the size range of 0.056-18 ?m were collected from March 2011 to February 2012. The size distributions of sulfate, ammonium, potassium and oxalate were characterized by a dominant droplet mode with a mass mean aerodynamic diameter (MMAD) in the range of ~ 0.7-0.9 ?m. Oxalate had a slightly larger MMAD than sulfate on days with temperatures above 22 °C as a result of the process of volatilization and repartitioning. Nitrate was mostly dominated by the coarse mode but enhanced presence in fine mode was detected on winter days with lower temperature and lower concentrations of sea salt and soil particles. This data set reveals an inversely proportional relationship between the fraction of nitrate in the fine mode and product of the sum of sodium and calcium in equivalent concentrations and the dissociation constant of ammonium nitrate (i.e., (1/([Na+] + 2[Ca2+]) × (1/Ke')) when Pn_fine is significant (> 10%). The seasonal variation observed for sea salt aerosol abundance, with lower values in summer and winter, is possibly linked with the lower marine salinities in these two seasons. Positive matrix factorization was applied to estimate the relative contributions of local formation and transport to the observed ambient sulfate level through the use of the combined data sets of size-segregated sulfate and select gaseous air pollutants. On average, the regional/super-regional transport of air pollutants was the dominant source at this receptor site, especially on high-sulfate days while local formation processes contributed approximately 30% of the total sulfate. This work provides field-measurement-based evidence important for understanding both local photochemistry and regional/super-regional transport in order to properly simulate sulfate aerosols in air quality models.

  14. Application of ?(18)O, ?(13)CDIC, and major ions to evaluate micropollutant sources in the Bay of Vidy, Lake Geneva.

    PubMed

    Halder, Janine; Pralong, Charles; Bonvin, Florence; Lambiel, Frederic; Vennemann, Torsten W

    2014-10-30

    Waters were sampled monthly from a profile at the wastewater outlet and a reference point in the Bay of Vidy (Lake Geneva) for a year. The samples were analyzed for (18)O/(16)O of water, (13)C/(12)C of dissolved inorganic carbon (DIC), major ions, and selected micropollutant concentrations. ?(18)O values, combined with the major ion concentrations, allowed discharged waste and storm-drainage water to be traced within the water column. On the basis of ?(18)O values, mole fractions of wastewater (up to 45?%), storm-drainage (up to 16?%), and interflowing Rhône River water (up to 34?%) could be determined. The results suggest that the stormwater fractions do not influence micropollutant concentrations in a measurable way. In contrast, the Rhône River interflow coincides with elevated concentrations of Rhône River-derived micropollutants in some profiles. ?(13)C values of DIC suggest that an increase in micropollutant concentrations at the sediment-water interface could be related to remineralization processes or resuspension. PMID:25358053

  15. A 20 Year Record of Major Ions in Aerosol and Rainwater from a Remote Location in the North Atlantic

    NASA Astrophysics Data System (ADS)

    Peters, A.

    2013-12-01

    High frequency ambient air sampling conducted near continuously for a period of 20 years from 1989 to 2009 at the second highest point of land on the island of Bermuda has provided a valuable record of major ion (H+, Na+, K+, Ca2+, Mg2+, SO42-, Cl-, and NO3-) chemistry in aerosol and rainwater representative of the marine atmospheric boundary layer over the North Atlantic Ocean. Over this period the acidity of rainwater has shown a significant decrease from a monthly volume weighted mean pH 4.4 to pH 5.5, and the monthly volume weighted mean concentration of non-sea-salt sulfate in rainfall also exhibited a significant decrease over the same time period, suggesting a decrease in anthropogenic sources of acidifying species in rainwater. The long term record of major ion constituents in rainwater and in aerosol are presented, and relationships between the chemical constituents and regional seasonal meteorology are analyzed and discussed.

  16. Wet deposition of major ions in a rural area impacted by biomass burning emissions

    NASA Astrophysics Data System (ADS)

    Coelho, Cidelmara H.; Allen, Andrew G.; Fornaro, Adalgiza; Orlando, Eduardo A.; Grigoletto, Tahuana L. B.; Campos, M. Lucia A. M.

    2011-09-01

    This work concerns the influence of industrialized agriculture in the tropics on precipitation chemistry. A total of 264 rain events were sampled using a wet-only collector in central São Paulo State, Brazil, between January 2003 and July 2007. Electroneutrality balance calculations (considering H +, K +, Na +, NH4+, Ca 2+, Mg 2+, Cl -, NO3-, SO42-, F -, PO43-, H 3CCOO -, HCOO -, CO42- and HCO3-) showed that there was an excess of cations (˜15%), which was attributed to the presence of unmeasured organic anion species originating from biomass burning and biogenic emissions. On average, the three ions NH4+, NO 3- and H + were responsible for >55% of the total ion concentrations in the rainwater samples. Concentrations (except of H +) were significantly higher ( t-test; P = 0.05), by between two to six-fold depending on species, during the winter sugar cane harvest period, due to the practice of pre-harvest burning of the crop. Principal component analysis showed that three components could explain 88% of the variance for measurements made throughout the year: PC1 (52%, biomass burning and soil dust resuspension); PC2 (26%, secondary aerosols); PC3 (10%, road transport emissions). Differences between harvest and non-harvest periods appeared to be mainly due to an increased relative importance of road transport/industrial emissions during the summer (non-harvest) period. The volume-weighted mean (VWM) concentrations of ammonium (23.4 ?mol L -1) and nitrate (17.5 ?mol L -1) in rainwater samples collected during the harvest period were similar to those found in rainwater from São Paulo city, which emphasizes the importance of including rural agro-industrial emissions in regional-scale atmospheric chemistry and transport models. Since there was evidence of a biomass burning source throughout the year, it appears that rainwater composition will continue to be affected by vegetation fires, even after sugar cane burning is phased out as envisaged by recent São Paulo State legislation.

  17. Groundwater quality in Scotland: major ion chemistry of the key groundwater bodies.

    PubMed

    Robins, N S

    2002-07-22

    Groundwater in Scotland is, for the most part, weakly to moderately mineralised and dominated by the Ca and HCO3 ions. The aquifer systems are almost entirely unconfined and most groundwater remains in contact with oxygen; some reducing groundwaters occur in deeper isolated cracks and joints within the many fractured bedrock aquifers such as Devonian sandstones. Groundwater depleted in oxygen is also common in the Coal Measures in the Midland Valley as a direct result of past coal and oil shale mining, when iron and other metals are taken into solution as the abandoned mine workings are allowed to flood. Low pH groundwaters are rare but do occur where calcite is absent in some basement rocks. Marine intrusion of coastal aquifers occurs locally in East Lothian and parts of Morayshire. Deeper circulating groundwaters are responsible for some of the more exotic spa waters, notably at Bridge of Earn near Perth. Nitrate contamination of groundwater is increasing in some areas, and is most prevalent in the south of Scotland. The Devonian aquifer in Fife and parts of the Permian sandstone aquifers of south-west Scotland are the worst affected. PMID:12169011

  18. Chemosystematic analyses of Gingidia volatiles.

    PubMed

    Sansom, Catherine E; Heenan, Peter B; Perry, Nigel B; Smallfield, Bruce M; van Klink, John W

    2013-12-01

    The leave volatiles of six Gingidia species from New Zealand and Australia and the seed volatiles of G. grisea were characterized by solid-phase microextraction (SPME)-GC/MS analysis. This technique, using a small quantity of samples and automated extraction, gave repeatable results, with maximum sensitivity for medium volatility compounds. The major monoterpenes among the volatiles, i.e., ?-phellandrene (4), limonene (6), and ?-terpinene (5), and phenylpropanoids, i.e., estragole (3), (E)-anethole (7), and myristicin (1), showed to be useful chemotaxonomic markers. For G. grisea leaves and seeds, similar compositions were detected, characterized by high contents of 4. As leaves were more readily available for study than seeds, they were used for further investigations. The G. grisea leaf volatiles showed infraspecific variation in the ratio of 4/5 between and within sites of collection. The G. montana leaf volatiles also showed infraspecific variation, with high contents of 3 at one site and high contents of 7 at another. The SPME-GC/MS analysis of G. montana herbarium voucher specimens resulted in the identification of further chemotypes for this species. The volatiles of the G. amphistoma samples were all dominated by 7 and those of the G. haematitica samples were rich in 5. Moreover, single plants of two Australian Gingidia species were analyzed; the volatiles of G. harveyana showed high concentrations of 5 and 7, whereas those of G. rupicola were dominated by 5 and 1. PMID:24327443

  19. HIGH-PERFORMANCE LIQUID CHROMATOGRAPHIC/MASS SPECTROMETRIC DETERMINATION OF VOLATILE CARBOXYLIC ACIDS USING ION-PAIR EXTRACTION AND THERMALLY INDUCED ALKYLATION

    EPA Science Inventory

    Low molecular weight volatile carboxylic acids have been analyzed by high-performance liquid chromatography/mass spectrometry (HPLC/MS) using post-column derivatization and a moving belt interface. In order to prevent loss of the volatile solutes during transport to the mass spec...

  20. Use of reconstituted waters to evaluate effects of elevated major ions associated with mountaintop coal mining on freshwater invertebrates

    USGS Publications Warehouse

    Kunz, James L.; Conley, Justin M.; Buchwalter, David B.; Norberg-King; Teresa, J.; Kemble, Nile E.; Wang, Ning; Ingersoll, Christopher G.

    2013-01-01

    In previous laboratory chronic 7-d toxicity tests conducted with the cladoceran Ceriodaphnia dubia, surface waters collected from Appalachian sites impacted by coal mining have shown toxic effects associated with elevated total dissolved solids (TDS). The objective of the present study was to evaluate the effects of elevated major ions in chronic laboratory tests with C. dubia (7-d exposure), a unionid mussel (Lampsilis siliquoidea; 28-d exposure), an amphipod (Hyalella azteca; 28-d exposure), and a mayfly (Centroptilum triangulifer; 35-d exposure) in 3 reconstituted waters designed to be representative of 3 Appalachian sites impacted by coal mining. Two of the reconstituted waters had ionic compositions representative of alkaline mine drainage associated with mountaintop removal and valley fill-impacted streams (Winding Shoals and Boardtree, with elevated Mg, Ca, K, SO4, HCO3), and a third reconstituted water had an ionic composition representative of neutralized mine drainage (Upper Dempsey, with elevated Na, K, SO4, and HCO3). The waters with similar conductivities but, with different ionic compositions had different effects on the test organisms. The Winding Shoals and Boardtree reconstituted waters were consistently toxic to the mussel, the amphipod, and the mayfly. In contrast, the Upper Dempsey reconstituted water was toxic to the mussel, the amphipod, and the cladoceran but was not toxic to the mayfly. These results indicate that, although elevated TDS can be correlated with toxicity, the specific major ion composition of the water is important. Moreover, the choice of test organism is critical, particularly if a test species is to be used as a surrogate for a range of faunal groups.

  1. Use of reconstituted waters to evaluate effects of elevated major ions associated with mountaintop coal mining on freshwater invertebrates.

    PubMed

    Kunz, James L; Conley, Justin M; Buchwalter, David B; Norberg-King, Teresa J; Kemble, Nile E; Wang, Ning; Ingersoll, Christopher G

    2013-12-01

    In previous laboratory chronic 7-d toxicity tests conducted with the cladoceran Ceriodaphnia dubia, surface waters collected from Appalachian sites impacted by coal mining have shown toxic effects associated with elevated total dissolved solids (TDS). The objective of the present study was to evaluate the effects of elevated major ions in chronic laboratory tests with C. dubia (7-d exposure), a unionid mussel (Lampsilis siliquoidea; 28-d exposure), an amphipod (Hyalella azteca; 28-d exposure), and a mayfly (Centroptilum triangulifer; 35-d exposure) in 3 reconstituted waters designed to be representative of 3 Appalachian sites impacted by coal mining. Two of the reconstituted waters had ionic compositions representative of alkaline mine drainage associated with mountaintop removal and valley fill-impacted streams (Winding Shoals and Boardtree, with elevated Mg, Ca, K, SO?, HCO?), and a third reconstituted water had an ionic composition representative of neutralized mine drainage (Upper Dempsey, with elevated Na, K, SO?, and HCO?). The waters with similar conductivities but, with different ionic compositions had different effects on the test organisms. The Winding Shoals and Boardtree reconstituted waters were consistently toxic to the mussel, the amphipod, and the mayfly. In contrast, the Upper Dempsey reconstituted water was toxic to the mussel, the amphipod, and the cladoceran but was not toxic to the mayfly. These results indicate that, although elevated TDS can be correlated with toxicity, the specific major ion composition of the water is important. Moreover, the choice of test organism is critical, particularly if a test species is to be used as a surrogate for a range of faunal groups. PMID:24243594

  2. The volatile compound BinBase mass spectral database

    PubMed Central

    2011-01-01

    Background Volatile compounds comprise diverse chemical groups with wide-ranging sources and functions. These compounds originate from major pathways of secondary metabolism in many organisms and play essential roles in chemical ecology in both plant and animal kingdoms. In past decades, sampling methods and instrumentation for the analysis of complex volatile mixtures have improved; however, design and implementation of database tools to process and store the complex datasets have lagged behind. Description The volatile compound BinBase (vocBinBase) is an automated peak annotation and database system developed for the analysis of GC-TOF-MS data derived from complex volatile mixtures. The vocBinBase DB is an extension of the previously reported metabolite BinBase software developed to track and identify derivatized metabolites. The BinBase algorithm uses deconvoluted spectra and peak metadata (retention index, unique ion, spectral similarity, peak signal-to-noise ratio, and peak purity) from the Leco ChromaTOF software, and annotates peaks using a multi-tiered filtering system with stringent thresholds. The vocBinBase algorithm assigns the identity of compounds existing in the database. Volatile compound assignments are supported by the Adams mass spectral-retention index library, which contains over 2,000 plant-derived volatile compounds. Novel molecules that are not found within vocBinBase are automatically added using strict mass spectral and experimental criteria. Users obtain fully annotated data sheets with quantitative information for all volatile compounds for studies that may consist of thousands of chromatograms. The vocBinBase database may also be queried across different studies, comprising currently 1,537 unique mass spectra generated from 1.7 million deconvoluted mass spectra of 3,435 samples (18 species). Mass spectra with retention indices and volatile profiles are available as free download under the CC-BY agreement (http://vocbinbase.fiehnlab.ucdavis.edu). Conclusions The BinBase database algorithms have been successfully modified to allow for tracking and identification of volatile compounds in complex mixtures. The database is capable of annotating large datasets (hundreds to thousands of samples) and is well-suited for between-study comparisons such as chemotaxonomy investigations. This novel volatile compound database tool is applicable to research fields spanning chemical ecology to human health. The BinBase source code is freely available at http://binbase.sourceforge.net/ under the LGPL 2.0 license agreement. PMID:21816034

  3. Fundamental Volatility's Eect on Asset Volatility

    Microsoft Academic Search

    Evan Allen Beard

    2009-01-01

    This paper examines the eect of macroeconomic variable volatility on implied and realized asset price level volatilities in the U.S. using monthly data from 1986 - 2008. Two approaches are taken: An autoregressive distributed lag model us- ing rolling standard deviations and a GARCH model. The S&P 500's volatility is used as a proxy for historical (actual) volatility and the

  4. Characterizing interactions between surface water and groundwater in the Jialu River basin using major ion chemistry and stable isotopes

    NASA Astrophysics Data System (ADS)

    Yang, L.; Song, X.; Zhang, Y.; Han, D.; Zhang, B.; Long, D.

    2012-11-01

    The Jialu River, a secondary tributary of the Huaihe River, has been severely contaminated from major contaminant sources, such as a number of untreated or lightly treated sewage waste in some cities. Groundwater along the river is not an isolated component of the hydrologic system, but is instead connected with the surface water. This study aims to investigate temporal and spatial variations in water chemistry affected by humans and to characterize the relationships between surface water (e.g. reservoirs, lakes and rivers) and groundwater near the river in the shallow Quaternary aquifer. Concentration of Cl- in north Zhengzhou City increased prominently due to the discharge of a large amount of domestic water. Nitrate and potassium show maximum concentrations in groundwater in Fugou County. These high levels can be attributed to the use of a large quantity of fertilizer over this region. Most surface water appeared to be continuously recharged from the surrounding groundwater (regional wells) based on comparison surface water with groundwater levels, stable-isotopes and major ion signatures. However, the groundwater of a transitional well (location SY3) seemed to be recharged by river water via bank infiltration in September 2010. Fractional contributions of river water to the groundwater were calculated based on isotopic and chemical data using a mass-balance approach. Results show that the groundwater was approximately composed of 60-70% river water. These findings should be useful for a better understanding of hydrogeological processes at the river-aquifer interface and ultimately benefit water management in the future.

  5. Origin of Volatiles in Earth: Indigenous Versus Exogenous Sources Based on Highly Siderophile, Volatile Siderophile, and Light Volatile Elements

    NASA Technical Reports Server (NTRS)

    Righter, K.; Danielson, L.; Pando, K. M.; Marin, N.; Nickodem, K.

    2015-01-01

    Origin of Earth's volatiles has traditionally been ascribed to late accretion of material after major differentiation events - chondrites, comets, ice or other exogenous sources. A competing theory is that the Earth accreted its volatiles as it was built, thus water and other building blocks were present early and during differentiation and core formation (indigenous). Here we discuss geochemical evidence from three groups of elements that suggests Earth's volatiles were acquired during accretion and did not require additional sources after differentiation.

  6. Evidence for deep pooling of low degree melts from volatile, major, and trace element chemistry of olivine-hosted melt inclusions and glasses from the ultra-slow spreading Gakkel Ridge

    NASA Astrophysics Data System (ADS)

    Shaw, A. M.; Behn, M. D.; Humphris, S. E.; Reves-Sohn, R. A.; Gregg, P. M.

    2009-12-01

    We present new analyses of volatiles and major elements for a suite of glasses and melt inclusions from ~85°E on the ultra-slow spreading Gakkel Ridge. The major element and volatile compositions of the melt inclusions are more variable and consistently more primitive than the glass data. CO2 contents in the melt inclusions extend to higher values (167-1596 ppm) than in the co-existing glasses (187-227 ppm), indicating that the melt inclusions were trapped at greater depths. Based on a vapor saturation model, we estimate that the melt inclusions were trapped between seafloor depths (~4 km) and ~9 km below seafloor, as compared to the glasses, which are all in equilibrium with their eruption depths. Melting conditions inferred from thermobarometry suggest relatively deep (25-40 km), cold (1240°-1325°C) melting conditions, consistent with the calculated thermal structure for the ultra-slow spreading Gakkel Ridge. The water contents and trace element compositions of the melt inclusions and glasses are remarkably homogeneous, an unexpected result for ultra-slow spreading environments where wide geochemical diversity is anticipated. Moreover, all melts can be described by a single liquid line of descent originating from a pooled melt composition that is consistent with the aggregate melt calculated from a thermal model for the Gakkel Ridge. These data suggest a model in which deep, low degree melts are efficiently pooled near the top of the melting column (9-20 km depth), after which crystallization commences and continues during ascent and eruption of the magma. Based on this melting model and the assumption that CO2 is perfectly incompatible, we show that the highest CO2 concentrations of the melt inclusions (~1600 ppm) are consistent with calculated CO2 concentrations of primary undegassed melts and yield a MORB source mantle CO2 content of ~90 ppm. This value is slightly lower than that inferred from the highest measured CO2/Nb ratio of Gakkel Ridge melt inclusions (443), which predicts a mantle CO2 content of 134 ppm and a global ridge flux of 2.0×1012 mol CO2/yr.

  7. The major-ion composition of Cenozoic seawater: the past 36 million years from fluid inclusions in marine halite

    USGS Publications Warehouse

    Brennan, Sean T.; Lowenstein, Tim K.; Cendon, Dioni I.

    2013-01-01

    Fluid inclusions from ten Cenozoic (Eocene-Miocene) marine halites are used to quantify the major-ion composition (Mg2+, Ca2+, K+, Na+, SO42?, and Cl?) of seawater over the past 36 My. Criteria used to determine a seawater origin of the halites include: (1) stratigraphic, sedimentologic, and paleontologic observations; (2) Br? in halite; (3) ?34S of sulfate minerals; (4) 87Sr/86Sr of carbonates and sulfates; and (5) fluid inclusion brine compositions and evaporation paths, which must overlap from geographically separated basins of the same age to confirm a “global” seawater chemical signal. Changes in the major-ion chemistry of Cenozoic seawater record the end of a systematic, long term (>150 My) shift from the Ca2+-rich, Mg2+- and SO42?-poor seawater of the Mesozoic (“CaCl2 seas”) to the “MgSO4 seas” (with higher Mg2+ and SO42?>Ca2+) of the Cenozoic. The major ion composition of Cenozoic seawater is calculated for the Eocene-Oligocene (36-34 Ma), Serravallian-Tortonian (13.5-11.8 Ma) and the Messinian (6-5 Ma), assuming chlorinity (565 mmolal), salinity, and the K+ concentration (11 mmolal) are constant and the same as in modern seawater. Fluid inclusions from Cenozoic marine halites show that the concentrations of Mg2+and SO42? have increased in seawater over the past 36 My and the concentration of Ca2+ has decreased. Mg2+ concentrations increased from 36 mmolal in Eocene-Oligocene seawater (36-34 Ma) to 55 mmolal in modern seawater. The Mg2+/Ca2+ ratio of seawater has risen from ?2.3 at the end of the Eocene, to 3.4 and 4.0, respectively, at 13.5 to 11.8 Ma and 6 to 5 Ma, and to 5 in modern seawater. Eocene-Oligocene seawater (36-34 Ma) has estimated ranges of SO42? = 14–23 mmolal and Ca2+ = 11–20 mmolal. If the (Ca2+)(SO42?) product is assumed to be the same as in modern seawater (?300 mmolal2), Eocene-Oligocene seawater had Ca2+ ?16 mmolal and SO42? ?19 mmolal. The same estimates of Ca2+ and SO42? for Serravallian-Tortonian seawater (13.5-11.8 Ma) are SO42? = 19–27 mmolal and Ca2+ = 8–16 mmolal and SO42? ?24 mmolal and Ca2+ ? 13 mmolal if the (Ca2+)(SO42?) product is equal to that in modern seawater. Messinian seawater has an estimated range of SO42? ?21–29 mmolal and Ca2+ ?7–15 mmolal with SO42? ?26 mmolal and Ca2+ ?12 mmolal assuming the (Ca2+)(SO42?) product is equal to that in modern seawater. Regardless of the estimation procedure, SO42? shows progressively increasing concentrations from 36 Ma to the present values, which are the highest of the Cenozoic.

  8. Predicting the toxicity of major ions in seawater to mysid shrimp (Mysidopsis bahia), sheepshead minnow (Cyprinodon variegatus), and inland silverside minnow (Menidia beryllina)

    SciTech Connect

    Pillard, D.A.; DuFresne, D.L.; Caudle, D.D.; Tietge, J.E.; Evans, J.M.

    2000-01-01

    Although marine organisms are naturally adapted to salinities well above those of freshwater, elevated concentrations of specific ions have been shown to cause adverse effects on some saltwater species. Because some ions are also physiologically essential, a deficiency of these ions can also cause significant effects. To provide a predictive tool to assess toxicity associated with major ions, mysid shrimp (Mysidopsis bahia), sheepshead minnows (Cyprinodon variegatus), and inland silverside minnows (Menidia beryllina) were exposed to saline solutions containing calcium, magnesium, potassium, strontium, bicarbonate, borate, bromide, and sulfate at concentrations above and below what would be found in seawater. Solution salinity was maintained at approximately 31% by increasing or decreasing sodium and chloride concentrations. Logistic regression models were developed with both the ion molar concentrations and ion activity. Toxicity to all three species was observed when either a deficiency or an excess of potassium and calcium occurred. Significant mortality occurred in all species when exposed to excess concentrations of magnesium, bicarbonate, and borate. The response to the remaining ions varied with species. Sheepshead minnows were the most tolerant of both deficient and elevated levels of the different ions. Mysid shrimp and inland silverside minnows demonstrated similar sensitivities to several ions, but silverside minnow response was more variable. As a result, the logistic models that predict inland silverside minnow survival generally were less robust than for the other two species.

  9. SPME-GC-MS versus Selected Ion Flow Tube Mass Spectrometry (SIFT-MS) analyses for the study of volatile compound generation and oxidation status during dry fermented sausage processing.

    PubMed

    Olivares, Alicia; Dryahina, Kseniya; Navarro, José Luis; Smith, David; Span?l, Patrik; Flores, Mónica

    2011-03-01

    The use of selected ion flow tube mass spectrometry (SIFT-MS) and gas chromatography-mass spectrometry together with solid phase microextraction (GC-MS-SPME) has been compared in the analysis of volatile compounds during dry fermented sausage processing. Thus, the headspace (HS) of samples of dry fermented sausages with different fat contents was analyzed during their manufacture using both techniques, and significant and positive correlations were found between SIFT-MS and SPME-GC-MS measurements for the compounds pentanal, hexanal, 2-heptenal, octanal, 2-nonenal, 2-butanone, 2-pentanone, ethanol, acetic acid, and hexanoic acid. The oxidative status of fermented sausages during processing was also evaluated, and a significant correlation was obtained between the HS concentration of lipid autoxidation volatile compounds measured by SIFT-MS and SPME-GC-MS and the level of thiobarbituric acid reactive substances (TBARS) in the sausage. The hexanal measured by SIFT-MS resulted in a higher correlation coefficient (r = 0.936) than that obtained using SPME-GC-MS (r = 0.927). SIFT-MS is shown to be a fast, real time analytical technique for monitoring changes in the profile of volatile compounds in dry fermented sausages during processing and a useful tool to evaluate the oxidative status of meat products. PMID:21294565

  10. Hydro-chemical evolution of groundwater and mixing between aquifers: a statistical approach based on major ions

    NASA Astrophysics Data System (ADS)

    Sun, Linhua; Gui, Herong

    2015-03-01

    Geochemical analysis is a useful tool in hydrogeological assessment, particularly in constructing a conceptual model of a hydrogeological system. In this study, major ion concentrations of 53 groundwater samples from the coal-bearing aquifer in the Qidong coal mine, northern Anhui Province of China have been processed by statistical analysis for understanding either hydro-chemical characteristics or hydrological evolution, which will be useful for the safety of coal mining. The results suggest that most of the samples are Na-SO4 and Na-HCO3 types, and their hydro-chemical compositions are mainly controlled by dissolution of more soluble minerals (e.g. calcite) and weathering of silicate minerals (e.g. plagioclase). Two groups of samples have been subdivided by quantile and scatter plots of factor scores, one is related to different degrees of water-rock interactions and another is related to groundwater mixing. Moreover, four end members have been identified and the mixing calculation suggests that the groundwater samples affected by mixing have 20-100 % contribution from the loose layer aquifer (LA), and therefore, groundwater from the LA in the coal mine should be taken seriously during coal mining. The study demonstrated that statistical analysis is useful for connecting the hydrochemistry of groundwater with hydrological evolution of the aquifer.

  11. Major ion chemistry and dissolved inorganic carbon cycling in a human-disturbed mountainous river (the Luodingjiang River) of the Zhujiang (Pearl River), China

    Microsoft Academic Search

    Shurong Zhang; X. X. Lu; Huiguo Sun; Jingtai Han; David Laurence Higgitt

    2009-01-01

    Major ion chemistry and dissolved inorganic carbon system (DIC, mainly HCO3? and gaseous CO2) in the Luodingjiang River, a mountainous tributary of the Zhujiang (Pearl River), China, were examined based on a seasonal and spatial sampling scheme in 2005. The diverse distribution of lithology and anthropogenic impacts in the river basin provided the basic idea to assess the effects of

  12. Estimates of average major ion concentrations in bulk precipitation at two high-altitude sites near the continental divide in Southwestern Colorado

    USGS Publications Warehouse

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

    1985-01-01

    The composition of bulk precipitation from two high-altitude sites, established in 1971 near the Continental Divide in southwestern Colorado, has been monitored by season during the past decade. Calcium ions are the predominant cationic species; sulfate is the major anionic constituent. Bulk precipitation major ion concentrations exhibit log-normal distributions. Representative mean and standard deviation values for the major inorganic ionic species present in bulk precipitation have been calculated for three years of consecutive seasons. Standard deviations for all species, except nitrate, are similar. For two years of data grouped into quarters, deviations from mean values fall well within the plus or minus two standard deviation limit. There does not seem to be a systematic deviation from the mean concentration values, with respect to either ionic component or season.

  13. Principal Locations of Major-Ion, Trace-Element, Nitrate, and Escherichia coli Loading to Emigration Creek, Salt Lake County, Utah, October 2005

    USGS Publications Warehouse

    Kimball, Briant A.; Runkel, Robert L.; Walton-Day, Katherine

    2008-01-01

    Housing development and recreational activity in Emigration Canyon have increased substantially since 1980, perhaps causing an observed decrease in water quality of this northern Utah stream located near Salt Lake City. To identify reaches of the stream that contribute to water-quality degradation, a tracer-injection and synoptic-sampling study was done to quantify mass loading of major ions, trace elements, nitrate, and Escherichia coli (E. coli) to the stream. The resulting mass-loading profiles for major ions and trace elements indicate both geologic and anthropogenic inputs to the stream, principally from tributary and spring inflows to the stream at Brigham Fork, Burr Fork, Wagner Spring, Emigration Tunnel Spring, Blacksmith Hollow, and Killyon Canyon. The pattern of nitrate loading does not correspond to the major-ion and trace-element loading patterns. Nitrate levels in the stream did not exceed water-quality standards at the time of synoptic sampling. The majority of nitrate mass loading can be considered related to anthropogenic input, based on the field settings and trends in stable isotope ratios of nitrogen. The pattern of E. coli loading does not correspond to the major-ion, trace-element, or nitrate loading patterns. The majority of E. coli loading was related to anthropogenic sources based on field setting, but a considerable part of the loading also comes from possible animal sources in Killyon Canyon, in Perkins Flat, and in Rotary Park. In this late summer sampling, E. coli concentrations only exceeded water-quality standards in limited sections of the study reach. The mass-loading approach used in this study provides a means to design future studies and to evaluate the loading on a catchment scale.

  14. Differential expression of genes encoding neuronal ion-channel subunits in major depression, bipolar disorder and schizophrenia: implications for pathophysiology.

    PubMed

    Smolin, Bella; Karry, Rachel; Gal-Ben-Ari, Shunit; Ben-Shachar, Dorit

    2012-08-01

    Evidence concerning ion-channel abnormalities in the pathophysiology of common psychiatric disorders is still limited. Given the significance of ion channels in neuronal activity, neurotransmission and neuronal plasticity we hypothesized that the expression patterns of genes encoding different ion channels may be altered in schizophrenia, bipolar and unipolar disorders. Frozen samples of striatum including the nucleus accumbens (Str-NAc) and the lateral cerebellar hemisphere of 60 brains from depressed (MDD), bipolar (BD), schizophrenic and normal subjects, obtained from the Stanley Foundation Brain Collection, were assayed. mRNA of 72 different ion-channel subunits were determined by qRT-PCR and alteration in four genes were verified by immunoblotting. In the Str-NAc the prominent change was observed in the MDD group, in which there was a significant up-regulation in genes encoding voltage-gated potassium-channel subunits. However, in the lateral cerebellar hemisphere (cerebellum), the main change was observed in schizophrenia specimens, as multiple genes encoding various ion-channel subunits were significantly down-regulated. The impaired expression of genes encoding ion channels demonstrates a disease-related neuroanatomical pattern. The alterations observed in Str-NAc of MDD may imply electrical hypo-activity of this region that could be of relevance to MDD symptoms and treatment. The robust unidirectional alteration of both excitatory and inhibitory ion channels in the cerebellum may suggests cerebellar general hypo-transcriptional activity in schizophrenia. PMID:22008100

  15. Academic Majors Undergraduate Majors

    E-print Network

    Weston, Ken

    Community Nutrition/Health Promotion · Food Science Food Allergy · Human/Athletic Performance NutritionAcademic Majors Undergraduate Majors Food & Nutrition Sciences Dietetics Exercise Science Athletic Training Masters Majors Nutrition & Food Sciences Exercise Physiology Sports Sciences Doctoral Majors

  16. A Test of a Major-ion Toxicity Model to Predict the Toxicity of Coal Bed Methane Product Waters to Aquatic Biota

    NASA Astrophysics Data System (ADS)

    Forbes, M. B.; Meyer, J. S.

    2003-12-01

    Coal bed methane (CBM) accounts for about 7.5% of the total natural gas production in the United States, and the Powder River Basin (PRB) in Montana and Wyoming has recently become a major production area. During CBM extraction, a coal seam is partially de-watered to relieve hydraulic pressure, thus causing methane gas to desorb. Some of this water (called product water) is discharged on the land surface and allowed to run into local drainages in the PRB. Due to the massive amounts of product water being discharged (rates up to 64,000 L/day per well), studies are needed to examine the potential effects on aquatic organisms. Additionally, models to predict such effects would be useful regulatory screening tools. To that end, we tested the ability of a multivariate logistic regression model of the toxicity of major inorganic ions (i.e., Na+, K+, Ca2+, Mg2+, Cl-, HCO3-, SO42-) to predict the acute toxicity of CBM-related waters to two aquatic invertebrates (Ceriodaphnia dubia and Daphnia magna) and fathead minnows (Pimephales promelas). First, we entered water chemistry data for several CBM product and receiving waters from the PRB into the major-ion model. Then we compared the model's predicted survival to the survival of the three species in toxicity tests we had previously conducted with those waters. For the majority of CBM product water and stream water samples in which CBM product water constituted the entire flow of the stream, the major-ion model consistently under-predicted survival by >50%. Therefore, from a regulatory standpoint, this model is conservative for detecting toxicity of CBM product waters (i.e., it over-predicts toxicity). Although the model appeared to be an excellent predictor of survival for receiving waters that contained no inputs from CBM processing (i.e., the difference between predicted and observed survival was <=10%), the majority of those cases were inconclusive tests of the model because the predicted and observed survival were either both >90% or both <10%. In such cases, it was not possible to test the accuracy of the regression coefficients in the major-ion model.

  17. Conference on Planetary Volatiles

    NASA Technical Reports Server (NTRS)

    Pepin, R. O. (compiler); Oconnell, R. (compiler)

    1982-01-01

    Initial and present volatile inventories and distributions in the Earth, other planets, meteorites, and comets; observational evidence on the time history of volatile transfer among reservoirs; and volatiles in planetary bodies, their mechanisms of transport, and their relation to thermal, chemical, geological and biological evolution are addressed.

  18. Conference on Planetary Volatiles

    NASA Technical Reports Server (NTRS)

    Hrametz, K.; Kofler, L.

    1982-01-01

    Initial and present volatile inventories and distributions in the Earth, other planets, meteorites, and comets; observational evidence on the time history of volatile transfer among reservoirs; and volatiles in planetary bodies, their mechanisms of transport, and their relation to thermal, chemical, geological and biological evolution were addressed.

  19. Current status of fluoride volatility method development

    SciTech Connect

    Uhlir, J.; Marecek, M.; Skarohlid, J. [UJV - Nuclear Research Institute, Research Centre Rez, CZ-250 68 Husinec - Rez 130 (Czech Republic)

    2013-07-01

    The Fluoride Volatility Method is based on a separation process, which comes out from the specific property of uranium, neptunium and plutonium to form volatile hexafluorides whereas most of fission products (mainly lanthanides) and higher transplutonium elements (americium, curium) present in irradiated fuel form nonvolatile tri-fluorides. Fluoride Volatility Method itself is based on direct fluorination of the spent fuel, but before the fluorination step, the removal of cladding material and subsequent transformation of the fuel into a powdered form with a suitable grain size have to be done. The fluorination is made with fluorine gas in a flame fluorination reactor, where the volatile fluorides (mostly UF{sub 6}) are separated from the non-volatile ones (trivalent minor actinides and majority of fission products). The subsequent operations necessary for partitioning of volatile fluorides are the condensation and evaporation of volatile fluorides, the thermal decomposition of PuF{sub 6} and the finally distillation and sorption used for the purification of uranium product. The Fluoride Volatility Method is considered to be a promising advanced pyrochemical reprocessing technology, which can mainly be used for the reprocessing of oxide spent fuels coming from future GEN IV fast reactors.

  20. Characterization of Coriander (Coriandrum sativum L.) Seeds and Leaves: Volatile and Non Volatile Extracts

    Microsoft Academic Search

    Muhammad Khuram Shahwar; Ahmed Hassan El-Ghorab; Faqir Muhammad Anjum; Masood Sadiq Butt; Shahzad Hussain; Muhammad Nadeem

    2012-01-01

    The main aim of this study was the characterization of coriander essential oil. The major volatile compounds in coriander seed essential oil were linalool, ?-terpinene, ?-pinene, camphor, decanal geranyl acetate, limonene, geraniol, camphene, and D-limonene, while the major volatile compounds identified in coriander leaves essential oil were (E)-2-decenal, linalool, (E)-2-dodecenal, (E)-2-tetradecenal, 2-decen-1-ol, (E)-2-undecenal, dodecanal, (E)-2-tridecenal, (E)-2-hexadecenal, pentadecenal, and ?-pinene. The

  1. CHARACTERIZATION OF CORIANDER (CORIANDRUM SATIVUM L.) SEEDS AND LEAVES: VOLATILE AND NON VOLATILE EXTRACTS

    Microsoft Academic Search

    Muhammad Khuram Shahwar; Ahmed Hassan El-Ghorab; Faqir Muhammad Anjum; Masood Sadiq Butt; Shahzad Hussain; Muhammad Nadeem

    2011-01-01

    The main aim of this study was the characterization of coriander essential oil. The major volatile compounds in coriander seed essential oil were linalool, ?-terpinene, ?-pinene, camphor, decanal geranyl acetate, limonene, geraniol, camphene and D- limonene. While the major volatile compounds identified in coriander leaves essential oil (CLEO) were (E)-2-decenal, linalool, (E)-2-dodecenal, (E)-2-tetradecenal, 2-decen-1-ol, (E)-2-undecenal, dodecanal, (E)-2-tridecenal, (E)-2-hexadecenal, pentadecenal, ?-pinene.

  2. Atmospheric trace element and major ion concentrations over the eastern Mediterranean Sea: Identification of anthropogenic source regions

    NASA Astrophysics Data System (ADS)

    Güllü, Gülen; Do?an, Güray; Tuncel, Gürdal

    Concentrations of elements and ions measured in aerosol samples collected from March 1992 to the end of December 1993 were investigated to identify source regions affecting chemical composition of aerosols in the eastern Mediterranean atmosphere. Collected samples were analyzed for approximately 40 elements and ions using a combination of atomic absorption spectrometry, instrumental neutron activation analysis, ion chromatography and colorimetry. Statistical techniques, such as enrichment factors and a non-parametric bootstrapped potential source contribution function, were applied on the data set to determine main source types and source regions of anthropogenic particles in the eastern Mediterranean basin. Source regions of two previously defined anthropogenic components, namely a long-range transported component and a local pollution component, were identified. The main source areas for pollutants reaching the eastern Mediterranean basin were determined as southern and western parts of Turkey, central and eastern regions of Ukraine, east of Belarus, Greece, Georgia, Romania, coastal areas along France and Spain and coastal areas around the Black Sea, Russia. More distant source regions in the South of UK and Sweden, the central part of Algeria, the northeastern part of Turkey, Russia, Germany, Hungary, Czech Republic, Bosnia and Herzegovina, and coastal areas of Egypt, Israel and Italy do affect aerosol composition in the eastern Mediterranean, but transport from these regions cannot account for the highest 20% of the measured pollutant concentrations.

  3. Volatile Components of Cuban Annona Fruits

    Microsoft Academic Search

    Jorge A. Pino

    2000-01-01

    Volatile components of cherimoya {Annona cherimoya Mill.) and bullock's heart (A. reticulata L.) were isolated by simultaneous steam distillation\\/solvent extraction and analysis by GC\\/MS. Forty-seven and 49 compounds were identified in both fruits, respectively. The major volatiles in cherimoya were ?-thujene, ?-pinene, terpinen-4-ol and germacrene D, while in bullock's hearts they were ?-pinene, ?-pinene and germacrene D.

  4. Extreme times for volatility processes

    NASA Astrophysics Data System (ADS)

    Masoliver, Jaume; Perelló, Josep

    2007-04-01

    Extreme times techniques, generally applied to nonequilibrium statistical mechanical processes, are also useful for a better understanding of financial markets. We present a detailed study on the mean first-passage time for the volatility of return time series. The empirical results extracted from daily data of major indices seem to follow the same law regardless of the kind of index thus suggesting an universal pattern. The empirical mean first-passage time to a certain level L is fairly different from that of the Wiener process showing a dissimilar behavior depending on whether L is higher or lower than the average volatility. All of this indicates a more complex dynamics in which a reverting force drives volatility toward its mean value. We thus present the mean first-passage time expressions of the most common stochastic volatility models whose approach is comparable to the random diffusion description. We discuss asymptotic approximations of these models and confront them to empirical results with a good agreement with the exponential Ornstein-Uhlenbeck model.

  5. Biogeochemical processes controlling the mobility of major ions and trace metals in aquitard sediments beneath an oil sand tailing pond: laboratory studies and reactive transport modeling.

    PubMed

    Holden, A A; Haque, S E; Mayer, K U; Ulrich, A C

    2013-08-01

    Increased production and expansion of the oil sand industry in Alberta are of great benefit to the economy, but they carry major environmental challenges. The volume of fluid fine tailings requiring storage is 840×10(6) m(3) and growing, making it imperative that we better understand the fate and transport of oil sand process-affected water (OSPW) seepage from these facilities. Accordingly, the current study seeks to characterize both a) the potential for major ion and trace element release, and b) the principal biogeochemical processes involved, as tailing pond OSPW infiltrates into, and interacts with, underlying glacial till sediments prior to reaching down gradient aquifers or surface waters. Objectives were addressed through a series of aqueous and solid phase experiments, including radial diffusion cells, an isotope analysis, X-ray diffraction, and sequential extractions. The diffusion cells were also simulated in a reactive transport framework to elucidate key reaction processes. The experiments indicate that the ingress and interaction of OSPW with the glacial till sediment-pore water system will result in: a mitigation of ingressing Na (retardation), displacement and then limited precipitation of exchangeable Ca and Mg (as carbonates), sulfate reduction and subsequent precipitation of the produced sulfides, as well as biodegradation of organic carbon. High concentrations of ingressing Cl (~375 mg L(-1)) and Na (~575 mg L(-1)) (even though the latter is delayed, or retarded) are expected to migrate through the till and into the underlying sand channel. Trace element mobility was influenced by ion exchange, oxidation-reduction, and mineral phase reactions including reductive dissolution of metal oxyhydroxides - in accordance with previous observations within sandy aquifer settings. Furthermore, although several trace elements showed the potential for release (Al, B, Ba, Cd, Mn, Pb, Si, Sr), large-scale mobilization is not supported. Thus, the present results suggest that in addition to the commonly cited naphthenic acids, remediation of OSPW-impacted groundwater will need to address high concentrations of major ions contributing to salinization. PMID:23727691

  6. Biogeochemical processes controlling the mobility of major ions and trace metals in aquitard sediments beneath an oil sand tailing pond: Laboratory studies and reactive transport modeling

    NASA Astrophysics Data System (ADS)

    Holden, A. A.; Haque, S. E.; Mayer, K. U.; Ulrich, A. C.

    2013-08-01

    Increased production and expansion of the oil sand industry in Alberta are of great benefit to the economy, but they carry major environmental challenges. The volume of fluid fine tailings requiring storage is 840 × 106 m3 and growing, making it imperative that we better understand the fate and transport of oil sand process-affected water (OSPW) seepage from these facilities. Accordingly, the current study seeks to characterize both a) the potential for major ion and trace element release, and b) the principal biogeochemical processes involved, as tailing pond OSPW infiltrates into, and interacts with, underlying glacial till sediments prior to reaching down gradient aquifers or surface waters. Objectives were addressed through a series of aqueous and solid phase experiments, including radial diffusion cells, an isotope analysis, X-ray diffraction, and sequential extractions. The diffusion cells were also simulated in a reactive transport framework to elucidate key reaction processes. The experiments indicate that the ingress and interaction of OSPW with the glacial till sediment-pore water system will result in: a mitigation of ingressing Na (retardation), displacement and then limited precipitation of exchangeable Ca and Mg (as carbonates), sulfate reduction and subsequent precipitation of the produced sulfides, as well as biodegradation of organic carbon. High concentrations of ingressing Cl (~ 375 mg L- 1) and Na (~ 575 mg L- 1) (even though the latter is delayed, or retarded) are expected to migrate through the till and into the underlying sand channel. Trace element mobility was influenced by ion exchange, oxidation-reduction, and mineral phase reactions including reductive dissolution of metal oxyhydroxides — in accordance with previous observations within sandy aquifer settings. Furthermore, although several trace elements showed the potential for release (Al, B, Ba, Cd, Mn, Pb, Si, Sr), large-scale mobilization is not supported. Thus, the present results suggest that in addition to the commonly cited naphthenic acids, remediation of OSPW-impacted groundwater will need to address high concentrations of major ions contributing to salinization.

  7. The use of laboratory-determined ion exchange parameters in the predictive modelling of field-scale major cation migration in groundwater over a 40-year period.

    PubMed

    Carlyle, Harriet F; Tellam, John H; Parker, Karen E

    2004-01-01

    An attempt has been made to estimate quantitatively cation concentration changes as estuary water invades a Triassic Sandstone aquifer in northwest England. Cation exchange capacities and selectivity coefficients for Na(+), K(+), Ca(2+), and Mg(2+) were measured in the laboratory using standard techniques. Selectivity coefficients were also determined using a method involving optimized back-calculation from flushing experiments, thus permitting better representation of field conditions; in all cases, the Gaines-Thomas/constant cation exchange capacity (CEC) model was found to be a reasonable, though not perfect, first description. The exchange parameters interpreted from the laboratory experiments were used in a one-dimensional reactive transport mixing cell model, and predictions compared with field pumping well data (Cl and hardness spanning a period of around 40 years, and full major ion analyses in approximately 1980). The concentration patterns predicted using Gaines-Thomas exchange with calcite equilibrium were similar to the observed patterns, but the concentrations of the divalent ions were significantly overestimated, as were 1980 sulphate concentrations, and 1980 alkalinity concentrations were underestimated. Including representation of sulphate reduction in the estuarine alluvium failed to replicate 1980 HCO(3) and pH values. However, by including partial CO(2) degassing following sulphate reduction, a process for which there is 34S and 18O evidence from a previous study, a good match for SO(4), HCO(3), and pH was attained. Using this modified estuary water and averaged values from the laboratory ion exchange parameter determinations, good predictions for the field cation data were obtained. It is concluded that the Gaines-Thomas/constant exchange capacity model with averaged parameter values can be used successfully in ion exchange predictions in this aquifer at a regional scale and over extended time scales, despite the numerous assumptions inherent in the approach; this has also been found to be the case in the few other published studies of regional ion exchanging flow. PMID:14698871

  8. SIMS analysis of volatiles in silicate glasses

    Microsoft Academic Search

    Erik Hauri; Jianhua Wang; Jacqueline E. Dixon; Penelope L. King; Charles Mandeville; Sally Newman

    2002-01-01

    This paper describes microanalysis techniques using secondary ion mass spectrometry (SIMS) to measure the abundances and isotopic compositions of hydrogen, carbon, fluorine, sulfur and chlorine in volcanic glasses. SIMS measurement of total H2O and total CO2 abundances compare very well with measurements on the same glasses using vibrational spectroscopy techniques (FTIR). A typical 10-min SIMS measurement for volatile abundances is

  9. Mercury Volatility in the Presence of Reducing Agents

    SciTech Connect

    Bibler, J.P.

    2001-03-23

    This document described a laboratory study designed to determine whether mercury is, in fact, reduced by bisulfite ion and ammonia and, if so, whether the reduced mercury is volatilized at the boiling point of water. The primary conclusions resulting from this study are that both bisulfite ion and ammonia are capable of reducing mercury in solution and that, when reduced, the mercury will all be volatilized and carried into the distillate.

  10. A BENCH SCALE STUDY ON BIODEGRADATION AND VOLATILIZATION OF ETHYLBENZOATE IN AQUIFERS. (R825549C039)

    EPA Science Inventory

    Experiments were conducted to investigate the fate of ethylbenzoate and soil microorganisms in shallow aquifers. Biodegradation and volatilization have been identified as the major mechanisms in attenuating ethylbenzoate in contaminated soils. The rate of volatilization was ex...

  11. Food price volatility

    PubMed Central

    Gilbert, C. L.; Morgan, C. W.

    2010-01-01

    The high food prices experienced over recent years have led to the widespread view that food price volatility has increased. However, volatility has generally been lower over the two most recent decades than previously. Variability over the most recent period has been high but, with the important exception of rice, not out of line with historical experience. There is weak evidence that grains price volatility more generally may be increasing but it is too early to say. PMID:20713400

  12. Iodine volatility. [PWR; BWR

    SciTech Connect

    Beahm, E.C.; Shockley, W.E.

    1984-01-01

    The ultimate aim of this program is to couple experimental aqueous iodine volatilities to a fission product release model. Iodine partition coefficients, for inorganic iodine, have been measured during hydrolysis and radiolysis. The hydrolysis experiments have illustrated the importance of reaction time on iodine volatility. However, radiolysis effects can override hydrolysis in determining iodine volatility. In addition, silver metal in radiolysis samples can react to form silver iodide accompanied by a decrease in iodine volatility. Experimental data are now being coupled to an iodine transport and release model that was developed in the Federal Republic of Germany.

  13. Lunar apatite with terrestrial volatile abundances.

    PubMed

    Boyce, Jeremy W; Liu, Yang; Rossman, George R; Guan, Yunbin; Eiler, John M; Stolper, Edward M; Taylor, Lawrence A

    2010-07-22

    The Moon is thought to be depleted relative to the Earth in volatile elements such as H, Cl and the alkalis. Nevertheless, evidence for lunar explosive volcanism has been used to infer that some lunar magmas exsolved a CO-rich and CO(2)-rich vapour phase before or during eruption. Although there is also evidence for other volatile species on glass spherules, until recently there had been no unambiguous reports of indigenous H in lunar rocks. Here we report quantitative ion microprobe measurements of late-stage apatite from lunar basalt 14053 that document concentrations of H, Cl and S that are indistinguishable from apatites in common terrestrial igneous rocks. These volatile contents could reflect post-magmatic metamorphic volatile addition or growth from a late-stage, interstitial, sulphide-saturated melt that contained approximately 1,600 parts per million H(2)O and approximately 3,500 parts per million Cl. Both metamorphic and igneous models of apatite formation suggest a volatile inventory for at least some lunar materials that is similar to comparable terrestrial materials. One possible implication is that portions of the lunar mantle or crust are more volatile-rich than previously thought. PMID:20651686

  14. Characterization of major-ion chemistry and nutrients in headwater streams along the Appalachian National Scenic Trail and within adjacent watersheds, Maine to Georgia

    USGS Publications Warehouse

    Argue, Denise M.; Pope, Jason P.; Dieffenbach, Fred

    2012-01-01

    An inventory of water-quality data on field parameters, major ions, and nutrients provided a summary of water quality in headwater (first- and second-order) streams within watersheds along the Appalachian National Scenic Trail (Appalachian Trail). Data from 1,817 sampling sites in 831 catchments were used for the water-quality summary. Catchment delineations from NHDPlus were used as the fundamental geographic units for this project. Criteria used to evaluate sampling sites for inclusion were based on selected physical attributes of the catchments adjacent to the Appalachian Trail, including stream elevation, percentage of developed land cover, and percentage of agricultural land cover. The headwater streams of the Appalachian Trail are generally dilute waters, with low pH, low acid neutralizing capacity (ANC), and low concentrations of nutrients. The median pH value was slightly acidic at 6.7; the median specific conductance value was 23.6 microsiemens per centimeter, and the median ANC value was 98.7 milliequivalents per liter (?eq/L). Median concentrations of cations (calcium, magnesium, sodium, and potassium) were each less than 1.5 milligrams per liter (mg/L), and median concentrations of anions (bicarbonate, chloride, fluoride, sulfate, and nitrate) were less than 10 mg/L. Differences in water-quality constituent levels along the Appalachian Trail may be related to elevation, atmospheric deposition, geology, and land cover. Spatial variations were summarized by ecological sections (ecosections) developed by the U.S. Forest Service. Specific conductance, pH, ANC, and concentrations of major ions (calcium, chloride, magnesium, sodium, and sulfate) were all negatively correlated with elevation. The highest elevation ecosections (White Mountains, Blue Ridge Mountains, and Allegheny Mountains) had the lowest pH, ANC, and concentrations of major ions. The lowest elevation ecosections (Lower New England and Hudson Valley) generally had the highest pH, ANC, and concentrations of major ions. The geology in discrete portions of these two ecosections was classified as containing carbonate minerals which has likely influenced the chemical character of the streamwater. Specific conductance, pH, ANC, and concentrations of major ions (calcium, chloride, magnesium, sodium, and sulfate) were all positively correlated with percentages of developed and agricultural land uses at the lower elevations of the central region of the Appalachian Trail (including the Green-Taconic-Berkshire Mountains, Lower New England, Hudson Valley, and Northern Ridge and Valley ecosections). The distinctly different chemical character of the streams in the central sections of the Appalachian Trail is likely related to the lower elevations, the presence of carbonate minerals in the geology, higher percentages of developed and agricultural land uses, and possibly the higher inputs of sulfate and nitrate from atmospheric deposition. Acid deposition of sulfate and nitrate are important influences on the acid-base chemistry of the surface waters of the Appalachian Trail. Atmospheric deposition estimates are consistently high (more than 18 kilograms per hectare (kg/ha) for sulfate, and more than 16 kg/ha for nitrate) at both the highest and lowest elevations. However, the lowest elevation (Green-Taconic-Berkshire Mountains, Lower New England, Hudson Valley, Northern Glaciated Allegheny Plateau, and Northern Ridge and Valley ecosections) included the largest spatial area of sustained high estimates of atmospheric deposition. Calcium-bicarbonate was the most frequently calculated water type in the Lower New England and Hudson Valley ecosections. In the northern and southern sections of the Appalachian Trail mix-cation water types were most prevalent and sulfate was the predominate anion. The predominance of the sulfate anion in the surface waters of the northern and southern ecosections likely reflects the influence of sulfate deposition. Although the central portion of the Appalachian Trail has the largest spatial area of high atmospheric acid deposition, the

  15. Volatile Analyzer for Lunar Polar Missions

    NASA Technical Reports Server (NTRS)

    Gibons, Everett K.; Pillinger, Colin T.; McKay, David S.; Waugh, Lester J.

    2011-01-01

    One of the major questions remaining for the future exploration of the Moon by humans concerns the presence of volatiles on our nearest neighbor in space. Observational studies, and investigations involving returned lunar samples and using robotic spacecraft infer the existence of volatile compounds particularly water [1]. It seems very likely that a volatile component will be concentrated at the poles in circumstances where low-temperatures exist to provide cryogenic traps. However, the full inventory of species, their concentration and their origin and sources are unknown. Of particular importance is whether abundances are sufficient to act as a resource of consumables for future lunar expeditions especially if a long-term base involving humans is to be established. To address some of these issues requires a lander designed specifically for operation at a high-lunar latitude. A vital part of the payload needs to be a volatile analyzer such as the Gas Analysis Package specifically designed for identification quantification of volatile substances and collecting information which will allow the origin of these volatiles to be identified [1]. The equipment included, particularly the gas analyzer, must be capable of operation in the extreme environmental conditions to be encountered. No accurate information yet exists regarding volatile concentration even for sites closer to the lunar equator (because of contamination). In this respect it will be important to understand (and thus limit) contamination of the lunar surface by extraneous material contributed from a variety of sources. The only data for the concentrations of volatiles at the poles comes from orbiting spacecraft and whilst the levels at high latitudes may be greater than at the equator, the volatile analyzer package under consideration will be designed to operate at the highest specifications possible and in a way that does not compromise the data.

  16. Air concentrations and wet deposition of major inorganic ions at five non-urban sites in China, 2001-2003

    NASA Astrophysics Data System (ADS)

    Aas, Wenche; Shao, Min; Jin, Lei; Larssen, Thorjørn; Zhao, Dawei; Xiang, Renjun; Zhang, Jinhong; Xiao, Jinsong; Duan, Lei

    Air and precipitation measurements at five sites were undertaken from 2001 to 2003 in four different provinces in China, as part of the acid rain monitoring program IMPACTS. The sites were located in Tie Shan Ping (TSP) in Chongqing, Cai Jia Tang (CJT) in Hunan, Lei Gong Shan (LGS) and Liu Chong Guan (LCG) in Guizhou and Li Xi He (LXH) in Guangdong. The site characteristics are quite varied with TSP and LCG located relatively near big cites while the three others are situated in more regionally representative areas. The distances to urban centres are reflected in the air pollution concentrations, with annual average concentrations of SO 2 ranging from 0.5 to above 40 ?g S m -3. The main components in the airborne particles are (NH 4) 2SO 4 and CaSO 4. Reduced nitrogen has a considerably higher concentration level than oxidised nitrogen, reflecting the high ammonia emissions from agriculture. The gas/particle ratio for the nitrogen compounds is about 1:1 at all the three intensive measurement sites, while for sulphur it varies from 2.5 to 0.5 depending on the distance to the emission sources. As in air, the predominant ions in precipitation are sulphate, calcium and ammonium. The volume weighted annual concentration of sulphate ranges from about 70 ?eq l -1 at the most rural site (LGS) to about 200 ?eq l -1 at TSP and LCG. The calcium concentration ranges from 25 to 250 ?eq l -1, while the total nitrogen concentration is between 30 and 150 ?eq l -1; ammonium is generally twice as high as nitrate. China's acid rain research has traditionally been focused on urban sites, but these measurements show a significant influence of long range transported air pollutants to rural areas in China. The concentration levels are significantly higher than seen in most other parts of the world.

  17. Integrated Chemical and Microorganism Monitoring of Air Using Gas Chromatography/Ion Mobility Spectometry: Toward an Expanded-Use Volatile Organic Analyzer (VOA)

    NASA Technical Reports Server (NTRS)

    Eiceman, G. A.

    1999-01-01

    The work described in this research program originated with the choice by NASA of an ion mobility spectrometer for air quality monitoring on-board the international spacestation. Though the gas chromatograph-ion mobility spectrometer analyzer known as VOA met or exceeded expectations, limitations in the basic understanding of response and the utilization of foundational principles into usable technology was considered unacceptable. In this research program, a comprehensive model for the origins of mobility spectra was proposed, tested and verified. The principles considered responsible for the appearance of mobility spectra have now been elucidated through this project. This understanding has been applied in automated identification of mobility spectra using neural networks and routine procedures for this now exist. Finally, the limitation on linear range has been shown to be a technical limitation and not a fundamental limitation so that a hardware component was crafted to extend the linear range of a mobility spectrometer by 10X. This project has led to one Ph.D. dissertation and one MS thesis. In addition, over ten public presentations at professional meetings and six journal publications have resulted from this program of research. The findings are so plentiful that total analysis of the findings may require four to six years or more. The findings confirm that the decision to use VOA was sound and that the chemical and physical principles of mobility spectrometry are both understandable and predictable.

  18. Nanosims Imaging of Volatile Elements (H, C, F and S) in Shergottites

    NASA Technical Reports Server (NTRS)

    Wang, J.; Usui, T.; Alexander, C. M. O'D.; Simon, J. I.; Jones, J. H.

    2012-01-01

    Volatiles, especially water, play a critical role in the evolution of Mars and other planetary bodies. Though the detection limit and spatial resolution in measuring volatiles in different phases of Martian meteorites have been greatly improved using ion microprobes (SIMS), it remains a challenge to accurately determine volatile concentrations due to contamination by terrestrial volatiles. Most Martian meteorites experienced cracking and shattering from the high-pressure shock either on the Martian surface and/or when coming to Earth. Martian meteorites generally contain volatiles in cracks even after careful sample preparation for SIMS analysis. We used the Cameca NanoSIMS 50L at Carnegie Institution of Washington to image volatile (H, C, F and S) distributions in two shergottite meteorites, LAR 06319 (L2) and Y-980456 (Y3). The mapping of volatiles in these meteorites greatly assisted us in understanding the distribution of volatile contamination and in improving future volatile measurement methods

  19. Determination of nanogram per liter concentrations of volatile organic compounds in water by capillary gas chromatography and selected ion monitoring mass spectrometry and its use to define groundwater flow directions in Edwards Aquifer, Texas

    USGS Publications Warehouse

    Buszka, P.M.; Rose, D.L.; Ozuna, G.B.; Groschen, G.E.

    1995-01-01

    A method has been developed to measure nanogram per liter amounts of selected volatile organic compounds (VOCs) including dichlorodifluoromethane, trichlorofluoromethane, cis-1,2-dichloroethene, trichloroethene, tetrachloroethene, and the isomers of dichlorobenzene in water. The method uses purge-and-trap techniques on a 100 mL sample, gas chromatography with a megabore capillary column, and electron impact, selected ion monitoring mass spectrometry. Minimum detection levels for these compounds ranged from 1 to 4 ng/L in water. Recoveries from organic-free distilled water and natural groundwater ranged from 70.5% for dichlorodifluoromethane to 107.8% for 1,4-dichlorobenzene. Precision was generally best for cis-1,2-dichloroethene, tetrachloroethene, and the dichlorobenzene isomers and worst for dichlorodifluoromethane and trichlorofluoromethane. Blank data indicated persistent, trace-level introduction of dichlorodifluoromethane, 1,4-dichlorobenzene, and tetrachloroemene to samples during storage and shipment at concentrations less than the method reporting limits. The largest concentrations of the selected VOCs in 27 water samples from the Edwards aquifer near San Antonio, TX, were from confined-zone wells near an abandoned landfill. The results defined a zone of water with no detectable VOCs in nearly all of the aquifer west of San Antonio and from part of the confined zone beneath San Antonio.

  20. Volatile liquid storage system

    Microsoft Academic Search

    R. J. Laverman; P. J. Winters; J. K. Rinehart

    1992-01-01

    This patent describes a method of collecting and abating emission from a volatile liquid in an above ground storage tank. It comprises the liquid storage tank having a bottom, a vertical cylindrical circular wall having a lower edge portion joined to the bottom, and an external fixed roof, the tank having an internal floating roof floating on a volatile liquid

  1. Characterizing interactions between surface water and groundwater in the Jialu River basin using major ion chemistry and stable isotopes

    NASA Astrophysics Data System (ADS)

    Yang, L.; Song, X.; Zhang, Y.; Han, D.; Zhang, B.; Long, D.

    2012-05-01

    The Jialu River, a secondary tributary of the Huaihe River, has been severely contaminated for the major contaminant sources, such as a number of untreated or lightly treated sewage wastes in some cities. Groundwater along the river is not an isolated component of the hydrologic system, but instead connected with the surface water. This study aims to characterize the relationships between surface water (e.g. reservoirs, lakes and rivers) and groundwater near the river in the shallow Quaternary aquifer. The concentration of Cl- in North Zhengzhou City increased prominently due to the discharge of a large amount of domestic water. Nitrate and potassium show maximum concentrations in groundwater in Fugou County. These high levels can be attributed to the use of a large quantity of fertilizer over this region. The regional well had water with a constant stable isotopic signature, which illustrates that the groundwater never or rarely receive recharge from surface water. However, the groundwater of transitional well (location SY3) seemed to be recharged by river water via bank infiltration in September 2010. Fractional contributions of river water to the groundwater were calculated based on isotopic and chemical data using a mass-balance approach. Results show that the groundwater was approximately composed of 60-70% river water. These findings would be useful for a better understanding of hydrogeological processes at the river-aquifer interface and ultimately benefit water management in the future.

  2. Major ion chemistry and hydrochemical studies of groundwater of parts of Palar river basin, Tamil Nadu, India.

    PubMed

    Dar, Mithas Ahmad; Sankar, K; Dar, Imran Ahmad

    2011-05-01

    Groundwater is almost globally important for human consumption as well as for the support of habitat and for maintaining the quality of base flow to rivers, while its quality assessment is essential to ensure sustainable safe use of the resources for drinking, agricultural, and industrial purposes. In the current study, 50 groundwater samples were collected from parts of Palar river basin to assess water quality and investigate hydrochemical nature by analyzing the major cations (Ca, Mg, Na, K) and anions (HCO(3), Cl, F,SO(4), NO(3), PO(4),CO(3), HCO(3), and F) besides some physical and chemical parameters (pH, electrical conductivity, alkalinity, and total hardness). Also, geographic information system-based groundwater quality mapping in the form of visually communicating contour maps was developed using ArcGIS-9.2 to delineate spatial variation in physicochemical characteristics of groundwater samples. Wilcox classification and US Salinity Laboratory hazard diagram suggests that 52% of the groundwater fall in the field of C2-S1, indicating water of medium salinity and low sodium, which can be used for irrigation in almost all types of soil with little danger of exchangeable sodium. Remaining 48% is falling under C1-SI, indicating water of low salinity and low sodium. PMID:20886289

  3. The effect of H2O gas on volatilities of planet-forming major elements. I - Experimental determination of thermodynamic properties of Ca-, Al-, and Si-hydroxide gas molecules and its application to the solar nebula

    NASA Technical Reports Server (NTRS)

    Hashimoto, Akihiko

    1992-01-01

    The vapor pressures of Ca(OH)2(g), Al(OH)3(g), and Si(OH)4(g) molecules in equilibrium with solid calcium-, aluminum, and silicon-oxides, respectively, were determined, and were used to derive the heats of formation and entropies of these species, which are expected to be abundant under the currently postulated physical conditions in the primordial solar nebula. These data, in conjunction with thermodynamic data from literature, were used to calculate the relative abundances of M, MO(x), and M(OH)n gas species and relative volatilities of Fe, Mg, Si, Ca, and Al for ranges of temperature, total pressure, and H/O abundance ratio corresponding to the plausible ranges of physical conditions in the solar nebula. The results are used to explain how Ca and Al could have evaporated from Ca,Al-rich inclusions in carbonaceous chondrites, while Si, Mg, and Fe condensed onto them during the preaccretion alteration of CAIs.

  4. Volatile composition and aroma activity of guava puree before and after thermal and dense phase carbon dioxide treatments.

    PubMed

    Plaza, Maria Lourdes; Marshall, Maurice R; Rouseff, Russell Lee

    2015-02-01

    Volatiles from initially frozen, dense phase carbon dioxide (DPCD)- and thermally treated guava purees were isolated by solid phase microextraction (SPME), chromatographically separated and identified using a combination of gas chromatography-mass spectrometry (GC-MS), GC-olfactometry (GC-O), and GC-pulsed flame photometric detector (GC-PFPD, sulfur mode). Fifty-eight volatiles were identified using GC-MS consisting of: 6 aldehydes, 2 acids, 15 alcohols, 6 ketones, 21 esters, and 8 terpenes. Eleven volatiles were newly identified in guava puree. Hexanal was the most abundant volatile in all 3 types of guava puree. Ten sulfur compounds were identified using GC-PFPD of which 3 possessed aroma activity and 3 were not previously reported in guava puree. Both treatments profoundly reduced total sulfur peak areas and produced different peak patterns compared to control. Thermal treatment reduced total sulfur peak area 47.9% compared to a loss of 34.7% with DPCD treatment. Twenty-six volatiles possessed aroma activity. (Z)-3-Hexenyl hexanoate was the major contributor to the aroma of the freshly thawed and DPCD-treated guava puree. DPCD treatment reduced total MS ion chromatogram (MS TIC) peak area 35% but produced a GC-O aroma profile very similar to control. Whereas thermal treatment reduced total TIC peak area only 8.7% compared to control but produced a 35% loss in total GC-O peak intensities. PMID:25588413

  5. ANTIOXIDANT ACTIVITY AND CHARACTERIZATION OF VOLATILE CONSTITUENTS OF TAHEEBO

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Volatiles were isolated from the dried inner bark of Tabebuia impetiginosa using steam distillation under reduced pressure followed by continuous liquid-liquid extraction. The extract was analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The major volatile const...

  6. Phase partitioning and volatility of secondary organic aerosol components formed from ?-pinene ozonolysis and OH oxidation: the importance of accretion products and other low volatility compounds

    NASA Astrophysics Data System (ADS)

    Lopez-Hilfiker, F. D.; Mohr, C.; Ehn, M.; Rubach, F.; Kleist, E.; Wildt, J.; Mentel, Th. F.; Carrasquillo, A.; Daumit, K.; Hunter, J.; Kroll, J. H.; Worsnop, D.; Thornton, J. A.

    2015-02-01

    We measured a large suite of gas and particle phase multi-functional organic compounds with a Filter Inlet for Gases and AEROsols (FIGAERO) coupled to a high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS) developed at the University of Washington. The instrument was deployed on environmental simulation chambers to study monoterpene oxidation as a secondary organic aerosol (SOA) source. We focus here on results from experiments utilizing an ionization method most selective towards acids (acetate negative ion proton transfer), but our conclusions are based on more general physical and chemical properties of the SOA. Hundreds of compounds were observed in both gas and particle phases, the latter being detected upon temperature programmed thermal desorption of collected particles. Particulate organic compounds detected by the FIGAERO HR-ToF-CIMS are highly correlated with, and explain at least 25-50% of, the organic aerosol mass measured by an Aerodyne Aerosol Mass Spectrometer (AMS). Reproducible multi-modal structures in the thermograms for individual compounds of a given elemental composition reveal a significant SOA mass contribution from large molecular weight organics and/or oligomers (i.e. multi-phase accretion reaction products). Approximately 50% of the HR-ToF-CIMS particle phase mass is associated with compounds having effective vapor pressures 4 or more orders of magnitude lower than commonly measured monoterpene oxidation products. The relative importance of these accretion-type and other extremely low volatility products appears to vary with photochemical conditions. We present a desorption temperature based framework for apportionment of thermogram signals into volatility bins. The volatility-based apportionment greatly improves agreement between measured and modeled gas-particle partitioning for select major and minor components of the SOA, consistent with thermal decomposition during desorption causing the conversion of lower volatility components into the detected higher volatility compounds.

  7. Identification of the hydrogeochemical processes in groundwater using major ion chemistry: a case study of Penna-Chitravathi river basins in Southern India.

    PubMed

    Reddy, A G S; Kumar, K Niranjan

    2010-11-01

    Hydrogeochemical studies were carried out in the Penna-Chitravathi river basins to identify and delineate the important geochemical processes which were responsible for the evolution of chemical composition of groundwater. The area is underlain by peninsular gneissic complex of Archaean age, Proterozoic meta-sediments, and strip of river alluvium. Groundwater samples were collected covering all the major hydrogeological environs in pre- and post-monsoon seasons. The samples were analyzed for major constituents such as Ca2+, Mg2+, Na+, K+, CO3-, HCO3-, Cl-, SO2(-4), NO3-, and F-. The groundwater in general is of Na+-Cl-, Na+-HCO3-, Ca2+-Mg2+-HCO3-, and Ca2+-Mg2+-Cl- types. Na+ among cations and Cl- and/or HCO3- among anions dominate the water; Na+ and Ca2+ are in the transitional state with Na+ replacing Ca2+ and HCO3- Cl- due to physiochemical changes in the aquifer and water-rock interactions. The Ca2+-Mg2+-Cl- HCO3- type water in one third samples suggest that ion exchange and dissolution processes are responsible for its origin. Change in storage of aquifer in a season does not influence the major geochemical makeup of groundwater. Gibbs plots indicate that the evolution of water chemistry is influenced by water-rock interaction followed by evapotranspiration process. The aquifer material mineralogy together with semiarid climate, poor drainage system, and low precipitation factors played major role in controlling groundwater quality of the area. PMID:19941064

  8. Major ion chemistry and dissolved inorganic carbon cycling in a human-disturbed mountainous river (the Luodingjiang River) of the Zhujiang (Pearl River), China.

    PubMed

    Zhang, Shurong; Lu, X X; Sun, Huiguo; Han, Jingtai; Higgitt, David Laurence

    2009-04-01

    Major ion chemistry and dissolved inorganic carbon system (DIC, mainly HCO3(-) and gaseous CO2) in the Luodingjiang River, a mountainous tributary of the Zhujiang (Pearl River), China, were examined based on a seasonal and spatial sampling scheme in 2005. The diverse distribution of lithology and anthropogenic impacts in the river basin provided the basic idea to assess the effects of lithology vs. human activities on water chemistry and carbon biogeochemistry in river systems. Major ions showed great spatial variations, with higher concentrations of total dissolved solids (TDS) and DIC in the regions with carbonate rocks and clastic sedimentary rocks, while lower in the regions with metamorphic sandstones and schists as well as granites. pCO2 at all sampling sites was oversaturated in June, ranging with a factor from 1.6 to 18.8 of the atmospheric concentration, reflecting the enhanced contribution from baseflow and interflow influx as well as in situ oxidation of organic matter. However, in April and December, undersaturated pCO2 was found in some shallow, clean rivers in the upstream regions. delta13C of DIC has a narrow range from -9.07 to -13.59 per thousand, which was more depleted in the regions with metamorphic rocks and granites than in the carbonate regions. Seasonally, it was slightly more depleted in the dry season (December) than in the wet season (June). The results suggested that lithological variability had a dominant control on spatial variations of water chemistry and carbon geochemistry in river systems. Besides, anthropogenic activities, such as agricultural and urban activities and in-stream damming, as well as river physical properties, such as water depth and transparency, also indicated their impacts. The seasonal variations likely reflected the changes of hydrological regime, as well as metabolic processes in the river. PMID:19185905

  9. Volatile Organic Compounds in Uremia

    PubMed Central

    Seifert, Luzia; Slodzinski, Rafael; Jankowski, Joachim; Zidek, Walter; Westhoff, Timm H.

    2012-01-01

    Background Although “uremic fetor” has long been felt to be diagnostic of renal failure, the compounds exhaled in uremia remain largely unknown so far. The present work investigates whether breath analysis by ion mobility spectrometry can be used for the identification of volatile organic compounds retained in uremia. Methods Breath analysis was performed in 28 adults with an eGFR ?60 ml/min per 1.73 m2, 26 adults with chronic renal failure corresponding to an eGFR of 10–59 ml/min per 1.73 m2, and 28 adults with end-stage renal disease (ESRD) before and after a hemodialysis session. Breath analysis was performed by ion mobility spectrometryafter gas-chromatographic preseparation. Identification of the compounds of interest was performed by thermal desorption gas chromatography/mass spectrometry. Results Breath analyses revealed significant differences in the spectra of patients with and without renal failure. Thirteen compounds were chosen for further evaluation. Some compounds including hydroxyacetone, 3-hydroxy-2-butanone and ammonia accumulated with decreasing renal function and were eliminated by dialysis. The concentrations of these compounds allowed a significant differentiation between healthy, chronic renal failure with an eGFR of 10–59 ml/min, and ESRD (p<0.05 each). Other compounds including 4-heptanal, 4-heptanone, and 2-heptanone preferentially or exclusively occurred in patients undergoing hemodialysis. Conclusion Impairment of renal function induces a characteristic fingerprint of volatile compounds in the breath. The technique of ion mobility spectrometry can be used for the identification of lipophilic uremic retention molecules. PMID:23049998

  10. Volatile terpenoids from aeciospores of Cronartium fusiforme.

    NASA Technical Reports Server (NTRS)

    Laseter, J. L.; Weete, J. D.; Walkinshaw, C. H.

    1973-01-01

    Identification of the terpenoids present in the volatile fraction from aeciospores of the gall rust fungus Cronartium fusiforme. The major monoterpenoid hydrocarbons found to be present with only traces of camphene include alpha-pinene, beta-pinene, delta(3)-carene, myrcene, linonene, beta-phellandrene, and delta-terpinene. A number of monoterpenoid alcohols, acyclic sesquiterpenes, and aromatic compounds were also present.

  11. Sodium channels as targets for volatile anesthetics.

    PubMed

    Herold, Karl F; Hemmings, Hugh C

    2012-01-01

    The molecular mechanisms of modern inhaled anesthetics are still poorly understood although they are widely used in clinical settings. Considerable evidence supports effects on membrane proteins including ligand- and voltage-gated ion channels of excitable cells. Na(+) channels are crucial to action potential initiation and propagation, and represent potential targets for volatile anesthetic effects on central nervous system depression. Inhibition of presynaptic Na(+) channels leads to reduced neurotransmitter release at the synapse and could therefore contribute to the mechanisms by which volatile anesthetics produce their characteristic end points: amnesia, unconsciousness, and immobility. Early studies on crayfish and squid giant axon showed inhibition of Na(+) currents by volatile anesthetics at high concentrations. Subsequent studies using native neuronal preparations and heterologous expression systems with various mammalian Na(+) channel isoforms implicated inhibition of presynaptic Na(+) channels in anesthetic actions at clinical concentrations. Volatile anesthetics reduce peak Na(+) current (I(Na)) and shift the voltage of half-maximal steady-state inactivation (h(?)) toward more negative potentials, thus stabilizing the fast-inactivated state. Furthermore recovery from fast-inactivation is slowed, together with enhanced use-dependent block during pulse train protocols. These effects can depress presynaptic excitability, depolarization and Ca(2+) entry, and ultimately reduce transmitter release. This reduction in transmitter release is more potent for glutamatergic compared to GABAergic terminals. Involvement of Na(+) channel inhibition in mediating the immobility caused by volatile anesthetics has been demonstrated in animal studies, in which intrathecal infusion of the Na(+) channel blocker tetrodotoxin increases volatile anesthetic potency, whereas infusion of the Na(+) channels agonist veratridine reduces anesthetic potency. These studies indicate that inhibition of presynaptic Na(+) channels by volatile anesthetics is involved in mediating some of their effects. PMID:22479247

  12. Mercury Volatility in the Presence of Reducing Agents

    Microsoft Academic Search

    Bibler

    2001-01-01

    This document described a laboratory study designed to determine whether mercury is, in fact, reduced by bisulfite ion and ammonia and, if so, whether the reduced mercury is volatilized at the boiling point of water. The primary conclusions resulting from this study are that both bisulfite ion and ammonia are capable of reducing mercury in solution and that, when reduced,

  13. Theoretical predictions of volatile bearing phases and volatile resources in some carbonaceous chondrites

    NASA Technical Reports Server (NTRS)

    Ganguly, Jibamitra; Saxena, Surendra K.

    1989-01-01

    Carbonaceous chondrites are usually believed to be the primary constituents of near-Earth asteroids and Phobos and Diemos, and are potential resources of fuels which may be exploited for future planetary missions. The nature and abundances are calculated of the major volatile bearing and other phases, including the vapor phase that should form in C1 and C2 type carbonaceous chondrites as functions of pressure and temperature. The results suggest that talc, antigorite plus or minus magnesite are the major volatile bearing phases and are stable below 400 C at 1 bar in these chondritic compositions. Simulated heating of a kilogram of C2 chondrite at fixed bulk composition between 400 and 800 C at 1 bar yields about 135 gm of volatile, which is made primarily of H2O, H2, CH4, CO2 and CO. The relative abundances of these volatile species change as functions of temperature, and on a molar basis, H2 becomes the most dominant species above 500 C. In contrast, Cl chondrites yield about 306 gm of volatile under the same condition, which consist almost completely of 60 wt percent H2O and 40 wt percent CO2. Preliminary kinetic considerations suggest that equilibrium dehydration of hydrous phyllosilicates should be attainable within a few hours at 600 C. These results provide the framework for further analyses of the volatile and economic resource potentials of carbonaceous chondrites.

  14. The implied volatility smirk

    Microsoft Academic Search

    Jin E. Zhang; Yi Xiang

    2008-01-01

    This paper provides an industry standard on how to quantify the shape of the implied volatility smirk in the equity index options market. Our local expansion method uses a second-order polynomial to describe the implied volatility–moneyness function and relates the coefficients of the polynomial to the properties of the implied risk-neutral distribution of the equity index return. We present a

  15. Volatile compound formation during argan kernel roasting.

    PubMed

    El Monfalouti, Hanae; Charrouf, Zoubida; Giordano, Manuela; Guillaume, Dominique; Kartah, Badreddine; Harhar, Hicham; Gharby, Saïd; Denhez, Clément; Zeppa, Giuseppe

    2013-01-01

    Virgin edible argan oil is prepared by cold-pressing argan kernels previously roasted at 110 degrees C for up to 25 minutes. The concentration of 40 volatile compounds in virgin edible argan oil was determined as a function of argan kernel roasting time. Most of the volatile compounds begin to be formed after 15 to 25 minutes of roasting. This suggests that a strictly controlled roasting time should allow the modulation of argan oil taste and thus satisfy different types of consumers. This could be of major importance considering the present booming use of edible argan oil. PMID:23472454

  16. Lunar volatiles: balancing science and resource development

    NASA Astrophysics Data System (ADS)

    Crider, Dana

    In the context of human exploration of the moon, the volatiles postulated to exist at the lunar poles have value as resources as well as scientific significance. Once sustained human operations commence on the moon, society will move from a paradigm in which examination of planetary materials has been unconstrained to one where use of those materials will support habitability and further exploration. A framework for the scientific investigation of lunar volatiles that allows for eventual economic exploitation can guide both activities and resolve the conflicts that will inevitably develop if the postulated lunar volatiles prove to be both extant and accessible. Scientific constraints on the framework include characterization at both poles of the isotopes, elements, and molecules in the volatiles, their relative and absolute abundances, and their horizontal and vertical distribution. A subset of this data is necessary in order to assess, develop, and initiate resource exploitation. In addition, the scientific record of volatiles in the cold traps can be contaminated by the cold-trapping of migrating volatiles released from operations elsewhere on the moon even if the indigenous, cold-trapped volatiles are not utilized. Possible decision points defining the transition from science-dominated to exploitation-dominated use include technology limits in the 70K environment, evolving science priorities (funding), and the resolution of major science issues. Inputs to policy development include any North vs. South Pole differences in volatile characteristics and the suitability of the volatiles to enable further scientific exploration of the moon. In the absence of national sovereignty on the moon, enforcement of any framework is an open question, particularly if science and commercial interests are in competition. The framework, processes, and precedent set by how we as a society choose to handle the scientific bounty and resource promise of lunar volatiles may eventually apply to Mars and near-earth asteroids. We believe there are useful lessons to be learned from the terrestrial experience with protected areas such as national parks, wilderness areas, and archeological sites. International agreements such as the Antarctic Treaty (in force since 1961), the Outer Space Treaty (1967), and the Moon Treaty (1979) carry relevant lessons as well.

  17. Volatiles of Chrysanthemum zawadskii var. latilobum K

    PubMed Central

    Chang, Kyung-Mi; Kim, Gun-Hee

    2012-01-01

    The volatile aroma constituents of Chrysanthemum zawadskii var. latilobum K. were separated by hydro distillation extraction (HDE) method using a Clevenger-type apparatus, and analyzed by gas chromatography-mass spectrometry (GC/MS). The yield of C. zawadskii var. latilobum K. flower essential oil (FEO) was 0.12% (w/w) and the color was light green. Fifty-five volatile chemical components, which make up 88.38% of the total aroma composition, were tentatively characterized. C. zawadskii var. latilobum K. FEOs contained 27 hydrocarbons, 12 alcohols, 7 ketones, 4 esters, 1 aldehyde, 1 amine, and 3 miscellaneous components. The major functional groups were terpene alcohol and ketone. Borneol (12.96), (±)-7-epi-amiteol (12.60), and camphor (10.54%) were the predominant volatiles. These compounds can be used in food and pharmaceutical industries due to their active bio-functional properties. PMID:24471090

  18. Using futures prices to filter short-term volatility and recover a latent, long-term price series for oil

    E-print Network

    Herce, Miguel Angel

    2006-01-01

    Oil prices are very volatile. But much of this volatility seems to reflect short-term,transitory factors that may have little or no influence on the price in the long run. Many major investment decisions should be guided ...

  19. Sub-annual Ice-Core Record of Major Ion and Heavy Metal Variability and Sources in the North Pacific Free Troposphere, Mt. Logan, Yukon, Canada

    NASA Astrophysics Data System (ADS)

    Osterberg, E. C.; Kurbatov, A. V.; Mayewski, P. A.; Kreutz, K. J.; Fisher, D.

    2005-12-01

    The Mt. Logan, Yukon, Canada summit plateau (PR Col; 5300 m.a.s.l.) ice core has been continuously sampled at high resolution (2-3 cm/sample) by a novel ice core melting system with discrete sampling, and analyzed for 8 major ions and 35 trace elements. Co-registered, sub-annual timeseries covering the past 500 years reveal seasonal aerosol fluctuations dominated by dust, with sea-salt contributing less than 5% of sulfate and calcium concentrations. Dating of the top 500 years of the record is by annual layer counting. Concentration spikes of sulfate greater than three times the standard deviation (60 ppb) above the mean (75 ppb) correspond in time with historical explosive volcanic eruptions. Sulfate spikes corresponding in time with large (VEI>4) historical Alaskan eruptions, including Katmai (1912) and St. Augustine (1986), are commonly associated with concentration and crustal enrichment factor spikes in lead, cadmium, antimony, copper, zinc, bismuth and thallium an order of magnitude above background (non-volcanic event) values. Sulfate spikes corresponding in time to large eruptions from distant volcanoes, including Agung (1963), do not show a corresponding rise in heavy metal concentrations. Apart from the periodic spikes in concentration, heavy metal timeseries largely mirror those of the major dust species (Al, Fe), but maintain significantly elevated crustal enrichment factors, probably due primarily to quiescent degassing of volcanoes. Such datasets are necessary to understand the cycling of heavy metals in the free troposphere, including the relative source strength of explosive eruptions vs. quiescent volcanic degassing, and the relative strength of natural vs. anthropogenic sources.

  20. Polycyclic aromatic hydrocarbons (PAHs) in ambient aerosols from Beijing: characterization of low volatile PAHs by positive-ion atmospheric pressure photoionization (APPI) coupled with Fourier transform ion cyclotron resonance.

    PubMed

    Jiang, Bin; Liang, Yongmei; Xu, Chunming; Zhang, Jingyi; Hu, Miao; Shi, Quan

    2014-05-01

    Aromatic fractions derived from aerosol samples were characterized by gas chromatography and mass spectrometry (GC-MS), high temperature simulated distillation (SIMDIS), and positive-ion atmospheric pressure photoionization (APPI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), respectively. It was found that about 27 wt % compounds in aromatic fractions could not be eluted from a GC column and some large molecule PAHs were neglected in GC-MS analysis. APPI FT-ICR MS was proven to be a powerful approach for characterizing the molecular composition of aromatics, especially for the large molecular species. An aromatic sample from Beijing urban aerosol was successfully characterized by APPI FT-ICR MS. Results showed that most abundant aromatic compounds in PM2.5 (particles with aerodynamic diameter ? 2.5 ?m) were highly condensed hydrocarbons with 4-8 aromatic rings and their homologues with very short alkyl chains. Furthermore, heteroatom-containing hydrocarbons were found as the significant components of the aromatic fractions: O1, O2, N1, and S1 class species with 10-28 DBEs (double bond equivalents) and 14-38 carbon numbers were identified by APPI FT-ICR MS. The heteroatom PAHs had similar DBEs and carbon number distribution as regular PAHs. PMID:24702199

  1. Quality of major ion and total dissolved solids data from groundwater sampled by the National Water-Quality Assessment Program, 1992–2010

    USGS Publications Warehouse

    Gross, Eliza L.; Lindsey, Bruce D.; Rupert, Michael G.

    2012-01-01

    Field blank samples help determine the frequency and magnitude of contamination bias, and replicate samples help determine the sampling variability (error) of measured analyte concentrations. Quality control data were evaluated for calcium, magnesium, sodium, potassium, chloride, sulfate, fluoride, silica, and total dissolved solids. A 99-percent upper confidence limit is calculated from field blanks to assess the potential for contamination bias. For magnesium, potassium, chloride, sulfate, and fluoride, potential contamination in more than 95 percent of environmental samples is less than or equal to the common maximum reporting level. Contamination bias has little effect on measured concentrations greater than 4.74 mg/L (milligrams per liter) for calcium, 14.98 mg/L for silica, 4.9 mg/L for sodium, and 120 mg/L for total dissolved solids. Estimates of sampling variability are calculated for high and low ranges of concentration for major ions and total dissolved solids. Examples showing the calculation of confidence intervals and how to determine whether measured differences between two water samples are significant are presented.

  2. Assessment of spatial variability of major-ion concentrations and del oxygen-18 values in surface snow, Upper Fremont Glacier, Wyoming, USA

    USGS Publications Warehouse

    Naftz, D.L.; Schuster, P.F.; Reddy, M.M.

    1994-01-01

    One hundred samples were collected from the surface of the Upper Fremont Glacier at equally spaced intervals defined by an 8100m2 snow grid to asesss the significance of lateral variability in major-ion concentrations and del oxygen-18 values. Comparison of the observed variability of each chemical constituent to the variability expected by measurement error indicated substantial lateral variability with the surface-snow layer. Results of the nested ANOVA indicate most of the variance for every constituent is in the values grouped at the two smaller geographic scales (between 506m2 and within 506m2 sections). The variance data from the snow grid were used to develop equations to evaluate the significance of both positive and negative concentration/value peaks of nitrate and del oxygen-18 with depth, in a 160m ice core. Values of del oxygen-18 in the section from 110-150m below the surface consistently vary outside the expected limits and possibly represents cooler temperatures during the Little Ice Age from about 1810 to 1725 A.D. -from Authors

  3. Sources of Terrestrial Volatiles

    NASA Technical Reports Server (NTRS)

    Zahnle, K. J.; Dones, L.

    1998-01-01

    Atmospheres are found enveloping those planets and satellites best able to hold them. The obvious conclusion is that volatile escape must have played nearly as great a role as volatile supply. A consequence of this view is that volatile supplies were probably much greater than the atmospheres that remain. The likeliest candidates are sources associated with the main events of planetary accretion itself such as volatile-rich planetesimals, or direct gravitational capture of nebular gases. Late asteroidal or cometary volatile-rich veneers are attractive, but they present quantitative difficulties. Comets in particular are inadequate, because the associated mass of stray comets that would have been scattered to the Oort Cloud or beyond is excessive. This difficulty applies to Uranus-Neptune planetesimals as well as to a putative massive early Kuiper Belt. Another potential problem with comets is that the D/H ratio in the three comets for which this has been measured is about twice that of Earth's oceans. Objects falling from a much augmented ancient asteroid belt remain a viable option, but timing is an issue: Can the depopulation of the asteroid belt be delayed long enough that it makes sense to talk of asteroids as a late veneer? Early accretion of asteroids as objects scattered into the maw of infant Earth makes more sense. Another appealing candidate population of volatile-rich objects for the inner solar system would be scattered planetesimals associated with the accretion of Jupiter, for two reasons: (1) Before there was Jupiter, there was no object in the solar system capable of expelling comets efficiently, and (2) the cross section of the inner solar system to stray objects was Greater when there were m many planetesimals.

  4. Can we control price volatility?

    SciTech Connect

    Hedden, B.

    1997-02-01

    Three steps for controlling the price volatility of petroleum products are discussed. These are: (1) speak to an expert. Oil dealers have never had more creative financial tools at our disposal for reducing price volatility. There are several experts that specialize in the industry. Let them help design a program that is best for you and your customers, (2) summer fill. Design a program to give customers incentives to fill their tanks in the late spring and early summer. If you have storage tanks, you should fill them by Labor Day. One of the major reasons prices stayed high this fall was that we filled the secondary and tertiary storage in September instead of June, and (3) talk to your suppliers. Fred Sacco, FMA-NJ`s executive vice president, has issued a warning that it is time for dealers to reexamine their relationship with their suppliers. {open_quotes}1996 may not be the season for marketers to stand back and see which terminal is posting the best number in the point-spread-per-gallon derby that has been so evident in recent heating seasons.

  5. Theoretical predictions of volatile bearing phases and volatile resources in some carbonaceous chondrites

    NASA Technical Reports Server (NTRS)

    Ganguly, Jibamitra; Saxena, Surendra K.

    1989-01-01

    Results are presented from theoretical calculations to predict the modal abundances and compositions of the major mineral phases and the vapor phase that could develop in the bulk compositions of carbonaceous chondrites. The abundances and compositions are obtained as functions of temperature and pressure. The calculations are used to evaluate the volatile and mineralogical resource potential of C1 and C2 carbonaceous chondrites.

  6. Institutions and the Volatility Curse

    E-print Network

    Leong, Weishu; Mohaddes, Kamiar

    2011-07-10

    , we find that while resource rents enhance real output per capita, their volatility exerts a negative impact on economic growth. Therefore, we argue that volatility, rather than abundance per se, drives the resource curse. However, we also find...

  7. SIMPLIFIED VOLATILE ORGANICS SAMPLER

    EPA Science Inventory

    The report describes the results of a task supporting EPA in its efforts to license hazardous waste incinerators. The study provided a design for a simplified sampling system for medium levels of volatile organic compounds (VOCs). Most of the study involved evaluation of sorbents...

  8. Stochastic volatility, smile & asymptotics

    Microsoft Academic Search

    K. Ronnie Sircar; George Papanicolaou

    1999-01-01

    We consider the pricing and hedging problem for options on stocks whose volatility is a random process. Traditional approaches, such as that of Hull and White, have been successful in accounting for the much observed smile curve, and the success of a large class of such models in this respect is guaranteed by a theorem of Renault and Touzi, for

  9. Economic geology: Volatile destruction

    NASA Astrophysics Data System (ADS)

    Scaillet, Bruno

    2010-07-01

    Direct evidence for the role of volatiles in magmatic ore formation has been elusive. Magma degassing at Merapi volcano in Indonesia is found to be directly linked to the selective leaching of metals from sulphide melts that ultimately form ore deposits.

  10. PREDICTING THE TOXICITY OF MAJOR IONS IN SEAWATER TO MYSID SHRIMP (MYSIDOPSIS BAHIA), SHEEPSHEAD MINNOW (CYPRINODON VARIEGATUS), AND INLAND SILVERSIDE MINNOW (MENIDIA BERYLLINA)

    EPA Science Inventory

    Although marine organisms are naturally adapted to salinities well above those of freshwater, elevated concentrations of specific ions have been shown to cause adverse effects on some saltwater species. Because some ions are also physiologically essential, a deficiency of these i...

  11. Analysis of volatile organic compounds from illicit cocaine samples

    SciTech Connect

    Robins, W.H.; Wright, B.W.

    1994-07-01

    Detection of illicit cocaine hydrochloride shipments can be improved if there is a greater understanding of the identity and quantity of volatile compounds present. This study provides preliminary data concerning the volatile organic compounds detected in a limited Set of cocaine hydrochloride samples. In all cases, cocaine was one of the major volatile compounds detected. Other tropeines were detected in almost all samples. Low concentrations of compounds that may be residues of processing solvents were observed in some samples. The equilibrium emissivity of. cocaine from cocaine hydrochloride was investigated and a value of 83 parts-per-trillion was determined.

  12. Atmospheric pressure chemical ionisation mass spectrometry for in vivo analysis of volatile flavour release

    Microsoft Academic Search

    A. J. Taylor; R. S. T. Linforth; B. A. Harvey; A. Blake

    2000-01-01

    To follow volatile flavour release in the expired air of people during eating, several physiological and analytical constraints must be observed to obtain good quality data. An interface has been developed to sample air from the nose and ionise the volatile compounds contained therein by atmospheric pressure chemical ionisation. The ions formed are detected in a quadrupole mass spectrometer. The

  13. Ag Ion Formation Mechanisms in Molten Glass Ion Emitters

    SciTech Connect

    Kessinger, Glen Frank; Huett, Thomas Allen; Delmore, James Edward

    2001-07-01

    Experimental and computational studies were conducted on silver/molten borosilicate glass (silica gel) ion emitters to better understand the physical and chemical processes associated with them, and in particular the chemistry of the molten glass solution that enhances ion emission. Based on the results of these studies and previous work, a model is proposed that explains the major features of the observed phenomena. It is believed that the molten glass dissolves both the analyte element and some Re from the filament. Rhenium is oxidized by the B2O3 of the borosilicate glass producing a rhenium oxide that migrates to the surface of the glass, providing a high work function surface that enhances cation emission. Last, we believe the analyte element (in this case Ag) resides in the glass primarily in the zero oxidation state (reduced by thermal decomposition of the oxide or nitrate) and volatilizes from the surface with a percentage of Ag atoms volatilizing as cations determined by the difference between the work function of the surface and the ionization potential of the analyte atom. This explanation may be applicable to other elements analyzed by silica gel technology that are readily reduced to the elemental form (by thermal decomposition or by reduction by the Re filament). Selected features of this explanation, such as analyte solubility and a high work function surface, may be applicable to analyte elements that are not readily reduced to elemental form.

  14. Predicting the emission of volatile organic compounds from silage systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As a precursor to smog, emission of volatile organic compounds (VOCs) to the atmosphere is an environmental concern in some regions. The major VOC emission source from farms is silage, with emissions coming from the silo face, mixing wagon, and feed bunk. The major compounds emitted are alcohols wit...

  15. PERTURBATION OF VOLTAGE-SENSITIVE Ca2+ CHANNEL FUNCTION BY VOLATILE ORGANIC SOLVENTS.

    EPA Science Inventory

    The mechanisms underlying the acute neurophysiological and behavioral effects of volatile organic compounds (VOCs) remain to be elucidated. However, the function of neuronal ion channels is perturbed by VOCs. The present study examined effects of toluene (TOL), trichloroethylene ...

  16. ANALYSIS OF VOLATILES AND SEMIVOLATILES BY DIRECT AQUEOUS INJECTION

    EPA Science Inventory

    Direct aqueous injection analysis (DAI) with gas chromatographic separation and ion trap mass spectral detection was used to analyze aqueous samples for g/L levels of 54 volatile and semivolatile compounds, and problematic non-purgeables and non-extractables. The method reduces ...

  17. Plants suppress their emission of volatiles when growing with conspecifics.

    PubMed

    Kigathi, Rose N; Weisser, Wolfgang W; Veit, Daniel; Gershenzon, Jonathan; Unsicker, Sybille B

    2013-04-01

    Plant volatiles mediate interactions with herbivores, herbivore enemies, and abiotic stresses, but these interactions mostly have been studied with individual isolated plants. It is not yet known how intra- and interspecific plant competition influence volatile emission. In a greenhouse experiment, we investigated the volatile emission by red clover (Trifolium pratense) growing alone, with a conspecific, or with an individual of the naturally co-occurring orchard grass, Dactylis glomerata. The individual and combined effects of above- and below ground plant contact were investigated. When T. pratense grew together with a conspecific, both total and herbivore-induced emission of volatiles was significantly reduced as compared to T. pratense growing with D. glomerata or growing alone. This reduction in emission occurred despite the fact that there was a significant reduction in T. pratense biomass due to competition with D. glomerata. The suppression of T. pratense volatile emission growing next to a conspecific was a general pattern observed for all major herbivore-induced volatiles and independent of whether plants were in contact above ground, below ground, or both above- and below ground. The reduction in volatile emission from plants growing with conspecifics may serve to reduce attack by specialist herbivores and minimize exploitation of herbivore attack information by neighbors. PMID:23525954

  18. Volatiles released from bean plants in response to agromyzid flies.

    PubMed

    Wei, Jia-Ning; Zhu, Junwei; Kang, Le

    2006-07-01

    Liriomyza sativae Blanchard and Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae) are two invasive flies in China that have caused economical damage on vegetables and ornamental plants. In this article, we report the profiles of emitted volatiles from healthy, mechanically damaged, and leafminer-damaged bean, Phaseolus vulgaris L., plants. Among 25 emitted volatiles identified, (E)-2-hexen-1-al, (3E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), (Z)-3-hexenyl acetate, (Z)-3-hexen-1-ol, (syn)- and (anti)-2-methylpropanal oxime, (syn)-2-methylbutanal oxime, linalool, and (E,E)-alpha-farnesene were consistently released from damaged bean plants. Combined amounts of these nine compounds made up more than 70% of the total volatiles emitted from each treatment. No qualitative differences in volatile emission were found between bean plants damaged by the two fly species; however, amounts of several major compounds induced by L. huidobrensis damage were significantly higher than those from plants damaged by L. sativae. The mechanically damaged plants released a higher proportion of green leaf volatiles than plants in the other treatments, whereas leafminer-damaged plants produced more terpenoids and oximes. Furthermore, the volatile profiles emitted from plants, damaged by adult leafminers, by second instar larvae, and even the plants with empty mines left by leafminer larvae (the pupal stage) were significantly different. The identification of volatile oximes released from damaged plants was confirmed and is discussed in a behavioral and biological control context. PMID:16404576

  19. Mechanism of Formation of the Major Estradiol Product Ions Following Collisional Activation of the Molecular Anion in a Tandem Quadrupole Mass Spectrometer

    NASA Astrophysics Data System (ADS)

    Wooding, Kerry M.; Barkley, Robert M.; Hankin, Joseph A.; Johnson, Christopher A.; Bradford, Andrew P.; Santoro, Nanette; Murphy, Robert C.

    2013-10-01

    The importance of the mass spectral product ion structure is highlighted in quantitative assays, which typically use multiple reaction monitoring (MRM), and in the discovery of novel metabolites. Estradiol is an important sex steroid whose quantitation and metabolite identification using tandem mass spectrometry has been widely employed in numerous clinical studies. Negative electrospray ionization tandem mass spectrometry of estradiol (E2) results in several product ions, including the abundant m/z 183 and 169. Although m/z 183 is one of the most abundant product ions used in many quantitative assays, the structure of m/z 183 has not been rigorously examined. We suggest a structure for m/z 183 and a mechanism of formation consistent with collision induced dissociation (CID) of E2 and several stable isotopes ([D4]-E2, [13C6]-E2, and [D1]-E2). An additional product ion from E2, namely m/z 169, has also been examined. MS3 experiments indicated that both m/z 183 and m/z 169 originate from only E2 [M - H]- m/z 271. These ions, m/z 183 and m/z 169, were also present in the collision induced decomposition mass spectra of other prominent estrogens, estrone (E1) and estriol (E3), indicating that these two product ions could be used to elucidate the estrogenic origin of novel metabolites. We propose two fragmentation schemes to explain the CID data and suggest a structure of m/z 183 and m/z 169 consistent with several isotopic variants and high resolution mass spectrometric measurements.

  20. Classification of Volatile Engine Particles

    SciTech Connect

    Cheng, Mengdawn [ORNL] [ORNL

    2013-01-01

    Volatile particles cannot be detected at the engine exhaust by an aerosol detector. They are formed when the exhaust is mixed with ambient air downstream. Lack of a precise definition of volatile engine particles has been an impediment to engine manufacturers and regulatory agencies involved in the development of an effective control strategy. It is beyond doubt that volatile particles from combustion sources contribute to the atmospheric particulate burden, and the effect of that contribution is a critical issue in the ongoing research in the areas of air quality and climate change. A new instrument, called volatile particle separator (VPS), has been developed. It utilizes a proprietary microporous metallic membrane to separate particles from vapors. VPS data were used in the development of a two-parameter function to quantitatively classify, for the first time, the volatilization behavior of engine particles. The value of parameter A describes the volatilization potential of an aerosol. A nonvolatile particle has a larger A-value than a volatile one. The value of parameter k, an effective evaporation energy barrier, is found to be much smaller for small engine particles than that for large engine particles. The VPS instrument provides a means beyond just being a volatile particle remover; it enables a numerical definition to characterize volatile engine particles.

  1. Volatile constituents of dog ( Canis familiaris ) and coyote ( Canis latrans ) anal sacs

    Microsoft Academic Search

    George Preti; Earl L. Muetterties; Joseph M. Furman; James J. Kennelly; Bradford E. Johns

    1976-01-01

    The volatile organic compounds from the anal sac secretions of male and female dogs and coyotes were examined using gas chromatography and gas chromatography-mass spectrometry. Short chain (C2–C6) acids and trimethylamine were major constituents. Changes in the type and abundance of the volatiles were examined across state of estrus, species, and gender. No consistent difference in the pattern of volatiles

  2. The glutamate-receptor ion channels (iGluRs), namely AMPA, kainate and NMDA receptors, are the major mediators of excitatory synaptic

    E-print Network

    Alford, Simon

    The glutamate-receptor ion channels (iGluRs), namely AMPA, kainate and NMDA receptors a unique role. NMDA receptors, which have attracted enormous interest, act as coincidence detectors and NMDA are synthetic agonists and naturally occurring toxins not found in the brain8 . AMPA receptors

  3. Volatile signals during pregnancy.

    PubMed

    Vaglio, Stefano

    2010-01-01

    Scents play a key role in mediating reproductive interactions in many vertebrates including mammals. Nowadays, several studies indicate that humans seem to use remarkably olfactory communication and are even able to produce and perceive pheromones. Furthermore, over the past several years, it became increasingly clear that pheromone-like chemical signals probably play a role in offspring identification and mother recognition. Recently developed technical procedures (solid-phase microextraction and dynamic headspace extraction) now allow investigators to characterize volatile compounds with high reliability. We analyzed the volatile compounds in sweat patch samples collected from the para-axillary and nipple-areola regions of women during pregnancy and after childbirth. We hypothesized that, at the time of birth and during the first weeks of life, the distinctive olfactory pattern of the para-axillary area is probably useful to newborn babies for recognizing and distinguishing their own mother, whereas the characteristic pattern of the nipple-areola region is probably useful as a guide to nourishment. PMID:20831951

  4. VOLATILIZATION OF ORGANIC POLLUTANTS FROM WATER

    EPA Science Inventory

    The volatilization of organic environmental contaminants from water bodies to the atmosphere was investigated. The general aim was to elucidate the factors that control the volatilization process and develop predictive methods for calculating volatilization rates for various comp...

  5. 1 Does Volatility Timing Matter?

    Microsoft Academic Search

    Jeff Fleming; Chris Kirby; Barbara Ostdiek

    This chapter examines the performance of volatility-timing strategies. We consider a short- horizon investor who uses mean-variance optimization to allocate funds between stocks, bonds, gold, and cash. Specifically, the investor rebalances his portfolio daily based on the current estimate of the conditional covariance matrix of returns. Our results indicate that volatility timing can yield substantial benefits. Moreover, the benefits are

  6. Oil and energy price volatility

    Microsoft Academic Search

    Eva Regnier

    2007-01-01

    It is commonly believed that since the 1973 oil crisis, oil and energy prices have been more volatile than other commodity prices. This study examines monthly producer prices for thousands of products over the period January 1945 through August 2005. The results show that crude oil, refined petroleum, and natural gas prices are more volatile than prices for about 95%

  7. Aroma volatiles in tangerine hybrids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Volatile compounds are well known to contribute to food flavor. In a breeding program, the knowledge of the identity and quantity of volatile compounds may help selecting fruit with desirable eating quality. Many studies report which compounds are responsible for orange juice flavor and aroma, but...

  8. Spiral mining for lunar volatiles

    Microsoft Academic Search

    H. H. Schmitt; G. L. Kulcinski; I. N. Sviatoslavsky; W. D. Carrier III

    1992-01-01

    Lunar spiral mining, extending outward from a periodically mobile central power and processing station represents an alternative for comparison with more traditional mining schemes. In this concept, a mining machine would separate regolith fines and extract the contained volatiles. Volatiles then would be pumped along the miner's support arm to the central station for refining and for export or storage.

  9. Major Ion Geochemistry of Horseshoe Lake, Mammoth Lakes, California: Water Quality in a Region with Elevated CO2 from Sub-Surface Leakage

    NASA Astrophysics Data System (ADS)

    Santilena, R.; Szutu, D.; Ellis, A. S.; Khachikian, C. S.

    2010-12-01

    Tree-kill areas around Horseshoe Lake indicate how naturally high levels of carbon dioxide (CO2) emitted from a cooling magma chamber are affecting the ecosystem. CO2 leakage from geologically sequestered CO2 sites may have similar effects. Weathering processes and water quality changes are two other environmental impacts of high levels of CO2 leaking from subsurface CO2 reservoirs. This study’s focus was to conduct a geochemical study of Horseshoe Lake with emphasis on water chemistry to determine any quantifiable effects from the high release of volcanic CO2. We collected 22 water samples, including 5 samples from streams that drained into the lake. Two interior locations were sampled at the surface and at depths of 2-meter intervals. The interior lake samples showed increasing Mg and Ca concentrations from the surface to 12 m in depth, and increasing Sr and Si from the surface to 4 m in depth. Water samples were measured for temperature, conductivity, pH, alkalinity, and analyzed for major ions Ca2+, K+, Na+, Mg2+, Cl-, SO42-, and HCO3- (from alkalinity). Amounts of Al, Ca, K, Mg, Na, and high levels of Si from elemental data are consistent with waters in granitic environments. Temperature in the lakes and streams ranged from 3.5 to 16 °C, pH ranged from 5.9-7.2, conductivity ranged from 8.66 to 21.93 ?S/cm, and alkalinity ranged from 0.137- 0.408 meq/L. A TSI Q-Trak™ measured soil and ambient CO2 concentrations in July and a Vernier LabQuest was used in August. A bottomless bottle was placed in the soil in a10cm deep hole with the probe inserted in the top. A probe about 1 m above ground measured the ambient CO2 concentrations. To determine the flux of soil CO2, concentrations were read over a 5-minute time period. CO2 gas concentrations in the tree kill area ranged from 600 to 1,700 ppm in ambient air, and over 99,000 ppm in the soil. Maximum readings were exceeded so actual values of CO2 in the soil are not known. The stream samples had a different solute composition than the lake. Stream samples tended to have higher Al and Si concentrations than the lake. For Al 9.3 x 10-7 to 1.8 x 10-6 moles/L in the streams and 4.8 x 10-7 to 1.2 x 10-6 moles/L in the lake, and for Si 1.3 x 10-4 to 2.1 x 10 -4 moles/L in the streams, 1.1 x 10-4 to 1.2 x 10-4 moles/L in the lake. Stream samples had and lower concentrations of Mg and Ca than lake perimeter and interior surface samples. Values for Mg were 6.0 x 10-6 to 1.1 x 10-5 moles/L in the streams and about 1.1 x 10-5 in the lake, and for Ca 9.3 x 10-7 to 1.8 x 10-6 moles/L in the stream, 4.3 x 10-5 to 4.5 x 10-5 in the lake. The difference could be because of weathering processes or because of unknown other inputs such as springs or groundwater. Additionally, Horseshoe Lake may be stratified, with different solutes dominating at different depths. Evaporation from the lake could also cause more concentrated solutes in solution. The data was generally consistent with results from previous USGS, but our samples were more dilute showing the impact of high precipitation during 2009 and 2010.

  10. Transformations of snow chemistry in the boreal forest: Accumulation and volatilization

    USGS Publications Warehouse

    Pomeroy, J.W.; Davies, T.D.; Jones, H.G.; Marsh, P.; Peters, N.E.; Tranter, M.

    1999-01-01

    This paper examines the processes and dynamics of ecologically-important inorganic chemical (primarily NO3-N) accumulation and loss in boreal forest snow during the cold winter period at a northern and southern location in the boreal forest of western Canada. Field observations from Inuvik, Northwest Territories and Waskesiu, Saskatchewan, Canada were used to link chemical transformations and physical processes in boreal forest snow. Data on the disposition and overwinter transformation of snow water equivalent, NO3-, SO42- and other major ions were examined. No evidence of enhanced dry deposition of chemical species to intercepted snow was found at either site except where high atmospheric aerosol concentrations prevailed. At Inuvik, concentrations of SO42- and Cl- were five to six times higher in intercepted snow than in surface snow away from the trees. SO4-S and Cl loads at Inuvik were correspondingly enhanced three-fold within the nearest 0.5 m to individual tree stems. Measurements of snow affected by canopy interception without rapid sublimation provided no evidence of ion volatilization from intercepted snow. Where intercepted snow sublimation rates were significant, ion loads in sub-canopy snow suggested that NO3- volatized with an efficiency of about 62% per snow mass sublimated. Extrapolating this measurement from Waskesiu to sublimation losses observed in other southern boreal environments suggests that 19-25% of snow inputs of NO3- can be lost during intercepted snow sublimation. The amount of N lost during sublimation may be large in high-snowfall, high N load southern boreal forests (Quebec) where 0.42 kg NO3-N ha-1 is estimated as a possible seasonal NO3- volatilization. The sensitivity of the N fluxes to climate and forest canopy variation and implications of the winter N losses for N budgets in the boreal forest are discussed.This paper examines the processes and dynamics of ecologically-important inorganic chemical (primarily NO3-N) accumulation and loss in boreal forest snow during the cold winter period at a northern and southern location in the boreal forest of western Canada. Field observations from Inuvik. Northwest Territories and Waskesiu, Saskatchewan, Canada were used to link chemical transformations and physical processes in boreal forest snow. Data on the disposition and overwinter transformation of snow water equivalent, NO3-, SO42- and other major ions were examined. No evidence of enhanced dry deposition of chemical species to intercepted snow was found at either site except where high atmospheric aerosol concentrations prevailed. At Inuvik, concentrations of SO42- and Cl- were five to six times higher in intercepted snow than in surface snow away from the trees. SO4-S and Cl loads at Inuvik were correspondingly enhanced three-fold within the nearest 0.5 m to individual tree stems. Measurements of snow affected by canopy interception without rapid sublimation provided no evidence of ion volatilization from intercepted snow. Where intercepted snow sublimation rates were significant, ion loads in sub-canopy snow suggested that NO3- volatized with an efficiency of about 62% per snow mass sublimated. Extrapolating this measurement from Waskesiu to sublimation losses observed in other southern boreal environments suggests that 19-25% of snow inputs of NO3- can be lost during intercepted snow sublimation. The amount of N lost during sublimation may be large in high-snowfall, high N load southern boreal forests (Quebec) where 0.42 kg NO3-N ha-1 is estimated as a possible seasonal NO3- volatilization. The sensitivity of the N fluxes to climate and forest canopy variation and implications of the winter N losses for N budgets in the boreal forest are discussed.

  11. Subduction and volatile recycling in Earth's mantle

    NASA Technical Reports Server (NTRS)

    King, S. D.; Ita, J. J.; Staudigel, H.

    1994-01-01

    The subduction of water and other volatiles into the mantle from oceanic sediments and altered oceanic crust is the major source of volatile recycling in the mantle. Until now, the geotherms that have been used to estimate the amount of volatiles that are recycled at subduction zones have been produced using the hypothesis that the slab is rigid and undergoes no internal deformation. On the other hand, most fluid dynamical mantle flow calculations assume that the slab has no greater strength than the surrounding mantle. Both of these views are inconsistent with laboratory work on the deformation of mantle minerals at high pressures. We consider the effects of the strength of the slab using two-dimensional calculations of a slab-like thermal downwelling with an endothermic phase change. Because the rheology and composition of subducting slabs are uncertain, we consider a range of Clapeyron slopes which bound current laboratory estimates of the spinel to perovskite plus magnesiowustite phase transition and simple temperature-dependent rheologies based on an Arrhenius law diffusion mechanism. In uniform viscosity convection models, subducted material piles up above the phase change until the pile becomes gravitationally unstable and sinks into the lower mantle (the avalanche). Strong slabs moderate the 'catastrophic' effects of the instabilities seen in many constant-viscosity convection calculations; however, even in the strongest slabs we consider, there is some retardation of the slab descent due to the presence of the phase change.

  12. Stochastic volatility models with persistent latent factors: theory and its applications to asset prices

    E-print Network

    Lee, Hyoung Il

    2008-10-10

    Major Subject: Economics iii ABSTRACT Stochastic Volatility Models with Persistent Latent Factors: Theory and Its Applications to Asset Prices. (August 2008) Hyoung Il Lee, B.A., Seoul National University Chair of Advisory Committee: Dr. Joon Y. Park We... . . . . . . . . . . . . . . . . . . . . . . . . . . 1 II STOCHASTIC VOLATILITY MODELS WITH SMOOTH TRANSITION REGIMES . . . . . . . . . . . . . . . . . . . . . 6 A. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 6 B. The Model . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 1...

  13. Volatile chemical reagent detector

    DOEpatents

    Chen, Liaohai; McBranch, Duncan; Wang, Rong; Whitten, David

    2004-08-24

    A device for detecting volatile chemical reagents based on fluorescence quenching analysis that is capable of detecting neutral electron acceptor molecules. The device includes a fluorescent material, a contact region, a light source, and an optical detector. The fluorescent material includes at least one polymer-surfactant complex. The polymer-surfactant complex is formed by combining a fluorescent ionic conjugated polymer with an oppositely charged surfactant. The polymer-surfactant complex may be formed in a polar solvent and included in the fluorescent material as a solution. Alternatively, the complex may be included in the fluorescent material as a thin film. The use of a polymer-surfactant complex in the fluorescent material allows the device to detect both neutral and ionic acceptor molecules. The use of a polymer-surfactant complex film allows the device and the fluorescent material to be reusable after exposing the fluorescent material to a vacuum for limited time.

  14. Plant Volatile Analogues Strengthen Attractiveness to Insect

    PubMed Central

    Sun, Yufeng; Yu, Hao; Zhou, Jing-Jiang; Pickett, John A.; Wu, Kongming

    2014-01-01

    Green leaf bug Apolygus lucorum (Meyer-Dür) is one of the major pests in agriculture. Management of A. lucorum was largely achieved by using pesticides. However, the increasing population of A. lucorum since growing Bt cotton widely and the increased awareness of ecoenvironment and agricultural product safety makes their population-control very challenging. Therefore this study was conducted to explore a novel ecological approach, synthetic plant volatile analogues, to manage the pest. Here, plant volatile analogues were first designed and synthesized by combining the bioactive components of ?-ionone and benzaldehyde. The stabilities of ?-ionone, benzaldehyde and analogue 3 g were tested. The electroantennogram (EAG) responses of A. lucorum adult antennae to the analogues were recorded. And the behavior assay and filed experiment were also conducted. In this study, thirteen analogues were acquired. The analogue 3 g was demonstrated to be more stable than ?-ionone and benzaldehyde in the environment. Many of the analogues elicited EAG responses, and the EAG response values to 3 g remained unchanged during seven-day period. 3 g was also demonstrated to be attractive to A. lucorum adults in the laboratory behavior experiment and in the field. Its attractiveness persisted longer than ?-ionone and benzaldehyde. This indicated that 3 g can strengthen attractiveness to insect and has potential as an attractant. Our results suggest that synthetic plant volatile analogues can strengthen attractiveness to insect. This is the first published study about synthetic plant volatile analogues that have the potential to be used in pest control. Our results will support a new ecological approach to pest control and it will be helpful to ecoenvironment and agricultural product safety. PMID:24911460

  15. Plant volatile analogues strengthen attractiveness to insect.

    PubMed

    Sun, Yufeng; Yu, Hao; Zhou, Jing-Jiang; Pickett, John A; Wu, Kongming

    2014-01-01

    Green leaf bug Apolygus lucorum (Meyer-Dür) is one of the major pests in agriculture. Management of A. lucorum was largely achieved by using pesticides. However, the increasing population of A. lucorum since growing Bt cotton widely and the increased awareness of ecoenvironment and agricultural product safety makes their population-control very challenging. Therefore this study was conducted to explore a novel ecological approach, synthetic plant volatile analogues, to manage the pest. Here, plant volatile analogues were first designed and synthesized by combining the bioactive components of ?-ionone and benzaldehyde. The stabilities of ?-ionone, benzaldehyde and analogue 3 g were tested. The electroantennogram (EAG) responses of A. lucorum adult antennae to the analogues were recorded. And the behavior assay and filed experiment were also conducted. In this study, thirteen analogues were acquired. The analogue 3 g was demonstrated to be more stable than ?-ionone and benzaldehyde in the environment. Many of the analogues elicited EAG responses, and the EAG response values to 3 g remained unchanged during seven-day period. 3 g was also demonstrated to be attractive to A. lucorum adults in the laboratory behavior experiment and in the field. Its attractiveness persisted longer than ?-ionone and benzaldehyde. This indicated that 3 g can strengthen attractiveness to insect and has potential as an attractant. Our results suggest that synthetic plant volatile analogues can strengthen attractiveness to insect. This is the first published study about synthetic plant volatile analogues that have the potential to be used in pest control. Our results will support a new ecological approach to pest control and it will be helpful to ecoenvironment and agricultural product safety. PMID:24911460

  16. Interactions between wine volatile compounds and grape and wine matrix components influence aroma compound headspace partitioning.

    PubMed

    Robinson, Anthony L; Ebeler, Susan E; Heymann, Hildegarde; Boss, Paul K; Solomon, Peter S; Trengove, Robert D

    2009-11-11

    A full-factorial design was used to assess the matrix effects of ethanol, glucose, glycerol, catechin, and proline on the volatile partitioning of 20 volatile compounds considered to play a role in wine aroma. Analysis of variance showed that the two-way interactions of ethanol and glucose, ethanol and glycerol, and glycerol and catechin significantly influenced headspace partitioning of volatiles. Experiments were conducted to observe the effect of varied ethanol and glucose concentrations on headspace partitioning of a constant concentration of volatiles. Analysis of variance and linear regression analysis showed that the presence of glucose increased the concentration of volatiles in the headspace, whereas increasing ethanol concentration was negatively correlated with headspace partitioning of volatiles. A subsequent study assessed the effect of diluting white and red wines with water and ethanol. It was again observed that increased ethanol concentration significantly reduced the relative abundance of volatile compounds in the sample headspace. This study investigates some of the complex matrix interactions of the major components of grape and wine that influence volatile compound headspace partitioning. The magnitude of each matrix-volatile interaction was ethanol > glucose > glycerol > catechin, whereas proline showed no apparent interaction. The results clearly identify that increasing ethanol concentrations significantly reduce the headspace concentration of volatile aroma compounds, which may contribute to explaining recent sensory research observations that indicate ethanol can suppress the fruit aroma attributes in wine. PMID:19845354

  17. Statistical Analysis of Major Ion and Trace Element Geochemistry of Water, 1986-2006, at Seven Wells Transecting the Freshwater/Saline-Water Interface of the Edwards Aquifer, San Antonio, Texas

    USGS Publications Warehouse

    Mahler, Barbara J.

    2008-01-01

    This report by the U.S. Geological Survey, in cooperation with the San Antonio Water System, describes the results of a statistical analysis of major ion and trace element geochemistry of water at seven wells transecting the freshwater/saline-water interface of the Edwards aquifer in San Antonio, Texas, either over time or in response to variations in hydrologic conditions. The data used in this report were collected during 1986-2006. The seven monitoring wells are screened at different depths in the aquifer at three sites that form a generally north-to-south transect. The three wells of the southern site and the deeper of the two middle-site wells are open to the freshwater/saline-water transition zone, which contains saline water. The shallower well of the middle site and the two wells of the northern site are open to the freshwater zone. Mean specific conductance (SC) values were greater at transition-zone wells than at freshwater-zone wells, but SC did not vary systematically with depth. Concentrations of all major ions except bicarbonate were greater at transition-zone wells than at freshwater-zone wells, but concentrations tended to be more variable at freshwater-zone wells. Mean molar ratios of magnesium:calcium, sulfate:chloride, and sodium:chloride were similar at transition-zone wells and freshwater-zone wells. Concentrations of trace elements for many water samples at the seven transect wells were below the laboratory analytical reporting level. Detections of trace elements were more frequent at transition-zone wells, and mean concentrations of cadmium, chromium, copper, lead, and silver were elevated at transition-zone wells relative to freshwater-zone wells. All strong correlations between SC and major ions were positive, and in general there were more and stronger correlations between SC and major ions in the water from the freshwater-zone wells than from the transition-zone wells. Except for the shallowest transition-zone well, the transition-zone wells had relatively few strong correlations overall. The lack of a strong correlation indicates that much of the variability in the major ion concentrations at these wells might be a result of analytical variability caused by the multiple laboratory analytical methods used. In most cases, strong correlations between concentrations of trace elements were positive, and transition-zone wells and freshwater-zone wells had water with a similar number of significant correlations. Principal components analysis indicates dilution of ground water by low-ionic-strength meteoric water at the three freshwater-zone wells and at the shallowest transition-zone well. At the two deeper transition-zone wells at the southern site, principal components analysis indicates that there is no systematic variation in major ion concentrations. At three transition-zone wells, there was a general trend toward less salinity over the 21-year period of sampling. Trends in SC at the freshwater-zone wells were less consistent. There is no systematic change in the direction of trend in SC by water type (saline or fresh), between sites, or with depth. In general, trends in major ion concentrations corresponded to those in SC. For each trace element over the 21-year sampling period, there was either no trend or a downward trend. Relations between SC, major ions, and major ion molar ratios and hydrologic indicators (concurrent or prior time-averaged measures of water level and effective rainfall) were investigated. Correlations between geochemical variables and measures of water level in the freshwater-zone wells were much more frequent than correlations between geochemical variables and measures of water level in the transition-zone wells. There were correlations between SC and all measures of water level at the two freshwater-zone wells at the northern site, but there were no correlations between SC and any measures of water level at any transition-zone wells. SC was correlated with effe

  18. Volatile analysis of ground almonds contaminated with naturally occurring fungi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxigenic aspergilli inflict major economic damage to the tree nut industry of California, with the highest negative impact to almonds. Aspergilli and fungi in general are known to emit volatiles in varying quantity and composition dependent upon their growth media. The goal of the study was to ...

  19. Modeling emissions of volatile organic compounds from silage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Photochemical smog is a major air pollution problem and a significant cause of premature death in the U.S. Smog forms in the presence of volatile organic compounds (VOCs), which are emitted primarily from industry and motor vehicles in the U.S. However, dairy farms may be an important source in so...

  20. Major Programs

    Cancer.gov

    The Division of Cancer Prevention supports major scientific collaborations and research networks at more than100 sites across the United States; investigator-initiated grants; postdoctoral training; and specialized resources for researchers.

  1. Lunar apatite with terrestrial volatile abundances Jeremy W. Boyce1,2

    E-print Network

    Perfect, Ed

    apatites in common terrestrial igneous rocks. These volatile contents could reflect post igneous rocks by measuring H, Cl and S contents of apatites in lunar basalt 14053 using secondary ion mass of indigenous H in lunar rocks. Here we report quantitative ion microprobe measurements of late-stage apatite

  2. Volatile Emission of Mechanically Damaged Almonds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mature almonds from the Monterey variety were evaluated for their volatile composition after mechanical damage and compared to the volatile composition of the corresponding undamaged almonds. Volatiles were collected on Tenax, desorbed with diethyl ether, and identified via GC-MS analyses. Volatile ...

  3. Volatiles on Mars

    NASA Technical Reports Server (NTRS)

    Jakosky, Bruce M.

    1988-01-01

    The long-term evolution of both the atmosphere and the surface of Mars can be understood by examining the history of volatiles in the Mars atmosphere, their non-atmospheric reservoirs, and the processes of exchange between the two. Clearly, the present state of both the surface and the atmosphere can only be seen, so that any inferences about the evolution of the climate system are just that, inferences. The processes which control the atmosphere and surface on a seasonal basis, however, are the same processes which can act on longer timescales; only the specific solar and atmospheric forcing will differ. Once the ability of each process to affect the seasonal behavior is understood, the long-timescale forcing may be applied to the various processes in order to clearly identify the ability of the processes to act over the entire history of Mars. The areas of surface-atmospheric interaction of Mars are addressed in the ongoing research. The climate system on Mars is controlled by processes involving the exchange between the surface and atmosphere, so it is important to understand the current behavior of those processes. This is especially so in light of the current interest in understanding Mars; the upcoming Mars Observer mission, and the potential for a future sample-return or human-exploration mission will focus emphasis on this area of Mars science.

  4. VOLATILIZATION OF METHYL PARATHION FROM FIELDS TREATED WITH MICROENCAPSULATED AND EMULSIFIABLE CONCENTRATE FORMULATIONS

    EPA Science Inventory

    Volatilization of pesticides from treated agricultural crops constitutes a major input of these chemicals into the atmosphere. Microencapsulated pesticide formulations are designed for slow release of biocides and thus increase the residence time on the plant foliage. The rate of...

  5. TREATMENT OF CHLORINATED VOLATILE ORGANIC COMPOUNDS IN UPFLOW WETLAND MESOCOSMS. (R828773C003)

    EPA Science Inventory

    Sorption, biodegradation and hydraulic parameters were determined in the laboratory for two candidate soil substrate mixtures for construction of an upflow treatment wetland for volatile organic compounds (VOCs) at a Superfund site. The major parent contaminants in the groundw...

  6. Project EARTH-13-BW1: Volatile loss from planets and asteroids Supervisor: Bernard Wood

    E-print Network

    Project EARTH-13-BW1: Volatile loss from planets and asteroids Supervisor: Bernard Wood One of the major questions concerning the chemical and isotopic evolution of the terrestrial planets and asteroids

  7. Evolution of Triton's volatile budget

    NASA Technical Reports Server (NTRS)

    Lunine, J. I.

    1993-01-01

    Triton's volatile budget provides important links to planetary formation processes in the cold outer solar nebula. However, the budget has been modified by processes subsequent to the accretion of this body. It is of interest to assess whether certain formation environments can be ruled out for Triton on the basis of its current volatile abundances, and also to quantify some of the post-accretional processes by which the abundances have been modified.

  8. Volatile organic compound emissions: an inventory for Western Europe

    SciTech Connect

    Edwards, A.H.; Campobasso, A.; Camps, R.; Cremer, G.; Long, M.D.

    1986-01-01

    The report gives details of an inventory compiled by CONCAWE and covering man-made non-methane volatile organic compound (VOC) emissions in Western Europe. The survey shows that the major man-made sources are road transport and solvents, each contributing around 40%. Total oil industry operations account for around 8%, with refining operations contribution about 2%. The major oil industry contribution comes from the distribution of gasoline, including vehicle refuelling (5%).

  9. Fruit volatile analysis using an electronic nose.

    PubMed

    Vallone, Simona; Lloyd, Nathan W; Ebeler, Susan E; Zakharov, Florence

    2012-01-01

    Numerous and diverse physiological changes occur during fruit ripening, including the development of a specific volatile blend that characterizes fruit aroma. Maturity at harvest is one of the key factors influencing the flavor quality of fruits and vegetables. The validation of robust methods that rapidly assess fruit maturity and aroma quality would allow improved management of advanced breeding programs, production practices and postharvest handling. Over the last three decades, much research has been conducted to develop so-called electronic noses, which are devices able to rapidly detect odors and flavors. Currently there are several commercially available electronic noses able to perform volatile analysis, based on different technologies. The electronic nose used in our work (zNose, EST, Newbury Park, CA, USA), consists of ultra-fast gas chromatography coupled with a surface acoustic wave sensor (UFGC-SAW). This technology has already been tested for its ability to monitor quality of various commodities, including detection of deterioration in apple; ripeness and rot evaluation in mango; aroma profiling of thymus species; C(6) volatile compounds in grape berries; characterization of vegetable oil and detection of adulterants in virgin coconut oil. This system can perform the three major steps of aroma analysis: headspace sampling, separation of volatile compounds, and detection. In about one minute, the output, a chromatogram, is produced and, after a purging cycle, the instrument is ready for further analysis. The results obtained with the zNose can be compared to those of other gas-chromatographic systems by calculation of Kovats Indices (KI). Once the instrument has been tuned with an alkane standard solution, the retention times are automatically converted into KIs. However, slight changes in temperature and flow rate are expected to occur over time, causing retention times to drift. Also, depending on the polarity of the column stationary phase, the reproducibility of KI calculations can vary by several index units. A series of programs and graphical interfaces were therefore developed to compare calculated KIs among samples in a semi-automated fashion. These programs reduce the time required for chromatogram analysis of large data sets and minimize the potential for misinterpretation of the data when chromatograms are not perfectly aligned. We present a method for rapid volatile compound analysis in fruit. Sample preparation, data acquisition and handling procedures are also discussed. PMID:22491160

  10. Fruit Volatile Analysis Using an Electronic Nose

    PubMed Central

    Vallone, Simona; Lloyd, Nathan W.; Ebeler, Susan E.; Zakharov, Florence

    2012-01-01

    Numerous and diverse physiological changes occur during fruit ripening, including the development of a specific volatile blend that characterizes fruit aroma. Maturity at harvest is one of the key factors influencing the flavor quality of fruits and vegetables1. The validation of robust methods that rapidly assess fruit maturity and aroma quality would allow improved management of advanced breeding programs, production practices and postharvest handling. Over the last three decades, much research has been conducted to develop so-called electronic noses, which are devices able to rapidly detect odors and flavors2-4. Currently there are several commercially available electronic noses able to perform volatile analysis, based on different technologies. The electronic nose used in our work (zNose, EST, Newbury Park, CA, USA), consists of ultra-fast gas chromatography coupled with a surface acoustic wave sensor (UFGC-SAW). This technology has already been tested for its ability to monitor quality of various commodities, including detection of deterioration in apple5; ripeness and rot evaluation in mango6; aroma profiling of thymus species7; C6 volatile compounds in grape berries8; characterization of vegetable oil9 and detection of adulterants in virgin coconut oil10. This system can perform the three major steps of aroma analysis: headspace sampling, separation of volatile compounds, and detection. In about one minute, the output, a chromatogram, is produced and, after a purging cycle, the instrument is ready for further analysis. The results obtained with the zNose can be compared to those of other gas-chromatographic systems by calculation of Kovats Indices (KI). Once the instrument has been tuned with an alkane standard solution, the retention times are automatically converted into KIs. However, slight changes in temperature and flow rate are expected to occur over time, causing retention times to drift. Also, depending on the polarity of the column stationary phase, the reproducibility of KI calculations can vary by several index units11. A series of programs and graphical interfaces were therefore developed to compare calculated KIs among samples in a semi-automated fashion. These programs reduce the time required for chromatogram analysis of large data sets and minimize the potential for misinterpretation of the data when chromatograms are not perfectly aligned. We present a method for rapid volatile compound analysis in fruit. Sample preparation, data acquisition and handling procedures are also discussed. PMID:22491160

  11. Essays on the Predictability and Volatility of Asset Returns

    E-print Network

    Jacewitz, Stefan A.

    2010-10-12

    ESSAYS ON THE PREDICTABILITY AND VOLATILITY OF ASSET RETURNS A Dissertation by STEFAN A. JACEWITZ Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment of the requirements for the degree of DOCTOR OF PHILOSOPHY... August 2009 Major Subject: Economics ESSAYS ON THE PREDICTABILITY AND VOLATILITY OF ASSET RETURNS A Dissertation by STEFAN A. JACEWITZ Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment of the requirements...

  12. Major ions anomalies and contamination status by trace metals in sediments from two hot spots along the Mediterranean Coast of Egypt.

    PubMed

    Shreadah, Mohamed A; Shobier, Aida H; Ghani, Safaa A Abdel; El Zokm, Gehan M; Said, Tarek O

    2015-05-01

    The major constituents and trace metals in the surface sediments collected from the Western Harbor and El-Mex Bay along the Egyptian Mediterranean Coast were studied. The concentrations of major constituents decreased in the following order: Ca?>?Si?>?Mg?>?Na?>?K for the Western Harbor and El-Mex Bay. Additionally, the ranking order of trace metals was Fe?>?Al?>?Pb?>?Zn?>?Mn?>?Cu?>?Sn?>?V?>?As?>?Cd?>?Se for the Western Harbor. For El-Mex Bay, the decreasing order was Fe?>?Al?>?Mn?>?Sn?>?Pb?>?Zn?>?Cu?>?V?>?As?>?Cd?>?Se. Fe, Al, Zn, Pb, Cu, V, Cd and Sn in the Western Harbor occurred in higher concentrations than in El-Mex Bay. A higher concentration of Mn was observed in El-Mex Bay. Two pollution indicators, enrichment factor (EF) and metal pollution index (MPI), and several sediment quality guidelines (SQGs) were used to evaluate the status of metal pollution. Based on the mean EF values of the studied metals, surface sediments of the Western Harbor and El-Mex Bay revealed that they are enriched with metals from anthropogenic sources. An analysis of variance (ANOVA) test showed that the mean measurements for all metals across the Western Harbor and El-Mex Bay are significantly different at a 0.05 significance level. Principal components analysis (PCA) was applied in result interpretation. The spatial distribution of the different parameters was illustrated. PMID:25899540

  13. The distillation and volatility of ionic liquids

    NASA Astrophysics Data System (ADS)

    Earle, Martyn J.; Esperança, José M. S. S.; Gilea, Manuela A.; Canongia Lopes, José N.; Rebelo, Luís P. N.; Magee, Joseph W.; Seddon, Kenneth R.; Widegren, Jason A.

    2006-02-01

    It is widely believed that a defining characteristic of ionic liquids (or low-temperature molten salts) is that they exert no measurable vapour pressure, and hence cannot be distilled. Here we demonstrate that this is unfounded, and that many ionic liquids can be distilled at low pressure without decomposition. Ionic liquids represent matter solely composed of ions, and so are perceived as non-volatile substances. During the last decade, interest in the field of ionic liquids has burgeoned, producing a wealth of intellectual and technological challenges and opportunities for the production of new chemical and extractive processes, fuel cells and batteries, and new composite materials. Much of this potential is underpinned by their presumed involatility. This characteristic, however, can severely restrict the attainability of high purity levels for ionic liquids (when they contain poorly volatile components) in recycling schemes, as well as excluding their use in gas-phase processes. We anticipate that our demonstration that some selected families of commonly used aprotic ionic liquids can be distilled at 200-300°C and low pressure, with concomitant recovery of significant amounts of pure substance, will permit these currently excluded applications to be realized.

  14. Arsenic(III, V) adsorption on a goethite-based adsorbent in the presence of major co-existing ions: Modeling competitive adsorption consistent with spectroscopic and molecular evidence

    NASA Astrophysics Data System (ADS)

    Kanematsu, Masakazu; Young, Thomas M.; Fukushi, Keisuke; Green, Peter G.; Darby, Jeannie L.

    2013-04-01

    Adsorption of the two oxyanions, arsenate (As(V)) and arsenite (As(III)), on a common goethite-based granular porous adsorbent is studied in the presence of major co-existing ions in groundwater (i.e., phosphate, silicic acid, sulfate, carbonate, magnesium, and calcium) and predicted using the extended triple layer model (ETLM), a dipole modified single-site triple layer surface complexation model consistent with spectroscopic and molecular evidence. Surface species of all ions were selected according to the previous ETLM studies and published experimental spectroscopic/theoretical molecular information. The adsorption equilibrium constants for all ions were determined using adsorption data obtained in single-solute systems. The adsorption equilibrium constants referenced to the site-occupancy standard state (indicated by K?) were compared with those for goethite in the literature if available. The values of these constants for the goethite-based adsorbent are found to be close to the values for goethite previously studied. These "constrained" adsorption equilibrium constants determined in single-solute systems were used in the ETLM to predict the competitive interactions of As(III, V) with the co-existing ions in binary-solute systems. The ETLM is capable of predicting As(III, V) adsorption in the presence of oxyanions (phosphate, silicic acid, sulfate, and carbonate). This study presents the first successful and systematic prediction of the competitive interactions of As(III, V) with these oxyanions using the ETLM. The ETLM prediction of surface (and aqueous) speciation also provides insights into the distinct adsorption behavior of As(III, V) in the presence of the oxyanions. Magnesium and calcium significantly enhanced As(V) adsorption at higher pH values, while they had little effect on As(III) adsorption. The enhanced adsorption of As(V), however, could not be predicted by the ETLM using the surface species proposed in previous ETLM studies. Further studies are necessary to identify ternary complexes, especially at high pH. Adsorption isotherms of As(V), a dominant form of arsenic in adsorptive water treatment systems, in the presence of the co-existing ions under relevant conditions of water treatment systems are also obtained and predicted by the ETLM to study and compare the effect of the co-existing ions on As(V) removal.

  15. Major Andre

    ERIC Educational Resources Information Center

    Henisch, B. A.; Henisch, H. K.

    1976-01-01

    If most Revolutionary era people seem two-dimensional their lives simpler to understand than ours, it may be only that history, with the benefit of hindsight, clarifies. Examines a profile of Major John Andre, the British liaison officer in Benedict Arnold's plan to surrender West Point, as both hero and villain to show the complexity of early…

  16. Radiation chemistry of major food components

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This book chapter summarizes radiolysis of lipids, proteins, carbohydrates and vitamins. The major focuses of the chapter are on recent developments in radiation chemistry and the use of irradiation to reduce undesirable chemicals in foods. Specifically, formation of volatile sulfur compounds from...

  17. Combination of a liquid chromatography-ultraviolet method with a non-volatile eluent, peak trapping and a liquid chromatography-mass spectrometry method with a volatile eluent to characterise erythromycin related substances.

    PubMed

    Pendela, Murali; Van den Bossche, Larissa; Hoogmartens, Jos; Van Schepdael, Ann; Adams, Erwin

    2008-02-01

    The selectivity and sensitivity obtained with volatile liquid chromatographic (LC) methods are often inferior compared to non-volatile ones. However, the buffers often used in the non-volatile system are incompatible to mass spectrometry (MS). So, the characterisation of unknown peaks in a non-volatile system, based on data obtained from a volatile LC-MS method, is problematic. In this study, the unknown peaks in a non-volatile liquid chromatography coupled with ultraviolet detection (LC-UV) system were directly characterised by a volatile LC-MS system using a peak trapping technique. Each peak eluted from the non-volatile system was trapped by a switching valve and sent to a LC-MS system using a volatile mobile phase. Mass spectral data were acquired on an LCQ ion trap mass spectrometer equipped with electrospray ionisation (ESI) operated in the positive ion mode. Using this technique, the fragmentation behaviour of erythromycin and its related substances was studied and the components occurring in commercial samples were investigated. In total 25 compounds mentioned in the literature were traced. Fourteen more unknown impurities were also studied. PMID:18177878

  18. Fragrance volatiles of developing and senescing carnation flowers.

    PubMed

    Schade, F; Legge, R L; Thompson, J E

    2001-04-01

    Thirteen major volatiles of the carnation flower fragrance signature have been identified by GC/MS. Of these, ten, hexanal, (2E)-hexenal, 1-hexanol, 2-hexanol, 3-hexen-1-ol, nonanal, benzaldehyde, benzyl alcohol, benzyl benzoate and caryophyllene, were quantified. The steady-state levels of these ten volatiles change independently as the flowers develop and senesce, suggesting that their synthesis is developmentally regulated. In addition, the chemical composition of the fragrance signature in naturally senesced flowers proved to be very different from that for flowers that had been induced to senesce prematurely by treatment with ethylene. Thus, senescence-related changes in carnation floral scent appear not to be directly regulated by ethylene. From cellular fractionation studies, it is evident that all of the volatiles, except 2-hexanol, are present in both membranous and cytosolic compartments, suggesting that their synthesis is membrane-associated and that they subsequently partition into the cytosol in accordance with partition coefficients. PMID:11314956

  19. Polyatomic Ion Bingo

    NSDL National Science Digital Library

    Perkins School for the Blind

    2012-06-26

    This activity was designed for blind learners, but all types of learners can play this game to learn about the major polyatomic ions (an ion that consists of two different elements). This game helps learners memorize the chemical formulas and names for the major polyatomic ions, which also helps learners in writing more complex expressions in chemistry.

  20. The relation between implied and realized volatility1

    Microsoft Academic Search

    B. J. Christensen; N. R. Prabhala

    1998-01-01

    Previous research finds the volatility implied by S&P 100 index option prices to be a biased and ineƒcient forecast of future volatility and to contain little or no incremental information beyond that in past realized volatility. In contrast, we find that implied volatility outperforms past volatility in forecasting future volatility and even subsumes the information content of past volatility in

  1. Areal distribution of selected trace elements, salinity, and major ions in shallow ground water, Tulare Basin, Southern San Joaquin Valley, California

    USGS Publications Warehouse

    Fujii, Roger; Swain, W.C.

    1995-01-01

    The distribution of salinity and selected trace elements in shallow ground water in the Tulare Basin, California, was assessed to evaluate potential problems related to disposal in evaporation ponds of irrigation drain water containing elevated concentrations of selenium and other trace elements. The constituents of primary concern were selenium, arsenic, and salinity; uranium, boron, and molybdenum also were evaluated. Samples from 117 shallow wells were analyzed, and the results for samples from 110 of the wells were interpreted in relation to surficial geology, sediment depositional environment, soil characteristics, and hydrologic processes to determine the geochemical and hydrologic factors affecting the distribution of these constituents in ground water. In general, shallow ground water in areas where concentrations of salinity and most trace elements are elevated is influenced primarily by sediments derived from marine sedimentary rocks originating in the Coast Range, San Emigdio Mountains, and Tehachapi Mountains, and probably by unusual exposures of similar marine formations in the Sierra Nevada. Ground water in areas where concentrations of salinity and trace elements are significantly lower generally is influenced by igneous and metamorphic rocks exposed in the Sierra Nevada. In addition to sources of sediments, evaporation of shallow ground water, as indicated by isotopic enrichment of oxygen-18 and deuterium, increases salinity and concentrations of conservative trace elements such as selenium (under oxidizing conditions) and boron. Redox conditions affect the oxidation state of all trace elements of concern, except boron, and were found to be a major influence on trace-element solubility. Under oxidized conditions, selenate predominates and behaves conservatively, and arsenate predominates and is affected by sorption reactions that can limit arsenic solubility. Under reduced conditions, selenium is reduced to insoluble elemental selenium and arsenite predominates and generally is more soluble than arsenate. Elevated concentrations of uranium in shallow ground water probably are associated with uranium deposits in Kern County and other parts of the basin where oxidized conditions cause the more solubleuranyl species to predominate. Boron was correlated with salinity and behaved conservatively, whereas adsorption and precipitation of molybdenum minerals probably limited molybdenum solubility. Inter- relations among constituents were examined with principal component analysis. The first two principal components explained 50.7 percent of the variance in the data. The first principal component was related to salinity, and the second principal component was related to redox conditions, reflecting two of the major influences on shallow ground-water quality found in this study.

  2. Comparative volatile profiles in soy sauce according to inoculated microorganisms.

    PubMed

    Lee, Kyung Eun; Lee, Sang Mi; Choi, Yong Ho; Hurh, Byung Serk; Kim, Young-Suk

    2013-01-01

    We compared the volatile profiles in soy sauce according to inoculation with Tetragenococcus halophilus and/or Zygosaccharomyces rouxii. Totals of 107 and 81 volatiles were respectively identified by using solid-phase microextraction and solvent extraction. The various volatile compounds identified included acids, aldehydes, esters, ketones, furans and furan derivatives, and phenols. The major volatiles in the samples treated with T. halophilus were acetic acid, formic acid, benzaldehyde, methyl acetate, ethyl 2-hydroxypropanoate, 2-hydroxy-3-methyl-2-cyclopenten-1-one, and 4-hydroxy-3-methoxybenzaldehyde, while those in the samples inoculated with Z. rouxii were mainly ethanol, acetaldehyde, ethyl propanoate, 2/3-methylbutanol, 1-butanol, 2-phenylethanol, ethyl 2-methylpropanoate, and 4-hydroxy-2-ethyl-5-methyl-3(2H)-furanone. The results indicate that T. halophilus produced significant acid compounds and could affect the Z. rouxii activity, supporting the notion that yeasts and lactic acid bacteria respectively have different metabolic pathways of alcoholic fermentation and lactic acid fermentation, and produce different dominant volatile compounds in soy sauce. PMID:24200796

  3. First evidence of a volatile sex pheromone in lady beetles.

    PubMed

    Fassotte, Bérénice; Fischer, Christophe; Durieux, Delphine; Lognay, Georges; Haubruge, Eric; Francis, Frédéric; Verheggen, François J

    2014-01-01

    To date, volatile sex pheromones have not been identified in the Coccinellidae family; yet, various studies have suggested that such semiochemicals exist. Here, we collected volatile chemicals released by virgin females of the multicolored Asian lady beetle, Harmonia axyridis (Pallas), which were either allowed or not allowed to feed on aphids. Virgin females in the presence of aphids, exhibited "calling behavior", which is commonly associated with the emission of a sex pheromone in several Coleoptera species. These calling females were found to release a blend of volatile compounds that is involved in the remote attraction (i.e., from a distance) of males. Gas Chromatography-Mass Spectrometry (GC-MS) analyses revealed that (-)-?-caryophyllene was the major constituent of the volatile blend (ranging from 80 to 86%), with four other chemical components also being present; ?-elemene, methyl-eugenol, ?-humulene, and ?-bulnesene. In a second set of experiments, the emission of the five constituents identified from the blend was quantified daily over a 9-day period after exposure to aphids. We found that the quantity of all five chemicals significantly increased across the experimental period. Finally, we evaluated the activity of a synthetic blend of these chemicals by performing bioassays which demonstrated the same attractive effect in males only. The results confirm that female H. axyridis produce a volatile sex pheromone. These findings have potential in the development of more specific and efficient biological pest-control management methods aimed at manipulating the behavior of this invasive lady beetle. PMID:25514321

  4. First Evidence of a Volatile Sex Pheromone in Lady Beetles

    PubMed Central

    Fassotte, Bérénice; Fischer, Christophe; Durieux, Delphine; Lognay, Georges; Haubruge, Eric; Francis, Frédéric; Verheggen, François J.

    2014-01-01

    To date, volatile sex pheromones have not been identified in the Coccinellidae family; yet, various studies have suggested that such semiochemicals exist. Here, we collected volatile chemicals released by virgin females of the multicolored Asian lady beetle, Harmonia axyridis (Pallas), which were either allowed or not allowed to feed on aphids. Virgin females in the presence of aphids, exhibited “calling behavior”, which is commonly associated with the emission of a sex pheromone in several Coleoptera species. These calling females were found to release a blend of volatile compounds that is involved in the remote attraction (i.e., from a distance) of males. Gas Chromatography-Mass Spectrometry (GC-MS) analyses revealed that (–)-?-caryophyllene was the major constituent of the volatile blend (ranging from 80 to 86%), with four other chemical components also being present; ?-elemene, methyl-eugenol, ?-humulene, and ?-bulnesene. In a second set of experiments, the emission of the five constituents identified from the blend was quantified daily over a 9-day period after exposure to aphids. We found that the quantity of all five chemicals significantly increased across the experimental period. Finally, we evaluated the activity of a synthetic blend of these chemicals by performing bioassays which demonstrated the same attractive effect in males only. The results confirm that female H. axyridis produce a volatile sex pheromone. These findings have potential in the development of more specific and efficient biological pest-control management methods aimed at manipulating the behavior of this invasive lady beetle. PMID:25514321

  5. Thermochromatography study of volatile tellurium species in various gas atmospheres

    NASA Astrophysics Data System (ADS)

    Maugeri, Emilio Andrea; Neuhausen, Jörg; Eichler, Robert; Piguet, David; Schumann, Dorothea

    2014-09-01

    The adsorption interaction of tellurium species with fused silica was studied by thermochromatography. Trace amounts of tellurium were obtained by irradiating elemental tin with ?-particles. Different tellurium species were obtained using carrier gases with varied redox potential. Adsorption enthalpies of the obtained species were calculated allowing for the identification of some species. Elemental tellurium or SnTe was deposited in thermochromatography experiments when using both dried and deoxygenated He and H2 as carrier gases. Tellurium dioxide was deposited in thermochromatography experiments when using dry oxygen as carrier gas. Tellurium dioxide was found to be significantly less volatile compared to elemental Te or SnTe. The deposition of a species with still lower volatility occurring under less oxidizing conditions was tentatively assigned to tellurium monoxide, TeO. Species more volatile than elemental tellurium or SnTe, most likely Te-hydroxides, were detected in experiments using moist H2 as carrier gas. In moist oxidizing gas, species more volatile than TeO2 were found, most likely Te-oxyhydroxides. The obtained results provide valuable input to design experiments for studying the volatility of tellurium's heavier homologue polonium and its compounds, which represent one of the major radiological concerns for the use of lead-bismuth-eutectic as coolant and target material for innovative accelerator-driven systems or spallation sources.

  6. Temperature- and fO2-Dependence of the Volatility and Condensation Behavior of Volatile Elements: Experimental Results

    NASA Astrophysics Data System (ADS)

    Ertel, W.; Dingwell, D. B.

    2010-12-01

    The volatility of elements is an important aspect in the Earths past, present and future: its present impact is reflected in elemental transport in the daily outgassing of volcanic vents. Its importance for understanding the earth also reaches back to the earliest periods of our solar system: nebular gases and matter underwent elemental fractionation processes based on the differences in the evaporation and condensation behaviour of matter within the solar nebula, which finally resulted in the formation of condensed matter from interplanetary dust particles up to the planets of the solar system. Precise knowledge of parameters controlling volatility as well as condensation of elements is, however, still lacking. The volatile or refractory behaviour of an element or component likely depends on the temperature and oxygen fugacity (fO2) conditions prevailing. To address this issue, a systematic study of the volatility of 18 volatile elements in respect to fO2 and temperature was launched applying a modified mechanically assisted equilibration technique (MAE): 60 g of a haplobasaltic starting composition (An-Di) was doped with up to 5000 ppm of volatile elements (Li, K, Na, Ti, Cr, Mn, Co, Cu, Cu, Zn, Ga, Rb, Cd, In, Sn, Sb, Cs, Tl) and heated to run temperature. For the fO2 dependence 2 experiments at logfO2 = -11.3 (~ IW -0.5) and - 0.7 (pure air) at a constant temperature of 1300 °C were performed, while T dependence was investigated at 1300 and 1500 °C at constant fO2 (pure air). The original MAE technique was modified by two Al2O3 plates extending from the hot spot region up to the upper, cooler regions in the muffle tube furnace, which was T calibrated prior to any experiment. In this way the plates function as condensation traps. Experiments lasted for up two weeks while experimental conditions were kept constant and monitored continuously. Up to 46 samples were taken from the melt by time-series sampling to measure the loss of volatile elements from the melt due to volatility. In the upper, cooler parts of the setup, condensation on the surface of the two Al2O3 plates was observed. In this way both evaporation as well as condensation behaviour of the investigated elements was investigated simultaneously. Quenched samples were investigated by electron microprobe analysis (major elements) and laser-ablation inductively coupled plasma mass spectrometry (LAMS) for their volatile content. The present data indicate a complex behaviour of volatility. 1. Volatile concentrations do not generally decrease for all elements continuously with time as anticipated in previous studies: concentrations of some elements generally assumed to be volatile exhibit very low volatility (independent of fO2: Cs, Rb, Na, K, Li). Some elements become more volatile with increasing fO2 (Cr, Ti, Mn), while others become less volatile (moderately: Cu, Co, Tl, Ga, Zn; dramatically: In, Sn, Sb, Cd). Condensation traps show clear indications (e.g.: differences in colour) for a continuous condensation sequence of components with decreasing T, which will require detailed analysis by LAMS.

  7. The Ion Implanter

    NSDL National Science Digital Library

    This web site displays and describes the major components of a modern high current ion implanter. It uses a series of clickable image maps to help navigate. The site describes the entire process of ion implantation.

  8. Production of volatile organohalogens by phytoplankton cultures

    NASA Astrophysics Data System (ADS)

    Tokarczyk, Ryszard; Moore, Robert M.

    1994-02-01

    Natural volatile halocarbons are important as carriers of reactive halogens to the troposphere and, in the case of the more stable compounds, to the stratosphere. Bromoform (CHBr3) has been of particular interest as a potential source of bromine which might account for sudden ozone depletion events in the Arctic boundary layer. The oceans have been shown to be major contributors of volatile halocarbons to the atmosphere, but the sources of halocarbons within them have been unknown except for macrophytic algae which are normally confined to the coastal zone. Here we report experiments that demonstrate that certain unialgal cultures of marine phytoplankton produce a suite of halocarbons (CHBr3, CHBr2Cl, CH2Br2). The production rate of each of these halocarbons is dependent on both species and growth stage. Chloroiodomethane which also appeared in the cultures could be attributable to photochemical production from a precursor (CH2I2). Great caution should be shown in extrapolating the rates estimated from these controlled experiments to the marine environment.

  9. Identification of a volatile phytotoxin from algae

    NASA Technical Reports Server (NTRS)

    Garavelli, J. S.; Fong, F.; Funkhouser, E. A.

    1984-01-01

    The objectives were to develop a trap system for isolating fractions of volatile algal phytotoxin and to characterize the major components of the isolated phytotoxin fractions. A bioassay using Phaseolus vulgaris seedlings was developed to aid in investigating the properties of the phytotoxin produced by cultures of Euglena gracilis var. bacillaris and Chlorella vulgaris. Two traps were found, 1.0 M hydrochloric acid and 0 C, which removed the phytotoxin from the algal effluent and which could be treated to release that phytotoxin as judged with the bioassay procedure. It was also determined that pretraps of 1.0 M sodium hydroxide and 1.0 M potassium biocarbonate could be used without lowering the phytotoxin effect. Ammonia was identified in trap solutions by ninhydrin reaction, indophenol reaction and derivatization with dansyl chloride and phenylisothiocyanate. Ammonia at the gaseous concentrations detected was found to have the same effects in the bioassay system as the volatile phytotoxin. It is possible that other basic, nitrogen containing compounds which augment the effects of ammonia were present at lower concentrations in the algal effluent.

  10. Syrtis Major

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 1 May 2002) The Science This image is from the region of Syrtis Major, which is dominated by a low-relief shield volcano. This area is believed to be an area of vigorous aeolian activity with strong winds in the east-west direction. The effects of these winds are observed as relatively bright streaks across the image, extending from topographic features such as craters. The brighter surface material probably indicates a smaller relative particle size in these areas, as finer particles have a higher albedo. The bright streaks seen off of craters are believed to have formed during dust storms. A raised crater rim can cause a reduction in the wind velocity directly behind it, which results in finer particles being preferentially deposited in this location. In the top half of the image, there is a large bright streak that crosses the entire image. There is no obvious topographic obstacle, therefore it is unclear whether it was formed in the same manner as described above. This image is located northwest of Nili Patera, a large caldera in Syrtis Major. Different flows from the caldera eruptions can be recognized as raised ridges, representing the edge of a flow lobe. The Story In the 17th century, Holland was in its Golden Age, a time of cultural greatness and immense political and economic influence in the world. In that time, lived a inquisitive person named Christian Huygens. As a boy, he loved to draw and to figure out problems in mathematics. As a man, he used these talents to make the first detailed drawings of the Martian surface - - only 50 years or so after Galileo first turned his telescope on Mars. Mars suddenly became something other than a small red dot in the sky. One of the drawings Huygens made was of a dark marking on the red planet's surface named Syrtis Major. Almost 350 years later, here we are with an orbiter that can show us this place in detail. Exploration lives! It's great we can study this area up close. In earlier periods of history, scientists were fascinated with Syrtis Major because this dark region varied so much through the seasons and years. Some people thought it might be a changing sea, and others thought it might be vegetation. Early spacecraft like Mariner and Viking revealed for the first time that the changes were caused by the wind blowing dust and sand across the surface. What we can see in this image is exactly that: evidence of a lot of wind action. Bright dust patches streak across this image, formed through wind interference from craters and other landforms. These wispy, bright streaks are spread on the surface by a vigorous, east-west wind that kicked up huge dust storms, scattering the fine particles of sand and dust in an almost etherial pattern. The bright streaks in the top part of the image might have formed in a slightly different way, because there is no landform standing in the wind's way. Beneath the bright surface dust are raised ridges that mark the edges of earlier lava flows from Nili Patera, a Martian 'caldera.' A caldera is a collapsed, bowl-shaped depression at the top of a volcano cone. Can you imagine how Christian Huygens would feel if he lived today and could see all of this knowledge unfold? Or how it would feel to be the first person to stand in this dark volcanic and cratered region, knowing how many discovers had paved the way to that moment? Yes, exploration lives!

  11. Syrtis Major

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 6 June 2002) The Science This image, located near the equator and 288W (72E), is near the southern edge of a low, broad volcanic feature called Syrtis Major. A close look at this image reveals a wrinkly texture that indicates a very rough surface that is associated with the lava flows that cover this region. On a larger scale, there are numerous bright streaks that trail topographic features such as craters. These bright streaks are in the wind shadows of the craters where dust that settles onto the surface is not as easily scoured away. It is important to note that these streaks are only bright in a relative sense to the surrounding image. Syrtis Major is one of the darkest regions on Mars and it is as dark as fresh basalt flows or dunes are on Earth. The Story Cool! It almost looks as if nature has 'painted' comets on the surface of Mars, using craters as comet cores and dust as streaky tails. Of course, that's just an illusion. As in many areas of Mars, the wind is behind the creation of such fantastic landforms. The natural phenomenon seen here gives this particular surface of Mars a very dynamic, fast-moving, almost luminous 'cosmic personality.' The bright, powdery-looking streaks of dust are in the 'wind shadows' of craters, where dust that settles onto the surface is not as easily scoured away. That's because the wind moves across the land in a particular direction, and a raised surface like the rim of a crater 'protects' dust from being completely blown away on the other side. The raised landforms basically act as a buffer. From the streaks seen above, you can tell the wind was blowing in a northeast to southwest direction. Why are the streaks so bright? Because they contrast with the really dark underlying terrain in this volcanic area of Mars. Syrtis Major is one of the darkest regions on Mars because it is made of basalt. Basalt is typically dark gray or black, and forms when a certain type of molten lava cools. The meaning of the word basalt has been traced back to an ancient Ethiopian word 'basal,' which means 'a rock from which you can obtain iron.' That must have made it a very desired material with ancient Earth civilizations long ago. Basalt is actually one of the most abundant types of rock found on Earth. Most of the volcanic islands in the ocean are made of basalt, including the large shield volcano of Mauna Loa, Hawaii, which is often compared to Martian shield volcanoes. Shield volcanoes don't have high, steep, mountain-like sides, but are instead low and broad humps upon the surface. They're created when highly fluid, molten-basalt flows spread out over wide areas. Over several millennia of basaltic layering upon layering, these volcanoes can reach massive sizes like the ones seen on Mars. You can see the wrinkly texture of dark lava flows (now hard and cool) in the above image beneath the brighter dust.

  12. Inhibition of prostate cancer (LNCaP) cell proliferation by volatile components from Nagami kumquats.

    PubMed

    Jayaprakasha, Guddadarangavvanahally K; Murthy, Kotamballi N Chidambara; Demarais, Rock; Patil, Bhimanagouda S

    2012-06-01

    Fresh Nagami kumquats (Fortunella margarita) were subjected to hydrodistillation using a Clevenger-type apparatus to obtain volatile oil. The chemical composition of the volatile oil was analyzed by GC-MS using Rtx-5 Sil MS and DB Wax columns. A total of 25 volatile compounds were identified by mass spectra, retention index, and comparison with known standards. The major identified compounds are d-limonene (41.64 %), ?-myrecene (16.54 %), linalyl propionate (9.55 %), and germacrene-D (5.93 %) from the Rtx-5 Sil MS column; d-limonene and ?-myrecene were also separated as major compounds on the DB wax column. The oil is rich in hydrocarbons (77.41 %) consisting of 60.05 % monoterpenes and 17.36 % sesquiterpenes. Interestingly, oxygenated hydrocarbons (17.6 %) were also found in kumquat volatile oil. Certain volatile compounds were also confirmed by positive chemical ionization and NMR spectra. Further, the volatile oil demonstrated good DPPH radical scavenging activity and antioxidant capacity. Kumquat volatile oil at 200 ppm concentration exhibited 55 %, 61 %, and 63.4 % inhibition of human prostate cancer (LNCaP) cell proliferation at 24, 48, and 72 h, respectively, by cell count assays. Significant increases in expression of bax/bcl2 and p53 proteins confirmed that volatile oil induces apoptosis. In addition, inhibition of inflammatory markers such as NF-?B and Cox-2 was observed. The cleavage of caspase-8 in the LNCaP cells treated with volatile oil demonstrated that apoptosis occurred through an extrinsic pathway. This is the first report of the identification and possible mechanisms of in vitro antiproliferative effects of kumquat volatile components on human prostate cancer (LNCaP) cells. PMID:22673830

  13. Implications of low SOA volatility and fragmentation reactions on the evolution of SOA in the atmosphere

    NASA Astrophysics Data System (ADS)

    Shrivastava, M.; Zelenyuk, A.; Imre, D. G.; Easter, R. C.; Beranek, J.; Zaveri, R. A.; Fast, J. D.

    2012-12-01

    We investigate the issues of low SOA volatility and gas-phase fragmentation reactions using both box and 3D model simulations. Analyzing both the laboratory and field data, we show that the observed slow evaporation behavior of SOA implies very low "effective volatility", under any realistic assumptions of mass accommodation coefficient. This analysis suggests that models may need to use different parameters to represent SOA formation versus its atmospheric evolution. A 5-product volatility basis set fit of ambient SOA evaporation rate measurements during the CARES field campaign show that a major fraction of the ambient SOA could be considered to be non-volatile under most atmospheric conditions. Accordingly, we revise our models to transform SOA "after formation" to a non-volatile non-absorbing organic aerosol (OA). We also develop simplified parameterizations to capture the first order effects of gas-phase fragmentation reactions. Using the box model, we show that, regardless of the fragmentation scheme, all multigenerational chemistry parameterizations predict one to two orders of magnitude higher SOA compared to models based on fixed smog chamber SOA yields. Increasing the amount of fragmentation reduces SOA loadings as expected. In addition, the box model shows that in our non-volatile SOA approach too, similar to the semi-volatile approach, the SOA is comprised of multi-generational oxidation products. But peak values of simulated O/C ratio are lower in the semi-volatile as compared to the non-volatile approach. Using the 3D model, we demonstrate complex variations in spatial and temporal distribution of SOA with varying degrees of fragmentation and the treatment of SOA as semi-volatile or non-volatile.

  14. Volatile Constituents of Agastache rugosa

    Microsoft Academic Search

    Peter Weyerstahl; Helga Marschall; Elfriede Manteuffel; Siegfried Huneck

    1992-01-01

    The volatile part of Agastache rugosa, (Labiatae) contains more than 90% of methyl chavicol. The fresh, herbaceous, spicy odor of the ground leaves was therefore caused by methyl chavicol in combination with some minor constituents such as anisaldehyde and p-methoxy cinnamaldehyde.

  15. Volatile Hydrocarbon Pheromones from Beetles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter reviews literature about hydrocarbons from beetles that serve as long-range pheromones. The most thoroughly studied beetles that use volatile hydrocarbon pheromones belong to the family Nitidulidae in the genera Carpophilus and Colopterus. Published pheromone research deals with behav...

  16. Passport options with stochastic volatility

    Microsoft Academic Search

    Vicky Henderson; David Hobson

    2001-01-01

    A passport option is a call option on the profits of a trading account. In this article, the robustness of passport option pricing is investigated by incorporating stochastic volatility. The key feature of a passport option is the holders' optimal strategy. It is known that in the case of exponential Brownian motion the strategy is to be long if the

  17. Spectroscopic Analysis of Volatile Elements

    NASA Astrophysics Data System (ADS)

    Manrao, E.; Fischer, D.

    2005-12-01

    We have performed spectral synthesis modeling to measure carbon and oxygen abundances for 297 stars from the Lick and AAT planet search surveys. Of these stars, 27 have known planetary companions and 270 are without detected planets. The abundance of these volatile elements is compared for stars with and without planetary companions, extending the analysis of Fischer & Valenti (2005).

  18. Volatile budget of Eyjafjallajokull magmas

    Microsoft Academic Search

    H. Sigurdsson; C. W. Mandeville

    2010-01-01

    Volatile elments played a critical role in the style of activity during the 2010 eruptions of the glacier-covered Eyjafjallajokull volcano in Iceland. The alkali basalt flank eruption at Fimmvorduhals was dominated by vigorous fire fountaining that produced dominantly spatter-fed aa lava flows. Production of fine ash during the subsequent summit eruption has been variously attributed to magma fragmentation, either due

  19. Alkaline dechlorination of chlorinated volatile organic compounds

    SciTech Connect

    Gu, B.; Siegrist, R.L.

    1996-06-01

    The vast majority of contaminated sites in the United States and abroad are contaminated with chlorinated volatile organic compounds (VOCs) such as trichloroethylene (TCE), trichloroethane (TCA), and chloroform. These VOCs are mobile and persistent in the subsurface and present serious health risks at trace concentrations. The goal of this project was to develop a new chemical treatment system that can rapidly and effectively degrade chlorinated VOCs. The system is based on our preliminary findings that strong alkalis such as sodium hydroxide (NaOH) can absorb and degrade TCE. The main objectives of this study were to determine the reaction rates between chlorinated VOCs, particularly TCE, and strong alkalis, to elucidate the reaction mechanisms and by-products, to optimize the chemical reactions under various experimental conditions, and to develop a laboratory bench- scale alkaline destruction column that can be used to destroy vapor- phase TCE.

  20. Volatile isoprenoid emissions from plastid to planet.

    PubMed

    Harrison, Sandy P; Morfopoulos, Catherine; Dani, K G Srikanta; Prentice, I Colin; Arneth, Almut; Atwell, Brian J; Barkley, Michael P; Leishman, Michelle R; Loreto, Francesco; Medlyn, Belinda E; Niinemets, Ülo; Possell, Malcolm; Peñuelas, Josep; Wright, Ian J

    2013-01-01

    Approximately 1-2% of net primary production by land plants is re-emitted to the atmosphere as isoprene and monoterpenes. These emissions play major roles in atmospheric chemistry and air pollution-climate interactions. Phenomenological models have been developed to predict their emission rates, but limited understanding of the function and regulation of these emissions has led to large uncertainties in model projections of air quality and greenhouse gas concentrations. We synthesize recent advances in diverse fields, from cell physiology to atmospheric remote sensing, and use this information to propose a simple conceptual model of volatile isoprenoid emission based on regulation of metabolism in the chloroplast. This may provide a robust foundation for scaling up emissions from the cellular to the global scale. PMID:23145556

  1. Plant Volatiles: Recent Advances and Future Perspectives

    Microsoft Academic Search

    Natalia Dudareva; Florence Negre; Dinesh A. Nagegowda; Irina Orlova

    2006-01-01

    Volatile compounds act as a language that plants use for their communication and interaction with the surrounding environment. To date, a total of 1700 volatile compounds have been isolated from more than 90 plant families. These volatiles, released from leaves, flowers, and fruits into the atmosphere and from roots into the soil, defend plants against herbivores and pathogens or provide

  2. Optimal portfolios when volatility can jump

    Microsoft Academic Search

    Nicole Branger; Christian Schlag; Eva Schneider

    2008-01-01

    We consider an asset allocation problem in a continuous-time model with stochastic volatility and jumps in both the asset price and its volatility. First, we derive the optimal portfolio for an investor with constant relative risk aversion. The demand for jump risk includes a hedging component, which is not present in models without volatility jumps. We further show that the

  3. The unemployment rate, unemployment volatility, and crime

    Microsoft Academic Search

    Firouz Fallahi; Hamed Pourtaghi; Gabriel Rodríguez

    2012-01-01

    Purpose – The paper aims to study the effect of the unemployment rate and its volatility on crime in the USA. It proposes that not only the unemployment rate, but also its volatility affect the crime. Design\\/methodology\\/approach – First, the volatility of the unemployment rate is calculated using ARCH models. Next, using the results from the first stage the ARDL

  4. Forecasting Volatility in Financial Markets: A Review

    Microsoft Academic Search

    Ser-Huang Poon; Clive W. J. Granger

    2003-01-01

    Financial market volatility is an important input for investment, option pricing, and financial market regulation. The emphasis of this review article is on forecasting instead of modelling; it compares the volatility forecasting findings in 93 papers published and written in the last two decades. Provided in this paper as well are volatility definitions, insights into problematic issues of forecast evaluation,

  5. The determinants of public deficit volatility

    Microsoft Academic Search

    Luca Agnello; Ricardo M. Sousay

    2009-01-01

    This paper empirically analyzes the political, institutional and economic sources of public deficit volatility. Using the system-GMM estimator for linear dynamic panel data models and a sample of 125 countries analyzed from 1980 to 2006, we show that higher public deficit volatility is typically associated with higher levels of political instability and less democracy. In addition, public deficit volatility tends

  6. Pyrolysis and volatilization of cocaine

    SciTech Connect

    Martin, B.R.; Lue, L.P.; Boni, J.P. (Virginia Commonwealth Univ., Richmond (USA))

    1989-05-01

    The increasing popularity of inhaling cocaine vapor prompted the present study, to determine cocaine's fate during this process. The free base of (3H)cocaine (1 microCi/50 mg) was added to a glass pipe, which was then heated in a furnace to simulate freebasing. Negative pressure was used to draw the vapor through a series of glass wool, ethanol, acidic, and basic traps. Air flow rate and temperature were found to have profound effects on the volatilization and pyrolysis of cocaine. At a temperature of 260 degrees C and a flow rate of 400 mL/min, 37% of the radioactivity remained in the pipe, 39% was found in the glass wool trap, and less than 1% in the remainder of the volatilization apparatus after a 10-min volatilization. Reducing the air flow rate to 100 mL/min reduced the amount of radioactivity collected in the glass wool trap to less than 10% of the starting material and increased the amount that remained in the pipe to 58%. GC/MS analysis of the contents of the glass wool trap after volatilization at 260 degrees C and a flow rate of 400 mL/min revealed that 60% of the cocaine remained intact, while approximately 6 and 2% of the starting material was recovered as benzoic acid and methylecgonidine, respectively. As the temperature was increased to 650 degrees C, benzoic acid and methylecgonidine accounted for 83 and 89% of the starting material, respectively, whereas only 2% of the cocaine remained intact. Quantitation of cocaine in the vapor during the course of volatilization revealed high concentrations during the first two min and low concentrations for the remaining time.

  7. Changes in streamflow and summary of major-ion chemistry and loads in the North Fork Red River basin upstream from Lake Altus, northwestern Texas and western Oklahoma, 1945-1999

    USGS Publications Warehouse

    Smith, S. Jerrod; Wahl, Kenneth L.

    2003-01-01

    Upstream from Lake Altus, the North Fork Red River drains an area of 2,515 square miles. The quantity and quality of surface water are major concerns at Lake Altus, and water-resource managers and consumers need historical information to make informed decisions about future development. The Lugert-Altus Irrigation District relies on withdrawals from the lake to sustain nearly 46,000 acres of agricultural land. Kendall's tau tests of precipitation data indicated no statistically significant trend over the entire 100 years of available record. However, a significant increase in precipitation occurred in the last 51 years. Four streamflow-gaging stations with more than 10 years of record were maintained in the basin. These stations recorded no significant trends in annual streamflow volume. Two stations, however, had significant increasing trends in the base-flow index, and three had significant decreasing trends in annual peak flows. Major-ion chemistry in the North Fork Red River is closely related to the chemical composition of the underlying bedrock. Two main lithologies are represented in the basin upstream from Lake Altus. In the upper reaches, young and poorly consolidated sediments include a range of sizes from coarse gravel to silt and clay. Nearsurface horizons commonly are cemented as calcium carbonate caliche. Finer-grained gypsiferous sandstones and shales dominate the lower reaches of the basin. A distinct increase in dissolved solids, specifically sodium, chloride, calcium, and sulfate, occurs as the river flows over rocks that contain substantial quantities of gypsum, anhydrite, and dolomite. These natural salts are the major dissolved constituents in the North Fork Red River.

  8. How Relevant is Volatility Forecasting for Financial Risk Management?

    Microsoft Academic Search

    Peter F. Christoffersen; Francis X. Diebold

    2000-01-01

    It depends. If volatility fluctuates in a forecastable way, volatility forecasts are useful for risk management (hence the interest in volatility forecastability in the risk management literature). Volatility forecastability, however, varies with horizon, and different horizons are relevant in different applications. Moreover, existing assessments of volatility forecastability are plagued by the fact that they are joint assessments of volatility forecastability

  9. Effect of gamma irradiation on curcuminoids and volatile oils of fresh turmeric ( Curcuma longa)

    NASA Astrophysics Data System (ADS)

    Dhanya, R.; Mishra, B. B.; Khaleel, K. M.

    2011-11-01

    In our earlier study a radiation dose of 5 kGy was reported to be suitable for microbial decontamination and shelf life extension of fresh turmeric ( Curcuma longa), while maintaining its quality attributes. In continuation of that work, the effect of gamma radiation on curcuminoids and volatile oil constituents in fresh turmeric was studied. Fresh peeled turmeric rhizomes were gamma irradiated at doses of 1, 3 and 5 kGy. Curcuminoid content and volatile oils were analyzed by reverse phase HPLC and GC-MS, respectively. The curcuminoid content was slightly increased by gamma irradiation. No statistically significant changes were observed due to irradiation in majority of the volatile oil constituents.

  10. Volatile Components of Sapodilla Fruit (Manilkara achras L.)

    Microsoft Academic Search

    Jorge A. Pino; Rolando Marbot; Juan Aguero

    2003-01-01

    The volatile components of sapodilla fruit, which were isolated by simultaneous steam distillation\\/solvent extraction with diethyl ether, were identified by a combination of retention indices and GC\\/MS. Sixty-nine constituents were identified in the aroma concentrate, from which methanethiol (32.0%), hexadecanoic acid (26.3%), 3-hydroxy-2-butanone (6.8%), ethyl acetate (6.0%) and isoamyl alcohol (5.9%) were found to be the major constituents.

  11. Volatile components of Discaria americana Gillies & Hook (Rhamnaceae)

    Microsoft Academic Search

    Silvana Rodriguez; Ana Paula Murray

    2008-01-01

    The volatile fraction from aerial parts (flowers, stems and leaves) of Discaria americana Gillies & Hook (Rhamnaceae) was obtained by hydrodistillation and the chemical composition of this oil was determined by gas chromatography and gas chromatography–mass spectrometry. The major constituents resulted to be 4-methylphenol (15.5%), eugenol (11%), 3-methylindole (9.7%) and ?-terpineol (6.2%). The essential oil of this plant displayed strong

  12. Pyrolysis of Spent Ion Exchange Resins - 12210

    SciTech Connect

    Braehler, Georg; Slametschka, Rainer [NUKEM Technologies GmbH (Germany)

    2012-07-01

    Organic ion exchangers (IEX) play a major and increasing role in the reactor coolant and other water purification processes. During their operation time they receive significant amounts of radioactivity, making their disposal, together with their organic nature, as medium active waste challenging. Processes applied so far do not eliminate the organic matter, which is unwanted in disposal facilities, or, if high temperatures are applied, raise problems with volatile radionuclides. NUKEM Technologies offers their well introduces process for the destruction of spent solvent (TBP), the pebble bed pyrolysis, now for the treatment of spent IEX (and other problematic waste), with the following benefits: the pyrolysis product is free of organic matter, and the operation temperature with approx. 500 deg. C keeps Cs radionuclides completely in the solid residue. (authors)

  13. Coumarin-Containing Grass: Volatiles from Sweet Vernalgrass (Anthoxanthum odoratum L.)

    Microsoft Academic Search

    Aldo Tava

    2001-01-01

    Anthoxanthum odoratum, which is a coumarin containing grass, was investigated for its volatile components. The essential oil obtained by steam distillation from the fresh leaves and hay, were analyzed by GC and GC\\/MS. The major volatile component of both leaf and hay oil was coumarin (96.3% and 46.8%, respectively). Aldehydes, alcohols, ketones, phenols, terpenes, hydrocarbons and acids were also identified

  14. The role of microorganisms in the production of volatile sulfhydryl compounds in cheddar cheese slurries

    E-print Network

    Ponce-Trevino, Raul

    1988-01-01

    THE ROLE OF MICROORGANISMS IN THE PRODUCTION OF VOLATILE SULFHYDRYL COMPOUNDS IN CHEDDAR CHEESE SLURRIES A Thesis By RAUL PONCE-TREVINO Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE December 1988 Major Subject: Food Science and Technology THE ROLE OF MICROORGANISMS IN THE PRODUCTION OF VOLATILE SULFHYDRYL COMPOUNDS IN CHEDDAR CHEESE SLURRIES A Thesis By RAUL PONCE-TREVINO Approved...

  15. Exchange-rate volatility in Latin America and its impact on foreign trade

    Microsoft Academic Search

    Augustine C. Arize; Thomas Osang; Daniel J. Slottje

    2008-01-01

    This paper investigates empirically the impact of real exchange-rate volatility on the export flows of eight Latin American countries over the quarterly period 1973–2004. Estimates of the cointegrating relations are obtained using different cointegration techniques. Estimates of the short-run dynamics are obtained for each country utilizing the error-correction technique. The major results show that increases in the volatility of the

  16. Chemical components and biological activities of volatile oil of Kaempferia galanga Linn

    Microsoft Academic Search

    Supinya Tewtrakul; Supreeya Yuenyongsawad; Sopa Kummee

    Volatile oil of dried rhizome of Kaempferia galanga obtained by water distillation was determined for its chemical components using gas chromatography and mass spectrometry (GC-MS). The major chemical constituents were identified as ethyl-p-methoxycinnamate (31.77%), methylcinnamate (23.23%), carvone (11.13%), eucalyptol (9.59%) and pentadecane (6.41%), respectively. Antimicrobial activity of the volatile oil was tested against various microbes using agar disc diffusion method

  17. Characterization of ammonia volatilization from liquid dairy manure

    NASA Astrophysics Data System (ADS)

    Koirala, Kedar

    Emission of gases, odor, and particulate matters from livestock manure is a major concern because of their potential adverse environmental impacts. For example, ammonia in the air has the potential to: negatively affect animal, human health and environment. Mitigation of ammonia emissions from livestock manure to protect animal and human health, and the environment, in general, is thus an important agenda for livestock producers, engineers, and environmental scientists. Proper understanding of the mechanisms or process of its volatilization from manure is the first step towards designing or formulating appropriate emissions mitigation strategies. This research investigated the effects of suspended solids, anaerobic digestion, and ionic strength on the ammonia (NH3) volatilization mechanism from liquid dairy manure. Experiments were conducted to: (i) assess the role of suspended solids characteristics on ammonia volatilization, (ii) evaluate the impacts of anaerobic digestion on the process governing NH 3 volatilization, and (iii) delineate the influences of suspended solids (SS) and ionic strength (IS) on the ammonia volatilization process from dairy manure. Two key parameters (the ammonia dissociation and the overall mass transfer coefficient (KoL)) that govern ammonia volatilization were evaluated to achieve these objectives. The physical and chemical properties of manure were also evaluated to further elucidate the respective processes. The suspended solids ammoniacal nitrogen adsorption properties did not significantly affect either the ammonium dissociation or the K oL; suggesting that the characteristics of manure suspended solids did not play a significant role in ammonia volatilization from liquid dairy manure. The dissociation of ammonium in anaerobically digested (AD) manure was significantly higher than in the undigested (UD) manure. However, KoL was less in AD manure than in UD manure, while an increase in total ammoniacal nitrogen (TAN) was observed after anaerobic digestion of manure. Overall, increases in ammonium dissociation and TAN after anaerobic digestion indicated higher potential of NH3 volatilization in AD manure. Significant increases in SS concentration and IS were necessary to influence the ammonium dissociation in dairy manure. For all practical purposes, therefore, the individual effects of suspended solids and ionic strength were deemed negligible within the normal ranges of liquid dairy manure characteristics.

  18. Streptopyridines, volatile pyridine alkaloids produced by Streptomyces sp. FORM5

    PubMed Central

    Groenhagen, Ulrike; Maczka, Michael; Dickschat, Jeroen S

    2014-01-01

    Summary Streptomyces sp. FORM5 is a bacterium that is known to produce the antibiotic streptazolin and related compounds. We investigated the strain for the production of volatiles using the CLSA (closed-loop stripping analysis) method. Liquid and agar plate cultures revealed the formation of new 2-alkylpyridines (streptopyridines), structurally closely related to the already known 2-pentadienylpiperidines. The structures of the streptopyridines A to E were confirmed by total synthesis. The analysis of the liquid phase by solvent extraction or extraction with an Oasis adsorbent showed that streptazolin and 2-pentadienylpiperidine are the major compounds, while the streptopyridines are only minor components. In the gas phase, only the streptopyridines could be detected. Therefore, an orthogonal set of analysis is needed to assess the metabolic profile of bacteria, because volatile compounds are obviously overlooked by traditional analytical methods. The streptopyridines are strain specific volatiles that are accompanied by a broad range of headspace constituents that occur in many actinomycetes. Volatiles might be of ecological importance for the producing organism, and, as biosynthetic intermediates or shunt products, they can be useful as indicators of antibiotic production in a bacterium. PMID:24991297

  19. Investigation of the Volatile Fraction of Rosemary Infusion Extracts

    PubMed Central

    Tschiggerl, Christine; Bucar, Franz

    2010-01-01

    The relative proportions of chemical classes (hydrocarbons, oxides, alcohols, ketones, esters) in the essential oil of rosemary (Rosmarinus officinalis L., Lamicaeae) and in the volatile fraction of the infusion extracts were examined and showed remarkable differences. The volatile compounds of the infusion were isolated by two different methods, hydrodistillation and solid phase extraction (SPE). The main constituents of the volatile fraction of the infusion were (hydrodistillation/SPE): 1,8-cineole (42.4%/44.7%), camphor (31.4%/31.8%), ?-terpineol (8.6%/8.1%) and borneol (8.3%/7.8%). The qualitative and quantitative composition of the volatile compounds of the infusion was compared to the essential oil isolated by hydrodistillation directly from the leaves. The major constituents of the essential oil of the leaves were 1,8-cineole (41.6%), camphor (17.0%), ?-pinene (9.9%), ?-terpineol (4.9%) and borneol (4.8%). Comparison of the total essential oil yield quantified by hydrodistillation of the infusion (0.36% v/w) with the essential oil yield of the leaves (1.84% v/w) revealed that only 19.6% of the initial oil could be extracted by infusion. PMID:21179360

  20. The volatile composition of comets

    NASA Technical Reports Server (NTRS)

    Weaver, H. A.

    1988-01-01

    Comets may be our best probes of the physical and chemical conditions in the outer regions of the solar nebula during that crucial period when the planets formed. The volatile composition of cometary nuclei can be used to decide whether comets are the product of a condensation sequence similar to that invoked to explain the compositions of the planets and asteroids, or if comets are simply agglomerations of interstellar grains which have been insignificantly modified by the events that shaped the other bodies in the solar system. Although cometary nuclei are not generally accessible to observation, observations of cometary comae can illuminate at least some of the mysteries of the nuclei provided one has a detailed knowledge of the excitation conditions in the coma and also has access to basic atomic and molecular data on the many species present in comets. Examined here is the status of our knowledge of the volatile composition of cometary nuclei and how these data are obtained.

  1. Trends in Volatile Substance Abuse

    Microsoft Academic Search

    Henry Spiller; Douglas J. Lorenz

    2009-01-01

    The purpose of this article is to evaluate whether social, geographic, and demographic factors have a relationship to trends in volatile substance abuse. Two datasets were obtained. Dataset 1 was all patients reported to U.S. poison centers with inhalation abuse of a non-pharmaceutical substance between 2000 and 2005. Dataset 2 was annual data from the U.S. Dept of Labor and

  2. NATURAL EMISSIONS OF NON-METHANE VOLATILE ORGANIC COMPOUNDS, CARBON MONOXIDE, AND OXIDES OF NITROGEN FROM NORTH AMERICA. (R825259)

    EPA Science Inventory

    Abstract The magnitudes, distributions, controlling processes and uncertainties associated with North American natural emissions of oxidant precursors are reviewed. Natural emissions are responsible for a major portion of the compounds, including non-methane volatile o...

  3. NATURAL EMISSIONS OF NON-METHANE VOLATILE ORGANIC COMPOUNDS, CARBON MONOXIDE, AND OXIDES OF NITROGEN FROM NORTH AMERICA

    EPA Science Inventory

    The magnitudes, distributions, controlling processes and uncertainties associated with North American natural emissions of oxidant precursors are reviewed. Natural emissions are repsonsible for a major portion of the compounds, including non-methane volatile organic compounds (N...

  4. Forecasting volatility of fuel oil futures in China: GARCH-type, SV or realized volatility models?

    NASA Astrophysics Data System (ADS)

    Wei, Yu

    2012-11-01

    In most previous works on forecasting oil market volatility, squared daily returns were taken as the proxy of unobserved actual volatility. However, as demonstrated by Andersen and Bollerslev (1998) [22], this proxy with too high measurement noise could be perfectly outperformed by a so-called realized volatility (RV) measure calculated by the cumulative sum of squared intraday returns. With this motivation, we further extend earlier works by employing intraday high-frequency data to compare the performance of three typical volatility models in the daily out-of-sample volatility forecasting of fuel oil futures on the Shanghai Futures Exchange (SHFE): the GARCH-type, stochastic volatility (SV) and realized volatility models. By taking RV as the proxy of actual daily volatility and then computing forecasting errors, we find that the realized volatility model based on intraday high-frequency data produces significantly more accurate volatility forecasts than the GARCH-type and SV models based on daily returns. Furthermore, the SV model outperforms many linear and nonlinear GARCH-type models that capture long-memory volatility and/or the asymmetric leverage effect in volatility. These results also prove that abundant volatility information is available in intraday high-frequency data, and can be used to construct more accurate oil volatility forecasting models.

  5. Direct injection ion chromatography for the control of chlorinated drinking water: simultaneous estimation of nine haloacetic acids and quantitation of bromate, chlorite and chlorate along with the major inorganic anions.

    PubMed

    Garcia-Villanova, Rafael J; Raposo Funcia, César; Oliveira Dantas Leite, M Vilani; Toruño Fonseca, Ivania M; Espinosa Nieto, Miguel; Espuelas India, Javier

    2014-09-01

    Most methods for the analysis of haloacetic acids published in recent years are based on ion chromatography with direct injection, employing a gradient elution with potassium hydroxide (KOH). This work reports the exploration of an alternative eluent, a buffer of sodium carbonate/sodium hydrogen carbonate, aimed at the simultaneous analysis of nine haloacetic acids along with bromate, chlorite and chlorate. The alternative of both a less alkaline eluent and a lower temperature of operation may prevent the partial decomposition of some of the haloacetic acids during the analytical process, especially the more vulnerable brominated ones. Gradient elution at temperature of 7 °C yielded the best results, with an acceptable separation of 17 analytes (which includes the major natural inorganic anions) and a good linearity. Precision ranges from 0.3 to 23.4 (% V.C.), and detection limits are within units of ?g L?¹, except for tribromoacetic acid - somewhat high in comparison with those of the official methods. Nonetheless, with the basic instrumentation setup herein described, this method may be suitable for monitoring when the drinking water treatments are to be optimized. This is especially interesting for small communities or for developing/developed countries in which regulations on disinfection by-products others than trihalomethanes are being addressed. PMID:25252348

  6. AMBIENT LEVEL VOLATILE ORGANIC COMPOUND (VOC) MONITORING USING SOLID ADSORBANTS - RECENT U.S. EPA STUDIES

    EPA Science Inventory

    Ambient air spiked with 1-10 ppbv concentrations of 41 toxic volatile organic compounds (VOCs) listed in U.S. Environmental Protection Agency (EPA) Compendium Method TO-14A was monitored using solid sorbents for sample collection and a Varian Saturn 2000 ion trap mass spectrome...

  7. COMPARISON OF EMISSION PROFILES FOR VOLATILE ORGANIC COMPOUNDS FROM COTTON AND POLYPROPYLENE-BASED TARP

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A high electric field, radio-frequency ion mobility analyzer (RF-IMS) was used as a small detector in gas chromatographic separations of mixtures of volatile organic compounds including alcohols, aldehydes, esters, ethers, pheromes, and other chemical attractants for insects. The detector was equip...

  8. Mars Volatiles and Climate Surveyor Integrated Payload

    NASA Astrophysics Data System (ADS)

    Paige, D. A.; Boynton, W. V.; Crisp, D.; Harri, A. M.; Hansen, C. J.; Keller, H. U.; Leshin, L. A.; May, R. D.; Smith, P. H.; Zurek, R. W.

    1997-07-01

    The Mars Volatiles and Climate Surveyor (MVACS) integrated payload package is being developed for NASA's Mars Surveyor Program (MSP) '98 lander mission. The lander will be targeted to a landing site at 77 degrees south during the Martian late southern spring season. Landed science activities will be conduced during a primary mission which starts in December, 1999, and ends 86 Earth-days later during mid-Martian summer. The MVACS payload will consist of four major science elements: (1) A mast-mounted Surface Stereo Imager (SSI) which will be used to characterize the general environment at the landing site, to make observations of aerosol opacities and column water vapor abundance in the Martian atmosphere, and to provide imaging support for the other payload elements; (2) A two-meter Robotic Arm (RA), which will be used to acquire samples of surface and subsurface materials; and a Robotic Arm Camera (RAC) which will be used to image the surface and subsurface at close range; (3) A mast-mounted Meteorology Package (MET), which will include pressure, wind, and temperature sensors, as well as a Tunable Diode Laser (TDL) sensor for accurately determining the surface concentration of atmospheric water vapor, as well as the abundances of carbon, oxygen, and hydrogen isotopes in atmospheric water vapor and carbon dioxide; and (4) A Thermal and Evolved Gas Analyzer (TEGA), which will use a Differential Scanning Calorimeter (DSC) to determine the abundances of ices and volatile-bearing minerals in surface and subsurface samples acquired by the robotic arm, and a two-wavelength TDL sensor to determine the abundances of carbon, oxygen, and hydrogen isotopes within carbon dioxide and water vapor gas evolved from samples heated in the DSC.

  9. Stochastic volatility models and Kelvin waves

    NASA Astrophysics Data System (ADS)

    Lipton, Alex; Sepp, Artur

    2008-08-01

    We use stochastic volatility models to describe the evolution of an asset price, its instantaneous volatility and its realized volatility. In particular, we concentrate on the Stein and Stein model (SSM) (1991) for the stochastic asset volatility and the Heston model (HM) (1993) for the stochastic asset variance. By construction, the volatility is not sign definite in SSM and is non-negative in HM. It is well known that both models produce closed-form expressions for the prices of vanilla option via the Lewis-Lipton formula. However, the numerical pricing of exotic options by means of the finite difference and Monte Carlo methods is much more complex for HM than for SSM. Until now, this complexity was considered to be an acceptable price to pay for ensuring that the asset volatility is non-negative. We argue that having negative stochastic volatility is a psychological rather than financial or mathematical problem, and advocate using SSM rather than HM in most applications. We extend SSM by adding volatility jumps and obtain a closed-form expression for the density of the asset price and its realized volatility. We also show that the current method of choice for solving pricing problems with stochastic volatility (via the affine ansatz for the Fourier-transformed density function) can be traced back to the Kelvin method designed in the 19th century for studying wave motion problems arising in fluid dynamics.

  10. Volatile components of vine leaves from two Portuguese grape varieties (Vitis vinifera L.), Touriga Nacional and Tinta Roriz, analysed by solid-phase microextraction.

    PubMed

    Fernandes, Bruno; Correia, Ana C; Cosme, Fernanda; Nunes, Fernando M; Jordão, António M

    2015-01-01

    The purpose of this work was to study the volatile composition of vine leaves and vine leaf infusion prepared from vine leaves collected at 30 and 60 days after grape harvest of two Vitis vinifera L. species. Eighteen volatile compounds were identified by gas chromatography-mass spectrometry in vine leaves and in vine leaf infusions. It was observed that the volatile compounds present in vine leaves are dependent on the time of harvest, with benzaldehyde being the major volatile present in vine leaves collected at 30 days after harvesting. There are significant differences in the volatile composition of the leaves from the two grape cultivars, especially in the sample collected at 60 days after grape harvest. This is not reflected in the volatile composition of the vine leaf infusion made from this two cultivars, the more important being the harvesting date for the volatile profile of vine leaf infusion than the vine leaves grape cultivar. PMID:25226431

  11. Contribution of volatiles to the antifungal effect of Lactobacillus paracasei in defined medium and yogurt.

    PubMed

    Aunsbjerg, S D; Honoré, A H; Marcussen, J; Ebrahimi, P; Vogensen, F K; Benfeldt, C; Skov, T; Knøchel, S

    2015-02-01

    Lactic acid bacteria with antifungal properties can be used to control spoilage of food and feed. Previously, most of the identified metabolites have been isolated from cell-free fermentate of lactic acid bacteria with methods suboptimal for detecting possible contribution from volatiles to the antifungal activity. The role of volatile compounds in the antifungal activity of Lactobacillus paracasei DGCC 2132 in a chemically defined interaction medium (CDIM) and yogurt was therefore investigated with a sampling technique minimizing volatile loss. Diacetyl was identified as the major volatile produced by L. paracasei DGCC 2132 in CDIM. When the strain was added to a yogurt medium diacetyl as well as other volatiles also increased but the metabolome was more complex. Removal of L. paracasei DGCC 2132 cells from CDIM fermentate resulted in loss of both volatiles, including diacetyl, and the antifungal activity towards two strains of Penicillium spp. When adding diacetyl to CDIM or yogurt without L. paracasei DGCC 2132, marked inhibition was observed. Besides diacetyl, the antifungal properties of acetoin were examined, but no antifungal activity was observed. Overall, the results demonstrate the contribution of diacetyl in the antifungal effect of L. paracasei DGCC 2132 and indicate that the importance of volatiles may have been previously underestimated. PMID:25461608

  12. Flavour compounds in tomato fruits: identification of loci and potential pathways affecting volatile composition

    PubMed Central

    Mathieu, Sandrine; Cin, Valeriano Dal; Fei, Zhangjun; Li, Hua; Bliss, Peter; Taylor, Mark G.; Klee, Harry J.; Tieman, Denise M.

    2009-01-01

    The unique flavour of a tomato fruit is the sum of a complex interaction among sugars, acids, and a large set of volatile compounds. While it is generally acknowledged that the flavour of commercially produced tomatoes is inferior, the biochemical and genetic complexity of the trait has made breeding for improved flavour extremely difficult. The volatiles, in particular, present a major challenge for flavour improvement, being generated from a diverse set of lipid, amino acid, and carotenoid precursors. Very few genes controlling their biosynthesis have been identified. New quantitative trait loci (QTLs) that affect the volatile emissions of red-ripe fruits are described here. A population of introgression lines derived from a cross between the cultivated tomato Solanum lycopersicum and its wild relative, S. habrochaites, was characterized over multiple seasons and locations. A total of 30 QTLs affecting the emission of one or more volatiles were mapped. The data from this mapping project, combined with previously collected data on an IL population derived from a cross between S. lycopersicum and S. pennellii populations, were used to construct a correlational database. A metabolite tree derived from these data provides new insights into the pathways for the synthesis of several of these volatiles. One QTL is a novel locus affecting fruit carotenoid content on chromosome 2. Volatile emissions from this and other lines indicate that the linear and cyclic apocarotenoid volatiles are probably derived from separate carotenoid pools. PMID:19088332

  13. Fatty Acid Composition and Volatile Constituents of Protaetia brevitarsis Larvae

    PubMed Central

    Yeo, Hyelim; Youn, Kumju; Kim, Minji; Yun, Eun-Young; Hwang, Jae-Sam; Jeong, Woo-Sik; Jun, Mira

    2013-01-01

    A total of 48 different volatile oils were identified form P. brevitarsis larvae by gas chromatography/mass spectrometry (GC/MS). Acids (48.67%) were detected as the major group in P. brevitarsis larvae comprising the largest proportion of the volatile compounds, followed by esters (19.84%), hydrocarbons (18.90%), alcohols (8.37%), miscellaneous (1.71%), aldehydes (1.35%) and terpenes (1.16%). The major volatile constituents were 9-hexadecenoic acid (16.75%), 6-octadecenoic acid (14.88%) and n-hexadecanoic acid (11.06%). The composition of fatty acid was also determined by GC analysis and 16 fatty acids were identified. The predominant fatty acids were oleic acid (C18:1, 64.24%) followed by palmitic acid (C16:0, 15.89%), palmitoleic acid (C16:1, 10.43%) and linoleic acid (C18:2, 4.69%) constituting more than 95% of total fatty acids. The distinguished characteristic of the fatty acid profile of P. brevitarsis larvae was the high proportion of unsaturated fatty acid (80.54% of total fatty acids) versus saturated fatty acids (19.46% of total fatty acids). Furthermore, small but significant amounts of linoleic, linolenic and ?-linolenic acids bestow P. brevitarsis larvae with considerable nutritional value. The novel findings of the present study provide a scientific basis for the comprehensive utilization of the insect as a nutritionally promising food source and a possibility for more effective utilization. PMID:24471125

  14. Volatile Release From The Siberian Traps Inferred From Melt Inclusions

    NASA Astrophysics Data System (ADS)

    Black, Benjamin A.; Elkins-Tanton, Linda T.; Rowe, Michael C.; Ukstins Peate, Ingrid

    2010-05-01

    The Siberian Traps Large Igneous Province is one of the largest known continental flood volcanic provinces in the Phanerozoic. The quantification of volatile degassing is particularly important because the Siberian Traps have often been invoked as a possible trigger for the end-Permian mass extinction (e.g. Campbell et al., 1992; Wignall, 2001). Volatile degassing provides a crucial mechanism to link mafic volcanic eruption with global environmental change. Mafic flood basalt magmas are expected to have low volatile contents (similar to mid-ocean ridge basalts). However, Siberian Traps magmas were chambered in and erupted through a thick sedimentary basin and may have interacted with, and obtained volatiles from, sedimentary lithologies such as limestone, coal, and evaporite. Melt inclusions from the Siberian Traps provide insight into the potential total volatile budget throughout the evolution of the large igneous province. These droplets of trapped melt may preserve volatile species that would otherwise have degassed at the time of eruption. We present data from the analysis of more than 100 melt inclusions, including both homogenized inclusions and rare glassy inclusions with low crystallinity. Many melt inclusions from tuffs and flows near the base of the Siberian Traps sequence are substantially enriched in chlorine and fluorine compared to Deccan Traps and Laki melt inclusions (Self et al., 2008; Thordarson et al., 1996). These inclusions record chlorine concentrations up to ~1400 ppm, and fluorine concentrations up to ~5000 ppm. Olivines from the Maymechinsky suite, recognized as the last extrusive products of Siberian Traps volcanism, contain melt inclusions with maximum sulfur concentrations in the range of ~5000 ppm and substantial concentrations of chlorine. Intrusive igneous rocks from the province also display significant volatile contents. A sill from the Ust-Ilimsk region yielded plagioclase-hosted melt inclusions which contain chlorine and fluorine concentrations in the range of one weight percent. Visscher et al. (2004) proposed that chlorofluorocarbon compounds (CFCs) may have played a major role in the terrestrial end-Permian extinction. These CFCs are powerful catalysts for the breakdown of ozone, a process which can expose the biosphere to increased ultraviolet radiation. Measurements of elevated chlorine and fluorine from the Siberian Traps may thus provide a concrete source for CFCs that could have triggered this kill mechanism.

  15. Bacterial volatiles and their action potential

    Microsoft Academic Search

    Marco Kai; Maria Haustein; Francia Molina; Anja Petri; Birte Scholz; Birgit Piechulla

    2009-01-01

    During the past few years, an increasing awareness concerning the emission of an unexpected high number of bacterial volatiles\\u000a has been registered. Humans sense, intensively and continuously, microbial volatiles that are released during food transformation\\u000a and fermentation, e.g., the aroma of wine and cheese. Recent investigations have clearly demonstrated that bacteria also employ\\u000a their volatiles during interactions with other organisms

  16. Magmatic volatiles in explosive rhyolitic eruptions

    Microsoft Academic Search

    J. C. Eichelberger; H. R. Westrich

    1981-01-01

    Obsidian clasts in rhyolitic tephra deposits preserve preeruption magmatic volatile contents, providing a direct means for determining the volatile content of explosively erupted magmas. Small to moderate volume Plinian eruptions (10⁻³ to 10⁻¹ km³) appear to be driven by 0.5--1.0 wt.% volatiles, consisting dominantly of HâO with minor COâ. Analysis of obsidian from eruptive sequences consisting of tephra and flows

  17. Silicon Nanowires for Non-Volatile Memory

    E-print Network

    Silicon Nanowires for Non-Volatile Memory P R O J E C T L E A D E R : Curt A. Richter (NIST) C O L approaches for silicon nanowire non-volatile memory. K E Y A C C O M P L I S H M E N T S Fabricated novel non-volatile memory cells with silicon nanowire channels and Al2 O3 /HfO2 /SiO2 gate dielectric storage stacks

  18. Citrus leaf volatiles as affected by developmental stage and genetic type.

    PubMed

    Azam, Muhammad; Jiang, Qian; Zhang, Bo; Xu, Changjie; Chen, Kunsong

    2013-01-01

    Major volatiles from young and mature leaves of different citrus types were analyzed by headspace-solid phase microextraction (HS-SPME)-GC-MS. A total of 123 components were identified form nine citrus cultivars, including nine aldehydes, 19 monoterpene hydrocarbons, 27 oxygenated monoterpenes, 43 sesquiterpene hydrocarbons, eight oxygenated sesquiterpenes, two ketones, six esters and nine miscellaneous. Young leaves produced higher amounts of volatiles than mature leaves in most cultivars. The percentage of aldehyde and monoterpene hydrocarbons increased, whilst oxygenated monoterpenes and sesquiterpenes compounds decreased during leaf development. Linalool was the most abundant compound in young leaves, whereas limonene was the chief component in mature ones. Notably, linalool content decreased, while limonene increased, during leaf development in most cultivars. Leaf volatiles were also affected by genetic types. A most abundant volatile in one or several genotypes can be absent in another one(s), such as limonene in young leaves of lemon vs. Satsuma mandarin and ?-terpinene in mature leaves of three genotypes vs. the other four. Compositional data was subjected to multivariate statistical analysis, and variations in leaf volatiles were identified and clustered into six groups. This research determining the relationship between production of major volatiles from different citrus varieties and leaf stages could be of use for industrial and culinary purposes. PMID:23994837

  19. Citrus Leaf Volatiles as Affected by Developmental Stage and Genetic Type

    PubMed Central

    Azam, Muhammad; Jiang, Qian; Zhang, Bo; Xu, Changjie; Chen, Kunsong

    2013-01-01

    Major volatiles from young and mature leaves of different citrus types were analyzed by headspace-solid phase microextraction (HS-SPME)-GC-MS. A total of 123 components were identified form nine citrus cultivars, including nine aldehydes, 19 monoterpene hydrocarbons, 27 oxygenated monoterpenes, 43 sesquiterpene hydrocarbons, eight oxygenated sesquiterpenes, two ketones, six esters and nine miscellaneous. Young leaves produced higher amounts of volatiles than mature leaves in most cultivars. The percentage of aldehyde and monoterpene hydrocarbons increased, whilst oxygenated monoterpenes and sesquiterpenes compounds decreased during leaf development. Linalool was the most abundant compound in young leaves, whereas limonene was the chief component in mature ones. Notably, linalool content decreased, while limonene increased, during leaf development in most cultivars. Leaf volatiles were also affected by genetic types. A most abundant volatile in one or several genotypes can be absent in another one(s), such as limonene in young leaves of lemon vs. Satsuma mandarin and ?-terpinene in mature leaves of three genotypes vs. the other four. Compositional data was subjected to multivariate statistical analysis, and variations in leaf volatiles were identified and clustered into six groups. This research determining the relationship between production of major volatiles from different citrus varieties and leaf stages could be of use for industrial and culinary purposes. PMID:23994837

  20. THEORETICAL EVALUATION OF STABILITY OF VOLATILE ORGANIC CHEMICALS AND POLAR VOLATILE ORGANIC CHEMICALS IN CANISTERS

    EPA Science Inventory

    A mathematical model was developed for describing loss by physical adsorption of volatile organic chemicals (VOCs) and polar volatile organic chemicals (PVOCs) in stainless steel canisters. he model incorporates compound specific properties such as polarizability, vapor concentra...

  1. Conference on Deep Earth and Planetary Volatiles

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The following topics are covered in the presented papers: (1) rare gases systematics and mantle structure; (2) volatiles in the earth; (3) impact degassing of water and noble gases from silicates; (4) D/H ratios and H2O contents of mantle-derived amphibole megacrysts; (5) thermochemistry of dense hydrous magnesium silicates; (6) modeling of the effect of water on mantle rheology; (7) noble gas isotopes and halogens in volatile-rich inclusions in diamonds; (8) origin and loss of the volatiles of the terrestrial planets; (9) structure and the stability of hydrous minerals at high pressure; (10) recycling of volatiles at subduction zones and various other topics.

  2. Volatile organic compound sensor system

    DOEpatents

    Schabron, John F. (Laramie, WY); Rovani, Jr., Joseph F. (Laramie, WY); Bomstad, Theresa M. (Waxahachie, TX); Sorini-Wong, Susan S. (Laramie, WY); Wong, Gregory K. (Laramie, WY)

    2011-03-01

    Generally, this invention relates to the development of field monitoring methodology for new substances and sensing chemical warfare agents (CWAs) and terrorist substances. It also relates to a portable test kit which may be utilized to measure concentrations of halogenated volatile organic compounds (VOCs) in the field. Specifically it relates to systems for reliably field sensing the potential presence of such items while also distinguishing them from other elements potentially present. It also relates to overall systems and processes for sensing, reacting, and responding to an indicated presence of such substance, including modifications of existing halogenated sensors and arrayed sensing systems and methods.

  3. How Relevant is Volatility Forecasting for Financial Risk Management?

    Microsoft Academic Search

    Peter F. Christoffersen; Francis X. Diebold

    1997-01-01

    It depends. If volatility fluctuates in a forecastable way, then volatility forecasts are useful for risk management; hence the interest in volatility forecastability in the risk management literature. Volatility forecastability, however, varies with horizon, and different horizons are relevant in different applications. Existing assessments are plagued by the fact that they are joint assessments of volatility forecastability and an assumed

  4. Improved Ambient Pressure Pyroelectric Ion Source

    NASA Technical Reports Server (NTRS)

    Beegle, Luther W.; Kim, Hugh I.; Kanik, Isik; Ryu, Ernest K.; Beckett, Brett

    2011-01-01

    The detection of volatile vapors of unknown species in a complex field environment is required in many different applications. Mass spectroscopic techniques require subsystems including an ionization unit and sample transport mechanism. All of these subsystems must have low mass, small volume, low power, and be rugged. A volatile molecular detector, an ambient pressure pyroelectric ion source (APPIS) that met these requirements, was recently reported by Caltech researchers to be used in in situ environments.

  5. Detection of variable groundwater inflow in rivers with geochemical tracers: Using major ion chemistry and radiochemistry to evaluate radon 222Rn as possible tracer, an example from the Avon and Mitchell rivers, southeast Australia

    NASA Astrophysics Data System (ADS)

    Hofmann, H.; Cartwright, I.

    2010-12-01

    Surface water-groundwater interactions are an important part of the hydrological cycle from ecological and resource perspectives. The dynamics have implications for ecosystems, pollutant transport, and the quality and quantity of water supply for domestic use, agriculture and recreational purposes. Chemical tracers are a valuable tool for understanding the interaction of rivers and the surrounding groundwater. The Gippsland Basin is a significant agricultural area in Southeast Australia. Increasing population has resulted in increased demand of water resources for domestic and agricultural supply. Despite the fact that the Gippsland area receives substantial rainfall, irrigation is still necessary to maintain agricultural production during summer and drier years. The used water resources encompass mostly shallow groundwater and surface water (reservoirs and streams). The effect on the environment range from rising water levels and soil salinisation in the case of irrigation and falling water levels with subsequent necrotization of the vegetation and land subsidence in the case of communal and industrial water extraction. While the surface water components of the hydrological cycle are relatively well understood, groundwater has often been neglected. In particular, constraining the interaction between surface water and groundwater is required for sustainable water management. Gaining and loosing conditions in streams are subject to high temporal and spatial variability and hence, influence the amount of water accessible for agricultural purposes. Following a general assumption recharge to the aquifer occurs during the winter and spring month whereas the river receives water from the aquifer mainly during low flow (base flow) conditions in summer and autumn on a larger scale. Spatial variation, however, are a function of the hydraulic conductivity of the riverbed and the head differences between the aquifer and the river along the river banks. Infiltration and exfiltration rates from changing water levels in the river based on hydraulic models are often underestimated. The hydraulic models do not take into account the complexity of the system and are purely based on discharge figures. Radon (222Rn), stable isotopes and major ion chemistry were used to locate groundwater inputs to the Mitchell and Avon rivers. While stable isotopes and major ion chemistry are useful tracers to determine long-term variability, radon can be used to detect very localised groundwater discharge. Using hydrogeochemistry to locate and quantify groundwater discharge to rivers allows a more accurate assumption on the dynamics of the interaction between surface water and groundwater in the Gippsland area. Radon has been used in similar applications elsewhere. Input parameters for mass balance equations, however, were often approximated and averaged. Radioisotope concentrations in groundwater has been assessed from 20 bores and 5 soil profiles to deliver a more confidential groundwater input water radon concentration by assessing spatial variability and emanation potential of the above-mentioned elements.

  6. The role of volatiles in the reduction of iron oxides

    NASA Astrophysics Data System (ADS)

    Sohn, Il

    With iron ore reduction processes using coal-ore pellets or mixtures, it is possible that volatiles from the coals can contribute to the overall reduction. By identifying the possible reducing species in the volatiles as H2/CO and simulating these constituents, the rates for H2 and CO were investigated in the temperature and reduction range of interest where hydrogen was the major reductant and studied in detail. In the initial stages of the present study, the fundamentals of hydrogen reduction of fine powder were found to be a complex mechanism of chemical kinetics and mass transfer. Complete uniform reduction for porous and dense iron ores were not observed contrary to existing work regarding this subject. Morphological observations of iron ores reduced at low and high temperatures showed a topochemical receding interface to be dominating with an intermediate region developing for higher temperature samples indicating the importance of pore mass transfer at the later stages of reduction. Although the activation energy of 50˜56 kJ/mole for these powder samples were comparable to the literature values for solely chemical kinetics controlled reactions, the reaction rates were not proportional to sample weight and also did not exhibit complete uniform internal reduction. The calculated mass transfer rates were comparable to the observed rate which suggested that bulk mass transfer is important to the mixed-control. The reaction rate at the mixed control regime was found to be first order with respect to hydrogen partial pressure. Results of reducing iron oxide powders in a mixture of He-40%H2 -5%CO and H2-1%H2S showed that H2S and CO which is involved with the volatiles does not affect the rate at the reduction range of interest indicating the role of volatiles is dominated by the hydrogen reduction. The single composite pellet experiments at 900 and 1000°C showed significant fixed carbon reduction to occur above 1000°C. Depending upon the type of carbon reductant in the composite pellet, secondary reactions with carbon and H2O was possible. Sintering of the pellets did not occur until a significant amount of reduction was obtained and thus for volatile reduction it is likely that the effects of sintering was negligible. To determine the possibility of volatile reduction, a layer of Fe 2O3 powders were spread over HV coals resulting in the reduction of the top layer by about 20% at 1000°C after 1000 seconds. The morphology of the reduced Fe2O3 layer indicated that the reduction is higher near the interface of Coal/Fe2O3. The volatile reduction of a single layer of composite pellet was found to be negligible. However, the reduction of Fe2O3 pellets at the top layer by the volatiles from the bottom layers of a three-layer pellet geometry was observed to be about 15%. From the morphological observations and the computed rates of bulk mass transfer, volatile reduction seems to be controlled by a mixed-controlled mechanism of bulk mass transfer and the limited-mixed control. Using the reduction information obtained from the single pellet experiments reduced in hydrogen, an empirical relationship was obtained to approximately predict the amount of volatile reduction up to 20%.

  7. Econometric analysis of realized volatility and its use in estimating stochastic volatility models

    Microsoft Academic Search

    Ole E. Barndorff-Nielsen; Neil Shephard

    2002-01-01

    The availability of intraday data on the prices of speculative assets means that we can use quadratic variation-like measures of activity in financial markets, called realized volatility, to study the stochastic properties of returns. Here, under the assumption of a rather general stochastic volatility model, we derive the moments and the asymptotic distribution of the realized volatility error-the difference between

  8. Volatile and Interlocked ClassVolatile and Interlocked Class Sandino Vargas

    E-print Network

    Yang, Zijiang "James"

    Volatile and Interlocked ClassVolatile and Interlocked Class Sandino Vargas CS 6030: Introduction to Multicore Programming Spring 2011 #12;General Idea You can use Volatile or Interlocked Class operations. for (;;) { if (finished) { Console.WriteLine("result = {0}", result); return; } } } } #12;Interlocked Class Provides

  9. Volatile Exchange between Undamaged Plants - a New Mechanism Affecting Insect Orientation in Intercropping

    PubMed Central

    Ninkovic, Velemir; Dahlin, Iris; Vucetic, Andja; Petrovic-Obradovic, Olivera; Glinwood, Robert; Webster, Ben

    2013-01-01

    Changes in plant volatile emission can be induced by exposure to volatiles from neighbouring insect-attacked plants. However, plants are also exposed to volatiles from unattacked neighbours, and the consequences of this have not been explored. We investigated whether volatile exchange between undamaged plants affects volatile emission and plant-insect interaction. Consistently greater quantities of two terpenoids were found in the headspace of potato previously exposed to volatiles from undamaged onion plants identified by mass spectrometry. Using live plants and synthetic blends mimicking exposed and unexposed potato, we tested the olfactory response of winged aphids, Myzus persicae. The altered potato volatile profile deterred aphids in laboratory experiments. Further, we show that growing potato together with onion in the field reduces the abundance of winged, host-seeking aphids. Our study broadens the ecological significance of the phenomenon; volatiles carry not only information on whether or not neighbouring plants are under attack, but also information on the emitter plants themselves. In this way responding plants could obtain information on whether the neighbouring plant is a competitive threat and can accordingly adjust their growth towards it. We interpret this as a response in the process of adaptation towards neighbouring plants. Furthermore, these physiological changes in the responding plants have significant ecological impact, as behaviour of aphids was affected. Since herbivore host plants are potentially under constant exposure to these volatiles, our study has major implications for the understanding of how mechanisms within plant communities affect insects. This knowledge could be used to improve plant protection and increase scientific understanding of communication between plants and its impact on other organisms. PMID:23922710

  10. Volatile fingerprints of seeds of four species indicate the involvement of alcoholic fermentation, lipid peroxidation, and Maillard reactions in seed deterioration during ageing and desiccation stress

    PubMed Central

    Colville, Louise

    2012-01-01

    The volatile compounds released by orthodox (desiccation-tolerant) seeds during ageing can be analysed using gas chromatography–mass spectrometry (GC-MS). Comparison of three legume species (Pisum sativum, Lathyrus pratensis, and Cytisus scoparius) during artificial ageing at 60% relative humidity and 50 °C revealed variation in the seed volatile fingerprint between species, although in all species the overall volatile concentration increased with storage period, and changes could be detected prior to the onset of viability loss. The volatile compounds are proposed to derive from three main sources: alcoholic fermentation, lipid peroxidation, and Maillard reactions. Lipid peroxidation was confirmed in P. sativum seeds through analysis of malondialdehyde and 4-hydroxynonenal. Volatile production by ageing orthodox seeds was compared with that of recalcitrant (desiccation-sensitive) seeds of Quercus robur during desiccation. Many of the volatiles were common to both ageing orthodox seeds and desiccating recalcitrant seeds, with alcoholic fermentation forming the major source of volatiles. Finally, comparison was made between two methods of analysis; the first used a Tenax adsorbent to trap volatiles, whilst the second used solid phase microextraction to extract volatiles from the headspace of vials containing powdered seeds. Solid phase microextraction was found to be more sensitive, detecting a far greater number of compounds. Seed volatile analysis provides a non-invasive means of characterizing the processes involved in seed deterioration, and potentially identifying volatile marker compounds for the diagnosis of seed viability loss. PMID:23175670

  11. Volatile components in defensive spray of the hog-nosed skunk, Conepatus mesoleucus

    Microsoft Academic Search

    William F. Wood; Christoph O. Fisher; Gary A. Graham

    1993-01-01

    GC-MS analysis of the anal sac secretion from the hog-nosed skunk,Conepatus mesoleucus, showed two major volatile components, (E)-2-butene-1-thiol and (E)-S-2-butenyl thioacetate. Minor volatile components identified from this secretion were phenylmethanethiol, 2-methylquinoline, 2-quinolinemethanethiol, and bis[(E)-2-butenyl] disulfide. 3-Methyl-1-butanethiol, a major component in the defensive spray of the striped skunk,Mephitis mephitis, and the spotted skunk,Spilogale putorius, was absent from this secretion.

  12. Non-volatile, solid state bistable electrical switch

    NASA Technical Reports Server (NTRS)

    Williams, Roger M. (inventor)

    1994-01-01

    A bistable switching element is made of a material whose electrical resistance reversibly decreases in response to intercalation by positive ions. Flow of positive ions between the bistable switching element and a positive ion source is controlled by means of an electrical potential applied across a thermal switching element. The material of the thermal switching element generates heat in response to electrical current flow therethrough, which in turn causes the material to undergo a thermal phase transition from a high electrical resistance state to a low electrical resistance state as the temperature increases above a predetermined value. Application of the electrical potential in one direction renders the thermal switching element conductive to pass electron current out of the ion source. This causes positive ions to flow from the source into the bistable switching element and intercalate the same to produce a non-volatile, low resistance logic state. Application of the electrical potential in the opposite direction causes reverse current flow which de-intercalates the bistable logic switching element and produces a high resistance logic state.

  13. PSYCHOLOGY MAJORS --1 PSYCHOLOGY MAJORS --2

    E-print Network

    Sanders, Matthew

    PSYCHOLOGY MAJORS -- 1 #12;PSYCHOLOGY MAJORS -- 2 Handbook for Undergraduate Psychology Majors......................................................................................................................................2 A. Psychology Program Goals and Purpose B. Declaration of Major C. History of Marquette University D. Facilities E. Graduate Program in Clinical Psychology 2. Department Faculty and Staff

  14. Fall 2012 Majors Counts Undergraduate # of Majors Degree Majors Total

    E-print Network

    Su, Xiao

    /Pictorial Arts 15 BFA Art/Spatial Arts 49 BA Art/Art History and Visual Culture 51 BA Art Design 201 BS Industrial Design 77 BFA Graphic Design 168 BFA Interior Design 453 BA Art/Design Studies English 408 BAFall 2012 Majors Counts Undergraduate # of Majors Degree Majors Total 164 BA Art/Studio Practice

  15. Relation of Specific Conductance in Ground Water to Intersection of Flow Paths by Wells, and Associated Major Ion and Nitrate Geochemistry, Barton Springs Segment of the Edwards Aquifer, Austin, Texas, 1978-2003

    USGS Publications Warehouse

    Garner, Bradley D.; Mahler, Barbara J.

    2007-01-01

    Understanding of karst flow systems can be complicated by the presence of solution-enlarged conduits, which can transmit large volumes of water through the aquifer rapidly. If the geochemistry at a well can be related to streamflow or spring discharge (springflow), or both, the relations can indicate the presence of recent recharge in water at the well, which in turn might indicate that the well intersects a conduit (and thus a major flow path). Increasing knowledge of the occurrence and distribution of conduits in the aquifer can contribute to better understanding of aquifer framework and function. To that end, 26 wells in the Barton Springs segment of the Edwards aquifer, Austin, Texas, were investigated for potential intersection with conduits; 26 years of arbitrarily timed specific conductance measurements in the wells were compared to streamflow in five creeks that provide recharge to the aquifer and were compared to aquifer flow conditions as indicated by Barton Springs discharge. A nonparametric statistical test (Spearman's rho) was used to divide the 26 wells into four groups on the basis of correlation of specific conductance of well water to streamflow or spring discharge, or both. Potential relations between conduit intersection by wells and ground-water geochemistry were investigated through analysis of historical major ion and nitrate geochemistry for wells in each of the four groups. Specific conductance at nine wells was negatively correlated with both streamflow and spring discharge, or streamflow only. These correlations were interpreted as evidence of an influx of surface-water recharge during periods of high streamflow and the influence at the wells of water from a large, upgradient part of the aquifer; and further interpreted as indicating that four wells intersect major aquifer flow paths and five wells intersect minor aquifer flow paths (short, tributary conduits). Specific conductance at six wells was positively correlated with spring discharge, which was interpreted as not intersecting a flow path (conduit). Of the 11 wells for which specific conductance did not correlate with either streamflow or spring discharge, no interpretations regarding flow-path intersection by wells were made. In some cases, specific conductance data might not have indicated intersection with a flow path because of small sample sets. Water in the Barton Springs segment generally is a calcium-magnesium-bicarbonate type, although some water compositions deviate from this. Multiple geochemical processes were identified that might affect geochemistry at the wells, but in general the geochemical composition of ground water, except for dilution by surface-water recharge, was not related to intersection of a well with a flow path. Some samples from wells indicate inflow of water from the saline zone to the east; this inflow is associated with low streamflow and spring discharge. Other samples indicate that the aquifer at some wells might be receiving water that has been in contact with rocks of the Trinity aquifer; this mixing is most evident when spring discharge is high. Occurrence of nitrate in ground water was unrelated to intersection of flow paths by wells and appeared to be the result of localized contamination. However, most of the wells with one or more samples contaminated by nitrate are in the more densely populated parts of the study area.

  16. SELECTION GUIDE FOR VOLATILIZATION TECHNOLOGIES FOR WATER TREATMENT

    EPA Science Inventory

    The guide presents a methodology for evaluating applicability of volatilization technologies for removing volatile organics from water. The volatilization technologies assessed in the study include: surface sprayers, surface aerators, bubble columns, cooling towers, steam strippe...

  17. Functional Data Analysis for Volatility Hans-Georg Muller1

    E-print Network

    Müller, Hans-Georg

    recur- ring patterns of volatility and for successful prediction of future volatility, through the idea of rolling sample volatility estimators, as in Foster and Nelson (1996); the kernel method in Fan

  18. Volatile components of Zalema white wines

    Microsoft Academic Search

    M. José Gómez-Míguez; Juan F. Cacho; Vicente Ferreira; Isabel M. Vicario; Francisco J. Heredia

    2007-01-01

    The volatile composition of young white wines from Vitis vinifera cv. Zalema, an autochthonous grape variety in Huelva (southern Spain), has been studied by gas chromatography-olfactometry (GC-O) and techniques of quantitative analysis. This is the first time that an olfactometric analysis has been reported in wines made from this grape variety. The quantitative chemical study has shown 71 volatile compounds,

  19. Analyzing volatile compounds in dairy products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Volatile compounds give the first indication of the flavor in a dairy product. Volatiles are isolated from the sample matrix and then analyzed by chromatography, sensory methods, or an electronic nose. Isolation may be performed by solvent extraction or headspace analysis, and gas chromatography i...

  20. Belief biases and volatility of assets

    NASA Astrophysics Data System (ADS)

    Lei-Sun, Wen-Zou, Hui

    2014-10-01

    Based on an overlapping generation model, this paper introduces the noise traders with belief biases and rational traders. With an equilibrium analysis, this paper examines the volatility of risky asset. The results show that the belief biases, the probability of economy state, and the domain capability are all the factors that have effects on the volatility of the market.

  1. VOLATILIZED LUBRICANT EMISSIONS FROM STEEL ROLLING OPERATIONS

    EPA Science Inventory

    The report gives results of a study of the volatilization of lubricants used in steel rolling. Data from nine steel mills were used to: define the volatilized portion of lubricants used in rolling; and prepare total oil, grease, and hydraulic material balances for actual and typi...

  2. Oil price volatility and the macroeconomy

    Microsoft Academic Search

    J. Peter Ferderer

    1996-01-01

    Recent theoretical work suggests that oil price shocks may have an adverse impact on the macroeconomy, not only because they increase the level of oil prices, but also because they raise oil price volatility. This paper provides empirical support for this proposition by showing that oil price volatility, measured by monthly standard deviations of daily oil prices, helps to forecast

  3. International Transmission Mechanism of Stock Market Volatilities

    Microsoft Academic Search

    Andrés Rivas; Rahul Verma; Antonio Rodriguez; Priti Verma

    2008-01-01

    We investigate the volatility spillover effects of European equity markets to the equity markets of Mexico, Brazil, and Chile. The results of the E-GARCH and VAR models suggest that the stock markets of Spain and Germany have stronger volatility spillover effects on Latin American markets than do Italy, the United Kingdom, and France. We find that these spillover effects of

  4. Fixture For Sampling Volatile Materials In Containers

    NASA Technical Reports Server (NTRS)

    Melton, Donald; Pratz, Earl Howard

    1995-01-01

    Fixture based on T-connector enables mass-spectrometric analysis of volatile contents of cylindrical containers without exposing contents to ambient conditions. Used to sample volatile contents of pressurized containers, contents of such enclosed processing systems as gas-phase reactors, gases in automotive emission systems, and gas in hostile environments.

  5. IN-HOUSE REFORMULATION AND EVALUATION OF MAJOR MANUFACTURER'S VEHICLE REFINISHING COATINGS

    EPA Science Inventory

    The goal is to develop high quality vehicle refinishing paint formulations that contain much less toxi and volatile solvents than the major manufacturer's Federal compliant and California complaint coatings. The reformulated coatings being developed will maintain or improve upo...

  6. Lunar Volatiles: An Earth-Moon Perspective

    NASA Technical Reports Server (NTRS)

    Jones, John H.

    2011-01-01

    It has generally been accepted that the Moon is depleted in volatile elements. However, the recent discovery of measurable water in lunar glasses and apatites suggests that volatiles are not as depleted as was once thought. And, in fact, some authors have claimed that water contents of the lunar and terrestrial mantles are similar. Moderately volatile alkali elements may have a bearing on this issue. In general, bulk Moon alkalis are depleted relative to the bulk silicate Earth. Although the bulk lunar chemical composition is difficult to reconstruct, good correlations of alkali elements with refractory lithophile incompatible trace elements make this conclusion robust. These observations have been taken to mean that the Moon overall is depleted in volatiles relative to the Earth. Since water is more volatile than any of the alkali elements, presumably this conclusion is true for water, or even more so.

  7. Ammonia volatilization loss from surface applied livestock manure.

    PubMed

    Paramasivam, S; Jayaraman, K; Wilson, Takela C; Alva, Ashok K; Kelson, Luma; Jones, Leandra B

    2009-03-01

    Ammonia (NH(3)) emission from livestock manures used in agriculture reduces N uptake by crops and negatively impacts air quality. This laboratory study was conducted to evaluate NH(3)emission from different livestock manures applied to two soils: Candler fins sand (CFS; light-textured soil, pH 6.8 and field capacity soil water content of 70 g kg(-1)) from Lake Alfred, Florida and Ogeechee loamy sand (OLS; medium-textured soil, pH 5.2 and field capacity soil water content of 140 g kg(-1)) from Savannah, Georgia. Poultry litter (PL) collected from a poultry farm near Douglas, Georgia, and fresh solid separate of swine manure (SM) collected from a farm near Clinton, North Carolina were used. Each of the soil was weighed in 100 g sub samples and amended with either PL or SM at rates equivalent to either 0, 2.24, 5.60, 11.20, or 22.40 Mg ha(-1) in 1L Mason jars and incubated in the laboratory at field capacity soil water content for 19 days to monitor NH(3) volatilization. Results indicated a greater NH(3) loss from soils amended with SM compared to that with PL. The cumulative NH(3)volatilization loss over 19 days ranged from 4 to 27% and 14 to 32% of total N applied as PL and SM, respectively. Volatilization of NH(3) was greater from light-textured CFS than that from medium-textured OLS. Volatilization loss increased with increasing rates of manure application. Ammonia volatilization was lower at night time than that during the day time. Differences in major factors such as soil water content, temperature, soil type and live stock manure type influenced the diurnal variation in volatilization loss of NH(3) from soils. A significant portion (> 50%) of cumulative NH(3) emission over 19 d occurred during the first 5-7 d following the application of livestock manures. Results of this study demonstrate that application of low rates of livestock manure (< or = 5.60 Mg ha(-1)) is recommended to minimize NH(3) emissions. PMID:19280486

  8. Biosynthesis and Emission of Terpenoid Volatiles from Arabidopsis Flowers

    PubMed Central

    Chen, Feng; Tholl, Dorothea; D'Auria, John C.; Farooq, Afgan; Pichersky, Eran; Gershenzon, Jonathan

    2003-01-01

    Arabidopsis is believed to be mostly self-pollinated, although several lines of genetic and morphological evidence indicate that insect-mediated outcrossing occurs with at least a low frequency in wild populations. Here, we show that Arabidopsis flowers emit both monoterpenes and sesquiterpenes, potential olfactory cues for pollinating insects. Of the 32 terpene synthase genes in the Arabidopsis genome, 20 were found to be expressed in flowers, 6 of these exclusively or almost exclusively so. Two terpene synthase genes expressed exclusively in the flowers and one terpene synthase gene expressed almost exclusively in the flowers were characterized and found to encode proteins that catalyze the formation of major floral volatiles. A ?-glucuronidase fusion construct with a promoter of one of these genes demonstrated that gene expression was restricted to the sepals, stigmas, anther filaments, and receptacles, reaching a peak when the stigma was receptive to cross pollen. The observation that Arabidopsis flowers synthesize and emit volatiles raises intriguing questions about the reproductive behavior of Arabidopsis in the wild and allows detailed investigations of floral volatile biosynthesis and its regulation to be performed with this model plant system. PMID:12566586

  9. Kinetics of volatile extraction from carbonaceous chondrites: Dehydration of talc

    NASA Technical Reports Server (NTRS)

    Bose, Kunal; Ganguly, Jibamitra

    1991-01-01

    Carbonaceous chondrites are believed to be the primary constituents of near-Earth asteroids and Phobos and Deimos, and are potential resources of fuels that may be exploited for future planetary missions. Calculations of equilibrium phase relations suggest that talc (Ta) and antigorite (Ant) are likely to be the major hydrous phases in the C1 and C2 meteorites (Ganguly and Saxena, 1989), which constitute the most volatile rich classes of carbonaceous chondrites. The dehydration kinetics of talc are studied as a function of temperature, grain size, composition and fluid fugacity, as part of a systematic study of the reaction kinetics of the volatile bearing phases that are either known or likely to be present in carbonaceous chondrites. The dehydration kinetics were investigated at 1 bar, 775 to 875 C by monitoring the in-situ weight loss as a function of time of a natural talc. The talc platelets had a dimension of 0.8 to 1 micron. The run durations varied from 233.3 hours at 775 C (48 percent dehydration) to 20.8 hours at 875 C (80 pct. dehydration). The results can be adequately represented by a given rate equation. Theoretical analysis suggests that the reduction in the concentration of H2O in the environment of dehydrating talc, as would be encountered in processing chondritic materials, will have negligible effect on the rate of dehydration, unless there is a change of reaction mechanism owing to the presence of other volatile species.

  10. Tropylium ion mediated ?-cyanation of amines.

    PubMed

    Allen, Julia M; Lambert, Tristan H

    2011-02-01

    Tropylium ion mediated ?-cyanation of amines is described. Even in the presence of KCN, tropylium ion is capable of oxidizing various amine substrates, and the resulting iminium ions undergo salt metathesis with cyanide ion to produce aminonitriles. The byproducts of this transformation are simply cycloheptatriene, a volatile hydrocarbon, and water-soluble potassium tetrafluoroborate. Thirteen total substrates are shown for the ?-cyanation procedure, including a gram scale synthesis of 17?-cyanosparteine. In addition, a tropylium ion mediated oxidative aza-Cope rearrangement is demonstrated. PMID:21204541

  11. Changes in the chemical composition of volatiles released by the flowers and fruits of the red raspberry ( Rubus idaeus) cultivar glen prosen

    Microsoft Academic Search

    G. W. Robertson; D. W. Griffiths; J. A. T. Woodford; A. N. E. Birch

    1995-01-01

    Volatiles at various stages of inflorescence development, bud formation, flowering, fruit formation and ripening of a red raspberry, were entrained on the porous polymer Tenax TA and analysed by thermal desorption-gas chromatography-mass spectrometry. Major classes of compound identified included aliphatic and aromatic hydrocarbons, aldehydes, ketones, alcohols and esters, monoterpenes and sesquiterpenes. As the inflorescences matured, levels of green leaf volatiles

  12. Volatile organic compound sensing devices

    DOEpatents

    Lancaster, Gregory D. (Idaho Falls, ID); Moore, Glenn A. (Idaho Falls, ID); Stone, Mark L. (Idaho Falls, ID); Reagen, William K. (Stillwater, MN)

    1995-01-01

    Apparatus employing vapochromic materials in the form of inorganic double complex salts which change color reversibly when exposed to volatile organic compound (VOC) vapors is adapted for VOC vapor detection, VOC aqueous matrix detection, and selective VOC vapor detection. The basic VOC vapochromic sensor is incorporated in various devices such as a ground probe sensor, a wristband sensor, a periodic sampling monitor, a soil/water penetrometer, an evaporative purge sensor, and various vacuum-based sensors which are particularly adapted for reversible/reusable detection, remote detection, continuous monitoring, or rapid screening of environmental remediation and waste management sites. The vapochromic sensor is used in combination with various fiber optic arrangements to provide a calibrated qualitative and/or quantitative indication of the presence of VOCs.

  13. Volatile organic compound sensing devices

    DOEpatents

    Lancaster, G.D.; Moore, G.A.; Stone, M.L.; Reagen, W.K.

    1995-08-29

    Apparatus employing vapochromic materials in the form of inorganic double complex salts which change color reversibly when exposed to volatile organic compound (VOC) vapors is adapted for VOC vapor detection, VOC aqueous matrix detection, and selective VOC vapor detection. The basic VOC vapochromic sensor is incorporated in various devices such as a ground probe sensor, a wristband sensor, a periodic sampling monitor, a soil/water penetrometer, an evaporative purge sensor, and various vacuum-based sensors which are particularly adapted for reversible/reusable detection, remote detection, continuous monitoring, or rapid screening of environmental remediation and waste management sites. The vapochromic sensor is used in combination with various fiber optic arrangements to provide a calibrated qualitative and/or quantitative indication of the presence of VOCs. 15 figs.

  14. Investigation of the volatile constituents of different Gynura species from two Chinese origins by SPME/GC-MS.

    PubMed

    Chen, Jian; Adams, An; Mangelinckx, Sven; Ren, Bing-Ru; Li, Wei-lin; Wang, Zheng-tao; De Kimpe, Norbert

    2012-05-01

    GC-MS analyses of the volatile constituents obtained by solid phase microextraction (SPME) of two Gynura species, i.e., G. divaricata and G. bicolor, collected from Nanjing and Nanping areas in the east of China, enabled the identification of more than 50 different components. Generally, a higher contents of sesquiterpene compounds such as beta-caryophyllene, alpha-caryophyllene and alpha-copaene were found in G. bicolor than in G. divaricata, regardless of their origin. Qualitatively, the detected major volatiles of G. bicolor and G. divaricata originating from Nanjing were the same, i.e., beta-caryophyllene, alpha-caryophyllene, alpha-copaene, alpha-pinene and beta-pinene. The volatile profile of a third species, G. medica, also originating from Nanjing was different with sesquiterpenes gamma-cadinene, beta-caryophyllene, elixene and monoterpene limonene as the major components. The volatile profiles of G. bicolor and G. divaricata originating from Nanping were more diverse. For both species beta-caryophyllene, alpha-copaene and limonene were the major volatiles, but G. bicolor also produced gamma-caryophyllene and carvone as major constituents, whereas for G. divariata o-cymene was detected. Overall, these results indicate that the biosynthesis of volatiles by Gynura species is not only species related, but is also possibly influenced by the local environmental conditions of growth. PMID:22799100

  15. Selenium detoxification by volatilization and precipitation in aquatic plants

    SciTech Connect

    Fan, T.W.M.; Higashi, R.M. [Univ. of California, Davis, CA (United States)

    1995-12-31

    The narrow margin of requirement and toxicity for selenium makes it a difficult pollution problem to solve. Selenium bioaccumulation has been a major threat to wildlife in California and is becoming a major concern in the San Francisco Bay/Estuaries. Despite the past efforts in Se nutrition, chemistry, and remediation, its toxicity and detoxification mechanism(s) in wildlife, particularly primary producers, is still unclear, due to a lack of understanding in Se biochemistry. This is becoming a critical issue in assessing Se risk and remediation. To address this gap, the authors have been characterizing Se speciation and its linkage to detoxification mechanism(s) of two indigenous aquatic plants, duckweed (Lemna minor) and a microphyte (Chlorella). Using GT-MS analysis, they found that Chlorella monocultures transformed Se oxyanions into volatile dimethylselenide and dimethyidiselenide and into insoluble So at extremely high Se (up to 750 ppm) concentrations. This alga did not accumulate selenomethionine which is among the most toxic forms of Se to wildlife. Dimethylsulfide was also volatilized, consistent with the hypothesis that dimethylsulfide/dimethylselenide emissions share a similar biochemical pathway. Se-treated Chlorella biomass released dimethylsulfide/dimethylselenide upon alkaline hydrolysis, suggesting the presence of dimethylsulfonium and dimethylselenonium propionates. Dimethylsulfoniumpropionate is known as an osmoprotectant in marine phytoplankton and as a major contributor to global biogenic dimethylsulfide emissions. Dimethylselenoniumpropionate has not been identified previously and may be a byproduct of dimethylsulfoniumpropionate synthesis. The unusual Se tolerance of Chlorella may be due to its ability to volatilize and precipitate Se. Such activities may be utilized for in situ Se bioremediation. Similar investigations with duckweed is underway.

  16. Breath measurements as volatile organic compound biomarkers.

    PubMed Central

    Wallace, L; Buckley, T; Pellizzari, E; Gordon, S

    1996-01-01

    A brief review of the uses of breath analysis in studies of environmental exposure to volatile organic compounds (VOCs) is provided. The U.S. Environmental Protection Agency's large-scale Total Exposure Assessment Methodology Studies have measured concentrations of 32 target VOCs in the exhaled breath of about 800 residents of various U.S. cities. Since the previous 12-hr integrated personal air exposures to the same chemicals were also measured, the relation between exposure and body burden is illuminated. Another major use of the breath measurements has been to detect unmeasured pathways of exposure; the major impact of active smoking on exposure to benzene and styrene was detected in this way. Following the earlier field studies, a series of chamber studies have provided estimates of several important physiological parameters. Among these are the fraction, f, of the inhaled chemical that is exhaled under steady-state conditions and the residence times. tau i in several body compartments, which may be associated with the blood (or liver), organs, muscle, and fat. Most of the targeted VOCs appear to have similar residence times of a few minutes, 30 min, several hours, and several days in the respective tissue groups. Knowledge of these parameters can be helpful in estimating body burden from exposure or vice versa and in planning environmental studies, particularly in setting times to monitor breath in studies of the variation with time of body burden. Improvements in breath methods have made it possible to study short-term peak exposure situations such as filling a gas tank or taking a shower in contaminated water. PMID:8933027

  17. Prey and Non-prey Arthropods Sharing a Host Plant: Effects on Induced Volatile Emission and Predator Attraction

    PubMed Central

    Hordijk, Cornelis A.; Posthumus, Maarten A.; Dicke, Marcel

    2008-01-01

    It is well established that plants infested with a single herbivore species can attract specific natural enemies through the emission of herbivore-induced volatiles. However, it is less clear what happens when plants are simultaneously attacked by more than one species. We analyzed volatile emissions of lima bean and cucumber plants upon multi-species herbivory by spider mites (Tetranychus urticae) and caterpillars (Spodoptera exigua) in comparison to single-species herbivory. Upon herbivory by single or multiple species, lima bean and cucumber plants emitted volatile blends that comprised mostly the same compounds. To detect additive, synergistic, or antagonistic effects, we compared the multi-species herbivory volatile blend with the sum of the volatile blends induced by each of the herbivore species feeding alone. In lima bean, the majority of compounds were more strongly induced by multi-species herbivory than expected based on the sum of volatile emissions by each of the herbivores separately, potentially caused by synergistic effects. In contrast, in cucumber, two compounds were suppressed by multi-species herbivory, suggesting the potential for antagonistic effects. We also studied the behavioral responses of the predatory mite Phytoseiulus persimilis, a specialized natural enemy of spider mites. Olfactometer experiments showed that P. persimilis preferred volatiles induced by multi-species herbivory to volatiles induced by S. exigua alone or by prey mites alone. We conclude that both lima bean and cucumber plants effectively attract predatory mites upon multi-species herbivory, but the underlying mechanisms appear different between these species. PMID:18185960

  18. Monitoring Trace Contaminants in Air Via Ion Trap Mass Spectrometry

    NASA Technical Reports Server (NTRS)

    Palmer, Peter T.; Karr, Dane; Pearson, Richard; Valero, Gustavo; Wong, Carla

    1995-01-01

    Recent passage of the Clean Air Act with its stricter regulation of toxic gas emissions, and the ever-growing number of applications which require faster turnaround times between sampling and analysis are two major factors which are helping to drive the development of new instrument technologies for in-situ, on-line, real-time monitoring. The ion trap, with its small size, excellent sensitivity, and tandem mass spectrometry capability is a rapidly evolving technology which is well-suited for these applications. In this paper, we describe the use of a commercial ion trap instrument for monitoring trace levels of chlorofluorocarbons (CFCs) and volatile organic compounds (VOCs) in air. A number of sample introduction devices including a direct transfer line interface, short column GC, and a cryotrapping interface are employed to achieve increasing levels of sensitivity. MS, MS/MS, and MS/MS/MS methods are compared to illustrate trade-offs between sensitivity and selectivity. Filtered Noise Field (FNF) technology is found to be an excellent means for achieving lower detection limits through selective storage of the ion(s) of interest during ionization. Figures of merit including typical sample sizes, detection limits, and response times are provided. The results indicate the potential of these techniques for atmospheric assessments, the High Speed Research Program, and advanced life support monitoring applications for NASA.

  19. Advanced steady-state model for the fate of hydrophobic and volatile compounds in activated sludge

    SciTech Connect

    Lee, K.C.; Rittmann, B.E.; Shi, J.; McAvoy, D.

    1998-09-01

    A steady-state, advanced, general fate model developed to study the fate of organic compounds in primary and activated-sludge systems. This model considers adsorption, biodegradation from the dissolved and adsorbed phases, bubble volatilization, and surface volatilization as removal mechanisms. A series of modeling experiments was performed to identify the key trends of these removal mechanisms for compounds with a range of molecular properties. With typical municipal wastewater treatment conditions, the results from the modeling experiments show that co-metabolic and primary utilization mechanisms give very different trends in biodegradation for the compounds tested. For co-metabolism, the effluent concentration increases when the influent concentration increases, while the effluent concentration remains unchanged when primary utilization occurs. For a highly hydrophobic compound, the fraction of compound removed from adsorption onto primary sludge can be very important, and the direct biodegradation of compound sorbed to the activated sludge greatly increases its biodegradation and reduces its discharge with the waste activated sludge. Volatilization from the surface of the primary and secondary systems is important for compounds with moderate to high volatilities, especially when these compounds are not biodegradable. Finally, bubble volatilization can be a major removal mechanism for highly volatile compounds even when they are highly biodegradable.

  20. Sulfur volatiles in guava (Psidium guajava L.) leaves: possible defense mechanism.

    PubMed

    Rouseff, Russell L; Onagbola, Ebenezer O; Smoot, John M; Stelinski, Lukasz L

    2008-10-01

    Volatiles from crushed and intact guava leaves (Psidium guajava L.) were collected using static headspace SPME and determined using GC-PFPD, pulsed flame photometric detection, and GC-MS. Leaf volatiles from four common citrus culitvars were examined similarly to determine the potential component(s) responsible for guava's protective effect against the Asian citrus psyllid (Diaphorina citri Kuwayama), which is the insect vector of Huanglongbing (HLB) or citrus greening disease. Seven sulfur volatiles were detected: hydrogen sulfide, sulfur dioxide, methanethiol, dimethyl sulfide (DMS), dimethyl disulfide (DMDS), methional, and dimethyl trisulfide (DMTS). Identifications were based on matching linear retention index values on ZB-5, DB-Wax, and PLOT columns and MS spectra in the case of DMDS and DMS. DMDS is an insect toxic, defensive volatile produced only by wounded guava but not citrus leaves and, thus, may be the component responsible for the protective effect of guava against the HLB vector. DMDS is formed immediately after crushing, becoming the major headspace volatile within 10 min. Forty-seven additional leaf volatiles were identified from LRI and MS data in the crushed guava leaf headspace. PMID:18778077

  1. Chemical composition of Silene morganae Freyn volatile oil.

    PubMed

    Azadi, Boshra; Sohrabi, Yousef

    2015-05-01

    The essential oil composition of flowering aerial parts of Iranian Silene morganae Freyn (Caryophyllaceae) was analysed for the first time using gas chromatography and gas chromatography-mass spectrometry. Thirty-one compounds consisting of 90.3% of the volatile oil were detected. The major constituents were benzaldehyde (11.6%), (Z)-3-hexenyl acetate (9.6%), (E)-?-ocimene (8.2%) and linalool (7.4%). Terpenoids (43.5%), particularly monoterpene hydrocarbons (24.2%), had the highest contribution in S. morganae Freyn flowering aerial parts oil. PMID:25422069

  2. Volatile Evolution of Magma Associated with the Solchiaro Eruption in the Phlegrean Volcanic District (Italy)

    NASA Astrophysics Data System (ADS)

    Esposito, R.; Bodnar, R. J.; de Vivo, B.; Lima, A.; Fedele, L.; Shimizu, N.; Belkin, H.

    2008-12-01

    The Phlegrean volcanic district (PVD) in southern Italy is one of the best known volcanic hazard areas in the world. More than 1.5 million people live in close proximity to the volcanic centers. The PVD comprises three volcanic fields: the Campi Flegrei caldera and the islands of Ischia and Procida. The area contains many volcanic centers (cinder cones, tuff rings, calderas) and has been the site of episodic volcanic activity for more than 60 ka. Some of these eruptions have been extremely violent. We studied volatiles in the magma associated with the Solchiaro eruption on the Island of Procida, Italy, to gain a better understanding of the relationship between eruptive style and intensity and the volatile content of the magma. The Solchiaro eruption is one of the more primitive products erupted in the PVD and provides information on the source of later more evolved magmas associated with this volcanic system. The composition of the magma before eruption was determined by analyzing melt inclusions (MIs) in forsteritic olivine and diopside. Several different types of MIs were observed in both phases. Some MI contained only glass, others contained glass plus one or more bubbles, and some contained glass plus bubbles plus crystals. We analyzed MIs containing only glass and those containing one or two bubbles. The composition of MIs ranges from basaltic to trachy-basaltic. Among major elements potassium shows the highest variability, from 1.48 to 3.73 wt %. Laser ablation-inductively coupled plasma mass spectroscopy (LA-ICPMS) analysis of MIs combined with major element analysis suggest assimilation of LILE and halogens from wallrock. Diopside-hosted MI have a higher H2O content than olivine-hosted MI, based on Secondary Ion Mass Spectrometric (SIMS) analysis. MI in olivine contain from 1.13 to 1.38 wt % H2O. F, Cl, S, CO2 contents are highly variable in both olivine and diopside-hosted MIs. The trend in H2O versus CO2 suggests emplacement of an originally CO2-saturated magma at >5 km that rises through the crust as it is undergoing crystallization. The magma eventually ponds at shallow depths (<1 km) before eruption. The inferred emplacement and crystallization history of magma at Campi Flegrei is similar to what was observed at Mt. St. Helens in the months immediately preceding the May 1980 eruption.

  3. Identification of Major Histocompatibility Complex-Regulated Body Odorants by Statistical Analysis of a Comparative Gas Chromatography/Mass Spectrometry Experiment

    SciTech Connect

    Willse, Alan R.; Belcher, Ann; Preti, George; Wahl, Jon H.; Thresher, Miranda; Yang, Peter; Yamazaki, Kunio; Beauchamp, Gary

    2005-04-15

    Gas chromatography (GC), combined with mass spectrometry (MS) detection, is a powerful analytical technique that can be used to separate, quantify, and identify volatile compounds in complex mixtures. This paper examines the application of GC-MS in a comparative experiment to identify volatiles that differ in concentration between two groups. A complex mixture might comprise several hundred or even thousands of volatile compounds. Because their number and location in a chromatogram generally are unknown, and because components overlap in populous chromatograms, the statistical problems offer significant challenges beyond traditional two-group screening procedures. We describe a statistical procedure to compare two-dimensional GC-MS profiles between groups, which entails (1) signal processing: baseline correction and peak detection in single ion chromatograms; (2) aligning chromatograms in time; (3) normalizing differences in overall signal intensities; and (4) detecting chromatographic regions that differ between groups. Compared to existing approaches, the proposed method is robust to errors made at earlier stages of analysis, such as missed peaks or slightly misaligned chromatograms. To illustrate the method, we identify differences in GC-MS chromatograms of ether-extracted urine collected from two nearly identical inbred groups of mice, to investigate the relationship between odor and genetics of the major histocompatibility complex.

  4. The effects of volatile anesthetics on synaptic and extrasynaptic GABA-induced neurotransmission.

    PubMed

    Kotani, Naoki; Akaike, Norio

    2013-04-01

    Examination of volatile anesthetic actions at single synapses provides more direct information by reducing interference by surrounding tissue and extrasynaptic modulation. We examined how volatile anesthetics modulate GABA release by measuring spontaneous or miniature GABA-induced inhibitory postsynaptic currents (mIPSCs, sIPSCs) or by measuring action potential-evoked IPSCs (eIPSCs) at individual synapses. Halothane increased both the amplitude and frequency of sIPSCs. Isoflurane and enflurane increased mIPSC frequency while sevoflurane had no effect. These anesthetics did not alter mIPSC amplitudes. Halothane increased the amplitude of eIPSCs, with a decrease in failure rate (Rf) and paired-pulse ratio. In contrast, isoflurane and enflurane decreased the eIPSC amplitude and increased Rf, while sevoflurane decreased the eIPSC amplitude without affecting Rf. Volatile anesthetics did not change kinetics except for sevoflurane, suggesting that presynaptic mechanisms dominate changes in neurotransmission. Each anesthetic showed somewhat different GABA-induced response and these results suggest that GABA-induced synaptic transmission cannot have a uniformly common site of action as suggested for volatile anesthetics. In contrast, all volatile anesthetics concentration-dependently enhanced the GABA-induced extrasynaptic currents. Extrasynaptic receptors containing ?4 and ?5 subunits are reported to have high sensitivities to volatile anesthetics. Also, inhibition of GABA uptake by volatile anesthetics results in higher extracellular GABA concentration, which may lead to prolonged activation of extrasynaptic GABAA receptors. The extrasynaptic GABA-induced receptors may be major site of volatile anesthetic-induced neurotransmission. This article is part of a Special Issue entitled 'Extrasynaptic ionotropic receptors'. PMID:22925739

  5. Reduction of volatile acidity of acidic wines by immobilized Saccharomyces cerevisiae cells.

    PubMed

    Vilela, A; Schuller, D; Mendes-Faia, A; Côrte-Real, M

    2013-06-01

    Excessive volatile acidity in wines is a major problem and is still prevalent because available solutions are nevertheless unsatisfactory, namely, blending the filter-sterilized acidic wine with other wines of lower volatile acidity or using reverse osmosis. We have previously explored the use of an empirical biological deacidification procedure to lower the acetic acid content of wines. This winemaker's enological practice, which consists in refermentation associated with acetic acid consumption by yeasts, is performed by mixing the acidic wine with freshly crushed grapes, musts, or marc from a finished wine fermentation. We have shown that the commercial strain Saccharomyces cerevisiae S26 is able to decrease the volatile acidity of acidic wines with a volatile acidity higher than 1.44 g?L(-1) acetic acid, with no detrimental impact on wine aroma. In this study, we aimed to optimize the immobilization of S26 cells in alginate beads for the bioreduction of volatile acidity of acidic wines. We found that S26 cells immobilized in double-layer alginate-chitosan beads could reduce the volatile acidity of an acidic wine (1.1 g?L(-1) acetic acid, 12.5 % (v/v) ethanol, pH 3.12) by 28 and 62 % within 72 and 168 h, respectively, associated with a slight decrease in ethanol concentration (0.7 %). Similar volatile acidity removal efficiencies were obtained in medium with high glucose concentration (20 % w/v), indicating that this process may also be useful in the deacidification of grape musts. We, therefore, show that immobilized S. cerevisiae S26 cells in double-layer beads are an efficient alternative to improve the quality of wines with excessive volatile acidity. PMID:23361840

  6. Flower volatiles, crop varieties and bee responses.

    PubMed

    Klatt, Björn K; Burmeister, Carina; Westphal, Catrin; Tscharntke, Teja; von Fragstein, Maximilian; von Fragstein, Maximillian

    2013-01-01

    Pollination contributes to an estimated one third of global food production, through both the improvement of the yield and the quality of crops. Volatile compounds emitted by crop flowers mediate plant-pollinator interactions, but differences between crop varieties are still little explored. We investigated whether the visitation of crop flowers is determined by variety-specific flower volatiles using strawberry varieties (Fragaria x ananassa Duchesne) and how this affects the pollination services of the wild bee Osmia bicornis L. Flower volatile compounds of three strawberry varieties were measured via headspace collection. Gas chromatography showed that the three strawberry varieties produced the same volatile compounds but with quantitative differences of the total amount of volatiles and between distinct compounds. Electroantennographic recordings showed that inexperienced females of Osmia bicornis had higher antennal responses to all volatile compounds than to controls of air and paraffin oil, however responses differed between compounds. The variety Sonata was found to emit a total higher level of volatiles and also higher levels of most of the compounds that evoked antennal responses compared with the other varieties Honeoye and Darselect. Sonata also received more flower visits from Osmia bicornis females under field conditions, compared with Honeoye. Our results suggest that differences in the emission of flower volatile compounds among strawberry varieties mediate their attractiveness to females of Osmia bicornis. Since quality and quantity of marketable fruits depend on optimal pollination, a better understanding of the role of flower volatiles in crop production is required and should be considered more closely in crop-variety breeding. PMID:23977347

  7. Flower Volatiles, Crop Varieties and Bee Responses

    PubMed Central

    Klatt, Björn K.; Burmeister, Carina; Westphal, Catrin; Tscharntke, Teja; von Fragstein, Maximillian

    2013-01-01

    Pollination contributes to an estimated one third of global food production, through both the improvement of the yield and the quality of crops. Volatile compounds emitted by crop flowers mediate plant-pollinator interactions, but differences between crop varieties are still little explored. We investigated whether the visitation of crop flowers is determined by variety-specific flower volatiles using strawberry varieties (Fragaria x ananassa Duchesne) and how this affects the pollination services of the wild bee Osmia bicornis L. Flower volatile compounds of three strawberry varieties were measured via headspace collection. Gas chromatography showed that the three strawberry varieties produced the same volatile compounds but with quantitative differences of the total amount of volatiles and between distinct compounds. Electroantennographic recordings showed that inexperienced females of Osmia bicornis had higher antennal responses to all volatile compounds than to controls of air and paraffin oil, however responses differed between compounds. The variety Sonata was found to emit a total higher level of volatiles and also higher levels of most of the compounds that evoked antennal responses compared with the other varieties Honeoye and Darselect. Sonata also received more flower visits from Osmia bicornis females under field conditions, compared with Honeoye. Our results suggest that differences in the emission of flower volatile compounds among strawberry varieties mediate their attractiveness to females of Osmia bicornis. Since quality and quantity of marketable fruits depend on optimal pollination, a better understanding of the role of flower volatiles in crop production is required and should be considered more closely in crop-variety breeding. PMID:23977347

  8. Securing non-volatile memory regions

    DOEpatents

    Faraboschi, Paolo; Ranganathan, Parthasarathy; Muralimanohar, Naveen

    2013-08-20

    Methods, apparatus and articles of manufacture to secure non-volatile memory regions are disclosed. An example method disclosed herein comprises associating a first key pair and a second key pair different than the first key pair with a process, using the first key pair to secure a first region of a non-volatile memory for the process, and using the second key pair to secure a second region of the non-volatile memory for the same process, the second region being different than the first region.

  9. Concentrations of Volatiles in the Lunar Regolith

    NASA Technical Reports Server (NTRS)

    Taylor, Jeff; Taylor, Larry; Duke, Mike

    2007-01-01

    To set lower and upper limits on the overall amounts and types of volatiles released during heating of polar regolith, we examined the data for equatorial lunar regolith and for the compositions of comets. The purpose, specifically, was to answer these questions: 1. Upper/Lower limits and 'best guess' for total amount of volatiles (by weight %) released from lunar regolith up to 150C 2. Upper/Lower limit and 'best guess' for composition of the volatiles released from the lunar regolith by weight %

  10. Volatile organic components of fresh leaves as indicators of indigenous and cultivated citrus species in Taiwan.

    PubMed

    Lin, Shu Yen; Roan, Su Feng; Lee, Ching Lung; Chen, Iou Zen

    2010-01-01

    The volatile components of fresh leaves from 15 citrus species were investigated by headspace SPME with a GC-MS analysis. Three indigenous Taiwan citrus species, Citrus taiwanica, C. tachibana and C. depressa, were the major subjects. Eighty volatile organic compounds were detected as indicators of the genetic relationship. Linalool was the most abundant compound, and citronellal, geranial, neral, limonene and trans-beta-ocimene were the major volatile compounds in fresh leaves. Linalool (56.37%) and myrcene (7.21%) were predominant in C. tawanica. An aldehyde-rich profile with citronellal (24.54%) contributed most to the aroma of leaves in C. tachibana, while Citrus depressa exhibited a high linalool/citronellal composition (23.56%/12.51%). The qualitative and quantitative patterns of the volatiles revealed that C. taiwanica was linked with sour orange, and either C. tachibana or C. depressa belonged to the mandarin group with C. tankan. Dendrograms also showed that the volatile patterns were related to the genetic classification. PMID:20378980

  11. Studies of volatiles and organic materials in early terrestrial and present-day outer solar system environments

    NASA Technical Reports Server (NTRS)

    Sagan, Carl; Thompson, W. Reid; Chyba, Christopher F.; Khare, B. N.

    1991-01-01

    A review and partial summary of projects within several areas of research generally involving the origin, distribution, chemistry, and spectral/dielectric properties of volatiles and organic materials in the outer solar system and early terrestrial environments are presented. The major topics covered include: (1) impact delivery of volatiles and organic compounds to the early terrestrial planets; (2) optical constants measurements; (3) spectral classification, chemical processes, and distribution of materials; and (4) radar properties of ice, hydrocarbons, and organic heteropolymers.

  12. Seasonal Variation in Volatile Compound Profiles of Preen Gland Secretions of the Dark-eyed Junco ( Junco hyemalis )

    Microsoft Academic Search

    Helena A. Soini; Sara E. Schrock; Kevin E. Bruce; Donald Wiesler; Ellen D. Ketterson; Milos V. Novotny

    2007-01-01

    Quantitative stir bar sorptive extraction methodology, followed by gas chromatography-mass spectrometry (GC-MS) and element-specific\\u000a atomic emission detection (AED) were utilized to analyze seasonal changes in volatile components of preen oil secretions in\\u000a Junco hyemalis. Juncos were held in long days to simulate breeding conditions, or short days to simulate nonbreeding conditions. Linear\\u000a alcohols (C10–C18) were the major volatile compounds found

  13. RELATIVE HUMIDITY AND ITS AFFECT ON THE ANALYSIS OF VOLATILE FATTY ACIDS ON SORBENT TUBES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Volatile fatty acids (VFA) are a major component of odor from swine operations. Thermodesorption has been used in the analysis of VFA in air; however, no study has been conducted to validate this air sampling technique. The objectives of this study were to determine the effects relative humidity h...

  14. Clinoptilolite zeolite and cellulose amendments to reduce ammonia volatilization in a calcareous sandy soil

    Microsoft Academic Search

    Z. L. He; D. V. Calvert; A. K. Alva; Y. C. Li; D. J. Banks

    2002-01-01

    Leaching of nitrate (NO3-) below the root zone and gaseous losses of nitrogen (N) such as ammonia (NH3) volatilization, are major mechanisms of N loss from agricultural soils. New techniques to minimize such losses are needed to maximize N uptake efficiency and minimize production costs and the risk of potential N contamination of ground and surface waters. The effects of

  15. Evolution or revolution? a study of price and wage volatility in England, 1200-1900

    Microsoft Academic Search

    Catherine Casson; J. M. Fry; Mark Casson

    2011-01-01

    Using annual data 1209-1914, this paper examines whether there are structural breaks in the movements of prices and wages that correspond to the major ‘revolutions’ identified in historical narratives. Econometric modelling of trend and volatility in prices and wages confirms the importance of the Commercial Revolution and the Glorious Revolution, but suggests that the Industrial Revolution may be better described

  16. Functional characterization of enzymes forming volatile esters from strawberry and banana

    Microsoft Academic Search

    M. J. Beekwilder; Mayte Alvarez-Huerta; Evert Neef; Francel W. A. Verstappen; Harro J. Bouwmeester; A. Aharoni

    2004-01-01

    Volatile esters are flavor components of the majority of fruits. The last step in their biosynthesis is catalyzed by alcohol acyltransferases (AATs), which link alcohols to acyl moieties. Full-length cDNAs putatively encoding AATs were isolated from fruit of wild strawberry (Fragaria vesca) and banana (Musa sapientum) and compared to the previously isolated SAAT gene from the cultivated strawberry (Fragaria x

  17. Agriculture and Trade Opportunities for Tanzania: Past Volatility and Future Climate Changerode_672 429..447

    E-print Network

    Pittendrigh, Barry

    Agriculture and Trade Opportunities for Tanzania: Past Volatility and Future Climate Changerode_672 global heterogeneity in climate-induced agricultural variability,Tanzania has the potential to substan owing to supply shocks in major exporting regions, Tanzania may be able to export more maize at higher

  18. Alcohol, volatile fatty acid, phenol, and methane emissions from dairy cows and fresh manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are approximately 2.5 million dairy cows in California. Emission inventories list dairy cows and their waste as the major source of regional air pollutants, but data on their actual emissions remain sparse, particularly for smog-forming volatile organic compounds (VOC) and greenhouse gases (GH...

  19. Experimental investigation of the volatility of elements in respect to temperature and fO2

    NASA Astrophysics Data System (ADS)

    Ertel, W.; Dingwell, D. B.; Pohl, S.

    2009-12-01

    The volatility of elements is an important variable during geological processes: its impact ranges from daily out gassing of volcanic vents to catastrophic emissions during volcanic eruptions which might result in global climate change. Volatility played, however, already a major role during the formation of our solar system regarding evaporation and condensation of matter of the solar nebula which finally formed our solar system. Precise knowledge of the parameters controlling volatility as well as condensation of elements is still lacking. We therefore initiated a systematic study of the volatility of 18 volatile elements in respect to oxygen fugacity (fO2) and temperature (T) using a modified mechanically assisted equilibration technique (MAE): Approx. 60 g of haplobasaltic starting composition (An-Di) doped with up to 5000 ppm of volatile element (Li, K, Na, Ti, Cr, Mn, Co, Cu, Cu, Zn, Ga, Rb, Cd, In, Sn, Sb, Cs, Tl) was heated to run temperature. To investigate the fO2 dependence 2 experiments at logfO2 = -11.3 (~ IW -0.5) and - 0,7 (pure air) at constant T (1300 °C) were performed, while T dependence was investigated at 1300 and 1500 °C at constant fO2 in pure air. Two Al2O3 plates extending from the hot spot region up to the upper, cooler regions of the muffle tube were used as condensation traps. The temperature profile of the entire setup including the Al2O3 plates was calibrated prior to any run. Experiments lasted for up two weeks while experimental conditions were kept strictly constant and monitored. Up to 46 samples were taken from the melt by time-series sampling to monitor the loss of volatile elements due to their volatility. In this way both evaporation of the investigated elements as well as their condensation behaviour can be investigated simultaneously. Major element composition was analyzed by electron microprobe analysis, while volatile concentrations were determined by laser- ablation inductively coupled plasma mass spectrometry (LAMS). Preliminary results show a highly complex behaviour of the investigated volatile elements: At low fO2, Li, Na, K, Ti, Cr, Mn, Rb, and Cs show no decrease due to evaporation. At high fO2, however, e.g., Cr and Mn decrease with time due to increased volatility, while Co, Cu, Sb and Tl become less volatile. Due to the relatively small temperature range (200 °C), the observed T effect is small compared to the fO2 dependence: The decrease in elemental concentrations with increasing T stays practically the same for Cr, In, Sn, Sb and Tl. Mn, Cu, Zn, and Ga show a slightly decreased volatility at a higher temperature, while Cs and Cd become slightly more volatile. The present data set indicates a complex behaviour of volatiles due to melt compositional aspects: Concentrations do not generally decrease linearly with time as anticipated earlier, but stay, e.g., constant for some elements due to the formation of stable phases. Additional experiments, however, are necessary to confirm our preliminary findings.

  20. Serratia odorifera : analysis of volatile emission and biological impact of volatile compounds on Arabidopsis thaliana

    Microsoft Academic Search

    Marco Kai; Elena Crespo; Simona M. Cristescu; Frans J. M. Harren; Wittko Francke; Birgit Piechulla

    2010-01-01

    Bacteria emit a wealth of volatiles. The combination of coupled gas chromatography\\/mass spectrometry (GC\\/MS) and proton-transfer-reaction\\u000a mass spectrometry (PTR-MS) analyses provided a most comprehensive profile of volatiles of the rhizobacterium Serratia odorifera 4Rx13. An array of compounds, highly dominated by sodorifen (approximately 50%), a bicyclic oligomethyl octadiene, could\\u000a be detected. Other volatiles included components of the biogeochemical sulfur cycle such

  1. Plant Volatiles as a Defense against Insect Herbivores

    Microsoft Academic Search

    Paul W. Pare; James H. Tumlinson

    1999-01-01

    Leaves normally release small quantities of volatile chemicals, but when a plant is damaged by herbivorous insects, many more volatiles are released. The chemical identity of the volatile compounds varies with the plant species and with the herbivorous insect species. These volatiles attract both parasitic and predatory insects that are natural enemies of the herbivores. They may also in- duce

  2. Reactive flash volatilization of fluid fuels

    DOEpatents

    Schmidt, Lanny D.; Dauenhauer, Paul J.; Dreyer, Bradon J.; Salge, James R.

    2013-01-08

    The invention provides methods for the production of synthesis gas. More particularly, various embodiments of the invention relate to systems and methods for volatilizing fluid fuel to produce synthesis gas by using a metal catalyst on a solid support matrix.

  3. Microwave spectra of some volatile organic compounds

    NASA Technical Reports Server (NTRS)

    White, W. F.

    1975-01-01

    A computer-controlled microwave (MRR) spectrometer was used to catalog reference spectra for chemical analysis. Tables of absorption frequency, peak absorption intensity, and integrated intensity are included for 26 volatile organic compounds, all but one of which contain oxygen.

  4. VOLATILE ORGANIC ANALYSIS BY DIRECT AQUEOUS INJECTION

    EPA Science Inventory

    Gas chromatographic environmental analysis by direct aqueous injection (DAI) was studied for 24 volatile organic analytes (VOAs). Internal standardization was used to determine the precision of analyzing these compounds by DAI. Aequous samples were directly introduced to a gas ch...

  5. The Metabolism of the Volatile Amines

    PubMed Central

    Tobe, Barry A.

    1963-01-01

    As part of a series of studies into the etiology of acute hepatic encephalopathy the identity of the volatile base, which had been extracted from blood and presumed to be ammonia, was investigated. In order to differentiate between ammonia and the other volatile bases with which it can be confused, a method of separating these compounds by the use of gas chromatography was developed. The technique is described in detail because it incorporates several novel ideas that can be applied to the isolation and identification of similar compounds in many biological systems. The volatile base extracted from blood was found to be ammonia, and no other volatile base was demonstrable in blood from both healthy subjects and patients suffering from acute hepatic encephalopathy. PMID:14101451

  6. Release of volatile mercury from vascular plants

    NASA Technical Reports Server (NTRS)

    Siegel, S. M.; Puerner, N. J.; Speitel, T. W.

    1974-01-01

    Volatile, organic solvent soluble mercury has been found in leaves and seeds of several angiosperms. Leaves of garlic vine, avocado, and haole-koa release mercury in volatile form rapidly at room temperature. In garlic vine, the most active release is temperature dependent, but does not parallel the vapor-pressure temperature relationship for mercury. Mercury can be trapped in nitric-perchloric acid digestion fluid, or n-hexane, but is lost from the hexane unless the acid mixture is present. Seeds of haole-koa also contain extractable mercury but volatility declines in the series n-hexane (90%), methanol (50%), water (10%). This suggests that reduced volatility may accompany solvolysis in the more polar media.

  7. Silicon microfabricated column with microfabricated differential mobility spectrometer for GC analysis of volatile organic compounds.

    PubMed

    Lambertus, Gordon R; Fix, Cory S; Reidy, Shaelah M; Miller, Ranaan A; Wheeler, David; Nazarov, Erkinjon; Sacks, Richard

    2005-12-01

    A 3.0-m-long, 150-microm-wide, 240-microm-deep channel etched in a 3.2-cm-square silicon chip, covered with a Pyrex wafer, and coated with a dimethyl polysiloxane stationary phase is used for the GC separation of volatile organic compounds. The column, which generates approximately 5500 theoretical plates, is temperature-programmed in a conventional convection oven. The column is connected through a heated transfer line to a microfabricated differential mobility spectrometer. The spectrometer incorporates a 63Ni source for atmospheric-pressure chemical ionization of the analytes. Nitrogen or air transport gas (flow 300 cm(3)/min) drives the analyte ions through the cell. The spectrometer operates with an asymmetric radio frequency (RF) electric field between a pair of electrodes in the detector cell. During each radio frequency cycle, the ion mobility alternates between a high-field and a low-field value (differential mobility). Ions oscillate between the electrodes, and only ions with an appropriate differential mobility reach a pair of biased collectors at the downstream end of the cell. A compensation voltage applied to one of the RF electrodes is scanned to allow ions with different differential mobilities to pass through the cell without being annihilated at the RF electrodes. A unique feature of the device is that both positive and negative ions are detected from a single experiment. The combined microfabricated column and detector is evaluated for the analysis of volatile organic compounds with a variety of functionalities. PMID:16316163

  8. Mercury volatilization from salt marsh sediments

    Microsoft Academic Search

    Lora M. Smith; John R. Reinfelder

    2009-01-01

    In situ volatilization fluxes of gaseous elemental mercury, Hg(0), were estimated for tidally exposed salt marsh sediments in the summer at the urban\\/industrial Secaucus High School Marsh, New Jersey Meadowlands (Secaucus, New Jersey) and in the early autumn at a regional background site in the Great Bay estuary (Tuckerton, New Jersey). Estimated daytime sediment-air mercury volatilization fluxes at the Secaucus

  9. S&P 100 Index Option Volatility

    Microsoft Academic Search

    Campbell R Harvey; Robert E Whaley

    1991-01-01

    Using transaction data on the S&P 100 index options, the authors study the effect of valuation simplifications that are commonplace in previous research on the time-series properties of implied market volatility. Using an American-style algorithm that accounts for the discrete nature of the dividends on the S&P 100 index, they find that spurious negative serial correlation in implied volatility changes

  10. Volatiles in Selected Commercial Breads 1

    Microsoft Academic Search

    L. M. Seitz; O. K. Chung; R. Rengarajan

    1998-01-01

    Cereal Chem. 75(6):847-853 Selected types of commercial breads obtained from local markets, in- cluding white sandwich, Irish oatmeal, soft rye, hearty rye, sour dough, home-like white, and onion-basil, were analyzed for volatiles. Using a purge and trap instrument, volatiles were purged directly from fresh crumb and crust samples of each bread type, collected on a trap (Tenax-TA), and transferred to

  11. ION CHROMATOGRAPHY OF ANIONS

    EPA Science Inventory

    A Dionex Model 10 Ion Chromatograph was evaluated for the measurement of anionic species in water. The theoretical effect of hydrogen ion activity (pH) on the elution time of phosphate and arsenate was tested and empirical selectivity coefficients were determined for the major pr...

  12. Gas chromatographic analysis of volatiles in fluid and gas inclusions

    USGS Publications Warehouse

    Andrawes, F.; Holzer, G.; Roedder, E.; Gibson, E.K., Jr.; Oro, J.

    1984-01-01

    Most geological samples and some synthetic materials contain fluid inclusions. These inclusions preserve for us tiny samples of the liquid and/or the gas phase that was present during formation, although in some cases they may have undergone significant changes from the original material. Studies of the current composition of the inclusions provide data on both the original composition and the change since trapping. These inclusions are seldom larger than 1 millimeter in diameter. The composition varies from a single major compound (e.g., water) in a single phase to a very complex mixture in one or more phases. The concentration of some of the compounds present may be at trace levels. We present here some analyses of inclusions in a variety of geological samples, including diamonds. We used a sample crusher and a gas chromatography-mass spectrometry (GC-MS) system to analyze for organic and inorganic volatiles present as major to trace constituents in inclusions. The crusher is a hardened stainless-steel piston cylinder apparatus with tungsten carbide crusing surfaces, and is operated in a pure helium atmosphere at a controlled temperature. Samples ranging from 1 mg to 1 g were crushed and the released volatiles were analyzed using multi-chromatographic columns and detectors, including the sensitive helium ionization detector. Identification of the GC peaks was carried out by GC-MS. This combination of procedures has been shown to provide geochemically useful information on the process involved in the history of the samples analyzed. ?? 1984.

  13. Measurement of volatile organic compounds inside automobiles.

    PubMed

    Fedoruk, Marion J; Kerger, Brent D

    2003-01-01

    The objective of the current study was to evaluate the types and concentrations of volatile organic compounds (VOCs) in the passenger cabin of selected sedan automobiles under static (parked, unventilated) and specified conditions of operation (i.e., driving the vehicle using air conditioning alone, vent mode alone, or driver's window half open). Data were collected on five different passenger sedan vehicles from three major automobile manufacturers. Airborne concentrations were assessed using 90-min time-weighted average (TWA) samples under U.S. Environmental Protection Agency (USEPA) Method IP-1B to assess individual VOC compounds and total VOCs (TVOCs) calibrated to toluene. Static vehicle testing demonstrated TVOC levels of approximately 400-800 microg/m(3) at warm interior vehicle temperatures (approximately 80 degrees F), whereas TVOCs at least fivefold higher were observed under extreme heat conditions (e.g., up to 145 degrees F). The profile of most prevalent individual VOC compounds varied considerably according to vehicle brand, age, and interior temperature tested, with predominant compounds including styrene, toluene, and 8- to 12-carbon VOCs. TVOC levels under varied operating conditions (and ventilation) were generally four- to eightfold lower (at approximately 50-160 microg/m(3)) than the static vehicle measurements under warm conditions, with the lowest measured levels generally observed in the trials with the driver's window half open. These data indicate that while relatively high concentrations of certain VOCs can be measured inside static vehicles under extreme heat conditions, normal modes of operation rapidly reduce the inside-vehicle VOC concentrations even when the air conditioning is set on recirculation mode. PMID:12595882

  14. Forecasting S&P 100 volatility: the incremental information content of implied volatilities and high-frequency index returns

    Microsoft Academic Search

    Bevan J. Blair; Ser-Huang Poon; Stephen J. Taylor

    2001-01-01

    The information content of implied volatilities and intraday returns is compared, in the context of forecasting index volatility over horizons from 1 to 20 days. Forecasts of two measures of realised volatility are obtained after estimating ARCH models using daily index returns, daily observations of the VIX index of implied volatility and sums of squares of 5-min index returns. The

  15. A Model Membrane Protein for Binding Volatile Anesthetics

    PubMed Central

    Ye, Shixin; Strzalka, Joseph; Churbanova, Inna Y.; Zheng, Songyan; Johansson, Jonas S.; Blasie, J. Kent

    2004-01-01

    Earlier work demonstrated that a water-soluble four-helix bundle protein designed with a cavity in its nonpolar core is capable of binding the volatile anesthetic halothane with near-physiological affinity (0.7 mM Kd). To create a more relevant, model membrane protein receptor for studying the physicochemical specificity of anesthetic binding, we have synthesized a new protein that builds on the anesthetic-binding, hydrophilic four-helix bundle and incorporates a hydrophobic domain capable of ion-channel activity, resulting in an amphiphilic four-helix bundle that forms stable monolayers at the air/water interface. The affinity of the cavity within the core of the bundle for volatile anesthetic binding is decreased by a factor of 4–3.1 mM Kd as compared to its water-soluble counterpart. Nevertheless, the absence of the cavity within the otherwise identical amphiphilic peptide significantly decreases its affinity for halothane similar to its water-soluble counterpart. Specular x-ray reflectivity shows that the amphiphilic protein orients vectorially in Langmuir monolayers at higher surface pressure with its long axis perpendicular to the interface, and that it possesses a length consistent with its design. This provides a successful starting template for probing the nature of the anesthetic-peptide interaction, as well as a potential model system in structure/function correlation for understanding the anesthetic binding mechanism. PMID:15465862

  16. The reduction of iron oxides by volatiles in a rotary hearth furnace process: Part III. The simulation of volatile reduction in a multi-layer rotary hearth furnace process

    SciTech Connect

    Sohn, I.; Fruehan, R.J. [Carnegie Mellon University, Pittsburgh, PA (United States)

    2006-04-15

    For reduction of iron oxides by volatiles from coal, the major reductant was found to be H{sub 2, and it can affect the overall reduction of iron oxides. In this study, the reduction by actual volatiles of composite pellets at 1000{sup o}C was studied. The volatile reduction of the hand-packed Fe{sub 2}O{sub 3}/Coal composite pellet as it is devolatilizing out of the pellet was found to be negligible. However, the reduction of iron oxide pellets at the top layer by volatiles from the bottom layers of a three-layer pellet geometry was observed to be about 15 pct. From the morphological observations of partially reduced pellets and the computed rates of bulk mass transfer, volatile reduction appears to be controlled by a mixed-controlled mechanism of bulk gas mass transfer and the limited-mixed control reduction kinetics. Using the reduction rate obtained from the single pellet experiments with pure hydrogen and extrapolating this rate to an H{sub 2 partial pressure corresponding to the H{sub 2 from the volatiles, an empirical relationship was obtained to approximately predict the amount of volatile reduction up to 20 pct.

  17. Native American Studies Major Major Advisors

    E-print Network

    Walker, Matthew P.

    Native American Studies Major Major Advisors Laura Jimenez-Olvera & Dewey St. Germaine 532 & 530://ethnicstudies.berkeley.edu/ Undergraduate Program The Native American Studies Program exists to broaden the understanding of students interested in the history, culture, and contemporary situations of Native Americans in the United States

  18. Volatile emissions from compressed tissue.

    PubMed

    Dini, Francesca; Capuano, Rosamaria; Strand, Tillan; Ek, Anna-Christina; Lindgren, Margareta; Paolesse, Roberto; Di Natale, Corrado; Lundström, Ingemar

    2013-01-01

    Since almost every fifth patient treated in hospital care develops pressure ulcers, early identification of risk is important. A non-invasive method for the elucidation of endogenous biomarkers related to pressure ulcers could be an excellent tool for this purpose. We therefore found it of interest to determine if there is a difference in the emissions of volatiles from compressed and uncompressed tissue. The ultimate goal is to find a non-invasive method to obtain an early warning for the risk of developing pressure ulcers for bed-ridden persons. Chemical analysis of the emissions, collected in compresses, was made with gas-chromatography-mass spectrometry and with a chemical sensor array, the so called electronic nose. It was found that the emissions from healthy and hospitalized persons differed significantly irrespective of the site. Within each group there was a clear difference between the compressed and uncompressed site. Peaks that could be certainly deemed as markers of the compression were, however, not identified. Nonetheless, different compounds connected to the application of local mechanical pressure were found. The results obtained with GC-MS reveal the complexity of VOC composition, thus an array of non-selective chemical sensors seems to be a suitable choice for the analysis of skin emission from compressed tissues; it may represent a practical instrument for bed side diagnostics. Results show that the adopted electronic noses are likely sensitive to the total amount of the emission rather than to its composition. The development of a gas sensor-based device requires then the design of sensor receptors adequate to detect the VOCs bouquet typical of pressure. This preliminary experiment evidences the necessity of studies where each given person is followed for a long time in a ward in order to detect the insurgence of specific VOCs pattern changes signalling the occurrence of ulcers. PMID:23874929

  19. EDITORIAL: Non-volatile memory based on nanostructures Non-volatile memory based on nanostructures

    NASA Astrophysics Data System (ADS)

    Kalinin, Sergei; Yang, J. Joshua; Demming, Anna

    2011-06-01

    Non-volatile memory refers to the crucial ability of computers to store information once the power source has been removed. Traditionally this has been achieved through flash, magnetic computer storage and optical discs, and in the case of very early computers paper tape and punched cards. While computers have advanced considerably from paper and punched card memory devices, there are still limits to current non-volatile memory devices that restrict them to use as secondary storage from which data must be loaded and carefully saved when power is shut off. Denser, faster, low-energy non-volatile memory is highly desired and nanostructures are the critical enabler. This special issue on non-volatile memory based on nanostructures describes some of the new physics and technology that may revolutionise future computers. Phase change random access memory, which exploits the reversible phase change between crystalline and amorphous states, also holds potential for future memory devices. The chalcogenide Ge2Sb2Te5 (GST) is a promising material in this field because it combines a high activation energy for crystallization and a relatively low crystallization temperature, as well as a low melting temperature and low conductivity, which accommodates localized heating. Doping is often used to lower the current required to activate the phase change or 'reset' GST but this often aggravates other problems. Now researchers in Korea report in-depth studies of SiO2-doped GST and identify ways of optimising the material's properties for phase-change random access memory [1]. Resistance switching is an area that has attracted a particularly high level of interest for non-volatile memory technology, and a great deal of research has focused on the potential of TiO2 as a model system in this respect. Researchers at HP labs in the US have made notable progress in this field, and among the work reported in this special issue they describe means to control the switch resistance and show that limiting the current during electroforming leads to the coexistence of two resistance switching modes in TiO2 memristive devices [2]. They also present spectromicroscopic observations and modelling results for the Joule heating during switching, providing insights into the ON/OFF switching process [3]. Researchers in Korea have examined in detail the mechanism of electronic bipolar resistance switching in the Pt/TiO2/Pt structure and show that degradation in switching performance of this system can be explained by the modified distribution of trap densities [4]. The issue also includes studies of TiO2 that demonstrate analog memory, synaptic plasticity, and spike-timing-dependent plasticity functions, work that contributes to the development of neuromorphic devices that have high efficiency and low power consumption [5]. In addition to enabling a wide range of data storage and logic applications, electroresistive non-volatile memories invite us to re-evaluate the long-held paradigms in the condensed matter physics of oxides. In the past three years, much attention has been attracted to polarization-mediated electronic transport [6, 7] and domain wall conduction [8] as the key to the next generation of electronic and spintronic devices based on ferroelectric tunnelling barriers. Typically local probe experiments are performed on an ambient scanning probe microscope platform under conditions of high voltage stresses, conditions highly conducive to electrochemical reactions. Recent experiments [9-13] suggest that ionic motion can heavily contribute to the measured responses and compete with purely physical mechanisms. Electrochemical effects can also be expected in non-ferroelectric materials such as manganites and cobaltites, as well as for thick ferroelectrics under high-field conditions, as in capacitors and tunnelling junctions where the ionic motion could be a major contributor to electric field-induced strain. Such strain, in turn, can affect the effective barrier width in tunnelling experiments, resulting in memristive ionic switching. These phenomena mu

  20. Geosmin and Related Volatiles in Bioreactor-Cultured Streptomyces citreus CBS 109.60

    PubMed Central

    Pollak, F. C.; Berger, R. G.

    1996-01-01

    Streptomyces citreus CBS 109.60 produced geosmin and a complex pattern of other volatile compounds during cultivation in a 2.5-liter laboratory bioreactor. Volatiles were isolated from disrupted cells, from the culture medium, and from the waste air of the bioreactor by adsorption on Lewatit OC 1064MD. Quantitative and qualitative analyses were carried out using capillary gas chromatography and coupled gas chromatography-mass spectroscopy. S. citreus produced 56 volatile compounds, which were mainly terpenoids but also included aliphatic ketones, alcohols, esters, pyrazines, furan(on)es, and aromatic types during the growth phase. The major components were geosmin and a germacradienol. A biosynthetic pathway for geosmin including eudesmanolides is proposed. PMID:16535293

  1. Pollen diversity and volatile variability of honey from Corsican Anthyllis hermanniae L. habitat.

    PubMed

    Yang, Yin; Battesti, Marie-José; Paolini, Julien; Costa, Jean

    2014-12-01

    Melissopalynological, physicochemical, and volatile analyses of 29 samples of Corsican 'summer maquis' honey were performed. The pollen spectrum was characterized by a wide diversity of nectariferous and/or polleniferous taxa. The most important were Anthyllis hermanniae and Rubus sp., associated with some endemic taxa. Castanea sativa was also determined in these honeys with a great variation. The volatile fraction was characterized by 37 compounds and dominated by phenolic aldehydes and linear acids. The major compounds were phenylacetaldehyde, benzaldehyde, and nonanoic acid. Statistical analysis of pollen and volatile data showed that 18 samples were characterized by a high abundance of phenylacetaldehyde, which might relate to the high amount of A. hermanniae and Rubus sp. Eleven other samples displayed a higher proportion of phenolic ketones and linear acids, which characterized the nectar contribution of C. sativa and Thymus herba-barona, respectively. PMID:25491334

  2. Volatile interaction between undamaged plants affects tritrophic interactions through changed plant volatile emission.

    PubMed

    Vucetic, Andja; Dahlin, Iris; Petrovic-Obradovic, Olivera; Glinwood, Robert; Webster, Ben; Ninkovic, Velemir

    2014-06-13

    Volatile interactions between unattacked plants can lead to changes in their volatile emissions. Exposure of potato plants to onion plant volatiles results in increased emission of 2 terpenoids, (E)-nerolidol and TMTT. We investigated whether this is detectable by the ladybird Coccinella septempunctata. The odor of onion-exposed potato was significantly more attractive to ladybirds than that of unexposed potato. Further, a synthetic blend mimicking the volatile profile of onion-exposed potato was more attractive than a blend mimicking that of unexposed potato. When presented individually, TMTT was attractive to ladybirds whereas (E)-nerolidol was repellent. Volatile exchange between unattacked plants and consequent increased attractiveness for ladybirds may be a mechanism that contributes to the increased abundance of natural enemies in complex plant habitats. PMID:24927115

  3. Volatile interaction between undamaged plants affects tritrophic interactions through changed plant volatile emission.

    PubMed

    Vucetic, Andja; Dahlin, Iris; Petrovic-Obradovic, Olivera; Glinwood, Robert; Webster, Ben; Ninkovic, Velemir

    2014-08-01

    Volatile interactions between unattacked plants can lead to changes in their volatile emissions. Exposure of potato plants to onion plant volatiles results in increased emission of 2 terpenoids, (E)-nerolidol and TMTT. We investigated whether this is detectable by the ladybird Coccinella septempunctata. The odor of onion-exposed potato was significantly more attractive to ladybirds than that of unexposed potato. Further, a synthetic blend mimicking the volatile profile of onion-exposed potato was more attractive than a blend mimicking that of unexposed potato. When presented individually, TMTT was attractive to ladybirds whereas (E)-nerolidol was repellent. Volatile exchange between unattacked plants and consequent increased attractiveness for ladybirds may be a mechanism that contributes to the increased abundance of natural enemies in complex plant habitats. PMID:25763628

  4. Enhanced life ion source for germanium and carbon ion implantation

    NASA Astrophysics Data System (ADS)

    Hsieh, Tseh-Jen; Colvin, Neil; Kondratenko, Serguei

    2012-11-01

    Germanium and carbon ions represent a significant portion of total ion implantation steps in the process flow. Very often ion source materials that used to produce ions are chemically aggressive, especially at higher temperatures, and result in fast ion source performance degradation and a very limited lifetime [B.S. Freer, et. al., 2002 14th Intl. Conf. on Ion Implantation Technology Proc, IEEE Conf. Proc., p. 420 (2003)]. GeF4 and CO2 are commonly used to generate germanium and carbon beams. In the case of GeF4 controlling the tungsten deposition due to the de-composition of WF6 (halogen cycle) is critical to ion source life. With CO2, the materials oxidation and carbon deposition must be controlled as both will affect cathode thermionic emission and anti-cathode (repeller) efficiencies due to the formation of volatile metal oxides. The improved ion source design Extended Life Source 3 (Eterna ELS3) together with its proprietary co-gas material implementation has demonstrated >300 hours of stable continuous operation when using carbon and germanium ion beams. Optimizing cogas chemistries retard the cathode erosion rate for germanium and carbon minimizes the adverse effects of oxygen when reducing gas is introduced for carbon. The proprietary combination of hardware and co-gas has improved source stability and the results of the hardware and co-gas development are discussed.

  5. Enhanced life ion source for germanium and carbon ion implantation

    SciTech Connect

    Hsieh, Tseh-Jen; Colvin, Neil; Kondratenko, Serguei [Axcelis Technologies, Inc. 108 Cherry Hill Drive, Beverly, MA 01915 (United States)

    2012-11-06

    Germanium and carbon ions represent a significant portion of total ion implantation steps in the process flow. Very often ion source materials that used to produce ions are chemically aggressive, especially at higher temperatures, and result in fast ion source performance degradation and a very limited lifetime [B.S. Freer, et. al., 2002 14th Intl. Conf. on Ion Implantation Technology Proc, IEEE Conf. Proc., p. 420 (2003)]. GeF{sub 4} and CO{sub 2} are commonly used to generate germanium and carbon beams. In the case of GeF{sub 4} controlling the tungsten deposition due to the de-composition of WF{sub 6} (halogen cycle) is critical to ion source life. With CO{sub 2}, the materials oxidation and carbon deposition must be controlled as both will affect cathode thermionic emission and anti-cathode (repeller) efficiencies due to the formation of volatile metal oxides. The improved ion source design Extended Life Source 3 (Eterna ELS3) together with its proprietary co-gas material implementation has demonstrated >300 hours of stable continuous operation when using carbon and germanium ion beams. Optimizing cogas chemistries retard the cathode erosion rate for germanium and carbon minimizes the adverse effects of oxygen when reducing gas is introduced for carbon. The proprietary combination of hardware and co-gas has improved source stability and the results of the hardware and co-gas development are discussed.

  6. [Research on volatile components of gualou guizhi decoction and its components in rat brain by GC-MS].

    PubMed

    Li, Huang; Xu, Wen; Xu, Wei; Zhang, Yu-Qin; Chu, Ke-Dan; Chen, Li-Dian; Chen, Xian-Wen

    2014-04-01

    To investigate the role of volatile components in the compound and to find the substance foundation of Gualou Guizhi decoction (GLGZD) for curing extremities spasticity after stroke. The chemical compositions of essential oil, obtained by hydrodistillation from Gualou Guizhi decoction and its major constituting herbs (Trichosanthis Radix, Paeoniae Alba Radix, Cinnamomi Ramulus, Zingiberis Recens Rhizoma, Glycyrrhizae Radix, Ziziphi Jujubae Fructus) were analyzed by GC-MS to evaluate the correlativity between volatile components of GLGZD and its major constituting herbs, and volatile components after oral administration of GLGZD in the rats' brain. Volatile components of GLGZD are mainly derived from Cinnamomi Ramulus, Zingiberis Recens Rhizoma, Ziziphi Jujubae Fructus, Trichosanthis Radix. The volatile components in the brain is mostly derived from radix trichosanthis. Compared with individual herbs of GLGZD, the dissolution of the components increase or new components appear after compatibility of six herbs. Adminstrated with GLGZD, the results point out that volatile components in the brain play a neuroprotective role through passing the brain. PMID:25039192

  7. Distribution of volatile composition in 'marion' ( rubus species hyb) blackberry pedigree.

    PubMed

    Du, Xiaofen; Finn, Chad; Qian, Michael C

    2010-02-10

    The distribution of volatile constituents in ancestral genotypes of 'Marion' blackberry's pedigree was investigated over two growing seasons. Each genotype in the pedigree had a specific volatile composition. Red raspberry was dominated by norisoprenoids, lactones, and acids. 'Logan' and 'Olallie' also had a norisoprenoid dominance but at much lower concentrations. The concentration of norisoprenoids in other blackberry genotypes was significantly lower. Terpenes and furanones were predominant in wild 'Himalaya' blackberry, whereas terpenes were the major volatiles in 'Santiam'. 'Marion', a selection from 'Chehalem' and 'Olallie', contained almost all of the volatile compounds in its pedigree at moderate amount. The chiral isomeric ratios of 11 pairs of compounds were also studied. Strong chiral isomeric preference was observed for most of the chiral compounds, and each cultivar had its unique chiral isomeric distribution. An inherent pattern was observed for some volatile compounds in the 'Marion' pedigree. Raspberry and 'Logan' had a very high concentration of beta-ionone, but was reduced by half in 'Olallie' and by another half in 'Marion' as the crossing proceeded. A high content of linalool in 'Olallie' and a low content in 'Chehalem' resulted in a moderate content of linalool in their progeny 'Marion'. However, the concentration of furaneol in 'Marion' was higher than in its parents. A high content of (S)-linalool in 'Olallie' and a racemic content of (S)-,(R)-linalool in 'Chehalem' resulted in a preference for the (S)-form in 'Marion'. PMID:20055446

  8. Trophic Complexity and the Adaptive Value of Damage-Induced Plant Volatiles

    PubMed Central

    Kaplan, Ian

    2012-01-01

    Indirect plant defenses are those facilitating the action of carnivores in ridding plants of their herbivorous consumers, as opposed to directly poisoning or repelling them. Of the numerous and diverse indirect defensive strategies employed by plants, inducible volatile production has garnered the most fascination among plant-insect ecologists. These volatile chemicals are emitted in response to feeding by herbivorous arthropods and serve to guide predators and parasitic wasps to their prey. Implicit in virtually all discussions of plant volatile-carnivore interactions is the premise that plants “call for help” to bodyguards that serve to boost plant fitness by limiting herbivore damage. This, by necessity, assumes a three-trophic level food chain where carnivores benefit plants, a theoretical framework that is conceptually tractable and convenient, but poorly depicts the complexity of food-web dynamics occurring in real communities. Recent work suggests that hyperparasitoids, top consumers acting from the fourth trophic level, exploit the same plant volatile cues used by third trophic level carnivores. Further, hyperparasitoids shift their foraging preferences, specifically cueing in to the odor profile of a plant being damaged by a parasitized herbivore that contains their host compared with damage from an unparasitized herbivore. If this outcome is broadly representative of plant-insect food webs at large, it suggests that damage-induced volatiles may not always be beneficial to plants with major implications for the evolution of anti-herbivore defense and manipulating plant traits to improve biological control in agricultural crops. PMID:23209381

  9. Potential Signatures of Semi-volatile Compounds Associated With Nuclear Processing

    SciTech Connect

    Probasco, Kathleen M.; Birnbaum, Jerome C.; Maughan, A. D.

    2002-06-01

    Semi-volatile chemicals associated with nuclear processes (e.g., the reprocessing of uranium to produce plutonium for nuclear weapons, or the separation of actinides from processing waste streams), can provide sticky residues or signatures that will attach to piping, ducting, soil, water, or other surface media. Volatile compounds, that are more suitable for electro-optical sensing, have been well studied. However, the semi-volatile compounds have not been well documented or studied. A majority of these semi-volatile chemicals are more robust than typical gaseous or liquid chemicals and can have lifetimes of several weeks, months, or years in the environment. However, large data gaps exist concerning these potential signature compounds and more research is needed to fill these data gaps so that important signature information is not overlooked or discarded. This report investigates key semi-volatile compounds associated with nuclear separations, identifies available chemical and physical properties, and discusses the degradation products that would result from hydrolysis, radiolysis and oxidation reactions on these compounds.

  10. The volatile metabolome of grapevine roots: first insights into the metabolic response upon phylloxera attack.

    PubMed

    Lawo, Nora C; Weingart, Georg J F; Schuhmacher, Rainer; Forneck, Astrid

    2011-09-01

    Many plant species respond to herbivore attack by an increased formation of volatile organic compounds. In this preliminary study we analysed the volatile metabolome of grapevine roots [Teleki 5C (Vitis berlandieri Planch. × Vitis riparia Michx.)] with the aim to gain insight into the interaction between phylloxera (Daktulosphaira vitifoliae Fitch; Hemiptera: Phylloxeridae) and grapevine roots. In the first part of the study, headspace solid phase microextraction (HS-SPME) coupled to gas chromatography - mass spectrometry (GC-MS) was used to detect and identify volatile metabolites in uninfested and phylloxera-infested root tips of the grapevine rootstock Teleki 5C. Based on the comparison of deconvoluted mass spectra with spectra databases as well as experimentally derived retention indices with literature values, 38 metabolites were identified, which belong to the major classes of plant volatiles including C6-compounds, terpenes (including modified terpenes), aromatic compounds, alcohols and n-alkanes. Based on these identified metabolites, changes in root volatiles were investigated and resulted in metabolite profiles caused by phylloxera infestation. Our preliminary data indicate that defence related pathways such as the mevalonate and/or alternative isopentenyl pyrophosphate-, the lipoxygenase- (LOX) as well as the phenylpropanoid pathway are affected in root galls as a response to phylloxera attack. PMID:21764593

  11. Volatile-bearing phases in carbonaceous chondrites: Compositions, modal abundance, and reaction kinetics

    NASA Technical Reports Server (NTRS)

    Ganguly, Jibamitra

    1990-01-01

    The spectral and density characteristics of Phobos and Deimos (the two small natural satellites of Mars) strongly suggest that a significant fraction of the near-earth asteroids are made of carbonaceous chondrites, which are rich in volatile components and, thus, could serve as potential resources for propellants and life supporting systems in future planetary missions. However, in order to develop energy efficient engineering designs for the extraction of volatiles, knowledge of the nature and modal abundance of the minerals in which the volatiles are structurally bound and appropriate kinetic data on the rates of the devolatilization reactions is required. Theoretical calculations to predict the modal abundances and compositions of the major volatile-bearing and other mineral phases that could develop in the bulk compositions of C1 and C2 classes (the most volatile rich classes among the carbonaceous chondrites) were performed as functions of pressure and temperature. The rates of dehydration of talc at 585, 600, 637, and 670 C at P(total) = 1 bar were determine for the reaction: Talc = 3 enstatite + quartz + water. A scanning electron microscopic study was conducted to see if the relative abundance of phases can be determined on the basis of the spectral identification and x ray mapping. The results of this study and the other studies within the project are discussed.

  12. Trophic complexity and the adaptive value of damage-induced plant volatiles.

    PubMed

    Kaplan, Ian

    2012-01-01

    Indirect plant defenses are those facilitating the action of carnivores in ridding plants of their herbivorous consumers, as opposed to directly poisoning or repelling them. Of the numerous and diverse indirect defensive strategies employed by plants, inducible volatile production has garnered the most fascination among plant-insect ecologists. These volatile chemicals are emitted in response to feeding by herbivorous arthropods and serve to guide predators and parasitic wasps to their prey. Implicit in virtually all discussions of plant volatile-carnivore interactions is the premise that plants "call for help" to bodyguards that serve to boost plant fitness by limiting herbivore damage. This, by necessity, assumes a three-trophic level food chain where carnivores benefit plants, a theoretical framework that is conceptually tractable and convenient, but poorly depicts the complexity of food-web dynamics occurring in real communities. Recent work suggests that hyperparasitoids, top consumers acting from the fourth trophic level, exploit the same plant volatile cues used by third trophic level carnivores. Further, hyperparasitoids shift their foraging preferences, specifically cueing in to the odor profile of a plant being damaged by a parasitized herbivore that contains their host compared with damage from an unparasitized herbivore. If this outcome is broadly representative of plant-insect food webs at large, it suggests that damage-induced volatiles may not always be beneficial to plants with major implications for the evolution of anti-herbivore defense and manipulating plant traits to improve biological control in agricultural crops. PMID:23209381

  13. Volatilization of cesium-137 from soil with chloride amendments during heating and vitrification

    SciTech Connect

    Spalding, B.P. (Oak Ridge National Lab., TN (United States))

    1994-06-01

    During vitrification of soil and soil:limestone mixtures, significant volatilization (> 10%) of the radioisotope [sup 137]Cs occurred particularly in the presence of small amounts (<5%) of chloride-containing species including sodium chloride, calcium chloride, hydrochloric acid, and poly-(vinyl chloride). Sodium chloride was found to be the most effective, resulting in volatilization of >99% of the [sup 137]Cs by repeated amendment and treatment at 1000[degree]C. Amendment with sodium borate and subsequent heating to 1200[degree]C also stimulated significant volatilization of [sup 137]Cs. However, amendments up to 10% of other chemicals including carbonates, nitrates, phosphates, sulfates, fluorides, polystyrene, graphite, stainless steels, iron, zinc oxide, and antimony oxide did not increase [sup 137]Cs volatilization compared to unamended samples. The majority of the chloride-induced volatilization occurred between 800 and 1000[degree]C for sodium chloride-amended samples of both soil and soil:limestone mixtures. Thus, an effective and potentially efficient soil decontamination technique for [sup 137]Cs has been identified. 17 refs., 8 figs., 3 tabs.

  14. Volatile Organic Compound Analysis in Istanbul

    NASA Astrophysics Data System (ADS)

    ?apraz, Ö.; Deniz, A.; Öztürk, A.; Incecik, S.; Toros, H.; Co?kun, M.

    2012-04-01

    Volatile Organic Compound Analysis in Istanbul Ö. Çapraz1, A. Deniz1,3, A. Ozturk2, S. Incecik1, H. Toros1 and, M. Coskun1 (1) Istanbul Technical University, Faculty of Aeronautics and Astronautics, Department of Meteorology, 34469, Maslak, Istanbul, Turkey. (2) Istanbul Technical University, Faculty of Chemical and Metallurgical, Chemical Engineering, 34469, Maslak, Istanbul, Turkey. (3) Marmara Clean Air Center, Ministry of Environment and Urbanization, Ni?anta??, 34365, ?stanbul, Turkey. One of the major problems of megacities is air pollution. Therefore, investigations of air quality are increasing and supported by many institutions in recent years. Air pollution in Istanbul contains many components that originate from a wide range of industrial, heating, motor vehicle, and natural emissions sources. VOC, originating mainly from automobile exhaust, secondhand smoke and building materials, are one of these compounds containing some thousands of chemicals. In spite of the risks to human health, relatively little is known about the levels of VOC in Istanbul. In this study, ambient air quality measurements of 32 VOCs including hydrocarbons, halogenated hydrocarbons and carbonyls were conducted in Ka??thane (Golden Horn) region in Istanbul during the winter season of 2011 in order to develop the necessary scientific framework for the subsequent developments. Ka??thane creek valley is the source part of the Golden Horn and one of the most polluted locations in Istanbul due to its topographical form and pollutant sources in the region. In this valley, horizontal and vertical atmospheric motions are very weak. The target compounds most commonly found were benzene, toluene, xylene and ethyl benzene. Concentrations of total hydrocarbons ranged between 1.0 and 10.0 parts per billion, by volume (ppbv). Ambient air levels of halogenated hydrocarbons appeared to exhibit unique spatial variations and no single factor seemed to explain trends for this group of compounds. N-octane, 3-methylheptane, n-nonane, 2,3,4-trimethylpentane and n-hexane parameters ranged between 3 ppbv and maximum value of 10 ppbv. The other VOC parameters are measured below 3 ppbv value. At participating urban locations for the year of data considered, levels of carbonyls were higher than the level of the other organic compound groups, suggesting that emissions from motor vehicles and photochemical reactions strongly in?uence ambient air concentrations of carbonyls. Of the most prevalent carbonyls, formaldehyde and acetaldehyde were the dominant compounds, ranging from 1.5-7.4 ppbv for formaldehyde, to 0.8-2.7 ppbv for acetaldehyde. Keywords: Air quality, Volatile Organic Compounds (VOC), industry, meteorology, urban, Ka??thane, ?stanbul. Acknowledgment: This work was part of the TUJJB-TUMEHAP-01-10 and Turkish Scientific and Technical Research Council Project No: 109Y132.

  15. Mechanisms involved in cardiac sensitization by volatile anesthetics: general applicability to halogenated hydrocarbons?

    PubMed

    Himmel, Herbert M

    2008-01-01

    An increased sensitivity of the heart to catecholamines or cardiac sensitization is a recognized risk during acute human exposure to halogenated hydrocarbons used as solvents, foam-blowing or fire-extinguishing agents, refrigerants, and aerosol propellants. Although cardiac sensitization to such "industrial" halocarbons can result in serious arrhythmia and death, research into its mechanistic basis has been limited, whereas the literature on volatile anesthetics (e.g., halothane, chloroform) is comparably extensive. A review of the literature on halocarbons and related volatile anesthetics was conducted. The available experimental evidence suggests that volatile anesthetics at physiologically relevant concentrations interact predominantly with the main repolarizing cardiac potassium channels hERG and I(Ks), as well as with calcium and sodium channels at slightly higher concentrations. On the level of the heart, inhibition of these ion channels is prone to alter both action potential shape (triangulation) and electrical impulse conduction, which may facilitate arrhythmogenesis by volatile anesthetics per se and is potentiated by catecholamines. Action potential triangulation by regionally heterogeneous inhibition of calcium and potassium channels will facilitate catecholamine-induced afterdepolarizations, triggered activity, and enhanced automaticity. Inhibition of cardiac sodium channels will reduce conduction velocity and alter refractory period; this is potentiated by catecholamines and promotes reentry arrhythmias. Other cardiac and/or neuronal mechanisms might also contribute to arrhythmogenesis. The few scattered in vitro data available for halocarbons (e.g., FC-12, halon 1301, trichloroethylene) suggest inhibition of cardiac sodium (conduction), calcium and potassium channels (triangulation), extraneuronal catecholamine reuptake, and various neuronal ion channels. Therefore, it is hypothesized that halocarbons promote cardiac sensitization by similar mechanisms as volatile anesthetics. Experimental approaches for further investigation of these sensitization mechanisms by selected halocarbons are suggested. PMID:18941968

  16. A volatile relationship: profiling an inter-kingdom dialogue between two plant pathogens, Ralstonia Solanacearum and Aspergillus Flavus.

    PubMed

    Spraker, Joseph E; Jewell, Kelsea; Roze, Ludmila V; Scherf, Jacob; Ndagano, Dora; Beaudry, Randolph; Linz, John E; Allen, Caitilyn; Keller, Nancy P

    2014-05-01

    Microbes in the rhizosphere have a suite of extracellular compounds, both primary and secondary, that communicate with other organisms in their immediate environment. Here, we describe a two-way volatile interaction between two widespread and economically important soil-borne pathogens of peanut, Aspergillus flavus and Ralstonia solanacearum, a fungus and bacterium, respectively. In response to A. flavus volatiles, R. solanacearum reduced production of the major virulence factor extracellular polysaccharide (EPS). In parallel, A. flavus responded to R. solanacearum volatiles by reducing conidia production, both on plates and on peanut seeds and by increasing aflatoxin production on peanut. Volatile profiling of these organisms using solid-phase micro-extraction gas chromatography mass spectroscopy (SPME-GCMS) provided a first glimpse at the compounds that may drive these interactions. PMID:24801606

  17. Volatile constituents of Murraya koenigii fresh leaves using headspace solid phase microextraction--gas chromatography-mass spectrometry.

    PubMed

    Sukkaew, Sayamol; Pripdeevech, Patcharee; Thongpoon, Chalermporn; Machan, Theeraphan; Wongchuphan, Rattana

    2014-12-01

    The volatile components of Murraya koenigii fresh leaves, collected from Surat Thani province, Thailand were studied by using headspace (HS) solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS). The four fibers employed to extract the volatiles were polydimethylsiloxane (PDMS), polydimethylsiloxane-divinylbenzene (PDMS-DVB), carboxane-polydimethylsiloxane (CAR-PDMS) and polydimethylsiloxane-divinylbenzene-carboxane (PDMS-DVB-CAR). The volatile constituents of M. koenigii fresh leaves were also extracted by hydrodistillation and analyzed by GC-MS. Fifty-one compounds were identified by these fibers. Five major compounds, ?-terpinene, ?-caryophyllene, ?-phellandrene, a-selinene and a-pinene, were detected in all fibers. The PDMS-DVB-CAR fiber was considered as the best for trapping key volatiles of M. koenigii fresh leaves. PMID:25632485

  18. Radiation Tolerance of Nanocrystal-Based Flash Memory Arrays Against Heavy Ion Irradiation

    Microsoft Academic Search

    Andrea Cester; Nicola Wrachien; Alberto Gasperin; Alessandro Paccagnella; Rosario Portoghese; Cosimo Gerardi

    2007-01-01

    We present new results on heavy-ion irradiation of nanocrystal non-volatile addressable memory arrays. We show that the effects of a single ion hit are negligible on these devices due to the discrete nature of the storage sites. We estimate that, in order to observe an appreciable threshold voltage shift, at least three to four ion hits are needed. Despite several

  19. Volatile compounds in shergottite and nakhlite meteorites

    NASA Technical Reports Server (NTRS)

    Gooding, James L.; Aggrey, Kwesi E.; Muenow, David W.

    1990-01-01

    Since discovery of apparent carbonate carbon in Nakhla, significant evidence has accumulated for occurrence of volatile compounds in shergotties and nakhlites. Results are presented from a study of volatile compounds in three shergottites, one nakhlite, and three eucrite control samples. Shergotties ALHA77005, EETA79001, and Shergotty, and the nakhlite Nakhla, all contain oxidized sulfur (sulfate) of preterrestrial origin; sulfur oxidation is most complete in EETA79001/Lith-C. Significant bulk carbonate was confirmed in Nakhla and trace carbonate was substantiated for EETA79001, all of which appears to be preterrestrial in origin. Chlorine covaries with oxidized sulfur, whereas carbonate and sulfate are inversely related. These volatile compounds were probably formed in a highly oxidizing, aqueous environment sometime in the late stage histories of the rocks that are now represented as meteorites. They are consistent with the hypothesis that shergottite and nakhlite meteorites originated on Mars and that Mars has supported aqueous geochemistry during its history.

  20. Volatile Species Retention During Metallic Fuel Casting

    SciTech Connect

    Randall S. Fielding; Douglas L. Proter

    2013-10-01

    Metallic nuclear fuels are candidate transmutation fuel forms for advanced fuel cycles. Through the operation of the Experimental Breeder Reactor II metallic nuclear fuels have been shown to be robust and easily manufactured. However, concerns have been raised concerning loss of americium during the casting process because of its high vapor pressure. In order to address these concerns a gaseous diffusion model was developed and a series of experiments using both manganese and samarium as surrogates for americium were conducted. The modeling results showed that volatility losses can be controlled to essentially no losses with a modest overpressure. Experimental results also showed volatile species retention down to no detectable losses through overpressure, although the loss values varied from the model results the same trend was seen. Bases on these results it is very probably that americium losses through volatility can be controlled to no detectable losses through application of a modest overpressure during casting.

  1. Catalyst for Oxidation of Volatile Organic Compounds

    NASA Technical Reports Server (NTRS)

    Wood, George M. (Inventor); Upchurch, Billy T. (Inventor); Schryer, David R. (Inventor); Davis, Patricia P. (Inventor); Kielin, Erik J. (Inventor); Brown, Kenneth G. (Inventor); Schyryer, Jacqueline L. (Inventor); DAmbrosia, Christine M. (Inventor)

    2000-01-01

    Disclosed is a process for oxidizing volatile organic compounds to carbon dioxide and water with the minimal addition of energy. A mixture of the volatile organic compound and an oxidizing agent (e.g. ambient air containing the volatile organic compound) is exposed to a catalyst which includes a noble metal dispersed on a metal oxide which possesses more than one oxidation state. Especially good results are obtained when the noble metal is platinum, and the metal oxide which possesses more than one oxidation state is tin oxide. A promoter (i.e., a small amount of an oxide of a transition series metal) may be used in association with the tin oxide to provide very beneficial results.

  2. Volatile fractionation and tektite source material

    NASA Technical Reports Server (NTRS)

    Walter, Louis S.

    1989-01-01

    The arguments used by Love and Woronow (1988) to assess the role played in the origin of bediasites by extensive volatile fractionation are critically examined. Using the ratios of 'refractory' oxides, CaO, Al2O3, and MgO, to the 'volatile' oxides, Na2O and K2O, these authors concluded that vapor fractionation did not play a significant role. In this paper, experimental evidence is presented that shows that the assumption of volatility for the alkali elements (as least with respect to silica) to be not valid under the conditions under which tektites formed. It is shown that the results of vapor fractionation in experiments on glasses of tektite composition are approximately parallel the trends seen in bediasite analysis.

  3. Volatile components and continental material of planets

    NASA Technical Reports Server (NTRS)

    Florenskiy, K. P.; Nikolayeva, O. V.

    1986-01-01

    It is shown that the continental material of the terrestrial planets varies in composition from planet to planet according to the abundances and composition of true volatiles (H20, CO2, etc.) in the outer shells of the planets. The formation of these shells occurs very early in a planet's evolution when the role of endogenous processes is indistinct and continental materials are subject to melting and vaporizing in the absence of an atmosphere. As a result, the chemical properties of continental materials are related not only to fractionation processes but also to meltability and volatility. For planets retaining a certain quantity of true volatile components, the chemical transformation of continental material is characterized by a close interaction between impact melting vaporization and endogeneous geological processes.

  4. Analyzing method on biogenic volatile organic compounds

    NASA Astrophysics Data System (ADS)

    Bai, J. H.; Wang, M. X.; Hu, F.; Greenberg, J. P.; Guenther, A. B.

    2002-02-01

    In order to analyze biogenic volatile organic compounds in the atmosphere, an automated gas chromatography is developed and employed at the laboratory of National Center for Atmospheric Research (NCAR) during January to July, 2000. A small refrigerator was used so as to remove water in the air sample from gas line, and get accurate concentrations of volatile organic compounds. At 5degreesC, good water removing efficiency can be obtained at controlled flow rate. Air samples were collected around the building of Mesa Lab. of NCAR and analyzed by this gas chromatography system. This paper reports this gas chromatography system and results of air samples. The experimental results show that this gas chromatography system has a good reproducibility and stability, and main interesting volatile organic compounds such as isoprene, monoterpenes have an evident diurnal variation.

  5. The Volatility and condensation behaviour of elements in dependence of T and fO2: a novel experimental approach

    NASA Astrophysics Data System (ADS)

    Ertel-Ingrisch, Werner; Dingwell, Don B.

    2010-05-01

    The volatility of elements is one of the most important variables during geological processes on Earth: its impact ranges from daily out gassing of volcanic vents to catastrophic emissions during volcanic eruptions which might scale up to global impacts on our climate. Volatility played, however, already a major role during the formation of our solar system: the nebular gases and their element budget passed through an elemental fractionation process based on differences in the evaporation and condensation behaviour of matter within the solar nebula - the origin of all the planets within our solar system. Precise knowledge of the parameters controlling volatility as well as condensation of elements is still lacking. Whether an element behaves volatile or refractory depends highly on the temperature and oxygen fugacity (fO2) conditions prevailing. To address this issue, we initiated a systematic study of the volatility of 18 volatile elements in respect to fO2 and temperature applying a modified mechanically assisted equilibration technique (MAE): Approx. 60 g of a haplobasaltic starting composition (An-Di) doped with up to 5000 ppm of volatile elements (Li, K, Na, Ti, Cr, Mn, Co, Cu, Cu, Zn, Ga, Rb, Cd, In, Sn, Sb, Cs, Tl) was heated to run temperatures. To investigate the fO2 dependence 2 experiments at logfO2 = -11.3 (~ IW -0.5) and - 0,7 (pure air) at a constant temperature of 1300 °C were performed, while T dependence was investigated at 1300 and 1500 °C at constant fO2 in pure air. The original MAE technique was modified by two Al2O3 plates extending from the hot spot region up to the upper, cooler regions of the muffle tube. These plates function as condensation traps. The temperature profile of the entire setup including the Al2O3 plates under run conditions was calibrated prior to any run. Experiments lasted for up two weeks while experimental conditions were kept strictly constant and were monitored. Up to 46 samples were taken from the melt by time-series sampling to monitor the loss of volatile elements within the melt composition due to their volatility. In the upper, cooler parts of the setup, condensation was observed successfully on the surface of the two Al2O3 plates. In this way both evaporation of the investigated elements as well as their condensation behavior can be investigated simultaneously. Major element composition was determined by electron microprobe analysis on quenched samples, while their volatile concentrations were determined by laser-ablation inductively coupled plasma mass spectrometry (LAMS). Preliminary results show a highly complex behaviour of the investigated volatile elements: At low fO2, Li, Na, K, Ti, Cr, Mn, Rb, and Cs show no decrease due to evaporation. At high fO2, however, e.g., Cr and Mn decrease with time due to increased volatility, while Co, Cu, Sb and Tl become less volatile. Due to the relatively small temperature range (200°C), the observed T effect is small compared to the fO2 dependence. Cr, In, Sn, Sb and Tl exhibit a similar T dependence of their volatility. Mn, Cu, Zn, and Ga show a decrease of their volatility, while Cs and Cd become slightly more volatile with increasing T. The present data indicate an unexpected and highly complex behaviour of the volatile elements due to melt compositional processes: Concentrations do not generally decrease continuously with time as anticipated in previous studies, but stay, e.g., constant for some elements due to the formation of a stable concentration regime. Condensation traps show clear indications for various phases condensing at varying temperature regimes above the hot spot region of the crucible. Additional experiments are necessary and planned to confirm our preliminary findings.

  6. Volatilization and Efflux of Mercury from Biologically Productive Ocean Regions.

    NASA Astrophysics Data System (ADS)

    Kim, Jonathan Philip

    Mercury volatilization and oceanic evasion to the atmosphere were investigated in the tropical Pacific Ocean with emphasis on the biologically productive equatorial region. Further studies were conducted at two stations in the oligiotrophic North Pacific gyre, and in the estuarine mesocosms at the Marine Ecosystems Research Laboratory (MERL), University of Rhode Island. Dissolved gaseous Hg (DGM) in the tropical Pacific along 150^circ W at 4 stations (10^circ N, 0^ circ, 5^circ S, 12^circ S) ranged from 35-85 femtomoles per liter (fM) in surface waters and from 105-185 fM in deeper waters (350-400 meters). Speciation experiments indicated that Hg^circ was the dominant form in surface waters, while evidence for (CH_3)_2Hg was found at depth. The increases of DGM with depth are consistent with a volatile Hg source in deeper waters. A significant correlation between DGM and apparent oxygen utilization (n = 23, r = 0.694) suggested bacterial methylation of Hg in the oxygen minimum zone. In equatorial Pacific surface waters (155-95 ^circ W), DGM varied between 60 and 225 fM. Elemental Hg appears to comprise the major fraction of DGM. Elevated DGM concentrations corresponded with increased chlorophyll a levels and cooler, nutrient-rich waters. These results suggest that phytoplankton might volatilize Hg in surface seawater or bacteria could produce Hg^circ in deeper waters which upwell to the sea surface. Surface waters of the equatorial Pacific were supersaturated with respect to Hg^circ (179-1769%). Local Hg effluxes, estimated with a thin-film gas exchange model, were between 225 and 1050 pmoles/m^2day. The anual Hg efflux from the equatorial Pacific, 1.6 +/- 1.3 times 10^{+6 } moles (megamoles), was estimated at 4-5% of the total global Hg flux to the atmosphere. When normalized to primary production, a yearly Hg efflux of 14 +/- 9 megamoles was predicted for the oceans. This is about 35% of the annual atmospheric Hg flux and is comparable to human-derived Hg emissions. Dissolved gaseous Hg in the MERL mesocosms ranged from <=q30 to 185 fM. In general, Hg^circ was the principal species, although (CH_3)_2Hg was detected twice. Supersaturated levels of Hg ^circ corresponded with phytoplankton blooms of Cerataulina pelagica, Leptocylindrus danicus, Leptocylindrus minimus, and Phaeocystis poucheti, suggesting that these phytoplankton could volatilize Hg in estuarine waters. Micro-flagellates may produce (CH_3) _2Hg. Mercury emanations from the mesocosms were estimated to be approximately 10% of the oceanic Hg effluxes to the atmosphere.

  7. Space-weathering processes and products on volatile-rich asteroids

    NASA Astrophysics Data System (ADS)

    Britt, D.; Schelling, P.; Consolmagno, G.; Bradley, T.

    2014-07-01

    Space weathering is a generic term for the effects on atmosphereless solid bodies in the solar system from a range of processes associated with direct exposure to the space environment. These include impact processes (shock, vaporization, fragmentation, heating, melting, and ejecta formation), radiation damage (from galactic and solar cosmic rays), solar-wind effects (irradiation, ion implantation, and sputtering), and the chemical reactions driven by these processes. The classic example of space weathering is the formation of the lunar spectral red slope associated with the production of nanophase Fe (npFe0) in the dusty lunar regolith (C.R. Chapman, 2004, Annual Review of Earth & Planet. Sci. 32, C.M. Pieters, 2000, MAPS 35). Similar npFe0 has been recovered from asteroid (25143) Itokawa and some asteroid classes do exhibit modest spectral red slopes (T. Noguchi, 2011, Science 333). Space weathering can be thought of as driven by a combination of the chemical environment of space (hard vacuum, low oxygen fugacity, solar-wind implantation of hydrogen) along with thermal energy supplied by micrometeorite impacts. The forward modeling of space weathering as thermodynamically-driven decomposition of common rock-forming minerals suggests the production of a range of daughter products: (1) The silicate products typically lose oxygen, other volatile elements (i.e., sulfur and sodium), and metallic cations, producing minerals that are typically more disordered and less optically active than the original parent materials. (2) The decomposed metallic cations form in nano-sized blebs including npFe0, on the surfaces or in condensing rims of mineral grains. This creates a powerful optical component as seen in the lunar red slope. Surfaces with exposed npFe0 are an ideal environment for catalyzing further reactions. (3) The liberated volatile elements and gases (O, S, Na) may form an observable exosphere (e.g., Moon and Mercury) and can either escape from the body or recombine with available solar-wind-implanted hydrogen to form trace amounts of water and OH. Mineral decomposition can be thought of as the first stage of space weathering. It produces weathered surfaces somewhat depleted in volatile elements, creates a predictable set of minor or trace minerals, and leaves the surfaces with catalytic species, primarily npFe0. However, a second stage of further reactions and weathering depends upon the presence of ''feed-stock'' components that can participate in catalyzed chemical reactions on exposed surfaces. For volatile-rich small bodies, the available materials are not only silicates, but a volatile feedstock that can include water, carbon monoxide, ammonia, to name a few. Thermodynamically-driven decomposition of silicates will produce trace amounts of npFe0 which are ideal sites for Fischer-Tropsch type (FTT) catalytic reactions that can produce organics in situ on the asteroids including alkanes, polyaromatic hydrocarbons, and amino acids (J.E. Elsila, 2012, MAPS 47). The mix and range of products depends on the composition and morphology of the mineral surface, energy inputs produced by the micrometeorite impacts or other processes, and the composition of the input volatile feedstock. FFT reactions generate long-chain carbon compounds and amino acids. Secondary reactions that generate more complex carbon compounds and amino acids are likely to occur as the organic material matures. Weathering maturity can be thought of as a function of the abundance and diversity of the weathering products. Since the npFe0 is not destroyed in the reaction, continued micrometeorite bombardment would result in continuing processing and recombination of the existing organic feedstock. More weathering would result in progressively longer-chain carbon compounds as well as more complex and diverse amino acids, and eventually the kerogen-like insoluble-organic matter that forms a large fraction of carbonaceous meteorites. This insight has several major implications for our planetary science and, potentially, the formation of the precursors of l

  8. Ion source

    DOEpatents

    Leung, Ka-Ngo (Hercules, CA); Ehlers, Kenneth W. (Alamo, CA)

    1984-01-01

    A magnetic filter for an ion source reduces the production of undesired ion species and improves the ion beam quality. High-energy ionizing electrons are confined by the magnetic filter to an ion source region, where the high-energy electrons ionize gas molecules. One embodiment of the magnetic filter uses permanent magnets oriented to establish a magnetic field transverse to the direction of travel of ions from the ion source region to the ion extraction region. In another embodiment, low energy 16 eV electrons are injected into the ion source to dissociate gas molecules and undesired ion species into desired ion species.

  9. Analysis of volatile organic compounds. [trace amounts of organic volatiles in gas samples

    NASA Technical Reports Server (NTRS)

    Zlatkis, A. (inventor)

    1977-01-01

    An apparatus and method are described for reproducibly analyzing trace amounts of a large number of organic volatiles existing in a gas sample. Direct injection of the trapped volatiles into a cryogenic percolum provides a sharply defined plug. Applications of the method include: (1) analyzing the headspace gas of body fluids and comparing a profile of the organic volatiles with standard profiles for the detection and monitoring of disease; (2) analyzing the headspace gas of foods and beverages and comparing the profile with standard profiles to monitor and control flavor and aroma; and (3) analyses for determining the organic pollutants in air or water samples.

  10. Asymptotic Behavior of the Stock Price Distribution Density and Implied Volatility in Stochastic Volatility Models

    SciTech Connect

    Gulisashvili, Archil, E-mail: guli@math.ohiou.ed [Ohio University, Department of Mathematics (United States); Stein, Elias M., E-mail: stein@math.princeton.ed [Princeton University, Department of Mathematics (United States)

    2010-06-15

    We study the asymptotic behavior of distribution densities arising in stock price models with stochastic volatility. The main objects of our interest in the present paper are the density of time averages of the squared volatility process and the density of the stock price process in the Stein-Stein and the Heston model. We find explicit formulas for leading terms in asymptotic expansions of these densities and give error estimates. As an application of our results, sharp asymptotic formulas for the implied volatility in the Stein-Stein and the Heston model are obtained.

  11. Major Depression Among Adults

    MedlinePLUS

    Major depression is one of the most common mental disorders in the United States. According to the World Health Organization (WHO; 2010), major depression also carries the heaviest burden of disability among mental ...

  12. Major Rock Groups

    NSDL National Science Digital Library

    This resource from the University of Saskatchewan contains general information on the major rock groups: igneous, metamorphic and sedimentary. Describes the rock cycle and the properties and formation of each major rock group.

  13. A compact PTR-ToF-MS instrument for airborne measurements of volatile organic compounds at high spatiotemporal resolution

    NASA Astrophysics Data System (ADS)

    Müller, M.; Mikoviny, T.; Feil, S.; Haidacher, S.; Hanel, G.; Hartungen, E.; Jordan, A.; Märk, L.; Mutschlechner, P.; Schottkowsky, R.; Sulzer, P.; Crawford, J. H.; Wisthaler, A.

    2014-11-01

    Herein, we report on the development of a compact proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) for airborne measurements of volatile organic compounds (VOCs). The new instrument resolves isobaric ions with a mass resolving power (m/?m) of ~1000, provides accurate m/z measurements (?m < 3 mDa), records full mass spectra at 1 Hz and thus overcomes some of the major analytical deficiencies of quadrupole-MS-based airborne instruments. 1 Hz detection limits for biogenic VOCs (isoprene, ? total monoterpenes), aromatic VOCs (benzene, toluene, xylenes) and ketones (acetone, methyl ethyl ketone) range from 0.05 to 0.12 ppbV, making the instrument well-suited for fast measurements of abundant VOCs in the continental boundary layer. The instrument detects and quantifies VOCs in locally confined plumes (< 1 km), which improves our capability of characterizing emission sources and atmospheric processing within plumes. A deployment during the NASA 2013 DISCOVER-AQ mission generated high vertical- and horizontal-resolution in situ data of VOCs and ammonia for the validation of satellite retrievals and chemistry transport models.

  14. Volatile Release from The Siberian Traps and the End-Permian Environment

    NASA Astrophysics Data System (ADS)

    Black, B. A.; Elkins-Tanton, L. T.; Rowe, M. C.; Ukstins Peate, I.

    2010-12-01

    The Siberian Traps (ca. 252 Ma) is one of the most voluminous known eruptions of continental basaltic magma, and has been invoked as a trigger for the end-Permian mass extinction: the single largest loss of biological diversity in the Phanerozoic. Constraining the degassing of volatiles such as sulfur, chlorine, fluorine, and carbon dioxide is critical to understanding the environmental consequences of flood basalt emplacement. We measured concentrations of these volatiles in melt inclusions in olivine, plagioclase and clinopyroxene crystals from Siberian Traps lavas, sills, and tuffs. New ion probe analysis results provide insight into the volatile budget of the earliest pyroclastic and later flow-dominated periods of flood volcanism. In particular, melt inclusions from four flows and tuffs belonging to the stratigraphically lowest extrusive suites provide the first estimates of dissolved volatiles within early-erupted Siberian Traps magmas. Comparison with studies of melt inclusions from Iceland’s Laki eruption, the Deccan Traps and the Columbia River flood basalts suggests that Cl, F, and S concentrations in some Siberian Traps magmas were anomalously high. Measured concentrations reach 0.75 wt % Cl and 1.95 wt % F in one sample. In other samples, we also measure significant concentrations of S, Cl, F, and C. We hypothesize that assimilation of evaporites and other sedimentary rocks from the Tunguska basin might have contributed to the volatile budget of Siberian magmatism. Our melt inclusion data, in conjunction with the present-day volumes of the associated flows, sills, and tuffs, indicate that even individual Siberian Traps eruption events probably carried massive volatile loads. We observe tuff sequences tens to hundreds of meters thick near the base of the volcanic sequence in the Maymecha-Kotuy and Angara regions; these volcaniclastic deposits may reach 700 meters in thickness in the central Tunguska basin. Locally well-preserved accretionary lapilli provide evidence that many of these deposits are primary pyroclastic rocks. These explosive episodes may have enhanced the efficiency with which degassing volatiles were entrained into an ascending thermal plume. The high volatile contents we observe in many Siberian Traps rocks, if injected into the stratosphere, may have significantly contributed to ozone depletion and a drastic deterioration in global environmental conditions at the time of the Permian-Triassic boundary.

  15. Ethnic Studies Undergraduate Major Major Advisors

    E-print Network

    Walker, Matthew P.

    . Students majoring in ethnic studies study the history, culture, politics, and sociology of Third World.e., Gender & Women's Studies, Sociology, Geography) Upper Division (9 courses) · Ethnic Studies 101A & 101B and Asian Diaspora Studies, Chicano Studies, Gender & Women's Studies, or Native American Studies

  16. Volatile pheromone signalling in Drosophila

    PubMed Central

    Smith, Dean P.

    2013-01-01

    Once captured by the antenna, 11-cis vaccenyl acetate (cVA) binds to an extracellular binding protein called LUSH that undergoes a conformational shift upon cVA binding. The stable LUSH–cVA complex is the activating ligand for pheromone receptors present on the dendrites of the aT1 neurones, comprising the only neurones that detect cVA pheromone. This mechanism explains the single molecule sensitivity of insect pheromone detection systems. The receptor that recognizes activated LUSH consists of a complex of several proteins, including Or67d, a member of the tuning odourant receptor family, Orco, a co-receptor ion channel, and SNMP, a CD36 homologue that may be an inhibitory subunit. In addition, genetic screens and reconstitution experiments reveal additional factors that are important for pheromone detection. Identification and functional dissection of these factors in Drosophila melanogaster Meigen should permit the identification of homologous factors in pathogenic insects and agricultural pests, which, in turn, may be viable candidates for novel classes of compounds to control populations of target insect species without impacting beneficial species. PMID:24347807

  17. TREATMENT OF VOLATILE ORGANIC COMPOUNDS IN DRINKING WATER

    EPA Science Inventory

    Volatile chlorinated and non-chlorinated compounds occur in both untreated and treated drinking water. Because volatilization is restricted, ground waters rather than surface waters are more likely to have high concentrations of these compounds. This document reviews properties, ...

  18. Information Technology and the Volatility of Firm Performance

    E-print Network

    Hunter, Starling

    2004-03-12

    This study investigates the impact of IT investments and several contextual variables on the volatility of future earnings. We find evidence that IT investments strongly increases the volatility of future earnings and that ...

  19. Apartment volatility determinants across the United States markets

    E-print Network

    Luo, Mai, S.M. Massachusetts Institute of Technology

    2011-01-01

    Much research has been done to examine the volatilities of return on public and private real estate investments. However, little is known about market volatility in real estate in general and in apartment real estate in ...

  20. Suiting Themselves: Major parties electoral databases & privacy

    Microsoft Academic Search

    Peter Van Onselen; Wayne Errington

    2005-01-01

    The potential benefits and pitfalls of information technology are on display in the databases used by Australia's major politica l parties. 1 The use of such technologies, which contain a host of informat ion about voters and their policy preferences, are a potentially useful conduit between citizens and their elected representatives. Instead, their d evelopment has been veiled in secrecy,

  1. Volatile (As and Hg) and non-volatile (Pb and Cd) toxic heavy metals analysis in rhizome of Zingiber officinale collected from different locations of North Western Himalayas by Atomic Absorption Spectroscopy.

    PubMed

    Gupta, S; Pandotra, P; Gupta, A P; Dhar, J K; Sharma, G; Ram, G; Husain, M K; Bedi, Y S

    2010-10-01

    Ginger is an important ingredient of spice and herbals. The monitoring of toxic heavy metals in the rhizome of ginger is important for protecting public health against the hazards of metal toxicity. The concentration of volatile and non-volatile metals (As, Hg, Pb and Cd), in the soil and rhizome of Zingiber officinale were analyzed using AAS. Soil analysis profile showed uniformity in the metal contents, in active root zone and subsoil, except mercury, which was present in higher quantity in one, out of the four sectors, of the field. The infield metal content in the soil in increasing order was, cadmium < arsenic < lead < mercury. In ginger rhizome the volatile toxic heavy metals arsenic (As) and mercury (Hg) varied from not detected to 0.13 ?g/g and 0.01 to 0.42 ?g/g, respectively. The non-volatile metals lead (Pb) and cadmium (Cd) ranged from 0.06 to 0.64 ?g/g and 0.002 to 0.03 ?g/g, respectively(.) The results illustrated the findings that soil is the major but not the only source of metal accumulation in the plants. In our study, the volatile metal content (As, Hg) was found more in rhizomes collected from Himachal Pradesh while the non-volatile metals were predominant in samples from Uttarakhand. PMID:20732845

  2. Inhibition of volatile compounds derived from fatty acid oxygenation with chilling and heating treatments and their influences on the oxylipin pathawy gene expression and enzyme activity levels in tomato (Solanum lycopersicon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hexanal, Z-3-hexenal, E-2-hexenal, hexanol and Z-3-hexenol are major tomato (Solanum Lycopersicon) volatile aromas derived from oxygenation of unsaturated fatty acids. Chilling or heating treatments suppress production of these C6 volatiles. The objective of this research was to determine the respon...

  3. Measurement of volatile organic compounds inside automobiles†

    Microsoft Academic Search

    Marion J Fedoruk; Brent D Kerger

    2003-01-01

    The objective of the current study was to evaluate the types and concentrations of volatile organic compounds (VOCs) in the passenger cabin of selected sedan automobiles under static (parked, unventilated) and specified conditions of operation (i.e., driving the vehicle using air conditioning alone, vent mode alone, or driver's window half open). Data were collected on five different passenger sedan vehicles

  4. Volatile Sulphur Compounds in UHT Milk

    Microsoft Academic Search

    Z. Al-Attabi; B. R. DArcy; H. C. Deeth

    2008-01-01

    Several volatile sulphur compounds have been detected in raw and processed milk. These are hydrogen sulphide, methanethiol, carbonyl sulphide, dimethyl sulphide, carbon disulphide, dimethyl disulphide, dimethyl trisulphide, dimethyl sulphoxide, and dimethyl sulphone. Many of these increase in milk during heat processing and are associated with the cooked flavor of heat-treated milks, particularly UHT and sterilized milk. Several researchers have attempted

  5. Volatile Contents of Grape Marcs in Portugal

    Microsoft Academic Search

    M. Luz Silva; F. Xavier Malcata; G. De Revel

    1996-01-01

    The present study reports on the composition of volatiles of most grape marcs (bagaceiras) commercially available in Portugal. These spirits, which are a valuable by-product of the winemaking industry, are obtained via steam-distillation of grape pomace after storage under anaerobic conditions for a given period of time. An impetus for this research is the increasingly strict European legal standards pertaining

  6. Stock Market Volatility and the Business Cycle

    Microsoft Academic Search

    James D. Hamilton; Lin Gang

    1996-01-01

    This paper investigates the joint time series behavior of monthly stock returns and growth in industrial production. We find that stock returns are well characterized by year-long episodes of high volatility, separated by longer quiet periods. Real output growth, on the other hand, is subject to abrupt changes in the mean associated with economic recessions. We study a bivariate model

  7. Analytical aspects of volatile substance abuse (VSA).

    PubMed

    Gaulier, Jean-Michel; Tonnay, Véronique; Faict, Thierry; Sayer, Hervé; Marquet, Pierre; Lachâtre, Gérard

    2003-07-01

    Through a case report, the authors illustrate the volatile substance abuse (VSA) toxicological investigation difficulties mainly due to evaporation of the compounds from postmortem samples and to the lack of reference data for interpretation. A 17-year-old man, student in a chemistry institute, was found dead with a plastic bag placed over his head. Several chemical substances were found in his belongings. Autopsy findings included serious pulmonary lesions and hemorrhagic digestive ulcerations. A large screening of drugs and toxic compounds and selective analyses for several classes of drugs of abuse were carried out in the autopsy samples. In particular, a headspace (HS), -gas chromatography/-mass spectrometry (GC/MS) technique was used to screen for volatile substances and metabolites in the biological samples and for residues of volatile substances on the surface of the plastic bag and in the chemicals found on the scene. The main analytical finding was the presence of alkanes (heptane, methyl-2-pentane, methyl-3-hexane, methylcyclohexane) in the gastric content. The literature data, VSA practices, long time-delay between death and autopsy, preservation conditions of the biological samples before analysis, and in-lab experiments on evaporation of volatile substances were considered to interpret this result. The present fatality was attributed to VSA with a gasoline-based stain remover like "eau écarlate," associated with a hypoxic recreation practice using a plastic bag. PMID:12877311

  8. Shaken and Stirred: Explaining Growth Volatility

    Microsoft Academic Search

    William Easterly; Roumeen Islam; Joseph E. Stiglitz

    2000-01-01

    Abstract: This paper attempts to set forth a framework for thinking about growth volatility which is general enough to incorporatethe important structural, institutional, and policy variations among countries which might account for differences in theirmacroeconomic performance. And it focuses particularly on the role of the financial sector. The paper is divided into 2sections. The first discusses the importance of short

  9. Volatile organic sampling train soot interference report

    Microsoft Academic Search

    G. Hinshaw; F. W. Wilshire; L. D. Johnson

    1993-01-01

    The U.S. Environmental Protection Agency uses Method 0030, the Volatile Organic Sampling Train (VOST), as a tool in determining the destruction and removal efficiencies of industrial boilers co-firing hazardous waste. Recently, concerns have been expressed over possible measurement biases due to soot deposits within the VOST. A laboratory study was initiated to investigate the collection efficiency of the method under

  10. Volatile Origin and Cycles: Nitrogen and Methane

    Microsoft Academic Search

    Sushil K. Atreya; Ralph D. Lorenz; J. Hunter Waite

    2010-01-01

    The story of Titan's two most abundant volatile constituents, nitrogen and methane, is intertwined. The focus of this paper is the origin and evolution of Titan's nitrogen atmosphere and the cycle of methane from its production to destruction to replenishment. Relevant observational results from Cassini---Huygens, Voyager and the Earth as well as various hypotheses and models are reviewed. The origin

  11. CHROMATOGRAPHIE EN PHASE GAZEUSE DES COMPOSS VOLATILS

    E-print Network

    Boyer, Edmond

    CHROMATOGRAPHIE EN PHASE GAZEUSE DES COMPOSÉS VOLATILS DES GLANDES A PHÉROMONES DES ABEILLES'introduction directe et en petit nombre des glances à phéromones à l'entrée d'une colonne à chromatographie; le procédé : chromatographie phase gazeuse, glande, phéromone, substance d'alarme, abeille ouvrière. INTRODUCTION La vie des

  12. COMPLETE CATALYTIC OXIDATION OF VOLATILE ORGANICS

    EPA Science Inventory

    The paper reviews heterogeneous catalytic oxidation, focusing on its application to the control of volatile organic compounds (VOCs) at operating conditions typical of field applications. The parameters for this review are: low to moderate temperatures (25-400 C), atmospheric pre...

  13. Lunar volatiles: balancing science and resource development

    Microsoft Academic Search

    Dana Crider

    2008-01-01

    In the context of human exploration of the moon, the volatiles postulated to exist at the lunar poles have value as resources as well as scientific significance. Once sustained human operations commence on the moon, society will move from a paradigm in which examination of planetary materials has been unconstrained to one where use of those materials will support habitability

  14. Volatiles in interplanetary dust particles and aerogels

    NASA Technical Reports Server (NTRS)

    Gibson, E. K., Jr.; Harmetz, C. P.

    1991-01-01

    Volatiles measured in 25 interplanetary dust particles (IDPs) are a mixture of both indigenous materials and contaminants associated with the collection and processing of the ODPs prior to analysis. Most IDPs have been collected in the stratosphere using a silicone oil/freon mixture (20:1 ratio) coated on collector plates. Studies have shown that silicone oil, freon and hexane residues remain with the ODPs, despite attempts to clean the IDPs. Analysis of the IDPs with the LMMS-technique produces spectra with a mixture of indigeneous and contaminants components. The contamination signal can be identified and removed; however, the contamination signal may obscure some of the indigeneous component's signal. Employing spectra stripping techniques, the indigenous volatile constituents associated with the IDPs can be identified. Volatiles are similar to those measured in CI or CM carbonaceous chondrites. Collection of IDPs in low-Earth orbit utilizing a Cosmic Dust Collection Facility attached to Space Station Freedom has been proposed. The low-density material aerogel has been proposed as a collection substrate for IDPs. Our studies have concentrated on identifying volatile contaminants that are associated with aerogel. We have found that solvents used for the preparation of aerogel remain in aerogel and methods must be developed for removing the entrapped solvents before aerogels can be used for an IDP collection substrate.

  15. Mars - Epochal climate change and volatile history

    Microsoft Academic Search

    Fraser P. Fanale; Susan E. Postawko; James B. Pollack; Michael H. Carr; Robert O. Pepin

    1992-01-01

    The epochal climate change and volatile history of Mars are examined, with special attention given to evidence for and mechanisms of long-term climate change. Long-term climate change on Mars is indicated most directly by the presence, age, and distribution of the valley networks. They were almost certainly formed by running water, but it seems more likely that they were formed

  16. COMMODITY PRICE VOLATILITY ACROSS EXCHANGE RATE REGIMES

    E-print Network

    1 COMMODITY PRICE VOLATILITY ACROSS EXCHANGE RATE REGIMES John T. Cuddington* and Hong Liang** March 10, 2003 ABSTRACT This paper documents a new "stylized fact" regarding the relative price 1880 to 1996, this key relative price among two categories of tradable goods is shown to exhibit

  17. Recent advances in volatile oxygen scavenger technology

    SciTech Connect

    Bain, D.I.; Engstrom, G.G. [GRACE Dearborn, Lake Zurich, IL (United States); Fryer, M.T. [Dearborn Chemical Co. Ltd., Mississauga, Ontario (Canada)

    1994-12-31

    In recent years alternatives to hydrazine for oxygen removal in boiler systems have been introduced. One technology based on diethyl hydroxylamine has proven successful in protecting boiler and steam systems. This paper introduces a new volatile oxygen scavenger technology to compliment diethyl hydroxylamine application. Both laboratory data and case studies are documented.

  18. VOLATILE ORGANIC SAMPLING TRAIN - SOOT INTERFERENCE REPORT

    EPA Science Inventory

    The U.S. Environmental Protection Agency uses Method 0030, the Volatile Organic Sampling Train (VOST), as a tool in determining the destruction and removal efficiencies of industrial boilers co-firing hazardous waste. ecently, concerns have been expressed over possible measuremen...

  19. ALIPHATIC HALOGENATED HYDROCARBONS PRODUCE VOLATILE 'SALMONELLA' MUTAGENS

    EPA Science Inventory

    Production of volatile mutagenic metabolites from 5 halogenated promutagens was examined by a simple modification of the conventional Salmonella/microsome mutagenicity assay. This method incorporates the taping together of 2 agar plates face to face during the initial portion of ...

  20. Volatiles in the outer solar system

    NASA Technical Reports Server (NTRS)

    Cruikshank, Dale P.

    1991-01-01

    Telescopic data on asteroids, comets, planets, and planetary satellites are acquired and analyzed in the study of volatile ices and gases that occur on their surfaces and in their atmospheres. Infrared spectral studies of certain classes of asteroids for an analysis of their mineralogical and organic constituents are included.

  1. On the dynamics of volatile meteorites

    NASA Astrophysics Data System (ADS)

    Coulson, S. G.; Wallis, M. K.; Wickramasinghe, N. C.

    2014-12-01

    Canonical models for bolides in the atmosphere predict that fragile bolides break up at much higher altitudes than those actually observed. Here, we investigate the hypothesis that such fragile bolides may survive to low altitudes by a protective outgassing sheath of volatile ices and organics that shields the meteoroid from direct atmospheric heating.

  2. Proboscis extension reflex platform for volatiles and semi-volatiles detection

    DOEpatents

    Wingo, Robert M. (Los Alamos, NM); McCabe, Kirsten J. (Los Alamos, NM); Haarmann, Timothy K. (Jemez Pueblo, NM)

    2010-11-30

    The present invention provides an apparatus for the detection of volatile and semi-volatile chemicals using the olfactory abilities of honey bees that are trained to respond to the presence of a specific chemical in a sample of gas with the proboscis extension reflex (PER). In particular, the geometry and arrangement of the parts of the apparatus are such that the amount of surface area in contact with the sample of gas prior to its introduction to the bees is minimized to improve the detection of particular volatile and semi-volatile that have a tendency to "stick" to contacting surfaces, especially certain chemicals associated with explosives and narcotics. According to another aspect of the present invention, a pre-concentrating means is incorporated with the device to effectively increase the concentration of "sticky" chemicals presented to the insects.

  3. VOLATILITY AND SOLUBILIZATION OF SYNTHETIC FRAGRANCES BY PLURONIC P-85

    Microsoft Academic Search

    Yoshihiro Saito; Kouichi Miura; Yoshikazu Tokuoka; Yukishige Kondo; Masahiko Abe; Takatoshi Sato

    1996-01-01

    The volatility of synthetic fragrances (benzyl formate, benzyl acetate, benzyl propionate) from pluronic P-85 aqueous solution has been investigated by the dynamic headspace method The experimental results showed that the volatility of a more hydrophobic fragrance was strongly controlled by pluronic P-85. This volatile behavior was explained by the solubilization constants of fragrances between the micelle and bulk phase by

  4. Gas chromatography column as an ambient-temperature volatile trap

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Open tube volatile traps have largely been shunned in favor of solid-adsorbent-containing traps. Anecdotally, there is a bias against open tube volatile traps due to the belief that they are only effective when chilled as volatiles are expected to pass through unchilled tubes’ lumens or chromatograp...

  5. Evolution of plant volatile production in insect-plant relationships

    Microsoft Academic Search

    Paul Harrewijn; Albert K. Minks; Chris Mollema

    1994-01-01

    Summary The production of volatile secondary plant substances during the evolution of terrestrial plants is reviewed in regard to the defensive systems of plants to microorganisms and herbivores. Plant volatiles can be produced by both anabolic and catabolic processes. Although attraction of pollinators is a well-studied phenomenon, functions of volatiles range from excretion of waste products to the production of

  6. Tail behavior of a Threshold Autoregressive Stochastic Volatility model

    E-print Network

    Boyer, Edmond

    Tail behavior of a Threshold Autoregressive Stochastic Volatility model Aliou DIOP Dominique GUEGAN of the process (t)t. keywords : Tail Behavior, Heavy Tail, Stochastic Volatility Model, Thresh- old as a particular model of the Stochastic Autoregressive Volatility (SARV) model introduced by Andersen (1994

  7. Enhancing vacuum extraction of volatile organics using electrical heating

    Microsoft Academic Search

    H. M. Buettner; W. Daily; A. Ramirez

    1991-01-01

    Vacuum extraction is an effective tool for the in situ removal of liquid, residual and vapor phase volatile hydrocarbons from subsurface soils (Trowbridge, 1990). The vacuum extraction process creates air flow through soils by decreasing the gas phase pressure in the soil matrix. As the air flows through the pore spaces, volatile organic compounds (VOC`s) are volatilized and moved from

  8. Enhancing vacuum extraction of volatile organics using electrical heating

    Microsoft Academic Search

    H. M. Buettner; W. Daily; A. Ramirez

    1991-01-01

    Vacuum extraction is an effective tool for the in situ removal of liquid, residual and vapor phase volatile hydrocarbons from subsurface soils (Trowbridge, 1990). The vacuum extraction process creates air flow through soils by decreasing the gas phase pressure in the soil matrix. As the air flows through the pore spaces, volatile organic compounds (VOC's) are volatilized and moved from

  9. Why Does Stock Market Volatility Change over Time?

    Microsoft Academic Search

    G William Schwert

    1989-01-01

    This paper analyzes the relation of stock volatility with real and nominal macroeconomic volatility, economic activity, financial leverage, and stock trading activity using monthly data from 1857 to 1987. An important fact, previously noted by Robert R. Officer (1973), is that stock return variability was unusually high during the 1929-39 Great Depression. While aggregate leverage is significantly correlated with volatility,

  10. Distribution of aroma volatiles in a population of tangerine hybrids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    While orange juice volatile composition has been well studied, little is known about volatiles in tangerines. This study was undertaken to determine the most common compounds present in 45 tangerine hybrids, and to find relationships among these hybrids based on volatile content. Fruits were harve...

  11. ENHANCEMENTS OF NONPOINT-SOURCE MONITORING PROGRAMS TO ASSESS VOLATILE

    E-print Network

    . National Synthesis studies of nutrients and pesticides began in 1991, a study of volatile organic compoundsENHANCEMENTS OF NONPOINT-SOURCE MONITORING PROGRAMS TO ASSESS VOLATILE ORGANIC COMPOUNDS IN GROUND.S. Geological Survey (USGS) has compiled a national retrospective data set of analyses of volatile organic

  12. Another Look at the Volatility of Stock Prices

    ERIC Educational Resources Information Center

    Maruszewski, Richard F., Jr.

    2007-01-01

    Investors are interested in the volatility of a stock for various reasons. One investor may desire to purchase a low volatility stock for peace of mind. Another may be interested in a high volatility stock in order to have the opportunity to buy low and sell high as the price of the stock oscillates. This author had the fortunate timing of reading…

  13. China's macroeconomic volatility — How important is the business cycle?

    Microsoft Academic Search

    James Laurenceson; Danielle Rodgers

    2010-01-01

    The existing literature that discusses China's macroeconomic volatility during the reform period does so with overwhelming reference to the business cycle. However, the business cycle is only a subset of macroeconomic volatility that occurs within a particular frequency band. In this paper we decompose various macroeconomic series by frequency and find that much volatility occurs at lower than business cycle

  14. System of extraction of volatiles from soil using microwave processes

    NASA Technical Reports Server (NTRS)

    Ethridge, Edwin C. (Inventor); Kaukler, William F. (Inventor)

    2013-01-01

    A device for the extraction and collection of volatiles from soil or planetary regolith. The device utilizes core drilled holes to gain access to underlying volatiles below the surface. Microwave energy beamed into the holes penetrates through the soil or regolith to heat it, and thereby produces vapor by sublimation. The device confines and transports volatiles to a cold trap for collection.

  15. Online measurements of the emissions of intermediate-volatility and semi-volatile organic compounds from aircraft

    E-print Network

    Herndon, S. C.

    A detailed understanding of the climate and air quality impacts of aviation requires measurements of the emissions of intermediate-volatility and semi-volatile organic compounds (I/SVOCs) from aircraft. Currently both the ...

  16. Volatile hydrocarbons inhibit methanogenic crude oil degradation

    PubMed Central

    Sherry, Angela; Grant, Russell J.; Aitken, Carolyn M.; Jones, D. Martin; Head, Ian M.; Gray, Neil D.

    2014-01-01

    Methanogenic degradation of crude oil in subsurface sediments occurs slowly, but without the need for exogenous electron acceptors, is sustained for long periods and has enormous economic and environmental consequences. Here we show that volatile hydrocarbons are inhibitory to methanogenic oil biodegradation by comparing degradation of an artificially weathered crude oil with volatile hydrocarbons removed, with the same oil that was not weathered. Volatile hydrocarbons (nC5–nC10, methylcyclohexane, benzene, toluene, and xylenes) were quantified in the headspace of microcosms. Aliphatic (n-alkanes nC12–nC34) and aromatic hydrocarbons (4-methylbiphenyl, 3-methylbiphenyl, 2-methylnaphthalene, 1-methylnaphthalene) were quantified in the total hydrocarbon fraction extracted from the microcosms. 16S rRNA genes from key microorganisms known to play an important role in methanogenic alkane degradation (Smithella and Methanomicrobiales) were quantified by quantitative PCR. Methane production from degradation of weathered oil in microcosms was rapid (1.1 ± 0.1 ?mol CH4/g sediment/day) with stoichiometric yields consistent with degradation of heavier n-alkanes (nC12–nC34). For non-weathered oil, degradation rates in microcosms were significantly lower (0.4 ± 0.3 ?mol CH4/g sediment/day). This indicated that volatile hydrocarbons present in the non-weathered oil inhibit, but do not completely halt, methanogenic alkane biodegradation. These findings are significant with respect to rates of biodegradation of crude oils with abundant volatile hydrocarbons in anoxic, sulphate-depleted subsurface environments, such as contaminated marine sediments which have been entrained below the sulfate-reduction zone, as well as crude oil biodegradation in petroleum reservoirs and contaminated aquifers. PMID:24765087

  17. Chemical composition and antimicrobial activity of the volatile oil from Fusarium tricinctum, the endophytic fungus in Paris polyphylla var. yunnanensis.

    PubMed

    Zhang, Ying; Zhao, Jianglin; Wang, Jihua; Shan, Tijiang; Mou, Yan; Zhou, Ligang; Wang, Jingguo

    2011-11-01

    The volatile oil, obtained by hydro-distillation from Fusarium tricinctum, the endophytic fungus isolated from Paris polyphylla var. yunnanensis, was analyzed by gas chromatography-mass spectrometry (GC-MS). trans-1,2,3,3a,4,7a-Hexahydro-7a-methyl-5H-inden-5-one (73.1%), 2-methylene-4,8,8-trimethyl-4-vinyl bicyclo [5.2.0] nonane (12.0%), and 2,6-dimethyl-6-(4-methyl-3-pentenyl) bicyclo [3.1.1] hept-2-ene (4.5%) were the major compounds of the 15 identified components accounting for 95.4% of the volatile oil. The antimicrobial activity of the volatile oil was assayed against eight bacteria and two fungi. The minimum inhibitory concentration (MIC) values of the volatile oil against the test bacteria ranged from 25 to 45 microg/mL. The MIC values against the fungi Candida albicans and Magnaporthe oryzae were 100 and 225 microg/mL, respectively. The mean inhibitory concentration (IC50) values of the volatile oil against the test bacteria ranged from 17.8 to 31.6 microg/mL, and those of the volatile oil against C. albicans and M. oryzae were 84.3 and 204.3 microg/mL, respectively. PMID:22224305

  18. Host habitat assessment by a parasitoid using fungal volatiles

    PubMed Central

    Steiner, Sven; Erdmann, Daniel; Steidle, Johannes LM; Ruther, Joachim

    2007-01-01

    Background The preference – performance hypothesis predicts that oviposition preference of insects should correlate with host suitability for offspring development. Therefore, insect females have to be able to assess not only the quality of a given host but also the environmental conditions of the respective host habitat. Chemical cues are a major source of information used by insects for this purpose. Primary infestation of stored grain by stored product pests often favors the intense growth of mold. This can lead to distinct sites of extreme environmental conditions (hot-spots) with increased insect mortality. We studied the influence of mold on chemical orientation, host recognition, and fitness of Lariophagus distinguendus, a parasitoid of beetle larvae developing in stored grain. Results Volatiles of wheat infested by Aspergillus sydowii and A. versicolor repelled female parasitoids in an olfactometer. Foraging L. distinguendus females are known to be strongly attracted to the odor of larval host feces from the granary weevil Sitophilus granarius, which may adhere in remarkable amounts to the surface of the grains. Feces from moldy weevil cultures elicited neutral responses but parasitoids clearly avoided moldy feces when non-moldy feces were offered simultaneously. The common fungal volatile 1-octen-3-ol was the major component of the odor of larval feces from moldy weevil cultures and repelled female parasitoids at naturally occurring doses. In bioassays investigating host recognition behavior of L. distinguendus, females spent less time on grains containing hosts from moldy weevil cultures and showed less drumming and drilling behavior than on non-moldy controls. L. distinguendus had a clearly reduced fitness on hosts from moldy weevil cultures. Conclusion We conclude that L. distinguendus females use 1-octen-3-ol for host habitat assessment to avoid negative fitness consequences due to secondary mold infestation of host patches. The female response to fungal volatiles is innate, suggesting that host-associated fungi played a crucial role in the evolution of host finding strategies of L. distinguendus. Research on the role of host-associated microorganisms in the chemically mediated orientation of parasitoids is still at the beginning. We expect an increasing recognition of this issue in the future. PMID:17284315

  19. Realized Volatility and Absolute Return Volatility: A Comparison Indicating Market Risk

    PubMed Central

    Takaishi, Tetsuya; Stanley, H. Eugene; Li, Baowen

    2014-01-01

    Measuring volatility in financial markets is a primary challenge in the theory and practice of risk management and is essential when developing investment strategies. Although the vast literature on the topic describes many different models, two nonparametric measurements have emerged and received wide use over the past decade: realized volatility and absolute return volatility. The former is strongly favored in the financial sector and the latter by econophysicists. We examine the memory and clustering features of these two methods and find that both enable strong predictions. We compare the two in detail and find that although realized volatility has a better short-term effect that allows predictions of near-future market behavior, absolute return volatility is easier to calculate and, as a risk indicator, has approximately the same sensitivity as realized volatility. Our detailed empirical analysis yields valuable guidelines for both researchers and market participants because it provides a significantly clearer comparison of the strengths and weaknesses of the two methods. PMID:25054439

  20. Volatile organic compounds and metal leaching from composite products made from fiberglass-resin portion of printed circuit board waste.

    PubMed

    Guo, Jie; Jiang, Ying; Hu, Xiaofang; Xu, Zhenming

    2012-01-17

    This study focused on the volatile organic compounds (VOCs) and metal leaching from three kinds of composite products made from fiberglass-resin portion (FRP) of crushed printed circuit board (PCB) waste, including phenolic molding compound (PMC), wood plastic composite (WPC), and nonmetallic plate (NMP). Released VOCs from the composite products were quantified by air sampling on adsorbent followed by thermal desorption and GC-MS analysis. The results showed that VOCs emitted from composite products originated from the added organic components during manufacturing process. Phenol in PMC panels came primarily from phenolic resin, and the airborne concentration of phenol emitted from PMC product was 59.4 ± 6.1 ?g/m(3), which was lower than odor threshold of 100% response for phenol (180 ?g/m(3)). VOCs from WPC product mainly originated from wood flour, e.g., benzaldehyde, octanal, and d-limonene were emitted in relatively low concentrations. For VOCs emitted from NMP product, the airborne concentration of styrene was the highest (633 ± 67 ?g/m(3)). Leaching characteristics of metal ions from composite products were tested using acetic acid buffer solution and sulphuric acid and nitric acid solution. Then the metal concentrations in the leachates were tested by ICP-AES. The results showed that only the concentration of Cu (average = 893 mg/L; limit = 100 mg/L) in the leachate solution of the FRP using acetic acid buffer solution exceeded the standard limit. However, concentrations of other metal ions (Pb, Cd, Cr, Ba, and Ni) were within the standard limit. All the results indicated that the FRP in composite products was not a major concern in terms of environmental assessment based upon VOCs tests and leaching characteristics. PMID:22142243

  1. Forecasting S&P 100 Volatility: The Incremental Information Content of Implied Volatilities and High-Frequency Index Returns

    Microsoft Academic Search

    Bevan J. Blair; Ser-Huang Poon; Stephen J. Taylor

    \\u000a The information content of implied volatilities and intraday returns is compared in the context of forecasting index volatility\\u000a over horizons from 1 to 20 days. Forecasts of two measures of realized volatility are obtained after estimating ARCH models\\u000a using daily index returns, daily observations of the VIX index of implied volatility, and sums of squares of 5-min index returns. The

  2. Synergy Between Astrochemical Models and Cometary Taxonomies of Parent Volatiles

    NASA Astrophysics Data System (ADS)

    Bonev, Boncho P.; Willacy, Karen; Mumma, Michael J.; Gibb, Erika L.; Millar, Tom; Charnley, Steve; DiSanti, Michael A.; Villanueva, Geronimo L.; Paganini, Lucas

    2014-11-01

    The principal output in taxonomic studies of cometary primary (parent) volatiles is the suite of “mixing ratios” between observed species. These ratios relate the abundances of different molecules (CH4/C2H2/C2H6/H2CO/CH3OH/H2O, etc.) or isotopologues (HDO/H2O, CH3D/CH4, etc.). Infrared and radio observations have found strong evidence that mixing ratios vary substantially among comets. However, we still face serious uncertainties in decoding the cosmogonic significance of the measured abundances. The observed composition of comets may be an end product of a variety of processes, including chemical evolution in the protoplanetary disk, dynamical evolution in the young solar system, and (perhaps) thermal evolution during successive perihelion passages. Improved understanding of their relative importance requires additional sensitive measurements and a comprehensive synergy with astrochemical models. These models find that protoplanetary disks can be divided into three distinct regions: (1) a cold midplane, where ices freeze to dust grains; (2) a warm molecular layer, where ices sublimate and are processed via gas-phase reactions; and (3) a hot disk atmosphere containing predominantly atoms and atomic ions. Material from the different layers can be mixed by transport processes.We will show how this synergy is being realized via close collaboration between modeling and observing teams. The goal is a deeper insight into the processes preceding comet formation that may have influenced the composition - what chemical reaction pathways dominated the synthesis of cometary compounds? What processes in the protoplanetary disk have left strong signatures in cometary ices? Can models provide testable predictions for the chemical diversity observed among comets? Addressing these questions, we will show initial comparisons between relative abundances for several cometary volatiles and those predicted for the midplane of the protoplanetary disk where comets formed. We will also discuss how models link observations of volatiles in comets with studies of protoplanetary disks around solar type stars.This work is supported by NSF (AAG) and NASA (Astrobiology, PATM, PAST). Astrophysics at QUB is supported by a grant from STFC.

  3. Synthetic grape volatiles attract mated Lobesia botrana females in laboratory and field bioassays.

    PubMed

    Anfora, Gianfranco; Tasin, Marco; De Cristofaro, Antonio; Ioriatti, Claudio; Lucchi, Andrea

    2009-09-01

    In laboratory experiments, we identified and quantified volatiles emitted by inflorescences and berries of two grape varieties (Trebbiano and Sangiovese) and examined the effects of the volatiles on oviposition by the grapevine moth Lobesia botrana. Compared to Trebbiano, Sangiovese is relatively more susceptible to L. botrana infestations under natural conditions. Chemical and electrophysiological analysis indicated only quantitative differences between the volatiles released by the two varieties. In a dual-choice oviposition bioassay based only on volatile cues, females did not show any preference between the two varieties. The six major components of the odor profiles that were GC-EAD-active to female antennae included: limonene, 4,8-dimethyl-1,(E)-3,7-nonatriene, (+/-)-linalool, (E)-caryophyllene, (E,E)-alpha-farnesene, and methyl salicylate. At the beginning of the berry touch phenological stage, their proportions were about 10:0.6:0.4:0.5:0.9:0.6 in Trebbiano and 10:1:0.4:1.5:0.4:0.3 in Sangiovese. A six-component synthetic lure (with the proportion 10:1:1:1:1:1, which approximated the ratio of components released by both varieties) was used in further laboratory oviposition bioassays. Depending on its dosage, the synthetic lure either attracted or repelled oviposition. L. botrana females laid significantly more eggs in the presence of either the grape bunches or the synthetic lure at the attractive dosage. In a release-capture experiment conducted in a field cage that covered two grapevine rows, the synthetic lure was more attractive than a grape cluster or a blank control, and it stimulated oviposition on the vegetation near the lure. The results indicate that L. botrana uses olfactory cues to select oviposition sites and that an artificial lure, containing the major volatiles released by two grape varieties, may be useful in monitoring female activity in the field. PMID:19779942

  4. Volatile organic components migrating from plastic pipes (HDPE, PEX and PVC) into drinking water

    Microsoft Academic Search

    Ingun Skjevrak; Anne Due; Karl Olav Gjerstad; Hallgeir Herikstad

    2003-01-01

    High-density polyethylene pipes (HDPE), crossbonded polyethylene pipes (PEX) and polyvinyl chloride (PVC) pipes for drinking water were tested with respect to migration of volatile organic components (VOC) to water. The odour of water in contact with plastic pipes was assessed according to the quantitative threshold odour number (TON) concept. A major migrating component from HDPE pipes was 2,4-di-tert-butyl-phenol (2,4-DTBP) which

  5. Dynamics of the Volatile Defense of Winter “Dormant” Balsam Poplar ( Populus balsamifera )

    Microsoft Academic Search

    Thomas P. Clausen; Janice Chen; John P. Bryant; Frederick D. Provenza; Juan Villalba

    2010-01-01

    6-Hydroxycylohex-2-en-1-one (6-HCH) has been reported as a major chemical defense of the winter-dormant internodes of balsam\\u000a poplar (Populus balsamifera) against feeding by herbivores such as the snowshoe hare (Lepus americanus). We report that the concentration of 6-HCH in the fall internodes is triggered by a single hard frost, and then undergoes\\u000a an exponential decline through volatilization over the winter that

  6. Volatile components in scent gland secretions of garter snakes ( Thamnophis spp.)

    Microsoft Academic Search

    William F. Wood; Joshua M. Parker; Paul J. Weldon

    1995-01-01

    Previous analyses of the scent gland secretions of snakes have focused on the nonvolatile components. Gas chromatography-mass spectrometry of secretions from North American garter snakes (Thamnophis butleri, T. couchi, T. elegans, T. melanogaster, andT. sirtalis) indicated the following seven major volatile components: acetic, propanoic, 2-methylpropanoic, butanoic, and 3-methylbutanoic acids, trimethylamine, and 2-piperidone. Five or more of these compounds were observed

  7. Proteomic and metabolomic analyses provide insight into production of volatile and non-volatile flavor components in mandarin hybrid fruit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although many of the volatile constituents of flavor and aroma in citrus have been identified, the molecular mechanism and regulation of volatile production is not well understood. Our aim was to understand mechanisms of flavor volatile production and regulation in mandarin fruit. To this end fruits...

  8. Hygroscopic behavior of partially volatilized coastal marine aerosols using the volatilization and humidification tandem differential mobility analyzer technique

    Microsoft Academic Search

    G. R. Johnson; Z. D. Ristovski; B. D'Anna; L. Morawska

    2005-01-01

    Coastal marine nucleation, Aitken, and accumulation mode aerosol particles with back trajectories indicative of marine origin were examined using a volatilization and humidification tandem differential mobility analyzer (VHTDMA) to reveal the volatilization temperatures of the various component species. The diameter hygroscopic growth factors of the residue particles were continually examined throughout the volatilization process. In each of the three modes

  9. Hydropower major rehabilitation projects

    SciTech Connect

    Norlin, J.A. [Army Corps of Engineers, Portland, OR (United States)

    1995-12-31

    The Corps of Engineers has developed an active Major Rehabilitation Program to handle large, long duration restoration projects. These projects are funded by specific appropriations and subsequently are required to have detailed rehabilitation plans to justify the work. The emphasis of the Major Rehabilitation Program is correcting reliability problems. Papers that were presented at Waterpower `93 discussed the basic concepts that are required in preparing a Major Rehabilitation Evaluation Report. This paper will cover the current status of each of the current major rehabilitation projects that the Corps of Engineers has in progress.

  10. ION CHROMATOGRAPHY

    EPA Science Inventory

    The theory of ion chromatography as a technique for analyzing ionic substances is discussed. The application of ion chromatography for analyzing ambient air samples is specifically described, with emphasis on determining sulfate, nitrate, and ammonium ions in aerosols, and sulfur...

  11. PREFACE: Emerging non-volatile memories: magnetic and resistive technologies Emerging non-volatile memories: magnetic and resistive technologies

    NASA Astrophysics Data System (ADS)

    Dieny, B.; Jagadish, Chennupati

    2013-02-01

    In 2010, the International Technology Roadmap for Semiconductors (ITRS) published an assessment of the potential and maturity of selected emerging research on memory technologies. Eight different technologies of non-volatile memories were compared (ferroelectric gate field-effect transistor, nano-electro-mechanical switch, spin-transfer torque random access memories (STTRAM), various types of resistive RAM, in particular redox RAM, nanothermal phase change RAM, electronic effects RAM, macromolecular memories and molecular RAM). In this report, spin-transfer torque MRAM and redox RRAM were identified as two emerging memory technologies recommended for accelerated research and development leading to scaling and commercialization of non-volatile RAM to and beyond the 16nm generation. Nowadays, there is an intense research and development effort in microelectronics on these two technologies, one based on spintronic phenomena (tunnel magnetoresistance and spin-transfer torque), the other based on migration of vacancies or ions in an insulating matrix driven by oxydo-reduction potentials. Both technologies could be used for standalone or embedded applications. In this context, it appeared timely to publish a cluster of review articles related to these two technologies. In this cluster, the first two articles introduce the general principles of spin-transfer torque RAM and of thermally assisted RAM. The third presents a broader range of applications for this integrated CMOS/magnetic tunnel junction technology for low-power electronics. The fourth paper presents more advanced research on voltage control of magnetization switching with the aim of dramatically reducing the write energy in MRAM. The last two papers deal with two categories of resistive RAM, one based on the migration of cations, the other one based on nanowires. We thank all the authors and reviewers for their contribution to this cluster issue. Our special thanks are due to Dr Olivia Roche, Publisher, and Dr Giovanna Lani and Mr Colin Adcock, Publishing Editors of the journal, for their help with this cluster issue.

  12. Pyrolysis of alanine and ?-aminoisobutyric acid: identification of less-volatile products using gas chromatography\\/Fourier transform infrared spectroscopy\\/mass spectrometry

    Microsoft Academic Search

    Vladimir A Basiuk; Rafael Navarro-González; Elena V Basiuk

    1998-01-01

    In addition to volatile low-molecular-weight decomposition compounds, ?-aminoisobutyric acid (Aib) and alanine (Ala) pyrolysis at 500°C under nitrogen atmosphere leads to less-volatile products resulting from amino acid intermolecular condensation. The major pathway is the formation of cyclic dipeptides piperazine-2,5-diones with the yields of 1% for Aib and 68% for Ala. To identify other pyrolysis products, they have been extracted by

  13. Investigation of the Treatability of the Primary Indoor Volatile Organic Compounds on Activated Carbon Fiber Cloths at Typical Indoor Concentrations

    Microsoft Academic Search

    Meng Yao; Qiong Zhang; David W. Hand; David L. Perram; Roy Taylor; Remedios ez; Sebastian Caparro´s; Manuel Díaz; Takashi Miwa; Yasuko Maruo; Kunihiko Akaoka; Tatsuya Kunioka; Jiro Nakamura; Johanna Gietl; Otto Klemm; Xinke Wang; Yinping Zhang; Jace Bauer; Xiao-Ying Yu; Robert Cary; Nels Laulainen; Carl Berkowitz; Juan Goncalves; Rakesh Govind; Chatchawan Vongmahadlek; Pham Thao; Boonsong Satayopas; Narisara Thongboonchoo; H. Frey; Po-Yao Kuo; Mohammad Al-Hamdan; William Crosson; Ashutosh Limaye; Douglas Rickman; Dale Quattrochi; Maurice Estes; Judith Qualters; Amber Sinclair; Dennis Tolsma; Kafayat Adeniyi; Amanda Niskar

    2009-01-01

    Volatile organic compounds (VOCs) are a major concern for indoor air pollution because of the impacts on human health. In recent years, interest has increased in the development and design of activated carbon filters for removing VOCs from indoor air. Although extensive information is available on sources, concentrations, and types of indoor VOCs, there is little or no information on

  14. A Novel Multifunctional Photocatalytic Oxidation (PCO) Gel Preventing Mold\\/Mildew Growth and Volatile Organic Compound (VOC) Emission

    Microsoft Academic Search

    Yao Gao

    2011-01-01

    With the increasing time people spend indoors, the indoor environment quality draws more and more attention. The concentration of indoor pollutants is usually much higher than outdoors, in which volatile organic compounds (VOCs) and mold\\/mildew are both major pollutants and cause many health problems to residents. Efforts devoted from academy and industry to protecting people from indoor environment problems are

  15. Gas Chromatographic Quantification of Major Volatile Compounds and Polyols in Wine by Direct Injection

    Microsoft Academic Search

    Rafael A. Peinado; Jose A. Moreno; David Muñoz; Manuel Medina; Juan Moreno

    2004-01-01

    Methanol, propanol, isobutanol, isoamyl alcohol, 2-phenylethanol, acetaldehyde, 1,1-diethoxyethane, acetoin, ethyl acetate, ethyl lactate, and ethyl succinate and the polyols 2,3-butanediol (levo and meso forms) and glycerol were quantified by direct injection of wine samples. Linear responses over the usual concentration ranges for these compounds and r2 values from 0.9932 to 0.9998 were obtained. The confidence limits for the mean values

  16. Geochemistry of volatile organic compounds in seawater: Mesocosm experiments with 14C-model compounds

    NASA Astrophysics Data System (ADS)

    Wakeham, Stuart G.; Canuel, Elizabeth A.; Doering, Peter H.

    1986-06-01

    A series of ten radiotracer experiments were conducted in controlled experimental ecosystems (mesocosms) to investigate the behavior of volatile organic compounds (VOC) in seawater. Time-series measurements of the redistribution of 14C-activity within several major pools - dissolved, particulate, intermediate metabolite, and CO 2 - in the ecosystem made possible an evaluation of the rates of processes - volatilization, biodegradation, Sorption and sedimentation - acting to remove VOC from seawater in summer. The behavior of the model 14C-VOC fell into three categories. Aromatic hydrocarbons (benzene, toluene, naphthalene) were subject to both volatilization and biodegradation, with mineralization dominating in summer. Chlorinated C 2-hydrocarbons (tetrachloroethylene) and chlorinated benzenes (chlorobenzene, 1,4-dichlorobenzene, and 1,2,4-trichlorobenzene) were affected only by volatilization and were relatively resistant to biodegradation. Of all the model VOC studied, only aliphatic hydrocarbons (decane and octadecane) were sorbed onto suspended paniculate matter; however, the primary route of loss from the water column appeared to be biodegradation rather than sedimentation. The mesocosm-derived removal rate constants were then applied to estimate summer VOC residence times in Narragansett Bay, Rhode Island of about 1 day for aromatic hydrocarbons, 1 week for the chlorinated VOC and about 1 day for aliphatic hydrocarbons. Residence times in winter might be on the order of 1 week for all VOC.

  17. Effect of soot build-up while sampling with the volatile organic sampling train (VOST)

    SciTech Connect

    Wilshire, F.W., Johnson, L.D. [Environmental Protection Agency, Research Triangle Park, NC (United States); Hinshaw, G.D. [Midwest Research Institute, Kansas City, MO (United States)

    1994-12-31

    The U.S. Environmental Protection Agency`s Method 0030, the Volatile Organic Sampling Train (VOST), is used to determine the destruction and removal efficiencies of volatile organic emission from industrial boilers co-firing hazardous waste. Previous reports detailing a hysteresis effect for volatile organic compounds (VOCs), resulting from soot build-up on the interior surfaces of boilers and industrial furnaces, raised concerns of possible VOST measurement biases due to soot deposits within the VOST. This possibility required laboratory investigation of the method under sooty conditions. Method collection efficiency was evaluated by comparing volatile organic compound levels collected in a control VOST (using a soot-free particulate filter in the sampling probe), to VOC recoveries while using a soot-laden particulate filter in the probe. Emphasis was directed to substances in the upper range of VOC boiling points (120 to 130{degrees}C). Statistical evaluation of the data collected indicated that recoveries for two of the higher boiling VOCs (chlorobenzene and octane) appeared to be negatively influenced by the presence of soot on the VOST fiber. It is not likely, however, that these findings will have a major impact on previously collected hazardous waste incinerator data, since the VOST-Soot effect was determined at moderately high soot loadings, which are atypical of properly operating hazardous waste incinerators. 8 refs., 3 figs., 4 tabs.

  18. Volatiles in amphiboles from xenoliths, Vulcan's Throne, Grand Canyon, Arizona, USA

    NASA Astrophysics Data System (ADS)

    Matson, Dean W.; Muenow, David W.; Garcia, Michael O.

    1984-08-01

    Analyses of major element and volatile components of amphiboles from Vulcan's Throne, a Recent volcano on the north rim of the Grand Canyon, Arizona, USA, have been performed by using the electron microprobe and high temperature mass spectrometry. The amphiboles occur as megacrysts, as oikocrysts in peridotite and pyroxenite xenoliths, in amphibole-rich selvages on lherzolite xenoliths, and as grains in hornblendite xenoliths. Total volatiles range from 1.27 to 1.75 wt.%. In all samples, H 2O is the principal volatile species. Lesser amounts of structurally bound fluorine, chlorine, and oxygen were also released. The amphiboles studied are hydroxyl-deficient. The O(3) site is probably partially occupied by O 2-, which was detected as O 2 during degassing of the amphibole. Ti shows a strong positive correlation with the amount of hydroxyl deficiency in the amphiboles except for one oxidized sample. Thus, Ti probably is significant in charge balancing the substitution of O 2- for OH - and the substitution probably occurred during crystallization rather than by dehydrogenation. Small amounts of both oxidized and reduced carbon and sulfur-bearing volatile species ( e.g., CO 2, CO, CH 4, SO 2, H 2S) were detected in all samples. The observation of reduced carbon species supports the hypothesis that the oxygen fugacity of at least portions of the upper mantle is probably less than the quartz-fayalite-magnetite buffer.

  19. Model studies of volatile diesel exhaust particle formation: organic vapours involved in nucleation and growth?

    NASA Astrophysics Data System (ADS)

    Pirjola, L.; Karl, M.; Rönkkö, T.; Arnold, F.

    2015-02-01

    High concentration of volatile nucleation mode particles (NUP) formed in the atmosphere during exhaust cools and dilutes have hazardous health effects and impair visibility in urban areas. Nucleation mechanisms in diesel exhaust are only poorly understood. We performed model studies using two sectional aerosol dynamics process models AEROFOR and MAFOR on the formation of particles in the exhaust of a diesel engine, equipped with an oxidative after-treatment system and running with low fuel sulphur content (FSC), under laboratory sampling conditions where the dilution system mimics real-world conditions. Different nucleation mechanisms were tested; based on the measured gaseous sulphuric acid (GSA) and non-volatile core and soot particle number concentrations of the raw exhaust, the model simulations showed that the best agreement between model predictions and measurements in terms of particle number size distribution was obtained by barrierless heteromolecular homogeneous nucleation between GSA and semi-volatile organic vapour (for example adipic acid) combined with the homogeneous nucleation of GSA alone. Major growth of the particles was predicted to occur by the same organic vapour at concentrations of (1-2) ×1012cm-3. The pre-existing core and soot mode concentrations had opposite trend on the NUP formation, and maximum NUP formation was predicted if a diesel particle filter (DPF) was used. On the other hand, NUP formation was ceased if the GSA concentration was less than 1010cm-3 which suggests, based on the measurements, the usage of biofuel to prevent volatile particles in diesel exhaust.

  20. Rust and schreibersite in Apollo 16 highland rocks - Manifestations of volatile-element mobility

    NASA Technical Reports Server (NTRS)

    Hunter, R. H.; Taylor, L. A.

    1982-01-01

    Rust is a manifestation of halogen and volatile-metal mobility in the lunar environment. Schreibersite is stable as the primary phosphorus-bearing phase in the highland rocks, a consequence of the inherently low oxygen fugacity within impact-generated melts. Apatite and whitlockite are subordinate in these rocks. The partitioning of P into phosphide in impact-generated melts, and the failure of phosphate to crystallize, effects a decoupling of the halogens and phosphorus. Of the Apollo 16 rocks, 63% contain rust, 70% contain schreibersite, and 52% contain both phases, thereby establishing the pervasiveness of volatile-elements throughout the highland rocks. The major portion of these volatile-bearing phases occur in impact melt-rocks or in breccia matrices. Rhabdites of schreibersite in some of the FeNi grains indicate that there is a meteoritic contribution to the phosphorus in these rocks. Cl/P2O5 ratios in lunar highland rocks are a function of secondary effects, with any apparent Cl-P correlations being coincidential. The present observations preclude the validity of models based on such elemental ratios in these rocks. The presence of rust in the clast laden matrices of pristine rocks indicates fugitive element localization. Pristine clasts may have been contaminated. The basis for a pristine volatile chemistry is questioned.

  1. Effects of gamma irradiation on the yields of volatile extracts of Angelica gigas Nakai

    NASA Astrophysics Data System (ADS)

    Seo, Hye-Young; Kim, Jun-Hyoung; Song, Hyun-Pa; Kim, Dong-Ho; Byun, Myung-Woo; Kwon, Joog-Ho; Kim, Kyong-Su

    2007-11-01

    The study was carried out to determine the effects of gamma irradiation on the volatile flavor components including essential oils, of Angelica gigas Nakai. The volatile organic compounds from non- and irradiated A. gigas Nakai at doses of 1, 3, 5, 10 and 20 kGy were extracted by a simultaneous steam distillation and extraction (SDE) method and identified by GC/MS analysis. A total of 116 compounds were identified and quantified from non- and irradiated A. gigas Nakai. The major volatile compounds were identified 2,4,6-trimethyl heptane, ?-pinene, camphene, ?-limonene, ?-eudesmol, ?-murrolene and sphatulenol. Among these compounds, the amount of essential oils in non-irradiated sample were 77.13%, and the irradiated samples at doses of 1, 3, 5, 10 and 20 kGy were 84.98%, 83.70%, 83.94%, 82.84% and 82.58%, respectively. Oxygenated terpenes such as ?-eudesmol, ?-eudesmol, and verbenone were increased after irradiation but did not correlate with the irradiation dose. The yields of active substances such as essential oil were increased after irradiation; however, the yields of essential oils and the irradiation dose were not correlated. Thus, the profile of composition volatiles of A. gigas Nakai did not change with irradiation.

  2. Detection of Volatile Indicators of Illicit Substances by the Olfactory Receptors of Drosophila melanogaster

    PubMed Central

    Marshall, Brenton; Warr, Coral G.

    2010-01-01

    Insects can detect a large range of odors with a numerically simple olfactory system that delivers high sensitivity and accurate discrimination. Therefore, insect olfactory receptors hold great promise as biosensors for detection of volatile organic chemicals in a range of applications. The array of olfactory receptor neurons of Drosophila melanogaster is rapidly becoming the best-characterized natural nose. We have investigated the suitability of Drosophila receptors as detectors for volatiles with applications in law enforcement, emergency response, and security. We first characterized responses of the majority of olfactory neuron types to a set of diagnostic odorants. Being thus able to correctly identify neurons, we then screened for responses from 38 different types of neurons to 35 agents. We identified 13 neuron types with responses to 13 agents. As individual Drosophila receptor genes have been mapped to neuron types, we can infer which genes confer responsiveness to the neurons. The responses were confirmed for one receptor by expressing it in a nonresponsive neuron. The fly olfactory system is mainly adapted to detect volatiles from fermenting fruits. However, our findings establish that volatiles associated with illicit substances, many of which are of nonnatural origin, are also detected by Drosophila receptors. PMID:20530374

  3. Physicochemical and volatiles characterization of trans-free solid fats produced by lipase-catalyzed interesterification.

    PubMed

    Lee, J H; Akoh, C C; Lee, K-T

    2007-08-01

    Trans-free solid fats were synthesized from fully hydrogenated soybean oil (FHSBO), olive oil (OO), and palm stearin (PS) at different substrate weight ratios (10:20:70, 10:40:50 and 10:50:40) via lipase-catalyzed interesterification. The interesterified products contained mostly TAG (98.8% to 99.0%), and small amounts of MAG and DAG as by-products. The major fatty acids were oleic acid, palmitic acid, and stearic acid in the interesterified products, and the melting points ranged from 39 to 45 degrees C. The amount of alpha-tocopherol was reduced by 75% to 92%. Volatile analysis by solid-phase microextraction indicated that OO and PS had distinct volatile profiles, in which 18 volatiles were retained in interesterified products. Furthermore, some volatiles disappeared or formed during processing. Electronic nose showed that the odors of substrates (OO and PS) were different from each other, and the odors of interesterified products were distinguishable from that of OO or PS. Among the interesterified products, the odor of blend FHSBO:OO:PS of 10:40:50 or 10:50:40 was different from that of blend FHSBO:OO:PS (10:20:70). However, no odor difference was observed between products blend FHSBO:OO:PS 10:40:50 and 10:50:40. PMID:17995682

  4. Music Majors ADVISING & REGISTRATION

    E-print Network

    Fernandez, Eduardo

    Music Majors ADVISING & REGISTRATION INFORMATION For any student looking to pursue a degree within the Department of Music please visit the following website for additional program information: http://www.fau.edu/music/ Advising and Registration Information: As a music major you will need to complete OARS as OARS provides

  5. CAPS and INMS Major Accomplishments

    NASA Astrophysics Data System (ADS)

    Waite, J. Hunter

    2014-05-01

    The Cassini-Huygens Ion Neutral Mass Spectrometer (Cassini INMS) and the Cassini Plasma Spectrometer (CAPS) have provided "discovery" science at Titan, Enceladus, Rhea/Dione, and throughout the magnetosphere of Saturn during the course of the mission. In this talk we will review some of the major scientific achievements: 1) the discovery of an extremely complex ion neutral organic chemistry in Titan's upper atmosphere that forms the building blocks for aerosol processes below, 2) the discovery of gases and grains emanating from Enceladus' cryo-geysers that tell us about chemical processes in an interior sea, 3) the first direct compositional measurements of sputtered icy moon surfaces, 4) the clearest example to date of the complex plasma interchange processes that occur in rapidly rotating magnetospheres of gas giants, initiating global dynamic processes that enable Saturn to shed the plasma from Enceladus' plume, and complete with a myriad of longitudinal and solar local-time variations, and 5) the dominance of Enceladus water outgassing as a source of magnetospheric plasma that stretches out to Titan and provides oxygen that can convert Titan's rich nitrile populations into amino acids.

  6. Exploring heterogeneous market hypothesis using realized volatility

    NASA Astrophysics Data System (ADS)

    Chin, Wen Cheong; Isa, Zaidi; Mohd Nor, Abu Hassan Shaari

    2013-04-01

    This study investigates the heterogeneous market hypothesis using high frequency data. The cascaded heterogeneous trading activities with different time durations are modelled by the heterogeneous autoregressive framework. The empirical study indicated the presence of long memory behaviour and predictability elements in the financial time series which supported heterogeneous market hypothesis. Besides the common sum-of-square intraday realized volatility, we also advocated two power variation realized volatilities in forecast evaluation and risk measurement in order to overcome the possible abrupt jumps during the credit crisis. Finally, the empirical results are used in determining the market risk using the value-at-risk approach. The findings of this study have implications for informationally market efficiency analysis, portfolio strategies and risk managements.

  7. Volatiles from rhizomes of Rhodiola rosea L.

    PubMed

    Rohloff, Jens

    2002-03-01

    Terpenes and aroma volatiles from rhizomes of Rhodiola rosea L. from Norway have been isolated by both steam distillation and headspace solid-phase micro-extraction coupled with gas chromatography and mass spectrometry analysis. The dried rhizomes contained 0.05% essential oil with the main chemical classes: monoterpene hydrocarbons (25.40%), monoterpene alcohols (23.61%) and straight chain aliphatic alcohols (37.54%). n-Decanol (30.38%), geraniol (12.49%) and 1,4-p-menthadien-7-ol (5.10%) were the most abundant volatiles detected in the essential oil, and a total of 86 compounds were identified in both the SD and HS-SPME samples. Geraniol was identified as the most important rose-like odour compound besides geranyl formate, geranyl acetate, benzyl alcohol and phenylethyl alcohol. Floral notes such as linalool and its oxides, nonanal, decanal, nerol and cinnamyl alcohol highlight the flowery scent of rose root rhizomes. PMID:11867098

  8. Volatile organic compounds in ambient aerosols

    NASA Astrophysics Data System (ADS)

    Matsumoto, Kiyoshi; Matsumoto, Kumi; Mizuno, Riichi; Igawa, Manabu

    2010-07-01

    In order to investigate the concentration levels of volatile organic compounds (VOCs) in ambient aerosols, monocyclic aromatic hydrocarbons (MAHs) and chlorinated hydrocarbons (CHs) in the particulate phase were measured simultaneously with those in the gas phase in the urban atmosphere. Six compounds were detected in the aerosols at concentrations from 0.051 (1,2-dichloroethane) to 1.75 ng m - 3 (benzene). Benzene was detected as the most dominant compound in the aerosols, although toluene was the most dominant compound in the gas phase. The VOCs in the aerosols had concentrations comparable to those reported for some semi-volatile organic compounds (SOCs) in the aerosols. The concentrations of the VOCs in the aerosols were primarily controlled by the aerosol mass loading. Temperature and relative humidity had no significant effect on the gas/particle partitioning of the VOCs. Our results also suggested that the hygroscopic properties of the aerosols should be considered to discuss the partitioning of the VOCs.

  9. Option volatility and the acceleration Lagrangian

    NASA Astrophysics Data System (ADS)

    Baaquie, Belal E.; Cao, Yang

    2014-01-01

    This paper develops a volatility formula for option on an asset from an acceleration Lagrangian model and the formula is calibrated with market data. The Black-Scholes model is a simpler case that has a velocity dependent Lagrangian. The acceleration Lagrangian is defined, and the classical solution of the system in Euclidean time is solved by choosing proper boundary conditions. The conditional probability distribution of final position given the initial position is obtained from the transition amplitude. The volatility is the standard deviation of the conditional probability distribution. Using the conditional probability and the path integral method, the martingale condition is applied, and one of the parameters in the Lagrangian is fixed. The call option price is obtained using the conditional probability and the path integral method.

  10. Volatile compounds released during lunar lava fountaining

    NASA Technical Reports Server (NTRS)

    Wasson, J. T.; Boynton, W. V.; Kallemeyn, G. W.; Sundberg, L. L.; Wai, C. M.

    1976-01-01

    A modified radiochemical neutron activation analysis was used to determine 24 elements in three sieve separates and in HCl leach, HF etch, and residue fractions of the 500-62 micron separate of orange glass fines 74220. Six elements - In, Cd, Zn, Ga, Ge, and Au - were strongly concentrated in the leach, indicating that they were present as a surface deposit, probably a sublimate resulting from condensation of lava-fountain volatiles which expelled the orange glass onto the lunar surface.

  11. Volatilization of metal powders in plasma sprays

    Microsoft Academic Search

    A. Vardelle; M. Vardelle; H. Zhang; N. J. Themelis; K. Gross

    2002-01-01

    Ideally, plasma spraying of metal powders must take place within a narrow processing “window” where the particles become fully\\u000a molten before they hit the substrate, but are not overheated to the point that substantial volatilization occurs. Metal evaporation\\u000a in flight results in a decrease in the deposition efficiency. In addiiton, the emission of vapors leads to the formation of\\u000a metal

  12. Volatile Metabolites of Pathogens: A Systematic Review

    PubMed Central

    Bos, Lieuwe D. J.; Sterk, Peter J.; Schultz, Marcus J.

    2013-01-01

    Ideally, invading bacteria are detected as early as possible in critically ill patients: the strain of morbific pathogens is identified rapidly, and antimicrobial sensitivity is known well before the start of new antimicrobial therapy. Bacteria have a distinct metabolism, part of which results in the production of bacteria-specific volatile organic compounds (VOCs), which might be used for diagnostic purposes. Volatile metabolites can be investigated directly in exhaled air, allowing for noninvasive monitoring. The aim of this review is to provide an overview of VOCs produced by the six most abundant and pathogenic bacteria in sepsis, including Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecalis, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli. Such VOCs could be used as biological markers in the diagnostic approach of critically ill patients. A systematic review of existing literature revealed 31 articles. All six bacteria of interest produce isopentanol, formaldehyde, methyl mercaptan, and trimethylamine. Since humans do not produce these VOCs, they could serve as biological markers for presence of these pathogens. The following volatile biomarkers were found for identification of specific strains: isovaleric acid and 2-methyl-butanal for Staphylococcus aureus; 1-undecene, 2,4-dimethyl-1-heptane, 2-butanone, 4-methyl-quinazoline, hydrogen cyanide, and methyl thiocyanide for Pseudomonas aeruginosa; and methanol, pentanol, ethyl acetate, and indole for Escherichia coli. Notably, several factors that may effect VOC production were not controlled for, including used culture media, bacterial growth phase, and genomic variation within bacterial strains. In conclusion, VOCs produced by bacteria may serve as biological markers for their presence. Goal-targeted studies should be performed to identify potential sets of volatile biological markers and evaluate the diagnostic accuracy of these markers in critically ill patients. PMID:23675295

  13. Autoregresive conditional volatility, skewness and kurtosis

    Microsoft Academic Search

    Ángel León; Gonzalo Rubio; Gregorio Serna

    2005-01-01

    This paper proposes a GARCH-type model allowing for time-varying volatility, skewness and kurtosis. The model is estimated assuming a Gram–Charlier (GC) series expansion of the normal density function for the error term, which is easier to estimate than the non-central t distribution proposed by [Harvey, C. R. & Siddique, A. (1999). Autorregresive Conditional Skewness. Journal of Financial and Quantitative Analysis

  14. Volatile fractionation and tektite source material

    SciTech Connect

    Walter, L.S. (Goddard Space Flight Center, Greenbelt, MD (USA))

    1989-09-01

    In discounting the possibility that vapor fractionation played a part in the origin of bediasites, it has been assumed that Na and K are lost to the vapor phase. Experimental work shows, however, that, under oxidizing conditions, neither Na nor K exhibit particularly volatile behavior. Indeed, the compositional variations exhibited by bediasites are very similar to those obtained during experimental high-temperature vapor fractionation of a high-silica melt.

  15. Volatilization of ethylene dibromide from water

    USGS Publications Warehouse

    Rathbun, R.E.; Tai, D.Y.

    1987-01-01

    Overall mass-transfer coefficients for the volatilization of ethylene dibromide from water were measured simultaneously with the oxygen absorption coefficient in a laboratory stirred tank. Coefficients were measured as a function of mixing conditions in the water for two windspeeds. The ethylene dibromide mass-transfer coefficient depended on windspeed; the ethylene dibromide liquid-film coefficient did not, in agreement with theory. A constant relation existed between the liquid-film coefficients for ethylene dibromide and oxygen.

  16. Volatile processes in Triton's atmosphere and surface

    NASA Technical Reports Server (NTRS)

    Lunine, J. I.

    1992-01-01

    A basic model for latitudinal transport of nitrogen is reviewed focusing on its limitations and some complications associated with surface and atmospheric physics. Data obtained by 1989 Voyager encounter with the Neptune system revealed the complexity in the pure nitrogen transport which is caused by the nonuniform albedo of the frosts. It is concluded that Triton is similar to Mars in terms of the complexity of volatile transport and to understand Triton's surface-atmosphere system, Mars may be a very good analog.

  17. Use of ion chromatography–electrospray mass spectrometry for the determination of ionic compounds in agricultural chemicals

    Microsoft Academic Search

    Sheher Bano Mohsin

    2000-01-01

    This paper reports the use of ion chromatography–electrospray mass spectrometry for the separation and structure elucidation of anionic compounds in a complex organophosphate matrix. Conventional HPLC with ion pairing reagents, pH adjustments or use of buffer solutions have limited compatibility with mass spectrometry, as the ion pairing reagents or buffers have to be volatile to be introduced into the mass

  18. A comparison of chemical, antioxidant and antimicrobial studies of cinnamon leaf and bark volatile oils, oleoresins and their constituents.

    PubMed

    Singh, Gurdip; Maurya, Sumitra; DeLampasona, M P; Catalan, Cesar A N

    2007-09-01

    The antioxidant, antifungal and antibacterial potentials of volatile oils and oleoresin of Cinnamomum zeylanicum Blume (leaf and bark) were investigated in the present study. The oleoresins have shown excellent activity for the inhibition of primary and secondary oxidation products in mustard oil added at the concentration of 0.02% which were evaluated using peroxide, thiobarbituric acid, p-anisidine and carbonyl values. Moreover, it was further supported by other complementary antioxidant assays such as ferric thiocyanate method in linoleic acid system, reducing power, chelating and scavenging effects on 1,1'-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radicals. In antimicrobial investigations, using inverted petriplate and food poison techniques, the leaf and bark volatile oils has been found to be highly effective against all the tested fungi except Aspergillus ochraceus. However, leaf oleoresin has shown inhibition only for Penicillium citrinum whereas bark oleoresin has caused complete mycelial zone inhibition for Aspergillus flavus and A. ochraceus along with Aspergillus niger, Aspergillus terreus, P. citrinum and Penicillium viridicatum at 6 microL. Using agar well diffusion method, leaf volatile oil and oleoresin have shown better results in comparison with bark volatile oil, oleoresin and commercial bactericide, i.e., ampicillin. Gas chromatographic-mass spectroscopy studies on leaf volatile oil and oleoresin resulted in the identification of 19 and 25 components, which accounts for the 99.4% and 97.1%, respectively of the total amount and the major component was eugenol with 87.3% and 87.2%, respectively. The analysis of cinnamon bark volatile oil showed the presence of 13 components accounting for 100% of the total amount. (E)-cinnamaldehyde was found as the major component along with delta-cadinene (0.9%), whereas its bark oleoresin showed the presence of 17 components accounting for 92.3% of the total amount. The major components were (E)-cinnamaldehyde (49.9%), along with several other components. PMID:17408833

  19. Financial market volatility and contagion effect: A copula-multifractal volatility approach

    NASA Astrophysics Data System (ADS)

    Chen, Wang; Wei, Yu; Lang, Qiaoqi; Lin, Yu; Liu, Maojuan

    2014-03-01

    In this paper, we propose a new approach based on the multifractal volatility method (MFV) to study the contagion effect between the U.S. and Chinese stock markets. From recent studies, which reveal that multifractal characteristics exist in both developed and emerging financial markets, according to the econophysics literature we could draw conclusions as follows: Firstly, we estimate volatility using the multifractal volatility method, and find out that the MFV method performs best among other volatility models, such as GARCH-type and realized volatility models. Secondly, we analyze the tail dependence structure between the U.S. and Chinese stock market. The estimated static copula results for the entire period show that the SJC copula performs best, indicating asymmetric characteristics of the tail dependence structure. The estimated dynamic copula results show that the time-varying t copula achieves the best performance, which means the symmetry dynamic t copula is also a good choice, for it is easy to estimate and is able to depict both the upper and lower tail dependence structure. Finally, with the results of the previous two steps, we analyze the contagion effect between the U.S. and Chinese stock markets during the subprime mortgage crisis. The empirical results show that the subprime mortgage crisis started in the U.S. and that its stock market has had an obvious contagion effect on the Chinese stock market. Our empirical results should/might be useful for investors allocating their portfolios.

  20. Comparison of the Volatile Leaf Oils of Juniperus davurica Pall. from Mongolia, with Plants Cultivated in Kazakhstan, Russia and Scotland

    Microsoft Academic Search

    Robert P. Adams; S. Shatar; A. D. Dembitsky

    1994-01-01

    The composition of the volatile leaf oils of Juniperus davurica, putative J. davurica plants cultivated in Alma Ata and Moscow, and cv. expansa variegata are reported. The major compounds of J. davurica (Mongolia) are sabinene (28.6%), cedrol (11.5%), methyl citronellate (7.4%), citronellol (6.5%), terpinen-4-ol (5.8%) and ?-pinene (4.1%). In contrast, the major compounds of J. davurica cv. expansa variegata are

  1. Membrane consisting of polyquaternary amine ion exchange polymer network interpenetrating the chains of thermoplastic matrix polymer

    NASA Technical Reports Server (NTRS)

    Rembaum, A.; Wallace, C. J. (inventors)

    1978-01-01

    An ion exchange membrane was formed from a solution containing dissolved matrix polymer and a set of monomers which are capable of reacting to form a polyquaternary ion exchange material; for example vinyl pyride and a dihalo hydrocarbon. After casting solution and evaporation of the volatile component's, a relatively strong ion exchange membrane was obtained which is capable of removing anions, such as nitrate or chromate from water. The ion exchange polymer forms an interpenetrating network with the chains of the matrix polymer.

  2. Activity of Thymus capitellatus volatile extract, 1,8-cineole and borneol against Leishmania species.

    PubMed

    Machado, M; Dinis, A M; Santos-Rosa, M; Alves, V; Salgueiro, L; Cavaleiro, C; Sousa, M C

    2014-02-24

    In the search for new leishmanicidal agents, Thymus capitellatus Hoffmanns. & Link (family Lamiaceae) volatile extract and its major compounds, 1,8-cineole and borneol, were tested against Leishmania infantum, Leishmania tropica and Leishmania major. Plant volatile extract (essential oil) was analysed by GC and GC-MS and the activity of essential oil on Leishmania promastigotes viability was assessed using tetrazolium-dye colorimetric method (MTT). The MTT test was also used to assess the cytotoxicity of essential oil on macrophages and bovine aortic endothelial cells. Effects on parasites were also analyzed by flow cytometry in order to assess mitochondrial transmembrane electrochemical gradient (JC-1), analyze phosphatidylserine externalization (annexin V-FITC, propidium iodide) and evaluate cell cycle (DNase-free, RNase, PI). Morphological and ultrastructural studies were performed by light, scanning and transmission electron microscopy. T. capitellatus volatile extract exhibited anti-parasite activity on Leishmania species, with IC50 values ranging from 35 to 62 ?g/ml. However, major compounds 1,8-cineole and borneol did not showed biological activity suggesting that these monoterpenes are not responsible for the antileishmanial activity of T. capitellatus essential oil. Appearance of aberrant-shaped cells, mitochondrial swelling and autophagosomal structures were some of the ultrastructural alterations exhibited among treated promastigote cells. T. capitellatus promoted leishmanicidal effect by triggering a programmed cell death as evidenced by externalization of phosphatidylserine, loss of mitochondrial membrane potential, and cell-cycle arrest at the G(0)/G(1) phase. The volatile extract did not induced cytotoxic effects on mammalian cells. Taken together, these results suggest that T. capitellatus may represent a valuable source for therapeutic control of leishmaniasis in humans and animals. PMID:24365244

  3. MECHANICAL ENGINEERING UNDERGRADUATE MAJOR

    E-print Network

    HANDBOOK FOR MECHANICAL ENGINEERING UNDERGRADUATE MAJOR Old Dominion University Department OF CONTENTS MECHANICAL ENGINEERING HANDBOOK............................................................ 14 #12;1 MECHANICAL ENGINEERING HANDBOOK This handbook has been designed to help you earn a Bachelor

  4. for Undergraduate CHEMISTRY MAJORS

    E-print Network

    Stuart, Steven J.

    , Geochemistry, Hazardous Waste Management, Inorganic Chemistry, Materials Science, Medicinal Chemistry, OilHANDBOOK for Undergraduate CHEMISTRY MAJORS DEPARTMENT OF CHEMISTRY Fall 2010 #12;#12;TABLE OF CONTENTS A Career in Chemistry - What It Means ___________________________________________ 4 What do

  5. DCTD — Major Initiatives

    Cancer.gov

    Skip to Content Click here to view the Site Map Home | Sitemap | Contact DCTD Search this site Major Initiatives Search Grants Search Clinical Trials Ongoing Projects NCI Grants Policies Grant Application and Review Process DCTD Programs Cancer Diagnosis

  6. CTEP — Major Initiatives

    Cancer.gov

    Skip to Content Home | Investigator Resources | Protocol Development | Initiatives/Programs/Collaborations | Links to More Resources | Funding Opportunities | About CTEP Home | Sitemap | Contact CTEP Search this site Major Initiatives CTEP Home CTEP

  7. Diesel oil volatilization processes affected by selected porous media.

    PubMed

    Ma, Yanfei; Zheng, Xilai; Anderson, S H; Lu, Jie; Feng, Xuedong

    2014-03-01

    Volatilization plays an important role in attenuating petroleum products in contaminated soils. The objective of this study was to evaluate the influence of wind speed, vessel diameter and mean grain size of porous media on diesel oil volatilization. Experiments were conducted to investigate the volatilization behavior of diesel oil from porous media by weighing contaminated samples pre- and post-volatilization. Three selected field porous media materials were evaluated: Silty Clay Loam, Fine Sand, and Coarse Sand along with six individual sand fractions of the Coarse Sand. Results indicate that increasing wind speed accelerates the diesel oil volatilization process, especially for wind speeds below 2.10ms(-1). The low-carbon components of diesel oil volatilize more rapidly, with the effects of wind speed more pronounced on C10 to C15 volatilization than on C16 and higher. The volatilization rate coefficient of diesel oil increases with decreasing mean grain size of porous media, and with increasing vessel diameter. A power function expressed the relationship with mean grain size. All processes (wind speed, vessel diameter, and mean grain size) were included in an equation which explained over 92% of the measured diesel oil volatilization rate coefficient variations for the experiments. Diesel oil volatilization appears to be boundary-layer regulated to some extent. PMID:24296030

  8. Volatile characterisations of Eyjafjallajokull volcano (Iceland): from the magmatic source at depth to the surface

    NASA Astrophysics Data System (ADS)

    Moune, S.; Sigmarsson, O.; Thordarson, T.

    2010-12-01

    Studies of volatiles in melt inclusions (MIs) can put constraints on the magma source, transport and storage as well as magma degassing processes. Here, we present new measurements and estimates of pre-eruptive volatile concentrations and their ratios in the parental magma of the Eyjafjallajökull volcano in Iceland. The first phase of its 2010 eruption started the 20 March along approximately 500 meters long fissure. It was characterized by 50-100 m-high lava fountains, effusion of fountain-fed lava. This flank eruption of relatively primitive basalt with a slightly alkali character presents a rare opportunity to assess the volatile composition of its mantle source as well as constraint on volatile behaviour during basalt differentiation and, finally, estimation of the volatile fluxes during eruption. For this purpose, tephra samples were collected March 25, a few hours after their eruption. Volatile (S, Cl, F) and major element concentrations were measured in MIs trapped in olivine (Fo73-87) and plagioclase (An69-70) phenocrysts. Same elements were also measured in the groundmass glass of the tephra. Significant range of composition was observed in the MIs with the most evolved MIs having up to 0.19wt%S, 0.24wt%Cl and 0.08wt%F. Several MIs are of relatively primitive composition with MgO contents up to 8.4wt% (in olivine Fo87). Their S/Cl range from 0.8 to 5 and they reveal the nature of the heterogeneity of the mantle plume beneath Iceland. The S/F and Cl/F range from 1.26 to 3.86 and 0.25 to 3.44, respectively. These values can be taken as preliminary estimates for the volatile concentrations and proportions in the Icelandic mantle plume. The measured compositional range of MIs (K2O ranging from 0.35 to 1.18 wt%) is readily explained by fractional crystallisation, and incompatible behaviour of the volatile elements. However, significantly higher Cl concentrations (and corresponding higher Cl/K) are found in MIs having the most evolved major element composition. These abnormally high volatile concentrations are most likely related to a late input of Cl-rich gas from deeper basaltic magma. Finally, the difference between volatile concentrations in MIs and those measured in the groundmass indicate 77% and 68% degassing of S and Cl, respectively. Scaled to the estimation of the volcanic gas flux emitted the 25th March (~10t/s; Icelandic Meteorological office and Institute of Earth Sciences’ report), this early phase of the flank eruption emitted 2600 tonnes of SO2 and 1600t of HCl per day, with a ratio of SO2/HCl of around 2. Errors on F measurements are too large to for it to be included in this estimate. These results will be discussed and compared with remote sensing results.

  9. Herbivore-induced Blueberry Volatiles and Intra-plant Signaling

    PubMed Central

    Rodriguez-Saona, Cesar R.

    2011-01-01

    Herbivore-induced plant volatiles (HIPVs) are commonly emitted from plants after herbivore attack1,2. These HIPVs are mainly regulated by the defensive plant hormone jasmonic acid (JA) and its volatile derivative methyl jasmonate (MeJA)3,4,5. Over the past 3 decades researchers have documented that HIPVs can repel or attract herbivores, attract the natural enemies of herbivores, and in some cases they can induce or prime plant defenses prior to herbivore attack. In a recent paper6, I reported that feeding by gypsy moth caterpillars, exogenous MeJA application, and mechanical damage induce the emissions of volatiles from blueberry plants, albeit differently. In addition, blueberry branches respond to HIPVs emitted from neighboring branches of the same plant by increasing the levels of JA and resistance to herbivores (i.e., direct plant defenses), and by priming volatile emissions (i.e., indirect plant defenses). Similar findings have been reported recently for sagebrush7, poplar8, and lima beans9.. Here, I describe a push-pull method for collecting blueberry volatiles induced by herbivore (gypsy moth) feeding, exogenous MeJA application, and mechanical damage. The volatile collection unit consists of a 4 L volatile collection chamber, a 2-piece guillotine, an air delivery system that purifies incoming air, and a vacuum system connected to a trap filled with Super-Q adsorbent to collect volatiles5,6,10. Volatiles collected in Super-Q traps are eluted with dichloromethane and then separated and quantified using Gas Chromatography (GC). This volatile collection method was used n my study6 to investigate the volatile response of undamaged branches to exposure to volatiles from herbivore-damaged branches within blueberry plants. These methods are described here. Briefly, undamaged blueberry branches are exposed to HIPVs from neighboring branches within the same plant. Using the same techniques described above, volatiles emitted from branches after exposure to HIPVs are collected and analyzed. PMID:22214939

  10. Choosing a Major

    NSDL National Science Digital Library

    Joslyn Heiniger

    2009-09-27

    By completing this tutorial, you should be able to: Find resources to help you find the correct business major for you. Access your business major options. Congratulations on choosing Utah State University and the Jon M. Huntsman School of Business as your educational partner. Now that you have been admitted to USU, you may have a few questions about where to go from here. Below you will find many resources that will help you ...

  11. The Accounting Major

    NSDL National Science Digital Library

    Joslyn Heiniger

    2009-12-04

    By completing this tutorial, you should be able to: Find resources to aid in your research of the Accounting Major. Identify key aspects of an accounting career. Congratulations on choosing Utah State University and the Jon M. Huntsman School of Business as your educational partner. Now that you have been admitted to USU and selected accounting as your Huntsman major, you may have a few questions about where to go from here. Below you will ...

  12. Regolith Volatile Characterization (RVC) in RESOLVE

    NASA Technical Reports Server (NTRS)

    Captain, Janine; Lueck, Dale; Gibson, Tracy; Levine, Lanfang

    2010-01-01

    Resource investigation in the lunar poles is of importance to the potential impact of in-situ resource utilization (ISRU). The RESOLVE project developed a payload to investigate the permanently shadowed areas of the lunar poles and demonstrate ISRU technology. As a part of the RESOLVE project, the regolith volatile characterization (RVC) subsystem was designed to examine the release of volatiles from sample cores. The test sample was heated in the reactor to release the volatiles where they were analyzed with gas chromatography. Subsequently, the volatile sample was introduced into the lunar water resource demonstration (LWRD) subsystem where the released hydrogen and water were selectively captured. The objective of the Regolith Volatile Characterization (RVC) subsystem was to heat the crushed core sample and determine the desorption of volatile species of interest. The RVC subsystem encompasses the reactor and the system for volatile analysis. The system was designed to analyze H2, He, CO, CO2, N2, 02, CH4, H2S and H2O. The GC chosen for this work is a Siemens MicroSAM process GC with 3 columns and 8 TCD detectors. Neon was chosen as the carrier gas to enhance the analysis of hydrogen and helium.The limit of detection for the gases is approx.1000ppm for H2, CO. CO2 , N2, O2 and H2 S. The limit of detection for CH4 is approx.4000ppm and the water limit of detection is -10000 ppm with a sample analysis time of 2-3 minutes. These values (with the exception of water and H2S) were determined by dilution of a six gas mixture from Scott Gas (5% CO2, CO, O2, N2, 4% CH4 and H2) using mass flow controllers (MFC5). Water was calibrated at low levels using an in house relative humidity (RH) generator. H 2S and high concentrations of H2 were calibrated by diluting a pure stream of gas with MFCs. Higher concentrations of N2 and 02 were calibrated using Air again diluting with MFCs. There were three modification goals for the GC in EBU2 that would allow this process GC to be used in the field demo for RESOLVE. The first modification was to decrease the weight associated with the GC, this included eliminating the explosion proof case (Figure 1) and replacing it with a lightweight case as well as using an on board COPV tank for the neon carrier gas. The next goal was to add a second oven for the molecular sieve column to allow for dual temperature control during GC operation; the separation of hydrogen and helium is optimum at lower temperatures while the water analysis required higher temperatures creating a competing design requirement. The second oven also allows a lower limit of detection for water quantification and avoids the possibility of water condensing in the GC which could ruin the column characteristics. The final goal was to modify the column arrangement to optimize the system for our specific application. Figure 2 shows the internal details of the module optimized optimized for our field application. The modifications and performance of the gas analysis system will be discussed in detail.

  13. Ditiocarb: decomposition in aqueous solution and effect of the volatile product on its pharmacological use.

    PubMed

    Martens, T; Langevin-Bermond, D; Fleury, M B

    1993-04-01

    The kinetic profile for the decomposition of ditiocarb sodium salt in aqueous solution was achieved with UV-visible absorption spectrometry. The kinetic profile indicates that the decomposition reaction is hydrogen ion-catalyzed over the entire 4-10 pH range and enables the determination of the value of the acid-base equilibrium constant (Ka = 4.0.10(-4) at 5 degrees C). Decomposition of ditiocarb produces volatile carbon disulfide, exclusive of hydrogen sulfide, as shown with electrochemical methods. This feature is of interest from a toxicological point of view. PMID:8385710

  14. ANALYTICAL STUDIES ON ION PROPULSION

    Microsoft Academic Search

    Boden

    1960-01-01

    Analyses of major problems associated with components of the ion rocket ; engine system were made. Component studies included electrical power generation ; systems, thermal power conversion, and accelerating electrode configurations. ; Analyses of ion beam dynamics, propellant mate rials, radiation damage to working ; fluid for a nuclear power plant, and missions using low-thrust vehicles are ; presented. Interpretation

  15. Characterisation of volatiles in dried white varieties figs (Ficus carica L.).

    PubMed

    Muji?, Ibrahim; Bavcon Kralj, Mojca; Joki?, Stela; Jug, Tjaša; Subari?, Drago; Vidovi?, Senka; Zivkovi?, Jelena; Jarni, Kristjan

    2014-09-01

    The aromatic profile of volatiles in dried figs varieties Bružetka Bijela and Zimnica were characterised by headspace solid-phase (HS-SPME) procedure with gas chromatography-mass spectrometry analysis (GC-MS). The volatile compounds were distributed by distinct chemical classes, including alcohols, aldehydes, esters, terpenic compounds, and other compounds. The figs were dried in a pilot plant cabinet dryer. Prior to drying process, figs were pre-treated by sulphur dioxide, immersed in solution of citric acid and ascorbic acid, respectively. Several mathematical thin-layer drying models, available in the literature, were fitted to experimental data of figs, implementing non-linear regression analysis techniques. The results showed that pre-treatments of figs decrease significantly the drying time. The best thin-layer drying model in terms of fitting performance was Wang and Singh model. The major volatile compound in dried figs was benzaldehyde. After benzaldehyde, the most abundant aldehyde in dried figs was hexanal. The comparison among dried figs showed the highest abundance of aldehydes, in general, in non-treated (control) dried figs compared to pre-treated samples. Furthermore, ascorbic acid was the most efficient in preserving esters and alcohols in case of Bružetka Bijela, whereas in case of Zimnica, sulphur dioxide was in advance compared to ascorbic acid. Ethyl acetate was the most abundant ester found in dried figs. Among other compounds, 2-butanone,3-hydroxy was the most abundant identified volatiles. Linalool, as the only identified terpen, was in case of both dried fig varieties, preserved by immersion into ascorbic acid. The immersion into citric acid has not been so successful in volatiles conservation. PMID:25190838

  16. Groundwater contamination by volatile halogenated alkanes: abiotic formation of volatile sulfur compounds under anaerobic conditions

    SciTech Connect

    Schwarzenbach, R.P.; Giger, W.; Schaffner, C.; Wanner, O.

    1985-01-01

    The investigation of a groundwater contamination caused by a leaking wastewater tank of a chemical plant revealed that in groundwaters, under highly reducing conditions in the presence of hydrogen sulfide, certain volatile bromo- and chloroalkanes may undergo second-order nucleophilic substitution reactions yielding very persistent and hazardous volatile sulfur-containing compounds including dialkyl sulfides. Rate constants determined in the laboratory indicate that these nucleophilic substitution reactions may compete with hydrolysis, even at the low hydrogen sulfide concentrations typically encountered in the aquatic environment.

  17. Volatiles in the Earth: All shallow and all recycled

    NASA Technical Reports Server (NTRS)

    Anderson, Don L.

    1994-01-01

    A case can be made that accretion of the Earth was a high-temperature process and that the primordial Earth was dry. A radial zone-refining process during accretion may have excluded low-melting point and volatile material, including large-ion lithophile elements toward the surface, leaving a refractory and zoned interior. Water, sediments and altered hydrous oceanic crust are introduced back into the interior by subduction, a process that may be more efficient today than in the past. Seismic tomography strongly suggests that a large part of the uppermantle is above the solidus, and this implies wet melting. The mantle beneath Archean cratons has very fast seismic velocities and appears to be strong to 150 km or greater. This is consistent with very dry mantle. It is argued that recycling of substantial quantities of water occurs in the shallow mantle but only minor amounts recycle to depths greater than 200 km. Recycling also oxidizes that mantle; ocean island ('hotspot') basalts are intermediate in oxidation state to island-arc and midocean ridge basalts (MORB). This suggests a deep uncontaminated reservoir for MORB. Plate tectonics on a dry Earth is discussed in order to focus attention on inconsistencies in current geochemical models of terrestrial evolution and recycling.

  18. Tungsten migration studies by controlled injection of volatile compounds

    NASA Astrophysics Data System (ADS)

    Rubel, M.; Coenen, J.; Ivanova, D.; Möller, S.; Petersson, P.; Brezinsek, S.; Kreter, A.; Philipps, V.; Pospieszczyk, A.; Schweer, B.

    2013-07-01

    Volatile tungsten hexa-fluoride was locally injected into the TEXTOR tokamak as a marker for material migration studies. The injection was accompanied by puffing N-15 rare isotope as a nitrogen tracer in discharges with edge cooling by impurity seeding. The objective was to assess material balance by qualitative and quantitative determination of a global and local deposition pattern, material mixing effects and fluorine residence in plasma-facing components. Spectroscopy and ex situ ion beam analysis techniques were used. Tungsten was detected on all types of limiter tiles and short-term probes retrieved from the vessel. Over 80% of the injected W was identified. The largest tungsten concentration, 1 × 1018 cm-2, was in the vicinity of the gas inlet. Co-deposits contained tungsten and a mix of light isotopes: H, D, He-4, B-10, B-11, C-12, C-13, N-14, N-15, O-16 and small quantities of F-19 thus showing that both He and nitrogen are trapped following wall conditioning (He glow) and edge cooling.

  19. Volcanic resurfacing rates and implications for volatiles on Io

    NASA Technical Reports Server (NTRS)

    Johnson, T. V.; Cook, A. F., II; Sagan, C.; Soderblom, L. A.

    1979-01-01

    The rates of volcanic resurfacing on Io are estimated on the basis of two separate observations and the implications of these rates for the volatile history of Io and the supply of material to the Jovian torus are discussed. Rates of resurfacing based on the lack of observable impact craters and assuming a Jovian cratering rate similar to those of the moon and Mars are found to be on the order of 0.1 cm/year. Estimated deposition rates of volcanic matter are found to be in general agreement with cratering rate determinations, if large particle deposition, undetected volcanic activity, volcanic flows and gas condensation are taken into account. Escape rates from Io estimated for sulfur, oxygen and sodium, based on their concentrations around Io, indicate that only a fraction of the present volcanic material can escape. Thermal and nonthermal escape mechanisms are suggested to account for the current loss of sulfur and oxygen from Io's upper atmosphere, while sputtering of atoms from the surface by impacting magnetospheric ions is suggested as the mechanism of sodium supply.

  20. Major issues and outstanding questions. [of planet Mars

    NASA Technical Reports Server (NTRS)

    Pepin, Robert O.; Carr, Michael H.

    1992-01-01

    The physical, chemical, geologic, and biological issues underlying current efforts to understand Mars are introduced and summarized. Attention is given not only to the present status and past history of Mars, and also to Mars as one member of the class of terrestrial planets and as one product of the evolution from the primordial accretion disk. The issue of the origin and evolution of Mars' inventory of volatile elements is treated in detail, as are the SNC meteorites, both for what these putative Martian samples indicate about volatile distributions and because of their profound impact on assessments on bulk chemical composition and the chronology of planetary differentiation and late-stage volcanism. Overviews of the major problems arising from multidisciplinary investigations of the planet are also presented.

  1. Volatile budget of the 2011 Cordon Caulle eruption (Chile) from various and integrated approaches

    NASA Astrophysics Data System (ADS)

    moune, S.; Carn, S. A.; Cluzel, N.; Aguilera, F.

    2013-12-01

    Estimates of volatile budgets for volcanic eruptions are often based on volatile concentrations measured in melt inclusions (MIs) versus groundmass glass and on measurements made by direct sampling and remote sensing techniques. Here, we present new measurements and estimates of volatile budget of the 2011 Cordon Caulle eruption in Chile. The eruption from the Cordón Caulle rift zone, part of the basaltic-to-rhyolitic Puyehue-Cordón Caulle volcanic complex, began on 4 June 2011. The first phase of the eruption was characterized by seismic events and an explosion from Cordón Caulle that produced a 5-km-wide ash-and-gas plume that rose to an altitude of 12.2 km a.s.l. We are using three different approaches to assess the volatile budget and to assess how the volatile content of the magma controls the explosivity of such an eruption. 1- Pumice samples were collected on June 18th, a few hours after their eruption. Volatile (S, Cl, F) and major element concentrations were measured in MIs trapped in plagioclase (An54-56) and pyroxene (Mg#39-44) phenocrysts. The same elements were also measured in the groundmass of the tephra. Homogeneous dacitic to ryolitic compositions were observed in the MIs with maximum concentrations up to 160ppm S, 2600ppm Cl and 800ppm F. Even if most of the MIs seem to have trapped a melt partially or totally degassed, the difference between the maximum volatile concentrations in the MIs and those measured in the groundmass indicates that ~0.2Mt SO2, 0.5Mt HCl and 0.3Mt HF were released into the atmosphere during the Cordon Caulle eruption. 2- Satellite remote sensing data from instruments in NASA's A-Train spacecraft constellation, including the Ozone Monitoring Instrument (OMI) on Aura and the Atmospheric Infrared Sounder (AIRS) on Aqua, indicate a total SO2 emission of ~0.2 Mt from the initial explosive phase of the 2011 Cordon Caulle eruption. The Microwave Limb Sounder (MLS) also detected HCl in the volcanic plume, providing some constraints on the SO2/HCl ratio. 3- These two previous preliminary results will be discussed and compared with ash-leachate analyses. Leachates from pristine ash collected on June 21st will also provide a plume-gas proxy.

  2. Model ion abundances for comet Halley

    SciTech Connect

    Huebner, W.F.; Boice, D.C.; Keady, J.J.; Schmidt, H.U.; Wegman, R.

    1986-10-27

    A computer model for comet comae has been applied to predict ion abundances for comet Halley. It is assumed that the volatile component of the nucleus is 85% water and that the remaining volatile molecules are composed of carbon, nitrogen, oxygen, and sulfur. Model parameters such as heliocentric distance, size, and albedo are chosen to be consistent with the 13-14 March 1986 encounter of the Giotto spacecraft with the comet. Photoprocesses, gas-phase chemical kinetics, coma energy balance including a separate electron temperature, multifluid hydrodynamics with a transition to free molecular flow, fast streaming atomic and molecular hydrogen, and counter and cross streaming of species in the coma-solar wind interaction are taken into consideration. A comparison of the model results is made with preliminary data from the ion mass spectrometer at 6000 and 1500 km from the nucleus. We find good overall agreement. The implications of the coma physics and chemistry are discussed. 2 tabs.

  3. Model ion abundances for Comet Halley

    NASA Technical Reports Server (NTRS)

    Huebner, W. F.; Boice, D. C.; Keady, J. J.; Schmidt, H. U.; Wegman, R.

    1986-01-01

    A computer model for comet comae was applied to predict ion abundances for comet Halley, assuming that the volatile component of the nucleus is 85% water and that the remaining volatile molecules are composed of carbon, nitrogen, oxygen, and sulfur. Model parameters such as heliocentric distance, size, and albedo are chosen to be consistent with the 13 to 14 March 1986 encounter of Giotto with the comet. Photoprocesses, gas-phase chemical kinetics, coma energy balance including a separate electron temperature, multifluid hydrodynamics with a transition to free molecular flow, fast streaming atomic and molecular hydrogen, and counter and cross streaming of species in the coma-solar wind interaction are taken into consideration. A comparison of the model results with data from the ion mass spectrometer at 6000 and 1500 km from the nucleus shows good agreement. Implications of the coma physics and chemistry are discussed.

  4. Variation of volatile compounds among wheat varieties and landraces.

    PubMed

    Starr, G; Petersen, M A; Jespersen, B M; Hansen, Å S

    2015-05-01

    Analysis of volatile compounds was performed on 81 wheat varieties and landraces, grown under controlled greenhouse conditions, in order to investigate the possibility of differentiating wheat varieties according to their volatile compound profiles. Volatile compounds from wheat samples were extracted by dynamic headspace extraction and analysed by gas chromatography-mass spectrometry. Seventy-two volatile compounds were identified in the wheat samples. Multivariate analysis of the data showed a large diversity in volatile profiles between samples. Differences occurred between samples from Austria compared to British, French and Danish varieties. Landraces were distinguishable from modern varieties and they were characterised by higher averaged peak areas for esters, alcohols, and some furans. Modern varieties were characterised by higher averaged peak areas for terpenes, pyrazines and straight-chained aldehydes. Differences in volatile profiles are demonstrated between wheat samples for the first time, based on variety. These results are significant to plant breeders and commercial users of wheat. PMID:25529715

  5. Volatile organic carbon/air separation test using gas membranes

    SciTech Connect

    King, C.V.; Kaschemekat, J.

    1993-08-01

    An estimated 900 metric tons of carbon tetrachloride were discharged to soil columns during the Plutonium Finishing Plant Operations at the Hanford Site. The largest percentage of this volatile organic compound was found in the vadose region of the 200 West Area. Using a Vacuum Extraction System, the volatile organic compound was drawn from the soil in an air mixture at a concentration of about 1,000 parts per million. The volatile organic compounds were absorbed from the air stream using granulated activated carbon canisters. A gas membrane separation system, developed by Membrane Technology and Research, Inc., was tested at the Vacuum Extraction System site to determine if the volatile organic compound load on the granulated activated carbon could be reduced. The Vacuum Extraction System condensed most of the volatile organic compound into liquid carbon tetrachloride and vented the residual gas stream into the granulated activated carbon. This system reduced the cost of operation about $5/kilogram of volatile organic compound removed.

  6. Analysis of Neutral Volatiles in Cheddar Cheese1

    Microsoft Academic Search

    W. A. McGugan; S. G. Howsam

    1962-01-01

    SUMMARY A method of producing highly resolved gas-liquid ehromatograms of neutral cheese volatiles is described. The volatiles are vacuum-distilled from fat obtained from cheese by high-speed centrifugation. Vapor samples taken from the dis- tillate traps are chromatographed on capilla~, columns. Relative retention times of the cheese volatiles with respect to known compounds are plotted from chromatograms obtained under three sets

  7. VOLATILE COMPONENTS IN DEFENSIVE SPRAY OF THE HOODED SKUNK, Mephitis macroura

    E-print Network

    William F. Wood; Brian G. Sollers; Gwen A. Dragoo; Jerry W. Dragoo

    2002-01-01

    Abstract—GC-MS analysis of the anal sac secretion from the hooded skunk, Mephitis macroura, showed the following seven major components comprised 99 % of the volatiles in this secretion: (E)-2-butene-1-thiol, 3-methyl-1-butanethiol, S-(E)-2-butenyl thioacetate, S-3-methylbutenyl thioacetate, 2-phenylethanethiol, 2-methylquinoline, and 2-quinolinemethanethiol. Minor volatile components identified in this secretion are phenylmethanethiol, S-phenylmethyl thioacetate, S-2-phenylethyl thioacetate, bis[(E)-2-butenyl] disulfide, (E)-2-butenyl 3-methylbutyl disulfide, bis(3-methylbutyl) disulfide, and S-2-quinolinemethyl thioacetate. This secretion is similar to that of the striped skunk, Mephitis mephitis, differing only in that it contains four compounds not reported from the striped skunk: phenylmethanethiol, S-phenylmethyl thioacetate, 2-phenylethanethiol, and S-2-phenylethyl thioacetate. Key Words—Mephitidae, Mephitis macroura, hooded skunk, anal sac secretion, (E)-2-butene-1-thiol, 3-methyl-1-butanethiol, S-(E)-2-butenyl thioacetate,

  8. Formation of volatile organics in the reaction of solid stearic acid with gas-phase OH

    NASA Astrophysics Data System (ADS)

    Vlasenko, A.; Abbatt, J.

    2006-12-01

    While in the atmosphere organic particles are continuously exposed to atmospheric oxidants and could undergo chemical transformations. As a result of oxidation initially long carbon chains could be broken forming smaller, more volatile molecules that could eventually leave the condensed aerosol phase. In this work this process is studied using stearic acid as a proxy for organic aerosol matter and OH radicals as the oxidant. The experiments are conducted using a coated-wall, flow-tube reactor coupled to both chemical ionization and a proton transfer mass spectrometers (for detection of OH and VOCs, respectively). The results indicate a rapid reaction of OH with stearic acid which is in agreement with previous studies. The majority of volatile products are identified as aldehydes and aldehydic acids. The quantitative product yield depends on concentrations of oxygen and nitrogen dioxide in the flow, which could be linked to the reaction mechanism.

  9. Application of horizontal spiral coil heat exchanger for volatile organic compounds (VOC) emission control.

    PubMed

    Deshpande, P M; Dawande, S D

    2013-04-01

    The petroleum products have wide range of volatility and are required to be stored in bulk. The evaporation losses are significant and it is a economic as well as environmental concern, since evaporative losses of petroleum products cause increased VOC in ambient air. Control of these losses poses a major problem for the storage tank designers. Ever rising cost of petroleum products further adds to the gravity of the problem. Condensation is one of the technologies for reducing volatile organic compounds emissions. Condensation is effected by condenser, which is basically a heat exchanger and the heat exchanger configuration plays an important role. The horizontal spiral coil heat exchanger is a promising configuration that finds an application in VOC control. This paper attempts to understand underlying causes of emissions and analyse the option of horizontal spiral coil heat exchanger as vent condenser. PMID:25464701

  10. Application of horizontal spiral coil heat exchanger for volatile organic compounds (VOC) emission control.

    PubMed

    Deshpande, P M; Dawande, S D

    2013-04-01

    The petroleum products have wide range of volatility and are required to be stored in bulk. The evaporation losses are significant and it is a economic as well as environmental concern, since evaporative losses of petroleum products cause increased VOC in ambient air. Control of these losses poses a major problem for the storage tank designers. Ever rising cost of petroleum products further adds to the gravity of the problem. Condensation is one of the technologies for reducing volatile organic compounds emissions. Condensation is effected by condenser, which is basically a heat exchanger and the heat exchanger configuration plays an important role. The horizontal spiral coil heat exchanger is a promising configuration that finds an application in VOC control. This paper attempts to understand underlying causes of emissions and analyse the option of horizontal spiral coil heat exchanger as vent condenser. PMID:25508332

  11. Extraction and GC determination of volatile aroma compounds from extracts of three plant species of the Apiaceae family

    NASA Astrophysics Data System (ADS)

    Stan, M.; Soran, M. L.; Varodi, C.; Lung, I.; Copolovici, L.; M?ruţoiu, C.

    2013-11-01

    Parsley (Petroselinum crispum), dill (Anethum graveolens) and celery (Apium graveolens), three aromatic plants belonging to the Apiaceae (Umbelliferae) botanical family, were selected as sources of essential or volatile oils. Essential oils are composed of a large diversity of volatile aroma compounds. Plant-derived essential oils and extracts have long been used as natural agents in food preservation, pharmaceuticals and medicinal therapies. In the present study, the plant extracts from leaves of parsley, dill and celery, were obtained by maceration, ultrasound-assisted extraction and microwave-assisted extraction. All extractions were performed at 30°C, using different solvents (ethanol, diethyl ether, n-hexane) and solvent mixtures (1:1, v/v). The most effective solvent system for the extraction of volatile aroma compounds was diethyl ether - n-hexane (1:1, v/v). Extraction efficiency and determination of aroma volatiles were performed by GC-FID and GC-MS, respectively. The major volatile compounds present in plant extracts were myristicin, ?-phellandrene, ?-phellandrene, 1,3,8-p-menthatriene, apiol, dill ether and allyl phenoxyacetate.

  12. Ammonia Volatilization from Urea-Application Influenced Germination and Early Seedling Growth of Dry Direct-Seeded Rice

    PubMed Central

    Qi, Xiaoli; Wu, Wei; Shah, Farooq; Peng, Shaobing; Huang, Jianliang; Cui, Kehui; Liu, Hongyan; Nie, Lixiao

    2012-01-01

    Poor seed germination and early seedling growth associated with urea-induced soil ammonia volatilization are major constraints in the adoption of dry direct-seeded rice. To directly examine soil ammonia volatilization and its damage to seed germination and early seedling growth of dry direct-seeded rice when urea is applied at seeding, two Petri-dish incubation experiments and a field experiment were conducted. Ammonia volatilization due to urea application significantly reduced seed germination and early seedling growth of dry direct-seedling rice. NBPT significantly reduced ammonia volatilization following urea application. The application of ammonium sulfate, instead of urea at seeding, may mitigate poor crop establishment of dry direct-seeded rice. Root growth of dry direct-seeded rice was more seriously inhibited by soil ammonia volatilization than that of shoot. Results suggest that roots are more sensitive to soil ammonia toxicity than shoots in dry direct-seeded rice system when N is applied as urea at seeding. PMID:22454611

  13. Determination of Volatile Compounds in Four Commercial Samples of Japanese Green Algae Using Solid Phase Microextraction Gas Chromatography Mass Spectrometry

    PubMed Central

    Yoshikawa, Keisuke; Fujita, Akira; Mase, Nobuyuki; Watanabe, Naoharu

    2014-01-01

    Green algae are of great economic importance. Seaweed is consumed fresh or as seasoning in Japan. The commercial value is determined by quality, color, and flavor and is also strongly influenced by the production area. Our research, based on solid phase microextraction gas chromatography mass spectrometry (SPME-GC-MS), has revealed that volatile compounds differ intensely in the four varieties of commercial green algae. Accordingly, 41 major volatile compounds were identified. Heptadecene was the most abundant compound from Okayama (Ulva prolifera), Tokushima (Ulva prolifera), and Ehime prefecture (Ulva linza). Apocarotenoids, such as ionones, and their derivatives were prominent volatiles in algae from Okayama (Ulva prolifera) and Tokushima prefecture (Ulva prolifera). Volatile, short chained apocarotenoids are among the most potent flavor components and contribute to the flavor of fresh, processed algae, and algae-based products. Benzaldehyde was predominant in seaweed from Shizuoka prefecture (Monostroma nitidum). Multivariant statistical analysis (PCA) enabled simple discrimination of the samples based on their volatile profiles. This work shows the potential of SPME-GC-MS coupled with multivariant analysis to discriminate between samples of different geographical and botanical origins and form the basis for development of authentication methods of green algae products, including seasonings. PMID:24592162

  14. Volatilization of trifluralin, atrazine, metolachlor, chlorpyrifos, alpha-endosulfan, and beta-endosulfan from freshly tilled soil.

    PubMed

    Rice, Clifford P; Nochetto, Cristina B; Zara, Pedro

    2002-07-01

    The volatile and soil loss profiles of six agricultural pesticides were measured for 20 days following treatment to freshly tilled soil at the Beltsville Agricultural Research Center. The volatile fluxes were determined using the Theoretical Profile Shape (TPS) method. Polyurethane foam plugs were used to collect the gas-phase levels of the pesticides at the TPS-defined critical height above a treated field. Surface-soil (0-8 cm) samples were collected on each day of air sampling. The order of the volatile flux losses was trifluralin > alpha-endosulfan > chlorpyrifos > metolachlor > atrazine > beta-endosulfan. The magnitude of the losses ranged from 14.1% of nominal applied amounts of trifluralin to 2.5% of beta-endosulfan. The daily loss profiles were typical of those observed by others for volatile flux of pesticides from moist soil. Even though heavy rains occurred from the first to third day after treatment, the majority of the losses took place within 4 days of treatment, that is, 59% of the total applied atrazine and metolachlor and >78% of the other pesticides. Soil losses generally followed pseudo-first-order kinetics; however, leaching due to heavy rainfall caused significant errors in these results. The portion of soil losses that were accounted for by the volatile fluxes was ordered as follows: alpha-endosulfan, 34.5%; trifluralin, 26.5%; chlorpyrifos, 23.3%; beta-endosulfan, 14.5%; metolachlor, 12.4%; and atrazine, 7.5%. PMID:12083875

  15. Trans-iron composition and volatility

    NASA Astrophysics Data System (ADS)

    Israel, Martin H.

    2013-02-01

    Recent results from the TIGER balloon instrument, combining results of two flights for a total of 50 days[1] and results from almost 14 years of data of the CRIS instrument on the ACE spacecraft [2] give individual-element abundances extending up to Sr (Z=38). When the source abundances of the trans-iron elements are compared with solar-system abundances [3], the factor of ~ 4 differences between volatile and refractory elements previously noted with elements of lower Z disappears. However when the cosmic-ray source is compared with a mixture of ~80% solar-system composition [3] and ~20% outflow and ejecta of massive stars [4], a neat ordering that depends on the volatile/refractory distinction clearly emerges, extending from the lighter elements through these elements with Z >= 38. This 80%/20% mixture is consistent with cosmic-ray acceleration in OB associations, as was indicated by the isotopic composition of the cosmic rays [5]. Refractory elements, those likely to be found in interstellar grains, are enhanced by a factor of ~4 relative to volatile elements, and the efficiency of acceleration appears to increase with increasing atomic number; both of these facts provide important constraints on any detailed model of cosmic-ray acceleration. The next step in extending and improving the trans-iron composition will be balloon flights of Super-TIGER, an instrument similar to TIGER but with four times the area [6]. The first flight of Super-TIGER, over Antarctica, is scheduled for launch in December 2012.

  16. GADOLINIUM SOLUBILITY AND VOLATILITY DURING DWPF PROCESSING

    SciTech Connect

    Reboul, S

    2008-01-30

    Understanding of gadolinium behavior, as it relates to potential neutron poisoning applications at the DWPF, has increased over the past several years as process specific data have been generated. Of primary importance are phenomena related to gadolinium solubility and volatility, which introduce the potential for gadolinium to be separated from fissile materials during Chemical Process Cell (CPC) and Melter operations. Existing data indicate that gadolinium solubilities under moderately low pH conditions can vary over several orders of magnitude, depending on the quantities of other constituents that are present. With respect to sludge batching processes, the gadolinium solubility appears to be highly affected by iron. In cases where the mass ratio of Fe:Gd is 300 or more, the gadolinium solubility has been observed to be low, one milligram per liter or less. In contrast, when the ratio of Fe:Gd is 20 or less, the gadolinium solubility has been found to be relatively high, several thousands of milligrams per liter. For gadolinium to serve as an effective neutron poison in CPC operations, the solubility needs to be limited to approximately 100 mg/L. Unfortunately, the Fe:Gd ratio that corresponds to this solubility limit has not been identified. Existing data suggest gadolinium and plutonium are not volatile during melter operations. However, the data are subject to inherent uncertainties preventing definitive conclusions on this matter. In order to determine if gadolinium offers a practical means of poisoning waste in DWPF operations, generation of additional data is recommended. This includes: Gd solubility testing under conditions where the Fe:Gd ratio varies from 50 to 150; and Gd and Pu volatility studies tailored to quantifying high temperature partitioning. Additional tests focusing on crystal aging of Gd/Pu precipitates should be pursued if receipt of gadolinium-poisoned waste into the Tank Farm becomes routine.

  17. Ion exchange phenomena

    SciTech Connect

    Bourg, I.C.; Sposito, G.

    2011-05-01

    Ion exchange phenomena involve the population of readily exchangeable ions, the subset of adsorbed solutes that balance the intrinsic surface charge and can be readily replaced by major background electrolyte ions (Sposito, 2008). These phenomena have occupied a central place in soil chemistry research since Way (1850) first showed that potassium uptake by soils resulted in the release of an equal quantity of moles of charge of calcium and magnesium. Ion exchange phenomena are now routinely modeled in studies of soil formation (White et al., 2005), soil reclamation (Kopittke et al., 2006), soil fertilitization (Agbenin and Yakubu, 2006), colloidal dispersion/flocculation (Charlet and Tournassat, 2005), the mechanics of argillaceous media (Gajo and Loret, 2007), aquitard pore water chemistry (Tournassat et al., 2008), and groundwater (Timms and Hendry, 2007; McNab et al., 2009) and contaminant hydrology (Chatterjee et al., 2008; van Oploo et al., 2008; Serrano et al., 2009).

  18. Dynamics of implied volatility surfaces from random matrix theory

    NASA Astrophysics Data System (ADS)

    Kim, Min Jae; Lee, Sun Young; Hwang, Dong Il; Kim, Soo Yong; Ko, In Kyu

    2010-07-01

    We analyze the dynamics of the implied volatility surface of KOSPI 200 futures options from random matrix theory. To extract the informative data, we use random matrix criteria. Implied volatility data have a colossal eigenvalue, and the order of eigenvalues in a noisy regime is distinguishably smaller than a random matrix theory prediction. We discern the marketwide knowledge of the implied volatility surface movement such as the level, skew, and smile effect. These dynamics has the ergodic property and long range autocorrelation. We also study the relationship between the three implied volatility surface dynamics and the underlying asset dynamics, and confirm the existence of leverage effect even in the short time interval.

  19. Deciphering the language of plant communication: volatile chemotypes of sagebrush

    E-print Network

    Ramírez, Santiago

    , herbivory, heritability, signal. Summary Volatile communication between sagebrush (Artemisia tridentata or whether particular species use unique compounds or combinations as cues. Sagebrush (Artemisia tridentata

  20. Volatiles as a link between planetary interiors and the environment

    E-print Network

    Black, Benjamin A. (Benjamin Alexander)

    2013-01-01

    Volatiles derived from planetary interiors influence magma evolution and environmental processes. Over appropriate timescales, Earth's mantle, crust, ocean, and atmosphere constitute coupled systems. The apparently synchronous ...