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Sample records for chemical composition chemical

  1. Chemical Composition

    NASA Astrophysics Data System (ADS)

    May, Willie; Cavanagh, Richard; Turk, Gregory; Winchester, Michael; Travis, John; Smith, Melody; Derose, Paul; Choquette, Steven; Kramer, Gary; Sieber, John; Greenberg, Robert; Lindstrom, Richard; Lamaze, George; Zeisler, Rolf; Schantz, Michele; Sander, Lane; Phinney, Karen; Welch, Michael; Vetter, Thomas; Pratt, Kenneth; Scott, John; Small, John; Wight, Scott; Stranick, Stephan

    Measurements of the chemical compositions of materials and the levels of certain substances in them are vital when assessing and improving public health, safety and the environment, are necessary to ensure trade equity, and are required when monitoring and improving industrial products and services. Chemical measurements play a crucial role in most areas of the economy, including healthcare, food and nutrition, agriculture, environmental technologies, chemicals and materials, instrumentation, electronics, forensics, energy, and transportation.

  2. 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.

  3. 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.

  4. 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...

  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. Chemical composition of Mars

    USGS Publications Warehouse

    Morgan, J.W.; Anders, E.

    1979-01-01

    The composition of Mars has been calculated from the cosmochemical model of Ganapathy and Anders (1974) which assumes that planets and chondrites underwent the same 4 fractionation processes in the solar nebula. Because elements of similar volatility stay together in these processes, only 4 index elements (U, Fe, K and Tl or Ar36) are needed to calculate the abundances of all 83 elements in the planet. The values chosen are U = 28 ppb, K = 62 ppm (based on K U = 2200 from orbital ??-spectrometry and on thermal history calculations by Tokso??z and Hsui (1978) Fe = 26.72% (from geophysical data), and Tl = 0.14 ppb (from the Ar36 and Ar40 abundances measured by Viking). The mantle of Mars is an iron-rich [Mg/(Mg + Fe) = 0.77] garnet wehrlite (?? = 3.52-3.54 g/cm3), similar to McGetchin and Smyth's (1978) estimate but containing more Ca and Al. It is nearly identical to the bulk Moon composition of Morgan et al. (1978b). The core makes up 0.19 of the planet and contains 3.5% S-much less than estimated by other models. Volatiles have nearly Moon-like abundances, being depleted relative to the Earth by factors of 0.36 (K-group, Tcond = 600-1300 K) or 0.029 (Tl group, Tcond < 600 K). The water abundance corresponds to a 9 m layer, but could be higher by as much as a factor of 11. Comparison of model compositions for 5 differentiated planets (Earth, Venus, Mars, Moon, and eucrite parent body) suggests that volatile depletion correlates mainly with size rather than with radial distance from the Sun. However, the relatively high volatile content of shergottites and some chondrites shows that the correlation is not simple; other factors must also be involved. ?? 1979.

  7. 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…

  8. 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

  9. 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.

  10. 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.

  11. Chemical degradation of composite restoratives.

    PubMed

    Yap, A U; Tan, S H; Wee, S S; Lee, C W; Lim, E L; Zeng, K Y

    2001-11-01

    The chemical environment is one aspect of the oral environment, which could have an appreciable influence on the in vivo degradation of composite restoratives. The effects of chemical media on surface hardness of four composite restoratives (Silux [SX], Z100 [ZO], Ariston [AR] and Surefil [SF]) were investigated. The relationship between hardness and the thickness of the degradation layer was also studied. Thirty six specimens (3 x 4 x 2 mm) were made for each material. Following polymerization, the specimens were stored in artificial saliva at 37 degrees C for 24 h. The specimens were then randomly divided into six groups of six, subjected to microhardness testing (load = 500 gf, dwell time = 15 s) and stored in the following chemicals for 1 week at 37 degrees C: artificial saliva (S), distilled water (W), 0.02 N citric acid (C), 0.02 N lactic acid (L), heptane (H) and 75-25% ethanol-water solution (E). After conditioning, the specimens were again subjected to hardness testing and sectioned. Change in hardness (DH) was computed and the thickness of the degradation layer (DL) was measured using a computerized image analysis system at 600x magnification. Results of statistical analysis (ANOVA/Scheffe's [P < 0.05]) of DH based on materials were as follows: SX - E > all other mediums; ZO - W > C; and AR - S, W, E > H (> indicates significantly greater hardness change). No significant difference in DH was observed between the different chemicals for SF. The effects of chemical media on DH were found to be material dependent. A significant but weak positive correlation (Pearson's correlation [P < 0.05]) exists between change in hardness and thickness of the degradation layer. PMID:11722717

  12. 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.)

  13. 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...

  14. Average chemical composition of the lunar surface

    NASA Technical Reports Server (NTRS)

    Turkevich, A. L.

    1973-01-01

    The available data on the chemical composition of the lunar surface at eleven sites (3 Surveyor, 5 Apollo and 3 Luna) are used to estimate the amounts of principal chemical elements (those present in more than about 0.5% by atom) in average lunar surface material. The terrae of the moon differ from the maria in having much less iron and titanium and appreciably more aluminum and calcium.

  15. 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

  16. 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.

  17. New Initiatives on RR Lyrae Chemical Compositions

    NASA Astrophysics Data System (ADS)

    Sneden, Christopher; For, Bi-Qing; Preston, George W.

    2011-08-01

    The serendipitous discovery by Preston and colleagues of the neutron-capture-enhanced RR Lyrae variable star TY Gru (a.k.a. CS 22881-071 in the ``HK'' survey of very metal-poor halo stars) has resulted in a growing set of initiatives on the chemical compositions of RR Lyrae stars and their application to broader topics in Galactic halo structure. Here we summarize the main aspects of our work on TY Gru, including a new discussion of our search for possible orbital motion of this star around a putative unseen companion. Then we describe a few of the results of a newly-completed intensive spectroscopic investigation of 10 additional field RR Lyr stars. We finish by outlining current projects that seek to contrast the atmospheres and chemical compositions of RRc stars with those of the RRab stars, and that employ a much larger RRab sample in a chemo-dynamical study of Galactic halo RR Lyr.

  18. 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.

  19. 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.

  20. Chemical composition of new Acapulcoites and Lodranites

    NASA Technical Reports Server (NTRS)

    Zipfel, J.; Palme, H.

    1993-01-01

    The bulk compositions of two Antarctic Lodranites, MAC 88177 and FRO 90011, and two Acapulcoites, ALH 81261 and Monument Draw, were determined with instrumental neutron activation analysis. Acapulcoites have essentially chondritic major and trace element abundances but achondritic texture. They consist of entirely recrystallized, fine grained mineral assemblages. Chondrules are extremely rare; one relict radiating pyroxene chondrule was described in Monument Draw (MD). The coarse grained Lodranites also have achondritic textures, but they are different compositionally with depletions in Al, Na, and incompatible elements probably a result of separation of partial, feldspar-rich melt. MAC 88177 is significantly more depleted in incompatible elements than FRO 90011 suggesting a higher degree of partial melting for the MAC-Lodranite. The chemical data support a genetic relationship between Lodranites and Acapulcoites inferred earlier from oxygen isotopes, petrology, and mineral composition.

  1. Environmental effects of oilfield chemicals on composite

    SciTech Connect

    Sorem, R.M.

    1998-12-31

    This paper presents a feasibility study of the effects of oilfield chemicals on composite materials. In this initial study only hydrochloric acid is considered. Initial attempts were made to test stressed specimens, but results were very poor. Subsequent testing was performed to determine how the composite material constituents reacted to the hydrochloric acid. The initial testing was performed on tubular specimens with axial and essentially hoop wound fibers of different materials with different resins. The specimens were loaded in bending to induce representative strains in the tubing. All specimens failed. The second tests consisted of only an environmental soak to determine the amount of mass uptake as well as the reduction in strength. The strength reduction results will be presented at a later time. Testing was performed on S-2 glass, carbon and Kevlar 49 as well as three different resins.

  2. 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 Gas and Ion Mass Spectrometer (NIGMS). Both of these instruments have substantial heritage as they are based on those developed for the CRAF Mission. The engineering instruments include a simplified Comet Dust Environmental Monitor (SCODEM) and a navigational Camera, NAVCAM. While neither of the instruments will be permitted to establish science requirements, it is anticipated that significant science return will be accomplished Radio science will also be included.

  3. Chemical provinces reveal Elysium Volcano's compositional evolution

    NASA Astrophysics Data System (ADS)

    Susko, D. A.; Karunatillake, S.; Wray, J. J.; Skok, J. R.; Hurowitz, J.; Ojha, L.; Judice, T.; Bently, R. O. J.

    2014-12-01

    Chemical provinces of Mars became definable[1-3] with the maps of elemental mass fractions generated with Mars Odyssey Gamma Ray Spectrometer (GRS) data[4,5]. Previous work highlighted the Elysium lava flow province as anomalous, with a depletion in K and Th relative to the average crust in the rest of Mars (ROM).[3] We characterize the elemental composition, geology, and geomorphology of the region to constrain the processes that have contributed to its evolution. We compare SE Elysium with its North West lava fields, advancing prior work on thermal evolution of the martian mantle.[6] Lava fields at both sites probably source from Elysium eruptions. Both show similar Si content, as well as a Ca-enrichment compared to ROM, consistent with prior models.[6,7] Nevertheless, the two fields are compositionally distinct from each other, with NW Elysium decisively depleted in Ca and Fe, but enriched in K and Th. Such distinctness, in elements that reflect magmatic fractionation, reveals the possibility that a single volcanic complex on Mars may evolve rapidly during the Amazonian era, causing variable flow compositions. Interestingly, a chemical province containing volcanics that is contemporaneous with Elysium, overlaps the Tharsis region.[3] Unlike Elysium, the K and Th distributions within Tharsis are indistinguishable from ROM. Meanwhile, the mass fraction signature in Tharsis is enriched in Cl and depleted in Si. Such contrast, in chemical anomalies between volcanic constructs of similar age, may indicate that the depletion of K and Th in SE Elysium did not arise from temporal evolution of the mantle. [1] Taylor, G. et al. Geology 38, 183-186, 2010 [2] Gasnault, O. et al. 207, 226-247, 2010 [3] Karunatillake, S. et al. J. Geophys. Res. 114, E12001, 2009 [4] Boynton, W. V. et al. J. Geophys. Res. 112, E12S99, 2007 [5] Feldman, W. C. et al. J. Geophys. Res. 109, E09006, 2004 [6] Baratoux, D. et al. Nature 472, 338-41, 2011 [7] Balta, J. et al. Geology 41, 1115-1118, 2013

  4. Chemical composition of Pinus sibirica (Pinaceae).

    PubMed

    Rogachev, Artem D; Salakhutdinov, Nariman F

    2015-01-01

    Siberian pine (Pinus sibirica), also known as Siberian cedar pine and Siberian cedar, is an important plant that has been long used as a source of natural compounds and materials (wood, needles, soft resin, turpentine, colophony). Its chemical composition has been studied well enough; however, to our surprise, no articles that compile the phytochemical data have been published so far. Presumably, this is due to the fact that most of the studies were published in journals difficult to access and not indexed by search systems. This review, for the first time, presents a systematic compilation of available data of secondary metabolites occurring in the needles, shoots, bark, wood, seeds, and oleoresin of Pinus sibirica. PMID:25641836

  5. 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

  6. Chemical Composition of Galactic Disk Stars

    NASA Astrophysics Data System (ADS)

    Mishenina, T. V.; Basak, N. Yu.; Gorbaneva, T. I.; Soubiran, C.; Kovtyukh, V. V.

    Abundances of Na, Al, Ca, in the stars of galactic disks are obtained. The separation of thin and stars on cinematic criterion was made early. The behavior of chemical element abundances with metallicity for studied stars was presented.

  7. Origin and Bulk Chemical Composition of Mercury

    NASA Astrophysics Data System (ADS)

    Prentice, Andrew J. R.; Jontof-Hutter, Daniel

    2005-01-01

    The planet Mercury is remarkable because its mean uncompressed density ˜5.3 g/cc implies a Fe-Ni mass content of ˜67%. This is more than twice the ˜32% metal fractions of Venus and Earth. This factor coupled with other marked chemical and isotopic differences between the four terrestrial planets points to the conclusion that each planet ?received the overwhelming majority of its mass from a narrow compositionally-distinct annulus of material around the Sun? (Drake & Righter 2002 Nature 416 39; Taylor & Scott 2001 in URL below). This situation finds an explanation within the Modern Laplacian theory of Solar system origin (Prentice 2001 Earth Moon & Planets 87 11; URL: www.lpi.usra.edu/meetings/mercury01). Here the planets condensed from a concentric family of circular gas rings shed by the proto-Solar cloud. The temperatures and mean orbit pressures of the gas rings scale with heliocentric distance r as T ~ 1/r0.9 and p ˜1/r4.0 respectively. At Mercury?s orbit T = 1640 K p= 0.16 bar and the three primary equilibrium condensates are Fe-Ni (67 %) gehlenite (26.1%) and spinel (4.1%). A simple 2-zone structural model of Mercury based on this mix has mean density 5.43 g/cc and axial moment-of-inertia coefficent C/MR2 = 0.325.

  8. 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.

  9. 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.

  10. 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

  11. 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}m IDPs only provide a direct constraint on the bulk chemical composition of the IDP parent body if the size-scale of the grains in the parent body is <<10 {micro}m. The stratospheric collections include many nonchondritic, mono-mineralic grains, collected along with the fine-grained chondritic IDPs. Some of these grains, which include volatile-poor olivine and pyroxene as well as calcophile-rich sulfides, have fine-grained, chondritic material (i.e., small bits of typical IDPs) adhering to their surfaces. This indicates that at least some of the non-chondritic grains found on the stratospheric collectors are fragments from the same parent as the fine-grained IDPs. Thus, the bulk composition of the IDP parent body can only be reconstructed by adding to the fine-grained, chondritic IDPs the correct amount of this non-chondritic material. Qualitatively, the addition of olivines and pyroxenes will reduce the mean content of many moderately volatile elements while the addition of sulfides will increase the content of some of these elements. However, the quantitative task of adding these monomineralic grains to the fine-grained IDPs cannot be accomplished by simply adding the non-chondritic material in proportion to its occurrence on the stratospheric collectors because: (1) it is not clear that all of the olivines, pyroxenes, sulfides or other mineral grains found on the stratospheric collectors are extraterrestrial; (2) the settling rate of a particle depends on its density and shape, thus the concentration factor for these high-density, mono-mineralic grains is lower at the collection altitude than it is for the lower-density, fine-grained aggregate IDPs; and (3) the atmospheric entry survival of a particle is a function of density, so higher density grains (e.g., sulfides) are more likely to vaporize on entry, even if they enter with the same velocity as fine-grained, lower-density aggregates. The collection of 'cluster IDPs,' which enter the atmosphere as large particles, some larger than 50 {micro}m in diameter, containing both fine-grained aggregate material and mono-mineralic grains 10 {micro}m in size and sometimes even larger, provides an opportunity to characterize the bulk chemistry and the mineralogy of the IDPs and their parent body at a significantly larger scale than we have done previously. A 10 {micro}m, porous IDP weighs only a few nanograms, while a 50 {micro}m IDP weighs about 125 times that much and frequently includes mono-mineralic grains up to at least {approx}10 {micro}m in size. By completely characterizing the composition and mineralogy of a single cluster IDP we characterize the IDP parent body at a mass scale more than two orders-of-magnitude larger than has been done by analyzing 10 {micro}m IDPs. Although most {approx}10 {micro}m IDPs are not significantly altered by atmospheric deceleration, modeling indicates only {approx}10% of 50 {micro}m IDPs with a density of 1 g/cc are not heated above 1000 K on entry.

  12. 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.

  13. Origin and chemical composition of evaporite deposits

    USGS Publications Warehouse

    Moore, George William

    1960-01-01

    A comparative study of marine evaporite deposits forming at the present time along the pacific coast of central Mexico and evaporite formations of Permian age in West Texas Basin was made in order to determine if the modern sediments provide a basis for understanding environmental conditions that existed during deposition of the older deposits. The field work was supplemented by investigations of artificial evaporite minerals precipitated in the laboratory and by study of the chemical composition of halite rock of different geologic ages. The environment of deposition of contemporaneous marine salt deposits in Mexico is acidic, is strongly reducing a few centimeters below the surface, and teems with microscopic life. Deposition of salt, unlike that of many other sediments, is not wholly a constructional phenomenon. Permanent deposits result only if a favorable balance exists between deposition in the dry season and dissolution in the wet season. Evaporite formations chosen for special study in the West Texas Basin are, in ascending order, the Castile, Salado, and Rustler formations, which have a combined thickness of 1200 meters. The Castile formation is largely composed of gypsum rock, the Salado, halite rock, and the Rustler, quartz and carbonate sandstone. The lower part of the Castile formation is bituminous and contains limestone laminae. The Castile and Rustler formations thicken to the south at the expense of salt of the intervening Salado formation. The clastic rocks of the Rustler formation are interpreted as the deposits of a series of barrier islands north of which halite rock of the Salado was deposited. The salt is believed to have formed in shallow water of uniform density that was mixed by the wind. Where water depth exceeded the depth of the wind mixing, density stratification developed, and gypsum was deposited. Dense water of high salinity below the density discontinuity was overlain by less dense, more normally saline water which was derived from the sea to the south. Mixing of the two water layers at their interface diluted the lower layer so as to prevent halite formation, but at the same time the depressed solubility of calcium sulfate in the mixture at the interface caused precipitation of gypsum. The upper water layer is believed to have supported a flourishing microscopic biota whose remains descended into semisterile brine below where reducing conditions prevailed. This environment generated the bituminous gypsum rock. At times, microcrystalline calcium carbonate of probable biochemical origin formed in the upper layer and settled below to form limestone laminae such as those of the lower part of the Castile formation. Chemical analyses of Permian and present-day salt were compared with analyses of marine salt as old as Cambrian age to determine if evaporite deposits can contribute information on the geologic history of sea water. The results contain uncertainties that cannot be fully resolved, but they suggest that the ratio between ions in sea water has been approximately constant since Precambrian time. In addition, the abrupt initial appearance of rock salt deposits in Cambrian time suggests that the Precambrian ocean may have been rather dilute, but this apparent relationship also could have been caused by other factors.

  14. 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.

  15. "Chemical" composition of the Quark Gluon Plasma

    NASA Astrophysics Data System (ADS)

    Scardina, Francesco; Colonna, Maria; Plumari, Salvatore; Greco, Vincenzo

    2013-09-01

    In this article we discuss the issue of the quark to gluon ratio in the Quark Gluon Plasma (QGP). Our model to describe the QGP evolution is based on transport theory including the mean field dynamics described by a quasi-particle model.The last is able to take into account for the lattice QCD thermodynamics and implies a "chemical" equilibrium ratio between quarks and gluons strongly increasing as T approaches to the temperature of the phase transition Tc. We present first the tests performed in a fixed box to check that our code is able to reproduce the equilibrium ratio and then the results obtained for the simulations of ultra-Relativistic Heavy Ion Collisions (uRHIC's) at RHIC and LHC energies. We observe a rapid evolution from a gluon dominated initial state to a quark dominated plasma and we see that near Tc almost 80% of the particles composing the plasma are quarks. This has potentially a strong impact on several quantitative aspects of QGP probes and furnishes a justification to the coalescence hadronization model.

  16. Functional composite materials based on chemically converted graphene.

    PubMed

    Bai, Hua; Li, Chun; Shi, Gaoquan

    2011-03-01

    Graphene, a one-atom layer of graphite, possesses a unique two-dimensional structure and excellent mechanical, thermal, and electrical properties. Thus, it has been regarded as an important component for making various functional composite materials. Graphene can be prepared through physical, chemical and electrochemical approaches. Among them, chemical methods were tested to be effective for producing chemically converted graphene (CCG) from various precursors (such as graphite, carbon nanotubes, and polymers) in large scale and at low costs. Therefore, CCG is more suitable for synthesizing high-performance graphene based composites. In this progress report, we review the recent advancements in the studies of the composites of CCG and small molecules, polymers, inorganic nanoparticles or other carbon nanomaterials. The methodology for preparing CCG and its composites has been summarized. The applications of CCG-based functional composite materials are also discussed. PMID:21360763

  17. Seasonal variation in the chemical composition of two tropical seaweeds.

    PubMed

    Marinho-Soriano, E; Fonseca, P C; Carneiro, M A A; Moreira, W S C

    2006-12-01

    The chemical composition of red seaweed Gracilaria cervicornis and brown seaweed Sargassum vulgare from Brazil was investigated. In this study, the relationship between the nutritive components of each species and the environment was established. Protein content varied from 23.05+/-3.04% to 15.97+/-3.04%. The highest value was found in G. cervicornis. The protein levels were positively correlated with nitrogen content and negatively with water temperature and salinity. Carbohydrate contents of both species varied significantly (p<0.01) and the values observed were superior to others chemical constituents. Contrary to carbohydrates, the lipid concentrations were the lowest recorded chemical component and varied slightly between the two species. Ash content was greater in S. vulgare (14.20+/-3.86) than in G. cervicornis (7.74+/-1.15). In general the variation in chemical composition was related to environment. PMID:16311028

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. The chemical composition and structure of the moon.

    NASA Technical Reports Server (NTRS)

    Gast, P. W.

    1972-01-01

    It is assumed that most of the igneous rocks on the lunar surface are the product of partial melting in the lunar interior, followed by segregation and upward transport of an igneous liquid. An attempt is made to determine constraints on the composition of the lunar interior that derive from the chemical composition of the lunar igneous rocks. The salient chemical characteristics of igneous rocks from the lunar surface are summarized, and are compared to analogous characteristics of terrestrial volcanic rocks so that major similarities and differences between terrestrial and lunar basaltic rocks can be established.

  4. 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.

  5. Chemical Composition of Chlamydospores of Candida albicans

    PubMed Central

    Jansons, Vilma K.; Nickerson, Walter J.

    1970-01-01

    A variety of analytical techniques was employed to study the composition of the chlamydospore of Candida albicans. The outer, thin, electron-transparent layer was found to be composed of glucan, together with a small amount of chitin. The inner, thick, electron-dense layer is proteinaceous. The central structure is composed largely of ribonucleic acid and lipid globules. In addition to being acid-fast, the chlamydospore was found to contain glycolipids and to lose the property of acid-fastness on extraction with ethanol-ether. Images PMID:4099099

  6. Chemical imaging of wood-polypropylene composites.

    PubMed

    Harper, David P; Wolcott, Michael P

    2006-08-01

    Recent investigations of wood plastic composites have revealed a detrimental effect of using lubricant systems in production. This includes nullifying part or all of the mechanical benefit of using a polar compatibilizer, maleic anhydride polypropylene (MAPP), in the composite formulation. This investigation utilizes lubricants labeled with deuterium in conjunction with Fourier transform infrared (FT-IR) spectroscopy to allow for the separation of individual lubricants from all other material constituents. All of the deuterium labeled lubricants, used without MAPP, revealed their expulsion from the wood interface during crystallization. MAPP coupling agent was found to exist near the wood, but it is unclear if any covalent bonding with the hydroxyl functionality on the wood surface occurred. The addition of zinc stearate lubricants appears to nullify the activity of the anhydride functionality near the wood surface as evidenced by a shift in the FT-IR spectra to the hydrolyzed form of the coupling agent. Most of the additives collect at the edges of the spherulites in mostly amorphous regions of the material. The consequence of this morphology may be a weak interface between crystallites. PMID:16925926

  7. Chemical composition of Hanford Tank SY-102

    SciTech Connect

    Birnbaum, E.; Agnew, S.; Jarvinen, G.; Yarbro, S.

    1993-12-01

    The US Department of Energy established the Tank Waste Remediation System (TWRS) to safely manage and dispose of the radioactive waste, both current and future, stored in double-shell and single-shell tanks at the Hanford sites. One major program element in TWRS is pretreatment which was established to process the waste prior to disposal using the Hanford Waste Vitrification Plant. In support of this program, Los Alamos National Laboratory has developed a conceptual process flow sheet which will remediate the entire contents of a selected double-shelled underground waste tank, including supernatant and sludge, into forms that allow storage and final disposal in a safe, cost-effective and environmentally sound manner. The specific tank selected for remediation is 241-SY-102 located in the 200 West Area. As part of the flow sheet development effort, the composition of the tank was defined and documented. This database was built by examining the history of liquid waste transfers to the tank and by performing careful analysis of all of the analytical data that have been gathered during the tank`s lifetime. In order to more completely understand the variances in analytical results, material and charge balances were done to help define the chemistry of the various components in the tank. This methodology of defining the tank composition and the final results are documented in this report.

  8. 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 mean Cl abundance at the surface by subtracting 0.3 yields a global near-surface Cl/K of 0.6, about half the chondritic value. These data provide one framework for understanding the details of aqueous alteration on Mars. A reasonable interpretation of the Cl/K ratio at the surface is that the moderately-volatile elements K and Cl are present in chondritic proportions in bulk Mars, but are redistributed by volcanic and aqueous processes. Considering their similar incompatible igneous behavior, any deviations in Cl/K are likely caused in part by aqueous processes on or near the surface. Thus, Cl/K might be a useful index for identifying regions enriched or depleted in deposits modified or formed by aqueous alteration. Enhancement of Cl/K above chondritic could also be caused by additions from volcanic outgassing and variations in the K concentration of igneous rocks, so additional parameters are clearly necessary (e.g., H and S concentrations). Although complicated, these compositional relationships emphasize the need to understand aqueous processing on Mars quantitatively.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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...

  15. 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 ...

  16. Chemical composition, antifungal and insecticidal activities of Hedychium essential oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The antimicrobial properties of essential oils have been documented, and their use as “biocides” is gaining popularity. The aims of this study were to analyze the chemical composition and assess the biological activities of Hedychium essential oils. Oils from 19 Hedychium species and cultivars were ...

  17. 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. (author)

  18. 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.

  19. Chemical composition and bioactivity studies of Alpinia nigra essential oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Free radical scavenging, bactericidal and bitting deterrent properties of Alpinia nigra essential oils (EOs) were investigated in the present study. Chemical composition of the EOs were analyzed using GC-MS/GC-FID which revealed the presence of 63 constituents including ß-caryophyllene as major comp...

  20. 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.

  1. Effect of Chemical Composition on Texture Using Response Surface Methodology

    NASA Astrophysics Data System (ADS)

    Velmanirajan, K.; Narayanasamy, R.; Anuradha, K.

    2013-11-01

    This study explores the effect of annealing temperature and chemical composition on crystallographic texture evolution of commercially pure aluminium alloy sheets using response surface methodology (RSM). The orientation of the crystal structure in Euler space using Bunge notation has been studied to know the behavior of the metal and estimate its volume fraction. The experimental procedure involves texture analysis with respect to annealing temperature and chemical composition in correlation with the results of formability and use of RSM. The effect of important input parameters, namely, annealing temperature and chemical composition (impurities) was used for predicting the numerical models using the volume fraction of texture output from the crystallographic study using Design Expert 8.0.7.1, trial software. Also this study explains the effect of individual chemical components, namely, iron, silicon, and copper in evolution of texture components. The volume fraction of Cube {1 0 0} <0 0 1>, Bs {1 1 0} <1 1 2>, and S {1 2 3} <6 3 4> components increase, whenever iron and copper content increase and silicon component decreases.

  2. Date fruit: chemical composition, nutritional and medicinal values, products.

    PubMed

    Tang, Zhen-Xing; Shi, Lu-E; Aleid, Salah M

    2013-08-15

    Date fruit has served as a staple food in the Arab world for centuries. Worldwide production of date fruit has increased almost threefold over the last 40 years, reaching 7.68 million tons in 2010. Date fruit can provide many essential nutrients and potential health benefits to the consumer. Date fruit goes through four ripening stages named kimri, khalal, rutab and tamer. The main chemical components of date fruit include carbohydrates, dietary fibre, enzymes, protein, fat, minerals, vitamins, phenolic acids and carotenoids. The chemical composition of date fruit varies according to ripening stage, cultivar, growing environment, postharvest conditions, etc. The nutritional and medicinal activities of date fruit are related to its chemical composition. Many studies have shown that date fruit has antioxidant, antimutagenic, anti-inflammatory, gastroprotective, hepatoprotective, nephroprotective, anticancer and immunostimulant activities. Various date fruit-based products such as date syrup, date paste, date juice and their derived products are available. Date by-products can be used as raw materials for the production of value-added products such as organic acids, exopolysaccharides, antibiotics, date-flavoured probiotic-fermented dairy produce, bakery yeasts, etc. In this paper the chemical composition and nutritional and medicinal values of date fruit as well as date fruit-based products are reviewed. PMID:23553505

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

    PubMed

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

    2016-03-01

    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

  4. Chemical composition and antimicrobial activity of Polish herbhoneys.

    PubMed

    Isidorov, V A; Bagan, R; Bakier, S; Swiecicka, I

    2015-03-15

    The present study focuses on samples of Polish herbhoneys (HHs), their chemical composition and antimicrobial activity. A gas chromatography-mass spectrometry (GC-MS) method was used to analyse eight samples of herbal honeys and three samples of nectar honeys. Their antimicrobial activities were tested on selected Gram-positive (Bacillus cereus, Staphylococcus aureus, Staphylococcus schleiferi) and Gram-negative (Escherichia coli) bacteria, as well as on pathogenic fungi Candida albicans. Ether extracts of HHs showed significant differences in composition but the principal groups found in the extracts were phenolics and aliphatic hydroxy acids typical of royal jelly and unsaturated dicarboxylic acids. In spite of the differences in chemical composition, antimicrobial activity of the extracts of HHs against all the tested microorganisms except E. coli was observed. PMID:25308646

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. 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 composition characteristics of the various origins flint. The obtained data indicates that in the flint nodules the amount of silicia is large and relatively stable, as well the presence of other chemical elements are uniform and relatively homogeneous. In turn, in the chalcedony saturated dolomite can be observed the highly variable quantity of silicia, the unstable proportion of Ca-Mg and other key chemical elements and the constantly present rare earth elements, whose concentration can be significant. The performed analysis confirmed that with the chemical composition analysis it is possible to distinguish flint formed in the different geological conditions, as well as to evaluate the indicative characteristics.

  11. 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.

  12. Chemical composition of exhaust from aircraft turbine engines

    SciTech Connect

    Spicer, C.W.; Holdren, M.W.; Smith, D.L. ); Hughes, D.P. ); Smith, M.D. )

    1992-01-01

    This paper reports measurement of the chemical composition of exhaust from two aircraft tubing engines. The two engines are the F101, used on the B-1B aircraft, and the F110, used on the F-16C and F-16D aircraft. Samples were collected from each engine using a probe positioned just behind the exhaust nozzle. The measurements reported her were made at four power settings from idle to intermediate power. Exhaust composition measurements included carbon monoxide, carbon dioxide, nitrogen oxides, total hydrocarbons, and individual organic species. The principle focus of this paper is on the detailed organic species results.

  13. 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.

  14. 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 samples. The results show that the average pH in city rainwater was pH=6.5; the elements found in the samples were S, Ca, Cu, Cr, Sr, P, Fe, Mn, Pb, K, Ti, V, Zn and the average concentrations of these elements were below the limits established by World Health Organization for drinking water, and show a high natural variability. The temporal evolution of inorganic ion concentration during rain events was analyzed and the scavenging coefficients were calculated and compared with data from literature. A comparison was made between the rainwater chemical composition and chemical composition in the aerosols scavenging during the rain. This study is the first in Córdoba city to analyze the chemical composition of rainwater and constitute a base for future comparison of variability in pH and elemental composition.

  15. 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.

  16. 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.

  17. Chemical composition of rocks and soils at Taurus-Littrow

    NASA Technical Reports Server (NTRS)

    Rose, H. J., Jr.; Cuttitta, F.; Berman, S.; Brown, F. W.; Carron, M. K.; Christian, R. P.; Dwornik, E. J.; Greenland, L. P.

    1974-01-01

    Seventeen soils and seven rock samples were analyzed for major elements, minor elements, and trace elements. Unlike the soils at previous Apollo sites, which showed little difference in composition at each collection area, the soils at Taurus-Littrow vary widely. Three soil types are evident, representative of (1) the light mantle at the South Massif, (2) the dark mantle in the valley, and (3) the surface material at the North Massif. The dark-mantle soils are chemically similar to those at Tranquillitatis. Basalt samples from the dark mantle are chemically similar although they range from fine to coarse grained. It is suggested that they originated from the same source but crystallized at varying depths from the surface.

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

    NASA Astrophysics Data System (ADS)

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

    1982-09-01

    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.

  19. Theoretical Adiabatic Temperature and Chemical Composition of Sodium Combustion Flame

    SciTech Connect

    Okano, Yasushi; Yamaguchi, Akira

    2003-12-15

    Sodium fire safety analysis requires fundamental combustion properties, e.g., heat of combustion, flame temperature, and composition. We developed the GENESYS code for a theoretical investigation of sodium combustion flame.Our principle conclusions on sodium combustion under atmospheric air conditions are (a) the maximum theoretical flame temperature is 1950 K, and it is not affected by the presence of moisture; the uppermost limiting factor is the chemical instability of the condensed sodium-oxide products under high temperature; (b) the main combustion product is liquid Na{sub 2}O in dry air condition and liquid Na{sub 2}O with gaseous NaOH in moist air; and (c) the chemical equilibrium prediction of the residual gaseous reactants in the flame is indispensable for sodium combustion modeling.

  20. 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.

  1. Chemical composition and biological activity of propolis from Brazilian meliponinae.

    PubMed

    Velikova, M; Bankova, V; Marcucci, M C; Tsvetkova, I; Kujumgiev, A

    2000-01-01

    Twenty-one propolis samples produced by 12 different Meliponinae species were analyzed by GC-MS. Several chemical types of stingless bees' propolis could be grouped, according to the prevailing type of compounds like: 'gallic acid", "diterpenic" and "triterpenic" types. The results confirm that neither the bee species nor the geographical location determine the chemical composition of Meliponinae propolis and the choice of its plant source, respectively. This could be explained by the fact that Meliponinae forage over short distances (maximum 500 m) and thus use as propolis source the first plant exudate they encounter during their flights. The antibacterial, antifungal and cytotoxic activities of the samples were also investigated. Most samples had weak or no activity against E. coli, weak action against Candida albicans. Some of them showed significant activity against St. aureus., presumably connected to the high concentration of diterpenic acids. Samples rich in diterpenic acids possessed also high cytotoxic activity (Artemia salina test). PMID:11098831

  2. 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.

  3. 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)

  4. 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; however, respiration rates were similar between DOM sources. Increased release of permafrost DOM from arctic soils to surface waters will change the chemical composition of DOM and its lability to bacteria, but this study suggests that these shifts in DOM composition and lability may not increase the carbon dioxide produced by bacterial respiration of permafrost DOM exported to arctic surface waters compared to DOM currently draining the shallow active layer.

  5. 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.

  6. 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.

  7. Modeling of chemical vapor infiltration for composite fabrication

    SciTech Connect

    Starr, T.L.; Besmann, T.M.

    1993-12-31

    We describe our ongoing efforts to develop a general, validated, 3-D, finite-volume model for the chemical vapor infiltration (CVI) process. The model simulates preform densification for both isothermal (ICVI) and forced flow-thermal gradient (FCVI) variations of the process, but is most useful for FCVI where specification and control of flow rates and temperature profiles are critical to rapid, uniform densification. The model has been validated experimentally for both ICVI and FCVI fabrication of SiC/SiC composites.

  8. Chemical composition of the lunar surface in sinus medii.

    PubMed

    Franzgrote, E J; Patterson, J H; Turkevich, A L; Economou, T E; Sowinski, K P

    1970-01-23

    More precise and comprehensive analytical results for lunar material in Sinus Medii have been derived from the alpha-scattering experiment on Surveyor VI. The amounts of the principal constituents at this mare are approximately the same as those of constituents at Mare Tranquillitatis. The sodium contents of both maria are lower than those of terrestrial basalts. The titanium content at Sinus Medii is lower than that at Mare Tranquillitatis; this suggests important differences in detailed chemical composition at different mare areas on the moon. PMID:17790147

  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. 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.

  11. 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.

  12. 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

  13. Composition and Chemical Variability of Ivoirian Xylopia staudtii Leaf Oil.

    PubMed

    Yapi, Thierry Acafou; Boti, Jean Brice; Ahibo, Antoine Coffy; Sutour, Sylvain; Bighelli, Ange; Casanova, Joseph; Tomi, Félix

    2015-06-01

    The chemical composition of a leaf oil sample from Ivoirian Xylopia staudtii Engler & Diels (Annonaceae) has been investigated by a combination of chromatographic [GC(RI)] and spectroscopic (GC-MS, 13C NMR) techniques. Thirty-five components that accounted for 91.8% of the whole composition have been identified. The oil composition was dominated by the furanoguaiadienes furanoguaia-1,4-diene (39.0%) and furanoguaia-1,3-diene(7.5%), and by germacrene D (17.5%). The composition of twelve other leaf oil samples demonstrated qualitative homogeneity, but quantitative variability. Indeed, the contents of the major components varied substantially: furanoguaia-1,4-diene (24.7-51.7%) and germacrene D (5.9-24.8%). The composition of X. staudtii leaf oil is close to that of X. rubescens leaf oil but varied drastically from those of the essential oils isolated from other Xylopia species. 13C NMR spectroscopy appeared as a powerful and complementary tool for analysis of sesquiterpene-rich essential oils. PMID:26197551

  14. 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.

  15. Chemical Composition of Organic Aerosol Particles over the Remote Ocean

    NASA Astrophysics Data System (ADS)

    Russell, L. M.; Frossard, A. A.; Keene, W. C.; Kieber, D. J.; Quinn, P.; Bates, T. S.

    2012-12-01

    Marine aerosol particles play an important role in Earth's radiative balance, yet the composition of the organic fraction of these important particles remains largely unconstrained. The composition of marine aerosol particles was measured in remote marine regions on board the R/V Atlantis during the CalNex 2010 campaign in May and June 2010, on board the R/V Point Sur during the E-PEACE campaign in July 2011, and on board the R/V Ronald Brown during the WACS campaign in August 2012. To understand the factors that control this composition, we compared the organic components of these particles to models of primary marine aerosol - i.e. those generated from bubbled and atomized seawater. The organic chemical composition was characterized by Fourier Transform Infrared (FTIR) spectroscopy to determine the functional group composition and high resolution time of flight aerosol mass spectrometer (HR-ToF-AMS) to identify characteristic mass fragments. Cluster analysis of FTIR organic spectra was used to identify different spectral signatures associated with location, seawater composition, and ambient conditions. Typical submicron organic mass (OM) concentrations were less than 0.80 μg m-3. The overall organic compositions of marine aerosol particles and generated seawater models were similar, with large fractions of organic hydroxyl functional groups in each. One cluster of FTIR spectra from the eastern Pacific showed the highest fraction of hydroxyl functional groups (77%) occurred during periods of high chlorophyll concentrations and high wind speeds (more than 10 m s-1). Detailed spectral comparisons revealed unique minor features that may be driven both by meteorology and regional differences in seawater composition for these and past studies.

  16. Description, chemical composition and noble gases of the chondrite Nogata

    NASA Astrophysics Data System (ADS)

    Shima, M.; Murayama, S.; Okada, A.; Yabuki, H.; Takaoka, N.

    1983-06-01

    Microscopic, electron-microprobe, chemical-composition, and noble-gas-isotopic-abundance studies of a 20-g sample of the ordinary chondrite Nogata are reported. The historical report of the fall of the chondrite at Nogata, Japan in the year 861 is supported by C-14 dating of the wooden box in which it has been stored in a Shinto shrine. The measurement data are presented in tables and discussed. Except for a low Fe content, the chemical composition and petrological structure of the chondrite are consistent with an L6 classification. Nogata is found to be more lightly shocked and to contain relatiely more radiogenic and spallogenic noble gases than other L chondrites. The gas-retention ages calculated for Nogata are 4.5 (He-4) and 4.7 (Ar-40) x 10 to the 9th years; the cosmic-ray-exposure age is about 4 x 10 to the 7th years. It is suggested that the metamorphism of the chondrite was completed within about 10 to the 8th years of the formation of its parent body.

  17. 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.

  18. 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 higher temperatures, clouds are formed from a variety of materials including metals, metal oxides, and aluminosilicates.

  19. 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

  20. 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.

  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. Relation of sensory perception with chemical composition of bioprocessed lingonberry.

    PubMed

    Viljanen, Kaarina; Heiniö, Raija-Liisa; Juvonen, Riikka; Kössö, Tuija; Puupponen-Pimiä, Riitta

    2014-08-15

    The impact of bioprocessing on lingonberry flavour was studied by sensory evaluation and chemical analysis (organic acids, mannitol, phenolic compounds, sugars and volatile compounds). Bioprocessing of lingonberries with enzymes, lactic acid bacteria (LAB) or yeast, or their combination (excluding pure LAB fermentation) affected their perceived flavour and chemical composition. Sweetness was associated especially with enzyme treatment but also with enzyme+LAB treatment. Yeast fermentation caused significant changes in volatile aroma compounds and perceived flavour, whereas minor changes were detected in LAB or enzyme-treated berries. Increased concentration of organic acids, ethanol and some phenolic acids correlated with perceived fermented odour/flavour in yeast fermentations, in which increase in benzoic acid level was significant. In enzymatic treatment decreasing anthocyanins correlated well with decreased perceived colour intensity. Enzyme treatment is a potential tool to decrease naturally acidic flavour of lingonberry. Fermentation, especially with yeast, could be an interesting new approach to increase the content of natural preservatives, such as antimicrobial benzoic acid. PMID:24679764

  3. 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

  4. 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.

  5. Chemical composition of Mount St. Helens volcanic ash

    NASA Astrophysics Data System (ADS)

    Taylor, H. E.; Lichte, F. E.

    1980-11-01

    Volcanic ash samples from the May 18, 1980, Mount St. Helens eruption were analyzed for major, minor, and trace composition by a variety of analytical techniques. Results indicate that the basic composition of the ash consists of approximately 65% SiO2, 18% Al2O3, 5% FetO3, 2% MgO, 4% CaO, 4% Na2O, and 0.1% S. Thirty seven trace metals are reported including Ba, Cu, Mn, Sr, V, Zn, and Zr. A change in the chemical composition of the ash as a function of distance from the volcano is related to a similar change in physical characteristics of the ash. Water soluble components were also determined after column leaching experiments were performed. Concentration levels of soluble salts were found to be moderately high (1500-2000 µg/g) with molar ratios suggesting the presence of NaCl, KCl, CaSO4, and MgSO4. Heavy metals such as Cu, Co, Mn, and Zn were found at appreciable concentrations (10-1000 µg/g). Unexpectedly high concentration levels of ammonium (45 µg/g) and nitrate (100 µg/g) ions as well as dissolved organic carbon (130 µg/g) were observed in several ash leachates. Results for fluoride and boron show low average levels of ˜5 and ˜ 0.5µg/g, respectively.

  6. 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.

  7. Chemical composition of seed oils in native Taiwanese Camellia species.

    PubMed

    Su, Mong Huai; Shih, Ming Chih; Lin, Kuan-Hung

    2014-08-01

    The aim of this study was to examine the fatty acid (FA) composition and levels in seeds of twelve native Camellia species collected in different populations of major producing regions in Taiwan. The constituents of FAs varied within and among populations. Oleic acid (OA) was found to be the predominant FA constituent in all species. Remarkably high levels of unsaturated OA and linoleic acid (LA), found in two populations of Camellia tenuiflora (CT), C. transarisanensis (CTA), and C. furfuracea (CFA), were similar to those reported for olive oil. The levels of saturated palmitic acid (PA) from most of the tested seed oils were less than 13%. Among the different fats, some FAs can be used as functional ingredients for topical applications. The seed oils of CT, CTA, and CFA possess chemical compounds that make them useful in health-oriented cooking due to their high OA and LA contents and low PA content. PMID:24629982

  8. Optimum conditions for composites fiber coating by chemical vapor infiltration

    SciTech Connect

    Griffiths, S.K.; Nilson, R.H.

    1997-04-01

    A combined analytical and numerical method is employed to optimize process conditions for composites fiber coating by chemical vapor infiltration (CVI). For a first-order deposition reaction, the optimum pressure yielding the maximum deposition rate at a preform center is obtained in closed form and is found to depend only on the activation energy of the deposition reaction, the characteristic pore size, and properties of the reactant and product gases. It does not depend on the preform specific surface area, effective diffusivity or preform thickness, nor on the gas-phase yield of the deposition reaction. Further, this optimum pressure is unaltered by the additional constraint of a prescribed deposition uniformity. Optimum temperatures are obtained using an analytical expression for the optimum value along with numerical solutions to the governing transport equations. These solutions account for both diffusive and advective transport, as well as both ordinary and Knudsen diffusion. Sample calculations are presented for coating preform fibers with boron nitride.

  9. Chemical composition and biological activity of Salvia verbenaca essential oil.

    PubMed

    Canzoneri, Marisa; Bruno, Maurizio; Rosselli, Sergio; Russo, Alessandra; Cardile, Venera; Formisano, Carmen; Rigano, Daniela; Senatore, Felice

    2011-07-01

    Salvia verbenaca L. (syn. S. minore) is a perennial herb known in the traditional medicine of Sicily as "spaccapetri" and is used to resolve cases of kidney stones, chewing the fresh leaves or in decoction. The chemical composition of the essential oil obtained from aerial parts of S. verbenaca collected in Piano Battaglia (Sicily) on July 2009, was analyzed by GC and GC-MS. The oil was strongly characterized by fatty acids (39.5%) and carbonylic compounds (21.2%), with hexadecanoic acid (23.1%), (Z)-9-octadecenoic acid (11.1%) and benzaldehyde (7.3%) as the main constituents. The in vitro activity of the essential oil against some microorganisms in comparison with chloramphenicol by the broth dilution method was determined. The oil exhibited a good activity as inhibitor of growth of Gram + bacteria. PMID:21834249

  10. Evolutionary changes in the chemical composition of /upsilon/Sgr

    SciTech Connect

    Leushin, V.V.; Topil'skaya, G.P.

    1988-11-01

    An analysis is made of the chemical composition of the atmosphere of the bright component of the close binary system /upsilon/ Sgr, which lost a hydrogen envelope as a result of mass transfer. Besides the deficit of hydrogen, an excess of helium, and changes in the abundances of carbon, nitrogen, and oxygen due to hydrogen burning into helium through the CNO cycle and partly of helium into carbon through the triple /alpha/ process, excesses in the abundances of many other elements are found. The abundances of the elements from hydrogen to nickel are similar to those obtained for a number of other stars with extremely large helium excesses, although in the case of /upsilon/ Sgr there are some differences due to its binary nature. For elements with Z > 30 there is a tendency for the excess to increase with increasing atomic number, similar to what is observed for Am stars.

  11. Chemical composition of precipitation in the coastal environment of India.

    PubMed

    Gobre, T; Salve, P R; Krupadam, R J; Bansiwal, A; Shastry, S; Wate, S R

    2010-07-01

    The present study investigated the chemical composition of precipitation at Comba, Madgaon, South Goa during southwest monsoon. The rainwater samples were collected on event basis during June-September 2008 and were analyzed for pH, major anions F, Cl, NO(3), SO(4)) and cations (Ca, Mg, Na, K, NH(4)). The pH value varied from 5.36 to 6.91 (6.25 +/- 0.28) indicating alkaline nature of rainwater and dominance of Cl and Na in precipitation. The Neutralization factors (NF) was found to be NFCa = 1.22, NFMg = 0.42, NFNH(4) = 0.37 and NFK = 0.14 indicating below cloud process in which crustal components are responsible for neutralization of anions. PMID:20424819

  12. Chemical composition of the circumstellar disk around AB Aurigae

    NASA Astrophysics Data System (ADS)

    Pacheco-Vázquez, S.; Fuente, A.; Agúndez, M.; Pinte, C.; Alonso-Albi, T.; Neri, R.; Cernicharo, J.; Goicoechea, J. R.; Berné, O.; Wiesenfeld, L.; Bachiller, R.; Lefloch, B.

    2015-06-01

    Aims: Our goal is to determine the molecular composition of the circumstellar disk around AB Aurigae (hereafter, AB Aur). AB Aur is a prototypical Herbig Ae star and the understanding of its disk chemistry is paramount for understanding the chemical evolution of the gas in warm disks. Methods: We used the IRAM 30-m telescope to perform a sensitive search for molecular lines in AB Aur as part of the IRAM Large program ASAI (a chemical survey of Sun-like star-forming regions). These data were complemented with interferometric observations of the HCO+ 1→0 and C17O 1→0 lines using the IRAM Plateau de Bure Interferometer (PdBI). Single-dish and interferometric data were used to constrain chemical models. Results: Throughout the survey, several lines of CO and its isotopologues, HCO+, H2CO, HCN, CN, and CS, were detected. In addition, we detected the SO 54→33 and 56→45 lines, confirming the previously tentative detection. Compared to other T Tauri and Herbig Ae disks, AB Aur presents low HCN 3→2/HCO+ 3→2 and CN 2→1/HCN 3→2 line intensity ratios, similar to other transition disks. AB Aur is the only protoplanetary disk detected in SO thus far, and its detection is consistent with interpretation of this disk being younger than those associated with T Tauri stars. Conclusions: We modeled the line profiles using a chemical model and a radiative transfer 3D code. Our model assumes a flared disk in hydrostatic equilibrium. The best agreement with observations was obtained for a disk with a mass of 0.01 M⊙, Rin = 110 AU, Rout = 550 AU, a surface density radial index of 1.5, and an inclination of 27°. The intensities and line profiles were reproduced within a factor of ˜2 for most lines. This agreement is reasonable considering the simplicity of our model that neglects any structure within the disk. However, the HCN 3→2 and CN 2→1 line intensities were predicted to be more intense by a factor of >10. We discuss several scenarios to explain this discrepancy. Appendix A is available in electronic form at http://www.aanda.org

  13. 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.

  14. Chemical composition of TiNxOy solar selective absorbers

    NASA Astrophysics Data System (ADS)

    Eitle, J.; Oelhafen, P.; Lazarov, Michel P.; Sizmann, R.

    1992-11-01

    TiNxOy films were prepared by activated reactive evaporation (ARE) on copper to produce a tandem solar absorber exhibiting a low emissivity (epsilon) (250 degree(s)C) 2/PO2) gas pressure ratios, show that maximum (epsilon) is obtained when the ratio PN2/PO2 is held approximately equals eight. The chemical composition of these TiNxOy films was determined by x-ray photoelectron spectroscopy (XPS) and related to solar selective properties. The investigated samples consist of about 38 - 42 atomic % titanium, 35 - 37 at% oxygen and 21 - 23 at% nitrogen (bulk values), depending on preparation conditions. A depth profile indicates an oxygen enrichment at the surface, partially due to the exposure of the samples to atmosphere. After sputtering the photoelectron spectra show a marked peak at the TiO and TiN positions and a weaker one at the TiO2 position. Therefore, with regard to the known composition, the film is mainly a TiO(-N) compound with a small admixture of TiO2. The surface layer is almost entirely consisting of TiO2. Additionally, there might also be a small amount of TiC (3 at% carbon impurity was detected).

  15. 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 of specific isotopes, including O, C and those produced by the exposure to the cosmic rays, such as 38 Ar or 21 Ne, can pinpoint to the family of meteorites, but such measurements are challenging with restricted resources. Instrument Payload Options. To define the most appropriate instrument(s) in terms of scientific return and technical constraints, various solutions have been studied. For the orbiter this includes an X-ray spectrometer with a solar monitor, and a gamma-ray spectrometer with a neutron sensor. For a lander, it has been demonstrated that an active X-ray spectrometer gives outstanding results for very low resources. If mass is available in the frame of an ambitious mission, one can consider active experiments such as a laser-induced breakdown spectrometer, a mass spectrometer (needing sample manipulation, a laser ablation system, or an ion source), or evolved gas analyzers. It is very difficult however to baseline the use of active experiments from the orbiter (very close fly-bys) such as those on board the Phobos missions. On the one hand the main constraints on the lander are related to the resources (mass, power, volume) and possibly the need for target contact/manipulation. On the other hand the difficulties from the orbiter are the sensitivity to prioritized chemical elements and the mapping resolution (e.g. of the order of 1/10 of the altitude for X-rays, and equivalent to the altitude for gamma-rays). Remote-sensing experiments have been evaluated from that perspective; It is possible to estimate the accumulation time needed to reach enough precision: of the order of 1 h for X-rays and several hours for gamma-rays above each pixel (defined by the spatial resolution, see above). In a classical orbital mission scenario these numbers translate into several weeks of observations (more than 1 month). Lessons learned from previous missions (Apollo, Lunar Prospector, NEAR, Mars Odyssey, SMART-1) are also taken into account: the difficulty to monitor the solar activity for the X-rays, the low signal to noise ratio for the gamma-rays. Previous experiments were successful when the ratio orbit-radius over body-radius was about 5-7 for X-rays and less than 2 for gamma-rays. All these points put strong constraints on the operations to measure properly the chemical composition of a NEO. 2

  16. 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

  17. [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

  18. 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 just two of the three major components or a mixture of these and a fourth component such as phosphate, gypsum, or iron oxide.

  19. 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...

  20. 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 in both the soil and near-bottom water. Since the water contamination in the White Sea has lasted for decades, it is necessary to examine the near-bottom water, in particular in its deeper areas, to reveal the possible accumulation and destruction of organic substances at the sea floor. It is evident that an unbiased assessment of the environmental situation can be obtained by involving all kinds of information processing technologies.

  1. 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 should be fluorinated ethylene/propylene (FEP), and one or more FEP O ring(s) should be used in the aluminum end fitting(s). This choice of materials is dictated by experimental observations that pure aluminum and FEP are the only materials suitable for long-term storage of hydrogen peroxide and that other materials tend to catalyze the decomposition of hydrogen peroxide to oxygen and water. Other thermoplastic liner materials that are suitable for some applications include nylon 6 and polyethylene. The processing temperatures for nylon 6 are lower than those for FEP. Nylon 6 is compatible with propane, natural gas, and other petroleum-based fuels. Polyethylene is compatible with petroleum- based products and can be used for short-term storage of hydrogen peroxide.

  2. Rainwater chemical composition at two sites in Central Mexico

    NASA Astrophysics Data System (ADS)

    Báez, A. P.; Belmont, R. D.; García, R. M.; Torres, M. C. B.; Padilla, H. G.

    2006-04-01

    Chemical analyses were performed on rainwater samples collected at the National Autonomous University of Mexico (UNAM) in Mexico City and at a wooded site, Rancho Viejo (RV) in the State of Mexico, for the periods 1994-2000 and 1994-1999, respectively. At UNAM, rainwater was collected for the entire rainy season period each year, while at RV, technical considerations limited collection to weekends only. The results showed large variations in rainwater chemical composition in most years, mainly because of the variability of meteorological conditions and also because of changes in source emissions. Sulfates and NH 4+ showed higher annual volume-weighted mean concentrations (VWMC) in both sites. At UNAM, the maximum annual VWMC for SO 42- occurred in March and the minimum in July and August. Lower concentrations of almost all ions were found at RV; however, the H + concentration was higher at this site. The pH in Mexico City, calculated from the annual VWMC of H +, was 4.95, which is a little higher than pH values reported in some other countries. Despite the fact that sulfate and NO 3- concentrations were lower at RV, the pH was lower. Air-mass back trajectories were calculated for individual concentrations of SO 42-, H +, NH 4+, Ca 2+, and Mg 2+, observed at each sampling site for weekend data. At RV, sulfate concentrations were higher when air-mass back trajectories indicated a wind flow from Mexico City and Toluca at 1000 MAGL (meters above ground level) and 3000 MAGL. The hydrogen ion exhibited the same behavior. Calcium and Mg 2+ concentrations were also higher when the wind blew from urban areas at 1000 and 3000 MAGL. At UNAM, H + concentration was lower and Ca 2+ and Mg 2+ were higher when wind blew from the northern sector of the city at 1000 and 3000 MAGL. In UNAM, the NO 3-/SO 42- and NH 4+/SO 42- ratios were 0.5 and 1.09 in 1994 and 0.86 and 1.64 in 2000, respectively, indicating a decrease in SO 2 emissions resulting from the change of fuel oil to gas fuel. The SO 42-/Ca 2+ ratio was significantly lower at the UNAM site (1.82) compared to RV (5.36), and the SO 42-/H + ratio was significantly higher at the UNAM site (6.77) compared to RV (2.01). The Spearman's rho correlation between ionic concentrations indicated a positive correlation in most cases ( p < 0.05) for data from UNAM and RV. The multiple regression correlation analysis to predict H + concentration in Mexico City showed that NO 3-, NH 4+, SO 42-, and Ca 2+ contributed 23.2%, 20.9%, 8.0%, and 6.1%, respectively, to the H + prediction, while Cl - plus Na + plus K + only contributed 2.2%, and Mg 2+ did not contribute. Sea-salt contribution to rainwater chemical composition was negligible with any wind direction at both levels. Excess sulfate (non-sea-salt sulfate) represented 98.7% of the total sulfate in rainwater collected during weekends at RV and 98.6% for weekend and annual rain samples at UNAM.

  3. Chemical Emergencies

    MedlinePlus

    Chemical Emergencies Under certain conditions, chemicals which are normally safe can be poisonous or harmful to your health. A major chemical emergency is an accident that releases a hazardous amount ...

  4. Reducing chemical vapour infiltration time for ceramic matrix composites.

    PubMed

    Timms, L. A.; Westby, W.; Prentice, C.; Jaglin, D.; Shatwell, R. A.; Binner, J. G. P.

    2001-02-01

    Conventional routes to producing ceramic matrix composites (CMCs) require the use of high temperatures to sinter the individual ceramic particles of the matrix together. Sintering temperatures are typically much higher than the upper temperature limits of the fibres. This paper details preliminary work carried out on producing a CMC via chemical vapour infiltration (CVI), a process that involves lower processing temperatures, thus avoiding fibre degradation. The CVI process has been modified and supplemented in an attempt to reduce the CVI process time and to lower the cost of this typically expensive process. To this end microwave-enhanced CVI (MECVI) has been chosen, along with two alternative pre-infiltration steps: electrophoretic infiltration and vacuum bagging. The system under investigation is based on silicon carbide fibres within a silicon carbide matrix (SiCf/SiC). The results demonstrate that both approaches result in an enhanced initial density and a consequent significant reduction in the time required for the MECVI processing step. Dual energy X-ray absorptiometry was used as a non-destructive, density evaluation technique. Initial results indicate that the presence of the SiC powder in the pre-form changes the deposition profile during the MECVI process. PMID:11207933

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. The chemical composition and distribution of interstellar grains

    NASA Technical Reports Server (NTRS)

    Greenberg, J. M.; Hong, S.-S.

    1974-01-01

    The chemical composition of interstellar grains is derived here on the basis of (1) the cosmic abundance of the elements; (2) the wavelength dependence of extinction and polarization; (3) the average total extinction; (4) the ratio of polarization to extinction; (5) the predominantly dielectric character of grains in the visible spectral region; and (6) infrared spectral characteristics of grains. Inferences of the core-mantle model with respect to spatial distribution are consistent with the proposition that growth of the mantles occurs in the galactic shock region predicted by the density-wave theory. Estimates of the total visual extinction toward the galactic center and the consequent estimates of the total amount of far infrared radiation are shown to depend critically on the grain model. Variations of the ratio of far ultraviolet to visual extinction are correlated with the conditions for growth of mantles on the bare small particles which are generally prevented from accreting mantles primarily because of their extreme temperature fluctuations produced by the ultraviolet photons in the radiation field.

  10. Chemical composition, antifungal and insecticidal activities of Hedychium essential oils.

    PubMed

    Sakhanokho, Hamidou F; Sampson, Blair J; Tabanca, Nurhayat; Wedge, David E; Demirci, Betul; Baser, Kemal Husnu Can; Bernier, Ulrich R; Tsikolia, Maia; Agramonte, Natasha M; Becnel, James J; Chen, Jian; Rajasekaran, Kanniah; Spiers, James M

    2013-01-01

    The antimicrobial properties of essential oils have been documented, and their use as "biocides" is gaining popularity. The aims of this study were to analyze the chemical composition and assess the biological activities of Hedychium essential oils. Oils from 19 Hedychium species and cultivars were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) techniques. The antifungal and insecticidal activities of these oils were tested against Colletotrichum acutatum, C. fragariae, and C. gloeosporioides, and three insects, the azalea lace bug (Stephanitis pyrioides), the yellow fever mosquito (Aedes aegypti), and the red imported fire ant (Solenopsis invicta). Hedychium oils were rich in monoterpenes and sesquiterpenes, especially 1,8-cineole (0.1%-42%), linalool (<0.1%-56%), a-pinene (3%-17%), b-pinene (4%-31%), and (E)-nerolidol (0.1%-20%). Hedychium oils had no antifungal effect on C. gloeosporioides, C. fragariae, and C. acutatum, but most Hedychium oils effectively killed azalea lace bugs. The oils also show promise as an adult mosquito repellent, but they would make rather poor larvicides or adulticides for mosquito control. Hedychium oils acted either as a fire ant repellent or attractant, depending on plant genotype and oil concentration. PMID:23579997

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

    PubMed

    Lpez, Molkary Andrea; Stashenko, Elena E; Fuentes, Jorge Luis

    2011-07-01

    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-?-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

  12. 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

  13. 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.

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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 300 m) with silles and elevations (<20 m), and also numerous islands. Thus variety of sediment composition is observed here - from rules and gravels to fine-grained clay silts [1]. The map of distribution of chemical elements was created by using bulk composition data with the help of program ArcView. Mn distribution in sedimentation mass is largely determed by influence of redox diagenesis. Reactive form of Mn dominates over less moving, litogenic form in sedimation mass of White Sea. Litogenic form remains in sediment, reactive form moves into silt near-bottom water, resulting Mn migration both in sediment and near-bottom layer of marine water. Mn oxidizes on the contact with oxygen of marine water and alters into insoluble form MnO2, causing Mn enrichment of surface layer of sediments. Highly movable silt deposit MnO2 and enriched by Mn suspension are moved by underflow and accumulate in bottom depressions and in central part of the sea, which is quite wide from both places of original sedimentation and run off sources [2]. Thus, the interrelation between granulometric composition of sediment and materials concentration can be shown by the example of Mn. Local conditions, leading to accumulation of clastic components, are: 1. Rise of content in sand owning to separation of heavy minerals 2. Rise of content in surface, mainly sandy clay sediments owning to presence of concretions 3. Rise of content in lower bunches roof owning to diagenetic contraction. Authors thank academic Lisitsyn for encourage, Andrey Apletalin for valuable help, and everybody, who helped in field and laboratory research of the White sea sediments. Work was being done under the auspices of Russian foundation of basic research (grants 09-05-10081, 09-05-00658 and 08-05-00860), RSA presidiums program of 17 fundamental researches (project 17.1). References: 1.Kuzmina T., Lein A., Lutchsheva L., Murdmaa I., Novigatsky A., Shevchenko V. Chemical composition of White Sea's sediments // Litology and mineral deposits . 2009. - № 2. - P 115-132. 2.Nevessky E., Medvedev V. , Kalinenko V. White sea, sedimentation and holocoen developmental history. - Moscow.: Nauka, 1977. - 236 p. 3.White Sea and it water collection affected by climatic and antropogenic factors. / under the editorship of Terzhevik A., Filatov N. - Petrozavodsk.: Karelsky nauchny centr RAN, 2007. - 335p

  1. Changes in chemical composition in male turkeys during growth.

    PubMed

    Rivera-Torres, V; Noblet, J; van Milgen, J

    2011-01-01

    In growing animals, requirements for many nutrients (and energy) are determined by the retention of these nutrients. During growth, this retention changes in an absolute way and also between nutrients and energy, resulting in changing nutrient requirements. The objective of this study was to describe the changes in chemical composition in male growing turkeys. The serial slaughter technique was used to determine the composition of amino acids, lipid, ash, and water in feather-free body (FFB) and feathers in male turkeys offered feed ad libitum from 1 to 15 wk of age. Allometric relations were used to describe changes in body composition. The feather content in the body decreased from 6% at 1 wk of age to less than 3% at 15 wk of age. The water and protein content in FFB decreased with increasing FFB mass, with allometric scalars (b) of, respectively, 0.967 and 0.970, whereas the lipid content increased with increasing FFB mass (b = 1.388). The water, protein, and ash content in fat-free FFB was constant and represented, respectively, 71.6, 24.2, and 4.2% of the fat-free FFB mass. The amino acid content of FFB protein was relatively constant and only the Cys content decreased between 1 and 15 wk of age, whereas the Ile content increased. Feathers were mostly composed of protein, and the protein content did not change during growth. During growth, the Lys, Met, Trp, His, Tyr, Asp, and Glu contents in feather protein decreased, whereas the Cys, Val, and Ser contents increased. The contribution of feathers to whole-body amino acid retention ranged from 5% for His to 33% for Cys. On average, the weight gain of FFB contained 21.3% protein and 12.7% lipid, corresponding to an energy content of 10.1 kJ/g. The weight gain of feathers contained 87.4% protein, corresponding to an energy content of 20.4 kJ/g. The results of the present study can be used in a factorial approach to determine nutrient requirements in growing turkeys. PMID:21177445

  2. 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.

  3. 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.

  4. 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...

  5. 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

  6. 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

  7. 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

  8. 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

  9. Chemical durability

    SciTech Connect

    Kreuer, K.D.; Warhus, U.

    1986-03-01

    The chemical durability of NASICON (Na/sub 1+x/Zr/sub 2/Si/sub x/P/sub 3-x/O/sub 12/, x=0-3) versus molten sodium and sulfur at 600 K has been investigated. Degradation by molten sodium has been observed for phosphorus-containing compositions only. The pure silicate (x=3), however, appeared to be stable, because reduction of silicon demanded by thermodynamics did not occur at the given temperature for kinetic reasons. The latter composition has also been shown to have good durability against molten sulfur.

  10. 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.

  11. 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

  12. 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.

  13. The Chemical Compositions of RR Lyrae Type c Variable Stars

    NASA Astrophysics Data System (ADS)

    Govea, Jose; Gomez, T. A.; Preston, G. W.; Sneden, C.

    2013-01-01

    We present the largest detailed chemical abundance study of RR Lyrae stars of c subclass. Chemical abundance ratios for 8 RRc Lyrae stars were obtained. The stars were chosen from the Blazhko candidates of Szczygiel & Fabrycky (2007, MNRAS, 377, 1263). Spectra were gathered using the 100 inch du Punt telescope at Las Campanas Observatory. Wavelength coverage of the spectra is 3800-9000 Å. Multiple exposures were taken throughout each star’s pulsation cycle. Atmospheric parameters, effective temperature, surface gravity, microturbulent velocity, and metallicity were derived. We find that alpha element enhancements are consistent with those of non-variable halo stars and our abundance results agree generally with other horizontal branch stars. In addition our derived atmospheric parameters produce abundance ratios that are independent of phase. This work has been supported by NSF grants AST-0908978 and AST-1211585 to CS and by the Baker Centennial Research Endowment to the Astronomy Department of the University of Texas.

  14. 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

  15. 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.

  16. Fog water chemical composition in different geographic regions of Poland

    NASA Astrophysics Data System (ADS)

    Błaś, Marek; Polkowska, Żaneta; Sobik, Mieczysław; Klimaszewska, Kamila; Nowiński, Kamil; Namieśnik, Jacek

    2010-03-01

    The fog water samples were collected with the use of both passive and active fog collectors during 2005-2006 at 3 sites: lowland in northern Poland (Borucino; 186 m a.s.l.), valley basin in southern Poland (Zakopane; 911 m a.s.l.) and mountain top (Szrenica Mt.; 1330 m a.s.l.) in south-western Poland. For all daily samples (Borucino—25; Zakopane—4 and Szrenica—155), electric conductivity, pH, and concentrations of some anions: Cl -, F -, Br -, NO 2-, NO 3-, SO 42-, PO 43-and cations: NH 4+, Ca 2+, K +, Na + and Mg 2+ were measured. The selected ions were determined using ion suppressed chromatography (IC). Fog consists of a specific type of atmospheric phenomena. Results obtained on the basis of analysis of suitable fog samples can be treated as a source of valuable information on the chemistry of the atmosphere. Statistical analysis revealed significant differences depending on region, altitude, local morphology and, last but not least, fog origin. A distinct contrast is evident in the concentration and chemical composition between lowland radiation fog (represents lower layers of the atmosphere which are more influenced by continental emissions) versus orographic slope fog represented by a summit station, Mt Szrenica. It is partly induced by a distinction in weather conditions favouring fog existence, height of fog formation and its microphysical parameters. Acidity was associated with high concentrations of excess sulphate and nitrate in the fog water samples. Ammonium and calcium concentrations represent the most important neutralizing inputs. Collected cloud water at Szrenica Mt. includes solute contributions from emission sources located at much larger upwind distances. The fact that 95% of fog/cloud deposition is concentrated during SW-W-NW-N-NE, atmospheric circulation exerts an influence on the environmental quality of montane forests in the Sudety Mts. At numerous conspicuous convex landforms, where fog/cloud deposition becomes at least as important as wet deposition via atmospheric precipitation, a distinct difference in the health of coniferous forests is clearly visible, with the areas of the NW aspect being the worst affected, contrary to SE slopes with relatively healthy forest stands.

  17. Chemical composition, toxicity and mosquito repellency of Ocimum selloi oil.

    PubMed

    Padilha de Paula, Josiane; Gomes-Carneiro, Maria Regina; Paumgartten, Francisco J R

    2003-10-01

    Ocimum spp. (Lamiaceae) and their essential oils have been traditionally used to kill or repel insects, and also to flavor foods and oral products, in fragrances, in folk medicine and as condiments. In Brazil, Ocimum selloi has been used to treat stomachaches and as an anti-inflammatory remedy. This study was performed to provide data on the chemical composition, acute toxicity, mutagenicity, skin irritant potential and mosquito repellency of Ocimum selloi oil. GC/MS analysis of Ocimum selloi oil revealed that its major constituents were methyl-chavicol or estragole (55.3%), trans-anethole (34.2%), cis-anethole (3.9%) and caryophyllene (2.1%). Ocimum selloi oil given by gavage to adult Swiss Webster mice produced no adverse effects at doses as high as 1250 mg/kg body weight. Deaths and symptoms (e.g. hypoactivity, ataxia and lethargy) were observed at doses > or =1500 mg/kg body weight, being females apparently more susceptible than males. Genotoxicity of Ocimum selloi oil was evaluated in the Salmonella/microsome assay without and with S9 mixture. The oil, tested up to the toxicity limit (500-700 microg/plate), was not mutagenic to tester strains TA97a, TA98 and TA100. None of 30 volunteers of either sex exposed to undiluted Ocimum selloi oil (4-h patch test) showed a positive skin irritant reaction. A field test (six volunteers, each individual his/her own control) was carried out to evaluate mosquito (Anopheles braziliensis) repellency of Ocimum selloi oil diluted in ethanol (10% v/v). The median number of mosquito bites on volunteers' skin-recorded for 30 min after application of Ocimum selloi oil (2, range 0-3) was much lower than that noted after application of the solvent alone (19.5, 3-25) (Wilcoxon test, P<0.01). In conclusion, results showed that Ocimum selloi oil is an effective mosquito repellent that presents a low acute toxicity, poses no mutagenic risk and seems not to be irritating to human skin. PMID:12963152

  18. Origin and Bulk Chemical Compositions of the Inner Planets

    NASA Astrophysics Data System (ADS)

    Prentice, A. J.

    2001-12-01

    The well-defined orbital gradation of the uncompressed mean densities /lineρunc of the terrestrial planets attest to the existence of similar heliocentric gradations of temperature and pressure in the nebular gas from which these bodies condensed (Lewis, Science 186 440-443 1974). This trend of /lineρunc, coupled with the very different chemical signatures of each planet, such as the almost zero state of Fe oxidisation in Mercury, the dryness of Venus' atmosphere, and the likely existence of liquid FeS in the Earth's core, suggest that each planet condensed within a narrow feeding zone, close to its present orbit. These features are explained by the modern Laplacian theory [MLT] of solar system origin (Earth, Moon & Planets 87 11-55 2001; Abstract # 8061 in Mercury 2001 Workshop - see URL below). According to the MLT, the planetary system condensed from a concentric family of orbiting gas rings which were shed by the contracting proto-solar cloud [PSC]. Discrete ring shedding occurs if there exists a steep density inversion at the cloud's photosurface, with the gas density ρ rising ~ 35-fold. Previously it has been suggested that such an inversion comes about solely through the action of a large turbulent stress pt arising from supersonic convective motions within a uniformly superadiabatic interior (BAAS 23 1232 1991; Eos Trans. AGU 76 F332 1995). For a non-rotating cloud pt = β ρ GM(r)/r, where M(r) is the mass inside radius r and β ~ 0.1 is a constant. This requires pt rising to ~ 35pgas, which seems unlikely. Here pgas = ρ ℜ T/μ , T is temperature and μ is molecular weight. I now report a new PSC model which incorporates the findings of a numerical simulation of supersonic thermal convection in a model atmospheric layer (BAAS 32 1102 2000). The new model has an adiabatic core of radius r1 in which β = β 1, a constant. This core is surrounded by a superadiabatic envelope of polytropic index n = -1 in which β falls to 0 at the surface [s] according 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.

  19. Quantitative mapping of chemical compositions with MRI using compressed sensing.

    PubMed

    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 22mm and a spatial resolution of 344?m344?m. 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 8min. In contrast, a conventional chemical shift imaging experiment at the same resolution would require about 17h. 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 2mol-% 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. PMID:26524651

  20. 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.

  1. Chemical sensor

    NASA Technical Reports Server (NTRS)

    Rauh, R. David (Inventor)

    1990-01-01

    A sensor for detecting a chemical substance includes an insertion element having a structure which enables insertion of the chemical substance with a resulting change in the bulk electrical characteristics of the insertion element under conditions sufficient to permit effective insertion; the change in the bulk electrical characteristics of the insertion element is detected as an indication of the presence of the chemical substance.

  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 of nebulosities in the magellanic clouds.

    PubMed

    Aller, L H; Czyzak, S J; Keyes, C D; Boeshaar, G

    1974-11-01

    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 degrees K, while the [OIII], [NeIII], [ArIII], and H radiations are produced primarily in regions with T(epsilon) = 10,000 degrees K, the derived chemical abundances in the clouds are enhanced. PMID:16592199

  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. 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.

  6. Chemical Compositions of Kinematically Selected Outer Halo Stars

    NASA Astrophysics Data System (ADS)

    Zhang, Lan; Ishigaki, Miho; Aoki, Wako; Zhao, Gang; Chiba, Masashi

    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 α-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 [α/Fe] with increasing [Fe/H] for the range of -3.5< [Fe/H] <-1, as found by Stephens & 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. Based on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

  7. Chemical Composition of Fine Particulate Matter and Life Expectancy

    PubMed Central

    Dominici, Francesca; Wang, Yun; Correia, Andrew W.; Ezzati, Majid; Pope, C. Arden; Dockery, Douglas W.

    2016-01-01

    Background In a previous study, we provided evidence that a decline in fine particulate matter (PM2.5) air pollution during the period between 2000 and 2007 was associated with increased life expectancy in 545 counties in the United States. In this article, we investigated which chemical constituents of PM2.5 were the main drivers of the observed association. Methods We estimated associations between temporal changes in seven major components of PM2.5 (ammonium, sulfate, nitrate, elemental carbon matter, organic carbon matter, sodium, and silicon) and temporal changes in life expectancy in 95 counties between 2002 and 2007. We included US counties that had adequate chemical components of PM2.5 mass data across all seasons. We fitted single pollutant and multiple pollutant linear models, controlling for available socioeconomic, demographic, and smoking variables and stratifying by urban and nonurban counties. Results In multiple pollutant models, we found that: (1) a reduction in sulfate was associated with an increase in life expectancy; and (2) reductions in ammonium and sodium ion were associated with increases in life expectancy in nonurban counties only. Conclusions Our findings suggest that recent reductions in long-term exposure to sulfate, ammonium, and sodium ion between 2002 and 2007 are associated with improved public health. PMID:25906366

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

    SciTech Connect

    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.

  9. 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.

  10. 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

  11. Chemical composition of clouds at Mt. Mitchell, North Carolina, USA

    NASA Astrophysics Data System (ADS)

    Kim, Deug-Soo; Aneja, Viney P.

    1992-02-01

    Using a recently developed cloud and rain acidity/conductivity (CRAC) real time analyzer, clouds atop Mt. Mitchell State Park, North Carolina — the highest peak (~ 2038 m MSL) in the eastern US — were investigated from May to October during 1987 to 1989. Measurements for chemical and physical climatology were performed to estimate exposure of pollutant at the forest canopy resulting from direct capture of cloud droplets. The mountain peak is exposed on the average to cloud episodes about 70% days per year. Results are reported for integrating times of cloud collection, approximately 5min, during several precipitating and non-precipitating cloud events. Cloud water was found to have higher acidity and higher concentrations of sulfate, nitrate and ammonium than previously observed in rain droplets. The pH of the cloud water was in the range of 2.4 to 4.9 during 1987 through 1989 field seasons, while the pH of the rain water was in the range of 3.5 to 5.5. The cloud water collected in summer season was more acidic than those collected in any other seasons (spring and fall). The maximum of average cloud pH value (i.e., low acidity) was found when the predominant wind direction was from south-east. On the other hand, the low average cloud pH values (i.e., high acidity) were found when the predominant wind direction was west through northeast. Total concentrations of major chemical species in cloud water at Mt. Mitchell State Park are significantly higher (~ 1250 to ~ 3020 µeq/1) than those reported for other rural locations. According to the time-sequential chemical concentration, a concave trend with total concentration decreasing at the beginning and rising toward the end of event was observed. It was also observed that changes in the individual ionic concentration are proportional to the changes in total concentration. It suggests that condensation and evaporation of cloud droplets are the important processes, during various stages of a cloud event, in determining the total pollutant concentration of cloud water.

  12. 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.

  13. 40 CFR 761.292 - Chemical extraction and analysis of individual samples and composite samples.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... individual samples and composite samples. 761.292 Section 761.292 Protection of Environment ENVIRONMENTAL....61(a)(6) § 761.292 Chemical extraction and analysis of individual samples and composite samples. Use... individual and composite samples of PCB remediation waste. Use Method 8082 from SW-846, or a method...

  14. 40 CFR 761.292 - Chemical extraction and analysis of individual samples and composite samples.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... individual samples and composite samples. 761.292 Section 761.292 Protection of Environment ENVIRONMENTAL....61(a)(6) § 761.292 Chemical extraction and analysis of individual samples and composite samples. Use... individual and composite samples of PCB remediation waste. Use Method 8082 from SW-846, or a method...

  15. 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...

  16. 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...

  17. 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.

  18. Using Chemical Compositions of Kinematically Selected Stars to Trace Galactic Mergers

    NASA Astrophysics Data System (ADS)

    Gregersen, Dylan; Ivans, Inese; Lackner, Claire; Allen, Christine

    2011-10-01

    Low ?-element chemical abundances discriminate rare stars from their place among the rest of the halo population of our Milky Way. The unusual chemical nature is thought to distinguish them as remnants of a now merged extragalactic system. Until now, these stars have only been found serendipitously, on the order of a few in a thousand. In this talk, we report stars with low enhancements of ?-elements found within two kinematically distinct candidate moving clusters. Stars within these candidate moving clusters were distinguished from common halo stars by shared stellar characteristics in orbital energy, angular momentum, and overall chemical enrichment (Allen et al, 2007, Proc. IAU, 2: 405-413). Using high-resolution spectra, we employed multi-line analysis code with stellar models to determine their chemical compositions. This study is part of a larger chemical composition investigation of these and other stars to search for other low-? star tracers of the dynamic formation of our Galaxy.

  19. 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.

  20. [Chemical weapons and chemical terrorism].

    PubMed

    Nakamura, Katsumi

    2005-10-01

    Chemical Weapons are kind of Weapons of Mass Destruction (WMD). They were used large quantities in WWI. Historically, large quantities usage like WWI was not recorded, but small usage has appeared now and then. Chemical weapons are so called "Nuclear weapon for poor countrys" because it's very easy to produce/possession being possible. They are categorized (1) Nerve Agents, (2) Blister Agents, (3) Cyanide (blood) Agents, (4) Pulmonary Agents, (5) Incapacitating Agents (6) Tear Agents from the viewpoint of human body interaction. In 1997 the Chemical Weapons Convention has taken effect. It prohibits chemical weapons development/production, and Organization for the Prohibition of Chemical Weapons (OPCW) verification regime contributes to the chemical weapons disposal. But possibility of possession/use of weapons of mass destruction by terrorist group represented in one by Matsumoto and Tokyo Subway Sarin Attack, So new chemical terrorism countermeasures are necessary. PMID:16296384

  1. 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/.

  2. 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 measurements indicated that during forest fire episodes, most of the aerosol mass consisted of organic particulate matter. Concentrations of biomass burning tracers levoglucosan, oxalate and potassium were elevated close to the forest fire areas observed by the MODIS satellite. The polluted air masses from Asia seem to have significant influences on the concentration levels of fine particles over south-eastern Russia.

  3. Chemical microsensors

    DOEpatents

    Li, DeQuan; Swanson, Basil I.

    1995-01-01

    An article of manufacture is provided including a substrate having an oxide surface layer and a selective thin film of a cyclodextrin derivative chemically bound upon said substrate, said film is adapted for the inclusion of a selected organic compound therewith. Such an article can be either a chemical sensor capable of detecting a resultant mass change from inclusion of the selected organic compound or a chemical separator capable of reversibly selectively separating a selected organic compound.

  4. Application of chemical vapor composites (CVC) to terrestrial thermionics

    NASA Astrophysics Data System (ADS)

    Miskolczy, Gabor; Reagan, Peter

    1995-01-01

    Terrestrial flame fired thermionics took a great leap forward in the earlier 1980's with the development of reliable long-lived hot shells. These results were presented by Goodale (1981). The hot shell protects the fractory emitter from oxidizing in the combustion environment. In earlier efforts with supralloys emitters it was found that superalloys were poor thermionic emitters since they operated at too low a temperature for practical and economical use as discussed by Huffman (1978). With the development of Chemical Vapor Deposited (CVD) silicon carbide and CVD tungsten, it became possible to fabricate long-lived thermionic converters. These results were shown by Goodale (1980). Further improvements were achieved with the use of oxygen additives on the electrodes. These developments made thermionics attractive for topping a power plant or as the energy conversion part of a cogeneration plant as described by Miskolczy (1982) and Goodale (1983). The feasibility of a thermonic steam boiler and a thermionic topped gas turbine plant become a possibility, as shown by Miskolczy (1980).

  5. Brazilian Red Propolis—Chemical Composition and Botanical Origin

    PubMed Central

    Daugsch, Andreas; Moraes, Cleber S.; Fort, Patricia

    2008-01-01

    Propolis contains resinous substances collected by honey bees from various plant sources and has been used as a traditional folk medicine since ca 300 BC. Nowadays, the use of evidence-based complementary and alternative medicine (CAM) is increasing rapidly and so is the use of propolis in order to treat or support the treatment of various diseases. Much attention has been focused on propolis from Populus sp. (Salicaceae) and Baccharis dracunculifolia (Asteracea), but scientific information about the numerous other types of propolis is still sparse. We gathered six samples of red propolis in five states of Northeastern Brazil. The beehives were located near woody perennial shrubs along the sea and river shores. The bees were observed to collect red resinous exudates on Dalbergia ecastophyllum (L) Taub. (Leguminosae) to make propolis. The flavonoids of propolis and red resinous exudates were investigated using reversed-phase high-performance liquid chromatography and reversed-phase high-performance thin-layer chromatography. We conclude that the botanical origin of the reddish propolis is D. ecastophyllum. In areas where this source (D. ecastophyllum) was scarce or missing, bees were collecting resinous material from other plants. Propolis, which contained the chemical constituents from the main botanical origin, showed higher antimicrobial activity. PMID:18955226

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Chemical composition and biological activities of Gerbera anandria.

    PubMed

    He, Fa; Wang, Miao; Gao, Minghuan; Zhao, Min; Bai, Yuhua; Zhao, Chunjie

    2014-01-01

    Gerbera anandria (Compositae) was extracted with 75% ethanol and the residue was fractionated using light petroleum, chloroform and ethyl acetate. The constituents of the extracts were separated by column chromatography employing solvents of different polarity. Column chromatography of the light petroleum fraction resulted in the isolation of methyl hexadecanoate, while the chloroform fraction afforded xanthotoxin, 2-hydroxy-6-methylbenzoic acid, 7-hydroxy-1(3H)-isobenzofuranone, a mixture of β-sitosterol and stigmasterol, and 8-methoxysmyrindiol and the ethyl acetate fraction gave gerberinside, apigenin-7-O-β-d-glucopyranoside and quercetin. A new coumarin, 8-methoxysmyrindiol, was found. The chemical structures of the isolated compounds were established by MS and NMR (HSQC, HMBC). Free radical scavenging and cytotoxic activities of crude extracts and 8-methoxysmyrindiol were further investigated. The ethyl acetate phase exerted the strongest DPPH free radical scavenging activity in comparison to the other fractions. The coumarin 8-methoxysmyrindiol demonstrated cytotoxicity against multiple human cancer cell lines, with the highest potency in HepG2 cells. PMID:24699147

  11. 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.

  12. Optical density and chemical composition of microfilled and microhybrid composite resins.

    PubMed

    Braun, Ana Paula; Grassi Soares, Clarissa; Glüer Carracho, Helena; Pereira da Costa, Nilza; Bauer Veeck, Elaine

    2008-01-01

    This study evaluated the optical density of two microfilled and two microhybrid resins, as well as the composition of these materials with regard to their optical density. Cavities prepared in 12 2-mm- or 4-mm-thick acrylic plastic plates were filled with Z250 (3M-ESPE), A110 (3M-ESPE), Charisma (Heraeus-Kulzer) and DurafillVS (Heraeus-Kulzer). The resin increments (2-mm-thick) were light-cured for 40 s. Three 0.12-s radiographic exposures were made of each #2 acrylic plastic plate. DenOptix system optical plates were used to obtain the digital images. Three readings of the composite resin surface were made in each radiograph, totalizing 216 readings. The mean of highest and lowest grey-scale values was obtained. Two specimens of each composite resin were prepared for SEM analysis of the chemical elements related to optical density, using energy dispersive x-ray analysis (EDX). The results were subjected to Shapiro-Wilk's test, ANOVA, Tukey's test at 1% level of significance and Pearson's correlation. The mean grey-scale values at 2 mm and 4 mm were: Z250 = 154.27a and 185.33w; A110 = 46.77b and 63.05y; Charisma = 163.40c and 200.46z; DurafillVS = 43.92b and 58.99x, respectively. Pearson's test did not show any positive correlation between optical density and percentage weight of optical density chemical elements. It was concluded that the microhybrid resins had higher optical density means than the microfilled resins; among the evaluated resins, Charisma had the highest optical density means. PMID:19089205

  13. 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

  14. 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 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. PMID:17195488

  15. Chemical sensors

    DOEpatents

    Lowell, Jr., James R.; Edlund, David J.; Friesen, Dwayne T.; Rayfield, George W.

    1991-01-01

    Sensors responsive to small changes in the concentration of chemical species are disclosed, comprising (a) a mechanochemically responsive polymeric film capable of expansion or contraction in response to a change in its chemical environment, operatively coupled to (b) a transducer capable of directly converting said expansion or contraction to a measurable electrical response.

  16. Chemical preconcentrator

    DOEpatents

    Manginell, Ronald P.; Frye-Mason, Gregory C.

    2001-01-01

    A chemical preconcentrator is disclosed with applications to chemical sensing and analysis. The preconcentrator can be formed by depositing a resistive heating element (e.g. platinum) over a membrane (e.g. silicon nitride) suspended above a substrate. A coating of a sorptive material (e.g. a microporous hydrophobic sol-gel coating or a polymer coating) is formed on the suspended membrane proximate to the heating element to selective sorb one or more chemical species of interest over a time period, thereby concentrating the chemical species in the sorptive material. Upon heating the sorptive material with the resistive heating element, the sorbed chemical species are released for detection and analysis in a relatively high concentration and over a relatively short time period. The sorptive material can be made to selectively sorb particular chemical species of interest while not substantially sorbing other chemical species not of interest. The present invention has applications for use in forming high-sensitivity, rapid-response miniaturized chemical analysis systems (e.g. a "chem lab on a chip").

  17. Chemical sensors

    DOEpatents

    Lowell, J.R. Jr.; Edlund, D.J.; Friesen, D.T.; Rayfield, G.W.

    1991-07-02

    Sensors responsive to small changes in the concentration of chemical species are disclosed. The sensors comprise a mechanochemically responsive polymeric film capable of expansion or contraction in response to a change in its chemical environment. They are operatively coupled to a transducer capable of directly converting the expansion or contraction to a measurable electrical response. 9 figures.

  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. [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

  20. Chemically synthesized lithium peroxide composite cathodes for closed system Li-O2 batteries.

    PubMed

    Bhargav, Amruth; Guo, Wei; Fu, Yongzhu

    2016-04-14

    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

  1. Physiological change in camel milk composition (Camelus dromedarius) 2: physico-chemical composition of colostrum.

    PubMed

    Konuspayeva, G; Faye, B; Loiseau, G; Narmuratova, M; Ivashchenko, A; Meldebekova, A; Davletov, S

    2010-03-01

    Eleven samples of dromedary camel colostrum in Kazakhstan, which originated from one farm only, were collected to study the changes in the physico-chemical composition (total fat, total protein, iodine index, lactose, calcium, phosphorus, iron, vitamin C, urea, ammonia, density, Dornic acidity, pH, and skimmed dry matter) all along the first postpartum week. At that time, the fat matter decreased from 25.9% to 3.1% and protein from 17.2% to 4.2%, in contrast to vitamin C which increased. Minerals showed high variations with lower values the first day after parturition and variable changes up to the end of the week where the values were stabilized. The iron concentration decreased from the second day postpartum. No clear changes of the other parameters were observed, notably for the non-protein nitrogen (urea and ammonia). PMID:19763867

  2. 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.

  3. 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.

  4. [Chemical degradation of 15 composites--an SEM study].

    PubMed

    Städtler, P; Pabst, M A

    1991-05-01

    SEM-micrographs of 15 untreated composites that were laid in 96% ethanol were investigated. The surface of untreated samples show different fissures and cracks. Under the influence of alcohol the fissures become wider, the bond between fillers and unfilled resin enlarges, and the filling particles become prominent or fall out. Fine-grained hybrid composites with an unfilled resin densely compacted with microfillers, are least prone to degradation. PMID:1882576

  5. 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.

  6. 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.

  7. 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...

  8. Chemical composition of the lunar surface in mare tranquillitatis.

    PubMed

    Turkevich, A L; Franzgrote, E J; Patterson, J H

    1969-07-18

    More precise and comprehensive analytical results have been derived for lunar material at the Surveyor V landing site from alpha-scattering data. The composition is, in general, basaltic; the low sodium and high titanium contents, however, are distinctly different from the abundances in meteorites or common terrestrial rocks. PMID:17814825

  9. Composition and chemical variability of Corsican Pinus halepensis cone oil.

    PubMed

    Nam, Anne-Marie; Casanova, Joseph; Tomi, Félix; Bighelli, Ange

    2014-09-01

    The composition of the essential oil isolated from cones of Pinus halepensis grown in Corsica has been investigated by a combination of chromatographic (CC, GC) and spectroscopic (MS, 13C NMR) techniques. In total, 48 compounds that accounted for 95.5% of the whole composition have been identified. α-Pinene (47.5%) was the major component followed by myrcene (11.0%), (E)-β-caryophyllene (8.3%) and caryophyllene oxide (5.9%). Various diterpenes have been identified by 13C NMR in the fractions of CC. Fifteen oil samples isolated from cones harvested in three forests have been analyzed and two groups of similar importance have been differentiated within the 15 compositions. Oil samples of the first group contained α-pinene (mean 45.0 g/100 g, SD = 5.5) as the major component. The composition of samples of the second group was dominated by myrcene (mean 30.3 g/100g, SD = 9.0) and α-pinene (mean 24.6 g/100 g, SD = 3.1). PMID:25918812

  10. The CBS spectra investigation as method of the PN chemical composition analysis

    NASA Astrophysics Data System (ADS)

    Shimanskaya, N. N.; Bikmaev, I. F.; Shimansky, V. V.; Sakhibullin, N. A.; Zhuchkov, R. Ya.; Shigapov, R. R.

    2007-10-01

    We report the results of the investigations of chemical composition of close binaries which had gone through the stage of common envelope and which are the remnants of planetary nebular cores. High resolution spectra for different phases of orbital period of V471 Tau were taken by RTT-150 telescope and were investigated by the modified SYNTH program. The spectra show noticeable variability with an appearance of emission components dependent of the orbital period phase. For chemical composition determination, the "solar" oscillator strengths of 700 lines were determined. It was found that the chemical content of V471 Tau is a composite one and is characterized by excess of α-process elements in the contrast to small underabundance of iron-peak elements. An estimation of different element abundances in the star allows to determine their contents in planetary nebular phase.

  11. The CBS Spectra Investigation as Method of the PN Chemical Composition Analysis

    NASA Astrophysics Data System (ADS)

    Shimanskaya, N. N.; Shimansky, V. V.; Bikmaev, I. F.; Sakhibullin, N. A.; Zhuchkov, R. Ya.

    We report the results of the investigations of chemical composition of close binaries which had gone through the stage of common envelope and which are the remnants of planetary nebular cores. High resolution spectra for different phases of orbital period of V471 Tau were taken by RTT-150 telescope and were investigated by the modified SYNTH-K program. It was found that the spectra show noticeable variability with appearance of emission components depended on the orbital period phase. For chemical composition determination the "solar" oscillator strengths for 700 lines were taken. It was found that the chemical content of V471 Tau is composite one and characterized by excess of ?-process elements in the contrast to small underabundance of iron-peak elements. The estimation of different elements excesses allows to determine their contents in planetary nebular phase.

  12. 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

  13. Unnecessary Chemicals

    ERIC Educational Resources Information Center

    Johnson, Anita

    1978-01-01

    Discusses the health hazards resulting from chemical additions of many common products such as cough syrups, food dyes, and cosmetics. Steps being taken to protect consumers from these health hazards are included. (MDR)

  14. Chemical pneumonitis

    MedlinePlus

    ... fertilizer dust Noxious fumes from pesticides Smoke (from house fires and wildfires) Chronic chemical pneumonitis can occur after only low levels of exposure to the irritant over a long time. This causes inflammation and may lead to ...

  15. Chemical Emergencies

    MedlinePlus

    ... be unintentional, as in the case of an industrial accident. They could also be planned, as in ... and VX. Many hazardous chemicals are used in industry - for example, chlorine, ammonia, and benzene. Some can ...

  16. Chemical Peels

    MedlinePlus

    ... under the eyes and around the mouth). Freckles. Melasma. Rough-feeling skin. Sun-damage skin. Insurance coverage: Chemical peels are considered a cosmetic treatment. Insurance does not cover the cost of cosmetic ...

  17. 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.

  18. 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).

  19. A statistical approach for characterizing chemical durability within a waste glass compositional region

    SciTech Connect

    Piepel, G.F.; Mellinger, G.B.; Reimus, M.A.H.

    1989-01-01

    In order to qualify nuclear waste forms for disposal in geological repositories, waste glass producers must adequately describe the properties of the glass. One of the most important of these properties is chemical durability (resistance to leaching). An approach for characterizing the chemical durability of a producer's waste glass form must take into account that the composition of the glass will vary during production. Thus, leach testing performed as part of the characterization effort must investigate the range of glasses that are likely to be produced. Also, the approach must account for the fact that only a limited number of compositional variations can be tested and that the leach test results will be subject to uncertainty. A statistical approach that satisfies these goals is presented. The statistical approach for characterizing the chemical durability of waste glasses in a specified compositional region involves the following steps: defining the compositional region of anticipated production glasses, selecting a test matrix of compositions via computer-aided experimental design techniques, leach testing, empirical modeling of the leach test results, investigating glass component effects, and using statistical confidence statements to describe chemical durability over the compositional region. These steps are illustrated using the results of work performed at Pacific Northwest Laboratory for West Valley Nuclear Services.

  20. Chemical sensors

    DOEpatents

    Lowell, Jr., James R.; Edlund, David J.; Friesen, Dwayne T.; Rayfield, George W.

    1992-01-01

    Sensors responsive to small changes in the concentration of chemical species are disclosed, comprising a mechanicochemically responsive polymeric film capable of expansion or contraction in response to a change in its chemical environment, either operatively coupled to a transducer capable of directly converting the expansion or contraction to a measurable electrical or optical response, or adhered to a second inert polymeric strip, or doped with a conductive material.

  1. Chemical sensors

    DOEpatents

    Lowell, J.R. Jr.; Edlund, D.J.; Friesen, D.T.; Rayfield, G.W.

    1992-06-09

    Sensors responsive to small changes in the concentration of chemical species are disclosed, comprising a mechanicochemically responsive polymeric film capable of expansion or contraction in response to a change in its chemical environment, either operatively coupled to a transducer capable of directly converting the expansion or contraction to a measurable electrical or optical response, or adhered to a second inert polymeric strip, or doped with a conductive material. 12 figs.

  2. 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.

  3. 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

  4. Poplar-type Propolis: Chemical Composition, Botanical Origin and Biological Activity.

    PubMed

    Ristivojević, Petar; Trifković, Jelena; Andrić, Filip; Milojković-Opsenica, Dusanka

    2015-11-01

    Propolis is one of the most used natural products known for centuries for its beneficial effects. Due to significant differences in chemical composition of samples originating from different geographic and climatic zones it is crucial to characterize reliably each type of propolis. This article comprises the latest findings concerning the poplar type propolis, i.e. it gives a cross section of chemical composition, botanical origin and biological activity of poplar type propolis in order to encourage further investigations that would indicate its beneficial effects. PMID:26749815

  5. Chemical composition of the essential oil of Stachys menthifolia Vis.

    PubMed

    ?avar, Sanja; Maksimovi?, Milka; Vidic, Danijela; oli?, Marija Edita

    2010-02-01

    Stachys menthifolia Vis. (Lamiaceae) is an endemic species from the Balkan Peninsula spread throughout Albania, Greece, Montenegro, and Croatia. This article presents the first investigation of the essential oil composition of this species from Croatia. Aerial parts of the plant were collected from three different natural habitats in the region of Biokovo Mountain. The studied populations showed similarity in qualitative, but not in quantitative, composition of their essential oils. Hydrodistilled volatile oil obtained from the plant material of S. menthifolia was subjected to gas chromatographic analysis coupled to mass spectrometry. More than 100 compounds were identified in the three samples, representing 86.8-90.8% of the total oil. The terpene profile of S. menthifolia is characterized by a high content of oxygenated sesquiterpenes (48.4-58.9%) and diterpene hydrocarbons (3.5-25.2%), with 8-alpha-acetoxyelemol (6.9-21.3%), abietatriene (3.5-21.1%), and 4'-methoxyacetophenone (4.5-17.0%) as the main constituents. PMID:20645835

  6. 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

  7. 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

  8. 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.

  9. 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, cerium oxide nanoparticles were chemically modified using a process known as doping, to alter their valence state. The size and shape of the cerium oxide nanoparticles remained constant. Overall, results indicated that cerium oxide was not toxic in both RLE-6TN and NR8383 pulmonary rat cells, however, chemically modifying the valence state of the nanomaterial did affect the antioxidant potential. To determine if this trend was measureable in vivo, rats were exposed to various cerium oxide nanoparticles via intratracheal instillation and damage, changes in pulmonary cell differentials, and phagocytic cell activity were assessed. Results implicate that chemically modifying the nanoparticles had an effect on the overall damage induced by the material but did not dramatically affect inflammatory potential or phagocytic cell activity. Overall the data from these studies imply that size, shape, chemical composition, and valence state of nanomaterials can be manipulated to alter their toxicity.

  10. Using high-pressure gel permeation chromatography to evaluate the chemical composition of blended asphalts

    SciTech Connect

    Garrick, N.W.

    1986-01-01

    One recent innovation in the asphalt industry is the production of asphalts from the products of residuum oil super critical extraction (ROSE) systems. The main purpose of this project was to evaluate such blended ROSE asphalts in order to determine the effects of chemical composition on asphalt properties, and to determine if blended asphalts are significantly different from asphalts produced by more traditional methods. An additional objective was to investigate a new procedure for characterizing the chemical composition of asphalts. High pressure-gel permeation chromatography (HP-GPC) was selected for this purpose. Products from two different ROSE plants were blended in the laboratory to produce asphalts of different composition. The physical properties of these asphalts and of commercial asphalts were then determined. In addition, tests were conducted on asphalt concrete mixes of these asphalts. High pressure-gel permeation chromatography was used to characterize the chemical composition of the asphalts. It was determined that chemical composition has a significant effect on the properties of asphalt and of asphalt concrete mixes. However, the results of this study do not support and content that blended, ROSE asphalts are different in any essential manner from asphalts produced by more traditional methods. The results also show that high pressure-gel permeation chromatography is suitable for use in characterizing asphalts. Good correlations were established between HP-GPC parameters and various physical properties of asphalts and of asphalt concrete mixes for the asphalts used in this study.

  11. Chemical Composition of Rocks and Soils at Gale Crater, Mars

    NASA Astrophysics Data System (ADS)

    Wiens, R. C.; Gellert, R.; Maurice, S.

    2012-12-01

    Gale crater was selected as the landing site for the Mars Science Laboratory rover for its 5 km tall sedimentary mound, which includes phyllosilicate-containing layers near its base. Gale (5.4°S 137.8°E) is located near the north-south dichotomy and is one of the deepest craters in the region (lowest elevation is -4674 m). The lower part of the crater, near the landing ellipse, features an alluvial fan descending from the rim and overlying a region of high thermal inertia which appears to be layered. In addition to the fan, inverted channels indicate that water flowed in this region prior to some deflation. Nearer to the mound lies a dune field, and water-carved canyons descend from the mound. The Curiosity rover is equipped with several instruments with broad elemental composition capabilities to investigate along the traverse the expected variations in rock and soil types representing different kinds of environments in early Martian history. The remote sensing instrument, ChemCam, determines semi-quantitative elemental compositions using laser induced breakdown spectroscopy (LIBS) to a distance of up to 7 m with an analysis footprint ≤ 0.5 mm in diameter, and also providing context images with better than 100 microradian resolution. ChemCam is capable of rapidly analyzing nearly all elements including light elements H through O, although atmospheric species can interfere with C and N observations. Using multiple laser pulses per analysis location allows dust to be removed from the analysis locations remotely, and facilitates depth profiles up to 1 mm in rocks and deeper in soils. For tactical operations, in addition to overall reconnaissance, ChemCam analyses will aid in determining placement for arm and sampling operations. Linescans and rasters provide information on sample heterogeneity, and facilitate rapid analysis of layered rock exposures. The arm-mounted APXS is an improved version of its predecessors on MER. The sensitivity is increased by a factor of ~ 3, allowing a rapid analysis in 15 minutes and a full analysis with low detection limits in 3 hours. About 20 elements from Na to Y are determined for typical Martian materials. Bound water or light elements in excess of ~ 5 wt% can be inferred by the scatter peaks of the primary x-ray radiation. Good quality spectra can be taken at temperatures of up to -10 degrees C using the built-in Peltier cooler. The APXS has a high accuracy, only limited by microscopic heterogeneity, and an unprecedented precision to identify elemental trends and local anomalies. The ~ 1.7 cm sample diameter is close to the drill diameter, producing bulk analysis to support powder analysis with SAM and Chemin. APXS sample preparation utilizes the dust removal tool, and analyses are also performed on the drill fines. The complementary analyses from ChemCam and APXS allow efficient selection of the most promising samples for extensive analysis with Chemin and SAM and provide a comparison of the unprocessed sample with the processed powder for these instruments. Both will be used to perform chemostratigraphy studies at Gale to understand Mars' climate and geological history. The talk will report the first Curiosity rover results on the compositions of rocks and soils at Gale crater.

  12. 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

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

    PubMed

    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

  14. Chemical compositions and kinematics of the Hercules stream

    NASA Astrophysics Data System (ADS)

    Ramya, P.; Reddy, Bacham E.; Lambert, David L.; Musthafa, M. M.

    2016-04-01

    An abundance analysis is reported of 58 K giants identified by Famaey et al. (2005) 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 biassed the selection from the Hipparcos catalogue against the selection of metal-poor stars. Our reconsideration of the recent extensive survey of FG dwarfs which included metal-poor stars (Bensby et al. 2014) 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. Suggestions in the literature that the stream includes metal-poor stars from the thick disc are discussed.

  15. 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

  16. 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

  17. 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

  18. Chemical composition and properties of soybean beta-amylase.

    PubMed

    Morita, Y; Yagi, F; Aibara, S; Yamashita, H

    1976-03-01

    The molecular weight of soybean beta-amylase [EC 3.2.1.2] was determined to be 57,000 daltons by the sedimentation equilibrium method, and the enzyme was found to consist of 494 amino acid residues. No difference was found in molecular weight or composition between two components of beta-amylase separated by ion-exchange chromatography. The N-terminus of the enzyme was not detectable by the fluorodinitrobenzene method or phenylisothiocyanate method, and the C-terminus was determined to be alanine by the carboxypeptidase [EC 3.4.12.2] method. Five half-cystine residues were found in the form of cysteine; all the sulfhydryl groups could be titrated by p-chloromercuribenzoate after denaturation of the enzyme with guanidine hydrochloride, but only some in the native enzyme. The rates of mercaptide formation of these groups were dependent on pH and were different from each other, all being much lower than the rate for the free sulfhydryl group in mercaptoethanol. Differential titration experiments at different pH's and in the presence of maltose showed that mercaptide formation by only one sulfhydryl group caused loss of activity, and the reaction was accompanied by changes in the environment around aromatic side chains in the enzyme, which were detected by difference spectra and fluorescence emission spectra. These facts suggest that modification of the sulfhydryl groups causes a conformational change of the enzyme. Some preliminary crystallographic data for crystals formed at pH 4.0 were obtained, and inactivation by heavy metal salts was examined in relation to the preparation of isomorphous heavy atom derivatives. PMID:985814

  19. Chemical sensors

    SciTech Connect

    Hubbard, C.W.; Gordon, R.L.

    1987-05-01

    The revolution in analytical chemistry promised by recent developments in the field of chemical sensors has potential for significant positive impact on both research and production activities conducted by and for the Department of Energy. Analyses which were, in the past, performed only with a roomful of expensive equipment can now be performed with miniature solid-state electronic devices or small optical probes. Progress in the development of chemical sensors has been rapid, and the field is currently growing at a great rate. In accordance, Pacific Northwest Laboratory initiated a survey of recent literature so that contributors to active programs in research on analytical methods could be made aware of principles and applications of this new technology. This report presents the results of that survey. The sensors discussed here are divided into three types: micro solid-state devices, optical sensors, and piezoelectric crystal devices. The report is divided into three corresponding sections. The first section, ''Micro Solid-State Devices,'' discusses the design, operation, and application of electronic sensors that are produced in much the same way as standard solid-state electronic devices. The second section, ''Optrodes,'' covers the design and operation of chemical sensors that use fiber optics to detect chemically induced changes in optical properties. The final section, ''Piezoelectric Crystal Detectors,'' discusses two types of chemical sensors that depend on the changes in the properties of an oscillating piezoelectric crystal to detect the presence of certain materials. Advantages and disadvantages of each type of sensor are summarized in each section.

  20. Chemical composition and antioxidant activity of certain Morus species

    PubMed Central

    Imran, Mohammad; Khan, Hamayun; Shah, Mohibullah; Khan, Rasool; Khan, Faridullah

    2010-01-01

    In the present work, the fruits of four Morus species, namely Morus alba (white mulberry), Morus nigra (black mulberry), Morus laevigata (large white fruit), and Morus laevigata (large black fruit), were analyzed for proximate composition, essential minerals, and antioxidant potentials. For this purpose, the ripe fruits were collected from the northern regions of Pakistan. The major nutritional components (moisture, ash, lipids, proteins, fibres, carbohydrates, and total sugar) were found to be in the suitable range along with good computed energy. Total dry weight, pH, and titratable acidity (percent citric acid) were (17.60±1.94)–(21.97±2.34) mg/100 g, (3.20±0.07)–(4.78±0.15), and (0.84±0.40)%–(2.00±0.08)%, respectively. Low riboflavin (vitamin B2) and niacin (vitamin B3) contents were recorded in all the fruits, while ascorbic acid (vitamin C) was in the range from (15.20±1.25) to (17.03±1.71) mg/100 g fresh weight (FW). The mulberry fruits were rich with regard to the total phenol and alkaloid contents, having values of (880±7.20)–(1650±12.25) mg/100 g FW and (390±.22)–(660±5.25) mg/100 g FW, respectively. Sufficient quantities of essential macro-(K, Ca, Mg, and Na) and micro-(Fe, Zn, and Ni) elements were found in all the fruits. K was the predominant element with concentration ranging from (1270±9.36) to (1731±11.50) mg/100 g, while Ca, Na, and Mg contents were (440±3.21)–(576±7.37), (260±3.86)–(280±3.50), and (24±3.51)–(360±4.20) mg/100 g, respectivly. The decreasing order of micro-minerals was Fe>Zn>Ni. The radical scavenging activity of methanolic extract of fruits was concentration-dependent and showed a correlation with total phenolic constituents of the respective fruits. Based on the results obtained, mulberry fruits were found to serve as a potential source of food diet and natural antioxidants. PMID:21121077

  1. 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.

  2. Generation rates and chemical compositions of waste streams in a typical crewed space habitat

    NASA Technical Reports Server (NTRS)

    Wydeven, Theodore; Golub, Morton A.

    1990-01-01

    A judicious compilation of generation rates and chemical compositions of potential waste feed streams in a typical crewed space habitat was made in connection with the waste-management aspect of NASA's Physical/Chemical Closed-Loop Life Support Program. Waste composition definitions are needed for the design of waste-processing technologies involved in closing major life support functions in future long-duration human space missions. Tables of data for the constituents and chemical formulas of the following waste streams are presented and discussed: human urine, feces, hygiene (laundry and shower) water, cleansing agents, trash, humidity condensate, dried sweat, and trace contaminants. Tables of data on dust generation and pH values of the different waste streams are also presented and discussed.

  3. 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

  4. Chemical networks

    NASA Astrophysics Data System (ADS)

    Thi, Wing-Fai

    2015-09-01

    This chapter discusses the fundamental ideas of how chemical networks are build, their strengths and limitations. The chemical reactions that occur in disks combine the cold phase reactions used to model cold molecular clouds with the hot chemistry applied to planetary atmosphere models. With a general understanding of the different types of reactions that can occur, one can proceed in building a network of chemical reactions and use it to explain the abundance of species seen in disks. One on-going research subject is finding new paths to synthesize species either in the gas-phase or on grain surfaces. Specific formation routes for water or carbon monoxide are discussed in more details. 13th Lecture of the Summer School "Protoplanetary Disks: Theory and Modelling Meet Observations"

  5. 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

  6. Wood chemical composition in species of Cactaceae: the relationship between lignification and stem morphology.

    PubMed

    Reyes-Rivera, Jorge; Canché-Escamilla, Gonzalo; Soto-Hernández, Marcos; Terrazas, Teresa

    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

  7. 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

  8. A snapshot in the effect of time of day on herbage toughness and chemical composition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Herbage chemical composition varies diurnally; however, it is not known if this variation affects herbage biomechanical properties. The objective of this study was to evaluate potential changes in herbage toughness and particle size reduction index (PSR) in relation to diurnal fluctuations of herbag...

  9. 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.

  10. Prediction of chemical contaminants and food compositions by near infrared spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prediction of Food Adulteration by Infrared Spectroscopy H. Zhuang Quality and Safety Assessment Research Unit, ARS-USDA, 950 College Station Road, Athens, GA 30605 Food adulteration, including both chemical contamination and composition alternation, has been one of major quality and/or safety c...

  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 ?g/m(3)), secondary inorganic aerosol (11.1 5.0 ?g/m(3)), and mineral dust (11.1 7.9 ?g/m(3)). Secondary inorganic PM2.5 concentrations exceeded 30 ?g/m(3) over East China. Sensitivity simulations suggested that population-weighted ambient PM2.5 from biofuel burning (11 ?g/m(3)) could be almost as large as from fossil fuel combustion sources (17 ?g/m(3)). These estimates offer information about global population exposure to the chemical components and sources of PM2.5. PMID:25343705

  12. Spectroscopic characterization of the chemical composition of the potent sweetener Vartamil

    NASA Astrophysics Data System (ADS)

    Kolosova, T. E.; Prokhodchenko, L. K.; Pilipenko, V. V.; Suboch, V. P.

    2008-03-01

    The chemical composition of the potent sweetener Vartamil was characterized using spectral methods. It was demonstrated that Vartamil is a mixture of saccharose chloro derivatives, the main one of which is 4,1',6'-trichloro-4,1',6'-trideoxygalactosaccharose (Sucralose).

  13. Determination of the chemical composition of human renal stones with MDCT: influence of the surrounding media

    NASA Astrophysics Data System (ADS)

    Grosjean, Romain; Sauer, Benoît; Guerra, Rui; Kermarrec, Isabelle; Ponvianne, Yannick; Winninger, Daniel; Daudon, Michel; Blum, Alain; Felblinger, Jacques; Hubert, Jacques

    2007-03-01

    The selection of the optimal treatment method for urinary stones diseases depends on the chemical composition of the stone and its corresponding fragility. MDCT has become the most used modality to determine rapidly and accurately the presence of stones when evaluating urinary lithiasis treatment. That is why several studies have tempted to determine the chemical composition of the stones based on the stone X-ray attenuation in-vitro and invivo. However, in-vitro studies did not reproduce the normal abdominal wall and fat, making uncertain the standardization of the obtained values. The aim of this study is to obtain X-ray attenuation values (in Hounsfield Units) of the six more frequent types of human renal stones (n=217) and to analyze the influence of the surrounding media on these values. The stones were first placed in a jelly, which X-ray attenuation is similar to that of the human kidney (30 HU at 120 kV). They were then stuck on a grid, scanned in a water tank and finally scanned in the air. Significant differences in CT-attenuation values were obtained with the three different surrounding media (jelly, water, air). Furthermore there was an influence of the surrounding media and consequently discrepancies in determination of the chemical composition of the renal stones. Consequently, CT-attenuation values found in in-vitro studies cannot really be considered as a reference for the determination of the chemical composition except if the used phantom is an anthropomorphic one.

  14. Numerical simulation of the middle atmosphere chemical composition and temperature under changing solar conditions

    NASA Technical Reports Server (NTRS)

    Zadorozhny, A. M.; Dyominov, I. G.; Tuchkov, G. A.

    1989-01-01

    There are given results of the numerical experiments on modelling the influence of solar activity on chemical composition and temperature of the middle atmosphere. The consideration is made for peculiarities of solar activity impact under different values of antropogenic pollution of the atmosphere with chlorofluorocarbons and other stuff.

  15. 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...

  16. Discerning the Chemical Composition and Mutagenic Effects of Soy Biodiesel PM

    EPA Science Inventory

    Discerning the Chemical Composition and Mutagenic Effects of Soy Biodiesel PM David G. Nashab, Esra Mutluc, William T. Prestond, Michael D. Haysb, Sarah H. Warrenc, Charly Kingc, William P. Linakb, M. lan Gilmourc, and David M. DeMarinic aOak Ridge Institute for Science and Ed...

  17. 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

  18. 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

  19. 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...

  20. Atmospheric aerosols: A literature summary of their physical characteristics and chemical composition

    NASA Technical Reports Server (NTRS)

    Harris, F. S., Jr.

    1976-01-01

    This report contains a summary of 199 recent references on the characterization of atmospheric aerosols with respect to their composition, sources, size distribution, and time changes, and with particular reference to the chemical elements measured by modern techniques, especially activation analysis.

  1. 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)...

  2. 40 CFR 761.292 - Chemical extraction and analysis of individual samples and composite samples.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Chemical extraction and analysis of individual samples and composite samples. 761.292 Section 761.292 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT POLYCHLORINATED BIPHENYLS (PCBs)...

  3. 40 CFR 761.292 - Chemical extraction and analysis of individual samples and composite samples.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Chemical extraction and analysis of individual samples and composite samples. 761.292 Section 761.292 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT POLYCHLORINATED BIPHENYLS (PCBs)...

  4. 40 CFR 761.292 - Chemical extraction and analysis of individual samples and composite samples.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Chemical extraction and analysis of individual samples and composite samples. 761.292 Section 761.292 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT POLYCHLORINATED BIPHENYLS (PCBs)...

  5. Chemical lasers

    NASA Astrophysics Data System (ADS)

    Ablekov, V. K.; Denisov, Iu. N.; Proshkin, V. V.

    1983-08-01

    Recent developments in the theory and application of chemical lasers (CLs) are surveyed in a translation of a book published in Russian in 1980. The laws governing the gas-phase chemical reactions typical of CLs are introduced, the principles of quantum-mechanical description of molecular systems are reviewed, and the kinetics of CL processes are examined. The four general classes of CL are then presented in detail: static-gas, subsonic, supersonic, and detonation CLs. Graphs, diagrams, and drawings of experimental setups are provided.

  6. Chemical releases

    NASA Technical Reports Server (NTRS)

    Heppner, J. P.; Evans, D. S.

    1978-01-01

    A Chemical Release Module to be carried into orbit by the shuttle is described. The module would release chemicals from orbiting satellites in order understand processes within the Earth's magnetosphere, atmosphere and ionosphere. A large number of potential experiments are identified, ranging from introducing traceable material into the solar wind in order to study its transport to and within the magnetosphere, to injecting material into the outer magnetosphere to simulate the precipitation of trapped charged particles, to the release of material at lower altitudes to create waves both mechanical and electromagnetic.

  7. Using Chemical Compositions of Kinematically Selected Stars to Trace Galactic Mergers

    NASA Astrophysics Data System (ADS)

    Gregersen, Dylan

    2011-10-01

    The chemical characteristic of low alpha element abundances distinguishes a few rare stars from their place among the halo population of our Milky Way. Encouraging the search for these stars, the unusual chemical nature is thought to distinguish them as remnants of a now merged extragalactic system. Until now, these stars have only been found serendipitously, on the order of a few in a thousand. In this talk, we report stars with low enhancements of alpha elements found within two kinematically distinct candidate moving clusters. Stars within these candidate moving clusters were distinguished from common halo stars by shared stellar characteristics: orbital energy, angular momentum, and overall chemical enrichment (Allen et al, 2007, Proc. IAU, 2: 405-413). We collected high-resolution spectra of these stars and employed multi-line analysis code with stellar models to determine their chemical compositions. This current research is part of a larger chemical composition investigation of these and other stars to search for other low alpha star tracers of the dynamic formation of our Galaxy.

  8. Investigation of the chemical composition-antibacterial activity relationship of essential oils by chemometric methods.

    PubMed

    Miladinović, Dragoljub L; Ilić, Budimir S; Mihajilov-Krstev, Tatjana M; Nikolić, Nikola D; Miladinović, Ljiljana C; Cvetković, Olga G

    2012-05-01

    The antibacterial effects of Thymus vulgaris (Lamiaceae), Lavandula angustifolia (Lamiaceae), and Calamintha nepeta (Lamiaceae) Savi subsp. nepeta var. subisodonda (Borb.) Hayek essential oils on five different bacteria were estimated. Laboratory control strain and clinical isolates from different pathogenic media were researched by broth microdilution method, with an emphasis on a chemical composition-antibacterial activity relationship. The main constituents of thyme oil were thymol (59.95%) and p-cymene (18.34%). Linalool acetate (38.23%) and β-linalool (35.01%) were main compounds in lavender oil. C. nepeta essential oil was characterized by a high percentage of piperitone oxide (59.07%) and limonene (9.05%). Essential oils have been found to have antimicrobial activity against all tested microorganisms. Classification and comparison of essential oils on the basis of their chemical composition and antibacterial activity were made by utilization of appropriate chemometric methods. The chemical principal component analysis (PCA) and hierachical cluster analysis (HCA) separated essential oils into two groups and two sub-groups. Thyme essential oil forms separate chemical HCA group and exhibits highest antibacterial activity, similar to tetracycline. Essential oils of lavender and C. nepeta in the same chemical HCA group were classified in different groups, within antibacterial PCA and HCA analyses. Lavender oil exhibits higher antibacterial ability in comparison with C. nepeta essential oil, probably based on the concept of synergistic activity of essential oil components. PMID:22389175

  9. Response of the global climate to changes in atmospheric chemical composition due to fossil fuel burning

    NASA Technical Reports Server (NTRS)

    Hameed, S.; Cess, R. D.; Hogan, J. S.

    1980-01-01

    Recent modeling of atmospheric chemical processes (Logan et al, 1978; Hameed et al, 1979) suggests that tropospheric ozone and methane might significantly increase in the future as the result of increasing anthropogenic emissions of CO, NO(x), and CH4 due to fossil fuel burning. Since O3 and CH4 are both greenhouse gases, increases in their concentrations could augment global warming due to larger future amounts of atmospheric CO2. To test the possible climatic impact of changes in tropospheric chemical composition, a zonal energy-balance climate model has been combined with a vertically averaged tropospheric chemical model. The latter model includes all relevant chemical reactions which affect species derived from H2O, O2, CH4, and NO(x). The climate model correspondingly incorporates changes in the infrared heating of the surface-troposphere system resulting from chemically induced changes in tropospheric ozone and methane. This coupled climate-chemical model indicates that global climate is sensitive to changes in emissions of CO, NO(x) and CH4, and that future increases in these emissions could augment global warming due to increasing atmospheric CO2.

  10. Response of the global climate to changes in atmospheric chemical composition due to fossil fuel burning

    NASA Astrophysics Data System (ADS)

    Hameed, Sultan; Cess, Robert D.; Hogan, Joseph S.

    1980-12-01

    Recent modeling of atmospheric chemical processes (Logan et al., 1978; Hameed et al., 1979) suggests that tropospheric ozone and methane might significantly increase in the future as the result of increasing anthropogenic emissions of CO, NOx, and CH4 due to fossil fuel burning. Since O3 and CH4 are both greenhouse gases, increases in their concentrations could augment global warming due to larger future amounts of atmospheric CO2. To test the possible climatic impact of changes in tropospheric chemical composition, a zonal energy-balance climate model has been combined with a vertically averaged tropospheric chemical model. The latter model includes all relevant chemical reactions which affect species derived from H2O, O2, CH4, and NOx. The climate model correspondingly incorporates changes in the infrared heating of the surface-troposphere system resulting from chemically induced changes in tropospheric ozone and methane. This coupled climate-chemical model indicates that global climate is sensitive to changes in emissions of CO, NOx, and CH4, and that future increases in these emissions could augment global warming due to increasing atmospheric CO2.

  11. Chemical Mahjong

    ERIC Educational Resources Information Center

    Cossairt, Travis J.; Grubbs, W. Tandy

    2011-01-01

    An open-access, Web-based mnemonic game is described whereby introductory chemistry knowledge is tested using mahjong solitaire game play. Several tile sets and board layouts are included that are themed upon different chemical topics. Introductory tile sets can be selected that prompt the player to match element names to symbols and metric

  12. Chemical Indicators.

    ERIC Educational Resources Information Center

    Prombain, Dorothy R.; And Others

    This science sourcebook was written for intermediate grade teachers to provide guidance in teaching a specially developed unit on chemical indicators. Directions and suggestions for guiding student science activities are given. Some of the activities concern soil testing, crystals, and household powders such as sugar and salt. A list of necessary…

  13. Chemical Mahjong

    ERIC Educational Resources Information Center

    Cossairt, Travis J.; Grubbs, W. Tandy

    2011-01-01

    An open-access, Web-based mnemonic game is described whereby introductory chemistry knowledge is tested using mahjong solitaire game play. Several tile sets and board layouts are included that are themed upon different chemical topics. Introductory tile sets can be selected that prompt the player to match element names to symbols and metric…

  14. Delicious Chemicals.

    ERIC Educational Resources Information Center

    Barry, Dana M.

    This paper presents an approach to chemistry and nutrition that focuses on food items that people consider delicious. Information is organized according to three categories of food chemicals that provide energy to the human body: (1) fats and oils; (2) carbohydrates; and (3) proteins. Minerals, vitamins, and additives are also discussed along with…

  15. Chemical compositions and classifica tion of five thermally altered carbonaceous chondrites

    NASA Astrophysics Data System (ADS)

    Noronha, Bianca A.; Friedrich, Jon M.

    2014-08-01

    To establish the chemical group provenance of the five thermally altered carbonaceous chondrites Asuka (A-) 881551, Asuka-882113, Elephant Moraine (EET) 96026, Mulga (west), and Northwest Africa (NWA) 3133, we quantified 44 trace elements in each of them. We also analyzed Larkman Nunatak (LAR) 04318 (CK4), Miller Range (MIL) 090001 (CR2), Roberts Massif (RBT) 03522 (CK5) as reference samples as their chemical group affinity is already recognized. We conclude that Asuka-881551, Asuka-882113, and Mulga (west) are thermally metamorphosed CK chondrites. Compositionally, Elephant Moraine 96026 most resembles the CV chondrites. NWA 3133 is the most significantly thermally altered carbonaceous chondrite in our suite of samples. It is completely recrystallized (no chondrules or matrix remain), but its bulk composition is consistent with a CV-CK clan provenance. The thermally labile element (e.g., Se, Te, Zn, and Bi) depletion in NWA 3133 indicates a chemically open system during the heating episode. It remains unclear if the heat necessary for its thermal alteration of NWA 3133 was due to the decay of 26Al or was impact related. Finally, we infer that MIL 090001, Mulga (west), and NWA 3133 show occasional compositional signatures indicative of terrestrial alteration. The alteration is especially evident within the elements Sr, Ba, La, Ce, Th, U, and possibly Sb. Despite the alteration, we can still confidently place each of the altered chondrites within an established chemical group or clan.

  16. Chemical Composition of Martian Soil and Rocks: Complex Mixing and Sedimentary Transport

    NASA Technical Reports Server (NTRS)

    McLennan, Scott M.

    2000-01-01

    Chemical compositions of Martian soil and rocks indicate complex mixing relationships. Mixing of rock and soil clearly takes place and explains some of the chemical variation because sulfur, chlorine, magnesium, and perhaps iron are positively correlated due to their control from a secondary 'sedimentary' mineralogy (e.g., Mg- and possibly Fe-sulfate; Fe-oxides) that is present within the soils. Certain deviations from simple soil-rock mixing are consistent with mineralogical fractionation of detrital iron and titanium oxides during sedimentary transport.

  17. Chemical Composition and Dynamics of the Upper Troposphere and the Lower Stratosphere: Overview of the Project

    NASA Astrophysics Data System (ADS)

    Sofieva, V. F.; Liu, C.; Huang, F.; Kyrola, E.; Liu, E.; Ialongo, I.; Zhang, Y.; Tiinanen, T.

    2014-11-01

    The DRAGON-3 cooperation study on the upper troposphere and the lower stratosphere (UTLS) is based on new satellite data and modern atmospheric models. The objectives of the project are: (i) assessment of sat-ellite data on chemical composition in UTLS, (ii) dy-namical and chemical structures of the UTLS and its variability, (iii) multi-scale variability of stratospheric ozone, (iv) climatology of the stratospheric aerosol layer and its variability, and (v) updated ozone climatology and its relation to tropopause/multiple tropopauses. In this paper, we present the main results of the project.

  18. Separating topographical and chemical analysis of nanostructure of polymer composite in low voltage SEM

    NASA Astrophysics Data System (ADS)

    Wan, Q.; Plenderleith, R. A.; Dapor, M.; Rimmer, S.; Claeyssens, F.; Rodenburg, C.

    2015-10-01

    The possibility of separating the topographical and chemical information in a polymer nano-composite using low-voltage SEM imaging is demonstrated, when images are acquired with a Concentric Backscattered (CBS) detector. This separation of chemical and topographical information is based on the different angular distribution of electron scattering which were calculated using a Monte Carlo simulation. The simulation based on angular restricted detection was applied to a semi-branched PNIPAM/PEGDA interpenetration network for which a linear relationship of topography SEM contrast and feature height data was observed.

  19. Simulating the evolution of the chemical composition of the 1988/89 winter vortex

    NASA Technical Reports Server (NTRS)

    Jones, R. L.; Mckenna, D. S.; Poole, L. R.; Solomon, S.

    1990-01-01

    During the 1988/89 Airborne Arctic Stratospheric Expedition (AASE) observations of the chemical composition and aerosol characteristics of the winter vortex were obtained from a NASA ER-2 aircraft. In this paper we present interpretations of observations obtained on three ER-2 flights using a Lagrangian coupled photochemical-microphysical model. It is argued that observations obtained on Jaunary 16 and 19, and February 10, represent different stages of the chemical evolution of the vortex, from the early stages of chlorine release, the onset of denitrification and the intensively processed state.

  20. 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

  1. [Study on the chemical compositions of VOCs emitted by cooking oils based on GC-MS].

    PubMed

    He, Wan-Qing; Nie, Lei; Tian, Gang; Li, Jing; Shao, Xia; Wang, Min-Yan

    2013-12-01

    Volatile organic compounds (VOCs) are key precursors of ozone and secondary organic aerosols in air, and the differences in the compositions of VOCs lead to their different contribution to atmospheric reaction. Cooking oil fume is one of the important sources of atmospheric VOCs, and its chemical compositions are distinct under different conditions of oil types, food types, cooking methods and heating temperatures etc. In this study, the production of cooking oil fume was simulated by heating typical pure vegetable oils (peanut oil, sunflower oil, soybean oil, olive oil and blend oil) at different temperatures in beakers to investigate the chemical compositions of VOCs. The emitted VOCs were sampled with a Tenax adsorption tube and analyzed using GC-MS after thermal desorption. According to spectral library search and map analysis, using area normalized semi-quantitative method, preliminary qualitative and quantitative tests were conducted for the specific components of VOCs under different conditions. PMID:24640897

  2. 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

  3. 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

  4. Multivariate Quantitative Chemical Analysis

    NASA Technical Reports Server (NTRS)

    Kinchen, David G.; Capezza, Mary

    1995-01-01

    Technique of multivariate quantitative chemical analysis devised for use in determining relative proportions of two components mixed and sprayed together onto object to form thermally insulating foam. Potentially adaptable to other materials, especially in process-monitoring applications in which necessary to know and control critical properties of products via quantitative chemical analyses of products. In addition to chemical composition, also used to determine such physical properties as densities and strengths.

  5. 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 silicate structure yielding information about network-forming structural units (Qn species, where n indicates the number of bridging oxygen), we combined the deconvoluted Raman spectra, in the rhyolitic field, with the chemical analyses and abundance of Qn species. This demonstrate how the evolution of silicate structure might control the bimodal eruptive style (explosive vs effusive) as shown by silica-rich volcanic systems. References: D. Morgavi et al., 2013. Morphochemistry of patterns produced by mixing of rhyolitic and basaltic melts. JVGR, 253, 87-96. D. R. Neuville, et al. 2014. Advances in Raman Spectroscopy Applied to Earth and Material Sciences. Rev. Min. Geochem., 78, 509-541.

  6. 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.

  7. Laboratory Inquiry for Determining the Chemical Composition of a Component in a Daily Use Detergent: Sodium Sesquicarbonate

    ERIC Educational Resources Information Center

    Koga, Nobuyoshi; Kimura, Tomoyasu; Shigedomi, Kana

    2011-01-01

    An inquiry-based laboratory activity to determine the chemical composition of a component in alkaline detergents, sodium sesquicarbonate (SSC), is proposed. On the basis of introductory demonstrations by the instructor on the chemical properties and reactions of SSC, students propose the hypothetical composition of SSC and possible quantitative

  8. Laboratory Inquiry for Determining the Chemical Composition of a Component in a Daily Use Detergent: Sodium Sesquicarbonate

    ERIC Educational Resources Information Center

    Koga, Nobuyoshi; Kimura, Tomoyasu; Shigedomi, Kana

    2011-01-01

    An inquiry-based laboratory activity to determine the chemical composition of a component in alkaline detergents, sodium sesquicarbonate (SSC), is proposed. On the basis of introductory demonstrations by the instructor on the chemical properties and reactions of SSC, students propose the hypothetical composition of SSC and possible quantitative…

  9. Chemical warfare

    PubMed Central

    Samuels, Richard Ian; Mattoso, Thalles Cardoso; Moreira, Denise D.O.

    2013-01-01

    Leaf-cutting ants are well known for their highly complex social organization, which provides them with a strong defense against parasites invading their colonies. Besides this attribute, these insects have morphological, physiological and structural characteristics further reinforcing the defense of their colonies. With the discovery of symbiotic bacteria present on the integument of leaf-cutting ants, a new line of defense was proposed and considered to be specific for the control of a specialized fungal parasite of the ants’ fungus gardens (Escovopsis). However, recent studies have questioned the specificity of the integumental bacteria, as they were also found to inhibit a range of fungi, including entomopathogens. The microbiota associated with the leaf-cutting ant gardens has also been proposed as another level of chemical defense, protecting the garden from parasite invasion. Here we review the chemical defense weaponry deployed by leaf-cutting ants against parasites of their fungus gardens and of the ants themselves. PMID:23795235

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. Chemical composition of the volatile oil from Zanthoxylum avicennae and antimicrobial activities and cytotoxicity

    PubMed Central

    Lin, Yin; Han, Wei; Ge, Wei-chen; Yuan, Ke

    2014-01-01

    Background: Through literature retrieval, there has been no report on the research of the chemical components in Zanthoxylum avicennae (Lam.) DC. This paper extracted and determined the chemical components of the volatile oil in Z. avicennae, and at the same time, measured and evaluated the bioactivity of the volatile oil in Z. avicennae. Materials and Methods: We extract the volatile oil in Z. avicennae by steam distillation method, determined the chemical composition of the volatile oil by GC-MS coupling technique, and adopt the peak area normalization method to measured the relative percentage of each chemical composition in the volatile oil. Meanwhile, we use the Lethal-to-prawn larva bioactivity experiment to screen the cytotoxicity activities of the volatile oil in Z. avicennae, and using the slanting test-tube experiment to determine and evaluate its antibacterial activities in vitro for the eight kinds of plant pathogenic fungi in the volatile oil of the Z. avicennae. Results: The results show that 68 kinds of compounds are determined from the volatile oil of Z. avicennae. The determined part takes up 97.89% of the total peak area. The main ingredients in the volatile oil of Z. avicennae are sesquiterpenoids and monoterpene. The test results show that the volatile oil in Z. avicennae has strong antibacterial activities and cytotoxicity, with the strongest antibacterial activity against the Rhizoctonia solani AG1-1A. Conclusion: This research results will provide reference data for understanding the chemical composition of the volatile oil in the aromatic plant of Z. avicennae and its bioactivity, and for its further development and application. PMID:24914299

  15. Chemical composition of a sample of bright solar-metallicity stars

    NASA Astrophysics Data System (ADS)

    Caffau, E.; Mott, A.; Steffen, M.; Bonifacio, P.; Strassmeier, K. G.; Gallagher, A.; Faraggiana, R.; Sbordone, L.

    2015-12-01

    We present a detailed analysis of seven young stars observed with the spectrograph SOPHIE at the Observatoire de Haute-Provence for which the chemical composition was incomplete or absent in the literature. For five stars, we derived the stellar parameters and chemical compositions using our automatic pipeline optimized for F, G, and K stars, while for the other two stars with high rotational velocity, we derived the stellar parameters by using other information (parallax), and performed a line-by-line analysis. Chromospheric emission-line fluxes from Ca II are obtained for all targets. The stellar parameters we derive are generally in good agreement with what is available in the literature. We provide a chemical analysis of two of the stars for the first time. The star HIP 80124 shows a strong Li feature at 670.8 nm implying a high lithium abundance. Its chemical pattern is not consistent with it being a solar sibling, as has been suggested. Data obtained at Observatoire de Haute Provence, with the SOPHIE spectrograph.

  16. 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.

  17. 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.

  18. An investigation of interurban variations in the chemical composition and mutagenic activity of airborne particulate organic matter using an integrated chemical class/bioassay system

    NASA Astrophysics Data System (ADS)

    Butler, J. P.; Kneip, T. J.; Daisey, J. M.

    Previous investigations in this laboratory have demonstrated that the mutagenic activities of extractable particulate organic matter (EOM) from cities which differ in their principal fuels and meteorology can vary significantly. To gain a better understanding of these interurban variations, an Integrated Chemical Class/Biological Screening System was developed and used for a more detailed examination of differences in the chemical composition and mutagenic activity of EOM. The screening system involved coupling in situ Ames mutagenicity determinations on high performance thin layer chromatography (HPTLC) plates with class specific chemical analyses on a second set of plates. The system was used to screen for mutagenic activity and selected chemical classes (including PAH, nitro-PAH, phenols, carboxylic acids, carbonyls, aza-arenes and alkylating agents) in EOM from the following sites: New York City; Elizabeth, N.J.; Mexico City; Beijing, China; Philadelphia, PA; and the Caldecott Tunnel (CA). The results of this study demonstrated mutagenic activity and chemical compositional differences in HPTLC subfractions of particulate organic matter from these cities and from the Caldecott Tunnel. The greatest interurban differences in chemical classes were observed for the phenols, carbonyl compounds and alkylating agents. Interurban variations in mutagenic activities were greatest for EOM subfractions of intermediate polarity. These differences are probably related to interurban differences in the fuels used, types of sources and atmospheric conditions. The relationships between these variables are not well understood at present.

  19. FY98 Final Report Initial Interfacial Chemical Control for Enhancement of Composite Material Strength

    SciTech Connect

    GE Fryxell; KL Alford; KL Simmons; RD Voise; WD Samuels

    1999-10-14

    The U.S. Army Armament Research Development and Engineering Center (ARDEC) sponsored this research project to support the development of new self-assembled monolayer fiber coatings. These coatings can greatly increase the bond strength between the fiber and the resin matrix of a composite material. Composite ammunition components molded from such materials will exhibit higher strength than current materials, and will provide a major improvement in the performance of composites in military applications. Use of composite materials in military applications is desirable because of the lighter weight of the materials and their high strengths. The FY97 project investigated initial interfacial chemical control for enhancement of composite material strength. The core of the project was to modify the covalent interface of glass fibers (or other reinforcing fibers) to induce strong, uniform, defect-free adhesion between the fibers' surfaces and the polymer matrix. Installing a self-assembled monolayer tailored to the specific matrix resin accomplished this. Simply, the self-assembled monolayer modifies the fiber to make it appear to have the same chemical composition as the resin matrix. The self-assembled monolayer creates a receptive, hydrophobic interface that the thermoset resin (or polymer precursors) would wet more effectively, leading to a higher contact surface area and more efficient adhesion. The FY97 work phase demonstrated that it is possible to increase the adhesive strength, as well as increase the heat deflection temperature through the use of self-assembled monolayer.

  20. Chemical composition of the essential oil and fixed oil Bauhinia pentandra (Bong.) D. Dietr

    PubMed Central

    de Almeida, Macia C. S.; Souza, Luciana G. S.; Ferreira, Daniele A.; Monte, Francisco J. Q.; Braz-Filho, Raimundo; de Lemos, Telma L. G.

    2015-01-01

    Background: Bauhinia pentandrais popularly known as “mororó” and inhabits the Caatinga and Savannah biomes. Objective: This paper reports the chemical composition of the essential and fatty oils of the leaves from B. pentandra. Materials and Methods: The essential oil was obtained by hydrodistillation and the fixed oil by extraction with hexane, followed by saponification with KOH/MeOH, and methylation using MeOH/HCl. The constituents were analyzed by gas chromatography-mass spectrometry. Results: The major constituent of the essential oil was the phytol (58.78% ±8.51%), and of the fatty oil were palmitic (29.03%), stearic (28.58%) and linolenic (10.53%) acids. Conclusion: Of the compounds identified in the essential oil, three are first reported in this species, and this is the first record of the chemical composition of the fixed oil. PMID:26664026

  1. Chemical composition and anti-proliferative properties of Bursera graveolens essential oil.

    PubMed

    Monzote, Lianet; Hill, Gabrielle M; Cuellar, Armando; Scull, Ramón; Setzer, William N

    2012-11-01

    Bursera graveolens is a wild tree of commercial importance native to the Neotropics, which has been widely used in folk medicine. In the present study, the chemical composition and anti-proliferative properties of the essential oil from B. graveolens were assayed. The chemical composition of the essential oil, determined by GC-MS, was complex and dominated by limonene (26.5%). Bursera oil inhibited the growth of MCF-7 breast tumor cells as well as amastigotes of L. amazonensis, with IC50 values of 48.9 +/- 4.3 and 36.7 +/- 4.7 microg/mL, respectively. In addition, the cytotoxicity of the oil was 103.9 +/- 7.2 microg/mL against peritoneal macrophages from BALB/c mice. These results demonstrate that the essential oil from B. graveolens is a promissory antiproliferative product. PMID:23285824

  2. Expected gamma ray emission spectra from the lunar surface as a function of chemical composition.

    NASA Technical Reports Server (NTRS)

    Reedy, R. C.; Arnold, J. R.; Trombka, J. I.

    1973-01-01

    The gamma rays emitted from the moon or any similar body carry information on the chemical composition of the surface layer. The elements most easily measured are K, U, Th, and major elements such as O, Si, Mg, and Fe. The expected fluxes of gamma ray lines are calculated for four lunar compositions and one chondritic chemistry from a consideration of the important emission mechanisms: natural radioactivity, inelastic scatter, neutron capture, and induced radioactivity. The models used for cosmic ray interactions are those of Reedy and Arnold (1972) and Lingenfelter et al. (1972). The areal resolution of the experiment is calculated to be around 70-140 km under the conditions of the Apollo 15 and 16 experiments. Finally, a method is described for recovering the chemical information from the observed scintillation spectra obtained in these experiments.

  3. Expected gamma-ray emission spectra from the lunar surface as a function of chemical composition

    NASA Technical Reports Server (NTRS)

    Reedy, R. C.; Arnold, J. R.; Trombka, J. I.

    1973-01-01

    The gamma rays emitted from the moon or any similar body carry information on the chemical composition of the surface layer. The elements most easily measured are K, U, Th and major elements such as O, Si, Mg, and Fe. The expected fluxes of gamma ray lines were calculated for four lunar compositions and one chondritic chemistry from a consideration of the important emission mechanisms: natural radioactivity, inelastic scatter, neutron capture, and induced radioactivity. The models used for cosmic ray interactions were those of Reedy and Arnold and Lingenfelter. The areal resolution of the experiment was calculated to be around 70 to 140 km under the conditions of the Apollo 15 and 16 experiments. Finally, a method was described for recovering the chemical information from the observed scintillation spectra obtained in these experiments.

  4. [Characteristics of chemical composition of glass finds from the Qiemo tomb sites on the Silk Road].

    PubMed

    Cheng, Qian; Guo, Jin-Long; Wang, Bo; Cui, Jian-Feng

    2012-07-01

    Qiemo was an ancient country on the south branch of the Silk Road. The Zagunluke tomb site is located at the Qiemo County of the Xinjiang Uygur Autonomous Region. Glass beads and only colourless glass cup were excavated from the 3rd cultural layer of the tomb site M133 and M49, dated between the 1st AD-6th AD. LA-ICP-AES was applied to analyse chemical composition of these glass finds with the corning glass as reference. According to the result, characteristics of chemical composition are very similar to typical soda-lime glass, which indicates the glasses were imported productions from the west. These soda-lime glasses were divided into two groups in terms of flux source: natron glass and plant ash glass. This analytical research indicates the history of glass trade and communication between the East and the West on the Silk Road. PMID:23016362

  5. SiC whisker/Si3N4 composites by a chemical mixing process

    SciTech Connect

    Wang, Hongyu; Fischman, G.S.

    1991-10-01

    A chemical mixing process has been developed for making SiC whisker/Si3N4 composites. The process involves in situ synthesis of SiC whiskers in Si3N4 powder by partial carbothermal reduction of silicon nitride in an argon atmosphere. The effects of reaction conditions and starting raw materials on the formation of SiC whiskers were studied. It has been demonstrated that the morphologies of the in situ synthesized whiskers can be modified by varying carbon-source materials and reaction conditions, and the amount of SiC formed in the product can be adjusted by changing the starting Si3N4-to-C ratio. The chemically mixed composite materials were densified by hot pressing with Y2O3 and Al2O3 as sintering aids. 12 refs.

  6. Antioxidant properties, physico-chemical characteristics and proximate composition of five wild fruits of Manipur, India.

    PubMed

    Sharma, Ph Baleshwor; Handique, Pratap Jyoti; Devi, Huidrom Sunitibala

    2015-02-01

    Antioxidant properties, physico-chemical characteristics and proximate composition of five wild fruits viz., Garcinia pedunculata, Garcinia xanthochymus, Docynia indica, Rhus semialata and Averrhoa carambola grown in Manipur, India were presented in the current study. The order of the antioxidant activity and reducing power of the fruit samples was found as R. semialata > D. indica > G. xanthochymus > A. carambola > G. pedunculata. Good correlation coefficient (R(2) > 0.99) was found among the three methods applied to determine antioxidant activity. Total phenolic content was positively correlated (R(2) = 0.960) with the antioxidant activity however, total flavonoid content was not positively correlated with the antioxidant activity. Physico-chemical and proximate composition of these fruits is documented for the first time. PMID:25694698

  7. 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

  8. 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.

  9. 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

  10. Extrusion conditions affect chemical composition and in vitro digestion of select food ingredients.

    PubMed

    Dust, Jolene M; Gajda, Angela M; Flickinger, Elizabeth A; Burkhalter, Toni M; Merchen, Neal R; Fahey, George C

    2004-05-19

    An experiment was conducted to determine the effects of extrusion conditions on chemical composition and in vitro hydrolytic and fermentative digestion of barley grits, cornmeal, oat bran, soybean flour, soybean hulls, and wheat bran. Extrusion conditions altered crude protein, fiber, and starch concentrations of ingredients. Organic matter disappearance (OMD) increased for extruded versus unprocessed samples of barley grits, cornmeal, and soybean flour that had been hydrolytically digested. After 8 h of fermentative digestion, OMD decreased as extrusion conditions intensified for barley grits and cornmeal but increased for oat bran, soybean hulls, and wheat bran. Total short-chain fatty acid production decreased as extrusion conditions intensified for barley grits, soybean hulls, and soybean flour. These data suggest that the effects of extrusion conditions on ingredient composition and digestion are influenced by the unique chemical characteristics of individual substrates. PMID:15137844

  11. Chemical composition and antibacterial activity of essential oil and extracts of Citharexylum spinosum flowers from Thailand.

    PubMed

    Mar, Ae; Pripdeevech, Patcharee

    2014-05-01

    The chemical composition and antibacterial and antioxidant activities of the essential oil and various solvent extracts of Citharexylum spinosum flowers are reported. The chemical compositions were determined by GC-MS with 151 volatile constituents identified. Methyl benzoate, piperitone, maltol, and maple furanone were the major constituents. All extracts were tested for their antibacterial activity against eight microorganisms. The flower oil had the greatest antibacterial activity against all bacterial strains (MIC values of 31.2 microg/mL), while the other solvent extracts had MIC values ranging from 31.2 to 1000 microg/mL. The essential oil had the highest antioxidant activity and total phenol content with IC50 values of 62.7 and 107.3 microg/mL, respectively. PMID:25026728

  12. Chemical Composition and Biological Activities of Fragrant Mexican Copal (Bursera spp.).

    PubMed

    Gigliarelli, Giulia; Becerra, Judith X; Curini, Massimo; Marcotullio, Maria Carla

    2015-01-01

    Copal is the Spanish word used to describe aromatic resins from several genera of plants. Mexican copal derives from several Bursera spp., Protium copal, some Pinus spp. (e.g., P. pseudostrobus) and a few Fabaceae spp. It has been used for centuries as incense for religious ceremonies, as a food preservative, and as a treatment for several illnesses. The aim of this review is to analyze the chemical composition and biological activity of commercial Mexican Bursera copal. PMID:26703535

  13. Relative toxicity of pyrolysis gases from materials - Effects of chemical composition and test conditions

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Cumming, H. J.

    1978-01-01

    Relative toxicity test data on 270 materials are presented, based on test procedures developed at the University of San Francisco. The effects of chemical composition, using data on 13 types of synthetic polymers and eight types of fabrics, are discussed. Selected materials were evaluated using nine test conditions with the USF method, and using methods developed at the FAA Civil Aeromedical Institute, Douglas Aircraft Company and San Jose State University.

  14. 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

  15. Chemical compositions of grain boundaries in bronze-processed pure and alloyed Nb3Sn

    SciTech Connect

    Suenaga, M.; Corderman, R.R.; Welch, D.O.

    1985-01-01

    Chemical compositions of grain boundaries in pure and alloyed Nb3Sn (with Ti and Ta) wires produced by the bronze process wire were measured using Auger electron spectroscopy. The amount of Ti at the grain boundaries was found to be approximately twice as much as that in the bulk. However, the amount of Ta at the grain boundaries was less than that in the bulk.

  16. Chemical Composition of the Magellanic Clouds, from Young to Old Stars

    NASA Astrophysics Data System (ADS)

    Hill, Vanessa

    I review the current state of our knowledge of the detailed chemical composition of the Magellanic Clouds, concentrating on the best probes of detailed elemental abundances, namely individual stars observed by means of high-resolution spectroscopy, probing stellar population of all ages from the oldest (>10 Gyr) stellar generations, intermediate-age populations (1--10 Gyr), and young massive stars, complemented by H ii region abundances.

  17. THE EFFECT OF DEGREE OF CORN PROCESSING ON THE CHEMICAL COMPOSITION OF CORN

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An experiment was conducted to determine the effect of degree of processing on the chemical composition of corn. Corn was processed by dry rolling to a bulk density of 0.59 kg/L (46 pounds/bushel, DR46) or steam flaking to a bulk density of 0.36 or 0.28 kg/L (28 [SF28] and 22 [SF22] pounds/bushel, ...

  18. 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.

  19. Chemical composition and antifungal activity of essential oil of Chrysactinia mexicana gray.

    PubMed

    Cárdenas-Ortega, Norma C; Zavala-Sánchez, Miguel A; Aguirre-Rivera, J Rogelio; Pérez-González, Cuauhtémoc; Pérez-Gutiérrez, Salud

    2005-06-01

    The chemical composition of the essential oil of Chysactinia mexicana was analyzed by gas chromatography-mass spectrometry. Seventeen compounds were characterized; eucalyptol (41.3%), piperitone (37.7%), and linalyl acetate (9.1%) were found as the major components. The essential oil of leaves and piperitone completely inhibited Aspergillus flavus growth at relatively low concentrations (1.25 and 0.6 mg/mL, respectively). PMID:15913293

  20. Concentration of mycotoxins and chemical composition of corn silage: a farm survey using infrared thermography.

    PubMed

    Schmidt, P; Novinski, C O; Junges, D; Almeida, R; de Souza, C M

    2015-09-01

    This work evaluated the chemical composition and mycotoxin incidence in corn silage from 5 Brazilian dairy-producing regions: Castro, in central-eastern Paraná State (n=32); Toledo, in southwestern Paraná (n=20); southeastern Goiás (n=14); southern Minas Gerais (n=23); and western Santa Catarina (n=20). On each dairy farm, an infrared thermography camera was used to identify 3 sampling sites that exhibited the highest temperature, a moderate temperature, and the lowest temperature on the silo face, and 1 sample was collected from each site. The chemical composition and concentrations of mycotoxins were evaluated, including the levels of aflatoxins B1, B2, G1, and G2; zearalenone; ochratoxin A; deoxynivalenol; and fumonisins B1 and B2. The corn silage showed a highly variable chemical composition, containing, on average, 7.1±1.1%, 52.5±5.4%, and 65.2±3.6% crude protein, neutral detergent fiber, and total digestible nutrients, respectively. Mycotoxins were found in more than 91% of the samples, with zearalenone being the most prevalent (72.8%). All samples from the Castro region contained zearalenone at a high average concentration (334±374µg/kg), even in well-preserved silage. The incidence of aflatoxin B1 was low (0.92%). Silage temperature and the presence of mycotoxins were not correlated; similarly, differences were not observed in the concentration or incidence of mycotoxins across silage locations with different temperatures. Infrared thermography is an accurate tool for identifying heat sites, but temperature cannot be used to predict the chemical composition or the incidence of mycotoxins that have been analyzed, within the silage. The pre-harvest phase of the ensiling process is most likely the main source of mycotoxins in silage. PMID:26162792

  1. On-line measurements of particle chemical composition with the Particle-Into-Liquid Sampler (PILS)

    NASA Astrophysics Data System (ADS)

    Weber, R. J.; Orsini, D.; Sullivan, A.; Ma, Y.; Meier, K.

    2002-12-01

    We describe a new instrument for near real-time quantitative measurements of bulk aerosol particle chemical composition. The device continuously captures particles into a small flow of purified water, whose flow rate can be selected. This flow may then be analyzed by existing analytical chemical techniques for measurements of the dissolved aerosol particle chemical composition. Coupled to a dual channel ion chromatograph, the instrument is capable of measuring a suite of aerosol ionic constituents at sensitivities down to approximately 10 ng per cubic meter of air with a duty cycle of roughly 4 minutes. Coupled to a total carbon analyzer, the water-soluble carbonaceous component of atmospheric aerosol particles can be determined with sensitivities down to approximately 0.2 ug per cubic meter at a duty cycle of 6 minutes. The device has been deployed for ground, ship, and airborne measurements in studies whose focus has ranged from urban air quality to characterization of Asian outflow. Current work is focused on speciation of the water-soluble organic carbon component and the extension of the technique to solvents other than water. Examples from various field studies will be presented along with future needs in composition measurements and ideas for addressing these needs.

  2. Microstructures and Mechanical Properties of Laser Welding Joint of a CLAM Steel with Revised Chemical Compositions

    NASA Astrophysics Data System (ADS)

    Chen, Shuhai; Huang, Jihua; Lu, Qi; Zhao, Xingke

    2016-05-01

    To suppress the tendency to form delta ferrite in weld metal (WM) of China low activation martensitic (CLAM) steel joint, a CLAM steel with revised chemical compositions was designed. Laser welding of the CLAM steel was investigated. The microstructures of the WM and heat-affected zone were analyzed. The impact toughness of the WM was evaluated by a Charpy impact test method with three V notches. The influence of temper temperature on mechanical properties was analyzed. It was found that the delta ferrite was eliminated almost completely in laser WM of CLAM steel with revised chemical compositions which has lower tendency to form delta ferrite than original chemical compositions. The joint has higher tensile strength than the parent metal. With increasing the heat input, the impact toughness of the joint is approximatively equal with that of parent metal first and then decreases obviously. Temper treatment could effectively improve mechanical property of the joint. When the temper temperature exceeds 600 °C, the impact toughness of the joint is higher than that of the parent metal.

  3. Microstructures and Mechanical Properties of Laser Welding Joint of a CLAM Steel with Revised Chemical Compositions

    NASA Astrophysics Data System (ADS)

    Chen, Shuhai; Huang, Jihua; Lu, Qi; Zhao, Xingke

    2016-03-01

    To suppress the tendency to form delta ferrite in weld metal (WM) of China low activation martensitic (CLAM) steel joint, a CLAM steel with revised chemical compositions was designed. Laser welding of the CLAM steel was investigated. The microstructures of the WM and heat-affected zone were analyzed. The impact toughness of the WM was evaluated by a Charpy impact test method with three V notches. The influence of temper temperature on mechanical properties was analyzed. It was found that the delta ferrite was eliminated almost completely in laser WM of CLAM steel with revised chemical compositions which has lower tendency to form delta ferrite than original chemical compositions. The joint has higher tensile strength than the parent metal. With increasing the heat input, the impact toughness of the joint is approximatively equal with that of parent metal first and then decreases obviously. Temper treatment could effectively improve mechanical property of the joint. When the temper temperature exceeds 600 °C, the impact toughness of the joint is higher than that of the parent metal.

  4. 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.

  5. Chemical composition and antioxidant activity of a Lebanese plant Euphorbia macroclada schyzoceras

    PubMed Central

    Farhan, Hussein; Rammal, Hassan; Hijazi, Akram; Daher, Ahmad; Reda, Mohamad; Annan, Hussein; Chokr, Ali; Bassal, Ali; Badran, Bassam; Ghaloub, Abdulameer Nasser

    2013-01-01

    Objective To determine the chemical composition, total phenolic and total flavonoid contents of the crude extracts from leaves and stems of a Lebanese plant Euphorbia macroclada schyzoceras (E. macroclada), and to evaluate their antioxidant potential using DPPH, H2O2, and chelating of ferrous ions tests. Methods Quantification of the total phenolic and total flavonoid contents of the crude extracts from leaves and stems and the antioxidant activities were evaluated using spectrophotometric analyses. The chemical composition has been estimated using different techniques such as IR, LC/MS and NMR. Results Ethanolic extract from leaves of E. macroclada was better than aqueous extract and showed higher content in total phenolic and total flavonoid than found in the stems. On the other hand, using DPPH and H2O2 tests, this extract from leaves showed higher antioxidant capacity than aqueous extract. However, using the chelating of ferrous ions test, the antioxidant activity of the aqueous extract of both stems and leaves was stronger than that of ethanolic once. The chemical composition of the whole plant showed the presence of some aromatic compounds and fatty acids. Conclusions Both ethanolic and water extracts from both parts of this plant are effective and have good antioxidant power. So, this plant can be used in the prevention of a number of diseases related to oxidative stress. PMID:23836193

  6. The influence of Wickerhamomyces anomalus killer yeast on the fermentation and chemical composition of apple wines.

    PubMed

    Satora, Pawel; Tarko, Tomasz; Sroka, Pawel; Blaszczyk, Urszula

    2014-08-01

    The aim of this study was to determine the influence of two different Wickerhamomyces anomalus strains, CBS 1982 and CBS 5759, on the chemical composition and sensory characteristics of Gloster apple wines. They were inoculated into unpasteurized as well as pasteurized apple musts together with a S. cerevisiae strain as a mixed culture. Fermentation kinetics, basic enological parameters, antioxidant properties as well as selected polyphenol, volatile compound, and organic acid contents were analyzed during the experiments. Apple wines obtained after spontaneous fermentation were characterized by high volatile acidity, increased concentrations of acetaldehyde, and volatile esters, as well as the lowest amounts of ethyl alcohol and higher alcohols compared with other samples. Addition of 0.05 g L(-1) W. anomalus killer strains to the unpasteurized must significantly changed the fermentation kinetics and chemical composition of apple wines. The value of volatile acidity was highly decreased, while the amount of higher alcohols and titratable acidity increased. Pasteurization of must improved the fermentation efficiency. Higher amounts of polyphenol compounds and lower amounts of malic acid were also detected. Application of W. anomalus strains together with S. cerevisiae yeast as a mixed culture positively influenced the chemical composition and sensory features of produced apple wines. PMID:24750993

  7. Differential characteristics in the chemical composition of bananas from Tenerife (Canary Islands) and Ecuador.

    PubMed

    Forster, Markus Paul; Rodríguez Rodríguez, Elena; Díaz Romero, Carlos

    2002-12-18

    The contents of moisture, protein, ash, ascorbic acid, glucose, fructose, total sugars, and total and insoluble fiber were determined in cultivars of bananas (Gran Enana and Pequeña Enana) harvested in Tenerife and in bananas (Gran Enana) from Ecuador. The chemical compositions in the bananas from Tenerife and from Ecuador were clearly different. The cultivar did not influence the chemical composition, except for insoluble fiber content. Variations of the chemical composition were observed in the bananas from Tenerife according to cultivation method (greenhouse and outdoors), farming style (conventional and organic), and region of production (north and south). A highly significant (r = 0.995) correlation between glucose and fructose was observed. Correlations of ash and protein contents tend to separate the banana samples according to origin. A higher content of protein, ash, and ascorbic acid was observed as the length of the banana decreased. Applying factor analysis, the bananas from Ecuador were well separated from the bananas produced in Tenerife. An almost total differentiation (91.7%) between bananas from Tenerife and bananas from Ecuador was obtained by selecting protein, ash, and ascorbic acid content and applying stepwise discriminant analysis. By selecting the bananas Pequeña Enana and using discriminant analysis, a clear separation of the samples according to the region of production and farming style was observed. PMID:12475275

  8. 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

  9. Chemical composition of fog and cloud water at the Erzgebirge summit, Germany

    NASA Astrophysics Data System (ADS)

    Schüttauf, S.; Zimmermann, F.; Matschullat, J.

    2010-07-01

    The Erzgebirge as part of the former "Black Triangle" was one of the most polluted forested areas in Central Europe. The local climate is characterized by above-average stable air stratification leading to an above-average amount of inversions with advection fog. Thus, "acid fog" was thought to play an important role in the acidic deposition and in the forest decline on both sides of the Erzgebirge ridge (800 - 900 m a.s.l.). The last data on chemical composition and deposition of fog and cloud water were reported from the 1990's. This work determined the current chemical composition of fog and cloud water from the region in respect to the 1999 Gothenburg protocol. Chemical composition data of fog samples are reported from two sites: (1) Zinnwald, 877 m a.s.l., eastern Erzgebirge, and (2) Fichtelberg, 1214 m a.s.l. The latter results are the first data on the chemical composition of cloud water from that site. Passive fog collectors were used, and only exposed when fog occurred. Two collectors at Zinnwald (one for ion analysis and one for trace elements) and one collector at Fichtelberg were used. Electrical conductivity, pH-value, and the concentration of major ions and trace metals (Ba, Pb, Zn, Al, Mn, Ti, V, Ni, Cu, Sr, Cd, Sb, As, Cr) were determined. TOC was analysed in selected samples. Fog frequency in the investigation period (10.2009 - 12.2009) was comparable to long-term observations. Modelled liquid water contents (LWC) were in the range of typical values for German low elevation mountains. Minimum pH values, 3.5 for Zinnwald and 3.7 for Fichtelberg, were still of phytotoxic relevance. The chemical composition of fog and cloud water differed considerably between the sites. Zinnwald still is a polluted site with high concentrations of sulphate, nitrate, ammonium and organic compounds, while Fichtelberg is much less influenced by air pollution. There, sodium and chloride dominated the composition. At Zinnwald, Al, Zn, Pb, and Cu showed the highest trace metal concentrations, while As, Ni, Cr, and Cd were also detected. Sulphate concentrations were lower than in the late 1990s, while nitrate concentrations were considerably higher than before. This is surprising in the light of decreasing NOx emissions in Saxony and needs further investigations.

  10. Chemical intolerance.

    PubMed

    Dantoft, Thomas M; Andersson, Linus; Nordin, Steven; Skovbjerg, Sine

    2015-01-01

    Chemical intolerance (CI) is a term used to describe a condition in which the sufferer experiences a complex array of recurrent unspecific symptoms attributed to low-level chemical exposure that most people regard as unproblematic. Severe CI constitutes the distinguishing feature of multiple chemical sensitivity (MCS). The symptoms reported by CI subjects are manifold, involving symptoms from multiple organs systems. In severe cases of CI, the condition can cause considerable life-style limitations with severe social, occupational and economic consequences. As no diagnostic tools for CI are available, the presence of the condition can only be established in accordance to criteria definitions. Numerous modes of action have been suggested to explain CI, with the most commonly discussed theories involving the immune system, central nervous system, olfactory and respiratory systems as well as altered metabolic capacity, behavioral conditioning and emotional regulation. However, in spite of more than 50 years of research, there is still a great deal of uncertainties regarding the event(s) and underlying mechanism( s) behind symptom elicitation. As a result, patients are often misdiagnosed or offered health care solutions with limited or no effect, and they experience being met with mistrust and doubt by health care professionals, the social care system and by friends and relatives. Evidence-based treatment options are currently unavailable, however, a person-centered care model based on a multidisciplinary treatment approach and individualized care plans have shown promising results. With this in mind, further research studies and health care solutions should be based on a multifactorial and interdisciplinary approach. PMID:26088215

  11. Chemical lasers

    NASA Astrophysics Data System (ADS)

    Khariton, Y.

    1984-08-01

    The application and the advances of quantum electronics, specifically, of optical quantum generators lasers is reviewed. Materials are cut, their surfaces are machined, chemical transformations of substances are carried out, surgical operations are performed, data are transmitted, three dimensional images are produced and the content of microimpurities, in the atmosphere, are analyzed by use of a beam. Laser technology is used in conducting investigations in the most diverse fields of the natural and technical sciences from controlled thermonuclear fusion to genetics. Many demands are placed on lasers as sources of light energy. The importance of low weight, compactness of the optical generator and the efficiency of energy conversion processes is emphasized.

  12. Chemical Composition of the essential oils from Vietnamese Clausena indica and C. anisum-olens.

    PubMed

    Thaia, Tran Huy; Bazzali, Ophélie; Hoi, Tran Minh; Hien, Nguyen Thi; Hung, Nguyen Viet; Félix Tomi; Casanova, Joseph; Bighelli, Ange

    2014-10-01

    The chemical composition of Vietnamese oil samples of the aerial parts of Clausena indica (Dalz.) Oliver and C. anisum-olens (Blanco) Merryll have been investigated using a combination of chromatographic and spectroscopic techniques. C. indica essential oil contained mainly terpinolene (53.9 and 56.1%), and myristicin (17.9 and 7.3%), whereas the major components of C. anisun-olens essential were citronellal (22.8%), geranial (21.4%) and neral (16.8%). The compositions of the investigated samples have been compared with those of essential oils from various origins. PMID:25522554

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

    NASA Astrophysics Data System (ADS)

    Neuland, M. B.; Mezger, K.; Riedo, A.; Tulej, M.; Wurz, P.

    2015-10-01

    A miniature laser ablation mass spectrometer (LMS) is presented. The LMS is designed as a flight instrument for planetary and space research and optimised for in situ measurements of the chemical composition of rocks and soils on a planetary surface. By means of measure-ments standard reference materials of soil and a sample of the Allende meteorite we demonstrate that LMS is a suitable instrument for in situ measurements of elemental and isotopic composition with high precision and accuracy. Furthermore, it is shown that LMS data allows deriving of the material mineralogy and petrology with high spatial resolution, lateral and vertical, and the application of in situ age dating methods.

  14. Chemical composition of whole body and carcass of Bos indicus and tropically adapted Bos taurus breeds.

    PubMed

    Bonilha, S F M; Tedeschi, L O; Packer, I U; Razook, A G; Nardon, R F; Figueiredo, L A; Alleoni, G F

    2011-09-01

    Relationships between the chemical composition of the 9th- to 11th-rib section and the chemical composition of the carcass and empty body were evaluated for Bos indicus (108 Nellore and 36 Guzerah; GuS) and tropically adapted Bos taurus (56 Caracu; CaS) bulls, averaging 20 to 24 mo of age at slaughter. Nellore cattle were represented by 56 animals from the selected herd (NeS) and 52 animals from the control herd (NeC). The CaS and GuS bulls were from selected herds. Selected herds were based on 20 yr of selection for postweaning BW. Carcass composition was obtained after grinding, homogenizing, sampling, and analyzing soft tissue and bones. Similarly, empty body composition was obtained after grinding, homogenizing, sampling, analyzing, and combining blood, hide, head + feet, viscera, and carcass. Bulls were separated into 2 groups. Group 1 was composed of 36 NeS, 36 NeC, 36 CaS, and 36 GuS bulls and had water, ether extract (EE), protein, and ash chemically determined in the 9th- to 11th-rib section and in the carcass. Group 2 was composed of 20 NeS, 16 NeC, and 20 CaS bulls and water, EE, protein, and ash were determined in the 9th- to 11th-rib section, carcass, and empty body. Linear regressions were developed between the carcass and the 9th- to 11th-rib section compositions for group 1 and between carcass and empty body compositions for group 2. The 9th- to 11th-rib section percentages of water (RWt) and EE (RF) predicted the percentages of carcass water (CWt) and carcass fat (CF) with high precision: CWt, % = 29.0806 + 0.4873 × RWt, % (r(2) = 0.813, SE = 1.06) and CF, % = 10.4037 + 0.5179 × RF, % (r(2) = 0.863, SE = 1.26), respectively. Linear regressions between percentage of CWt and CF and empty body water (EBWt) and empty body fat (EBF) were also predicted with high precision: EBWt, % = -9.6821 + 1.1626 × CWt, % (r(2) = 0.878, SE = 1.43) and EBF, % = 0.3739 + 1.0386 × CF, % (r(2) = 0.982, SE = 0.65), respectively. Chemical composition of the 9th- to 11th-rib section precisely estimated carcass percentages of water and EE. These regressions can accurately predict carcass and empty body compositions for Nellore, Guzerah, and Caracu breeds. PMID:21498655

  15. 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.

  16. Refinery piping fires resulting from variations in chemical composition of piping materials

    SciTech Connect

    Setterlund, R.B.

    1996-07-01

    A number of refinery fires in recent years are traceable to variations in the chemical composition of piping materials. These fires are typically more destructive than those due to other causes and can take place without warning. Some, but not all, were the result of the inadvertent use of carbon steel in alloy steel piping systems. Others were the result of alloy welds in carbon steel systems while still others were due to variations in residual elements leading to anomalous corrosion behavior. Recommendations are given on areas of refinery units where the greatest need for close control of material composition exists.

  17. Exploring the chemical sensitivity of a carbon nanotube/green tea composite.

    PubMed

    Chen, Yanan; Lee, Yang Doo; Vedala, Harindra; Allen, Brett L; Star, Alexander

    2010-11-23

    Single-walled carbon nanotubes (SWNTs) possess unique electronic and physical properties, which make them very attractive for a wide range of applications. In particular, SWNTs and their composites have shown a great potential for chemical and biological sensing. Green tea, or more specifically its main antioxidant component, epigallocatechin gallate (EGCG), has been found to disperse SWNTs in water. However, the chemical sensitivity of this SWNT/green tea (SWNT/EGCG) composite remained unexplored. With EGCG present, this SWNT composite should have strong antioxidant properties and thus respond to reactive oxygen species (ROS). Here we report on fabrication and characterization of SWNT/EGCG thin films and the measurement of their relative conductance as a function of H(2)O(2) concentrations. We further investigated the sensing mechanism by Fourier transform infrared (FTIR) spectroscopy and field-effect transistor measurements (FET). We propose here that the response to H(2)O(2) arises from the oxidation of EGCG in the composite. These findings suggest that SWNT/green tea composite has a great potential for developing simple resistivity-based sensors. PMID:21043457

  18. Exploring the Chemical Sensitivity of a Carbon Nanotube/Green Tea Composite

    PubMed Central

    Chen, Yanan; Lee, Yang Doo; Vedala, Harindra; Allen, Brett L.; Star, Alexander

    2010-01-01

    Single-walled carbon nanotubes (SWNTs) possess unique electronic and physical properties, which make them very attractive for a wide range of applications. In particular, SWNTs and their composites have shown a great potential for chemical and biological sensing. Green tea, or more specifically its main antioxidant component, epigallocatechin gallate (EGCG), has been found to disperse SWNTs in water. However, the chemical sensitivity of this SWNT/green tea (SWNT/EGCG) composite remained unexplored. With EGCG present, this SWNT composite should have strong antioxidant properties and thus respond to reactive oxygen species (ROS). Here we report on fabrication and characterization of SWNT/EGCG thin films and the measurement of their relative conductance as a function of H2O2 concentrations. We further investigated the sensing mechanism by Fourier-transform infrared (FTIR) spectroscopy and field-effect transistor measurements (FET). We propose here that the response to H2O2 arises from the oxidation of EGCG in the composite. These findings suggest that SWNT/green tea composite has a great potential for developing simple resistivity-based sensors. PMID:21043457

  19. Comparison surface characteristics and chemical composition of conventional metallic and nickel-free brackets.

    PubMed

    Shintcovsk, Ricardo Lima; Knop, Luegya Amorim Henriques; Gandini, Luiz Gonzaga; Martins, Lidia Parsekian; Pires, Aline Segatto

    2015-01-01

    This study aims at comparing conventional and nickel-free metal bracket surface characteristics with elemental composition by scanning electron microscopy (SEM), using energy dispersive spectroscopy (EDS). The sample consisted of 40 lower incisor brackets divided into four groups: ABZ = conventional brackets, Kirium Abzil 3M® (n = 10); RL = conventional brackets, Roth Light Morelli® (n = 10); NF = nickel-free brackets, Nickel-Free Morelli® (n = 10); and RM = nickel-free brackets, Roth Max Morelli® (n = 10). Qualitative evaluation of the bracket surface was performed using SEM, whereby surface features were described and compared. The elemental composition was analyzed by EDS. According to surface analysis, groups ABZ and RL showed a homogeneous surface, with better finishing, whereas the surfaces in groups NF and RM were rougher. The chemical components with the highest percentage were Fe, Cr and C. Groups NF and MR showed no nickel in their composition. In conclusion, the bracket surface of the ABZ and RL groups was more homogeneous, with grooves and pores, whereas the surfaces in groups NF and RM showed numerous flaws, cracks, pores and grooves. The chemical composition analysis confirmed that the nickel-free brackets had no Ni in their composition, as confirmed by the manufacturer's specifications, and were therefore safe to use in patients with a medical history of allergy to this metal. PMID:25590508

  20. 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.

  1. Modification of Chemically Exfoliated Graphene to Produce Efficient Piezoresistive Polystyrene-Graphene Composites

    NASA Astrophysics Data System (ADS)

    Nasirpouri, Farzad; Pourmahmoudi, Hassan; Abbasi, Farhang; Littlejohn, Samuel; Chauhan, Ashok S.; Nogaret, Alain

    2015-10-01

    We report the chemical exfoliation of grapheneoxide from graphite and its subsequent reduction to graphene nanosheets (GN) to obtain highly conducting composites of graphene sheets in a polymer matrix. The effect of using graphite nanoparticles or flakes as precursors, and different drying methods, was investigated to obtain multilayer graphene sheets of atomically controlled thickness, which was essential to optimizing their dispersion in a polystyrene (PS) polymer matrix. In situ emulsion polymerization of the styrene monomer in the presence of GN was performed to obtain thin composite films with highly uniform dispersion and fewer graphene layers when GN were obtained from graphite flakes then freeze drying. The highest electrical conductivity of PS-GN composites was ~0.01 S/m for a graphene filling fraction of 2%. The piezoresistance of the PS-GN composites was evaluated and used in pressure sensor arrays with pressure field imaging capability.

  2. Chemical compositions of soluble aerosols around the last termination in the NEEM (Greenland) ice core

    NASA Astrophysics Data System (ADS)

    Oyabu, Ikumi; Iizuka, Yoshinori; Karlin, Torbjorn; Fukui, Manabu; Hondoh, Takeo; Hansson, Margareta

    2013-04-01

    The polar ice cores provide us with reconstruction of past atmospheric aerosols. Atmospheric aerosols such as dust and sea salt in both Arctic and Antarctic ice cores are well discussed by using the proxy of ion concentration/flux. Recently, studies on the chemical compositions of soluble aerosols in the ice cores have been carried out. The chemical compositions and transition of soluble aerosols in the Dome Fuji (Antarctica) has been revealed, however, there are few studies on those of soluble aerosols in Greenland ice cores. Using ice sublimation method #1, we analyzed the chemical compositions of soluble aerosols around the last termination in the NEEM (Greenland) ice core. A total of 43 samples were distributed from NEEM ice core section from 1280 to 1580 m. Soluble aerosols were extracted from the samples by sublimation system. Constituent elements and diameter of each non-volatile particle were measured by scanning electron micro scope (SEM) and energy dispersive X-ray spectroscopy (EDS). By using a method in our recent paper #2, we assumed that particles containing Ca and S are calcium sulfate and particles containing Na and S are sodium sulfate. We divided around the last termination into 4 stages by focusing on the temperature; Holocene, Younger Dryas (YD), Bølling-Allerød (B-A) and Last Glacial Period (LGP), and compared the mass ratio of sulfate and chloride aerosols in each stage. During the cold stage in YD and LGP, calcium sulfate accounted large percentage of soluble aerosols. On the other hand, during the warm stage in Holocene and B-A, sodium sulfate accounted large percentage of soluble aerosols. These relationships between chemical composition and temperature are probably related to non sea salt (nss)-calcium ion concentration. We will discuss the relationship between nss-calcium ion concentration and chemical compositions of soluble aerosols in the presentation. References #1 Iizuka et al., J. Glaciol., 55(191), 58-64, 2009. #2 Iizuka, Y. et al. J. Geophys. Res. 117, D04308, 2012.

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

    NASA Astrophysics Data System (ADS)

    Limpens, Juul; Nilsson, Mats

    2014-05-01

    Decomposition of organic material is one of the key processes that determines the size of the soil-feedback to global warming, but it is also a process surrounded with one of the largest uncertainties, making understanding its mechanistic drivers of crucial importance. In organic soils decomposition is closely determined by the organo-chemical composition of the litter entering the soil. But what, in turn drives the organo-chemical composition? Is it an emergent feature of the environment the species producing the litter grow in, or is it an evolutionary trait that can be tracked through the species' phylogeny? We set out to answer this question for one of the most import peat-forming plants on earth: the genus Sphagnum. We sampled 18 Sphagnum species, about equally distributed over 6 sites spanning a wide range of environmental conditions: most species were collected at multiple sites. For all species we characterised the chemical composition, focussing on three functional chemistry groups: (i) mineral elements, (ii) carbohydrate polymers (iii) non-carbohydrate polymers (aromatic and aliphatic compounds) . For each group of compounds we used multivariate statistical techniques to derive the degree of variation explained by environment: (site, position within site) and phylogeny (sections within genus Sphagnum). We found that the variation in mineral element concentrations was mostly explained by environment, with the biggest differences in the concentrations of basic cat-ions calcium and magnesium. In contrast, the variation in carbohydrates was mostly explained by phylogeny, with clear associations between sections and monosaccharides. The monosaccharide rhamnose was associated with species from the Acutifolia section known for their poor degradability, whereas xylose and galactose were closely associated with degradable species from the Cuspidata section. The composition non-carbohydrate polymers took an intermediate position: both environment and phylogeny 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.

  4. Chemical Composition and Antioxidant Activities of Three Polysaccharide Fractions from Pine Cones

    PubMed Central

    Xu, Ren-Bo; Yang, Xin; Wang, Jing; Zhao, Hai-Tian; Lu, Wei-Hong; Cui, Jie; Cheng, Cui-Lin; Zou, Pan; Huang, Wei-Wei; Wang, Pu; Li, Wen-Jing; Hu, Xing-Long

    2012-01-01

    The traditional method of gas chromatography-mass spectrometry for monosaccharide component analysis with pretreatment of acetylation is described with slight modifications and verified in detail in this paper. It was then successfully applied to the quantitative analysis of component monosaccharides in polysaccharides extracted from the pine cones. The results demonstrated that the three pine cone polysaccharides all consisted of ribose, rhamnose, arabinose, xylose, mannose, glucose and galactose in different molar ratios. According to the recovery experiment, the described method was proved accurate and practical for the analysis of pine cone polysaccharides, meeting the need in the field of chemical analysis of Pinus plants. Furthermore; the chemical characteristics, such as neutral sugar, uronic acids, amino acids, molecular weights, and antioxidant activities of the polysaccharides were investigated by chemical and instrumental methods. The results showed that the chemical compositions of the polysaccharides differed from each other, especially in the content of neutral sugar and uronic acid. In the antioxidant assays, the polysaccharide fractions exhibited effective scavenging activities on ABTS radical and hydroxyl radical, with their antioxidant capabilities decreasing in the order of PKP > PAP > PSP. Therefore, although the polysaccharide fractions had little effect on superoxide radical scavenging, they still have potential to be developed as natural antioxidant agents in functional foods or medicine. PMID:23203063

  5. 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.

  6. Chemical and Biological Influences on the Organic Composition and Cloud Activity of Sea Spray Aerosol

    NASA Astrophysics Data System (ADS)

    Collins, D. B.; Ault, A. P.; Corrigan, C.; Ruppel, M. J.; Hersey, S. P.; Mui, W.; Guasco, T.; Cuadra-Rodriguez, L. A.; Seinfeld, J.; Roberts, G. C.; Grassian, V. H.; Prather, K. A.

    2012-12-01

    Sea spray aerosol (SSA), which is directly ejected from the ocean surface, is composed of both inorganic and organic matter. While the inorganic salt component dominates on a mass basis, organic matter tends to reside in the smaller (< 200 nm), less massive, more numerous particles that play a critical role in cloud condensation nuclei (CCN) activity. The impact of the chemical and biological conditions of the seawater from which SSA are derived has been shown to be important to aerosol chemical and physical properties in both field and laboratory studies, however the range of controlling factors on the organic content and CCN activity of SSA is not well constrained. Here we present experiments that explore the variability of CCN activity in regimes of seawater chemical and biological conditions not typically utilized in SSA experiments. The mixing state and chemical composition of the aerosol will be explored in order to gain closure between expected and measured CCN activity. Our results indicate that changes in CCN activity may be forced by factors not currently accounted for in model parameterizations of organic matter partitioning to SSA.

  7. Some General Laws of Chemical Elements Composition Dynamics in the Hydrosphere

    NASA Astrophysics Data System (ADS)

    Korzh, V.

    2012-12-01

    The biophysical oceanic composition is a result of substance migration and transformation on river-sea and ocean- atmosphere boundaries. Chemical composition of oceanic water is a fundamental multi-dimensional constant for our planet. Detailed studies revealed three types of chemical element distribution in the ocean: 1) Conservative: concentration normalized to salinity is constant in space and time; 2) Nutrient-type: element concentration in the surface waters decreases due to the biosphere consumption; and 3) Litho-generative: complex character of distribution of elements, which enter the ocean with the river runoff and interred almost entirely in sediments (Fig. 1). The correlation between the chemical compositions of the river and oceanic water is high (r = 0.94). We conclude that biogeochemical features of each element are determined by the relationship between its average concentration in the ocean and the intensity of its migration through hydrosphere boundary zones. In Fig.1 we show intensities of global migration and average concentrations in the ocean in the coordinates lgC - lg τ, where C is an average element concentration and τ is its residual time in the ocean. Fig. 1 shows a relationship between three main geochemical parameters of the dissolved forms of chemical elements in the hydrosphere: 1) average concentration in the ocean, 2) average concentration in the river runoff and 3) the type of distribution in oceanic water. Using knowledge of two of these parameters, it allows gaining theoretical knowledge of the third. The System covers all chemical elements for the entire range of observed concentrations. It even allows to predict the values of the annual river transport of dissolved Be, C, N, Ge, Tl, Re, to refine such estimates for P, V, Zn, Br, I, and to determine the character of distribution in the ocean for Au and U. Furthermore, the System allowed to estimate natural (unaffected by anthropogenic influence) mean concentrations of elements in the river runoff and use them as ecological reference data. Finally, due to the long response time of the ocean, the mean concentrations of elements and patterns of their distribution in the ocean can be used to determine pre-technogenic concentrations of elements in the river runoff. An example of such studies for the Northern Eurasia Arctic Rivers will be presented at the conference. References Korzh 1974: J. de Recher. Atmos, 8, 653-660. Korzh 2008: J. Ecol., 15, 13-21. Korzh 2012: Water: Chem. & Ecol., No. 1, 56-62; Fig.1. The System of chemical elements distribution in the hydrosphere. Types of distribution in the ocean: 1) conservative; 2) nutrient-type; 3) litho-generative.

  8. Fabrication of Nanocarbon Composites Using In Situ Chemical Vapor Deposition and Their Applications.

    PubMed

    He, Chunnian; Zhao, Naiqin; Shi, Chunsheng; Liu, Enzuo; Li, Jiajun

    2015-09-23

    Nanocarbon (carbon nanotubes (CNTs) and graphene (GN)) composites attract considerable research interest due to their fascinating applications in many fields. Here, recent developments in the field of in situ chemical vapor deposition (CVD) for the design and controlled preparation of advanced nanocarbon composites are highlighted, specifically, CNT-reinforced bulk structural composites, as well as CNT, GN, and CNT/GN functional composites, together with their practical and potential applications. In situ CVD is a very attractive approach for the fabrication of composites because of its engaging features, such as its simplicity, low-cost, versatility, and tunability. The morphologies, structures, dispersion, and interface of the resulting nanocarbon composites can be easily modulated by varying the experimental parameters (such as temperature, catalysts, carbon sources, templates or template catalysts, etc.), which enables a great potential for the in situ synthesis of high-quality nanocarbons with tailored size and dimension for constructing high-performance composites, which has not yet been achieved by conventional methods. In addition, new trends of the in situ CVD toward nanocarbon composites are discussed. PMID:26283470

  9. Chemical composition of odorous secretions in the Tasmanian short-beaked echidna (Tachyglossus aculeatus setosus).

    PubMed

    Harris, Rachel L; Davies, Noel W; Nicol, Stewart C

    2012-11-01

    The short-beaked echidna is believed to use olfactory cues from a cloacal scent gland to attract and locate mates during the breeding season. We investigated the chemical composition of echidna secretions, including cloacal swabs and solid, "waxy" exudates from the cloaca and spurs. Scent samples from 37 individuals were collected over a 1-year period and analyzed using a range of different analytical techniques. A total of 186 compounds were identified, including volatile carboxylic acids, aldehydes, ketones, fatty acids, methyl esters, ethyl esters, terpenes, nitrogen- and sulphur-containing compounds, alcohols, and aromatics. Long chain and very long chain monounsaturated fatty acids, sterols, and sterol esters were identified as the major constituents of solid exudates, some of which have not previously been described from any animal skin gland. There was a high degree of composition overlap between male and female cloaca swabs; however, there is significant variation, which could mediate echidna mating behavior. Many of the volatile and nonvolatile chemicals detected are used for communication in other species, suggesting that chemical signals have important and diverse functions in echidna social interactions. PMID:22871649

  10. 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.

  11. 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

  12. Effects of chemical composition, water and temperature on physical properties of continental crust

    NASA Astrophysics Data System (ADS)

    Guerri, Mattia; Cammarano, Fabio; Connolly, James A. D.

    2015-07-01

    We explore the influence of major elements chemistry and H2O-content on the density and seismic velocity of crustal rocks by computing stable and metastable crustal mineralogy and elastic properties as a function of pressure and temperature (P-T). Proposed average compositions of continental crust result in significantly different properties, for example a difference in computed density of ˜ 4 % is obtained at a given P-T. Phase transformations affect crustal properties at the point that crustal seismic discontinuities can be explained with mineral reactions rather than chemical stratification. H2O, even if introduced in small amount in the chemical system, has an effect on physical properties comparable to that attributed to variations in major elements composition. Thermodynamical relationships between physical properties differ significantly from commonly used empirical relationships. Density models obtained by inverting CRUST 1.0 compressional wave velocity are different from CRUST 1.0 density and translate into variations in isostatic topography and gravitational field that ranges ±600 m and ±150 mGal respectively. Inferred temperatures are higher than reference geotherms in the upper crust and in the deeper portions of thick orogenic crust, consistently with presence of metastable rocks. Our results highlight interconnections/dependencies among chemistry, pressure, temperature, seismic velocities and density that need to be addressed to better understand the crustal thermo-chemical state.

  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 effect of natural weathering on the chemical and isotopic compositions of biotites

    USGS Publications Warehouse

    Clauer, Norbert; O'Neil, J.R.; Bonnot-Courtois, C.

    1982-01-01

    The effect of progressive natural weathering on the isotopic (Rb-Sr, K-Ar, ??D, ??18O) and chemical (REE, H2O+) compositions of biotite has been studied on a suite of migmatitic biotites from the Chad Republic. During the early stages of weathering the Rb-Sr system is strongly affected, the hydrogen and oxygen isotope compositions change markedly, the minerals are depleted in light REE, the water content increases by a factor of two, and the K-Ar system is relatively little disturbed. During intensive weathering the K-Ar system is more strongly disturbed than the Rb-Sr system. Most of the isotopic and chemical modifications take place under nonequilibrium conditions and occur before newly formed kaolinite and/or smectite can be detected. These observations suggest that 1. (a) "protominerals" may form within the biotite structure during the initial period of weathering, and 2. (b) only when chemical equilibrium is approached in the weathering profile are new minerals able to form. ?? 1982.

  15. Dittrichia graveolens (L.) Greuter Essential Oil: Chemical Composition, Multivariate Analysis, and Antimicrobial Activity.

    PubMed

    Mitic, Violeta; Stankov Jovanovic, Vesna; Ilic, Marija; Jovanovic, Olga; Djordjevic, Aleksandra; Stojanovic, Gordana

    2016-01-01

    The chemical composition and in vitro antimicrobial activities of Dittrichia graveolens (L.) Greuter essential oil was studied. Moreover, using agglomerative hierarchical cluster (AHC) and principal component analyses (PCA), the interrelationships of the D. graveolens essential-oil profiles characterized so far (including the sample from this study) were investigated. To evaluate the chemical composition of the essential oil, GC-FID and GC/MS analyses were performed. Altogether, 54?compounds were identified, accounting for 92.9% of the total oil composition. The D. graveolens oil belongs to the monoterpenoid chemotype, with monoterpenoids comprising 87.4% of the totally identified compounds. The major components were borneol (43.6%) and bornyl acetate (38.3%). Multivariate analysis showed that the compounds borneol and bornyl acetate exerted the greatest influence on the spatial differences in the composition of the reported oils. The antimicrobial activity against five bacterial and one fungal strain was determined using a disk-diffusion assay. The studied essential oil was active only against Gram-positive bacteria. PMID:26765355

  16. 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.

  17. The Perils of Partition: Difficulties in Retrieving Magma Compositions from Chemically Equilibrated Basaltic Meteorites

    NASA Technical Reports Server (NTRS)

    Treiman, Allan H.

    1996-01-01

    The chemical compositions of magmas can be derived from the compositions of their equilibrium minerals through mineral/magma partition coefficients. This method cannot be applied safely to basaltic rocks, either solidified lavas or cumulates, which have chemically equilibrated or partially equilibrated at subsolidus temperatures, i.e., in the absence of magma. Applying mineral/ melt partition coefficients to mineral compositions from such rocks will typically yield 'magma compositions' that are strongly fractionated and unreasonably enriched in incompatible elements (e.g., REE's). In the absence of magma, incompatible elements must go somewhere; they are forced into minerals (e.g., pyroxenes, plagioclase) at abundance levels far beyond those established during normal mineral/magma equilibria. Further, using mineral/magma partition coefficients with such rocks may suggest that different minerals equilibrated with different magmas, and the fractionation sequence of those melts (i.e., enrichment in incompatible elements) may not be consistent with independent constraints on the order of crystallization. Subsolidus equilibration is a reasonable cause for incompatible- element-enriched minerals in some eucrites, diogenites, and martian meteorites and offers a simple alternative to petrogenetic schemes involving highly fractionated magmas or magma infiltration metasomatism.

  18. Chemical Analyses

    NASA Technical Reports Server (NTRS)

    Bulluck, J. W.; Rushing, R. A.

    1994-01-01

    As a preliminary study on the effects of chemical aging of polymer materials MERL and TRI have examined two polymeric materials that are typically used for offshore umbilical applications. These two materials were Tefzel, a copolymer of ethylene and tetrafluoroethylene, and Coflon, polyvinylidene fluoride. The Coflon specimens were cut from pipe sections and exposed to H2S at various temperatures and pressures. One of these specimens was tested for methane permeation, and another for H2S permeation. The Tefzel specimens were cut from .05 mm sheet stock material and were exposed to methanol at elevated temperature and pressure. One of these specimens was exposed to methanol permeation for 2 days at 100 C and 2500 psi. An additional specimen was exposed to liquid methanol for 3 days at 150 C and 15 Bar. Virgin specimens of each material were similarly prepared and tested.

  19. 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.

  20. 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

  1. The Planetary Host Red Giant HD47536 - Chemical Composition and Signs of Accretion

    NASA Astrophysics Data System (ADS)

    Yushchenko, A. V.; Rittipruk, P.; Yushchenko, V. A.; Kang, Y.-W.

    The spectra of HD47536 with resolving power R=30,000 and signal to noise ratio near 100 was obtained at 1.5 meter SMART telescope of CTIO, Chile. The analysis of chemical composition allowed to find the abundances of 33 chemical elements including thorium. The star belongs to halo or intermediate population, it's metallicity is [Fe/H]=-0.58±0.11, the r- and s-processes elements are overabundant with respect to iron. The overabundance of thorium with respect to iron is +0.72 dex. The abundance patternexhibits the clear signs of accretion. The star is a host of two planets, that is why it can be the result of the accretion in planetary system or the accretion of interstellar gas. The signs of accretion are clearly detected and prevent the determination of stellar age.

  2. [Comparison of green coffee beans volatiles chemical composition of Hainan main area].

    PubMed

    Hu, Rong-Suo; Chu, Zhong; Gu, Feng-Lin; Lu, Min-Quan; Lu, Shao-Fang; Wu, Gui-Ping; Tan, Le-He

    2013-02-01

    Chemical component of Hainan green coffee beans was analyzed with solid phase microextraction-gas chromatography-mass spectrometry, and the discrepancy between two green coffee beans was differentiated through the spectrum database retrieval and retention index of compound characterization. The experimental results show that: the chemical composition of Wanning coffee beans and Chengmai coffee beans is basically the same. The quantity of analyzed compound in Wanning area coffee is 91, and in Chengmai area coffee is 106, the quantity of the same compound is 66, and the percent of the same component is 75.52%. The same compounds accounted for 89.86% of the total content of Wanning area coffee, and accounted for 85.70% of the total content of Chengmai area coffee. PMID:23697152

  3. Recent Progress of Propolis for Its Biological and Chemical Compositions and Its Botanical Origin

    PubMed Central

    Toreti, Viviane Cristina; Sato, Helia Harumi; Pastore, Glaucia Maria; Park, Yong Kun

    2013-01-01

    Propolis is the generic name given to the product obtained from resinous substances, which is gummy and balsamic and which is collected by bees from flowers, buds, and exudates of plants. It is a popular folk medicine possessing a broad spectrum of biological activities. These biological properties are related to its chemical composition and more specifically to the phenolic compounds that vary in their structure and concentration depending on the region of production, availability of sources to collect plant resins, genetic variability of the queen bee, the technique used for production, and the season in which propolis is produced. Many scientific articles are published every year in different international journal, and several groups of researchers have focused their attention on the chemical compounds and biological activity of propolis. This paper presents a review on the publications on propolis and patents of applications and biological constituents of propolis. PMID:23737843

  4. Chemical compositions and antioxidant activities of water extracts of Chinese propolis.

    PubMed

    Guo, Xiali; Chen, Bin; Luo, Liping; Zhang, Xi; Dai, Ximo; Gong, Shangji

    2011-12-14

    The present study investigated the chemical composition and antioxidant activity of the water extract of propolis (WEP) collected from 26 locations in China. Spectrophotometry was used to determine the physicochemical properties and the chemical constituents of WEP. Phenolic compounds in WEP were identified by RP-HPLC-DAD with reference standards. The antioxidant activities [characterized by reducing power and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging ability] of WEP were also measured. Results show that epicatechin, p-coumaric acid, morin, 3,4-dimethoxycinnamic acid, naringenin, ferulic acid, cinnamic acid, pinocembrin, and chrysin are the major functional phenolic compounds in Chinese WEPs. Furthermore, most WEPs show strong antioxidant activities, which are significantly correlated with E(1cm)(1%), an index for the estimation of the quality of WEP. WEPs also contain many more active constituents than ethanol extracts of propolis. PMID:22026502

  5. Chemical composition and biological activity of the essential oil of Amomum biflorum.

    PubMed

    Singtothong, Chakkrapat; Gagnon, Michel J; Legault, Jean

    2013-02-01

    The aim of this study was to investigate the chemical composition and bioactivity of Amomum biflorum Jack harvested in the region of Petchaboon, Thailand. The essential oil of the fresh whole plant obtained by hydrodistillation was analyzed by gas chromatography (GC) (Kovats index) and gas chromatography coupled with mass spectrometry (GC/MS). The average yield of essential oil of A. biflorum was 0.21 +/- 0.05 % (w/w). The major chemical constituents were camphor (17.6 %), alpha-bisabolol (16.0 %), camphene (8.2 %) and alpha-humulene (5.1%). The essential oil was active against Staphylococcus aureus (MIC: 30 microg/mL) and had an antioxidant activity with an ORAC index of 23 +/- 5 micromol Trolox/mg. PMID:23513745

  6. The Cell Wall of Rickettsia mooseri I. Morphology and Chemical Composition1

    PubMed Central

    Wood, William H.; Wisseman, Charles L.

    1967-01-01

    Cell walls prepared by mechanically disrupting intact Rickettsia mooseri (R. typhi) were examined in an electron microscope and analyzed chemically. Electron micrographs of metal-shadowed and negatively stained rickettsial cell walls revealed no significant differences, except for smaller size, from bacterial cell walls prepared in a similar manner. The chemical composition was complex, and resembled that of gram-negative bacterial cell walls more closely than that of gram-positive bacterial cell walls. R. mooseri cell walls contained the sugars, glucose, galactose, and glucuronic acid, the amino sugars, glucosamine, and muramic acid, and at least 15 amino acids. Diaminopimelic acid, a compound hitherto found only in bacteria and blue-green algae, was demonstrated in rickettsiae for the first time. Teichoic acids were not detected. The compounds identified accounted for about 70% of the dry weight of the cell walls. Images PMID:6025416

  7. Chemical composition and antibacterial activity of the essential oil from Pyrrosia tonkinensis (Giesenhagen) Ching.

    PubMed

    Xin, Xiaowei; Liu, Qingshen; Zhang, Yingying; Gao, Demin

    2016-04-01

    The present study aimed to analyse the chemical components of the essential oil from Pyrrosia tonkinensis by GC-MS and evaluate the in vitro antibacterial activity. Twenty-eight compounds, representing 88.1% of the total essential oil, were identified and the major volatile components were trans-2-hexenal (22.1%), followed by nonanal (12.8%), limonene (9.6%), phytol (8.4%), 1-hexanol (3.8%), 2-furancarboxaldehyde (3.5%) and heptanal (3.1%). The antibacterial assays showed that the essential oil of P. tonkinensis had good antibacterial activities against all the tested microorganisms. This paper first reported the chemical composition and antimicrobial activity of the essential oil from P. tonkinensis. PMID:26214127

  8. Process for the preparation of fiber-reinforced ceramic composites by chemical vapor deposition

    DOEpatents

    Lackey, Jr., Walter J.; Caputo, Anthony J.

    1986-01-01

    A chemical vapor deposition (CVD) process for preparing fiber-reinforced ceramic composites. A specially designed apparatus provides a steep thermal gradient across the thickness of a fibrous preform. A flow of gaseous ceramic matrix material is directed into the fibrous preform at the cold surface. The deposition of the matrix occurs progressively from the hot surface of the fibrous preform toward the cold surface. Such deposition prevents the surface of the fibrous preform from becoming plugged. As a result thereof, the flow of reactant matrix gases into the uninfiltrated (undeposited) portion of the fibrous preform occurs throughout the deposition process. The progressive and continuous deposition of ceramic matrix within the fibrous preform provides for a significant reduction in process time over known chemical vapor deposition processes.

  9. 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.

  10. Upper limit to the mass of pulsationally stable stars with uniform chemical composition

    NASA Technical Reports Server (NTRS)

    Stothers, Richard B.

    1992-01-01

    Nuclear-energized pulsational instability is a well-known feature of models of chemically homogeneous stars above a critical mass. With the Rogers-Iglesias opacities, the instability occurs above 120-150 solar mass for normal Galactic Population I chemical compositions, and above approximately 90 solar mass for stars in metal-poor environments like the outer Galaxy and the Small Magellanic Cloud. Models of homogeneous helium-burning stars are unstable above masses of 19 and 14 solar mass, respectively. These significant increases of the critical masses, in the normal metallicity cases, over the values derived previously with the Los Alamos opacities can explain the stability of the brightest observed O-type stars, but they do not exclude the possibility that the most luminous hydrogen-deficient Wolf-Rayet stars are experiencing this type of instability.

  11. Recent progress of propolis for its biological and chemical compositions and its botanical origin.

    PubMed

    Toreti, Viviane Cristina; Sato, Helia Harumi; Pastore, Glaucia Maria; Park, Yong Kun

    2013-01-01

    Propolis is the generic name given to the product obtained from resinous substances, which is gummy and balsamic and which is collected by bees from flowers, buds, and exudates of plants. It is a popular folk medicine possessing a broad spectrum of biological activities. These biological properties are related to its chemical composition and more specifically to the phenolic compounds that vary in their structure and concentration depending on the region of production, availability of sources to collect plant resins, genetic variability of the queen bee, the technique used for production, and the season in which propolis is produced. Many scientific articles are published every year in different international journal, and several groups of researchers have focused their attention on the chemical compounds and biological activity of propolis. This paper presents a review on the publications on propolis and patents of applications and biological constituents of propolis. PMID:23737843

  12. 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 was classified in four categories, chemical reagents comprising 18.2%, solvents with 52.3%, dyes and tracers with 18.2% and solid waste with 11.4% w/w of the total. The total production of chemical waste comprised 1.8% w/w of the total hazardous medical waste produced by the hospital. Thus, the sum of pharmaceutical and chemical waste was 5.7% w/w of the total hazardous medical waste produced by the hospital. The unit production rates for total chemical waste for the hospital were 5.8 (2.2) g/patient/d and 1.1 (0.4) g/exam/d. The respective unit production rates were: (1) for reagents 1.7 (2.4) g/patient/d and 0.3 (0.4) g/examination/d, (2) for solvents 248 (127) g/patient/d and 192 (101) g/examination/d, (3) for dyes and tracers 4.7 (1.4) g/patient/d and 2.5 (0.9) g/examination/d and (4) for solid waste 54 (28) g/patient/d and 42 (22) g/examination/d.

  13. Determining the chemical composition of cloud condensation nuclei. Second progress report

    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.

    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.

  14. Aspen defense chemicals influence midgut bacterial community composition of gypsy moth.

    PubMed

    Mason, Charles J; Rubert-Nason, Kennedy F; Lindroth, Richard L; Raffa, Kenneth F

    2015-01-01

    Microbial symbionts are becoming increasingly recognized as mediators of many aspects of plant - herbivore interactions. However, the influence of plant chemical defenses on gut associates of insect herbivores is less well understood. We used gypsy moth (Lymantria dispar L.), and differing trembling aspen (Populus tremuloides Michx.) genotypes that vary in chemical defenses, to assess the influence of foliar chemistry on bacterial communities of larval midguts. We evaluated the bacterial community composition of foliage, and of midguts of larvae feeding on those leaves, using next-generation high-throughput sequencing. Plant defense chemicals did not influence the composition of foliar communities. In contrast, both phenolic glycosides and condensed tannins affected the bacterial consortia of gypsy moth midguts. The two most abundant operational taxonomic units were classified as Ralstonia and Acinetobacter. The relative abundance of Ralstonia was higher in midguts than in foliage when phenolic glycoside concentrations were low, but lower in midguts when phenolic glycosides were high. In contrast, the relative abundance of Ralstonia was lower in midguts than in foliage when condensed tannin concentrations were low, but higher in midguts when condensed tannins were high. Acinetobacter showed a different relationship with host chemistry, being relatively more abundant in midguts than with foliage when condensed tannin concentrations were low, but lower in midguts when condensed tannins were high. Acinetobacter tended to have a greater relative abundance in midguts of insects feeding on genotypes with high phenolic glycoside concentrations. These results show that plant defense chemicals influence herbivore midgut communities, which may in turn influence host utilization. PMID:25475786

  15. Household Chemical Emergencies

    MedlinePlus

    ... Hazardous Materials Incidents Household Chemical Emergencies Nuclear Power Plants Main Content Household Chemical Emergencies Nearly every household uses products containing hazardous materials or chemicals. Although the ...

  16. 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.

  17. Characterizing the origins of bottled water on the South Korean market using chemical and isotopic compositions.

    PubMed

    Bong, Yeon-Sik; Ryu, Jong-Sik; Lee, Kwang-Sik

    2009-01-12

    We analyzed the major elements and stable isotopes of oxygen, hydrogen, and carbon (dissolved inorganic carbon: DIC) in various types of bottled water (domestic and foreign) commercially available in South Korea to classify the water types and to identify their origins. Only marine waters and some sparkling waters could be discriminated by their physicochemical compositions. Oxygen and hydrogen isotopes made marine waters more distinguishable from other water types. The determination of the carbon isotope composition of DIC was clearly useful for distinguishing between naturally and artificially sparkling waters. In addition, statistical analysis also appeared to aid in the discrimination of bottled water types. Our results indicate that a method that combines chemical and stable isotope composition analysis with statistical analysis is the most useful for discriminating water types and characterizing the origins of bottled water. PMID:19084625

  18. Chemical composition of the essential oil from Croton kimosorum, an endemic species to Madagascar.

    PubMed

    Rabehaja, Delphin J R; Ihandriharison, Harilala; Ramanoelina, Panja A R; Benja, Rakotonirina; Ratsimamanga-Urverg, Suzanne; Bighelli, Ange; Casanova, Joseph; Tomi, Félix

    2014-01-01

    Croton kimosorum Leandri is an endemic species to Madagascar. The chemical composition of aerial parts, leaf and stem oils is reported for the first time. Analysis was carried out by combination of chromatographic (CC, GC), spectroscopic and spectrometric (MS, 13C NMR) techniques. In total, 76 compounds have been identified. Essential oil isolated from aerial parts contained mainly linalool (21.6%), sabinene (10.4%), 1,8-cineole (6.3%), beta-pinene (6.2%), (E)-beta-caryophyllene (5.9%), terpinen-4-ol (4.8%), geraniol (4,5%) and germacrene D (2.3%). In comparison with the first sample, the composition of leaf and stem oils varied slightly, while essential oil isolated by vapor distillation from a semi-industrial still exhibited similar composition. PMID:24660481

  19. Thermal expansion of laminated, woven, continuous ceramic fiber/chemical-vapor-infiltrated silicon carbide matrix composites

    NASA Technical Reports Server (NTRS)

    Eckel, Andrew J.; Bradt, Richard C.

    1990-01-01

    Thermal expansions of three two-dimensional laminate, continuous fiber/chemical-vapor-infiltrated silicon carbide matrix composites reinforced with either FP-Alumina (alumina), Nextel (mullite), or Nicalon (Si-C-O-N) fibers are reported. Experimental thermal expansion coefficients parallel to a primary fiber orientation were comparable to values calculated by the conventional rule-of-mixtures formula, except for the alumina fiber composite. Hysteresis effects were also observed during repeated thermal cycling of that composite. Those features were attributed to reoccurring fiber/matrix separation related to the micromechanical stresses generated during temperature changes and caused by the large thermal expansion mismatch between the alumina fibers and the silicon carbide matrix.

  20. The Chemical Nature of the Fiber/resin Interface in Composite Materials

    NASA Technical Reports Server (NTRS)

    Diefendorf, R. J.

    1984-01-01

    Carbon fiber/epoxy resin composites are considered. The nature of the fiber structure and the interaction that occurs at the interface between fiber and matrix are emphasized. Composite toughness can be improved by increased axial tensile and compressive strengths in the fibers. The structure of carbon fibers indicates that the fiber itself can fail transversely, and different transverse microstructures could provide better transverse strengths. The higher surface roughness of lower modulus and surface-treated carbon fibers provides better mechanical interlocking between the fiber and matrix. The chemical nature of the fiber surface was determined, and adsorption of species on this surface can be used to promote wetting and adhesion. Finally, the magnitude of the interfacial bond strength should be controlled such that a range of composites can be made with properties varying from relatively brittle and high interlaminar shear strength to tougher but lower interlaminar shear strength.

  1. Plant Species Rather Than Climate Greatly Alters the Temporal Pattern of Litter Chemical Composition During Long-Term Decomposition

    PubMed Central

    Li, Yongfu; Chen, Na; Harmon, Mark E.; Li, Yuan; Cao, Xiaoyan; Chappell, Mark A.; Mao, Jingdong

    2015-01-01

    A feedback between decomposition and litter chemical composition occurs with decomposition altering composition that in turn influences the decomposition rate. Elucidating the temporal pattern of chemical composition is vital to understand this feedback, but the effects of plant species and climate on chemical changes remain poorly understood, especially over multiple years. In a 10-year decomposition experiment with litter of four species (Acer saccharum, Drypetes glauca, Pinus resinosa, and Thuja plicata) from four sites that range from the arctic to tropics, we determined the abundance of 11 litter chemical constituents that were grouped into waxes, carbohydrates, lignin/tannins, and proteins/peptides using advanced 13C solid-state NMR techniques. Decomposition generally led to an enrichment of waxes and a depletion of carbohydrates, whereas the changes of other chemical constituents were inconsistent. Inconsistent convergence in chemical compositions during decomposition was observed among different litter species across a range of site conditions, whereas one litter species converged under different climate conditions. Our data clearly demonstrate that plant species rather than climate greatly alters the temporal pattern of litter chemical composition, suggesting the decomposition-chemistry feedback varies among different plant species. PMID:26515033

  2. Plant Species Rather Than Climate Greatly Alters the Temporal Pattern of Litter Chemical Composition During Long-Term Decomposition.

    PubMed

    Li, Yongfu; Chen, Na; Harmon, Mark E; Li, Yuan; Cao, Xiaoyan; Chappell, Mark A; Mao, Jingdong

    2015-01-01

    A feedback between decomposition and litter chemical composition occurs with decomposition altering composition that in turn influences the decomposition rate. Elucidating the temporal pattern of chemical composition is vital to understand this feedback, but the effects of plant species and climate on chemical changes remain poorly understood, especially over multiple years. In a 10-year decomposition experiment with litter of four species (Acer saccharum, Drypetes glauca, Pinus resinosa, and Thuja plicata) from four sites that range from the arctic to tropics, we determined the abundance of 11 litter chemical constituents that were grouped into waxes, carbohydrates, lignin/tannins, and proteins/peptides using advanced (13)C solid-state NMR techniques. Decomposition generally led to an enrichment of waxes and a depletion of carbohydrates, whereas the changes of other chemical constituents were inconsistent. Inconsistent convergence in chemical compositions during decomposition was observed among different litter species across a range of site conditions, whereas one litter species converged under different climate conditions. Our data clearly demonstrate that plant species rather than climate greatly alters the temporal pattern of litter chemical composition, suggesting the decomposition-chemistry feedback varies among different plant species. PMID:26515033

  3. Plant Species Rather Than Climate Greatly Alters the Temporal Pattern of Litter Chemical Composition During Long-Term Decomposition

    NASA Astrophysics Data System (ADS)

    Li, Yongfu; Chen, Na; Harmon, Mark E.; Li, Yuan; Cao, Xiaoyan; Chappell, Mark A.; Mao, Jingdong

    2015-10-01

    A feedback between decomposition and litter chemical composition occurs with decomposition altering composition that in turn influences the decomposition rate. Elucidating the temporal pattern of chemical composition is vital to understand this feedback, but the effects of plant species and climate on chemical changes remain poorly understood, especially over multiple years. In a 10-year decomposition experiment with litter of four species (Acer saccharum, Drypetes glauca, Pinus resinosa, and Thuja plicata) from four sites that range from the arctic to tropics, we determined the abundance of 11 litter chemical constituents that were grouped into waxes, carbohydrates, lignin/tannins, and proteins/peptides using advanced 13C solid-state NMR techniques. Decomposition generally led to an enrichment of waxes and a depletion of carbohydrates, whereas the changes of other chemical constituents were inconsistent. Inconsistent convergence in chemical compositions during decomposition was observed among different litter species across a range of site conditions, whereas one litter species converged under different climate conditions. Our data clearly demonstrate that plant species rather than climate greatly alters the temporal pattern of litter chemical composition, suggesting the decomposition-chemistry feedback varies among different plant species.

  4. Chemical composition and biological activity of essential oils of Dracocephalum heterophyllum and Hyssopus officinalis from Western Himalaya

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The essential oils of two representatives of the Lamiaceae-family, Dracocephalum heterophyllum Benth. and Hyssopus officinalis L., are described for their antifungal, antibacterial and larvicidal as well as biting deterrent activities. Additionally, the essential oils’ chemical compositions, analyze...

  5. 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

  6. Change in the surface morphology and chemical composition of some oxide crystals under UV laser irradiation

    SciTech Connect

    Kuzanyan, A S; Badalyan, G R; Kuzanyan, V S; Nikogosyan, V R; Pilosyan, S Kh; Nesterov, V M

    2011-07-31

    The effect of the 248-nm KrF and 355-nm YAG:Nd{sup 3+} laser radiation on the surface morphology and chemical composition of SrTiO{sub 3}, Sr{sub 2}RuO{sub 4}, PbMoO{sub 4}, LiNbO{sub 3}, Y{sub 3}Al{sub 5}O{sub 12}, and Al{sub 2}O{sub 3} crystals has been studied. A relationship between the laser energy density on the sample surface and the surface roughness caused by the irradiation is determined. A technique for determining exactly the geometric surface characteristics is proposed. The effect of the surface roughness on the results of energy-dispersive X-ray (EDX) microanalysis has been investigated. A method for correcting the EDX data for samples with a rough surface has been developed. It is shown that the small variation in the composition of PbMoO{sub 4}, LiNbO{sub 3}, Y{sub 3}Al{sub 5}O{sub 12}, and Al{sub 2}O{sub 3} samples after laser irradiation can be explained by the measurement error, related to the change in the surface roughness. At the same time, the irradiation of SrTiO{sub 3} and Sr{sub 2}RuO{sub 4} crystals by a YAG:Nd laser changes the chemical composition of their surface layers. (interaction of laser radiation with matter)

  7. Physical, morphological, and chemical studies of dusts derived from the machining of composite-epoxy materials.

    PubMed

    Boatman, E S; Covert, D; Kalman, D; Luchtel, D; Omenn, G S

    1988-04-01

    This work (in three parts) inquires into whether respirable dusts derived from the machining of six composite-epoxy materials (e.g., aircraft industry) may pose a health risk to the operators. Dust samples representative of a variety of composites and structural components were aerodynamically sized and fractionated. Bulk and fractionated samples were examined by light and electron microscopy and analyzed chemically by thermogravimetry (TGA), gas chromatography (GC) and mass spectrometry (MS). Relative fractions of respirable to total mass of bulk samples were less than 3%; aerodynamic diameters of fractionated particles ranged from 0.8 to 2.0 microns. By microscopy, bulk particles ranged from 7 to 11 microns in diameter, with mean aspect ratios from 4 to 8:1. Mean diameter of fractionated particles was 2.7 microns. By TGA, weight losses were negligible below 250 degrees C and variable but elevated at temperatures up to 860 degrees C. In assays of vapors released at 250 degrees C, GC/MS indicated a variety of compounds in different amounts for each sample. We conclude that under the present machining protocols, dusts at the tool face contained few particles of respirable size with no evidence of splitting of fibers longitudinally and were of a low volatilizable chemical content. Overall, composites were judged to be well cured and thermally stable. PMID:3349976

  8. Effect of season on heavy metal contents and chemical compositions of chub mackerel (Scomber japonicus) muscle.

    PubMed

    Bae, J H; Lim, S Y

    2012-02-01

    Seasonal variations of heavy metals concentrations and overall chemical compositions were determined in chub mackerel caught in the Southern Sea of Korea. The average mercury and lead content varied between 0.04 and 0.08 mg/kg and between 0.01 and 0.02 mg/kg, respectively. Seasonal variations were not detected in lead, but mercury displayed maximal values in winter (P < 0.05). A distinct seasonal pattern was found in crude fat content with maximal values in December and minimal values in April. Fatty acid composition showed that monounsaturated fatty acids levels were the highest in August, while polyunsaturated fatty acids (PUFA) levels were the highest in April. The major contributing factors to the seasonal variation of PUFA amounted to 20:5n-3 and 22:6n-3. The total amino acids content varied from 180.6 to 187.7 mg/g. There were no significant seasonal variations in total amounts of amino acids. Practical Application:  Mackerel (Scomber japonicus) is one of the most important fishing resources in Korea. The effects of polyunsaturated fatty acids (PUFA) on the human body have been identified, and consequently, the intake of fish lipids has steadily increased among the human population. There have been few studies on safety and alterations in chemical composition of mackerel attributed to seasonal fluctuations. Therefore, the results presented in this study could be used to improve the safety and nutrition information available to consumers. PMID:22251075

  9. Mapping the nebular condensates and the chemical composition of the terrestrial planets

    NASA Astrophysics Data System (ADS)

    Saxena, Surendra K.; Hrubiak, Rostislav

    2014-05-01

    We demonstrate that the condensation theory of planet formation yields solids of suitable compositions in the solar nebula that accrete to form the terrestrial planetary bodies. The mineral chemistry of the condensed objects provides definite criteria to establish the pressure and temperature of their formation. The solids condensing at a high nebular pressure of 0.01 to 0.001 bar and temperature of ∼1530 K had the best chemical composition and density to form Mercury (64 wt% iron and 36 wt% oxides, density ∼5.32 g cm). Solids that condensed around a pressure of 0.0001 bar or less and a temperature of ∼700 K formed Earth and Venus (31 wt% iron, Ni and S and 69 wt% oxides, density ∼4 g cm), and Mars (33.6 wt% Fe and S and 66.4 wt% oxides, density ∼3.7 g cm). Iron sulfide provided S (3 wt%) for the core. Hydrous minerals forming in the lower temperature region provided water to the mantle. These results are highly significant because we have used only the chemical composition of the solar nebula, thermochemistry and astrophysical data on densities of the planets.

  10. 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

  11. Characterization of the chemical composition of polyisobutylene-based oil-soluble dispersants by fluorescence.

    PubMed

    Pirouz, Solmaz; Wang, Yulin; Chong, J Michael; Duhamel, Jean

    2014-04-10

    A novel methodology based on fluorescence quenching measurements is introduced to determine quantitatively the amine content of polyisobutylene succinimide (PIBSI) dispersants used as engine oil-additives. To this end, a series of five PIBSI dispersants were prepared by reacting 2 mol equiv of polyisobutylene succinic anhydride (PIBSA) with 1 mol equiv of hexamethylenediamine (HMDA), diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine to yield the corresponding b-PIBSI dispersants. After having demonstrated that the presence of hydrogen bonds between the polyamine linker and the succinimide carbonyls of the dispersants prevents the quantitative analysis of the (1)H NMR and FTIR spectra of the dispersants to determine their chemical composition, alternative procedures based on gel permeation chromatography (GPC) and fluorescence quenching were implemented to estimate the amine content of the b-PIBSI dispersants. Taking advantage of the doubling in size that occurs when 2 mol of PIBSA are reacted with 1 mol of HMDA, a combination of GPC and FTIR was employed to follow how the chemical composition and molecular weight distribution of the polymers produced evolved with the reaction of PIBSA and HMDA mixed at different molar ratios. These experiments provided the PIBSA-to-HMDA molar ratio yielding the largest b-PIBSI dispersants and this molar ratio was then selected to prepare the four other dispersants. Having prepared five b-PIBSI dispersants with well-defined secondary amine content, the fluorescence of the succinimide groups was found to decrease with increasing number of secondary amines present in the polyamine linker. This result suggests that fluorescence quenching provides a valid method to determine the chemical composition of b-PIBSI dispersants which is otherwise difficult to characterize by standard (1)H NMR and FTIR spectroscopies. PMID:24628080

  12. 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

  13. In situ chemical composition measurements with a miniature laser ablation mass spectrometer for planetary exploration

    NASA Astrophysics Data System (ADS)

    Neuland, M. B.; Meyer, S.; Mezger, K.; Riedo, A.; Tulej, M.; Wurz, P.

    2013-09-01

    We present a miniature laser ablation mass spectrometer (LMS) for planetary and space research. For demonstrating the performance of the instrument, a sample of Allende meteorite is investigated as an analogue to a planetary surface. Investigation of a very inhomogeneous structure like the surface of a chondritic meteorite requires high spatially resolved data of chemical content, elemental and isotopic. We measure the composition of the Allende meteorite and show that by using a ns-laser for ablation, elemental analysis is accomplished with high quality allowing to study the mineralogy. The results will be compared to measurements using a fs-laser system to show improvements of the technique.

  14. Chemical composition and physicochemical properties of green banana (Musa acuminata x balbisiana Colla cv. Awak) flour.

    PubMed

    Haslinda, W H; Cheng, L H; Chong, L C; Noor Aziah, A A

    2009-01-01

    Flour was prepared from peeled and unpeeled banana Awak ABB. Samples prepared were subjected to analysis for determination of chemical composition, mineral, dietary fibre, starch and total phenolics content, antioxidant activity and pasting properties. In general, flour prepared from unpeeled banana was found to show enhanced nutrition values with higher contents of mineral, dietary fibre and total phenolics. Hence, flour fortified with peel showed relatively higher antioxidant activity. On the other hand, better pasting properties were shown when banana flour was blended with peel. It was found that a relatively lower pasting temperature, peak viscosity, breakdown, final viscosity and setback were evident in a sample blended with peel. PMID:19449278

  15. The purification procedure for human gastric juice FSA and its chemical composition.

    PubMed Central

    Häkkinen, I P

    1980-01-01

    A purification procedure for a gastric cancer-associated glycoprotein FSA is described. This substance was considered to be sulphated but is now found to derive its charge from carboxylic groups and has been renamed foetal sialoglycoprotein. The chemical composition is similar to blood group substances with differences which may reflect its origin from gastric cancer. The molecular size differs from that of the carcinoembryonic antigen. The calculation of the yield based on dry weight measurements is not possible until a radioimmunoassay technique becomes available and development of such an assay is now in progress in our laboratory. PMID:7460391

  16. Chemical composition and antioxidant activity of the essential oil of Juniperus phoenicea L. berries.

    PubMed

    Medini, Hanène; Elaissi, Ameur; Larbi Khouja, Med; Piras, Alessandra; Porcedda, Silvia; Falconieri, Danilo; Marongiu, Bruno; Chemli, Rachid

    2011-10-01

    This study is designed to examine the chemical composition and antioxidant activity of the essential oil of Juniperus phoenicea L. ripe and unripe berries. GC and GC/MS analyses resulted in the detection of 42 components representing approximately 96.50-99.57% of the oils. Major components of the oils were α-pinene (58.61-77.39%), camphene (0.67-9.31%), δ-3-carene (0-10.01%) and trans-verbenol (0-5.24%). Antioxidant activities were determined by two different test systems, DPPH and ABTS radical scavenging activities. In both systems ripe berries exhibited better activity potential than the unripe ones. PMID:21838538

  17. Characteristics of egg parts, chemical composition and nutritive value of Japanese quail eggs--a review.

    PubMed

    Tolik, Dominika; Poławska, Ewa; Charuta, Anna; Nowaczewski, Sebastian; Cooper, Ross

    2014-01-01

    All nutrients including proteins, lipids, vitamins, minerals and growth factors required by the developing embryo, as well as a number of defense factors, can be found in avian eggs. Eggs are also a source of other substances with biological functions and activities inter alia immune proteins and enzymes. Although chicken egg consumption is currently at the highest level, eggs from other species are also becoming popular. Since our knowledge about Japanese quail eggs is still limited, the aim of this review was to shed light on characteristics of egg parts, chemical composition and nutritive value of quail eggs. PMID:25916155

  18. Impacts of aerosol chemical composition on microphysics and precipitation in deep convection

    NASA Astrophysics Data System (ADS)

    Lee, Seoung Soo; Donner, Leo J.; Phillips, Vaughan T. J.

    2009-10-01

    Aerosols affect precipitation by modifying cloud properties such as cloud droplet number concentration (CDNC). Aerosol effects on CDNC depend on aerosol properties such as number concentration, size spectrum, and chemical composition. This study focuses on the effects of aerosol chemical composition on CDNC and, thereby, precipitation in a mesoscale cloud ensemble (MCE) driven by deep convective clouds. The MCE was observed during the 1997 department of energy's Atmospheric Radiation Measurement (ARM) summer experiment. Double-moment microphysics with explicit nucleation parameterization, able to take into account those three properties of aerosols, is used to investigate the effects of aerosol chemical composition on CDNC and precipitation. The effects of aerosol chemical compositions are investigated for both soluble and insoluble substances in aerosol particles. The effects of soluble substances are examined by varying mass fractions of two representative soluble components of aerosols in the continental air mass: sulfate and organics. The increase in organics with decreasing sulfate lowers critical supersaturation ( Sc) and leads to higher CDNC. Higher CDNC results in smaller autoconversion of cloud liquid to rain. This provides more abundant cloud liquid as a source of evaporative cooling, leading to more intense downdrafts, low-level convergence, and updrafts. The resultant stronger updrafts produce more condensation and thus precipitation, as compared to the case of 100% sulfate aerosols. The conventional assumption of sulfate aerosol as a surrogate for the whole aerosol mass can be inapplicable for the case with the strong sources of organics. The less precipitation is simulated when an insoluble substance replaces organics as compared to when it replaces sulfate. When the effects of organics on the surface tension of droplet and solution term in the Khler curve are deactivated by the insoluble substance, Sc is raised more than when the effects of sulfate on the solution term are deactivated by the insoluble substance. This leads to lower CDNC and, thus, larger autoconversion of cloud liquid to rain, providing less abundant cloud liquid as a source of evaporative cooling. The resultant less evaporative cooling produces less intense downdrafts, weaker low-level convergence, updrafts, condensation and, thereby, less precipitation in the case where organics is replaced by the insoluble substance than in the case where sulfate is replaced by the insoluble substance. The variation of precipitation caused by the change in the mass fraction between the soluble and insoluble substances is larger than that caused by the change in the mass fraction between the soluble substances.

  19. 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

  20. Chemical composition of the essential oil of Kaliphora madagascariensis Hook. f.

    PubMed

    Rakotosaona, Rianasoambolanoro; Nicoletti, Marcello; Papa, Fabrizio; Randrianarivo, Emmanuel; Rasoanaivo, Philippe; Maggi, Filippo

    2016-04-01

    Kaliphora madagascariensis is an evergreen shrub or small tree endemic to Madagascar where it is traditionally used for the treatment of persistent cephalalgia by a strong inhalation of its odour. In this work, we analysed for the first time the essential oil obtained from leaves by Gas Chromatography-Mass Spectrometry. The chemical composition was dominated by oxygenated sesquiterpenes (68.1%), with caryophyllene oxide (14.7%) and β-eudesmol (10.7%) as the most abundant constituents. These compounds are endowed with documented healthy effects such as analgesic, anti-inflammatory, neuritogenic, antiepileptic and hypotensive, and its abundance might explain the traditional use of the plant in Madagascar. PMID:26360928

  1. 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

  2. Evaluating the influence of chemical weathering on the composition of the continental crust using lithium and its isotopes

    NASA Astrophysics Data System (ADS)

    Rudnick, R. L.; Liu, X.

    2011-12-01

    The continental crust has an "intermediate" bulk composition that is distinct from primary melts of peridotitic mantle (basalt or picrite). This mismatch between the "building blocks" and the "edifice" of the continental crust points to the operation of processes that preferentially remove mafic to ultramafic material from the continents. Such processes include lower crustal recycling (via density foundering or lower crustal subduction - e.g., relamination, Hacker et al., 2011, EPSL), generation of evolved melts via slab melting, and/or chemical weathering. Stable isotope systems document the influence of chemical weathering on the bulk crust composition: the oxygen isotope composition of the bulk crust is distinctly heavier than that of primary, mantle-derived melts (Simon and Lecuyer, 2005, G-cubed) and the Li isotopic composition of the bulk crust is distinctly lighter than that of mantle-derive melts (Teng et al., 2004, GCA; 2008, Chem. Geol.). Both signatures mark the imprint of chemical weathering on the bulk crust composition. Here, we use a simple mass balance model for lithium inputs and outputs from the continental crust to quantify the mass lost due to chemical weathering. We find that a minimum of 15%, a maximum of 60%, and a best estimate of ~40% of the original juvenile rock mass may have been lost via chemical weathering. The accumulated percentage of mass loss due to chemical weathering leads to an average global chemical weathering rate (CWR) of ~ 8×10^9 to 2×10^10 t/yr since 3.5 Ga, which is about an order of magnitude higher than the minimum estimates based on modern rivers (Gaillardet et al., 1999, Chem. Geol.). While we cannot constrain the exact portion of crustal mass loss via chemical weathering, given the uncertainties of the calculation, we can demonstrate that the weathering flux is non-zero. Therefore, chemical weathering must play a role in the evolution of the composition and mass of the continental crust.

  3. 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.

  4. Properties of thermo-chemically surface treated carbon fibers and of their epoxy and vinyl ester composites

    SciTech Connect

    Vautard, Frederic; Ozcan, Soydan; Meyer III, Harry M

    2012-01-01

    High strength carbon fibers were surface treated by a continuous gas phase thermo-chemical surface treatment. The surface and the mechanical properties of the fibers were investigated before and after treatment and compared to the properties obtained with a conventional industrial electro-chemical surface treatment. An increase of the oxygen atomic content from 3 % to 20 % with a preferential generation of carboxylic acid functionalities and hydroxyl groups was highlighted after the thermo-chemical surface treatment, compared to an oxygen atomic content of 7 % and a wide variety of oxygen moieties with the electro-chemical surface treatment. The tensile strength of the fibers increased slightly after the thermo-chemical surface treatment and remained the same after the electro-chemical surface treatment. Short beam shear and 90 flexural tests of composites revealed that the improvement of interfacial adhesion with a vinyl ester matrix was limited, revealing that oxidation of the carbon fiber surface alone cannot tremendously improve the mechanical properties of carbon fiber-vinyl ester composites. Atomic force microscopy showed that the creation of roughness with both surface treatments at a nanometric scale. Although the surface is slightly rougher after the electro-chemical surface treatment and is expected to lead to higher adhesion due to mechanical interlocking between the fiber surface and the matrix, the effect of covalent bonding coming from the high concentration of chemical groups on the surface results in higher adhesion strength, as obtained with the thermo-chemical surface treatment.

  5. Meteorological and chemical factors controlling the composition of precipitation in eastern North America

    SciTech Connect

    Lamb, D.; Comrie, L.

    1991-07-01

    Precipitation in eastern North America is characterized by high concentrations of free acidity and sulfate that are generally attributed to anthropogenic air pollution. The relatively long record of precipitation chemistry measurements at the Penn State MAP3S site is used to analyze the seasonal and interannual variability of precipitation composition in terms of specific mechanisms of atmospheric transport and chemical transformation. The interrelationships of the chemical variables in the precipitation record and in recent air measurements clearly link the precipitation acidity with the wet deposition of sulfate derived from the in-cloud oxidation of sulfur dioxide. High-deposition events are shown through meteorological trajectory analyses to be associated with moist air from the Gulf of Mexico that passes through the upper midwestern parts of the United States. The main chemical factor controlling the deposition of sulfate appears to be the availability of strong oxidants for transforming dissolved sulfur dioxide into aqueous sulfate. Excess sulfur dioxide is expected to exit the storm systems at high altitudes and experience truly long-range transport. This interpretation of the data gives confidence that episodes will occur even after sulfur dioxide emissions have been reduced substantially.

  6. 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

  7. Quantum Dot and Polymer Composite Cross-Reactive Array for Chemical Vapor Detection.

    PubMed

    Bright, Collin J; Nallon, Eric C; Polcha, Michael P; Schnee, Vincent P

    2015-12-15

    A cross-reactive chemical sensing array was made from CdSe Quantum Dots (QDs) and five different organic polymers by inkjet printing to create segmented fluorescent composite regions on quartz substrates. The sensor array was challenged with exposures from two sets of analytes, including one set of 14 different functionalized benzenes and one set of 14 compounds related to security concerns, including the explosives trinitrotoluene (TNT) and ammonium nitrate. The array was broadly responsive to analytes with different chemical functionalities due to the multiple sensing mechanisms that altered the QDs' fluorescence. The sensor array displayed excellent discrimination between members within both sets. Classification accuracy of more than 93% was achieved, including the complete discrimination of very similar dinitrobenzene isomers and three halogenated, substituted benzene compounds. The simple fabrication, broad responsivity, and high discrimination capacity of this type of cross-reactive array are ideal qualities for the development of sensors with excellent sensitivity to chemical and explosive threats while maintaining low false alarm rates. PMID:26548712

  8. The impact of infield biomass burning on PM levels and its chemical composition.

    PubMed

    Dambruoso, P; de Gennaro, G; Di Gilio, A; Palmisani, J; Tutino, M

    2014-12-01

    In the South of Italy, it is common for farmers to burn pruning waste from olive trees in spring. In order to evaluate the impact of the biomass burning source on the physical and chemical characteristics of the particulate matter (PM) emitted by these fires, a PM monitoring campaign was carried out in an olive grove. Daily PM10 samples were collected for 1 week, when there were no open fires, and when biomass was being burned, and at two different distances from the fires. Moreover, an optical particle counter and a polycyclic aromatic hydrocarbon (PAH) analyzer were used to measure the high time-resolved dimensional distribution of particles emitted and total PAHs concentrations, respectively. Chemical analysis of PM10 samples identified organic and inorganic components such as PAHs, ions, elements, and carbonaceous fractions (OC, EC). Analysis of the collected data showed the usefulness of organic and inorganic tracer species and of PAH diagnostic ratios for interpreting the impact of biomass fires on PM levels and on its chemical composition. Finally, high time-resolved monitoring of particle numbers and PAH concentrations was performed before, during, and after biomass burning, and these concentrations were seen to be very dependent on factors such as weather conditions, combustion efficiency, and temperature (smoldering versus flaming conditions), and moisture content of the wood burned. PMID:24310905

  9. 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

  10. 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.

  11. 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 individual immunities of Australian honeybees.

  12. 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 individual immunities of Australian honeybees. PMID:26521267

  13. Size-segregated aerosol mass closure and chemical composition in Monte Cimone (I) during MINATROC

    NASA Astrophysics Data System (ADS)

    Putaud, J.-P.; van Dingenen, R.; Dell'Acqua, A.; Raes, F.; Matta, E.; Decesari, S.; Facchini, M. C.; Fuzzi, S.

    2003-07-01

    Physical and chemical characterizations of the atmospheric aerosol was carried out at Mt. Cimone (Italy) during the 4 June-4 July 2000 period. Particle size distributions in the size range 6 nm-10 ?m were measured with a differential mobility analyzer (DMA) and a optical particle counter (OPC). Size-segregated aerosol was sampled using a 6-stage low pressure impactor. Aerosol samples were submitted to gravimetric and chemical analyses. Ionic, carbonaceous and refractory components of the aerosol were quantified. We compared the sub- and super-?m aerosol mass concentrations determined by gravimetric measurements (mGM), chemical analyses (mCA), and by converting particle size distribution to aerosol mass concentrations (mSC). Mean random uncertainties associated with the determination of mGM, mCA, and mSD were assessed. The three estimates of the sub-?m aerosol mass concentration agreed, which shows that within experimental uncertainty, the sub-?m aerosol was composed of the quantified components. The three estimates of the super-mm aerosol mass concentration did not agree, which indicates that random uncertainties and/or possible systematic errors in aerosol sampling, sizing or analyses were not adequately accounted for. Aerosol chemical composition in air masses from different origins showed differences, which were significant in regard to experimental uncertainties. During the Saharan dust advection period, coarse dust and fine anthropogenic particles were externally mixed. No anthropogenic sulfate could be found in the super-?m dust particles. In contrast, nitrate was shifted towards the aerosol super-?m fraction in presence of desert dust.

  14. 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 oxides that ranged from about 98 to 101.5 wt % for the study glasses, indicating excellent recovery of all the components in the chemical composition analyses. Comparisons of the targeted and measured chemical compositions indicated that, in general, the measured values for the glasses met the targeted concentrations. Exceptions were Cr{sub 2}O{sub 3}, MgO, and P{sub 2}O{sub 5}. The measured values for Cr{sub 2}O{sub 3} were somewhat low when compared to the targeted values for all of the study glasses targeting Cr{sub 2}O{sub 3} concentrations above 0.5 wt %. Many of the measured MgO and P{sub 2}O{sub 5} values were below the targeted values for those glasses that contained these components. Two of the study glasses exhibited differences from the targeted compositions that may indicate a batching error. Glasses EWG-HAI-Centroid-2 and EWG-OL-1672 had measured values for Al{sub 2}O{sub 3} and SiO{sub 2} that were lower than the targeted values, and measured values for B{sub 2}O{sub 3} that were higher than the targeted values. Glass EWG-HAI-Centroid-2 also had a measured value for Fe{sub 2}O{sub 3} that was lower than the targeted value. A review of the PCT data, including standards and blanks, revealed no issues with the performance of the tests. The PCT results were normalized to both the targeted and measured compositions of the study glasses. Comparisons of the normalized PCT results for both the quenched and Canister Centerline Cooled versions of the study glasses are made with the Environmental Assessment benchmark glass for reference.

  15. Thermodynamic Modeling of the Chemical Composition of Calcine at the Idaho Nuclear Technology and Engineering Center

    SciTech Connect

    C. M. Frazee; J. D. Christian

    2004-02-01

    To send calcine produced at Idaho National Engineering and Environmental Laboratory to the Yucca Mountain Project for disposal, characterization information will be required. To sample calcine from its existing storage location would require extensive personnel exposure. Sufficient analyses of the chemical composition of the calcine would be extremely difficult and very expensive. In support of characterization development, the chemical composition of calcine from Bin 3 of Calcine Solid Storage Facility II was thermodynamic modeled. This calcine was produced in the Waste Calcination Facility during its second processing campaign, operating with indirect heating at 400 C and 0.744 bar (0.734 atm) during processing of aluminum high-level liquid waste (first cycle extraction raffinate from reprocessing aluminum-clad fuels) from tanks WM-180 and -182 from December 27, 1966 through August 26, 1967. The current modeling effort documents the input compositional data (liquid feed and calciner off-gas) for Batches 300 - 620 and a methodology for estimating the calcine chemical composition. The results, along with assumptions and limitations of the thermodynamic calculations, will serve as a basis for benchmarking subsequent calculations. This will be done by comparing the predictions against extensive analytical results that are currently being obtained on representative samples of the modeled calcine. A commercial free-energy minimization program and database, HSC 5.1, was used to perform the thermodynamic calculations. Currently available experimental data and process information on the calcine were used to make judgments about specific phases and compounds to include and eliminate in the thermodynamic calculations. Some off-gas species were eliminated based on kinetics restrictions evidenced by experimental data and other estimates, and some calcine components and off-gas compounds were eliminated as improbable species (unreliable thermodynamic data). The current Yucca Mountain Project level of concern is 0.1 wt % of individual cations in the waste package. Chemical composition of the individual calcine components was calculated down to 0.02 mol % and 0.09 wt % of metal components of the calcine. The results reproduce closely existing experimental information on calcine chemical and phase composition. This paper discusses specific conditions accepted for the final calculations. The major calcine components, exceeding 0.15 mol % and 0.65 wt %, are: amorphous Al2O3 (85.30 mol %, 81.20 wt %); amorphous NaNO3 (8.23 mol %, 6.53 wt %); dolomite – CaMg 0.9235 (CO3)1.9235 (1.66 mol %, 2.75 wt %); amorphous HgO (0.99 mol %, 2.00 wt %); CaSO4 (0.64 mol %, 0.82 wt %); amorphous KNO3 (0.63 mol %, 0.59 wt %); amorphous Al4B2O9 (0.54 mol %, 1.37 wt %); and amorphous Al18B4O33 (0.16 mol %, 1.57 wt %). Na is present 99.8 % as NaNO3, 99.9 % of K is present as KNO3, and 53 % NOx is NO2(g), showing that the kinetics limiting effects have been empirically accounted for in the modeling. Approximately 87 % of the mercury is in calcine.

  16. 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 organic nitrogen compounds, with an average N/C ratio ~3.8 times that of OOA. Most strikingly is the enhancement of the CxHyN2+ family ions in FOM spectra, indicating the presence of imidazole compounds, which commonly result from the aqueous phase reactions of tropospheric aldehyde such as glyoxal, formaldehyde or acetaldehyde with amino compounds. The results of this study demonstrate that aqueous phase reactions in fog water lead to the formation of some oxidized and nitrogen-containing compounds. Details and the environmental implications of results will be discussed.

  17. A composite numerical model for assessing subsurface transport of oily wastes and chemical constituents

    NASA Astrophysics Data System (ADS)

    Panday, S.; Wu, Y. S.; Huyakorn, P. S.; Wade, S. C.; Saleem, Z. A.

    1997-02-01

    Subsurface fate and transport models are utilized to predict concentrations of chemicals leaching from wastes into downgradient receptor wells. The contaminant concentrations in groundwater provide a measure of the risk to human health and the environment. The level of potential risk is currently used by the U.S. Environmental Protection Agency to determine whether management of the wastes should conform to hazardous waste management standards. It is important that the transport and fate of contaminants is simulated realistically. Most models in common use are inappropriate for simulating the migration of wastes containing significant fractions of nonaqueous-phase liquids (NAPLs). The migration of NAPL and its dissolved constituents may not be reliably predicted using conventional aqueous-phase transport simulations. To overcome this deficiency, an efficient and robust regulatory assessment model incorporating multiphase flow and transport in the unsaturated and saturated zones of the subsurface environment has been developed. The proposed composite model takes into account all of the major transport processes including infiltration and ambient flow of NAPL, entrapment of residual NAPL, adsorption, volatilization, degradation, dissolution of chemical constituents, and transport by advection and hydrodynamic dispersion. Conceptually, the subsurface is treated as a composite unsaturated zone-saturated zone system. The composite simulator consists of three major interconnected computational modules representing the following components of the migration pathway: (1) vertical multiphase flow and transport in the unsaturated zone; (2) areal movement of the free-product lens in the saturated zone with vertical equilibrium; and (3) three-dimensional aqueous-phase transport of dissolved chemicals in ambient groundwater. Such a composite model configuration promotes computational efficiency and robustness (desirable for regulatory assessment applications). Two examples are presented to demonstrate the model verification and a site application. Simulation results obtained using the composite modeling approach are compared with a rigorous numerical solution and field observations of crude oil saturations and plume concentrations of total dissolved organic carbon at a spill site in Minnesota, U.S.A. These comparisons demonstrate the ability of the present model to provide realistic depiction of field-scale situations.

  18. Interspecies differences in the empty body chemical composition of domestic animals.

    PubMed

    Maeno, H; Oishi, K; Hirooka, H

    2013-07-01

    Domestication of animals has resulted in phenotypic changes by means of natural and human-directed selection. Body composition is important for farm animals because it reflects the status of energy reserves. Thus, there is the possibility that farm animals as providers of food have been more affected by human-directed selection for body composition than laboratory animals. In this study, an analysis was conducted to determine what similarities and differences in body composition occur between farm and laboratory animals using literature data obtained from seven comparative slaughter studies (n = 136 observations). Farm animals from four species (cattle, goats, pigs and sheep) were all castrated males, whereas laboratory animals from three species (dogs, mice and rats) comprised males and/or females. All animals were fed ad libitum. The allometric equation, Y = aX b , was used to determine the influence of species on the accretion rates of chemical components (Y, kg) relative to the growth of the empty body, fat-free empty body or protein weights (X, kg). There were differences between farm and laboratory animals in terms of the allometric growth coefficients for chemical components relative to the empty BW and fat-free empty BW (P < 0.01); farm animals had more rapid accretion rates of fat (P < 0.01) but laboratory animals had more rapid accretion rates of protein, water and ash (P < 0.01). In contrast, there was no difference in terms of the allometric growth coefficients for protein and water within farm animals (P > 0.2). The allometric growth coefficients for ash weight relative to protein weight for six species except sheep were not different from a value of 1 (P > 0.1), whereas that of sheep was smaller than 1 (P < 0.01). When compared at the same fat content of the empty body, the rate of change in water content (%) per unit change in fat content (%) was not different (P > 0.05) across farm animal species and similar ash-to-protein ratios were obtained except for dogs. The fraction of empty body energy gain retained as fat increased in a curvilinear manner, and there was little variation among farm animals at the same fat content of the empty body. These findings may provide the opportunity to develop a general model to predict empty body composition across farm animal species. In contrast, there were considerable differences of chemical body composition between farm and laboratory animals. PMID:23438510

  19. The effect of variations in rainfall on the chemical composition of vulcano fumaroles (Italy)

    NASA Astrophysics Data System (ADS)

    Martini, M.; Piccardi, G.; Legittimo, P. Cellini

    1981-03-01

    Analytical data for samples collected over a period of 17 months at the crater fumaroles of Vulcano are given. Fluids are both condensed and absorbed in KOH solutions, thus providing a complete analysis of acid and condensable species. Variations in H2O, CO2, SO2, H2S, HCl, B, F, Br, NH4 concentrations are taken into account. Rainwater represents an important modifying facor of the basic chemical composition of the investigated discharges, which do not seem to have undergone any other significant change during the above mentioned span of time. While acting essentially as a diluting factor for CO2 and SO2, the inflow of meteoric water can introduce substantial modifications in concentrations of other constituents. As a consequence, any correct comparison of fumaroles compositions either for different systems or for different samplings at the same system should take into consideration the influence of meteorological conditions.

  20. Chemical composition of boulder-2 rocks and soils, Apollo 17, Station 2

    NASA Technical Reports Server (NTRS)

    Laul, J. C.; Schmitt, R. A.

    1974-01-01

    The bulk and trace element composition of five small samples from four rocks is remarkably similar. This result indicates that the metaclastic rocks studied are relatively uniform in their chemical composition. The elemental abundances found in the study are presented in two tables and the implications of the data are considered, giving attention to siderophiles, atmophile elements, and questions of element correlations. The 'dark mantle' valley soil 75081 at Camelot Crater is low in siderophiles. Since the soil is low in alkalis, a derivation from low-alkali mare basalt is suggested. The identical volatile contents in the surface soil 72461 and the 4 cm depth soil 72441 under a 0.7 m boulder argue against any surficial volatization by galactic and solar particles.

  1. Titan's Lakes Chemical Composition: Sources Of Uncertainties And Variability, Implications For Noble Gases Sequestration

    NASA Astrophysics Data System (ADS)

    Cordier, Daniel; Mousis, O.; Lunine, J.; Lebonnois, S.; Rannou, P.; Lavvas, P.; Lobo, L.; Ferreira, A.

    2010-10-01

    In 2007, the instruments of the CASSINI spacecraft, orbiting within the system of Saturn, allowed the discovery of RADAR dark-patches in the polar regions of the main kronian moon. These features are interpreted as hydrocarbon lakes with ethane identified as the main compound. In order to detail the composition of these lakes, numerical simulations have been recently performed assuming thermodynamic equilibrium between the atmosphere and the liquid phase. Here we first explore the influence of thermodynamic data uncertainties on the computed lakes chemical composition. To do so, we perform Monte-Carlo simulations in order to mimic the relevant uncertainties. In a second stage we examine the hypothesis that Titan's hydrocarbon lakes could be at the origin of the strong noble gas depletion measured in the atmosphere by the Huygens probe.

  2. Chemical composition and binary mixture of human urinary stones using FT-Raman spectroscopy method

    NASA Astrophysics Data System (ADS)

    Selvaraju, R.; Raja, A.; Thiruppathi, G.

    2013-10-01

    In the present study the human urinary stones were observed in their different chemical compositions of calcium oxalate monohydrate, calcium oxalate dihydrate, calcium phosphate, struvite (magnesium ammonium phosphate), uric acid, cystine, oxammite (ammonium oxalate monohydrate), natroxalate (sodium oxalate), glushinkite (magnesium oxalate dihydrate) and moolooite (copper oxalate) were analyzed using Fourier Transform-Raman (FT-Raman) spectroscopy. For the quantitative analysis, various human urinary stone samples are used for ratios calculation of binary mixtures compositions such as COM/COD, HAP/COD, HAP/COD, Uric acid/COM, uric acid/COD and uric acid/HAP. The calibration curve is used for further analysis of binary mixture of human urinary stones. For the binary mixture calculation the various intensities bands at 1462 cm-1 (ICOM), 1473 cm-1 (ICOD), 961 cm-1 (IHAP) and 1282 cm-1 (IUA) were used.

  3. Chemical composition and antibacterial activity of essential oil of Nepeta graciliflora Benth. (Lamiaceae).

    PubMed

    Sharma, Pankaj; Shah, G C; Sharma, Rabia; Dhyani, Praveen

    2016-06-01

    The chemical composition of the essential oil obtained from aerial parts of Nepeta graciliflora was analysed, for the first time, by GC-FID and GC-MS. A total of 27 compounds were identified, constituting over 91.44% of oil composition. The oil was strongly characterised by sesquiterpenes (86.72%), with β-sesquiphellandrene (28.75%), caryophyllene oxide (12.15%), α-bisabolol (8.97%), α-bergamotene (8.51%), β-bisabolene (6.33%) and β-Caryophyllene (5.34%) as the main constituents. The in vitro activity of the essential oil was determined against four micro-organisms in comparison with chloramphenicol by the agar well diffusion and broth dilution method. The oil exhibited good activity against all tested organisms. PMID:26140331

  4. Effect of chemical composition on the shock response of Zr-based metallic glasses

    NASA Astrophysics Data System (ADS)

    Brown, A. D.; Wang, F.; Laws, K. J.; Eakins, D.; Chapman, D. J.; Hazell, P. J.; Ferry, M.; Escobedo, J. P.

    2015-06-01

    Plate impact experiments were conducted on Zr-based bulk metallic glasses (BMG) with nominal compositions of Zr55Cu30Ni5Al30 and Zr46Cu38Ag8Al38. Velocity interferometry was used to measure the free surface velocity (FSV) histories. These measurements allowed calculation of the Hugoniot elastic limits and onset stresses of fracture (i.e. spall strength) for each alloy. The soft recovered specimens were fully characterized by means of optical and electron microscopy, x-ray diffraction and differential scanning calorimetry. The characterization results aided to assess the effect of chemical composition on the microstructural evolution, i.e. phase changes or crystallization, within the BMGs during shock loading. These changes were then correlated to the differences in strength and ductility on the nominally brittle amorphous BMGs. The most significant results from this study will be presented. State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology.

  5. Chemical compositions of the rhizome, leaf and stem oils from Malaysian Hornstedtia leonurus.

    PubMed

    Jani, Nor Akmalazura; Sirat, Mohd Hasnah; Ali, NorAzah Mohamad; Aziz, Azrina

    2013-04-01

    The chemical compositions of the essential oil of the rhizome, leaf and stem of Hornstedtia leonurus Retz., collected from Negeri Sembilan, Malaysia,are reported for the first time. The essential oils were extracted using hydrodistillation and analyzed by gas chromatography (GC-FID) and gas chromatography/mass spectrometry (GC/MS). Seventeen (96.4%), thirteen (89.2%) and nine components (98.8%) were successfully identified from the rhizome, stem and leaf oils, respectively. Phenylpropanoids were found to be the major fraction, with methyleugenol being the most abundant compound in all oils with percentage compositions of 76.4% (rhizome), 80.3% (stem) and 74.5% (leaf). PMID:23738467

  6. Composition and chemical changes during storage of fish meal from Capelin (Mallotus villosus).

    PubMed

    Bragadóttir, Margrét; Pálmadóttir, Heida; Kristbergsson, Kristberg

    2004-03-24

    The stability of fish meal depends on processing and storage conditions, but habitat and seasonal variations in composition and naturally occurring anti- and pro-oxidants may be equally important. Capelin meal from four different seasons was examined by measuring chemical composition and monitoring lipid oxidation during storage. The results revealed that lipid content was high in the summer but low in the spring. It was further demonstrated that among naturally occurring antioxidants, astaxanthin was high during summer, whereas alpha-tocopherol was highest in spring. Mineral content varied, with a high copper content in the summer, whereas iron, selenium, and zinc were highest in the winter. Measurements on the stability of capelin meal indicated a decrease in peroxide values, oxygen uptake, and thiobarbituric acid reactive compounds with storage, whereas browning and CO concentration increased with time. Rancidity was highest in autumn, but free fatty acids were highest during spring and summer. PMID:15030213

  7. Photothermal method for in situ microanalysis of the chemical composition of coal samples

    DOEpatents

    Amer, N.M.

    1983-10-25

    Successive minute regions along a scan path on a coal sample are individually analyzed, at a series of different depths if desired, to determine chemical composition including the locations, sizes and distributions of different maceral inclusions. A sequence of infrared light pulses of progressively changing wavelengths is directed into each minute region and a probe light beam is directed along the sample surface adjacent the region. Infrared wavelengths at which strong absorption occurs in the region are identified by detecting the resulting deflections of the probe beam caused by thermally induced index of refraction changes in the air or other medium adjacent the region. The detected peak absorption wavelengths are correlated with known characteristic peak absorption wavelengths of specific coal constituents to identify the composition of each such minute region of the sample. The method enables rapid, convenient and non-destructive analyses of coal specimens to facilitate mining, processing and utilization of coals. 2 figures.

  8. Chemical diversity of Ziziphora clinopodioides: composition of the essential oil of Z. clinopodioides from Tajikistan.

    PubMed

    Sharopov, Farukh S; Setzer, William N

    2011-05-01

    The chemical composition of the essential oils of Ziziphora clinopodioides Lam. from the aerial flowering parts, collected during two different years, were obtained by hydrodistillation and analyzed by gas chromatography - mass spectrometry. Forty-five components representing 100% and 94.7% of the total oil were identified. The main constituents of the essential oils were pulegone (72.8 and 35.0%), neomenthol (6.5 and 23.1%), menthone (6.2 and 13.3%), p-menth-3-en-8-ol (1.7 and 3.5%), piperitenone (2.6 and 1.1%) and piperitone (0.7 and 1.2%). A cluster analysis was carried out on the essential oil compositions of Z. clinopodioides. PMID:21615034

  9. 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).

  10. 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.

  11. The chemical durability of glass and graphite-glass composite doped with cesium oxide

    NASA Astrophysics Data System (ADS)

    Hamodi, Nasir H.; Abram, Timothy J.; Lowe, Tristan; Cernik, Robert J.; López-Honorato, Eddie

    2013-01-01

    The role of temperature in determining the chemical stability of a waste form, as well as its leach rate, is very complex. This is because the dissolution kinetics is dependent both on temperature and possibility of different rate-controlling mechanisms that appear at different temperature regions. The chemical durability of Alumina-Borosilicate Glass (ABG) and Glass-Graphite Composite (GGC), bearing Tristructural Isotropic (TRISO) fuel particles impregnated with cesium oxide, were compared using a static leach test. The purpose of this study is to examine the chemical durability of glass-graphite composite to encapsulate coated fuel particles, and as a possible alternative for recycling of irradiated graphite. The test was based on the ASTM C1220-98 methodology, where the leaching condition was set at a temperature varying from 298 K to 363 K for 28 days. The release of cesium from ABG was in the permissible limit and followed the Arrhenius's law of a surface controlled reaction; its activation energy (Ea) was 65.6 ± 0.5 kJ/mol. Similar values of Ea were obtained for Boron (64.3 ± 0.5) and Silicon (69.6 ± 0.5 kJ/mol) as the main glass network formers. In contrast, the dissolution mechanism of cesium from GGC was a rapid release, with increasing temperature, and the activation energy of Cs (91.0 ± 5 kJ/mol) did not follow any model related to carbon kinetic dissolution in water. Microstructure analysis confirmed the formation of Crystobalite SiO2 as a gel layer and Cs+1 valence state on the ABG surface.

  12. Recent laboratory and field observations of the chemical composition of atmospheric nanoparticles

    NASA Astrophysics Data System (ADS)

    Smith, J. N.; Winkler, P.; Hildebrandt Ruiz, L.; Lawler, M. J.; Ortega, J.; Fry, J.; Barsanti, K. C.; McMurry, P. H.; Johnston, M. V.

    2012-12-01

    This presentation will focus on understanding the species and mechanisms that are responsible for the formation and growth of atmospheric nanoparticles. We report 10 - 40 nm diameter nanoparticle chemical composition measurements performed in two coastal sites (Mace Head, Ireland, and Lewes, Delaware USA) and two forested sites (Hyytiälä, Finland, and Manitou Forest, Colorado USA) with the recently-developed High Resolution Time-of-Flight Thermal Desorption Chemical Ionization Mass Spectrometer (HTOF-TDCIMS). These field measurements are supplemented by laboratory experiments of particle formation and growth performed at NCAR using a flow tube apparatus and a Teflon bag reaction chamber, and by thermodynamic modeling. Together, our field and laboratory observations point to crucial roles played in nanoparticle growth by two compounds: organic acids and organonitrates. The first, organic acids, are major contributors to the organic fraction in sub-20 nm diameter biogenic nanoparticles but appear to be less abundant in the organic fraction of larger particles, the latter of which are dominated by multifunctional carbonyl- and alcohol-containing compounds. The observed changes in chemical composition of the organic fraction as a function of particle size are supported by thermodynamic modeling results. The second, organonitrates, are commonly found in ambient nanoparticles as small as 10 nm in diameter. However unlike organic acids, organonitrates become increasingly more important in nanoparticle growth as particle size increases. Laboratory experiments suggest that organonitrates formed from the nitrate radical oxidation of biogenic organic compounds, a subset of total organonitrates, exhibit particularly low volatility and can thus partition into the smallest nanoparticles. This is confirmed by HTOF-TDCIMS measurements of 10 - 20 nm diameter particles, which show that particulate phase organonitrates peak in the morning, shortly following the period where organonitrates are believed to be formed by nitrate radical chemistry.

  13. Chemical compositions and antioxidant activities of polysaccharides from the sporophores and cultured products of Armillaria mellea.

    PubMed

    Zhang, Shanshan; Liu, Xiaoqian; Yan, Lihua; Zhang, Qiwei; Zhu, Jingjing; Huang, Na; Wang, Zhimin

    2015-01-01

    Armillaria mellea is a traditional Chinese medicinal and edible mushroom. Many cultured products of A. mellea have been used to develop commercial medicines in recent years. The chemical composition and activities of the major bioactive chemical components-polysaccharides-may be different because of differences in the raw materials used. Four polysaccharides (SP, CMP, CFBP and CFMP) were obtained from wild sporophores and cultured products (including mycelia, fermentation broth and fermentation mixture) of A. mellea. Their yields, carbohydrate contents, monosaccharide compositions, FT-IR spectra, NMR spectroscopy and antioxidant activities were investigated. All of the polysaccharides were composed of xylose, glucose and galactose without protein. Glucose was the dominant monosaccharide in SP, CMP and CFMP, whereas galactose was the dominant monosaccharide in CFBP. SP and CMP showed higher scavenging DPPH• and ABTS•+ activities and reducing power among four polysaccharides. The carbohydrate content and corresponding glucose percentage were positive influences on the antioxidant activities, whereas the corresponding xylose and galactose percentage were negative influences. A. mellea polysaccharides are potential natural antioxidants. Polysaccharides from cultured products, especially mycelia, are good substitutes for SP and are also potential sources for both dietary supplements and food industries. PMID:25838171

  14. 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

  15. On the binary helium star DY Centauri: chemical composition and evolutionary state

    SciTech Connect

    Pandey, Gajendra; Rao, N. Kameswara; Jeffery, C. Simon; Lambert, David L. E-mail: nkrao@iiap.res.in E-mail: dll@astro.as.utexas.edu

    2014-10-01

    DY Cen has shown a steady fading of its visual light by about one magnitude in the last 40 yr, suggesting a secular increase in its effective temperature. We have conducted non-local thermodynamic equilibrium (LTE) and LTE abundance analyses to determine the star's effective temperature, surface gravity, and chemical composition using high-resolution spectra obtained over two decades. The derived stellar parameters for three epochs suggest that DY Cen has evolved at a constant luminosity and has become hotter by about 5000 K in 23 yr. We show that the derived abundances remain unchanged for the three epochs. The derived abundances of the key elements, including F and Ne, are as observed for the extreme helium stars resulting from a merger of a He white dwarf with a C-O white dwarf. Thus DY Cen by chemical composition appears to also be a product of a merger of two white dwarfs. This appearance seems to be at odds with the recent suggestion that DY Cen is a single-lined spectroscopic binary.

  16. Chemical composition, mineral content and amino acid and lipid profiles in bones from various fish species.

    PubMed

    Toppe, Jogeir; Albrektsen, Sissel; Hope, Britt; Aksnes, Anders

    2007-03-01

    The chemical composition, content of minerals and the profiles of amino acids and fatty acids were analyzed in fish bones from eight different species of fish. Fish bones varied significantly in chemical composition. The main difference was lipid content ranging from 23 g/kg in cod (Gadus morhua) to 509 g/kg in mackerel (Scomber scombrus). In general fatty fish species showed higher lipid levels in the bones compared to lean fish species. Similarly, lower levels of protein and ash were observed in bones from fatty fish species. Protein levels differed from 363 g/kg lipid free dry matter (dm) to 568 g/kg lipid free dm with a concomitant inverse difference in ash content. Ash to protein ratio differed from 0.78 to 1.71 with the lowest level in fish that naturally have highest swimming and physical activity. Saithe (Pollachius virens) and salmon (Salmo salar) were found to be significantly different in the levels of lipid, protein and ash, and ash/protein ratio in the bones. Only small differences were observed in the level of amino acids although species specific differences were observed. The levels of Ca and P in lipid free fish bones were about the same in all species analyzed. Fatty acid profile differed in relation to total lipid levels in the fish bones, but some minor differences between fish species were observed. PMID:17208480

  17. Chemical composition of ground water in the Yucca Mountain area, Nevada, 1971-84

    USGS Publications Warehouse

    Benson, L.V.; McKinley, P.W.

    1985-01-01

    Fifteen wells in the Yucca Mountain area of southern Nevada have been sampled for chemical analysis. Samples were obtained by pumping water from the entire well bore (composite sample), and, in three instances, by pumping from one or more isolated intervals within a well bore. Sodium is the most abundant cation , and biocarbonate is the most abundant anion in all water samples. Samples from the Paleozoic carbonate aquifer penetrated by well UE-25p 1 contain higher relative concentrations of calcium and magnesium than samples from overlying volcanic tuffs. Values of the stable isotope concentrations of oxygen and hydrogen are relatively negative (light) and have deuterium excess values ranging from +5 to +10. The distribution of uncorrected radiocarbon ages of tuffaceous groundwater from samples within one kilometer of the exploratory block ranges from 12,000 to 18,500 years before present. Variation in the inorganic, stable, and radioactive isotope composition of samples indicates a significant degree of lateral and vertical chemical inhomogeneity in groundwater of the Yucca Mountain area. (USGS)

  18. 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.

  19. 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

  20. Superconducting properties and chemical composition of NbTiN thin films with different thickness

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Peng, W.; You, L. X.; Wang, Z.

    2015-09-01

    In this research, we systematically investigated the superconducting properties and chemical composition of NbTiN thin films prepared on single-crystal MgO substrates. The NbTiN thin films with different thicknesses (4-100 nm) were deposited by reactive DC magnetron sputtering at ambient temperature. We measured and analyzed the crystal structure and thickness dependence of the chemical composition using X-ray diffraction and X-ray photoelectron spectroscopy depth profiles. The films exhibited excellent superconducting properties, with a high superconducting critical temperature of 10.1 K, low resistivity (ρ20 = 93 μΩ cm), and residual resistivity ratio of 1.12 achieved for 4-nm-thick ultrathin NbTiN films prepared at the deposition current of 2.4 A. The stoichiometry and electrical properties of the films varied gradually between the initial and upper layers. A minimum ρ20 of 78 μΩ cm and a maximum residual resistivity ratio of 1.15 were observed for 12-nm-thick films, which significantly differ from the properties of NbN films with the same NaCl structure.

  1. Effect of chemical composition and density of the pelvic structure in intracavitary brachytherapy dosimetry

    NASA Astrophysics Data System (ADS)

    Chávez-Aguilera, N.; Torres-García, E.; Mitsoura, E.

    2011-03-01

    High dose rate (HDR) and low dose rate (LDR) intracavitary brachytherapies dosimetry in clinical practice are typically performed by commercial treatment planning systems. However, these systems do not fully consider the heterogeneities present in the real structure of the patient. The aim of this work is to obtain isodose curves and surfaces around the usual array of sources used in LDR ( 137Cs) and HDR ( 192Ir) intracavitary brachytherapy by Monte Carlo simulation, considering the real anatomic structure, density and chemical composition of media and tissues from the female pelvic region. The structural information was obtained from computed tomography images in the DICOM format. A voxel phantom (VP) was developed to perform ionizing radiation transport, considering the gamma spectrum of 137Cs and 192Ir. The absorbed dose was computed within each voxel of 2×2×3 mm 3. Four materials were considered in the VP—air, fat, muscle tissue and bone; however, one material per voxel was defined. Results show and quantify the effect of density and chemical composition of the medium on the absorbed dose distribution. According to them, the treatment planning systems underestimate the absorbed dose by 8% approximately for both radionuclides. In a heterogeneous medium, the absorbed dose distribution of 192Ir is more irregular than that of 137Cs but spatially better defined.

  2. Toxicological evaluation of an electrically heated cigarette. Part 2: Chemical composition of mainstream smoke.

    PubMed

    Stabbert, R; Voncken, P; Rustemeier, K; Haussmann, H-J; Roemer, E; Schaffernicht, H; Patskan, G

    2003-01-01

    The chemical composition of mainstream smoke from an electrically heated cigarette (EHC) and that of mainstream smoke from the University of Kentucky Reference Cigarette 1R4F was analyzed. In contrast to the 1R4F, which is a conventional, lit-end cigarette, the EHC is smoked in a microprocessor-controlled lighter with electrical heater elements. The electrical heating causes the tobacco under the heater element to burn at a low temperature during each puff. A comprehensive list of chemical constituents was analyzed in mainstream smoke. The list is a combination of those compounds suggested for analysis in cigarette smoke by a US Consumer Product Safety Commission proposal in 1993, and those cigarette smoke constituents identified by the International Agency on Research on Cancer as being present in cigarette smoke and characterized as carcinogens. The low pyrolysis/combustion temperature of tobacco in the EHC causes distinct shifts in the composition of the smoke compared with a conventional cigarette. A significant drop was seen in the yields of almost all toxicologically relevant constituents. On a per cigarette basis almost two-thirds of the constituents were reduced by at least 80%, whereas on an equal total particulate matter basis about two-thirds of the constituents were reduced by at least 50%, with many constituents reduced by more than 90%. PMID:12975772

  3. Chemical composition and Zn bioavailability of the soil solution extracted from Zn amended variable charge soils.

    PubMed

    Zampella, Mariavittoria; Adamo, Paola

    2010-01-01

    A study on variable charge soils (volcanic Italian and podzolic Scottish soils) was performed to investigate the influence of soil properties on the chemical composition of soil solution. Zinc speciation, bioavailability and toxicity in the soil solution were examined. The soils were spiked with increasing amounts of Zn (0, 100, 200, 400 and 1000 mg/kg) and the soil solutions were extracted using rhizon soil moisture samplers. The pH, total organic carbon (TOC), base cations, anions, total Zn and free Zn2+ in soil solution were analysed. A rapid bioassay with the luminescent bacterium Escherichia coli HB101 pUCD607 was performed to assess Zn toxicity. The influence of soil type and Zn treatments on the chemical composition of soil solution and on Zn toxicity was considered and discussed. Different trends of total and free Zn concentrations, base cations desorption and luminescence of E. coli HB101 pUCD607 were observed. The soil solution extracted from the volcanic soils had very low total and free Zn concentrations and showed specific Zn2+/Ca2+ exchange. The soil solution from the podzolic soil had much higher total and free Zn concentrations and showed no evidence of specific Zn2+/Ca2+ exchange. In comparison with the subalkaline volcanic soils, the acidic podzol showed enhanced levels of toxic free Zn2+ and consequently stronger effects on E. coli viability. PMID:21174971

  4. 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

  5. Chemical composition of essential oils of Litsea cubeba harvested from its distribution areas in China.

    PubMed

    Si, Linlin; Chen, Yicun; Han, Xiaojiao; Zhan, Zhiyong; Tian, Shengping; Cui, Qinqin; Wang, Yangdong

    2012-01-01

    Litsea cubeba (Lour.) Pers. is a promising industrial crop with fruits rich in essential oils. The chemical composition of essential oils of L. cubeba (EOLC) were determined for fruits harvested from eight regions in China. The overall essential oil content, obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS), ranged from 3.04% to 4.56%. In total, 59 compounds were identified, the dominant components being monoterpenes (94.4-98.4%), represented mainly by neral and geranial (78.7-87.4%). D-Limonene was unexpectedly a lesser constituent (0.7-5.3%) in fruits, which differed from previous reports (6.0-14.6%). Several components were only detected in certain regions and compounds such as o-cymene and eremophilene have never before been reported in EOLC. These results demonstrate significant regional variation in the chemical composition of EOLC. This investigation provides important information with regard to the bioactivity, breeding work and industrial applications of L. cubeba. PMID:22683894

  6. Superconducting properties and chemical composition of NbTiN thin films with different thickness

    SciTech Connect

    Zhang, L.; Peng, W.; You, L. X.; Wang, Z.

    2015-09-21

    In this research, we systematically investigated the superconducting properties and chemical composition of NbTiN thin films prepared on single-crystal MgO substrates. The NbTiN thin films with different thicknesses (4–100 nm) were deposited by reactive DC magnetron sputtering at ambient temperature. We measured and analyzed the crystal structure and thickness dependence of the chemical composition using X-ray diffraction and X-ray photoelectron spectroscopy depth profiles. The films exhibited excellent superconducting properties, with a high superconducting critical temperature of 10.1 K, low resistivity (ρ{sub 20} = 93 μΩ cm), and residual resistivity ratio of 1.12 achieved for 4-nm-thick ultrathin NbTiN films prepared at the deposition current of 2.4 A. The stoichiometry and electrical properties of the films varied gradually between the initial and upper layers. A minimum ρ{sub 20} of 78 μΩ cm and a maximum residual resistivity ratio of 1.15 were observed for 12-nm-thick films, which significantly differ from the properties of NbN films with the same NaCl structure.

  7. Chemical, isotopic, and gas compositions of selected thermal springs in Arizona, New Mexico, and Utah

    USGS Publications Warehouse

    Mariner, R.H.; Presser, T.S.; Evans, William C.

    1977-01-01

    Twenty-seven thermal springs in Arizona, New Mexico, and Utah were sampled for detailed chemical and isotopic analysis. The springs issue sodium chloride, sodium bicarbonate, or sodium mixed-anion waters of near neutral (6.2) to alkaline (9.2) pH. High concentrations of fluoride, more than 8 milligrams per liter, occur in Arizona in waters from Gillard Hot Springs, Castle Hot Springs, and the unnamed spring of Eagle Creek, and in New Mexico from springs along the Gila River. Deuterium compositions of the thermal waters cover the same range as those expected for meteoric waters in the respective areas. The chemical compositions of the thermal waters indicate that Thermo Hot Springs in Utah and Gillard Hot Springs in Arizona represent hydrothermal systems which are at temperatures higher than 125 deg C. Estimates of subsurface temperature based on the quartz and Na-K-Ca geothermometer differ by up to 60 deg C for Monroe, Joseph, Red Hill, and Crater hot springs in Utah. Similar conflicting estimates of aquifer temperature occur for Verde Hot Springs, the springs near Clifton and Coolidge Dam, in Arizona; and the warm springs near San Ysidro, Radium Hot Springs, and San Francisco Hot Springs, in New Mexico. Such disparities could result from mixing, precipitation of calcium carbonate, or perhaps appreciable concentrations of magnesium. (Woodard-USGS)

  8. Seasonal variation, chemical composition and antioxidant activity of Brazilian propolis samples.

    PubMed

    Teixeira, Erica Weinstein; Message, Dejair; Negri, Giuseppina; Salatino, Antonio; Stringheta, Paulo Csar

    2010-09-01

    Total phenolic contents, antioxidant activity and chemical composition of propolis samples from three localities of Minas Gerais state (southeast Brazil) were determined. Total phenolic contents were determined by the Folin-Ciocalteau method, antioxidant activity was evaluated by DPPH, using BHT as reference, and chemical composition was analyzed by GC/MS. Propolis from Itapecerica and Paula Cndido municipalities were found to have high phenolic contents and pronounced antioxidant activity. From these extracts, 40 substances were identified, among them were simple phenylpropanoids, prenylated phenylpropanoids, sesqui- and diterpenoids. Quantitatively, the main constituent of both samples was allyl-3-prenylcinnamic acid. A sample from Virginpolis municipality had no detectable phenolic substances and contained mainly triterpenoids, the main constituents being ?- and ?-amyrins. Methanolic extracts from Itapecerica and Paula Cndido exhibited pronounced scavenging activity towards DPPH, indistinguishable from BHT activity. However, extracts from Virginpolis sample exhibited no antioxidant activity. Total phenolic substances, GC/MS analyses and antioxidant activity of samples from Itapecerica collected monthly over a period of 1 year revealed considerable variation. No correlation was observed between antioxidant activity and either total phenolic contents or contents of artepillin C and other phenolic substances, as assayed by CG/MS analysis. PMID:18955317

  9. Mineral and chemical composition of the Jezersko meteorite—A new chondrite from Slovenia

    NASA Astrophysics Data System (ADS)

    Miler, Miloš; Ambrožič, Bojan; Mirtič, Breda; Gosar, Mateja; Å turm, Sašo.; Dolenec, Matej; Jeršek, Miha

    2014-10-01

    The Jezersko meteorite is a newly confirmed stony meteorite found in 1992 in the Karavanke mountains, Slovenia. The meteorite is moderately weathered (W2), indicating short terrestrial residence time. Chondrules in partially recrystallized matrix are clearly discernible but often fragmented and have mean diameter of 0.73 mm. The meteorite consists of homogeneous olivine (Fa19.4) and low-Ca pyroxenes (Fs16.7Wo1.2), of which 34% are monoclinic, and minor plagioclase (Ab83An11Or6) and Ca-pyroxene (Fs6Wo45.8). Troilite, kamacite, zoned taenite, tetrataenite, chromite, and metallic copper comprise about 16.5 vol% of the meteorite. Phosphates are represented by merrillite and minor chlorapatite. Undulatory extinction in some olivine grains and other shock indicators suggests weak shock metamorphism between stages S2 and S3. The bulk chemical composition generally corresponds to the mean H chondrite composition. Low siderophile element contents indicate the oxidized character of the Jezersko parent body. The temperatures recorded by two-pyroxene, olivine-chromite, and olivine-orthopyroxene geothermometers are 854 °C, 737-787 °C, and 750 °C, respectively. Mg concentration profiles across orthopyroxenes and clinopyroxenes indicate relatively fast cooling at temperatures above 700 °C. A low cooling rate of 10 °C Myr-1 was obtained from metallographic data. Considering physical, chemical, and mineralogical properties, meteorite Jezersko was classified as an H4 S2(3) ordinary chondrite.

  10. Effects of aerosol sources and chemical compositions on cloud drop sizes and glaciation temperatures

    NASA Astrophysics Data System (ADS)

    Zipori, Assaf; Rosenfeld, Daniel; Tirosh, Ofir; Teutsch, Nadya; Erel, Yigal

    2015-09-01

    The effect of aerosols on cloud properties, such as its droplet sizes and its glaciation temperatures, depends on their compositions and concentrations. In order to examine these effects, we collected rain samples in northern Israel during five winters (2008-2011 and 2013) and determined their chemical composition, which was later used to identify the aerosols' sources. By combining the chemical data with satellite-retrieved cloud properties, we linked the aerosol types, sources, and concentrations with the cloud glaciation temperatures (Tg). The presence of dust increased Tg from -26°C to -12°C already at relatively low dust concentrations. This result is in agreement with the conventional wisdom that desert dust serves as good ice nuclei (INs). With higher dust concentrations, Tg saturated at -12°C, even though cloud droplet sizes decreased as a result of the cloud condensation nucleating (CCN) activity of the dust. Marine air masses also encouraged freezing, but in this case, freezing was enhanced by the larger cloud droplet sizes in the air masses (caused by low CCN concentrations) and not by IN concentrations or by aerosol type. An increased fraction of anthropogenic aerosols in marine air masses caused a decrease in Tg, indicating that these aerosols served as poor IN. Anthropogenic aerosols reduced cloud droplet sizes, which further decreased Tg. Our results could be useful in climate models for aerosol-cloud interactions, as we investigated the effects of aerosols of different sources on cloud properties. Such parameterization can simplify these models substantially.

  11. Chemical composition, antibacterial, antifungal and antioxidant activities of Algerian Eryngium tricuspidatum L. essential oil.

    PubMed

    Merghache, Djamila; Boucherit-Otmani, Zahia; Merghache, Salima; Chikhi, Ilyas; Selles, Chaouki; Boucherit, Kebir

    2014-01-01

    This study describes the chemical composition and the antibacterial, antifungal and antioxidant activities of the essential oil extracted from aerial parts of the Algerian Eryngium tricuspidatum L., obtained by hydrodistillation and analysed by using the combination of gas chromatography (GC) and GC/mass spectrometry. A total of 63 compounds were identified accounting for 93.1% of the total oil. Chemical composition of oil was characterised by a high proportion of oxygenated sesquiterpenes (49.6%) among which α-bisabolol (32.6%) was the predominant compound. The sesquiterpene hydrocarbons represent the second major fraction (31.9%) with α-curcumene (6.5%) being the predominant one. Antibacterial and antifungal activities of the oil were tested using the micro-well determination of minimum inhibitory concentration (MIC) assay against eleven bacteria and two Candida species. It was found that the aerial parts of E. tricuspidatum exhibited interesting antibacterial and anticandidal activities (MIC = 9 μg/mL against several strains of bacteria and MIC = 4.6 μg/mL against Candida albicans). The antioxidant effect of this oil was evaluated using the 2,2-diphenyl-l-1-picrylhydrazil (DPPH) and ferric reducing antioxidant power (FRAP) assays. Results revealed significant activities (DPPH method: IC₅₀ = 510 μg/mL; FRAP assay: reducing power of oil increases from 0.0188 at 5 μg/mL to 0.5016 at 1000 μg/mL). PMID:24559136

  12. Quantitative imaging of chemical composition using dual-energy, dual-source CT

    NASA Astrophysics Data System (ADS)

    Liu, Xin; Primak, Andrew N.; Yu, Lifeng; McCollough, Cynthia H.; Morin, Richard L.

    2008-03-01

    Dual-energy x-ray material decomposition has been proposed as a noninvasive quantitative imaging technique for more than 20 years. In this paper, we summarize previously developed dual-energy material decomposition methods and propose a simple yet accurate method for quantitatively measuring chemical composition in vivo. In order to take advantage of the newly developed dual-source CT, the proposed method is based upon post reconstruction (image space) data. Different from other post reconstruction methods, this method is designed to directly measure element composition (mass fraction) in a tissue by a simple table lookup procedure. The method has been tested in phantom studies and also applied to a clinical case. The results showed that this method is capable of accurately measuring elemental concentrations, such as iron in tissue, under low noise imaging conditions. The advantage of this method lies in its simplicity and fast processing times. We believe that this method can be applied clinically to measure the mass fraction of any chemical element in a two-material object, such as to quantify the iron overload in the liver (hemochromatosis). Further investigations on de-noising techniques, as well as clinical validation, are merited.

  13. What do microbes encounter at the plant surface? Chemical composition of pea leaf cuticular waxes.

    PubMed

    Gniwotta, Franka; Vogg, Gerd; Gartmann, Vanessa; Carver, Tim L W; Riederer, Markus; Jetter, Reinhard

    2005-09-01

    In the cuticular wax mixtures from leaves of pea (Pisum sativum) cv Avanta, cv Lincoln, and cv Maiperle, more than 70 individual compounds were identified. The adaxial wax was characterized by very high amounts of primary alcohols (71%), while the abaxial wax consisted mainly of alkanes (73%). An aqueous adhesive of gum arabic was employed to selectively sample the epicuticular wax layer on pea leaves and hence to analyze the composition of epicuticular crystals exposed at the outermost surface of leaves. The epicuticular layer was found to contain 74% and 83% of the total wax on adaxial and abaxial surfaces, respectively. The platelet-shaped crystals on the adaxial leaf surface consisted of a mixture dominated by hexacosanol, accompanied by substantial amounts of octacosanol and hentriacontane. In contrast, the ribbon-shaped wax crystals on the abaxial surface consisted mainly of hentriacontane (63%), with approximately 5% each of hexacosanol and octacosanol being present. Based on this detailed chemical analysis of the wax exposed at the leaf surface, their importance for early events in the interaction with host-specific pathogenic fungi can now be evaluated. On adaxial surfaces, approximately 80% of Erysiphe pisi spores germinated and 70% differentiated appressoria. In contrast, significantly lower germination efficiencies (57%) and appressoria formation rates (49%) were found for abaxial surfaces. In conclusion, the influence of the physical structure and the chemical composition of the host surface, and especially of epicuticular leaf waxes, on the prepenetration processes of biotrophic fungi is discussed. PMID:16113231

  14. 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

  15. Dissolution of cerium(IV)-lanthanide(III) oxides: Comparative effect of chemical composition, temperature, and acidity

    SciTech Connect

    Horlait, D.; Clavier, N.; Szenknect, S.; Dacheux, N.; Dubois, V.

    2012-03-15

    The dissolution of Ce{sub 1-x}Ln{sub x}O{sub 2-x/2} solid solutions was undertaken in various acid media in order to evaluate the effects of several physicochemical parameters such as chemical composition, temperature, and acidity on the reaction kinetics. The normalized dissolution rates (R{sub L,0}) were found to be strongly modified by the trivalent lanthanide incorporation rate, due to the presence of oxygen vacancies decreasing the samples cohesion. Conversely, the nature of the trivalent cation considered only weakly impacted the R{sub L,0} values. The dependence of the normalized dissolution rates on the temperature then appeared to be of the same order of magnitude than that of chemical composition. Moreover, it allowed determining the corresponding activation energy (E{sub A} ≅ 60-85 kJ.mol{sup -1}) which accounts for a dissolution driven by surface-controlled reactions. A similar conclusion was made regarding the acidity of the solution: the partial order related to (H{sub 3}O{sup +}) reaching about 0.7. Finally, the prevailing effect of the incorporation of aliovalent cations in the fluorite-type CeO{sub 2} matrix on the dissolution kinetics precluded the observation of slight effects such as those linked to the complexing agents or to the crystal structure of the samples. (authors)

  16. Taste and mouthfeel properties of red wines proanthocyanidins and their relation to the chemical composition.

    PubMed

    Gonzalo-Diago, Ana; Dizy, Marta; Fernández-Zurbano, Purificación

    2013-09-18

    The aim of this work is to assess the relationship between the in-mouth sensory properties of proanthocyanidins (PAs) and its chemical composition. To achieve such a goal, the proanthocyanidin fraction from six different young commercial red wines was obtained by gel permeation chromatography. A sensory panel, selected on the basis of their PROP status and trained in taste and mouthfeel sensations, described both the wines and fractions. MALDI-TOF-MS and UPLC-MS were used to identify thoroughly the polyphenolic composition of each proanthocyanidin fraction. The results showed that the PAs fractions were exclusively described as astringent and persistent. The astringent subqualities studied (velvety and puckering/drying) were mainly related to the quantity of proanthocyanidins and the proportion of the extension flavanol units linked to proanthocyanidins. A significant negative correlation was found between both of the astringencies (velvety and puckering/drying). Furthermore, both subqualities appeared to contribute to the persistence. A significant correlation was observed between the astringency and the persistence data of the wines and fractions. Significant multiple linear regressions were found between the sensory astringency data and the chemical compounds analyzed. The concentration of proanthocyanidins present in young red wines is the major determinant of the differences perceived in the astringency. Additionally, the extension flavanol units linked to the proanthocyanidins seem to have a different impact on the astringent subqualities. PMID:23889258

  17. Chemical composition and antimicrobial activity of the essential oil from leaves of Algerian Melissa officinalis L.

    PubMed Central

    Abdellatif, Fahima; Boudjella, Hadjira; Zitouni, Abdelghani; Hassani, Aicha

    2014-01-01

    The essential oil obtained from leaves of Melissa officinalis L. (Family of Lamiaceae) growing in Algeria, was investigated for its chemical composition and in vitro antimicrobial activity. The chemical composition was determined by hydrodistillation and analyzed by GC/MS and GC-FID. Sixty-three compounds were identified in the essential oil, representing 94.10 % of the total oil and the yields were 0.34 %. The major component was geranial (44.20 %). Other predominant components were neral (30.20 %) and citronellal (6.30 %). The in vitro antimicrobial activity was determined by paper disk agar diffusion testing and minimum inhibitory concentration (MIC) using 7 bacteria (3 Gram-positive and 4 Gram-negative), 2 yeasts and 3 fungi. The results showed that the essential oil presented high antimicrobial activity against all microorganisms targeted mainly against five human pathogenic bacteria, one yeast Candida albicans and two phytopathogenic fungi tested. The minimum inhibitory concentrations (MIC) ranged from 1.00 to 5.00 µL/mL. PMID:26417300

  18. Cow's urine concoction: its chemical composition, pharmacological actions and mode of lethality.

    PubMed

    Oyebola, D D

    1983-03-01

    A review of current information on the composition, pharmacological actions and mode of death from cow's urine concoction (CUC) toxicity is presented. The concoction is prepared from leaves of tobacco, garlic and basil; lemon juice, rock salt and bulbs of onion. The latter items are soaked in the urine from cows which acts as the vehicle in which the active principles in these constituents dissolve. Over fifty chemical compounds have been identified in CUC. The major compounds it contains are benzoic acid, phenylacetic acid, p-cresol, thymol and nicotine. The chemical composition and pharmacological cations of the individual components of CUC are also reviewed. Observations of CUC poisoning in man and experimental animals showed that the main effects of CUC are severe depression of respiration, cardiovascular system, the central nervous system and hypoglycaemia. These toxic effects acting singly or in combination are believed to be the cause(s) of death from CUC. Management is geared towards correcting these adverse effects. PMID:6314793

  19. The microstructure of SiC/TiC in situ composites by chemical vapor deposition

    SciTech Connect

    Lin, T.T.; Hon, M.H. . Dept. of Materials Science and Engineering)

    1994-11-01

    Silicon carbide has many excellent mechanical properties such as high hardness, high temperature strength, thermal shock resistance, oxidation resistance, and chemical inertness. It is an attractive material for wear and structural applications, but the modest fracture toughness value, about 3--4 MPam[sup 1/2], limits its use at high contact stress loading. It is very desirable to improve the fracture toughness with adding second phases of whiskers, fibers or particles. Adding dispersive second-phase particles, TiC or TiB[sub 2], to increase the fracture toughness values of SiC has been successful. Many of the researchers have studied this strengthening with hot-press sintered specimens, but only a few with chemical vapor deposited (CVD) ones. The main purpose of this study is to investigate the microstructure and fracture mechanisms of SiC/TiC composites made by CVD method. It is well known that both SiC and TiC are brittle materials, but the composites have a good toughness and strength due to their differential coefficient of thermal expansion (CTE). Internal stresses can be introduced during cooling after deposition.

  20. Seasonal Variation, Chemical Composition and Antioxidant activity of Brazilian Propolis Samples

    PubMed Central

    Teixeira, Érica Weinstein; Message, Dejair; Negri, Giuseppina; Stringheta, Paulo César

    2010-01-01

    Total phenolic contents, antioxidant activity and chemical composition of propolis samples from three localities of Minas Gerais state (southeast Brazil) were determined. Total phenolic contents were determined by the Folin–Ciocalteau method, antioxidant activity was evaluated by DPPH, using BHT as reference, and chemical composition was analyzed by GC/MS. Propolis from Itapecerica and Paula Cândido municipalities were found to have high phenolic contents and pronounced antioxidant activity. From these extracts, 40 substances were identified, among them were simple phenylpropanoids, prenylated phenylpropanoids, sesqui- and diterpenoids. Quantitatively, the main constituent of both samples was allyl-3-prenylcinnamic acid. A sample from Virginópolis municipality had no detectable phenolic substances and contained mainly triterpenoids, the main constituents being α- and β-amyrins. Methanolic extracts from Itapecerica and Paula Cândido exhibited pronounced scavenging activity towards DPPH, indistinguishable from BHT activity. However, extracts from Virginópolis sample exhibited no antioxidant activity. Total phenolic substances, GC/MS analyses and antioxidant activity of samples from Itapecerica collected monthly over a period of 1 year revealed considerable variation. No correlation was observed between antioxidant activity and either total phenolic contents or contents of artepillin C and other phenolic substances, as assayed by CG/MS analysis. PMID:18955317

  1. 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.

  2. On the Morphology and Chemical Composition of the HR 4796A Debris Disk

    NASA Technical Reports Server (NTRS)

    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

    2014-01-01

    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 micrometers, 0.91 micrometers, 0.99 micrometers, 2.15 micrometers, 3.1 micrometers, 3.3 micrometers, and 3.8 micrometers. 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 approximately 0.5-2 micrometers, 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.

  3. 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.

  4. Analysis of Chemical Composition of Atmospheric Aerosols Above a South East Asian Rainforest

    NASA Astrophysics Data System (ADS)

    Robinson, N. H.; Allan, J. D.; Williams, P. I.; Hamilton, J. F.; Chen, Q.; Martin, S. T.; Coe, H.; McFiggans, G. B.

    2008-12-01

    The tropics emit a huge amount of volatile organic compounds (VOCs) into the Earth's atmosphere. The processes by which these gases are oxidised to form secondary organic aerosol (SOA) are not well understood or quantified. Insight into the origins and properties of these particles can be gained by analysis of their composition. Intensive field measurements were carried out as part of the Oxidant and Particle Photochemical Processes (OP3) and the Aerosol Coupling in the Earth System (ACES) projects in the rainforest in Malaysian Borneo. This is the first campaign of its type in a South East Asian rainforest. We present detailed organic aerosol composition measurements made using an Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) at Bukit Atur, a Global Atmosphere Watch site located in the Danum Valley Conservation Area. This is a state-of-the-art field deployable instrument that can provide real time composition, mass loading and aerodynamic particle sizing information. In addition, the mass spectral resolution is sufficient to perform an analysis of the elemental composition of the organic species present. Other tools such as positive matrix factorisation (PMF) have been used to help assess the relative source contributions to the organic aerosol. The aerosol's chemical origins have been further investigated by comparing these spectra to chamber experiments, mass spectral libraries and data from comparable locations in other locations. These data are also being analysed in conjunction with high complexity offline techniques applied to samples collected using filters and a Particle-Into-Liquid Sampler (PILS). Methods used include liquid chromatography and comprehensive two-dimensional gas chromatography coupled to time of flight mass spectrometry. These techniques provide a more detailed chemical characterisation of the SOA and water soluble organic carbon, allowing direct links back to gas phase precursors.

  5. 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.

  6. Chemical evolution of dense clouds

    NASA Technical Reports Server (NTRS)

    Chappelle, E. W.; Donn, B. D.; Payne, W. A., Jr.; Stief, L. J.

    1972-01-01

    Chemical processes that could determine the molecular composition of the cloud during the several stages of its evolution are considered. Reactions at the relatively interstellar densities are emphasized.

  7. Predicting corn digestible and metabolizable energy content from its chemical composition in growing pigs

    PubMed Central

    2014-01-01

    Background The nutrient composition of corn is variable. To prevent unforeseen reductions in growth performance, grading and analytical methods are used to minimize nutrient variability between calculated and analyzed values. This experiment was carried out to define the sources of variation in the energy content of corn and to develop a practical method to accurately estimate the digestible energy (DE) and metabolisable energy (ME) content of individual corn samples for growing pigs. Twenty samples were taken from each of five provinces in China (Jilin, Hebei, Shandong, Liaoning, and Henan) to obtain a range of quality. Results The DE and ME contents of the 100 corn samples were measured in 35.3 ± 1.92 kg growing pigs (six pigs per corn sample). Sixty corn samples were used to build the prediction model; the remaining forty samples were used to test the suitability of these models. The chemical composition of each corn sample was determined, and the results were used to establish prediction equations for DE or ME content from chemical characteristics. The mean DE and ME content of the 100 samples were 4,053 and 3,923 kcal/kg (dry matter basis), respectively. The physical characteristics were determined, as well, and the results indicated that the bulk weight and 1,000-kernel weight were not associated with energy content. The DE and ME values could be accurately predicted from chemical characteristics. The best fit equations were as follows: DE, kcal/kg of DM = 1062.68 + (49.72 × EE) + (0.54 × GE) + (9.11 × starch), with R2 = 0.62, residual standard deviation (RSD) = 48 kcal/kg, and P < 0.01; ME, kcal/kg of dry matter basis (DM) = 671.54 + (0.89 × DE) – (5.57 × NDF) – (191.39 × ash), with R2 = 0.87, RSD = 18 kcal/kg, and P < 0.01. Conclusion This experiment confirms the large variation in the energy content of corn, describes the factors that influence this variation, and presents equations based on chemical measurements that may be used to predict the DE and ME content of individual corn samples. PMID:24521251

  8. 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 sources between the size-segregated particulate samples will be investigated in toxicological cell and animal studies.

  9. 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 (?18OSMOW = -19.5 - -17.5) and hydrogen (?DSMOW = -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 (?34SCDT = +25 - +30) prevails in the therms. Sulphate-ion enters solution not as a result of sulfide oxidation, but dissolution of sulphate minerals of may be originally sedimentary and magmatic rocks. Microelement contents in waters depend on total mineralization. In particular, this regulation is clearly observed for rare alkaline and alkaline-earth elements. We established dependence of one microelement concentrations on temperature of solutions (Sc, Al, W) and that of the other ones - on extent of water - rock (Sr, Ba) interaction. Active use of thermal water for purposes of thermal energetic can contribute to inflow of highly mineralized solutions into water collecting reservoir and result in breakdowns of heat-net work. The study has been carried out with financial support of RFBR. Grant N09-05-00726, Integration Project N87 of SB RAS.

  10. 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.

  11. Comparison of the chemical compositions and nutritive values of various pumpkin (Cucurbitaceae) species and parts

    PubMed Central

    Kim, Mi Young; Kim, Eun Jin; Kim, Young-Nam; Choi, Changsun

    2012-01-01

    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

  12. Integration of calcium and chemical looping combustion using composite CaO/CuO-based materials.

    PubMed

    Manovic, Vasilije; Anthony, Edward J

    2011-12-15

    Calcium looping cycles (CaL) and chemical looping combustion (CLC) are two new, developing technologies for reduction of CO(2) emissions from plants using fossil fuels for energy production, which are being intensively examined. Calcium looping is a two-stage process, which includes oxy-fuel combustion for sorbent regeneration, i.e., generation of a concentrated CO(2) stream. This paper discuss the development of composite materials which can use copper(II)-oxide (CuO) as an oxygen carrier to provide oxygen for the sorbent regeneration stage of calcium looping. In other words, the work presented here involves integration of calcium looping and chemical looping into a new class of postcombustion CO(2) capture processes designated as integrated CaL and CLC (CaL-CLC or Ca-Cu looping cycles) using composite pellets containing lime (CaO) and CuO together with the addition of calcium aluminate cement as a binder. Their activity was tested in a thermogravimetric analyzer (TGA) during calcination/reduction/oxidation/carbonation cycles. The calcination/reduction typically was performed in methane (CH(4)), and the oxidation/carbonation stage was carried out using a gas mixture containing both CO(2) and O(2). It was confirmed that the material synthesized is suitable for the proposed cycles; with the very favorable finding that reduction/oxidation of the oxygen carrier is complete. Various schemes for the Ca-Cu looping process have been explored here that would be compatible with these new composite materials, along with some different possibilities for flow directions among carbonator, calciner, and air reactor. PMID:22022778

  13. 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

  14. 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.

  15. Chemical composition of snow in the northern Sierra Nevada and other areas

    USGS Publications Warehouse

    Feth, John Henry Frederick; Rogers, S.M.; Roberson, Charles Elmer

    1964-01-01

    Melting snow provides a large part of the water used throughout the western conterminous United States for agriculture, industry, and domestic supply. It is an active agent in chemical weathering, supplies moisture for forest growth, and sustains fish and wildlife. Despite its importance, virtually nothing has been known of the chemical character of snow in the western mountains until the present study. Analysis of more than 100 samples, most from the northern Sierra Nevada, but some from Utah, Denver, Colo., and scattered points, shows that melted snow is a dilute solution containing measurable amounts of some or all of the inorganic constituents commonly found in natural water. There are significant regional differences in chemical composition; the progressive increase in calcium content with increasing distance eastward from the west slope of the Sierra Nevada is the most pronounced. The chemical character of individual snowfalls is variable. Some show predominant influence of oceanic salt; others show strong effects of mineralization from continental sources, probably largely dust. Silica and boron were found in about half the samples analyzed for these constituents; precipitation is seldom analyzed for these substances. Results of the chemical analyses for major constituents in snow samples are summarized in the following table. The median and mean values for individual constituents are derived from 41-78 samples of Sierra Nevada snow, 6-18 samples of Utah snow, and 6-17 samples of Denver, Colo., snow. [Table] The sodium, chloride, and perhaps boron found in snow are probably incorporated in moisture-laden air masses as they move over the Pacific Ocean. Silica, although abundant in the silicate-mineral nuclei found in some snowflakes, may be derived in soluble form largely from dust. Calcium, magnesium, and some bicarbonate are probably added by dust of continental origin. The sources of the other constituents remain unknown. When snowmelt comes in contact with the lithosphere, the earlier diversity of chemical type largely disappears. The melt water rapidly increases its content of dissolved solids and becomes calcium magnesium bicarbonate in type. Silica, whose concentration increases more than tenfold, shows the largest gain; calcium and bicarbonate contents also increase markedly. Most of the additional mineral matter is from soft and weathered rock; bicarbonate, however, is largely from the soil atmosphere: Investigators, some reporting as much as a century ago, concentrated attention largely on nitrogen compounds and seldom reported other consituents except chloride and sulfate. The Northern European precipitation-sampling network provides the most comprehensive collection of data on precipitation chemistry, but it does not segregate snow from other forms of precipitation. The present study establishes with confidence the chemical character of snow in the Sierra Nevada, and suggests that the dissolved-solids content of precipitation increases with increasing distance inland from the Pacific Coast.

  16. Controls on the chemical and isotopic compositions of urban stormwater in a semiarid zone

    NASA Astrophysics Data System (ADS)

    Asaf, L.; Nativ, R.; Shain, D.; Hassan, M.; Geyer, S.

    2003-04-01

    The temporal variations in the chemical and isotopic compositions of urban stormwater under different land uses, and their dependence on physical parameters such as precipitation intensity, stormwater discharge, cumulative stormwater volumes and the size of the drainage area, were investigated in the coastal city of Ashdod, Israel. During 2000/2001 and 2001/2002, 39 stormwater events were intensively monitored for precipitation distribution and intensity at three stations across the city and for stormwater discharge at seven stations draining 85% of the city area. Thirty nine and 202 precipitation samples were collected and analyzed for chemical and isotopic compositions, respectively as were 149 stormwater samples, collected from the drains during 10 of the 39 events. Because the stormwater stations drained areas of different sizes and land uses, their impact on the stormwater chemistry could be evaluated. Land use had only a minor effect on the concentrations of major ions and trace elements. Conversely, the concentrations and variety of volatile and semi-volatile organic compounds were significantly higher in stormwater generated in the industrial area than in that draining from residential areas. Ion and trace-metal concentrations were very low (below drinking-water standards) in 97% of the stormwater samples collected from all drains. Stormwater concentrations were higher in stations draining a larger area, thereby linking concentrations to the length of stormwater flowpaths. A first-flush effect was documented on both a seasonal and an event basis for both ions and trace elements. The high concentrations of fecal coliform bacteria exceeded the drinking-water standards and displayed a random pattern. The isotopic ratios of oxygen and hydrogen in the stormwater suggest very little exposure to the atmosphere, resulting in very limited fractionation. The presence of fecal coliforms, ammonium in some samples, and specific ratios of oxygen and nitrogen isotopes, suggest that although the sewer and stormwater=collection systems are separated, wastewater, possibly from overflowing sewers, contributed to the drained stormwater. The chemical composition of stormwater collected from the residential areas in the city of Ashdod suggests that this water can be reused with little treatment (e.g. filtering and chlorination).

  17. 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.

  18. 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 highly susceptible to all the other essential oils at the diagnostic dose. Conclusions C. citratus, E. tereticornis, E. citriodora, C. ambrosioides and C. schoenanthus are potential promising plant sources for alternative compounds to pyrethroids, for the control of the Anopheles malaria vector in Benin. The efficacy of their essential oils is possibly based on their chemical compositions in which major and/or minor compounds have reported insecticidal activities on various pests and disease vectors such as Anopheles. PMID:24298981

  19. 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/mL) against E. coli, S. aureus, E. faecalis, and C. albicansThe essential oil of P. heptaphyllum has activity against S. mutans (MIC = 0.5 mg/mL)The essential oil showed a protection against cyclophosphamide-induced genotoxicity in the micronuclei assay. Abbreviations used: GC–MS: Gas Chromatography–Mass Spectrometry, MTT: 3-(4,5dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, Annexin V-FITC: Annexin V conjugated with fluorescein isothiocyanate, TNF-α: Tumor necrosis factor alpha, MIC: Minimum Inhibitory Concentration PMID:27041857

  20. Particulate matter concentration and chemical composition in the metro system of Rome, Italy.

    PubMed

    Perrino, C; Marcovecchio, F; Tofful, L; Canepari, S

    2015-06-01

    Air quality at the main station of the metro system of Rome (Termini hub) has been characterized by the point of view of particulate matter (PM) concentration and chemical composition. Indoor air in different environments (underground train platform and shopping center, metro carriages with and without air conditioning system) has been studied and compared with outdoor air at a nearby urban site. Air quality at the railway station, located outdoor at surface level, has been also considered for comparison. PM chemical characterization included ions, elemental carbon, organic carbon, macro-elements, and the bio-accessible and residual fractions of micro- and trace elements. Train platform and carriages without air conditioning resulted to be the most polluted environments, with indoor/outdoor ratio up to two orders of magnitude for many components. PM mass concentration was determined on filter membranes by the gravimetric procedure as well as from the optical particle counter (OPC) number concentration measurements. The OPC results, taken with the original calibration factor, were below 40 % of the value obtained by the gravimetric measurements. Only a chemical and morphological characterization of the collected dust could lead to a reconciliation of the results yielded by the two methods. Macro-components were used to estimate the strength of the main macro-sources. The most significant contribution is confirmed to derive from wheels, rails, and brakes abrasion; from soil re-suspension (over 50 % at the subway platform); and from organics (about 25 %). The increase in the concentration of elements was mostly due to the residual fraction, but also the bio-accessible fraction showed a remarkable enrichment, particularly in the case of Ba, Zn, Cd, and Ni. PMID:25586611

  1. The puzzling chemical composition of GJ 436B'S atmosphere: Influence of tidal heating on the chemistry

    SciTech Connect

    Agúndez, Marcelino; Selsis, Franck; Venot, Olivia; Iro, Nicolas

    2014-02-01

    The dissipation of the tidal energy deposited on eccentric planets may induce a heating of the planet that affects its atmospheric thermal structure. Here we study the influence of tidal heating on the atmospheric composition of the eccentric (e = 0.16) 'hot Neptune' GJ 436b, for which inconclusive chemical abundances are retrieved from multiwavelength photometric observations carried out during primary transit and secondary eclipse. We build up a one-dimensional model of GJ 436b's atmosphere in the vertical direction and compute the pressure-temperature and molecular abundances profiles for various plausible internal temperatures of the planet (up to 560 K) and metallicities (from solar to 100 times solar), using a radiative-convective model and a chemical model which includes thermochemical kinetics, vertical mixing, and photochemistry. We find that the CO/CH{sub 4} abundance ratio increases with metallicity and tidal heating, and ranges from 1/20 to 1000 within the ranges of metallicity and internal temperature explored. Water vapor locks most of the oxygen and reaches a very high abundance, whatever the metallicity and internal temperature of the planet. The CO{sub 2}/H{sub 2}O abundance ratio increases dramatically with metallicity, and takes values between 10{sup –5}-10{sup –4} with solar elemental abundances and ∼0.1 for a metallicity 100 times solar. None of the atmospheric models based on solid physical and chemical grounds provide a fully satisfactory agreement with available observational data, although the comparison of calculated spectra and observations seems to point to models with a high metallicity and efficient tidal heating, in which high CO/CH{sub 4} abundance ratios and warm temperatures in the dayside atmosphere are favored.

  2. Effect of Chemical Structure and Composition of the Resin Phase on Vinyl Conversion of Amorphous Calcium Phosphate-filled Composites

    PubMed Central

    Skrtic, D.; Antonucci, J.M.

    2008-01-01

    The objective of this study was to elucidate the effect of chemical structure and composition of the polymer matrix on the degree of vinyl conversion (DC) of copolymers (unfilled resins) and their amorphous calcium phosphate (ACP) composites attained upon photo-polymerization. The DC can also be an indicator of the relative potential of these polymeric materials to leach out into the oral environment un-reacted monomers that could adversely affect their biocompatibility. The following resins were examined: 1) 2,2-bis[p-(2′-hydroxy-3′-methacryloxypropoxy)phenyl]propane (Bis-GMA)/triethylene glycol dimethacrylate (TEGDMA) (1:1 mass ratio; BT resin) combined with hydroxyethyl methacrylate (HEMA; BTH resin) and with HEMA and zirconyl dimethacrylate (BTHZ resin), 2) urethane dimethacrylate (UDMA)/HEMA resins, and 3) pyromellitic glycerol dimethacrylate (PMGDMA)/TEGDMA (PT resin). To make composite specimens, resins were mixed with a mass fraction of 40 % zirconia-hybridized ACP. Copolymers and their composites were evaluated by near infra-red spectroscopy for DC after 1 d and 28 d post-cure at 23 °C. Inclusion of HEMA into the BT and UDMA resins yielded copolymers and composites with the highest DCs. The significantly lower DCs of PT copolymers and their composites are attributed to the rigid aromatic core structure, tetra-vinyl functionality and limited methacrylate side-chain flexibility of the surface-active PMGDMA monomer. There was, however, an increase in the 28 d DC for the PT materials as there was for the BTHZ system. Surprisingly, the usual decrease observed in DC in going from unfilled polymer to composite was reversed for the PT system. PMID:18714369

  3. Effect of Chemical Structure and Composition of the Resin Phase on Vinyl Conversion of Amorphous Calcium Phosphate-filled Composites.

    PubMed

    Skrtic, D; Antonucci, J M

    2007-01-01

    The objective of this study was to elucidate the effect of chemical structure and composition of the polymer matrix on the degree of vinyl conversion (DC) of copolymers (unfilled resins) and their amorphous calcium phosphate (ACP) composites attained upon photo-polymerization. The DC can also be an indicator of the relative potential of these polymeric materials to leach out into the oral environment un-reacted monomers that could adversely affect their biocompatibility. The following resins were examined: 1) 2,2-bis[p-(2'-hydroxy-3'-methacryloxypropoxy)phenyl]propane (Bis-GMA)/triethylene glycol dimethacrylate (TEGDMA) (1:1 mass ratio; BT resin) combined with hydroxyethyl methacrylate (HEMA; BTH resin) and with HEMA and zirconyl dimethacrylate (BTHZ resin), 2) urethane dimethacrylate (UDMA)/HEMA resins, and 3) pyromellitic glycerol dimethacrylate (PMGDMA)/TEGDMA (PT resin). To make composite specimens, resins were mixed with a mass fraction of 40 % zirconia-hybridized ACP. Copolymers and their composites were evaluated by near infra-red spectroscopy for DC after 1 d and 28 d post-cure at 23 C. Inclusion of HEMA into the BT and UDMA resins yielded copolymers and composites with the highest DCs. The significantly lower DCs of PT copolymers and their composites are attributed to the rigid aromatic core structure, tetra-vinyl functionality and limited methacrylate side-chain flexibility of the surface-active PMGDMA monomer. There was, however, an increase in the 28 d DC for the PT materials as there was for the BTHZ system. Surprisingly, the usual decrease observed in DC in going from unfilled polymer to composite was reversed for the PT system. PMID:18714369

  4. Morphology and Chemical composition of Atmospheric Particles over Semi-Arid region (Jaipur, Rajasthan) of India

    NASA Astrophysics Data System (ADS)

    Mishra, S. K.; Agnihotri, R.; Yadav, P.; Singh, S.; Tawale, J. S.; Rashmi, R.; Prasad, M.; Arya, B. C.; Mishra, N.

    2012-12-01

    Uncertainties associated with the radiative forcing of atmospheric dust particles is highest, owing to lack of region-specific dust morphology (particle shape, size) and mineralogy (chemical composition) database, needed for modeling their optical properties (Mishra and Tripathi, 2008). To fill this gap for the Indian region, we collected atmospheric particles (with aerodynamic size <5um, PM5 and a few bulk particles; TSP) from seven sites of Jaipur and nearby locales (semi-arid region, in the vicinity of Thar Desert of Rajasthan) at varying altitude, during late winters of ca. 2012. PM5 particles were collected on Teflon filters (for bulk chemical analyses), while pure Tin substrates (~1×1 mm2) were used for investigating individual particle morphology. Using Scanning Electron Microscope equipped with Energy Dispersive X ray (SEM-EDX) facility at NPL, images of individual particles were recorded and the morphological parameters (e.g. Aspect ratio; AR, Circulatory parameter; CIR.) were retrieved following Okada et al. (2001), whereas chemical compositions of individual particles were determined by EDX and bulk samples by X ray fluorescence (XRF). The geometrical size distributions of atmospheric particles were generated for each site. Based on NIST (National Institute of Standard and Technology, USA) morphology database, the site-specific individual particle shapes reveal predominance of "Layered" (calcite and quartz rich), "Angular" structures (quartz rich) and "Flattened" particles over all the sites. Particles were found to be highly non-spherical with irregular shapes (CIR varying from 1 to 0.22 with median value ~0.76; AR varying from 1 to 5.4 with median value ~1.64). Noteworthy to mention, that unit values of AR and CIR represent spherical particles. Chemical analyses of PM5 particles revealed dominance of crustal elements e.g. Si, Al, Fe, Ca, Mg, in general. Particles over Kukas Hill (27.027° N, 75.919° E; ~800 MAGL) showed highest Fe mass fractions (~43%), i.e. a key element (in form of hematite; Fe2O3) for solar (visible) energy absorption and thus heating the atmosphere. The retrieved morphological parameters help to construct particle shape and number size distribution that are highly useful to reduce the uncertainty in radiative forcing of dust particles appreciably when combined with particle chemical composition as suggested by Kalashnikova and Sokolik (2004). References : Mishra, S. K., and S. N. Tripathi (2008), Modeling optical properties of mineral dust over the Indian Desert, J. Geophys. Res., 113, D23201, 19 PP., doi:10.1029/2008JD010048. Okada, K., J. Heintzenberg, K. Kai, and Y. Qin (2001), Shape of atmospheric mineral particles collected in three Chinese arid-regions, Geophys. Res. Lett., 28, 3123-3126 Kalashnikova OV, Sokolik IN. (2004) Modeling the radiative properties of nonspherical soil-derived mineral aerosols, J Quant Spectrosc Radiat Transfer, 87, 137-66.

  5. Correlating Titania Morphology and Chemical Composition with Dye-sensitized Solar Cell Performance

    SciTech Connect

    Santulli, A.C.; Wong, S.; Koenigsmann, C.; Tiano, A.L., DeRosa, D.

    2011-04-20

    We have investigated the use of various morphologies, including nanoparticles, nanowires, and sea-urchins of TiO{sub 2} as the semiconducting material used as components of dye-sensitized solar cells (DSSCs). Analysis of the solar cells under AM 1.5 solar irradiation reveals the superior performance of hydrothermally derived nanoparticles, by comparison with two readily available commercial nanoparticle materials, within the DSSC architecture. The sub-structural morphology of films of these nanostructured materials has been directly characterized using SEM and indirectly probed using dye desorption. Furthermore, the surfaces of these nanomaterials were studied using TEM in order to visualize their structure, prior to their application within DSSCs. Surface areas of the materials have been quantitatively analyzed by collecting BET adsorption and dye desorption data. Additional investigation using open circuit voltage decay measurements reveals the efficiency of electron conduction through each TiO{sub 2} material. Moreover, the utilization of various chemically distinctive titanate materials within the DSSCs has also been investigated, demonstrating the deficiencies of using these particular chemical compositions within traditional DSSCs.

  6. 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

  7. Chemical composition of Eucalyptus spp. essential oils and their insecticidal effects on Lutzomyia longipalpis.

    PubMed

    Maciel, M V; Morais, S M; Bevilaqua, C M L; Silva, R A; Barros, R S; Sousa, R N; Sousa, L C; Brito, E S; Souza-Neto, M A

    2010-01-20

    The chemical composition of essential oils from three species of plants belonging to the Eucalyptus genus was determined and, their insecticidal effects on egg, larva and adult phases of Lutzomyia longipalpis were assessed. The insects were collected in the municipality of Sobral in the State of Ceará, Brazil. Five treatments with different concentrations were performed along with two negative controls, distilled water and Tween 80 (3%), and a positive control, cypermethrin (0.196mg/ml). The tests were carried out in plastic pots internally coated with sterile plaster and filled with a substrate made of rabbit feces and crushed cassava leaves. The eggs, larvae and adults were sprayed with the oils. The hatched larvae were counted for 10 consecutive days and observed until pupation. Insect mortality was observed after 24, 48 and 72h. E. staigeriana oil was the most effective on all three phases of the insect, followed by E. citriodora and E. globulus oils, respectively. The major constituents of the oils were Z-citral and alpha-citral (E. staigeriana), citronellal (E. citriodora) and 1,8-cineole (E. globulus). The Eucalyptus essential oils constitute alternative natural products for the control of L. longipalpis since the median effective concentration (EC(50)) values revealed relevant action as compared with other natural products, some of their chemical constituents are already known for their insecticidal activity and these oils are produced in commercial scale in Brazil. PMID:19896276

  8. Chemical composition and tectonic setting of the Dokhan Volcanic Formation, Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Ressetar, R.; Monrad, J. R.

    The late Precambrian-Cambrian Dokhan Volcanic Formation represents the youngest component of the basement complex in the Egyptian Eastern Desert. Volcanic and sedimentary rocks predating the Dokhan Formation evolved in an oceanic island arc setting and were metamorphosed during the Pan-African event. The Dokhan rocks were subjected to low grade alteration during the waning stages of the Pan-African event. Post-dating the Dokhan Formation are terrestrial sediments and post-tectonic alkali-rich granites. Chemical analyses of the Dokhan volcanic rocks reveal a range of compositions from basaltic andesite to rhyolite (SiO 2 contents from 53 to 79 wt. %). Abundances of most other oxides and trace elements follow patterns similar to those seen in volcanic rocks in orogenic belts. However, certain elements diagnostic of tectonic setting for volcanic rocks (notably alkalis, Ti, Zr and Nb) are elevated in the Dokhan Formation with respect to worldwide averages of igneous rocks from active continental margins. These chemical characteristics are interpreted as reflecting genesis of the Dokhan lavas in a setting that was transitional toward a stable continental craton.

  9. Chemical composition measurements of the atmosphere of Jupiter with the Galileo Probe mass spectrometer

    NASA Technical Reports Server (NTRS)

    Niemann, H. B.; Atreya, S. K.; Carignan, G. R.; Donahue, T. M.; Haberman, J. A.; Harpold, D. N.; Hartle, R. E.; Hunten, D. M.; Kasprzak, W. T.; Mahaffy, P. R.; Owen, T. C.; Spencer, N. W.

    1998-01-01

    The Galileo Probe entered the atmosphere of Jupiter on December 7, 1995. Measurements of the chemical and isotopic composition of the Jovian atmosphere were obtained by the mass spectrometer during the descent over the 0.5 to 21 bar pressure region over a time period of approximately 1 hour. The sampling was either of atmospheric gases directly introduced into the ion source of the mass spectrometer through capillary leaks or of gas, which had been chemically processed to enhance the sensitivity of the measurement to trace species or noble gases. The analysis of this data set continues to be refined based on supporting laboratory studies on an engineering unit. The mixing ratios of the major constituents of the atmosphere hydrogen and helium have been determined as well as mixing ratios or upper limits for several less abundant species including: methane, water, ammonia, ethane, ethylene, propane, hydrogen sulfide, neon, argon, krypton, and xenon. Analysis also suggests the presence of trace levels of other 3 and 4 carbon hydrocarbons, or carbon and nitrogen containing species, phosphine, hydrogen chloride, and of benzene. The data set also allows upper limits to be set for many species of interest which were not detected. Isotope ratios were measured for 3He/4He, D/H, 13C/12C, 20Ne/22Ne, 38Ar/36Ar and for isotopes of both Kr and Xe.

  10. Influence of deposition time on the chemical bonding and composition of amorphous carbon nitride films

    NASA Astrophysics Data System (ADS)

    Azman, Nurul Izzati; Awang, Rozidawati; Kamal, Shafarina Azlinda Ahmad

    2014-09-01

    Amorphous carbon nitride (a-CNx) films have been deposited using radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) under various deposition times. The effects on chemical bonding and composition of this film were characterized by using Fourier Transform Infrared Spectroscopy (FTIR) and Energy Dispersive X-Rays Spectroscopy (EDX) respectively. The spectrum shows several band that exist in this film such as CN (1020-1280 cm-1), CC (1300-1500 cm-1), CN (1500-1800 cm-1), CN (2000 - 2300 cm-1), CH (2800-3000 cm-1), and NH/OH (3300-3500 cm-1). The longer deposition time allows the increase in occurrences of breaking the CN bonds which results in the decrease in nitrogen content.

  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. [Chemical Compositions and Sources Apportionment of Re-suspended Dust in Jincheng].

    PubMed

    Wang, Yan; Peng, Lin; Li, Li-juan; Zhang, Teng; Liu, Hai-li; Mu, Ling

    2016-01-15

    In order to make effective plan to provide the scientific basis for prevention and control of re-suspended dust (RD), samples of particulate sources including RD and other pollution sources of Jincheng were collected. Elements, ions and carbon in particulate sources were analyzed. Enrichment factor, potential ecological risk assessment, and chemical mass balance model were used to analyze the chemical composition and the source of RD. The result indicated that the main components in RD of Jingeheng were Si, TC, Ca, OC, Al, Mg, Na, Fe, K and SO4(2-), contributing 61.14% of total mass of RD. The most abundant content of RD was crustal elements, and the ions were enriched in the fine particles. The mass fraction of OC in PM2. was higher, whereas the mass fraction of EC in PM10 was higher, indicating that secondary organic pollutants were mainly dominated in the fine particles. The dust PM2.5 and PM10 potential ecological risk indexes were extremely strong, and PM2.5 had higher ecological harm than PM10. Pb had the highest enrichment factor of 196.97 in PM2.5, which was followed by As, Cr, Ni, V, Zn and Cu, the enrichment factors of which were all greater than 10, indicating that they were apparently enriched and affected by human activities. Soil dust, construction dust, vehicle exhaust, and coal dust were the main sources of RD. PMID:27078944

  13. Chemical composition of essential oils from four Vietnamese species of piper (piperaceae).

    PubMed

    Hieu, Le D; Thang, Tran D; Hoi, Tran M; Ogunwande, Isiaka A

    2014-01-01

    The chemical composition of essential oils from four Piper species, Piper retrofractum Vahl., P. boehmeriaefolium (Miq.) C. DC., P. sarmentosum Roxb., and P. maclurei Merr., were analysed by gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Nineteen to sixty-four compounds representing 92.0%-98.4% of the total contents were identified in the oil samples. The major constituents identified in P. retrofractum leaf oil were benzyl benzoate (14.4%), myrcene (14.4%), bicycloelemene (9.9%), bicyclogermacrene (7.0%) and β-caryophyllene (5.3%). On the other hand, the main constituents of P. boehmeriaefolium were α-copaene (28.3%), α-pinene (7.4%) and 1, 8-cineole (5.7%). P. sarmentosum showed a very different chemical profile characterized mainly by aromatic compounds and devoid of monoterpene hydrocarbons. The major constituents were benzyl benzoate (49.1%), benzyl alcohol (17.9%), 2-hydroxy-benzoic acid phenylmethyl ester (10.0%) and 2-butenyl-benzene (7.9%). The leaf of P. maclurei was characterized by higher amount of (E)-cinnamic acid (37.4%) and (E)-nerolidol (19.4%). Moreover, (Z)-9-octadecanoic acid methyl ester (28.0%), (E)-cinnamyl acetate (17.2%), phytol (12.2%) and (E)-cinnamaldehyde (8.8%) were the major compounds identified in the stem oil. PMID:24712088

  14. Hygroscopic properties of the Paris urban aerosol in relation to its chemical composition

    NASA Astrophysics Data System (ADS)

    Kamilli, K. A.; Poulain, L.; Held, A.; Nowak, A.; Birmili, W.; Wiedensohler, A.

    2014-01-01

    Aerosol hygroscopic growth factors and chemical properties were measured as part of the MEGAPOLI "Megacities Plume Case Study" at the urban site Laboratoire d'Hygiène de la Ville de Paris (LHVP) in the city center of Paris from June to August 2009, and from January to February 2010. Descriptive hygroscopic growth factors (DGF) were derived in the diameter range from 25 to 350 nm at relative humidities of 30, 55, 75, and 90% by applying the summation method on humidified and dry aerosol size distributions measured simultaneously with a humidified differential mobility particle sizer (HDMPS) and a twin differential mobility particle sizer (TDMPS). For 90% relative humidity, the DGF varied from 1.06 to 1.46 in summer, and from 1.06 to 1.66 in winter. Temporal variations in the observed mean DGF could be well explained with a simple growth model based on the aerosol chemical composition measured by aerosol mass spectrometry (AMS) and black carbon photometry (MAAP). In particular, good agreement was observed when sulfate was the predominant inorganic factor. A clear overestimation of the predicted growth factor was found when the nitrate mass concentration exceeded values of 10 μg m-3, e.g., during winter.

  15. Age dependence of the chemical composition of stars in globular clusters

    NASA Astrophysics Data System (ADS)

    Kipper, T.

    An overview of recent investigations of the age dependence of the chemical composition of stars in globular clusters is presented. Attention is given to two contradictory hypotheses on the issue of cluster age and metallicity. According to Carney (1980), there is a metallicity-age dependence. According to Gratton (1985), all globular clusters are the same age - approximately 16 x 10 exp 9 years old. The metallicity of the most metal-abundant clusters is discussed. The Fe/H metallicity of the object 47 Tuc is determined to range from -1.1 to -0.4. The chemical homogeneity of clusters is examined. Spectral investigations of NGC 6752 stars from the main sequence up to the upper part of the giants' branch did not show Fe/H dispersion. The study by Cohen (1980) of the relative distribution of heavy elements in clusters of different metallicity show that in spite of the significant difference in Fe/H (up to 2.0 dex) the relative abundances are quite similar.

  16. Matrix effects in biological SIMS using cluster ion beams of different chemical composition.

    PubMed

    Alnajeebi, Afnan M; Vickerman, John C; Lockyer, Nicholas P

    2016-06-01

    The influence of the matrix effect on secondary ion yield presents a very significant challenge in quantitative secondary ion mass spectrometry (SIMS) analysis, for example, in determining the relative concentrations of metabolites that characterize normal biological activities or disease progression. Not only the sample itself but also the choice of primary ion beam may influence the extent of ionization suppression/enhancement due to the local chemical environment. In this study, an assessment of ionization matrix effects was carried out on model systems using C60 (+), Arn (+), and (H2O)n (+) cluster ion beams. The analytes are pure and binary mixtures of amino acids arginine and histidine biological standards. Ion beams of 20 keV were compared with a range of cluster sizes n = 1000-10 000. The component secondary ion yields were assessed for matrix effects using different primary ion beams and sample composition. The presence of water in the cluster beam is associated with a reduction in the observed matrix effects, suggesting that chemically reactive ion beams may provide a route to more quantitative SIMS analysis of complex biological systems. PMID:26825287

  17. The surface chemical composition of lunar samples and its significance for optical properties

    NASA Technical Reports Server (NTRS)

    Gold, T.; Bilson, E.; Baron, R. L.

    1976-01-01

    The surface Fe, Ti, Ca, and Si concentrations in a variety of soil and rock samples from all the Apollo sites are determined using an Auger spectrometer plus a single-pass cylindrical-mirror analyzer with a standard 15-stage BeCu electron multiplier. It is found that there are no great differences between the surface and bulk concentrations of any of the four elements in the rock samples, but the surface Fe and Ti concentrations in soil samples are higher than the bulk concentrations. Results are also reported for solar-wind simulation experiments in which a pulverized rock sample was bombarded with 2-keV alpha-particles corresponding to about a 30,000-yr dose of the solar-wind proton component. These results indicate that the chemical change induced on the surface of a rock powder by positive-ion bombardment is similar to the change from bulk to surface chemical composition in lunar soil samples. A clear correlation is observed between the surface Fe concentration and albedo of the soil samples.

  18. Mumijo Traditional Medicine: Fossil Deposits from Antarctica (Chemical Composition and Beneficial Bioactivity)

    PubMed Central

    Aiello, Anna; Fattorusso, Ernesto; Menna, Marialuisa; Vitalone, Rocco; Schröder, Heinz C.; Müller, Werner E. G.

    2011-01-01

    Mumijo is a widely used traditional medicine, especially in Russia, Altai Mountains, Mongolia, Iran Kasachstan and in Kirgistan. Mumijo preparations have been successfully used for the prevention and treatment of infectious diseases; they display immune-stimulating and antiallergic activity as well. In the present study, we investigate the chemical composition and the biomedical potential of a Mumijo(-related) product collected from the Antarctica. The yellow material originates from the snow petrels, Pagodroma nivea. Extensive purification and chemical analysis revealed that the fossil samples are a mixture of glycerol derivatives. In vitro experiments showed that the Mumijo extract caused in cortical neurons a strong neuroprotective effect against the apoptosis-inducing amyloid peptide fragment β-fragment 25–35 (Aβ25–35). In addition, the fraction rich in glycerol ethers/wax esters displayed a significant growth-promoting activity in permanent neuronal PC12 cells. It is concluded that this new Mumijo preparation has distinct and marked neuroprotective activity, very likely due to the content of glycerol ether derivatives. PMID:18996940

  19. Determining the chemical composition of cloud condensation nuclei. Third progress report

    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.

    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.

  20. New chemical determinations of zinc in basalts, and rocks of similar composition

    USGS Publications Warehouse

    Rader, L.F.; Swadley, W.C.; Huffman, C., Jr.; Lipp, H.H.

    1963-01-01

    New determinations of zinc in 124 basalts by the chemical method described (Huff-Man et al. 1963) are reported. Average zinc values, in per cent, for basalts from diverse regions are as follows: Idaho, 28 samples, 0.013; Hawaii, 33 samples, 0.010; Connecticut, 27 samples, 0.0090; Oregon, 17 samples, 0.0081; California, 8 samples, 0.0071; and New Mexico, 11 samples, 0.0086; average, all samples, 0.0099 per cent zinc. A plot of differentiation indicator ratios calculated from the conventional rock analyses, CaO/(Na2O + K2O) as the ordinate and SiO2/MgO as the abscissa, was used to select, from different localities, samples essentially the same in chemical composition that were to be used for comparisons of zinc and other minor elements. Zinc correlates with MnO and with total iron as FeO. An inverse relationship found for zinc and manganese is related to the total iron content of the basalts. Thus for a given iron concentration as zinc increases, manganese decreases and vice versa. Ratios of zinc, the common denominator, to 11 other minor elements determined spectro-graphically show correlations with cobalt, gallium, scandium, yttrium, and zirconium. ?? 1963.