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Sample records for chemical composition study

  1. Chemical composition studies of flint with different origins

    NASA Astrophysics Data System (ADS)

    Zarina, Liga; Seglins, Valdis; Kostjukovs, Juris; Burlakovs, Juris

    2015-04-01

    Flint is a widely used material in the Stone Age because of its physical characteristics, which makes the material suitable for obtaining tools with sharp working edges. Chert, flint, chalcedony, agate and jasper in composition and several other physical characteristics are very similar. Therefore in archaeology most often they are determined simplified and are not distinguished, but described as flint or chert, denoting only the material in a general sense. However, in-depth studies it is necessary accurately identify the rock type and, in addition, to determine the origin of the flint and the conditions of the formation for the various archaeological research needs. As a typical example can be noted the localization problems in determining whether flint is local, or have emerged in the region through the exchange or by transportation. Flint consists mainly from quartz and mostly it has cryptocrystalline or amorphous structure. In nature it occurs as nodules and interbedded inclusions in sedimentary deposits as a result of digenesis processes when calcium carbonate is replaced with silicia. Bedded chert primarily is accumulations originated from excess alkalinity in the sediments. Flint can also be formed in the crystallization processes of the chemically unstable amorphous silicia. In this context, it should be noted that flint is naturally heterogeneous and very varied material by the physical properties and therefore problematic in many contemporary studies. In the study different origin flint samples from England, Denmark and Latvia were compared after their chemical composition. Flint nodules from Northern Europe chalk cliffs formed as inclusions in interbedded deposits or results of the digenesis and samples of chalcedony saturated dolomite from Latvia formed in hydrothermal processes were analysed using XRD and XRF methods. The obtained data were statistically analysed, identifying major, minor and trace elements and subsequently assessing the chemical

  2. IR spectroscopic study of the chemical composition of epiphytic lichens

    NASA Astrophysics Data System (ADS)

    Meysurova, A. F.; Khizhnyak, S. D.; Pakhomov, P. M.

    2011-11-01

    Changes in the chemical composition of lichens exposed to pollutants are investigated by means of FTIR spectroscopy. According to model experiments, alkyl nitrates, ammonium salts, amines, and sulfones develop in the lichen thallus through the action of ammonia and nitric and sulfuric acids. Spectroscopic data of modeling experiments enabled nitrogen- and sulfur-containing substances to be identified as the main air pollutants in the vicinity of a pig-breeding complex and information to be obtained on the content of the pollutants and their impact on the lichens.

  3. Photovoltaic Study of Chemically Derived Titanium-Doped Polythiophene Composites

    NASA Astrophysics Data System (ADS)

    Takpire, S. R.; Waghuley, S. A.

    2015-08-01

    In the present work, titanium (Ti)-doped polythiophene (PTh) was synthesized by a chemical route using titanium chloride as oxidant. As-synthesized composites were further used for fabrication of photovoltaic (PV) cells with indium tin oxide/Ti-doped PTh/aluminum architecture. Structural, morphological, and optical analyses of as-synthesized composites were carried out through x-ray diffraction (XRD) analysis, Fourier-transform infrared (FTIR) spectroscopy, field-emission scanning electron microscopy (FE-SEM), ultraviolet-visible (UV-Vis) spectroscopy, and photoluminescence (PL) measurements. A broad peak was found in the PL spectra of the composites at around 480 nm, indicating high charge generation efficiency. Different PV parameters of the fabricated PV cells were measured at room temperature under incandescent light of 100 W/m2. The optimized PV cell exhibited short-circuit current ( I sc) and open-circuit voltage ( V oc) on the order of 176 μA and 0.595 V, respectively. The values of I sc and V oc were used to compute the fill factor, which was found to be 0.521. The corresponding power conversion efficiency associated with the optimized cell was found to be 2.41%.

  4. Study of Aerosol Chemical Composition Based on Aerosol Optical Properties

    NASA Astrophysics Data System (ADS)

    Berry, Austin; Aryal, Rudra

    2015-03-01

    We investigated the variation of aerosol absorption optical properties obtained from the CIMEL Sun-Photometer measurements over three years (2012-2014) at three AERONET sites GSFC; MD Science_Center and Tudor Hill, Bermuda. These sites were chosen based on the availability of data and locations that can receive different types of aerosols from land and ocean. These absorption properties, mainly the aerosol absorption angstrom exponent, were analyzed to examine the corresponding aerosol chemical composition. We observed that the retrieved absorption angstrom exponents over the two sites, GSFC and MD Science Center, are near 1 (the theoretical value for black carbon) and with low single scattering albedo values during summer seasons indicating presence of black carbon. Strong variability of aerosol absorption properties were observed over Tudor Hill and will be analyzed based on the air mass embedded from ocean side and land side. We will also present the seasonal variability of these properties based on long-range air mass sources at these three sites. Brent Holben, NASA GSFC, AERONET, Jon Rodriguez.

  5. Computing Equilibrium Chemical Compositions

    NASA Technical Reports Server (NTRS)

    Mcbride, Bonnie J.; Gordon, Sanford

    1995-01-01

    Chemical Equilibrium With Transport Properties, 1993 (CET93) computer program provides data on chemical-equilibrium compositions. Aids calculation of thermodynamic properties of chemical systems. Information essential in design and analysis of such equipment as compressors, turbines, nozzles, engines, shock tubes, heat exchangers, and chemical-processing equipment. CET93/PC is version of CET93 specifically designed to run within 640K memory limit of MS-DOS operating system. CET93/PC written in FORTRAN.

  6. Chemical composition and Biological studies of Ficus benjamina

    PubMed Central

    2014-01-01

    Background Current study has been designed to estimate the possible antioxidant, antimicrobial and hemolytic potential of Ficus benjamina different parts (leaves, stem and root). Results All examined extracts and fractions were significantly rich in antioxidants and exhibited potent antimicrobial activity. GC/MS analysis of essential oil identified four compounds in stem and eight compounds in root, respectively. HPLC analysis indicated four phenolic compounds (chlorogenic, p-coumaric, ferulic and syringic acids) in roots, three (chlorogenic p-coumaric and ferulic acids) in stem and only one (caffeic acid) in leaves. Extracts of all three parts of F. benjamina exhibited substantial hemolytic activity. Conclusions Considering these results, it is concluded that F. benjamina can be used as a potential source for the exploration of new antioxidant compounds and antimicrobial agents. PMID:24524349

  7. A study on chemical composition and detection of chemical adulteration in tetra pack milk samples commercially available in Multan.

    PubMed

    Awan, Adeela; Naseer, Misbah; Iqbal, Aasfa; Ali, Muhammad; Iqbal, Rehana; Iqbal, Furhan

    2014-01-01

    The aim of this study was to analyze and compare the chemical composition of 8 tetra pack milk samples, Olpers (S1), Haleeb (S2), Good milk (S3), Everyday (S4), Milk Pack (S5), Dairy Queen (S6), Dairy Umang (S7), Nurpur (S8) available in local markets and to detect the presence of various chemical adulterants in tetra pack milk samples in Southern Punjab (Pakistan). Density, pH, solid not fat, total solids, lactometer reading, specific gravity and fat contents were analyzed to determine the chemical composition of milk samples. Our results revealed that all the studied parameters had statistically non significant differences (P>0.05) except total fat in milk samples which was significantly different (P=0.03) among the 8 studied milk samples. Presence of a number of chemical adulterants, formalin, cane sugar, starch, glucose, ammonium sulphate, salt, pulverized soap, detergents, skim milk powder, benzoic acid, salicylic acid, borax, boric acid and alkalinity were also detected in milk samples following standard procedures. Results indicated that formalin, cane sugar, glucose, alkalinity and benzoic acid were present in all samples while salt test was positive only for Olper milk. All other studied adulterants were not detected in 8 milk samples under study. % fat was the only significantly different feature among the studied milk quality parameters with S8 containing lowest while S5 having the maximum % fat. PMID:24374447

  8. Studies on the chemical composition of kohl stone by X-ray diffractometer.

    PubMed

    Ullah, Pervaiz Habib; Mahmood, Zafar Alam; Sualeh, Mohammad; Zoha, S M S

    2010-01-01

    Use of Kohl (Surma) creates toxicity or protects eye, is one of the most controversial topic of modern medicines. However, modern researches show that kohl forms a thin film on the eye lens thus avoiding the direct contract of harmful UV radiation and glare of sun with lens. Black and shining particles of galena in kohl shield the eyes from glare and reflection of sun and thus protect them from harmful effect of UV radiation emerging from the sun. Based on these findings and other properties of kohl, it was decided to undertake this study to ascertain it's chemical composition and to correlate these properties scientifically. In the present study, kohl stone obtained from Madina (Saudi Arabia) was analyzed to ascertain it's chemical composition. The chemical analysis and X-ray diffractometer results obtained, showed that the main component of kohl stone is galena (PbS). PMID:20067866

  9. The use of chemical composition data in waste management planning - A case study

    SciTech Connect

    Burnley, S.J.

    2007-07-01

    As the waste industry continues to move from a disposal-based system to one based on a combination of recovery options, the need for information on the composition of waste increases and this is reflected by the amount of information on the physical composition of municipal solid wastes that is now available. However, there is far less information on the chemical composition of municipal solid waste. The results from a number of chemical surveys from Europe are compared and show a reasonable degree of agreement, but several problems were identified with the data. Chemical and physical compositional data are combined in a case study example to investigate the flow of key potential pollutants in an integrated solid waste management system that uses materials recycling, composting, incineration and landfilling. This case study has shown that an integrated waste management strategy diverts lead and cadmium away from composting and recycling to incineration, which effectively isolates these elements from the environment through efficient capture of the pollutants followed by secure landfilling or recycling of the residues. However, further work is needed to determine the distribution of mercury in incineration residues and its fate when the residues are landfilled.

  10. GC-MS studies of the chemical composition of two inedible mushrooms of the genus Agaricus

    PubMed Central

    Petrova, Assya; Alipieva, Kalina; Kostadinova, Emanuela; Antonova, Daniela; Lacheva, Maria; Gjosheva, Melania; Popov, Simeon; Bankova, Vassya

    2007-01-01

    Background Mushrooms in the genus Agaricus have worldwide distribution and include the economically important species A. bisporus. Some Agaricus species are inedible, including A. placomyces and A. pseudopratensis, which are similar in appearance to certain edible species, yet are known to possess unpleasant odours and induce gastrointestinal problems if consumed. We have studied the chemical composition of these mushrooms using GC-MS. Results Our GC-MS studies on the volatile fractions and butanol extracts resulted in the identification of 44 and 34 compounds for A. placomyces and A. pseudopratensis, respectively, including fatty acids and their esters, amino acids, and sugar alcohols. The most abundant constituent in the volatiles and butanol were phenol and urea respectively. We also identified the presence of ergosterol and two Δ7-sterols. In addition, 5α,8α-Epidioxi-24(ξ)-methylcholesta-6,22-diene-3β-ol was isolated for the first time from both mushrooms. Our study is therefore the first report on the chemical composition of these two species. Conclusion The results obtained contribute to the knowledge of the chemical composition of mushrooms belonging to the Agaricus genus, and provide some explanation for the reported mild toxicity of A. placomyces and A. pseudopratensis, a phenonomenon that can be explained by a high phenol content, similar to that found in other Xanthodermatei species. PMID:18096035

  11. Determination of Chemical Compositions on Adult Kidney Stones—A Spectroscopic Study

    NASA Astrophysics Data System (ADS)

    Raju, K.; Rakkappan, C.

    2008-11-01

    The chemical compositions of the kidney stones of both the sexes of patients, aged from 40 to 70, living in and around Chidambaram town are determined by using FT-IR and X-RD technique. The kidney stone samples used in the present study were procured from the Rajah Muthiah Medical College and Hospital, Annamalai University. The FT-IR spectra of different kidney stone samples were recorded in the range of 4000-400 cm-1. By identifying the characteristic frequency, the chemical compositions of the samples are determined. The results analyzed by FTIR technique were confirmed by X-RD method, in which the recorded X-ray diffractogram are compared with JCPDS files using search match method. Further analysis of XRD pattern also reveals the same.

  12. Chemical composition of Mars

    NASA Technical Reports Server (NTRS)

    Morgan, J. W.; Anders, E.

    1979-01-01

    The chemical composition of Mars is estimated from the cosmochemical model of Ganapathy and Anders (1974) with additional petrological and geophysical constraints. The model assumes that planets and chondrites underwent the same fractionation processes in the solar nebula, and constraints are imposed by the abundance of the heat-producing elements, U, Th and K, the volatile-rich component and the high density of the mantle. Global abundances of 83 elements are presented, and it is noted that the mantle is an iron-rich garnet wehrlite, nearly identical to the bulk moon composition of Morgan at al. (1978) and that the core is sulfur poor (3.5% S). The comparison of model compositions for the earth, Venus, Mars, the moon and a eucrite parent body suggests that volatile depletion correlates mainly with size rather than with radial distance from the sun.

  13. Chemical Compositions of Stars

    NASA Astrophysics Data System (ADS)

    Leckrone, D.; Murdin, P.

    2000-11-01

    In 1835, in a famously inaccurate forecast, the French philosopher Auguste Comte wrote of stars that, `We understand the possibility of determining their shapes, their distances, their sizes and their movements; whereas we would never know how to study by any means their chemical composition…'. At the close of the 20th century the accurate measurement of the abundances of the chemical elements in...

  14. Time-resolved fluorescence spectroscopic study of crude petroleum oils: influence of chemical composition.

    PubMed

    Ryder, Alan G

    2004-05-01

    The fluorescence of crude petroleum oils is sensitive to changes in chemical composition and many different fluorescence methods have been used to characterize crude oils. The use of fluorescence lifetimes to quantitatively characterize oil composition has practical advantages over steady-state measurements, but there have been comparatively few studies in which the lifetime behavior is correlated with gross chemical compositional data. In this study, the fluorescence lifetimes for a series of 23 crude petroleum oils with American Petroleum Institute (API) gravities of between 10 and 50 were measured at several emission wavelengths (450-785 nm) using a 380 nm light emitting diode (LED) excitation source. It was found that the intensity average fluorescence lifetime (tau) at any emission wave-length does not correlate well with either API gravity or aromatic concentration. However, it was found that tau is strongly negatively correlated with both the polar and sulfur concentrations and positively correlated with the corrected alkane concentration. This indicates that the fluorescence behavior of crude petroleum oils is governed primarily by the concentration of quenching species. All the strong lifetime-concentration correlations are nonlinear and show a high degree of scatter, especially for medium to light oils with API gravities of between 25 and 40. The degree of scatter is greatest for oils where the concentrations (wt %) of the polar fraction is approximately 10 +/- 4%, the asphaltene component is approximately 1 +/- 0.5%, and sulfur is 0.5 +/- 0.4%. This large degree of scatter precludes the use of average fluorescence lifetime data obtained with 380 nm excitation for the accurate prediction of the common chemical compositional parameters of crude petroleum oils. PMID:15165340

  15. PM2.5 chemical composition in five European Mediterranean cities: A 1-year study

    NASA Astrophysics Data System (ADS)

    Salameh, Dalia; Detournay, Anais; Pey, Jorge; Pérez, Noemi; Liguori, Francesca; Saraga, Dikaia; Bove, Maria Chiara; Brotto, Paolo; Cassola, Federico; Massabò, Dario; Latella, Aurelio; Pillon, Silvia; Formenton, Gianni; Patti, Salvatore; Armengaud, Alexandre; Piga, Damien; Jaffrezo, Jean Luc; Bartzis, John; Tolis, Evangelos; Prati, Paolo; Querol, Xavier; Wortham, Henri; Marchand, Nicolas

    2015-03-01

    The seasonal and spatial characteristics of PM2.5 and its chemical composition in the Mediterranean Basin have been studied over a 1-year period (2011-2012) in five European Mediterranean cities: Barcelona (BCN), Marseille (MRS), Genoa (GEN), Venice (VEN), and Thessaloniki (THE). During the year under study, PM10 annual mean concentration ranged from 23 to 46 μg m- 3, while the respective PM2.5 ranged from 14 to 37 μg m- 3, with the highest concentrations observed in THE and VEN. Both cities presented an elevated number of exceedances of the PM10 daily limit value, as 32% and 20% of the days exceeded 50 μg m- 3, respectively. Similarly, exceedances of the WHO guidelines for daily PM2.5 concentrations (25 μg m- 3) were also more frequent in THE with 78% of the days during the period, followed by VEN with 39%. The lowest PM levels were measured in GEN. PM2.5 exhibited significant seasonal variability, with much higher winter concentrations for VEN and MRS, in fall for THE and in spring for BCN. PM2.5 chemical composition was markedly different even for similar PM2.5 levels. On annual average, PM2.5 was dominated by OM except in THE. OM contribution was higher in Marseille (42%), while mineral matter was the most abundant constituent in THE (32%). Moreover, PM2.5 relative mean composition during pollution episodes (PM2.5 > 25 μg m- 3) as well as the origins of the exceedances were also investigated. Results outline mainly the effect of NO3- being the most important driver and highlight the non-negligible impact of atmospheric mixing and aging processes during pollution episodes.

  16. Chemical mixing model studies of lunar orbital geochemical data - Apollo 16 and 17 highlands compositions

    NASA Technical Reports Server (NTRS)

    Spudis, P. D.; Hawke, B. R.

    1982-01-01

    Chemical mixing model studies of lunar geochemical data for the central and Taurus-Littrow lunar highlands were performed utilizing pristine highland rock types as end member compositions. The central highlands show considerable diversity in composition; anorthosite is the principal rock type in the Apollo 16/Descartes region, while norite predominates in the highlands west of the landing site. This change in crustal composition is coincident with a major color boundary seen in earth-based multispectral data and probably represents the presence of distinct geochemical provinces within the central highlands. The Taurus-Littrow highlands are dominated by norite; anorthosite is far less abundant than in the central highlands. This suggests that the impact target for the Serenitatis basin was different than that of the Nectaris basin and further strengthens the hypothesis that the lunar highlands are petrologically heterogeneous on a regional basis. It is suggested that the lunar highlands should be viewed in terms of geochemical provinces that have undergone distinct and complex igneous and impact histories.

  17. Formation of anodic layers on InAs (111)III. Study of the chemical composition

    SciTech Connect

    Valisheva, N. A. Tereshchenko, O. E.; Prosvirin, I. P.; Kalinkin, A. V.; Goljashov, V. A.; Levtzova, T. A.; Bukhtiyarov, V. I.

    2012-04-15

    The chemical composition of {approx}20-nm-thick anodic layers grown on InAs (111)III in alkaline and acid electrolytes containing or not containing NH{sub 4}F is studied by X-ray photoelectron spectroscopy. It is shown that the composition of fluorinated layers is controlled by the relation between the concentrations of fluorine and hydroxide ions in the electrolyte and by diffusion processes in the growing layer. Fluorine accumulates at the (anodic layer)/InAs interface. Oxidation of InAs in an acid electrolyte with a low oxygen content and a high NH{sub 4}F content brings about the formation of anodic layers with a high content of fluorine and elemental arsenic and the formation of an oxygen-free InF{sub x}/InAs interface. Fluorinated layers grown in an alkaline electrolyte with a high content of O{sup 2-} and/or OH{sup -} groups contain approximately three times less fluorine and consist of indium and arsenic oxyfluorides. No distinction between the compositions of the layers grown in both types of fluorine-free electrolytes is established.

  18. Thin film of lignocellulosic nanofibrils with different chemical composition for QCM-D study.

    PubMed

    Kumagai, Akio; Lee, Seung-Hwan; Endo, Takashi

    2013-07-01

    Thin films of lignocellulosic nanofibrils (LCNFs) with different chemical compositions were prepared for real-time observation of their enzymatic adsorption and degradation behavior by using a quartz crystal microbalance with dissipation monitoring (QCM-D). LCNFs were obtained by disk milling followed by high-pressure homogenization of Hinoki cypress. The lignin contents were adjusted by the sodium chlorite treatment. The film thickness was adjusted by controlling the concentration of the LCNF suspension, which was determined from its proportional relationship to the UV absorbance of lignin. The enzymatic degradation behavior was investigated with a commercial enzyme mixture. The results of the QCM-D showed that changes in frequency and dissipation in the initial reaction stage were different from the typical changes reported for pure cellulose. To the best of our knowledge, this is the first report of the preparation of thin films of LCNFs with high lignin and hemicellulose contents and their application in a QCM-D study. PMID:23721319

  19. Studies on Chemical Composition, Antimicrobial and Antioxidant Activities of Five Thymus vulgaris L. Essential Oils.

    PubMed

    Mancini, Emilia; Senatore, Federica; Del Monte, Donato; De Martino, Laura; Grulova, Daniela; Scognamiglio, Mariarosa; Snoussi, Mejdi; De Feo, Vincenzo

    2015-01-01

    This study is aimed at assessing the essential oil composition, total phenolic content, antimicrobial and antioxidant activities of Thymus vulgaris collected in five different area of the Campania Region, Southern Italy. The chemical composition of the essential oils was studied by GC-flame ionization detector (FID) and GC/MS; the biological activities were evaluated through determination of MIC and minimum bactericidal concentration (MBC) and evaluation of antioxidant activity. In total, 134 compounds were identified. The oils were mainly composed of phenolic compounds, and all oils belonged to the chemotype thymol. The antimicrobial activity of the five oils was assayed against ten bacterial strains. The oils showed different inhibitory activity against some Gram-positive pathogens. The total phenol content in the essential oils ranged from 77.6-165.1 mg gallic acid equivalents (GAE)/g. The results reported here may help to shed light on the complex chemotaxonomy of the genus Thymus. These oils could be used in many fields as natural preservatives of food and as nutraceuticals. PMID:26140436

  20. Chemical Composition of Wildland and Agricultural Biomass Burning Particles Measured Downwind During BBOP Study

    NASA Astrophysics Data System (ADS)

    Fortner, E.; Onasch, T. B.; Shilling, J.; Pekour, M. S.; Kleinman, L. I.; Sedlacek, A. J., III; Worsnop, D. R.

    2014-12-01

    The Biomass Burning Observation Project (BBOP), a Department of Energy (DOE) sponsored study, measured wildland fires in the Pacific Northwest and prescribed agricultural burns in the Central Southeastern US from the DOE Gulfstream-1 (G-1) aircraft platform over a four month period in 2013. The chemical composition of the emitted particulate emissions were characterized using an Aerodyne Soot Particle Aerosol Mass Spectrometer (SP-AMS) and will be presented in the context of the fire location and source. The SP-AMS was operated with both laser and resistively heated tungsten vaporizers, alternatively turning the laser vaporizer on and off. With the laser vaporizer off, the instrument operated as a standard HR-AMS. Under these sampling conditions, the non-refractory chemical composition of the biomass burning particles will be characterized as a function of the fuel type burned and the observed modified combustion efficiency and observed changes during downwind transport. Specific attention will focus on the level of oxidation (i.e., O:C, H:C, and OM:OC ratios), anhydrosugar, and aromatic content. With the laser vaporizer on, the SP-AMS was also sensitive to the refractory black carbon content, in addition to the non-refractory components, and will be presented within the context of technique-specific collection efficiencies. Under these sampling conditions, addition information on the mass of black carbon, the OM/BC ratio, and the RBC(coat-to-core) ratio will be examined, with a focus on correlating with the simultaneous optical measurements.

  1. Chemical Compositional, Biological, and Safety Studies of a Novel Maple Syrup Derived Extract for Nutraceutical Applications

    PubMed Central

    2015-01-01

    Maple syrup has nutraceutical potential given the macronutrients (carbohydrates, primarily sucrose), micronutrients (minerals and vitamins), and phytochemicals (primarily phenolics) found in this natural sweetener. We conducted compositional (ash, fiber, carbohydrates, minerals, amino acids, organic acids, vitamins, phytochemicals), in vitro biological, and in vivo safety (animal toxicity) studies on maple syrup extracts (MSX-1 and MSX-2) derived from two declassified maple syrup samples. Along with macronutrient and micronutrient quantification, thirty-three phytochemicals were identified (by HPLC-DAD), and nine phytochemicals, including two new compounds, were isolated and identified (by NMR) from MSX. At doses of up to 1000 mg/kg/day, MSX was well tolerated with no signs of overt toxicity in rats. MSX showed antioxidant (2,2-diphenyl-1-picrylhydrazyl (DPPH) assay) and anti-inflammatory (in RAW 264.7 macrophages) effects and inhibited glucose consumption (by HepG2 cells) in vitro. Thus, MSX should be further investigated for potential nutraceutical applications given its similarity in chemical composition to pure maple syrup. PMID:24983789

  2. Chemical compositional, biological, and safety studies of a novel maple syrup derived extract for nutraceutical applications.

    PubMed

    Zhang, Yan; Yuan, Tao; Li, Liya; Nahar, Pragati; Slitt, Angela; Seeram, Navindra P

    2014-07-16

    Maple syrup has nutraceutical potential given the macronutrients (carbohydrates, primarily sucrose), micronutrients (minerals and vitamins), and phytochemicals (primarily phenolics) found in this natural sweetener. We conducted compositional (ash, fiber, carbohydrates, minerals, amino acids, organic acids, vitamins, phytochemicals), in vitro biological, and in vivo safety (animal toxicity) studies on maple syrup extracts (MSX-1 and MSX-2) derived from two declassified maple syrup samples. Along with macronutrient and micronutrient quantification, thirty-three phytochemicals were identified (by HPLC-DAD), and nine phytochemicals, including two new compounds, were isolated and identified (by NMR) from MSX. At doses of up to 1000 mg/kg/day, MSX was well tolerated with no signs of overt toxicity in rats. MSX showed antioxidant (2,2-diphenyl-1-picrylhydrazyl (DPPH) assay) and anti-inflammatory (in RAW 264.7 macrophages) effects and inhibited glucose consumption (by HepG2 cells) in vitro. Thus, MSX should be further investigated for potential nutraceutical applications given its similarity in chemical composition to pure maple syrup. PMID:24983789

  3. Comparative Study of Chemical Composition and Biological Activity of Yellow, Green, Brown, and Red Brazilian Propolis

    PubMed Central

    Machado, Christiane Schineider; Mokochinski, João Benhur; de Lira, Tatiana Onofre; de Oliveira, Fátima de Cassia Evangelista; Cardoso, Magda Vieira; Ferreira, Roseane Guimarães; Sawaya, Alexandra Christine Helena Frankland; Ferreira, Antonio Gilberto; Pessoa, Cláudia; Cuesta-Rubio, Osmany; Monteiro, Marta Chagas; de Campos, Mônica Soares

    2016-01-01

    The chemical composition and biological activity of a sample of yellow propolis from Mato Grosso do Sul, Brazil (EEP-Y MS), were investigated for the first time and compared with green, brown, and red types of Brazilian propolis and with a sample of yellow propolis from Cuba. Overall, EEP-Y MS had different qualitative chemical profiles, as well as different cytotoxic and antimicrobial activities when compared to the other types of propolis assessed in this study and it is a different chemotype of Brazilian propolis. Absence of phenolic compounds and the presence of mixtures of aliphatic compounds in yellow propolis were determined by analysing 1H-NMR spectra and fifteen terpenes were identified by GC-MS. EEP-Y MS showed cytotoxic activity against human tumour strain OVCAR-8 but was not active against Gram-negative or Gram-positive bacteria. Our results confirm the difficulty of establishing a uniform quality standard for propolis from diverse geographical origins. The most appropriate pharmacological applications of yellow types of propolis must be further investigated. PMID:27525023

  4. Comparative Study of Chemical Composition and Biological Activity of Yellow, Green, Brown, and Red Brazilian Propolis.

    PubMed

    Machado, Christiane Schineider; Mokochinski, João Benhur; de Lira, Tatiana Onofre; de Oliveira, Fátima de Cassia Evangelista; Cardoso, Magda Vieira; Ferreira, Roseane Guimarães; Sawaya, Alexandra Christine Helena Frankland; Ferreira, Antonio Gilberto; Pessoa, Cláudia; Cuesta-Rubio, Osmany; Monteiro, Marta Chagas; de Campos, Mônica Soares; Torres, Yohandra Reyes

    2016-01-01

    The chemical composition and biological activity of a sample of yellow propolis from Mato Grosso do Sul, Brazil (EEP-Y MS), were investigated for the first time and compared with green, brown, and red types of Brazilian propolis and with a sample of yellow propolis from Cuba. Overall, EEP-Y MS had different qualitative chemical profiles, as well as different cytotoxic and antimicrobial activities when compared to the other types of propolis assessed in this study and it is a different chemotype of Brazilian propolis. Absence of phenolic compounds and the presence of mixtures of aliphatic compounds in yellow propolis were determined by analysing (1)H-NMR spectra and fifteen terpenes were identified by GC-MS. EEP-Y MS showed cytotoxic activity against human tumour strain OVCAR-8 but was not active against Gram-negative or Gram-positive bacteria. Our results confirm the difficulty of establishing a uniform quality standard for propolis from diverse geographical origins. The most appropriate pharmacological applications of yellow types of propolis must be further investigated. PMID:27525023

  5. Method of forming a chemical composition

    DOEpatents

    Bingham, Dennis N.; Wilding, Bruce M.; Klingler, Kerry M.; Zollinger, William T.; Wendt, Kraig M.

    2007-10-09

    A method of forming a chemical composition such as a chemical hydride is described and which includes the steps of selecting a composition having chemical bonds and which is capable of forming a chemical hydride; providing a source of hydrogen; and exposing the selected composition to an amount of ionizing radiation to encourage the changing of the chemical bonds of the selected composition, and chemically reacting the selected composition with the source of hydrogen to facilitate the formation of a chemical hydride.

  6. A model for studying the composition and chemical effects of stratospheric aerosols

    SciTech Connect

    Tabazadeh, A.; Turco, R.P.; Jacobson, M.Z.

    1994-06-01

    We developed polynomial expressions for the temperature dependence of the mean binary and water activity coefficients for H2SO4 and HNO3 solutions. These activities were used in an equilibrium model to predict the composition of stratospheric aerosols under a wide range of environmental conditions. For typical concentrations of H2O, H2SO4, HNO3, HCl, HBr, HF, and HOCl in the lower stratosphere, the aerosol composition is estimated as a function of the local temperature and the ambient relative humidity. For temperatures below 200 K, our results indicate that (1) HNO3 contributes a significant mass fraction to stratospheric aerosols, and (2) HCl solubility is considerably affected by HNO3 dissolution into sulfate aerosols. We also show that, in volcanically disturbed periods, changes in stratospheric aerosol composition can significantly alter the microphysics that leads to the formation of polar stratospheric clouds. The effects caused by HNO3 dissolution on the physical and chemical properties of stratospheric aerosols are discussed.

  7. A model for studying the composition and chemical effects of stratospheric aerosols

    NASA Technical Reports Server (NTRS)

    Tabazadeh, Azadeh; Turco, Richard P.; Jacobson, Mark Z.

    1994-01-01

    We developed polynomial expressions for the temperature dependence of the mean binary and water activity coefficients for H2SO4 and HNO3 solutions. These activities were used in an equilibrium model to predict the composition of stratospheric aerosols under a wide range of environmental conditions. For typical concentrations of H2O, H2SO4, HNO3, HCl, HBr, HF, and HOCl in the lower stratosphere, the aerosol composition is estimated as a function of the local temperature and the ambient relative humidity. For temperatures below 200 K, our results indicate that (1) HNO3 contributes a significant mass fraction to stratospheric aerosols, and (2) HCl solubility is considerably affected by HNO3 dissolution into sulfate aerosols. We also show that, in volcanically disturbed periods, changes in stratospheric aerosol composition can significantly alter the microphysics that leads to the formation of polar stratospheric clouds. The effects caused by HNO3 dissolution on the physical and chemical properties of stratospheric aerosols are discussed.

  8. TGA-DTA and chemical composition study of raw material of Bikaner region for electrical porcelain

    NASA Astrophysics Data System (ADS)

    Tak, S. K.; Shekhawat, M. S.; Mangal, R.

    2013-06-01

    Porcelains are vitrified and a fine grained ceramic product, used either glazed or unglazed and is often manufactured from a tri-axial body mix of clays, quartz and alkaline feldspar. Physical properties associated with porcelain include those of permeability, high strength, hardness, glassiness, durability, whiteness, translucence, resonance, brittleness, high resistance to the passage of electricity, high resistance to thermal shock and high elasticity[1,2]. Porcelain insulators are made from three raw materials; clay; feldspar and quartz. For porcelain manufacture the clay is categorized in two groups; ball clay and kaolin, each of which plays an important role, either in the preparation of the product or in the properties of the finished products. The following research highlights the importance that suits these materials for their contributions to the final properties of the product. Keeping this view a TGA-DTA and chemical composition of these raw materials were observed and these materials are found suitable for production of Electrical Porcelain.

  9. The Chemical Composition of Honey

    ERIC Educational Resources Information Center

    Ball, David W.

    2007-01-01

    Honey is a supersaturated sugar solution, created by bees, and used by human beings as a sweetener. However, honey is more than just a supersaturated sugar solution; it also contains acids, minerals, vitamins, and amino acids in varying quantities. In this article, we will briefly explore the chemical composition of honey. (Contains 2 figures and…

  10. Chemical recycling of scrap composites

    NASA Technical Reports Server (NTRS)

    Allred, Ronald E.; Salas, Richard M.

    1994-01-01

    There are no well-developed technologies for recycling composite materials other than grinding to produce fillers. New approaches are needed to reclaim these valuable resources. Chemical or tertiary recycling, conversion of polymers into low molecular weight hydrocarbons for reuse as chemicals or fuels, is emerging as the most practical means for obtaining value from waste plastics and composites. Adherent Technologies is exploring a low-temperature catalytic process for recycling plastics and composites. Laboratory results show that all types of plastics, thermosets as well as thermoplastics, can be converted in high yields to valuable hydrocarbon products. This novel catalytic process runs at 200 C, conversion times are rapid, the process is closed and, thus, nonpolluting, and no highly toxic gas or liquid products have been observed so no negative environmental impact will result from its implementation. Tests on reclamation of composite materials show that epoxy, imide, and engineering thermoplastic matrices can be converted to low molecular weight hydrocarbons leaving behind the reinforcing fibers for reuse as composite reinforcements in secondary, lower-performance applications. Chemical recycling is also a means to dispose of sensitive or classified organic materials without incineration and provides a means to eliminate or reduce mixed hazardous wastes containing organic materials.

  11. Comparative study of the chemical composition of wild and cultivated beans (Phaseolus vulgaris).

    PubMed

    Sotelo, A; Sousa, H; Sánchez, M

    1995-02-01

    Five wild Phaseolus vulgaris beans were compared with five cultivated Phaseolus vulgaris beans in proximate composition, total (true) protein, amino acid composition, and toxic and antinutritional factors. The wild beans contained more protein (25.5% vs. 21.7%), ash (5.15 vs. 4.15%), crude fiber (7.08% vs. 5.04%) compared to cultivated beans while the former contained less fat (0.56 vs. 0.89%) and carbohydrates (61.64 vs. 68.05%). Sulfur amino acids were found to be limiting in both groups of bean as expected; however, the cultivated beans had a higher content of the limiting amino acids. Therefore, the cultivated beans showed a better amino acid profile than the wild beans. Toxic factors were not found in either type of bean; the determinations included saponins, alkaloids, and cyanogenic glycosides. The antinutritional factors investigated were hemagglutinins (lectins) and trypsin inhibitors. The wild beans presented a higher content of trypsin inhibitors (28 TUI per mg) and lectins (9.6) than the cultivated beans did (21 TUI per mg and 7 respectively). From the chemical point of view, domestication seems to be positive; however, the better protein nutritive quality of the cultivated beans should be further confirmed by biological assays. PMID:7792267

  12. Chemical compositions, methods of making the chemical compositions, and structures made from the chemical compositions

    DOEpatents

    Yang, Lei; Cheng, Zhe; Liu, Ze; Liu, Meilin

    2015-01-13

    Embodiments of the present disclosure include chemical compositions, structures, anodes, cathodes, electrolytes for solid oxide fuel cells, solid oxide fuel cells, fuel cells, fuel cell membranes, separation membranes, catalytic membranes, sensors, coatings for electrolytes, electrodes, membranes, and catalysts, and the like, are disclosed.

  13. A study on chemical composition of spices irradiated by electron beam

    NASA Astrophysics Data System (ADS)

    Lianzhong, Ding; Shiyue, Ding; Yan, Zhu; Yixu, Li; Songmei, Zhu

    1998-06-01

    Quantitative changes in common organic acids and inorganic acids from spices irradiated by electron beam were studied by Dionex-4000i ion chromograph. The results showed that the acids content of either chilli or the five-spice powder (3) irradiated with a dose of 9.94 kGy did not undergo significant changes in comparison with the control samples. The flavour composition in the five-spice powder irradiated by electron beam was also determined by Finnigan MAT-8230B gas chromatograph-mass spectrometer, and compared to the results by heating treatment (120°C, 30min). The comparison indicated that the effect of electron beam treatment on flavour composition was less than that of heating.

  14. Combined studies of chemical composition of urine sediments and kidney stones by means of infrared microspectroscopy.

    PubMed

    Tamošaitytė, Sandra; Hendrixson, Vaiva; Želvys, Arūnas; Tyla, Ramūnas; Kučinskienė, Zita A; Jankevičius, Feliksas; Pučetaitė, Milda; Jablonskienė, Valerija; Šablinskas, Valdas

    2013-02-01

    Results of the structural analysis of urinary sediments by means of infrared spectral microscopy are presented. The results are in good agreement with the results of standard optical microscopy in the case of single-component and crystalline urinary sediments. It is found that for noncrystalline or multicomponent sediments, the suggested spectroscopic method is superior to optical microscopy. The chemical structure of sediments of any molecular origin can be elucidated by this spectroscopic method. The method is sensitive enough to identify solid particles of drugs present in urine. Sulfamethoxazole and traces of other medicines are revealed in this study among the other sediments. We also show that a rather good correlation exists between the type of urinary sediments and the renal stones removed from the same patient. Spectroscopic studies of urinary stones and corresponding sediments from 76 patients suffering from renal stone disease reveal that in 73% of cases such correlation exists. This finding is a strong argument for the use of infrared spectral microscopy to prevent kidney stone disease because stones can be found in an early stage of formation by using the nonintrusive spectroscopic investigation of urinary sediments. Some medical recommendations concerning the overdosing of certain pharmaceuticals can also be derived from the spectroscopic studies of urinary sediments. PMID:23429795

  15. Combined studies of chemical composition of urine sediments and kidney stones by means of infrared microspectroscopy

    NASA Astrophysics Data System (ADS)

    Tamošaitytė, Sandra; Hendrixson, Vaiva; Želvys, Arūnas; Tyla, Ramūnas; Kučinskienė, Zita A.; Jankevičius, Feliksas; Pučetaitė, Milda; Jablonskienė, Valerija; Šablinskas, Valdas

    2013-02-01

    Results of the structural analysis of urinary sediments by means of infrared spectral microscopy are presented. The results are in good agreement with the results of standard optical microscopy in the case of single-component and crystalline urinary sediments. It is found that for noncrystalline or multicomponent sediments, the suggested spectroscopic method is superior to optical microscopy. The chemical structure of sediments of any molecular origin can be elucidated by this spectroscopic method. The method is sensitive enough to identify solid particles of drugs present in urine. Sulfamethoxazole and traces of other medicines are revealed in this study among the other sediments. We also show that a rather good correlation exists between the type of urinary sediments and the renal stones removed from the same patient. Spectroscopic studies of urinary stones and corresponding sediments from 76 patients suffering from renal stone disease reveal that in 73% of cases such correlation exists. This finding is a strong argument for the use of infrared spectral microscopy to prevent kidney stone disease because stones can be found in an early stage of formation by using the nonintrusive spectroscopic investigation of urinary sediments. Some medical recommendations concerning the overdosing of certain pharmaceuticals can also be derived from the spectroscopic studies of urinary sediments.

  16. Study on the pretreatment of poly(ether ether ketone)/multiwalled carbon nanotubes composites through environmentally friendly chemical etching and electrical properties of the chemically metallized composites.

    PubMed

    Zhai, Tong; Di, Lizhi; Yang, De'an

    2013-12-11

    The high-volume resistivity and surface resistance of poly(ether ether ketone)/multiwalled carbon nanotubes (PEEK/MWCNT) composites restrict their use in an electronic field. To decrease the volume resistivity and surface resistance, we metalized the composites by electroless plating. The composites and metal coatings were characterized by SEM, XPS, AFM, EDX, and XRD spectroscopy. The swelling ratio of the composites, volume resistivity of two-side-coated composites, sheet resistance of plated composites, and adhesion between the coating and PEEK/MWCNT were tested. The results are as follows. A high roughness and a small swelling ratio were obtained by swelling in 18 mol/L H2SO4 for 3 min. Most of the MWCNT on the surface were still wrapped with PEEK after swelling. To expose the MWCNT, an environmentally friendly and effective etchant (MnO2-NaH2PO4-H2SO4) was used. After etching, not only were high roughness and partially exposed MWCNT obtained but also the percentage of hydrophilic groups on the surface was increased. A dense cauliflower-like Ni-P coating was produced, and the exposed MWCNT were embedded in the metal coating after electroless plating for 20 min. The coating exhibited an amorphous structure with a phosphorus content of 11.21 wt %. The volume resistivity of two-side-coated PEEK/MWCNT dropped sharply to 38 Ω·m after electroless plating for 5 min. The sheet resistance decreased with increasing the electroless-plating time, and it dropped to 0.88 Ω/square after electroless plating for 40 min. The adhesion of the coating reached the highest 5 B scale (ASTM D3359) and could even undergo the test 20 times. PMID:24221995

  17. Chemical studies of H chondrites. 6: Antarctic/non-Antarctic compositional differences revisited

    NASA Technical Reports Server (NTRS)

    Wolf, Stephen F.; Lipschutz, Michael E.

    1995-01-01

    We report data for the trace elements Au, Co, Sb, Ga, Rb, Ag, Se, Cs, Te, Zn, Cd, Bi, T1, and In (ordered by putative volatility during nebular condensation and accretion) determined by radiochemical neutron activation analysis of 14 additional H5 and H6 chondrite falls. Data for the 10 most volatile elements (Rb to In) treated by the multivariate techniques of linear discriminant analysis and logistic regression in these and 44 other falls are compared with those of 59 H4-6 chondrites from Antarctica. Various populations are tested by the multivariate techniques, using the previously developed method of randomization-simulation to assess significance levels. An earlier conclusion, based on fewer examples, that H4-6 chondrite falls are compositionally distinguishable from the Antarctic suite is verified by the additional data. This distinctiveness is highly significant because of the presence of samples from Victoria Land in the Antarctic population, which differ compositionally from falls beyond any reasonable doubt. However, it cannot be proven unequivocally that falls and Antarctic samples from Queen Maud Land are compositionally distinguishable. Trivial causes (e.g., analyst bias, weathering) cannot explain the Victoria Land (Antarctic)/non-Antarctic compositional difference for paradigmatic H4-6 chondrites. This seems to reflect a time-dependent variation of near-Earth meteoroid source regions differing in average thermal history.

  18. Lunar Skylights and Their Chemical Compositions

    NASA Astrophysics Data System (ADS)

    Wong, J.; Torres, J.; FitzHoward, S.; Luu, E.; Hua, J.; Irby, R.

    2013-12-01

    In 2009, the Japanese orbiter, SELenological and Engineering Explorer (SELENE) discovered a skylight on the near side of the moon. Skylights are collapsed ceilings of rilles, thought to be caused by moonquakes, meteoroids, or incomplete formation of these lava tube ceilings. Since then, NASA's Lunar Reconnaissance Orbiter has discovered two more skylights, also located on the near side of the moon. Previous research has shown that the physical characteristics of known rilles, can be used as indicators of the presence of yet undiscovered rille and lava dome locations across the lunar surface. We hypothesize that skylights have a signature chemical composition that is unique, and can be used to predict the location of additional skylights on the surface of the moon. For this study, we compared chemical composition data of the three mare sites containing skylights with the 21 mare sites without skylights. Using the software JMARS for the Moon, we compiled multiple datasets to measure the concentrations of 13 different chemical compounds including calcium, iron oxide, titanium dioxide, and thorium. We then conducted a two-tailed T-test of the data, which generated probability values for the mean differences across all 13 chemical compounds of the maria sites with skylights and the maria sites without skylights. Our results show that there is no statistical difference in chemical composition across all of the maria sites examined. Therefore, we conclude that chemical composition does not predict or indicate potential skylight locations on the moon. Further research on other skylight characteristics, for example depth and surrounding underground lava channels, may shed light on the relationships between mare and skylights locations. Three Skylight Locations Found on Lunar Surface 100m View of Mare Tranquilitatis Skylight

  19. The influence of climate variability on chemical composition of European wines: a regional scale study (Italy and Slovenia)

    NASA Astrophysics Data System (ADS)

    Barbante, Carlo; Polo, Fabio; Cozzi, Giulio; Ogrinc, Nives; Turetta, Clara

    2016-04-01

    Climate change is having an increasing influence on vine phenology and grape composition, affecting vinifications, wine chemistry and the quality of productions. Wine grape cultivation provides a good test case for measuring indirect impacts mediated by changes in agriculture, because viticulture is sensitive to climate and is concentrated in Mediterranean climate regions that are global biodiversity hotspots. Moreover, on a regional level and on a shorter time scale, the seasonal weather conditions modify the quality of yields determining the final properties of wine. In the present research, we studied wines from Italy and Slovenia with the purpose of differentiating them by the different vintages (from 2009 to 2012), which are supposed to be influenced by temperature and rain during each year's growing season. Specific chemical techniques were used, in particular mass spectrometry (ICP-MS) and isotopic mass spectrometry (IRMS), both of which are usually employed to detect wine adulterations and to establish the geographical provenance of wines. In particular, we investigated the relationship between macro- and micro-elements, Rare Earth Elements and stable isotopes [δ13C, δ18O, (D/H)I, (D/H)II]. The datasets were examined via statistical techniques to show their relation to weather conditions as well as their mutual connection. Italian and Slovenian wines were distinguished, with the exception of few samples, by both TEs and REEs results. This separation, due to different elemental compositions, may be justified as being part of two distinct environmental and geographical belongings (terroir) but also to the processes of wine production, from the harvest to the bottling, which have certainly interfered and characterized the products. In the case of Italian wines the weather conditions were evidenced with an important separation of stable isotopes which they confirmed to be very sensitive Regarding Slovenian wines, the studied regions were characterized of

  20. A study of acidity on PM 2.5 in Hong Kong using online ionic chemical composition measurements

    NASA Astrophysics Data System (ADS)

    Xue, Jian; Lau, Alexis K. H.; Yu, Jian Zhen

    2011-12-01

    Particle in-situ pH ( pHIS), defined as pH of the aqueous phase on aerosols, is an important factor in influencing aerosol-phase chemistry and uptake of gaseous species by particles. In this study, a continuous system, Particle-into-Liquid System (PILS) coupled with two ion chromatographs, was used to obtain PM 2.5 ionic chemical composition at a time resolution of 30 min at a suburban site in Hong Kong under three different synoptic conditions. The chemical composition data and meteorological parameters (e.g., temperature, relative humidity (RH)) are input into Aerosol Inorganic Model (AIM-III) for estimation of in-situ pH through calculation of H + amount and aerosol liquid water content (LWC). The particle pHIS ranged from -1.87 to 3.12, with an average at -0.03, indicating the PM 2.5 particles in Hong Kong are highly acidic. Unlike particle strong acidity, which was dominated by sulfate concentration, the amount of aerosol liquid water content could significantly influence in-situ particle acidity. Principal factor analysis has identified the equivalent concentration ratio between cations and anions (i.e., R+/-) and RH to be the two most important factors influencing the particle pHIS. pHIS under different synoptic conditions in this study could be well approximated by a single linear regression equation (slope: 0.95, R2: 0.93), i.e., pHIS = 4.94 R+/- + 3.11 RH - 5.70. Such an empirical equation provides a convenient mean in estimating particle in-situ acidity for assessing the role of acid-catalyzed aerosol reactions.

  1. Chemical compositional study of 35 iron meteorites and its application in taxonomy

    NASA Technical Reports Server (NTRS)

    Wang, D.; Malvin, D. J.; Wasson, J. T.

    1985-01-01

    Structural and compositional data are reported as a guide to the classification of 35 iron meteorites. The Xinjiang iron meteorite, previously classified as III AB, is reclassified as III E on the basis of its lower Ga/Ni and Ge/Ni ratios, its wider, swollen kamacite bands, and the ubiquitous presence of haxonite, (Fe,Ni)22C. The Dongling (III CD) appears not to be a new meteorite, but to be paired with the Nantan. Four Antarctic iron meteorites, IAB Allan Hills A77250, A77263, A77289, and A77290, are classified as a paired meteorite because of their similarities in structure and in concentrations of various elements. It is shown that Cu shares certain properties with Ga and Ge, which makes them excellent taxonomic parameters.

  2. Impact of oil on groundwater chemical composition

    NASA Astrophysics Data System (ADS)

    Brakorenko, N. N.

    2015-11-01

    The objective of the paper is to characterize the chemical composition of groundwater samples from the monitoring wells drilled in the petrol station areas within the vicinity of Tomsk. The level of contamination has increased since many macro - and microcomponent concentrations (such as petroleum products, chlorine, sulphates, carbon dioxide and lead, etc.) in groundwater samples of the present study is higher than that in previous period samples.

  3. Compositional study of silicon oxynitride thin films deposited using electron cyclotron resonance plasma-enhanced chemical vapor deposition technique

    SciTech Connect

    Baumann, H.; Sah, R.E.

    2005-05-01

    We have used backscattering spectrometry and {sup 15}N({sup 1}H,{alpha},{gamma}){sup 12}C nuclear reaction analysis techniques to study in detail the variation in the composition of silicon oxynitride films with deposition parameters. The films were deposited using 2.45 GHz electron cyclotron resonance plasma-enhanced chemical vapor deposition (PECVD) technique from mixtures of precursors argon, nitrous oxide, and silane at deposition temperature 90 deg. C. The deposition pressure and nitrous oxide-to-silane gas flow rates ratio have been found to have a pronounced influence on the composition of the films. When the deposition pressure was varied for a given nitrous oxide-to-silane gas flow ratio, the amount of silicon and nitrogen increased with the deposition pressure, while the amount of oxygen decreased. For a given deposition pressure, the amount of incorporated nitrogen and hydrogen decreased while that of oxygen increased with increasing nitrous oxide-to-silane gas flow rates ratio. For nitrous oxide-to-silane gas flow ratio of 5, we obtained films which contained neither chemically bonded nor nonbonded nitrogen atoms as revealed by the results of infrared spectroscopy, backscattering spectrometry, and nuclear reaction analysis. Our results demonstrate the nitrogen-free nearly stoichiometric silicon dioxide films can be prepared from a mixture of precursors argon, nitrous oxide, and silane at low substrate temperature using high-density PECVD technique. This avoids the use of a hazardous and an often forbidden pair of silane and oxygen gases in a plasma reactor.

  4. Comparative study of the chemical composition of essential oils of five Tagetes species collected in Venezuela.

    PubMed

    Armas, Kaylin; Rojas, Janne; Rojas, Luis; Morales, Antonio

    2012-09-01

    The leaves and inflorescences of five species of Tagetes, family Asteraceae, were collected from different locations in Mérida state, Venezuela, and their essential oils analyzed by GC and GC/MS. Several differences were observed in the composition of these oils, mainly regarding the major components, which for T. caracasana were trans-ocimenone (64.3%) and cis-tagetone (13.7%), and for T. erecta, piperitone (35.9%) and terpinolene (22.2%). High amounts of trans-anethole (87.5%) and estragole (10.7%) were observed in T. filifolia, while T. subulata essential oil contained terpinolene (26.0%), piperitenone (13.1%) and limonene (10.8%). For T. patula, two different oil samples were analyzed, leaves (TPL) and inflorescences (TPI). The TPL oil showed terpinolene (20.9%) and piperitenone (14.0%) as main components, while the TPI sample was composed mainly of beta-caryophyllene (23.7%), terpinolene (15.6%) and cis-beta-ocimene (15.5%). PMID:23074915

  5. Chemical composition of mate tea leaves (Ilex paraguariensis): a study of extraction methods.

    PubMed

    Assis Jacques, Rosângela; dos Santos Freitas, Lisiane; Flores Peres, Valéria; Dariva, Cláudio; de Oliveira, José Vladimir; Bastos Caramão, Elina

    2006-12-01

    The objective of this work was to investigate the extraction of Ilex paraguariensis leaves by means of three extraction techniques: pressurized liquid extraction (PLE, also called accelerated solvent extraction--ASE), maceration, and sonication. Samples of mate tea leaves were collected from an experiment conducted under agronomic control at Indfistria e Comércio de Erva-Mate Barão LTDA, Brazil. Six solvents with increasing polarities (n-hexane, toluene, dichloromethane, ethyl acetate, acetone, and methanol) were used in this investigation. Chemical analysis of the extracts was performed by GC coupled with a mass spectrometer detector. The identification and quantification were accomplished by coinjections of certified standards. The results showed that no significant differences in the qualities of the extracts were noticed regarding the extraction methods. On the other hand, the PLE technique was found to be more effective for the extractions of caffeine, phytol, palmitic, and stearic acid. The use of PLE led to a significant decrease in the total extraction time, amount of solvent consumption, and manipulation of samples compared to maceration and ultrasound-assisted extraction methods. PMID:17305239

  6. Micro Raman spectroscopy used for the study of corrosion products on copper alloys: study of the chemical composition of artificial patinas used for restoration purposes.

    PubMed

    Hayez, Valerie; Costa, Virginia; Guillaume, Joseph; Terryn, Herman; Hubin, Annick

    2005-04-01

    Studying the atmospheric corrosion of copper alloy artifacts is important to acquire a better knowledge about the condition of the object and its possible conservation and restoration. The nature of the formed product, e.g. sulfate, carbonate or chloride, depends on factors such as the amount of polluting elements or humidity but may also depend on the nature of the underlying aesthetic patina, applied by the artist. The composition of the patination solution and the method of patination will both influence the nature of this aesthetic patina, i.e. its chemical composition and morphology. However, although a lot of patination recipes exist, little is known about these patinas as far as composition, structure and ageing is concerned. Therefore, a combination of several surface analytical techniques is required for the complete characterization of patina layers. In this paper, Raman spectroscopy is used to study the characteristics of several patinas obtained on copper following different traditional recipes. PMID:15776167

  7. Semi-Continuous Measurements of Aerosol Chemical Composition During the Summer 2002 Yosemite National Park Special Study

    SciTech Connect

    Collette, J; Lee, T; Heath, J; Carrico, C; Herckes, P; Engling, G; McMeeking, G; Kreidenweis, S; Day, D; Malm, W; Cahill, T

    2003-02-16

    Semi-continuous measurements of fine particle composition were made over a period of several weeks in summer 2002 in Yosemite National Park, California. These included measurement of aerosol ionic composition (by PILS- Particle-Into-Liquid System) and aerosol carbon (by dual wavelength aethalometer and an R&P particulate carbon monitor). The data reveal that aerosol composition at the site is highly :variable in time, with a strong diurnal cycle. Interestingly, however, different diurnal cycles were sometimes observed for different chemical constituents of the particles. Organic carbon was observed to dominate fine particle mass, with some periods apparently associated with influx of smoke from wildfires in the western U.S. Measurements of fine particle carbon isotopes revealed the fraction of carbon from biogenic sources to range from approximately 73 to 95%. The ionic fraction of the aerosol was usually dominated by ammoniated sulfate. During most periods, PM{sub 2.5} nitrate was found primarily in sea salt particles from which chloride had been displaced. Strong variations in the extent of ammonia neutralization of sulfate were also observed. The ability to observe rapid changes in aerosol composition using these semi-continuous aerosol composition measurements is helpful for understanding the dynamic chemical composition of fine particles responsible for regional haze.

  8. Chemical compositions of primitive solar system particles

    NASA Technical Reports Server (NTRS)

    Sutton, Steve R.; Bajt, S.

    1994-01-01

    Chemical studies of micrometeorites are of fundamental importance primarily because atmospheric entry selection effects (such as destruction of friable objects) are less significant than those for conventional meteorites. As a result, particles that have experienced very little postaccretional processing have a significant chance of surviving the Earth encounter and subsequent collection. Thus, chemical analyses of these relatively unaltered micrometeorites may lead to a better understanding of the compositions of the most primitive materials in the solar system and thereby constrain the conditions (physical and chemical) that existed in the early solar nebula. Micrometeorites have been collected from the stratosphere, polar ices, and ocean sediments, but the stratospheric collection is the best source for the most unaltered material because they are small and are not heated to their melting points. Despite the fact that the stratospheric micrometeorites have masses in the nanogram range, a variety of microanalytical techniques have been applied to bulk chemical analyses with part-per-million sensitivity. In some cases, multi-disciplinary studies (e.g., chemistry and mineralogy) have been performed on individual particles. The first-order conclusion is that the chondrite-like particles are chemically similar to carbonaceous chondrites but in detail are distinct from members of the conventional meteorite collection. The purpose of this paper is to provide an overview of the results to date and identify important areas for further study.

  9. A case study of Asian dust storm particles: chemical composition, reactivity to SO2 and hygroscopic properties.

    PubMed

    Ma, Qingxin; Liu, Yongchun; Liu, Chang; Ma, Jinzhu; He, Hong

    2012-01-01

    Mineral dust comprises a great fraction of the global aerosol loading, but remains the largest uncertainty in predictions of the future climate due to its complexity in composition and physico-chemical properties. In this work, a case study characterizing Asian dust storm particles was conducted by multiple analysis methods, including SEM-EDS, XPS, FT-IR, BET, TPD/mass and Knudsen cell/mass. The morphology, elemental fraction, source distribution, true uptake coefficient for SO2, and hygroscopic behavior were studied. The major components of Asian dust storm particles are aluminosilicate, SiO2 and CaCO3, with organic compounds and inorganic nitrate coated on the surface. It has a low reactivity towards SO2 with a true uptake coefficient, 5.767 x 10(-6), which limits the conversion of SO2 to sulfate during dust storm periods. The low reactivity also means that the heterogeneous reactions of SO2 in both dry and humid air conditions have little effect on the hygroscopic behavior of the dust particles. PMID:22783615

  10. Studies on chemical composition and energy transformation in river Ganga at Kanpur and Varanasi due to environmental degradation.

    PubMed

    Kumar, Amit; Jaiswal, Dolly; Watal, Geeta

    2009-05-01

    Impact of effluents discharged in Ganga through various sources on chemical composition, energy transformation rate and level of heavy metals was studied at Kanpur and Varanasi. The effluents were found to be nil in oxygen with acidic in oxygen with acidic to neutral pH (6.8-7.0) and having very high values of free CO2 (40-68 mg l(-1)), alkalinity (300.0-412.0 mg l(-1)), conductance (1082.0-1824.0 micromhos), total dissolved solids (542.0-912.0 mg l(-1)), hardness (228.0-330.0 mg l(-1)), chloride (42.0-60.0 mg l(-1)), organic matter (8.4-18.2 mg l(-1)) and BOD load (98.0-248.0 mg l(-1)). The heavy metals Cu, Cr, Cd, Pb and Zn were also quite high in the effluents (48.6-78.4, 54.0-84.6, 9.8-12.4, 72.4-84.0 and 148.6-284.0 microg l(-1) respectively). The discharged effluents induced severe reduction in oxygen (av. 0.82-3.4 mg l(-1)) and sharp increase in the level of free CO2 (av. 10.8-24.8 mg l(-1)), alkalinity (182.4-288.4 mg l(-1)), conductance (480.0- 628.0 mmhos), total dissolved solids (254.0-315.0 mg l(-1)), hardness (170.0-259.0 mg l(-1)), chloride (36.0-52.0 mg l(-1)), organic matter (4.8-6.8 mg l(-1)) and BOD load (36.4-58.4 mg l(-1)) at the discharge point (OF zones) from their comparatively much lower values before discharge (AOF zone). The rate of energy transformation and photosynthetic efficiency also reduced considerably at the discharge point (av. 1060-2101 calm(-2)day(-1) and 0.09-0.18%) from high values before discharged point (av. 4045-4733 calm(-2)day(-1) and 0.34-0.42%). The level of Cu, Cr, Cd, Pb and Zn also showed higher values at the discharged point (20.4-38.0, 22.4-54.8, 5.2-7.8, 30.8-72.0 and 64.8-120.8 microg l(-1) respectively). Considerable improvement was observed below the discharge (BOF zone). Comparison with earlier observation revealed that the magnitude of impact has reduced considerably after the regulation in the discharge both in he respect of chemical composition and energy transformation rates. PMID:20120476

  11. 2-year study of chemical composition of bulk deposition in a South China coastal city: comparison with East Asian cities

    SciTech Connect

    K.M. Wai; P.A. Tanner; C.W.F. Tam

    2005-09-01

    Using the emission strengths of the precursor gases, the nature of soil in China, the ventilation power and half value rainout region length, the nss-SO{sub 4}{sup 2-}, NO{sub 3}{sup -}, Ca{sup 2+}, and NH{sub 4}{sup +} concentrations, and pH of rainwater at Hong Kong and other cities of China and Japan are compared and rationalized. The chemical composition of Hong Kong bulk deposition from 1998 to 2000 is taken from the collection and analysis of 156 daily samples. The volume-weighted average (VWA) pH is 4.2 over the whole study period. Nonsea salt- (nss-) sulfate is the most abundant species in the samples, and the pH mostly depended upon the concentrations of the major species nss-SO{sub 4}{sup 2-}, NO{sub 3}{sup -}, Ca{sup 2+}, and NH{sub 4}{sup +}. All species concentrations show higher levels in the cold season (especially NO{sub 3}- and Ca{sup 2+}), which indicates the dominant dilution effects in the warm season due to heavy rainfall and the influence of the continental outflow of pollutants during the cold season. For Hong Kong bulk deposition, the VWA pH is slightly lower in the cold season, and there is a slight decrease in VWA pH over the period from 1994 to 2000. The impact of acid rain in Hong Kong is briefly discussed. 36 refs., 3 figs., 5 tabs.

  12. 2-year study of chemical composition of bulk deposition in a south China coastal city: comparison with east Asian cities.

    PubMed

    Wai, K M; Tanner, P A; Tam, C W F

    2005-09-01

    Using the emission strengths of the precursor gases, the nature of soil in China, the ventilation power and half value rainout region length, the nss-SO42-, NO3-, Ca2+, and NH4+ concentrations, and pH of rainwater at Hong Kong and other cities of China and Japan are compared and rationalized. The chemical composition of Hong Kong bulk deposition from 1998 to 2000 is taken from our collection and analysis of 156 daily samples. The volume-weighted average (VWA) pH is 4.2 over the whole study period. Nonsea salt- (nss-) sulfate is the most abundant species in the samples, and the pH mostly depended upon the concentrations of the major species nss-SO42, NO3-, Ca2+, and NH4+. All species concentrations show higher levels in the cold season (especially NO3- and Ca2+), which indicates the dominant dilution effects in the warm season due to heavy rainfall and the influence of the continental outflow of pollutants during the cold season. For Hong Kong bulk deposition, the VWA pH is slightly lower in the cold season, and there is a slight decrease in VWA pH over the period from 1994 to 2000. The impact of acid rain in Hong Kong is briefly discussed. PMID:16190210

  13. The Chemical Composition of Maple Syrup

    ERIC Educational Resources Information Center

    Ball, David W.

    2007-01-01

    Maple syrup is one of several high-sugar liquids that humans consume. However, maple syrup is more than just a concentrated sugar solution. Here, we review the chemical composition of maple syrup. (Contains 4 tables and 1 figure.)

  14. Chemical composition of Earth-like planets

    NASA Astrophysics Data System (ADS)

    Ronco, M. P.; Thiabaud, A.; Marboeuf, U.; Alibert, Y.; de Elía, G. C.; Guilera, O. M.

    2015-08-01

    Models of planet formation are mainly focused on the accretion and dynamical processes of the planets, neglecting their chemical composition. In this work, we calculate the condensation sequence of the different chemical elements for a low-mass protoplanetary disk around a solar-type star. We incorporate this sequence of chemical elements (refractory and volatile elements) in our semi-analytical model of planet formation which calculates the formation of a planetary system during its gaseous phase. The results of the semi-analytical model (final distributions of embryos and planetesimals) are used as initial conditions to develope N-body simulations that compute the post-oligarchic formation of terrestrial-type planets. The results of our simulations show that the chemical composition of the planets that remain in the habitable zone has similar characteristics to the chemical composition of the Earth. However, differences exist that can be associated to the dynamical environment in which they were formed.

  15. Study of chemical composition and morphology of airborne particles in Chandigarh, India using EDXRF and SEM techniques.

    PubMed

    Sharma, S G; Srinivas, M S N

    2009-03-01

    The elemental composition and morphology of aerosols, collected from March 95 to February 96 and March 96 to August 96 respectively in the city of Chandigarh, India is determined using Energy Dispersive X-ray fluorescence and scanning electron microscopic techniques. The elemental concentration levels are found to be higher by a factor of 2-7 in the spring season as compared to the rainy season. The concentration of spherical and non-spherical (i.e. elongated) aerosols is more in the spring season and is reduced drastically in the rainy season due to the prominent wash out effect of rains. More accurate particle classification and source identification is obtained when based on combination of chemical composition and particle morphology. Possible sources identified from this analysis are soil dust, Industrial activity, Agricultural and Garbage burning, Maritime aerosols and Automobile exhaust. PMID:18418721

  16. Chemical composition of fat and oil products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fats and oils are an important dietary component, and contribute to the nutritional and sensory quality of foods. This chapter focuses on the chemical composition of fats and oils, and how these compositions affect the functional properties of fats and oils in foods. The focus will remain on the mos...

  17. Evaluation of chemical composition and efficacy of Chinese propolis extract on Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans: An in vitro study

    PubMed Central

    Agarwal, Garima; Vemanaradhya, Gayathri G.; Mehta, Dhoom S.

    2012-01-01

    Background: Propolis as a natural remedy has maintained its popularity over long periods of time. The aim of this study was to determine the chemical composition in terms of total phenolic compounds and flavonoids present in Chinese propolis and to carry out an in vitro evaluation of its antimicrobial activity and the minimal inhibitory concentrations for Porphyromonas gingivalis (Pg) and Aggregatibacter actinomycetemcomitans (Aa). Materials and Methods: From the ethanolic extract of propolis (EEP), total phenol content was determined by the Folin–Ciocalteau method, flavones and flavonols by the modified aluminum chloride colorimetric method, and flavanones by the 2.4-dinitrophenylhydrazine (2,4-DNP) method. Agar well diffusion assay was used to evaluate the antimicrobial potential of propolis against Pg and Aa. The minimum inhibitory concentration of propolis against the two bacteria was determined using serial tube dilution technique. Results: The total concentration of phenol in the EEP was 19.44%, flavones and flavonols 2.616%, and flavanones 16.176%. The inhibitory zone depicting antimicrobial activity ranged from 18 to 25 mm for Pg and from 12 to 14 mm for Aa. The concentration range of Chinese propolis that is sensitive to inhibit the growth of Pg was 0.1–0.0125 μg/ml and for Aa it was 0.1–0.025 μg/ml. Conclusion: These data suggest that Chinese propolis has potent antimicrobial activity against the two periodontopathogens, suggesting its possible use as a natural alternative to the widely used synthetic antibiotics for periodontal therapy. PMID:23293477

  18. AES study on the chemical composition of ferroelectric BaTiO3 thin films RF sputter-deposited on silicon

    NASA Technical Reports Server (NTRS)

    Dharmadhikari, V. S.; Grannemann, W. W.

    1983-01-01

    AES depth profiling data are presented for thin films of BaTiO3 deposited on silicon by RF sputtering. By profiling the sputtered BaTiO3/silicon structures, it was possible to study the chemical composition and the interface characteristics of thin films deposited on silicon at different substrate temperatures. All the films showed that external surface layers were present, up to a few tens of angstroms thick, the chemical composition of which differed from that of the main layer. The main layer had stable composition, whereas the intermediate film-substrate interface consisted of reduced TiO(2-x) oxides. The thickness of this intermediate layer was a function of substrate temperature. All the films showed an excess of barium at the interface. These results are important in the context of ferroelectric phenomena observed in BaTiO3 thin films.

  19. Cometary Coma Chemical Composition (C4) Mission

    NASA Technical Reports Server (NTRS)

    Carle, Glenn C.; Clark, Benton C.; Knocke, Philip C.; OHara, Bonnie J.; Adams, Larry; Niemann, Hasso B.; Alexander, Merle; Veverka, Joseph; Goldstein, Raymond; Huebner, Walter; Morrison, David (Technical Monitor)

    1994-01-01

    Cometary exploration remains of great importance to virtually all of space science. Because comets are presumed to be remnants of the early solar nebula, they are expected to provide fundamental knowledge as to the origin and development of the solar system as well as to be key to understanding of the source of volatiles and even life itself in the inner solar system. Clearly the time for a detailed study of the composition of these apparent messages from the past has come. A comet rendezvous mission, the Cometary Coma Chemical Composition (C4) Mission, is now being studied as a candidate for the new Discovery program. This mission is a highly-focussed and usefully-limited subset of the Cometary Rendezvous Asteroid Flyby (CRAF) Mission. The C4 mission will concentrate on measurements that will produce an understanding of the composition and physical makeup of a cometary nucleus. The core science goals of the C4 mission are 1) to determine the chemical, elemental, and isotopic composition of a cometary nucleus and 2) to characterize the chemical and isotopic nature of its atmosphere. A related goal is to obtain temporal information about the development of the cometary coma as a function of time and orbital position. The four short-period comets -- Tempel 1, Tempel 2, Churyumov-Gerasimenko, and Wirtanen -which all appear to have acceptable dust production rates, were identified as candidate targets. Mission opportunities have been identified beginning as early as 1998. Tempel I with a launch in 1999, however, remains the baseline comet for studies of and planning the C4 mission. The C4 mission incorporates two science instruments and two engineering instruments in the payload to obtain the desired measurements. The science instruments include an advanced version of the Cometary Ice and Dust Experiment (CIDEX), a mini-CIDEX with a sample collection system, an X-ray Fluorescence Spectrometer and a Pyrolysis-Gas Chromatograph, and a simplified version of the Neutral

  20. Chemical Industry Bandwidth Study

    SciTech Connect

    none,

    2006-12-01

    The Chemical Bandwidth Study provides a snapshot of potentially recoverable energy losses during chemical manufacturing. The advantage of this study is the use of "exergy" analysis as a tool for pinpointing inefficiencies.

  1. Chemical composition of cometary nuclei

    NASA Technical Reports Server (NTRS)

    Delsemme, A. H.

    1982-01-01

    Observational evidence pertaining to the origin and composition of cometary material is reviewed. Arguments favoring the undifferentiated character of the icy conglomerate are summarized. Theoretical descriptions of the sublimation of a cometary nucleus and the velocity field of the expanding gas are presented and compared with observations. The nature of cometary dust and the atomic abundances of H, C, N, O, and S in the volatile fraction are examined, and data on the dust and volatile fractions are combined to derive elemental abundances. It is shown that O, N, and S in cometary nuclei appear to have essentially cosmic abundances but that both H and C are drastically depleted with respect to the cosmic abundances. The apparent depletion of C by a factor of more than three is discussed. It is suggested that the missing carbon might be hidden in the dust fraction in the form of heavy organic molecules or might have remained in either the primeval solar nebula or interstellar space.

  2. [EDXRF study on the chemical composition and raw material recipe of Jindezhen porcelains in the five dynasties].

    PubMed

    zhang, Mao-lin; Zhou, Jian; Li, Qi-jiang; Wu, Jun-ming; Gan, Ke

    2012-05-01

    Early crafts of porcelain making in Jindezhen were an important issue in ceramic history of China. The chemical composition of white porcelain and celadon samples excavated from Xianghu Kiln in the five dynasties was analyzed using energy dispersive X-ray fluorescence (EDXRF). Raw material recipes of the samples were discussed. The results showed that white porcelain bodies of Xianghu Kiln in the Five Dynasties were made from porcelain stone, while celadon bodies were made from porcelain stone and Zijin clay. Glaze ash and glaze stone were both used in the formula of white porcelain and celadon glaze, and the amount of glaze ash in the celadon was higher than that in the white porcelain samples. PMID:22827103

  3. Chemical compositions and radiative properties of dust and anthropogenic air masses study in Taipei Basin, Taiwan, during spring of 2004

    NASA Astrophysics Data System (ADS)

    Chang, Shih-Yu; Fang, Guor-Cheng; Chou, Charles C.-K.; Chen, Wei-Nai

    Asia is one of the major sources of not only mineral dust but also anthropogenic aerosols. Continental air masses associated with the East Asian winter monsoon always contain high contents of mineral dust and anthropogenic species and transported southeastward to Taiwan, which have significant influences on global atmospheric radiation transfer directly by scattering and absorbing solar radiation in each spring. However, few measurements for the long-range transported aerosol and its optical properties were announced in this area, between the Western Pacific and the southeastern coast of Mainland China. The overall objective of this work is to quantify the optical characteristics of different aerosol types in the Eastern Asian. In order to achieve this objective, meteorological parameters, concentrations of PM 10 and its soluble species, and optical property of atmospheric scattering coefficients were measured continuously with 1 h time-resolved from 11 February to 7 April 2004 in Taipei Basin (25°00'N, 121°32'E). In this work, the dramatic changes of meteorological parameters such as temperature and winds were used to determine the influenced period of each air mass. Continental, strong continental, marine, and stagnant air masses defined by the back-trajectory analysis and local meteorology were further characterized as long-range transport pollution, dust, clean marine, and local pollution aerosols, respectively, according to the diagnostic ratios. The aerosol mass scattering efficiency of continental pollution, dust, clean marine, and local pollution aerosols were ranged from 1.3 to 1.6, 0.7 to 1.0, 1.4 and 1.4 to 2.3 m 2 g -1, respectively. Overall, there are two distinct populations of aerosol mass scattering efficiencies, one for an aerosol chemical composition dominated by dust (<1.0 m 2 g -1) and the other for an aerosol chemical composition dominated by anthropogenic pollutants (1.3-2.3 m 2 g -1), which were similar to the previous measurements with

  4. Chemical composition, effective atomic number and electron density study of trommel sieve waste (TSW), Portland cement, lime, pointing and their admixtures with TSW in different proportions.

    PubMed

    Kurudirek, Murat; Aygun, Murat; Erzeneoğlu, Salih Zeki

    2010-06-01

    The trommel sieve waste (TSW) which forms during the boron ore production is considered to be a promising building material with its use as an admixture with Portland cement and is considered to be an alternative radiation shielding material, also. Thus, having knowledge on the chemical composition and radiation interaction properties of TSW as compared to other building materials is of importance. In the present study, chemical compositions of the materials used have been determined using a wavelength dispersive X-ray fluorescence spectrometer (WDXRFS). Also, TSW, some commonly used building materials (Portland cement, lime and pointing) and their admixtures with TSW have been investigated in terms of total mass attenuation coefficients (mu/rho), photon interaction cross sections (sigma(t)), effective atomic numbers (Z(eff)) and effective electron densities (N(e)) by using X-rays at 22.1, 25keV and gamma-rays at 88keV photon energies. Possible conclusions were drawn with respect to the variations in photon energy and chemical composition. PMID:20080413

  5. A study of the chemical composition of black cumin oil and its effect on penetration enhancement from transdermal formulations.

    PubMed

    Amin, Saima; Mir, Showkat R; Kohli, Kanchan; Ali, Babar; Ali, Mohd

    2010-07-01

    The chemical composition of the solvent extracted fixed oil of black cumin (Nigella sativa L.) seeds was determined by capillary GC and GC/MS. Thirty-two fatty acids (99.9%) have been identified in the fixed oil. The major fatty acids were linoleic acid (50.2%), oleic acid (19.9%), margaric acid (10.3%), cis-11,14-eicosadienoic acid (7.7%) and stearic acid (2.5%). The effect of black cumin oil on in vitro percutaneous absorption of the model lipophilic drug carvedilol was investigated using excised rat abdominal skin. Transdermal flux, permeability coefficient and enhancement factor were calculated for different concentrations of oil in isopropyl alcohol. Black cumin oil (5% v/v) exhibited the highest enhancement in permeation. The increase in the permeability of the drug is due to increased drug diffusivity through the stratum corneum under the influence of black cumin oil. A higher content of linoleic acid (and other unsaturated fatty acids) in the oil has been postulated to be responsible for the enhancement of in vitro percutaneous absorption of the drug. PMID:20582810

  6. A Statistical Approach for Judging Stability of Whole Mixture Chemical Composition over Time for Highly Complex Disinfection By-Product Mixtures from EPA's Four Lab Study

    EPA Science Inventory

    Chemical characterization of complex mixtures and assessment of stability over time of the characterized chemicals is crucial both to characterize exposure and to use data from one mixture as a surrogate for other similar mixtures. The chemical composition of test mixtures can va...

  7. Chemical composition of Luna 16 lunar regolith

    NASA Technical Reports Server (NTRS)

    Vinogradov, A. P.; Chupakhin, M. S.; Belyayev, Y. I.

    1974-01-01

    Data on the chemical composition of regolith returned by the Luna 16 automatic station and two fragments of basalts from the lower layer of the core are presented. Spark mass spectrometric, primary X-ray spectral, emission spectral, and atomic absorption methods were used in the analysis. The regolith of mare provinces were shown to be a mixture of material of various origins. The source of the material of the mare regolith was principally basalts of the corresponding lunar lava maria. The regolith is genetically related to it. This follows from a comparison of the chemical composition, mineralogical, and petrochemical features of the basesalts and the regolith from the Sea of Fertility, Sea of Tranquillity, and Ocean of Storms, respectively.

  8. On-line chemical composition analyzer development

    SciTech Connect

    Roberts, M.J.; Garrison, A.A.; Muly, E.C.; Moore, C.F.

    1992-02-01

    The energy consumed in distillation processes in the United States represents nearly three percent of the total national energy consumption. If effective control of distillation columns can be accomplished, it has been estimated that it would result in a reduction in the national energy consumption of 0.3%. Real-time control based on mixture composition could achieve these savings. However, the major distillation processes represent diverse applications and at present there does not exist a proven on-line chemical composition sensor technology which can be used to control these diverse processes in real-time. This report presents a summary of the findings of the second phase of a three phase effort undertaken to develop an on-line real-time measurement and control system utilizing Raman spectroscopy. A prototype instrument system has been constructed utilizing a Perkin Elmer 1700 Spectrometer, a diode pumped YAG laser, two three axis positioning systems, a process sample cell land a personal computer. This system has been successfully tested using industrially supplied process samples to establish its performance. Also, continued application development was undertaken during this Phase of the program using both the spontaneous Raman and Surface-enhanced Raman modes of operation. The study was performed for the US Department of Energy, Office of Industrial Technologies, whose mission is to conduct cost-shared R D for new high-risk, high-payoff industrial energy conservation technologies. Although this document contains references to individual manufacturers and their products, the opinions expressed on the products reported do not necessarily reflect the position of the Department of Energy.

  9. Chemical microsensors based on polymer fiber composites

    NASA Astrophysics Data System (ADS)

    Kessick, Royal F.; Levit, Natalia; Tepper, Gary C.

    2005-05-01

    There is an urgent need for new chemical sensors for defense and security applications. In particular, sensors are required that can provide higher sensitivity and faster response in the field than existing baseline technologies. We have been developing a new solid-state chemical sensor technology based on microscale polymer composite fiber arrays. The fibers consist of an insulating polymer doped with conducting particles and are electrospun directly onto the surface of an interdigitated microelectrode. The concentration of the conducting particles within the fiber is controlled and is near the percolation threshold. Thus, the electrical resistance of the polymer fiber composite is very sensitive to volumetric changes produced in the polymer by vapor absorption. Preliminary results are presented on the fabrication and testing of the new microsensor. The objective is to take advantage of the very high surface to volume ratio, low thermal mass and linear geometry of the composite fibers to produce sensors exhibiting an extremely high vapor sensitivity and rapid response. The simplicity and low cost of a resistance-based chemical microsensor makes this sensing approach an attractive alternative to devices requiring RF electronics or time-of-flight analysis. Potential applications of this technology include battlespace awareness, homeland security, environmental surveillance, medical diagnostics and food process monitoring.

  10. Cometary coma chemical composition (C4) mission. [Abstract only

    NASA Technical Reports Server (NTRS)

    Carle, G. C.; Clark, B. C.; Niemann, H. B.; Alexander, M.; Knocke, P. C.; O'Hara, B. J.

    1994-01-01

    Cometary missions are of enormous fundamental importance for many different space science disciplines, including exobiology. Comets are presumed relics of the earliest, most primitive material in the solar nebula and are related to the planetesimals. They undoubtedly provided a general enrichment of volatiles to the inner solar system (contributing to atmospheres and oceans) and may have been key to the origin of life. A Discovery class, comet rendezvous mission, the Cometary Coma Chemical Composition (C4) Mission, was selected for further study by NASA earlier this year. The C4 Mission is a highly focused and usefully-limited subset of the Cometary Rendezvous Asteroid Flyby (CRAF) Mission, concentrating exclusively on measurements which will lead to an understanding of the chemical composition and make-up of the cometary nucleus. The scientific goals of the Cometary Coma Chemical Composition (C4) Mission are to rendezvous with a short-period comet and (1) to determine the elemental, chemical, and isotopic composition of the nucleus and (2) to characterize the chemical and isotopic nature of its atmosphere. Further, it is a goal to obtain preliminary data on the development of the coma (dust and gas composition) as a function of time and orbital position.

  11. Spatial and Temporal Variation in Fine Particulate Matter Mass and Chemical Composition: The Middle East Consortium for Aerosol Research Study

    PubMed Central

    Abdeen, Ziad; Heo, Jongbae; Wu, Bo; Shpund, Jacob; Vanger, Arye; Sharf, Geula; Moise, Tamar; Brenner, Shmuel; Nassar, Khaled; Saleh, Rami; Al-Mahasneh, Qusai M.; Sarnat, Jeremy A.; Schauer, James J.

    2014-01-01

    Ambient fine particulate matter (PM2.5) samples were collected from January to December 2007 to investigate the sources and chemical speciation in Palestine, Jordan, and Israel. The 24-h PM2.5 samples were collected on 6-day intervals at eleven urban and rural sites simultaneously. Major chemical components including metals, ions, and organic and elemental carbon were analyzed. The mass concentrations of PM2.5 across the 11 sites varied from 20.6 to 40.3 μg/m3, with an average of 28.7 μg/m3. Seasonal variation of PM2.5 concentrations was substantial, with higher average concentrations (37.3 μg/m3) in the summer (April–June) months compared to winter (October–December) months (26.0 μg/m3) due mainly to high contributions of sulfate and crustal components. PM2.5 concentrations in the spring were greatly impacted by regional dust storms. Carbonaceous mass was the most abundant component, contributing 40% to the total PM2.5 mass averaged across the eleven sites. Crustal components averaged 19.1% of the PM2.5 mass and sulfate, ammonium, and nitrate accounted for 16.2%, 6.4%, and 3.7%, respectively, of the total PM2.5 mass. The results of this study demonstrate the need to better protect the health and welfare of the residents on both sides of the Jordan River in the Middle East. PMID:25045751

  12. A neutron diffraction study of hydrogen positions at 13 K, domain model, and chemical composition of staurolite

    NASA Astrophysics Data System (ADS)

    Ståhl, K.; Kvick, Å.; Smith, J. V.

    1988-04-01

    Comparison of new neutron and old X-ray diffraction data for single crystals of staurolite from Pizzo Forno yielded unique answers to some, but not all, outstanding structural questions. Neutron data were collected at 13(1) K for a crystal with assumed composition Li 0.07Mg 0.87Ti 0.14V 0.01Cr 0.01Mn 0.04Fe 2+3.00 Fe 3+0.06Co 0.01Zn 0.05Al 17.69Si 7.67O 48H 3.41F 0.01, Mw = 1671, a = 7.8639(10), b = 16.625(2), c = 5.651(2) Å, β = 90.015(14)°, {C2}/{m}, Z = 1, D x = 3.75 g cm-3; 1874 (1024 unique) reflections, λ = 1.1598(1) Å, R( F) = 3.3%. The diffraction evidence is consistent with full occupancy of the Si, Al(1), Al(2), and Al(3) sites, but not of the other ones. Detailed assignment of atoms is based on diffraction evidence and crystal-chemical arguments, but some uncertainties remain; thus exchange of (Li + Fe) by two Mg would have little effect on diffraction data. A structural model with three types of domains is proposed: ˜63% type 1, (Fe, etc.) + H(1); ˜22% type 2, (Mg, etc.) + H(2); ˜15% type 3, (Fe, etc.) without hydrogen. For the orthorhombic pseudostructure, the occupancies of the two hydrogen sites place strong restrictions on the other site occupancies. The 25(4)% observed occupancy of H(2) limits the occupancy of the nearby (Fe, etc.) site to a maximum of 75(4)%. To explain the neutron scattering, the Fe site must be occupied mainly by Fe; Li, Mn, Zn, and Mg may also occupy this site. A good ionic balance is attained for the type 2 domain if the U site from the old X-ray work is occupied simultaneously with H(2). To match the neutron data, assignment of 21(2)% Mg to the U site is plausible, but other substituents are possible. H(2) lies directly between two O(1) atoms at ˜0.9 and 2.3 Å, and H(1) is displaced away from the Fe site so that it is bonded to one O(1) at 1.01 Å and one O(3) at 2.07 Å. Four-fifths of the Fe atoms should be displaced from z = 0.25 because of electrostatic repulsion from H(1), and one-fifth should not be. This is

  13. Chemical Composition of Fresh and Aged Biochars

    NASA Astrophysics Data System (ADS)

    Cooper, W. T.; Hamdan, R.; Mukherjee, A.; Zimmerman, A. R.

    2014-12-01

    It is possible to manipulate the chemical and physical properties of pyrogenic organic matter ('black carbon' or 'biochar') during its production and tailor its composition for intended environmental management applications. In this study biochars made from grass (Tripsacum floridanum), oak (Quercus lobata), and pine (Pinus taeda) at 250 ºC in air and 400 and 650 ºC under N2 were characterized by solid state 13C-NMR spectroscopy and desorption atmospheric pressure photoionization mass spectrometry. Among the biochars produced, those originating from pine showed distinct characteristics, with greater amounts of oxygenated aromatic clusters after low temperature combustion and more condensed aromatic clusters after higher temperature pyrolysis. Although a mixture of small and large aromatic clusters occurred across the temperature profile, cluster size increased and functionality decreased with increasing combustion temperature (Figure 1). At medium and high temperatures, aromatic clusters of up to 60- carbon aromatic rings inter-connected with small chains dominated the biochars examined. These structures are intermediate in size between the linearly condensed structures and the predominantly condensed aromatic clusters proposed in earlier studies. Field aging of the pure biochars for 15 months decreased the total acid functional group content as determined by Boehm titration, but solid-state 13C-NMR analyses suggested the creation and transformation of a range of functional groups via leaching, oxidation, and addition of microbially-produced organic matter. Similar trends were observed when the biochars were mixed with soils, suggesting that the same biochar aging processes occurred in the soil environment. These findings demonstrate that biochar transformations occur over time through a multitude of processes that are both biochar and soil type-dependent.

  14. Surface and Compositional Study of Graphene grown on Lithium Niobate (LiNbO3) substrates by Chemical Vapour Deposition

    NASA Astrophysics Data System (ADS)

    Karamat, Shumaila; Celik, Umit; Oral, Ahmet

    The diversity required in the designing of electronic devices motivated the community to always attempt for new functional materials and device structures. Graphene is considered as one of the most promising candidate materials for future electronics and carbon based devices. It is very exciting to combine graphene with new dielectric materials which exhibit multifunctional properties. Lithium Niobate exhibits ferro-, pyro-, and piezoelectric properties with large electro-optic, acousto-optic, and photoelastic coefficients as well as strong photorefractive and photovoltaic effects which made it one of the most extensively studied materials over the last 50 years. We used ambient pressure chemical vapour deposition to grow graphene on LiNbO3 substrates without any catalyst. The growth was carried out in presence of methane, argon and hydrogen. AFM imaging showed very unique structures on the surface which contains triangular domains. X-ray photoelectron spectroscopy (XPS) was used to get information about the presence of necessary elements, their bonding with LiNbO3 substrates. Detailed characterization is under process which will be presented later.

  15. Comparative study of the methane production based on the chemical compositions of Mangifera Indica and Manihot Utilissima leaves.

    PubMed

    Mambanzulua Ngoma, Philippe; Hiligsmann, Serge; Sumbu Zola, Eric; Culot, Marc; Fievez, Thierry; Thonart, Philippe

    2015-01-01

    Leaves of Mangifera Indica (MI, mango leaves) and Manihot Utilissima (MU, cassava leaves) are available in tropical regions and are the most accessible vegetal wastes of Kinshasa, capital of Democratic Republic of Congo. These wastes are not suitably managed and are not rationally valorized. They are abandoned in full air, on the soil and in the rivers. They thus pollute environment. By contrast, they can be recuperated and treated in order to produce methane (energy source), organic fertilizer and clean up the environment simultaneously. The main objective of this study was to investigate methane production from MI and MU leaves by BMP tests at 30°C. The yields achieved from the anaerobic digestion of up to 61.3 g raw matter in 1 l medium were 0.001 l/g and 0.100 l CH4/g volatile solids of MI and MU leaves, respectively. The yield of MU leaves was in the range mentioned in the literature for other leaves because of a poor presence of bioactive substrates, and low C/N ratio. This methane yield corresponded to 7% of calorific power of wood. By contrast, the methane yield from MI leaves was almost nil suggesting some metabolism inhibition because of their rich composition in carbon and bioactive substrates. Whereas classical acidogenesis and acetogenesis were recorded. Therefore, methane production from the sole MI leaves seems unfavorable by comparison to MU leaves at the ambient temperature in tropical regions. Their solid and liquid residues obtained after anaerobic digestion would be efficient fertilizers. However, the methane productivity of both leaves could be improved by anaerobic co-digestion. PMID:25825684

  16. Observations about chemical composition of aerosols in the Brazilian Amazon region - Case study: Biomass burning in the subequatorial Amazon region

    NASA Astrophysics Data System (ADS)

    Gioda, A.; Monteiro, I. L.; Almeida, A. C.; Hacon, S. S.; Dallacort, R.; Ignotti, E.; Godoy, J. M.; Loureiro, A. L.; Morais, F.; Artaxo, P.

    2012-04-01

    The study was carried out in two cities in the Brazilian Amazon region, Tangará da Serra (14 ° 37'10 "S, 57 ° 29'09" W, 427 m asl), located in a transition area between the Amazon biome and the Cerrado and has the characteristics of urban area in Amazon region; and Alta Floresta (9 ° 52 '32 "S, 56 ° 5' 10" W, 283 m asl) situated in the extreme north of the state of Mato Grosso (MT), both in the subequatorial Amazon region. Tangara da Serra has the largest production of sugar cane in the subequatorial Amazon region. They are located 800 km from each other. These two regions are inserted in a region with typical cycles of drought and rain that alter air pollution levels, and lies in the dispersion path of the pollution plume resulting from burnings in the Brazilian Amazon and pollution emanating from neighboring countries. Both cities have wet tropical climate with two well defined seasons: rainy summer (November to May) and dry winter (June to October). During the dry winter, biomass burnings are frequent in these regions. In 2008, the Department of the Environment has banned fires in the period from July 15 to September 15 throughout the State. In this study chemical characterization was performed for approximately 100 aerosol samples collected in each site during 2008. Fine and coarse aerosol samples collected in SFUs were analyzed by ion chromatography for determination of cations (Na+, K+, NH3+, Ca2+ and Mg2+), anions (SO42-, Cl- and NO3-) and organic acids (acetate and formiate) and also measures of black carbon (BC) (Aethalometer). The results showed that for both sites the average concentrations were quite similar for PM2.5 (16 µg/m3), PM10 (11 and 13 µg/m3) and black carbon (1.4 µg/m3 for PM2.5 and 1.6 µg/m3 for PM10). Sulfate was the predominant species in fine (45%) and coarse (26%) particles in both sites. The sulfate concentrations ranged from 0.01-1.92 µg/m3 in PM2.5 and 0.01-1.66 µg/m3 in PM10 in Tangará da Serra and 0.01-2.93 µg/m3 in PM2

  17. Chemical Composition and Photometry of BE Lyncis

    NASA Astrophysics Data System (ADS)

    Kim, Chulhee; Yushchenko, A. V.; Kim, S.-L.; Jeon, Y.-B.; Kim, Chun-Hwey

    2012-05-01

    High-resolution spectroscopic observation was carried out to find the chemical composition of BE Lyn. The abundances of 25 chemical elements from carbon to neodymium were found. The deficiency of iron appeared to be equal to Δ log N(Fe) = -0.26 ± 0.08 with respect to the solar metallicity, and the abundances of other elements were mainly undersolar. Only nitrogen, sodium, aluminum, and sulfur showed overabundances near 0.2-0.3 dex. The abundance pattern showed no clear signs of accretion or mass transfer events. It is not possible to exclude the classification of BE Lyn as a SX Phe-type star with slightly undersolar abundances of chemical elements. In addition, new differential time-series observations of BE Lyn were secured using V filters, and seven new times of light maximum were identified. We collected 162 times of light maximum from the literature, unpublished data, and an open database, and we proceeded to investigate the pulsational properties of BE Lyn. All five harmonic frequencies were identified using the Fourier decomposition method.

  18. Surface chemical composition analysis of heat-treated bamboo

    NASA Astrophysics Data System (ADS)

    Meng, Fan-dan; Yu, Yang-lun; Zhang, Ya-mei; Yu, Wen-ji; Gao, Jian-min

    2016-05-01

    In this study, the effect of heat treatment on the chemical composition of bamboo slivers was studied. The chemical properties of the samples were examined by chemical analysis. Results showed a decrease in the contents of holocellulose and α-cellulose, as well as an increase in the contents of lignin and extractives. Changes in the chemical structure of bamboo components were analyzed by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). FTIR spectroscopy results indicated that hemicellulose contents decrease, whereas lignin contents increase after heat treatment. Ester formation linked to lignin decreased the hygroscopicity of the bamboo samples and consequently improved their dimensional stability and durability. XPS spectroscopy results showed that hemicelluloses and celluloses are relatively more sensitive to the heating process than lignin. As a consequence, hemicellulose and cellulose contents decreased, whereas lignin contents increased during heat treatment. The results obtained in this study provide useful information for the future utilization of heat-treated bamboo.

  19. Chemical composition of selected edible nut seeds.

    PubMed

    Venkatachalam, Mahesh; Sathe, Shridhar K

    2006-06-28

    Commercially important edible nut seeds were analyzed for chemical composition and moisture sorption. Moisture (1.47-9.51%), protein (7.50-21.56%), lipid (42.88-66.71%), ash (1.16-3.28%), total soluble sugars (0.55-3.96%), tannins (0.01-0.88%), and phytate (0.15-0.35%) contents varied considerably. Regardless of the seed type, lipids were mainly composed of mono- and polyunsaturated fatty acids (>75% of the total lipids). Fatty acid composition analysis indicated that oleic acid (C18:1) was the main constituent of monounsaturated lipids in all seed samples. With the exception of macadamia, linoleic acid (C18:2) was the major polyunsaturated fatty acid. In the case of walnuts, in addition to linoleic acid (59.79%) linolenic acid (C18:3) also significantly contributed toward the total polyunsaturated lipids. Amino acid composition analyses indicated lysine (Brazil nut, cashew nut, hazelnut, pine nut, and walnut), sulfur amino acids methionine and cysteine (almond), tryptophan (macadamia, pecan), and threonine (peanut) to be the first limiting amino acid as compared to human (2-5 year old) amino acid requirements. The amino acid composition of the seeds was characterized by the dominance of hydrophobic (range = 37.16-44.54%) and acidic (27.95-33.17%) amino acids followed by basic (16.16-21.17%) and hydrophilic (8.48-11.74%) amino acids. Trypsin inhibitory activity, hemagglutinating activity, and proteolytic activity were not detected in the nut seed samples analyzed. Sorption isotherms (Aw range = 0.08-0.97) indicated a narrow range for monolayer water content (11-29 mg/g of dry matter). No visible mold growth was evident on any of the samples stored at Aw < 0.53 and 25 degrees C for 6 months. PMID:16787018

  20. Seasonal variations in the chemical composition of particulate matter: a case study in the Po Valley. Part I: macro-components and mass closure.

    PubMed

    Perrino, C; Catrambone, M; Dalla Torre, S; Rantica, E; Sargolini, T; Canepari, S

    2014-03-01

    The seasonal variability in the mass concentration and chemical composition of atmospheric particulate matter (PM10 and PM2.5) was studied during a 2-year field study carried out between 2010 and 2012. The site of the study was the area of Ferrara (Po Valley, Northern Italy), which is characterized by frequent episodes of very stable atmospheric conditions in winter. Chemical analyses carried out during the study allowed the determination of the main components of atmospheric PM (macro-elements, ions, elemental carbon, organic matter) and a satisfactory mass closure was obtained. Accordingly, chemical components could be grouped into the main macro-sources of PM: soil, sea spray, inorganic compounds from secondary reactions, vehicular emission, organics from domestic heating, organics from secondary formation, and other sources. The more significant seasonal variations were observed for secondary inorganic species in the fine fraction of PM; these species were very sensitive to air mass age and thus to the frequency of stable atmospheric conditions. During the winter ammonium nitrate, the single species with the highest concentration, reached concentrations as high as 30 μg/m(3). The intensity of natural sources was fairly constant during the year; increases in natural aerosols were linked to medium and long-range transport episodes. The ratio of winter to summer concentrations was roughly 2 for combustion product, close to 3 for secondary inorganic species, and between 2 and 3 for organics. The winter increase of organics was due to poorer atmospheric dispersion and to the addition of the emission from domestic heating. A similar winter to summer ratio (around 3) was observed for the fine fraction of PM. PMID:24019138

  1. Advanced Chemical Propulsion Study

    NASA Technical Reports Server (NTRS)

    Woodcock, Gordon; Byers, Dave; Alexander, Leslie A.; Krebsbach, Al

    2004-01-01

    A study was performed of advanced chemical propulsion technology application to space science (Code S) missions. The purpose was to begin the process of selecting chemical propulsion technology advancement activities that would provide greatest benefits to Code S missions. Several missions were selected from Code S planning data, and a range of advanced chemical propulsion options was analyzed to assess capabilities and benefits re these missions. Selected beneficial applications were found for higher-performing bipropellants, gelled propellants, and cryogenic propellants. Technology advancement recommendations included cryocoolers and small turbopump engines for cryogenic propellants; space storable propellants such as LOX-hydrazine; and advanced monopropellants. It was noted that fluorine-bearing oxidizers offer performance gains over more benign oxidizers. Potential benefits were observed for gelled propellants that could be allowed to freeze, then thawed for use.

  2. Preparation and Evaluation of Hybrid Composites of Chemical Fuel and Multi-walled Carbon Nanotubes in the Study of Thermopower Waves.

    PubMed

    Hwang, Hayoung; Yeo, Taehan; Cho, Yonghwan; Shin, Dongjoon; Choi, Wonjoon

    2015-01-01

    When a chemical fuel at a certain position in a hybrid composite of the fuel and a micro/nanostructured material is ignited, chemical combustion occurs along the interface between the fuel and core materials. Simultaneously, dynamic changes in thermal and chemical potentials across the micro/nanostructured materials result in concomitant electrical energy generation induced by charge transfer in the form of a high-output voltage pulse. We demonstrate the entire procedure of a thermopower wave experiment, from synthesis to evaluation. Thermal chemical vapor deposition and the wet impregnation process are respectively employed for the synthesis of a multi-walled carbon nanotube array and a hybrid composite of picric acid/sodium azide/multi-walled carbon nanotubes. The prepared hybrid composites are used to fabricate a thermopower wave generator with connecting electrodes. The combustion of the hybrid composite is initiated by laser heating or Joule-heating, and the corresponding combustion propagation, direct electrical energy generation, and real-time temperature changes are measured using a high-speed microscopy system, an oscilloscope, and an optical pyrometer, respectively. Furthermore, the crucial strategies to be adopted in the synthesis of hybrid composite and initiation of their combustion that enhance the overall thermopower wave energy transfer are proposed. PMID:25938793

  3. Chemical and isotopic compositions in acid residues from various meteorites

    NASA Technical Reports Server (NTRS)

    Kano, N.; Yamakoshi, K.; Matsuzaki, H.; Nogami, K.

    1993-01-01

    We are planning to carry out systematic isotopic investigations of Ru, Mg, etc., in primordial samples. The investigations will be pursued in the context of a study of the pre-history of the solar system. It is hoped that the study will yield direct evidence for processes of nucleosynthesis in the pre-solar stage and detection of extinct radioactive nuclides. In this paper, we present the results of chemical compositions of acid residues obtained from three types of meteorites: Canyon Diablo (IA), Allende (CV3), and Nuevo Mercuro (H5); and the preliminary results of Ru isotopic compositions.

  4. Chemical composition and sources of ambient aerosol in an urban environment over Athens, Greece: Case study on the role of wintertime biomass burning

    NASA Astrophysics Data System (ADS)

    Theodosi, Christina

    2016-04-01

    This study examines the chemical composition of aerosols over the Greater Athens Area (GAA). To achieve this, particulate matter sampling has been conducted on a 6h-24h basis and more than 700 aerosol samples were collected at downtown Athens, in Thissio from January 2013 to December 2015. All samples, after mass quantification, were analyzed for major anions (Cl^-, Br^-, NO{_3^-}, SO{_4-2}, PO{_4-3}, C_2O{_4-2}), cations (NH{_4^+}, K^+, Na^+, Mg+2, Ca+2), trace elements (Al, As, Ca, Cd, Co, Cr, Cu, Fe, V, Zn, Mn, Ni, Pb, P, S, Sb), organic carbon (OC) and elemental carbon (EC). Aerosol chemical mass closure calculations indicated that carbonaceous aerosol constitutes a major component, along with nitrate and sulfate anions, dust, cations and EC. Moreover, during the winter periods of December 2012-January 2013 and December 2013-January 2014, air pollution due to excessive use of biomass for domestic heating has been reported as a major environmental problem in the area. To assess the importance of biomass burning as a source of air pollution over the GAA three main sugars specific biomass burning tracers (levoglucosan, mannosan and galactosan) and Polycyclic aromatic hydrocarbons (PAHs) were also analyzed during the winter period. Acknowledgments This work was supported by the State Scholarship Foundation ("IKY Fellowships of Excellence for Postgraduate Studies in Greece - Siemens Programme") in the framework of the Hellenic Republic-Siemens Settlement Agreement.

  5. Chemical composition and medicinal significance of Fagonia cretica: a review.

    PubMed

    Qureshi, Huma; Asif, Saira; Ahmed, Haroon; Al-Kahtani, Hassan A; Hayat, Khizar

    2016-01-01

    Members of the family Zygophyllaceae are distributed in arid areas of the world and are traditionally used against various health insults ranging from skin lesions to lethal cancer. Fagonia cretica Linn. is a plant having novel compounds responsive in diseases that are still considered as incurable or are curable with serious side effects. Researchers, particularly of the Asian region elaborately studied the chemical composition and pharmacological activities of this plant. But further studies are still required to evaluate this plant in clinical trials in order to save humanity from synthetic chemical drugs yet disputed as 'friends or foe'. PMID:25921950

  6. Structural and Compositional Study of Graphene grown on SrTiO3 by Chemical Vapour Deposition

    NASA Astrophysics Data System (ADS)

    Karamat, Shumaila; Celik, Umit; Oral, Ahmet

    Graphene, a monolayer of sp2 bonded carbon atom, is considered as one of the most promising candidate materials for future electronics. The most critical step in graphene research is its transfer from the growth catalyst to the dielectric substrate, many unavoidable issues in the transfer process are: contamination from etchants, photoresist residues, wrinkles, and mechanical breakage. The direct growth of graphene on the substrates without using catalyst offer new opportunities in device fabrication without any transfer process. But till now, the field of direct graphene growth on dielectrics or insulating substrates is not mature like growth on metallic catalysts using CVD. We used chemical vapour deposition to grow graphene on SrTiO3 (110) substrates. The growth was carried out in presence of methane, argon and hydrogen. Raman Spectrum clearly showed the D and G peaks which were absent in bare substrate. XPS was used to get information about the presence of necessary elements, their bonding with STO substrates. AFM imaging clearly showed graphene island formation on substrates.

  7. Effect of chemical composition on the elastic and electrical properties of the boron-oxygen-yttrium system studied by ab initio and experimental means

    NASA Astrophysics Data System (ADS)

    Music, Denis; Chirita, Valeriu; Schneider, Jochen M.; Helmersson, Ulf

    2004-03-01

    The effect of chemical composition on the elastic and electrical properties is studied for the BOxYz system with 0.27⩽x⩽1.14 and 0.36⩽z⩽0.08. We use ab initio calculations to obtain the elastic constants and density of states for BO1.5 and the BOY phase (yttrium substituting for oxygen in the boron suboxide structure). For decreasing x values, the elastic modulus is predicted to increase from 11 to 340 GPa, while electronic structure calculations suggest a shift in electrical properties from insulating to metallic. Thin films in the B-O-Y system are grown by reactive rf magnetron sputtering. As x decreases from 1.14 to 0.27, the elastic modulus increases from 12 to 282 GPa, which is a factor of 24, while resistivity decreases from 7.6±0.4 to (3.8±0.1)×10-2 Ωm. The observed shifts in elasticity and resistivity are shown to be induced by the associated changes in chemical bonding from van der Waals type in BO1.5 to icosahedral type in the BOY phase.

  8. Chemical and physical studies of chondrites: 10. Cathodoluminescence and phase composition studies of metamorphism and nebular processes in chondrules of type 3 ordinary chondrites

    SciTech Connect

    DeHart, J.M.; Lu Jie; Benoit, P.H.; Sears, D.W.G. ); Lofgren, G.E. )

    1992-10-01

    The cathodoluminescence (CL) properties of eight type 3 ordinary chondrites and one L5 chondrite have been determined, and phenocryst and mesostasis compositions have been analyzed in the chondrules of four of them (Semarkona, type 3.0; Krymka, 3.1; Allan Hills A77214, 3.5; and Dhajala, 3.8) in order to investigate their origins and metamorphic history. In the present study, the authors discuss the CL properties of nine ordinary chondrites of a variety of petrologic types with particular emphasis on detailed studies of the compositions of the relevant phases in four of these: Semarkona (3.0), Krymka (3.1), Allan Hills A77214 (3.5), and Dhajala (3.8). They describe a means of classifying chondrules that is based on the composition of their two major components, the mesostasis and phenocrysts. The system is applicable to > 90-95% off the chondrules in a given meteorite and it describes the range of material produced by nebular material and of the effect of metamorphism on the chondrules. They also discuss the relevance of the results for the origin of the nine chondrite classes.

  9. Chemical compositions of large cluster IDPs

    SciTech Connect

    Flynn, G.J.; Lanzirotti, A.; Sutton, S.R.

    2006-12-06

    We performed X-ray fluorescence spectroscopy on two large cluster IDPs, which sample the IDP parent body at a mass scale two orders-of-magnitude larger than {approx}10 {micro}m IDPs, allowing proper incorporation of larger mineral grains into the bulk composition of the parent body. We previously determined that {approx}10 {micro}m interplanetary dust particles (IDPs) collected from the Earth's stratosphere are enriched in many moderately volatile elements by a factor of {approx}3 over the CI meteorites. However, these IDP measurements provide no direct constraint on the bulk chemical composition of the parent body (or parent bodies) of the IDPs. Collisions are believed to be the major mechanism for dust production by the asteroids, producing dust by surface erosion, cratering and catastrophic disruption. Hypervelocity impact experiments at {approx}5 km/sec, which is the mean collision velocity in the main belt, performed by Flynn and Durda on ordinary chondrite meteorites and the carbonaceous chondrite meteorite Allende show that the 10 {micro}m debris is dominated by matrix material while the debris larger than {approx}25 {micro}m is dominated by chondrule fragments. Thus, if the IDP parent body is similar in structure to the chondritic meteorites, it is likely that the {approx}10 {micro}m IDPs oversample the fine-grained component of the parent body. We have examined the matrix material from the few meteorites that are sufficiently fine-grained to be samples of potential IDP parent bodies. This search has, thus far, not produced a compositional and mineralogical match to either the hydrous or anhydrous IDPs. This result, coupled with our recent mapping of the element distributions, which indicates the enrichment of moderately volatile elements is not due to contamination on their surfaces, suggests the IDPs represent a new type of extraterrestrial material. Nonetheless, the meteorite fragmentation results suggest that compositional measurements on 10 {micro

  10. A study of chemical composition and radiation attenuation properties in clinoptilolite-rich natural zeolite from Turkey

    NASA Astrophysics Data System (ADS)

    Kurudirek, Murat; Özdemir, Yüksel; Türkmen, İbrahim; Levet, Aytaç

    2010-11-01

    Clinoptilolite, a type of natural zeolite, has been commonly used as pozzolanic additive in concrete. This type of natural zeolite is generally used as a mineral admixture by substitution in Portland cement to produce high performance concretes. In the present study, the major, minor and trace element levels present in the clinoptilolite-rich natural zeolite (CRNZ) have been determined using a wavelength dispersive X-ray fluorescence spectrometer. Also, the clinoptilolite-rich natural zeolite has been compared with Portland cement with respect to the radiation attenuation properties. From the results it can be concluded that due to the natural radioactive content of clinoptilolite-rich natural zeolite (CRNZ) even if it is in trace level and also due to the poorer X-ray attenuation compared with Portland cement, special care should be taken to use this type of natural zeolite as blend materials in cements, etc.

  11. Fundamental Parameters and Chemical Composition of Arcturus

    NASA Astrophysics Data System (ADS)

    Ramírez, I.; Allende Prieto, C.

    2011-12-01

    We derive a self-consistent set of atmospheric parameters and abundances of 17 elements for the red giant star Arcturus: T eff = 4286 ± 30 K, log g = 1.66 ± 0.05, and [Fe/H] = -0.52 ± 0.04. The effective temperature was determined using model atmosphere fits to the observed spectral energy distribution from the blue to the mid-infrared (0.44 to 10 μm). The surface gravity was calculated using the trigonometric parallax of the star and stellar evolution models. A differential abundance analysis relative to the solar spectrum allowed us to derive iron abundances from equivalent width measurements of 37 Fe I and 9 Fe II lines, unblended in the spectra of both Arcturus and the Sun; the [Fe/H] value adopted is derived from Fe I lines. We also determine the mass, radius, and age of Arcturus: M = 1.08 ± 0.06 M ⊙, R = 25.4 ± 0.2 R ⊙, and τ = 7.1+1.5 - 1.2 Gyr. Finally, abundances of the following elements are measured from an equivalent width analysis of atomic features: C, O, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, and Zn. We find the chemical composition of Arcturus typical of that of a local thick-disk star, consistent with its kinematics.

  12. FUNDAMENTAL PARAMETERS AND CHEMICAL COMPOSITION OF ARCTURUS

    SciTech Connect

    Ramirez, I.; Allende Prieto, C. E-mail: callende@iac.es

    2011-12-20

    We derive a self-consistent set of atmospheric parameters and abundances of 17 elements for the red giant star Arcturus: T{sub eff} = 4286 {+-} 30 K, log g = 1.66 {+-} 0.05, and [Fe/H] = -0.52 {+-} 0.04. The effective temperature was determined using model atmosphere fits to the observed spectral energy distribution from the blue to the mid-infrared (0.44 to 10 {mu}m). The surface gravity was calculated using the trigonometric parallax of the star and stellar evolution models. A differential abundance analysis relative to the solar spectrum allowed us to derive iron abundances from equivalent width measurements of 37 Fe I and 9 Fe II lines, unblended in the spectra of both Arcturus and the Sun; the [Fe/H] value adopted is derived from Fe I lines. We also determine the mass, radius, and age of Arcturus: M = 1.08 {+-} 0.06 M{sub Sun }, R = 25.4 {+-} 0.2 R{sub Sun }, and {tau} = 7.1{sup +1.5}{sub -1.2} Gyr. Finally, abundances of the following elements are measured from an equivalent width analysis of atomic features: C, O, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, and Zn. We find the chemical composition of Arcturus typical of that of a local thick-disk star, consistent with its kinematics.

  13. Chemical composition of rainwater in Eastern France

    NASA Astrophysics Data System (ADS)

    Sanusi, Astrid; Wortham, Henri; Millet, Maurice; Mirabel, Philippe

    Rainwater sampled weekly at nine sites in eastern France from October 1991 to March 1992 has been analysed for major ions (Cl -, NO 3-, SO s2-, NH 4+, Na +, K +, Mg 2+ and Ca 2+), pH and conductivity. The major elements are SO 42- and Cl - for the anions and NH 4+ and Ca 2+ for the cations. The major ion concentrations are higher in urban areas, especially at Colmar (no.2), where rainfall amounts are low. Surprisingly, the acidity is higher at the sites in rural areas [i.e. mean pH of 4.4 for Ban sur Meurthe (no. 7)] and lower in the urban areas [mean pH of 5.0 for Strasbourg (no. 1) and pH of 5.7 for Colmar (no. 2)]. This is probably due to the presence of CaCO 3 in the "loess", which is the major constituent of soils in the upper Rhine valley. The relationship between the chemical composition of rain andair-mass trajectories for four humid weeks which presented only one rain event are also examined.

  14. In situ synchrotron x-ray studies of strain and composition evolution during metal-organic chemical vapor deposition of InGaN.

    SciTech Connect

    Richard, M.-I.; Highland, M. J.; Fister, T. T.; Munkholm, A.; Mei, J.; Streiffer, S. K.; Thompson, C.; Fuoss, P. H.; Stephenson, G. B.; Univ. Paul Cezanne; Philips Lumileds Lighting Co.; Northern Illinois Univ.; Faculte des Sciences de St. Jerome

    2010-01-01

    Composition and strain inhomogeneities strongly affect the optoelectronic properties of InGaN but their origin has been unclear. Here we report real-time x-ray reciprocal space mapping that reveals the development of strain and composition distributions during metal-organic chemical vapor deposition of In{sub x}Ga{sub 1-x}N on GaN. Strong, correlated inhomogeneities of the strain state and In fraction x arise during growth in a manner consistent with models for instabilities driven by strain relaxation.

  15. Vector diagram of the chemical compositions of tektites and earth lavas

    NASA Technical Reports Server (NTRS)

    Kvasha, L. G.; Gorshkov, G. S.

    1978-01-01

    The chemical compositions of tektites and various volcanic glasses, similar in composition to tektites are compared by a petrochemical method. The advantage of the method is that a large number of chemical analyses of igneous rocks can be graphically compared with the help of vectors, plotted in relation to six parameters. These parameters, calculated from ratios of the main oxides given by silicate analysis, reflect the chief characteristics of igneous rock. Material for the study was suppled by data from chemical analysis characterizing tektites of all known locations and data from chemical analyses of obsidians similar in chemical composition to tektites of various petrographical provinces.

  16. The study of chemical composition and elemental mappings of colored over-glaze porcelain fired in Qing Dynasty by micro-X-ray fluorescence

    NASA Astrophysics Data System (ADS)

    Lin, Cheng; Meitian, Li; Youshi, Kim; Changsheng, Fan; Shanghai, Wang; Qiuli, Pan; Zhiguo, Liu; Rongwu, Li

    2011-02-01

    It is very difficult to measure the chemical composition of colored pigments of over-glaze porcelain by X-ray fluorescence because it contains high concentration of Pb. One of the disadvantages of our polycapillary optics is that it has low transmission efficiency to the high energy X-ray. However, it is beneficial to measure the chemical compositions of rich Pb sample. In this paper, we reported the performances of a tabletop setup of micro-X-ray fluorescence system base on slightly focusing polycapillary and its applications for analysis of rich Pb sample. A piece of Chinese ancient over-glaze porcelain was analyzed by micro-X-ray fluorescence. The experimental results showed that the Cu, Fe and Mn are the major color elements. The possibilities of the process of decorative technology were discussed in this paper, also.

  17. Morphology and Chemical Composition of soot particles emitted by Wood-burning Cook-Stoves: a HRTEM, XPS and Elastic backscattering Studies.

    NASA Astrophysics Data System (ADS)

    Carabali-Sandoval, G. A., Sr.; Castro, T.; Peralta, O.; De la Cruz, W.; Días, J.; Amelines, O.; Rivera-Hernández, M.; Varela, A.; Muñoz-Muñoz, F.; Policroniades, R.; Murillo, G.; Moreno, E.

    2014-12-01

    The morphology, microstructure and the chemical composition on surface of soot particles were studied by using high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and elastic backscattering spectrometry. In order to obtain freshly soot particles emitted by home-made wood-burning cook stoves, copper grids for Transmission Electron Microscope (TEM) were placed on the last two of an 8-stages MOUDI cascade impactor. The analysis of HRTEM micrographs revealed the nanostructure and the particle size of soot particles. The XPS survey spectra show a large carbon peak around 285 eV and the oxygen signal at 533 eV. Some differences observed in the carbon/oxygen (C/O) ratio of the particles probably depend on the combustion process efficiency of each cook-stove analyzed. The C-1s XPS spectra show an asymmetric broad peak and other with low intensity that corresponds to sp2 and sp3hybridization, which were fitted with a convolution using Gaussian functions. Elastic backscattering technique allows a chemical elemental analysis of samples and confirms the presence of C, O and Si observed by XPS. Additionally, the morphological properties of soot aggregates were analyzed calculating the border-based fractal dimension (Df). Particles exhibit complex shapes with high values of Df. Also, real-time absorption (σabs) and scattering (σsct) coefficients of fine (with aerodynamic diameter < 2.5 µm) soot particles were measured. The trend in σabs and σsct indicate that the cooking process has two important combustion stages which varied in its flaming strength, being vigorous in the first stage and soft in the second one.

  18. Study on the chemical composition features of Longquan celadon excavated from the Chuzhou site of Huai'an City in Jiangsu Province by EDXRF

    NASA Astrophysics Data System (ADS)

    Li, Li; Feng, Song-Lin; Feng, Xiang-Qian; Xu, Qing; Yan, Ling-Tong; Ma, Bo; Huo, Hua

    2011-07-01

    A mass of Longquan celadon shards were excavated from the Chuzhou site of Huai'an City in Jiangsu Province, China. These celadon shards were fired during the period of the Late Yuan Dynasty to the Tianshun era of the Ming Dynasty, as identified by archaeologists at Nanjing Museum. In order to research the chemical composition features of this ancient celadon porcelain, energy dispersive X-ray fluorescence (EDXRF) for non-destructive analysis was used to determine the chemical composition of the porcelain body and glaze in these shards. The results indicate that Ti and Fe in the body of Longquan celadon are characteristic elements which can distinguish porcelain produced during the Late Yuan Dynasty from those produced in the Ming Dynasties. The results of the principal component analysis (PCA) show that different body and glaze raw materials were used for the production of porcelain in different periods and the raw materials of the body and glaze are also different for various vessel shapes. The chemical compositions in the porcelain body of civilian ware are slightly different. The imperial and civilian Longquan celadon porcelains produced during the Hongwu era to the Tianshun era of the Ming Dynasty are distinguishable by the MnO, Fe2O3, Rb2O and SrO content in their porcelain glaze.

  19. Preparation and Characterization of Chemically Synthesized Hybrid Composites for Bone Tissue Regeneration

    NASA Astrophysics Data System (ADS)

    Raucci, M. G.; Guarino, V.; Ambrosio, L.

    2008-08-01

    The aim of this study concerns the development of bioresorbable composite materials for bone repair and regeneration. Hydroxyapatite loaded composites were synthesized by a colloidal non-aqueous chemical precipitation technique at room temperature. This study describes the synthesis and characterization of HA/PCL composite material, in order to verify the interaction between the ceramic and the polymer phases by a morphological investigation.

  20. Morphology, chemical composition and nanostructure of single carbon-rich particles studied by transmission electron microscopy: source apportionment in workroom air of aluminium smelters.

    PubMed

    Weinbruch, Stephan; Benker, Nathalie; Kandler, Konrad; Ebert, Martin; Ellingsen, Dag G; Berlinger, Balázs; Thomassen, Yngvar

    2016-02-01

    Sources of C-rich particles at work places in two aluminium smelters in Norway were studied by transmission electron microscopy and energy-dispersive X-ray microanalysis. Based on morphology, nanostructure and chemistry, three different types of C-rich particles are distinguished: (a) chain-like agglomerates (70-100% by number, relative to the sum of C-rich particles) consisting of primary particles with typical onion-shell structure of graphene layers, (b) multi-walled carbon nanotube particles (≈3%) and (c) spheres or agglomerates of amorphous C-rich particles (0-30%). Chain-like agglomerates are interpreted as diesel soot in accordance with literature data on primary particle diameter, chemical composition and nanostructure of primary particles. The source of the observed multi-walled carbon nanotubes is not known. The amorphous C-rich particles most likely consist of organic carbon species which cannot be characterized further by X-ray microanalysis. Unaltered graphitic electrode material was not found among the C-rich particles. The high fraction of diesel soot particles indicates that elemental carbon is generally suited as proxy for diesel soot in aluminium smelters. However, due to the presence of carbon nanotubes and amorphous C-rich particles, detailed characterization of sources of carbon-rich particles by electron microscopy is recommended for accurate assessment of adverse health effects. PMID:26637216

  1. Chemical composition of dissolved organic matter draining permafrost soils

    NASA Astrophysics Data System (ADS)

    Ward, Collin P.; Cory, Rose M.

    2015-10-01

    Northern circumpolar permafrost soils contain roughly twice the amount of carbon stored in the atmosphere today, but the majority of this soil organic carbon is perennially frozen. Climate warming in the arctic is thawing permafrost soils and mobilizing previously frozen dissolved organic matter (DOM) from deeper soil layers to nearby surface waters. Previous studies have reported that ancient DOM draining deeper layers of permafrost soils was more susceptible to degradation by aquatic bacteria compared to modern DOM draining the shallow active layer of permafrost soils, and have suggested that DOM chemical composition may be an important control for the lability of DOM to bacterial degradation. However, the compositional features that distinguish DOM drained from different depths in permafrost soils are poorly characterized. Thus, the objective of this study was to characterize the chemical composition of DOM drained from different depths in permafrost soils, and relate these compositional differences to its susceptibility to biological degradation. DOM was leached from the shallow organic mat and the deeper permafrost layer of soils within the Imnavait Creek watershed on the North Slope of Alaska. DOM draining both soil layers was characterized in triplicate by coupling ultra-high resolution mass spectrometry, 13C solid-state NMR, and optical spectroscopy methods with multi-variate statistical analyses. Reproducibility of replicate mass spectra was high, and compositional differences resulting from interfering species or isolation effects were significantly smaller than differences between DOM drained from each soil layer. All analyses indicated that DOM leached from the shallower organic mat contained higher molecular weight, more oxidized, and more unsaturated aromatic species compared to DOM leached from the deeper permafrost layer. Bacterial production rates and bacterial efficiencies were significantly higher for permafrost compared to organic mat DOM

  2. Measurements of aerosol chemical composition in boreal forest summer conditions

    NASA Astrophysics Data System (ADS)

    ńijälä, M.; Junninen, H.; Ehn, M.; Petäjä, T.; Vogel, A.; Hoffmann, T.; Corrigan, A.; Russell, L.; Makkonen, U.; Virkkula, A.; Mäntykenttä, J.; Kulmala, M.; Worsnop, D.

    2012-04-01

    Boreal forests are an important biome, covering vast areas of the northern hemisphere and affecting the global climate change via various feedbacks [1]. Despite having relatively few anthropogenic primary aerosol sources, they always contain a non-negligible aerosol population [2]. This study describes aerosol chemical composition measurements using Aerodyne Aerosol Mass Spectrometer (C-ToF AMS, [3]), carried out at a boreal forest area in Hyytiälä, Southern Finland. The site, Helsinki University SMEAR II measurement station [4], is situated at a homogeneous Scots pine (Pinus sylvestris) forest stand. In addition to the station's permanent aerosol, gas phase and meteorological instruments, during the HUMPPA (Hyytiälä United Measurements of Photochemistry and Particles in Air) campaign in July 2010, a very comprehensive set of atmospheric chemistry measurement instrumentation was provided by the Max Planck Institute for chemistry, Johannes Gutenberg-University, University of California and the Finnish Meteorological institute. In this study aerosol chemical composition measurements from the campaign are presented. The dominant aerosol chemical species during the campaign were the organics, although periods with elevated amounts of particulate sulfates were also seen. The overall AMS measured particle mass concentrations varied from near zero to 27 μg/m observed during a forest fire smoke episode. The AMS measured aerosol mass loadings were found to agree well with DMPS derived mass concentrations (r2=0.998). The AMS data was also compared with three other aerosol instruments. The Marga instrument [5] was used to provide a quantitative semi-online measurement of inorganic chemical compounds in particle phase. Fourier Transform Infrared Spectroscopy (FTIR) analysis was performed on daily filter samples, enabling the identification and quantification of organic aerosol subspecies. Finally an Atmospheric Pressure Chemical Ionization Ion Trap Mass Spectrometer (APCI

  3. The physical and chemical composition of the lower mantle.

    PubMed

    Bovolo, C Isabella

    2005-12-15

    This article reviews some of the recent advances made within the field of mineral physics. In order to link the observed seismic and density structures of the lower mantle with a particular mineral composition, knowledge of the thermodynamic properties of the candidate materials is required. Determining which compositional model best matches the observed data is difficult because of the wide variety of possible mineral structures and compositions. State-of-the-art experimental and analytical techniques have pushed forward our knowledge of mineral physics, yet certain properties, such as the elastic properties of lower mantle minerals at high pressures and temperatures, are difficult to determine experimentally and remain elusive. Fortunately, computational techniques are now sufficiently advanced to enable the prediction of these properties in a self-consistent manner, but more results are required.A fundamental question is whether or not the upper and lower mantles are mixing. Traditional models that involve chemically separate upper and lower mantles cannot yet be ruled out despite recent conflicting seismological evidence showing that subducting slabs penetrate deep into the lower mantle and that chemically distinct layers are, therefore, unlikely.Recent seismic tomography studies giving three-dimensional models of the seismic wave velocities in the Earth also base their interpretations on the thermodynamic properties of minerals. These studies reveal heterogeneous velocity and density anomalies in the lower mantle, which are difficult to reconcile with mineral physics data. PMID:16286292

  4. Chemical composition of yak colostrum and transient milk.

    PubMed

    Cui, N; Wen, P C; Liang, Q; Liu, H N; Zhang, W B; Wang, P J; Guo, H Y; Ren, F Z

    2015-10-01

    The objective of this study was to assess the changes in the chemical composition of yak colostrum and transient milk. Samples were collected from 12 yaks on days 1, 2, 3, 4, 5, 6 and 7 post-partum (PP). The gross composition, nitrogen fraction distribution, amino acid (AA) profile and fatty acid (FA) profile were analysed. All the components decreased rapidly during the first 3 days except lactose which increased. The ratio of whey protein to casein protein decreased from 46:54 to 17:83 during the first 7 days PP. The content of all the AAs decreased, while the percentages of eight essential AAs in protein of samples increased during the study period. Monounsaturated FAs and polyunsaturated FAs decreased in the first 7 days PP, whereas saturated FAs increased. In conclusion, the changes in chemical composition were remarkable during the first 3 days. The slight variations, happened during the transient period, are not negligible, which also should be taken into account in the development of yak colostrum supplements. PMID:25545664

  5. THE CHEMICAL COMPOSITION OF PRAESEPE (M44)

    SciTech Connect

    Boesgaard, Ann Merchant; Roper, Brian W.; Lum, Michael G. E-mail: brianwroper@gmail.com

    2013-09-20

    Star clusters have long been used to illuminate both stellar evolution and Galactic evolution. They also hold clues to the chemical and nucleosynthetic processes throughout the history of the Galaxy. We have taken high signal-to-noise (S/N), high-resolution spectra of 11 solar-type stars in the Praesepe open cluster to determine the chemical abundances of 16 elements: Li, C, O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Fe, Ni, Y, and Ba. We have determined Fe from Fe I and Fe II lines and find [Fe/H] = +0.12 ±0.04. We find that Li decreases with temperature due to increasing Li depletion in cooler stars; it matches the Li-temperature pattern found in the Hyades. The [C/Fe] and [O/Fe] abundances are below solar and lower than the field star samples due to the younger age of Praesepe (0.7 Gyr) than the field stars. The alpha-elements, Mg, Si, Ca, and Ti, have solar ratios with respect to Fe, and are also lower than the field star samples. The Fe-peak elements, Cr and Ni, track Fe and have solar values. The neutron capture element [Y/Fe] is found to be solar, but [Ba/Fe] is enhanced relative to solar and to the field stars. Three Praesepe giants were studied by Carrera and Pancino; they are apparently enhanced in Na, Mg, and Ba relative to the Praesepe dwarfs. The Na enhancement may indicate proton-capture nucleosynthesis in the Ne → Na cycling with dredge-up into the atmospheres of the red giants.

  6. Spectral analysis of four meteors. [chemical compositions and spectral emissions

    NASA Technical Reports Server (NTRS)

    Harvey, G. A.

    1973-01-01

    Four meteor spectra are analyzed for chemical composition and radiative processes. The chemical compositions of the Taurid, Geminid, and Perseid meteors were found to be similar to that of a typical stony meteorite. The chemical composition of the sporadic meteor was found to be similar to that of a nickel iron meteorite. The radiation from optical meteors was found to be similar to that of a low temperature gas, except that strong, anomalous ionic radiation is superposed on the neutral radiation in bright, fast meteors.

  7. Design of an artificial skin. II. Control of chemical composition.

    PubMed

    Yannas, I V; Burke, J F; Gordon, P L; Huang, C; Rubenstein, R H

    1980-03-01

    Detailed methodology is described for the reproducible preparation of collagen--glycosaminoglycan (GAG) membranes with known chemical composition. These membranes have been used to cover satisfactorily large experimental full-thickness skin wounds in guinea pigs over the past few years. Such membranes have effectively protected these wounds from infection and fluid loss for over 25 days without rejection and without requiring change or other invasive manipulation. When appropriately designed for the purpose, the membranes have also strongly retarded wound contraction and have become replaced by newly synthesized, stable connective tissue. In our work, purified, fully native collagen from two mammalian sources is precipitated from acid dispersion by addition of chondroitin 6-sulfate. The relative amount of GAG in the coprecipitate varies with the amount of GAG added and with the pH. Since coprecipitated GAG is generally eluted from collagen fibers by physiological fluids, control of the chemical composition of membranes is arrived at by crosslinking the collagen--GAG ionic complex with glutaraldehyde, or, alternately, by use of high-temperature vacuum dehydration. Appropriate use of the crosslinking treatment allows separate study of changes in membrane composition due to elution of GAG by extracellular fluid in animal studies from changes in composition due to enzymatic degradation of the grafted or implanted membrane in these studies. Exhaustive in vitro elution studies extending up to 20 days showed that these crosslinking treatments insolubilize in an apparently permanent manner a fraction of the ionically complexed GAG, although it could not be directly confirmed that glutaraldehyde treatment covalently crosslinks GAG to collagen. By contrast, the available evidence suggests strongly that high-temperature vacuum dehydration leads to formation of chemical bonds between collagen and GAG. Procedures are described for control of insolubilized and "free" GAG in

  8. A bootstrap estimation scheme for chemical compositional data with nondetects

    USGS Publications Warehouse

    Palarea-Albaladejo, J; Martín-Fernández, J.A; Olea, Ricardo A.

    2014-01-01

    The bootstrap method is commonly used to estimate the distribution of estimators and their associated uncertainty when explicit analytic expressions are not available or are difficult to obtain. It has been widely applied in environmental and geochemical studies, where the data generated often represent parts of whole, typically chemical concentrations. This kind of constrained data is generically called compositional data, and they require specialised statistical methods to properly account for their particular covariance structure. On the other hand, it is not unusual in practice that those data contain labels denoting nondetects, that is, concentrations falling below detection limits. Nondetects impede the implementation of the bootstrap and represent an additional source of uncertainty that must be taken into account. In this work, a bootstrap scheme is devised that handles nondetects by adding an imputation step within the resampling process and conveniently propagates their associated uncertainly. In doing so, it considers the constrained relationships between chemical concentrations originated from their compositional nature. Bootstrap estimates using a range of imputation methods, including new stochastic proposals, are compared across scenarios of increasing difficulty. They are formulated to meet compositional principles following the log-ratio approach, and an adjustment is introduced in the multivariate case to deal with nonclosed samples. Results suggest that nondetect bootstrap based on model-based imputation is generally preferable. A robust approach based on isometric log-ratio transformations appears to be particularly suited in this context. Computer routines in the R statistical programming language are provided. 

  9. Chemical composition and temperature influence on honey texture properties.

    PubMed

    Oroian, Mircea; Paduret, Sergiu; Amariei, Sonia; Gutt, Gheorghe

    2016-01-01

    The aim of this study is to evaluate the chemical composition and temperatures (20, 30, 40, 50 and 60 °C) influence on the honey texture parameters (hardness, viscosity, adhesion, cohesiveness, springiness, gumminess and chewiness). The honeys analyzed respect the European regulation in terms of moisture content and inverted sugar concentration. The texture parameters are influenced negatively by the moisture content, and positively by the °Brix concentration. The texture parameters modelling have been made using the artificial neural network and the polynomial model. The polynomial model predicted better the texture parameters than the artificial neural network. PMID:26787962

  10. Chemical Composition of Rainwater in Córdoba City, Argentina

    NASA Astrophysics Data System (ADS)

    López, M. L.; Asar, M. L.; Ceppi, S.; Bürgesser, R. E.; Avila, E.

    2013-05-01

    Sampling and chemical analysis of rainwater has proved to be a useful technique for studying its chemical composition and provides a greater understanding of local and regional dispersion of pollutants and their potential impacts to ecosystems through deposition processes. Samples of rainwater were collected during 2009-2012, in Córdoba city, Argentina. Two kind of sampling were performed: event-specific and sequential. The objective of the first of these was to determine the chemical concentration of the total rain, while the objective of the second one was to analyze the variability of the chemical concentration during an individual rain event. The total volume of each sample was divided in halves. One half was filtered through 0.45 μm membrane filter. After this, all the samples were reduced by evaporation to a final volume of 10 ml. The non-filtered samples were acidified and digested in accordance to the method 3050B of the Environmental Protection Agency (EPA) for acid digestion of sediments. Multi-elemental standard solutions in different concentrations were prepared by adequate dilutions. Gallium was added as an internal standard in all standard solutions and samples. Exactly 5 μL of these solutions were deposited on acrylic supports. When these droplets were dried, Synchrotron Radiation Total Reflection X-Ray Fluorescence technique was used for determining the chemical elements. Spectra were analyzed with the AXIL package for spectrum analysis. Due to the intrinsic characteristics of the total reflection technique, the background of the measurements is significantly reduced and there are no matrix effects, therefore quantification can be obtained from the linear correlation between fluorescence intensity and the concentration of the element of interest. The elements quantified were S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, and Pb. For all of them a calibration curve was performed in order to quantify their concentrations on the

  11. Chemical vapor deposited fiber coatings and chemical vapor infiltrated ceramic matrix composites

    SciTech Connect

    Kmetz, M.A.

    1992-01-01

    Conventional Chemical Vapor Deposition (CVD) and Organometallic Chemical Vapor Deposition (MOCVD) were employed to deposit a series of interfacial coatings on SiC and carbon yarn. Molybdenum, tungsten and chromium hexacarbonyls were utilized as precursors in a low temperature (350[degrees]C) MOCVD process to coat SiC yarn with Mo, W and Cr oxycarbides. Annealing studies performed on the MoOC and WOC coated SiC yarns in N[sub 2] to 1,000[degrees]C establish that further decomposition of the oxycarbides occurred, culminating in the formation of the metals. These metals were then found to react with Si to form Mo and W disilicide coatings. In the Cr system, heating in N[sub 2] above 800[degrees]C resulted in the formation of a mixture of carbides and oxides. Convention CVD was also employed to coat SiC and carbon yarn with C, Bn and a new interface designated BC (a carbon-boron alloy). The coated tows were then infiltrated with SiC, TiO[sub 2], SiO[sub 2] and B[sub 4]C by a chemical vapor infiltration process. The B-C coatings were found to provide advantageous interfacial properties over carbon and BN coatings in several different composite systems. The effectiveness of these different coatings to act as a chemically inert barrier layer and their relationship to the degree of interfacial debonding on the mechanical properties of the composites were examined. The effects of thermal stability and strength of the coated fibers and composites were also determined for several difference atmospheres. In addition, a new method for determining the tensile strength of the as-received and coated yarns was also developed. The coated fibers and composites were further characterized by AES, SEM, XPS, IR and X-ray diffraction analysis.

  12. Chemical and anatomical compositions of coal precursors

    SciTech Connect

    Ryan, N.J.

    1985-01-01

    Four cores of peat from various environments in the Florida Everglades and one from the Okefenokee Swamp, Georgia have been studied with the objective of clarifying the roles of cellulose, lignin and other vascular plant polymers as input to coalification. The peat was first separated by set sieving into a coarse fraction consisting of fragments of plant organs and tissues, and a fine fraction containing an amorphous humic matrix mixed with a minority of disrupted cellular material. Microscopic examination, Curie-point pyrolysis/mass spectrometry with multivariate statistical analyses of the data, supplemented by pyrolysis/gas chromatography and PY/GC/MD, revealed substantial differences in the degree of preservation of plant tissues and in chemistry between peats derived from different types of plants. Some ..cap alpha..-cellulose is present in the upper levels of the peats, but the total polysaccharide content decreases markedly with depth, perhaps due in some cases to changes in the source vegetation, but mainly due to selective enzymatic removal of certain monomer units from polymeric lignin, thereby concentrating the structural types remaining (notably structures related to p.coumaryl alcohol). Polymeric aliphatic hydrocarbon structures are present in nearly all samples, but are more abundant at the lower depths. The chemical and morphological differences in peats are likely to be reflected in the coals that may form from them.

  13. Chemical composition and health effects of Tartary buckwheat.

    PubMed

    Zhu, Fan

    2016-07-15

    Tartary buckwheat (Fagopyrum tataricum) contains a range of nutrients including bioactive carbohydrates and proteins, polyphenols, phytosterols, vitamins, carotenoids, and minerals. The unique composition of Tartary buckwheat contributes to their various health benefits such as anti-oxidative, anti-cancer, anti-hypertension, anti-diabetic, cholesterol-lowering, and cognition-improving. Compared with the more widely cultivated and utilised common buckwheat (F. esculentum), Tartary buckwheat tends to contain higher amounts of certain bioactive components such as rutin, therefore, showing higher efficiency in preventing/treating various disorders. This review summarises the current knowledge of the chemical composition of Tartary buckwheat, and their bio-functions as studied by both in vitro and in vivo models. Tartary buckwheat can be further developed as a sustainable crop for functional food production to improve human health. PMID:26948610

  14. WOOD STOVE EMISSIONS: PARTICLE SIZE AND CHEMICAL COMPOSITION

    EPA Science Inventory

    The report summarizes wood stove particle size and chemical composition data gathered to date. [NOTE: In 1995, EPA estimated that residential wood combustion (RWC), including fireplaces, accounted for a significant fraction of national particulate matter with aerodynamic diameter...

  15. Essential Oils, Part III: Chemical Composition.

    PubMed

    de Groot, Anton C; Schmidt, Erich

    2016-01-01

    Data on the chemistry of essential oils which have caused contact allergy are provided. The largest group of chemicals found in essential oils consists of terpenes. The number of identified components usually ranges from 100 to 250, but in some oils (lavender, geranium, rosemary) 450 to 500 chemicals have been found. Many chemicals are present in a large number of oils, up to 98% for β-caryophyllene and 97% for limonene. Chemicals that are important constituents of >20 oils are limonene, linalool, and α-pinene. In many essential oils, there are 2 to 5 components which together constitute over 50% to 60% of the oil. In some oils, however, there is one dominant ingredient, making up more than 50% of the oil, including (E)-anethole in aniseed and star anise oil, carvone in spearmint oil, 1,8-cineole (eucalyptol) in Eucalyptus globulus oil, and (E)-cinnamaldehyde in cassia oil. The most important chemicals in 93 individual oils are specified. PMID:27427817

  16. Clouds Composition in Super-Earth Atmospheres: Chemical Equilibrium Calculations

    NASA Astrophysics Data System (ADS)

    Kempton, Eliza M.-R.; Mbarek, Rostom

    2015-12-01

    Attempts to determine the composition of super-Earth atmospheres have so far been plagued by the presence of clouds. Yet the theoretical framework to understand these clouds is still in its infancy. For the super-Earth archetype GJ 1214b, KCl, Na2S, and ZnS have been proposed as condensates that would form under the condition of chemical equilibrium, if the planet’s atmosphere has a bulk composition near solar. Condensation chemistry calculations have not been presented for a wider range of atmospheric bulk composition that is to be expected for super-Earth exoplanets. Here we provide a theoretical context for the formation of super-Earth clouds in atmospheres of varied composition by determining which condensates are likely to form, under the assumption of chemical equilibrium. We model super-Earth atmospheres assuming they are formed by degassing of volatiles from a solid planetary core of chondritic material. Given the atomic makeup of these atmospheres, we minimize the global Gibbs free energy of over 550 gases and condensates to obtain the molecular composition of the atmospheres over a temperature range of 350-3,000 K. Clouds should form along the temperature-pressure boundaries where the condensed species appear in our calculations. The super-Earth atmospheres that we study range from highly reducing to oxidizing and have carbon to oxygen (C:O) ratios that are both sub-solar and super-solar, thereby spanning a diverse range of atmospheric composition that is appropriate for low-mass exoplanets. Some condensates appear across all of our models. However, the majority of condensed species appear only over specific ranges of H:O and C:O ratios. We find that for GJ 1214b, KCl is the primary cloud-forming condensate at solar composition, in agreement with previous work. However, for oxidizing atmospheres, where H:O is less than unity, K2SO4 clouds form instead. For carbon-rich atmospheres with super-solar C:O ratios, graphite clouds additionally appear. At

  17. Dynamics of the chemical composition of rainwater throughout Hurricane Irene

    NASA Astrophysics Data System (ADS)

    Mullaugh, K. M.; Willey, J. D.; Kieber, R. J.; Mead, R. N.; Avery, G. B., Jr.

    2013-03-01

    Sequential sampling of rainwater from Hurricane Irene was carried out in Wilmington, NC, USA on 26 and 27 August 2011. Eleven samples were analyzed for pH, major ions (Cl-, NO3-, SO42-, Na+, K+, Mg2+, Ca2+, NH4+), dissolved organic carbon (DOC) and hydrogen peroxide (H2O2). Hurricane Irene contributed 16% of the total rainwater and 18% of the total chloride wet deposition received in Wilmington NC during all of 2011. This work highlights the main physical factors influencing the chemical composition of tropical storm rainwater: wind speed, wind direction, back trajectory and vertical mixing, time of day and total rain volume. Samples collected early in the storm, when winds blew out of the east, contained dissolved components indicative of marine sources (salts from sea spray and low DOC). The sea-salt components in the samples had two maxima in concentration during the storm the first of which occurred before the volume of rain had sufficiently washed out sea salt from the atmosphere and the second when back trajectories showed large volumes of marine surface air were lifted. As the storm progressed and winds shifted to a westerly direction, the chemical composition of the rainwater became characteristic of terrestrial storms (high DOC and NH4+ and low sea salt). This work demonstrates that tropical storms are not only responsible for significant wet deposition of marine components to land, but terrestrial components can also become entrained in rainwater, which can then be delivered to coastal waters via wet deposition. This study also underscores why analysis of one composite sample can lead to an incomplete interpretation of the factors that influence the chemically divergent analytes in rainwater during extreme weather events.

  18. Chemical and physical studies of chondrites. X - Cathodoluminescence and phase composition studies of metamorphism and nebular processes in chondrules of type 3 ordinary chondrites

    NASA Technical Reports Server (NTRS)

    Dehart, John M.; Lofgren, Gary E.; Jie, LU; Benoit, Paul H.; Sears, Derek W. G.

    1992-01-01

    The cathodoluminescence (CL) characteristics of eight type-3 ordinary chondrites and one L5 chondrite were investigated with particular emphasis on detailed compositions of the relevant phases in four of these chondrites: Semarkona (type-3.0); Krymka (3.1); Allan Hills A77214 (3.5); and Dhajala (3.8). By sorting the chondrules into eight groups according to the CL of mesostasis and to certain compositional criteria and by determining the number of chondrules in these groups as a function of petrological type, it was possible to deduce genetic/evolutionary sequences of the chondrules. It is shown that there are major compositional differences in chondrules, which account for their CL properties and the chondrule groups.

  19. Public Health Risk Conditioned by Chemical Composition of Ground Water

    NASA Astrophysics Data System (ADS)

    Yankovich, E.; Osipova, N.; Yankovich, K.; Matveenko, I.

    2016-03-01

    The article studies the public health potential risk originated from water consumption and estimated on the basis of the groundwater chemical composition. We have processed the results of chemical groundwater analysis in different aquifers of Tomsk district (Tomsk Oblast, Russia). More than 8400 samples of chemical groundwater analyses were taken during long-term observation period. Human health risk assessment of exposure to contaminants in drinking water was performed in accordance with the risk assessment guidance for public health concerning chemical pollution of the environment (Russian reference number: 2.1.10.1920-04-M, 2004). Identified potential risks were estimated for consuming water of each aquifer. The comparative analysis of water quality of different aquifers was performed on the basis of the risk coefficient of the total non-carcinogenic effects. The non-carcinogenic risk for the health of the Tomsk district population due to groundwater consumption without prior sanitary treatment was admitted acceptable. A rather similar picture is observed for all aquifers, although deeper aquifers show lower hazard coefficients.

  20. Honey: Chemical composition, stability and authenticity.

    PubMed

    da Silva, Priscila Missio; Gauche, Cony; Gonzaga, Luciano Valdemiro; Costa, Ana Carolina Oliveira; Fett, Roseane

    2016-04-01

    The aim of this review is to describe the chemical characteristics of compounds present in honey, their stability when heated or stored for long periods of time and the parameters of identity and quality. Therefore, the chemical characteristics of these compounds were examined, such as sugars, proteins, amino acids, enzymes, organic acids, vitamins, minerals, phenolic and volatile compounds present in honey. The stability of these compounds in relation to the chemical reactions that occur by heating or prolonged storage were also discussed, with increased understanding of the behavior regarding the common processing of honey that may compromise its quality. In addition, the identity and quality standards were described, such as sugars, moisture, acidity, ash and electrical conductivity, color, 5-HMF and diastase activity, along with the minimum and maximum limits established by the Codex Alimentarius. PMID:26593496

  1. The relationship of argon retentivity and chemical composition of hornblende

    SciTech Connect

    Leake, B.E.; Farrow, C.M. ); Elias, E.M. )

    1988-08-01

    K-Ar ages of 26 hornblende separates from Connemara, western Ireland do not show any correlation with the chemical composition of the hornblendes, including their iron contents. It is suggested that this is the usual pattern as there are only rare reports of compositional control of K-Ar ages.

  2. Chemical Equilibrium Composition of Aqueous Systems

    Energy Science and Technology Software Center (ESTSC)

    1996-12-30

    MINEQL is a subroutine package to calculate equilibrium composition of an aqueous system, accounting for mass transfer. MINEQL-EIR contains an additional base on enthalpy and heat capacity data and has the option to do calculations at temperatures different from 25 degrees C.

  3. Ethylene vinylacetate copolymer and nanographite composite as chemical vapour sensor

    NASA Astrophysics Data System (ADS)

    Stepina, Santa; Sakale, Gita; Knite, Maris

    2013-12-01

    Polymer-nanostructured carbon composite as chemical vapour sensor is described, made by the dissolution method of a non-conductive polymer, ethylene vinylacetate copolymer, mixed with conductive nanographite particles (carbon black). Sensor exhibits relative electrical resistance change in chemical vapours, like ethanol and toluene. Since the sensor is relatively cheap, easy to fabricate, it can be used in air quality monitoring and at industries to control hazardous substance concentration in the air, for example, to protect workers from exposure to chemical spills.

  4. Chemical composition of Earth, Venus, and Mercury

    PubMed Central

    Morgan, John W.; Anders, Edward

    1980-01-01

    Model compositions of Earth, Venus, and Mercury are calculated from the premise that planets and chondrites underwent four identical fractionation processes in the solar nebula. Because elements of similar properties stay together in these processes, five constraints suffice to define the composition of a planet: mass of the core, abundance of U, and the ratios K/U, Tl/U, and FeO/(FeO + MgO). Complete abundance tables, and normative mineralogies, are given for all three planets. Review of available data shows only a few gross trends for the inner planets: FeO decreases with heliocentric distance, whereas volatiles are depleted and refractories are enriched in the smaller planets. Images PMID:16592930

  5. Chemical composition of earth, Venus, and Mercury

    NASA Technical Reports Server (NTRS)

    Morgan, J. W.; Anders, E.

    1980-01-01

    Model compositions of the earth, Venus, and Mercury are calculated from the premise that planets and chondrites underwent four identical fractionation processes in the solar nebula. Because elements of similar properties stay together in these processes, five constraints suffice to define the composition of a planet: mass of the core, abundance of U, and the ratios K/U, TI/U, and FeO/(FeO + MgO). Complete abundance tables, and normative mineralogies, are given for all three planets. A review of available data shows only a few gross trends for the inner planets: FeO decreases with heliocentric distance, whereas volatiles are depleted and refractories are enriched in the smaller planets.

  6. Chemical composition of Earth, Venus, and Mercury.

    PubMed

    Morgan, J W; Anders, E

    1980-12-01

    Model compositions of Earth, Venus, and Mercury are calculated from the premise that planets and chondrites underwent four identical fractionation processes in the solar nebula. Because elements of similar properties stay together in these processes, five constraints suffice to define the composition of a planet: mass of the core, abundance of U, and the ratios K/U, Tl/U, and FeO/(FeO + MgO). Complete abundance tables, and normative mineralogies, are given for all three planets. Review of available data shows only a few gross trends for the inner planets: FeO decreases with heliocentric distance, whereas volatiles are depleted and refractories are enriched in the smaller planets. PMID:16592930

  7. Comparison of Chemical Composition of Complex Disinfection Byproduct (DBP) Mixtures Produced by Different Treatment Methods - slides

    EPA Science Inventory

    Analyses of the chemical composition of complex DBP mixtures, produced by different drinking water treatment processes, are essential to generate toxicity data required for assessing their risks to humans. For mixture risk assessments, whole mixture toxicology studies generally a...

  8. Comparison of Chemical Composition of Complex Disinfection Byproduct (DBP) Mixtures Produced by Different Treatment Methods

    EPA Science Inventory

    Analyses of the chemical composition of complex DBP mixtures, produced by different drinking water treatment processes, are essential to generate toxicity data required for assessing their risks to humans. For mixture risk assessments, whole mixture toxicology studies generally a...

  9. Chemical constraints on fly ash glass compositions

    SciTech Connect

    John H. Brindle; Michael J. McCarthy

    2006-12-15

    The major oxide content and mineralogy of 75 European fly ashes were examined, and the major element composition of the glass phase was obtained for each. Correlation of compositional trends with the glass content of the ash was explored. Alkali content was deduced to have a major influence on glass formation, and this in turn could be related to the probable chemistry of clay minerals in the source coals. Maximal glass content corresponded to high aluminum content in the glass, and this is in accordance with the theoretical mechanism of formation of aluminosilicate glasses, in which network-modifying oxides are required to promote tetrahedral coordination of aluminum in glass chain structures. Iron oxide was found to substitute for alkali oxides where the latter were deficient, and some indications of preferred eutectic compositions were found. The work suggests that the proportion of the glass phase in the ash can be predicted from the coal mineralogy and that the utility of a given ash for processing into geopolymers or zeolites is determined by its source. 23 refs., 7 figs., 1 tab.

  10. The Effect of Chemical Functionalization on Mechanical Properties of Nanotube/Polymer Composites

    NASA Technical Reports Server (NTRS)

    Odegard, G. M.; Frankland, S. J. V.; Gates, T. S.

    2003-01-01

    The effects of the chemical functionalization of a carbon nanotube embedded in a nanotube/polyethylene composite on the bulk elastic properties are presented. Constitutive equations are established for both functionalized and non-functionalized nanotube composites systems by using an equivalent-continuum modeling technique. The elastic properties of both composites systems are predicted for various nanotube lengths, volume fractions, and orientations. The results indicate that for the specific composite material considered in this study, most of the elastic stiffness constants of the functionalized composite are either less than or equal to those of the non-functionalized composite.

  11. Review of Knowledge on the Occurrence, Chemical Composition, and Potential Use for Desalination of Saline Ground Water in Arizona, New Mexico, and Texas with a Discussion of Potential Future Study Needs

    USGS Publications Warehouse

    Huff, G.F.

    2004-01-01

    Increasing demand on the limited supplies of freshwater in the desert Southwest, as well as other parts of the United States, has increased the level of interest in saline-water resources. Saline ground water has long been recognized as a potentially important contributor to water supply in the Southwest, as demonstrated by the number of hydrologic, geologic, and engineering studies on the distribution of saline water and the feasibility of desalination. Potential future study needs include investigating and documenting the three-dimensional distribution of salinity and chemical composition of saline-water resources and the hydraulic properties of aquifers containing these saline-water resources, assessing the chemical suitability of saline water for use with existing and anticipated desalination technologies, simulating the effect of withdrawal of saline ground water on water levels and water composition in saline and adjoining or overlying freshwater aquifers, and determining the suitability of target geologic formations for injection of desalination-generated waste.

  12. Energetic composites and method of providing chemical energy

    DOEpatents

    Danen, Wayne C.; Martin, Joe A.

    1997-01-01

    A method for providing chemical energy and energetic compositions of matter consisting of thin layers of substances which will exothermically react with one another. The layers of reactive substances are separated by thin layers of a buffer material which prevents the reactions from taking place until the desired time. The reactions are triggered by an external agent, such as mechanical stress or an electric spark. The compositions are known as metastable interstitial composites (MICs). This class of compositions includes materials which have not previously been capable of use as energetic materials. The speed and products of the reactions can be varied to suit the application.

  13. Energetic composites and method of providing chemical energy

    DOEpatents

    Danen, W.C.; Martin, J.A.

    1997-02-25

    A method is described for providing chemical energy and energetic compositions of matter consisting of thin layers of substances which will exothermically react with one another. The layers of reactive substances are separated by thin layers of a buffer material which prevents the reactions from taking place until the desired time. The reactions are triggered by an external agent, such as mechanical stress or an electric spark. The compositions are known as metastable interstitial composites (MICs). This class of compositions includes materials which have not previously been capable of use as energetic materials. The speed and products of the reactions can be varied to suit the application. 3 figs.

  14. Model studies of the meteorology and chemical composition of the troposphere over the North Atlantic during August 18-30, 1993

    NASA Astrophysics Data System (ADS)

    FlatøY, Frode; Hov, Øystein; Gerbig, Christoph; Oltmans, Samuel J.

    1996-12-01

    A mesoscale chemistry transport model driven by meteorological data from a numerical weather prediction model is used to calculate ozone, carbon monoxide, oxides of nitrogen, and other chemical species over the North Atlantic for a 13-days period (August 18-30, 1993). The model has a circumpolar grid so that the boundary condition problems are minimized, and the influence of North American emissions on the chemical composition of the troposphere over the North Atlantic and Europe is calculated. During the first part of the period there is a zonal flow across the North Atlantic in the free troposphere; later, there is a strong north-south as well as vertical component in the advection field. The variability in the concentrations of ozone in the free troposphere is mainly caused by dynamical processes, while the chemical modification is small over an integration time of less than two weeks. A continental plume off the North American continent extending 2000 km or more into the North Atlantic is identified toward the end of the calculation period. There is then a maximum in the concentration of ozone around 1 km above the sea surface, with a much lower concentration in the marine boundary layer close to the ocean surface. Measurements from the U.K. Meteorological Office Hercules C-130 in the free troposphere off the Atlantic Provinces, across the Atlantic Ocean, and around the Azores together with ozone soundings from the Azores, Bermuda, and Iceland were used for model comparison. The calculations indicate that in the free troposphere the initial conditions as well as the upper boundary conditions are important for ozone distribution. In the upper troposphere the net change in the chemical formation rate of ozone due to a change in the NOx concentration is quite independent of the absolute value of the ozone concentration itself and, consequently, the choice of boundary conditions for ozone is not so important in this context. In the lower troposphere the change in

  15. Studies on acid oils and fatty acids for chickens III. Effect of chemical composition on metabolisable energy of by-products of vegetable oil refining.

    PubMed

    Vila, B; Esteve-Garcia, E

    1996-03-01

    1. Fourteen by-products of oil refining, selected for their variability in free fatty acid and unsaponifiable contents, were analysed chemically with the objective of relating the determined ME values of the products to chemical composition by means of multiple linear regression analysis. Refined sunflower oil was included as a reference fat. 2. Twenty-one 2-week-old chicks were used to determine fat digestibilities and AMEn values of diets, using the total collection method. Fats were included in a wheat-soyabean meal diet at 100 g/kg. Multiple linear regression analysis was used to express the ME values of fats as functions of the parameters measured (moisture, gross energy, impurities, unsaponifiables, non eluted material, free fatty acid content, unsaturated: saturated ratio, peroxide value, TBA test). 3. The ME of the fat products lay in the range l2.62 to 24.35 MJ/kg, and 29.26 MJ/kg for refined sunflower oil. Free fatty acid content of the fats was shown to be a poor predictor of their ME values, whereas non eluted material (NEM) of the fat products showed a good correlation with their ME. A regression equation could be derived (R2 0.6548; SEE 2.0064) with the unsaturated: saturated ratio (U:S) and NEM. An ME prediction equation based on the U:S, NEM and unsaponifiable content is also proposed (R2= 0.7l68; SEE= 1.9058). PMID:8833534

  16. Chemical composition of rainwater in western Amazonia — Brazil

    NASA Astrophysics Data System (ADS)

    Honório, B. A. D.; Horbe, A. M. C.; Seyler, P.

    2010-11-01

    An extensive sample study in western Amazonia, Brazil was performed over the course of one year to i) establish the natural influence of the forest, ii) determine the contribution of the vegetation and fossil fuel burning and iii) detect the geographical and temporal influences on the rainwater composition. Six sampling stations were chosen on two 1000 km-long orthogonal axes. Parintins, Itapiranga, Manaus, Tabatinga were the stations from East to West, and Boa Vista, Manaus, and Apui were the stations from North to South. The results indicate a complex control of the chemical composition of the rainwater and a rather high heterogeneity among the stations. This heterogeneity can be explained by the influence of biogenic, terrestrial dust, agriculture activities and biomass-burning aerosols, and the urban development of Manaus City with its rapid increase in the use of fossil fuel. The isotopic composition of the rainwater indicates that from the north and west sides to the south and east sides, a slight geographical and temporal gradient exists, and more δ180 enriched rainwater tends to be present in the west (Tabatinga) and in the North (Boa Vista). During the dry season a more negative δ180 rainwater was observed in Manaus and Boa Vista stations, as compared to others stations. This observation indicates the more intense evaporative contribution of rainwater as a consequence of a rapid deforestation (savannization) process in the Manaus region.

  17. Switchgrass biomass and chemical composition for biofuel in eastern Canada

    SciTech Connect

    Madakadze, I.C.; Stewart, K.; Peterson, P.R.; Coulman, B.E.; Smith, D.L.

    1999-08-01

    Switchgrass (Panicum virgatum L.) is one of several warm-season grasses that have been identified as potential biomass crops in North America. A two-year field study was conducted, on a free-draining sandy clay loam (St. Bernard, Typic Hapludalf), to characterize the growth and evaluate changes in biomass accumulation and composition of switchgrass at Montreal, QC. Three cultivars, Cave-in-Rock, Pathfinder, and Sunburst, were grown in solid stands in a randomized complete block design. Canopy height, dry matter (DM) accumulation and chemical composition were monitored biweekly throughout the growing season. Average maximum canopy heights were 192.5 cm for Cave-in-Rock, 169.9 for Pathfinder, and 177.8 for Sunburst. The respective end-of-season DM yields were 12.2, 11.5, and 10.6 Mg/ha. Biomass production among cultivars appeared to be related to time of maturation. Nitrogen concentration of DM decreased curvilinearly from 25 g/kg at the beginning of the season to 5 g/kg DM at season's end. Both acid-detergent fiber (ADF) and neutral-detergent fiber (NDF) concentrations increased to a maximum early in the season, after which no changes were detected. The average maximum values of ADF and NDF were, respectively, 647.6 and 849.0 g/kg DM for Cave-in-Rock, 669.1 and 865.2 for Pathfinder, and 661.8 and 860.9 for Sunburst. Changes in canopy height, DM accumulation, and chemical composition could all be described by predictive regression equations. These results indicate that switchgrass has potential as a biomass crop in a short-season environment.

  18. Unraveling the chemical composition of caramel.

    PubMed

    Golon, Agnieszka; Kuhnert, Nikolai

    2012-03-28

    Caramel is one of mankind's best known dietary materials obtained from carbohydrates by heating. Much effort has been expended toward the chemical characterization of the components of caramel but impeded by a lack of suitable analytical techniques sufficiently powerful for providing insight into an extraordinarily complex material. This paper reports the characterization of caramel formed by heating from glucose, fructose, and saccharose using a conceptually novel combination of mass spectrometrical techniques. The analytical strategy employed uses high-resolution mass spectrometry (MS) followed by targeted liquid chromatography-tandem MS experiments. Caramel is composed from several thousand compounds formed by a small number of unselective and chemoselective reactions. Caramelization products include oligomers with up to six carbohydrate units formed through unselective glycosidic bond formation, dehydration products of oligomers losing up to a maximum of eight water molecules, hydration products of sugar oligomers, disproportionation products, and colored aromatic products. PMID:22375847

  19. Aqueous Alteration and Martian Bulk Chemical Composition

    NASA Astrophysics Data System (ADS)

    Taylor, J.; Boynton, W. V.; McLennan, S. M.

    2009-12-01

    The bulk compositions of the terrestrial planets are fundamentally important in testing models for planetary accretion. This is particularly true for the abundances of volatile elements. In the absence of direct samples of the mantle, we must rely on samples of surface materials obtained from orbit (specifically from the Mars Odyssey Gamma-Ray Spectrometer, GRS), Martian meteorites, and in situ analyses. Use of these databases requires understanding the processes that formed and modified the igneous rocks composing the crust; aqueous processes are particularly important. Halogens are useful elements for understanding Martian bulk composition and surface aqueous alteration. Here, we focus on Cl, which is an incompatible element during partial melting. Cosmochemically, Cl is a moderately volatile element with a condensation temperature of 948 Kelvin, only slightly below that of K (1006 Kelvin), another incompatible lithophile element. Cl is substantially lost during magma degassing at or near the surface, making it difficult to determine its abundances in the interior through analyses of rocks, leading to an underestimate of Cl abundance in bulk silicate Mars. GRS data for Mars between approximately 52 degrees north and south show that K and Cl are uncorrelated. This is not surprising as they fractionate easily by release of Cl-bearing gases from magmas near the surface and during eruptions, by aqueous alteration of surface materials, and by the large solubility of Cl salts in water. A positive correlation of Cl with H supports the role of water in Cl redistribution. In spite of the lack of correlation between K and Cl, the mean Cl/K ratio is roughly chondritic: 1.5 ±0.1 compared to 1.28 in CI chondrites. However, Cl appears to be enriched at least in the uppermost few tens of cm analyzed by the GRS: Cl correlates with both H and S, but a linear fit to the data shows a positive Cl intercept of about 0.3, which suggests a decoupling of Cl from S and H. Adjusting the

  20. Chemical composition in relation with biomass ash structure

    NASA Astrophysics Data System (ADS)

    Holubcik, Michal; Jandacka, Jozef

    2014-08-01

    Biomass combustion can be more complicated like combustion of fossil fuels because it is necessary to solve problems with lower ash melting temperature. It can cause a lot of problems during combustion process. Chemical composition of biomass ash has great impact on sinters and slags creation in ash because it affects structure of heated ash. In this paper was solved relation between chemical composition and structure of heated ash from three types of biomass (spruce wood, miscanthus giganteus and wheat straw). Amount of SiO2, CaO, MgO, Al2O3 and K2O was determined. Structure of heated ash was optically determined after heating to 1000 °C or 1200 °C. Results demonstrated that chemical composition has strong effect on structure and color of heated ash.

  1. Chemical composition analysis and authentication of whisky.

    PubMed

    Wiśniewska, Paulina; Dymerski, Tomasz; Wardencki, Waldemar; Namieśnik, Jacek

    2015-08-30

    Whisky (whiskey) is one of the most popular spirit-based drinks made from malted or saccharified grains, which should mature for at least 3 years in wooden barrels. High popularity of products usually causes a potential risk of adulteration. Thus authenticity assessment is one of the key elements of food product marketing. Authentication of whisky is based on comparing the composition of this alcohol with other spirit drinks. The present review summarizes all information about the comparison of whisky and other alcoholic beverages, the identification of type of whisky or the assessment of its quality and finally the authentication of whisky. The article also presents the various techniques used for analyzing whisky, such as gas and liquid chromatography with different types of detectors (FID, AED, UV-Vis), electronic nose, atomic absorption spectroscopy and mass spectrometry. In some cases the application of chemometric methods is also described, namely PCA, DFA, LDA, ANOVA, SIMCA, PNN, k-NN and CA, as well as preparation techniques such SPME or SPE. PMID:25315338

  2. The chemical composition of Galactic beat Cepheids

    NASA Astrophysics Data System (ADS)

    Kovtyukh, V.; Lemasle, B.; Chekhonadskikh, F.; Bono, G.; Matsunaga, N.; Yushchenko, A.; Anderson, R. I.; Belik, S.; da Silva, R.; Inno, L.

    2016-08-01

    We determine the metallicity and detailed chemical abundances (α, iron-peak and neutron-capture elements) for the almost complete (18/24) sample of Galactic double mode Cepheids (also called beat Cepheids). Double mode Cepheids are Cepheids that pulsate in two modes simultaneously. We calibrate a new relation between their metallicity and their period ratio P1/P0. This linear relation allows to determine the metallicity of bimodal Cepheids with an accuracy of 0.03 dex in the range of [Fe/H] from +0.2 to -0.5 dex. By extrapolating the relation to Magellanic Clouds beat Cepheids, we provide their metallicity distribution function. Moreover, by using this relation, we also provide the first metallicity estimate for two double-mode F/1O Cepheids located in and beyond the Galactic bulge. Finally, we report the discovery of a super-Lithium rich double mode Cepheid V371 Per which has a Lithium abundance of logA(Li) = 3.54 ± 0.09 dex. Along with V1033 Cyg (which is an ordinary classical Cepheid), it is the second known Cepheid of such type in the Galaxy.

  3. Major element chemical compositions of chondrules in unequilibrated chondrites

    NASA Technical Reports Server (NTRS)

    Ikeda, Y.

    1984-01-01

    The chemical compositions (except for metals and sulfides in chondrules) of more than 500 chondrules from unequilibrated E, H, L, LL, and C chondrites were measured using a broad beam of an electron-probe microanalyzer. The compositions of chondrules can be represented by various mixtures of normative compositions of olivine, low-Ca pyroxene, plagioclase, and high-Ca pyroxene with minor amounts of spinel, feldspathoid, SiO2-minerals, etc., indicating that the chondrule precursor materials consisted of aggregates of these minerals. The Al, Na, and K contents of most chondrules reflect the compositions of the ternary feldspar (An-Ab-Kf) of the chondrule precursor materials, and chemical types of chondrules (KF, SP, IP, and CP) are defined on the basis of the atomic proportion of Al, Na, and K.

  4. Thymus vulgaris essential oil: chemical composition and antimicrobial activity.

    PubMed

    Borugă, O; Jianu, C; Mişcă, C; Goleţ, I; Gruia, A T; Horhat, F G

    2014-01-01

    The study was designed to determine the chemical composition and antimicrobial properties of the essential oil of Thymus vulgaris cultivated in Romania. The essential oil was isolated in a yield of 1.25% by steam distillation from the aerial part of the plant and subsequently analyzed by GC-MS. The major components were p-cymene (8.41%), γ-terpinene (30.90%) and thymol (47.59%). Its antimicrobial activity was evaluated on 7 common food-related bacteria and fungus by using the disk diffusion method. The results demonstrate that the Thymus vulgaris essential oil tested possesses strong antimicrobial properties, and may in the future represent a new source of natural antiseptics with applications in the pharmaceutical and food industry. PMID:25870697

  5. Fuel options from microalgae with representative chemical compositions

    SciTech Connect

    Feinberg, D. A.

    1984-07-01

    Representative species of microalgae are examined with respect to their reported chemical compositions. Each species is analyzed under a variety of culture conditions, with the objective being to characterize an optimum mixture of fuel products (e.g., methane, ethanol, methylester) which should be produced by the particular species. Historically the emphasis has been on the entire algal cell mass. Using the reported chemical composition for the representative species under specific sets of growth conditions, some conclusions can be drawn about the preferred fuel product conversion routes that could be employed. 10 references, 7 figures, 12 tables.

  6. Chemical vapor infiltration of non-oxide ceramic matrix composites

    SciTech Connect

    Besmann, T.M.; Stinton, D.P.; Lowden, R.A.

    1993-12-31

    Continuous fiber ceramic composites are enabling new, high temperature structural applications. Chemical vapor infiltration methods for producing these composites are being investigated, with the complexity of filament weaves and deposition chemistry merged with standard heat and mass transport relationships. Silicon carbide- based materials are, by far, the most mature, and are already being used in aerospace applications. This paper addresses the state-of-the-art of the technology and outlines current issues.

  7. Early salt stress effects on the changes in chemical composition in leaves of ice plant and Arabidopsis. A Fourier transform infrared spectroscopy study.

    PubMed

    Yang, Jyisy; Yen, Hungchen E

    2002-10-01

    A technique based on Fourier transform infrared (FT-IR) spectrometry was developed to detect the corresponding changes in chemical composition associated with the rapid changes in sodium and water content in 200 mM NaCl-stressed halophyte ice plants (Mesembryanthemum crystallinum). The changes in glycophyte Arabidopsis stressed with 50 mM NaCl were also examined for comparison. The obtained IR spectra were further processed by deconvolution and curve fitting to examine the chemical nature of the responding sources in the leaves. Using three stages of ice plant leaves, absorption bands corresponding to carbohydrates, cell wall pectin, and proteins were identified, with distinct IR spectra representing each developmental stage. Within 48 h of mild salt stress, the absorption band intensities in the fingerprint region increased continuously in both plants, suggesting that the carbon assimilation was not affected at the early stage of stress. The intensities of ester and amide I absorption bands decreased slightly in Arabidopsis but increased in ice plant, suggesting that the cell expansion and protein synthesis ceased in Arabidopsis but continued in ice plant. In both plants, the shift in amide I absorption band was observed hourly after salt stress, indicating a rapid conformational change of cellular proteins. Analyses of the ratio between major and minor amide I absorption band revealed that ice plant was able to maintain a higher-ordered form of proteins under stress. Furthermore, the changes in protein conformation showed a positive correlation to the leaf sodium contents in ice plant, but not in Arabidopsis. PMID:12376666

  8. Towards a better understanding of the origins, chemical composition and aging of oxygenated organic aerosols: case study of a Mediterranean industrialized environment, Marseille

    NASA Astrophysics Data System (ADS)

    El Haddad, I.; D'Anna, B.; Temime-Roussel, B.; Nicolas, M.; Boreave, A.; Favez, O.; Voisin, D.; Sciare, J.; George, C.; Jaffrezo, J.-L.; Wortham, H.; Marchand, N.

    2013-08-01

    As part of the FORMES summer 2008 experiment, an Aerodyne compact time-of-flight aerosol mass spectrometer (cToF-AMS) was deployed at an urban background site in Marseille to investigate the sources and aging of organic aerosols (OA). France's second largest city and the largest port in the Mediterranean, Marseille, provides a locale that is influenced by significant urban industrialized emissions and an active photochemistry with very high ozone concentrations. Particle mass spectra were analyzed by positive matrix factorization (PMF2) and the results were in very good agreement with previous apportionments obtained using a chemical mass balance (CMB) approach coupled to organic markers and metals (El Haddad et al., 2011a). AMS/PMF2 was able to identify for the first time, to the best of our knowledge, the organic aerosol emitted by industrial processes. Even with significant industries in the region, industrial OA was estimated to contribute only ~ 5% of the total OA mass. Both source apportionment techniques suggest that oxygenated OA (OOA) constitutes the major fraction, contributing ~ 80% of OA mass. A novel approach combining AMS/PMF2 data with 14C measurements was applied to identify and quantify the fossil and non-fossil precursors of this fraction and to explicitly assess the related uncertainties. Results show with high statistical confidence that, despite extensive urban and industrial emissions, OOA is overwhelmingly non-fossil, formed via the oxidation of biogenic precursors, including monoterpenes. AMS/PMF2 results strongly suggest that the variability observed in the OOA chemical composition is mainly driven in our case by the aerosol photochemical age. This paper presents the impact of photochemistry on the increase of OOA oxygenation levels, formation of humic-like substances (HULIS) and the evolution of α-pinene SOA (secondary OA) components.

  9. Chemical composition of some wild peanut species (Arachis L.) seeds.

    PubMed

    Grosso, N R; Nepote, V; Guzmán, C A

    2000-03-01

    Oil, protein, ash, and carbohydrate contents, iodine value, and fatty acid and sterol compositions were studied in seeds of Arachis trinitensis, A. chiquitana, A. kempff-mercadoi, A. diogoi, A. benensis, A. appressipila, A. valida, A. kretschmeri, A. helodes, A. kuhlmannii, A. williamsii, A. sylvestris, A. matiensis, A. pintoi, A. hoehnei, A. villosa, and A. stenosperma. Oil content was greatest in A.stenosperma (mean value = 51.8%). The protein level was higher in A. sylvestris (30.1%) and A. villosa (29.5%). Mean value of oleic acid varied between 30.6% (A. matiensis) and 46.8% (Arachis villosa), and linoleic acid oscillated between 34.1% (A. villosa) and 47.4% (A. appressipila). The better oleic-to-linoleic (O/L) ratio was exhibited by A. villosa (1.38). Some species showed higher concentration of behenic acid. The greatest level of this fatty acid was found in A. matiensis (6.2%). Iodine value was lower in A. valida (99.2). The sterol composition in the different peanut species showed higher concentration of beta-sitosterol (mean values oscillated between 55.7 and 60.2%) followed by campesterol (12.4-16. 5%), stigmasterol (9.7-13.3%), and Delta(5)-avenasterol (9.7-13.4%). The chemical quality and stability of oils (iodine value and O/L ratio) from wild peanut studied in this work are not better than those of cultivated peanut. PMID:10725154

  10. Bee Pollen: Chemical Composition and Therapeutic Application

    PubMed Central

    Komosinska-Vassev, Katarzyna; Olczyk, Pawel; Kaźmierczak, Justyna; Olczyk, Krystyna

    2015-01-01

    Bee pollen is a valuable apitherapeutic product greatly appreciated by the natural medicine because of its potential medical and nutritional applications. It demonstrates a series of actions such as antifungal, antimicrobial, antiviral, anti-inflammatory, hepatoprotective, anticancer immunostimulating, and local analgesic. Its radical scavenging potential has also been reported. Beneficial properties of bee pollen and the validity for their therapeutic use in various pathological condition have been discussed in this study and with the currently known mechanisms, by which bee pollen modulates burn wound healing process. PMID:25861358

  11. Chemical composition of cottonseed affected by cropping management practices

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cottonseed is a valuable raw material for a range of food, animal feed, and industrial (such as adhesives) products. Chemical composition is one of the critical parameters to evaluate cottonseed's quality and potential end use. However, the information on the impacts of cropping management practices...

  12. Computer program determines chemical composition of physical system at equilibrium

    NASA Technical Reports Server (NTRS)

    Kwong, S. S.

    1966-01-01

    FORTRAN 4 digital computer program calculates equilibrium composition of complex, multiphase chemical systems. This is a free energy minimization method with solution of the problem reduced to mathematical operations, without concern for the chemistry involved. Also certain thermodynamic properties are determined as byproducts of the main calculations.

  13. Composition and Thermodynamic Properties of Air in Chemical Equilibrium

    NASA Technical Reports Server (NTRS)

    Moeckel, W E; Weston, Kenneth C

    1958-01-01

    Charts have been prepared relating the thermodynamic properties of air in chemical equilibrium for temperatures to 15,000 degrees k and for pressures 10(-5) to 10 (plus 4) atmospheres. Also included are charts showing the composition of air, the isentropic exponent, and the speed of sound. These charts are based on thermodynamic data calculated by the National Bureau of Standards.

  14. Chemical composition of defatted cottonseed and soy meal products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chemical composition is critical information for product quality and exploration of new use. Hence defatted cottonseed meals from both glanded (with gossypol) and glandless (without gossypol) cotton seeds were separated into water soluble and insoluble fractions, or water soluble, alkali soluble as ...

  15. Coma chemical composition at the Abydos landing site

    NASA Astrophysics Data System (ADS)

    Morse, A.; Sheridan, S.; Morgan, G.; Andrews, D.; Barber, S.; Wright, I.

    2015-10-01

    The Ptolemy instrument, onboard the Rosetta Philae Lander, made measurements of the chemical composition of the coma mid-bounce, just after the non-nominal landing on the surface, and subsequently at the Abydos landing site. This presentation will discuss Ptolemy's operations throughout this 45 hour period and the results obtained.

  16. Chemical composition of various Ephedra species.

    PubMed

    Ibragic, Saida; Sofić, Emin

    2015-01-01

    The medicinal significance of Ephedra is based on the sympathomimetic properties of ephedrine (E) alkaloids. Pharmacological effects depend on the phytocomposition of individual Ephedra species. The aim of this study was to measure the total alkaloids content (TAC), total phenolics content (TPC), and total flavonoids content (TFC) and determine their relationship in dry herb of Ephedra major, Ephedra distachya subsp. helvetica, Ephedra monosperma, Ephedra fragilis, Ephedra foeminea, Ephedra alata, Ephedra altissima and Ephedra foliata. Nowadays, medicinal use of Ephedrae herba is limited, but the abuse of its psychostimulants is rising. In this study, TAC, TPC and TFC were determined using spectrophotometric methods. For the first time, ultra-performance liquid chromatography with ultraviolet detection (UPLC-UV) was used for separation and quantification of E-type alkaloids of various Ephedra species. The highest TPC and TFC were found in E. alata (53.3 ± 0.1 mg Gallic acid equivalents/g dry weight, 2.8 mg quercetin equivalents/g dry weight, respectively). The total content of E and pseudoephedrine determined by UPLC-UV varied between 20.8 mg/g dry weight (E. distachya subsp. helvetica) and 34.7 mg/g dry weight (E. monosperma). The variable content and ratio between secondary metabolites determined in different Ephedra species reflects their metabolic activities. Utilization of UPLC-UV unveiled that this technique is sensitive, selective, and useful for separation and quantification of different alkaloids in complex biological matrixes. The limit of detection was 5 ng. Application of UPLC-UV can be recommended in quick analyses of E-type alkaloids in forensic medicine and quality control of pharmaceutical preparations. PMID:26295290

  17. Chemical composition of various Ephedra species

    PubMed Central

    Ibragic, Saida; Sofić, Emin

    2015-01-01

    The medicinal significance of Ephedra is based on the sympathomimetic properties of ephedrine (E) alkaloids. Pharmacological effects depend on the phytocomposition of individual Ephedra species. The aim of this study was to measure the total alkaloids content (TAC), total phenolics content (TPC), and total flavonoids content (TFC) and determine their relationship in dry herb of Ephedra major, Ephedra distachya subsp. helvetica, Ephedra monosperma, Ephedra fragilis, Ephedra foeminea, Ephedra alata, Ephedra altissima and Ephedra foliata. Nowadays, medicinal use of Ephedrae herba is limited, but the abuse of its psychostimulants is rising. In this study, TAC, TPC and TFC were determined using spectrophotometric methods. For the first time, ultra-performance liquid chromatography with ultraviolet detection (UPLC-UV) was used for separation and quantification of E-type alkaloids of various Ephedra species. The highest TPC and TFC were found in E. alata (53.3 ± 0.1 mg Gallic acid equivalents/g dry weight, 2.8 mg quercetin equivalents/g dry weight, respectively). The total content of E and pseudoephedrine determined by UPLC-UV varied between 20.8 mg/g dry weight (E. distachya subsp. helvetica) and 34.7 mg/g dry weight (E. monosperma). The variable content and ratio between secondary metabolites determined in different Ephedra species reflects their metabolic activities. Utilization of UPLC-UV unveiled that this technique is sensitive, selective, and useful for separation and quantification of different alkaloids in complex biological matrixes. The limit of detection was 5 ng. Application of UPLC-UV can be recommended in quick analyses of E-type alkaloids in forensic medicine and quality control of pharmaceutical preparations. PMID:26295290

  18. Fast, Contactless Monitoring of the Chemical Composition of Raw Materials

    NASA Astrophysics Data System (ADS)

    Ivanov, O.; Stoyanov, Zh.; Stoyanov, B.; Nadoliisky, M.; Vaseashta, Ashok

    A technique to monitor chemical composition of materials during manufacturing of ceramic products, in particular - of bricks, is investigated. The technique of monitoring is likely to offset environmental pollution and save energy. For this purpose, we use the Surface photo charge effect, which is generated for each solid body interacting with electromagnetic field. The measurement is express and can be performed in-situ in production conditions. The experimental work has shown that different samples of the investigated materials with different compositions produce different signals specific to each sample. For the same material, the signal varies with the change in chemical composition. More specifically, it is shown that for the material from which the bricks are fired, the signal is a function of the percentage of coal sludge. The results indicate that the characterization technique as a viable technique for control of incoming raw materials.

  19. To measure the chemical composition of a Near Earth Object

    NASA Astrophysics Data System (ADS)

    Gasnault, 0.; Ball, A.; Biele, J.; D'Uston, C.; Forni, O.; Klingelhofer, G.; Maurice, S.; Ulamec, S.

    Introduction. Scenarios for a Near Earth Object (NEO) rendezvous mission were discussed recently in Europe. Such a mission would address scientific questions about the initial conditions and evolutionary history of the solar nebula, as well as mitigation considerations to prevent impact with the Earth. In our opinion the measurement of the elemental composition and the distribution of volatiles in the shallow sub-surface are two of the key observations to be conducted, either from an orbiter or a lander. These measurements are also valuable for documentation (landing site candidates and sample context). This report is limited to the chemical composition, but we assume that remote and/or in-situ observations of physical characteristics, interior, morphology, mineralogy, and organic compounds will also be made as essential complements to achieve the mission scientific objectives. Scientific Interest. The analysis of the bulk composition addresses three fundamental aspects of the scientific mission: (1) the formation of the asteroid or the comet; (2) the evolution of the object; (3) the relation between the parent body and collected meteorites on Earth. Classification of an asteroid/comet can be based on its global composition (abundances of Mg, Si, Fe, Al, Ca, etc. along with its mineralogy), which bears the signature of the feeding zone where it formed. For example the K/U and K/Th ratios seem to increase with distance from the Sun (decreasing temperature). The hydrogen content is another measurable to study the distribution of volatiles in the Solar System. The surface composition is also the result of the degree of evolution of the object and of the interactions with its environment. Building a compositional map of the major elements is necessary to identify and characterize the processes that influenced the asteroid along its history. Finally, knowing the chemical composition will obviously help to relate the parent 1 body to meteorites. Ideally the measurement

  20. Development of chemical vapor composites, CVC materials. Final report

    SciTech Connect

    1998-10-05

    Industry has a critical need for high-temperature operable ceramic composites that are strong, non-brittle, light weight, and corrosion resistant. Improvements in energy efficiency, reduced emissions and increased productivity can be achieved in many industrial processes with ceramic composites if the reaction temperature and pressure are increased. Ceramic composites offer the potential to meet these material requirements in a variety of industrial applications. However, their use is often restricted by high cost. The Chemical Vapor composite, CVC, process can reduce the high costs and multiple fabrication steps presently required for ceramic fabrication. CVC deposition has the potential to eliminate many difficult processing problems and greatly increase fabrication rates for composites. With CVC, the manufacturing process can control the composites` density, microstructure and composition during growth. The CVC process: can grow or deposit material 100 times faster than conventional techniques; does not require an expensive woven preform to infiltrate; can use high modulus fibers that cannot be woven into a preform; can deposit composites to tolerances of less than 0.025 mm on one surface without further machining.

  1. [Chemical composition of deposits on IUD removed from uterus].

    PubMed

    Liu, T Y

    1984-05-01

    An electroprobe is used to analyze the elements and x-ray diffraction technology to determine the crystal structure of deposits on IUDs removed from the uterus, so that the chemical composition of these deposits may be studied. Deposits on a number of copper or stainless steel IUDs are removed and undergo electroprobe analysis, the results of which are compare dwith the results of calcite analysis done using the same method. Several deposit samples are studied using x-ray diffraction technology. The results of the latter study are compared with the results of the x-ray diffraction studies of calcium carbonate and calcite. Both copper and stainless steel IUDs were found to have the same type of deposits, containing traces of cooper, magnesium, potassium, sodium, iron, sulphur, phosphorus, and chlorine. The x-ray diffraction spectrum for these deposits was found to be the same as those of calcium carbonate and calcite (hexagonal crystal). Deposits on stainless steel and copper IUDs were found to be similar to calcite. With the exception of calcium, the other elements are thought to come from amino acid, which is readily combined with calcium carbonate in the uterus. These findings confirm the fact that IUDs cause the presence of more calcium ions in th uterus. 120 copper IUDs place in the uterus from 1 to 7 years and 156 stainless steel IUDs placed in the uterus from 1 month to 19 years were used. The volume of the deposits was so small that electroprobing was the only method which could accurately determine all the chemical elements these deposits contained. PMID:12313205

  2. Field-structured composite studies.

    SciTech Connect

    Martin, James Ellis; Williamson, Rodney L.

    2004-04-01

    Field-structured composites (FSCs) were produced by hosting micron-sized gold-coated nickel particles in a pre-polymer and allowing the mixture to cure in a magnetic field environment. The feasibility of controlling a composite's electrical conductivity using feedback control applied to the field coils was investigated. It was discovered that conductivity in FSCs is primarily determined by stresses in the polymer host matrix due to cure shrinkage. Thus, in cases where the structuring field was uniform and unidirectional so as to produce chainlike structures in the composite, no electrical conductivity was measured until well after the structuring field was turned off at the gel point. In situations where complex, rotating fields were used to generate complex, three-dimensional structures in a composite, very small, but measurable, conductivity was observed prior to the gel point. Responsive, sensitive prototype chemical sensors were developed based on this technology with initial tests showing very promising results.

  3. Composition and placement process for oil field chemicals

    SciTech Connect

    Cantu, L.A.; Yost, M.E.

    1991-01-22

    This patent describes a process for the continuous release of an oil field chemical within a subterranean hydrocarbon bearing formation or wellbore penetrating such formation. It comprises placing the oil field chemical in a polymeric microcapsule; dispersing such polymeric microcapsules; introducing the wellbore fluid containing the microcapsules into a well bore or subterranean formation through a wellbore; then allowing water and temperature at formation conditions to degrade; continuously releasing the chemical from the degraded microcapsules. This patent describes a composition comprising an oil field chemical incorporated in a polymeric microcapsule comprising the condensation product of hydroxyacetic acid monomer or hydroxyacetic acid co-condensed with up to 15 percent by weight of other hydroxy-, carboxylic acid-, or hydroxycarboxylic acid- containing moieties. The product has a number average molecular weight of from about 200 to about 4000.

  4. Quantification of aerosol chemical composition using continuous single particle measurements

    NASA Astrophysics Data System (ADS)

    Jeong, C.-H.; McGuire, M. L.; Godri, K. J.; Slowik, J. G.; Rehbein, P. J. G.; Evans, G. J.

    2011-07-01

    Mass concentrations of sulphate, nitrate, ammonium, organic carbon (OC), elemental carbon (EC) were determined from real time single particle data in the size range 0.1-3.0 μm measured by an Aerosol Time-of-Flight Mass Spectrometer (ATOFMS) at urban and rural sites in Canada. To quantify chemical species within individual particles measured by an ATOFMS, ion peak intensity of m/z -97 for sulphate, -62 for nitrate, +18 for ammonium, +43 for OC, and +36 for EC were scaled using the number and size distribution data by an Aerodynamic Particle Sizer (APS) and a Fast Mobility Particle Sizer (FMPS). Hourly quantified chemical species from ATOFMS single-particle analysis were compared with collocated fine particulate matter (aerodynamic diameter < 2.5 μm, PM2.5) chemical composition measurements by an Aerosol Mass Spectrometer (AMS) at a rural site, a Gas-Particle Ion Chromatograph (GPIC) at an urban site, and a Sunset Lab field OCEC analyzer at both sites. The highest correlation was found for nitrate, with correlation coefficients (Pearson r) of 0.89 (ATOFMS vs. GPIC) and 0.85 (ATOFMS vs. AMS). ATOFMS mass calibration factors, determined for the urban site, were used to calculate mass concentrations of the major PM2.5 chemical components at the rural site near the US border in southern Ontario. Mass reconstruction using the ATOFMS mass calibration factors agreed very well with the PM2.5 mass concentrations measured by a Tapered Element Oscillating Microbalance (TEOM, r = 0.86) at the urban site and a light scattering monitor (DustTrak, r = 0.87) at the rural site. In the urban area nitrate was the largest contributor to PM2.5 mass in the winter, while organics and sulphate contributed ~64 % of the summer PM2.5 in the rural area, suggesting a strong influence of regional/trans-boundary pollution. The mass concentrations of five major species in ten size-resolved particle-types and aerosol acidity of each particle-type were determined for the rural site. On a mass basis

  5. Use of high-volume outdoor smog chamber photo-reactors for studying physical and chemical atmospheric aerosol formation and composition

    NASA Astrophysics Data System (ADS)

    Borrás, E.; Ródenas, M.; Vera, T.; Muñoz, A.

    2015-12-01

    The atmospheric particulate matter has a large impact on climate, biosphere behaviour and human health. Its study is complex because of large number of species are present at low concentrations and the continuous time evolution, being not easily separable from meteorology, and transport processes. Closed systems have been proposed by isolating specific reactions, pollutants or products and controlling the oxidizing environment. High volume simulation chambers, such as EUropean PHOtoREactor (EUPHORE), are an essential tool used to simulate atmospheric photochemical reactions. This communication describes the last results about the reactivity of prominent atmospheric pollutants and the subsequent particulate matter formation. Specific experiments focused on organic aerosols have been developed at the EUPHORE photo-reactor. The use of on-line instrumentation, supported by off-line techniques, has provided well-defined reaction profiles, physical properties, and up to 300 different species are determined in particulate matter. The application fields include the degradation of anthropogenic and biogenic pollutants, and pesticides under several atmospheric conditions, studying their contribution on the formation of secondary organic aerosols (SOA). The studies performed at the EUPHORE have improved the mechanistic studies of atmospheric degradation processes and the knowledge about the chemical and physical properties of atmospheric particulate matter formed during these processes.

  6. Chemical composition of biomass generated in the guava tree pruning

    PubMed Central

    Camarena-Tello, Julio César; Rocha-Guzmán, Nuria Elizabeth; Gallegos-Infante, José Alberto; González-Laredo, Rubén Francisco; Pedraza-Bucio, Fabiola Eugenia; López-Albarrán, Pablo; Herrera-Bucio, Rafael; Rutiaga-Quiñones, José Guadalupe

    2015-01-01

    Psidium guajava L. (Myrtaceae) is a native plant of Central America and is now widely cultivated in many tropical regions of the world for the fruit production. In Mexico, in the guava orchards common practices to control fruit production are: water stress, defoliation and pruning. In this study, we report the chemical composition of the biomass (branches and leaves) generated in the pruning practices. The results ranged as follows: pH (4.98-5.88), soda solubility (39.01-70.49 %), ash (1.87-8.20 %); potassium and calcium were the major inorganic elements in ash. No heavy metals were detected in the studied samples; total solubility (15.21-46.60 %), Runkel lignin (17.77-35.26 %), holocellulose (26.56 -69.49 %), α-cellulose (15.53-35.36 %), hemicelluloses (11.02-34.12 %), tannins in aqueous extracts (3.81-9.06 %), and tannins in ethanolic extracts (3.42-15.24 %). PMID:26417359

  7. Chemical composition of biomass generated in the guava tree pruning.

    PubMed

    Camarena-Tello, Julio César; Rocha-Guzmán, Nuria Elizabeth; Gallegos-Infante, José Alberto; González-Laredo, Rubén Francisco; Pedraza-Bucio, Fabiola Eugenia; López-Albarrán, Pablo; Herrera-Bucio, Rafael; Rutiaga-Quiñones, José Guadalupe

    2015-01-01

    Psidium guajava L. (Myrtaceae) is a native plant of Central America and is now widely cultivated in many tropical regions of the world for the fruit production. In Mexico, in the guava orchards common practices to control fruit production are: water stress, defoliation and pruning. In this study, we report the chemical composition of the biomass (branches and leaves) generated in the pruning practices. The results ranged as follows: pH (4.98-5.88), soda solubility (39.01-70.49 %), ash (1.87-8.20 %); potassium and calcium were the major inorganic elements in ash. No heavy metals were detected in the studied samples; total solubility (15.21-46.60 %), Runkel lignin (17.77-35.26 %), holocellulose (26.56 -69.49 %), α-cellulose (15.53-35.36 %), hemicelluloses (11.02-34.12 %), tannins in aqueous extracts (3.81-9.06 %), and tannins in ethanolic extracts (3.42-15.24 %). PMID:26417359

  8. Pereskia aculeata Muller (Cactaceae) Leaves: Chemical Composition and Biological Activities.

    PubMed

    Souza, Lucèia Fàtima; Caputo, Lucia; Inchausti De Barros, Ingrid Bergman; Fratianni, Florinda; Nazzaro, Filomena; De Feo, Vincenzo

    2016-01-01

    The aims of this work were to study the chemical composition of the essential oil from the leaves of Pereskia aculeata and to evaluate some biological activities of three leaf extracts. The phenolic content, antioxidant activity, and in vitro antimicrobial and antifungal activities were determined. The methanol extract showed antioxidant activity (EC50 7.09 mg/mL) and high polyphenols content (15.04 ± 0.31 mg gallic acid equivalents (GAE)/g). The petroleum ether extract exhibited potent antibacterial activity against Escherichia coli, whereas the chloroform extract showed inhibitory activity against Bacillus cereus and Staphylococcus aureus. The petroleum ether and methanol extracts were more effective in inhibiting the growth of Aspergillus versicolor. The possible cytotoxicity of extracts on neuroblastoma SH-SY5Y cancer cell line and the influence on adenylate cyclase (ADCY) expression was also studied. P. aculeata chloroform extract showed antiproliferative activity with an IC50 value of 262.83 µg/mL. Treatments of SH-SY5Y neuroblastoma cells with 100 µg/mL of methanol extract significantly reduced ADCY1 expression. PMID:27598154

  9. Effect of flares on the chemical composition of exoplanets atmospheres

    NASA Astrophysics Data System (ADS)

    Venot, O.; Decin, L.

    2015-10-01

    M stars are very abundant in our Galaxy, and very likely harbour the majority of planetary systems. But a particularity of M stars is that they are the most active class of stars. Indeed, they experience stellar variability such as flares. These violent and unpredictable outbursts originate from the photosphere and are caused by magnetic processus. During such an event, the energy emitted by the star can vary by several orders of magnitude for the whole wavelength range. It results in an enhancement of the H# emission and of the continuum. Different studies on the effect of flares on exoplanets have already been conducted [1, 2]. Here we are interested in the effect of a flare on the atmospheric composition of a warm Neptune orbiting around an M star. Using the stellar flux of AD Leo recorded during a flare event [1] and the chemical model of [3], we have studied the impact on the atmosphere. We have also computed the synthetic spectra assuming that such an event occurs during a transit. We will present these results.

  10. Chemical Composition of Defatted Cottonseed and Soy Meal Products.

    PubMed

    He, Zhongqi; Zhang, Hailin; Olk, Dan C

    2015-01-01

    Chemical composition is critical information for product quality and exploration of new use. Hence defatted cottonseed meals from both glanded (with gossypol) and glandless (without gossypol) cotton seeds were separated into water soluble and insoluble fractions, or water soluble, alkali soluble as well as total protein isolates. The contents of gossypol, total protein and amino acids, fiber and carbohydrates, and selected macro and trace elements in these products were determined and compared with each other and with those of soy meal products. Data reported in this work improved our understanding on the chemical composition of different cottonseed meal products that is helpful for more economical utilization of these products. These data would also provide a basic reference for product standards and quality control when the production of the cottonseed meal products comes to pilot and industrial scales. PMID:26079931

  11. Chemical Composition of Defatted Cottonseed and Soy Meal Products

    PubMed Central

    He, Zhongqi; Zhang, Hailin; Olk, Dan C.

    2015-01-01

    Chemical composition is critical information for product quality and exploration of new use. Hence defatted cottonseed meals from both glanded (with gossypol) and glandless (without gossypol) cotton seeds were separated into water soluble and insoluble fractions, or water soluble, alkali soluble as well as total protein isolates. The contents of gossypol, total protein and amino acids, fiber and carbohydrates, and selected macro and trace elements in these products were determined and compared with each other and with those of soy meal products. Data reported in this work improved our understanding on the chemical composition of different cottonseed meal products that is helpful for more economical utilization of these products. These data would also provide a basic reference for product standards and quality control when the production of the cottonseed meal products comes to pilot and industrial scales. PMID:26079931

  12. Apparatus for rapid measurement of aerosol bulk chemical composition

    DOEpatents

    Lee, Yin-Nan E.; Weber, Rodney J.; Orsini, Douglas

    2006-04-18

    An apparatus for continuous on-line measurement of chemical composition of aerosol particles with a fast time resolution is provided. The apparatus includes an enhanced particle size magnifier for producing activated aerosol particles and an enhanced collection device which collects the activated aerosol particles into a liquid stream for quantitative analysis by analytical means. Methods for on-line measurement of chemical composition of aerosol particles are also provided, the method including exposing aerosol carrying sample air to hot saturated steam thereby forming activated aerosol particles; collecting the activated aerosol particles by a collection device for delivery as a jet stream onto an impaction surface; and flushing off the activated aerosol particles from the impaction surface into a liquid stream for delivery of the collected liquid stream to an analytical instrument for quantitative measurement.

  13. Apparatus for rapid measurement of aerosol bulk chemical composition

    DOEpatents

    Lee, Yin-Nan E.; Weber, Rodney J.

    2003-01-01

    An apparatus and method for continuous on-line measurement of chemical composition of aerosol particles with a fast time resolution are provided. The apparatus includes a modified particle size magnifier for producing activated aerosol particles and a collection device which collects the activated aerosol particles into a liquid stream for quantitative analysis by analytical methods. The method provided for on-line measurement of chemical composition of aerosol particles includes exposing aerosol carrying sample air to hot saturated steam thereby forming activated aerosol particles; collecting the activated aerosol particles by a collection device for delivery as a jet stream onto an impaction surface; flushing off the activated aerosol particles from the impaction surface into a liquid stream for delivery of the collected liquid stream to an analytical instrument for quantitative measurement.

  14. An investigation into the chemical composition of alternative invertebrate prey.

    PubMed

    Oonincx, D G A B; Dierenfeld, E S

    2012-01-01

    The aim of this study was to determine the chemical composition of eight invertebrate species and evaluate their suitability as alternative prey. The species selected were rusty red cockroaches (Blatta lateralis), six-spotted cockroaches (Eublaberus distanti), Madagascar hissing cockroaches (Gromphadorhina portentosa), fruit flies (Drosophila melanogaster), false katydids (Microcentrum rhombifolium), beetles of the mealworm (Tenebrio molitor), and superworm beetles (Zophobas morio), as well as woodlice (Porcellio scaber). Dry matter (DM), crude protein, crude fat, neutral detergent fiber, acid detergent fiber, ash, macro and trace minerals, vitamins A and E, and carotenoid concentrations were quantified. Significant differences were found between species. Crude protein content ranged from 38 to 76% DM, fat from14 to 54% DM, and ash from 2 to 8% DM. In most species, calcium:phosphorus was low (0.08-0.30:1); however, P. scaber was an exception (12:1) and might prove useful as a dietary source of calcium for insectivores. Vitamin E content was low for most species (6-16 mg/kg DM), except for D. melanogaster and M. rhombifolium (112 and 110 mg/kg DM). The retinol content, as a measure of vitamin A activity, was low in all specimens, but varied greatly among samples (0.670-886 mg/kg DM). The data presented can be used to alter diets to better suit the estimated requirements of insectivores in captivity. Future research on the topic of composition of invertebrate prey species should focus on determination of nutrient differences owing to species, developmental stage, and diet. PMID:21442652

  15. Long-term chemical composition and temperature variations on Titan

    NASA Astrophysics Data System (ADS)

    Coustenis, Athena; Bampasidis, G.; Achterberg, R.; Lavvas, P.; Nixon, C.; Jennings, D. E.; Teanby, N.; Michael, F. F.; Orton, G.; Vinatier, S.; Carlson, R. C.

    2013-10-01

    Nine years after Cassini's Saturn orbit insertion, we look at the evolution of the thermal and chemical composition of Titan’s atmosphere by combining Cassini CIRS recordings and the related ground- and space- based observations. In particular, we use Cassini/CIRS data from 2004-2013 to derive the temperature structure [1,2,7] and the neutral chemistry at latitudes between 50°S and 50°N [2]. The peak in abundance is observed around the northern spring equinox, with a rapid decrease after mid-2009, indicating that the vortex has shrunk. The fulfillment of one Titanian year of space observations provides us for the first time with the opportunity to evaluate the relative role of different physical processes in the long term evolution of this complex environment, as also reported by other studies [8-10]. By comparing V1 (1980), ISO (1997) and Cassini (2010) [2-6] data we find that a return to the 1980 abundance values is achieved for most molecules at all latitudes, indicative of the solar radiation being the dominating energy source at 10 AU, as for the Earth, in agreement with predictions by GCM and photochemical models. The few exceptions set important constraints. We show that wrt V1 the stratospheric chemical composition shows higher values near the northern fall equinox (near 1997) and lower ones at the spring equinox (near 2009). The cause could be spatial changes (due to Titan's inclination) in the energy input to Titan's atmosphere as a driver for changes in the advection patterns, circulation, etc which in turn provide a stronger variability in the latitudinal abundances of photochemical species after some time. References [1] Achterberg R., et al., Icarus, 211, 686-698, 2011. [2] Bampasidis et al., ApJ 760, 144, 8 p., 2012. [3] Coustenis, A., Bézard, B., Icarus,115, 126-140, 1995. [4] Coustenis, A., et al., Icarus, 161, 383-403, 2003. [5] Coustenis, A., et al., Icarus, 189, 35-62, 2007. [6] Coustenis, A., et al., Icarus, 207, 461-476, 2010. [7

  16. Seasonal variations in the chemical composition of particulate matter: a case study in the Po Valley. Part II: concentration and solubility of micro- and trace-elements.

    PubMed

    Canepari, S; Astolfi, M L; Farao, C; Maretto, M; Frasca, D; Marcoccia, M; Perrino, C

    2014-03-01

    Size distribution (fine and coarse fraction) and solubility distribution (extracted and residual fraction) of 20 elements (As, Ba, Be, Cd, Co, Cu, Fe, Li, Mn, Pb, Ni, Rb, S, Sb, Se, Sn, Sr, Ti, Tl, V) in atmospheric particulate matter (PM) were determined during a 5-year field study carried out in the Po Valley (peri-urban area of Ferrara, in Northern Italy). By studying the contribution of the two size fractions and the two solubility fractions to the atmospheric concentration of each element, it was possible to obtain interesting information about the variability of PM sources, to assess the role played by atmospheric stability in determining pollution episodes, and to obtain an estimate of the bio-accessible fraction. Atmospheric stability is confirmed to be one of the main causes of atmospheric pollution in this area and is to be responsible for the pronounced winter increase in both PM and elemental concentration. Long-range transport of natural and polluted air masses caused temporary increases in PM and elemental concentration, while local industrial emission seemed to play a secondary role. Regulated elements were well below their concentration limit, but many toxic elements were in the form of fine particles and soluble chemical species, more accessible to the environment, and the human body. PMID:24234760

  17. The chemical composition of precipitated austenite in 9Ni steel

    NASA Astrophysics Data System (ADS)

    Fultz, B.; Kim, J. I.; Kim, Y. H.; Morris, J. W.

    1986-06-01

    Analytical scanning transmission electron microscopy and a novel Mössbauer spectrometry technique were used to measure the chemical composition of austenite particles which precipitate during intercritical tempering of 9Ni steel. Both techniques showed an enrichment of Ni, Mn, Cr, and Si in the austenite. A straightforward analysis involving data on both austenite composition and austenite formation kinetics suggests that the growth of austenite particles is controlled by a 3-dimensional diffusion process. The segregation of solutes to the austenite accounts for much of its stability against the martensitic transformation at low temperatures. Composition inhomogeneities develop in austenite particles after long temperings; the central regions of the particles are lean in solutes and are first to undergo the martensitic transformation. However, changes in solute concentrations of the austenite during long temperings seem too small to account for the large changes in austenite stability. It appears that some of the stability of precipitated austenite must be microstructural in origin.

  18. [Chemical composition and daily variation of melt water during ablation season in monsoonal temperate Glacier region: a case study of Baishui Glacier No. 1].

    PubMed

    Zhu, Guo-Feng; Pu, Tao; He, Yuan-Qing; Wang, Pei-Zhen; Kong, Jian-Long; Zhang, Ning-Ning; Xin, Hui-Juan

    2012-12-01

    Melt water samples collected continuously from 29 August to 3 September 2009 in the Baishui Glacier No. 1 at elevation of 4750 m were analyzed for pH, conductivity, delta18O and inorganic ions. The results showed that the pH had obvious diurnal variations and was increased slightly by the influence of precipitation. The dissolution of alkaline soluble salts in the dust was the main reason for the increase of melt water conductivity; the value of delta18O was relatively low in strong ablation period and high in slight ablation period. Different from other research areas, the concentrations of Na+, K+, which were influenced by lithological and marine water vapor, were higher than that of Mg2+ in the study area; HCO3- and Ca2+ accounted for more than 80% of total ions in snow and ice melt water, indicating that the ions mainly came from limestone and the melt water was a typical carbonate solution; The content of melt water had an obvious daily change with temperature change, but the response amplitudes were different; Monsoon transport, local rock lithology, human industrial and agricultural activities were the main sources of inorganic ions and the deciding factors of the ion composition in the Baishui Glacier No. 1. PMID:23379156

  19. A computational study into the (tetrahedral) distortion of TX {sub 2} {alpha}-quartz materials: The effect of changing the chemical composition away from SiO{sub 2}

    SciTech Connect

    Zwijnenburg, Martijn A. . E-mail: martijn@ri.ac.uk; Huenerbein, Robert; Bell, Robert G.; Cora, Furio

    2006-11-15

    We report a periodic density functional study into the tetrahedral distortion of a range of quartz-like TX {sub 2} materials. The total tetrahedral distortion and its most sizable contribution, the angular part (angular tetrahedral distortion), are found to be strongly dependent on the chemical composition and to increase in the order of BeF{sub 2}chemical composition. The sulphide materials in the study were found to have tetrahedral distortion values commonly associated in silica with experimentally unrealizable hypothetical frameworks, suggesting that such frameworks might become realizable when stepping away from silica. None of the tetrahedra were found to be strictly regular, in line with the analysis of Smith [Acta. Cryst. 16 (1963) 542-545], demonstrating that regular tetrahedra are in principle possible in quartz but that distortions from ideality are energetically advantageous. The energetic reason for this distortion is still an open question; we propose a simple electrostatic model that explains the ease with which tetrahedra can be distorted in terms of charge transfer and the relative charge on the X (O,S,F) atom. - Graphical Abstract: View on a quartz unit-cell with TX {sub 4} tetrahedra. Display Omitted.

  20. Microbial population, chemical composition and silage fermentation of cassava residues.

    PubMed

    Napasirth, Viengsakoun; Napasirth, Pattaya; Sulinthone, Tue; Phommachanh, Kham; Cai, Yimin

    2015-09-01

    In order to effectively use the cassava (Manihot esculenta Crantz) residues, including cassava leaves, peel and pulp for livestock diets, the chemical and microbiological composition, silage preparation and the effects of lactic acid bacteria (LAB) inoculants on silage fermentation of cassava residues were studied. These residues contained 10(4) to 10(5) LAB and yeasts, 10(3) to 10(4) coliform bacteria and 10(4) aerobic bacteria in colony forming units (cfu) on a fresh matter (FM) basis. The molds were consistently at or below the detectable level (10(2) cfu of FM) in three kinds of cassava residues. Dry matter (DM), crude protein (CP) and neutral detergent fiber (NDF) content of cassava residues were 17.50-30.95%, 1.30-16.41% and 25.40-52.90% on a DM basis, respectively. The silage treatments were designed as control silage without additive (CO) or with LAB inoculants Chikuso-1 (CH, Lactobacillus plantarum) and Snow Lacto (SN, Lactobacillus rhamnosus) at a rate of 5 mg/kg of FM basis. All silages were well preserved with a low pH (below 4.0) value and when cassava residues silage treated with inoculants CH and SN improved fermentation quality with a lower pH, butyric acid and higher lactic acid than control silage. PMID:25781881

  1. Calorimetry, chemical composition and in vitro digestibility of oilseeds.

    PubMed

    Ítavo, Luís Carlos Vinhas; Soares, Cláudia Muniz; Ítavo, Camila Celeste Brandão Ferreira; Dias, Alexandre Menezes; Petit, Hélène Veronique; Leal, Eduardo Souza; de Souza, Anderson Dias Vieira

    2015-10-15

    The objective of the study was to determine the quality of sunflower, soybean, crambe, radish forage and physic nut, by measuring chemical composition, in vitro digestibility and kinetics of thermal decomposition processes of mass loss and heat flow. Lipid was inversely correlated with protein of whole seed (R = -0.67), meal (R = -0.95), and press cake (R = -0.78), and positively correlated with the enthalpy (ΔH) of whole seed. Soybean seed and meal presented a high in vitro digestibility but poor energy sources with ΔH averaging 5907.5 J/g and 2570.1J/g for whole seed and meal, respectively. As suggested by the release of heat, measured by ΔH, whole seeds of crambe (6295.1J/g), radish forage (6182.7 J/g), and physic nut (6420.0 J/g) may be potential energy sources for ruminant animals. The thermal analysis provided additional information besides that obtained from the usual wet chemistry and in vitro measurements. PMID:25952861

  2. The average chemical composition of the lunar surface

    NASA Technical Reports Server (NTRS)

    Turkevich, A. L.

    1973-01-01

    The available analytical data from twelve locations on the moon are used to estimate the average amounts of the principal chemical elements (O, Na, Mg, Al, Si, Ca, Ti, and Fe) in the mare, the terra, and the average lunar surface regolith. These chemical elements comprise about 99% of the atoms on the lunar surface. The relatively small variability in the amounts of these elements at different mare (or terra) sites, and the evidence from the orbital measurements of Apollo 15 and 16, suggest that the lunar surface is much more homogeneous than the surface of the earth. The average chemical composition of the lunar surface may now be known as well as, if not better than, that of the solid part of the earth's surface.

  3. Surface chemical composition of human maxillary first premolar as assessed by X-ray photoelectron spectroscopy (XPS)

    NASA Astrophysics Data System (ADS)

    Lou, Leo; Nelson, Alan E.; Heo, Giseon; Major, Paul W.

    2008-08-01

    The surface chemical composition of dental enamel has been postulated as a contributing factor in the variation of bond strength of brackets bonded to teeth, and hence, the probability of bracket failure during orthodontic treatment. This study systematically investigated the chemical composition of 98 bonding surfaces of human maxillary premolars using X-ray photoelectron spectroscopy (XPS) to ascertain compositional differences between right and left first premolars. The major elements detected in all samples were calcium, phosphorus, oxygen, nitrogen and carbon. Surface compositions were highly variable between samples and several elements were found to be highly correlated. No statistical significant difference in the chemical composition of the maxillary right and left first premolars was found ( p > 0.05). Knowledge of the chemical composition of enamel surfaces will facilitate future studies that relate this information to the variations in dental enamel bond strength.

  4. Chemical Composition of Different Botanical Origin Honeys Produced by Sicilian Black Honeybees (Apis mellifera ssp. sicula).

    PubMed

    Mannina, Luisa; Sobolev, Anatoly P; Di Lorenzo, Arianna; Vista, Silvia; Tenore, Gian Carlo; Daglia, Maria

    2015-07-01

    In 2008 a Slow Food Presidium was launched in Sicily (Italy) for an early warning of the risk of extinction of the Sicilian native breed of black honeybee (Apis mellifera L. ssp sicula). Today, the honey produced by these honeybees is the only Sicilian honey produced entirely by the black honeybees. In view of few available data regarding the chemical composition of A. mellifera ssp. sicula honeys, in the present investigation the chemical compositions of sulla honey (Hedysarum coronarium L.) and dill honey (Anethum graveolens L.) were studied with a multimethodological approach, which consists of HPLC-PDA-ESI-MSn and NMR spectroscopy. Moreover, three unifloral honeys (lemon honey (obtained from Citrus limon (L.) Osbeck), orange honey (Citrus arantium L.), and medlar honey (Eriobotrya japonica (Thunb.) Lindl)), with known phenol and polyphenol compositions, were studied with NMR spectroscopy to deepen the knowledge about sugar and amino acid compositions. PMID:25730368

  5. Features of water chemical composition of oligotrophic and eutrophic bogs in the South of the Tomsk region

    NASA Astrophysics Data System (ADS)

    Naymushina, O.

    2016-03-01

    On the basis of the actual material the analysis of chemical composition of bog waters in the territory of the South of the Tomsk region is carried out. The data on average concentration of macro and trace components, organic matter, pH of bog waters are obtained. Significant distinctions in a chemical composition of surface water for different types of bogs are revealed. The composition and macrostructure of humic acids by the example of eutrophic bogs is studied.

  6. Nanograined WC-Co Composite Powders by Chemical Vapor Synthesis

    NASA Astrophysics Data System (ADS)

    Ryu, Taegong; Sohn, H. Y.; Han, Gilsoo; Kim, Young-Ugk; Hwang, Kyu Sup; Mena, M.; Fang, Zhigang Z.

    2008-02-01

    Nanograined tungsten carbide (WC) Co composite powders were prepared by a chemical vapor synthesis (CVS) process that has previously been used for preparing the aluminides of titanium and nickel and other metallic and intermetallic powders at the University of Utah. To determine the optimum condition for producing nanograined WC-Co composite powders, the effects of carburization temperature, CH4 to WCl6 ratio, CH4 to H2 ratio, CoCl2 contents, and residence time of WC on the powder composition and particle size were investigated. The reduction and carburization of the vaporized chlorides by CH4-H2 mixtures produced nanograined WC and Co composite powder, which sometimes contained small levels of W2C, W, or the η (Co3W3C) phase. The presence of these incompletely carburized phases can be tolerated because they can be fully carburized during the subsequent sintering process. These phases can also be fully carburized by a separate post-treatment. The products were characterized by using X-ray diffraction (XRD) and a transmission electron microscope (TEM). As a result, nanograined WC-Co composite with the particle size less than 30 nm was obtained.

  7. Study of the chemical composition, proteolysis, volatile compounds, and textural properties of industrial and traditional Beaten (Bieno sirenje) ewe milk cheese.

    PubMed

    Sulejmani, E; Hayaloglu, A A; Rafajlovska, V

    2014-03-01

    The objective of this study was to determine the gross composition, proteolysis, and volatile and texture profiles during ripening of industrial (IND) and traditional (TRD) Beaten (Bieno sirenje) cheeses made by using ewe milk. In the course of the analyses, statistical differences were determined in some physicochemical parameters, nitrogen fractions, and total free amino acid levels between TRD and IND types of cheese. Higher levels of proteolysis were observed in IND cheeses than in TRD cheeses during ripening. Levels of residual β- and αs-caseins were 72.2 and 48.7%, respectively, in 180-d-old TRD cheeses. However, the residual levels were 52.8% for β-casein and 18% for αs-casein in IND cheeses. Similar differences were noted for the reversed-phase HPLC peptide profiles of 2 types of cheeses. Also, higher concentrations of peptides were eluted in IND cheeses than in TRD cheeses during ripening. A total of 73 volatile compounds, including alcohols (16), esters (17), acids (14), terpenes (7), ketones (5), aldehydes (4), and miscellaneous (10) were identified. The IND cheeses contained higher levels of carboxylic acids, esters, alcohols, and terpenes than the TRD cheeses; however, the same levels of methyl ketones were determined in the 2 types of cheeses at the end of ripening. These may be due to some differences (e.g., pasteurization and scalding temperature, among other factors) in the manufacture of the 2 types of Beaten cheeses. The textural profile of Beaten cheeses showed that TRD production method resulted in firmer, less fracturable, and stiffer cheeses than the IND production method. In conclusion, the results suggest that the use of industrial production method (pasteurization of cheese milk and curd scalding at 70°C) in the manufacture of Beaten ewe milk cheese enriched the volatile profile of the cheese. PMID:24377800

  8. Level and Chemical Composition of Cryoglobulins in Schizophrenia

    NASA Astrophysics Data System (ADS)

    Khoyetsyan, Aren; Boyajyan, Anna; Melkumova, Maya

    The blood samples of 40 schizophrenic patients were tested for the presence of cryoglobulins (Cgs) and composition of Cgs was examined. The elevated levels of type III Cgs, containing complement components, were detected in all study subjects.

  9. [Studies on chemical constituents from Psychotria straminea].

    PubMed

    Fu, Yan-hui; Huang, Li-gang; Wang, Xiao-cui; Li, Xiao-bao; Li, Ke-kai; Wu, Shui-ling; Liu, Yan-ping

    2015-06-01

    The chemical consituents from Psychotria straminea were separated and purified by column chromatographies on silica gel, Sephadex LH-20, ODS and RP-HPLC. The strictures of the isolated compounds were identified on the basis of physicochemical properties and spectroscopic analysis, as well as comparisons with the data in literature. Sixteen compounds were isolated and elucidated as tectochrysin (1), apigenin (2), kaempferol (3), luteolin (4), diosmetin (5), quercetin (6), kaempferol-4'-O-methylether (7), rhamnetin (8), 7-hydroxycoumarin (9), 7-methoxycoumarin (10), scopoletin (11), lupeol (12), 30-oxo-lupeol (13), lupenyl acetate (14), α-amyrin (15), and ursolic acid (16). This is the first study on the chemical composition of P. Straminea, and all compounds were isolated from P. straminea for the first time. In addition to compounds 6 and 9, the other compounds were isolated from the genus Psychotria for the first time. PMID:26552170

  10. Essential Oil Composition of Phagnalon sordidum (L.) from Corsica, Chemical Variability and Antimicrobial Activity.

    PubMed

    Brunel, Marion; Vitrac, Caroline; Costa, Jean; Mzali, Fatima; Vitrac, Xavier; Muselli, Alain

    2016-03-01

    The chemical composition of Phagnalon sordidum (L.) essential oil was investigated for the first time using gas chromatography and chromatography/mass spectrometry. Seventy-six compounds, which accounted for 87.9% of the total amount, were identified in a collective essential oil of P. sordidum from Corsica. The main essential oil components were (E)-β-caryophyllene (14.4%), β-pinene (11.0%), thymol (9.0%), and hexadecanoic acid (5.3%). The chemical compositions of essential oils from 19 Corsican locations were investigated. The study of the chemical variability using statistical analysis allowed identifying direct correlation between the three populations of P. sordidum widespread in Corsica and the essential oil compositions they produce. The in vitro antimicrobial activity of P. sordidum essential oil was evaluated and it exhibited a notable activity on a large panel of clinically significant microorganisms. PMID:26916729

  11. Chemical composition and temperature structure of Titan's stratosphere

    NASA Astrophysics Data System (ADS)

    Coustenis, A.; Bampasidis, G.; Achterberg, R.; Lavvas, P.; Vinatier, S.; Nixon, C.; Jennings, D.; Teanby, N.; Flasar, F. M.; Orton, G.; Romani, P.; Carlson, R.; Guandique, E. A.

    2013-09-01

    We have explored the thermal and chemical composition of Titan's atmosphere by combining Cassini CIRS recordings and the related ground - and space - based observations. The fulfillment of one Titanian year of space observations provides us for the first time with the opportunity to evaluate the relative role of different physical processes in the long term evolution of this complex environment. We find indication for a weakening of the temperature gradient with warming of the stratosphere and cooling of the lower mesosphere. In addition, we infer precise concentrations for the trace gases and their main isotopologues and find that the chemical composition in Titan's stratosphere varies significantly with latitude during the 6 years investigated here, with increased mixing ratios towards the northern latitudes. In particular, we monitor and quantify the amplitu de of a maximum enhancement of several gases observed at northern latitudes up to 50°N around mid-2009, at the time of the NSE. We find that this raise is followed by a rapid decrease in chemical inventory in 2010 probably due to a weakening north polar vortex with reduced lateral mixing across the vortex boundary. By comparing the Cassini/CIRS results from both the limb and the nadir observations with past V1 (1980) and ISO (1997)inferences we find indication for seasonal variations.

  12. Biological activities and chemical composition of lichens from Serbia

    PubMed Central

    Kosanic, Marijana; Rankovic, Branislav; Stanojkovic, Tatjana; Vasiljevic, Perica; Manojlovic, Nedeljko

    2014-01-01

    The aim of this study is to investigate chemical composition of acetone extracts of the lichens Parmelia arseneana and Acarospora fuscata and in vitro antioxidant, antimicrobial, and anticancer activities of these extracts and gyrophoric acid isolated from A. fuscata. The HPLC-UV method was used for the identification of secondary metabolites. Stictic acid, norstictic acid, gyrophoric acid, usnic acid, atranorin and chloroatranorin were identified in the A. fuscata. In P. arseneana, we detected stictic acid, norstictic acid, usnic acid and atranorin, while gyrophoric acid was not identified. Antioxidant activity was evaluated by measuring the scavenging capacity of tested samples on DPPH and superoxide anion radicals, reducing the power of samples and determination of total phenolic compounds in extracts. As a result of the study, gyrophoric acid was found to have the largest DPPH radical scavenging activity with an IC50 value of 105.75 µg/ml. Moreover, the tested samples had an effective superoxide anion radical scavenging and reducing power. The total content of phenol in extracts was determined as pyrocatechol equivalent. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration by the broth microdilution method. The most active was also gyrophoric acid, with minimum inhibitory concentration values ranging from 0.019 to 1.25 mg/ml. Anticancer activity was tested against LS174 (human colon carcinoma cell line), A549 (human lung carcinoma cell line), Fem-x (malignant melanoma cell line), and a chronic myelogeneous leukaemia K562 cell line using the MTT method. Extract of P. arseneana expressed the strongest anticancer activity against all cell lines with IC50 values ranging from 11.61 to 47.06 µg/ml. PMID:26417336

  13. The temperature dependent variation of bulk and surface composition of In(x)Ga(1-x)As on GaAs grown by chemical beam epitaxy studied by RHEED, X-ray diffraction and XPS

    NASA Technical Reports Server (NTRS)

    Hansen, H. S.; Bensaoula, A.; Tougaard, S.; Zborowski, J.; Ignatiev, A.

    1992-01-01

    The paper investigates the bulk as well as near-surface composition of In(x)Ga(1-x)As epilayers on GaAs grown by chemical beam epitaxy (CBE) as a function of triethylindium flow rate and substrate temperature by reflection high energy electron diffraction (RHEED), X-ray diffraction, and XPS. To clarify whether the bulk stoichiometry of CBE-grown ternaries can be extracted from the growth rate change as determined by the change in the period of RHEED oscillations from binary to ternary compound growth, a systematic study of growth rate change as a function of ternary bulk composition determined by X-ray diffraction was performed at various temperatures. It is shown that for low growth temperatures there is a linear relationship between the two methods of determination, whereas no correlation is found for higher growth temperatures, in contrast to the MBE case where the two methods of determination yield identical results. In the near surface region the epilayer composition is determined in situ by XPS.

  14. Quantitative Estimation of Chemical Weathering versus Total Denudation Ratio within Tributaries of Yangtze River Basin Based on Size Dependent Chemical Composition Ratio of River Sediment

    NASA Astrophysics Data System (ADS)

    Kuboki, Y.; Chao, L.; Tada, R.; Saito, K.; Zheng, H.; Irino, T.; He, M.; Ke, W.; Suzuki, Y.

    2014-12-01

    Quantitative estimation of chemical weathering rate and evaluation of its controlling factors are critical to understand its role on landscape evolution and carbon cycle on a long time scale. In order to reconstruct the past changes in intensities of chemical weathering and erosion, it is necessary to establish a proxy for chemical versus physical weathering intensities based on chemical composition of sediments. However, the chemical composition of sediments is controlled not only by chemical weathering, but by type of source rock and grain size, too. This study aims to develop a method to quantitatively evaluate the contribution of chemical weathering relative to total denudation in the entire Yangtze River basin based on chemical composition of three different grain size fractions of river sediments. Chemical compositions of three different grain size fractions, and grain size distribution of suspended particles and river bed sediments as well as chemical composition of dissolved materials of water samples are analyzed. The result revealed that suspended particles and river bed sediments are composed of three components, aluminosilicate, quartz, and carbonate. K/Al is smaller in the smallest size fraction. We preliminary interpret that original composition of aluminosilcates within different size fractions of the same sample is the same, and the decrease in K/Al with decreasing grain size would reflect increasing influence of chemical weathering. If correct, K/Al of fine to coarse fraction can be used as an index of chemical weathering intensity. To test this idea, we examined the relationship between K/Al of fine to coarse fraction and the ratio of chemical weathering contribution to total denudation rate based on observational data. The result will be presented and its implication will be discussed.

  15. Raman spectra of Martian glass analogues: a tool to approximate their chemical composition

    NASA Astrophysics Data System (ADS)

    Di Genova, Danilo; Kolzenburg, Stephan; Vona, Alessandro; Chevrel, Magdalena O.; Hess, Kai-Uwe; Neuville, Daniel R.; Ertel-Ingrisch, Werner; Romano, Claudia; Dingwell, Donald B.

    2016-04-01

    We present a study on the systematic changes of Raman spectra of a series of glasses as a function of their chemistry. These glass compositions are considered as analogues for rock materials identified on Mars. We performed a diffusion experiment between an iron-rich basaltic and a rhyolitic melt under reducing conditions to produce a wide range of intermediate chemical compositions. We then systematically acquired Raman spectra of the intermediate composition glasses across the diffusion interface and correlate them with the corresponding chemical compositions derived by electron microprobe analysis. Using a linear mixing model for the spectral evolution as a function of chemistry, we fitted a Raman parameter to each spectrum to estimate the chemical composition of each glass. The Raman model was verified using external natural and synthetic samples. This study: 1) expands the Raman database of silicate glasses including alkali and iron-rich compositions as expected to be found on Mars; and 2) contributes to develop Raman spectroscopy as a quantitative tool in geological and planetary science to estimate the chemistry of glasses on a microscopic level. Moreover, as Raman spectrometers have been developed for two forthcoming Mars missions [ExoMars program (2016-2018) and Mars 2020], with the benefit of this calibration, Raman spectroscopy will allow rapid, in-situ and remotely controlled identification and investigation of silicate glasses on future extraterrestrial rover missions.

  16. Study Acoustic Emissions from Composites

    NASA Technical Reports Server (NTRS)

    Walker, James; Workman,Gary

    1998-01-01

    The purpose of this work will be to develop techniques for monitoring the acoustic emissions from carbon epoxy composite structures at cryogenic temperatures. Performance of transducers at temperatures ranging from ambient to cryogenic and the characteristics of acoustic emission from composite structures will be studied and documented. This entire effort is directed towards characterization of structures used in NASA propulsion programs such as the X-33.

  17. Composition and Chemical Variability of Ivoirian Polyalthia oliveri Leaf Oil.

    PubMed

    Ouattara, Zana A; Boti, Jean Brice; Ahibo, Coffy Antoine; Bekro, Yves-Alain; Casanova, Joseph; Tomi, Félix; Bighelli, Ange

    2016-03-01

    The chemical composition of 45 essential oil samples isolated from the leaves of Polyalthia oliveri harvested in three Ivoirian forests was investigated by GC-FID (retention indices measured on two columns of different polarities), and by (13) C-NMR, following a method developed in our laboratory. In total, 41 components were identified. The content of the main components varied drastically from sample to sample: (E)-β-caryophyllene (1.2 - 50.8%), α-humulene (0.6 - 47.7%), isoguaiene (0 - 27.9%), alloaromadendrene (0 - 24.7%), germacrene B (0 - 18.3%), δ-cadinene (0.4 - 19.3%), and β-selinene (0.2 - 18.5%). The analysis of six oil samples selected in function of their chromatographic profiles is reported in detail. The 45 oil compositions were submitted to hierarchical cluster and principal components analysis, which allowed the distinction of three groups within the oil samples. The compositions of the oils from group I (15 samples) and II (12 samples) were dominated by (E)-β-caryophyllene and α-humulene, respectively. Oil samples of group III (18 samples) needed to be partitioned into four subgroups III.1-III.4 whose compositions were dominated by alloaromadenrene, isoguaiene, germacrene B, and δ-cadinene, respectively. PMID:26916629

  18. Structure and chemical composition of the dentin-enamel junction analyzed by Confocal Raman Microscopy

    NASA Astrophysics Data System (ADS)

    Desoutter, A.; Salehi, H.; Slimani, A.; Marquet, P.; Jacquot, B.; Tassery, H.; Cuisinier, F. J. G.

    2014-02-01

    The structure and chemical composition of the human dentin-enamel junction (DEJ) was studied using confocal Raman microscopy - a chemical imaging technique. Slices of non-fixed, sound teeth were prepared with an Isomet diamond saw and scanned with Witec Alpha300R system. The combination of different characteristics peaks of phosphate, carbonate and organic matrix (respectively 960, 1072 and 1545 cm-1), generates images representing the chemical composition of the DEJ area. Images are also calculated using peak ratios enabling precise determination of the chemical composition across the DEJ. Then, with two characterized peaks, different pictures are calculated to show the ratio of two components. The images of the spatial distribution of mineral phosphate (960cm-1) to organic matrix (1545 cm-1) ratios, mineral carbonates (1072cm-1) to mineral phosphate ratios; and mineral carbonates to organic matrix ratios were reconstructed. Cross sectional and calculated graphic profile show the variations of the different chemical component ratios through the enamel and the dentin. Phosphate to organic ratio shows an accumulation of organic material under the enamel surface. The cross sectional profile of these pictures shows a high phosphate content compared to enamel in the vicinity of the DEJ. The Confocal Raman imaging technique can be used to further provide full chemical imaging of tooth, particularly of the whole DEJ and to study enamel and dentin decay.

  19. XANES and IR spectroscopy study of the electronic structure and chemical composition of porous silicon on n- and p-type substrates

    SciTech Connect

    Lenshin, A. S. Kashkarov, V. M.; Seredin, P. V.; Spivak, Yu. M.; Moshnikov, V. A.

    2011-09-15

    The differences in the electronic structure and composition of porous silicon samples obtained under identical conditions of electrochemical etching on the most commonly used n- and p-type substrates with different conductivities are demonstrated by X-ray absorption near-edge spectroscopy (XANES) and Fourier transform IR spectroscopy (FTIR) methods. It is shown that significantly higher oxidation and saturation with hydrogen is observed for the porous layer on n-type substrates.

  20. Chemical composition of HAL, an isotopically-unusual Allende inclusion

    NASA Technical Reports Server (NTRS)

    Davis, A. M.; Tanaka, T.; Grossman, L.; Lee, T.; Wasserburg, G. J.

    1982-01-01

    Samples of hibonite, black rim, and portions of friable rim from an unusual Allende inclusion, named HAL, were analyzed by INAA and RNAA for 37 major, minor, and trace elements. An unusually low amount of Ce was found in HAL, although it otherwise was highly enriched in REE compared to C1 chondrites. HAL is also depleted in Sr, Ba, U, V, Ru, Os, and Ir relative to other refractory elements. It is concluded that the distribution of REE between hibonite and rims was established when hibonite and other refractory minerals were removed at slightly different temperatures from a hot, oxidizing gas in which they previously coexisted as separate grains. Possible locations for the chemical and mass dependent isotopic fractionation are considered to be in ejecta from the low temperature helium-burning zone of a supernova and in the locally oxidizing environment generated by evaporation of interstellar grains of near-chondritic chemical composition.

  1. Physical Characterization and Steam Chemical Reactivity of Carbon Fiber Composites

    SciTech Connect

    Anderl, Robert Andrew; Pawelko, Robert James; Smolik, Galen Richard

    2001-05-01

    This report documents experiments and analyses that have been done at the Idaho National Engineering and Environmental Laboratory (INEEL) to measure the steam chemical reactivity of two types of carbon fiber composites, NS31 and NB31, proposed for use at the divertor strike points in an ITER-like tokamak. These materials are 3D CFCs constituted by a NOVOLTEX preform and densified by pyrocarbon infiltration and heat treatment. NS31 differs from NB31 in that the final infiltration was done with liquid silicon to reduce the porosity and enhance the thermal conductivity of the CFC. Our approach in this work was twofold: (1) physical characterization measurements of the specimens and (2) measurements of the chemical reactivity of specimens exposed to steam.

  2. Chemical feasibility of lithium as a matrix for structural composites

    NASA Technical Reports Server (NTRS)

    Swann, R. T.; Esterling, D. M.

    1984-01-01

    The chemical compatibility of lithium with tows of carbon and aramid fibers and silicon carbide and boron monofilaments was investigated by encapsulating the fibers in liquid lithium and also by sintering. The lithium did not readily wet the various fibers. In particular, very little lithium infiltration into the carbon and aramid tows was achieved and the strength of the tows was seriously degraded. The strength of the boron and silicon carbide monofilaments, however, was not affected by the liquid lithium. Therefore lithium is not feasible as a matrix for carbon and aramid fibers, but a composite containing boron or silicon carbide fibers in a lithium matrix may be feasible for specialized applications.

  3. Model atmospheres for cool stars. [varying chemical composition

    NASA Technical Reports Server (NTRS)

    Johnson, H. R.

    1974-01-01

    This report contains an extensive series of model atmospheres for cool stars having a wide range in chemical composition. Model atmospheres (temperature, pressure, density, etc.) are tabulated, along with emergent energy flux distributions, limb darkening, and information on convection for selected models. The models are calculated under the usual assumptions of hydrostatic equilibrium, constancy of total energy flux (including transport both by radiation and convection) and local thermodynamic equilibrium. Some molecular and atomic line opacity is accounted for as a straight mean. While cool star atmospheres are regimes of complicated physical conditions, and these atmospheres are necessarily approximate, they should be useful for a number of kinds of spectral and atmospheric analysis.

  4. Unusual chemical compositions of noctilucent-cloud particle nuclei

    NASA Technical Reports Server (NTRS)

    Hemenway, C. L.

    1973-01-01

    Two sounding rocket payloads were launched from the ESRO range in Sweden during a noctilucent cloud display. Large numbers of submicron particles were collected, most of which appear to be made up of a high density material coated with a low density material. Typical electron micrographs are shown. Particle chemical compositions have been measured by use of dispersive X-ray analysis equipment attached to an electron microscope and have revealed that most of the high density particle nuclei have atomic weights greater than iron.

  5. Chemical composition and biological activity of the essential oil of rhizome of Zingiber zerumbet (L.) smith

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Technical Abstract: The aim was designed to study the biological activity and chemical composition of essential oil of Zingiber zerumbet (L.) Smith. The essential oil extracted from the rhizome of the plant was analysed by gas chromatography-mass spectroscopy and its major components amounting t...

  6. Creation and Analysis of the Chemical Composition Map of Eros and Its Cosmochemical Interpretation

    NASA Technical Reports Server (NTRS)

    Gorenstein, Paul; Morgan, Thomas (Technical Monitor)

    2003-01-01

    The data was analyzed and two papers were written and published in the refereed journal: Meteoritics and Planetary Science. These paper describes the results of the study of the surface chemical composition of the asteroid Eros by the NEAR X-ray Fluorescence Spectrometer.

  7. Chemical composition and cell wall polysaccharide degradability of pith and rind tissues from mature maize internodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our study was undertaken to identify tissue-specific biochemical traits that may be targeted in breeding programs for improving forage digestibility. We compared cell wall chemical composition and 24- and 96-h in vitro degradabilities in separated pith and rind tissues from six maize inbred lines. A...

  8. Chemical composition and cell wall polysaccharide degradability of pith and rind tissues from mature maize internodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was undertaken to identify tissue-specific biochemical traits that may be targeted in breeding programs for improving forage digestibility. We compared cell wall chemical composition and 24- and 96-h in vitro degradabilities in separated pith and rind tissues of the fourth above-ground in...

  9. Chemical composition and antispasmodic effect of Casimiroa pringlei essential oil on rat uterus.

    PubMed

    Ponce-Monter, Héctor; Campos, María G; Pérez, Salud; Pérez, Cuauhtémoc; Zavala, Miguel; Macías, Arturo; Oropeza, Martha; Cárdenas, Norma

    2008-09-01

    The Casimiroa pringlei essential oil was analyzed to determine its chemical composition. Its effect on rat uterine smooth muscle was studied and compared with verapamil. Pure commercial piperitone, eucalyptol, and alpha-terpineol, the major constituents of C. pringlei essential oil, were tested on the uterine tonic contraction induced by high-potassium depolarizing solution (KCl 60 mM). PMID:18538506

  10. Effects of extrusion cooking on the chemical composition and functional properties of dry bean powders

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study aimed to investigate the impacts of extrusion cooking on the chemical composition and functional properties of bean powders from four bean varieties. The raw bean powders were extruded under eight different conditions, and the extrudates were then dried and ground (particle size = 0.5 mm)...

  11. Phoenix dactylifera L. spathe essential oil: Chemical composition and repellent activity against the yellow fever mosquito

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Date palm, Phoenix dactylifera L. (Arecaceae), grows commonly in the Arabian Peninsula and is traditionally used to treat various diseases. The aim of the present study was to identify chemical composition of the essential oil and to investigate the repellent activity. The essential oil of P. dacty...

  12. Determining the chemical composition of cloud condensation nuclei

    SciTech Connect

    Williams, A.L.; Rothert, J.E.; McClure, K.E. ); Alofs, D.J.; Hagen, D.E.; White, D.R.; Hopkins, A.R.; Trueblood, M.B. . Cloud and Aerosol Science Lab.)

    1992-02-01

    This second progress report describes the status of the project one and one-half years after the start. The goal of the project is to develop the instrumentation to collect cloud condensation nuclei (CCN) in sufficient amounts to determine their chemical composition, and to survey the CCN composition in different climates through a series of field measurements. Our approach to CCN collection is to first form droplets on the nuclei under simulated cloud humidity conditions, which is the only known method of identifying CCN from the background aerosol. Under cloud chamber conditions, the droplets formed become larger than the surrounding aerosol, and can then be removed by inertial impaction. The residue of the evaporated droplets represents the sample to be chemically analyzed. Two size functions of CCN particles are collected by first forming droplets on the large particles are collected by first forming droplets on the large CCN in a haze chamber at 100% relative humidity, and then activating the remaining CCN at 1% supersaturation in a cloud chamber. The experimental apparatus is a serious flow arrangement consisting of an impactor to remove the large aerosol particles, a haze chamber to form droplets on the remaining larger CCN, another impactor to remove the haze droplets containing the larger CCN particles for chemical analysis, a continuous flow diffusion (CFD) cloud chamber to form droplets on the remaining smaller CCN, and a third impactor to remove the droplets for the small CCN sample. Progress is documented here on the development of each of the major components of the flow system. Chemical results are reported on tests to determine suitable wicking material for the different plates. Results of computer modeling of various impactor flows are discussed.

  13. Characterization of Indian beers: chemical composition and antioxidant potential.

    PubMed

    Pai, Tapasya V; Sawant, Siddhi Y; Ghatak, Arindam A; Chaturvedi, Palak A; Gupte, Arpita M; Desai, Neetin S

    2015-03-01

    Chemical composition, antioxidant potential and corresponding lipid preoxidation of Indian commercial beers were evaluated. The presence of polyphenolic compounds such as tannic acid, gallic acid, catechol, vanillin, caffeic acid, quercetin, p-coumaric acid and rutin was quantified using LC-MS while the organic acids including tartaric, malic, acetic, citric and succinic acids were analysed using HPLC. Beer sample B8 had the greatest concentration of phenolic and flavonoid components (0.620 ± 0.084 mg/mL and 0.379 ± 0.020 mg/mL respectively) among the beer samples studied. The DPPH radical scavenging activity was observed in the range of 68.34 ± 0.85 % to 89.90 ± 0.71 % and ABTS radical cation scavenging activity was in the range of 59.75 ± 0.20 % to 76.22 ± 0.50 %. Percent protection in lipid peroxidation was quantified to be maximum (54.45 ± 3.39 %) in sample B5. Total phenolic content positively correlates with antioxidant assays, DPPH and ABTS (r = 0.35 and r = 0.58 respectively) with p < 0.001 and also with lipid peroxidation (r = 0.04) with p < 0.001. Negative correlation was observed between total flavonoid content with ABTS and lipid peroxidation (r = -0.1 and r = -0.05) respectively. The process of brewing warrants additional research to determine how the concentration of selected phenolic compounds can be increased. PMID:25745209

  14. Brazilian Propolis: Correlation Between Chemical Composition and Antimicrobial Activity

    PubMed Central

    Salomão, Kelly; Pereira, Paulo Roberto S.; Campos, Leila C.; Borba, Cintia M.; Cabello, Pedro H.; Marcucci, Maria Cristina

    2008-01-01

    The chemical composition of ethanol extracts from samples of Brazilian propolis (EEPs) determined by HPLC and their activity against Trypanosoma cruzi, Staphylococcus aureus, Streptococcus pneumoniae, Klebisiella pneumoniae, Candida albicans, Sporothrix schenckii and Paracoccidioides brasiliensis were determined. Based on the predominant botanical origin in the region of samples' collection, the 10 extracts were separated into three groups: A (B. dracunculifolia + Auraucaria spp), B (B. dracunculifolia) and C (Araucaria spp). Analysis by the multiple regression of all the extracts together showed a positive correlation, higher concentrations leading to higher biological effect, of S. aureus with p-coumaric acid (PCUM) and 3-(4-hydroxy-3-(oxo-butenyl)-phenylacrylic acid (DHCA1) and of trypomastigotes of T. cruzi with 3,5-diprenyl-4-hydroxycinnamic acid derivative 4 (DHCA4) and 2,2-dimethyl-6-carboxyethenyl-2H-1-benzopyran (DCBEN). When the same approach was employed for each group, due to the small number of observations, the statistical test gave unreliable results. However, an overall analysis revealed for group A an association of S. aureus with caffeic acid (CAF) and dicaffeoylquinic acid 3 (CAFQ3), of S. pneumoniae with CAFQ3 and monocaffeoylquinic acid 2 (CAFQ2) and of T. cruzi also with CAFQ3. For group B, a higher activity against S. pneumoniae was associated DCBEN and for T. cruzi with CAF. For group C no association was observed between the anitmicrobial effect and any component of the extracts. The present study reinforces the relevance of PCUM and derivatives, especially prenylated ones and also of caffeolyquinic acids, on the biological activity of Brazilian propolis. PMID:18830454

  15. Porosity prediction of calcium phosphate cements based on chemical composition.

    PubMed

    Öhman, Caroline; Unosson, Johanna; Carlsson, Elin; Ginebra, Maria Pau; Persson, Cecilia; Engqvist, Håkan

    2015-07-01

    The porosity of calcium phosphate cements has an impact on several important parameters, such as strength, resorbability and bioactivity. A model to predict the porosity for biomedical cements would hence be a useful tool. At the moment such a model only exists for Portland cements. The aim of this study was to develop and validate a first porosity prediction model for calcium phosphate cements. On the basis of chemical reaction, molar weight and density of components, a volume-based model was developed and validated using calcium phosphate cement as model material. 60 mol% β-tricalcium phosphate and 40 mol% monocalcium phosphate monohydrate were mixed with deionized water, at different liquid-to-powder ratios. Samples were set for 24 h at 37°C and 100% relative humidity. Thereafter, samples were dried either under vacuum at room temperature for 24 h or in air at 37 °C for 7 days. Porosity and phase composition were determined. It was found that the two drying protocols led to the formation of brushite and monetite, respectively. The model was found to predict well the experimental values and also data reported in the literature for apatite cements, as deduced from the small absolute average residual errors (<2.0%). In conclusion, a theoretical model for porosity prediction was developed and validated for brushite, monetite and apatite cements. The model gives a good estimate of the final porosity and has the potential to be used as a porosity prediction tool in the biomedical cement field. PMID:26169187

  16. XPS analysis of combustion aerosols for chemical composition, surface chemistry, and carbon chemical state.

    PubMed

    Vander Wal, Randy L; Bryg, Vicky M; Hays, Michael D

    2011-03-15

    Carbonaceous aerosols can vary in elemental content, surface chemistry, and carbon nano-structure. Each of these properties is related to the details of soot formation. Fuel source, combustion process (affecting formation and growth conditions), and postcombustion exhaust where oxidation occurs all contribute to the physical structure and surface chemistry of soot. Traditionally such physical and chemical parameters have been measured separately by various techniques. Presented here is the unified measurement of these characteristics using X-ray photoelectron spectroscopy (XPS). In the present study, XPS is applied to combustion soot collected from a diesel engine (running biodiesel and pump-grade fuels); jet engine; and institutional, plant, and residential oil-fired boilers. Elemental composition is mapped by a survey scan over a broad energy range. Surface chemistry and carbon nanostructure are quantified by deconvolution of high-resolution scans over the C1s region. This combination of parameters forms a distinct matrix of identifiers for the soots from these sources. PMID:21322576

  17. A study of the chemical composition of the passive film on a Ti-Mo alloy in HCl and H{sub 2}SO{sub 4}

    SciTech Connect

    Wang, G.; Wang, H.; Liu, X.

    1997-04-01

    The composition of the passive film on Ti-15Mo alloy, formed in 1 mol/L and 4 mol/L HCl and 2 mol/L H{sub 2}SO{sub 4} solutions at 70 C (160 F) under anodic polarization is investigated by XPS and electrochemical techniques. Anodic polarization potential is found to have an obvious influence on the content of Mo in the film. At lower anodic polarization potentials, the surface of the passive film is enriched in Mo. However, at higher anodic polarization potentials, the surface is diluted in Mo. The anions of the electrolytes influence the composition of the passive film. In HCl solution, chloride ions are incorporated with the passive film during its formation. The passive film consists of a compound containing chloride and oxide ions. While in H{sub 2}SO{sub 4} solution, the passive film only consists of titanium-molybdenum oxide. Sulfide ions and other sulfur are not incorporated. Ti-Mo alloys have a better passivity than pure Ti in HCl and H{sub 2}SO{sub 4} solutions. This passivity is related to the enrichment of Mo in the surface of the passive film.

  18. Chemical composition of Titan's lakes and noble gases sequestration

    NASA Astrophysics Data System (ADS)

    Cordier, D.; Mousis, O.; Lunine, J.-I.; Lavvas, P.; Lobo, L.; Ferreira, A.

    2010-04-01

    Titan is one of the most enigmatic objects in the Solar System. The presence of hydrocarbon lakes and even a global ocean have been suspected for decades. The dark features discovered by the CASSINI spacecraft are good candidates for these expected lakes (see McEwen et al. 2005 and Stofan et al. 2007). Their chemical composition has still not been measured but numerical models can give relatively accurate predictions. In the present work, we use the recent model of Titan's lakes chemical composition elaborated by Cordier et al. (2009) in light of the recent Cassini-Huygens measurements in order to investigate the possibility of sequestration of large quantities of noble gases in these liquids. Indeed, the noble gas abundances have been found to be largely in subsolar abundances in the atmosphere of Titan and the origin of this impoverishment is still poorly understood. Our preliminary results show that, under specific circumstances, at least the atmospheric depletion in krypton could be caused by its dissolution in the Titan's surface hydrocarbon liquid phase.

  19. Cuticle Structure in Relation to Chemical Composition: Re-assessing the Prevailing Model

    PubMed Central

    Fernández, Victoria; Guzmán-Delgado, Paula; Graça, José; Santos, Sara; Gil, Luis

    2016-01-01

    The surface of most aerial plant organs is covered with a cuticle that provides protection against multiple stress factors including dehydration. Interest on the nature of this external layer dates back to the beginning of the 19th century and since then, several studies facilitated a better understanding of cuticular chemical composition and structure. The prevailing undertanding of the cuticle as a lipidic, hydrophobic layer which is independent from the epidermal cell wall underneath stems from the concept developed by Brongniart and von Mohl during the first half of the 19th century. Such early investigations on plant cuticles attempted to link chemical composition and structure with the existing technologies, and have not been directly challenged for decades. Beginning with a historical overview about the development of cuticular studies, this review is aimed at critically assessing the information available on cuticle chemical composition and structure, considering studies performed with cuticles and isolated cuticular chemical components. The concept of the cuticle as a lipid layer independent from the cell wall is subsequently challenged, based on the existing literature, and on new findings pointing toward the cell wall nature of this layer, also providing examples of different leaf cuticle structures. Finally, the need for a re-assessment of the chemical and structural nature of the plant cuticle is highlighted, considering its cell wall nature and variability among organs, species, developmental stages, and biotic and abiotic factors during plant growth. PMID:27066059

  20. The Relationship Between the Surface Morphology and Chemical Composition of Gunshot Residue Particles.

    PubMed

    Kara, Ilker; Lisesivdin, Sefer Bora; Kasap, Mehmet; Er, Elif; Uzek, Ugur

    2015-07-01

    In this study, chemical composition and morphology of gunshot residue (GSR) of 9 × 19 mm Parabellum-type MKE (Turkey)-brand ammunition were analyzed by scanning electron microscope and energy dispersive X-ray spectrometer. GSR samples were collected by "swab" technique from the shooter's right hand immediately after shooting. According to general principles of thermodynamics, it is likely that the structures will have a more regular (homogeneous) spherical form to minimize their surface area due to very high temperatures and pressures that occur during explosion. Studied samples were collected under the same conditions with the same original ammunition, from the same firearm and a single shooter. This is because many other variables may affect size, structure, and composition in addition to the concentrations of elements of the structure. Results indicated that the chemical compositions are effective in the formation of GSR morphological structures. PMID:25864563

  1. A Study on the Chemical Compositions of the Yinqiaosan (Lonicerae and Forsythiae Powder) at Different Time of Later-decoction by Gas Chromatography Mass Spectrometry

    PubMed Central

    Shu, Yachun; Chen, Yajun; Qin, Kunming; Liu, Xiao; Cai, Baochang

    2016-01-01

    Background: Yinqiaosan (Lonicerae and Forsythiae Powder), as a famous prescription of Dr. Wu Jutong in Qing dynasty of China, has the effects of diaphoresis cooling, fire-purging, and detoxicaton. It is mainly used in the treatment of influenza, hand-foot-mouth disease, esophagitis, pneumonia, acute tonsillitis, mumps, and other viral infections. It is one of the widely used traditional Chinese medicine prescriptions with proven curative effects in clinical use. Objective: To research the material basis of Yinqiaosan decoction when decocting mint, herba schizonepetae in different length of later-decoction time, to find the influence on volatile components of Yinqiaosan decoction decocted later in different length of time, to lay the foundation to further clarify the after-decoction mechanism of Yinqiaosan, and the specification of Yinqiaosan decoction process. Materials and Methods: Gas chromatography mass spectrometry method is used to analyze the volatile components of Yinqiaosan decoction samples decocted for 0, 3, 5, 8, and 10 min. Results: Later-decocting mint and herba schizonepetae at different time when decocting Yinqiaosan had a significant influence on the volatile components of the solution. 54 different chemical components were identified: 25 were identified when later-decocting the sample for 3 min; 13 were identified when later-decocting the sample for 5 min; 11 were identified when later-decocting the sample for 8 min; 7 were identified when later-decocting the sample for 10 min; and 26 were identified when later-decocting the sample for 0 min. There were more volatile components in the sample after-decocted for 3 min. A total of 54 different chemical components were identified in different later-decocting solution samples. These components form the basis of the Yinqiaosan drug effect. Conclusions: The length of later-decoction time of mint and herba schizonepetae was confirmed to be 3 min when decocting Yinqiaosan. SUMMARY Later-decocting mint and

  2. Metal Oxide Nanoparticles: The Importance of Size, Shape, Chemical Composition, and Valence State in Determining Toxicity

    NASA Astrophysics Data System (ADS)

    Dunnick, Katherine

    Nanoparticles, which are defined as a structure with at least one dimension between 1 and 100 nm, have the potential to be used in a variety of consumer products due to their improved functionality compared to similar particles of larger size. Their small size is associated with increased strength, improved catalytic properties, and increased reactivity; however, their size is also associated with increased toxicity in vitro and in vivo. Numerous toxicological studies have been conducted to determine the properties of nanomaterials that increase their toxicity in order to manufacture new nanomaterials with decreased toxicity. Data indicates that size, shape, chemical composition, and valence state of nanomaterials can dramatically alter their toxicity profile. Therefore, the purpose of this dissertation was to determine how altering the shape, size, and chemical composition of various metal oxide nanoparticles would affect their toxicity. Metal oxides are used in variety of consumer products, from spray-sun screens, to food coloring agents; thus, understanding the toxicity of metal oxides and determining which aspects affect their toxicity may provide safe alternatives nanomaterials for continued use in manufacturing. Tungstate nanoparticles toxicity was assessed in an in vitro model using RAW 264.7 cells. The size, shape, and chemical composition of these nanomaterials were altered and the effect on reactive oxygen species and general cytotoxicity was determined using a variety of techniques. Results demonstrate that shape was important in reactive oxygen species production as wires were able to induce significant reactive oxygen species compared to spheres. Shape, size, and chemical composition did not have much effect on the overall toxicity of these nanoparticles in RAW 264.7 cells over a 72 hour time course, implicating that the base material of the nanoparticles was not toxic in these cells. To further assess how chemical composition can affect toxicity

  3. Effect of chemical treatment of Kevlar fibers on mechanical interfacial properties of composites.

    PubMed

    Park, Soo-Jin; Seo, Min-Kang; Ma, Tae-Jun; Lee, Douk-Rae

    2002-08-01

    In this work, the effects of chemical treatment on Kevlar 29 fibers have been studied in a composite system. The surface characteristics of Kevlar 29 fibers were characterized by pH, acid-base value, X-ray photoelectron spectroscopy (XPS), and FT-IR. The mechanical interfacial properties of the final composites were studied by interlaminar shear strength (ILSS), critical stress intensity factor (K(IC)), and specific fracture energy (G(IC)). Also, impact properties of the composites were investigated in the context of differentiating between initiation and propagation energies and ductile index (DI) along with maximum force and total energy. As a result, it was found that chemical treatment with phosphoric acid solution significantly affected the degree of adhesion at interfaces between fibers and resin matrix, resulting in improved mechanical interfacial strength in the composites. This was probably due to the presence of chemical polar groups on Kevlar surfaces, leading to an increment of interfacial binding force between fibers and matrix in a composite system. PMID:16290785

  4. Wood Chemical Composition in Species of Cactaceae: The Relationship between Lignification and Stem Morphology

    PubMed Central

    Canché-Escamilla, Gonzalo; Soto-Hernández, Marcos

    2015-01-01

    In Cactaceae, wood anatomy is related to stem morphology in terms of the conferred support. In species of cacti with dimorphic wood, a unique process occurs in which the cambium stops producing wide-band tracheids (WBTs) and produces fibers; this is associated with the aging of individuals and increases in size. Stem support and lignification have only been studied in fibrous tree-like species, and studies in species with WBTs or dimorphic wood are lacking. In this study, we approach this process with a chemical focus, emphasizing the role of wood lignification. We hypothesized that the degree of wood lignification in Cactaceae increases with height of the species and that its chemical composition varies with wood anatomy. To test this, we studied the chemical composition (cellulose, hemicellulose, and lignin content) in 13 species (2 WBTs wood, 3 dimorphic, and 8 fibrous) with contrasting growth forms. We also analyzed lignification in dimorphic and fibrous species to determine the chemical features of WBTs and fibers and their relationship with stem support. The lignin contents were characterized by Fourier transform infrared spectroscopy and high performance liquid chromatography. We found that 11 species have a higher percentage (>35%) of lignin in their wood than other angiosperms or gymnosperms. The lignin chemical composition in fibrous species is similar to that of other dicots, but it is markedly heterogeneous in non-fibrous species where WBTs are abundant. The lignification in WBTs is associated with the resistance to high water pressure within cells rather than the contribution to mechanical support. Dimorphic wood species are usually richer in syringyl lignin, and tree-like species with lignified rays have more guaiacyl lignin. The results suggest that wood anatomy and lignin distribution play an important role in the chemical composition of wood, and further research is needed at the cellular level. PMID:25880223

  5. (Laser enhanced chemical reaction studies)

    SciTech Connect

    Not Available

    1992-01-01

    Experimental studies of dynamic molecular processes are described with particular emphasis on the use of a powerful infrared diode laser probe technique developed in our laboratory. This technique allows us to determine the final states of CO{sub 2} (and other molecules) produced by collisions, photofragmentation, or chemical reactions with a spectral resolution of 0.0003 cm{sup {minus}1} and a time resolution of 10{sup {minus}7} sec. Such high spectral resolution provides a detailed picture of the vibrational and rotational states of molecules produced by these dynamic events. We have used this experimental method to probe collisions between hot hydrogen/deuterium atoms and CO{sub 2}, between O({sup 1}D) atoms and CO{sub 2}, to study the final states of DC1 molecules produced as a result of the reactions of hot Cl atoms, and to investigate the dynamics of the reaction between OH and CO molecules. Advances in our techniques over the past two years have allowed us to identify and study more than 200 final rotational states in ten different vibrational levels of CO{sub 2} encompassing all 3 normal modes, many overtones, and combination states of the molecule. We have extended the technique to probe a variety of new molecules such as OCS, N{sub 2}O, DCl, and CS{sub 2}. All of this work is aimed at providing experimental tests for polyatomic molecule potential energy surfaces, chemical transition states in complex systems, and theories of reaction dynamic in molecules with more than 3 atoms.

  6. The chemical composition of the Earth: Enstatite chondrite models

    NASA Astrophysics Data System (ADS)

    Javoy, M.; Kaminski, E.; Guyot, F.; Andrault, D.; Sanloup, C.; Moreira, M.; Labrosse, S.; Jambon, A.; Agrinier, P.; Davaille, A.; Jaupart, C.

    2010-05-01

    We propose a new model of Earth's bulk composition based on enstatite chondrites (E-chondrites), the only chondrite group isotopically identical to the Earth. This model allows a quantitative study of accretion and differentiation processes in the early Earth. Conditions for core formation are evaluated using data on silica-iron equilibrium at high pressure and temperature and the exchange budget equation SiO2 + 2Fe = Si + 2FeO, which is the result of IW and Si-SiO2 oxygen buffers' interaction and controls the evolution of mantle fO2. Based on that equation, ranges for the compositions of the Bulk Silicate Earth, the lower mantle and the core are deduced from the compositions of E-chondrites and their constituents. For these ranges of compositions, we show that during core differentiation, the mantle fO2 evolves naturally from ≈ IW-3.2 to IW-1.4 ± 0.1. The model compositions are tightened using geophysical constraints on (1) the amount of light elements in the core, (2) the petrology of the upper and lower mantle and (3) the thermal and convective structure of the lower mantle. Our results indicate that the lower mantle is enriched in Si and Fe, which is consistent with recent geophysical studies, and depleted in highly refractory elements, notably in Uranium and Thorium.

  7. Hyphenation of Thermal Analysis to Ultrahigh-Resolution Mass Spectrometry (Fourier Transform Ion Cyclotron Resonance Mass Spectrometry) Using Atmospheric Pressure Chemical Ionization For Studying Composition and Thermal Degradation of Complex Materials.

    PubMed

    Rüger, Christopher P; Miersch, Toni; Schwemer, Theo; Sklorz, Martin; Zimmermann, Ralf

    2015-07-01

    In this study, the hyphenation of a thermobalance to an ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometer (UHR FTICR MS) is presented. Atmospheric pressure chemical ionization (APCI) is used for efficient ionization. The evolved gas analysis (EGA), using high-resolution mass spectrometry allows the time-resolved molecular characterization of thermally induced processes in complex materials or mixtures, such as biomass or crude oil. The most crucial part of the setup is the hyphenation between the thermobalance and the APCI source. Evolved gases are forced to enter the atmospheric pressure ionization interface of the MS by applying a slight overpressure at the thermobalance side of the hyphenation. Using the FTICR exact mass data, detailed chemical information is gained by calculation of elemental compositions from the organic species, enabling a time and temperature resolved, highly selective detection of the evolved species. An additional selectivity is gained by the APCI ionization, which is particularly sensitive toward polar compounds. This selectivity on the one hand misses bulk components of petroleum samples such as alkanes and does not deliver a comprehensive view but on the other hand focuses particularly on typical evolved components from biomass samples. As proof of principle, the thermal behavior of different fossil fuels: heavy fuel oil, light fuel oil, and a crude oil, and different lignocellulosic biomass, namely, beech, birch, spruce, ash, oak, and pine as well as commercial available softwood and birch-bark pellets were investigated. The results clearly show the capability to distinguish between certain wood types through their molecular patterns and compound classes. Additionally, typical literature known pyrolysis biomass marker were confirmed by their elemental composition, such as coniferyl aldehyde (C10H10O3), sinapyl aldehyde (C11H12O4), retene (C18H18), and abietic acid (C20H30O2). PMID:26024433

  8. Effect of Chemical Treatments on Flax Fibre Reinforced Polypropylene Composites on Tensile and Dome Forming Behaviour

    PubMed Central

    Wang, Wentian; Lowe, Adrian; Kalyanasundaram, Shankar

    2015-01-01

    Tensile tests were performed on two different natural fibre composites (same constituent material, similar fibre fraction and thickness but different weave structure) to determine changes in mechanical properties caused by various aqueous chemical treatments and whether any permanent changes remain on drying. Scanning electronic microscopic examinations suggested that flax fibres and the flax/polypropylene interface were affected by the treatments resulting in tensile property variations. The ductility of natural fibre composites was improved significantly under wet condition and mechanical properties (elongation-to-failure, stiffness and strength) can almost retain back to pre-treated levels when dried from wet condition. Preheating is usually required to improve the formability of material in rapid forming, and the chemical treatments performed in this study were far more effective than preheating. The major breakthrough in improving the formability of natural fibre composites can aid in rapid forming of this class of material system. PMID:25789505

  9. Chemical Compositions of Stars in Globular Cluster NGC 2419

    NASA Astrophysics Data System (ADS)

    Kadakia, Shimonee; Smecker-Hane, T.; Bosler, T.

    2007-05-01

    We determine the chemical abundances of 19 red giant branch stars in the Galactic globular cluster NGC 2419. Lying at a distance of 84.2 kpc and a galactocentric distance of 91.5 kpc, NGC 2419 is the fourth brightest globular cluster in the Milky Way with a total magnitude of M_V = -9.6 mag, which is significantly brighter than M_V = -7.5 mag, the typical peak of the globular cluster luminosity functions in external galaxies. Our results will give an insight of whether NGC 2419 is in fact a globular cluster or a core of a disrupted galaxy that merged with the Milky Way. We have used IRAF to reduce spectra we have taken with the DEIMOS spectrograph on the the Keck I 10-meter telescope. Using the strengths of the Ca II triplet absorption lines at approximately 8600 Angstrom, we will determine the chemical abundance of each star. If the chemical abundances differ by significantly more than the observational errors would predict then we can conclude the cluster is a remnant of the core of a galaxy that merged with the Milky Way and not a normal globular cluster, because most globular clusters formed quickly from a well mixed gas cloud, and thus their stars have nearly identical ages and chemical compositions. We gratefully acknowledge financial support from a UROP grant to SK and NSF grant AST-0307863 to TSH. These data were obtained at the Keck Observatory, operated by the California Inst. of Technology, Univ. of California and NASA and made possible by generous financial support from the W.M. Keck Foundation.

  10. Global Chemical Composition of Ambient Fine Particulate Matter for Exposure Assessment

    PubMed Central

    2015-01-01

    Epidemiologic and health impact studies are inhibited by the paucity of global, long-term measurements of the chemical composition of fine particulate matter. We inferred PM2.5 chemical composition at 0.1° × 0.1° spatial resolution for 2004–2008 by combining aerosol optical depth retrieved from the MODIS and MISR satellite instruments, with coincident profile and composition information from the GEOS-Chem global chemical transport model. Evaluation of the satellite-model PM2.5 composition data set with North American in situ measurements indicated significant spatial agreement for secondary inorganic aerosol, particulate organic mass, black carbon, mineral dust, and sea salt. We found that global population-weighted PM2.5 concentrations were dominated by particulate organic mass (11.9 ± 7.3 μg/m3), secondary inorganic aerosol (11.1 ± 5.0 μg/m3), and mineral dust (11.1 ± 7.9 μg/m3). Secondary inorganic PM2.5 concentrations exceeded 30 μg/m3 over East China. Sensitivity simulations suggested that population-weighted ambient PM2.5 from biofuel burning (11 μg/m3) could be almost as large as from fossil fuel combustion sources (17 μg/m3). These estimates offer information about global population exposure to the chemical components and sources of PM2.5. PMID:25343705

  11. Global chemical composition of ambient fine particulate matter for exposure assessment.

    PubMed

    Philip, Sajeev; Martin, Randall V; van Donkelaar, Aaron; Lo, Jason Wai-Ho; Wang, Yuxuan; Chen, Dan; Zhang, Lin; Kasibhatla, Prasad S; Wang, Siwen; Zhang, Qiang; Lu, Zifeng; Streets, David G; Bittman, Shabtai; Macdonald, Douglas J

    2014-11-18

    Epidemiologic and health impact studies are inhibited by the paucity of global, long-term measurements of the chemical composition of fine particulate matter. We inferred PM2.5 chemical composition at 0.1° × 0.1° spatial resolution for 2004-2008 by combining aerosol optical depth retrieved from the MODIS and MISR satellite instruments, with coincident profile and composition information from the GEOS-Chem global chemical transport model. Evaluation of the satellite-model PM2.5 composition data set with North American in situ measurements indicated significant spatial agreement for secondary inorganic aerosol, particulate organic mass, black carbon, mineral dust, and sea salt. We found that global population-weighted PM2.5 concentrations were dominated by particulate organic mass (11.9 ± 7.3 μg/m(3)), secondary inorganic aerosol (11.1 ± 5.0 μg/m(3)), and mineral dust (11.1 ± 7.9 μg/m(3)). Secondary inorganic PM2.5 concentrations exceeded 30 μg/m(3) over East China. Sensitivity simulations suggested that population-weighted ambient PM2.5 from biofuel burning (11 μg/m(3)) could be almost as large as from fossil fuel combustion sources (17 μg/m(3)). These estimates offer information about global population exposure to the chemical components and sources of PM2.5. PMID:25343705

  12. Global Chemical Composition of Ambient Fine Particulate Matter for Exposure Assessment

    DOE PAGESBeta

    Philip, Sajeev; Martin, Randall V.; van Donkelaar, Aaron; Lo, Jason Wai-Ho; Wang, Yuxuan; Chen, Dan; Zhang, Lin; Kasibhatla, Prasad S.; Wang, Siwen; Zhang, Qiang; et al

    2014-10-24

    Epidemiologic and health impact studies are inhibited by the paucity of global, long-term measurements of the chemical composition of fine particulate matter. We inferred PM2.5 chemical composition at 0.1° × 0.1° spatial resolution for 2004–2008 by combining aerosol optical depth retrieved from the MODIS and MISR satellite instruments, with coincident profile and composition information from the GEOS-Chem global chemical transport model. Evaluation of the satellite-model PM2.5 composition data set with North American in situ measurements indicated significant spatial agreement for secondary inorganic aerosol, particulate organic mass, black carbon, mineral dust, and sea salt. We found that global population-weighted PM2.5 concentrationsmore » were dominated by particulate organic mass (11.9 ± 7.3 μg/m3), secondary inorganic aerosol (11.1 ± 5.0 μg/m3), and mineral dust (11.1 ± 7.9 μg/m3). Secondary inorganic PM2.5 concentrations exceeded 30 μg/m3 over East China. Sensitivity simulations suggested that population-weighted ambient PM2.5 from biofuel burning (11 μg/m3) could be almost as large as from fossil fuel combustion sources (17 μg/m3). In conclusion, these estimates offer information about global population exposure to the chemical components and sources of PM2.5.« less

  13. Chemical composition of black rockfish (Sebastes melanops) fillets and byproducts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Black rockfish are important in the near shore fishery of Southeast Alaska. They are the only species among the pelagic shelf rockfishes for which there is a directed fishery in state waters. The purpose of this study was to determine the composition black rockfish fillets and its major processing b...

  14. Access to data on chemical composition of products used in auto repair and body shops.

    PubMed

    Karstadt, M; Bobal, R

    1984-01-01

    Some information on chemical composition of products used in the workplace can be obtained by requesting composition data from product marketers. Workers in auto repair and body shops identified 253 products used in their shops. Full disclosure of composition was obtained for approximately 20% of the 174 products marketed by companies which answered our letters. Composition was partially disclosed for approximately 40% of the products, and about 10% of the product formulations were claimed to be trade secret or confidential. The study reported in this paper was carried out in New York State in 1980, before the effective date of the New York State right-to-know law. The results of this study can be used as a benchmark to judge the effectiveness of worker right-to-know laws and product labeling regulations. PMID:6517067

  15. Rapid fabrication of ceramic composite tubes using chemical vapor infiltration

    SciTech Connect

    Starr, T.L.; Chiang, D.; Besmann, T.M.; Stinton, D.P.; McLaughlin, J.C.; Matlin, W.M.

    1996-06-01

    Ceramic composite tubes can be fabricated with silicon carbide matrix and Nicalon fiber reinforcement using forced flow-thermal gradient chemical vapor infiltration (FCVI). The process model GTCVI is used to design the equipment configuration and to identify conditions for rapid, uniform densification. The initial injector and mandrel design produced radial and longitudinal temperature gradients too large for uniform densification. Improved designs have been evaluated with the model. The most favorable approach utilizes a free-standing preform and an insulated water-cooled gas injector. Selected process conditions are based on the temperature limit of the fiber, matrix stoichiometry and reagent utilization efficiency. Model runs for a tube 12 inches long, 4 inches OD and 1/4 inch wall thickness show uniform densification in approximately 15 hours.

  16. Chemical vapor infiltration of TiB{sub 2} composites

    SciTech Connect

    Besmann, T.M.

    1995-05-01

    This program is designed to develop a Hall-Heroult aluminum smelting cathode with substantially improved properties. The carbon cathodes in current use require significant anode-to-cathode spacing in order to prevent shorting, causing significant electrical inefficiencies. This is due to the non-wettability of carbon by aluminum which causes instability in the cathodic aluminum pad. It is suggested that a fiber reinforced-TiB{sub 2} matrix composite would have the requisite wettability, strength, strain-to-failure, cost, and lifetime to solve this problem. The approach selected to fabricate such a cathode material is chemical vapor infiltration (CVI). This program is designed to evaluate potential fiber reinforcements, fabricate test specimens, and test the materials in a static bath and lab-scale Hall cell.

  17. Chemical composition effects on the crazing of PS-PMMA block copolymers

    NASA Astrophysics Data System (ADS)

    Kim, Won; Han, Junwon; Yang, Hoichang; Ryu, Chang

    2006-03-01

    Using a large scale separation technique adopting interaction chromatography, we have fractionated as-synthesized PS-PMMA block copolymers in terms of the average chemical composition difference, while maintaining the same average molecular weight. Copper grid technique with optical, atomic force and transmission electron microscopy has been employed for the fracture study to reveal how the composition-dependent morphology affect the crazing of the glassy-glassy block copolymers, while maintaining the same level of Chi*N. In addition, we study how the thermal annealing affects the median strains for crazing and catastrophic failure.

  18. Detail Chemical Composition of M33 Globular Clusters

    NASA Astrophysics Data System (ADS)

    McWilliam, Andrew

    2008-08-01

    I propose to perform the first high-resolution detailed chemical abundance study of globular clusters (GCs) in the Local Group spiral galaxy M33 with Keck HIRES. My integrated-light technique permits detailed chemical abundance measurement (and approximate ages) for old populations at larger distance than ever done before. The basic goal is to accurately define the chemical abundance properties of the M33 GC system, for a comparison with the Milky Way, LMC, SMC and Local Group dwarf galaxies. Abundances of Fe, (alpha)-elements, Na and Al will constrain the relative contributions of Type Ia and Type II SNe and probe ~1 Gyr enrichment timescales. The s-process elements (e.g. Zr, Y, Ba, La), made by AGB stars, will probe timescales of several Gyr. These elements are sensitive to whether chemical enrichment occurred slowly, or in a burst, and whether the enrichment was global, or occurred in disparate systems, such as dwarf galaxies that were later accreted. The project will provide basic information to advance an understanding of chemical enrichment and nucleosynthesis, and galaxy evolution.

  19. Chemical Information: Print. Directed Study.

    ERIC Educational Resources Information Center

    Stone, Catherine C.

    This report provides a survey and evaluation of chemical information literature. Contained in this survey are an overview of the chemical literature field, comments on obtaining access to this literature and annotated bibliographies of primary, secondary, and tertiary sources as well as special topics. Primary sources include journals, patents,…

  20. Chemical vapor composite silicon carbide for space telescopes

    NASA Astrophysics Data System (ADS)

    Tanaka, C. T.; Webb, K.

    2006-06-01

    Components for space telescopes using high quality silicon carbide (SiC) produced via the chemical vapor composite (CVC) process are currently under development. This CVC process is a modification of chemical vapor deposition (CVD) and results in a dramatic reduction in residual stress of the SiC deposit. The resultant CVC SiC material has high modulus, high thermal conductivity and can be polished to better than 1nm RMS surface roughness, making it ideal for space telescopes requiring lightweight, stiff and thermally stable components. Moreover, due to its lower intrinsic stress, CVC SiC is much more readily scaled to large sizes and manufactured into the complex geometries needed for the telescope assemblies. Results are presented on the optical figure for a lightweight 15cm CVC SiC mirror demonstrating low wavefront error (<30nm peak-to-valley and <5.1nm rms). Theoretical and experimental modal analysis measured the first four resonant modes of the mirror and found a first modal frequency in the vicinity of 2100 Hz, representing a highly stiff mirror.

  1. Determining the chemical composition of cloud condensation nuclei

    SciTech Connect

    Williams, A.L.; Rothert, J.E.; McClure, K.E. ); Alofs, D.J.; Hagen, D.E.; Schmitt, J.; White, D.R.; Hopkins, A.R.; Trueblood, M.B. . Cloud and Aerosol Science Lab.)

    1992-12-01

    This third progress report describes the status of our efforts to develop the instrumentation to collect cloud condensation nuclei (CCN) in amounts sufficient for chemical analysis. During the fall of 1992 we started collecting filter samples of CCN with the laboratory version of the apparatus at Rolla -MO. The mobile version of the apparatus is in the latter stages of construction. This report includes a fairly rigorous discussion of the operation of the CCN sampling system. A statistical model of the operation of the system is presented to show the ability of the system to collect CCN in the two different size ranges for which we plan to determine the chemical composition. A question is raised by the model results about the operation of one of the virtual impactors. It appears to pass a small percent of particles larger than its cut-point that has the potential of contaminating the smallest CCN sample with larger CCN material. Further tests are necessary, but it may be necessary to redesign that impactor. The appendices of the report show pictures of both the laboratory version and the mobile version of the CCN sampling system. The major hardware has been completed, and the mobile version will be in operation within a few weeks.

  2. Differences in Chemical Composition of Soil Organic Carbon Resulting From Long-Term Fertilization Strategies

    PubMed Central

    Li, Zengqiang; Zhao, Bingzi; Wang, Qingyun; Cao, Xiaoyan; Zhang, Jiabao

    2015-01-01

    Chemical composition of soil organic carbon (SOC) is central to soil fertility. We hypothesize that change in SOC content resulting from various long-term fertilization strategies accompanies the shift in SOC chemical structure. This study examined the effect of fertilization strategies along with the time of fertilizer application on the SOC composition by 13C nuclear magnetic resonance (NMR) spectroscopy. The soils (Aquic Inceptisol) subjected to seven fertilizer treatments were collected in 1989, 1999 and 2009, representing 0, 10 and 20 years of fertilization, respectively. The seven fertilizer treatments were (1–3) balanced fertilization with application of nitrogen (N), phosphorus (P) and potassium (K) including organic compost (OM), half organic compost plus half chemical fertilizer (1/2OM), and pure chemical NPK fertilizer (NPK); (4–6) unbalanced chemical fertilization without application of one of the major elements including NP fertilizer (NP), PK fertilizer (PK), and NK fertilizer (NK); and (7) an unamended control (CK). The SOC content in the balanced fertilization treatments were 2.3–52.6% and 9.4–64.6% higher than in the unbalanced fertilization/CK treatments in 1999 and 2009, respectively, indicating significant differences in SOC content with time of fertilizer application between the two treatment groups. There was a significantly greater proportion of O-alkyl C and a lower proportion of aromatic C in the balanced fertilization than in unbalanced fertilization/CK treatments in 1999, but not in 2009, because their proportions in the former treatments approached the latter in 2009. Principal component analysis further showed that the C functional groups from various fertilization strategies tended to become compositionally similar with time. The results suggest that a shift in SOC chemical composition may be firstly dominated by fertilization strategies, followed by fertilization duration. PMID:25884713

  3. Inorganic chemical composition and chemical reactivity of settled dust generated by the World Trade Center building collapse

    USGS Publications Warehouse

    Plumlee, Geoffrey S.; Hageman, Philip L.; Lamothe, Paul J.; Ziegler, Thomas L.; Meeker, Gregory P.; Theodorakos, Peter M.; Brownfield, Isabelle; Adams, Monique G.; Swayze, Gregg A.; Hoefen, Todd M.; Taggart, Joseph E.; Clark, Roger N.; Wilson, S.; Sutley, Stephen J.

    2009-01-01

    Samples of dust deposited around lower Manhattan by the September 11, 2001, World Trade Center (WTC) collapse have inorganic chemical compositions that result in part from the variable chemical contributions of concrete, gypsum wallboard, glass fibers, window glass, and other materials contained in the buildings. The dust deposits were also modified chemically by variable interactions with rain water or water used in street washing and fire fighting. Chemical leach tests using deionized water as the extraction fluid show the dust samples can be quite alkaline, due primarily to reactions with calcium hydroxide in concrete particles. Calcium and sulfate are the most soluble components in the dust, but many other elements are also readily leached, including metals such as Al, Sb, Mo Cr, Cu, and Zn. Indoor dust samples produce leachates with higher pH, alkalinity, and dissolved solids than outdoor dust samples, suggesting most outdoor dust had reacted with water and atmospheric carbon dioxide prior to sample collection. Leach tests using simulated lung fluids as the extracting fluid suggest that the dust might also be quite reactive in fluids lining the respiratory tract, resulting in dissolution of some particles and possible precipitation of new phases such as phosphates, carbonates, and silicates. Results of these chemical characterization studies can be used by health scientists as they continue to track and interpret health effects resulting from the short-term exposure to the initial dust cloud and the longer-term exposure to dusts resuspended during cleanup.

  4. Influence of chemical composition of precipitation on migration of radioactive caesium in natural soils.

    PubMed

    Thørring, H; Skuterud, L; Steinnes, E

    2014-08-01

    The aim of the present work was to study the impact of the chemical composition of precipitation on radiocaesium mobility in natural soil. This was done through column studies. Three types of precipitation regimes were studied, representing a natural range found in Norway: Acidic precipitation (southernmost part of the country); precipitation rich in marine cations (highly oceanic coastal areas); and low concentrations of sea salts (slightly continental inland areas). After 50 weeks and a total precipitation supply of ∼10 000 L m(-2) per column, results indicate that acidic precipitation increased the mobility of (134)Cs added during the experiment. However, depth distribution of already present Chernobyl fallout (137)Cs was not significantly affected by the chemical composition of precipitation. PMID:24704765

  5. Raman spectra of Martian glass analogues: A tool to approximate their chemical composition

    NASA Astrophysics Data System (ADS)

    Di Genova, Danilo; Kolzenburg, Stephan; Vona, Alessandro; Chevrel, Magdalena Oryaëlle; Hess, Kai-Uwe; Neuville, Daniel R.; Ertel-Ingrisch, Werner; Romano, Claudia; Dingwell, Donald B.

    2016-05-01

    Raman spectrometers will form a key component of the analytical suite of future planetary rovers intended to investigate geological processes on Mars. In order to expand the applicability of these spectrometers and use them as analytical tools for the investigation of silicate glasses, a database correlating Raman spectra to glass composition is crucial. Here we investigate the effect of the chemical composition of reduced silicate glasses on their Raman spectra. A range of compositions was generated in a diffusion experiment between two distinct, iron-rich end-members (a basalt and a peralkaline rhyolite), which are representative of the anticipated compositions of Martian rocks. Our results show that for silica-poor (depolymerized) compositions the band intensity increases dramatically in the regions between 550-780 cm-1 and 820-980 cm-1. On the other hand, Raman spectra regions between 250-550 cm-1 and 1000-1250 cm-1 are well developed in silica-rich (highly polymerized) systems. Further, spectral intensity increases at ~965 cm-1 related to the high iron content of these glasses (~7-17 wt % of FeOtot). Based on the acquired Raman spectra and an ideal mixing equation between the two end-members we present an empirical parameterization that enables the estimation of the chemical compositions of silicate glasses within this range. The model is validated using external samples for which chemical composition and Raman spectra were characterized independently. Applications of this model range from microanalysis of dry and hydrous silicate glasses (e.g., melt inclusions) to in situ field investigations and studies under extreme conditions such as extraterrestrial (i.e., Mars) and submarine volcanic environments.

  6. Advanced Chemical Propulsion System Study

    NASA Technical Reports Server (NTRS)

    Portz, Ron; Alexander, Leslie; Chapman, Jack; England, Chris; Henderson, Scott; Krismer, David; Lu, Frank; Wilson, Kim; Miller, Scott

    2007-01-01

    A detailed; mission-level systems study has been performed to show the benefit resulting from engine performance gains that will result from NASA's In-Space Propulsion ROSS Cycle 3A NRA, Advanced Chemical Technology sub-topic. The technology development roadmap to accomplish the NRA goals are also detailed in this paper. NASA-Marshall and NASA-JPL have conducted mission-level studies to define engine requirements, operating conditions, and interfaces. Five reference missions have been chosen for this analysis based on scientific interest, current launch vehicle capability and trends in space craft size: a) GTO to GEO, 4800 kg, delta-V for GEO insertion only approx.1830 m/s; b) Titan Orbiter with aerocapture, 6620 kg, total delta V approx.210 m/s, mostly for periapsis raise after aerocapture; c) Enceladus Orbiter (Titan aerocapture) 6620 kg, delta V approx.2400 m/s; d) Europa Orbiter, 2170 kg, total delta V approx.2600 m/s; and e) Mars Orbiter, 2250 kg, total delta V approx.1860 m/s. The figures of merit used to define the benefit of increased propulsion efficiency at the spacecraft level include propulsion subsystem wet mass, volume and overall cost. The objective of the NRA is to increase the specific impulse of pressure-fed earth storable bipropellant rocket engines to greater than 330 seconds with nitrogen tetroxide and monomothylhydrazine propellants and greater than 335 , seconds with nitrogen tetroxide and hydrazine. Achievement of the NRA goals will significantly benefit NASA interplanetary missions and other government and commercial opportunities by enabling reduced launch weight and/or increased payload. The study also constitutes a crucial stepping stone to future development, such as pump-fed storable engines.

  7. Chemical and mineral composition of dust and its effect on the dielectric constant

    SciTech Connect

    Sharif, S.

    1995-03-01

    Chemical analysis is carried out for dust sample collected from central Sudan and the dust chemical constituents are obtained. The mineral composition of dust are identified by the X-ray diffraction techniques. The mineral quantities are obtained by a technique developed based on the chemical analytical methods. Analyses show that Quartz is the dominant mineral while the SiO{sub 2} is the dominant oxide. A simple model is derived for the dust chemical constituents. This model is used with models for predicting the mixture dielectric constant to estimate the dust dielectric constant; the results of which are seen to be in a good agreement with the measured values. The effects of the different constituents on the dust dielectric constant are studied and results are given.

  8. External application of the volatile oil from Blumea balsamifera may be safe for liver--a study on its chemical composition and hepatotoxicity.

    PubMed

    Pang, Yu-Xin; Fan, Zuo-Wang; Wang, Dan; Yang, Quan; Wang, Kai; Chen, Xiao-Lu; Hu, Xuan; Yu, Fu-Lai; Chen, Zhen-Xia

    2014-01-01

    Ainaxiang (Blumea balsamifera), also known as Sambong, is an important ancient medicinal herb in Southeast Asia. It is rich in volatile oil, and still widely used nowadays for skin wound healing and treatment of sore throats. We analyzed the volatile oil from Blumea balsamifera (BB oil) by gas chromatography-mass spectrometry (GC-MS). Forty one components, including l-borneol, were identified. Next, the damaging effects of BB oil diluted with olive oil on liver at different concentrations (100%, 50%, 20%), were evaluated, using both normal and wounded skin. Plasma ALT, AST, ALP and TBili were assessed, along with liver histopathology. The results showed that serum levels of liver toxicity markers in the high concentration groups (100% w/v) increased compared with control groups, whereas no significant changes was observed in histopathology of liver samples. In the wound groups, treatment with BB oil resulted in a decrease in serum toxicity index, compared with normal animal groups. This study confirms the safety of short term BB oil consumption, though high BB oil doses may lead to mild liver injury and this response might be weakened in the case of cutaneous wounds. These results are expected to be helpful for guiding appropriate therapeutic use of BB oil. PMID:25401394

  9. Effect of chemical composition and superheat on macrostructure of high Cr white iron castings

    SciTech Connect

    Dogan, Omer N.

    2005-08-01

    White cast irons are frequently used in applications requiring high wear resistance. High Cr white cast irons have a composite microstructure composed of hard (Fe,Cr)7C3 carbides in a steel matrix. Previous research has indicated that the equiaxed region of these high Cr white iron castings is much more wear resistant under high stress abrasive conditions than the columnar region, when the carbides are oriented perpendicular to the wear surface. In the present study, the effect of both the chemical composition, particularly carbon content, and the pouring superheat of the melt on the macrostructure of high Cr white iron castings is investigated.

  10. Chemical composition of oils from recently discovered fields in West Lithuania

    NASA Astrophysics Data System (ADS)

    Zdanavičiūtė, Onytė; Dakhnova, Marina; Kleinas, Arūnas

    2008-01-01

    Four minor oil discoveries have been made in West Lithuania in recent years. Studies of the oil composition show that its physical and chemical properties (density, viscosity, petrol content, etc.) and the group composition of hydrocarbons (content of saturated and aromatic hydrocarbons, tars and asphaltenes) mainly depend on the formation conditions and distances of migration between the kitchen and accumulation areas. According to the distribution patterns of n-alkanes and isoprenoids, the examined oils are comparable and generated from sapropel organic matter. There are certain differences in biomarker and carbon isotope data, indicating oil generation from different source rocks containing organic matter of different catagenesis.

  11. A textural and chemical study of Icelandic palagonite of varied composition and its bearing on the mechanism of the glass-palagonite transformation

    SciTech Connect

    Thorseth, I.H.; Furnes, H.; Tumyr, O. )

    1991-03-01

    Palagonite of basalt and basaltic andesite parentages from hyaloclastite deposits in Iceland has been investigated. SEM studies indicate a sharp to diffuse alteration front which may propagate along microfractures in the glass, resulting in a progressive partial dissolution yielding palagonite of variable, but generally increasing porosity towards grain surfaces. The palagonite has a granular texture. Incipient alteration is indicated by the development of individual globules, whereas at an advanced stage chains of globules, defining a sponge-like texture, characterize the palagonite. In the basaltic andesite, the precursor to brown Ti- and FE-rich palagonite is a white variety, for which an evolutionary model is presented. EDS line-scans across the fresh glass-palagonite boundary show the existence of a 2-4 {mu}m thick zone of glass-like material in which all elements have been depleted, except Si, and in some cases Al, which have been relatively enriched. This gives evidence for selective element mobility prior to a variable degree of congruent network dissolution of the Si-rich residue, yielding zoned palagonite with a different porosity. In order for Fe, Ti, and Al to dissolve, a pH < 3 is necessary. In an oxidizing environment and at pH-values > 3, Fe, Ti, and Al will precipitate in the pores of the white palagonite as oxides/hydroxides, thus creating the brown variety, which is characterized by highly variable contents of the above-mentioned elements. The applicability of this model to palagonite derived from basalt parentages at different pH conditions is discussed.

  12. A textural and chemical study of Icelandic palagonite of varied composition and its bearing on the mechanism of the glass-palagonite transformation

    NASA Astrophysics Data System (ADS)

    Thorseth, I. H.; Furnes, H.; Tumyr, O.

    1991-03-01

    Palagonite of basalt and basaltic andesite parentages from hyaloclastite deposits in Iceland has been investigated. SEM studies indicate a sharp to diffuse alteration front which may propagate along microfractures in the glass, resulting in a progressive partial dissolution yielding palagonite of variable, but generally increasing porosity towards grain surfaces. The palagonite has a granular texture. Incipient alteration is indicated by the development of individual globules (ca. 0.01 μm in diameter), whereas at an advanced stage chains of globules, defining a sponge-like texture, characterize the palagonite. In the basaltic andesite, the precursor to brown Ti- and Fe-rich palagonite is a white variety, for which an evolutionary model is presented. EDS line-scans across the fresh glass-palagonite boundary show the existence of a 2-4 μm thick zone of glass-like material in which all elements have been depleted, except Si, and in some cases Al, which have been relatively enriched. The white palagonite is characterized by strong depletion of Ti, Fe, Na, Mg, and to lesser extent, Ca, Al (in order of decreasing loss). Regardless of the degree of porosity development (ca. 1-43 vol%), the extent of element depletion relative to SiO 2 is constant. This gives evidence for selective element mobility prior to a variable degree of congruent network dissolution of the Si-rich residue, yielding zoned palagonite with a different porosity. In order for Fe, Ti, and Al to dissolve, a pH < 3 is necessary. In an oxidizing environment and at pH-values > 3, Fe, Ti, and Al will precipitate in the pores of the white palagonite as oxides/hydroxides, thus creating the brown variety, which is characterized by highly variable contents of the above-mentioned elements. The applicability of this model to palagonite derived from basalt parentages at different pH conditions is discussed.

  13. Chemical composition and variability of the volatile components from inflorescences of Cirsium species.

    PubMed

    Kozyra, Małgorzata; Mardarowicz, Marek; Kochmańska, Joanna

    2015-01-01

    The present study aimed to investigate the chemical composition of the essential oils of inflorescences Cirsium spp. (Asteraceae) by GC/MS method. Essential oils were extracted from the inflorescences of Cirsium pannonicum (Link), Cirsium ligulare Boiss., Cirsium heterophyllum (L.) Hill., Cirsium acaule (L.) Scop., Cirsium oleraceum (L.) Scop., Cirsium dissectum (L.) Hill., Cirsium decussatum (Janka) and Cirsium eriophorum (L.) Scop., using the steam distillation method. A gas chromatography-mass spectrometry method was employed for the analysis of essential oils. Our study shows the differences in chemical composition of volatile oils in the inflorescences of Cirsium spp. The main components of the essential oil were ketones and aldehydes with a long carbon side-chain. Volatile oils also contained small amounts of terpenes: thymol, β-linalool, eugenol, carvacrol and fatty acids with odd number of carbon atoms-waxes. The compounds in the essential oils obtained from inflorescences Cirsium L. species have been identified for the first time. PMID:25674834

  14. Chemical Composition and Antibacterial Activity of Essential Oils of Two Species of Lamiaceae against Phytopathogenic Bacteria.

    PubMed

    Gormez, Arzu; Bozari, Sedat; Yanmis, Derya; Gulluce, Medine; Sahin, Fikrettin; Agar, Guleray

    2015-01-01

    In this study, we aimed to determine chemical composition and antibacterial activities of Satureja hortensis and Calamintha nepeta against to 20 phytopathogenic bacteria causing serious crop loss. The essential oils of S. hortensis and C. nepeta were isolated by the hydrodistillation method and the chemical composition of the essential oils were analyzed by GC-MS. The antibacterial properties of the essential oils were evaluated against 20 phytopathogenic bacteria through Disc diffusion assay and micro dilution assay. The results revealed that the essential oils of S. hortensis and C. nepeta have significant antibacterial activity. Furthermore, the findings of the study are valuable for future investigations focusing on the alternative natural compounds to control plant diseases. PMID:26373171

  15. Effect of amine activators on the properties of chemical cured dental composites.

    PubMed

    Mathew, L; Joseph, R; Krishnan, V K

    1997-01-01

    The purpose of this study was to evaluate the reactivity and the effect of concentration of three tertiary amines upon the mechanical properties of a chemical curing dental composite. Chemical cured composite pastes were prepared by keeping peroxide concentration constant at 1 wt% (by weight of resin mixture) and by varying the amine/peroxide molar ratio from 0.25 to 1.5. Composite samples were prepared for all three amine pastes aged for 1, 15, 30, 45, and 60 d stored at 8, 22, and 37 degrees C. The loss in activity of the tertiary amine with time was measured. Changes in compressive strength, diametral tensile strength, and microhardness were also measured. A sharp decrease in working and setting times corresponding to increased activity was noticed with an increased amine content. The activity was found to vary in the order N,N-dimethyl p-toluidine (DMPT) > 2-(4-dimethylaminophenyl)ethanol (DMAPEA) > N,Ndiethanol p-toluidine (DEPT). DMPT is found to be more temperature sensitive than DMAPEA and DEPT. However, DEPT is found to provide better storage stability out of all three amines tested. Each amine was found to possess optimum concentrations at which the mechanical properties showed maximum values. DEPT is preferred for long-term storage stability in chemical-cured dental composites where aging tends to reduce the activity of the amine. PMID:9067811

  16. Compositional studies of primitive asteroids

    NASA Technical Reports Server (NTRS)

    Vilas, F.

    1988-01-01

    The composition of primitive asteroids and their relationship to satellites in the solar system will be studied by analyzing existing narrowband charge coupled device (CCD) reflectance spectra, acquiring additional spectra of asteroids and small satellites in the 0.5 to 1.0 micrometer spectral range, and exploring possibilities for obtaining compositional information in the blue-UV spectral region. Comparison with laboratory spectra of terrestrial chlorites and serpentines (phyllosilicates) and the clay minerals found in carbonaceous chondrite meteorites will continue. During 1987, narrowband CCD reflectance spectra of 17 additional asteroids were acquired. These spectra and spectra of 34 other asteroids have been used primarily for two studies: weak absorption features similar to those due to Fe2(+) and Fe2(+) - Fe3(+) transitions in iron oxides f ound in terrestrial chlorites and serpentines and carbonaceous chondrites have been identified in some primitive asteroid spectra. There is a first indication that asteroids grouped by heliocentric distance show similar weak absorption features. Nonparametric statistics are being applied to test the hypothesis of discrete remnants of a gradation in composition of outer-belt asteroids.

  17. Study Acoustic Emissions from Composites

    NASA Technical Reports Server (NTRS)

    Walker, James L.; Workman, Gary L.

    1997-01-01

    The nondestructive evaluation (NDE) of future propulsion systems utilizing advanced composite structures for the storage of cryogenic fuels, such as liquid hydrogen or oxygen, presents many challenges. Economic justification for these structures requires, light weight, reusable components with an infrastructure allowing periodic evaluation of structural integrity after enduring demanding stresses during operation. A major focus has been placed on the use of acoustic emission NDE to detect propagating defects, in service, necessitating an extensive study into characterizing the nature of acoustic signal propagation at very low temperatures and developing the methodology of applying AE sensors to monitor cryogenic components. This work addresses the question of sensor performance in the cryogenic environment. Problems involving sensor mounting, spectral response and durability are addressed. The results of this work provides a common point of measure from which sensor selection can be made when testing composite components at cryogenic temperatures.

  18. Exploring the chemical composition of water in the Kandalaksha Bay

    NASA Astrophysics Data System (ADS)

    Mazukhina, Svetlana; Masloboev, Vladimir; Chudnenko, Konstantin; Khaitov, Vadim; Maksimova, Victoria; Belkina, Natalia

    2014-05-01

    Oil films were noted at the head of the Kandalaksha Bay as far back as in 1971, as soon as the first stage of the oil tank farm had been commissioned (the autumn of 1970). In 1997-1998 there were accidental oil spills posing a real threat to the Kandalaksha Reserve biota. In May 2011, oil spills from the Belomorsk oil tank farm resulted in a local environmental emergency. In this work we have traced the evolution of polluted water by means of hydrogeochemical monitoring and reconstructing the chemical composition of surface and near-bottom water of the Kandalaksha Bay by using physical-chemical modeling (Selector software package, Chudnenko, 2010). The surface and near-bottom water was sampled in the summer of 2012 and 2013 at the following sites: under the numbers 3 (N 67.2.673, E 32.23.753); 4 (N 67.3.349, E 32.28.152); 1 (N 67.5.907, E 32.29.779), and 2 (N 67.6.429, E 32.30.539). The monitored objects and sampling time were sensitive to both the effects of the White Sea water (high tide), fresh water, and water affected by human impact (the oil tank farm). At each site, three samples were taken. The next stage involved reconstructing of the sea water ion composition by modeling within the Al-B-Br-Ar-He-Ne-C-Ca-Cl-F-K-Mg-Mn-N-Na-P-S-Si-Sr-Cu-Zn-H-O-e system, where e is an electron. Modeling of the chemical composition of near-bottom water (site 3) has revealed high contents of carbon dioxide, hydrogen disulphide, hydrocarbonates, and no oxygen (Eh<0). All this suggests a transformation of hydrocarbons that might have got to the sampling area in May 2011, or as the result of constant leakage of petroleum hydrocarbons from the oil tank farm. Sampling at site 4 in 2013 has revealed petroleum hydrocarbons both in surface (0.09 mg/l) and near-bottom (0.1 mg/l) water. Both monitoring and modeling have demonstrated that hydrobionts on areas adjoining the oil tank farm are far from prospering. Monitoring should be accompanied by express analysis of oxidizing conditions

  19. Composite-Material Tanks with Chemically Resistant Liners

    NASA Technical Reports Server (NTRS)

    DeLay, Thomas K.

    2004-01-01

    Lightweight composite-material tanks with chemically resistant liners have been developed for storage of chemically reactive and/or unstable fluids . especially hydrogen peroxide. These tanks are similar, in some respects, to the ones described in gLightweight Composite-Material Tanks for Cryogenic Liquids h (MFS-31379), NASA Tech Briefs, Vol. 25, No. 1 (January, 2001), page 58; however, the present tanks are fabricated by a different procedure and they do not incorporate insulation that would be needed to prevent boil-off of cryogenic fluids. The manufacture of a tank of this type begins with the fabrication of a reusable multisegmented aluminum mandrel in the shape and size of the desired interior volume. One or more segments of the mandrel can be aluminum bosses that will be incorporated into the tank as end fittings. The mandrel is coated with a mold-release material. The mandrel is then heated to a temperature of about 400 F (approximately equal to 200 C) and coated with a thermoplastic liner material to the desired thickness [typically approxiamtely equal to 15 mils (approximately equal to 0.38 mm)] by thermal spraying. In the thermal-spraying process, the liner material in powder form is sprayed and heated to the melting temperature by a propane torch and the molten particles land on the mandrel. The sprayed liner and mandrel are allowed to cool, then the outer surface of the liner is chemically and/or mechanically etched to enhance bonding of a composite overwrap. The etched liner is wrapped with multiple layers of an epoxy resin reinforced with graphite fibers; the wrapping can be done either by manual application of epoxy-impregnated graphite cloth or by winding of epoxy-impregnated filaments. The entire assembly is heated in an autoclave to cure the epoxy. After the curing process, the multisegmented mandrel is disassembled and removed from inside, leaving the finished tank. If the tank is to be used for storing hydrogen peroxide, then the liner material

  20. Composition and submicron structure of chemically deposited Cu2Se-In2Se3 films

    NASA Astrophysics Data System (ADS)

    Markov, V. F.; Tulenin, S. S.; Maskaeva, L. N.; Kuznetsov, M. V.; Barbin, N. M.

    2012-03-01

    Films of substitutional solid solutions of the Cu2Se-In2Se3 system containing up to 7.5 at. % In have been obtained by chemical deposition from aqueous media. The composition, structure, and morphology of the films have been studied. Data of X-ray diffraction and X-ray photoelectron spectroscopy showed that copper in the solid solution occurs in a single-valence state (Cu+). The deposited layers possess a globular morphology and are nanostructured.

  1. Composite propellant combustion modeling studies

    NASA Technical Reports Server (NTRS)

    Ramohalli, K.

    1977-01-01

    A review is presented of theoretical and experimental studies of composite propellant combustion. The theoretical investigations include a model of the combustion of a nonmetallized ammonium perchlorate (AP) propellant (noting time scales for vapor-phase combustion and the condensed phase) and response functions in pressure-coupled oscillations. The experimental studies are discussed with reference to scale-modeling apparatus, flame standoff distance versus velocity as a function of pressure, and results from T-burner firings of a nonmetallized AP/polysulfide propellant. Research applications including problems with nitramine propellants, the feasibility of stop-restart rockets with salt quench, and combustion problems in large boosters are outlined.

  2. Chemical composition of the haze in Malaysia 2005

    NASA Astrophysics Data System (ADS)

    Norela, S.; Saidah, M. S.; Mahmud, M.

    2013-10-01

    A study of the chemical composition of the haze was conducted in two areas: Klang Valley and Malacca in Peninsular Malaysia, from July to September of 2005. The data is based on the reports of the air quality monitoring for particulate matter (PM10), pH of rainwater, anions (NO3-, SO42-, Cl-), cations (NH4+, Na2+, Ca2+, K+, Mg2+), heavy metals (Fe, Zn, Pb, Mn, Cu, Ni) and a meteorology parameter, the wind speed. The monthly concentrations of PM10 for the Klang Valley ranged from 35.90 to 104.46 μg m-3 whilst in Malacca the concentration ranged from 35.80 to 54.30 μg m-3 which was over the permitted level of 50 μg m-3 for the time period of a month as stipulated by the Department of Environment Malaysia (DOE). The pH of rainwater collected in the Klang Valley ranged from 4.26 ± 0.12 to 5.45 ± 0.58, while in Malacca the pH varied from 4.35 ± 0.20 to 5.43 ± 0.12. The mean concentrations for NO3-, SO42-, Cl-, NH4+, Ca2+, Na2+, K+, Mg2+ for three months in the Klang Valley were 46.40 ± 11.16 μeq L-1, 34.84 ± 9.82 μeq L-1, 12.34 ± 4.13 μeq L-1, 29.28 ± 11.02 μeq L-1, 8.92 ± 0.88 μeq L-1, 8.18 ± 1.00 μeq L-1, 2.08 ± 0.34 μeq L-1, 1.38 ± 0.24 μeq L-1, respectively, whilst in Malacca, the mean concentrations were 24.46 ± 6.99 μeq L-1, 28.4 ± 7.24 μeq L-1, 27.32 ± 7.36 μeq L-1, 30.92 ± 1.26 μeq L-1, 4.10 ± 2.56 μeq L-1, 21.44 ± 7.54 μeq L-1, 3.18 ± 1.82 μeq L-1 and 1.54 ± 1.66 μeq L-1, respectively. These values were lower than the non haze period (January to March and April to June) except for the Cl- ion which recorded the highest anion in Malacca. However, the mean values were similar for the period from October to December. The mean concentrations of metals showed that Cu > Ni, whilst in Malacca, in descending order, were Fe > Zn > Cu > Mn > Pb > Ni.

  3. Chemical Composition and Antioxidant Activities of Broussonetia papyrifera Fruits

    PubMed Central

    Sun, Jie; Liu, Shao-fang; Zhang, Chu-shu; Yu, Li-na; Bi, Jie; Zhu, Feng; Yang, Qing-li

    2012-01-01

    Fruits of Broussonetia papyrifera from South China were analyzed for their total chemical composition, and antioxidant activities in ethanol and aqueous extracts. In the fruit of this plant, the crude protein, crude fat and carbohydrates was 7.08%, 3.72% and 64.73% of dry weight, respectively. The crude protein, crude fat and carbohydrates were 15.71%, 20.51% and 36.09% of dry weight, respectively. Fatty acid and amino acid composition of the fruit were analyzed. Unsaturated fatty acid concentration was 70.6% of the total fatty acids. The percentage of the essential amino acids (EAAs) was 40.60% of the total amino acids. Furthermore, B. papyrifera fruit are rich in many mineral elements and vitamins. Total phenolic content was assessed using the Folin-Ciocalteau assay, whereas antioxidant activities were assessed by measuring the ability of the two extracts to scavenge DPPH radicals, inhibit peroxidation, and chelate ferric ions. Their reducing power was also assessed. Results indicated that the aqueous extract of B. papyrifera was a more potent reducing agent and radical-scavenger than the ethanol extract. GC–MS analysis of the ethanol extract showed the presence of some acid-containing compounds. The changes in total phenolic content and antioxidant capacity in B. papyrifera from four different regions grown under normal conditions were assessed. The antioxidant activity of different extracts was positively associated with their total phenolic content. These results suggest that the fruit of B. papyrifera could be used in dietary supplement preparations, or as a food additive, for nutritional gain, or to prevent oxidation in food products. PMID:22389678

  4. Microbial and chemical composition of liquid-associated bacteria in goats' rumen and fermenters.

    PubMed

    Abecia, L; Soto, E C; Ramos-Morales, E; Molina-Alcaide, E

    2014-10-01

    This study was undertaken to investigate the relationship between chemical composition and microbial profile of rumen liquid-associated bacteria (LAB) in vivo (Murciano-Granadina goats) and in a rumen simulation system (single-flow continuous-culture fermenters). To achieve this aim, analyses of purine bases along with some molecular techniques (quantitative PCR to assess abundance and DGGE to identify biodiversity and bacterial profile) were carried out. A control diet (AHC) based on alfalfa hay (AH) and concentrate (C) in a 1:1 ratio and two experimental diets (AHCBI and AHCBII), in which concentrate was partially replaced with multinutrient blocks, were used. Diets AHCBI and AHCBII included multinutrient blocks differing in the relative amount of two-stage olive cake and the source of protein (sunflower meal vs. fava beans). We aimed to investigate the effect of these blocks on rumen microbiota to evaluate their potential as safe substitutes of cereal-based concentrates. Similar patterns of response to diet were found for chemical composition, microbial abundances and diversity in LAB isolated from goat's rumen and fermenters. Whereas bacterial density (log10 gene copies/g FM: 11.6 and 9.4 for bacteria and methanogens, respectively, in rumen) and diversity indexes (Shannon index: 3.6) were not affected by diet, DGGE analyses showed that bacterial community profile was affected. The cluster analysis suggested differences in bacterial profile between LAB pellets isolated from the rumen of goat and fermenters. A relationship between chemical composition and bacterial community composition in LAB pellets seems to exist. Changes in the former were reflected in the bacterial community profile. Further research is needed to clarify the relationship between chemical and microbial composition of ruminal bacterial pellets with diets of different quality. PMID:24460876

  5. The chemical composition of Galactic ring nebulae around massive stars

    NASA Astrophysics Data System (ADS)

    Esteban, C.; Mesa-Delgado, A.; Morisset, C.; García-Rojas, J.

    2016-08-01

    We present deep spectra of ring nebulae associated with Wolf-Rayet (WR) and O-type stars: NGC 6888, G2.4+1.4, RCW 58, S 308, NGC 7635 and RCW 52. The data have been taken with the 10m Gran Telescopio Canarias and the 6.5m Clay Telescope. We extract spectra of several apertures in some of the objects. We derive C$^{++}$ and O$^{++}$ abundances from faint recombination lines in NGC 6888 and NGC 7635, permitting to derive their C/H and C/O ratios and estimate the abundance discrepancy factor (ADF) of O$^{++}$. The ADFs are larger than the typical ones of normal HII regions but similar to those found in the ionised gas of star-forming dwarf galaxies. We find that chemical abundances are rather homogeneous in the nebulae where we have spectra of several apertures: NGC 6888, NGC 7635 and G2.4+1.4. We obtain very high values of electron temperature in a peripheral zone of NGC 6888, finding that shock excitation can reproduce its spectral properties. We find that all the objects associated with WR stars show N enrichment. Some of them also show He enrichment and O deficiency as well as a lower Ne/O than expected, this may indicate the strong action of the ON and NeNa cycles. We have compared the chemical composition of NGC 6888, G2.4+1.4, RCW 58 and S 308 with the nucleosynthesis predicted by stellar evolution models of massive stars. We find that non-rotational models of stars of initial masses between 25 and 40 solar masses seem to reproduce the observed abundance ratios of most of the nebulae.

  6. The chemical composition of Galactic ring nebulae around massive stars

    NASA Astrophysics Data System (ADS)

    Esteban, C.; Mesa-Delgado, A.; Morisset, C.; García-Rojas, J.

    2016-08-01

    We present deep spectra of ring nebulae associated with Wolf-Rayet (WR) and O-type stars: NGC 6888, G2.4+1.4, RCW 58, S 308, NGC 7635 and RCW 52. The data have been taken with the 10m Gran Telescopio Canarias and the 6.5m Clay Telescope. We extract spectra of several apertures in some of the objects. We derive C2+ and O2+ abundances from faint recombination lines in NGC 6888 and NGC 7635, permitting to derive their C/H and C/O ratios and estimate the abundance discrepancy factor (ADF) of O2+. The ADFs are larger than the typical ones of normal H II regions but similar to those found in the ionized gas of star-forming dwarf galaxies. We find that chemical abundances are rather homogeneous in the nebulae where we have spectra of several apertures: NGC 6888, NGC 7635 and G2.4+1.4. We obtain very high values of electron temperature in a peripheral zone of NGC 6888, finding that shock excitation can reproduce its spectral properties. We find that all the objects associated with WR stars show N enrichment. Some of them also show He enrichment and O deficiency as well as a lower Ne/O than expected, this may indicate the strong action of the ON and NeNa cycles. We have compared the chemical composition of NGC 6888, G2.4+1.4, RCW 58 and S 308 with the nucleosynthesis predicted by stellar evolution models of massive stars. We find that non-rotational models of stars of initial masses between 25 and 40 M⊙ seem to reproduce the observed abundance ratios of most of the nebulae.

  7. Chemical composition of sediments from White Sea, Russian Arctic

    NASA Astrophysics Data System (ADS)

    Gamza, Olga; Shevchenko, Vladimir; Novigatsky, Aleksandr

    2010-05-01

    The White Sea, the only Russian inland sea, is located on the north of outlying districts of the European part of Russia, belongs to Arctic Ocean. Area of water of sea occupies about 90 tousend square kilometers. The sea can be divided into some general parts: neck, funnel, basin and 4 Bays: Dvina Bay, Kandalaksha Bay, Mezen Bay and Onega Bay. The purpose of this work was geochemical mapping of the surface sediments of this area. The main tasks were: compilation data base of element composition of the surface sediments, geochemical mapping of each element, research of the anormal concentration of elements on the surface. To detect the content of chemical elements several methods were used: atomic absorption spectrometry (P.P. Shirshov Institute of Oceanology); neutron activation analysis (Vernadsky Institute of Geochemistry and Analytical Chemistry), total and organic carbon analysis, photometric method to detection Si, Al, P (P.P. Shirshov Institute of Oceanology). Bulk composition is one of the fundamental characteristics of sediments and bottom deposites of modern basins. Coarse-grained sediments with portion of pelitic component <50% is spread on the shallow area (Kandalaksha Bay), in areas with high hydrodynamic activity of near-bottom water. Under the conditions of their low activity, fine-grained facies are common(>80%). Character of elements distribution correlates with facial distribution of sediments from White Sea. According to litologic description, bottom surface of Dvina Bay is practically everywhere covered by layer of fine-grained sand. In the border area between Dvina Bay and White Sea basin on terraced subwater slope aleurite politic silts are abundant. They tend to exhange down the slope to clay silts. In Onega Bay fractions of non-deposition are observed. They are characterized by wide spread of thin blanket poorgraded sediments, which are likely to be relic. Relief of Kandalakscha Bay bottom is presented as alternation of abyssal fosses (near

  8. Wet chemically grown composite thin film for room temperature LPG sensor

    NASA Astrophysics Data System (ADS)

    Birajadar, Ravikiran; Desale, Dipalee; Shaikh, Shaheed; Mahajan, Sandip; Upadhye, Deepak; Ghule, Anil; Sharma, Ramphal

    2014-04-01

    We have synthesized thin film of zinc oxide-polyaniline (ZnO/PANI) composite using a simple wet chemical approach. As-synthesized ZnO/PANI composite thin film studied using different characterization techniques. The optical study reveals the penetration and interaction of PANI molecules with ZnO thin film. Prominent blue shift in UV-vis due to interaction between ZnO and PANI indicate presence of zinc oxide in polyaniline matrix. It is observed that ZnO thin film is not sensitive to LPG (liquefied petroleum gas) at room temperature. On the other hand ZnO/PANI composite thin film shows good response and recovery behaviors at room temperature.

  9. Chemical composition of sedimentary rocks in California and Hawaii

    USGS Publications Warehouse

    Hill, Thelma P., (compiler)

    1981-01-01

    A compilation of published chemical analyses of sedimentary rocks of the United States was undertaken by the U.S. Geological Survey in 1952 to make available scattered data that are needed for a wide range of economic and scientific uses. About 20,000-25,000 chemical analyses of sedimentary rocks in the United States have been published. This report brings together 2,312 of these analyses from California and Hawaii. The samples are arranged by general lithologic characteristics and locality. Indexes of stratigraphy, rock name, commercial uses, and minor elements are provided. The sedimentary rocks are classified into groups and into categories according to the chemical analyses. The groups (A through F2) are defined by a system similar to that proposed by Brian Mason in 1952, in which the main parameters are the three major components of sedimentary rocks: (1) uncombined silica, (2) clay (R203 ? 3Si02 ? nH20), and (3) calcium-magnesium carbonate. The categories are based on the degree of admixture of these three major components with other components, such as sulfate, phos- phate, and iron oxide. Common-rock, mixed-rock, and special-rock categories apply to rocks consisting of 85 percent or more, 50-84 percent, and less than 49 percent, respectively, of the three major components combined. Maps show distribution of sample localities by States; triangular diagrams show the lithologic characteristics and classification groups. Cumulative-frequency curves of each constituent in each classification group of the common-rock and mixed-rock categories are also included. The numerous analyses may not adequately represent the geochemical nature of the rock types and formations of the region because of sampling bias. Maps showing distribution of sample localities indicate that many of the localities are in areas where, for economic or other reasons, special problems attracted interest. Most of the analyzed rocks tended to be fairly simple in composition - mainly mixtures of

  10. Chemical composition and antigenotoxic properties of Lippia alba essential oils

    PubMed Central

    López, Molkary Andrea; Stashenko, Elena E.; Fuentes, Jorge Luis

    2011-01-01

    The present work evaluated the chemical composition and the DNA protective effect of the essential oils (EOs) from Lippia alba against bleomycin-induced genotoxicity. EO constituents were determined by Gas Chromatography/Mass Spectrometric (GC-MS) analysis. The major compounds encountered being citral (33% geranial and 25% neral), geraniol (7%) and trans-β-caryophyllene (7%) for L. alba specimen COL512077, and carvone (38%), limonene (33%) and bicyclosesquiphellandrene (8%) for the other, COL512078. The genotoxicity and antigenotoxicity of EO and the compounds citral, carvone and limonene, were assayed using the SOS Chromotest in Escherichia coli. The EOs were not genotoxic in the SOS chromotest, but one of the major compound (limonene) showed genotoxicity at doses between 97 and 1549 mM. Both EOs protected bacterial cells against bleomycin-induced genotoxicity. Antigenotoxicity in the two L. alba chemotypes was related to the major compounds, citral and carvone, respectively. The results were discussed in relation to the chemopreventive potential of L. alba EOs and its major compounds. PMID:21931523

  11. Chemical vapor infiltration of TiB[sub 2] composites

    SciTech Connect

    Besmann, T.M.; Miller, J.H.; Cooley, K.C.; Lowden, R.A. ); Starr, T.L. )

    1993-01-01

    Efficiency of the Hall-Heroult electrolytic reduction of aluminum can be substantially improved by the use of a TiB[sub 2] cathode surface. The use of TiB[sub 2], however, has been hampered by the brittle nature of the material and the grain-boundary attack of sintering-aid phases by molten aluminum. In the current work, TiB[sub 2] is toughened through the use of reinforcing fibers, with chemical vapor infiltration (CVI) used to produce pure TiB[sub 2]. It has been observed, however, that the formation of TiB[sub 2] from chloride precursors at fabrication temperatures below 900 to 1000[degrees]C alloys the retention of destructive levels of chlorine in the material. At higher fabrication temperatures and under appropriate infiltration conditions, as determined from the use of a process model, a TIB[sub 2]THORNEL P-25 fiber composite, 45 mm in diam and 6 mm thick, has been fabricated in 20 h. The material has been demonstrated to be stable in molten aluminum in short-duration tests.

  12. Chemical vapor infiltration of TiB{sub 2} composites

    SciTech Connect

    Besmann, T.M.; Miller, J.H.; Cooley, K.C.; Lowden, R.A.; Starr, T.L.

    1993-01-01

    Efficiency of the Hall-Heroult electrolytic reduction of aluminum can be substantially improved by the use of a TiB{sub 2} cathode surface. The use of TiB{sub 2}, however, has been hampered by the brittle nature of the material and the grain-boundary attack of sintering-aid phases by molten aluminum. In the current work, TiB{sub 2} is toughened through the use of reinforcing fibers, with chemical vapor infiltration (CVI) used to produce pure TiB{sub 2}. It has been observed, however, that the formation of TiB{sub 2} from chloride precursors at fabrication temperatures below 900 to 1000{degrees}C alloys the retention of destructive levels of chlorine in the material. At higher fabrication temperatures and under appropriate infiltration conditions, as determined from the use of a process model, a TIB{sub 2}THORNEL P-25 fiber composite, 45 mm in diam and 6 mm thick, has been fabricated in 20 h. The material has been demonstrated to be stable in molten aluminum in short-duration tests.

  13. Brazilian kefir: structure, microbial communities and chemical composition

    PubMed Central

    Magalhães, Karina Teixeira; de Melo Pereira, Gilberto Vinícius; Campos, Cássia Roberta; Dragone, Giuliano; Schwan, Rosane Freitas

    2011-01-01

    Microbial ecology and chemical composition of Brazilian kefir beverage was performed. The microorganisms associated with Brazilian kefir were investigated using a combination of phenotypic and genotypic methods. A total of 359 microbial isolates were identified. Lactic acid bacteria (60.5%) were the major isolated group identified, followed by yeasts (30.6%) and acetic acid bacteria (8.9%). Lactobacillus paracasei (89 isolates), Lactobacillus parabuchneri (41 isolates), Lactobacillus casei (32 isolates), Lactobacillus kefiri (31 isolates), Lactococcus lactis (24 isolates), Acetobacter lovaniensis (32 isolates), Kluyveromyces lactis (31 isolates), Kazachstania aerobia (23 isolates), Saccharomyces cerevisiae (41 isolates) and Lachancea meyersii (15 isolates) were the microbial species isolated. Scanning electron microscopy showed that the microbiota was dominated by bacilli (short and curved long) cells growing in close association with lemon-shaped yeasts cells. During the 24 h of fermentation, the protein content increased, while lactose and fat content decreased. The concentration of lactic acid ranged from 1.4 to 17.4 mg/ml, and that of acetic acid increased from 2.1 to 2.73 mg/ml. The production of ethanol was limited, reaching a final mean value of 0.5 mg/ml. PMID:24031681

  14. Chemical composition of biomass from tall perennial tropical grasses

    SciTech Connect

    Prine, G.M.; Stricker, J.A.; Anderson, D.L.

    1995-11-01

    The tall perennial tropical grasses, elephantgrass (Pennisetum purpureum Schum.), sugarcane and energycane (Saccharum sp.) and erianthus (Erianthus arundenaceum (Retz) Jesw.) have given very high oven dry biomass yields in Florida and the warm Lower South USA. No good complete analyses of the chemical composition of these grasses for planning potential energy use was available. We sampled treatments of several tall grass demonstrations and experiments containing high-biomass yielding genotypes of the above tall grass crops at several locations in Florida over the two growing seasons, 1992 and 1993. These samples were analyzed for crude protein, NDF, ADF, cellulose, hemicellulose, lignin, and IVDMD or IVOMD. The analysis for the above constituents are reported, along with biomass yields where available, for the tall grass accessions in the various demonstrations and experiments. Particular attention is given to values obtained from the high-yielding tall grasses grown on phosphatic clays in Polk County, FL, the area targeted by a NREL grant to help commercialize bioenergy use from these crops.

  15. Tea tree oil: contact allergy and chemical composition.

    PubMed

    de Groot, Anton C; Schmidt, Erich

    2016-09-01

    In this article, contact allergy to, and the chemical composition of, tea tree oil (TTO) are reviewed. This essential oil is a popular remedy for many skin diseases, and may be used as neat oil or be present in cosmetics, topical pharmaceuticals and household products. Of all essential oils, TTO has caused most (published) allergic reactions since the first cases were reported in 1991. In routine testing, prevalences of positive patch test reactions have ranged from 0.1% to 3.5%. Nearly 100 allergic patients have been described in case reports and case series. The major constituents of commercial TTO are terpinen-4-ol, γ-terpinene, 1,8-cineole, α-terpinene, α-terpineol, p-cymene, and α-pinene. Fresh TTO is a weak to moderate sensitizer, but oxidation increases its allergenic potency. The major sensitizers appear to be ascaridole, terpinolene, α-terpinene, 1,2,4-trihydroxymenthane, α-phellandrene, and limonene. The clinical picture of allergic contact dermatitis caused by TTO depends on the products used. Most reactions are caused by the application of pure oil; cosmetics are the culprits in a minority of cases. Patch testing may be performed with 5% oxidized TTO. Co-reactivity to turpentine oil is frequent, and there is an overrepresentation of reactions to fragrance mix I, Myroxylon pereirae, colophonium, and other essential oils. PMID:27173437

  16. Broadening Our Portfolio in the Genetic Improvement of Maize Chemical Composition.

    PubMed

    Wen, Weiwei; Brotman, Yariv; Willmitzer, Lothar; Yan, Jianbing; Fernie, Alisdair R

    2016-08-01

    The adoption of recombinant inbred line and introgression line populations, as well as the study of association mapping panels, has greatly accelerated our ability to identify the genes underlying plant phenotypic variance. In tandem, the development of metabolomics approaches has greatly enhanced our ability to comprehensively define cellular chemical composition. As a consequence, breeding for chemical composition is being extended beyond our traditional targets of oil and protein to include components such as essential amino acids, vitamins, and antioxidant secondary metabolites with considerable purported consequences for human health. Here, we review the above-mentioned developments paying particular attention to the genetic architecture of metabolic traits as well as updating the perspective for utilizing metabolomics in maize improvement. PMID:27235112

  17. A Raman model for determining the chemical composition of silicate glasses

    NASA Astrophysics Data System (ADS)

    Di Genova, Danilo; Morgavi, Daniele; Hess, Kai-Uwe; Neuville, Daniel R.; Perugini, Diego; Dingwell, Donald B.

    2015-04-01

    Raman spectroscopy is a spectroscopic technique based on inelastic scattering of monochromatic light which provides information about molecular vibrations of the investigated sample. Since the discovery of the Raman Effect (1928) in scattered light from liquids, the Raman investigation has been extended to a large number of substances at different pressure-temperature conditions. Recently, the Raman instrument setup has rapidly grown thanks to the progress in development of lasers, charge coupled devices and confocal systems (see Neuville et al. 2014 for a review). Here we present the first Raman model able to determine the chemical composition of silicate glasses. In this study we combine chemical analysis from magma mixing experiments between remelted basaltic and rhyolitic melts, with a high spatial resolution Raman spectroscopy investigation; we focus on tracking the evolution of the Raman spectrum with chemical composition of silicate glasses. The mixing process is driven by a recently-developed apparatus that generates chaotic streamlines in the melts (Morgavi et al., 2013), mimicking the development of magma mixing in nature. From these experiments we obtained a glassy filament with a chemical composition ranging from a basalt to a rhyolite. Raman and microprobe measurements have been performed on a filament of ~1000 μm diameter, every 2.5-20 μm. The evolution of the acquired Raman spectra with the measured chemical composition has been parametrized by combining both the Raman spectra of the basaltic and rhyolitic end-members. Using the developed Raman model we have been able to determine the chemical composition (mol% of SiO2, Al2O3, FeO, CaO, MgO, Na2O and K2O) of the investigated filament. Additionally, the proposed Raman model has been successfully tested using external remelted natural samples; reference glasses (Jochum et al., 2000), a remelted basalt, andesite from Etna and Montserrat respectively. Finally, as the Raman spectrum depends on the

  18. Chemical composition and lipoxygenase activity in soybeans (Glycine max L. Merr.) submitted to gamma irradiation

    NASA Astrophysics Data System (ADS)

    Barros, Érica Amanda de; Broetto, Fernando; Bressan, Dayanne F.; Sartori, Maria M. P.; Costa, Vladimir E.

    2014-05-01

    Soybeans are an important food due to their functional and nutritional characteristics. However, consumption by western populations is limited by the astringent taste of soybeans and their derivatives which results from the action of lipoxygenase, an enzyme activated during product processing. The aim of this study was to evaluate the effect of gamma irradiation on the chemical composition and specific activity of lipoxygenase in different soybean cultivars. Soybeans were stored in plastic bags and irradiated with doses of 2.5, 5 and 10 kGy. The chemical composition (moisture, protein, lipids, ashes, crude fiber, and carbohydrates) and lipoxygenase specific activity were determined for each sample. Gamma irradiation induced a small increase of protein and lipid content in some soybean cultivars, which did not exceed the highest content of 5% and 26%, respectively, when compared to control. Lipoxygenase specific activity decreased in the three cultivars with increasing gamma irradiation dose. In conclusion, the gamma irradiation doses used are suitable to inactivate part of lipoxygenase while not causing expressive changes in the chemical composition of the cultivars studied.

  19. Essential-oil composition and chemical variability of Senecio vulgaris L. from Corsica.

    PubMed

    Andreani, Stéphane; Paolini, Julien; Costa, Jean; Muselli, Alain

    2015-05-01

    The chemical composition of the essential oils isolated from the aerial parts of Senecio vulgaris plants collected in 30 Corsican localities was characterized using GC-FID and GC/MS analyses. Altogether, 54 components, which accounted for 95.2% of the total oil composition, were identified in the 30 essential-oil samples. The main compounds were α-humulene (1; 57.3%), (E)-β-caryophyllene (2; 5.6%), terpinolene (3; 5.3%), ar-curcumene (4; 4.3%), and geranyl linalool (5; 3.4%). The chemical composition of the essential oils obtained from separate organs and during the complete vegetative cycle of the plants were also studied, to gain more knowledge about the plant ecology. The production of monoterpene hydrocarbons, especially terpinolene, seems to be implicated in the plant-flowering process and, indirectly, in the dispersal of this weed species. Comparison of the present results with the literature highlighted the originality of the Corsican S. vulgaris essential oils and indicated that α-humulene might be used as taxonomical marker for the future classification of the Senecio genus. A study of the chemical variability of the 30 S. vulgaris essential oils using statistical analysis allowed the discrimination of two main clusters according to the soil nature of the sample locations. These results confirmed that there is a relation between the soil nature, the chemical composition of the essential oils, and morphological plant characteristics. Moreover, they are of interest for commercial producers of essential oil in selecting the most appropriate plants. PMID:26010664

  20. Crystal Structure and Chemical Composition of a Presolar Silicate from the Queen Elizabeth Range 99177 Meteorite

    NASA Technical Reports Server (NTRS)

    Nguyen, A. N.; Keller, L. P.; Rahman, Z.; Messenger, S.

    2013-01-01

    Mineral characterization of presolar silicate grains, the most abundant stardust phase, has provided valuable information about the formation conditions in circumstellar environments and in super-nova (SN) outflows. Spectroscopic observations of dust around evolved stars suggest a majority of amor-phous, Mg-rich olivine grains, but crystalline silicates, most of which are pyroxene, have also been observed [1]. The chemical compositions of hundreds of presolar silicates have been determined by Auger spectroscopy and reveal high Fe contents and nonstoichiometric compositions intermediate to olivine and pyroxene [2-6]. The unexpectedly high Fe contents can partly be attributed to secondary alteration on the meteorite parent bodies, as some grains have Fe isotopic anomalies from their parent stellar source [7]. Only about 35 presolar silicates have been studied for their mineral structures and chemical compositions by transmission electron microscopy (TEM). These grains display a wide range of compositions and structures, including crystalline forsterite, crystalline pyroxene, nanocrystalline grains, and a majority of amorphous nonstoichiometric grains. Most of these grains were identified in the primitive Acfer 094 meteorite. Presolar silicates from this meteorite show a wide range of Fe-contents, suggestive of secondary processing on the meteorite parent body. The CR chondrite QUE 99177 has not suffered as much alteration [8] and displays the highest presolar silicate abundance to date among carbonaceous chondrites [3, 6]. However, no mineralogical studies of presolar silicates from this meteorite have been performed. Here we examine the mineralogy of a presolar silicate from QUE 99177.

  1. Modeling the Chemical Composition of the Fluid that Formed the ALH84001 Carbonates

    NASA Astrophysics Data System (ADS)

    Niles, P. B.; Leshin, L.

    2005-12-01

    The character of aqueous systems on Mars can provide us with important information regarding the history of water and the possibilities for the presence of life on Mars. Evidence of these aqueous systems has been preserved in carbonates found in the martian meteorite ALH84001 whose crystallization age of 4.5 Ga indicates that it has experienced almost all of Mars' history. In addition, the 3.9 Ga age of the carbonates places their formation at a critical time that has been argued to have been `warm and wet' by many studies. The carbonates in the ALH84001 meteorite provide the best opportunity, among all of the martian meteorites, to understand the details of an ancient aqueous system on Mars. Their unique chemical, isotopic and mineralogical composition provides the opportunity to make conclusive statements about the geological conditions in which they formed including the temperature, association with the atmosphere, chemistry of the fluids, and the presence or absence of life. This study uses an empirical model to understand the attributes of the formation fluid based on the unique chemical compositions of the carbonates. This requires the assumption that the ALH84001 carbonate globules formed from a single fluid whose chemical composition changed due to the precipitation of carbonates more calcium rich than the overall fluid composition. The model consists of a simple stepwise stoichiometric calculation of the precipitation of the ALH84001 carbonates from a hypothetical solution. From extensive measurements of the chemical composition of the globules and their abundance in the rock, one can calculate the total amount of magnesium, calcium, and iron removed from the formation fluid as the carbonates precipitated. The unique zoned nature of the ALH84001 carbonates provides a real constraint on the possible fluid compositions consistent with their precipitation. Our results indicate that the fluid that formed the ALH84001 carbonates had an Mg/Ca ratio that was

  2. Chemical composition analysis of simulated waste glass T10-G-16A

    SciTech Connect

    Fox, K. M.

    2015-08-01

    In this report, SRNL provides chemical composition analyses of a simulated LAW glass designated T10-G-16A.The measured chemical composition data are reported and compared with the targeted values for each component. No issues were identified in reviewing the analytical data.

  3. Effects of reversible chemical reaction on Li diffusion and stresses in spherical composition-gradient electrodes

    SciTech Connect

    Li, Yong; Zhang, Kai; Zheng, Bailin Zhang, Xiaoqian; Wang, Qi

    2015-06-28

    Composition-gradient electrode materials have been proven to be one of the most promising materials in lithium-ion battery. To study the mechanism of mechanical degradation in spherical composition-gradient electrodes, the finite deformation theory and reversible chemical theory are adopted. In homogeneous electrodes, reversible electrochemical reaction may increase the magnitudes of stresses. However, reversible electrochemical reaction has different influences on stresses in composition-gradient electrodes, resulting from three main inhomogeneous factors—forward reaction rate, backward reaction rate, and reaction partial molar volume. The decreasing transition form of forward reaction rate, increasing transition form of backward reaction rate, and increasing transition form of reaction partial molar volume can reduce the magnitudes of stresses. As a result, capacity fading and mechanical degradation are reduced by taking advantage of the effects of inhomogeneous factors.

  4. Evaluation of the performance of four chemical transport models in predicting the aerosol chemical composition in Europe in 2005

    NASA Astrophysics Data System (ADS)

    Prank, Marje; Sofiev, Mikhail; Tsyro, Svetlana; Hendriks, Carlijn; Semeena, Valiyaveetil; Vazhappilly Francis, Xavier; Butler, Tim; Denier van der Gon, Hugo; Friedrich, Rainer; Hendricks, Johannes; Kong, Xin; Lawrence, Mark; Righi, Mattia; Samaras, Zissis; Sausen, Robert; Kukkonen, Jaakko; Sokhi, Ranjeet

    2016-05-01

    Four regional chemistry transport models were applied to simulate the concentration and composition of particulate matter (PM) in Europe for 2005 with horizontal resolution ~ 20 km. The modelled concentrations were compared with the measurements of PM chemical composition by the European Monitoring and Evaluation Programme (EMEP) monitoring network. All models systematically underestimated PM10 and PM2.5 by 10-60 %, depending on the model and the season of the year, when the calculated dry PM mass was compared with the measurements. The average water content at laboratory conditions was estimated between 5 and 20 % for PM2.5 and between 10 and 25 % for PM10. For majority of the PM chemical components, the relative underestimation was smaller than it was for total PM, exceptions being the carbonaceous particles and mineral dust. Some species, such as sea salt and NO3-, were overpredicted by the models. There were notable differences between the models' predictions of the seasonal variations of PM, mainly attributable to different treatments or omission of some source categories and aerosol processes. Benzo(a)pyrene concentrations were overestimated by all the models over the whole year. The study stresses the importance of improving the models' skill in simulating mineral dust and carbonaceous compounds, necessity for high-quality emissions from wildland fires, as well as the need for an explicit consideration of aerosol water content in model-measurement comparison.

  5. Global Chemical Composition of Ambient Fine Particulate Matter for Exposure Assessment

    SciTech Connect

    Philip, Sajeev; Martin, Randall V.; van Donkelaar, Aaron; Lo, Jason Wai-Ho; Wang, Yuxuan; Chen, Dan; Zhang, Lin; Kasibhatla, Prasad S.; Wang, Siwen; Zhang, Qiang; Lu, Zifeng; Streets, David G.; Bittman, Shabtai; Macdonald, Douglas J.

    2014-10-24

    Epidemiologic and health impact studies are inhibited by the paucity of global, long-term measurements of the chemical composition of fine particulate matter. We inferred PM2.5 chemical composition at 0.1° × 0.1° spatial resolution for 2004–2008 by combining aerosol optical depth retrieved from the MODIS and MISR satellite instruments, with coincident profile and composition information from the GEOS-Chem global chemical transport model. Evaluation of the satellite-model PM2.5 composition data set with North American in situ measurements indicated significant spatial agreement for secondary inorganic aerosol, particulate organic mass, black carbon, mineral dust, and sea salt. We found that global population-weighted PM2.5 concentrations were dominated by particulate organic mass (11.9 ± 7.3 μg/m3), secondary inorganic aerosol (11.1 ± 5.0 μg/m3), and mineral dust (11.1 ± 7.9 μg/m3). Secondary inorganic PM2.5 concentrations exceeded 30 μg/m3 over East China. Sensitivity simulations suggested that population-weighted ambient PM2.5 from biofuel burning (11 μg/m3) could be almost as large as from fossil fuel combustion sources (17 μg/m3). In conclusion, these estimates offer information about global population exposure to the chemical components and sources of PM2.5.

  6. Chemical composition and antibacterial activity of Pinus halepensis Miller growing in West Northern of Algeria

    PubMed Central

    Fekih, Nadia; Allali, Hocine; Merghache, Salima; Chaïb, Faïza; Merghache, Djamila; El Amine, Mohamed; Djabou, Nassim; Muselli, Alain; Tabti, Boufeldja; Costa, Jean

    2014-01-01

    Objective To find new bioactive natural products, the chemical composition and to sudy the antibacterial activity of essential oil components extracted from the aerial parts of the Algerian aromatic plant Pinus halepensis Miller (P. halepensis) (needles, twigs and buds). Methods The essential oil used in this study was isolated by hydrodistillation using a Clevenger-type apparatus according to the European Pharmacopoeia. The chemical composition was investigated using GC-retention indices (RI) and GC-MS. Results Forty-nine compounds, representing 97.9% of the total collective oil, were identified. Essential oil was dominated by hydrocarbon compounds (80.6%) especially monoterpenes (65.5%). The major compounds from ten oils stations were: myrcene (15.2%-32.0%), α-pinene (12.2%-24.5%), E-β-caryophyllene (7.0%-17.1%), terpinolene (1.8%-13.3%), 2-phenyl ethyl isovalerate (4.8%-10.9%), terpinene-4-ol (1.0%-8.2 %) and sabinene (1.5%-6.3%). The intra-species variations of the chemical compositions of P. halepensis aerial parts essential oils from ten Algerian sample locations were investigated using statistical analysis. Essential oil samples were clustered in 2 groups by hierarchical cluster analysis, according to their chemical composition. The essential oil revealed an interesting antimicrobial effect against Lysteria monocytogenes, Enterococcus faecalis, Pseudomonas aeruginosa, Acinetobacter baumanii, Citrobacter freundii and Klebsiella pneumoniae. Conclusions These results suggest that the essential oil from P. halepensis may be a new potential source as natural antimicrobial applied in pharmaceutical and food industries.

  7. Relationship between the surface chemical composition of implants and contact with the substrate.

    PubMed

    Lima da Costa Valente, Mariana; Shimano, Antonio Carlos; Marcantonio Junior, Elcio; Reis, Andréa Candido Dos

    2015-02-01

    The purpose of the study was to use scanning electron microscopy and energy dispersive x-ray spectrometry to assess possible morphologic and chemical changes after performing double-insertion and pullout tests of implants of different shapes and surface treatments. Four different types of implants were used-cylindrical machined-surface implants, cylindrical double-surface-treated porous implants, cylindrical surface-treated porous implants, and tapered surface-treated porous implants-representing a total of 32 screws. The implants were inserted into synthetic bone femurs, totaling 8 samples, before performing each insertion with standardized torque. After each pullout the implants were analyzed by scanning electron microscopy and energy dispersive x-ray spectrometry using a universal testing machine and magnified 35 times. No structural changes were detected on morphological surface characterization, only substrate accumulation. As for composition, there were concentration differences in the titanium, oxygen, and carbon elements. Implants with surface acid treatment undergo greater superficial changes in chemical composition than machined implants, that is, the greater the contact area of the implant with the substrate, the greater the oxide layer change. In addition, prior manipulation can alter the chemical composition of implants, typically to a greater degree in surface-treated implants. PMID:23339297

  8. Application of infrared spectroscopy for assessing quality (chemical composition) of peatland plants, litter and soil

    NASA Astrophysics Data System (ADS)

    Straková, Petra; Laiho, Raija

    2016-04-01

    In this presentation, we assess the merits of using Fourier transform infrared (FTIR) spectra to estimate the organic matter composition in different plant biomass and peat soil samples. Infrared spectroscopy has a great potential in large-scale peatland studies that require low cost and high throughput techniques, as it gives a unique "chemical overview" of a sample, with all the chemical compounds present contributing to the spectrum produced. Our extensive sample sets include soil samples ranging from boreal to tropical peatlands, including sites under different environmental and/or land-use changes; above- and below-ground biomass of different peatland plant species; plant root mixtures. We mainly use FTIR to estimate (1) chemical composition of the samples (e.g., total C and N, C:N ratio, holocellulose, lignin and ash content), (2) proportion of each plant species in root mixtures, and (3) respiration of surface peat. The satisfactory results of our predictive models suggest that this experimental approach can, for example, be used as a screening tool in the evaluation of organic matter composition in peatlands during monitoring of their degradation and/or restoration success.

  9. Chemical composition of primary cosmic rays with IceCube

    NASA Astrophysics Data System (ADS)

    Xu, Chen

    Ground detector arrays have been used to measure high energy cosmic rays for decades to overcome their very low rate. IceCube is a special case with its 3D deployment and unique location---the South Pole. Although all 86 strings and 81 stations of IceCube were completed in 2011, IceCube began to take data in 2006, after the completion of the first 9 strings. In this thesis, experimental data taken in 2009 with 59 strings are used for composition analysis albeit some techniques are illustrated with the 40-string data. Simulation is essential in the composition work. Simulated data must be compared against the experimental data to find the right mix of cosmic ray components. However, because of limited computing resources and complexities of cosmic rays, the simulation in IceCube is well behind the experiment. The lower and upper bounds of primary energy in simulation for events that go through IceTop and the deep arrays of IceCube are 1014 eV and 1017 eV. However, since IceCube has a threshold energy about several hundred TeV, and an upper limit of 10 18 eV, the full energy range cannot be explored in this thesis. The approach taken to the composition problem in this thesis is a 2D Bayesian unfolding. It takes account of the measured IceTop and InIce energy spectrum and outputs the expected primary energy spectrum of different mass components. Studies of the uncertainties in the results are not complete because of limited simulation and understanding of the new detector and South Pole environment.

  10. Anisotropy vs chemical composition at ultra-high energies

    SciTech Connect

    Lemoine, Martin; Waxman, Eli E-mail: eli.waxman@weizmann.ac.il

    2009-11-01

    This paper proposes and discusses a test of the chemical composition of ultra-high energy cosmic rays that relies on the anisotropy patterns measured as a function of energy. In particular, we show that if one records an anisotropy signal produced by heavy nuclei of charge Z above an energy E{sub thr}, one should record an even stronger (possibly much stronger) anisotropy at energies >E{sub thr}/Z due to the proton component that is expected to be associated with the sources of the heavy nuclei. This conclusion remains robust with respect to the parameters characterizing the sources and it does not depend at all on the modelling of astrophysical magnetic fields. As a concrete example, we apply this test to the most recent data of the Pierre Auger Observatory. Assuming that the anisotropy reported above 55 EeV is not a statistical accident, and that no significant anisotropy has been observed at energies ∼<10 EeV, we show that the apparent clustering toward Cen A cannot be attributed to heavy nuclei. Similar conclusions are drawn regarding the apparent excess correlation with nearby active galactic nuclei. We then discuss a robust lower bound to the magnetic luminosity that a source must possess in order to be able to accelerate particles of charge Z up to 100 EeV, L{sub B} ∼> 10{sup 45} Z{sup −2} erg/s. Using this bound in conjunction with the above conclusions, we argue that the current PAO data does not support the model of cosmic ray origin in active radio-quiet or even radio-loud galaxies. Finally, we demonstrate that the apparent clustering in the direction of Cen A can be explained by the contribution of the last few gamma-ray bursts or magnetars in the host galaxy thanks to the scattering of the cosmic rays on the magnetized lobes.

  11. Phylogenetic or environmental control on the organo-chemical composition of Sphagnum mosses?

    NASA Astrophysics Data System (ADS)

    Limpens, Juul; Nilsson, Mats

    2014-05-01

    explained a significant part of the variation. We conclude that organo-chemical composition a function of both environment and phylogeny, but that the relative importance of these drivers depends on the type of compounds studied. Environment mainly drives the mineral element composition and a large part of the non-carbohydrate polymer composition, whereas phylogeny drives the variation in carbohydrate polymers. In our presentation we discuss the implications of our findings for carbon accumulation in peatlands and decomposition processes in general.

  12. Chem I Supplement: The Chemical Composition of the Cell.

    ERIC Educational Resources Information Center

    Holum, John R.

    1984-01-01

    Describes the principal chemical substances which occur in most cells. These chemicals are the lipids, carbohydrates, proteins, and nucleic acids. Suggests that the structures of these substances be taught first since structure determines function. (JN)

  13. Chemical Composition and Antioxidant Capacity of Brazilian Passiflora Seed Oils.

    PubMed

    de Santana, Fernanda Carvalho; Shinagawa, Fernanda Branco; Araujo, Elias da Silva; Costa, Ana Maria; Mancini-Filho, Jorge

    2015-12-01

    The seed oils of different varieties of 4 Passiflora species cultivated in Brazil were analyzed and compared regarding their physicochemical parameters, fatty acid composition and the presence of minor components, such as phytosterols, tocopherols, total carotenoids, and phenolic compounds. The antioxidant capacities of the oil extracts were determined using the 2,2'azinobis [3-ethylbenzothiazoline-6-sulfonic acid] and oxygen radical absorbance capacity methods. The results revealed that all studied Passiflora seed oils possessed similar physicochemical characteristics, except for color, and predominantly contained polyunsaturated fatty acids with a high percentage of linolenic acid (68.75% to 71.54%). Other than the total phytosterol content, the extracted oil from Passiflora setacea BRS Pérola do Cerrado seeds had higher quantities (% times higher than the average of all samples), of carotenoids (44%), phenolic compounds (282%) and vitamin E (215%, 56%, 398%, and 100% for the α-tocopherol, β-tocopherol, γ-tocopherol, and δ-tocopherol isomers, respectively). The methanolic extracts from Passiflora setacea BRS Pérola do Cerrado seed oil also showed higher antioxidant activity, which was positively correlated with the total phenolic, δ-tocopherol, and vitamin E contents. For the first time, these results indicate that Passiflora species have strong potential regarding the use of their seeds for oil extraction. Due to their interesting composition, the seed oils may be used as a raw material in manufacturing industries in addition to other widely used vegetable oils. PMID:26512548

  14. Laboratory analogues simulating Titan's atmospheric aerosols: Compared chemical compositions of grains and thin films

    NASA Astrophysics Data System (ADS)

    Carrasco, Nathalie; Jomard, François; Vigneron, Jackie; Etcheberry, Arnaud; Cernogora, Guy

    2016-09-01

    Two sorts of solid organic samples can be produced in laboratory experiments simulating Titan's atmospheric reactivity: grains in the volume and thin films on the reactor walls. We expect that grains are more representative of Titan's atmospheric aerosols, but films are used to provide optical indices for radiative models of Titan's atmosphere. The aim of the present study is to address if these two sorts of analogues are chemically equivalent or not, when produced in the same N2-CH4 plasma discharge. The chemical compositions of both these materials are measured by using elemental analysis, XPS analysis and Secondary Ion Mass Spectrometry. The main parameter probed is the CH4/N2 ratio to explore various possible chemical regimes. We find that films are homogeneous but significantly less rich in nitrogen and hydrogen than grains produced in the same experimental conditions. This surprising difference in their chemical compositions could be explained by the efficient etching occurring on the films, which stay in the discharge during the whole plasma duration, whereas the grains are ejected after a few minutes. The higher nitrogen content in the grains possibly involves a higher optical absorption than the one measured on the films, with a possible impact on Titan's radiative models.

  15. Gamma irradiation effect on the chemical composition and the antioxidant activity of Ipomoea batatas L

    SciTech Connect

    Tahir, D. Halide, H. Kurniawan, D.; Wahab, A. W.

    2014-09-25

    The chemical composition and antioxidant activity of Ipomoea batatas L. (sweet potato) were studied by x-ray fluorescence (XRF) spectroscopy, Fourier transform infrared spectroscopy, and by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity. The irradiation treatment was performed by using Cs-137 as a gamma sources in experimental equipment. Treatment by irradiation emerges as a possible conservation technique that has been tested successfully in several food products. The amount of chemical composition was changed and resulting new chemical for absorbed dose 40 mSv. Interestingly, it was found that gamma irradiation significantly increased the antioxidant activity, as measured by DPPH radical scavenging capacity. The antioxidant activity of Ipomoea batatas L. extract was dramatically increased in the non-irradiated sample to the sample irradiated at 40 mSv. These results indicate that gamma irradiation of Ipomoea batatas L. extract can enhance its antioxidant activity through the formation of a new chemical compound. Based on these results, increased antioxidant activity of Ipomoea batatas L. extracts by gamma rays can be applied to various industries, especially cosmetics, foodstuffs, and pharmaceuticals.

  16. Gamma irradiation effect on the chemical composition and the antioxidant activity of Ipomoea batatas L.

    NASA Astrophysics Data System (ADS)

    Tahir, D.; Halide, H.; Wahab, A. W.; Kurniawan, D.

    2014-09-01

    The chemical composition and antioxidant activity of Ipomoea batatas L. (sweet potato) were studied by x-ray fluorescence (XRF) spectroscopy, Fourier transform infrared spectroscopy, and by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity. The irradiation treatment was performed by using Cs-137 as a gamma sources in experimental equipment. Treatment by irradiation emerges as a possible conservation technique that has been tested successfully in several food products. The amount of chemical composition was changed and resulting new chemical for absorbed dose 40 mSv. Interestingly, it was found that gamma irradiation significantly increased the antioxidant activity, as measured by DPPH radical scavenging capacity. The antioxidant activity of Ipomoea batatas L. extract was dramatically increased in the non-irradiated sample to the sample irradiated at 40 mSv. These results indicate that gamma irradiation of Ipomoea batatas L. extract can enhance its antioxidant activity through the formation of a new chemical compound. Based on these results, increased antioxidant activity of Ipomoea batatas L. extracts by gamma rays can be applied to various industries, especially cosmetics, foodstuffs, and pharmaceuticals.

  17. CHEMICAL COMPOSITIONS OF KINEMATICALLY SELECTED OUTER HALO STARS

    SciTech Connect

    Zhang Lan; Zhao Gang; Ishigaki, Miho; Chiba, Masashi; Aoki, Wako E-mail: zhanglan@bao.ac.c E-mail: chiba@astr.tohoku.ac.j

    2009-12-01

    Chemical abundances of 26 metal-poor dwarfs and giants are determined from high-resolution and high signal-to-noise ratio spectra obtained with the Subaru/High Dispersion Spectrograph. The sample is selected so that most of the objects have outer-halo kinematics. Self-consistent atmospheric parameters were determined by an iterative procedure based on spectroscopic analysis. Abundances of 13 elements, including alpha-elements (Mg, Si, Ca, Ti), odd-Z light elements (Na, Sc), iron-peak elements (Cr, Mn, Fe, Ni, Zn), and neutron-capture elements (Y, Ba), are determined by two independent data reduction and local thermodynamic equillibrium analysis procedures, confirming the consistency of the stellar parameters and abundances results. We find a decreasing trend of [alpha/Fe] with increasing [Fe/H] for the range of -3.5< [Fe/H] <-1, as found by Stephens and Boesgaard. [Zn/Fe] values of most objects in our sample are slightly lower than the bulk of halo stars previously studied. These results are discussed as possible chemical properties of the outer halo in the Galaxy.

  18. Antimicrobial activity and chemical composition of some essential oils.

    PubMed

    Aridoğan, Buket Cicioğlu; Baydar, Hasan; Kaya, Selçuk; Demirci, Mustafa; Ozbaşar, Demir; Mumcu, Ethem

    2002-12-01

    In this study the composition and antimicrobial properties of essential oils obtained from Origanum onites, Mentha piperita, Juniperus exalsa, Chrysanthemum indicum, Lavandula hybrida, Rosa damascena, Echinophora tenuifolia, Foeniculum vulgare were examined. To evaluate the in vitro antibacterial activities of these eight aromatic extracts; their in vitro antimicrobial activities were determined by disk diffusion testing, according to the NCCLS criteria. Escherichia coli (ATTC 25922), Staphylococcus aureus (ATCC 25923) and Pseudomonas aeruginosa (ATTC 27853 were used as standard test bacterial strains. Origanum onites recorded antimicrobial activity against all test bacteria, and was strongest against Staphylococcus aureus. For Rosa damascena, Mentha piperita and Lavandula hybrida antimicrobial activity was recorded only to Staphylococcus aureus. Juniperus exalsa, and Chrysanthemum indicum exhibited antibacterial activities against both Staphylococcus aureus and Escherichia coli. We also examined the in vitro antimicrobial activities of some components of the essential oils and found some components with antimicrobial activity. PMID:12510839

  19. The Chemical Composition of Planet-Harboring Stars in M67

    NASA Astrophysics Data System (ADS)

    Holzer, Parker H.; Ivans, Inese; Galbraith-Frew, Jessica; Anderton, Tim; Apogee Team

    2016-03-01

    At the forefront of observational astronomy is the search for, and an understanding about the nature of, stars containing planetary companions. To contribute to this search, we have studied stars in the open cluster Messier 67 (M67), a cluster known to have many stars very comparable to the Sun. At least four dwarf stars in this cluster have shown evidence in previous studies to contain planets. We studied these, as well as about thirty four other F-dwarf stars in M67, by using high signal-to-noise infrared stellar spectra from APOGEE (Apache Point Observatory Galactic Evolution Experiment; a part of the Sloan Digital Sky Survey). Because stars in an open cluster are born from the same material and approximately at the same time, they are in general expected to all have very similar chemical compositions. However, after using spectral synthesis to derive the temperature, gravitational acceleration at the surface, and overall chemical enrichment of the stars in our sample, we have shown that the chemical composition of stars in the cluster is not homogeneous, but instead exhibits a spread. Further, we have shown that this spread may possibly be due to the presence of planet-harboring stars. Our findings suggest that planet-harboring stars are richer in refractory elements and poorer in volatile elements, giving a deeper understanding of the environments in which planets are likely to form.

  20. Quantifying the chemical composition of soil organic carbon with solid-state 13C NMR

    NASA Astrophysics Data System (ADS)

    Baldock, J. A.; Sanderman, J.

    2011-12-01

    The vulnerability of soil organic carbon (SOC) to biological decomposition and mineralisation to CO2 is defined at least partially by its chemical composition. Highly aromatic charcoal-like SOC components are more stable to biological decomposition than other forms of carbon including cellulose. Solid-state 13C NMR has gained wide acceptance as a method capable of defining SOC chemical composition and mathematical fitting processes have been developed to estimate biochemical composition. Obtaining accurate estimates depends on an ability to quantitatively detect all carbon present in a sample. Often little attention has been paid to defining the proportion of organic carbon present in a soil that is observable in solid-state 13C NMR analyses of soil samples. However, if such data is to be used to inform carbon cycling studies, it is critical that quantitative assessments of SOC observability be undertaken. For example, it is now well established that a significant discrimination exists against the detection of the low proton content polyaromatic structures typical of charcoal using cross polarisation 13C NMR analyses. Such discrimination does not exist where direct polarisation analyses are completed. In this study, the chemical composition of SOC as defined by cross polarisation and direct polarisation13C NMR analyses will be compared for Australian soils collected from under a diverse range of agricultural managements and climatic conditions. Results indicate that where significant charcoal C contents exist, it is highly under-represented in the acquired CP spectra. For some soils, a discrimination against alkyl carbon was also evident. The ability to derive correction factors to compensate for such discriminations will be assessed and presented.

  1. Nanoscale chemical interaction enhances the physical properties of bioglass composites.

    PubMed

    Ravarian, Roya; Zhong, Xia; Barbeck, Mike; Ghanaati, Shahram; Kirkpatrick, Charles James; Murphy, Ciara M; Schindeler, Aaron; Chrzanowski, Wojciech; Dehghani, Fariba

    2013-10-22

    Bioglasses are favorable biomaterials for bone tissue engineering; however, their applications are limited due to their brittleness. In addition, the early failure in the interface is a common problem of composites of bioglass and a polymer with high mechanical strength. This effect is due to the phase separation, nonhomogeneous mixture, nonuniform mechanical strength, and different degradation properties of two compounds. To address these issues, in this study a nanoscale interaction between poly(methyl methacrylate) (PMMA) and bioactive glass was formed via silane coupling agent (3-trimethoxysilyl)propyl methacrylate (MPMA). A monolith was produced at optimum composition from this hybrid by the sol-gel method at 50 °C with a rapid gelation time (<50 min) that possessed superior physicochemical properties compared to pure bioglass and physical mixture. For instance, the Young's modulus of bioglass was decreased 40-fold and the dissolution rate of silica was retarded 1.5-fold by integration of PMMA. Prolonged dissolution of silica fosters bone integration due to the continuous dissolution of bioactive silica. The primary osteoblast cells were well anchored and cell migration was observed on the surface of the hybrid. The in vivo studies in mice demonstrated that the integrity of the hybrids was maintained in subcutaneous implantation. They induced mainly a mononuclear phagocytic tissue reaction with a low level of inflammation, while bioglass provoked a tissue reaction with TRAP-positive multinucleated giant cells. These results demonstrated that the presence of a nanoscale interaction between bioglass and PMMA affects the properties of bioglass and broadens its potential applications for bone replacement. PMID:24001050

  2. Composites in manufacturing - Case studies

    SciTech Connect

    Strong, A.B. )

    1991-01-01

    The papers presented in this volume focus on 19 cases of applied technology in composites design and manufacturing, all of them dealing with specific products. Topics covered include design using composite in aerospace, innovative materials and processing, tooling, fasteners and adhesives, finishing, repair, specialty applications of composites, and applications in the automotive industry. Papers are presented on the filament winding of isogrid fuselage structures; design and use of aramid fiber in aircraft structures; resin transfer molding of a complex composite aircraft structure; and field repair of an advanced helicopter vertical fin structure.

  3. Chemical composition, stratigraphy, and depositional environments of the Black River Group (Middle Ordovician), southwestern Ohio.

    USGS Publications Warehouse

    Stith, David A.

    1981-01-01

    The chemical composition and stratigraphy of the Black River Group in southwestern Ohio were studied. Chemical analyses were done on two cores of the Black River from Adams and Brown Counties, Ohio. These studies show that substantial reserves of high-carbonate rock are present in the Black River at depths of less than 800 ft, in proximity to Cincinnati and the Ohio River. Stratigraphic studies show that the Black River Group has eight marker beds in its middle and upper portions and three distinct lithologic units in its lower portion; these marker beds and units are present throughout southwestern Ohio. The Black River Group correlates well with the High Bridge Group of Kentucky. Depositional environments of the Black River are similar to those of the High Bridge and to present-day tidal flats in the Bahamas.-Author

  4. A New Reference Chemical Composition for TMC-1

    NASA Astrophysics Data System (ADS)

    Gratier, P.; Majumdar, L.; Ohishi, M.; Roueff, E.; Loison, J. C.; Hickson, K. M.; Wakelam, V.

    2016-08-01

    Recent detections of complex organic molecules in dark clouds have rekindled interest in the astrochemical modeling of these environments. Because of its relative closeness and rich molecular complexity, TMC-1 has been extensively observed to study the chemical processes taking place in dark clouds. We use local thermodynamical equilibrium radiative transfer modeling coupled with a Bayesian statistical method which takes into account outliers to analyze the data from the Nobeyama spectral survey of TMC-1 between 8 and 50 GHz. We compute the abundance relative to molecular hydrogen of 57 molecules, including 19 isotopologues in TMC-1 along with their associated uncertainty. The new results are in general agreement with previous abundance determination from Ohishi & Kaifu and the values reported in the review from Agúndez & Wakelam. However, in some cases, large opacity and low signal to noise effects allow only upper or lower limits to be derived, respectively.

  5. The biological activities and chemical composition of Pereskia species (Cactaceae)--a review.

    PubMed

    Pinto, Nícolas de Castro Campos; Scio, Elita

    2014-09-01

    The exploration of nature as a source of sustainable, novel bioactive substances continues to grow as natural products play a significant role in the search for new therapeutic and agricultural agents. In this context, plants of the genus Pereskia (Cactaceae) have been studied for their biological activities, and are evolving as an interesting subject in the search for new, bioactive compounds. These species are commonly used as human foodstuffs and in traditional medicine to treat a variety of diseases. This review focuses on the bioactivity and chemical composition of the genus Pereskia, and aims to stimulate further studies on the chemistry and biological potential of the genus. PMID:24862084

  6. Chemical Weathering of Black Shales and Rare Earth Element Composition of Surface Waters and Groundwater

    NASA Astrophysics Data System (ADS)

    Hannigan, R. E.; Johannesson, K. H.

    2001-05-01

    Weathering processes dominate the dissolved and suspended loads of most of the world's major rivers. Among sedimentary rocks, black shales are particularly sensitive to chemical weathering. Therefore, shale systems are useful for investigating the partitioning of chemical elements during chemical weathering. Recent studies, such as those by Peucker-Ehrenbrink, Ravizza and others, link chemical weathering of black shales to changes in marine isotopic composition. Rare earth elements (REE) have a unique chemistry and are ideal for such tracer studies. We explored the effect of modern chemical weathering of black shales on the hydrochemistry of surface and groundwaters in the Mohawk Valley of New York State. This region provides an ideal site for the investigation of trace element remobilization during the chemical weathering of black shales. In this region, surface and groundwaters, in intimate contact with black shales and have high dissolved metal concentrations presumably due to water-rock interactions. The extent to which the dissolved REE composition of the surface and ground waters retains the rock signature is, in someway related to the length of time that the water remains in contact with the rock. We compared the REE compositions of surface and groundwaters in areas draining black shale to those of waters draining regions of dolostone-limestone to explore the extent of metal release due to chemical weathering. Shale normalized REE patterns for stream waters exhibit slight heavy REE enrichments and, at some locations, LREE depletion. REE patterns of the waters normalized to their respective sediments show some LREE depletion. However, waters associated with the Little Falls dolomite show fractionation predominantly enriched in the heavy REEs. Differences between the black shale sites, recorded as light REE depletion and/or middle REE enrichment, may be related to the discharge of the streams and the total dissolved solids. The dissolved REE chemistry of

  7. Feasibility Study for Casting of High Temperature Refractory Superalloy Composites

    NASA Technical Reports Server (NTRS)

    Lee, Jonathan A.

    1998-01-01

    Abstract This study investigated the feasibility of using conventional casting technique to fabricate refractory wires reinforced superalloy composites. These composites were being developed for advanced rocket engine turbine blades and other high temperature applications operating up to 2000 F. Several types of refractory metal wires such as W- Th, W-Re, Mo-Hf-C and W-HF-C reinforced waspaloy were experimentally cast and heat treated at 2000 F up to 48 hrs. Scanning electron microscope analysis was conducted in regions adjacent to the wire-matrix interface to determine the reaction zone and chemical compatibility resulting from material interdiffusion. It was concluded that fabrication using conventional casting may be feasible because the wire-matrix reaction zone thickness was comparable to similar composites produced by arc-sprayed monotape with hot isostatic pressing technique, Moreover, it was also found that the chemical compatibility could be improved significantly through a slight modification of the superalloy matrix compositions.

  8. The chemical compositions of RR Lyrae type c variable stars

    SciTech Connect

    Govea, Jose; Gomez, Thomas; Sneden, Christopher; Preston, George W. E-mail: chris@verdi.as.utexas.edu

    2014-02-20

    We present a detailed chemical abundance study of eight RR Lyrae variable stars of subclass c (RRc). The target RRc stars chosen for study exhibit 'Blazhko-effect' period and amplitude modulations to their pulsational cycles. Data for this study were gathered with the echelle spectrograph of the 100 inch du Pont telescope at Las Campanas Observatory. Spectra were obtained throughout each star's pulsation cycle. Atmospheric parameters—effective temperature, surface gravity, microturbulent velocity, and metallicity—were derived at multiple phase points. We found metallicities and element abundance ratios to be constant within observational uncertainties over the pulsational cycles of all stars. Moreover, the α-element and Fe-group abundance ratios with respect to iron are consistent with other horizontal-branch members (RRab, blue and red non-variables). Finally, we have used the [Fe/H] values of these eight RRc stars to anchor the metallicity estimates of a large-sample RRc snapshot spectroscopic study being conducted with the same telescope and instrument combination employed here.

  9. Prediction of physical and chemical body compositions of purebred and crossbred Nellore cattle using the composition of a rib section.

    PubMed

    Marcondes, M I; Tedeschi, L O; Valadares Filho, S C; Chizzotti, M L

    2012-04-01

    The goal of this research was to develop empirical equations to predict chemical and physical compositions of the carcass and the body using the composition of the 9th- to 11th-rib section (rib(9-11)) and other measurements. A database (n = 246) from 6 studies was developed and comprised 37 bulls (BU), 115 steers (STR), and 94 heifers (HF), of which 132 were Nellore (NEL), 76 were NEL × Angus crossbreds (NA), and 38 were NEL × Simmental crossbreds (NS). The right half carcass and the rib(9-11) from the left half carcass were analyzed for ether extract (EE), CP, and water. The remaining components were chemically analyzed to determine the composition of the body. A stepwise procedure was used to determine the variable inclusion in the regression models. The variables included were EE in the rib(9-11) (EER; %), CP in the rib(9-11) (CPR; %), water in the rib(9-11) (WR; %), visceral fat (VF; %; KPH and mesenteric fats), organs plus viscera (OV; %), carcass dressing percentage (CD; %), cold carcass weight (kg), and empty BW (EBW; kg). No sex or breed effects were found on EE and CP compositions of the carcass (C(EE) and C(CP), respectively; %); the equations were as follows: C(EE) = 4.31 + 0.31 × EER + 1.37 × VF [n = 241; R(2) = 0.83; mean square error (MSE) = 4.53] and C(CP) = 17.92 + 0.60 × CPR - 0.17 × CD (n = 238; R(2) = 0.50; MSE = 1.58). Breed affected water content in the carcass (C(W), %); the equations were as follows: C(W) = 48.74 + 0.28 × WR - 0.017 × EBW for NEL; C(W) = 46.69 + 0.32 × WR - 0.017 × EBW for NA; and C(W) = 38.06 + 0.48 × WR - 0.017 × EBW for NS (n = 243; R(2) = 0.67; MSE = 5.17). A sex effect was found on body chemical EE composition (BW(EE)); the equations were as follows: BW(EE) = 2.75 + 0.33 × EER + 1.80 × VF for BU; BW(EE) = 1.84 + 0.33 × EER + 1.91 × VF for STR; and BW(EE) = 4.77 + 0.33 × EER + 1.28 × VF for HF (n = 243; R(2) = 0.89; MSE = 3.88). No sex or breed effects were found on CP composition in the body (BW

  10. Chemical composition and antibacterial activity of essential oils from the Tunisian Allium nigrum L.

    PubMed Central

    Rouis-Soussi, Lamia Sakka; Ayeb-Zakhama, Asma El; Mahjoub, Aouni; Flamini, Guido; Jannet, Hichem Ben; Harzallah-Skhiri, Fethia

    2014-01-01

    The chemical composition of the essential oils of different Allium nigrum L. organs and the antibacterial activity were evaluated. The study is particularly interesting because hitherto there are no reports on the antibacterial screening of this species with specific chemical composition. Therefore, essential oils from different organs (flowers, stems, leaves and bulbs) obtained separately by hydrodistillation were analyzed using gas chromatography–mass spectrometry (GC–MS). The antibacterial activity was evaluated using the disc and microdilution assays. In total, 39 compounds, representing 90.8-96.9 % of the total oil composition, were identified. The major component was hexadecanoic acid (synonym: palmitic acid) in all the A. nigrum organs oils (39.1-77.2 %). We also noted the presence of some sesquiterpenes, mainly germacrene D (12.8 %) in leaves oil) and some aliphatic compounds such as n-octadecane (30.5 %) in bulbs oil. Isopentyl isovalerate, 14-oxy-α-muurolene and germacrene D were identified for the first time in the genus Allium L. All the essential oils exhibited antimicrobial activity, especially against Enterococcus faecalis and Staphylococcus aureus. The oil obtained from the leaves exhibited an interesting antibacterial activity, with a Minimum Inhibitory Concentration (MIC) of 62.50 µg/mL against these two latter strains. The findings showed that the studied oils have antibacterial activity, and thus great potential for their application in food preservation and natural health products. PMID:26417280

  11. Effect of the Chemical Composition on The Pyroplastic Deformation of Sanitaryware Porcelain Body

    NASA Astrophysics Data System (ADS)

    Yeşim Tunçel, Derya; Kerim Kara, Mustafa; Özel, Emel

    2011-10-01

    Pyroplastic deformation is the bending of a ceramic specimen caused by gravity during heat treatment. It can be defined as the loss of shape of product during its firing. Pyroplastic deformation is related to properties of liquid phases formed during firing. Therefore, the effect of the chemical composition on the pyroplastic deformation of sanitaryware porcelain was investigated in this study. Systematical compositional arrangements were made according to different combinations of (SiO2/Al2O3) and (Na2O/K2O) ratios by using Seger formula approach. Pyroplastic deformation behaviour of compositions within a controlled firing regime was investigated by using fleximeter. The bodies were also prepared in a special form by slip casting method at laboratory scale in order to determine the pyroplastic deformation of the samples. The experimental results showed that a definite combination at SiO2/Al2O3 ratio of 5 and Na2O/K2O ratio of 4 give the lowest pyroplastic deformation in the porcelain body formulations. The pyroplastic deformation value of this composition was determined as 25 mm which is 44% lower than that of the standard composition (45 mm).

  12. Vegetation change impacts on soil organic carbon chemical composition in subtropical forests

    NASA Astrophysics Data System (ADS)

    Guo, Xiaoping; Meng, Miaojing; Zhang, Jinchi; Chen, Han Y. H.

    2016-07-01

    Changes in the chemical composition of soil organic carbon (SOC) might strongly affect the global carbon cycle as it controls the SOC decomposition rate. Vegetation change associated with long-term land use changes is known to strongly impact the chemical composition of SOC; however, data on the impacts of vegetation change following disturbance events of short durations and succession that occur frequently in forest ecosystems via diverse management objectives on SOC chemical composition are negligible. Here we examined the impacts of vegetation changes on the chemical composition of SOC by sampling soils of native broad-leaved forests, planted mixed broad-leaved and coniferous forests, and tea gardens in eastern China. We used nuclear magnetic resonance spectroscopy to quantify SOC chemical composition. We found that among all components of SOC chemical composition, alkyl carbon (C) and aryl C were more liable to change with vegetation than other SOC components. Soil pH was negatively correlated to the relative abundances of alkyl C and N-alkyl C, and Shannon’s index of overstory plant species was positively correlated to the relative abundances of phenolic C and aromaticity. Our results suggest that vegetation changes following short disturbance events and succession may strongly alter SOC chemical composition in forest ecosystems.

  13. Vegetation change impacts on soil organic carbon chemical composition in subtropical forests

    PubMed Central

    Guo, Xiaoping; Meng, Miaojing; Zhang, Jinchi; Chen, Han Y. H.

    2016-01-01

    Changes in the chemical composition of soil organic carbon (SOC) might strongly affect the global carbon cycle as it controls the SOC decomposition rate. Vegetation change associated with long-term land use changes is known to strongly impact the chemical composition of SOC; however, data on the impacts of vegetation change following disturbance events of short durations and succession that occur frequently in forest ecosystems via diverse management objectives on SOC chemical composition are negligible. Here we examined the impacts of vegetation changes on the chemical composition of SOC by sampling soils of native broad-leaved forests, planted mixed broad-leaved and coniferous forests, and tea gardens in eastern China. We used nuclear magnetic resonance spectroscopy to quantify SOC chemical composition. We found that among all components of SOC chemical composition, alkyl carbon (C) and aryl C were more liable to change with vegetation than other SOC components. Soil pH was negatively correlated to the relative abundances of alkyl C and N-alkyl C, and Shannon’s index of overstory plant species was positively correlated to the relative abundances of phenolic C and aromaticity. Our results suggest that vegetation changes following short disturbance events and succession may strongly alter SOC chemical composition in forest ecosystems. PMID:27403714

  14. Vegetation change impacts on soil organic carbon chemical composition in subtropical forests.

    PubMed

    Guo, Xiaoping; Meng, Miaojing; Zhang, Jinchi; Chen, Han Y H

    2016-01-01

    Changes in the chemical composition of soil organic carbon (SOC) might strongly affect the global carbon cycle as it controls the SOC decomposition rate. Vegetation change associated with long-term land use changes is known to strongly impact the chemical composition of SOC; however, data on the impacts of vegetation change following disturbance events of short durations and succession that occur frequently in forest ecosystems via diverse management objectives on SOC chemical composition are negligible. Here we examined the impacts of vegetation changes on the chemical composition of SOC by sampling soils of native broad-leaved forests, planted mixed broad-leaved and coniferous forests, and tea gardens in eastern China. We used nuclear magnetic resonance spectroscopy to quantify SOC chemical composition. We found that among all components of SOC chemical composition, alkyl carbon (C) and aryl C were more liable to change with vegetation than other SOC components. Soil pH was negatively correlated to the relative abundances of alkyl C and N-alkyl C, and Shannon's index of overstory plant species was positively correlated to the relative abundances of phenolic C and aromaticity. Our results suggest that vegetation changes following short disturbance events and succession may strongly alter SOC chemical composition in forest ecosystems. PMID:27403714

  15. A miniature laser ablation mass spectrometer for quantitative in situ chemical composition investigation of lunar surface

    NASA Astrophysics Data System (ADS)

    Brigitte Neuland, Maike; Grimaudo, Valentine; Mezger, Klaus; Moreno-García, Pavel; Riedo, Andreas; Tulej, Marek; Wurz, Peter

    2016-04-01

    The chemical composition of planetary bodies, moons, comets and asteroids is a key to understand their origin and evolution [Wurz,2009]. Measurements of the elemental and isotopic composition of rocks yield information about the formation of the planetary body, its evolution and following processes shaping the planetary surface. From the elemental composition, conclusions about modal mineralogy and petrology can be drawn. Isotope ratios are a sensitive indicator for past events on the planetary body and yield information about origin and transformation of the matter, back to events that occurred in the early solar system. Finally, measurements of radiogenic isotopes make it possible to carry out dating analyses. All these topics, particularly in situ dating analyses, quantitative elemental and highly accurate isotopic composition measurements, are top priority scientific questions for future lunar missions. An instrument for precise measurements of chemical composition will be a key element in scientific payloads of future landers or rovers on lunar surface. We present a miniature laser ablation mass spectrometer (LMS) designed for in situ research in planetary and space science and optimised for measurements of the chemical composition of rocks and soils on a planetary surface. By means of measurements of standard reference materials we demonstrate that LMS is a suitable instrument for in situ measurements of elemental and isotopic composition with high precision and accuracy. Measurements of soil standards are used to confirm known sensitivity coefficients of the instrument and to prove the power of LMS for quantitative elemental analyses [Neuland,2016]. For demonstration of the capability of LMS to measure the chemical composition of extraterrestrial material we use a sample of Allende meteorite [Neuland,2014]. Investigations of layered samples confirm the high spatial resolution in vertical direction of LMS [Grimaudo,2015], which allows in situ studying of past

  16. Chemical composition and thermal behavior of five brands of thermoplasticized gutta-percha

    PubMed Central

    Maniglia-Ferreira, Claudio; Gurgel-Filho, Eduardo Diogo; de Araújo Silva, João Batista; de Paula, Regina Célia Monteiro; de Andrade Feitosa, Judith Pessoa; de Sousa-Filho, Francisco José

    2013-01-01

    Objective: The aim of this study was determine the chemical composition and thermal behavior of Thermafil (TH), Microseal Cone (MC), Microseal Microflow (MF), Obtura (OB) and Obtura Flow (OF). In addition, their thermal behavior in response to temperature variations was studied by differential scanning calorimetry (DSC) to determine the temperature at which gutta-percha switches from the beta to alpha form, and from the alpha to the amorphous phase. Materials and Methods: The organic and inorganic fractions were separated by dissolution in chloroform. Gutta-percha (GP) was precipitated with acetone. The inorganic fraction was analyzed via Elemental Microanalysis. Energy Dispersive X-ray Microanalysis and X-ray Diffraction were used to identify the chemical elements and compounds (BaSO4 and ZnO). Thermal analysis was conducted using DSC. Results: The organic and inorganic fractions ranged from 21.3% and 26.9% of weights, respectively. MC and MF showed the highest percentages of organic compounds (P = 0.0125). All specimens exhibited two crystalline transformations when heated from ambient temperature to 130°C. MC presented the highest percentage of GP. Conclusions: No correlation was observed between chemical composition and thermal behavior. Each of the products showed thermal behavior that is typical of beta-phase gutta-percha. PMID:24883027

  17. Body chemical composition of Nellore bulls with different residual feed intakes.

    PubMed

    Bonilha, E F M; Branco, R H; Bonilha, S F M; Araujo, F L; Magnani, E; Mercadante, M E Z

    2013-07-01

    Empty body and carcass chemical compositions, expressed as content of water, ether extract, protein, minerals, and energy, were evaluated in Nellore bulls with different residual feed intakes (RFI). Forty-nine not castrated males, with 343 kg of average initial BW and 398 kg of average slaughter BW, were studied. Animals were divided in two subgroups: reference group (RG) and ad libitum feeding group. At the end of the adaptation period, animals of subgroup RG were slaughtered and the other animals were finished in individual pens for approximately 100 d, until they reached a subcutaneous fat thickness over the LM of 4 mm, and were slaughtered at an average age of 540 d. Body composition was obtained after grinding, homogenizing, sampling, analyzing, and combining blood, hide, head + feet, viscera, and carcass. Tissue deposition rates and chemical composition of gain were also measured based on gains estimated by comparative slaughter technique. No significant differences in slaughter BW (P = 0.8639), empty BW (P = 0.7288), HCW (P = 0.6563), or empty body and carcass rates of gain were observed between RFI groups, demonstrating that the low (-0.331 kg DM/d) and high (+0.325 kg DM/d) RFI animals presented similar body sizes and growth rates. No significant differences in empty body or carcass content of water, ether extract, protein, minerals, and energy were observed between the low and high RFI animals. And also there were no significant differences in empty BW or carcass gain, demonstrating that low and high RFI animals had a similar growth potential. More efficient animals (low RFI) consumed less feed than less efficient animals (high RFI) but presented similar body sizes, growth rates, and empty body and carcass chemical composition. PMID:23658334

  18. Inhable particulate matter from lime industries: Chemical composition and deposition in human respiratory tract

    NASA Astrophysics Data System (ADS)

    Godoi, Ricardo H. M.; Braga, Darci M.; Makarovska, Yaroslava; Alfoldy, Balint; Carvalho Filho, Marco A. S.; Van Grieken, Réne; Godoi, Ana Flavia L.

    Air pollution caused by the lime production industry has become a serious problem with potential effects to human health, especially in developing countries. Colombo is a city included in the Metropolitan Region of Curitiba (capital of Paraná State) in South Brazil. In Colombo city, a correlation has been shown between the lime production and the number of persons who need respiratory treatment in a local hospital, indicating that the lime industry can cause deleterious health effects in the exposed workers and population. This research was conducted to deal firstly with the characterization of the size distribution and chemical compositions of particles emitted from lime manufacturing and subsequently to assess the deposition rate of inhaled dolomitic lime aerosol particles in the human respiratory tract. The elemental chemical composition and particle size of individual atmospheric particles was quantitatively elucidated, including low-Z components like C, N and O, as well as higher-Z elements, using automated electron probe microanalysis. Information concerning the bulk composition is provided by energy-dispersive X-ray detection. The majority of the respirable particulate matter identified was composed of aluminosilicates, Ca-Mg oxides, carbon-rich particles, mixtures of organic particles and Ca-Mg carbonates, soot and biogenic particles. In view of the chemical composition and size distribution of the aerosol particles, local deposition efficiencies in the human respiratory system were calculated, revealing the deposition of CaO·MgO at extrathoracic, tracheobronchial and pulmonary levels. The results of this study offer evidence to the threat of the fine and coarse particles emitted from dolomite lime manufacturing, allowing policy-makers to better focus their mitigation strategies in an effective way, as well as to the dolomite producers for the purpose of designing and/or implementing improved emission controls.

  19. Chemical composition, quality and histochemical characteristics of individual dromedary camel (Camelus dromedarius) muscles.

    PubMed

    Kadim, I T; Al-Karousi, A; Mahgoub, O; Al-Marzooqi, W; Khalaf, S K; Al-Maqbali, R S; Al-Sinani, S S H; Raiymbek, G

    2013-03-01

    This study characterized the chemical composition, quality and histological traits of six muscles from 10 dromedary carcasses. There were significant differences in moisture, fat, protein, mineral, saturated and unsaturated fatty acid contents between muscles. The longissimus thoracis (LT) had the highest cooking loss (33.5%) and triceps brachii (TB) the lowest (29.2%). The shear force value of semitendinosus (ST), semimembranosus (SM) and biceps femoris (BF) were significantly higher than infraspinatus (IS), TB and LT. The LT had significantly higher values for L*, a*, b* than ST. The SM had the lowest MFI (65.3), while IS had the highest value (75.8). The ST significantly had the highest and lowest proportions of Type I and Type IIA muscle fibers, respectively than other muscles. This study indicated that composition, quality, and histochemical parameters varied among camel muscles and the knowledge of this variation allows for better marketing and processing of camel meat. PMID:23273465

  20. On the visual binary υ Car and the chemical composition of its brighter component.

    NASA Astrophysics Data System (ADS)

    Samedov, Z. A.

    On the basis of the method for studying the composite spectrum of a double system, the following values of effective temperatures and surface gravities are obtained for the components of the visual binary υ Car: Teff = 7600±350K, lg g = 1.1±0.3 for the brighter component υ Car A, Teff = 23000±1600K, lg g = 3.3±0.1 for the fainter component υ Car B. By comparing the evolutionary calculations the author has found masses, radii, luminosities; the age is 107years. Using spectroscopic data, the microturbulent velocity and the chemical composition are studied in the atmosphere of υ Car A. The analysis of Ti II, Fe II, Cr II lines showed higher values in comparison with Fe I lines. The element abundances are defined using relatively weak lines, on average it is close to that of the Sun.

  1. Fine particulate chemical composition and light extinction at Meadview, AZ

    SciTech Connect

    Delbert J. Eatough; Wenxuan Cui; Jeffery Hull; Robert J. Farber

    2006-12-15

    The concentration of fine particulate nitrate, sulfate, and carbonaceous material was measured for 12-hr daynight samples using diffusion denuder samplers during the Project Measurement of Haze and Visibility Effects (MOHAVE) July to August 1992 Summer Intensive study at Meadview, AZ, just west of Grand Canyon National Park. Organic material was measured by several techniques. Only the diffusion denuder method measured the semivolatile organic material. Fine particulate sulfate and nitrate (using denuder technology) determined by various groups agreed. Based on the various collocated measurements obtained during the Project MOHAVE study, the precision of the major fine particulate species was {+-} 0.6 {mu}g/m{sup 3} organic material, {+-} 0.3 {mu}g/m{sup 3} ammonium sulfate, and {+-} 0.07 {mu}g/m{sup 3} ammonium nitrate. Fine particulate organic material was the principal particulate contributor to light extinction during the study period, with fine particulate sulfate as the second most important contributor. Particle light extinction was dominated by sulfate and organic material during periods of lowest light extinction. Combination of the extinction data and chemical mass balance analysis of sulfur oxides sources in the region indicate that the major anthropogenic contributors to light extinction were from the Los Angeles, CA, and Las Vegas, NV, urban areas. Mohave Power Project associated secondary sulfate was a negligible contributor to light extinction. 49 refs., 12 figs., 7 tabs.

  2. Effects of chemical fuel composition on energy generation from thermopower waves

    NASA Astrophysics Data System (ADS)

    Yeo, Taehan; Hwang, Hayoung; Jeong, Dong-Cheol; Lee, Kang Yeol; Hong, Jongsup; Song, Changsik; Choi, Wonjoon

    2014-11-01

    Thermopower waves, which occur during combustion within hybrid structures formed from nanomaterials and chemical fuels, result in a self-propagating thermal reaction and concomitantly generate electrical energy from the acceleration of charge carriers along the nanostructures. The hybrid structures for thermopower waves are composed of two primary components: the core thermoelectric material and the combustible fuel. So far, most studies have focused on investigating various nanomaterials for improving energy generation. Herein, we report that the composition of the chemical fuel used has a significant effect on the power generated by thermopower waves. Hybrid nanostructures consisting of mixtures of picric acid and picramide with sodium azide were synthesized and used to generate thermopower waves. A maximum voltage of ˜2 V and an average peak specific power as high as 15 kW kg-1 were obtained using the picric acid/sodium azide/multiwalled carbon nanotubes (MWCNTs) array composite. The average reaction velocity and the output voltage in the case of the picric acid/sodium azide were 25 cm s-1 and 157 mV, while they were 2 cm s-1 and 3 mV, in the case of the picramide/sodium azide. These marked differences are attributable to the chemical and structural differences of the mixtures. Mixing picric acid and sodium azide in deionized water resulted in the formation of 2,4,6-trinitro sodium phenoxide and hydrogen azide (H-N3), owing to the exchange of H+ and Na+ ions, as well as the formation of fiber-like structures, because of benzene π stacking. The negative enthalpy of formation of the new compounds and the fiber-like structures accelerate the reaction and increase the output voltage. Elucidating the effects of the composition of the chemical fuel used in the hybrid nanostructures will allow for the control of the combustion process and help optimize the energy generated from thermopower waves, furthering the development of thermopower waves as an energy source.

  3. Origin and Bulk Chemical Compositions of the Inner Planets

    NASA Astrophysics Data System (ADS)

    Prentice, A. J.

    2001-12-01

    as β = β 1(θ - θ s})/(θ {1 - θ s). Here θ = μ cT(r)/μ Tc, c means the centre, θ 1 = μ c}T(r{1})/μ_{1 Tc, etc. If the controlling parameters β 1, θ s, θ 1 stay constant, then the contracting cloud sheds gas rings whose mean orbital radii Rn (n=0,1,2, ...) form a closely geometric sequence. The choice β = 0.1253, θ s = 0.00232 and θ 1 = 7.6 θ s leads to the detachment of a family of gas rings whose evolved radii Rn match the observed mean planetary spacings and whose condensate bulk chemical compositions yield densities in accord with the values /lineρunc. The maximum value of pt}/p{gas in the PSC, occurring at radius r = r1, is now only 11.3. The initial mass of the PSC is 1.197M⊙ . The loss of cloud mass during contraction to present solar size results in the orbital expansion of all gas rings and condensate material after ring detachment. Earth's gas ring was shed at 0.917 AU. Details of the gas ring temperatures, mean orbit pressures and condensate compositions are given in the URL below. Notably, Mercury formed at 1632 K and consists mostly of Fe-Ni-Cr-Co-V alloy (mass fraction: 0.670) and gehlenite (0.254). For Venus (911 K), the condensate contains metal alloy (0.326) and MgO-SiO2 (0.575). (Fe-Ni)S (0.087) and tremolite (0.102) first condense at Earth's orbit (674 K). FeO, as fayalite (0.180), first forms at Mars' (459 K). I thank Mr. David Warren [Tasmania], Dr. John D. Anderson [NASA/JPL] and the ARC for support.

  4. Spectroscopic Investigations of the Chemical Composition and Coma Morphology of Comets

    NASA Astrophysics Data System (ADS)

    Pierce, D.; Lewis, B.; Vaughan, C.; Cochran, A.

    2014-12-01

    Ground-based emission spectroscopy at optical wavelengths is important for understanding the chemical composition of comets. We have made spectroscopic observations of comets using both long-slit and integral-field unit spectrographs on the Harlan J. Smith telescope at the University of Texas McDonald Observatory in order to study radical species in cometary comae. We will discuss the techniques used to extract chemical abundances in comets from these data and show how the spatial distribution of the observed species and large-scale coma morphological features (e.g. jets or fans) are mapped and characterized. Analyses of data we have acquired for several comets to date will be presented that examine their chemical abundances, track the temporal evolution of coma morphology in relation to nuclear rotational behavior (where known), and gauge potential chemical heterogeneity of cometary nuclei. We will also place this work into broader context by comparing our results to existing large-sample photometric and spectroscopic surveys of comets, as well as comparing our results to those obtained during prior apparitions to determine whether these comets show any evolutionary changes in measured chemical abundances or sources of outgassing on their surfaces. This work has been funded by the NSF GK-12 STEM Fellowship program, NASA's Planetary Astronomy and Planetary Atmospheres programs, and the Fund for Astrophysical Research, Inc.

  5. Chemical and phytochemical compositions of Voandzeia subterranea seeds.

    PubMed

    Marcel, Andzouana; Bienvenu, Mombouli Jean; Attibayeba

    2014-09-01

    The seeds of Voandzeia subterranean (L.) Thouars (Fabaceae), from Congo-Brazzaville were studied for proximate, qualitative and quantitative compositions. Phytochemical screening of various solvent extracts showed the presence of alkaloids, flavonoids, glycosides, saponins, steroids, triterpenoids, phenols, anthocyanins and carotenoids. Tannins and anthraquinones were not found. Quantitative analysis showed a high amount of alkaloids (34.40 ±0.2%), flavonoids (4.93 ± 0.17%), saponins (2.20 ± 0.11%) and anthocyanins (1.00 ± 0.12%) in decreasing order. Phenols (0.60 ± 0.12%) and carotenoids had low yields (0.26 ± 0.07%). Proximate analysis of the seeds showed high moisture, carbohydrate and energy content values (49.14, 20.53% and 956.14 kJ 100 g(-1), respectively). The results showed low ash content (3.84%) and the relatively high fat (7.84%) and protein content (18.65%). The mineral analysis revealed that potassium (3.15%) and phosphorus (1.74%) were the most abundant minerals. Calcium (0.35) and magnesium (0.39%), were found in low amounts. Sodium, iron and aluminum were detected in trace quantities (0.01%). Manganese was not detected in the present study. The seeds were found to be important both for their nutrients and non-nutrients which determined the medicinal and nutritional value of the plant. PMID:26031031

  6. The Uses of Toulmin in Composition Studies

    ERIC Educational Resources Information Center

    Bizup, Joseph

    2009-01-01

    This article examines the various uses to which Stephen Toulmin has been put in composition studies. It presents data on citations of Toulmin in nine journals, considers appeals to Toulmin in several strains of composition scholarship, and argues that composition scholars ought to attend more carefully to Toulmin's later works. (Contains 4 tables…

  7. Superhybrid composite blade impact studies

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Lark, R. F.; Sinclair, J. H.

    1980-01-01

    The feasibility of superhybrid composite blades for meeting the mechanical design and impact resistance requirements of large fan blades for aircraft turbine engine applications was investigated. Two design concepts were evaluated: leading edge spar (TiCom) and center spar (TiCore), both with superhybrid composite shells. The investigation was both analytical and experimental. The results obtained show promise that superhybrid composites can be used to make light weight, high quality, large fan blades with good structural integrity. The blades tested successfully demonstrated their ability to meet steady state operating conditions, overspeed, and small bird impact requirements.

  8. Superhybrid composite blade impact studies

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Lark, R. F.; Sinclair, J. H.

    1981-01-01

    An investigation was conducted to determine the feasibility of superhybrid composite blades for meeting the mechanical design and impact resistance requirements of large fan blades for aircraft turbine engine applications. Two design concepts were evaluated: (1) leading edge spar (TiCom) and (2) center spar (TiCore), both with superhybrid composite shells. The investigation was both analytical and experimental. The results obtained show promise that superhybrid composites can be used to make light-weight, high-quality, large fan blades with good structural integrity. The blades tested successfully demonstrated their ability to meet steady-state operating conditions, overspeed, and small bird impact requirements.

  9. Growth of multi-component alloy films with controlled graded chemical composition on sub-nanometer scale

    DOEpatents

    Bajt, Sasa; Vernon, Stephen P.

    2005-03-15

    The chemical composition of thin films is modulated during their growth. A computer code has been developed to design specific processes for producing a desired chemical composition for various deposition geometries. Good agreement between theoretical and experimental results was achieved.

  10. Microbial Mineralization of Soil Organic Matter: Role of Chemical Composition and Structural Organization

    NASA Astrophysics Data System (ADS)

    Khalaf, M. M. R.; Chilom, G.; Rice, J. A.

    2014-12-01

    The purpose of this study is to quantitatively assess the effect of organic matter self-assembly on its resistance to microbial mineralization. Humic acids isolated from leonardite, two peats and a mineral soil were used as organic matter samples because they provide a broad range of variability in terms of the origin and nature of their organic components. Using a solvent-based fractionation method, humic acid samples were disassembled into a humic-like component and a humic-lipid composite. The humic-lipid composite was further disassembled into an amphiphilic and a lipid component using an alkaline aqueous solution. Mixtures that reproduced the composition of self-assembled samples were prepared by mixing the solid individual fractions in the exact proportions that they were present in the original material. The original humic acids or their corresponding mixtures were added as the sole carbon source in separate aerobic cultures containing a microbial consortium isolated from a mineral soil. After incubation for 125 days mineralization of the self-assembled samples was shown to be higher by as much as 70% compared to their corresponding physical mixtures. The extent of mineralization of the self-assembled samples was not correlated to the material's chemical composition or hydrophobicity index obtained from their 13C solid-state NMR spectra. In contrast, mineralization of the physical mixtures and the individual fractions did vary with chemical composition and was accompanied by preferential mineralization of alkyl carbon. These results suggest the microbial mineralization of humic acids is related to their self-assembly.

  11. Antimicrobial Activity and Chemical Composition of Essential Oil From the Seeds of Artemisia aucheri Boiss

    PubMed Central

    Asghari, Gholamreza; Jalali, Mohamad; Sadoughi, Ehsan

    2012-01-01

    Background Artemisia aerial parts are well known for antimicrobial activities including anti malaria. Objectives This study was carried out to evaluate the antimicrobial activity and chemical composition of essential oil from the seeds of Artemisia aucheri Boiss (Asteraceae). Materials and Methods Essential oil was extracted from the powdered seeds of Artemisia aucheri by hydrodistillation. Antimicrobial activity against five bacterial species was tested using the disc diffusion method, and the chemical composition of the essential oil was analyzed by gas chromatography-mass spectrometry (GC-MS). Results The essential oil of Artemisia aucheri seed showed activity against Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes. The essential oil constituents identified by GC-MS were as follows: decane, ρ-cymene, 1,8-cineole, linalool, ρ-mentha-8-ol, triene, borneol, lavandulol, bornyl acetate, chrysanthenyl acetate, dehydro aromadenderene, and caryophyllene oxide. Most of these compounds are also found in the aerial parts of Artemisia aucheri. Conclusions Variation in the compositions of essential oils from Artemisia aucheri, and thus variation in the antimicrobial activity of these oils, may be due to the plant parts used for essential oil prepration. PMID:24624145

  12. Gummosis in grape hyacinth (Muscari armeniacum) bulbs: hormonal regulation and chemical composition of gums.

    PubMed

    Miyamoto, Kensuke; Kotake, Toshihisa; Sasamoto, Makiko; Saniewski, Marian; Ueda, Junichi

    2010-05-01

    The purpose of this study was to investigate the hormonal regulation of gummosis in grape hyacinth (Muscari armeniacum) bulbs, focusing especially on the chemical composition of the gums. The application of ethephon (2-chloroethylphosphonic acid), an ethylene-releasing compound, at 1% and 2% (w/w) in lanolin as well as ethylene induced gummosis in the bulbs within several days. Methyl jasmonate (JA-Me, 0.1-2% in lanolin) alone had no effect on gummosis. However, simultaneous application of JA-Me and ethephon led to extreme stimulation of ethephon-induced gummosis. Ethephon-induced gummosis in the bulbs depended on the maturation stage of the bulbs, increasing from April to July, but decreasing from August to September. Regardless of the presence of JA-Me, the application of ethephon to the inflorescence axis of grape hyacinths did not induce gummosis. Gel permeation chromatography analysis revealed that gums were homogenous polysaccharides with an average molecular mass of ca. 8.3 kDa. Analysis of the sugar composition of the gums after hydrolysis revealed that the molar ratio of Rha:Ara:Gal:GalA:GlcA was 25:10:40:7:15. These results suggest that principal factors of gummosis as well as the chemical composition of gums differ between species of bulbous plants. PMID:19941030

  13. Chemical Composition and Vasorelaxant and Antispasmodic Effects of Essential Oil from Rosa indica L. Petals

    PubMed Central

    Rasheed, Hafiz Majid; Khan, Taous; Wahid, Fazli; Khan, Rasool; Shah, Abdul Jabbar

    2015-01-01

    Rosa indica L. belongs to the family Rosaceae and is locally known as gulaab. It has different traditional uses in cardiovascular and gastrointestinal disorders but there is no scientific data available in this regard. Therefore, the basic aim of this study was to explore the chemical composition and gastrointestinal and cardiovascular effects of the essential oil obtained from R. indica. The chemical composition of the essential oil was investigated using gas chromatography-mass spectrometry (GC-MS) technique. The cardiovascular and gastrointestinal effects were investigated using electrophysiological measurements. The GC-MS analysis of the essential oil showed various chemical components including acetic acid, mercaptohexyl ester, butanoic acid, 2-methyl-5-oxo-1-cyclopentene-1-yl ester, artemiseole, methyl santonilate, isosteviol, caryophyllene oxide, pentyl phenyl acetate, dihydromyrcene, 1,5-octadecadien, octadecanoic acid, ethyl ester, palmitic acid (2-phenyl-1,3-dioxolan-4-yl methyl ester), santolina epoxide, and 9-farnesene. The electrophysiological measurements revealed that essential oil was more potent against K+ (80 mM) than phenylephrine precontractions using isolated rabbit aorta preparations. In isolated rabbit jejunum preparations, it showed more potency against high K+ induced contractions than spontaneous contractions. Considering these evidences, it can be concluded that R. indica essential oil may work as a complementary and alternative medicine in gastrointestinal and cardiovascular diseases. PMID:26357519

  14. The chemical composition and band gap of amorphous Si:C:N:H layers

    NASA Astrophysics Data System (ADS)

    Swatowska, Barbara; Kluska, Stanislawa; Jurzecka-Szymacha, Maria; Stapinski, Tomasz; Tkacz-Smiech, Katarzyna

    2016-05-01

    In this work we presented the correlation between the chemical composition of amorphous Si:C:N:H layers of various content of silicon, carbon and nitrogen, and their band gap. The series of amorphous Si:C:N:H layers were obtained by plasma assisted chemical vapour deposition method in which plasma was generated by RF (13.56 MHz, 300 W) and MW (2.45 GHz, 2 kW) onto monocrystalline silicon Si(001) and borosilicate glass. Structural studies were based on FTIR transmission spectrum registered within wavenumbers 400-4000 cm-1. The presence of Sisbnd C, Sisbnd N, Csbnd N, Cdbnd N, Cdbnd C, Ctbnd N, Sisbnd H and Csbnd H bonds was shown. The values band gap of the layers have been determined from spectrophotometric and ellipsometric measurements. The respective values are contained in the range between 1.64 eV - characteristic for typical semiconductor and 4.21 eV - for good dielectric, depending on the chemical composition and atomic structure of the layers.

  15. Chemical Composition and Vasorelaxant and Antispasmodic Effects of Essential Oil from Rosa indica L. Petals.

    PubMed

    Rasheed, Hafiz Majid; Khan, Taous; Wahid, Fazli; Khan, Rasool; Shah, Abdul Jabbar

    2015-01-01

    Rosa indica L. belongs to the family Rosaceae and is locally known as gulaab. It has different traditional uses in cardiovascular and gastrointestinal disorders but there is no scientific data available in this regard. Therefore, the basic aim of this study was to explore the chemical composition and gastrointestinal and cardiovascular effects of the essential oil obtained from R. indica. The chemical composition of the essential oil was investigated using gas chromatography-mass spectrometry (GC-MS) technique. The cardiovascular and gastrointestinal effects were investigated using electrophysiological measurements. The GC-MS analysis of the essential oil showed various chemical components including acetic acid, mercaptohexyl ester, butanoic acid, 2-methyl-5-oxo-1-cyclopentene-1-yl ester, artemiseole, methyl santonilate, isosteviol, caryophyllene oxide, pentyl phenyl acetate, dihydromyrcene, 1,5-octadecadien, octadecanoic acid, ethyl ester, palmitic acid (2-phenyl-1,3-dioxolan-4-yl methyl ester), santolina epoxide, and 9-farnesene. The electrophysiological measurements revealed that essential oil was more potent against K(+) (80 mM) than phenylephrine precontractions using isolated rabbit aorta preparations. In isolated rabbit jejunum preparations, it showed more potency against high K(+) induced contractions than spontaneous contractions. Considering these evidences, it can be concluded that R. indica essential oil may work as a complementary and alternative medicine in gastrointestinal and cardiovascular diseases. PMID:26357519

  16. Influence of electropolishing and anodic oxidation on morphology, chemical composition and corrosion resistance of niobium.

    PubMed

    Sowa, Maciej; Greń, Katarzyna; Kukharenko, Andrey I; Korotin, Danila M; Michalska, Joanna; Szyk-Warszyńska, Lilianna; Mosiałek, Michał; Zak, Jerzy; Pamuła, Elżbieta; Kurmaev, Ernst Z; Cholakh, Seif O; Simka, Wojciech

    2014-09-01

    The work presents results of the studies performed on electropolishing of pure niobium in a bath that contained: sulphuric acid, hydrofluoric acid, ethylene glycol and acetanilide. After the electropolishing, the specimens were subjected to anodic passivation in a 1moldm(-3) phosphoric acid solution at various voltages. The surface morphology, thickness, roughness and chemical composition of the resulting oxide layers were analysed. Thusly prepared niobium samples were additionally investigated in terms of their corrosion resistance in Ringer's solution. The electropolished niobium surface was determined to be smooth and lustrous. The anodisation led to the growth of barrier-like oxide layers, which were enriched in phosphorus species. PMID:25063150

  17. Chemical composition and possible in vitro phytotoxic activity of Helichrsyum italicum (Roth) Don ssp. italicum.

    PubMed

    Mancini, Emilia; De Martino, Laura; Marandino, Aurelio; Scognamiglio, Maria Rosa; De Feo, Vincenzo

    2011-01-01

    The chemical composition of the essential oil of Helichrysum italicum (Roth) Don ssp. italicum, collected in the National Park of Cilento and Diano Valley, Southern Italy, was studied by means of GC and GC/MS. Forty four compounds of 45 constituents were identified in the oil, mainly oxygenated sesquiterpenes. The essential oil was evaluated for its potential in vitro phytotoxic activity against germination and early radicle elongation of radish and garden cress. The radicle elongation of radish was significantly inhibited at the highest doses tested, while germination of both seeds was not affected. PMID:21904272

  18. Chemical composition of the underutilized legume Cassia hirsuta L.

    PubMed

    Vadivel, V; Janardhanan, K

    2000-01-01

    Seven accessions of the underutilized legume, Cassia hirsuta L., seeds collected from seven different agroclimatic regions of Tamil Nadu, India, were analyzed for proximate composition, total proteins, protein fractions, mineral profiles and selected antinutritional factors. Crude protein ranged from 15.52 to 20.74%, crude lipid 3.77-7.04%, crude fiber 4.68-6.92%, ash 3.98-6.42% and carbohydrates 62.45-70.16%. Energy values of the seeds were 1549-1634 kJ/100 g (DM), which are comparable to those of other legumes. Data on seed protein fractions revealed that globulins constituted the bulk of the seed protein as in most legumes. Mineral contents of the seeds showed greater variation. Potassium was the most abundant mineral (1029-1786 mg/100 g), whereas manganese was low (2.1-2.2 mg/100 g). Antinutritional factors such as total free phenolics, tannins, L-DOPA and lectins were analyzed. The results of the study demonstrated that the accessions of C. hirsuta seeds collected from Tamil Nadu, India, could be good sources of some important nutrients for humans. PMID:11086879

  19. The chemical compositions of solar twins in the open cluster M67

    NASA Astrophysics Data System (ADS)

    Liu, F.; Asplund, M.; Yong, D.; Meléndez, J.; Ramírez, I.; Karakas, A. I.; Carlos, M.; Marino, A. F.

    2016-08-01

    Stars in open clusters are expected to share an identical abundance pattern. Establishing the level of chemical homogeneity in a given open cluster deserves further study as it is the basis of the concept of chemical tagging to unravel the history of the Milky Way. M67 is particularly interesting given its solar metallicity and age as well as being a dense cluster environment. We conducted a strictly line-by-line differential chemical abundance analysis of two solar twins in M67: M67-1194 and M67-1315. Stellar atmospheric parameters and elemental abundances were obtained with high precision using Keck/HIRES spectra. M67-1194 is essentially identical to the Sun in terms of its stellar parameters. M67-1315 is warmer than M67-1194 by ≈ 150 K as well as slightly more metal-poor than M67-1194 by ≈ 0.05 dex. M67-1194 is also found to have identical chemical composition to the Sun, confirming its solar twin nature. The abundance ratios [X/Fe] of M67-1315 are similar to the solar abundances for elements with atomic number Z ≤ 30, while most neutron-capture elements are enriched by ≈ 0.05 dex, which might be attributed to enrichment from a mixture of AGB ejecta and r-process material. The distinct chemical abundances for the neutron-capture elements in M67-1315 and the lower metallicity of this star compared to M67-1194, indicate that the stars in M67 are likely not chemically homogeneous. This poses a challenge for the concept of chemical tagging since it is based on the assumption of stars forming in the same star-forming aggregate.

  20. Chemical composition of groundwater and relative mortality for cardiovascular diseases in the Slovak Republic.

    PubMed

    Rapant, S; Fajčíková, K; Cvečková, V; Ďurža, A; Stehlíková, B; Sedláková, D; Ženišová, Z

    2015-08-01

    The study deals with the analysis of relationship between chemical composition of the groundwater/drinking water and the data on relative mortality for cardiovascular diseases (ReI) in the Slovak Republic. Primary data consist of the Slovak national database of groundwater analyses (20,339 chemical analyses, 34 chemical elements/compounds) and data on ReI collected for the 10-year period (1994-2003). The chemical and health data were unified in the same form and expressed as the mean values for each of 2883 municipalities within the Slovak Republic for further analysis. Artificial neural network was used as mathematic method for model data analysis. The most significant chemical elements having influence on ReI were identified together with their limit values (maximal acceptable, minimal necessary and optimal). Based on the results of calculations, made through the neural networks, the following ten chemical elements/parameters in the groundwater were defined as the most significant for ReI: Ca + Mg (mmol l(-1)), Ca, Mg, TDS, Cl, HCO3, SO4, NO3, SiO2 and PO4. The obtained results document the highest relationship between ReI and the groundwater contents of Ca + Mg (mmol l(-1)), Ca and Mg. Following limit values were set for the most significant groundwater chemicals/parameters: Ca + Mg 4.4-7.6 mmol l(-1), Ca > 89.4 mg l(-1) and Mg 42-78.1 mg l(-1). At these concentration ranges, the relative mortality for cardiovascular diseases in the Slovak Republic reaches the lowest levels. These limit values are about twice higher in comparison with the current Slovak valid guideline values for the drinking water. PMID:25840565

  1. The chemical compositions of Galactic disc F and G dwarfs

    NASA Astrophysics Data System (ADS)

    Reddy, Bacham E.; Tomkin, Jocelyn; Lambert, David L.; Allende Prieto, Carlos

    2003-03-01

    Photospheric abundances are presented for 27 elements from carbon to europium in 181 F and G dwarfs from a differential local thermodynamic equilibrium (LTE) analysis of high-resolution and high signal-to-noise ratio spectra. Stellar effective temperatures (Teff) were adopted from an infrared flux method calibration of Strömgren photometry. Stellar surface gravities (g) were calculated from Hipparcos parallaxes and stellar evolutionary tracks. Adopted Teff and g values are in good agreement with spectroscopic estimates. Stellar ages were determined from evolutionary tracks. Stellar space motions (U, V, W) and a Galactic potential were used to estimate Galactic orbital parameters. These show that the vast majority of the stars belong to the Galactic thin disc. Relative abundances expressed as [X/Fe] generally confirm previously published results. We give results for C, N, O, Na, Mg, Al, Si, S, K, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, Ce, Nd and Eu. The α elements - O, Mg, Si, Ca and Ti - show [α/Fe] to increase slightly with decreasing [Fe/H]. Heavy elements with dominant contributions at solar metallicity from the s-process show [s/Fe] to decrease slightly with decreasing [Fe/H]. Scatter in [X/Fe] at a fixed [Fe/H] is entirely attributable to the small measurement errors, after excluding the few thick disc stars and the s-process-enriched CH subgiants. Tight limits are set on `cosmic' scatter. If a weak trend with [Fe/H] is taken into account, the composition of a thin disc star expressed as [X/Fe] is independent of the star's age and birthplace for elements contributed in different proportions by massive stars (Type II supernovae), exploding white dwarfs (Type Ia supernovae) and asymptotic red giant branch stars. By combining our sample with various published studies, comparisons between thin and thick disc stars are made. In this composite sample, thick disc stars are primarily identified by their VLSR in the range -40 to -100 km s-1. These are

  2. Fine particulate chemical composition and light extinction at Meadview, AZ.

    PubMed

    Eatough, Delbert J; Cui, Wenxuan; Hull, Jeffery; Farber, Robert J

    2006-12-01

    The concentration of fine particulate nitrate, sulfate, and carbonaceous material was measured for 12-hr day-night samples using diffusion denuder samplers during the Project Measurement of Haze and Visibility Effects (MOHAVE) July to August 1992 Summer Intensive study at Meadview, AZ, just west of Grand Canyon National Park. Organic material was measured by several techniques. Only the diffusion denuder method measured the semivolatile organic material. Fine particulate sulfate and nitrate (using denuder technology) determined by various groups agreed. Based on the various collocated measurements obtained during the Project MOHAVE study, the precision of the major fine particulate species was +/- 0.6 microg/m3 organic material, +/- 0.3 microg/m3 ammonium sulfate, and +/- 0.07 microg/m3 ammonium nitrate. Data were also available on fine particulate crustal material, fine and coarse particulate mass from the Interagency Monitoring of Protected Visual Environments sampling system, and relative humidity (RH), light absorption, particle scattering, and light extinction measurements from Project MOHAVE. An extinction budget was obtained using mass scattering coefficients estimated from particle size distribution data. Literature data were used to estimate the change in the mass scattering coefficients for the measured species as a function of RH and for the absorption of light by elemental carbon. Fine particulate organic material was the principal particulate contributor to light extinction during the study period, with fine particulate sulfate as the second most important contributor. During periods of highest light extinction, contributions from fine particulate organic material, sulfate, and light-absorbing carbon dominated the extinction of light by particles. Particle light extinction was dominated by sulfate and organic material during periods of lowest light extinction. Combination of the extinction data and chemical mass balance analysis of sulfur oxides

  3. CHEMICAL COMPOSITION AND PCT DATA FOR THE INITIAL SET OF HANFORD ENHANCED WASTE LOADING GLASSES

    SciTech Connect

    Fox, K.; Edwards, T.

    2014-06-02

    In this report, the Savannah River National Laboratory provides chemical analyses and Product Consistency Test results for 20 simulated high level waste glasses fabricated by the Pacific Northwest National Laboratory. The results of these analyses will be used as part of efforts to revise or extend the validation ranges of the current Hanford Waste Treatment and Immobilization Plant glass property models to cover a broader span of waste compositions. The measured chemical composition data are reported and compared with the targeted values for each component for each glass. Two components of the study glasses, fluorine and silver, were not measured since each of these species would have required the use of an additional preparation method and their measured values were likely to be near or below analytical detection limits. Some of the glasses were difficult to prepare for chemical analysis. A sodium peroxide fusion dissolution method was successful in completely dissolving the glasses. Components present in the glasses in minor concentrations can be difficult to measure using this dissolution method due to dilution requirements. The use of a lithium metaborate preparation method for the minor components (planned for use since it is typically successful in digesting Defense Waste Processing Facility HLW glasses) resulted in an unacceptable amount of undissolved solids remaining in the sample solutions. An acid dissolution method was used instead, which provided more thorough dissolution of the glasses, although a small amount of undissolved material remained for some of the study glasses. The undissolved material was analyzed to determine those components of the glasses that did not fully dissolve. These components (e.g., calcium and chromium) were present in sufficient quantities to be reported from the measurements resulting from the sodium peroxide fusion preparation method, which did not leave undissolved material. Overall, the analyses resulted in sums of

  4. Diesel Surrogate Fuels for Engine Testing and Chemical-Kinetic Modeling: Compositions and Properties

    PubMed Central

    Mueller, Charles J.; Cannella, William J.; Bays, J. Timothy; Bruno, Thomas J.; DeFabio, Kathy; Dettman, Heather D.; Gieleciak, Rafal M.; Huber, Marcia L.; Kweon, Chol-Bum; McConnell, Steven S.; Pitz, William J.; Ratcliff, Matthew A.

    2016-01-01

    The primary objectives of this work were to formulate, blend, and characterize a set of four ultralow-sulfur diesel surrogate fuels in quantities sufficient to enable their study in single-cylinder-engine and combustion-vessel experiments. The surrogate fuels feature increasing levels of compositional accuracy (i.e., increasing exactness in matching hydrocarbon structural characteristics) relative to the single target diesel fuel upon which the surrogate fuels are based. This approach was taken to assist in determining the minimum level of surrogate-fuel compositional accuracy that is required to adequately emulate the performance characteristics of the target fuel under different combustion modes. For each of the four surrogate fuels, an approximately 30 L batch was blended, and a number of the physical and chemical properties were measured. This work documents the surrogate-fuel creation process and the results of the property measurements. PMID:27330248

  5. Chemical composition of atmospheric aerosols between Moscow and Vladivostok

    NASA Astrophysics Data System (ADS)

    Kuokka, S.; Teinilä, K.; Saarnio, K.; Aurela, M.; Sillanpää, M.; Hillamo, R.; Kerminen, V.-M.; Vartiainen, E.; Kulmala, M.; Skorokhod, A. I.; Elansky, N. F.; Belikov, I. B.

    2007-05-01

    The TROICA-9 expedition (Trans-Siberian Observations Into the Chemistry of the Atmosphere) was carried out at the Trans-Siberian railway between Moscow and Vladivostok in October 2005. Measurements of aerosol physical and chemical properties were made from an observatory carriage connected to a passenger train. Black carbon (BC) concentrations in fine particles (PM2.5, aerodynamic diameter <2.5 μm) were measured with an aethalometer using a five-minute time resolution. Concentrations of inorganic ions and some organic compounds (Cl-, NO3-, SO42-, Na+, NH4+, K+, Ca2+, Mg2+, oxalate and methane sulphonate) were measured continuously by using an on-line system with a 15-min time resolution. In addition, particle volume size distributions were determined for particles in the diameter range 3-850 nm using a 10-min. time resolution. The continuous measurements were completed with 24-h. PM2.5 filter samples which were stored in a refrigerator and later analyzed in chemical laboratory. The analyses included mass concentrations of PM2.5, ions, monosaccharide anhydrides (levoglucosan, galactosan and mannosan) and trace elements (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sb, V and Zn). The mass concentrations of PM2.5 varied in the range of 4.3-34.8 μg m-3 with an average of 21.6 μg m-3. Fine particle mass consisted mainly of BC (average 27.6%), SO42- (13.0%), NH4+ (4.1%), and NO3- (1.4%). One of the major constituents was obviously also organic carbon which was not determined. The contribution of BC was high compared with other studies made in Europe and Asia. High concentrations of ions, BC and particle volume were observed between Moscow and roughly 4000 km east of it, as well as close to Vladivostok, primarily due to local anthropogenic sources. In the natural background area between 4000 and 7200 km distance from Moscow, observed concentrations were low, even though there were local particle sources, such as forest fires, that increased occasionally concentrations. The

  6. Constraints on melting, temperature and chemical composition from full waveform tomographic images

    NASA Astrophysics Data System (ADS)

    Cobden, L. J.; Trampert, J.; Fichtner, A.

    2014-12-01

    The recent development of full waveform tomography on continental scales has provided new insights into the seismic structure of the lithosphere and asthenosphere. In particular, we can map shorter wavelength, high-amplitude velocity anomalies which would traditionally be damped and spatially smeared using classical methods. Quantitative interpretation of these anomalies - expressed as absolute rather than relative velocities - may open up the possibility of identifying important dynamic processes such as melting, that would otherwise go undetected or unconstrained. In this study we focus on the S-wave speed structure beneath Europe, as obtained from full waveform inversion. On average, the European continent is slow compared to 1-D reference models such as AK135, but of particular interest are regions beneath the Atlantic and Iberian Peninsula which are 6-8% slower. Traditional interpretation of a regional tomography model would assume a fixed chemical composition, and from this estimate lateral temperature variations. In our case we allow both the temperature and composition to vary at random within very broad ranges, and generate thousands of different thermochemical structures in a Monte Carlo procedure. We then convert these thermochemical structures into S-wave speeds using thermodynamic modelling, and including a correction for temperature-dependent intrinsic attenuation. Although we cannot uniquely define the chemical composition in a given location, due to trade-offs between different chemical components and the temperature, this does not affect our interpretation of the very slow regions. We find that in order to generate such low velocities without melting, either prohibitively high temperatures (above the melting temperature) or extremely low Q values (in contradiction with seismic constraints) are required. Our study demonstrates: 1. The importance of using absolute rather than relative seismic wave speeds in constraining the thermochemical structure

  7. Evaluation of various feedstuffs of ruminants in terms of chemical composition and metabolisable energy content

    PubMed Central

    Kumar, Dinesh; Datt, Chander; Das, L. K.; Kundu, S. S.

    2015-01-01

    Aim: The aim was to determine the chemical composition and metabolisable energy (ME) content of feedstuffs used in ruminant animals using in vitro method. Materials and Methods: A total of 18 feedstuffs used for ruminant feeding including cultivated non-leguminous fodders like maize, sorghum, pearl millet, and oat; leguminous fodders like cowpea and berseem; agro-industrial by-products such as wheat bran, deoiled rice bran, rice polish, wheat straw, and concentrates such as mustard oil cake, groundnut cake, soybean meal, cotton seed cake, grains like maize, oat, wheat, and barley were taken for this study. Chemical compositions and cell wall constituents of test feeds were determined in triplicate. The crude protein (CP) content was calculated as nitrogen (N) × 6.25. True dry matter digestibility (TDMD), true organic matter digestibility (TOMD), ME, and partitioning factor (PF) values were determined by in vitro gas production technique (IVGPT). Results: The CP content of non-leguminous fodders varied from 7.29% (sorghum) to 9.51% (maize), but leguminous fodders had less variation in CP. Oilseed cakes/meals had high CP and ether extract (EE) content than other feedstuffs except rice polish, which had 12.80% EE. Wheat straw contained highest fiber fractions than the other ingredients. ME content was highest in grains (wheat-12.02 MJ/kg) and lowest in wheat straw (4.65 MJ/kg) and other roughages. TDMD of grains and oilseed cakes/meals were higher than the fodders and agro-industrial by-products. The same trend was observed for TOMD. Conclusions: It was concluded that the energy feeds showed a great variation in chemical composition and ME content. The results of this study demonstrated that the kinetics of gas production of energy feed sources differed among themselves. Evaluation of various feedstuffs is helpful in balanced ration formulation for field animals and under farm conditions for better utilization of these commonly available feed resources. PMID:27047142

  8. Synthetic waste chemical mechanism studies

    SciTech Connect

    Ashby, E.C.; Annis, A.; Barefield, E.K.

    1994-10-01

    This research involved three main tasks: Kinetic studies of gas evolution and metal complexant decomposition in simulated waste media (SWM); Product identification from metal complexant decomposition in SWM; and Determination of the pathway by which N{sub 2}O, N{sub 2}, and NH{sub 3} are formed in SWM. Results are given on these 3 tasks under the following subtitles: 1. Kinetic studies--Reactions of HEDTA in SWM at different temperatures; Determination of the activation energies for gas formation in HEDTA decomposition under argon; Kinetics and mechanism of thermal degradation of glycolate in SWM; A possible explanation for the temperature dependence of gaseous product ratios for reactions of HEDTA and glycolate; Stoichiometry and kinetics of decomposition of nitrosamines; and Factors affecting the reactions of HEDTA, EDTA, and related compounds in SWM; 2. Product identification--Identification of HEDTA degradation products using {sup 13}C NMR spectroscopy; Identification of irradiated HEDTA degradation products using NMR; Degradation of model systems in SWM; and Role of Al in degradation of organic complexants; 3. Source of gases--Reactions in SY1-SIM-91B mixtures utilizing N-15 labelled reagents; Decomposition of nitrous oxide; Mechanistic pathways for formation of gases containing nitrogen from nitrite; and A redox analysis of HEDTA decomposition--How much ammonia might be formed?

  9. CHEMICAL COMPOSITION OF EXHAUST PARTICLES FROM GAS TURBINE ENGINES

    EPA Science Inventory

    A program was conducted to chemically characterize particulate emissions from a current technology, high population, gas turbine engine. Attention was focused on polynuclear aromatic compounds, phenols, nitrosamines and total organics. Polynuclear aromatic hydrocarbons (PAH) were...

  10. Variability of biomass chemical composition and rapid analysis using FT-NIR techniques

    SciTech Connect

    Liu, Lu; Ye, Philip; Womac, A.R.; Sokhansanj, Shahabaddine

    2010-04-01

    A quick method for analyzing the chemical composition of renewable energy biomass feedstock was developed by using Fourier transform near-infrared (FT-NIR) spectroscopy coupled with multivariate analysis. The study presents the broad-based model hypothesis that a single FT-NIR predictive model can be developed to analyze multiple types of biomass feedstock. The two most important biomass feedstocks corn stover and switchgrass were evaluated for the variability in their concentrations of the following components: glucan, xylan, galactan, arabinan, mannan, lignin, and ash. A hypothesis test was developed based upon these two species. Both cross-validation and independent validation results showed that the broad-based model developed is promising for future chemical prediction of both biomass species; in addition, the results also showed the method's prediction potential for wheat straw.

  11. Differential effects of conifer and broadleaf litter inputs on soil organic carbon chemical composition through altered soil microbial community composition.

    PubMed

    Wang, Hui; Liu, Shi-Rong; Wang, Jing-Xin; Shi, Zuo-Min; Xu, Jia; Hong, Pi-Zheng; Ming, An-Gang; Yu, Hao-Long; Chen, Lin; Lu, Li-Hua; Cai, Dao-Xiong

    2016-01-01

    A strategic selection of tree species will shift the type and quality of litter input, and subsequently magnitude and composition of the soil organic carbon (SOC) through soil microbial community. We conducted a manipulative experiment in randomized block design with leaf litter inputs of four native subtropical tree species in a Pinus massoniana plantation in southern China and found that the chemical composition of SOC did not differ significantly among treatments until after 28 months of the experiment. Contrasting leaf litter inputs had significant impacts on the amounts of total microbial, Gram-positive bacterial, and actinomycic PLFAs, but not on the amounts of total bacterial, Gram-negative bacterial, and fungal PLFAs. There were significant differences in alkyl/O-alkyl C in soils among the leaf litter input treatments, but no apparent differences in the proportions of chemical compositions (alkyl, O-alkyl, aromatic, and carbonyl C) in SOC. Soil alkyl/O-alkyl C was significantly related to the amounts of total microbial, and Gram-positive bacterial PLFAs, but not to the chemical compositions of leaf litter. Our findings suggest that changes in forest leaf litter inputs could result in changes in chemical stability of SOC through the altered microbial community composition. PMID:27256545

  12. Differential effects of conifer and broadleaf litter inputs on soil organic carbon chemical composition through altered soil microbial community composition

    PubMed Central

    Wang, Hui; Liu, Shi-Rong; Wang, Jing-Xin; Shi, Zuo-Min; Xu, Jia; Hong, Pi-Zheng; Ming, An-Gang; Yu, Hao-Long; Chen, Lin; Lu, Li-Hua; Cai, Dao-Xiong

    2016-01-01

    A strategic selection of tree species will shift the type and quality of litter input, and subsequently magnitude and composition of the soil organic carbon (SOC) through soil microbial community. We conducted a manipulative experiment in randomized block design with leaf litter inputs of four native subtropical tree species in a Pinus massoniana plantation in southern China and found that the chemical composition of SOC did not differ significantly among treatments until after 28 months of the experiment. Contrasting leaf litter inputs had significant impacts on the amounts of total microbial, Gram-positive bacterial, and actinomycic PLFAs, but not on the amounts of total bacterial, Gram-negative bacterial, and fungal PLFAs. There were significant differences in alkyl/O-alkyl C in soils among the leaf litter input treatments, but no apparent differences in the proportions of chemical compositions (alkyl, O-alkyl, aromatic, and carbonyl C) in SOC. Soil alkyl/O-alkyl C was significantly related to the amounts of total microbial, and Gram-positive bacterial PLFAs, but not to the chemical compositions of leaf litter. Our findings suggest that changes in forest leaf litter inputs could result in changes in chemical stability of SOC through the altered microbial community composition. PMID:27256545

  13. Chemical and stable-radiogenic isotope compositions of Polatlı-Haymana thermal waters (Ankara, Turkey)

    NASA Astrophysics Data System (ADS)

    Akilli, Hafize; Mutlu, Halim

    2016-04-01

    Complex tectono-magmatic evolution of the Anatolian land resulted in development of numerous geothermal areas through Turkey. The Ankara region in central Anatolia is surrounded by several basins which are filled with upper Cretaceous-Tertiary sediments. Overlying Miocene volcanics and step faulting along the margins of these basins played a significant role in formation of a number of low-enthalpy thermal waters. In this study, chemical and isotopic compositions of Polatlı and Haymana geothermal waters in the Ankara region are investigated. The Polatlı-Haymana waters with a temperature range of 24 to 43 °C are represented by Ca-(Na)-HCO3 composition implying derivation from carbonate type reservoir rocks. Oxygen-hydrogen isotope values of the waters are conformable with the Global Meteoric Water Line and point to a meteoric origin. The carbon isotopic composition in dissolved inorganic carbon (DIC) of the studied waters is between -21.8 and -1.34 permil (vs. VPDB). Marine carbonates and organic rocks are the main sources of carbon. There is a high correlation between oxygen (3.7 to 15.0 permil; VSMOW) and sulfur (-9.2 to 19.5 permil; VCDT) isotope compositions of sulfate in waters. The mixing of sulfate from dissolution of marine carbonates and terrestrial evaporite units is the chief process behind the observed sulfate isotope systematics of the samples. 87Sr/86Sr ratios of waters varying from 0.705883 to 0.707827 are consistent with those of reservoir rocks. The temperatures calculated by SO4-H2O isotope geothermometry are between 81 and 138 °C nearly doubling the estimates from chemical geothermometers.

  14. Influence of the chemical composition on gamma ray attenuation by fatty acids.

    PubMed

    Bhandal, G S; Singh, K

    1992-04-01

    The dependence of gamma ray attenuation on the chemical composition of fatty acids is investigated in the energy range from 10(-3) to 10(5) MeV. The mass attenuation coefficients (muF) and effective atomic numbers (Zeff) have been calculated for 27 different fatty acids. They show appreciable variation with the chemical composition of fatty acids in the region of gamma ray energies from 10(-3) to 10(5) MeV. PMID:1314792

  15. Growth, chemical composition and soil properties of Tipuana speciosa (Benth.) Kuntze seedlings irrigated with sewage effluent

    NASA Astrophysics Data System (ADS)

    Ali, Hayssam M.; Khamis, Mohamed H.; Hassan, Fatma A.

    2012-06-01

    This study was carried out at a greenhouse of Sabahia Horticulture Research Station, Alexandria, Egypt, to study the effect of sewage effluent on the growth and chemical composition of Tipuana speciosa (Benth.) Kuntze seedlings as well as on soil properties for three stages. The irrigation treatments were primary-treated wastewater and secondary-treated wastewater, in addition to tap water as control. Therefore, the treated wastewater was taken from oxidation ponds of New Borg El-Arab City. Results of these study revealed that the primary effluent treatment explored the highest significant values for vegetative growth and biomass, compared to the other treatments. In addition, the higher significant concentration and uptake of chemical composition in different plant parts were obtained from the primary effluent treatment during the three stages of irrigation. It was found that the concentration of heavy metals in either plant or soil was below as compared to the world-recommended levels. These findings suggested that the use of sewage effluent in irrigating T. speciosa seedlings grown in calcareous soil was beneficial for the improvement of soil properties and production of timber trees, and also important for the safe manner of disposal of wastewater.

  16. Surface composition determination of Pt--Sn alloys by chemical titration with carbon monoxide

    SciTech Connect

    Haner, A.H.; Ross, P.N. ); Bardi, U.; Atrei, A. )

    1992-07-01

    The use of chemical titration with carbon monoxide to determine the surface composition of Pt--Sn alloys was studied using Pt{sub 3}Sn single crystals of known surface composition. The surface composition of the (111) and (100) faces were determined independently by the combination of low-energy electron diffraction (LEED) crystallography and low-energy ion scattering (LEIS). CO was adsorbed on these surfaces to saturation at 250 K and thermally desorbed into a mass spectrometer. The area under the thermal desorption spectroscopy curve for the alloy surface was compared to the area under the curve for the pure Pt surface of the same orientation. The ratios were 0.5{plus minus}0.05 for Pt{sub 3}Sn(100) and 0.7{plus minus}0.05 for Pt{sub 3}Sn(111), in excellent agreement with the 50% Pt and 75% Pt surface compositions derived from LEED and LEIS. The success of the titration method in this case appears to be due to (a) selective adsorption of CO on Pt atoms and (b) the relatively weak effect of the Pt--Sn intermetallic bond on the Pt--CO bonding.

  17. Comparison of the chemical compositions and nutritive values of various pumpkin (Cucurbitaceae) species and parts.

    PubMed

    Kim, Mi Young; Kim, Eun Jin; Kim, Young-Nam; Choi, Changsun; Lee, Bog-Hieu

    2012-02-01

    Pumpkins have considerable variation in nutrient contents depending on the cultivation environment, species, or part. In this study, the general chemical compositions and some bioactive components, such as tocopherols, carotenoids, and β-sitosterol, were analyzed in three major species of pumpkin (Cucurbitaceae pepo, C. moschata, and C. maxima) grown in Korea and also in three parts (peel, flesh, and seed) of each pumpkin species. C. maxima had significantly more carbohydrate, protein, fat, and fiber than C. pepo or C. moschata (P < 0.05). The moisture content as well as the amino acid and arginine contents in all parts of the pumpkin was highest in C. pepo. The major fatty acids in the seeds were palmitic, stearic, oleic, and linoleic acids. C. pepo and C. moschata seeds had significantly more γ-tocopherol than C. maxima, whose seeds had the highest β-carotene content. C. pepo seeds had significantly more β-sitosterol than the others. Nutrient compositions differed considerably among the pumpkin species and parts. These results will be useful in updating the nutrient compositions of pumpkin in the Korean food composition database. Additional analyses of various pumpkins grown in different years and in different areas of Korea are needed. PMID:22413037

  18. Chemical Composition of Gas-Phase Oxidation Products from Biogenic Sources in the Southeast US during SOAS

    NASA Astrophysics Data System (ADS)

    Stark, H.; Massoli, P.; Thompson, S.; Yatavelli, L. R.; Mohr, C.; Brophy, P.; Murschell, T.; Hu, W.; Canagaratna, M.; Krechmer, J.; Junninen, H.; Hakala, J. P.; Day, D. A.; Campuzano Jost, P.; Palm, B. B.; Ortega, A. M.; Kimmel, J.; Cubison, M.; Lopez-Hilfiker, F.; Thornton, J. A.; Baumann, K.; Edgerton, E.; Farmer, D.; Jimenez, J. L.; Jayne, J. T.; Worsnop, D. R.

    2013-12-01

    Reduced species emitted to the atmosphere are chemically transformed by atmospheric oxidants. The measurement of the large number of resulting oxidized compounds is crucial to understand and quantify these transformation processes. We analyzed datasets from four high-resolution time-of-flight chemical ionization mass spectrometers (HRToF-CIMS) during the Southern Oxidant and Aerosol Study (SOAS) in June and July 2013 at the Alabama Supersite in the Southeast U.S. These datasets allow specification and quantification of the multiple gas-phase compounds produced by chemical oxidation. The mass spectrometers used different reagent ions, nitrate (NO3-), acetate (CH3COO-), and iodide (I-). In this study, we will present the chemical composition of isoprene and terpene oxidation products as measured by the different techniques. When comparing the concentration and composition at different conditions (e.g., time of day, NOx levels, aerosol loading, RH), differences in gas-phase composition provide indications of both the changes in chemical processing arising from the different conditions as well as different sensitivities of the reagent ions. We will discuss these differences in terms of bulk chemical parameters such as carbon oxidation state, carbon number and oxygen-to-carbon ratio.

  19. Chemical compositions, free amino acid contents and antioxidant activities of Hanwoo (Bos taurus coreanae) beef by cut

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to evaluate chemical compositions, free amino acid contents, and antioxidant activities of different cuts of Hanwoo (Bos taurus coreanae) beef. Beef preferences and prices in the Korean market depend on cut. Therefore, comparisons were made between high-preference (gr...

  20. Nextel{trademark}/SiC composites fabricated using forced chemical vapor infiltration

    SciTech Connect

    Weaver, B.L.; Lowden, R.A.; McLaughlin, J.C.; Stinton, D.P.; Besmann, T.M.; Schwarz, O.J.

    1993-06-01

    Oxide fiber-reinforced silicon carbide matrix composites were fabricated employing the forced-flow, thermal gradient chemical vapor infiltration (FCVI) process. Composites using Nextel{sup TM} fibers of varying composition were prepared to investigate the effectiveness of each Nextel{sup TM} fiber as a reinforcement for the given matrix. A carbon interface coating was used for the baseline materials, however, alternate interlayers with improved oxidation resistance were also explored Room-temperature flexure strengths of as-fabricated composites and specimens heated in air at 1273 K were measured and compared to results for other SiC-matrix composites.

  1. Chemical and sulfur isotopic composition of precipitation in Beijing, China.

    PubMed

    Zhu, Guangxu; Guo, Qingjun; Chen, Tongbin; Lang, Yunchao; Peters, Marc; Tian, Liyan; Zhang, Hanzhi; Wang, Chunyu

    2016-03-01

    China is experiencing serious acid rain contamination, with Beijing among the worst-hit areas. To understand the chemical feature and the origin of inorganic ions in precipitation of Beijing, 128 precipitation samples were collected and analyzed for major water-soluble ions and δ(34)S. The pH values ranged from 3.68 to 7.81 and showed a volume weighted average value (VWA) of 5.02, with a frequency of acid rain of 26.8 %. The VWA value of electrical conductivity (EC) was 68.6 μS/cm, which was nearly 4 times higher than the background value of northern China. Ca(2+) represented the main cation; SO4 (2-) and NO3 (-) were the dominant anion in precipitation. Our study showed that SO4 (2-) and NO3 (-) originated from coal and fossil fuel combustion; Ca(2+), Mg(2+), and K(+) were from the continental sources. The δ(34)S value of SO4 (2-) in precipitation ranged from +2.1 to +12.8‰ with an average value of +4.7‰. The δ(34)S value showed a winter maximum and a summer minimum tendency, which was mainly associated with temperature-dependent isotope equilibrium fractionation as well as combustion of coal with relatively positive δ(34)S values in winter. Moreover, the δ(34)S values revealed that atmospheric sulfur in Beijing are mainly correlated to coal burning and traffic emission; coal combustion constituted a significant fraction of the SO4 (2-) in winter precipitation. PMID:26573310

  2. Chemical compositions of the moon, earth, and eucrite parent body

    NASA Technical Reports Server (NTRS)

    Anders, E.

    1977-01-01

    Model compositions of the moon and earth were calculated on the assumption that these planets had experienced chondrite-like nebular fractionation processes. The model correctly predicts the abundance ratios of certain volatile/refractory element pairs (e.g., Cd/Ba, Ga/La, Sn/Th, and Pb/U), the density of the moon, and the major rock types. The model is also used to reconstruct the composition of the parent eucrite body, which resembles the moon except for a lower content of refractory elements.

  3. A new Method to Study Aerosol Source Contributions Along the Tracks of air Parcels and its Application to the Near-ground Level Aerosol Chemical Composition in Central Europe

    NASA Astrophysics Data System (ADS)

    Lammel, G.; Brüggemann, E.; Gnauk, T.; Müller, K.; Neusüss, C.; Röhrl, A.

    2002-12-01

    A novel method is presented to reveal significance and contribution of source types and characteristic formation times for individual aerosol constituents: Backward trajectory analyses are used to allocate time resolved information about residence time of air masses over different types of ground surfaces. The correlation coefficients between the concentrations of individual aerosol constituents and the residence times of air masses over certain types of ground surfaces at a certain time difference to arrival time were used to compose time profiles. The method has been applied to aerosol chemical composition data from various seasons and from rural and urban sites in Germany. For various ground types we obtain correlations between weighted (and normalized) residence times on one hand and the abundances of trace constituents known as markers for marine (Na, Cl), continental-rural (e.g. mineral dust components) and industrial sources (e.g., organic and elemental C, As, Pb) on the other hand. The occurrence of super-A~¦m particulate NO3- in central Europe is found to originate largely in the marginal seas. The time profiles indicate that the characteristic formation time of the secondary aerosol is 48-72 h, while the coarse mode particulate matter including some heavy metals was determined by emissions < 36 h back. The occurrence of particulate elemental carbon was temporally bimodal with regard to the elapsed time since emission (maxima at Δt ~ 60 h and Δt = 12-24 h), which indicates the presence of two types undergoing a selection process during aging. The factors which explained most of the variability of the aerosol chemical composition were the season and the type of ground surface in contact with the air mass during its transport. More immediate influences on the samples, such as the weather conditions during sampling and the type of site (rural or urban) were distinctly less significant.

  4. Chemical composition of aerosols over Bay of Bengal during pre-monsoon: Dominance of anthropogenic sources

    NASA Astrophysics Data System (ADS)

    Nair, Prabha R.; George, Susan K.; Aryasree, S.; Jacob, Salu

    2014-03-01

    Total suspended particulates were collected from the marine boundary layer of Bay of Bengal (BoB) as part of the Integrated Campaign for Aerosols gases & Radiation Budget (ICARB) conducted under the Geosphere Biosphere Programme of Indian Space Research Organisation during pre-monsoon period. These samples were analyzed to quantify various chemical species and to bring out a comprehensive and quantitative picture of the chemical composition of aerosols in the marine environment of Bay of Bengal. Almost all the species showed highest mass concentration over north/head BoB. On the other hand, their mass fractions were high over mid/south BoB which has implications on the radiative forcing in this region. The source characteristics of various species were identified using specific chemical components as tracers. Presence of significant amount of non-sea-salt aerosols (~7-8 times of sea-salt) and several trace species like Ni, Pb, Zn, etc were observed in this marine environment indicating significant continental/anthropogenic influence. An approximate estimate of the contributions of anthropogenic and natural aerosols to the total aerosol mass loading showed prominence of anthropogenic component over mid and south BoB also. Based on this study first-cut aerosol chemical models were evolved for BoB region.

  5. Empirical Studies on Television Composition.

    ERIC Educational Resources Information Center

    Metallinos, Nikos

    A review of research on television's major compositional factors was undertaken to determine the status of such research and to note the major variables involved in the structure of television pictures. It was found that such research could be grouped in four categories--lighting and color, staging, editing, and sound--and that these areas covered…

  6. ON THE MORPHOLOGY AND CHEMICAL COMPOSITION OF THE HR 4796A DEBRIS DISK

    SciTech Connect

    Rodigas, Timothy J.; Weinberger, Alycia; Stark, Christopher C.; Debes, John H.; Chen, Christine; Hinz, Philip M.; Close, Laird; Smith, Paul S.; Males, Jared R.; Skemer, Andrew J.; Follette, Katherine B.; Morzinski, Katie; Wu, Ya-Lin; Schneider, Glenn; Puglisi, Alfio; Briguglio, Runa; Esposito, Simone; Pinna, Enrico; Riccardi, Armando; Xompero, Marco

    2015-01-10

    We present resolved images of the HR 4796A debris disk using the Magellan adaptive optics system paired with Clio-2 and VisAO. We detect the disk at 0.77 μm, 0.91 μm, 0.99 μm, 2.15 μm, 3.1 μm, 3.3 μm, and 3.8 μm. We find that the deprojected center of the ring is offset from the star by 4.76 ± 1.6 AU and that the deprojected eccentricity is 0.06 ± 0.02, in general agreement with previous studies. We find that the average width of the ring is 14{sub −2}{sup +3}% (11.1{sub −1.6}{sup +2.4} AU), also comparable to previous measurements. Combining our new scattered light data with archival Hubble Space Telescope images at ∼0.5-2 μm, along with previously unpublished Spitzer/MIPS thermal emission data and all other literature thermal data, we set out to constrain the chemical composition of the dust grains. After testing 19 individual root compositions and more than 8400 unique mixtures of these compositions, we find that good fits to the scattered light alone and thermal emission alone are discrepant, suggesting that caution should be exercised if fitting to only one or the other. When we fit to both data sets simultaneously, we find that silicates and organics are generally the most favored, while large abundances of water ice are usually not favored. These results suggest the HR 4796A dust grains are similar to interstellar dust and solar system comets, though improved modeling is necessary to place better constraints on the exact chemical composition of the dust.

  7. Chemical vapor deposited diamond-on-diamond powder composites (LDRD final report)

    SciTech Connect

    Panitz, J.K.; Hsu, W.L.; Tallant, D.R.; McMaster, M.; Fox, C.; Staley, D.

    1995-12-01

    Densifying non-mined diamond powder precursors with diamond produced by chemical vapor infiltration (CVI) is an attractive approach for forming thick diamond deposits that avoids many potential manufacturability problems associated with predominantly chemical vapor deposition (CVD) processes. The authors developed techniques for forming diamond powder precursors and densified these precursors in a hot filament-assisted reactor and a microwave plasma-assisted reactor. Densification conditions were varied following a fractional factorial statistical design. A number of conclusions can be drawn as a result of this study. High density diamond powder green bodies that contain a mixture of particle sizes solidify more readily than more porous diamond powder green bodies with narrow distributions of particle sizes. No composite was completely densified although all of the deposits were densified to some degree. The hot filament-assisted reactor deposited more material below the exterior surface, in the interior of the powder deposits; in contrast, the microwave-assisted reactor tended to deposit a CVD diamond skin over the top of the powder precursors which inhibited vapor phase diamond growth in the interior of the powder deposits. There were subtle variations in diamond quality as a function of the CVI process parameters. Diamond and glassy carbon tended to form at the exterior surface of the composites directly exposed to either the hot filament or the microwave plasma. However, in the interior, e.g. the powder/substrate interface, diamond plus diamond-like-carbon formed. All of the diamond composites produced were grey and relatively opaque because they contained flawed diamond, diamond-like-carbon and glassy carbon. A large amount of flawed and non-diamond material could be removed by post-CVI oxygen heat treatments. Heat treatments in oxygen changed the color of the composites to white.

  8. On the Morphology and Chemical Composition of the HR 4796A Debris Disk

    NASA Astrophysics Data System (ADS)

    Rodigas, Timothy J.; Stark, Christopher C.; Weinberger, Alycia; Debes, John H.; Hinz, Philip M.; Close, Laird; Chen, Christine; Smith, Paul S.; Males, Jared R.; Skemer, Andrew J.; Puglisi, Alfio; Follette, Katherine B.; Morzinski, Katie; Wu, Ya-Lin; Briguglio, Runa; Esposito, Simone; Pinna, Enrico; Riccardi, Armando; Schneider, Glenn; Xompero, Marco

    2015-01-01

    We present resolved images of the HR 4796A debris disk using the Magellan adaptive optics system paired with Clio-2 and VisAO. We detect the disk at 0.77 μm, 0.91 μm, 0.99 μm, 2.15 μm, 3.1 μm, 3.3 μm, and 3.8 μm. We find that the deprojected center of the ring is offset from the star by 4.76 ± 1.6 AU and that the deprojected eccentricity is 0.06 ± 0.02, in general agreement with previous studies. We find that the average width of the ring is 14+3-2% (11.1+2.4-1.6 AU), also comparable to previous measurements. Combining our new scattered light data with archival Hubble Space Telescope images at ~0.5-2 μm, along with previously unpublished Spitzer/MIPS thermal emission data and all other literature thermal data, we set out to constrain the chemical composition of the dust grains. After testing 19 individual root compositions and more than 8400 unique mixtures of these compositions, we find that good fits to the scattered light alone and thermal emission alone are discrepant, suggesting that caution should be exercised if fitting to only one or the other. When we fit to both data sets simultaneously, we find that silicates and organics are generally the most favored, while large abundances of water ice are usually not favored. These results suggest the HR 4796A dust grains are similar to interstellar dust and solar system comets, though improved modeling is necessary to place better constraints on the exact chemical composition of the dust. This paper includes data obtained at the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

  9. Chemically synthesized lithium peroxide composite cathodes for closed system Li-O2 batteries.

    PubMed

    Bhargav, Amruth; Guo, Wei; Fu, Yongzhu

    2016-04-28

    A binder-free lithium peroxide-carbon nanofiber composite cathode was synthesized chemically to be used in a closed system lithium-oxygen battery without external supply of oxygen. This cathode enhances the closed system performance and exhibits good rechargeability with cyclability up to 50 cycles. This composite cathode provides scope for full cell development. PMID:27032704

  10. Lunar clinopyroxenes: Chemical composition, structural state, and texture

    USGS Publications Warehouse

    Ross, M.; Bence, A.E.; Dwornik, E.J.; Clark, J.R.; Papike, J.J.

    1970-01-01

    Single-crystal x-ray diffraction, microprobe, optical and electron optical examinations of clinopyroxenes from Apollo 11 lunar samples 10003, 10047, 10050, and 10084 show that generally the crystals are composed of (001) augite-pigeonite intergrowths in varying ratios. Transmission electron micrographs reveal abundant exsolution lamellae, many only 60 A?? thick. In addition to the phase inhomogeneities, primary chemical inhomogeneities are clearly demonstrated. There are reciprocal relationships between calcium and iron and between Ti4+ + 2Al and R2+ + 2Si. Our evidence suggests that a chemically inhomogeneous subcalcic C2/c augite was the only primary pyroxene from which pigeonite later exsolved.

  11. The Composition of 433 Eros: A Mineralogical-Chemical Synthesis

    NASA Technical Reports Server (NTRS)

    McCoy, T. J.; Gaffey, M.; Bell, J. F., III; Boynton, W. V.; Burbine, T. H.; Chapman, C. R.; Cheng, A.; Clark, P. E.; Evans, L. G.; Gorenstein, P.

    2001-01-01

    We report on an effort with the Near-Infrared Spectrometer/Multi-Spectral Imager (NIS/MSI) and X-ray/Gamma-ray Spectrometer (XGRS) teams to synthesize our data sets to constrain the relationship between Eros and meteorites; the mineralogy, abundances and compositions of Eros; and the processes that formed Eros. Additional information is contained in the original extended abstract.

  12. Rapid computation of chemical equilibrium composition - An application to hydrocarbon combustion

    NASA Technical Reports Server (NTRS)

    Erickson, W. D.; Prabhu, R. K.

    1986-01-01

    A scheme for rapidly computing the chemical equilibrium composition of hydrocarbon combustion products is derived. A set of ten governing equations is reduced to a single equation that is solved by the Newton iteration method. Computation speeds are approximately 80 times faster than the often used free-energy minimization method. The general approach also has application to many other chemical systems.

  13. The influence of chemical composition of commercial lemon essential oils on the growth of Candida strains.

    PubMed

    Białoń, M; Krzyśko-Łupicka, T; Koszałkowska, M; Wieczorek, P P

    2014-02-01

    Candida yeasts are saprophytes naturally present in the environment and forming colonies on human mucous membranes and skin. They are opportunistic fungi that cause severe and even fatal infections in immunocompromised individuals. Several essential oils, including eucalyptus, pine, cinnamon and lemon, have been shown to be effective against Candida strains. This study addresses the chemical composition of some commercial lemon essential oils and their antifungal potential against selected Candida yeast strains. Antifungal potential and minimum inhibitory concentrations were determined for six commercial lemon essential oils against five Candida yeast strains (Candida albicans 31, Candida tropicalis 32, Candida glabrata 33, Candida glabrata 35 and Candida glabrata 38). On the basis of the GCMS analysis, it was found that the tested lemon essential oils had different chemical compositions, but mostly, they contained almost exclusively terpenes and oxygenated terpenes. The tests show that antifungal potential of lemon essential oils against Candida yeast strains was related to the high content of monoterpenoids and the type of Candida strains. From six tested commercial oils, only four (ETJA, Vera-Nord, Avicenna-Oil and Aromatic Art) shows antifungal potential against three Candida species (C. albicans, C. tropicalis and C. glabrata). Vera-Nord and Avicenna-Oil show the best activity and effectively inhibit the growth of the C. albicans strain across the full range of the concentrations used. Our study characterises lemon essential oils, which could be used as very effective natural remedies against candidiasis caused by C. albicans. PMID:24436010

  14. [Nondestructive analysis of chemical composition, structure and mineral constitution of jadeite jade].

    PubMed

    Sun, Fang-Ce; Zhao, Hong-Xia; Gan, Fu-Xi

    2011-11-01

    The techniques of portable energy-dispersive X-ray fluorescence analysis (PXRF), proton induced X-ray emission spectroscopy (LRS) were employed to analyze the chemical composition, structure and mineral constitution of 12 samples. The results indicated that the chemical compositions determined by PXRF and PIXE are well comparable and most samples are constituted by almost pure jadeite with low concentration of secondary elements. One sample contains a little omphacite and one sample is composed only by omphacite. Raman characteristic peaks of jadeite occurred at 201, 372, 698, 985 and 1 037 cm(-1), while those of omphacite located at 680 and 1 017 cm(-1). By using laser Raman spectroscopy for testing the fissures of the samples, wax in 3 samples and epoxy resin in one sample were found. Raman characteristic peaks of wax located at 2 846 and 2 880 cm(-1) and those of epoxy resin occurred at 2 924 and 3 065 c(-1). The application of nondestructive techniques in jadeite jade broadens the range of samples for future study and provides technical support for jadeite jade's further study, identification and classification. PMID:22242534

  15. Influence of aqueous chemistry on the chemical composition of fog water and interstitial aerosol in Fresno

    NASA Astrophysics Data System (ADS)

    Kim, Hwajin; Ge, Xinlei; Collier, Sonya; Xu, Jianzhong; Sun, Yele; Wang, Youliang; Herckes, Pierre; Zhang, Qi

    2015-04-01

    A measurement study was conducted in the Central Valley (Fresno) of California in January 2010, during which radiation fog events were frequently observed. Fog plays important roles in atmospheric chemistry by scavenging aerosol particles and trace gases and serving as a medium for various aqueous-phase reactions. Understanding the effects of fog on the microphysical and chemical processing of aerosol particles requires detailed information on their chemical composition. In this study, we characterized the chemical composition of fog water and interstitial aerosol particles to study the effects of fog processing on aerosol properties. Fog water samples were collected during the 2010 Fresno campaigns with a Caltech Active Strand Cloud water Collector (CASCC) while interstitial submicron aerosols were characterized in real time with an Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and a scanning Mobility Particle Sizer (SMPS). The fog water samples were later analyzed using the HR-ToF-AMS, ion chromatography, and a total carbon analyzer. The chemical composition and characteristics of interstitial particles during the fog events were compared to those of dissolved inorganic and organic matter in fog waters. Compared to interstitial aerosols, fog water is composed of a higher fraction of ammonium nitrate and oxygenated organics, due to aqueous formation of secondary aerosol species as well as enhanced gas-to-particle partitioning of water soluble species under water rich conditions. Sulfate is formed most efficiently in fog water although its contribution to total dissolved mass is relatively low. The HR-ToF-AMS mass spectra of organic matter in fog water (FOM) are very similar to that of oxygenated organic aerosols (OOA) derived from positive matrix factorization (PMF) of the HR-ToF-AMS spectra of ambient aerosol (r2 = 0.96), but FOM appears to contain a large fraction of acidic functional groups than OOA. FOM is also enriched of

  16. Floral Scent in Wisteria: Chemical Composition, Emission Pattern and Regulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Volatile chemicals emitted from the flowers of Chinese wisteria (Wisteria sinenesis) and Japanese wisteria (W. floribunda) were collected using a dynamic headspace technique and identified by a gas chromatography-mass spectrometry. About 30 and 22 compounds were detected from Chinese wisteria and Ja...

  17. [Rapid identification of chemical composition in safflower with UHPLC-LTQ-Orbitrap].

    PubMed

    Wang, Song-song; Ma, Yan; Zhang, Yi; Li, De-feng; Yang, Hong-jun; Liang, Ri-xin

    2015-04-01

    The UHPLC-LTQ-Orbitrap high resolution mass spectrometer was used to explore the chemical compositions in safflower. The rapid separation of the compositions was conducted by the UHPLC, following by high resolution full scan and MS2 scan, under the positive and negative ion mode. The chemical formula of compositions were deduced by full scan data in less than 5, then the potential structures were confirmed by the MS2 data. Forty-nine compounds were detected, of which 26 was identified, and 5 compounds was validated by the standard substances. PMID:26281560

  18. ENERGY SPECTRUM AND CHEMICAL COMPOSITION OF ULTRAHIGH ENERGY COSMIC RAYS FROM SEMI-RELATIVISTIC HYPERNOVAE

    SciTech Connect

    Liu Ruoyu; Wang Xiangyu

    2012-02-10

    It has been suggested that hypernova remnants, with a substantial amount of energy in semi-relativistic ejecta, can accelerate intermediate mass or heavy nuclei to ultrahigh energies and provide a sufficient amount of energy in cosmic rays to account for the observed flux. We here calculate the expected energy spectrum and chemical composition of ultrahigh energy cosmic rays from such semi-relativistic hypernovae. With a chemical composition equal to that of the hypernova ejecta and a flat or hard spectrum for cosmic rays at the sources, the spectrum and composition of the propagated cosmic rays observed at the Earth can be compatible with the measurements by the Pierre Auger Observatory.

  19. Tying Biological Activity to Changes in Sea Spray Aerosol Chemical Composition via Single Particle Analyses

    NASA Astrophysics Data System (ADS)

    Sultana, C. M.; Lee, C.; Collins, D. B.; Axson, J. L.; Laskina, O.; Grandquist, J. R.; Grassian, V. H.; Prather, K. A.

    2014-12-01

    In remote marine environments, sea spray aerosols (SSA) often represent the greatest aerosol burden, thus having significant impacts on direct radiative interactions and cloud processes. Previous studies have shown that SSA is a complex mixture of inorganic salts and an array of dissolved and particulate organic components. Enrichment of SSA organic content is often correlated to seawater chlorophyll concentrations, a measure of oceanic biological activity. As the physical and chemical properties of aerosols control their radiative effects, recent studies conducted by the Center for Aerosol Impacts on Climate and the Environment have endeavored to further elucidate the ties between marine biological activity and primary SSA chemical composition using highly time resolved single particle analyses. A series of experiments performed in the recently developed Marine Aerosol Reference Tank evaluated the effect of changing marine microbial populations on SSA chemical composition, which was monitored via an aerosol time-of-flight mass spectrometer and a variety of offline spectroscopic and microscopic techniques. Each experiment was initiated using unfiltered and untreated seawater, thus maintaining a high level of biogeochemical complexity. This study is the first of its kind to capture daily changes in the primary SSA mixing state over the growth and death of a natural phytoplankton bloom. Increases in organic aerosol types (0.4-3 μm), internally and externally mixed with sea salt, could not be correlated to chlorophyll concentrations. Maximum production of these populations occurred two to four days after the in vivo chlorophyll fluorescence peaked in intensity. This work is in contrast to the current paradigm of correlating SSA organic content to seawater chlorophyll concentration.

  20. A rapid method for the computation of equilibrium chemical composition of air to 15000 K

    NASA Technical Reports Server (NTRS)

    Prabhu, Ramadas K.; Erickson, Wayne D.

    1988-01-01

    A rapid computational method has been developed to determine the chemical composition of equilibrium air to 15000 K. Eleven chemically reacting species, i.e., O2, N2, O, NO, N, NO+, e-, N+, O+, Ar, and Ar+ are included. The method involves combining algebraically seven nonlinear equilibrium equations and four linear elemental mass balance and charge neutrality equations. Computational speeds for determining the equilibrium chemical composition are significantly faster than the often used free energy minimization procedure. Data are also included from which the thermodynamic properties of air can be computed. A listing of the computer program together with a set of sample results are included.

  1. Fabrication of fiber-reinforced composites by chemical vapor infiltration

    SciTech Connect

    Besmann, T.M.; Stinton, D.P.; Matlin, W.M.; Liaw, P.K.

    1996-08-01

    Processing equipment for the infiltration of fiber-reinforced composite tubes is being designed that incorporates improvements over the equipment used to infiltrate disks. A computer-controlled machine-man interface is being developed to allow for total control of all processing variables. Additionally, several improvements are being made to the furnace that will reduce the complexity and cost of the process. These improvements include the incorporation of free standing preforms, cast mandrels, and simpler graphite heating elements.

  2. The chemical composition of the Lambda Bootis stars

    NASA Technical Reports Server (NTRS)

    Baschek, B.; Slettebak, A.

    1988-01-01

    Measurements of the equivalent widths of 24 ultraviolet lines from IUE spectra of 10 Lambda Bootis or suspected Lambda Bootis stars and 19 normal standard stars of spectral types B8-A7 have been compared with line strengths determined using model atmospheres. Abundance differences are estimated via a differential analysis technique. It is found that the ratio of C, N, and O to the heavier elements Mg to Ni is significantly larger than that for solar composition stars.

  3. Fabrication of fiber-reinforced composites by chemical vapor infiltration

    SciTech Connect

    Besmann, T.M.; Matlin, W.M.; Stinton, D.P.; Liaw, P.K.

    1996-06-01

    Processing equipment for the infiltration of fiber-reinforced composite tubes is being designed that incorporates improvements over the equipment used to infiltrate disks. A computer-controlled machine-man interface is being developed to allow for total control of all processing variables. Additionally, several improvements are being made to the furnace that will reduce the complexity and cost of the process. These improvements include the incorporation of free standing preforms, cast mandrels, and simpler graphite heating elements.

  4. Chemical Case Studies: Science-Society "Bonding."

    ERIC Educational Resources Information Center

    Hofstein, Avi; Nae, Nehemia

    1981-01-01

    Describes a unit designed to illustrate the "science-society-technology connection," in which three case studies of the chemical industry in Israel are presented to high school chemistry students. Chosen for the unit are case studies on copper production in Timna, on plastics, and on life from the Dead Sea. (CS)

  5. On the chemical composition of L-chondrites

    NASA Technical Reports Server (NTRS)

    Neal, C. W.; Dodd, R. T.; Jarosewich, E.; Lipschutz, M. E.

    1980-01-01

    Radiochemical neutron activation analysis of Ag, As, Au, Bi, Co, Cs, Ga, In, Rb, Sb, Te, Tl, and Zn and major element data in 14 L4-6 and 3 LL5 chondrites indicates that the L group is unusually variable and may represent at least 2 subgroups differing in formation history. Chemical trends in the S/Fe rich subgroup support textural evidence indicating late loss of a shock formed Fe-Ni-S melt; the S/Fe poor subgroup seemingly reflects nebular fractionation only. Highly mobile In and Zn apparently reflect shock induced loss from L chondrites. However, contrasting chemical trends in several L chondrite sample sets indicate that these meteorites constitute a more irregular sampling of, or more heterogeneous parent material than do carbonaceous or enstatite chondrites. Data for 15 chondrites suggest higher formation temperatures and/or degrees of shock than for LL5 chondrites.

  6. Chemical Composition of Micrometer-Sized Filaments in an Aragonite Host by a Miniature Laser Ablation/Ionization Mass Spectrometer.

    PubMed

    Tulej, Marek; Neubeck, Anna; Ivarsson, Magnus; Riedo, Andreas; Neuland, Maike B; Meyer, Stefan; Wurz, Peter

    2015-08-01

    Detection of extraterrestrial life is an ongoing goal in space exploration, and there is a need for advanced instruments and methods for the detection of signatures of life based on chemical and isotopic composition. Here, we present the first investigation of chemical composition of putative microfossils in natural samples using a miniature laser ablation/ionization time-of-flight mass spectrometer (LMS). The studies were conducted with high lateral (∼15 μm) and vertical (∼20-200 nm) resolution. The primary aim of the study was to investigate the instrument performance on micrometer-sized samples both in terms of isotope abundance and element composition. The following objectives had to be achieved: (1) Consider the detection and calculation of single stable isotope ratios in natural rock samples with techniques compatible with their employment of space instrumentation for biomarker detection in future planetary missions. (2) Achieve a highly accurate chemical compositional map of rock samples with embedded structures at the micrometer scale in which the rock matrix is easily distinguished from the micrometer structures. Our results indicate that chemical mapping of strongly heterogeneous rock samples can be obtained with a high accuracy, whereas the requirements for isotope ratios need to be improved to reach sufficiently large signal-to-noise ratio (SNR). PMID:26247475

  7. Chemical composition of Nigella sativa Linn: Part 2 Recent advances.

    PubMed

    Akram Khan, M; Afzal, M

    2016-06-01

    The black cumin or Nigella sativa L. seeds have many acclaimed medicinal properties such as bronchodilatory, hypotensive, antibacterial, antifungal, analgesic, anti-inflammatory and immunopotentiating. This review article is an update on the previous article published on Nigella sativa L. in this journal in 1999. It covers the medicinal properties and chemical syntheses of the alkaloids isolated from the seeds of the herb. PMID:27068721

  8. Regulating continent growth and composition by chemical weathering

    USGS Publications Warehouse

    Lee, C.-T.A.; Morton, D.M.; Little, M.G.; Kistler, R.; Horodyskyj, U.N.; Leeman, W.P.; Agranier, A.

    2008-01-01

    Continents ride high above the ocean floor because they are underlain by thick, low-density, Si-rich, and Mg-poor crust. However, the parental magmas of continents were basaltic, which means they must have lost Mg relative to Si during their maturation into continents. Igneous differentiation followed by lower crustal delamination and chemical weathering followed by subduction recycling are possible solutions, but the relative magnitudes of each process have never been quantitatively constrained because of the lack of appropriate data. Here, we show that the relative contributions of these processes can be obtained by simultaneous examination of Mg and Li (an analog for Mg) on the regional and global scales in arcs, delaminated lower crust, and river waters. At least 20% of Mg is lost from continents by weathering, which translates into >20% of continental mass lost by weathering (40% by delamination). Chemical weathering leaves behind a more Si-rich and Mg-poor crust, which is less dense and hence decreases the probability of crustal recycling by subduction. Net continental growth is thus modulated by chemical weathering and likely influenced by secular changes in weathering mechanisms. ?? 2008 by The National Academy of Sciences of the USA.

  9. Regulating continent growth and composition by chemical weathering

    PubMed Central

    Lee, Cin-Ty Aeolus; Morton, Douglas M.; Little, Mark G.; Kistler, Ronald; Horodyskyj, Ulyana N.; Leeman, William P.; Agranier, Arnaud

    2008-01-01

    Continents ride high above the ocean floor because they are underlain by thick, low-density, Si-rich, and Mg-poor crust. However, the parental magmas of continents were basaltic, which means they must have lost Mg relative to Si during their maturation into continents. Igneous differentiation followed by lower crustal delamination and chemical weathering followed by subduction recycling are possible solutions, but the relative magnitudes of each process have never been quantitatively constrained because of the lack of appropriate data. Here, we show that the relative contributions of these processes can be obtained by simultaneous examination of Mg and Li (an analog for Mg) on the regional and global scales in arcs, delaminated lower crust, and river waters. At least 20% of Mg is lost from continents by weathering, which translates into >20% of continental mass lost by weathering (40% by delamination). Chemical weathering leaves behind a more Si-rich and Mg-poor crust, which is less dense and hence decreases the probability of crustal recycling by subduction. Net continental growth is thus modulated by chemical weathering and likely influenced by secular changes in weathering mechanisms. PMID:18362343

  10. Effect of bio-regulator and foliar fertilizers on chemical composition and yield of soybean.

    PubMed

    Piccinin, Gleberson Guillen; Braccini, Alessandro Lucca; da Silva, Luiz Henrique; Mariucci, Giovanna Emanuêlle Gonçalves; Suzukawa, Andréia Kazumi; Dan, Lilian Gomes de Morais; Tonin, Telmo António

    2013-11-15

    Current study evaluates the effects of bio-regulator associated with foliar fertilizers on the yield components, productivity and chemical composition of soybean. The experimental design was entirely randomized blocks, with four replications. The treatments consisted of: T1-absolute control, T2-application of 0.25 L h(-1) Stimulate in R1 stage of development, T3-application of 0.25 L h(-1) Stimulate and 3 L h(-1) Sett in R1, T4-application of 0.25 L h(-1) Stimulate and 3 L h(-1) Sett in R1 and 0.25 L h(-1) Stimulate and 2 L h(-1) Mover in R5.1; T5-application of 0.25 L h(-1) Stimulate and 3 L h(-1) Sett in R1 and 2 L h(-1) Mover in R5.1, T6-application of 3 L h(-1) Sett in R1 and 0.25 L h(-1) Stimulate and 2 L h(-1) Mover in R5.1 and T7-application of 0.25 L h(-1) Stimulate and 2 L h(-1) Mover in R1. Application of Sett and Mover is a potentially efficient handling as it favors the soybean agronomic performance in R1 stage. Chemical composition of processed grains has influence with applying bio-regulator and foliar fertilizers. PMID:24511692

  11. Chemical composition and starch digestibility in flours from Polish processed legume seeds.

    PubMed

    Piecyk, Małgorzata; Wołosiak, Rafał; Drużynska, Beata; Worobiej, Elwira

    2012-12-01

    The study was undertaken to determine the effect of various treatments, i.e. cooking after soaking, freezing after cooking and storage at a low temperature (-18°C, 21days), and autoclaving, of Polish cultivars of bean, pea and lentil seeds on the chemical composition and starch digestibility of the resultant flours. The cooking of seeds caused a significant decrease in contents of ash (by 11-48%), polyphenols (by 10-70%) and protein (to 19%) in flours made of bean. In addition, analyses demonstrated significantly decreased contents of resistant starch, RS (by 61-71%) and slowly digestible starch, SDS (by 56-84%). Storage of frozen seeds resulted in insignificant changes in the chemical composition, and in increased contents of both RS and SDS. The flours produced upon the autoclaving process were characterized by similar changes in the contents of ash and protein as in cooked seeds, yet losses of polyphenols were lower and, simultaneously, contents of RS and SDS were higher. All the analyzed flours were shown to be characterized by a reduced content of amylose in starch, which might have affected its digestibility. This was indicated by a strict negative correlation reported between the value of the starch digestion index (SDRI) and amylose content of starch (r=0.84, p>0.05). PMID:22953824

  12. Chemical Compositions and Antimicrobial Activities of Ocimum sanctum L. Essential Oils at Different Harvest Stages

    PubMed Central

    Saharkhiz, Mohammad Jamal; Kamyab, Amir Alam; Kazerani, Narges Khatoon; Zomorodian, Kamiar; Pakshir, Keyvan; Rahimi, Mohammad Javad

    2014-01-01

    Background: Essential Oils (EOs) possess antibacterial properties and represent a natural source to treat infections and prevent food spoilage. Their chemical composition might be affected by the environmental condition and the developmental growth stages of the plant. Objectives: The current study aimed to determine the variations in chemical compositions and antimicrobial activities of the EOs of Ocimum sanctum L. at different stages of harvesting. Materials and Methods: The oils constituents were analyzed by gas chromatography/mass spectrometry (GC/MS). The effects of three different harvest stages of O. sanctum EOs against most common causes of food-borne were evaluated by broth micro-dilution method as recommended by the Clinical and Laboratory Standards Institute (CLSI). Results: The analysis of the EOs indicated that eugenol was the major compound of the EOs at all developmental stages which reached its maximum level at the second stage. The results showed that the tested EOs exhibited antimicrobial activities against all of the examined pathogens at concentrations of 0.125-32 µL/mL, except Pseudomonas aeruginosa which was only inhibited by high concentrations of the floral budding and full flowering EOs. EO distilled from the second developmental growth stage (floral budding) of O. sanctum exhibited the strongest antibacterial activities against the food borne bacteria. Conclusions: Considering the wide range of antimicrobial activities of the examined EOs, they might have the potential to be used to manage infectious diseases or extend the shelf life of food products. PMID:25763132

  13. The musk chemical composition and microbiota of Chinese forest musk deer males

    PubMed Central

    Li, Diyan; Chen, Binlong; Zhang, Long; Gaur, Uma; Ma, Tianyuan; Jie, Hang; Zhao, Guijun; Wu, Nan; Xu, Zhongxian; Xu, Huailiang; Yao, Yongfang; Lian, Ting; Fan, Xiaolan; Yang, Deying; Yang, Mingyao; Zhu, Qing; Satkoski Trask, Jessica

    2016-01-01

    Male musk deer secrete musk from the musk gland located between their naval and genitals. Unmated male forest musk deer generate a greater amount of musk than mated males, potentially allowing them to attract a greater number of females. In this study, we used gas chromatography and mass spectrometry (GC/MS) to explore musk chemical composition of the musk pods of captive mated and unmated sexually mature Chinese forest musk deer and used next-generation sequencing to intensively survey the bacterial communities within them. Analysis of the chemical composition of the musk showed that unmated males have more muscone and cholesterol. Features of the musk16S rRNA gene showed that mated Chinese forest musk deer have both a greater Shannon diversity (p < 0.01) and a greater number of estimated operational taxonomic units than unmated ones; many bacterial genera were overrepresented in unmated Chinese forest musk deer males. Members of these genera might be involved in musk odor fermentation. PICRUSt analysis revealed that metabolic pathways such as aldosterone-regulated sodium reabsorption, metabolism of terpenoids and polyketides, flavone and flavonol biosynthesis, and isoflavonoid biosynthesis were enriched in the musk of unmated Chinese forest musk deer males. PMID:26744067

  14. Changes in chemical composition and antioxidative properties of rye ginger cakes during their shelf-life.

    PubMed

    Zieliński, Henryk; del Castillo, Maria Dolores; Przygodzka, Małgorzata; Ciesarova, Zuzana; Kukurova, Kristina; Zielińska, Danuta

    2012-12-15

    Changes in chemical composition and antioxidative properties of rye ginger cakes during their shelf-life were investigated in this study. In particular, the changes in antioxidants content, antioxidative and reducing capacity, and Maillard reaction development in rye ginger cakes after long-term storage were addressed. Ginger cakes produced according to the traditional and current recipe were stored for 5 years at room temperature in a dark place. The total phenolic compounds (TPC), inositol hexaphosphate (IP6), reduced (GSH) and oxidised glutathione (GSSG) contents, antioxidant and reducing capacity and Maillard reaction products (MRPs) were determined in ginger cakes after storage and then compared to those measured after baking. After long-term storage a decrease in TPC and IP6 contents in cakes was noted. In contrast, an increase in antioxidative and reducing capacity of stored cakes was observed. Long-term storage induced formation of furosine, advanced and final Maillard reaction products and caused changes in both reduced and oxidised forms of glutathione. After long-term storage the modest changes in furosine, FAST index and browning in ginger cake formulated with dark rye flour may suggest that this product is the healthiest among others. Therefore, traditional rye ginger cakes can be considered as an example of a healthy food that is also relatively stable during long term storage as noted by the small chemical changes observed in its composition. PMID:22980898

  15. The musk chemical composition and microbiota of Chinese forest musk deer males.

    PubMed

    Li, Diyan; Chen, Binlong; Zhang, Long; Gaur, Uma; Ma, Tianyuan; Jie, Hang; Zhao, Guijun; Wu, Nan; Xu, Zhongxian; Xu, Huailiang; Yao, Yongfang; Lian, Ting; Fan, Xiaolan; Yang, Deying; Yang, Mingyao; Zhu, Qing; Satkoski Trask, Jessica

    2016-01-01

    Male musk deer secrete musk from the musk gland located between their naval and genitals. Unmated male forest musk deer generate a greater amount of musk than mated males, potentially allowing them to attract a greater number of females. In this study, we used gas chromatography and mass spectrometry (GC/MS) to explore musk chemical composition of the musk pods of captive mated and unmated sexually mature Chinese forest musk deer and used next-generation sequencing to intensively survey the bacterial communities within them. Analysis of the chemical composition of the musk showed that unmated males have more muscone and cholesterol. Features of the musk16S rRNA gene showed that mated Chinese forest musk deer have both a greater Shannon diversity (p < 0.01) and a greater number of estimated operational taxonomic units than unmated ones; many bacterial genera were overrepresented in unmated Chinese forest musk deer males. Members of these genera might be involved in musk odor fermentation. PICRUSt analysis revealed that metabolic pathways such as aldosterone-regulated sodium reabsorption, metabolism of terpenoids and polyketides, flavone and flavonol biosynthesis, and isoflavonoid biosynthesis were enriched in the musk of unmated Chinese forest musk deer males. PMID:26744067

  16. Influence of Aerosol Acidity on the Chemical Composition of Secondary Organic Aerosol from β-caryophyllene

    NASA Astrophysics Data System (ADS)

    Chan, M.; Surratt, J. D.; Chan, A. W.; Schlling, K.; Offenberg, J. H.; Lewandowski, M.; Edney, E.; Kleindienst, T. E.; Jaoui, M.; Edgerton, E. S.; Tanner, R. L.; Shaw, S. L.; Zheng, M.; Knipping, E. M.; Seinfeld, J.

    2011-12-01

    The secondary organic aerosol (SOA) yield of β-caryophyllene photooxidation is enhanced by aerosol acidity. In the present study, the influence of aerosol acidity on the chemical composition of β-caryophyllene SOA is investigated using ultra performance liquid chromatography/electrospray ionization-time-of-flight mass spectrometry (UPLC/ESI- TOFMS). A number of first- , second- and higher-generation gas-phase products having carbonyl and carboxylic acid functional groups are detected in the particle phase. Particle-phase reaction products formed via hydration and organosulfate formation processes are also detected. Increased acidity leads to different effects on the abundance of individual products; significantly, abundances of organosulfates are correlated with aerosol acidity. The increase of certain particle-phase reaction products with increased acidity provides chemical evidence to support the acid-enhanced SOA yields. Based on the agreement between the chromatographic retention times and accurate mass measurements of chamber and field samples, three β-caryophyllene products (i.e., β-nocaryophyllon aldehyde, β-hydroxynocaryophyllon aldehyde, and β-dihydroxynocaryophyllon aldehyde) are suggested as chemical tracers for β-caryophyllene SOA. These compounds are detected in both day and night ambient samples collected in downtown Atlanta, GA and rural Yorkville, GA during the 2008 August Mini-Intensive Gas and Aerosol Study (AMIGAS).

  17. Influence of aerosol acidity on the chemical composition of secondary organic aerosol from β-caryophyllene

    NASA Astrophysics Data System (ADS)

    Chan, M. N.; Surratt, J. D.; Chan, A. W. H.; Schilling, K.; Offenberg, J. H.; Lewandowski, M.; Edney, E. O.; Kleindienst, T. E.; Jaoui, M.; Edgerton, E. S.; Tanner, R. L.; Shaw, S. L.; Zheng, M.; Knipping, E. M.; Seinfeld, J. H.

    2011-02-01

    The secondary organic aerosol (SOA) yield of β-caryophyllene photooxidation is enhanced by aerosol acidity. In the present study, the influence of aerosol acidity on the chemical composition of β-caryophyllene SOA is investigated using ultra performance liquid chromatography/electrospray ionization-time-of-flight mass spectrometry (UPLC/ESI-TOFMS). A number of first-, second- and higher-generation gas-phase products having carbonyl and carboxylic acid functional groups are detected in the particle phase. Particle-phase reaction products formed via hydration and organosulfate formation processes are also detected. Increased acidity leads to different effects on the abundance of individual products; significantly, abundances of organosulfates are correlated with aerosol acidity. To our knowledge, this is the first detection of organosulfates and nitrated organosulfates derived from a sesquiterpene. The increase of certain particle-phase reaction products with increased acidity provides chemical evidence to support the acid-enhanced SOA yields. Based on the agreement between the chromatographic retention times and accurate mass measurements of chamber and field samples, three β-caryophyllene products (i.e., β-nocaryophyllon aldehyde, β-hydroxynocaryophyllon aldehyde, and β-dihydroxynocaryophyllon aldehyde) are suggested as chemical tracers for β-caryophyllene SOA. These compounds are detected in both day and night ambient samples collected in downtown Atlanta, GA and rural Yorkville, GA during the 2008 August Mini-Intensive Gas and Aerosol Study (AMIGAS).

  18. Influence of aerosol acidity on the chemical composition of Secondary Organic Aerosol from β-caryophyllene

    NASA Astrophysics Data System (ADS)

    Chan, M. N.; Surratt, J. D.; Chan, A. W. H.; Schilling, K.; Offenberg, J. H.; Lewandowski, M.; Edney, E. O.; Kleindienst, T. E.; Jaoui, M.; Edgerton, E. S.; Tanner, R. L.; Shaw, S. L.; Zheng, M.; Knipping, E. M.; Seinfeld, J. H.

    2010-11-01

    The secondary organic aerosol (SOA) yield of β-caryophyllene photooxidation is enhanced by aerosol acidity. In the present study, the influence of aerosol acidity on the chemical composition of β-caryophyllene SOA is investigated using ultra performance liquid chromatography/electrospray ionization-time-of-flight mass spectrometry (UPLC/ESI-TOFMS). A number of first-, second- and higher-generation gas-phase products having carbonyl and carboxylic acid functional groups are detected in the particle phase. Particle-phase reaction products formed via hydration and organosulfate formation processes are also detected. Increase of acidity leads to different effects on the abundance of individual products; significantly, abundances of organosulfates are correlated with aerosol acidity. To our knowledge, this is the first detection of organosulfates and nitrated organosulfates derived from a sesquiterpene. The increase of certain particle-phase reaction products with increased acidity provides chemical evidence to support the acid-enhanced SOA yields. Based on the agreement between the chromatographic retention times and accurate mass measurements of chamber and field samples, three β-caryophyllene products (i.e., β-nocaryophyllon aldehyde, β-hydroxynocaryophyllon aldehyde, and β-dihydroxynocaryophyllon aldehyde) are identified as chemical tracers for β-caryophyllene SOA. These compounds are detected in both day and night ambient samples collected in downtown Atlanta, GA and rural Yorkville, GA during the 2008 August Mini-Intensive Gas and Aerosol Study (AMIGAS).

  19. Influence of origin and extraction method on argan oil physico-chemical characteristics and composition.

    PubMed

    Hilali, Miloudi; Charrouf, Zoubida; Soulhi, Abd El Aziz; Hachimi, Larbi; Guillaume, Dominique

    2005-03-23

    Twenty one samples of argan oil of different geographical origin (Tidzi, Tamanar, Benaiznassen, Ait mzal, Ait Baha, Ighrem, Aoulouz) and/or prepared following a different process (traditional, mechanical, or industrial) were collected and their physico-chemical properties analyzed. Sample acidity was found between 0.14 and 1.40%, unsaponifiable matter between 0.34 and 0.79%, saponification value between 180.0 and 199.6, highest peroxide index was 5.72 meq/kg, refractive index (20 degrees C) between 1.4644 and 1.4705, and UV absorption at 270 nm between 0.228 and 0.605. This study, carried out on randomly selected samples, clearly demonstrates that press extraction does not alter either the chemical composition of argan oil or its physico-chemical characteristics. It also demonstrates that press extraction respects the critical factors reported for traditionally prepared oils and necessary to obtain a beneficial effect on human health (a specific fatty acid balance and high tocopherol and sterol levels). In addition, this study should be useful for the establishment of a national quality standard. PMID:15769139

  20. Novel Approach for Evaluating Secondary Organic Aerosol from Aromatic Hydrocarbons: SOA Yield and Chemical Composition

    NASA Astrophysics Data System (ADS)

    Li, Lijie; Tang, Ping; Nakao, Shunsuke; Qi, Li; Kacarab, Mary; Cocker, David

    2016-04-01

    Aromatic hydrocarbons account for 20%-30% of urban atmospheric VOCs and are major contributors to anthropogenic secondary organic aerosol (SOA). However, prediction of SOA from aromatic hydrocarbons as a function of structure, NOx concentration, and OH radical levels remains elusive. Innovative SOA yield and chemical composition evaluation approaches are developed here to investigate SOA formation from aromatic hydrocarbons. SOA yield is redefined in this work by adjusting the molecular weight of all aromatic precursors to the molecular weight of benzene (Yield'= Yieldi×(MWi/MWBenzene); i: aromatic hydrocarbon precursor). Further, SOA elemental ratio is calculated on an aromatic ring basis rather than the classic mole basis. Unified and unique characteristics in SOA formed from aromatic hydrocarbons with different alkyl groups (varying in carbon number and location on aromatic ring) are explored by revisiting fifteen years of UC Riverside/CE-CERT environmental chamber data on 129 experiments from 17 aromatic precursors at urban region relevant low NOx conditions (HC:NO 11.1-171 ppbC:ppb). Traditionally, SOA mass yield of benzene is much greater than that of other aromatic species. However, when adjusting for molecular weight, a similar yield is found across the 17 different aromatic precursors. More importantly, four oxygens per aromatic ring are observed in the resulting SOA regardless of the alkyl substitutes attached to the ring, which majorly affect H/C ratio in SOA. Therefore, resulting SOA bulk composition from aromatic hydrocarbons can be predicted as C6+nH6+2nO4 (n: alkyl substitute carbon number). Further, the dominating role of the aromatic ring carbons is confirmed by studying the chemical composition of SOA formed from the photooxidation of an aromatic hydrocarbon with a 13C isotopically labeled alkyl carbon. Overall, this study unveils the similarity in SOA formation from aromatic hydrocarbons enhancing the understanding of SOA formation from

  1. Direct aerosol chemical composition measurements to evaluate the physicochemical differences between controlled sea spray aerosol generation schemes

    NASA Astrophysics Data System (ADS)

    Collins, D. B.; Zhao, D. F.; Ruppel, M. J.; Laskina, O.; Grandquist, J. R.; Modini, R. L.; Stokes, M. D.; Russell, L. M.; Bertram, T. H.; Grassian, V. H.; Deane, G. B.; Prather, K. A.

    2014-11-01

    Controlled laboratory studies of the physical and chemical properties of sea spray aerosol (SSA) must be under-pinned by a physically and chemically accurate representation of the bubble-mediated production of nascent SSA particles. Bubble bursting is sensitive to the physico-chemical properties of seawater. For a sample of seawater, any important differences in the SSA production mechanism are projected into the composition of the aerosol particles produced. Using direct chemical measurements of SSA at the single-particle level, this study presents an intercomparison of three laboratory-based, bubble-mediated SSA production schemes: gas forced through submerged sintered glass filters ("frits"), a pulsed plunging-waterfall apparatus, and breaking waves in a wave channel filled with natural seawater. The size-resolved chemical composition of SSA particles produced by breaking waves is more similar to particles produced by the plunging waterfall than those produced by sintered glass filters. Aerosol generated by disintegrating foam produced by sintered glass filters contained a larger fraction of organic-enriched particles and a different size-resolved elemental composition, especially in the 0.8-2 μm dry diameter range. Interestingly, chemical differences between the methods only emerged when the particles were chemically analyzed at the single-particle level as a function of size; averaging the elemental composition of all particles across all sizes masked the differences between the SSA samples. When dried, SSA generated by the sintered glass filters had the highest fraction of particles with spherical morphology compared to the more cubic structure expected for pure NaCl particles produced when the particle contains relatively little organic carbon. In addition to an intercomparison of three SSA production methods, the role of the episodic or "pulsed" nature of the waterfall method on SSA composition was under-taken. In organic-enriched seawater, the continuous

  2. Influence of alkaline suspended particles on the chemical composition of acid deposition in Kaohsiung City, Taiwan

    SciTech Connect

    Yuan, C.S.; Lin, Z.J.; Wu, M.Y.; Liu, J.I.; Yuan, C.

    1998-12-31

    This study investigated the influence of alkaline suspended particles on the chemical composition of acid deposition both temporally and spatially in Kaohsiung metropolitan area in Taiwan. During the period of January--December, 1996, both wet and dry deposition samples were collected by automatic acid precipitation samplers at six sampling sites which covered the entire metropolitan area. Major cations (NH{sub 4}{sup +}, K{sup +}, Na{sup +}, Ca{sup +2}, and Mg{sup +2}) and anions (F{sup {minus}}, Cl{sup {minus}}, NO{sub 3}{sup {minus}}, and SO{sub 4}{sup {minus}2}) of acid deposition samples were analyzed in a central laboratory, while the pH value and conductivity of rainwater samples were measured in situ. Results from chemical analysis indicated that Ca{sup +2} was the most abundant cation in acid deposition samples. Major cations were Ca{sup +2} and NH{sub 4}{sup +}, while major anions were SO{sub 4}{sup {minus}2} and NO{sub 3}{sup {minus}}. This study also revealed that the pH value, suspended solids, Ca{sup +2}, and NH{sub 4}{sup +} of rainwater decreased with rainy time in a sequential rainwater sampling process. It was estimated that approximately 80% of suspended particles could be washed out by rain droplets in the first hour of raining process. Therefore, alkaline suspended particles in the atmosphere played an very important role on the chemical composition of acid precipitation in Kaohsiung metropolitan area in Taiwan.

  3. Chemical and isotope compositions of nitric thermal water of Baikal rift zone

    NASA Astrophysics Data System (ADS)

    Plyusnin, A. M.; Chernyavsky, M. K.; Peryazeva, E. G.

    2010-05-01

    Three types of hydrotherms (nitric, carbonaceous and methane) are distinguished within the Baikal Rift Zone. The unloading sites of nitric therms are mostly located in the central and north-eastern parts of the Rift. Several chemical types are found among nitric therms (Pinneker, Pisarsky, Lomonosov, 1968; Lomonosov, 1974, etc.). The formation of terms being various in chemical compositions is associated with effect of several factors, i.e. various chemical, mineralogical compositions of rocks, various temperatures, extent of interaction in water-rock system, etc. The ratio data of water oxygen and hydrogen isotopes of the studied thermal springs indicate that water is largely of meteoric origin. All established ratios of oxygen (δ18OSMOW = -19.5‰ - -17.5‰) and hydrogen (δDSMOW = -155‰ - - 130‰) isotopes are along the line of meteoric waters. Oxygen values from -20‰ to -5‰ are characteristic of the current meteoric and surface waters in the region. The average value equals -16.5‰ in Lake Baikal. By our data, a large group with oxygen lighter isotope composition that corresponds to isotope ratio being specific for glaciers is revealed in fissure-vein waters. Significant shift toward the oxygen getting heavier is observed in some springs. It is mostly observed in the springs that form chemical composition within the area of the intrusive and metamorphic rock distribution. As a result of hydrolysis reaction of alumosilicates, heavy isotope passes from rocks into water molecule, whereas oxygen heavy isotope passes from rocks into solutes during decomposition of carbonates. High contents of fluoride and sulfate-ions are specific feature of the Baikal Rift Zone most nitric therms. Water is tapped in one of the drill holes, where fluoride-ion dominates in its anion composition (46.7 mg/dm3) and pH reaches 10, 12. The sulphate sulphur isotope composition studies carried out allow to conclude that its heavy isotope (δ34SCDT = +25‰ - +30‰) prevails in

  4. Dissolved organic matter in Lake Superior: insights into the effects of extraction methods on chemical composition.

    PubMed

    Li, Hongyu; Minor, Elizabeth C

    2015-10-01

    Dissolved organic matter (DOM) in aquatic systems plays many biogeochemical roles, acting as a sunscreen, a food source, a trace metal chelator, and a photosensitizer. The efficiency of DOM in these roles is, in part, a function of its composition, which is difficult to determine due to its heterogeneity and the difficulty in isolating representative portions for subsequent molecular level analyses. In this study, the performance of two major types of solid phase extraction (SPE) resins (C18 vs. polymeric SDVB) in disk format (C18 disk vs. SDB-XC disk) was studied using DOM from Lake Superior, the earth's largest lake by area. The performance of the two SPE disks and their influences on the molecular chemical composition of the extracted retentates were studied with UV-vis spectrometry and negative-ion electrospray Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS). We found that SDB-XC disks outperformed C18 disks in the isolation of DOM in terms of both higher recovery and less fractionation relative to the initial DOM composition. Extracts of the same samples obtained with the different resins shared 70% of molecular formulae. Compounds exclusive to the SDB-XC extractions exhibited similar compound distributions to those of the shared formulae but were enriched in N, P, and S and more aromatic. The C18 exclusive compounds had somewhat higher H/C ratios and contained a large proportion of compounds with oxygen and nitrogen (CHON). Cluster analysis and principle component analysis confirmed that sample location was the main driver of the composition of extracted samples but showed some fractionation of the samples based upon the type of resin. PMID:26350791

  5. Chemical composition of fogwater collected along the California coast

    SciTech Connect

    Jacob, D.J.; Waldman, J.M.; Munger, J.W.; Hoffman, M.R.

    1985-01-01

    Fogwater collected at both urban and nonurban coastal sites in California ws found to be consistently acidic. Millimolar concentrations of NO/sub 3//sup -/, and fogwater pH values below 3, were observed at sites downwind of the Los Angeles basin. Fogwater composition at remote sites showed evidence of substantial continental and anthropogenic contributions. Acid-neutralizing capacities in coastal air were found to be very low and insufficient to neutralize even small acid inputs. Chloride loss relative to its sea salt contribution was observed at sites furthest from anthropogenic sources.

  6. Chemical composition and mass closure of ambient PM10 at urban sites

    NASA Astrophysics Data System (ADS)

    Terzi, Eleni; Argyropoulos, George; Bougatioti, Aikaterini; Mihalopoulos, Nikolaos; Nikolaou, Kostas; Samara, Constantini

    2010-06-01

    The chemical composition of PM10 was studied during summer and winter sampling campaigns conducted at two different urban sites in the city of Thessaloniki, Greece (urban-traffic, UT and urban-industrial, UI). PM10 samples were chemically analysed for minerals (Si, Al, Ca, Mg, Fe, Ti, K), trace elements (Cd, Cr, Cu, Mn, Pb, V, Zn, Te, Co, Ni, Se, Sr, As, and Sb), water-soluble ions (Cl -, NO 3-, SO 42-, Na +, K +, NH 4+, Ca 2+, Mg 2+) and carbonaceous compounds (OC, EC). Spatial variations of atmospheric concentrations showed significantly higher levels of minerals, some trace metals and TC at the UI site, while at the UT site significantly higher levels of elements like Cd, Ba, Sn, Sb and Te were observed. Crustal elements, excepting Ca at the UI site, did not exhibit significant seasonal variations at any site pointing to constant emissions throughout the year. In order to reconstruct the particle mass, the determined components were classified into six classes as follows: mineral matter (MIN), trace elements (TE), organic matter (OM), elemental carbon (EC), sea salt (SS) and secondary inorganic aerosol (SIA). Good correlations with slopes close to 1 were found between chemically determined and gravimetrically measured PM10 masses for both sites. According to the chemical mass closure obtained, the major components of PM10 at both sites were MIN (soil-derived compounds), followed by OM and SIA. The fraction unaccounted for by chemical analysis comprised on average 8% during winter and 15% during summer at the urban-industrial site, while at the urban-traffic site the percentages were 21.5% in winter and 4.8% in summer.

  7. Chemical Erosion Studies of Lithiated Graphite

    NASA Astrophysics Data System (ADS)

    Raman, Priya; Surla, Vijay; Burns, David; Ruzic, David

    2010-11-01

    Lithium evaporation treatments in the National Spherical Torus Experiment (NSTX) have shown dramatic improvements in plasma performance increasing the viability of lithium as Plasma facing Component (PFC) material. In order to understand the complex system of lithiated ATJ graphite, chemical erosion measurements of plain and lithiated ATJ graphite are conducted in the newly built RF plasma facility. A differential pumping scheme is employed and a Residual Gas Analyzer is used for chemical erosion measurements. Target is mounted on a substrate heater (0-500C) and it is connected to a biasing circuitry to allow for temperature dependent studies and energy dependent measurements. To study the effect of lithium on chemical erosion, lithium is evaporated in-situ onto ATJ graphite. The dominant chemical erosion products are known to be CD4 and C2D2. The challenges in measuring C2D2, as it interferes with N2 and CO peaks, are presented. It was found that lithium treatments have suppressed the CD4 signal, and the effect of lithium on other peaks is presented. The effect of temperature on chemical erosion is also investigated and it was found that temperature increases the erosion of graphite.

  8. Simulation of aerosol chemical compositions in the Western Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Chrit, Mounir; Kata Sartelet, Karine; Sciare, Jean; Marchand, Nicolas; Pey, Jorge; Sellegri, Karine

    2016-04-01

    This work aims at evaluating the chemical transport model (CTM) Polair3d of the air-quality modelling platform Polyphemus during the ChArMex summer campaigns of 2013, using ground-based measurements performed at ERSA (Cape Corsica, France), and at determining the processes controlling organic aerosol concentrations at ERSA. Simulations are compared to measurements for concentrations of both organic and inorganic species, as well as the ratio of biogenic versus anthropogenic particles, and organic aerosol properties (oxidation state). For inorganics, the concentrations of sulphate, sodium, chloride, ammonium and nitrate are compared to measurements. Non-sea-salt sulphate and ammonium concentrations are well reproduced by the model. However, because of the geographic location of the measurement station at Cape Corsica which undergoes strong wind velocities and sea effects, sea-salt sulphate, sodium, chloride and nitrate concentrations are strongly influenced by the parameterizations used for sea-salt emissions. Different parameterizations are compared and a parameterization is chosen after comparison to sodium measurements. For organics, the concentrations are well modelled when compared to experimental values. Anthropogenic particles are influenced by emission of semi-volatile organic compounds (SVOC). Measurements allow us to refine the estimation of those emissions, which are currently missing in emission inventories. Although concentrations of biogenic particles are well simulated, the organic chemical compounds are not enough oxidised in the model. The observed oxidation state of organics shows that the oligomerisation of pinonaldehyde was over-estimated in Polyphemus. To improve the oxidation property of organics, the formation of extremely low volatile organic compounds from autoxidation of monoterpenes is added to Polyphemus, using recently published data from chamber experiments. These chemical compounds are highly oxygenated and are formed rapidly, as first

  9. Quantitative mapping of chemical compositions with MRI using compressed sensing

    NASA Astrophysics Data System (ADS)

    von Harbou, Erik; Fabich, Hilary T.; Benning, Martin; Tayler, Alexander B.; Sederman, Andrew J.; Gladden, Lynn F.; Holland, Daniel J.

    2015-12-01

    In this work, a magnetic resonance (MR) imaging method for accelerating the acquisition time of two dimensional concentration maps of different chemical species in mixtures by the use of compressed sensing (CS) is presented. Whilst 2D-concentration maps with a high spatial resolution are prohibitively time-consuming to acquire using full k -space sampling techniques, CS enables the reconstruction of quantitative concentration maps from sub-sampled k -space data. First, the method was tested by reconstructing simulated data. Then, the CS algorithm was used to reconstruct concentration maps of binary mixtures of 1,4-dioxane and cyclooctane in different samples with a field-of-view of 22 mm and a spatial resolution of 344 μm × 344 μm . Spiral based trajectories were used as sampling schemes. For the data acquisition, eight scans with slightly different trajectories were applied resulting in a total acquisition time of about 8 min. In contrast, a conventional chemical shift imaging experiment at the same resolution would require about 17 h. To get quantitative results, a careful weighting of the regularisation parameter (via the L-curve approach) or contrast-enhancing Bregman iterations are applied for the reconstruction of the concentration maps. Both approaches yield relative errors of the concentration map of less than 2 mol-% without any calibration prior to the measurement. The accuracy of the reconstructed concentration maps deteriorates when the reconstruction model is biased by systematic errors such as large inhomogeneities in the static magnetic field. The presented method is a powerful tool for the fast acquisition of concentration maps that can provide valuable information for the investigation of many phenomena in chemical engineering applications.

  10. Disability Studies in the Composition Classroom

    ERIC Educational Resources Information Center

    Browning, Ella R.

    2014-01-01

    Although attention to disability is becoming more apparent in first-year composition curricula, too often disability is simply "tacked on" to existing courses. Scholars have argued that composition instructors interested in fully integrating a disability studies perspective into their curriculum would do well, instead, to think…

  11. Study of chloride ion transport of composite by using cement and starch as a binder

    NASA Astrophysics Data System (ADS)

    Armynah, Bidayatul; Halide, Halmar; Zahrawani, Reski, Nurhadi; Tahir, Dahlang

    2016-03-01

    This study presents the chemical bonding and the structural properties of composites from accelerator chloride test migration (ACTM). The volume fractions between binder (cement and starch) and charcoal in composites are 20:80 and 60:40. The effect of the binder to the chemical composition, chemical bonding, and structural properties before and after chloride ion passing through the composites was determined by X-ray fluorescence (XRF), by Fourier transform infra-red (FTIR), and x-ray diffraction (XRD), respectively. From the XRD data, XRF data, and the FTIR data shows the amount of chemical composition, the type of binding, and the structure of composites are depending on the type of binder. The amount of chloride migration using starch as binder is higher than that of cement as a binder due to the density effects.

  12. Variations in chemical composition of Apollo 15 mare basalts

    NASA Technical Reports Server (NTRS)

    Butler, J. C.

    1976-01-01

    Chemical analyses of 30 different Apollo 15 mare basalts were examined to evaluate the effects of closure on the pearson moment correlation coefficient. It is shown possible to describe the Apollo 15 mare basalts in terms of an opaque, an olivine/pyroxene, an anorthite, and a KREEP component, if significant correlations are identified using the expected correlations as null values. Using Q-mode cluster analysis and nonlinear mapping, it is possible to recognize three groups of the mare basalts, groups 1 and 2 belonging to the olivine normative basalt cluster and group 3 to the quartz normative cluster.

  13. Fabrication of fiber-reinforced composites by chemical vapor infiltration

    SciTech Connect

    Besmann, T.M.; McLaughlin, J.C.; Probst, K.J.; Anderson, T.J.; Starr, T.L.

    1997-12-01

    Silicon carbide-based heat exchanger tubes are of interest to energy production and conversion systems due to their excellent high temperature properties. Fiber-reinforced SiC is of particular importance for these applications since it is substantially tougher than monolithic SiC, and therefore more damage and thermal shock tolerant. This paper reviews a program to develop a scaled-up system for the chemical vapor infiltration of tubular shapes of fiber-reinforced SiC. The efforts include producing a unique furnace design, extensive process and system modeling, and experimental efforts to demonstrate tube fabrication.

  14. Fabrication of fiber-reinforced composites by chemical vapor infiltration

    SciTech Connect

    Matlin, W.M.; Stinton, D.P.; Besmann, T.M.

    1995-08-01

    A two-step forced chemical vapor infiltration process was developed that reduced infiltration times for 4.45 cm dia. by 1.27 cm thick Nicalon{sup +} fiber preforms by two thirds while maintaining final densities near 90 %. In the first stage of the process, micro-voids within fiber bundles in the cloth were uniformly infiltrated throughout the preform. In the second stage, the deposition rate was increased to more rapidly fill the macro-voids between bundles within the cloth and between layers of cloth. By varying the thermal gradient across the preform uniform infiltration rates were maintained and high final densities achieved.

  15. Separation of parent homopolymers from polystyrene and poly(ethylene oxide) based block copolymers by liquid chromatography under limiting conditions of desorption-3. Study of barrier efficiency according to block copolymers' chemical composition.

    PubMed

    Rollet, Marion; Pelletier, Bérengère; Berek, Dušan; Maria, Sébastien; Phan, Trang N T; Gigmes, Didier

    2016-09-01

    Liquid Chromatography under Limiting Conditions of Desorption (LC LCD) is a powerful separation tool for multicomponent polymer systems. This technique is based on a barrier effect of an appropriate solvent, which is injected in front of the sample, and which decelerates the elution of selected macromolecules. In this study, the barrier effects have been evaluated for triblock copolymers polystyrene-b-poly(ethylene oxide)-b-polystyrene (PS-b-PEO-b-PS) according to the content of polystyrene (wt% PS) and PEO-block molar mass. PS-b-PEO-b-PS samples were prepared by Atom Transfer Radical Polymerization (ATRP). The presence of respective parent homopolymers was investigated by applying optimized LC LCD conditions. It was found that the barrier composition largely affects the efficiency of separation and it ought to be adjusted for particular composition range of block copolymers. PMID:27495367

  16. Vitrified metal finishing wastes I. Composition, density and chemical durability.

    PubMed

    Bingham, P A; Hand, R J

    2005-03-17

    Durable phosphate glasses were formed by vitrifying waste filter cakes from two metal finishing operations. Some melts formed crystalline components during cooling. Compositional analysis of dried, heat treated and vitrified samples was made using energy-dispersive X-ray spectroscopy, X-ray fluorescence spectroscopy, inductively-coupled plasma spectroscopy and Leco induction furnace combustion analysis. Hydrolytic dissolution, measured by an adapted product consistency test, was reduced by up to 3 orders of magnitude upon heat treatment or vitrification, surpassing the performance of borosilicate glass in some cases. This was attributed to the high levels of iron and zinc in the wastes, which greatly improve the durability of phosphate glasses. One of the wastes arose from a metal phosphating process and was particularly suitable for vitrification due to its high P2O5 content and favourable melting behaviour. The other waste, which arose from a number of processes, was less suitable as it had a low P2O5 content and during heating it emitted harmful corrosive gases and underwent violent reactions. Substantial volume reductions were obtained by heat treatment and vitrification of both wastes. Compositions and performances of some vitrified wastes were comparable with those of glasses which are under consideration for the immobilisation of toxic and nuclear wastes. PMID:15752857

  17. Chemical composition of Eastern Black Sea aerosol--preliminary results.

    PubMed

    Balcılar, Ilker; Zararsız, Abdullah; Kalaycı, Yakup; Doğan, Güray; Tuncel, Gürdal

    2014-08-01

    Trace element composition of atmospheric particles collected at a high altitude site on the Eastern Black Sea coast of Turkey was investigated to understand atmospheric transport of pollutants to this semi-closed basin. Aerosol samples were collected at a timber-storage area, which is operated by the General Directorate of Forestry. The site is situated at a rural area and is approximately 50 km to the Black Sea coast and 200 km to the Georgia border of Turkey. Coarse (PM2.5-10) and fine (PM2.5) aerosol samples were collected between 2011 and 2013 using a "stacked filter unit". Collected samples were shipped to the Middle East Technical University in Ankara, where Na, Mg, Al, Si, S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Ba, Pb were measured by Energy dispersive x-ray fluorescence technique (EDXRF). Comparison of measured concentrations of elements with corresponding data generated at other parts of Turkey demonstrated that concentrations of pollution derived elements are higher at Eastern Black Sea than their corresponding concentrations measured at other parts of Turkey, which is attributed to frequent transport of pollutants from north wind sector. Positive matric factorization revealed four factors including three anthropogenic and a crustal factor. Southeastern parts of Turkey, Georgia and Black Sea coast of Ukraine were identified as source regions affecting composition of particles at our site, using trajectory statistics, namely "potential source contribution function" (PSCF). PMID:24373640

  18. AN ESTIMATE OF THE CHEMICAL COMPOSITION OF TITAN's LAKES

    SciTech Connect

    Cordier, Daniel; Mousis, Olivier; Lunine, Jonathan I.; Lavvas, Panayotis; Vuitton, Veronique

    2009-12-20

    Hundreds of radar-dark patches interpreted as lakes have been discovered in the north and south polar regions of Titan. We have estimated the composition of these lakes by using the direct abundance measurements from the Gas Chromatograph Mass Spectrometer aboard the Huygens probe and recent photochemical models based on the vertical temperature profile derived by the Huygens Atmospheric Structure Instrument. Thermodynamic equilibrium is assumed between the atmosphere and the lakes, which are also considered nonideal solutions. We find that the main constituents of the lakes are ethane (C{sub 2}H{sub 6}) (approx76%-79%), propane (C{sub 3}H{sub 8}) (approx7%-8%), methane (CH{sub 4}) (approx5%-10%), hydrogen cyanide (HCN) (approx2%-3%), butene (C{sub 4}H{sub 8}) (approx1%), butane (C{sub 4}H{sub 10}) (approx1%), and acetylene (C{sub 2}H{sub 2}) (approx1%). The calculated composition of lakes is then substantially different from what has been expected from models elaborated prior to the exploration of Titan by the Cassini-Huygens spacecraft.

  19. Chemical composition of the Howardite Parent Body deduced from Kapoeta primary 'mafic' magmas

    NASA Technical Reports Server (NTRS)

    Smith, M. R.; Schmitt, R. A.

    1982-01-01

    Chemical data are presented for three 'mafic' clasts extracted from the Kapoeta howardite. Bulk compositions and petrologic observations suggest that two of these lithic clasts represent olivine-plagioclase bearing orthopyroxenites. Chondrite-relative refractory large ion lithophile abundances of two of the clasts are inferred to represent primary Mg-rich magmas produced by extensive (greater than about 70%) partial melting of a source composition indistinguishable from the silicate fraction of average CH-CL ordinary chondrites, with the exception of the depletion of the alkalis Na and K by a factor of 13 + or - 1 in the source composition. A metal-free and volatile depleted Kapoeta Parent Body (KPB) is subsequently deduced and is shown to compare very well with other similarly derived Achondrite Parent Body and Howardite Parent Body estimates but not to parent body estimates derived from inferences based on eucrite phase equilibrium studies. Other implications suggest that the KPB is heterogeneous with respect to Fe/Mg ratios.

  20. Cellulose nanocrystals mediated assembly of graphene in rubber composites for chemical sensing applications.

    PubMed

    Cao, Jie; Zhang, Xinxing; Wu, Xiaodong; Wang, Shuman; Lu, Canhui

    2016-04-20

    In this study, we report a green assembled approach to prepare natural rubber (NR) composites with 3D interconnected graphene-based conductive networks. Taking advantage of the water-dispersity and amphiphilicity of cellulose nanocrystals (CNC), well suspended graphene@CNC aqueous colloids could be prepared by the CNC-mediated reduction of graphene oxide. When homogenized with NR latex under ultrasonication and subsequently co-coagulation, the graphene@CNC nanohybrids selectively located in the interstitial space between the NR latex microspheres and constructed an ordered 3D conductive structure. This unique 3D conductive network endowed the NR composites with remarkably enhanced electric conductivity (the percolation threshold is twofold lower than that of the conventional NR/graphene composites), mechanical properties and more importantly resistivity response to organic liquids. Our strategy offered a novel, simple and eco-friendly route for the fabrication of liquid sensors capable of sensing and discriminating various solvent leakage in chemical industry as well as environmental monitoring. PMID:26876831

  1. CHEMICAL COMPOSITION OF COMET C/2007 N3 (LULIN): ANOTHER ''ATYPICAL'' COMET

    SciTech Connect

    Gibb, Erika L.; Sudholt, Emily; Bonev, Boncho P.; Villanueva, Geronimo; Radeva, Yana; DiSanti, Michael A.; Mumma, Michael J.

    2012-05-10

    We measured the volatile chemical composition of comet C/2007 N3 (Lulin) on three dates from 2009 January 30 to February 1 using NIRSPEC, the high-resolution ({lambda}/{Delta}{lambda} Almost-Equal-To 25,000), long-slit echelle spectrograph at Keck 2. We sampled nine primary (parent) volatile species (H{sub 2}O, C{sub 2}H{sub 6}, CH{sub 3}OH, H{sub 2}CO, CH{sub 4}, HCN, C{sub 2}H{sub 2}, NH{sub 3}, CO) and two product species (OH* and NH{sub 2}). We also report upper limits for HDO and CH{sub 3}D. C/2007 N3 (Lulin) displayed an unusual composition when compared to other comets. Based on comets measured to date, CH{sub 4} and C{sub 2}H{sub 6} exhibited 'normal' abundances relative to water, CO and HCN were only moderately depleted, C{sub 2}H{sub 2} and H{sub 2}CO were more severely depleted, and CH{sub 3}OH was significantly enriched. Comet C/2007 N3 (Lulin) is another important and unusual addition to the growing population of comets with measured parent volatile compositions, illustrating that these studies have not yet reached the level where new observations simply add another sample to a population with well-established statistics.

  2. Confocal Raman microspectroscopy reveals a convergence of the chemical composition in methanogenic archaea from a Siberian permafrost-affected soil.

    PubMed

    Serrano, Paloma; Hermelink, Antje; Lasch, Peter; de Vera, Jean-Pierre; König, Nicole; Burckhardt, Oliver; Wagner, Dirk

    2015-12-01

    Methanogenic archaea are widespread anaerobic microorganisms responsible for the production of biogenic methane. Several new species of psychrotolerant methanogenic archaea were recently isolated from a permafrost-affected soil in the Lena Delta (Siberia, Russia), showing an exceptional resistance against desiccation, osmotic stress, low temperatures, starvation, UV and ionizing radiation when compared to methanogens from non-permafrost environments. To gain a deeper insight into the differences observed in their resistance, we described the chemical composition of methanogenic strains from permafrost and non-permafrost environments using confocal Raman microspectroscopy (CRM). CRM is a powerful tool for microbial identification and provides fingerprint-like information about the chemical composition of the cells. Our results show that the chemical composition of methanogens from permafrost-affected soils presents a high homology and is remarkably different from strains inhabiting non-permafrost environments. In addition, we performed a phylogenetic reconstruction of the studied strains based on the functional gene mcrA to prove the different evolutionary relationship of the permafrost strains. We conclude that the permafrost methanogenic strains show a convergent chemical composition regardless of their genotype. This fact is likely to be the consequence of a complex adaptive process to the Siberian permafrost environment and might be the reason underlying their resistant nature. PMID:26499486

  3. Software for analysis of chemical mixtures--composition, occurrence, distribution, and possible toxicity

    USGS Publications Warehouse

    Scott, Jonathon C.; Skach, Kenneth A.; Toccalino, Patricia L.

    2013-01-01

    The composition, occurrence, distribution, and possible toxicity of chemical mixtures in the environment are research concerns of the U.S. Geological Survey and others. The presence of specific chemical mixtures may serve as indicators of natural phenomena or human-caused events. Chemical mixtures may also have ecological, industrial, geochemical, or toxicological effects. Chemical-mixture occurrences vary by analyte composition and concentration. Four related computer programs have been developed by the National Water-Quality Assessment Program of the U.S. Geological Survey for research of chemical-mixture compositions, occurrences, distributions, and possible toxicities. The compositions and occurrences are identified for the user-supplied data, and therefore the resultant counts are constrained by the user’s choices for the selection of chemicals, reporting limits for the analytical methods, spatial coverage, and time span for the data supplied. The distribution of chemical mixtures may be spatial, temporal, and (or) related to some other variable, such as chemical usage. Possible toxicities optionally are estimated from user-supplied benchmark data. The software for the analysis of chemical mixtures described in this report is designed to work with chemical-analysis data files retrieved from the U.S. Geological Survey National Water Information System but can also be used with appropriately formatted data from other sources. Installation and usage of the mixture software are documented. This mixture software was designed to function with minimal changes on a variety of computer-operating systems. To obtain the software described herein and other U.S. Geological Survey software, visit http://water.usgs.gov/software/.

  4. Chemical Composition of Nebulosities in the Magellanic Clouds

    PubMed Central

    Aller, L. H.; Czyzak, S. J.; Keyes, C. D.; Boeshaar, G.

    1974-01-01

    From photoelectric spectrophotometric data secured at Cerro Tololo Interamerican Observatory we have attempted to derive electron densities and temperatures, ionic concentrations, and chemical abundances of He, C, N, O, Ne, S, and Ar in nebulosities in the Magellanic Clouds. Although 10 distinct nebulosities were observed in the Small Cloud and 20 such objects in the Large Cloud, the most detailed observations were secured only for the brighter objects. Results for 30 Doradus are in harmony with those published previously and recent work by Peimbert and Torres-Peimbert. Nitrogen and heavier elements appear to be less abundant in the Small Cloud than in the Large Cloud, in accordance with the conclusions of Dufour. A comparison with the Orion nebula suggests He, N, Ne, O, and S may all be less abundant in the Megellanic Clouds, although adequate evaluations will require construction of detailed models. For example, if we postulate that the [NII], [OII], and [SII] radiations originate primarily in regions with electron temperatures near 8000°K, while the [OIII], [NeIII], [ArIII], and H radiations are produced primarily in regions with Tε = 10,000° K, the derived chemical abundances in the clouds are enhanced. PMID:16592199

  5. Effects of chemical fuel composition on energy generation from thermopower waves.

    PubMed

    Yeo, Taehan; Hwang, Hayoung; Jeong, Dong-Cheol; Lee, Kang Yeol; Hong, Jongsup; Song, Changsik; Choi, Wonjoon

    2014-11-01

    Thermopower waves, which occur during combustion within hybrid structures formed from nanomaterials and chemical fuels, result in a self-propagating thermal reaction and concomitantly generate electrical energy from the acceleration of charge carriers along the nanostructures. The hybrid structures for thermopower waves are composed of two primary components: the core thermoelectric material and the combustible fuel. So far, most studies have focused on investigating various nanomaterials for improving energy generation. Herein, we report that the composition of the chemical fuel used has a significant effect on the power generated by thermopower waves. Hybrid nanostructures consisting of mixtures of picric acid and picramide with sodium azide were synthesized and used to generate thermopower waves. A maximum voltage of ∼2 V and an average peak specific power as high as 15 kW kg(-1) were obtained using the picric acid/sodium azide/multiwalled carbon nanotubes (MWCNTs) array composite. The average reaction velocity and the output voltage in the case of the picric acid/sodium azide were 25 cm s(-1) and 157 mV, while they were 2 cm s(-1) and 3 mV, in the case of the picramide/sodium azide. These marked differences are attributable to the chemical and structural differences of the mixtures. Mixing picric acid and sodium azide in deionized water resulted in the formation of 2,4,6-trinitro sodium phenoxide and hydrogen azide (H-N3), owing to the exchange of H(+) and Na(+) ions, as well as the formation of fiber-like structures, because of benzene π stacking. The negative enthalpy of formation of the new compounds and the fiber-like structures accelerate the reaction and increase the output voltage. Elucidating the effects of the composition of the chemical fuel used in the hybrid nanostructures will allow for the control of the combustion process and help optimize the energy generated from thermopower waves, furthering the development of thermopower waves as an energy

  6. Antimicrobial activity and chemical composition of the essential oils of Portuguese Foeniculum vulgare fruits.

    PubMed

    Mota, Ana S; Martins, M Rosário; Arantes, Sílvia; Lopes, Violeta R; Bettencourt, Eliseu; Pombal, Sofia; Gomes, Arlindo C; Silva, Lúcia A

    2015-04-01

    The aim of this study was to investigate the chemical composition and antimicrobial activity of essential oils obtained by hydrodistillation from fruits of six fennel accessions collected from wild populations occurring in the centre and south of Portugal. Composition of essential oils was established by Gas Chromatography-Flame Ionization Detector (GC-FID) and Gas Chromatography-Mass Spectrometry (GC-MS) analysis. The obtained yields of the essential oils were found to vary greatly in the range of 1.1 to 2.9% (v/w) and the chemical composition varied with the region of collection. A total of 16 compounds were identified. The main compounds were fenchone (16.9 - 34.7%), estragole (2.5 - 66.0%) and trans-anethole (7.9 - 77.7%). The percentages of these three main compounds were used to determine the relationship between the different oil samples and to group them into four different chemotypes: anethole/fenchone; anethole; estragole and anethole/estragole. Antifungal activity of essential oils was evaluated against six food spoilage fungi: Aspergillus niger, A. japonicus, A. oryzae, Fusarium oxysporum, Rhizophus oryzae and R. stolonifer. Antibacterial activity was assessed against three Gram-positive strains: Enterococcus faecalis ATCC 29212, Staphylococcus epidermidis ATCC 12228 and S. aureus ATCC 28213; and against six Gram-negative strains: Escherichia coli ATCC 25922; Morganella morganii LFG 08; Proteus mirabilis LFG 04; Salmonella enteritidis LFG 05; S. entiritidis serovar typhimurium LFG 06 and Pseudomonas aeruginosa ATCC 27853 by the disc diffusion agar method; the minimal inhibitory concentration (MIC) was determined using the broth macro-dilution method. The MIC values varied from 62.5 (E. coli ATCC 25922) to 2000 µmL (P. aeruginosa ATCC 27853). PMID:25973507

  7. The detailed chemical composition of the terrestrial planet host Kepler-10

    NASA Astrophysics Data System (ADS)

    Liu, F.; Yong, D.; Asplund, M.; Ramírez, I.; Meléndez, J.; Gustafsson, B.; Howes, L. M.; Roederer, I. U.; Lambert, D. L.; Bensby, T.

    2016-03-01

    Chemical abundance studies of the Sun and solar twins have demonstrated that the solar composition of refractory elements is depleted when compared to volatile elements, which could be due to the formation of terrestrial planets. In order to further examine this scenario, we conducted a line-by-line differential chemical abundance analysis of the terrestrial planet host Kepler-10 and 14 of its stellar twins. Stellar parameters and elemental abundances of Kepler-10 and its stellar twins were obtained with very high precision using a strictly differential analysis of high quality Canada-France-Hawaii Telescope, Hobby-Eberly Telescope and Magellan spectra. When compared to the majority of thick disc twins, Kepler-10 shows a depletion in the refractory elements relative to the volatile elements, which could be due to the formation of terrestrial planets in the Kepler-10 system. The average abundance pattern corresponds to ˜13 Earth masses, while the two known planets in Kepler-10 system have a combined ˜20 Earth masses. For two of the eight thick disc twins, however, no depletion patterns are found. Although our results demonstrate that several factors [e.g. planet signature, stellar age, stellar birth location and Galactic chemical evolution (GCE)] could lead to or affect abundance trends with condensation temperature, we find that the trends give further support for the planetary signature hypothesis.

  8. Investigation of the composition of anabolic tablets using near infrared spectroscopy and Raman chemical imaging.

    PubMed

    Rebiere, Hervé; Ghyselinck, Céline; Lempereur, Laurent; Brenier, Charlotte

    2016-03-01

    The use of performance enhancing drugs is a widespread phenomenon in professional and leisure sports. A spectroscopic study was carried out on anabolic tablets labelled as 5 mg methandienone tablets provided by police departments. The analytical approach was based on a two-step methodology: a fast analysis of tablets using near infrared (NIR) spectroscopy to assess sample homogeneity based on their global composition, followed by Raman chemical imaging of one sample per NIR profile to obtain information on sample formulation. NIR spectroscopy assisted by a principal components analysis (PCA) enabled fast discrimination of different profiles based on the excipient formulation. Raman hyperspectral imaging and multivariate curve resolution - alternating least square (MCR-ALS) provided chemical images of the distribution of the active substance and excipients within tablets and facilitated identification of the active compounds. The combination of NIR spectroscopy and Raman chemical imaging highlighted dose-to-dose variations and succeeded in the discrimination of four different formulations out of eight similar samples of anabolic tablets. Some samples contained either methandienone or methyltestosterone whereas one sample did not contain an active substance. Other ingredients were sucrose, lactose, starch or talc. Both techniques were fast and non-destructive and therefore can be carried out as exploratory methods prior to destructive screening methods. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26198290

  9. Composite nanoparticles based on hyaluronic acid chemically cross-linked with alpha,beta-polyaspartylhydrazide.

    PubMed

    Pitarresi, G; Craparo, E F; Palumbo, F S; Carlisi, B; Giammona, G

    2007-06-01

    In this paper, new composite nanoparticles based on hyaluronic acid (HA) chemically cross-linked with alpha,beta-polyaspartylhydrazide (PAHy) were prepared by the use of a reversed-phase microemulsion technique. HA-PAHy nanoparticles were characterized by FT-IR spectroscopy, confirming the occurrence of the chemical cross-linking, dimensional analysis, and transmission electron micrography, showing a sub-micrometer size and spherical shape. Zeta potential measurements demonstrated the presence of HA on the nanoparticle surface. A remarkable affinity of the obtained nanoparticles toward aqueous media that simulate some biological fluids was found. Stability studies showed the absence of chemical degradation in various media, while in the presence of hyaluronidase, a partial degradation occurred. Cell compatibility was evaluated by performing in vitro assays on human chronic myelogenous leukaemia cells (K-562) chosen as a model cell line and a haemolytic test. HA-PAHy nanoparticles were also able to entrap 5-fluorouracil, chosen as a model drug, and release it in a simulated physiological fluid and in human plasma with a mechanism essentially controlled by a Fickian diffusion. PMID:17521164

  10. Variation in chemical composition and acaricidal activity against Dermanyssus gallinae of four eucalyptus essential oils.

    PubMed

    George, David R; Masic, Dino; Sparagano, Olivier A E; Guy, Jonathan H

    2009-06-01

    The results of this study suggest that certain eucalyptus essential oils may be of use as an alternative to synthetic acaricides in the management of the poultry red mite, Dermanyssus gallinae. At a level of 0.21 mg/cm(2), the essential oil from Eucalyptus citriodora achieved 85% mortality in D. gallinae over a 24 h exposure period in contact toxicity tests. A further two essential oils from different eucalyptus species, namely E. globulus and E. radiata, provided significantly (P < 0.05) lower mite mortality (11 and 19%, respectively). Notable differences were found between the eucalyptus essential oils regarding their chemical compositions. There appeared to be a trend whereby the essential oils that were composed of the fewer chemical components were the least lethal to D. gallinae. It may therefore be the case that the complexity of an essential oil's chemical make up plays an important role in dictating the toxicity of that oil to pests such as D. gallinae. PMID:19089590

  11. Investigation of the detailed chemical composition of organic aerosol in a South East Asian Rainforest

    NASA Astrophysics Data System (ADS)

    Hamilton, Jacqueline; Ward, Martyn; Rami Alfarra, M.; Lewis, Alastair; McFiggans, Gordon; Robinson, Niall

    2010-05-01

    The formation of secondary organic aerosol (SOA) in tropical regions is a key uncertainty in quantifying the effect of man made emissions on the climate. Large quantities of volatile organic compounds are emitted from natural biogenic sources in the tropics, including isoprene, monoterpenes and sequiterpenes. There are very few studies of the detailed chemical composition of organic aerosols in tropical rainforest regions, but these would provide information on the importance of primary versus secondary organic aerosols, the key VOC precursors, oxidation state and volatility. Particle samples were collected in a tropical rainforest at Danum Valley in Borneo as part of the OP3 field campaign in 2008. Twenty four hour filter samples were collected at the Global Atmospheric Watch station at a height of around 10 m and shipped back to the laboratory (below -4 °C) for offline analysis. The OA composition was studied using multiple high resolution chromatographic techniques including comprehensive two dimensional gas chromatography coupled to time of flight mass spectrometry (GCXGC-TOFMS) and liquid chromatography coupled to ion trap mass spectrometry (LC-MSn). The composition was directly compared to chamber generated SOA (as part of the Aerosol Coupling in the Earths System , ACES, experiment) to determine SOA tracers. A biogenic SOA tracer MS fragmentation library was constructed and a number of SOA components from limonene, linalool and -pinene were identified in the rainforest OA. Very high resolution mass spectrometry (Fourier Transform Ion Cyclotron Resonance FTICR-MS) allowed the O:C and H:C ratios to be determined and these will be compared to those obtained by aerosol mass spectrometry (AMS). In addition, the OA composition from the rainforest will be compared to other locations.

  12. Chemical compositions and larvicidal activities of leaf essential oils from two eucalyptus species.

    PubMed

    Cheng, Sen-Sung; Huang, Chin-Gi; Chen, Ying-Ju; Yu, Jane-Jane; Chen, Wei-June; Chang, Shang-Tzen

    2009-01-01

    In the current study, the mosquito larvicidal activity of leaf essential oils and their constituents from two eucalyptus species (Eucalyptus camaldulensis and Eucalyptus urophylla) against two mosquito species, Aedes aegypti and Aedes albopictus, was investigated. In addition, the chemical compositions of the leaf essential oils were analyzed using gas chromatography-mass spectrometry. Results from the larvicidal tests revealed that essential oil from the leaves of E. camaldulensis had an excellent inhibitory effect against both A. aegypti and A. albopictus larvae. The 12 pure constituents extracted from the two eucalyptus leaf essential oils were also tested individually against two mosquito larvae. Among the six effective constituents, alpha-terpinene exhibits the best larvicidal effect against both A. aegypti and A. albopictus larvae. Results of this study show that the leaf essential oil of E. camaldulensis and its effective constituents might be considered as a potent source for the production of fine natural larvicides. PMID:18396398

  13. The chemical composition of fogs and clouds in Southern California

    SciTech Connect

    Munger, J.W.

    1989-01-01

    The major inorganic species in cloud and fog water samples were NH{sub 4}{sup +}, H{sup +}, NO{sub 3}{sup {minus}}, and SO{sub 4}{sup 2{minus}}. Concentrations in fog water samples were 1 - 10 {times} 10{sup {minus}3} M; pH values ranged from {approx equal} 2 to 6. Nitrate usually exceeded sulfate. Acidity depended on the availability of NH{sub 3} from agricultural operations. Stratus cloudwater had somewhat lower concentrations; pH values were in the range 3-4. The major factors accounting for variation in fog- or cloudwater composition were the preexisting aerosol and gas concentrations and variations in liquid water content. Deposition and entrainment or advection of different air masses were also important during extended cloud or fog episodes. The droplet size dependence of cloudwater composition was investigated on one occasion in an intercepted coastal stratus clouds. Concentrations of S(IV) and CH{sub 2}O in the range 100-1000 {mu}M were observed in fogwater from urban sites in Southern California. Lower concentrations were observed in stratus clouds. The high levels of S(IV) and CH{sub 2}O were attributed to the formation of hydroxymethanesulfonate (HMSA), the S(IV) adduct of CH{sub 2}O. Direct measurements of HMSA in fogwater samples from Bakersfield, CA were made by ion-pairing chromatography. Glyoxal and methyglyoxal were observed at concentrations comparable to CH{sub 2}O in fogwater samples from Riverside, CA and in stratus cloudwater samples from sites along the Santa Barbara Channel.

  14. Method for residual household waste composition studies.

    PubMed

    Sahimaa, Olli; Hupponen, Mari; Horttanainen, Mika; Sorvari, Jaana

    2015-12-01

    The rising awareness of decreasing natural resources has brought forward the idea of a circular economy and resource efficiency in Europe. As a part of this movement, European countries have identified the need to monitor residual waste flows in order to make recycling more efficient. In Finland, studies on the composition of residual household waste have mostly been conducted using different methods, which makes the comparison of the results difficult. The aim of this study was to develop a reliable method for residual household waste composition studies. First, a literature review on European study methods was performed. Also, 19 Finnish waste composition studies were compared in order to identify the shortcomings of the current Finnish residual household waste composition data. Moreover, the information needs of different waste management authorities concerning residual household waste were studied through a survey and personal interviews. Stratification, sampling, the classification of fractions and statistical analysis were identified as the key factors in a residual household waste composition study. The area studied should be divided into non-overlapping strata in order to decrease the heterogeneity of waste and enable comparisons between different waste producers. A minimum of six subsamples, each 100 kg, from each stratum should be sorted. Confidence intervals for each waste category should be determined in order to evaluate the applicability of the results. A new three-level classification system was created based on Finnish stakeholders' information needs and compared to four other European waste composition study classifications. PMID:26337965

  15. Does forest fire effect chemical composition of surface water

    SciTech Connect

    Sanders, A.T. . Dept. of Geography and Geology)

    1992-01-01

    Chemical Data for stream drainages in Yellowstone National Park area have been examined for trends associated with the 1988 burn. Limited pre-fire data make assessment difficult. Data from the Snake River (at maximum recorded discharge) suggest that TDS decreases, total Nitrogen remains constant and total Phosphorus increases from pre-fire (and very dry conditions) to post-fire (and more normal conditions). To test these apparent trends post-fire data from adjacent valleys (Jones Creek, burned; Crow Creek, unburned) were compared. Each shows a decrease in TDS, similar nearly constant total Nitrogen and an increase in total Phosphorus. Although year to year changes in surface water seem greater from the burned valley, the data from the unburned valley show similar trends. Therefore these data do not clearly distinguish trends resulting solely from the burn.

  16. Calculations of the Chemical Composition of the Sacramento Urban Plume

    NASA Astrophysics Data System (ADS)

    Perez, I. M.; Cohen, R. C.

    2007-12-01

    Recent measurements within the Sacramento urban plume have provided a detailed benchmark for testing our understanding of tropospheric chemistry. Available measurements include a wide suite of VOC and BVOC, NOy,i, O3, and CO at the source and at a receptor site five hours downwind. Further, the meteorology in the region is extremely regular making it possible to evaluate effects of temperature or day-of-week patterns with a single season of measurements. Here we use a Lagrangian model representing transport from Granite Bay, a suburb at the eastern edge of Sacramento, to the University of California Blodgett Forest Research Station (UC- BFRS). The model represents chemistry based on MCM v3.1 along with mixing and dilution. The model is initiated with concentrations of NOx, peroxynitrates, alkyl and multifunctional nitrates, HNO3, VOCs and O3 based on measurements at the edge of the Sacramento suburban sprawl east of the city. Biogenic VOC emissions throughout the transect are included. The outputs of the model are compared with ozone measurements at Cool three hours downwind, and detailed measurements of VOC, the speciation of the nitrogen oxides and O3 at UC-BFRS, 5 hours downwind of the Sacramento suburbs in the center of the Mountain counties air basin. The comparisons indicate 1) O3 at UC-BFRS and Cool is largely driven by the combination of rural biogenic emissions and urban NOx emissions, 2) that OH is underestimated by standard chemical models, 3) that partitioning of NOy is dominated by peroxy and other multifunctional nitrates that are not represented in standard chemical models and which have a strong impact on how much NO2 is available for ozone production. We also investigate model representation of temperature and weekend/weekday effects.

  17. Chemical composition and antimicrobial activity of honeybee (Apis mellifera ligustica) propolis from subtropical eastern Australia.

    PubMed

    Massaro, Carmelina Flavia; Simpson, Jack Bruce; Powell, Daniel; Brooks, Peter

    2015-12-01

    Propolis is a material manufactured by bees and contains beeswax, bee salivary secretions and plant resins. Propolis preparations have been used for millennia by humans in food, cosmetics and medicines due to its antibacterial effects. Within the hive, propolis plays an important role in bees' health, with much of its bioactivity largely dependent on the plant resins the bees select for its production. Few chemical studies are available on the chemistry of propolis produced by Australian honeybees (Apis mellifera, Apidae). This study aimed to determine the chemical composition as well as in vitro antimicrobial effects of propolis harvested from honeybees in subtropical eastern Australia. Honeybee propolis was produced using plastic frames and multiple beehives in two subtropical sites in eastern Australia. Methanolic extracts of propolis were analysed by liquid chromatography with ultraviolet detection and high-resolution mass spectrometry (ultra-high-pressure liquid chromatography (UHPLC)-UV-high-resolution tandem mass spectrometry (HR-MS/MS)) and by gas chromatography mass spectrometry (GC-MS). The resulting chemical data were dereplicated for compound characterisation. The two crude extracts in abs. ethanol were tested in vitro by the agar diffusion and broth dilution methods, using a phenol standard solution as the positive control and abs. ethanol as the negative control. Chemical constituents were identified to be pentacyclic triterpenoids and C-prenylated flavonoids, including Abyssinoflavanone VII, Propolin C and Nymphaeol C. The two propolis crude extracts showed bactericidal effects at the minimal inhibitory concentrations of 0.37-2.04 mg mL(-1) against Staphylococcus aureus ATCC 25923. However, the extracts were inactive against Klebsiella pneumoniae ATCC 13883 and Candida albicans ATCC 10231. The antistaphylococcal potential of propolis was discussed, also in relation to honeybees' health, as it warrants further investigations on the social and

  18. Chemical composition and antimicrobial activity of honeybee ( Apis mellifera ligustica) propolis from subtropical eastern Australia

    NASA Astrophysics Data System (ADS)

    Massaro, Carmelina Flavia; Simpson, Jack Bruce; Powell, Daniel; Brooks, Peter

    2015-12-01

    Propolis is a material manufactured by bees and contains beeswax, bee salivary secretions and plant resins. Propolis preparations have been used for millennia by humans in food, cosmetics and medicines due to its antibacterial effects. Within the hive, propolis plays an important role in bees' health, with much of its bioactivity largely dependent on the plant resins the bees select for its production. Few chemical studies are available on the chemistry of propolis produced by Australian honeybees ( Apis mellifera, Apidae). This study aimed to determine the chemical composition as well as in vitro antimicrobial effects of propolis harvested from honeybees in subtropical eastern Australia. Honeybee propolis was produced using plastic frames and multiple beehives in two subtropical sites in eastern Australia. Methanolic extracts of propolis were analysed by liquid chromatography with ultraviolet detection and high-resolution mass spectrometry (ultra-high-pressure liquid chromatography (UHPLC)-UV-high-resolution tandem mass spectrometry (HR-MS/MS)) and by gas chromatography mass spectrometry (GC-MS). The resulting chemical data were dereplicated for compound characterisation. The two crude extracts in abs. ethanol were tested in vitro by the agar diffusion and broth dilution methods, using a phenol standard solution as the positive control and abs. ethanol as the negative control. Chemical constituents were identified to be pentacyclic triterpenoids and C-prenylated flavonoids, including Abyssinoflavanone VII, Propolin C and Nymphaeol C. The two propolis crude extracts showed bactericidal effects at the minimal inhibitory concentrations of 0.37-2.04 mg mL-1 against Staphylococcus aureus ATCC 25923. However, the extracts were inactive against Klebsiella pneumoniae ATCC 13883 and Candida albicans ATCC 10231. The antistaphylococcal potential of propolis was discussed, also in relation to honeybees' health, as it warrants further investigations on the social and

  19. Chemically modified electrodes and related solution studies

    SciTech Connect

    Elliott, C.M.

    1990-01-01

    This report briefly discusses work done in the following areas of chemically modified electrodes: Spectroscopic studies of the modes of interactions of pyridine containing ligands with metal surfaces; attempted synthesis of gem-dihalide containing polymers for attachment of Mo{sub 2}S{sub 4} clusters; Synthesis of oxo-ruthenium dimer complexes as catalysts for H{sub 2} oxidation; and, studies of porphyrin based polymers which catalyze the oxidation (oxygenation) of olefins and benzylic carbons. (JDL)

  20. Chemical Composition Analysis, Antimicrobial Activity and Cytotoxicity Screening of Moss Extracts (Moss Phytochemistry).

    PubMed

    Klavina, Laura; Springe, Gunta; Nikolajeva, Vizma; Martsinkevich, Illia; Nakurte, Ilva; Dzabijeva, Diana; Steinberga, Iveta

    2015-01-01

    Mosses have been neglected as a study subject for a long time. Recent research shows that mosses contain remarkable and unique substances with high biological activity. The aim of this study, accordingly, was to analyze the composition of mosses and to screen their antimicrobial and anticancer activity. The total concentration of polyphenols and carbohydrates, the amount of dry residue and the radical scavenging activity were determined for a preliminary evaluation of the chemical composition of moss extracts. In order to analyze and identify the substances present in mosses, two types of extrahents (chloroform, ethanol) and the GC/MS and LC-TOF-MS methods were used. The antimicrobial activity was tested on four bacteria strains, and the anticancer activity on six cancer cell lines. The obtained results show the presence of a high number of primary (fatty acids and amino acids), but mainly secondary metabolites in moss extracts-including, sterols, terpenoids, polyphenols and others-and a high activity with respect to the studied test organisms. PMID:26393559

  1. Chemical composition of the essential oils of Rhodiola rosea L. of three different origins

    PubMed Central

    Evstatieva, Ljuba; Todorova, Milka; Antonova, Daniela; Staneva, Jordanka

    2010-01-01

    Rhodiola rosea L. (Crassulaceae), or “rose root” is a perennial herbaceous plant, distributed in the Northern Hemisphere. Pharmacological studies have shown that R. rosea exhibits different biological activities – antioxidant, antidepressant, anticancer, etc. The aim of this study was to compare the chemical composition of essential oils from rhizomes of three commercial samples of R. rosea originated from Bulgaria (sample 1), China (sample 2) and India (sample 3). The oils were analyzed by GC and GC-MS. Thus, the main volatile component in the Bulgaria and Chinese R. rosea was geraniol, followed by myrthenol in sample 1 or octanol in sample 2. Phenethylalcohol was a principal constituent in the Indian oil. Myrtenol and octanol were in significant amounts too. Aliphatic hydrocarbons were characteristic of the latter sample. It is notable that cinnamyl alcohol, which was present in large concentration in Bulgarian sample, was not detected in the other two samples. The obtained results showed considerable differences in the composition of the studied three origins of R. rosea. PMID:21120024

  2. The Chemical Composition of Halo Stars on Extreme Orbits

    NASA Astrophysics Data System (ADS)

    Stephens, Alex

    1999-04-01

    Presented within is a fine spectroscopic analysis of 11 metal-poor (-2.15<[Fe/H]<-1.00) dwarf stars on orbits that penetrate the outermost regions of the Galactic halo. Abundances for a select group of light metals (Na, Mg, Si, Ca, and Ti), Fe-peak nuclides (Cr, Fe, and Ni), and neutron-capture elements (Y and Ba) were calculated using line strengths measured from high-resolution (R~48,000), high signal-to-noise ratio (S/N~110pixel^-1) echelle spectra acquired with the Keck I 10 m telescope and HIRES spectrograph. Ten of the stars have apogalactica, a proxy for stellar birthplace, which stretch between 25 and 90 kpc; however, these ``outer halo'' stars exhibit strikingly uniform abundances. The average, Fe-normalized abundances-<[Mg/Fe]>=+0.23+/-0.09, <[Si/Fe]>=+0.24+/-0.10, <[Ca/Fe]>=+0.22+/-0.07, <[Ti/Fe]>=+0.20+/-0.08, <[Cr/Fe]>=0.02+/-0.07, <[Ni/Fe]>=-0.09+/-0.07, and <[Ba/Fe]>=+0.01+/-0.12-exhibit little intrinsic scatter; moreover, the evolution of individual ratios (as a function of [Fe/H]) is generally consistent with the predictions of galactic chemical evolution models dominated by the ejecta of core-collapse supernovae. Only <[Y/Fe]>=-0.13+/-0.21 exhibits a dispersion larger than observational uncertainties, which suggests a different nucleosynthesis site for this element. It has been conjectured that stars on high-energy orbits-either those that penetrate the remote halo or ones with extreme retrograde velocities-were once associated with a cannibalized satellite galaxy. Such stars, as shown here, are indistinguishable from metal-poor dwarfs of the inner Galactic halo. The uniformity of the abundances, regardless of kinematic properties, suggests that physically, spatially, and temporally distinct star-forming regions within (or near) the growing Milky Way experienced grossly similar chemical evolution histories. Implications for galaxy formation scenarios are discussed.

  3. Chemical Composition, Antioxidant, and Antibacterial Activity of Wood Vinegar from Litchi chinensis.

    PubMed

    Yang, Jyh-Ferng; Yang, Cheng-Hong; Liang, Ming-Tsai; Gao, Zi-Jie; Wu, Yuh-Wern; Chuang, Li-Yeh

    2016-01-01

    The antioxidant and antibacterial activities of wood vinegar from Litchi chinensis, and its components have been studied. The chemical compositions of wood vinegar were analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 17 chemical compounds were identified, representing 83.96% of the compositions in the wood vinegar. Three major components, included 2,6-dimethoxyphenol (syringol, 29.54%), 2-methoxyphenol (guaiacol, 12.36%), and 3,5-dimethoxy-4-hydroxytoluene (11.07%), were found in the wood vinegar. Antioxidant activities of the acids were investigated from the aspects of 1,1-Diphyl-2-picrylhydrazyl (DPPH) free radicals scavenging capacity, superoxide anion radical scavenging capacity, and reducing power. The pyroligneous acid exhibited high antioxidant activity which was comparable to the reference standards (vitamin C and butylated hydroxyl toluene) at the same dose with IC50 values of 36.5 ppm calculated by the DPPH radical scavenging assay, 38.38 g Trolox equivalent/100 g DW by the trolox equivalent antioxidant capacity (TEAC) assay, and 67.9 by the reducing power analysis. Antibacterial activity was evaluated using the disc diffusion and microdilution methods against a group of clinically antibiotic resistant isolates. The major components exhibited broad spectrum inhibition against all the bacterial strains with a range of disc inhibition zoon between 15-19 mm. The minimum inhibition concentration and minimum bactericide concentration against the test strains was ranging in 0.95-3.80 μL/100 μL and 1.90-3.80 μL/100 μL, respectively. Most of the antibiotic resistant strains were more susceptible to the wood vinegar than the non-antibiotic resistant strain except the strain of ornithine resistant Staphylococcus aureus. Based on the chemical profile, it was considered that the strongest antioxidant and antibacterial activity of Litchi chinensis wood vinegar was due to its highly phenolic compositions. This study revealed that the Litchi

  4. Chemical compositions and kinematics of the Hercules stream

    NASA Astrophysics Data System (ADS)

    Ramya, P.; Reddy, Bacham E.; Lambert, David L.; Musthafa, M. M.

    2016-08-01

    An abundance analysis is reported of 58-K giants identified by Famaey et al. (2005, A&A, 430, 165) as highly probable members of the Hercules stream selected from stars north of the celestial equator in the Hipparcos catalogue. The giants have compositions spanning the interval [Fe/H] from -0.17 to +0.42 with a mean value of +0.15 and relative elemental abundances [El/Fe] representative of the Galactic thin disc. Selection effects may have biased the selection from the Hipparcos catalogue against the selection of metal-poor stars. Our reconsideration of the recent extensive survey by Bensby et al. of FG dwarfs, including metal-poor stars, provides a [Fe/H] distribution for the Hercules stream, which is similar to that from the 58 giants. It appears that the stream is dominated by metal-rich stars from the thin disc. We discuss suggestions in the literature that the stream includes metal-poor stars from the thick disc.

  5. Chemical composition of precipitation in a Mexican Maya region

    NASA Astrophysics Data System (ADS)

    Bravo, H. A.; Saavedra, M. I. R.; Sánchez, P. A.; Torres, R. J.; Granada, L. M. M.

    The chemical characteristics of wet precipitation in Puerto Morelos, Quintana Roo State, Mexico, were measured from April 1994 to December 1995. Puerto Morelos is located in the Caribbean Mayan coastal region of the Peninsula of Yucatan, and is normally exposed to winds from the Caribbean region. Wetfall was analyzed for pH, conductivity and Cl -, NO 3-, SO 42-, Na +, NH 4+, K +, Mg 2+ and Ca 2+ ion concentrations. Volume-weighted mean pH for the whole sampling period was 5.35, although values as low as 4.6 were measured in several rain samples. Concentrations of all species correlated negatively with rain volume. Sea-salt aerosols contributed with most of the Na +, Cl -, Mg 2+, K + and SO 42- found in wet precipitation. The mean [SO 42-excess] was 9.7 μEq l -1, which agrees with the background hemispheric values of ≈10 μEq l -1 reported elsewhere. The mean [NO 3-] was 11.4 μEq l -1, almost four times higher than the background hemispheric value of ≈2.5 μEq l -1 reported elsewhere. However, a major component causing the slight acidity character of rain in Puerto Morelos seems to be H 2SO 4.

  6. The chemical composition of the mild barium star HD 202109

    NASA Astrophysics Data System (ADS)

    Yushchenko, A. V.; Gopka, V. F.; Kim, C.; Liang, Y. C.; Musaev, F. A.; Galazutdinov, G. A.

    2004-01-01

    We present chemical abundances of the mild barium star HD 202109 (\\zeta Cyg) determined from the analysis of a spectrum obtained by using the 2-m telescope at the Peak Terskol Observatory and a high-resolution spectrometer with R=80 000, signal to noise ratio >100. We also present the atmospheric parameters of the star determined using various methods including iron-line abundance analysis. For line identifications, we use whole-range synthetic spectra computed from Kurucz's database and the latest lists of spectral lines. Among the determined abundances of 51 elements, those of P, S, K, Cu, Zn, Ge, Rb, Sr, Nb, Mo, Ru, Rh, Pd, In, Sm, Gd, Tb, Dy, Er, Tm, Hf, Os, Ir, Pt, Tl, and Pb were not investigated previously. Assuming that the overabundance pattern of Ba stars is due to binary accretion, the observed abundance pattern of the neutron-capture process elements in HD 202109 can be explained by combining the AGB star nucleosynthesis and the wind accretion scenario. Based on observations obtained at the 2-m telescope of Peak Terskol observatory near Mt. Elbrus, Northern Caucasus, Russia - International Center for Astronomical, Medical and Ecological Research (ICAMER), Ukraine & Russia.

  7. Conical intersection seams in polyenes derived from their chemical composition

    NASA Astrophysics Data System (ADS)

    Nenov, Artur; de Vivie-Riedle, Regina

    2012-08-01

    The knowledge of conical intersection seams is important to predict and explain the outcome of ultrafast reactions in photochemistry and photobiology. They define the energetic low-lying reachable regions that allow for the ultrafast non-radiative transitions. In complex molecules it is not straightforward to locate them. We present a systematic approach to predict conical intersection seams in multifunctionalized polyenes and their sensitivity to substituent effects. Included are seams that facilitate the photoreaction of interest as well as seams that open competing loss channels. The method is based on the extended two-electron two-orbital method [A. Nenov and R. de Vivie-Riedle, J. Chem. Phys. 135, 034304 (2011)], 10.1063/1.3608924. It allows to extract the low-lying regions for non-radiative transitions, which are then divided into small linear segments. Rules of thumb are introduced to find the support points for these segments, which are then used in a linear interpolation scheme for a first estimation of the intersection seams. Quantum chemical optimization of the linear interpolated structures yields the final energetic position. We demonstrate our method for the example of the electrocyclic isomerization of trifluoromethyl-pyrrolylfulgide.

  8. Conical intersection seams in polyenes derived from their chemical composition

    SciTech Connect

    Nenov, Artur; Vivie-Riedle, Regina de

    2012-08-21

    The knowledge of conical intersection seams is important to predict and explain the outcome of ultrafast reactions in photochemistry and photobiology. They define the energetic low-lying reachable regions that allow for the ultrafast non-radiative transitions. In complex molecules it is not straightforward to locate them. We present a systematic approach to predict conical intersection seams in multifunctionalized polyenes and their sensitivity to substituent effects. Included are seams that facilitate the photoreaction of interest as well as seams that open competing loss channels. The method is based on the extended two-electron two-orbital method [A. Nenov and R. de Vivie-Riedle, J. Chem. Phys. 135, 034304 (2011)]. It allows to extract the low-lying regions for non-radiative transitions, which are then divided into small linear segments. Rules of thumb are introduced to find the support points for these segments, which are then used in a linear interpolation scheme for a first estimation of the intersection seams. Quantum chemical optimization of the linear interpolated structures yields the final energetic position. We demonstrate our method for the example of the electrocyclic isomerization of trifluoromethyl-pyrrolylfulgide.

  9. The chemical composition of red giants in 47 Tucanae. I. Fundamental parameters and chemical abundance patterns

    NASA Astrophysics Data System (ADS)

    Thygesen, A. O.; Sbordone, L.; Andrievsky, S.; Korotin, S.; Yong, D.; Zaggia, S.; Ludwig, H.-G.; Collet, R.; Asplund, M.; Ventura, P.; D'Antona, F.; Meléndez, J.; D'Ercole, A.

    2014-12-01

    Context. The study of chemical abundance patterns in globular clusters is key importance to constraining the different candidates for intracluster pollution of light elements. Aims: We aim at deriving accurate abundances for a wide range of elements in the globular cluster 47 Tucanae (NGC 104) to add new constraints to the pollution scenarios for this particular cluster, expanding the range of previously derived element abundances. Methods: Using tailored 1D local thermodynamic equilibrium (LTE) atmospheric models, together with a combination of equivalent width measurements, LTE, and NLTE synthesis, we derive stellar parameters and element abundances from high-resolution, high signal-to-noise spectra of 13 red giant stars near the tip of the RGB. Results: We derive abundances of a total 27 elements (O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Mo, Ru, Ba, La, Ce, Pr, Nd, Eu, Dy). Departures from LTE were taken into account for Na, Al, and Ba. We find a mean [Fe/H] = -0.78 ± 0.07 and [ α/ Fe ] = 0.34 ± 0.03 in good agreement with previous studies. The remaining elements show good agreement with the literature, but including NLTE for Al has a significant impact on the behavior of this key element. Conclusions: We confirm the presence of an Na-O anti-correlation in 47 Tucanae found by several other works. Our NLTE analysis of Al shifts the [Al/Fe] to lower values, indicating that this may be overestimated in earlier works. No evidence of an intrinsic variation is found in any of the remaining elements. Based on observations made with the ESO Very Large Telescope at Paranal Observatory, Chile (Programmes 084.B-0810 and 086.B-0237).Full Tables 2, 5, and 9 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/572/A108Appendix A is available in electronic form at http://www.aanda.org

  10. 75 FR 29754 - Claims of Confidentiality of Certain Chemical Identities Contained in Health and Safety Studies...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-27

    ..., 2010 (75 FR 3462) (FRL-8807-9), EPA announced that `` here a health and safety study submitted under... chemical substances of unknown or variable composition, complex reaction products and biological materials... AGENCY Claims of Confidentiality of Certain Chemical Identities Contained in Health and Safety...

  11. Composition and production rate of pharmaceutical and chemical waste from Xanthi General Hospital in Greece

    SciTech Connect

    Voudrias, Evangelos; Goudakou, Lambrini; Kermenidou, Marianthi; Softa, Aikaterini

    2012-07-15

    Highlights: Black-Right-Pointing-Pointer We studied pharmaceutical and chemical waste production in a Greek hospital. Black-Right-Pointing-Pointer Pharmaceutical waste comprised 3.9% w/w of total hazardous medical waste. Black-Right-Pointing-Pointer Unit production rate for total pharmaceutical waste was 12.4 {+-} 3.90 g/patient/d. Black-Right-Pointing-Pointer Chemical waste comprised 1.8% w/w of total hazardous medical waste. Black-Right-Pointing-Pointer Unit production rate for total chemical waste was 5.8 {+-} 2.2 g/patient/d. - Abstract: The objective of this work was to determine the composition and production rates of pharmaceutical and chemical waste produced by Xanthi General Hospital in Greece (XGH). This information is important to design and cost management systems for pharmaceutical and chemical waste, for safety and health considerations and for assessing environmental impact. A total of 233 kg pharmaceutical and 110 kg chemical waste was collected, manually separated and weighed over a period of five working weeks. The total production of pharmaceutical waste comprised 3.9% w/w of the total hazardous medical waste produced by the hospital. Total pharmaceutical waste was classified in three categories, vial waste comprising 51.1%, syringe waste with 11.4% and intravenous therapy (IV) waste with 37.5% w/w of the total. Vial pharmaceutical waste only was further classified in six major categories: antibiotics, digestive system drugs, analgesics, hormones, circulatory system drugs and 'other'. Production data below are presented as average (standard deviation in parenthesis). The unit production rates for total pharmaceutical waste for the hospital were 12.4 (3.90) g/patient/d and 24.6 (7.48) g/bed/d. The respective unit production rates were: (1) for vial waste 6.4 (1.6) g/patient/d and 13 (2.6) g/bed/d, (2) for syringe waste 1.4 (0.4) g/patient/d and 2.8 (0.8) g/bed/d and (3) for IV waste 4.6 (3.0) g/patient/d and 9.2 (5.9) g/bed/d. Total chemical waste

  12. Chemical composition and mass closure of particulate matter at six urban sites in Europe

    NASA Astrophysics Data System (ADS)

    Sillanpää, Markus; Hillamo, Risto; Saarikoski, Sanna; Frey, Anna; Pennanen, Arto; Makkonen, Ulla; Spolnik, Zoya; Van Grieken, René; Braniš, Martin; Brunekreef, Bert; Chalbot, Marie-Cecile; Kuhlbusch, Thomas; Sunyer, Jordi; Kerminen, Veli-Matti; Kulmala, Markku; Salonen, Raimo O.

    The chemical composition of fine (PM 2.5) and coarse (PM 2.5-10) particulate matter was investigated in 7-week field campaigns of contrasting air pollution at six urban background sites in Europe. The campaigns were scheduled to include seasons of local public health concern due to high particulate concentrations or findings in previously conducted epidemiological studies. The sampling campaigns were carried out as follows: Duisburg/Germany October-November 2002 (autumn), Prague/Czech Republic November 2002-January 2003 (winter), Amsterdam/Netherlands January-March 2003 (winter), Helsinki/Finland March-May 2003 (spring), Barcelona/Spain March-May 2003 (spring) and Athens/Greece June-July 2003 (summer). Aerosol samples were collected in 3+4-day periods per week ( N=14) using two identical virtual impactors (VI). All the filter samples were analysed with the same instruments to obtain particulate mass, inorganic ions, total and watersoluble elements, and elemental and organic carbon content. The campaign means of PM 2.5 and PM 2.5-10 ranged from 8.3 to 30 and 5.4 to 29 μg m -3, respectively. The "wet and cool" seasons favoured a low coarse-to-fine particulate mass ratio (<1), whereas the ratio was high (>1) during the warmer and drier spring and summer campaigns. According to chemical mass closure, the major components in PM 2.5 were carbonaceous compounds (organic matter+elemental carbon), secondary inorganic ions and sea salt, whereas those in PM 2.5-10 were soil-derived compounds, carbonaceous compounds, sea salt and nitrate. The major and minor components together accounted for 79-106% and 77-96% of the gravimetrically measured PM 2.5 and PM 2.5-10 mass, respectively. In conclusion, the measured PM 2.5 and PM 2.5-10 in the campaigns could be reconstructed to a large extent with the help of harmonized particulate sampling and analysis of the selected chemical constituents. The health significance of the observed differences in chemical composition and emission

  13. Chemical composition of nuts and seeds sold in Korea.

    PubMed

    Chung, Keun Hee; Shin, Kyung Ok; Hwang, Hyo Jeong; Choi, Kyung-Soon

    2013-04-01

    Eleven types of nuts and seeds were analyzed to determine their energy (326-733 mg), moisture (1.6-18.3 mg), carbohydrate (8.8-70.9 mg), protein (4.9-30.5 mg), lipid (2.5-69.8 mg), and ash (1.2-5.5 mg) contents per 100 g of sample. Energy content was highest in pine nuts (733 mg/100 g), carbohydrate level was highest in dried figs (70.9 mg/100 g) and protein was highest in peanuts (30.5 mg/100 g). The amino acid compositions of nuts and seeds were characterized by the dominance of hydrophobic (range = 1,348.6-10,284.6 mg), hydrophilic (range = 341.1-3,244.3 mg), acidic (range = 956.1-8,426.5 mg), and basic (range = 408.6-4,738.5 mg) amino acids. Monounsaturated fatty acids (MUFA) were highest in macadamia nuts (81.3%), whereas polyunsaturated fatty acids (PUFA) were highest in the walnuts (76.7%). Macadamia nuts did not contain any vitamin E, whereas sunflower seeds contained the highest level (60.3 mg/kg). Iron (Fe) content was highest in pumpkin seeds (95.85 ± 33.01 ppm), zinc (Zn) content was highest in pistachios (67.24 ± 30.25 ppm), copper (Cu) content was greatest in walnuts (25.45 ± 21.51 ppm), and lead (Pb) content was greatest in wheat nuts (25.49 ± 4.64 ppm), significantly (P < 0.05). In conclusion, current commercial nuts and seeds have no safety concerns, although further analysis of Pb contents is necessary to ensure safety. PMID:23610599

  14. Chemical composition of urban airborne particulate matter in Ulaanbaatar

    NASA Astrophysics Data System (ADS)

    Nishikawa, Masataka; Matsui, Ichiro; Batdorj, Dashdondog; Jugder, Dulam; Mori, Ikuko; Shimizu, Atsushi; Sugimoto, Nobuo; Takahashi, Katsuyuki

    2011-10-01

    Atmospheric pollution caused by airborne particulate matter in the winter season in Ulaanbaatar, Mongolia is a very serious problem. However, there is a complete lack of scientific observation data to define the situation prior to any remediation. PM10 and PM2.5 average monthly values obtained by continuous monitoring showed the concentrations of particles of both size categories exceeded 100 μg m-3 during November to February (winter). PM10 particles were sampled with filters in January (i.e. during the heating period) and June (i.e.non-heating period) of 2008 in central Ulaanbaatar. To determine the composition of urban airborne particulate matter we analyzed a range of ionic components, multiple elements including heavy metals, and organic and inorganic carbon (soot). We also measured the stable carbon isotope ratio of the soot. Total carbon (sum of organic carbon and inorganic carbon) accounted for 47% of the mass of the PM10 during the heating period and 33% during the non-heating period, and was the largest component of urban airborne particulate matter in Ulaanbaatar. Stable isotope ratios (δ13C) of soot generated during the heating period (-23.4 ± 0.2‰) approximated the ratios for coal used in Ulaanbaatar (-21.3 to -24.4‰), while the ratios during the non-heating period (-27.1 ± 0.4‰) were clearly different from the coal values. In the heating period, a very high correlation was observed between soot and organic carbon, SO42-, NO3-, F-, Zn, As, and Pb, and we concluded that they were derived from coal combustion along with soot. In addition, the concentrations and their ratios relative to each other of Al, Fe, Ca, K, Na, Mg, and Mn hardly differed between the heating period and the non-heating period, and it was concluded that they were derived from soil dust.

  15. Chemical composition of nuts and seeds sold in Korea

    PubMed Central

    Shin, Kyung Ok; Hwang, Hyo Jeong; Choi, Kyung-Soon

    2013-01-01

    Eleven types of nuts and seeds were analyzed to determine their energy (326-733 mg), moisture (1.6-18.3 mg), carbohydrate (8.8-70.9 mg), protein (4.9-30.5 mg), lipid (2.5-69.8 mg), and ash (1.2-5.5 mg) contents per 100 g of sample. Energy content was highest in pine nuts (733 mg/100 g), carbohydrate level was highest in dried figs (70.9 mg/100 g) and protein was highest in peanuts (30.5 mg/100 g). The amino acid compositions of nuts and seeds were characterized by the dominance of hydrophobic (range = 1,348.6-10,284.6 mg), hydrophilic (range = 341.1-3,244.3 mg), acidic (range = 956.1-8,426.5 mg), and basic (range = 408.6-4,738.5 mg) amino acids. Monounsaturated fatty acids (MUFA) were highest in macadamia nuts (81.3%), whereas polyunsaturated fatty acids (PUFA) were highest in the walnuts (76.7%). Macadamia nuts did not contain any vitamin E, whereas sunflower seeds contained the highest level (60.3 mg/kg). Iron (Fe) content was highest in pumpkin seeds (95.85 ± 33.01 ppm), zinc (Zn) content was highest in pistachios (67.24 ± 30.25 ppm), copper (Cu) content was greatest in walnuts (25.45 ± 21.51 ppm), and lead (Pb) content was greatest in wheat nuts (25.49 ± 4.64 ppm), significantly (P < 0.05). In conclusion, current commercial nuts and seeds have no safety concerns, although further analysis of Pb contents is necessary to ensure safety. PMID:23610599

  16. Chemical composition and antioxidant activities of the essential oil from Nandina domestica fruits.

    PubMed

    Bi, Shu-Feng; Zhu, Guang-Qi; Wu, Jie; Li, Zhong-Kang; Lv, Yong-Zhan; Fang, Ling

    2016-01-01

    The chemical composition and antioxidant activities of the essential oil from Nandina domestica fruits were studied for the first time. Twenty-two compounds, representing 82.79% of the oil, were identified from the oil. The major compounds were 3-hexen-1-ol (12.9%), linalool (12.3%), 2-methoxy-4-vinylphenol (9.9%), oleic acid (8.0%), furfural (5.8%) and 2,6-di-tert-butyl-4-methylphenol (5.7%). The antioxidant activities of the oil were evaluated using reducing power, metal chelating ability and scavenging capacity against 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis-3-ethylbenzthiazoline-6-sulfonate (ABTS) and superoxide anion free radical. The oil exhibited significant antioxidant activities. PMID:26199150

  17. Consequences of the accretion of planetary matter on the chemical composition of the stars.

    NASA Astrophysics Data System (ADS)

    Vauclair, S.; Vauclair, G.

    2014-12-01

    The question of the possible modification of the abundances observed at the surface of stars in case of accretion of planetary matter has been debated for several years. Here we present some recent studies on this subject. At the beginning of the stars' life on the main sequence, contrary to what was assumed in the past, heavy matter accretion cannot lead to any overabundance of heavy elements because of the double-diffusive instability induced by the inversion of the mean molecular weight. This instability leads to partial extra-mixing which, in some cases, may induce lithium destruction. On the other hand, helium settling leads to stabilizing μ-gradients inside the stars during stellar evolution, so that heavy matter accretion can modify the observed chemical composition as long as the global μ-gradient does not become unstable.

  18. Chemical composition and cytotoxic and antimicrobial activity of Calycotome villosa (Poiret) link leaves.

    PubMed

    Loy, G; Cottiglia, F; Garau, D; Deidda, D; Pompei, R; Bonsignore, L

    2001-01-01

    The chemical composition of the essential oil and methanol extract of Calycotome villosa (Poiret) Link leaves collected in Sardinia (Italy) has been studied by analytical and spectroscopic methods. Falcarinol and some alcohols, terpenes, furan derivatives, and paraffins have been isolated from the essential oil. Thirteen alkaloids and falcarinol have been identified in the chloroform fraction of the basic methanol extract. Six flavonoids and four anthraquinones have been isolated in the chloroform fraction after acidification of the basic methanol extract. The cytotoxic and antimicrobial activities have also been evaluated. The essential oil, the methanol extract in toto, and the fraction of the basic extract showed strong cytotoxicity, whereas the fraction of the acid extract showed lower cytotoxicity. Furthermore, this fraction showed good antibacterial activity against Staphylococcus aureus, Bacillus lentus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Providencia rettgeri, and Morganella morganii. It can therefore be stated that this plant's cytotoxicity is prevalently due to falcarinol. PMID:11482772

  19. Chemical composition of vegetation along urbanisation gradients in two European cities.

    PubMed

    Sæbø, A; Hanslin, H M; Torp, T; Lierhagen, S; Gawronska, H; Dzierzanowski, K; Gawronski, S

    2015-03-01

    Accumulation of particulate matter (PM) and metals on leaves of three deciduous woody species was studied along urbanisation gradients in Stavanger and Warsaw. Differences between rural and urban sites explained most of the observed variation in leaf chemistry, followed by differences between regions. Highest leaf accumulation of elements was found in Warsaw, but also composition of elements differed between the cities. Overall, species showed similar patterns of element accumulation, but differed in accumulation of specific elements. These differences could in part be explained by differences in epicuticular waxes and PM accumulation. Expected source of elements and their chemical characteristics did not explain the observed accumulation patterns. A better differentiation between elements taken up from soil and air would be required for his. Species specific accumulation of elements has to be taken into consideration using leaf samples for biomonitoring. PMID:25590129

  20. Antioxidant activity and chemical composition of three Tunisian Cistus: Cistus monspeliensis, Cistus villosus and Cistus libanotis.

    PubMed

    Nicoletti, Marcello; Toniolo, Chiara; Venditti, Alessandro; Bruno, Maurizio; Ben Jemia, Mariem

    2015-02-01

    The chemical composition of three rockrose Cistus species, Cistus monspeliensis, Cistus libanotis and Cistus villosus, collected in Tunisia, was studied by HPTLC, focusing on the terpenes and phenols constituents. Diterpenes of Cistus are important as the main constituents of the leaf sticky aromatic resin, known as labdanum, which are highly appreciated in perfumery. Polyphenols in the methanolic extracts of each species were identified, quantified as total and as flavonoids and tannins, and tested for antioxidant activity. Diterpenes were evident in C. libanotis and C. monspeliensis, whereas they were practically absent in C. villosus; C. libanotis had higher phenolic amount, whereas antioxidant activities were important, but different according to the following tests: DPPH radical scavenging, conversion of the Fe(3+/)ferricyanide complex and inhibition of β-carotene bleaching. The reported data confirm the validity of utilisation of Cistus sp. in marketed herbal products, as well as the relevant presence of diterpenes in species actually not used for labdanum production. PMID:25116860

  1. Essential oil yield and chemical composition changes during leaf ontogeny of palmarosa (Cymbopogon martinii var. motia).

    PubMed

    Rao, Bhaskaruni R Rajeswara; Rajput, Dharmendra K; Patel, Rajendra P; Purnanand, Somasi

    2010-12-01

    Changes in leaf biomass yield, essential oil yield, and chemical composition were investigated during leaf ontogeny of palmarosa {Cymbopogon martinii (Roxb.) Wats. var. motia Burk., family Poaceae}. Eleven leaves representing different developmental stages, serially numbered from the apex to the base of the plant were utilized for the study. Leaf biomass yield increased up to the eighth leaf. Essential oil recovery increased up to the third leaf; thereafter it decreased. Minimum essential oil recovery was observed in the eleventh leaf. Essential oil yield/leaf increased up to the sixth leaf. Essential oil yield and concentrations of linalool, alpha-terpineol, geranyl isobutyrate and geraniol were relatively higher in the essential oils of mature, older leaves. Essential oil recovery, and percentages of myrcene, beta-caryophyllene, geranyl acetate, (E,Z) farnesol and geranyl hexanoate were higher in the essential oils of young, expanding leaves. PMID:21299128

  2. Spectral Analysis by XANES Reveals that GPNMB Influences the Chemical Composition of Intact Melanosomes

    SciTech Connect

    T Haraszti; C Trantow; A Hedberg-Buenz; M Grunze; M Anderson

    2011-12-31

    GPNMB is a unique melanosomal protein. Unlike many melanosomal proteins, GPNMB has not been associated with any forms of albinism, and it is unclear whether GPNMB has any direct influence on melanosomes. Here, melanosomes from congenic strains of C57BL/6J mice mutant for Gpnmb are compared to strain-matched controls using standard transmission electron microscopy and synchrotron-based X-ray absorption near-edge structure analysis (XANES). Whereas electron microscopy did not detect any ultrastructural changes in melanosomes lacking functional GPNMB, XANES uncovered multiple spectral phenotypes. These results directly demonstrate that GPNMB influences the chemical composition of melanosomes and more broadly illustrate the potential for using genetic approaches in combination with nano-imaging technologies to study organelle biology.

  3. Chemical composition and biological activities of the essential oil from Anredera cordifolia grown in Brazil.

    PubMed

    Souza, Lucéia Fátima; de Barros, Ingrid Bergman Inchausti; Mancini, Emilia; De Martino, Laura; Scandolera, Elia; De Feo, Vincenzo

    2014-07-01

    The chemical composition of the essential oil of Anredera cordifolia (Ten.) Steenis (Basellaceae), grown in Brazil, was studied by means of GC and GC-MS analysis. In all, 19 compounds were identified, accounting for 91.6% of the total oil; hydrocarbons were the main constituents (67.7%). The essential oil was evaluated for its in vitro potential phytotoxic activity against germination and initial radicle growth of Raphanus sativus L., Sinapis arvensis L., and Phalaris canariensis L. seeds. At 1.25 microg/mL and 0.625 microg/mL, the oil significantly promoted the germination of S. arvensis. Moreover, the antimicrobial activity of the essential oil was assayed against ten bacterial strains. The essential oil showed a weak inhibitory activity against the Gram-positive pathogens. PMID:25230514

  4. [Chemical composition and chromaticity characteristic of Jilan glaze of Ming and Qing official kilns].

    PubMed

    Wu, Jun-ming; Zhang, Mao-lin; Li, Qi-jiang; Wu, Juan; Quan, Kui-shan; Cao, Jian-wen

    2012-08-01

    Color glazes of Ming and Qing official kilns are excellent representatives of the famous ancient Chinese porcelains. The study of official ware with Jilan glaze has been an important topic. But it made slow progress due to the rarity of samples with strict production management and using system. The recipes, chemical composition and chromaticity characteristic of the Jilan samples excavated from official kilns in the Ming and Qing dynasties were first discussed by systematical testing with the energy dispersive X-ray fluorescence (EDXRF) and color difference meter. The results showed that the porcelain stone content in Jilan bodies of official kiln in the Ming dynasty is higher than the samples of the Qing dynasty. The manganese content in Jilan glazes of the Ming dynasty is higher than that in the Qing dynasty, while the glaze ash addition and the lightness value in the glaze are opposite. PMID:23156793

  5. Chemical composition, dietary fibre, tannins and minerals of grain amaranth genotypes.

    PubMed

    Mustafa, Arif F; Seguin, Philippe; Gélinas, Bruce

    2011-11-01

    The objective of this study was to determine the chemical composition of 28 white and coloured grain amaranth (Amaranthus spp.) genotypes. Neutral detergent fibre (NDF) concentration was greater while strach concentration was lower for coloured seeds genotypes than white seeds genotypes. Total dietary fibre followed a similar trend to that observed for NDF. Total tannin concentrations ranged between 20.7 and 0 g/kg with total and hydrolysed tannin concentrations being higher for white than for coloured seeds genotypes. Coloured seeds genotypes contained higher Mg and Ca concentrations than white seeds genotypes. However, seed colour had no influence on K, Na and P concentrations. Copper and Fe were the most variable micro-minerals in the evaluated genotypes with no significant effect of seed colour on the concentration of either mineral. PMID:21599462

  6. Formation and chemical composition of atmospheric aerosols in an equatorial forest area

    NASA Astrophysics Data System (ADS)

    Clairac, B.; Delmas, R.; Cros, B.; Cachier, H.; Buat-Menard, P.

    1988-05-01

    The physical properties and the chemical composition of atmospheric aerosols have been studied in an equatorial region in the southern Congo (Africa). Field experiments were conducted between 1978 and 1983 in the equatorial forest of the Mayombe during periods where the influence of biomass burning was minimum. The results indicate that the forest is a net source of both fine particles resulting primarily from gas-to-particle conversion and coarse particles produced by mechanical processes. Carbonaceous matter is the major component of these biogenic particles but the forest is also a significant source of sulfate, nitrate, ammonium and potassium. Half of this carbon is attached to submicron particles and likely derives from organic gaseous precursors naturally emitted by the local biosphere.

  7. Chemical composition and biological activities of the essential oils from two Pereskia species grown in Brazil.

    PubMed

    Souza, Lucéia Fatima; De Barros, Ingrid Bergman Inchausti; Mancini, Emilia; De Martino, Laura; Scandolera, Elia; De Feo, Vincenzo

    2014-12-01

    The chemical composition of the essential oils of Pereskia aculeata Mill. and P. grandifolia Haw. (Cactaceae), grown in Brazil, was studied by means of GC and GC-MS. In all, 37 compounds were identified, 30 for P. aculeata and 15 for P. grandifolia. Oxygenated diterpenes are the main constituents, both in the oil ofP. grandifolia (55.5%) and in that ofP. aculeata (29.4%). The essential oils were evaluated for their in vitro phytotoxic activity against germination and initial radicle growth of Raphanus sativus L., Sinapis arvensis L., and Phalaris canariensis L. seeds. The essential oil of P. grandifolia, at all doses tested, significantly inhibited the radicle elongation of R. sativus. Moreover, the antimicrobial activity of the essential oils was assayed against ten bacterial strains. The essential oils showed weak inhibitory activity against the Gram-positive pathogens. PMID:25632490

  8. Chemical composition and antigerminative activity of the essential oils from five Salvia species.

    PubMed

    De Martino, Laura; Roscigno, Graziana; Mancini, Emilia; De Falco, Enrica; De Feo, Vincenzo

    2010-02-01

    The chemical composition of the essential oils of Salvia africana L., Salvia elegans Vahl, Salvia greggii A. Gray, Salvia mellifera Green and Salvia munzii Epling, cultivated in Eboli (Salerno, Southern Italy), was studied by means of GC and GC-MS analyses. In all, 88 compounds were identified, 54 for S. africana, accounting for 95.4% of the total oil, 55 for S. elegans (92.9%), 50 for S. greggii (96.9%), 54 for S. mellifera (90.4%) and 47 for S. munzii (97.5%), respectively. In S. africana,the amount of monoterpenoids and sesquiterpenoids is very similar. For other species, the monoterpenoid percentage is greater than the amount of sesquiterpenoids. The oils of S. elegans, S. greggii and S. munzii were active inhibitors of germination and radical elongation of Raphanus sativus L. and Lepidium sativum L. PMID:20335942

  9. Chemical composition of inks of diverse marine molluscs suggests convergent chemical defenses.

    PubMed

    Derby, Charles D; Kicklighter, Cynthia E; Johnson, P M; Zhang, Xu

    2007-05-01

    Some marine molluscs, notably sea hares, cuttlefish, squid, and octopus, release ink when attacked by predators. The sea hare Aplysia californica releases secretions from the ink gland and opaline gland that protect individuals from injury or death from predatory spiny lobsters through a combination of mechanisms that include chemical deterrence, sensory disruption, and phagomimicry. The latter two mechanisms are facilitated by millimolar concentrations of free amino acids (FAA) in sea hare ink and opaline, which stimulate the chemosensory systems of predators, ultimately leading to escape by sea hares. We hypothesize that other inking molluscs use sensory disruption and/or phagomimicry as a chemical defense. To investigate this, we examined concentrations of 21 FAA and ammonium in the defensive secretions of nine species of inking molluscs: three sea hares (Aplysia californica, Aplysia dactylomela, Aplysia juliana) and six cephalopods (cuttlefish: Sepia officinalis; squid: Loligo pealei, Lolliguncula brevis, Dosidicus gigas; octopus: Octopus vulgaris, Octopus bimaculoides). We found millimolar levels of total FAA and ammonium in these secretions, and the FAA in highest concentration were taurine, aspartic acid, glutamic acid, alanine, and lysine. Crustaceans and fish, which are major predators of these molluscs, have specific receptor systems for these FAA. Our chemical analysis supports the hypothesis that inking molluscs have the potential to use sensory disruption and/or phagomimicry as a chemical defense. PMID:17393278

  10. Model nebulae and determination of the chemical composition of the Magellanic Clouds.

    PubMed

    Aller, L H; Keyes, C D; Czyzak, S J

    1979-04-01

    An analysis of previously presented photoelectric spectrophotometry of HII regions (emission-line diffuse nebulae) in the two Magellanic Clouds is carried out with the aid of theoretical nebular models, which are used primarily as interpolation devices. Some advantages and limitations of such theoretical models are discussed. A comparison of the finally obtained chemical compositions with those found by other observers shows generally a good agreement, suggesting that it is possible to obtain reliable chemical compositions from low excitation gaseous nebulae in our own galaxy as well as in distant stellar systems. PMID:16592633

  11. Model nebulae and determination of the chemical composition of the Magellanic Clouds

    PubMed Central

    Aller, L. H.; Keyes, C. D.; Czyzak, S. J.

    1979-01-01

    An analysis of previously presented photoelectric spectrophotometry of HII regions (emission-line diffuse nebulae) in the two Magellanic Clouds is carried out with the aid of theoretical nebular models, which are used primarily as interpolation devices. Some advantages and limitations of such theoretical models are discussed. A comparison of the finally obtained chemical compositions with those found by other observers shows generally a good agreement, suggesting that it is possible to obtain reliable chemical compositions from low excitation gaseous nebulae in our own galaxy as well as in distant stellar systems. PMID:16592633

  12. Factors of the chemical composition of seepage and groundwaters in the intertropical zone (West Africa)

    NASA Astrophysics Data System (ADS)

    Roose, Eric Jean; Lelong, Francois

    1981-12-01

    In connection with a large research programme about the actual dynamics of ferrallitic and ferruginous soils of West Africa, 5000 samples of rainfall, throughfall, runoff, drainage and phreatic waters have been analysed during 4-11 years of field observations. Samples of eight stations, representative of different bioclimatic conditions (sub-Equatorial to pre-Sahelian), have been tested. The analysed parameters are: pH, resistivity, major cations and anions, total organic carbon and nitrogen, phosphorus, silica, aluminium and iron. The results show: (1) The slight influence of the bioclimatic differentiation on the mean chemical composition of the waters: all analysed waters are lightly mineralized (strong resistivity, total chemical charge generally lower than 100 mg/l), with an increasing mineralization from rainfall water to seepage water, at 2 m depth, but decreasing at the water table level (except for Si and Na). (2) The marked variability of the amounts of dissolved chemical species compared to the seasons and the flow volumes. (3) The complexity of phenomena controlling the chemical composition of waters. In the soil layers, this composition would depend principally on biological and biochemical processes, in relation to the activity of organisms but at the level of phreatic waters the chemical composition would rather be controlled by physicochemical conditions (solution-mineral equilibria).

  13. Effect of interfacial chemical bonding and surface topography on adhesion in carbon fiber/epoxy composites

    SciTech Connect

    Drzal, L.T.; Sugiura, N.; Hook, D. |

    1994-12-31

    A series of PAN-based IM6 carbon fibers having varying amounts of surface treatment were, pretreated with compounds representing the constituents encountered in epoxy composites to pre-react any groups on the fiber surface before composite fabrication in order to determine the effect of chemical bonding on fiber-matrix adhesion. Chemical bonding was quantified using XPS. Chemical bonding between reactive groups in amine cured epoxy matrices and the surface groups present on IN46 carbon fibers as a result of commercial surface treatments has been detected although the absolute amount of chemical bonding is low (1-3%). It was found that reaction with monofunctional epoxy groups having hydrocarbon functionalities blocked the surface from further reaction and reduced the adhesion that could be attained to its lowest value. Prereaction with difunctional amines had little effect on adhesion when compared to normal composite fabrication procedures. Prereaction with difunctional epoxy groups did enhance adhesion levels over the level attained in normal composite fabrication methods. These results showed that chemical bonding between epoxy and the carbon fiber surface could increases the adhesion between fiber and matrix about 25% while between the amino group and the carbon fiber surface about 15%. Quantitative measurements of the fiber surface microtopography were made with scanning tunneling microscopy. An increase in roughness was detected with increasing surface treatment. It was concluded that surface roughness also accounted for a significant increase in fiber-matrix adhesion.

  14. Studying chemical reactivity in a virtual environment.

    PubMed

    Haag, Moritz P; Reiher, Markus

    2014-01-01

    Chemical reactivity of a set of reactants is determined by its potential (electronic) energy (hyper)surface. The high dimensionality of this surface renders it difficult to efficiently explore reactivity in a large reactive system. Exhaustive sampling techniques and search algorithms are not straightforward to employ as it is not clear which explored path will eventually produce the minimum energy path of a reaction passing through a transition structure. Here, the chemist's intuition would be of invaluable help, but it cannot be easily exploited because (1) no intuitive and direct tool for the scientist to manipulate molecular structures is currently available and because (2) quantum chemical calculations are inherently expensive in terms of computational effort. In this work, we elaborate on how the chemist can be reintroduced into the exploratory process within a virtual environment that provides immediate feedback and intuitive tools to manipulate a reactive system. We work out in detail how this immersion should take place. We provide an analysis of modern semi-empirical methods which already today are candidates for the interactive study of chemical reactivity. Implications of manual structure manipulations for their physical meaning and chemical relevance are carefully analysed in order to provide sound theoretical foundations for the interpretation of the interactive reactivity exploration. PMID:25340884

  15. High-resolution chemical composition of geothermal scalings from Hungary: Preliminary results

    NASA Astrophysics Data System (ADS)

    Boch, Ronny; Dietzel, Martin; Deák, József; Leis, Albrecht; Mindszenty, Andrea; Demeny, Attila

    2015-04-01

    Geothermal fluids originating from several hundreds to thousands meters depth mostly hold a high potential for secondary mineral precipitation (scaling) due to high total dissolved solid contents at elevated temperature and pressure conditions. The precipitation of e.g. carbonates, sulfates, sulfides, and silica has shown to cause severe problems in geothermal heat and electric power production, when clogging of drill-holes, downhole pumps, pipes and heat exchangers occurs (e.g. deep geothermal doublet systems). Ongoing scaling reduces the efficiency in energy extraction and might even question the abandonment of installations in worst cases. In an attempt to study scaling processes both temporally and spatially we collected mineral precipitates from selected sites in Hungary (Bükfürdo, Szechenyi, Szentes, Igal, Hajduszoboszlo). The samples of up to 8 cm thickness were recovered from different positions of the geothermal systems and precipitated from waters of various temperatures (40-120 °C) and variable overall chemical composition. Most of these scalings show fine lamination patterns representing mineral deposition from weeks up to 45 years at our study sites. Solid-fluid interaction over time captured in the samples are investigated applying high-resolution analytical techniques such as laser-ablation mass-spectrometry and electron microprobe, micromill-sampling for stable isotope analysis, and micro-XRD combined with hydrogeochemical modeling. A detailed investigation of the processes determining the formation and growth of precipitates can help to elucidate the short-term versus long-term geothermal performance with regard to anthropogenic and natural reservoir and production dynamics. Changes in fluid chemistry, temperature, pressure, pH, degassing rate (CO2) and flow rate are reflected by the mineralogical, chemical and isotopic composition of the precipitates. Consequently, this high-resolution approach is intended as a contribution to decipher the

  16. The chemical composition of the cores of the terrestrial planets and the moon

    NASA Technical Reports Server (NTRS)

    Kuskov, O. L.; Khitarov, N. I.

    1977-01-01

    Using models of the quasi-chemical theory of solutions, the activity coefficients of silicon are calculated in the melts Fe-Si, Ni-Si, and Fe-Ni-Si. The calculated free energies of solution of liquid nickel and silicon in liquid iron in the interval 0 to 1400 kbar and 1500 to 4000 K, shows that Fe-Ni-Si alloy is stable under the conditions of the outer core of the earth and the cores of the terrestrial planets. The oxidation-reduction conditions are studied, and the fugacity of oxygen in the mantles of the planets and at the core-mantle boundary are calculated. The mechanism of reduction of silicon is analyzed over a broad interval of p and T. The interaction between the matter of the core and mantle is studied, resulting in the extraction of silicon from the mantle and its solution in the material of the core. It is concluded that silicon can enter into the composition of the outer core of the earth and Venus, but probably does not enter into the composition of the cores of Mercury, Mars, and the moon, if in fact the latter possesses one.

  17. Chemical composition profiles during alkaline flooding at different temperatures and extended residence times

    SciTech Connect

    Aflaki, R.; Handy, L.L.

    1992-12-01

    The objective of this work was to investigate whether or not caustic sweeps the major portion of the reservoir efficiently during an alkaline flood process. It was also the objective of this work to study the state of final equilibrium during a caustic flood through determination of the pH and chemical composition profiles along the porous medium. For this purpose, a long porous medium which provided extended residence times was required. It was necessary to set up the porous medium such that the changes in the pH and chemical composition of the solution could be monitored. Four Berea sandstone cores (8 in. length and1 in. diameter) placed in series provided the desired length and the opportunity for sampling in-between cores. This enabled establishment of pH and chemical composition profiles. The experiments were run at, temperatures up.to 180{degrees}C, and the flow rates varied from 4.8 to 0.2 ft/day. The samples were analyzed for pH and for Si and Al concentrations.The results show that caustic consumption is insignificant for temperatures up to 100{degrees}C. Above 100{degrees}C consumption increases and is accompanied by a significant decrease in pH. The sharp decline in pH also coincides with a sharp decline in concentration of silica in solution. The results also show that alumina is removed from the solution and solubility of alumina ultimately reaches zero. Sharp silica and pH declines take place even in the absence of any alumina in solution. As a result, removal of silica from solution is attributed to the irreversible caustic/rock interaction. This interaction is in the form of chemisorption reactions in which silica is adsorbed onto the rock surface consuming hydroxyl ion. Once these reactions were satisfied, caustic breakthrough occurs at a high pH. However, significant pore volumes of caustic must be injected for completion of the chemisorption.

  18. Chemical composition profiles during alkaline flooding at different temperatures and extended residence times

    SciTech Connect

    Aflaki, R.; Handy, L.L.

    1992-12-01

    The objective of this work was to investigate whether or not caustic sweeps the major portion of the reservoir efficiently during an alkaline flood process. It was also the objective of this work to study the state of final equilibrium during a caustic flood through determination of the pH and chemical composition profiles along the porous medium. For this purpose, a long porous medium which provided extended residence times was required. It was necessary to set up the porous medium such that the changes in the pH and chemical composition of the solution could be monitored. Four Berea sandstone cores (8 in. length and1 in. diameter) placed in series provided the desired length and the opportunity for sampling in-between cores. This enabled establishment of pH and chemical composition profiles. The experiments were run at, temperatures up.to 180[degrees]C, and the flow rates varied from 4.8 to 0.2 ft/day. The samples were analyzed for pH and for Si and Al concentrations.The results show that caustic consumption is insignificant for temperatures up to 100[degrees]C. Above 100[degrees]C consumption increases and is accompanied by a significant decrease in pH. The sharp decline in pH also coincides with a sharp decline in concentration of silica in solution. The results also show that alumina is removed from the solution and solubility of alumina ultimately reaches zero. Sharp silica and pH declines take place even in the absence of any alumina in solution. As a result, removal of silica from solution is attributed to the irreversible caustic/rock interaction. This interaction is in the form of chemisorption reactions in which silica is adsorbed onto the rock surface consuming hydroxyl ion. Once these reactions were satisfied, caustic breakthrough occurs at a high pH. However, significant pore volumes of caustic must be injected for completion of the chemisorption.

  19. Inferring tectonic provenance of siliciclastic rocks from their chemical compositions: A dissent

    NASA Astrophysics Data System (ADS)

    Basu, Abhijit; Bickford, Marion E.; Deasy, Ryan

    2016-05-01

    Chemical compositions of siliciclastic sedimentary rocks are commonly used to infer their tectonic provenance. We have tested the universal applicability of the underlying principle in a small, but controlled study expecting 100% confirmation of the practice. A comparison is made between the chemical composition of the ~ 1480 Ma Butler Hill Granite in an uplifted cratonic block of the St. Francois Mountain Igneous Complex and that of a small ~ 1-m-thick regolith body, a weathered granite sample, and the basal quartz arenites of the ~ 520 Ma Lamotte Formation immediately above the regolith. The results show that in plots of K2O/Na2O vs. SiO2/Al2O3, the regolith and sandstone samples correctly plot in the Passive Margin field, although the weathered granite plots in the Arc field. In plots of Th-Sc-Zr/10 and La-Th-Sc, the results plot in the Passive and Active Continental Margins and their extensions. In other common plots to discriminate tectonic provenance (e.g., SiO2 vs. K2O/Na2O, Fe2O3 + MgO vs. Al2O3/SiO2, Fe2O3 + MgO vs. TiO2, Sc/Cr vs. La/Y) a few points plot in the Passive Margin field but scatter into and outside of other fields of tectonic provenances. The chondrite-normalized REE distributions show variable degrees of negative Eu anomalies, with flat HREE, conforming to a felsic source. The LREE distributions show both positive and negative Ce anomalies that can be ascribed to the variability of redox conditions during weathering and diagenesis of the original siliciclastic sediments. The variability of the Eu anomaly was likely affected by post-erosion processes in addition to whatever was inherited from the parent rocks. We conclude that chemical compositions can provide good clues, but are neither strong indicators nor unique identifiers of their tectonic provenance. Rather, they indicate a dominantly felsic or dominantly mafic, or a mixed set of source rocks.

  20. Decomposition Dynamics and Changes in Chemical Composition of Wheat Straw Residue under Anaerobic and Aerobic Conditions.

    PubMed

    Gao, Hongjian; Chen, Xi; Wei, Junling; Zhang, Yajie; Zhang, Ligan; Chang, Jiang; Thompson, Michael L

    2016-01-01

    Soil aeration is a crucial factor that regulates crop residue decomposition, and the chemical composition of decomposing crop residues may change the forms and availability of soil nutrients, such as N and P. However, to date, differences in the chemical composition of crop straw residues after incorporation into soil and during its decomposition under anaerobic vs. aerobic conditions have not been well documented. The objective of the present study was to assess changes in the C-containing functional groups of wheat straw residue during its decomposition in anaerobic and aerobic environments. A 12-month incubation experiment was carried out to investigate the temporal variations of mass, carbon, and nitrogen loss, as well as changes in the chemical composition of wheat (Triticum aestivum L) straw residues under anaerobic and aerobic conditions by measuring C-containing functional groups using solid state nuclear magnetic resonance (NMR) spectroscopy. The residual mass, carbon content, and nitrogen content of the straw residue sharply declined during the initial 3 months, and then slowly decreased during the last incubation period from 3 to 12 months. The decomposition rate constant (k) for mass loss under aerobic conditions (0.022 d-1) was higher than that under anaerobic conditions (0.014 d-1). The residual mass percentage of cellulose and hemicellulose in the wheat straw gradually declined, whereas that of lignin gradually increased during the entire 12-month incubation period. The NMR spectra of C-containing functional groups in the decomposing straw under both aerobic and anaerobic conditions were similar at the beginning of the incubation as well as at 1 month, 6 months, and 12 months. The main alterations in C-containing functional groups during the decomposition of wheat straw were a decrease in the relative abundances of O-alkyl C and an increase in the relative abundances of alkyl C, aromatic C and COO/N-C = O functional groups. The NMR signals of alkyl C

  1. Decomposition Dynamics and Changes in Chemical Composition of Wheat Straw Residue under Anaerobic and Aerobic Conditions

    PubMed Central

    Gao, Hongjian; Chen, Xi; Wei, Junling; Zhang, Yajie; Zhang, Ligan; Chang, Jiang; Thompson, Michael L.

    2016-01-01

    Soil aeration is a crucial factor that regulates crop residue decomposition, and the chemical composition of decomposing crop residues may change the forms and availability of soil nutrients, such as N and P. However, to date, differences in the chemical composition of crop straw residues after incorporation into soil and during its decomposition under anaerobic vs. aerobic conditions have not been well documented. The objective of the present study was to assess changes in the C-containing functional groups of wheat straw residue during its decomposition in anaerobic and aerobic environments. A 12-month incubation experiment was carried out to investigate the temporal variations of mass, carbon, and nitrogen loss, as well as changes in the chemical composition of wheat (Triticum aestivum L) straw residues under anaerobic and aerobic conditions by measuring C-containing functional groups using solid state nuclear magnetic resonance (NMR) spectroscopy. The residual mass, carbon content, and nitrogen content of the straw residue sharply declined during the initial 3 months, and then slowly decreased during the last incubation period from 3 to 12 months. The decomposition rate constant (k) for mass loss under aerobic conditions (0.022 d-1) was higher than that under anaerobic conditions (0.014 d-1). The residual mass percentage of cellulose and hemicellulose in the wheat straw gradually declined, whereas that of lignin gradually increased during the entire 12-month incubation period. The NMR spectra of C-containing functional groups in the decomposing straw under both aerobic and anaerobic conditions were similar at the beginning of the incubation as well as at 1 month, 6 months, and 12 months. The main alterations in C-containing functional groups during the decomposition of wheat straw were a decrease in the relative abundances of O-alkyl C and an increase in the relative abundances of alkyl C, aromatic C and COO/N-C = O functional groups. The NMR signals of alkyl C

  2. Chemical composition and insecticidal activity of plant essential oils from Benin against Anopheles gambiae (Giles)

    PubMed Central

    2013-01-01

    Background Insecticide resistance in sub-Saharan Africa and especially in Benin is a major public health issue hindering the control of the malaria vectors. Each Anopheles species has developed a resistance to one or several classes of the insecticides currently in use in the field. Therefore, it is urgent to find alternative compounds to conquer the vector. In this study, the efficacies of essential oils of nine plant species, which are traditionally used to avoid mosquito bites in Benin, were investigated. Methods Essential oils of nine plant species were extracted by hydrodistillation, and their chemical compositions were identified by GC-MS. These oils were tested on susceptible “kisumu” and resistant “ladji-Cotonou” strains of Anopheles gambiae, following WHO test procedures for insecticide resistance monitoring in malaria vector mosquitoes. Results Different chemical compositions were obtained from the essential oils of the plant species. The major constituents identified were as follows: neral and geranial for Cymbopogon citratus, Z-carveol, E-p-mentha-1(7),8-dien-2-ol and E-p-mentha-2,8-dienol for Cymbopogon giganteus, piperitone for Cymbopogon schoenanthus, citronellal and citronellol for Eucalyptus citriodora, p-cymene, caryophyllene oxide and spathulenol for Eucalyptus tereticornis, 3-tetradecanone for Cochlospermum tinctorium and Cochlospermum planchonii, methyl salicylate for Securidaca longepedunculata and ascaridole for Chenopodium ambrosioides. The diagnostic dose was 0.77% for C. citratus, 2.80% for E. tereticornis, 3.37% for E. citriodora, 4.26% for C. ambrosioides, 5.48% for C. schoenanthus and 7.36% for C. giganteus. The highest diagnostic doses were obtained with S. longepedunculata (9.84%), C. tinctorium (11.56%) and C. planchonii (15.22%), compared to permethrin 0.75%. A. gambiae cotonou, which is resistant to pyrethroids, showed significant tolerance to essential oils from C. tinctorium and S. longepedunculata as expected but was

  3. Essential Oil from the Resin of Protium heptaphyllum: Chemical Composition, Cytotoxicity, Antimicrobial Activity, and Antimutagenicity

    PubMed Central

    de Lima, Ewelyne Miranda; Cazelli, Didley Sâmia Paiva; Pinto, Fernanda Endringer; Mazuco, Renata Alves; Kalil, Ieda Carneiro; Lenz, Dominik; Scherer, Rodrigo; de Andrade, Tadeu Uggere; Endringer, Denise Coutinho

    2016-01-01

    Background: Protium heptaphyllum (Aubl.) March is popularly used as an analgesic and anti-inflammatory agent. Objective: This study aimed to evaluate the chemical composition of P. heptaphyllum essential oil, its cytotoxicity in a breast cancer cell line (MCF-7), antimicrobial activity, and its antimutagenicity in vivo. Materials and Methods: The chemical composition of the essential oil collected in three 3 years was determined by gas chromatography-mass spectrometry. The cytotoxicity was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Annexin V conjugated with fluorescein isothiocyanate, caspase-3, and tumor necrosis factor-alpha (TNF-α) assays were performed to evaluate apoptosis and inflammatory events. The antimutagenic activity at doses of 25, 50, and 100 mg/kg was determined using a micronucleus test in murine bone marrow. Results: The essential oil showed a predominance of monoterpene compounds, being the terpinolene, p-cymene-8-ol, and p-cymene, present in the essential oil extracted in the 3 years. The essential oil showed a protection against cyclophosphamide-induced genotoxicity, and the cytotoxicity index polychromatic erythrocytes/normochromatic erythrocytes ratio in animals treated with oil at all doses (1.34 ± 0.33; 1.15 ± 0.1; 1.11 ± 0.13) did not differ from the negative control animal (1.31 ± 0.33), but from the cyclophosphamide group (0.61 ± 0.12). Cytotoxicity, at a concentration of 40.0 μg/mL, and antimicrobial activity were not observed for the essential oil (minimum inhibitory concentration ≥0.5 mg/mL). The essential oil did not change the levels of caspase-3 in the TNF-α level. Conclusion: The essential oil showed antimutagenic activity due to its chemical composition. SUMMARY Terpinolene, p-cymene-8-ol, and p-cymene are the main constituents of the essential oil of P. heptaphyllum collected within 3-yearsThe essential oil of P. heptaphyllum did not show antimicrobial activity (MIC >0.5 mg

  4. Apxs Chemical Composition of the Kimberley Sandstone in Gale Crater

    NASA Astrophysics Data System (ADS)

    Gellert, R.; Boyd, N.; Campbell, J. L.; VanBommel, S.; Thompson, L. M.; Schmidt, M. E.; Berger, J. A.; Clark, B. C.; Grotzinger, J. P.; Yen, A. S.; Fisk, M. R.

    2014-12-01

    Kimberley was chosen as a major waypoint of the MSL rover Curiosity on its way to Mount Sharp. APXS data before drilling showed interestingly high K, Fe and Zn. This warranted drilling of the fine-grained sandstone for detailed investigations with SAM and Chemin. With significantly lower Na, Al and higher K, Mg and Fe, the composition of the drill target Windjana is very distinct from the previous ones in the mudstones at Yellowknife Bay. Up to 2000 ppm Br and 4000 ppm Zn post-brush were among the highest measured values in Gale Crater. The excavated fines, stemming from about 6cm, showed lower Br, but even higher Zn. Preliminary Chemin results indicate K-feldspar and magnetite being major mineral phases in Windjana, which is consistent with the pre drill APXS result and derived CIPW norms. Inside the accessible work volume of the arm at the drill site ChemCam exposed a greyish, shinier patch of rock underneath the dust, dubbed Stephen. ChemCam sees a high Mn signal in most of the spots. An APXS integration revealed high MnO as well (~4%), in addition to high Mg, Cl,K,Ni,Zn,Br,Cu,Ge and for the first time an APXS detectable amount of ~300 ppm Co. The surface might reflect a thin surface layer and may underestimate the higher Z elemental concentration since the APXS analysis assumes an infinite sample. Important elemental correlations are likely not impacted. A four spot daytime raster of Stephen before leaving the drill site showed a good correlation of Mn with Zn, Cu and Ni. All spots have 3-3.5% Cl, the highest values measured on Mars so far. While the stratigraphic setting of the Stephen sample is discussed elsewhere, the similarity with Mn deep-sea nodules is striking, e.g. the APXS calibration sample GBW07296. Whatever process formed Stephen, the process of Mn scavenging high Z trace metals from solutions seems to have happened similarly at this site on Mars.

  5. Quantum chemical study of methane oxidation species

    NASA Technical Reports Server (NTRS)

    Jackels, Charles F.

    1993-01-01

    The research funded by this project has focused on quantum chemical investigations of molecular species thought to be important in the chemistry of the earth's upper and lower atmospheres. The body of this report contains brief discussions of the results of the several phases of this investigation. In many instances these results have been presented at scientific meetings and/or published in refereed journals. Those bibliographic references are given. In addition to the study of specific chemical systems, there were several phases during the course of this investigation where much of the effort went into the development and modification of computer codes necessary to carry out these calculations on the wide range of computer equipment used during this study. This type of code maintenance and development work did not generally result in publications and presentations, but a brief review is given.

  6. CHEMICAL COMPOSITION OF PRODUCED WATER AT SOME OFFSHORE OIL PLATFORMS

    EPA Science Inventory

    The effectiveness of produced water treatment was briefly studied in offshore oil and gas extraction operations in Cook Inlet, Alaska, and the Gulf of Mexico. Three offshore oil extraction facilities were examined in the Cook Inlet production field, and seven platforms were studi...

  7. Study of Body Composition by Impedance Analysis

    NASA Astrophysics Data System (ADS)

    González-Solís, J. L.; Vargas-Luna, M.; Sosa-Aquino, M.; Bernal-Alvarado, J.; Gutiérrez-Juárez, G.; Huerta-Franco, R.; Sanchis-Sabater, A.

    2002-08-01

    This work presents a set of impedance measurements and preliminary results on the analysis of body composition using impedance spectroscopy. This study is made using a pork meat sample and spectra from fat and flesh region were independently obtained using the same electrodes array. From these measurements, and theoretical considerations, it is possible to explain the behavior of the composite sample flesh-fat-flesh and, fitting the electrical parameters of the model, it shows the plausibility of a physical and quantitative application to human corporal composition.

  8. Rabbit Tamm–Horsfall urinary glycoprotein. Chemical composition and subunit structure

    PubMed Central

    Marr, Anne M. S.; Neuberger, A.; Ratcliffe, Wendy A.

    1971-01-01

    1. Tamm–Horsfall glycoprotein from rabbit urine has been isolated and characterized. The homogeneity of the preparation has been established by a variety of procedures including disc gel electrophoresis and ultracentrifugation in aqueous solution, sodium dodecyl sulphate and formic acid. 2. The chemical composition has been determined and a carbohydrate content of approx. 31% was obtained. The relative contents of the amino acids were shown to be very similar to those in human Tamm–Horsfall glycoprotein. A trace of lipid was also detected. 3. Leucine was identified as the only N-terminal amino acid. 4. The subunit structure was investigated in the presence of sodium dodecyl sulphate by gel filtration and disc gel electrophoresis. These studies indicated that the subunit possessed a molecular weight of approx. 84000±6000. A similar value was obtained after reduction and S-alkylation of the glycoprotein indicating that the disulphide bonds were all intrachain. 5. A minimum value for the chemical molecular weight of 85000±6000 was obtained from the number of N-terminal amino acids released by cyanogen bromide cleavage of the glycoprotein. 6. The immunological properties of the glycoprotein were studied. Cross reactivity was demonstrated between human Tamm–Horsfall glycoprotein and a guinea-pig anti-rabbit Tamm–Horsfall antiserum. ImagesFig. 2.Fig. 4.Fig. 5. PMID:5129252

  9. A further tool to monitor the coffee roasting process: aroma composition and chemical indices.

    PubMed

    Ruosi, Manuela R; Cordero, Chiara; Cagliero, Cecilia; Rubiolo, Patrizia; Bicchi, Carlo; Sgorbini, Barbara; Liberto, Erica

    2012-11-14

    Coffee quality is strictly related to its flavor and aroma developed during the roasting process, that, in their turn, depend on variety and origin, harvest and postharvest practices, and the time, temperature, and degree of roasting. This study investigates the possibility of combining chemical (aroma components) and physical (color) parameters through chemometric approaches to monitor the roasting process, degree of roasting, and aroma formation by analyzing a suitable number of coffee samples from different varieties and blends. In particular, a correlation between the aroma composition of roasted coffee obtained by HS-SPME-GC-MS and degree of roasting, defined by the color, has been researched. The results showed that aroma components are linearly correlated to coffee color with a correlation factor of 0.9387. The study continued looking for chemical indices: 11 indices were found to be linearly correlated to the color resulting from the roasting process, the most effective of them being the 5-methylfurfural/2-acetylfuran ratio (index). PMID:23083340

  10. Aerosols near by a coal fired thermal power plant: chemical composition and toxic evaluation.

    PubMed

    Jayasekher, T

    2009-06-01

    Industrial processes discharge fine particulates containing organic as well as inorganic compounds into the atmosphere which are known to induce damage to cell and DNA, both in vitro and in vivo. Source and area specific studies with respect to the chemical composition, size and shape of the particles, and toxicity evaluations are very much limited. This study aims to investigate the trace elements associated with the aerosol particles distributed near to a coal burning thermal power plant and to evaluate their toxicity through Comet assay. PM(10) (particles determined by mass passing an inlet with a 50% cut-off efficiency having a 10-microm aerodynamic diameter) samples were collected using respirable dust samplers. Twelve elements (Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb, Se, Hg, and As) were analyzed using ICP-AES. Comet assay was done with the extracts of aerosols in phosphate buffered saline (PBS). Results show that Fe and Zn were found to be the predominant elements along with traces of other analyzed elements. Spherical shaped ultrafine particles of <1 microm aerodynamic diameter were detected through scanning electron microscope. PM(10) particles near to the coal burning power plant produced comets indicating their potential to induce DNA damage. DNA damage property is found to be depending upon the chemical characteristics of the components associated with the particles besides the physical properties such as size and shape. PMID:19264341

  11. Chemical Composition and in Vitro Antifungal Activity Screening of the Allium ursinum L. (Liliaceae)

    PubMed Central

    Bagiu, Radu Vasile; Vlaicu, Brigitha; Butnariu, Monica

    2012-01-01

    The objective of the study was to summarize the methods for isolating and identifying natural sulfur compounds from Allium ursinum (ramson) and to discuss the active constituents with regard to antifungal action. Using chromatographic techniques, the active constituents were isolated and subsequently identified. Analyses by high-performance liquid chromatography (HPLC) suggested that these compounds were sulfur constituents, with a characteristic absorbance at 250 nm. Gas chromatography-mass spectrometry (GC-MS) analyses allowed the chemical structures of the isolated constituents to be postulated. We adopted the same methods to identify the health-giving profiling of ramsons and the effects are thought to be primarily derived from the presence and breakdown of the alk(en)ylcysteine sulphoxide, alliin and its subsequent breakdown to allicin (sulfur-compounds of ramson) in connection with antifungal action. The aim of the study was the characterization of the chemical composition of ramsons and the testing of the action of the in vitro extracts, on different strains of Candida albicans. The main goal was to highlight the most efficient extracts of Allium ursinum that can provide long-term antifungal activity without remissions. The extracts from Allium ursinum plants, inhibited growth of Candida spp. cells at concentrations ranging from 0.5 to 4.0 mg/mL, while that of adherent cells at concentrations ranging from 1.0 to > 4.0 mg/mL, depending on the yeast and plant species. PMID:22408399

  12. Study of chemical and radiation induced carcinogenesis

    SciTech Connect

    Chmura, A.

    1995-11-01

    The study of chemical and radiation induced carcinogenesis has up to now based many of its results on the detection of genetic aberrations using the fluorescent in situ hybridization (FISH) technique. FISH is time consuming and this tends to hinder its use for looking at large numbers of samples. We are currently developing new technological advances which will increase the speed, clarity and functionality of the FISH technique. These advances include multi-labeled probes, amplification techniques, and separation techniques.

  13. Renewable resources as reinforcement of polymeric matrices: composites based on phenolic thermosets and chemically modified sisal fibers.

    PubMed

    Megiatto, Jackson D; Oliveira, Franciéli B; Rosa, Derval S; Gardrat, Christian; Castellan, Alain; Frollini, Elisabete

    2007-09-11

    Lignocellulosic materials can significantly contribute to the development of composites, since it is possible to chemically and/or physically modify their main components, cellulose, hemicelluloses and lignin. This may result in materials more stable and with more uniform properties. It has previously been shown that chemically modified sisal fibers by ClO(2) oxidation and reaction with FA and PFA presented a thin coating layer of PFA on their surface. FA and PFA were chosen as reagents because these alcohols can be obtained from renewable sources. In the present work, the effects of the polymeric coating layer as coupling agent in phenolic/sisal fibers composites were studied. For a more detailed characterization of the fibers, IGC was used to evaluate the changes that occurred at the sisal fibers surface after the chemical modifications. The dispersive and acid-base properties of untreated and treated sisal fibers surfaces were determined. Biodegradation experiments were also carried out. In a complementary study, another PFA modification was made on sisal fibers, using K2Cr2O(7) as oxidizing agent. In this case the oxidation effects involve mainly the cellulose polymer instead of lignin, as observed when the oxidation was carried out with ClO(2). The SEM images showed that the oxidation of sisal fibers followed by reaction with FA or PFA favored the fiber/phenolic matrix interaction at the interface. However, because the fibers were partially degraded by the chemical treatment, the impact strength of the sisal-reinforced composites decreased. By contrast, the chemical modification of fibers led to an increase of the water diffusion coefficient and to a decrease of the water absorption of the composites reinforced with modified fibers. The latter property is very important for certain applications, such as in the automotive industry. PMID:17676656

  14. Kinetic studies of elementary chemical reactions

    SciTech Connect

    Durant, J.L. Jr.

    1993-12-01

    This program concerning kinetic studies of elementary chemical reactions is presently focussed on understanding reactions of NH{sub x} species. To reach this goal, the author is pursuing experimental studies of reaction rate coefficients and product branching fractions as well as using electronic structure calculations to calculate transition state properties and reaction rate calculations to relate these properties to predicted kinetic behavior. The synergy existing between the experimental and theoretical studies allow one to gain a deeper insight into more complex elementary reactions.

  15. Theoretical studies of chemical reaction dynamics

    SciTech Connect

    Schatz, G.C.

    1993-12-01

    This collaborative program with the Theoretical Chemistry Group at Argonne involves theoretical studies of gas phase chemical reactions and related energy transfer and photodissociation processes. Many of the reactions studied are of direct relevance to combustion; others are selected they provide important examples of special dynamical processes, or are of relevance to experimental measurements. Both classical trajectory and quantum reactive scattering methods are used for these studies, and the types of information determined range from thermal rate constants to state to state differential cross sections.

  16. Comparative results of 327 chemical carcinogenicity studies.

    PubMed Central

    Haseman, J K; Huff, J E; Zeiger, E; McConnell, E E

    1987-01-01

    The National Cancer Institute (NCI) and the National Toxicology Program (NTP) have carried out a number of laboratory animal carcinogenicity studies and presented the results of these experiments in a series of Technical Reports. This paper tabulates the results of the 327 NCI/NTP studies carried out to date on 308 distinct chemicals, and discusses certain issues relevant to the evaluation of carcinogenicity in these experiments. This compilation of results from NCI/NTP carcinogenicity experiments provides a large database that can be used to study structure-activity correlations, interspecies concordance, and associations between laboratory animal carcinogenicity and other toxicological effects. PMID:3691430

  17. Primary and secondary particles chemical composition of marine emissions from Mediterranean seawaters

    NASA Astrophysics Data System (ADS)

    D'Anna, Barbara; Meme, Aurelie; Rmili, Badr; Pey, Jorge; Marchand, Nicolas; Schwier, Allison; Sellegri, Karine; Charriere, Bruno; Sempere, Richard; Mas, Sebastien; Parin, David

    2015-04-01

    Marine emissions are among the largest source of both primary particles and do highly contribute secondary organic aerosols (SOA) at a global scale. Whereas physical processes control the primary production of marine aerosols, biological activity is responsible for most of the organic fraction released from marine sources, potentially transformed into SOA when exposed to atmospheric oxidants. The Mediterranean atmosphere displays important concentrations of SOA, especially in summer, when atmospheric oxidants and photochemical activity are at their maximum. The origin of these elevated concentrations of SOA remain unclear. Here we present the results from a mesocosms study in a remote location in Corsica and a chamber study (using fresh sea water from Western Mediterranean) as part of the Source of marine Aerosol particles in the Mediterranean atmosphere (SAM) project. The mesocosm study was conducted at the Oceanographic and Marine Station STARESO (Corsica) in May 2013. One mesocosm was used as a control (with no enrichment) and the other two were enriched with nitrate and phosphate respecting Redfield ratio (N:P = 16) in order to produce a bloom of biological activity. Physical and chemical properties of the enclosed water samples together with their surrounding atmosphere were monitored during 20 days by a multi-instrumental high-time resolution set-up. In parallel, numerous additional measurements were conducted including water temperature, incident light, pH, conductivity, chemical and biological analyses, fluorescence of chlorophyll, dissolved oxygen concentration. The chamber studies were performed in a Teflon chamber of 1. 5m3 that accommodates a pyrex-container for the fresh sea-water samples. After injection of sea-water in the pyrex-container, the system is allowed to stabilize to 20-30 minutes, then it was exposed to 60-100ppbv of ozone and/or UV-A irradiation. Aerosol concentrations and their physical characteristics were followed by means of Scanning

  18. The cosmic ray composition as viewed from the chemical abundances of the solar system

    NASA Technical Reports Server (NTRS)

    Sakurai, K.

    1985-01-01

    It is shown that the chemical composition of cosmic rays at their sources for the elements up to the atomic number as 80 is quite similar to that of the carbonaceous chondrites, which have been keeping the properties of the protosolar nebula. In particular, the similarity between these two compositions is significant to the elements classified as refractory and siderphile, in addition to the elements, Ca and Al. These results as cited above suggest that cosmic rays, being currently observed near the Earth, may have been accelerated from the matter with the composition similar to that which is found of these chondrites as Allende.

  19. Mantle Metasomatism in Mars: Evidence from Bulk Chemical Compositions of Martian Basalts

    NASA Technical Reports Server (NTRS)

    Treiman, A. H.

    2003-01-01

    Bulk compositions of martian meteorite basalts suggest that they formed from a highly depleted mantle that was variably metasomatised and enriched in incompatible elements. These results are consistent with radio-isotope results. Bulk chemical compositions of basaltic rocks retain clues and tracers to their origins and histories. Interpretations of bulk compositions are not so straight-forward as once envisioned, because real-world magmatic processes can be far from theoretical simple models like one-stage partial melting or closed-system fractional crystallization. Yet, bulk chemistry can shed a broad (if dim) light on Martian basalt petrogenesis that complements the sharply focussed illumination of radio-isotope systematics.

  20. Frost flowers growing in the Arctic ocean-atmosphere-sea ice-snow interface: 1. Chemical composition

    NASA Astrophysics Data System (ADS)

    Douglas, Thomas A.; Domine, Florent; Barret, Manuel; Anastasio, Cort; Beine, Harry J.; Bottenheim, Jan; Grannas, Amanda; Houdier, Stephan; Netcheva, Stoyka; Rowland, Glenn; Staebler, Ralf; Steffen, Alexandra

    2012-07-01

    Frost flowers, intricate featherlike crystals that grow on refreezing sea ice leads, have been implicated in lower atmospheric chemical reactions. Few studies have presented chemical composition information for frost flowers over time and many of the chemical species commonly associated with Polar tropospheric reactions have never been reported for frost flowers. We undertook this study on the sea ice north of Barrow, Alaska to quantify the major ion, stable oxygen and hydrogen isotope, alkalinity, light absorbance by soluble species, organochlorine, and aldehyde composition of seawater, brine, and frost flowers. For many of these chemical species we present the first measurements from brine or frost flowers. Results show that major ion and alkalinity concentrations, stable isotope values, and major chromophore (NO3- and H2O2) concentrations are controlled by fractionation from seawater and brine. The presence of these chemical species in present and future sea ice scenarios is somewhat predictable. However, aldehydes, organochlorine compounds, light absorbing species, and mercury (part 2 of this research and Sherman et al. (2012)) are deposited to frost flowers through less predictable processes that probably involve the atmosphere as a source. The present and future concentrations of these constituents in frost flowers may not be easily incorporated into future sea ice or lower atmospheric chemistry scenarios. Thinning of Arctic sea ice will likely present more open sea ice leads where young ice, brine, and frost flowers form. How these changing ice conditions will affect the interactions between ice, brine, frost flowers and the lower atmosphere is unknown.