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Sample records for ii collected chemical

  1. Devices for collecting chemical compounds

    DOEpatents

    Scott, Jill R; Groenewold, Gary S

    2013-12-24

    A device for sampling chemical compounds from fixed surfaces and related methods are disclosed. The device may include a vacuum source, a chamber and a sorbent material. The device may utilize vacuum extraction to volatilize the chemical compounds from a fixed surface so that they may be sorbed by the sorbent material. The sorbent material may then be analyzed using conventional thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS) instrumentation to determine presence of the chemical compounds. The methods may include detecting release and presence of one or more chemical compounds and determining the efficacy of decontamination. The device may be useful in collection and analysis of a variety of chemical compounds, such as residual chemical warfare agents, chemical attribution signatures and toxic industrial chemicals.

  2. Chemical Bonds II

    ERIC Educational Resources Information Center

    Sanderson, R. T.

    1972-01-01

    The continuation of a paper discussing chemical bonding from a bond energy viewpoint, with a number of examples of single and multiple bonds. (Part I appeared in volume 1 number 3, pages 16-23, February 1972.) (AL)

  3. Current evaluation of the millennium phytomedicine- ginseng (II): Collected chemical entities, modern pharmacology, and clinical applications emanated from traditional Chinese medicine.

    PubMed

    Jia, Lee; Zhao, Yuqing; Liang, Xing-Jie

    2009-01-01

    This review, a sequel to part 1 in the series, collects about 107 chemical entities separated from the roots, leaves and flower buds of Panax ginseng, quinquefolius and notoginseng, and categorizes these entities into about 18 groups based on their structural similarity. The bioactivities of these chemical entities are described. The 'Yin and Yang' theory and the fundamentals of the 'five elements' applied to the traditional Chinese medicine (TCM) are concisely introduced to help readers understand how ginseng balances the dynamic equilibrium of human physiological processes from the TCM perspectives. This paper concerns the observation and experimental investigation of biological activities of ginseng used in the TCM of past and present cultures. The current biological findings of ginseng and its medical applications are narrated and critically discussed, including 1) its antihyperglycemic effect that may benefit type II diabetics; in vitro and in vivo studies demonstrated protection of ginseng on beta-cells and obese diabetic mouse models. The related clinical trial results are stated. 2) its aphrodisiac effect and cardiovascular effect that partially attribute to ginseng's bioactivity on nitric oxide (NO); 3) its cognitive effect and neuropharmacological effect that are intensively tested in various rat models using purified ginsenosides and show a hope to treat Parkinson's disease (PD); 4) its uses as an adjuvant or immunotherapeutic agent to enhance immune activity, appetite and life quality of cancer patients during their chemotherapy and radiation. Although the apoptotic effect of ginsenosides, especially Rh2, Rg3 and Compound K, on various tumor cells has been shown via different pathways, their clinical effectiveness remains to be tested. This paper also updates the antioxidant, anti-inflammatory, anti-apoptotic and immune-stimulatory activities of ginseng, its ingredients and commercial products, as well as common side effects of ginseng mainly due to its

  4. Current Evaluation of the Millennium Phytomedicine— Ginseng (II): Collected Chemical Entities, Modern Pharmacology, and Clinical Applications Emanated from Traditional Chinese Medicine

    PubMed Central

    Jia, Lee; Zhao, Yuqing; Liang, Xing-Jie

    2009-01-01

    This review, a sequel to part 1 in the series, collects about 107 chemical entities separated from the roots, leaves and flower buds of Panax ginseng, quinquefolius and notoginseng, and categorizes these entities into about 18 groups based on their structural similarity. The bioactivities of these chemical entities are described. The ‘Yin and Yang’ theory and the fundamentals of the ‘five elements’ applied to the traditional Chinese medicine (TCM) are concisely introduced to help readers understand how ginseng balances the dynamic equilibrium of human physiological processes from the TCM perspectives. This paper concerns the observation and experimental investigation of biological activities of ginseng used in the TCM of past and present cultures. The current biological findings of ginseng and its medical applications are narrated and critically discussed, including 1) its antihyperglycemic effect that may benefit type II diabetics; in vitro and in vivo studies demonstrated protection of ginseng on beta-cells and obese diabetic mouse models. The related clinical trial results are stated. 2) its aphrodisiac effect and cardiovascular effect that partially attribute to ginseng’s bioactivity on nitric oxide (NO); 3) its cognitive effect and neuropharmacological effect that are intensively tested in various rat models using purified ginsenosides and show a hope to treat Parkinson’s disease (PD); 4) its uses as an adjuvant or immunotherapeutic agent to enhance immune activity, appetite and life quality of cancer patients during their chemotherapy and radiation. Although the apoptotic effect of ginsenosides, especially Rh2, Rg3 and Compound K, on various tumor cells has been shown via different pathways, their clinical effectiveness remains to be tested. This paper also updates the antioxidant, anti-inflammatory, anti-apoptotic and immune-stimulatory activities of ginseng, its ingredients and commercial products, as well as common side effects of ginseng

  5. Collective surfing of chemically active particles.

    PubMed

    Masoud, Hassan; Shelley, Michael J

    2014-03-28

    We study theoretically the collective dynamics of immotile particles bound to a 2D surface atop a 3D fluid layer. These particles are chemically active and produce a chemical concentration field that creates surface-tension gradients along the surface. The resultant Marangoni stresses create flows that carry the particles, possibly concentrating them. For a 3D diffusion-dominated concentration field and Stokesian fluid we show that the surface dynamics of active particle density can be determined using nonlocal 2D surface operators. Remarkably, we also show that for both deep or shallow fluid layers this surface dynamics reduces to the 2D Keller-Segel model for the collective chemotactic aggregation of slime mold colonies. Mathematical analysis has established that the Keller-Segel model can yield finite-time, finite-mass concentration singularities. We show that such singular behavior occurs in our finite-depth system, and study the associated 3D flow structures. PMID:24724685

  6. Collective Surfing of Chemically Active Particles

    NASA Astrophysics Data System (ADS)

    Masoud, Hassan; Shelley, Michael J.

    2014-03-01

    We study theoretically the collective dynamics of immotile particles bound to a 2D surface atop a 3D fluid layer. These particles are chemically active and produce a chemical concentration field that creates surface-tension gradients along the surface. The resultant Marangoni stresses create flows that carry the particles, possibly concentrating them. For a 3D diffusion-dominated concentration field and Stokesian fluid we show that the surface dynamics of active particle density can be determined using nonlocal 2D surface operators. Remarkably, we also show that for both deep or shallow fluid layers this surface dynamics reduces to the 2D Keller-Segel model for the collective chemotactic aggregation of slime mold colonies. Mathematical analysis has established that the Keller-Segel model can yield finite-time, finite-mass concentration singularities. We show that such singular behavior occurs in our finite-depth system, and study the associated 3D flow structures.

  7. COLLECTION OF SULFUR GASES WITH CHEMICALLY-TREATED FILTERS

    EPA Science Inventory

    Chemically treated membrane filters were evaluated to collect hydrogen sulfide and sulfur dioxide. Four chemical treatments were tested. Silver nitrate and silver nitrate-tartaric acid filters were used to collect hydrogen sulfide, and lithium hydroxide and potassium bicarbonate ...

  8. Collective effects in the PEP-II B-factory

    SciTech Connect

    Corlett, J.N.

    1995-10-01

    The expected major collective effects in the PEP-II B-factory are discussed and thresholds presented. Broadband and narrow band impedance values are reviewed. Instabilities not related to impedance are discussed.

  9. Instrument to collect fogwater for chemical analysis

    SciTech Connect

    Jacob, D.J.; Waldman, J.M.; Haghi, M.; Hoffmann, M.R.; Flagan, R.C.

    1985-06-01

    An instrument is presented which collects large samples of ambient fogwater by impaction of droplets on a screen. The collection efficiency of the instrument is determined as a function of droplet size, and it is shown that fog droplets in the range 3--100-..mu..m diameter are efficiently collected. No significant evaporation or condensation occurs at any stage of the collection process. Field testing indicates that samples collected are representative of the ambient fogwater. The instrument may easily be automated, and is suitable for use in routine air quality monitoring programs.

  10. Collection of quantitative chemical release field data.

    SciTech Connect

    Demirgian, J.; Macha, S.; Loyola Univ.

    1999-01-01

    Detection and quantitation of chemicals in the environment requires Fourier-transform infrared (FTIR) instruments that are properly calibrated and tested. This calibration and testing requires field testing using matrices that are representative of actual instrument use conditions. Three methods commonly used for developing calibration files and training sets in the field are a closed optical cell or chamber, a large-scale chemical release, and a small-scale chemical release. There is no best method. The advantages and limitations of each method should be considered in evaluating field results. Proper calibration characterizes the sensitivity of an instrument, its ability to detect a component in different matrices, and the quantitative accuracy and precision of the results.

  11. COLLECTION AND CHEMICAL ANALYSIS OF LICHENS FOR BIOMONITORING

    EPA Science Inventory

    This chapter discusses the interrelated aspects of biomonitoring using chemical analysis of lichens. Many unique aspects of study objectives, study design (including design tasks, considerations, and sampling schemes), sample collection, sample preparation, and sample analysis th...

  12. Device for collecting chemical compounds and related methods

    DOEpatents

    Scott, Jill R.; Groenewold, Gary S.; Rae, Catherine

    2013-01-01

    A device for sampling chemical compounds from fixed surfaces and related methods are disclosed. The device may include a vacuum source, a chamber and a sorbent material. The device may utilize vacuum extraction to volatilize the chemical compounds from the fixed surfaces so that they may be sorbed by the sorbent material. The sorbent material may then be analyzed using conventional thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS) instrumentation to determine presence of the chemical compounds. The methods may include detecting release and presence of one or more chemical compounds and determining the efficacy of decontamination. The device may be useful in collection and analysis of a variety of chemical compounds, such as residual chemical warfare agents, chemical attribution signatures and toxic industrial chemicals.

  13. Collection and chemical analysis of lichens for biomonitoring. Book chapter

    SciTech Connect

    Jackson, L.L.; Ford, J.; Schwartzman, D.

    1991-01-01

    The chapter discusses the interrelated aspects of biomonitoring using chemical analysis of lichens. Many unique aspects of study objectives, study design (including design tasks, considerations, and sampling schemes), sample collection, sample preparation, and sample analysis that are required for a successful biomonitoring program using chemical analysis are emphasized. The advantages and disadvantages of common analytical methods suitable for chemical analysis of lichens are briefly discussed. Aspects of a quality assurance program and final contract reports are highlighted. In addition, some examples of studies using chemical analysis of lichens are discussed.

  14. Mixing enhancement in chemical lasers. II. Theory

    SciTech Connect

    Driscoll, R.J.

    1987-07-01

    A phenomenological model for reactant mixing in trip nozzle chemical lasers by means of a surface-stretching mechanism is used in conjunction with a two-level laser model to derive scaling laws for numerous features noted in the trip nozzle data. This mixing model is then employed with an aerokinetics code in order to obtain quantitative laser gain predictions. The results yielded by the code are in good agreement with small-signal data. It is determined that trip jet mixing will not increase laser efficiency at low cavity pressures, but will at high cavity pressures result in a doubling of laser power output. 12 references.

  15. Featured collection introduction: contaminants of emerging concern II

    USGS Publications Warehouse

    Battaglin, William A.; Kolok, Alan

    2014-01-01

    This collection of 13 articles focuses on CECs, and each of the articles highlights a specific aspect of this broad topic. The articles were solicited from researchers who participated in the second summer specialty conference on this topic, organized by the American Water Resources Association. The title of the conference was “CECs in Water Resources II: Research, Engineering and Community Action,” and the conference, as well as the articles in this featured collection, focus on a better and more comprehensive understanding of these contaminants. The conference was held in Denver, Colorado, on June 25-27, 2012, and approximately 125 conference attendees participated in an interdisciplinary forum of more than 75 presentations including keynote or plenary presentations by Dana Kolpin, Jorg Drewes, Heiko Schoenfuss, Chris Metcalfe, Vicki Blazer, and Tyrone Hayes. The first conference was held in 2007 and also produced a featured collection of articles (Battaglin and Kolpin, 2009).

  16. Dissecting chemical interactions governing RNA polymerase II transcriptional fidelity.

    PubMed

    Kellinger, Matthew W; Ulrich, Sébastien; Chong, Jenny; Kool, Eric T; Wang, Dong

    2012-05-16

    Maintaining high transcriptional fidelity is essential to life. For all eukaryotic organisms, RNA polymerase II (Pol II) is responsible for messenger RNA synthesis from the DNA template. Three key checkpoint steps are important in controlling Pol II transcriptional fidelity: nucleotide selection and incorporation, RNA transcript extension, and proofreading. Some types of DNA damage significantly reduce transcriptional fidelity. However, the chemical interactions governing each individual checkpoint step of Pol II transcriptional fidelity and the molecular basis of how subtle DNA base damage leads to significant losses of transcriptional fidelity are not fully understood. Here we use a series of "hydrogen bond deficient" nucleoside analogues to dissect chemical interactions governing Pol II transcriptional fidelity. We find that whereas hydrogen bonds between a Watson-Crick base pair of template DNA and incoming NTP are critical for efficient incorporation, they are not required for efficient transcript extension from this matched 3'-RNA end. In sharp contrast, the fidelity of extension is strongly dependent on the discrimination of an incorrect pattern of hydrogen bonds. We show that U:T wobble base interactions are critical to prevent extension of this mismatch by Pol II. Additionally, both hydrogen bonding and base stacking play important roles in controlling Pol II proofreading activity. Strong base stacking at the 3'-RNA terminus can compensate for loss of hydrogen bonds. Finally, we show that Pol II can distinguish very subtle size differences in template bases. The current work provides the first systematic evaluation of electrostatic and steric effects in controlling Pol II transcriptional fidelity. PMID:22509745

  17. Impedances and collective instabilities of the Tevatron at Run II

    SciTech Connect

    Ng, King-Yuen, FERMI

    1998-09-01

    The longitudinal and transverse coupling impedances of the Tevatron vacuum chamber are estimated and summed up. The resistive-wall impedances of the beam pipe and the laminations in the Lambertson magnets dominate below {approximately} 50 MHz. Then come the inductive parts of the bellows and BPM`s. The longitudinal and transverse collective instabilities, for both single bunch and multi bunches, are studied using Run II parameters. As expected the transverse coupled-bunch instability driven by the resistive-wall impedance is the most severe collective instability. However, it can be damped by a transverse damper designed for the correction of injection offsets. The power of such a damper has been studied.

  18. Diversity in Chemical Constituents of Ligularia longihastata Collected in China.

    PubMed

    Okamoto, Yasuko; Taniguchi, Mizuho; Terada, Kaori; Nakashima, Katsuyuki; Gong, Xun; Hanai, Ryo; Tori, Motoo; Kuroda, Chiaki

    2016-02-01

    Root constituents of Ligularia longihastata were examined for the first time. Fourteen eremophilane sesquiterpenes, including two new eremophilanes identified as 3α-isobutyroyloxy-7βH-eremophila-9,11-dien-8-one and 3β-angeloyloxy-1β,10β-epoxyfuranoeremophilan-9-one, and three eudesmanes were isolated. From samples collected in Baiyu County, Sichuan Province, furanoeremophilane derivatives were isolated, while various eremophilan-8-ones were isolated from samples collected in Kangding County, Sichuan. The results suggest chemical diversity in the species. PMID:27032187

  19. PWR steam generator chemical cleaning. Phase II. Final report

    SciTech Connect

    Not Available

    1980-01-01

    Two techniques believed capable of chemically dissolving the corrosion products in the annuli between tubes and support plates were developed in laboratory work in Phase I of this project and were pilot tested in Indian Point Unit No. 1 steam generators. In Phase II, one of the techniques was shown to be inadequate on an actual sample taken from an Indian Point Unit No. 2 steam generator. The other technique was modified slightly, and it was demonstrated that the tube/support plate annulus could be chemically cleaned effectively.

  20. Appendix C. Collection of Samples for Chemical Agent Analysis

    SciTech Connect

    Koester, C; Thompson, C; Doerr, T; Scripsick, R

    2005-09-23

    This chapter describes procedures for the collection and analysis of samples of various matrices for the purpose of determining the presence of chemical agents in a civilian setting. This appendix is intended to provide the reader with sufficient information to make informed decisions about the sampling and analysis process and to suggest analytical strategies that might be implemented by the scientists performing sampling and analysis. This appendix is not intended to be used as a standard operating procedure to provide detailed instructions as to how trained scientists should handle samples. Chemical agents can be classified by their physical and chemical properties. Table 1 lists the chemical agents considered by this report. In selecting sampling and analysis methods, we have considered procedures proposed by the Organization for Prohibition of Chemical Weapons (OPCW), the U. S. Environmental Protection Agency (EPA), and peer-reviewed scientific literature. EPA analytical methods are good resources describing issues of quality assurance with respect to chain-of-custody, sample handling, and quality control requirements.

  1. 78 FR 41785 - Agency Information Collection Activities; Comment Request; Implementation of Title I/II Program...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-11

    ... Agency Information Collection Activities; Comment Request; Implementation of Title I/II Program... notice will be considered public records. Title of Collection: Implementation of Title I/II Program... Estimated Number of Annual Burden Hours: 6,573. Abstract: The Implementation of Title I/II...

  2. The Proximal Lilly Collection: Mapping, Exploring and Exploiting Feasible Chemical Space.

    PubMed

    Nicolaou, Christos A; Watson, Ian A; Hu, Hong; Wang, Jibo

    2016-07-25

    Venturing into the immensity of the small molecule universe to identify novel chemical structure is a much discussed objective of many methods proposed by the chemoinformatics community. To this end, numerous approaches using techniques from the fields of computational de novo design, virtual screening and reaction informatics, among others, have been proposed. Although in principle this objective is commendable, in practice there are several obstacles to useful exploitation of the chemical space. Prime among them are the sheer number of theoretically feasible compounds and the practical concern regarding the synthesizability of the chemical structures conceived using in silico methods. We present the Proximal Lilly Collection initiative implemented at Eli Lilly and Co. with the aims to (i) define the chemical space of small, drug-like compounds that could be synthesized using in-house resources and (ii) facilitate access to compounds in this large space for the purposes of ongoing drug discovery efforts. The implementation of PLC relies on coupling access to available synthetic knowledge and resources with chemo/reaction informatics techniques and tools developed for this purpose. We describe in detail the computational framework supporting this initiative and elaborate on the characteristics of the PLC virtual collection of compounds. As an example of the opportunities provided to drug discovery researchers by easy access to a large, realistically feasible virtual collection such as the PLC, we describe a recent application of the technology that led to the discovery of selective kinase inhibitors. PMID:27286472

  3. Chemical Constituents of Ligularia wilsoniana Collected in Chongqing, China.

    PubMed

    Okamoto, Yasuko; Taniguchi, Mizuho; Nakashima, Katsuyuki; Gong, Xun; Hanai, Ryo; Kuroda, Chiaki; Tori, Motoo

    2016-02-01

    The chemical constituents of Ligularia wilsoniana were studied for the first time, using four samples collected in Chongqing City, China. Two new compounds, 6β-(2',3'-epoxy-2'-methylpropanoyloxy)-β,10β-epoxyfuranoeremophilane and 11αH-6β-(2'-hydroxymethylacryloyloxy)-1β,10β;7β,8β- diepoxyeremophilanolide, as well as eight known compounds, were isolated from one of the samples, while three to four known furanoeremophilanes were isolated from the other three samples. No compound was common to the two classes of the samples, demonstrating the presence of at least two chemotypes of this species. PMID:27032188

  4. 78 FR 74173 - Notice of Proposed Information Collection Requests: Heritage Health Index II on the State of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-10

    ... ARTS AND THE HUMANITIES Notice of Proposed Information Collection Requests: Heritage Health Index II on... of the Heritage Health Index II on the State of America's Collections (HHI II) is to assess the state.... Title: Heritage Health Index II on the State of America's Collections (HHI II). OMB Number: To...

  5. Chemical values from solvent refined coal SRC-II

    SciTech Connect

    Swift, H.E.; Sinnett, C.A.; Harris, G.A.

    1980-01-01

    Gulf Oil Corp.'s SRC-II process, developed for the production of synthetic fuels from coal, can also produce chemical feedstocks. Estimates based on a 30,000 ton/day plant show that ethane-propane cracking would produce (in millions of lb/yr) 1100 of ethylene and 110 of propylene; conversion of the naphtha alone into aromatics would produce 970 of benzene, toluene, and xylenes (BTX); conversion of the naphtha and light oil to aromatics would give 1500 of BTX and significant amounts of gasoline, jet fuel, and diesel fuel; and the light fuel oil alone, e.g., of Kentucky No. 9 coal, could yield 276 of phenol, 463 of cresols, and 64 of naphthalene. Detailed product slates and cost estimates projected for 1990 show that ethylene from ethane-propane cracking offers $0.016/lb advantage over a natural gas-derived feedstock; that cost of ethylene from SRC-II hydrotreated naphtha is comparable to that from a Kuwait full-range naphtha and higher than ethylene from Kuwait gas oil; and that the cost of BTX from SRC-II naphtha is $0.87/gal compared with $1.22/gal for petroleum naphtha-derived BTX. The coal-derived petrochemical feedstocks are expected to be competitive with the petroleum-derived feedstocks by 1990.

  6. Improved Devices for Collecting Sweat for Chemical Analysis

    NASA Technical Reports Server (NTRS)

    Feedback, Daniel L.; Clarke, Mark S. F.

    2011-01-01

    Improved devices have been proposed for collecting sweat for biochemical analysis - especially for determination of the concentration of Ca2+ ions in sweat as a measure of loss of Ca from bones. Unlike commercially available sweat-collection patches used previously in monitoring osteoporosis and in qualitative screening for some drugs, the proposed devices would not allow evaporation of the volatile chemical components (mostly water) of sweat. Moreover, the proposed devices would be designed to enable determination of the volumes of collected sweat. From these volumes and the quantities of Ca(2+) and/or other analytes as determined by other means summarized below, one could determine the concentrations of the analytes in sweat. A device according to the proposal would be flexible and would be worn like a commercial sweat-collection patch. It would be made of molded polydimethylsiloxane (silicone rubber) or other suitable material having properties that, for the purpose of analyzing sweat, are similar to those of glass. The die for molding the silicone rubber would be fabricated by a combination of lithography and electroplating. The die would reproducibly form, in the silicone rubber, a precisely defined number of capillary channels per unit area, each channel having a precisely defined volume. Optionally, electrodes for measuring the Ca(2+) content of the sweat could be incorporated into the device. The volume of sweat collected in the capillary channels of the device would be determined from (1) the amount of light or radio waves of a given wavelength absorbed by the device and (2) the known geometry of the array of capillary channels. Then, in one of two options, centrifugation would be performed to move the sweat from the capillary tubes to the region containing the electrodes, which would be used to measure the Ca(2+) content by a standard technique. In the other option, centrifugation would be performed to remove the sweat from the device to make the sweat

  7. Improved Devices for Collecting Sweat for Chemical Analysis

    NASA Technical Reports Server (NTRS)

    Feeback, Daniel L.; Clarke, Mark S. F.

    2011-01-01

    Improved devices have been proposed for collecting sweat for biochemical analysis especially for determination of the concentration of Ca2+ ions in sweat as a measure of loss of Ca from bones. Unlike commercially available sweat-collection patches used previously in monitoring osteoporosis and in qualitative screening for some drugs, the proposed devices would not allow evaporation of the volatile chemical components (mostly water) of sweat. Moreover, the proposed devices would be designed to enable determination of the volumes of collected sweat. From these volumes and the quantities of Ca2+ and/or other analytes as determined by other means summarized below, one could determine the concentrations of the analytes in sweat. A device according to the proposal would be flexible and would be worn like a commercial sweat-collection patch. It would be made of molded polydimethylsiloxane (silicone rubber) or other suitable material having properties that, for the purpose of analyzing sweat, are similar to those of glass. The die for molding the silicone rubber would be fabricated by a combination of lithography and electroplating. The die would reproducibly form, in the silicone rubber, a precisely defined number of capillary channels per unit area, each channel having a precisely defined volume. Optionally, electrodes for measuring the Ca2+ content of the sweat could be incorporated into the device. The volume of sweat collected in the capillary channels of the device would be determined from (1) the amount of light or radio waves of a given wavelength absorbed by the device and (2) the known geometry of the array of capillary channels. Then, in one of two options, centrifugation would be performed to move the sweat from the capillary tubes to the region containing the electrodes, which would be used to measure the Ca2+ content by a standard technique. In the other option, centrifugation would be performed to remove the sweat from the device to make the sweat available

  8. 77 FR 60743 - Proposed Collection; Comment Request for Schedule F, Part II and III (Form 1040)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-04

    ... Internal Revenue Service Proposed Collection; Comment Request for Schedule F, Part II and III (Form 1040... Law 104-13 (44 U.S.C. 3506(c)(2)(A)). Currently, the IRS is soliciting comments concerning Schedule F... Number: Schedule F, Part II and III (Form 1040). Abstract: Schedule F, Part II and III (Form 1040)...

  9. Chemical Pathways Connecting Lead(II) Iodide and Perovskite via Polymeric Plumbate(II) Fiber.

    PubMed

    Guo, Yunlong; Shoyama, Kazutaka; Sato, Wataru; Matsuo, Yutaka; Inoue, Kento; Harano, Koji; Liu, Chao; Tanaka, Hideyuki; Nakamura, Eiichi

    2015-12-23

    Despite tremendous progress in optoelectronic devices using lead perovskite (CH3NH3(+)PbI3(-)), there has been a paucity of mechanistic information on how photoactive micron-sized crystals of lead perovskite grow from a mixture of a layered crystal of lead(II) iodide and methylammonium iodide mediated by a polar solvent, DMSO or DMF. We report here that the whole process of the lead perovskite synthesis consists of a series of equilibria driven by reversible solvent participation involving a polymeric strip of plumbate(II) oligomer as a key intermediate. A significant finding includes quick decomposition of perovskite crystal upon exposure to DMSO or DMF at room temperature, where the solvent molecules act as a base to remove acidic ammonium iodide from the perovskite crystal. This observation accounts for the difficulty in controlling perovskite solar cell fabrication. Overall, the polar solvent is indispensible first to degrade a 2-D sheet of crystals of lead(II) iodide into 1-D fibrous intermediates and then to promote Oswald ripening of perovskite crystals. The detailed chemical information provided here will help to rationalize the photovoltaic device studies that have so far remained empirical and to open a new venue to a developing field of microscale lead perovskite devices, as illustrated by fabrication of photovoltaic devices and photodetectors. PMID:26617161

  10. Chemical bath deposition of II-VI compound thin films

    NASA Astrophysics Data System (ADS)

    Oladeji, Isaiah Olatunde

    II-VI compounds are direct bandgap semiconductors with great potentials in optoelectronic applications. Solar cells, where these materials are in greater demand, require a low cost production technology that will make the final product more affordable. Chemical bath deposition (CBD) a low cost growth technique capable of producing good quality thin film semiconductors over large area and at low temperature then becomes a suitable technology of choice. Heterogeneous reaction in a basic aqueous solution that is responsible for the II-VI compound film growth in CBD requires a metal complex. We have identified the stability constant (k) of the metal complex compatible with CBD growth mechanism to be about 106.9. This value is low enough to ensure that the substrate adsorbed complex relax for subsequent reaction with the chalcogen precursor to take place. It is also high enough to minimize the metal ion concentration in the bath participating in the precipitation of the bulk compounds. Homogeneous reaction that leads to precipitation in the reaction bath takes place because the solubility products of bulk II-VI compounds are very low. This reaction quickly depletes the bath of reactants, limit the film thickness, and degrade the film quality. While ZnS thin films are still hard to grow by CBD because of lack of suitable complexing agent, the homogeneous reaction still limits quality and thickness of both US and ZnS thin films. In this study, the zinc tetraammine complex ([Zn(NH3) 4]2+) with k = 108.9 has been forced to acquire its unsaturated form [Zn(NH3)3]2+ with a moderate k = 106.6 using hydrazine and nitrilotriacetate ion as complementary complexing agents and we have successfully grown ZnS thin films. We have also, minimized or eliminated the homogeneous reaction by using ammonium salt as a buffer and chemical bath with low reactant concentrations. These have allowed us to increase the saturation thickness of ZnS thin film by about 400% and raise that of US film

  11. 77 FR 22559 - Proposed Information Collection; Comment Request; Chemical Weapons Convention Provisions of the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-16

    ... Bureau of Industry and Security Proposed Information Collection; Comment Request; Chemical Weapons Convention Provisions of the Export Administration Regulations AGENCY: Bureau of Industry and Security...) 482-4895, Lawrence.Hall@bis.doc.gov . SUPPLEMENTARY INFORMATION: I. Abstract The Chemical...

  12. Recovery of Cu(II) by chemical reduction using sodium dithionite.

    PubMed

    Chou, Yi-Hsuan; Yu, Jui-Hsuan; Liang, Yang-Min; Wang, Pin-Jan; Li, Chi-Wang; Chen, Shiao-Shing

    2015-12-01

    Wastewaters containing Cu(II) along with ligands are ubiquitous in various industrial sectors. Efficacy of treatment processes for copper removal, especially precipitation, is greatly debilitated by ligands. Chemical reduction being commonly employed for production of metal nanoparticles has also been used for removing copper. Addition of ammonia was reported to be essential for improving copper reduction efficiency by increasing copper solubility at alkaline pH values. In this study, chemical reduction was employed to treat ligand-containing wastewater, exploiting the fact that ligands and metals are coexisted in many wastewaters. Result shows that copper ions were removed by either reduction or precipitation mechanisms depending on pH, type of ligands, and mixing condition. Complete copper reduction/removal was achieved under optimal condition. The lowest removal efficiency observed at pH 9.0 for ammonia system is due to formation of nano-sized particles, which are readily to pass through 0.45μm filter used for sample pretreatment before copper analysis. Instead of producing metallic copper, cuprous and copper oxide are identified in the samples collected from ammonia system and EDTA system, respectively. Re-oxidation of metallic copper particles by atmospheric oxygen during sample handling or incomplete reduction of Cu(II) ions during reduction process might be the cause. Finally, reduction process was applied to treat real wastewater, achieving complete removal of copper but only 10% of nickel. PMID:26210323

  13. The holothuroids, echinoids and asteroids (echinodermata) collected by the Snellius-II expedition

    NASA Astrophysics Data System (ADS)

    Jangoux, Michel; De Ridder, Chantal; Massin, Claude; Darsono, Prapto

    Together the holothuroids, echinoids and asteroids collected by the Snellius-II Expedition represent 144 different species (40 species of holothuroids, 45 species of echinoids and 59 species of asteroids). The collection includes 14 species new to science. Among the remaining 130 species there are five new records for the Austro-Malayan region and 13 new records for the Indonesian seas.

  14. 77 FR 1084 - Agency Information Collection Activities Under Review; Title II of the Americans With...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-09

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF JUSTICE Agency Information Collection Activities Under Review; Title II of the Americans With Disabilities Act of 1990/Section 504 of the Rehabilitation Act of 1973 Discrimination Complaint Form ACTION: 30-Day Notice of Information Collection under review...

  15. 40 CFR Table II-2 to Subpart II - Collection Efficiencies of Anaerobic Processes

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Industrial Wastewater Treatment Pt. 98... process type Cover type Methane collection efficiency Covered anaerobic lagoon (biogas capture) Bank...

  16. 40 CFR Table II-2 to Subpart II - Collection Efficiencies of Anaerobic Processes

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Industrial Wastewater Treatment Pt. 98... process type Cover type Methane collection efficiency Covered anaerobic lagoon (biogas capture) Bank...

  17. 75 FR 68370 - Agency Information Collection Activities: Office of Infrastructure Protection; Chemical Security...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-05

    .... DHS previously published this ICR in the Federal Register on August 27, 2010 at 75 FR 52768, for a 60... in the chemical industry sector. Information is automatically collected in a computer database as... training is designed for the general chemical facility employee. U.S. chemical industry direct...

  18. 76 FR 40377 - Agency Information Collection Activities; Proposed Collection; Comment Request; Class II Special...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-08

    ... sexually transmitted diseases. Respondents to this collection of information are manufacturers and... medically accurate regarding the overall effectiveness or lack of effectiveness in preventing sexually... final rule (64 FR 13254, March 17, 1999). Because the packaging requirements for condoms are similar...

  19. Sustainability Indicators for Chemical Processes : II. Data Needs

    EPA Science Inventory

    In order to begin repair of the environmental quality of the planet, there is a need to embrace sustainable development at many levels of the chemical industry and society. One way that the chemical industry is responding to this need is through sustainability evaluations, retrof...

  20. 76 FR 7841 - Agency Information Collection Activities; Proposed Collections; Toxic Chemical Release Reporting...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-11

    ... Ratio-Based Burden Methodology AGENCY: Environmental Protection Agency. ACTION: Notice. SUMMARY: In... to Ratio-Based Methodology,'' describes the nature of the information collection (including proposed... the burden of the proposed collection of information, including the validity of the new...

  1. Responses of photosystems I and II of Acutodesmus obliquus to chemical stress caused by the use of recycled nutrients.

    PubMed

    Patzelt, Dominik J; Hindersin, Stefan; Kerner, Martin; Hanelt, Dieter

    2016-01-01

    Nutrients derived from hydrothermal gasification of Acutodesmus obliquus were tested on its biological compatibility to support growth of the same microalgae. Photosynthetic parameters of photosystems I and II (PS I and PS II) were investigated to study physiological effects on the microalgal cell. The nutrients were collected as liquid residues. Dilutions of 1:500 showed no effect on both photosystems. Lower dilutions affected PS II initially and later also PS I. Cyclic electron flow around PS I compensated for loss of electrons due to partially inhibited PS II. The highest tested concentration of liquid residue erased any photosynthetic activity of PS II after 28 min and onwards. In contrast, PS I remained active. The results suggest that PS I is less susceptible than PS II and that the mixture of chemicals in the liquid residue did not directly affect PS I but PS II. The toxicants in the residues seemed to interfere with linear electron flow of PS II even though light-driven formation of radicals and subsequent damage to one of the photosystems can be excluded as demonstrated in darkness. Lowered photosynthetic activity of PS I during actinic irradiation was caused due to lack of supply of electrons from PS II. The cyclic electron flow might play a key role in delivering the energy needed to restore PS II activity and to biodegrade the toxicants when linear electron flow failed. These negative effects of liquid residue towards microalgal cells require a remediation step for direct application of the liquid residue to substitute commercial fertilizers in microalgal mass cultures. PMID:26433968

  2. Chemical composition of fogwater collected along the California coast

    SciTech Connect

    Jacob, D.J.; Waldman, J.M.; Munger, J.W.; Hoffman, M.R.

    1985-01-01

    Fogwater collected at both urban and nonurban coastal sites in California ws found to be consistently acidic. Millimolar concentrations of NO/sub 3//sup -/, and fogwater pH values below 3, were observed at sites downwind of the Los Angeles basin. Fogwater composition at remote sites showed evidence of substantial continental and anthropogenic contributions. Acid-neutralizing capacities in coastal air were found to be very low and insufficient to neutralize even small acid inputs. Chloride loss relative to its sea salt contribution was observed at sites furthest from anthropogenic sources.

  3. METEORLOGICAL AND CHEMICAL DATA COLLECTED IN THE UNITED STATES TO INFER DRY DEPOSITION OF TRACE CONTAMINANTS

    EPA Science Inventory

    The Atmospheric Turbulence and Diffusion Division is responsible for the operation of a prototype network developed to collect meteorological and surface condition data. The network of meteorological and chemical filterpack monitoring stations has been in operation since the summ...

  4. Thermodynamics of natural selection II: Chemical Carnot cycles.

    PubMed

    Smith, Eric

    2008-05-21

    This is the second in a series of three papers devoted to energy flow and entropy changes in chemical and biological processes, and to their relations to the thermodynamics of computation. In the first paper of the series, it was shown that a general-form dimensional argument from the second law of thermodynamics captures a number of scaling relations governing growth and development across many domains of life. It was also argued that models of physiology based on reversible transformations provide sensible approximations within which the second-law scaling is realized. This paper provides a formal basis for decomposing general cyclic, fixed-temperature chemical reactions, in terms of the chemical equivalent of Carnot's cycle for heat engines. It is shown that the second law relates the minimal chemical work required to perform a cycle to the Kullback-Leibler divergence produced in its chemical output ensemble from that of a Gibbs equilibrium. Reversible models of physiology are used to create reversible models of natural selection, which relate metabolic energy requirements to information gain under optimal conditions. When dissipation is added to models of selection, the second-law constraint is generalized to a relation between metabolic work and the combined energies of growth and maintenance. PMID:18367209

  5. High Throughput Pharmacokinetics for Environmental Chemicals (FutureToxII)

    EPA Science Inventory

    Pharmacokinetic (PK) models are critical to determine whether chemical exposures produce potentially hazardous tissue concentrations. For bioactivity identified in vitro (e.g. ToxCast) – hazardous or not – PK models can forecast exposure thresholds, below which no significant bio...

  6. Collection, chemical analysis, and evaluation of coal samples in 1975

    USGS Publications Warehouse

    Swanson, Vernon Emanuel; Medlin, J.H.; Hatch, J.R.; Coleman, S.L.; Wood, G.H., Jr.; Woodruff, S.D.; Hildebrand, R.T.

    1976-01-01

    During 1975, the U.S. Geological Survey, in cooperation with other Federal and State agencies, university groups, and private companies, continued its program to augment and refine information on the composition of coal in the United States. This report includes all analytical data on 799 channel samples of coal beds from major operating mines and core holes in 28 States, collected mainly by State Geological Surveys under a cooperative program funded largely by the U.S. Energy Research and Development Administration. For each sample, the U.S. Geological Survey has quantitatively determined the amounts of 24 major, minor, and trace elements (including AI, As, Cd, Cu, F, Hg, Mn, Na, Pb, Se, U, and Zn), and has semiquantitatively determined the concentrations of 15 to 20 additional trace elements (including B, Be, Cr, Ge, Mo, Ni, and V). In addition, the U.S. Bureau of Mines has provided proximate and ultimate analyses, and Btu and forms-of-sulfur determinations on 488 of the samples. Statistical summaries of the data are given for all coal samples in the United States, for coal divided by rank (53 anthracite, 509 bituminous coal, 183 subbituminous coal, and 54 lignite samples), and the arithmetic means, ranges, and geometric means and deviations are given for the coal in each of seven different major coal areas in the United States. For example, the average coal in the United States contains 11.3 percent ash, 10.0 percent moisture, 2.0 percent sulfur, and has 11,180 Btu per pound; of the 10 major oxides determined on the 525?C ash, the average SiO2 content is 38 percent, Al2O3 20 percent, and Na2O 0.67 percent; the average Cd content is 7.3 ppm, Pb 114 ppm, and Zn 151 ppm (range 1 ppm to 6.0 percent). As determined on the raw coal, the average Hg content is 0.18 ppm (range <0.01 to 63.0 ppm), the Se content 4.1 ppm (range <0.1 to 150 ppm), and the U content 1.8 ppm (range <0.2 to 42.9 ppm).

  7. Chemical Posttranslational Modification with Designed Rhodium(II) Catalysts.

    PubMed

    Martin, S C; Minus, M B; Ball, Z T

    2016-01-01

    Natural enzymes use molecular recognition to perform exquisitely selective transformations on nucleic acids, proteins, and natural products. Rhodium(II) catalysts mimic this selectivity, using molecular recognition to allow selective modification of proteins with a variety of functionalized diazo reagents. The rhodium catalysts and the diazo reactivity have been successfully applied to a variety of protein folds, the chemistry succeeds in complex environments such as cell lysate, and a simple protein blot method accurately assesses modification efficiency. The studies with rhodium catalysts provide a new tool to study and probe protein-binding events, as well as a new synthetic approach to protein conjugates for medical, biochemical, or materials applications. PMID:27586326

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

    PubMed

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

    1980-03-01

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

  9. A structurally diverse Ru(II),Pt(II) tetrametallic motif for photoinitiated electron collection and photocatalytic hydrogen production.

    PubMed

    Knoll, Jessica D; Arachchige, Shamindri M; Brewer, Karen J

    2011-02-18

    Coupling a reactive metal to light absorbers affords molecular devices for photoinitiated electron collection and photocatalytic conversion of substrates to fuels. A new Ru(II),Pt(II) tetrametallic supramolecule, [{(phen)(2)Ru(dpp)}(2)Ru(dpq)PtCl(2)](PF(6))(6), and the trimetallic precursors, [{(phen)(2)Ru(dpp)}(2)RuCl(2)](PF(6))(4) and [{(phen)(2)Ru(dpp)}(2)Ru(dpq)](PF(6))(6), have been synthesized, and their redox, spectroscopic, spectroelectrochemical, photophysical and photocatalytic properties studied. They efficiently absorb UV and visible light. The electrochemistry of [{(phen)(2)Ru(dpp)}(2)Ru(dpq)PtCl(2)](PF(6))(6) suggests a lowest-lying terminal Ru→dpq charge-separated state that quenches the emission of the parent complex with non-unity population of the emissive (3)MLCT excited state. Photolysis of [{(phen)(2)Ru(dpp)}(2)Ru(dpq)PtCl(2)](6+) at 470 nm with DMA gives multielectron reduction, storing electrons in a new manner on the central (dpp)(2)Ru(II)(dpq) moiety. Addition of H(2)O to the photolysis system produces 21 μmol of H(2) in 5 h, with 115 turnovers of the tetrametallic photocatalyst. PMID:21328554

  10. Chemical abundances in LMC stellar populations. II. The bar sample

    NASA Astrophysics Data System (ADS)

    Van der Swaelmen, M.; Hill, V.; Primas, F.; Cole, A. A.

    2013-12-01

    Aims: This paper compares the chemical evolution of the Large Magellanic Cloud (LMC) to that of the Milky Way (MW) and investigates the relation between the bar and the inner disc of the LMC in the context of the formation of the bar. Methods: We obtained high-resolution and mid signal-to-noise ratio spectra with FLAMES/GIRAFFE at ESO/VLT and performed a detailed chemical analysis of 106 and 58 LMC field red giant stars (mostly older than 1 Gyr), located in the bar and the disc of the LMC respectively. To validate our stellar parameter determinations and abundance measurement procedures, we performed thorough tests using the well-known mildly metal-poor Milky-Way thick disc giant Arcturus (HD 124897, α Boo). We measured elemental abundances for O, Mg, Si, Ca, Ti (α-elements), Na (light odd element), Sc, V, Cr, Co, Ni, Cu (iron-peak elements), Y, Zr, Ba, La, and Eu (s- and r-elements). Results: We find that the α-element ratios [Mg/Fe] and [O/Fe] are lower in the LMC than in the MW while the LMC has similar [Si/Fe], [Ca/Fe], and [Ti/Fe] to the MW. As for the heavy elements, [Ba,La/Eu] exhibit a strong increase with increasing metallicity starting from [Fe/H] ≈ -0.8 dex, and the LMC has lower [Y + Zr/Ba + La] ratios than the MW. Cu is almost constant over all metallicities and about 0.5 dex lower in the LMC than in the MW. The LMC bar and inner disc exhibit differences in their [α/ Fe] (slightly larger scatter for the bar in the metallicity range [-1, -0.5]), their Eu (the bar trend is above the disc trend for [Fe/H] ≥ -0.5 dex), their Y and Zr, their Na and their V (offset between the bar and the disc distributions). Conclusions: Our results show that the chemical history of the LMC experienced a strong contribution from type Ia supernovae as well as a strong s-process enrichment from metal-poor AGB winds. Massive stars made a smaller contribution to the chemical enrichment compared to the MW. The observed differences between the bar and the disc speak in

  11. Chemical vapor deposition of low reflective cobalt (II) oxide films

    NASA Astrophysics Data System (ADS)

    Amin-Chalhoub, Eliane; Duguet, Thomas; Samélor, Diane; Debieu, Olivier; Ungureanu, Elisabeta; Vahlas, Constantin

    2016-01-01

    Low reflective CoO coatings are processed by chemical vapor deposition from Co2(CO)8 at temperatures between 120 °C and 190 °C without additional oxygen source. The optical reflectivity in the visible and near infrared regions stems from 2 to 35% depending on deposition temperature. The combination of specific microstructural features of the coatings, namely a fractal "cauliflower" morphology and a grain size distribution more or less covering the near UV and IR wavelength ranges enhance light scattering and gives rise to a low reflectivity. In addition, the columnar morphology results in a density gradient in the vertical direction that we interpret as a refractive index gradient lowering reflectivity further down. The coating formed at 180 °C shows the lowest average reflectivity (2.9%), and presents an interesting deep black diffuse aspect.

  12. Photochemical Formation of Hydroxyl Radical, Hydrogen Peroxide and Fe(II) in the Sea Surface Microlayer (SML) Collected in Okinawa, Japan

    NASA Astrophysics Data System (ADS)

    Higaonna, Y.; Tachibana, C.; Kasaba, T.; Ishikawa, R.; Arakaki, T.

    2014-12-01

    The sea surface microlayer (SML) covers upper 1 to 1000 μm deep boundary layer of the ocean, where important biogeochemical processes take place. Photo-chemical reactions are activated by sunlight, so it is assumed that more photo-chemical reactions occur in SML than underlying bulk seawater (bulk). We initiated a study to understand chemical changes occurring in the SML by studying photochemical formation of oxidants such as hydrogen peroxide and hydroxyl radical (OH), both of which react with various organic substances and determine their lifetimes. Since OH can be formed by reaction between hydrogen peroxide and Fe(II), Fe(II) photoformation was also studied. We collected SML samples using a widely-used glass plate method and bulk samples by using a polyethylene bottles near the coast of Okinawa Island, Japan. Results showed that dissolved organic carbon (DOC) concentrations in the SML were about twice those of bulk seawater samples. Hydrogen peroxide formation in the SML samples was ca. 2.8 times faster than the bulk seawater samples. On the other hand, Fe(II) and OH photoformation kinetics was similar for both SML and bulk samples. Although it was predicted that more OH could be formed from reaction between hydrogen peroxide and Fe(II), OH formation kinetics was similar in both SML and bulk, suggesting that either Fe(II) did not react with hydrogen peroxide or reaction is very slow, possibly by forming a complex with organic compounds in the SML and bulk.

  13. Tree Resin Composition, Collection Behavior and Selective Filters Shape Chemical Profiles of Tropical Bees (Apidae: Meliponini)

    PubMed Central

    Leonhardt, Sara D.; Schmitt, Thomas; Blüthgen, Nico

    2011-01-01

    The diversity of species is striking, but can be far exceeded by the chemical diversity of compounds collected, produced or used by them. Here, we relate the specificity of plant-consumer interactions to chemical diversity applying a comparative network analysis to both levels. Chemical diversity was explored for interactions between tropical stingless bees and plant resins, which bees collect for nest construction and to deter predators and microbes. Resins also function as an environmental source for terpenes that serve as appeasement allomones and protection against predators when accumulated on the bees' body surfaces. To unravel the origin of the bees' complex chemical profiles, we investigated resin collection and the processing of resin-derived terpenes. We therefore analyzed chemical networks of tree resins, foraging networks of resin collecting bees, and their acquired chemical networks. We revealed that 113 terpenes in nests of six bee species and 83 on their body surfaces comprised a subset of the 1,117 compounds found in resins from seven tree species. Sesquiterpenes were the most variable class of terpenes. Albeit widely present in tree resins, they were only found on the body surface of some species, but entirely lacking in others. Moreover, whereas the nest profile of Tetragonula melanocephala contained sesquiterpenes, its surface profile did not. Stingless bees showed a generalized collecting behavior among resin sources, and only a hitherto undescribed species-specific “filtering” of resin-derived terpenes can explain the variation in chemical profiles of nests and body surfaces from different species. The tight relationship between bees and tree resins of a large variety of species elucidates why the bees' surfaces contain a much higher chemodiversity than other hymenopterans. PMID:21858119

  14. Tree resin composition, collection behavior and selective filters shape chemical profiles of tropical bees (Apidae: Meliponini).

    PubMed

    Leonhardt, Sara D; Schmitt, Thomas; Blüthgen, Nico

    2011-01-01

    The diversity of species is striking, but can be far exceeded by the chemical diversity of compounds collected, produced or used by them. Here, we relate the specificity of plant-consumer interactions to chemical diversity applying a comparative network analysis to both levels. Chemical diversity was explored for interactions between tropical stingless bees and plant resins, which bees collect for nest construction and to deter predators and microbes. Resins also function as an environmental source for terpenes that serve as appeasement allomones and protection against predators when accumulated on the bees' body surfaces. To unravel the origin of the bees' complex chemical profiles, we investigated resin collection and the processing of resin-derived terpenes. We therefore analyzed chemical networks of tree resins, foraging networks of resin collecting bees, and their acquired chemical networks. We revealed that 113 terpenes in nests of six bee species and 83 on their body surfaces comprised a subset of the 1,117 compounds found in resins from seven tree species. Sesquiterpenes were the most variable class of terpenes. Albeit widely present in tree resins, they were only found on the body surface of some species, but entirely lacking in others. Moreover, whereas the nest profile of Tetragonula melanocephala contained sesquiterpenes, its surface profile did not. Stingless bees showed a generalized collecting behavior among resin sources, and only a hitherto undescribed species-specific "filtering" of resin-derived terpenes can explain the variation in chemical profiles of nests and body surfaces from different species. The tight relationship between bees and tree resins of a large variety of species elucidates why the bees' surfaces contain a much higher chemodiversity than other hymenopterans. PMID:21858119

  15. Multiplicity among chemically peculiar stars. II. Cool magnetic Ap stars

    NASA Astrophysics Data System (ADS)

    Carrier, F.; North, P.; Udry, S.; Babel, J.

    2002-10-01

    We present new orbits for sixteen Ap spectroscopic binaries, four of which might in fact be Am stars, and give their orbital elements. Four of them are SB2 systems: HD 5550, HD 22128, HD 56495 and HD 98088. The twelve other stars are: HD 9996, HD 12288, HD 40711, HD 54908, HD 65339, HD 73709, HD 105680, HD 138426, HD 184471, HD 188854, HD 200405 and HD 216533. Rough estimates of the individual masses of the components of HD 65339 (53 Cam) are given, combining our radial velocities with the results of speckle interferometry and with Hipparcos parallaxes. Considering the mass functions of 74 spectroscopic binaries from this work and from the literature, we conclude that the distribution of the mass ratio is the same for cool Ap stars and for normal G dwarfs. Therefore, the only differences between binaries with normal stars and those hosting an Ap star lie in the period distribution: except for the case of HD 200405, all orbital periods are longer than (or equal to) 3 days. A consequence of this peculiar distribution is a deficit of null eccentricities. There is no indication that the secondary has a special nature, like e.g. a white dwarf. Based on observations collected at the Observatoire de Haute-Provence (CNRS), France. Tables 1 to 3 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/394/151 Appendix B is only available in electronic form at http://www.edpsciences.org

  16. Students' Chemical Information Project, October 1967 - September 1968. Final Report: Part II.

    ERIC Educational Resources Information Center

    Callaghan, A.; And Others

    Part II of the Students' Chemical Information Project (SCIP), designed to spread the use of computer-based information services among research scientists and technologists, contains details of the project operations, statistics, results of questionnaires and research reports from liaison scientists (See LI 002 562 for Part I). Chapter I: Operation…

  17. Sensors, Volume 3, Part II, Chemical and Biochemical Sensors Part II

    NASA Astrophysics Data System (ADS)

    Göpel, Wolfgang; Jones, T. A.; Kleitz, Michel; Lundström, Ingemar; Seiyama, Tetsuro

    1997-06-01

    'Sensors' is the first self-contained series to deal with the whole area of sensors. It describes general aspects, technical and physical fundamentals, construction, function, applications and developments of the various types of sensors. This is the second of two volumes focusing on chemical and biochemical sensors. It includes a detailed description of biosensors which often make use of transducer properties of the basic sensors and usually have additional biological components. This volume provides a unique overview of the applications, the possibilities and limitations of sensors in comparison with conventional instrumentation in analytical chemistry. Specific facettes of applications are presented by specialists from different fields including environmental, biotechnological, medical, or chemical process control. This book is an indispensable reference work for both specialits and newcomers, researchers and developers.

  18. Biotechnology for producing fuels and chemicals from biomass. Volume II. Fermentation chemicals from biomass

    SciTech Connect

    Villet, R.

    1981-02-01

    The technological and economic feasibility of producing some selected chemicals by fermentation is discussed: acetone, butanol, acetic acid, citric acid, 2,3-butanediol, and propionic acid. The demand for acetone and butanol has grown considerably. They have not been produced fermentatively for three decades, but instead by the oxo and aldol processes. Improved cost of fermentative production will hinge on improving yields and using cellulosic feedstocks. The market for acetic acid is likely to grow 5% to 7%/yr. A potential process for production is the fermentation of hydrolyzed cellulosic material to ethanol followed by chemical conversion to acetic acid. For about 50 years fermentation has been the chief process for citric acid production. The feedstock cost is 15% to 20% of the overall cost of production. The anticipated 5%/yr growth in demand for citric acid could be enhanced by using it to displace phosphates in detergent manufacture. A number of useful chemicals can be derived from 2,3-butanediol, which has not been produced commercially on a large scale. R and D are needed to establish a viable commercial process. The commercial fermentative production of propionic acid has not yet been developed. Recovery and purification of the product require considerable improvement. Other chemicals such as lactic acid, isopropanol, maleic anhydride, fumarate, and glycerol merit evaluation for commercial fermentative production in the near future.

  19. A Chemical Confirmation of the Faint Boötes II Dwarf Spheroidal Galaxy

    NASA Astrophysics Data System (ADS)

    Koch, Andreas; Rich, R. Michael

    2014-10-01

    We present a chemical abundance study of the brightest confirmed member star of the ultra-faint dwarf galaxy Boötes II from Keck/HIRES high-resolution spectroscopy at moderate signal-to-noise ratios. At [Fe/H] = -2.93 ± 0.03(stat.) ± 0.17(sys.), this star chemically resembles metal-poor halo field stars and the signatures of other faint dwarf spheroidal galaxies at the same metallicities in that it shows enhanced [α/Fe] ratios, Solar Fe-peak element abundances, and low upper limits on the neutron-capture element Ba. Moreover, this star shows no chemical peculiarities in any of the eight elements we were able to measure. This implies that the chemical outliers found in other systems remain outliers pertaining to the unusual enrichment histories of the respective environments, while Boo II appears to have experienced an enrichment history typical of its very low mass. We also re-calibrated previous measurements of the galaxy's metallicity from the calcium triplet (CaT) and find a much lower value than reported before. The resulting broad metallicity spread, in excess of one dex, the very metal-poor mean, and the chemical abundance patterns of the present star imply that Boötes II is a low-mass, old, metal-poor dwarf galaxy and not an overdensity associated with the Sagittarius Stream as has been previously suggested based on its sky position and kinematics. The low, mean CaT metallicity of -2.7 dex falls right on the luminosity-metallicity relation delineated over four orders of magnitude from the more luminous to the faintest galaxies. Thus Boötes II's chemical enrichment appears representative of the galaxy's original mass, while tidal stripping and other mass loss mechanisms were probably not significant as for other low-mass satellites.

  20. A chemical confirmation of the faint Boötes II dwarf spheroidal galaxy

    SciTech Connect

    Koch, Andreas; Rich, R. Michael

    2014-10-10

    We present a chemical abundance study of the brightest confirmed member star of the ultra-faint dwarf galaxy Boötes II from Keck/HIRES high-resolution spectroscopy at moderate signal-to-noise ratios. At [Fe/H] = –2.93 ± 0.03(stat.) ± 0.17(sys.), this star chemically resembles metal-poor halo field stars and the signatures of other faint dwarf spheroidal galaxies at the same metallicities in that it shows enhanced [α/Fe] ratios, Solar Fe-peak element abundances, and low upper limits on the neutron-capture element Ba. Moreover, this star shows no chemical peculiarities in any of the eight elements we were able to measure. This implies that the chemical outliers found in other systems remain outliers pertaining to the unusual enrichment histories of the respective environments, while Boo II appears to have experienced an enrichment history typical of its very low mass. We also re-calibrated previous measurements of the galaxy's metallicity from the calcium triplet (CaT) and find a much lower value than reported before. The resulting broad metallicity spread, in excess of one dex, the very metal-poor mean, and the chemical abundance patterns of the present star imply that Boötes II is a low-mass, old, metal-poor dwarf galaxy and not an overdensity associated with the Sagittarius Stream as has been previously suggested based on its sky position and kinematics. The low, mean CaT metallicity of –2.7 dex falls right on the luminosity-metallicity relation delineated over four orders of magnitude from the more luminous to the faintest galaxies. Thus Boötes II's chemical enrichment appears representative of the galaxy's original mass, while tidal stripping and other mass loss mechanisms were probably not significant as for other low-mass satellites.

  1. Insights into collective cell behaviour from populations of coupled chemical oscillators.

    PubMed

    Taylor, Annette F; Tinsley, Mark R; Showalter, Kenneth

    2015-08-21

    Biological systems such as yeast show coordinated activity driven by chemical communication between cells. Here, we show how experiments with coupled chemical oscillators can provide insights into collective behaviour in cellular systems. Two methods of coupling the oscillators are described: exchange of chemical species with the surrounding solution and computer-controlled illumination of a light-sensitive catalyst. The collective behaviour observed includes synchronisation, dynamical quorum sensing (a density dependent transition to population-wide oscillations), and chimera states, where oscillators spontaneously split into coherent and incoherent groups. At the core of the different types of behaviour lies an intracellular autocatalytic signal and an intercellular communication mechanism that influences the autocatalytic growth. PMID:26195263

  2. Type II ligands as chemical auxiliaries to favor enzymatic transformations by P450 2E1.

    PubMed

    Ménard, Amélie; Fabra, Camilo; Huang, Yue; Auclair, Karine

    2012-11-26

    The remarkable ability of P450 enzymes to oxidize inactivated C-H bonds and the high substrate promiscuity of many P450 isoforms have inspired us and others to investigate their use as biocatalysts. Our lab has pioneered a chemical-auxiliary approach to control the promiscuity of P450 3A4 and provide product predictability. The recent realization that type II ligands are sometimes also P450 substrates has prompted the design of a new generation of chemical auxiliaries with type II binding properties. This approach takes advantage of the high affinity of type II ligands for the active site of these enzymes. Although type II ligands typically block P450 activity, we report here that type II ligation can be harnessed to achieve just the opposite, that is, to favor biocatalysis and afford predictable oxidation of small hydrocarbon substrates with P450 2E1. Moreover, the observed predictability was rationalized by molecular docking. We hope that this approach might find future use with other P450 isoforms and yield complimentary products. PMID:23129539

  3. Equilibrium and thermodynamic studies of Cd (II) biosorption by chemically modified orange peel.

    PubMed

    Kumar, Arbind; Kumar, Vipin

    2016-03-01

    Agricultural wastes have great potential of removing heavy metal ions from aqueous solution. Removal of Cd (II) from aqueous solutions onto chemically modified orange peel was studied at different pH, contact time, initial metal concentrations, adsorbent doses and temperature. Batch experiments were carried out under optimized conditions to evaluate the adsorption capacity of orange peel chemically modified with NaOH. The results showed that maximum adsorption capacity of modified orange peel, approximately 97.0%, was observed 3 mg 1⁻¹ of initial Cd(II) concentration pH 6 for 4 g 1⁻¹ adsorbent dosage, 200 min contact time and 298 K temperature. Adsorption efficiency of modified orange peel decreased with increase in temperature indicated exothermic nature of adsorption. A negative value of ΔG⁰(-8.59 kJ mol⁻¹) confirmed the feasibility of adsorption process and spontaneous nature of adsorption. A negative value of ΔH⁰ (-28.08 kJ mol⁻¹) indicated exothermic nature while a negative ΔS⁰ (-66.86 J K⁻¹ mol⁻¹) value suggested decrease in degree of freedom of the adsorbed species. The results showed that biosorption process of Cd(II) ions by chemically modified orange peel is feasible, spontaneous and exothermic under studied conditions. Chemically by modified orange peel investigated in the present study showed good potential for the removal of cadmium from aqueous solutions. PMID:27097438

  4. EXPERIMENTAL EVALUATION OF CHEMICAL SEQUESTRATION OF CARBON DIOXIDE IN DEEP AQUIFER MEDIA - PHASE II

    SciTech Connect

    Neeraj Gupta; Bruce Sass; Jennifer Ickes

    2000-11-28

    In 1998 Battelle was selected by the U.S. Department of Energy's (DOE) National Energy Technology Laboratory (NETL) under a Novel Concepts project grant to continue Phase II research on the feasibility of carbon dioxide (CO{sub 2}) sequestration in deep saline formations. The focus of this investigation is to conduct detailed laboratory experiments to examine factors that may affect chemical sequestration of CO{sub 2} in deep saline formations. Reactions between sandstone and other geologic media from potential host reservoirs, brine solutions, and CO{sub 2} are being investigated under high-pressure conditions. Some experiments also include sulfur dioxide (SO{sub 2}) gases to evaluate the potential for co-injection of CO{sub 2} and SO{sub 2} related gases in the deep formations. In addition, an assessment of engineering and economic aspects is being conducted. This current Technical Progress Report describes the status of the project as of September 2000. The major activities undertaken during the quarter included several experiments conducted to investigate the effects of pressure, temperature, time, and brine composition on rock samples from potential host reservoirs. Samples (both powder and slab) were taken from the Mt. Simon Sandstone, a potential CO{sub 2} host formation in the Ohio, the Eau Claire Shale, and Rome Dolomite samples that form the caprock for Mt. Simon Sandstone. Also, a sample with high calcium plagioclase content from Frio Formation in Texas was used. In addition, mineral samples for relatively pure Anorthite and glauconite were experimented on with and without the presence of additional clay minerals such as kaolinite and montmorillonite. The experiments were run for one to two months at pressures similar to deep reservoirs and temperatures set at 50 C or 150 C. Several enhancements were made to the experimental equipment to allow for mixing of reactants and to improve sample collection methods. The resulting fluids (gases and liquids) as

  5. Congenital anomalies in the teratological collection of Museum Vrolik in Amsterdam, The Netherlands. II: Skeletal dysplasias.

    PubMed

    Oostra, R J; Baljet, B; Dijkstra, P F; Hennekam, R C

    1998-05-01

    The Museum Vrolik collection of the Department of Anatomy and Embryology of the University of Amsterdam, founded by Gerardus Vrolik (1775-1859) and his son Willem Vrolik (1801-1863), consists of more than five thousand specimens of human and animal anatomy, embryology, pathology, and congenital anomalies. Recently, the collection of congenital anomalies was recatalogued and redescribed according to contempory syndromological views. The original descriptions, as far as preserved, were compared with the clinical and radiographical findings. In 18 specimens the following skeletal dysplasias were diagnosed: achondrogenesis, achondroplasia, Blomstrand chondrodysplasia, Majewski syndrome, osteodysplastic primordial dwarfism, osteogenesis imperfecta type I, osteogenesis imperfecta type II, and thanatophoric dysplasia with and without cloverleaf skull. Radiography did not yield a diagnosis in 4 specimens. The use of additional diagnostical techniques, such as MRI and CT scanning and fluorescence in situ hybridization in these specimens, is currently being investigated. PMID:9605285

  6. [Chemical and genetic diversity of Ligularia plants collected in the Hengduan Mountains, China].

    PubMed

    Saito, Yoshinori

    2012-01-01

    The Hengduan Mountains area of China is rich in plant resources. The Ligularia species, which belong to Senecioneae and Asteraceae, distributed in this area are highly diversified and contain 6 sections and over 100 species, and are considered to be in on-going evolution and diversification. To understand the inter- and intra-specific diversity of these plants and to elucidate the mechanism of diversification, we analyzed Ligularia plants by chemical, genetic, geographical, ecological, and morphological approaches. We investigated 4 species, and isolated 26 novel compounds. Based on the chemical composition of root extract as well as nucleotide sequence variations in internal transcribed spacers (ITS), we obtained 3 findings. (i) L. virgaurea is classified into two groups, ligularol type and virgaurenone type from the view point of chemical constituents, which are phylogenetically distinguished from each other, (ii) L. subspicata and L. lamarum have an overlapped chemical spectrum, but showed no clear genetic correlation, and (iii) L. cyathiceps showed no significant variations in either chemical constituents or nucleotide sequences. PMID:23208053

  7. Analysis of the Noble Metals on Silicon Wafers by Chemical Collection and ICPMS

    NASA Astrophysics Data System (ADS)

    Fontaine, H.; Hureau, D.; Groz, M.; Despois, D.; Louis, C.

    2011-11-01

    The measurement of Ag, Pt and Au on wafer surfaces was addressed by a liquid phase chemical collection coupled to ICPMS analysis. Three chemistries were evaluated from intentionally contaminated wafers in the E12 to E15 at/cm2 concentration range. Different modes of voluntary wafer contamination allowed us to consider both the chemical form of the contaminant (i.e. ionic and metal forms) and its localization (i.e. on the surface and included in the oxide layer). Diluted HNO3 was used for Ag collection on the wafer surface allowing a collection efficiency (CE) higher than 90%. Regarding Pt and Au, diluted aqua regia and diluted HF/aqua regia were used. The first solution leads to a good collection of Au and Pt on the wafer surface (CE >90%) and is inefficient for contamination included in the oxide layer while the second one addresses the two cases with collection rates higher than 94%. Finally, detection limits of few E10 at/cm2 were determined showing the relevance of the technique implemented.

  8. Evolution of chemical diversity by coordinated gene swaps in type II polyketide gene clusters

    PubMed Central

    Hillenmeyer, Maureen E.; Vandova, Gergana A.; Berlew, Erin E.; Charkoudian, Louise K.

    2015-01-01

    Natural product biosynthetic pathways generate molecules of enormous structural complexity and exquisitely tuned biological activities. Studies of natural products have led to the discovery of many pharmaceutical agents, particularly antibiotics. Attempts to harness the catalytic prowess of biosynthetic enzyme systems, for both compound discovery and engineering, have been limited by a poor understanding of the evolution of the underlying gene clusters. We developed an approach to study the evolution of biosynthetic genes on a cluster-wide scale, integrating pairwise gene coevolution information with large-scale phylogenetic analysis. We used this method to infer the evolution of type II polyketide gene clusters, tracing the path of evolution from the single ancestor to those gene clusters surviving today. We identified 10 key gene types in these clusters, most of which were swapped in from existing cellular processes and subsequently specialized. The ancestral type II polyketide gene cluster likely comprised a core set of five genes, a roster that expanded and contracted throughout evolution. A key C24 ancestor diversified into major classes of longer and shorter chain length systems, from which a C20 ancestor gave rise to the majority of characterized type II polyketide antibiotics. Our findings reveal that (i) type II polyketide structure is predictable from its gene roster, (ii) only certain gene combinations are compatible, and (iii) gene swaps were likely a key to evolution of chemical diversity. The lessons learned about how natural selection drives polyketide chemical innovation can be applied to the rational design and guided discovery of chemicals with desired structures and properties. PMID:26499248

  9. Chemical synthesis of lactic acid from cellulose catalysed by lead(II) ions in water.

    PubMed

    Wang, Yanliang; Deng, Weiping; Wang, Binju; Zhang, Qinghong; Wan, Xiaoyue; Tang, Zhenchen; Wang, Ye; Zhu, Chun; Cao, Zexing; Wang, Guichang; Wan, Huilin

    2013-01-01

    The direct transformation of cellulose, which is the main component of lignocellulosic biomass, into building-block chemicals is the key to establishing biomass-based sustainable chemical processes. Only limited successes have been achieved for such transformations under mild conditions. Here we report the simple and efficient chemocatalytic conversion of cellulose in water in the presence of dilute lead(II) ions, into lactic acid, which is a high-value chemical used for the production of fine chemicals and biodegradable plastics. The lactic acid yield from microcrystalline cellulose and several lignocellulose-based raw biomasses is >60% at 463 K. Both theoretical and experimental studies suggest that lead(II) in combination with water catalyses a series of cascading steps for lactic acid formation, including the isomerization of glucose formed via the hydrolysis of cellulose into fructose, the selective cleavage of the C3-C4 bond of fructose to trioses and the selective conversion of trioses into lactic acid. PMID:23846730

  10. Interview-Based Qualitative Research in Emergency Care Part II: Data Collection, Analysis and Results Reporting

    PubMed Central

    Ranney, Megan L.; Meisel, Zachary; Choo, Esther K.; Garro, Aris; Sasson, Comilla; Morrow, Kathleen

    2015-01-01

    Qualitative methods are increasingly being used in emergency care research. Rigorous qualitative methods can play a critical role in advancing the emergency care research agenda by allowing investigators to generate hypotheses, gain an in-depth understanding of health problems or specific populations, create expert consensus, and develop new intervention and dissemination strategies. In Part I of this two-article series, we provided an introduction to general principles of applied qualitative health research and examples of its common use in emergency care research, describing study designs and data collection methods most relevant to our field (observation, individual interviews, and focus groups). Here in Part II of this series, we outline the specific steps necessary to conduct a valid and reliable qualitative research project, with a focus on interview-based studies. These elements include building the research team, preparing data collection guides, defining and obtaining an adequate sample, collecting and organizing qualitative data, and coding and analyzing the data. We also discuss potential ethical considerations unique to qualitative research as it relates to emergency care research. PMID:26284572

  11. Chemical Speciation of PM-2.5 Collected During Prescribed Burns of the Coconino National Forest

    NASA Astrophysics Data System (ADS)

    Robinson, M.; Chavez, J.; Valazquez, S.

    2001-12-01

    In 1997, the EPA promulgated regulations for fine particulate matter (PM-2.5) due to concerns that PM-2.5 can contribute to pulmonary disease. A major source of PM-2.5 is smoke from forest fires (natural or prescribed). The use of prescribed fire is expected to increase in the next decade as a method for restoring wildland ecosystems. The fire-suppression policy of the past century has left forests overgrown with heavy fuel loads, increasing the likelihood of catastrophic fire. Prescribed fire, combined with mechanical thinning, is a method-of-choice to reduce this fuel load. The apparent conflict between the intentional use of fire and air quality can be addressed by increasing our understanding of PM-2.5 and its toxicity. To this end, we will monitor the chemical composition of PM-2.5 generated during three prescribed fires of the Coconino National Forest in October 2001. PM-2.5 will be collected using a battery-operated chemical speciation sampler (MetOne SuperSASS) positioned to collect smoke during the fire. Samples will be taken during the ignition and combustion phases, as well as the day after the burn. Each sampling period will collect 3 filters (PTFE, nylon + MgO denuder, and quartz), which will be analyzed (Research Triangle International) respectively for mass and elements, ions, and total, organic, and elemental carbon. In addition, a fourth PTFE filter will be collected and analyzed at NAU for lead isotope ratios using inductively-coupled plasma mass spectrometry. Results will be correlated to meteorological factors collected during the burns (relative humidity, wind speed, air stability, and surface temperature, etc.) and to characteristics of the burn itself (fuel load, fuel type, fire type, combustion phase, etc.). Results will be compared to the national database collected in EPA's PM-2.5 speciation trends monitoring network (STN).

  12. Adsorption/desorption of Cd(II), Cu(II) and Pb(II) using chemically modified orange peel: Equilibrium and kinetic studies

    NASA Astrophysics Data System (ADS)

    Lasheen, Mohamed R.; Ammar, Nabila S.; Ibrahim, Hanan S.

    2012-02-01

    Waste materials from industries such as food processing may act as cost effective and efficient biosorbents to remove toxic contaminants from wastewater. This study aimed to establish an optimized condition and closed loop application of processed orange peel for metals removal. A comparative study of the adsorption capacity of the chemically modified orange peel was performed against environmentally problematic metal ions, namely, Cd 2+, Cu 2+ and Pb 2+, from aqueous solutions. Chemically modified orange peel (MOP) showed a significantly higher metal uptake capacity compared to original orange peel (OP). Fourier Transform Infrared (FTIR) Spectra of peel showed that the carboxylic group peak shifted from 1637 to 1644 cm -1 after Pb (II) ions binding, indicated the involvement of carboxyl groups in Pb(II) ions binding. The metals uptake by MOP was rapid and the equilibrium time was 30 min at constant temperature and pH. Sorption kinetics followed a second-order model. The mechanism of metal sorption by MOP gave good fits for Freundlich and Langmuir models. Desorption of metals and regeneration of the biosorbent was attained simultaneously by acid elution. Even after four cycles of adsorption-elution, the adsorption capacity was regained completely and adsorption efficiency of metal was maintained at around 90%.

  13. An intelligent data collection tool for chemical safety/risk assessment.

    PubMed

    Verdonck, Frederik A M; Van Sprang, Patrick A; Vanrolleghem, Peter A

    2008-02-01

    REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) is the new European chemical legislation which aims to assess risk or safety of tens of thousands of chemicals to improve the protection of human health and the environment. The chemical safety assessment process is of an iterative nature. First, an initial, worst-case assessment is conducted after which refinements are made until no risk has been estimated or the risk is adequately controlled. Wasting time and resources on additional testing and implementing risk management measures with low effect on risk conclusions should be avoided as much as possible. This paper demonstrates the usefulness of an intelligent data collection strategy based on a sensitivity (and uncertainty) analysis on the risk assessment model EUSES to identify and order the most important "within-EU-TGD-reducible" input parameters influencing the local and regional risk characterisation ratios. The ordering can be adjusted for the costs involved in additional testing (e.g. ecotoxicity, physico-chemical properties, emission estimates, etc.). The risk refinement tool therefore reduces the resources needed to obtain a realistic risk estimate (both less conservative and less uncertain) as efficient as possible. PMID:17959222

  14. Occurrence of classes I and II integrons in Enterobacteriaceae collected from Zagazig University Hospitals, Egypt

    PubMed Central

    Malek, Mai M.; Amer, Fatma A.; Allam, Ayman A.; El-Sokkary, Rehab H.; Gheith, Tarek; Arafa, Mohamed A.

    2015-01-01

    Integrons are genetic units characterized by the ability to capture and incorporate gene cassettes, thus can contribute to the emergence and transfer of antibiotic resistance. The objectives of this study were: (1) to investigate the presence and distribution of class I and class II integrons and the characteristics of the gene cassettes they carry in Enterobacteriaceae isolated from nosocomial infections at Zagzig University Hospital in Egypt, (2) to determine their impact on resistance, and (3) to identify risk factors for the existence of integrons. Relevant samples and full clinical history were collected from 118 inpatients. Samples were processed; isolated microbes were identified and tested for antibiotic susceptibilities. Integrons were detected by polymerase chain reaction (PCR) and were characterized into class I or II by restriction fragment length polymorphism (RFLP). Integron-positive isolates were subjected to another PCR to detect gene cassette, followed by gene cassette sequencing. Risk factors were analyzed by logistic regression analysis. Seventy-six Enterobacteriaceae isolates were recognized, 41 of them (53.9%) were integron-positive; 39 strains carried class I and 2 strains carried class II integrons. Integrons had gene cassettes encoding different combinations and types of resistance determinants. Interestingly, blaOXA129 gene was found and ereA gene was carried on class I integrons. The same determinants were carried within isolates of the same species as well as isolates of different species. The presence of integrons was significantly associated with multidrug resistance (MDR). No risk factors were associated for integron carriage. We conclude that integrons carrying gene cassettes encoding antibiotic resistance are significantly present among Enterobacteriaceae causing nosocomial infection in our hospital. Risk factors for acquisition remain to be identified. PMID:26157425

  15. The KIVA-II computer program for transient multidimensional chemically reactive flows with sprays

    SciTech Connect

    Amsden, A.A.; Butler, T.D.; O'Rourke, P.J.

    1987-01-01

    Since its public release in 1985, the KIVA computer program has been utilized for the time dependent analysis of chemically reacting flows with sprays in two and three space dimensions. This paper describes some of the improvements to the original version that have been made since that time. The new code called KIVA-II is planned for public release in early 1988. KIVA-II improves the earlier version in the accuracy and efficiency of the computational procedure, the accuracy of the physics submodels, and in versatility and ease of use. Numerical improvements include the use of the ICE solution procedure in place of the acoustic subcycling method and the implementation of a quasi-second-order-accurate convection scheme. Major extensions to the physical submodels include the inclusion of an optional k-epsilon turbulence model, and several additions to the spray model. We illustrate some of the new capabilities by means of example solutions. 25 refs., 7 figs.

  16. DOE SBIR Phase II Final Report: Distributed Relevance Ranking in Heterogeneous Document Collections

    SciTech Connect

    Abe Lederman

    2007-01-08

    This report contains the comprehensive summary of the work performed on the SBIR Phase II project (“Distributed Relevance Ranking in Heterogeneous Document Collections”) at Deep Web Technologies (http://www.deepwebtech.com). We have successfully completed all of the tasks defined in our SBIR Proposal work plan (See Table 1 - Phase II Tasks Status). The project was completed on schedule and we have successfully deployed an initial production release of the software architecture at DOE-OSTI for the Science.gov Alliance's search portal (http://www.science.gov). We have implemented a set of grid services that supports the extraction, filtering, aggregation, and presentation of search results from numerous heterogeneous document collections. Illustration 3 depicts the services required to perform QuickRank™ filtering of content as defined in our architecture documentation. Functionality that has been implemented is indicated by the services highlighted in green. We have successfully tested our implementation in a multi-node grid deployment both within the Deep Web Technologies offices, and in a heterogeneous geographically distributed grid environment. We have performed a series of load tests in which we successfully simulated 100 concurrent users submitting search requests to the system. This testing was performed on deployments of one, two, and three node grids with services distributed in a number of different configurations. The preliminary results from these tests indicate that our architecture will scale well across multi-node grid deployments, but more work will be needed, beyond the scope of this project, to perform testing and experimentation to determine scalability and resiliency requirements. We are pleased to report that a production quality version (1.4) of the science.gov Alliance's search portal based on our grid architecture was released in June of 2006. This demonstration portal is currently available at http://science.gov/search30 . The portal

  17. Chemical weathering on Mars. Collection of papers. LPI-MSATT Workshop on Chemical Weathering on Mars, Cocoa Beach, FL (USA), 10 - 12 Sep 1992.

    NASA Astrophysics Data System (ADS)

    Burns, R. G.; Banin, A.

    1993-10-01

    The Workshop on Chemical Weathering on Mars consisted of thirty papers, extended abstracts of which were published in the LPI Technical Report, No. 92-04. The collection of seven papers in this issue report new data and interpretations about the chemical evolution of the Martian surface.

  18. Topoisomerase I and II inhibitors: chemical structure, mechanisms of action and role in cancer chemotherapy

    NASA Astrophysics Data System (ADS)

    Dezhenkova, L. G.; Tsvetkov, V. B.; Shtil, A. A.

    2014-01-01

    The review summarizes and analyzes recent published data on topoisomerase I and II inhibitors as potential antitumour agents. Functions and the mechanism of action of topoisomerases are considered. The molecular mechanism of interactions between low-molecular-weight compounds and these proteins is discussed. Topoisomerase inhibitors belonging to different classes of chemical compounds are systematically covered. Assays for the inhibition of topoisomerases and the possibilities of using the computer-aided modelling for the rational design of novel drugs for cancer chemotherapy are presented. The bibliography includes 127 references.

  19. The Law and Collective Negotiations in Education. Volume II, Collective Action by Public School Teachers. Final Report.

    ERIC Educational Resources Information Center

    Wildman, Wesley A.

    This volume on law and collective negotiations in the schools is the second in a series of 4 monographs comprising a broad investigation of teacher collective action in local school districts in the United States. Part I (30 pages) of this volume deals with emerging local doctrine relating to the rights of teachers and other public employees to…

  20. Relationships between chemical structure and rat repellency: II. compounds screened between 1950 and 1960

    USGS Publications Warehouse

    Bowles, Walter A.; Adomaitis, V.A.; DeWitt, J.B.; Pratt, J.J., Jr.

    1974-01-01

    Over 4,600 compounds, chiefly organic types, were evaluated using both a food acceptance test (Part A) and a barrier penetration bioassay (Part B), to correlate relationships between chemical structure and rodent repellency. These chemicals are indexed and classified according to the functional groups present and to the degree of substitution within their molecular structures. The results of reduction in food consumption for each compound appraised are calculated and their K values listed in Table 1. The repellent activities of the functional groups represented, alone or in combinations, are expressed in Table II by a Functional Group Repellency Index.. A ranking of these indices suggests that acyclic and heteroyclic compounds containing tri- or pentavalent nitrogen would be a parent compound of choice for synthesizing novel repellents. Other molecular arrangements, spatial configurations and combinations of functional groups are compared. There were 123 active, interesting or promising compounds included in the 699 having K values of 85 or greater, which were selected for the barrier appraisal study. These chemicals were formulated in selective solvents at several concentrations and applied to burlap. Small food bags were fashioned using the fabric impregnated with the candidate formulation, and exposed to rodent attack following storage periods of varying intervals. The results of these tests are listed in Table III. Again, those compounds containing nitrogen in the functional groupings indicated a high order of effectiveness. Several commercial patents covering rodent repellents were issued using the data from the food acceptance and barrier studies. Organizations and cooperators which supplied samples for the program are listed in Appendix I. The Wiswesser cipher for compounds in Table I is used in Appendix II to facilitate location of chemicals by sample code number as they appear under the index headings, and for computer storage and analysis.

  1. Relationships between chemical structure and rat repellency. II. Compounds screened between 1950 and 1960

    USGS Publications Warehouse

    Bowles, W.A.; Adomaitis, V.A.; DeWitt, J.B.; Pratt, J.J., Jr.

    1974-01-01

    Over 4,600 compounds, chiefly organic types, were evaluated using both a food acceptance test (Part A) and a barrier penetration bioassay (Part B), to correlate relationships between chemical structure and rodent repellency.These chemicals are indexed and classified according to the functional groups present and to the degree of substitution within their molecular structures. The results of reduction in foot consumption for each compound appraised are calculated and their K values listed in Table I.The repellent activities of the functional groups represented, alone or in combinations, are expressed in Table II by a Functional Group Repellency Index. A ranking of these indices suggests that acyclic and heteroyclic compounds containing tri- or pentavalent nitrogen would be a parent compound of choice for synthesizing novel repellents. Other molecular arrangements, spatial configurations and combinations of functional groups are compared.There were 123 active, interesting or promising compounds included in the 699 having K values of 85 or greater, which were selected for the barrier appraisal study. These chemicals were formulated in selective solvents at several concentrations and applied to burlap. Small foot bags were fashioned using the fabric impregnated with the candidate formulation, and exposed to rodent attack following storage periods of varying intervals. The results of these tests are listed in Table III. Again, those compounds containing nitrogen in the functional groupings indicated a high order of effectiveness. Several commercial patents covering rodent repellents were issued using the data from the food acceptance and barrier studies.Organizations and cooperators which supplied samples for the program are listed in Appendix I. The Wiswesser cipher for compounds in Table I is used in Appendix II to facilitate location of chemicals by sample code number as they appear under the index headings, and for computer storage and analysis.

  2. Ototoxic occupational exposures for a stock car racing team: II. chemical surveys.

    PubMed

    Gwin, Kristin K; Wallingford, Kenneth M; Morata, Thais C; Van Campen, Luann E; Dallaire, Jacques; Alvarez, Frank J

    2005-08-01

    The National Institute for Occupational Safety and Health (NIOSH) conducted a series of surveys to evaluate occupational exposure to noise and potentially ototoxic chemical agents among members of a professional stock car racing team. Exposure assessments included site visits to the team's race shop and a worst-case scenario racetrack. During site visits to the race team's shop, area samples were collected to measure exposures to potentially ototoxic chemicals, including, organic compounds (typical of solvents), metals, and carbon monoxide (CO). Exposures to these chemicals were all below their corresponding Occupational Safety and Health Administration (OSHA) permissible exposure limits (PELs), NIOSH recommended exposure limits (RELs), and American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit values (TLVs). During site visits to the racetrack, area and personal samples were collected for organic compounds, lead, and CO in and around the "pit" area where the cars undergo race preparation and service during the race. Exposures to organic compounds and lead were either nondetectable or too low to quantify. Twenty-five percent of the CO time-weighted average concentrations exceeded the OSHA PEL, NIOSH REL, and ACGIH TLV after being adjusted for a 10-hour workday. Peak CO measurements exceeded the NIOSH recommended ceiling limit of 200 ppm. Based on these data, exposures to potentially ototoxic chemicals are probably not high enough to produce an adverse effect greater than that produced by the high sound pressure levels alone. However, carbon monoxide levels occasionally exceeded all evaluation criteria at the racetrack. PMID:16009649

  3. Integrated Data Collection Analysis (IDCA) Program - RDX Type II Class 5 Standard, Data Set 1

    SciTech Connect

    Sandstrom, Mary M.; Brown, Geoffrey W.; Preston, Daniel N.; Pollard, Colin J.; Warner, Kirstin F.; Sorenson, Daniel N.; Remmers, Daniel L.; Moran, Jesse S.; Shelley, Timothy J.; Reyes, Jose A.; Hsu, Peter C.; Whipple, Richard E.; Reynolds, John G.

    2011-04-11

    This document describes the results of the first reference sample material—RDX Type II Class 5—examined in the proficiency study for small-scale safety and thermal (SSST) testing of explosive materials for the Integrated Data Collection Analysis (IDCA) Program. The IDCA program is conducting proficiency testing on homemade explosives (HMEs). The reference sample materials are being studied to establish the accuracy of traditional explosives safety testing for each performing laboratory. These results will be used for comparison to results from testing HMEs. This effort, funded by the Department of Homeland Security (DHS), ultimately will put the issues of safe handling of these materials in perspective with standard military explosives. The results of the study will add SSST testing results for a broad suite of different HMEs to the literature, potentially suggest new guidelines and methods for HME testing, and possibly establish what are the needed accuracies in SSST testing to develop safe handling practices. Described here are the results for impact, friction, electrostatic discharge, and scanning calorimetry analysis of a reference sample of RDX Type II Class 5. The results from each participating testing laboratory are compared using identical test material and preparation methods wherever possible. Note, however, the test procedures differ among the laboratories. These results are then compared to historical data from various sources. The performers involved are Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Air Force Research Laboratory/ RXQL (AFRL), Indian Head Division, Naval Surface Warfare Center, (IHD-NSWC), and Sandia National Laboratories (SNL). These tests are conducted as a proficiency study in order to establish some consistency in test protocols, procedures, and experiments and to understand how to compare results when test protocols are not identical.

  4. Toxicity Screening of the ToxCast Phase II Chemical Library Using a Zebrafish Developmental Assay (SOT)

    EPA Science Inventory

    As part of the chemical screening and prioritization research program of the US EPA, the ToxCast Phase II chemicals were assessed using a vertebrate screen for developmental toxicity. Zebrafish embryos (Danio rerio) were exposed in 96-well plates from late-blastula stage (6hr pos...

  5. Chemical pollutants in field-collected canvasback tissues, eggs, and food materials

    USGS Publications Warehouse

    White, D.H.; Dieter, M.P.; Stendell, R.C.

    1976-01-01

    In 1972 studies began on the levels of environmental pollutants in canvasback tissues, eggs, and food items. The purpose of the studies were to determine if the levels of toxic chemicals found in canvasbacks were of the magnitude to cause problems affecting reproduction and survival. Overall, levels of organochlorine pesticides and PCB's were low in canvasbacks and their eggs. Some individual birds, however, laid eggs with elevated residues of DDE (12.1 ppm) or PCB's (28.6 ppm). There was no significant difference between eggshell thicknesses of 1972-73 and pre-1946 collections. About 12% of the canvasbacks analyzed had elevated levels of blood lead with reduced ALAD enzyme activity. Adult canvasbacks collected from the Chesapeake Bay in 1975 had moderate to high levels of cadmium in their kidneys. Cadmium, in excessive amounts is very toxic and can curtail spermatogenesis in male birds. Although no single toxic chemical found in wild canvasbacks appears to be a major factor in population declines, the cumulative effects of sublethal levels of all the pollutants may render birds susceptible to disease, hunting pressure or predation.

  6. A new sampler for collecting separate dry and wet atmospheric depositions of trace organic chemicals

    NASA Astrophysics Data System (ADS)

    Waite, Don T.; Cessna, Allan J.; Gurprasad, Narine P.; Banner, James

    Studies conducted in Saskatchewan and elsewhere have demonstrated the atmospheric transport of agricultural pesticides and other organic contaminants and their deposition into aquatic ecosystems. To date these studies have focused on ambient concentrations in the atmosphere and in wet precipitation. To measure the dry deposition of organic chemicals, a new sampler was designed which uses a moving sheet of water to passively trap dry particles and gasses. The moving sheet of water drains into a reservoir and, during recirculation through the sampler, is passed through an XAD-2 resin column which adsorbs the trapped organic contaminants. All surfaces which contact the process water are stainless steel or Teflon. Chemicals collected can be related to airborne materials depositing into aquatic ecosystems. The sampler has received a United States patent (number 5,413,003 - 9 May 1996) with the Canadian patent pending. XAD-2 resin adsorption efficiencies for 10 or 50 μg fortifications of ten pesticides ranged from 76% for atrazine (2-chloro-4-ethylamino-6-isopropylamino- S-triazine) to 110% for triallate [ S-(2,3,3-trichloro-2-phenyl)bis(1-methylethyl)carbamothioate], dicamba (2-methoxy-3,6-dichlorobenzoic acid) and toxaphene (chlorinated camphene mixture). Field testing using duplicate samplers showed good reproducibility and amounts trapped were consistent with those from high volume and bulk pan samplers located on the same site. Average atmospheric dry deposition rates of three chemicals, collected for 5 weeks in May and June, were: dicamba, 69 ng m -2 da -1; 2,4-D (2,4-dichlorophenoxyacetic acid), 276 ng m -2 da -1: and, γ-HCH ( γ-1, 2, 3, 4, 5, 6-hexachlorocyclohexane), 327 ng m -2 da -1.

  7. Neurocinematography in Pre-World War II Netherlands: The Magnus-Rademaker Collection.

    PubMed

    Koehler, Peter J; Lameris, Bregt; Hielscher, Eva

    2016-01-01

    Historical films made by neuroscientists have shown up in several countries during past years. Although originally supposed to have been lost, we recently found a collection of films produced between 1909 and 1940 by Rudolf Magnus (1873-1927), professor of pharmacology (Utrecht) and his student Gysbertus Rademaker (1887-1957), professor of physiology (1928, succeeding Willem Einthoven) and neurology (1945, both in Leiden). Both collections deal with the physiology of body posture by the equilibrium of reflex musculature contractions for which experimental studies were done with animals (labyrinthectomies, cerebellectomies, and brainstem sections) and observations on patients. The films demonstrate the results of these studies. Moreover, there are films with babies showing tonic neck reflexes and moving images capturing adults with cerebellar symptoms following cerebellectomies for tumors and several other conditions. Magnus' studies resulted in his well-known Körperstellung (1924, "Body Posture") and Rademaker's research in his Das Stehen (1931, "Standing"). The films probably had an educative and scientific purpose. Magnus demonstrated his films at congresses, including the Eighth International Congress of Physiologists (Vienna, 1910) and Rademaker screened his moving images at meetings of the Amsterdam Neurologists Society (at several occasions as reflected in the Winkler-Monakow correspondence and the Nederlands Tijdschrift voor Geneeskunde). Next to these purposes, the films were used to analyze movement and a series of images from the films were published in articles and books. The films are important historical sources that provide a portrait of the pre-World War II era in neuroscience, partly answering questions on how physicians dealt with patients and researchers with their laboratory animals. Moreover, the films confirm that cinematography was an important scientific tool in neuroscience research. PMID:26684426

  8. Chemical management in fungicide sensitivity of Mycosphaerella fijiensis collected from banana fields in México.

    PubMed

    Aguilar-Barragan, Alejandra; García-Torres, Ana Elisa; Odriozola-Casas, Olga; Macedo-Raygoza, Gloria; Ogura, Tetsuya; Manzo-Sánchez, Gilberto; James, Andrew C; Islas-Flores, Ignacio; Beltrán-García, Miguel J

    2014-01-01

    The chemical management of the black leaf streak disease in banana caused by Mycosphaerella fijiensis (Morelet) requires numerous applications of fungicides per year. However this has led to fungicide resistance in the field. The present study evaluated the activities of six fungicides against the mycelial growth by determination of EC50 values of strains collected from fields with different fungicide management programs: Rustic management (RM) without applications and Intensive management (IM) more than 25 fungicide application/year. Results showed a decreased sensitivity to all fungicides in isolates collected from IM. Means of EC50 values in mg L(-1) for RM and IM were: 13.25 ± 18.24 and 51.58 ± 46.14 for azoxystrobin, 81.40 ± 56.50 and 1.8575 ± 2.11 for carbendazim, 1.225 ± 0.945 and 10.01 ± 8.55 for propiconazole, 220 ± 67.66 vs. 368 ± 62.76 for vinclozolin, 9.862 ± 3.24 and 54.5 ± 21.08 for fludioxonil, 49.2125 ± 34.11 and 112.25 ± 51.20 for mancozeb. A molecular analysis for β-tubulin revealed a mutation at codon 198 in these strains having an EC50 greater than 10 mg L(-1) for carbendazim. Our data indicate a consistency between fungicide resistance and intensive chemical management in banana fields, however indicative values for resistance were also found in strains collected from rustic fields, suggesting that proximity among fields may be causing a fungus interchange, where rustic fields are breeding grounds for development of resistant strains. Urgent actions are required in order to avoid fungicide resistance in Mexican populations of M. fijiensis due to fungicide management practices. PMID:24948956

  9. Chemical management in fungicide sensivity of Mycosphaerella fijiensis collected from banana fields in México

    PubMed Central

    Aguilar-Barragan, Alejandra; García-Torres, Ana Elisa; Odriozola-Casas, Olga; Macedo-Raygoza, Gloria; Ogura, Tetsuya; Manzo-Sánchez, Gilberto; James, Andrew C.; Islas-Flores, Ignacio; Beltrán-García, Miguel J.

    2014-01-01

    The chemical management of the black leaf streak disease in banana caused by Mycosphaerella fijiensis (Morelet) requires numerous applications of fungicides per year. However this has led to fungicide resistance in the field. The present study evaluated the activities of six fungicides against the mycelial growth by determination of EC50 values of strains collected from fields with different fungicide management programs: Rustic management (RM) without applications and Intensive management (IM) more than 25 fungicide application/year. Results showed a decreased sensitivity to all fungicides in isolates collected from IM. Means of EC50 values in mg L−1 for RM and IM were: 13.25 ± 18.24 and 51.58 ± 46.14 for azoxystrobin, 81.40 ± 56.50 and 1.8575 ± 2.11 for carbendazim, 1.225 ± 0.945 and 10.01 ± 8.55 for propiconazole, 220 ± 67.66 vs. 368 ± 62.76 for vinclozolin, 9.862 ± 3.24 and 54.5 ± 21.08 for fludioxonil, 49.2125 ± 34.11 and 112.25 ± 51.20 for mancozeb. A molecular analysis for β-tubulin revealed a mutation at codon 198 in these strains having an EC50 greater than 10 mg L−1 for carbendazim. Our data indicate a consistency between fungicide resistance and intensive chemical management in banana fields, however indicative values for resistance were also found in strains collected from rustic fields, suggesting that proximity among fields may be causing a fungus interchange, where rustic fields are breeding grounds for development of resistant strains. Urgent actions are required in order to avoid fungicide resistance in Mexican populations of M. fijiensis due to fungicide management practices. PMID:24948956

  10. Chemical investigations of Atlantis II and discovery brines in the Red Sea

    NASA Astrophysics Data System (ADS)

    Danielsson, Lars-Göran; Dyrssen, David; Granéli, Anders

    1980-12-01

    Analytical data for the Atlantis II and Discovery deeps in the Red Sea are given. The data were collected in March and June 1976 during the 22nd cruise of R/V Akademik Kurchatov in the Indian Ocean. On board analyses were performed of density, chlorinity, Mg, Ca, Sr and trace elements. The salinity, calculated from the density, is related to the chlorinity by S = 1.67 Cl + 4.02. The Ca-salinity relation is linear for both deeps showing that intermediate waters are formed by mixing of the brines with Red Sea water (RSDW). The hot brine (62°C) in the Atlantis II deep contains approx. 80 mg/kg of Fe and Mn while the warm brine (45°C) in the Discovery deep has a very low concentration of Fe and approx. 50 mg/kg of Mn. Mixing of RSDW containing 2 ml/l of oxygen with the anoxic deep brines causes precipitation of hydrous Mn(IV) and Fe(III) hydroxides. These two processes occur at different depths in the two deeps due to the formation of the warm (48-49°) intermediate brine in the Atlantis II deep. The oxidation-hydrolysis reactions proposed are supported by alkalinity-depth profiles and measurements of pH. These reactions also explain most of the trace element distributions and the composition of the SiO 2-Fe(III) hydroxide slurry recovered by some water samplers in the Atlantis II deep.

  11. Chemical mass balances in metalliferous deposits from the Atlantis II Deep, Red Sea

    NASA Astrophysics Data System (ADS)

    Anschutz, Pierre; Blanc, Gérard

    1995-10-01

    In order to assess the quantitative distribution of mineral species within the sedimentary series of the Atlantis II Deep, we have examined the chemical composition, mineralogy, and physical properties of 120 sediment samples from two cores that sampled the entire sediment sequences in the West and South-West basins. Biostratigraphic correlations and chemical budget calculations indicate that the nonmetalliferous solid fractions (i.e., detrital and biogenic particles) in the older sedimentary unit (unit 1 in the West basin) represent 46% wt of the total, and that they were deposited between 23,000 and 15-12,000 years BP with a mass accumulation rate between 109 and 150 kg per thousand years per square metre. The muddy sediment in the upper part of the West basin core (units 2, 3, and 4) consists mainly of metalliferous particles which account for less than 15% wt of the mud, and yield a mass accumulation rate (130-162 kg/k.y./M 2) close to that of nonmetalliferous particles deposited simultaneously. Nonmetalliferous particles were probably the major source of Si and a significant source of Pb through dissolution in the brine system and diagenesis in the metalliferous mud. The metalliferous sediments in the upper unit of the South-West basin (unit U, 1100 cm) were deposited at the same time as those of the upper unit in the West basin (unit 4,335 cm). The calculated mass accumulation rate is about 700 kg/k.y./m 2 for unit U. The recent sediments of the South-West basin are more enriched in Zn and Cu, and more depleted in Mn relative to Fe than the contemporary sediments in the West basin, suggesting that the hydrothermal source has been in, or near, the South-West basin during the last 2,250 years. Assuming that a Salton Sea-like solution supplies all the Fe contained in the West basin metalliferous sedimentary pile, the mineralizing brine flowed at a minimum rate of 30 L/s. Except for the period of Mn-oxide deposition, the difference between the metal/Fe ratios in

  12. Chemical Analysis of Fractionated Halogens in Atmospheric Aerosols Collected in Okinawa, Japan

    NASA Astrophysics Data System (ADS)

    Tsuhako, A.; Miyagi, Y.; Somada, Y.; Azechi, S.; Handa, D.; Oshiro, Y.; Murayama, H.; Arakaki, T.

    2013-12-01

    Halogens (Cl, Br and I) play important roles in the atmosphere, e.g. ozone depletion by Br during spring in Polar Regions. Sources of halogens in atmospheric aerosols are mainly from ocean. But, for example, when we analyzed Br- with ion chromatography, its concentrations were almost always below the detection limit, which is also much lower than the estimated concentrations from sodium ion concentrations. We hypothesized that portions of halogens are escaped to the atmosphere, similar to chlorine loss, changed their chemical forms to such as BrO3- and IO3-, and/or even formed precipitates. There was few reported data so far about fractionated halogen concentrations in atmospheric aerosols. Thus, purpose of this study was to determine halogen concentrations in different fractions; free ion, water-soluble chemically transformed ions and precipitates using the authentic aerosols. Moreover, we analyzed seasonal variation for each fraction. Atmospheric aerosol samples were collected at Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS) of Okinawa, Japan during January 2010 and August 2013. A high volume air sampler was used for collecting total particulate matters on quartz filters on a weekly basis. Ultrapure water was used to extract water-soluble factions of halogens. The extracted solutions were filtered with the membrane filter and used for chemical analysis with ion chromatography and ICP-MS. Moreover, the total halogens in aerosols were obtained after digesting aerosols with tetramethylammonium hydroxide (TMAH) using the microwave and analysis with ICP-MS. For Cl, water-soluble Cl- accounted for about 70% of the estimates with Na content. No other forms of water-soluble Cl were found. About 30% of Cl was assumed volatilized to the gas-phase. For Br, water-soluble Br accounted for about 43% of the estimates with Na content, and within the 43%, about 10% of Br was not in the form of Br-. About 46% of Br was assumed volatilized to the gas-phase. For I

  13. Chemical and biological effects of heavy distillate recycle in the SRC-II process

    SciTech Connect

    Wilson, B.W.; Pelroy, R.A.; Anderson, R.P.; Freel, J.

    1983-12-01

    Recent work from the Merriam Laboratory continuous coal liquefaction units shows that heavy distillate from the SRC-II process can be recycled to extinction, and hence a distillate product boiling entirely below 310/sup 0/C (590/sup 0/F) (or other selected boiling points) is feasible. In these runs distillate yield was not reduced; gas make was unaffected; and hydrogen consumption was increased only slightly, in keeping with the generally higher hydrogen content of lighter end products. Total distillate yield (C/sub 5/-590/sup 0/F) was 56 wt %, MAF coal in runs with subbituminous coal from the Amax Belle Ayr mine. Product endpoint is well below 371/sup 0/C (700/sup 0/F), the temperature above which coal distillates appear to become genotoxic; and the product was shown to be free of mutagenic activity in the Ames test. Chemical analyses showed both the < 270/sup 0/C (< 518/sup 0/F) and the < 310/sup 0/C (< 590/sup 0/F) distillates to be essentially devoid of several reference polycyclic compounds known to be carcinogenic in laboratory animals. Tests for tumorigenic or carcinogenic activity were not carried out on these materials. However, a comparison of chemical data from the Merriam heavy distillate samples with data on the other SRC-II distillates where carcinogenesis or tumorigenesis data is available leads to the expectation that < 371/sup 0/C (< 700/sup 0/F) materials from the Merriam Laboratory will have greatly reduced tumorigenic and carcinogenic activity in skin painting tests. Other studies suggest the product should be more readily upgraded than full-range (C/sub 5/-900/sup 0/F) distillate.

  14. Non-peptide angiotensin II receptor antagonists: chemical feature based pharmacophore identification.

    PubMed

    Krovat, Eva M; Langer, Thierry

    2003-02-27

    Chemical feature based pharmacophore models were elaborated for angiotensin II receptor subtype 1 (AT(1)) antagonists using both a quantitative and a qualitative approach (Catalyst HypoGen and HipHop algorithms, respectively). The training sets for quantitative model generation consisted of 25 selective AT(1) antagonists exhibiting IC(50) values ranging from 1.3 nM to 150 microM. Additionally, a qualitative pharmacophore hypothesis was derived from multiconformational structure models of the two highly active AT(1) antagonists 4u (IC(50) = 0.2 nM) and 3k (IC(50) = 0.7 nM). In the case of the quantitative model, the best pharmacophore hypothesis consisted of a five-features model (Hypo1: seven points, one hydrophobic aromatic, one hydrophobic aliphatic, a hydrogen bond acceptor, a negative ionizable function, and an aromatic plane function). The best qualitative model consisted of seven features (Hypo2: 11 points, two aromatic rings, two hydrogen bond acceptors, a negative ionizable function, and two hydrophobic functions). The obtained pharmacophore models were validated on a wide set of test molecules. They were shown to be able to identify a range of highly potent AT(1) antagonists, among those a number of recently launched drugs and some candidates presently undergoing clinical tests and/or development phases. The results of our study provide confidence for the utility of the selected chemical feature based pharmacophore models to retrieve structurally diverse compounds with desired biological activity by virtual screening. PMID:12593652

  15. Dissociation of I II in chemical oxygen-iodine lasers: experiment, modeling, and pre-dissociation by electrical discharge

    NASA Astrophysics Data System (ADS)

    Katz, A.; Waichman, K.; Dahan, Z.; Rybalkin, V.; Barmashenko, B. D.; Rosenwaks, S.

    2007-06-01

    The dissociation of I II molecules at the optical axis of a supersonic chemical oxygen-iodine laser (COIL) was studied via detailed measurements and three dimensional computational fluid dynamics calculations. Comparing the measurements and the calculations enabled critical examination of previously proposed dissociation mechanisms and suggestion of a mechanism consistent with the experimental and theoretical results obtained in a supersonic COIL for the gain, temperature and I II dissociation fraction at the optical axis. The suggested mechanism combines the recent scheme of Azyazov and Heaven (AIAA J. 44, 1593 (2006)), where I II(A' 3Π 2u), I II(A 3Π 1u) and O II(a1Δ g, v) are significant dissociation intermediates, with the "standard" chain branching mechanism of Heidner et al. (J. Phys. Chem. 87, 2348 (1983)), involving I(2P 1/2) and I II(X1Σ + g, v). In addition, we examined a new method for enhancement of the gain and power in a COIL by applying DC corona/glow discharge in the transonic section of the secondary flow in the supersonic nozzle, dissociating I II prior to its mixing with O II(1Δ). The loss of O II(1Δ) consumed for dissociation was thus reduced and the consequent dissociation rate downstream of the discharge increased, resulting in up to 80% power enhancement. The implication of this method for COILs operating beyond the specific conditions reported here is assessed.

  16. THE CHEMICALLY CONTROLLED SYNTHESIS OF DUST IN TYPE II-P SUPERNOVAE

    SciTech Connect

    Sarangi, Arkaprabha; Cherchneff, Isabelle E-mail: isabelle.cherchneff@unibas.ch

    2013-10-20

    We study the formation of molecules and dust clusters in the ejecta of solar metallicity, Type II-P supernovae (SNe) using a chemical kinetic approach. We follow the evolution of molecules and small dust cluster masses from day 100 to day 1500 after explosion. We consider stellar progenitors with initial masses of 12, 15, 19, and 25 M{sub ☉} that explode as SNe with stratified ejecta. The molecular precursors to dust grains comprise molecular chains, rings and small clusters of silica, silicates, metal oxides, sulfides and carbides, pure metals, and carbon, where the nucleation of silicate clusters is described by a two-step process of metal and oxygen addition. We study the impact of the {sup 56}Ni mass on the type and amount of synthesized dust. We predict that large masses of molecules including CO, SiO, SiS, O{sub 2}, and SO form in the ejecta. We show that the discrepancy between the small dust masses detected at infrared wavelengths some 500 days post-explosion and the larger amounts of dust recently detected with Herschel in SN remnants can be explained by the non-equilibrium chemistry linked to the formation of molecules and dust clusters in the ejected material. Dust gradually builds up from small (∼10{sup –5} M{sub ☉}) to large masses (∼5 × 10{sup –2} M{sub ☉}) over a 5 yr period after explosion. Subsequent dust formation and/or growth is hampered by the shortage of chemical agents participating in the dust nucleation and the long timescale for accretion. The results highlight the dependence of the dust chemical composition and mass on the amount of {sup 56}Ni synthesized during the explosion. This dependence may partly explain the diversity of epochs at which dust forms in SNe. More generally, our results indicate that Type II-P SNe are efficient but moderate dust producers with an upper limit on the mass of synthesized dust ranging from ∼0.03 to 0.09 M{sub ☉}. Other dust sources must then operate at high redshift to explain the large

  17. Collection and Chemical Composition of Phloem Sap from Citrus sinensis L. Osbeck (Sweet Orange)

    PubMed Central

    Hijaz, Faraj; Killiny, Nabil

    2014-01-01

    Through utilizing the nutrient-rich phloem sap, sap feeding insects such as psyllids, leafhoppers, and aphids can transmit many phloem-restricted pathogens. On the other hand, multiplication of phloem-limited, uncultivated bacteria such as Candidatus Liberibacter asiaticus (CLas) inside the phloem of citrus indicates that the sap contains all the essential nutrients needed for the pathogen growth. The phloem sap composition of many plants has been studied; however, to our knowledge, there is no available data about citrus phloem sap. In this study, we identified and quantified the chemical components of phloem sap from pineapple sweet orange. Two approaches (EDTA enhanced exudation and centrifugation) were used to collect phloem sap. The collected sap was derivatized with methyl chloroformate (MCF), N-methyl-N- [tert-butyl dimethylsilyl]-trifluroacetamide (MTBSTFA), or trimethylsilyl (TMS) and analyzed with GC-MS revealing 20 amino acids and 8 sugars. Proline, the most abundant amino acid, composed more than 60% of the total amino acids. Tryptophan, tyrosine, leucine, isoleucine, and valine, which are considered essential for phloem sap-sucking insects, were also detected. Sucrose, glucose, fructose, and inositol were the most predominant sugars. In addition, seven organic acids including succinic, fumaric, malic, maleic, threonic, citric, and quinic were detected. All compounds detected in the EDTA-enhanced exudate were also detected in the pure phloem sap using centrifugation. The centrifugation technique allowed estimating the concentration of metabolites. This information expands our knowledge about the nutrition requirement for citrus phloem-limited bacterial pathogen and their vectors, and can help define suitable artificial media to culture them. PMID:25014027

  18. 76 FR 25723 - Proposed Information Collection for Growing America Through Entrepreneurship (GATE) II Evaluation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-05

    ... Entrepreneurship (GATE) II Evaluation; Comment Request AGENCY: Employment and Training Administration, Labor... that investigated the impact of providing entrepreneurship training services to individuals interested..., K., & Kahvecioglu, D. ``Growing America Through Entrepreneurship: Findings from the Evaluation...

  19. Preparation of polyethylene sacks for collection of precipitation samples for chemical analysis

    USGS Publications Warehouse

    Schroder, L.J.; Bricker, A.W.

    1985-01-01

    Polyethylene sacks are used to collect precipitation samples. Washing polyethylene with acetone, hexane, methanol, or nitric acid can change the adsorptive characteristics of the polyethylene. In this study, simulated precipitation at pH 4.5 was in contact with the polyethylene sacks for 21 days; subsamples were removed for chemical analysis at 7, 14, and 21 days after intitial contact. Sacks washed with acetone adsorbed iron and lithium; sacks washed with hexane adsorbed barium, iron , and lithium; sacks washed with methanol adsorbed calcium and iron; and sacks washed with 0.30 N nitric acid adsorbed iron. Leaching the plastic sacks with 0.15 N nitric acid did not result in 100-percent recovery of any of the adsorbed metals. Washing polyethylene sacks with dilute nitric acid caused the pH of the simulated precipitation to be decreased by 0.2 pH unit after 1 week of contact with the polyethylene. The specific conductance increased by 10 microsiemens per centimeter. Contamination of precipitation samples by lead was determined to be about 0.1 microgram per liter from contact with precleaned polyethylene sacks. No measurable contamination of precipitation samples by zinc occurred. (USGS)

  20. Hydrodynamics of a quark droplet II: Implications of a non-zero baryon chemical potential

    NASA Astrophysics Data System (ADS)

    Bjerrum-Bohr, Johan J.; Mishustin, Igor N.; Døssing, Thomas

    2014-03-01

    We present an extended version of the dynamical model for a multi-quark droplet evolution described in our proceeding paper. The model includes collective expansion of the droplet, effects of the vacuum pressure and surface tension, and now a non-zero baryon number. The hadron emission from the droplet is described following Weisskopf's statistical model. We consider evolutions of droplets with different initial temperatures and net baryon number. It is found that the introduction of a non-zero net baryon number does not change the lifetime of the droplets significantly. Only when we consider an initially very baryon-rich, low-temperature droplets is the lifetime is decreased significantly. We have, furthermore, found a convergence of both baryon chemical potential and temperature toward the values μB≈450 MeV and T≈150 MeV. This convergence is linked to the competing emission of baryons versus mesons.

  1. BIOLOGICAL ASSESSMENT OF TOXICITY CAUSED BY CHEMICAL CONSTITUENTS ELUTED FROM SITE SOILS COLLECTED AT THE DRAKE CHEMICAL SUPERFUND SITE

    EPA Science Inventory

    The site was used to manufactured specialty intermediate chemicals for the producers of dyes, pharmaceuticals, cosmetics, herbicides, and pesticides. he herbicide Fenac (2,3,6-trichlorophenylacetic acid) is a major on- and off-site contaminant. ne hundred twenty -eight soils were...

  2. Separation of Corn Fiber and Conversion to Fuels and Chemicals Phase II: Pilot-scale Operation

    SciTech Connect

    Abbas, Charles; Beery, Kyle; Orth, Rick; Zacher, Alan

    2007-09-28

    The purpose of the Department of Energy (DOE)-supported corn fiber conversion project, “Separation of Corn Fiber and Conversion to Fuels and Chemicals Phase II: Pilot-scale Operation” is to develop and demonstrate an integrated, economical process for the separation of corn fiber into its principal components to produce higher value-added fuel (ethanol and biodiesel), nutraceuticals (phytosterols), chemicals (polyols), and animal feed (corn fiber molasses). This project has successfully demonstrated the corn fiber conversion process on the pilot scale, and ensured that the process will integrate well into existing ADM corn wet-mills. This process involves hydrolyzing the corn fiber to solubilize 50% of the corn fiber as oligosaccharides and soluble protein. The solubilized fiber is removed and the remaining fiber residue is solvent extracted to remove the corn fiber oil, which contains valuable phytosterols. The extracted oil is refined to separate the phytosterols and the remaining oil is converted to biodiesel. The de-oiled fiber is enzymatically hydrolyzed and remixed with the soluble oligosaccharides in a fermentation vessel where it is fermented by a recombinant yeast, which is capable of fermenting the glucose and xylose to produce ethanol. The fermentation broth is distilled to remove the ethanol. The stillage is centrifuged to separate the yeast cell mass from the soluble components. The yeast cell mass is sold as a high-protein yeast cream and the remaining sugars in the stillage can be purified to produce a feedstock for catalytic conversion of the sugars to polyols (mainly ethylene glycol and propylene glycol) if desirable. The remaining materials from the purification step and any materials remaining after catalytic conversion are concentrated and sold as a corn fiber molasses. Additional high-value products are being investigated for the use of the corn fiber as a dietary fiber sources.

  3. Microbial production of isotopically light iron(II) in a modern chemically precipitated sediment and implications for isotopic variations in ancient rocks

    USGS Publications Warehouse

    Tangalos, G.E.; Beard, B.L.; Johnson, C.M.; Alpers, C.N.; Shelobolina, E.S.; Xu, H.; Konishi, H.; Roden, E.E.

    2012-01-01

    The inventories and Fe isotope composition of aqueous Fe(II) and solid-phase Fe compounds were quantified in neutral-pH, chemically precipitated sediments downstream of the Iron Mountain acid mine drainage site in northern California, USA. The sediments contain high concentrations of amorphous Fe(III) oxyhydroxides [Fe(III)am] that allow dissimilatory iron reduction (DIR) to predominate over Fe–S interactions in Fe redox transformation, as indicated by the very low abundance of Cr(II)-extractable reduced inorganic sulfur compared with dilute HCl-extractable Fe. δ56Fe values for bulk HCl- and HF-extractable Fe were ≈ 0. These near-zero bulk δ56Fe values, together with the very low abundance of dissolved Fe in the overlying water column, suggest that the pyrite Fe source had near-zero δ56Fe values, and that complete oxidation of Fe(II) took place prior to deposition of the Fe(III) oxide-rich sediment. Sediment core analyses and incubation experiments demonstrated the production of millimolar quantities of isotopically light (δ56Fe ≈ -1.5 to -0.5‰) aqueous Fe(II) coupled to partial reduction of Fe(III)am by DIR. Trends in the Fe isotope composition of solid-associated Fe(II) and residual Fe(III)am are consistent with experiments with synthetic Fe(III) oxides, and collectively suggest an equilibrium Fe isotope fractionation between aqueous Fe(II) and Fe(III)am of approximately -2‰. These Fe(III) oxide-rich sediments provide a model for early diagenetic processes that are likely to have taken place in Archean and Paleoproterozoic marine sediments that served as precursors for banded iron formations. Our results suggest pathways whereby DIR could have led to the formation of large quantities of low-δ56Fe minerals during BIF genesis.

  4. Type II Cepheids in the Milky Way disc. Chemical composition of two new W Virginis stars: DD Vel and HQ Car

    NASA Astrophysics Data System (ADS)

    Lemasle, B.; Kovtyukh, V.; Bono, G.; François, P.; Saviane, I.; Yegorova, I.; Genovali, K.; Inno, L.; Galazutdinov, G.; da Silva, R.

    2015-07-01

    Context. A robust classification of Cepheids into their different sub-classes and, in particular, between classical and Type II Cepheids, is necessary to properly calibrate the period-luminosity relations and for populations studies in the Galactic disc. Type II Cepheids are, however, very diverse, and classifications based either on intrinsic (period, light curve) or external parameters (e.g., [Fe/H], | z |) do not provide a unique classification. Aims: We want to ascertain the classification of two Cepheids, HQ Car and DD Vel, that are sometimes classified as classical Cepheids and sometimes as Type II Cepheids. Methods: To achieve this goal, we examine both their chemical composition and the presence of specific features in their spectra. Results: We find emission features in the Hα and in the 5875.64 Å He I lines that are typical of W Vir stars. The [Na/Fe] (or [Na/Zn]) abundances are typical of thick-disc stars, while BL Her stars are Na-overabundant ([Na/Fe] > +0.5 dex). Finally, the two Cepheids show a possible (HQ Car) or probable (DD Vel) signature of mild dust-gas separation that is usually observed only in long-period type II Cepheids and RV Tau stars. Conclusions: These findings clearly indicate that HQ Car and DD Vel are both Type II Cepheids from the W Vir sub-class. Several studies have reported an increase in the Cepheids' abundance dispersion towards the outer (thin) disc. A detailed inspection of the Cepheid classification, in particular for those located in the outer disc, will indicate whether this feature is real or simply an artefact of the inclusion of type II Cepheids belonging to the thick disc in the current samples. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile (prog. ID: 060.A-9120 and 082.D-0901).Appendices are available in electronic form at http://www.aanda.org

  5. Characteristics and chemical compositions of particulate matter collected at the selected metro stations of Shanghai, China.

    PubMed

    Guo, Li; Hu, Yunjie; Hu, Qingqing; Lin, Jun; Li, Chunlin; Chen, Jianmin; Li, Lina; Fu, Hongbo

    2014-10-15

    A campaign was conducted to assess and compare the air quality at the different metro platforms at Shanghai City, focusing on particulate matter (PM) levels, chemical compositions, morphology and mineralogy, as well as species of iron. Our results indicated that the average PM₂.₅ concentrations for the three metro lines were 177.7 μg/m(3), 105.7 μg/m(3) and 82.5 μg/m(3), respectively, and the average PM1 concentrations for the three lines were 122.3 μg/m(3), 84.1 μg/m(3) and 59.6 μg/m(3), respectively. Fe, Mn, Cr, Cu, Sr, Ba and Pb concentrations in all of the sampling sites were significantly higher than that in the urban ambient air, implicating that these trace metals may be associated with the metro systems working. Individual airborne dusts were studied for morphology and mineralogy characteristics. The results revealed that the presence of most individual particles were with no definite shape and most of them were with a large metal content. Furthermore, Fe-rich particles had significantly higher abundance in the metro systems, which were more frequently encountered in the underground lines than the aboveground line. The 2D distribution map of an interested Fe-rich particle showed an uneven Fe distribution, implying that a hollow or core of other substance exists in the particle center during the formation process. Cluster analysis revealed that Fe-rich particles were possibly a mixture of Fe species. Fitting of X-ray absorption near-edge fine structure spectra (XANES) showed the main iron species within the particles collected from the three contrasting metro lines of Shanghai to be hematite, magnetite, iron-metal and mineral Fe. Hematite and mineral Fe were all found in three lines, while magnetite only existed in aboveground metro line. Iron-metal was determined in both the older and younger underground lines, based on the X-ray diffraction (XRD) analysis. As diverse Fe species have different physical-chemical characteristics and toxicity, the

  6. Structural, spectroscopic and quantum chemical studies of acetyl hydrazone oxime and its palladium(II) and platinum(II) complexes

    NASA Astrophysics Data System (ADS)

    Kaya, Yunus; Icsel, Ceyda; Yilmaz, Veysel T.; Buyukgungor, Orhan

    2015-09-01

    Acetyl hydrazone oxime, [(1E,2E)-2-(hydroxyimino)-1-phenylethylidene]acetohydrazone (hipeahH2) and its palladium(II) and platinum(II) complexes, [M(hipeahH)2] (M = PdII and PtII), have been synthesized and characterized by elemental analysis, UV-vis IR, NMR and LC-MS techniques. X-ray diffraction analysis of [Pd(hipeahH)2] shows that the two hipeahH2 ligands are not equal; one of the ligands loses the hydrazone proton, while the other one loses the oxime proton, resulting in a different coordination behavior to form five- and six-membered chelate rings. The molecular geometries from X-ray experiments in the ground state were compared using the density functional theory (DFT) with the B3LYP method combined with the 6-311++G(d,p) basis set for the ligand and the LanL2DZ basis set for the complexes. Comprehensive theoretical and experimental structural studies on the molecule have been carried out by FT-IR, NMR and UV-vis spectrometry. In addition, the isomer studies of ligand and its complexes were made by DFT.

  7. Physical, Chemical, and Mineralogical Properties of Comet 81P/Wild 2 Particles Collected by Stardust

    SciTech Connect

    Flynn, G.

    2008-01-01

    NASA's Stardust spacecraft collected dust from the coma of Comet 81P/Wild 2 by impact into aerogel capture cells or into Al-foils. The first direct, laboratory measurement of the physical, chemical, and mineralogical properties of cometary dust grains ranging from <10-15 to ?10-4 g were made on this dust. Deposition of material along the entry tracks in aerogel and the presence of compound craters in the Al-foils both indicate that many of the Wild 2 particles in the size range sampled by Stardust are weakly bound aggregates of a diverse range of minerals. Mineralogical characterization of fragments extracted from tracks indicates that most tracks were dominated by olivine, low-Ca pyroxene, or Fe-sulfides, although one track was dominated by refractory minerals similar to Ca-Al inclusions in primitive meteorites. Minor mineral phases, including Cu-Fe-sulfide, Fe-Zn-sulfide, carbonate and metal oxides, were found along some tracks. The high degree of variability of the element/Fe ratios for S, Ca, Ti, Cr, Mn, Ni, Cu, Zn, and Ga among the 23 tracks from aerogel capture cells analyzed during Stardust Preliminary Examination is consistent with the mineralogical variability. This indicates Wild 2 particles have widely varying compositions at the largest size analyzed (>10 ?m). Because Stardust collected particles from several jets, sampling material from different regions of the interior of Wild 2, these particles are expected to be representative of the non-volatile component of the comet over the size range sampled. Thus, the stream of particles associated with Comet Wild 2 contains individual grains of diverse elemental and mineralogical compositions, some rich in Fe and S, some in Mg, and others in Ca and Al. The mean refractory element abundance pattern in the Wild 2 particles that were examined is consistent with the CI meteorite pattern for Mg, Si, Cr, Fe, and Ni to 35%, and for Ca, Ti and Mn to 60%, but S/Si and Fe/Si both show a statistically significant

  8. Chemical trend of exchange coupling in diluted magnetic II-VI semiconductors: Ab initio calculations

    NASA Astrophysics Data System (ADS)

    Chanier, T.; Virot, F.; Hayn, R.

    2009-05-01

    We have calculated the chemical trend of magnetic exchange parameters ( Jdd , Nα , and Nβ ) of Zn-based II-VI semiconductors ZnA ( A=O , S, Se, and Te) doped with Co or Mn. We show that a proper treatment of electron correlations by the local spin-density approximation (LSDA)+U method leads to good agreement between experimental and theoretical values of the nearest-neighbor exchange coupling Jdd between localized 3d spins in contrast to the LSDA method. The exchange couplings between localized spins and doped electrons in the conduction band Nα are in good agreement with experiment as well. But the values for Nβ (coupling to doped holes in the valence band) indicate a crossover from weak coupling (for A=Te and Se) to strong coupling (for A=O ) and a localized hole state in ZnO:Mn. This hole localization explains the apparent discrepancy between photoemission and magneto-optical data for ZnO:Mn.

  9. Possible Role of Metal(II) Octacyanomolybdate(IV) in Chemical Evolution: Interaction with Ribose Nucleotides

    NASA Astrophysics Data System (ADS)

    Kumar, Anand; Kamaluddin

    2013-02-01

    We have proposed that double metal cyanide compounds (DMCs) might have played vital roles as catalysts in chemical evolution and the origin of life. We have synthesized a series of metal octacyanomolybdates (MOCMos) and studied their interactions with ribose nucleotides. MOCMos have been shown to be effective adsorbents for 5'-ribonucleotides. The maximum adsorption level was found to be about 50 % at neutral pH under the conditions studied. The zinc(II) octacyanomolybdate(IV) showed larger adsorption compared to other MOCMos. The surface area seems to important parameter for the adsorption of nucleotides. The adsorption followed a Langmuir adsorption isotherms with an overall adsorption trends of the order of 5'-GMP > 5'-AMP > 5'-CMP > 5'-UMP. Purine nucleotides were adsorbed more strongly than pyrimidine nucleotides on all MOCMos possibly because of the additional binding afforded by the imidazole ring in purines. Infrared spectral studies of adsorption adducts indicate that adsorption takes place through interaction between adsorbate molecules and outer divalent ions of MOCMos.

  10. Chemical Characterization and Removal of Carbon-14 from Irradiated Graphite II - 13023

    SciTech Connect

    Dunzik-Gougar, Mary Lou; Cleaver, James; LaBrier, Daniel; McCrory, Shilo; Smith, Tara E.

    2013-07-01

    Approximately 250,000 tonnes of irradiated graphite waste exists worldwide and that quantity is expected to increase with decommissioning of Generation II reactors and deployment of Generation IV gas-cooled, graphite moderated reactors. This situation indicates the need for a graphite waste management strategy. Of greatest concern for long-term disposal of irradiated graphite is carbon-14 (C-14), with a half-life of 5730 years. Study of irradiated graphite from some nuclear reactors indicates C-14 is concentrated on the outer 5 mm of the graphite structure. The aim of the research presented last year and updated here is to identify the chemical form of C-14 in irradiated graphite and develop a practical method by which C-14 can be removed. A nuclear-grade graphite, NBG-18, and a high-surface-area graphite foam, POCOFoam{sup R}, were exposed to liquid nitrogen (to increase the quantity of C-14 precursor) and neutron-irradiated (10{sup 13} neutrons/cm{sup 2}/s). Finer grained NBG-25 was not exposed to liquid nitrogen prior to irradiation at a neutron flux on the order of 10{sup 14} /cm{sup 2}/s. Characterization of pre- and post-irradiation graphite was conducted to determine the chemical environment and quantity of C-14 and its precursors via the use of surface sensitive characterization techniques. Scanning Electron Microscopy (SEM) was used to evaluate the morphological features of graphite samples. The concentration, chemical composition, and bonding characteristics of C-14 and its precursors were determined through X-ray Photoelectron Spectroscopy (XPS), Time-of-Flight Secondary Ion Mass Spectrometry (SIMS), and Energy Dispersive X-ray Analysis Spectroscopy (EDX). Results of post-irradiation characterization of these materials indicate a variety of surface functional groups containing carbon, oxygen, nitrogen and hydrogen. During thermal treatment, irradiated graphite samples are heated in the presence of an inert carrier gas (with or without oxidant gas), which

  11. Operation and Maintenance of Wastewater Collection Systems. Volume II. Third Edition. A Field Study Training Program.

    ERIC Educational Resources Information Center

    California State Univ., Sacramento. Dept. of Civil Engineering.

    Proper installations, inspections, operations, maintenance and repairs of wastewater collection, conveyance and treatment facilities have a significant impact on the operation and maintenance costs, and the effectiveness of these facilities. This manual is the second volume of a two-part program designed to provide wastewater collection system…

  12. Guidelines for Community Relations Personnel. Criminal Justice Research. Prevention and Control of Collective Violence, Volume II.

    ERIC Educational Resources Information Center

    Callahan, W. Thomas; Knoblauch, Richard L.

    The objective of this study is to provide local law enforcement agencies with guidelines for the collection and dissemination of elements of information required for sound decision making in response to the threat or actual initiation of collective violence. Informal, semi-structured interviews in fourteen selected cities and six State police…

  13. COMPARISON OF MICROBIAL TRANSFORMATION RATE COEFFICIENTS OF XENOBIOTIC CHEMICALS BETWEEN FIELD-COLLECTED AND LABORATORY MICROCOSM MICROBIOTA

    EPA Science Inventory

    Two second-order transformation rate coefficients--kb, based on total plate counts, and kA, based on periphyton-colonized surface areas--were used to compare xenobiotic chemical transformation by laboratory-developed (microcosm) and by field-collected microbiota. Similarity of tr...

  14. Data Collection and Description of HEA II-B Institutes - 1968-1969. Final Report.

    ERIC Educational Resources Information Center

    DeProspo, Ernest R.

    This study examines the first two years of the Higher Education Act (HEA) Title II-B Institute Program, 1968 and 1969. The primary objective is to describe the institutes and provide a data base for the program. The data base includes Division of Library Programs records, final evaluative reports, "plans of operation," and information on the…

  15. Agricultural hydrology and water quality II: Introduction to the featured collection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural hydrology and water quality is a multidisciplinary field devoted to understanding the interrelationship between modern agriculture and water resources. This paper summarizes a featured collection of 10 manuscripts emanating from the 2013 American Water Resources Association Specialty Co...

  16. Chemical analysis of carbon stars in the Local Group. II. The Carina dwarf spheroidal galaxy

    NASA Astrophysics Data System (ADS)

    Abia, C.; de Laverny, P.; Wahlin, R.

    2008-04-01

    Aims:We present new results of our ongoing chemical study of carbon stars in Local Group galaxies to test the critical dependence of s-process nucleosynthesis on the stellar metallicity. Methods: We collected optical spectra with the VLT/UVES instrument of two carbon stars found in the Carina Dwarf Spheroidal (dSph) galaxy, namely ALW-C6 and ALW-C7. We performed a full chemical analysis using the new generation of hydrostatic, spherically symmetric carbon-rich model atmospheres and the spectral synthesis method in LTE. Results: The luminosities, atmosphere parameters and chemical composition of ALW-C6 and ALW-C7 are compatible with these stars being in the TP-AGB phase undergoing third dredge-up episodes, although their extrinsic nature (external pollution in a binary stellar system) cannot be definitively excluded. Our chemical analysis shows that the metallicity of both stars agree with the average metallicity ([Fe/H] -1.8 dex) previously derived for this satellite galaxy from the analysis of both low resolution spectra of RGB stars and the observed colour magnitude diagrams. ALW-C6 and ALW-C7 present strong s-element enhancements, [ s/Fe] = +1.6, +1.5, respectively. These enhancements and the derived s-process indexes [ ls/Fe] , [ hs/Fe] and [ hs/ls] are compatible with theoretical s-process nucleosynthesis predictions in low mass AGB stars ( 1.5 M_⊙) on the basis that the 13C(α,n)16O is the main source of neutrons. Furthermore, the analysis of C2 and CN bands reveals a large carbon enhancement (C/O 7 and 5, respectively), much larger than the values typically found in galactic AGB carbon stars (C/O 1{-}2). This is also in agreement with the theoretical prediction that AGB carbon stars are formed more easily through third dredge-up episodes as the initial stellar metallicity drops. However, theoretical low-mass AGB models apparently fail to simultaneously fit the observed s-element and carbon enhancements. On the other hand, Zr is found to be less enhanced in

  17. Low Budget Biology II: A Collection of Low Cost Labs and Activities.

    ERIC Educational Resources Information Center

    Wartski, Bert; Wartski, Lynn Marie

    This document contains 13 low budget labs, demonstrations, and activities to be used in the biology classroom. Each activity has a teacher preparation section which states the purpose of each lab, some basic information, a list of materials and what they do, and how to prep the different solutions and chemicals. All labs are designed for a…

  18. Temporal and spatial trends of chemical composition of wet deposition samples collected in Austria

    NASA Astrophysics Data System (ADS)

    Schreiner, Elisabeth; Kasper-Giebl, Anne; Lohninger, Hans

    2016-04-01

    Triggered by the occurrence of acid rain a sampling network for the collection of wet deposition samples was initiated in Austria in the early 1980s. Now the data set covers a time period of slightly more than 30 years for the stations being operable since the beginning. Sampling of rain water and snow was and is performed with Wet and Dry Only Samplers (WADOS) on a daily basis. Chemical analysis of rain water and snow samples comprised anions (chloride, nitrate, sulfate) and cations (sodium, ammonium, potassium, calcium and magnesium) as well as pH and electrical conductivity. Here we evaluate and discuss temporal trends of both, ion concentrations and wet deposition data for twelve sampling stations, which were operable for most of the observation period of 30 years. As expected concentrations and wet deposition loads of sulfate and acidity decreased significantly during the last three decades - which is also reflected by a strong decrease of sulfur emissions in Austria and neighboring countries. Regarding nitrate the decrease of concentrations and wet deposition loads is less pronounced. Again this is in accordance with changes in emission data. In case of ammonium even less stations showed a significant decrease of annual average concentrations and depositions. Reasons for that might be twofold. On one hand emissions of ammonia did not decrease as strongly as e.g. sulfur emissions. Furthermore local sources will be more dominant and can influence the year to year variability. Seasonality of ion concentrations and deposition loads were investigated using Fourier analysis. Sulfate, nitrate, ammonium, acidity and also precipitation amount showed characteristic seasonal patterns for most of the sites and for concentrations as well as deposition loads. However the maxima in ion concentrations and deposition loads were observed during different times of the year. Concentrations of basic cations and chloride, on the contrary, hardly showed any seasonality. However, as

  19. Morphological and chemical composition characteristics of summertime atmospheric particles collected at Tokchok Island, Korea

    NASA Astrophysics Data System (ADS)

    Geng, Hong; Jung, Hae-Jin; Park, YooMyung; Hwang, HeeJin; Kim, HyeKyeong; Kim, Yoo Jung; Sunwoo, Young; Ro, Chul-Un

    Determination of the chemical compositions of atmospheric single particles in the Yellow Sea region is critical for evaluating the environmental impact caused by air pollutants emitted from mainland China and the Korean peninsula. After ambient aerosol particles were collected by the Dekati PM10 cascade impactor on July 17-23, 2007 at Tokchok Island (approximately 50 km west of the Korean coast nearby Seoul), Korea, overall 2000 particles (on stage 2 and 3 with cut-off diameters of 2.5-10 μm and 1.0-2.5 μm, respectively) in 10 samples were determined by using low- Z particle electron probe X-ray microanalysis. X-ray spectral and secondary electron image (SEI) data showed that soil-derived and sea-salt particles which had reacted or were mixed with SO 2 and NO x (or their acidic products) outnumbered the primary and "genuine" ones (59.2% vs. 19.2% in the stage 2 fraction and 41.3% vs. 9.9% in the stage 3 fraction). Moreover, particles containing nitrate in the secondary soil-derived species greatly outnumbered those containing sulfate. Organic particles, mainly consisting of marine biogenic species, were more abundant in the stage 2 fraction than in the stage 3 fraction (11.6% vs. 5.1%). Their relative abundance was greater than the sum of carbon-rich, K-containing, Fe-containing, and fly ash particles, which exhibited low frequencies in all the samples. In addition, many droplets rich in C, N, O, and S were observed. They tended to be small, exhibiting a dark round shape on SEI, and generally included 8-20 at.% C, 0-12 at.% N, 60-80 at.% O, and 4-10 at.% S (sometimes with <3 at.% Mg and Na). They were attributed to be a mixture of carbonaceous matter, H 2SO 4, and NH 4HSO 4/(NH 4) 2SO 4, mostly from the reaction of atmospheric SO 2 with NH 3 under high relative humidity. The analysis of the relationship between the aerosol particle compositions and 72-h backward air-mass trajectories suggests that ambient aerosols at Tokchok Island are strongly affected not only

  20. Chemical characterization of binding properties of opacity-associated protein II from Neisseria gonorrhoeae.

    PubMed Central

    Bessen, D; Gotschlich, E C

    1987-01-01

    Binding of an opacity-associated protein II (PIIop) from Neisseria gonorrhoeae to eucaryotic macromolecules was studied. HeLa cell extracts were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and transferred to nitrocellulose, and purified PIIop bound to approximately 50 distinct molecular species. The binding of PIIop to HeLa cell components was stable in high salt and nonionic detergent and was not inhibited by a variety of monosaccharides and polyionic substances. PIIop binding behavior was compared with that of two model carbohydrate-binding proteins, wheat germ agglutinin (WGA) and concanavalin A (ConA). Model glycoproteins (ovomucoid, fetuin, mucin, ovalbumin) inhibited binding by PIIop, WGA, and ConA to various degrees. HeLa cell glycopeptides, generated by pronase digestion of chloroform-methanol-extracted cells, were tested for their ability to inhibit binding by PIIop to Western blots of HeLa cell macromolecules. HeLa cell extracts inhibited PIIop binding before pronase treatment, but inhibitory activity was lost as a result of pronase digestion. Direct binding to defined glycosylated and nonglycosylated proteins revealed that ConA and WGA bound only glycoproteins, whereas PIIop bound to proteins lacking carbohydrate as well. PIIop binding to human and bovine serum albumins was of high affinity and required partial unfolding of albumin; native albumin was not bound by PIIop; however, both the denatured, reduced form of albumin and the compact, nonreduced form of carboxymethylated albumin were bound strongly by PIIop. Albumin-PIIop interaction did not involve covalent bond formation through sulfhydryl groups. The predominant binding interactions of PIIop found in this study were with protein rather than carbohydrate, and the chemical nature of the interactions is more complex than involvement of purely ionic or hydrophobic forces. Images PMID:3098683

  1. Vesicle-based method for collecting, manipulating, and chemically processing trace macromolecular species

    DOEpatents

    Davalos, Rafael V.; Ellis, Christopher R. B.

    2010-08-17

    Disclosed is an apparatus and method for inserting one or several chemical or biological species into phospholipid containers that are controlled within a microfluidic network, wherein individual containers are tracked and manipulated by electric fields and wherein the contained species may be chemically processed.

  2. Vesicle-based method and apparatus for collecting, manipulating, and chemically processing trace macromolecular species

    DOEpatents

    Davalos, Rafael V.; Ellis, Christopher R. B.

    2008-03-04

    Disclosed is an apparatus and method for inserting one or several chemical or biological species into phospholipid containers that are controlled within a microfluidic network, wherein individual containers are tracked and manipulated by electric fields and wherein the contained species may be chemically processed.

  3. Odor and chemical emissions from dairy and swine facilities: Part 1 - project overview and collection methods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Livestock facilities have received numerous criticisms due to their emissions of odorous air and chemicals. Hence, there is a significant need for odor emission factors and identification of principle odorous chemicals. Odor emission factors are used as inputs to odor setback models, while chemica...

  4. Law and psychiatry. Doing forensic work, II: fees, billing, and collections.

    PubMed

    Reid, William H

    2012-05-01

    Forensic practice fees, billing, and collection procedures are quite different from those in general psychiatry. Most forensic practices have far fewer "clients," and individual bills are usually larger. Collections are usually better (and less frequently discounted) in forensic practice, and resolving billing disputes is far more straightforward. Medicare, Medicaid, other insurance coverage, provider networks and agreements, procedure codes, and diagnosis-related groups (DRGs) are all largely irrelevant in forensic work (although sometimes important to direct clinical services in correctional psychiatry or forensic treatment clinics). An understanding of the practicalities and ethics of charging and billing for forensic services greatly simplifies practice management. PMID:22617086

  5. Study of coupled-bunch collective effects in the PEP-II B-Factory

    SciTech Connect

    Byrd, J.

    1993-05-01

    We present an overview of the calculated longitudinal and transverse coupled-bunch (CB) growth using the measured RF cavity higher order mode impedance and estimated resistive wall (RW) impedance for the proposed PEP-II B-Factory, a dual-ring electron-positron collider. We also describe a visual method of representing the effective beam impedance and corresponding growth rates which is especially useful for understanding the dependence of growth rate on higher order mode frequency and Q, spread of HOM frequencies between cells, and for determining the requirements of the CB feedback systems.

  6. The promising chemical kinetics for the simulation of propane-air combustion with KIVA-II code

    NASA Technical Reports Server (NTRS)

    Ying, S. J.; Gorla, Rama S. R.; Kundu, Krishna P.

    1993-01-01

    The development of chemical kinetics for the simulation of propane-air combustion with the use of computer code KIVA-II since 1989 is summarized here. In order to let readers understand the general feature well, a brief description of the KIVA-II code, specially related with the chemical reactions is also given. Then the results of recent work with 20 reaction mechanism is presented. It is also compared with the 5 reaction mechanism. It may be expected that the numerical stability of the 20 reaction mechanism is better as compared to that of 5 reaction mechanism, but the CPU time of the CRAY computer is much longer. Details are presented in the paper.

  7. Chemical and genetic similarity and diversity of Ligularia anoleuca and L. fischeri collected in the Hengduan Mountains of China.

    PubMed

    Shimizu, Anna; Suzuki, Yurika; Hanai, Ryo; Okamoto, Yasuko; Tori, Motoo; Gong, Xun; Kuroda, Chiaki

    2014-06-01

    The sesquiterpenoid composition in the root and the DNA sequences of evolutionarily neutral regions were studied in Ligularia anoleuca and Ligularia fischeri (Asteraceae) collected in the Sichuan Province of China. LC-MS analysis showed that L. anoleuca populations from different localities had different chemical compositions. However, the isolated compounds were similar to each other, indicating that the differences in chemical composition were not large. The DNA analysis suggested that the two species were indistinguishable. Seventeen furanoeremophilanes and an eremophilane acetal were isolated. PMID:24725977

  8. Chemical speciation and bioavailability of Cu(II). Study of the ionic copper(II) and bis(glycinate)-copper(II) accumulation by Lemna species

    SciTech Connect

    Benda, F.; Kouba, J. )

    1991-03-01

    In this paper, the authors examined the accumulation of copper(II) in, and its toxic effect on, duckweed, a plant which exhibits extremely high concentration factors. The effect of copper(II) was investigated by adding it to the minimal medium in two forms: CuSO{sub 4} and (Cu(Gly){sub 2}). The neutral (2:1) tetracoordinated bis(glycinate)-copper(II) complex is constituted by two five-membered rings bonded to the central copper atom with the cis configuration. This complex was chosen to model the function of a neutral species (eliminating the charge effect) involving a nontoxic ligand, for which - in contrast to the hydrated Cu{sup 2+} species - direct permeation through the cell wall is conceivable.

  9. 78 FR 9915 - Agency Information Collection Activities: Submission for OMB Review; Comment Request; Basel II...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-12

    ..., Capital Adequacy, Transition Provisions, and Prompt Corrective Action (77 FR 52792); Regulatory Capital... FR 52888); Regulatory Capital Rules: Advanced Approaches Risk-Based Capital Rule; Market Risk Capital Rule (77 FR 52978), and OMB review and action on proposed changes to the collection arising from...

  10. Spectroscopic and quantum chemical study of the structure of a new paramagnetic dimeric palladium(II,III) complex with creatine

    NASA Astrophysics Data System (ADS)

    Mitewa, Mariana; Enchev, Venelin; Bakalova, Tatyana

    2002-05-01

    The structure and coordination mode of the newly synthesized dimeric paramagnetic Pd(II,III) complex are studied using magneto-chemical, EPR and IR spectroscopic methods. In order to perform reliable assignment of the IR bands, the structure and IR spectrum of the free creatine were calculated using ab initio method. For calculation of the configuration of its deprotonated and doubly deprotonated forms the semiempirical AM1 method was used.

  11. Computer simulation of plasma electron collection by PIX-II. [solar array-space plasma interaction

    NASA Technical Reports Server (NTRS)

    Mandell, M. J.; Katz, I.; Jongeward, G. A.; Roche, J. C.

    1985-01-01

    A wake model was defined for the NASCAP/LEO finite element model for the plasma interaction experiment (PIX-II) launched to study the interaction between high-voltage large solar arrays with the space plasma environment. The cell surface model considers the individual cells, distances between interconnects, and the fraction of surface covered by interconnects. Account is taken of the electrostatic potential around the spacecraft, which travels at 7500 mps, over five times the speed of thermal ions. Ram ions are produced ahead of the array and the wake ion density is described with a geometric shadowing model. The model correctly predicted the currents in high and low bias voltages when compared to orbital data. The panel snapover, however, was projected to occur at 100 V and instead occurred at 300 V, which indicates that the snapover state is bistable. Finally, a low potential was both predicted and measured in the wake.

  12. West Hackberry Strategic Petroleum Reserve site brine-disposal monitoring, Year I report. Volume II. Physical and chemical oceanography. Final report

    SciTech Connect

    DeRouen, L.R.; Hann, R.W.; Casserly, D.M.; Giammona, C.; Lascara, V.J.

    1983-02-01

    This project centers around the Strategic Petroleum Site (SPR) known as the West Hackberry salt dome which is located in southwestern Louisiana, and which is designed to store 241 million barrels of crude oil. Oil storage caverns are formed by injecting water into salt deposits, and pumping out the resulting brine. Studies described in this report were designed as follow-on studies to three months of pre-discharge characterization work, and include data collected during the first year of brine leaching operations. The objectives were to: (1) characterize the environment in terms of physical, chemical and biological attributes; (2) determine if significant adverse changes in ecosystem productivity and stability of the biological community are occurring as a result of brine discharge; and (3) determine the magnitude of any change observed. Contents of Volume II include: introduction; physical oceanography; estuarine hydrology and hydrography; analysis of discharge plume; and water and sediment quality.

  13. Chemometric investigation of complex equilibria in solution phase II: Sensitivity of chemical models for the interaction of AADH and FAH with Ni(II) in aqueous medium.

    PubMed

    Babu, A R; Krishna, D M; Rao, R S

    1993-12-01

    A detailed study of the species formed in the complex equilibria involving adipic acid dihydrazide (AADH)/2-furoic acid hydrazide (FAH) with Ni(II) using pH titration with glass electrode is performed. The results of modeling studies and effect of errors on the equilibrium constants of AADH/FAH with Ni(II) refined by the non-linear least squares program MINIQUAD75 are reported. Based on the expert system approach developed in our laboratory for the species formed from secondary formation data (n and n (H)), several preliminary chemical models were tested. For the four species identified (MLH, ML, ML(2)H, ML(2)), an exhaustive search of a different combination of models (15) was performed. Then other suspected minor species (ML(2)H(2), ML(3) and ML(3)H) were tested. The final best fit chemical model was found to contain ML(3)H to an extent of 3% along with the other four major species. In order to ascertain the accuracy of the stability constants and consequently distribution of the species, a detailed error analysis is attempted. As the existing least squares procedures cannot suppress the systematic errors, three-dimensional plots of the simultaneous effects of pH and TLO:TMO (1.5:1 to 5:1) on the percentage of species are drawn which are of immense use in arriving at optimum conditions for the preparation of a complex of definite stoichiometry. PMID:18965865

  14. Environmental Technology Verification Report: Grouts for Wastewater Collection Systems, Avanti International AV-118 Acrylic Chemical Grout

    EPA Science Inventory

    Municipalities are discovering rapid degradation of infrastructures in wastewater collection and treatment facilities due to the infiltration of water from the surrounding environments. Wastewater facilities are not only wet, but also experience hydrostatic pressure conditions un...

  15. ADH-PGE2 interactions in cortical collecting tubule. II. inhibition of Ca and P reabsorption.

    PubMed

    Holt, W F; Lechene, C

    1981-10-01

    In the absence of ADH, microperfused cortical collecting tubules of rabbits reabsorb calcium and phosphorus. Antidiuretic hormone (ADH) (200 microunits/ml Pitressin or synthetic arginine vasopressin) inhibits the reabsorption and may promote the secretion of calcium and phosphorus. At 5 min after incubation with ADH, there was a transitory increase in the potential difference and the reabsorption of sodium. The fluxes of calcium and phosphorus, however, showed no significant change from the control values. At 30-50 min after treatment with ADH, the reabsorption of calcium and phosphorus was inhibited and in some tubules calcium and phosphorus were secreted. The removal of vasopressin from the bath or the addition of 10(-5) M meclofenamate in vitro prevented ADH from inhibiting the reabsorption of calcium and phosphorus. Treatment of tubules with 10(-5) M prostaglandin E2 (PGE2) subsequent to incubation in a medium containing ADH and meclofenamate inhibited the reabsorption or even promoted the secretin of calcium and phosphorus, as did the prolonged incubation with ADH alone. We conclude that cortical collecting tubules reabsorb calcium and phosphorus in the absence of vasopressin and that ADH inhibits calcium and phosphorus reabsorption. Endogenous synthesis of PGE2 may mediate the inhibitory action of ADH, since meclofenamate (an inhibitor of the synthesis of prostaglandins) opposes and exogenous PGE2 mimics ADH. PMID:6947697

  16. H II Regions and Abundances in the ``Dark Galaxy'' DDO 154 and the Chemical Evolution of Dwarf Irregular Galaxies

    NASA Astrophysics Data System (ADS)

    Kennicutt, Robert C., Jr.; Skillman, Evan D.

    2001-03-01

    We present Hα imaging and optical spectrophotometry of H II regions in the low surface brightness dwarf irregular galaxy DDO 154. The galaxy possesses a very small population of faint discrete H II regions and larger diffuse H II regions and ionized shells. We confirm the very low star formation rate and extremely long gas consumption times reported previously by van Zee, Haynes, & Salzer. The current star formation rate is ~2-4 times lower than its average past rate, confirming the previous characterization of DDO 154 as a ``quiescent'' dwarf irregular galaxy. Spectrophotometry of two of the brightest H II regions yields a relatively low oxygen abundance of 0.055+/-0.008 (O/H)solar, in agreement with the previous determination by van Zee et al., and in accordance with the previously determined metallicity-luminosity relationship for dwarf irregular galaxies. We also find an N/O ratio of 0.037+/-0.003, which is marginally higher than the typical value of 0.025 found in low-metallicity blue compact galaxies. Although DDO 154 has been labeled ``the dark galaxy'' and is a prototype for low surface brightness galaxies with large H I content, its chemical abundances are consistent with an average, low-mass, dwarf irregular galaxy. Assuming that the neutral gas is chemically homogeneous, we derive an effective oxygen yield of roughly 50% of the solar value, a value that is close to the theoretically favored values for the true oxygen yield. Thus, it is possible that DDO 154 is evolving nearly as a closed system. On the other hand, if the abundances in the extended H I disk are lower than in the H II regions, the derived value of the effective yield has been artificially inflated, and DDO 154 may have experienced significant loss of metal-enriched gas. Observations reported in this paper were obtained at the MMT Observatory, a joint facility of the University of Arizona and the Smithsonian Institution.

  17. TESTING DUPLICATE DIET SAMPLE COLLECTION METHODS FOR MEASURING PERSONAL DIETARY EXPOSURES TO CHEMICAL CONTAMINANTS

    EPA Science Inventory

    Dietary ingestion may be a significant pathway of human exposure to many potentially toxic chemicals. The U.S.Environmental Protection Agency-National Human Exposure Laboratory has made the development of methods for measuring persoanl dietary exposures a high priority for its di...

  18. A new technology for harnessing the dye polluted water and dye collection in a chemical factory.

    PubMed

    Pu, J P; Pu, P M; Hu, C H; Qian, J L; Pu, J X; Hua, J K

    2001-04-01

    A new technology for harnessing the dye polluted water and dye collection was developed. It is based on the enhanced evaporation by using solar, wind and air temperature energy and additional heat-electric energy. It consists of four parts: (1) evaporation carrier system (evaporation carrier and frame for evaporation carrier) for polluted water; (2) polluted water circulating system (pumping-spraying-collecting); (3) heating system; (4) workshop with polluted water reservoir-tanks and rainfall prevention roof. The polluted water was (heated in case necessary) sprayed to the evaporation carrier system and the water was evaporated when it moved in the space and downward along the carrier mainly by using natural (solar, wind and air temperature energy). In case, when there is no roof for the carrier system, the polluted water can be stored in the reservoirs (storage volume for about 20 days). The first 10-25 mm rainfall also need to be stored in the reservoirs to meet the state standard for discharging wastewater. The dye may be collected at the surface in the reservoir-tanks and the crystallized salt may be collected at the bottom plate. The black-color wastewater released by the factory is no more discharged to the surface water system of Taihu Lake Basin. About 2 kg dye and 200 kg industrial salt may be collected from each tone of the polluted water. The non-pollution production of dye may be realized by using this technology with environmental, economical and social benefits. PMID:11590742

  19. The Origin of MN II Emission in the Spectra of Chemically Peculiar Stars

    NASA Astrophysics Data System (ADS)

    Sigut, T. A. A.

    2001-01-01

    Emission from Mn II multiplet 13 (λλ6122-6132) in the spectrum of the 3He star 3 Centauri A and the hot, mild, HgMn star 46 Aquilae can be naturally explained by interlocked non-LTE effects. However, reproduction of the strength of the Mn II emission in both stars requires vertical stratification of the manganese abundance, with manganese concentrated high in the photosphere (column mass <~10-2 g cm-2). If this formation picture is correct, several additional transitions of Mn II with λ>8000 Å should also be present in emission in the spectrum of 3 Cen A. The wide range in the strength of Mn II multiplet 13 among upper main-sequence stars (ranging from absorption to emission) is made possible by the interplay in the non-LTE radiative transfer solution of the stellar Teff, manganese abundance, and manganese stratification profile. In particular, emission is strongly suppressed by a large manganese overabundance in the photosphere. This explains why the hot, mild, HgMn star 46 Aql, which has only a modest manganese enhancement, is detected in emission in Mn II multiplet 13 while other HgMn stars of similar Teff but with large photospheric manganese overabundances, such as κ Cancri, present Mn II multiplet 13 in absorption.

  20. Long-term observation of water-soluble chemical components in the bulk atmospheric aerosols collected at Okinawa, Japan

    NASA Astrophysics Data System (ADS)

    Handa, Daishi; Somada, Yuka; Ijyu, Moriaki; Azechi, Sotaro; Nakaema, Fumiya; Arakaki, Takemitsu; Tanahara, Akira

    2010-05-01

    The economic development and population growth in recent Asia spread air pollution. Emission rate of air pollutants from Asia, in particular oxides of nitrogen, surpassed those from North America and Europe and should continue to exceed them for decades. The study of the long-range transported air pollution from Asian continent has gained a special attention in Japan because of increase in photochemical oxidants in relatively remote islands. Okinawa Island is situated approximately 1500 km south of Tokyo, Japan, 2000 km southeast of Beijing, China, and 1000 km south of South Korea. Its location in Asia is well suited for studying long-range transport of air pollutants in East Asia because maritime air mass prevails during summer, while continental air mass dominates during fall, winter, and spring. The maritime air mass data can be seen as background and can be compared with continental air masses which have been affected by anthropogenic activities. Bulk aerosol samples were collected on quartz filters by using a high volume air sampler. Sampling duration was one week for each sample. We determined the concentrations of water-soluble anions, cations and dissolved organic carbon (DOC) in the bulk aerosols collected at the Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS) using ion chromatography, atomic absorption spectrometry, and total organic carbon analyzer, respectively. We will report water-soluble chemical components data of anions, cations and DOC in bulk atmospheric aerosols collected at CHAAMS during August, 2005 to April, 2010. Seasonal variation of water-soluble chemical components showed that the concentrations were relatively low in summer, higher in fall and winter, and the highest in spring. When air mass came from Asian Continent, the concentrations of water-soluble chemical components were much higher compared to the other directions. In addition, we calculated background concentration of water-soluble chemical components at Okinawa

  1. Chemical speciation of size-segregated floor dusts and airborne magnetic particles collected at underground subway stations in Seoul, Korea.

    PubMed

    Jung, Hae-Jin; Kim, BoWha; Malek, Md Abdul; Koo, Yong Sung; Jung, Jong Hoon; Son, Youn-Suk; Kim, Jo-Chun; Kim, HyeKyoung; Ro, Chul-Un

    2012-04-30

    Previous studies have reported the major chemical species of underground subway particles to be Fe-containing species that are generated from wear and friction processes at rail-wheel-brake and catenaries-pantographs interfaces. To examine chemical composition of Fe-containing particles in more details, floor dusts were collected at five sampling locations of an underground subway station. Size-segregated floor dusts were separated into magnetic and non-magnetic fractions using a permanent magnet. Using X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDX), iron metal, which is relatively harmless, was found to be the dominating chemical species in the floor dusts of the <25 μm size fractions with minor fractions of Mg, Al, Si, Ca, S, and C. From SEM analysis, the floor dusts of the <25 μm size fractions collected on railroad ties appeared to be smaller than 10 μm, indicating that their characteristics should somewhat reflect the characteristics of airborne particles in the tunnel and the platform. As most floor dusts are magnetic, PM levels at underground subway stations can be controlled by removing magnetic indoor particles using magnets. In addition, airborne subway particles, most of which were smaller than 10 μm, were collected using permanent magnets at two underground subway stations, namely Jegi and Yangjae stations, in Seoul, Korea. XRD and SEM/EDX analyses showed that most of the magnetic aerosol particles collected at Jegi station was iron metal, whereas those at Yangjae station contained a small amount of Fe mixed with Na, Mg, Al, Si, S, Ca, and C. The difference in composition of the Fe-containing particles between the two subway stations was attributed to the different ballast tracks used. PMID:22381374

  2. Spatial distribution and temporal variation of chemical species in the bulk atmospheric aerosols collected at the Okinawa archipelago, Japan

    NASA Astrophysics Data System (ADS)

    Handa, D.; Somada, Y.; Ijyu, M.; Azechi, S.; Nakaema, F.; Arakaki, T.; Tanahara, A.

    2009-12-01

    The economic development and population growth in recent Asia have been increasing air pollution. A computer simulation study showed that air pollutants emitted from Asian continent could spread quickly within northern hemisphere. We initiated a study to elucidate the special distribution and chemical characterization of atmospheric aerosols around Okinawa archipelago, Japan. Okinawa Island is situated approximately 1500 km south of Tokyo, Japan, 2000 km southeast of Beijing, China, and 1000 km south of South Korea. Its location in Asia is well suited for studying long-range transport of air pollutants in East Asia because maritime air mass prevails during summer, while continental air mass dominates during fall, winter, and spring. The maritime air mass data can be seen as background and can be compared with continental air masses which have been affected by anthropogenic activities. We simultaneously collected bulk aerosol samples by using the same types of high volume air samplers at Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS, Okinawa Island), Kume Island (ca. 160 km south-west of CHAAMS) and Minami-daitou Island (ca. 320 km south-east of CHAAMS). We determined the concentrations of water-soluble anions, cations and dissolved organic carbon (DOC) using ion chromatography, atomic absorption spectrometry, and total organic carbon analyzer, respectively. We report and discuss spatial distribution and temporal variation of chemical species concentrations in bulk atmospheric aerosols collected during July, 2008 to July, 2009. We determine “background” concentration of chemical components in Okinawa archipelago. We then compare each chemical component among CHAAMS, Kume Island and Minami-daito Island to elucidate the influence of the long-range transport of chemical species from Asian continent.

  3. 77 FR 59891 - Proposed Information Collection; Comment Request; Chemical Weapons Convention Declaration and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-01

    ...The Department of Commerce, as part of its continuing effort to reduce paperwork and respondent burden, invites the general public and other Federal agencies to take this opportunity to comment on proposed and/or continuing information collections, as required by the Paperwork Reduction Act of...

  4. ANALYTICAL METHODS FOR A NATIONAL STUDY OF CHEMICAL RESIDUES IN FISH - II. PESTICIDES AND POLYCHLORINATED BIPHENYLS

    EPA Science Inventory

    Analytical methods and a quality assurance plan have been developed to determine the concentration of a select group of bioaccumulatable chemicals in fish tissue. he analytes include PCBs and 21 pesticides and industrial chemicals. he methodology has been used to conduct a survey...

  5. PHYSICAL-CHEMICAL TREATMENT OF A MUNICIPAL WASTEWATER USING POWDERED CARBON. NO. II

    EPA Science Inventory

    Salt Lake City municipal wastewater was treated in a nominal 100 gpm pilot plant by chemical coagulation-precipitation, powdered activated carbon adsorption and granular media filtration. Chemical-primary sludge was gravity thickened and vacuum filter dewatered. Spent carbon was ...

  6. Cd(II), Zn(II) and Cu(II) Bioadsorption on Chemically Treated Waste Brewery Yeast Biomass: The Role of Functional Groups.

    PubMed

    Tonk, Szende; Nagy, Boldizsár; Török, Anamaria; Indolean, Cerasella; Majdik, Cornelia

    2015-01-01

    Here we study the role of functional groups from waste brewery yeast Saccharomyces cerevisiae cells in the bioadsorption of Cd(2+), Zn(2+) and Cu(2+) ions. In order to clarify the role of these functional groups, the brewery yeast was pretreated chemically, thereby helping to determine the mechanisms responsible for binding the target metals. SEM studies were performed to examine the surface microstructure of the adsorbent in pure as well as pretreated forms. The biomass was characterized using FTIR analysis, which indicated that hydroxyl, carboxyl and amid groups are present on the biomass surface. When carboxyl groups were modified by various chemical treatments, the adsorption capacity decreased dramatically, showing that carboxyl groups play a fundamental role in the bioadsorption process. The residual metallic ion concentrations were determined using an Atomic Absorption Spectrophotometer (AAS). Pseudo-first and second-order kinetic models were used to describe the bioadsorption process. PMID:26454609

  7. CHEMICALLY BONDED CEMENTS FROM BOILER ASH AND SLUDGE WASTES. PHASE II REPORT, SEPT.1998-JULY 1999.

    SciTech Connect

    SUGAMA,T.YAGER,K.A.BLANKENHORN,D.

    1999-08-01

    Based upon the previous Phase I research program aimed at looking for ways of recycling the KeySpan-generated wastes, such as waste water treatment sludge (WWTS) and bottom ash (BA), into the potentially useful cementitious materials called chemically bonded cement (CBC) materials, the emphasis of this Phase II program done at Brookhaven National Laboratory, in a period of September 1998 through July 1999, was directed towards the two major subjects: One was to assess the technical feasibility of WWTS-based CBC material for use as Pb-exchange adsorbent (PEA) which remediates Pb-contaminated soils in the field; and the other was related to the establishment of the optimum-packaging storage system of dry BA-based CBC components that make it a promising matrix material for the steam-cured concrete products containing sand and coarse aggregate. To achieve the goal of the first subject, a small-scale field demonstration test was carried out. Using the PEA material consisting of 30 wt% WWTS, 13 wt% Type I cement and 57 wt% water, the PES slurry was prepared using a rotary shear concrete mixer, and then poured on the Pb-contaminated soil. The PEA-to-soil ratio by weight was a factor of 2.0. The placed PEA slurry was blended with soil using hand mixing tools such as claws and shovels. The wettability of soils with the PEA was very good, thereby facilitating the soil-PEA mix procedures. A very promising result was obtained from this field test; in fact, the mount of Pb leached out from the 25-day-aged PEA-treated soil specimen was only 0.74 mg/l, meeting the requirement for EPA safe regulation of < 5 mg/l. In contrast, a large amount (26.4 mg/l) of Pb was detected from the untreated soil of the same age. Thus, this finding demonstrated that the WWTS-based CBC has a potential for use as PEA material. Regarding the second subject, the dry-packed storage system consisting of 68.7 wt% BA, 13.0 wt% calcium aluminate cement (CAC), 13.0 wt% Type I portland cement and 5.3 wt

  8. Oxidative damage induced in A549 cells by physically and chemically characterized air particulate matter (PM2.5) collected in Abidjan, Côte d'Ivoire.

    PubMed

    Kouassi, Kouakou S; Billet, Sylvain; Garçon, Guillaume; Verdin, Anthony; Diouf, Amadou; Cazier, Fabrice; Djaman, Joseph; Courcot, Dominique; Shirali, Pirouz

    2010-05-01

    Exposure to high levels of air pollution particulate matter (PM) is strongly associated with increased pulmonary morbidity and mortality. However, the underlying mechanisms of action whereby PM cause adverse health effects are still unclear. In developing countries, like in the sub-Saharian region of Africa, people are often exposed to high PM levels. Hence, three PM(2.5) samples were collected in the District of Abidjan (Côte d'Ivoire), under rural, urban or industrial influences. Their most toxicologically relevant physical and chemical characteristics were determined--thereby showing that most of them were equal or smaller than 2.5 microm--and the influence of both natural (Ca, Na, Mg, Ti, etc.) and anthropic (Al, Fe, Mn, Cr, Pb, Zn, Cu, Ni, benzene and its derivatives, paraffins, etc.) emission sources. The toxicity induced by the three PM samples was studied through 5-bromodeoxyuridine incorporation to DNA, mitochondrial dehydrogenase activity and extracellular lactate dehydrogenase activity. Hence, effect concentrations at 10 and 50% (EC(10) and EC(50), respectively) were as follows: (i) rural PM--EC(10) = 5.91 microg cm(-2) and EC(50) = 29.55 microg cm(-2); (ii) urban PM--EC(10) = 5.45 microg cm(-2) and EC(50) = 27.23 microg cm(-2); and (iii) industrial PM--EC(10) = 6.86 microg cm(-2) and EC(50) = 34.29 microg cm(-2). Moreover, PM-induced oxidative damage in A549 cells was observed through the induction of lipid peroxidation, the alteration of superoxide dismutase activity, and the disruption of glutathione status. Both the transition metals and the organic chemicals within the three collected PM samples under study might be involved in the oxidative damage and, therefore, the toxicity they induced in A549 cells. PMID:19943358

  9. Chemical and isotopic properties and origin of coarse airborne particles collected by passive samplers in industrial, urban, and rural environments

    NASA Astrophysics Data System (ADS)

    Guéguen, Florence; Stille, Peter; Dietze, Volke; Gieré, Reto

    2012-12-01

    Passive air samplers have been installed in industrial, urban, rural and remote forested environments in order to collect coarse airborne particles for subsequent chemical characterization. To identify principal polluting sources, isotopic tracers, such as Sr, Nd and Pb isotopic ratios, have been used. The mass deposition rates (MDRs) of trace metals, determined for each of the studied environments, clearly indicate that industrial and traffic sites are especially affected by air pollution. Elements such as V, Pb, Fe, Cr, Co, Mo, Cd, Ni, As, Sb and Zn are notably enriched in samples from industrial zones, whereas V, Mn, Ba, Sr, Al, U, Th, rare earth elements (REE), Zr, Y, Cs, Rb, Sb, Sn and Cu are principal components of the airborne particles collected close to areas influenced by heavy traffic. The chemical/isotopic baseline composition derived from the airborne particles is the result of mixing of particles from different industrial sources, traffic and fertilizers. The monthly analysis of trace-metal MDRs of the collected airborne particle samples from different stations around the industrial zone allows for the detection of distinct atmospheric dust-deposition events during the year, characterized by high MDRs. "Natural" dusts from regional soil re-suspension, including from more distant regions like the Sahara desert, might overprint the regional atmospheric baseline composition, as suggested by trace metal trajectories in ternary diagrams and by Sr, Nd and Pb isotope data.

  10. Bridging the gap between sample collection and laboratory analysis: using dried blood spots to identify human exposure to chemical agents

    NASA Astrophysics Data System (ADS)

    Hamelin, Elizabeth I.; Blake, Thomas A.; Perez, Jonas W.; Crow, Brian S.; Shaner, Rebecca L.; Coleman, Rebecca M.; Johnson, Rudolph C.

    2016-05-01

    Public health response to large scale chemical emergencies presents logistical challenges for sample collection, transport, and analysis. Diagnostic methods used to identify and determine exposure to chemical warfare agents, toxins, and poisons traditionally involve blood collection by phlebotomists, cold transport of biomedical samples, and costly sample preparation techniques. Use of dried blood spots, which consist of dried blood on an FDA-approved substrate, can increase analyte stability, decrease infection hazard for those handling samples, greatly reduce the cost of shipping/storing samples by removing the need for refrigeration and cold chain transportation, and be self-prepared by potentially exposed individuals using a simple finger prick and blood spot compatible paper. Our laboratory has developed clinical assays to detect human exposures to nerve agents through the analysis of specific protein adducts and metabolites, for which a simple extraction from a dried blood spot is sufficient for removing matrix interferents and attaining sensitivities on par with traditional sampling methods. The use of dried blood spots can bridge the gap between the laboratory and the field allowing for large scale sample collection with minimal impact on hospital resources while maintaining sensitivity, specificity, traceability, and quality requirements for both clinical and forensic applications.

  11. Impact of geothermal technology improvements on royalty collections on federal lands: Volume II: Appendices

    SciTech Connect

    Not Available

    1988-10-01

    This volume contains the appendices for the ''Impact of Geothermal Technology Improvements on Royalty Collections on Federal Lands, Final Report, Volume I.'' The material in this volume supports the conclusions presented in Volume I and details each Known Geothermal Resource Area's (KGRA's) royalty estimation. Appendix A details the physical characteristics of each KGRA considered in Volume I. Appendix B supplies summary narratives on each state which has a KGRA. The information presented in Appendix C shows the geothermal power plant area proxies chosen for each KGRA considered within the report. It also provides data ranges which fit into the IMGEO model for electric energy cost estimates. Appendix D provides detailed cost information from the IMGEO model if no Geothermal Program RandD goals were completed beyond 1987 and if all the RandD goals were completed by the year 2000. This appendix gives an overall electric cost and major system costs, which add up to the overall electric cost. Appendix E supplies information for avoided cost projections for each state involved in the study that were used in the IMGEO model run to determine at what cost/kWh a 50 MWe plant could come on line. Appendix F supplies the code used in the determination of royalty income, as well as, tabled results of the royalty runs (detailed in Appendix G). The tabled results show royalty incomes, assuming a 10% discount rate, with and without RandD and with and without a $0.01/kWh transmission cost. Individual data sheets for each KGRA royalty income run are presented in Appendix G.

  12. Screening of novel chemical compounds as possible inhibitors of carbonic anhydrase and photosynthetic activity of photosystem II.

    PubMed

    Karacan, Mehmet Sayım; Zharmukhamedov, Sergei K; Mamaş, Serhat; Kupriyanova, Elena V; Shitov, Alexandr V; Klimov, Vyacheslav V; Özbek, Neslihan; Özmen, Ümmühan; Gündüzalp, Ayla; Schmitt, Franz-Josef; Karacan, Nurcan; Friedrich, Thomas; Los, Dmitry A; Carpentier, Robert; Allakhverdiev, Suleyman I

    2014-08-01

    Thirty novel chemical compounds were designed and synthesized expecting that they would be possible inhibitors. From this number eleven were organic bases, twenty-four were their organic derivatives and fourteen were metal complexes. Screening of these chemicals by their action on photosynthetic electron transfer (PET) and carbonic anhydrase (CA) activity (CAA) of photosystem II (PSII), α-CA, as well as β-CA was done. Several groups were revealed among them. Some of them are capable to suppress either one, two, three, or even all of the measured activities. As example, one of the Cu(II)-phenyl sulfonylhydrazone complexes (compound 25) suppresses CAA of α-CA by 88%, CAA of β-CA by 100% inhibition; CAA of PSII by 100% and the PSII photosynthetic activity by 66.2%. The Schiff base compounds (12, 15) and Cu(II)-phenyl sulfonylhydrazone complexes (25, 26) inhibited the CAA and PET of PSII significantly. The obtained data indicate that the PSII donor side is a target of the inhibitory action of these agents. Some physico- or electrochemical properties such as diffusion coefficient, number of transferred electrons, peak potential and heterogeneous standard rate constants of the compounds were determined in nonaqueous media. pKa values were also determined in nonaqueous and aqueous media. Availability in the studied group of novel chemical agents possessing different inhibitory activity allow in future to isolate the "active part" in the structure of the inhibitors responsible for different inhibitory mechanisms, as well as to determine the influence of side substituters on its inhibitory efficiency. PMID:24418071

  13. Thin films of tin(II) sulphide (SnS) by aerosol-assisted chemical vapour deposition (AACVD) using tin(II) dithiocarbamates as single-source precursors

    NASA Astrophysics Data System (ADS)

    Kevin, Punarja; Lewis, David J.; Raftery, James; Azad Malik, M.; O'Brien, Paul

    2015-04-01

    The synthesis of the asymmetric dithiocarbamates of tin(II) with the formula [Sn(S2CNRR')2] (where R=Et, R'=n-Bu (1); R=Me, R'=n-Bu (2); R=R'=Et (3)) and their use for the deposition of SnS thin films by aerosol-assisted chemical vapour deposition (AACVD) is described. The effects of temperature and the concentration of the precursors on deposition were investigated. The stoichiometry of SnS was best at higher concentrations of precursors (250 mM) and at 450 °C. The direct electronic band gap of the SnS produced by this method was estimated from optical absorbance measurements as 1.2 eV. The composition of films was confirmed by powder X-ray diffraction (p-XRD) and energy dispersive analysis of X-rays (EDAX) spectroscopy.

  14. Test Driving ToxCast: Endocrine Profiling for 1858 Chemicals Included in Phase II

    PubMed Central

    Filer, Dayne; Patisaul, Heather B.; Schug, Thaddeus; Reif, David; Thayer, Kristina

    2014-01-01

    Identifying chemicals, beyond those already implicated, to test for potential endocrine disruption is a challenge and high throughput approaches have emerged as a potential tool for this type of screening. This review focused the Environmental Protection Agency’s (EPA) ToxCast™ high throughput in vitro screening (HTS) program. Utility for identifying compounds was assessed and reviewed by using it to run the recently expanded chemical library (from 309 compounds to 1858) through the ToxPi™ prioritization scheme for endocrine disruption. The analysis included metabolic and neuroendocrine targets. This investigative approach simultaneously assessed the utility of ToxCast, and helped identify novel chemicals which may have endocrine activity. Results from this exercise suggest the spectrum of environmental chemicals with potential endocrine activity is much broader than indicated, and that some aspects of endocrine disruption are not fully covered in ToxCast. PMID:25460227

  15. Test driving ToxCast: endocrine profiling for 1858 chemicals included in phase II.

    PubMed

    Filer, Dayne; Patisaul, Heather B; Schug, Thaddeus; Reif, David; Thayer, Kristina

    2014-12-01

    Identifying chemicals, beyond those already implicated, to test for potential endocrine disruption is a challenge and high throughput approaches have emerged as a potential tool for this type of screening. This review focused the Environmental Protection Agency's (EPA) ToxCast(TM) high throughput in vitro screening (HTS) program. Utility for identifying compounds was assessed and reviewed by using it to run the recently expanded chemical library (from 309 compounds to 1858) through the ToxPi(TM) prioritization scheme for endocrine disruption. The analysis included metabolic and neuroendocrine targets. This investigative approach simultaneously assessed the utility of ToxCast, and helped identify novel chemicals which may have endocrine activity. Results from this exercise suggest the spectrum of environmental chemicals with potential endocrine activity is much broader than indicated, and that some aspects of endocrine disruption are not fully covered in ToxCast. PMID:25460227

  16. STRUCTURE-TOXICITY RELATIONSHIPS FOR INDUSTRIAL CHEMICALS CAUSING TYPE(II) NARCOSIS SYNDROME

    EPA Science Inventory

    Several structure-activity relationships have been published for estimating the lethality of nonpolar nonelectrolytes to fish. The vast majority of non-reactive industrial chemicals produce toxicity symptoms consistent with narcosis. However, researchers have found that many chem...

  17. Chemical characterization, antioxidant, anti-inflammatory and cytotoxic properties of bee venom collected in Northeast Portugal.

    PubMed

    Sobral, Filipa; Sampaio, Andreia; Falcão, Soraia; Queiroz, Maria João R P; Calhelha, Ricardo C; Vilas-Boas, Miguel; Ferreira, Isabel C F R

    2016-08-01

    Bee venom (BV) or apitoxin is a complex mixture of substances with reported biological activity. In the present work, five bee venom samples obtained from Apis mellifera iberiensis from the Northeast Portugal (two different apiaries) were chemically characterized and evaluated for their antioxidant, anti-inflammatory and cytotoxic properties. The LC/DAD/ESI-MS(n) analysis of the samples showed that melittin was the most abundant compound, followed by phospholipase A2 and apamin. All the samples revealed antioxidant and anti-inflammatory activity but without a direct relation with any of the individual chemical components identified. The results highlight that there are specific concentrations (present in BV5) in which these compounds are more active. The BV samples showed similar cytotoxicity for all the tested tumour cell lines (MCF-7, NCI-H460, HeLa and HepG2), being MCF-7 and HeLa the most susceptible ones. Nevertheless, the studied samples seem to be suitable to treat breast, hepatocellular and cervical carcinoma because at the active concentrations, the samples were not toxic for non-tumour cells (PLP2). Regarding the non-small cell lung carcinoma, BV should be used under the toxic concentration for non-tumour cells. Overall, the present study corroborates the enormous bioactive potential of BV being the first report on samples from Portugal. PMID:27288930

  18. Rethinking data collection and signal processing. 1. Real-time oversampling filter for chemical measurements.

    PubMed

    Laude, Nicholas D; Atcherley, Christopher W; Heien, Michael L

    2012-10-01

    Minimizing noise in chemical measurements is critical to achieve low limits of detection and accurate measurements. We describe a real-time oversampling filter that offers a method to reduce stochastic noise in a time-dependent chemical measurement. The power of this technique is demonstrated in its application to the separation of dopamine and serotonin by micellar electrokinetic chromatography with amperometric detection. Signal-to-noise ratios were increased by almost an order of magnitude, allowing for limits of detection of 100 and 120 amol, respectively. Real-time oversampling filters can be implemented using simple software algorithms and require no change to existing experimental apparatus. The application is not limited to analytical separations, and this technique can be used to improve the signal-to-noise ratio in any experiment where the necessary sampling rate is less than the maximum sampling rate of the analog-to-digital converter. Theory, implementation, and the performance of this filter are described. We propose that this technique should be the default mode of operation for an analog-to-digital converter. PMID:22978644

  19. Salmonella mutagenicity tests. II. Results from the testing of 270 chemicals

    SciTech Connect

    Mortelmans, K.; Haworth, S.; Lawlor, T.; Speck, W.; Tainer, B.; Zeiger, E.

    1986-01-01

    This publication includes data of Salmonella mutagenicity results on 270 coded chemicals, encompassing 329 tests performed by three laboratories under contract to the National Toxicology Program (NTP). The preincubation modification of the Salmonella/mammalian microsome assay was used to test chemicals in up to five Salmonella strains in the presence and absence of rat and hamster liver S-9. With a few exceptions, inter- and intralaboratory reproducibility was good.

  20. Collection method for chemical particulates on surfaces with detection using thermal desorption-ion trap mass spectrometry.

    PubMed

    Ewing, K J; Gibson, D; Sanghera, J; Miklos, F

    2013-05-01

    Successful analysis of particulate/low vapor pressure analytes such as explosives and toxic chemicals, and commercial pesticides require new sampling tools that enable detection of these analytes using current vapor phase detection instruments. We describe a sampling approach that uses stainless steel screens coated with a sticky polydimethyl siloxane (PDMS) coating to capture particulates from surfaces. Preliminary results for the collection of dimethyl methylphosphonate (DMMP) sorbed onto silica gel (SG) particulates (DMMP/SG) from a surface with subsequent analysis by thermal desorption-cylindrical ion trap mass spectrometry (TD-CITMS) are reported. PMID:23601282

  1. CHEMICAL INTERACTIONS OF ARSENATE, ARSENITE, PHOSPHATE, AND SILICATE WITH IRON (II, III) HYDROXYCARBONATE GREEN RUST

    EPA Science Inventory

    Granular zerovalent iron has been proposed to be used as a medium in permeable reactive barriers (PRBs) to remove arsenic from contaminated groundwater. Iron(II, III) hydroxycarbonate green rust (carbonate green rust, or CGR) is a major corrosion product of zerovalent iron under ...

  2. CHEMICAL INTERACTIONS OF ARSENATE, ARSENITE, PHOSPHATE, AND SILICATE WITH IRON (II,III) HYDROXYCARBONATE GREEN RUST

    EPA Science Inventory

    Granular zerovalent iron has been proposed to be used as a medium in permeable reactive barriers (PRBs) to remove arsenic from contaminated groundwater. Iron(II, III) hydroxycarbonate green rust (carbonate green rust, or CGR) is a major corrosion product of zerovalent iron under ...

  3. Chemical Remediation of Nickel(II) Waste: A Laboratory Experiment for General Chemistry Students

    ERIC Educational Resources Information Center

    Corcoran, K. Blake; Rood, Brian E.; Trogden, Bridget G.

    2011-01-01

    This project involved developing a method to remediate large quantities of aqueous waste from a general chemistry laboratory experiment. Aqueous Ni(II) waste from a general chemistry laboratory experiment was converted into solid nickel hydroxide hydrate with a substantial decrease in waste volume. The remediation method was developed for a…

  4. In Vitro Screening of 1877 Industrial and Consumer Chemicals, Pesticides and Pharmaceuticals in up to 782 Assays: ToxCast Phase I and II (SOT)

    EPA Science Inventory

    In Phase II of the ToxCast program, the U.S. EPA and Tox21 partners screened 1,877 chemicals, including pesticides; food, cosmetics and personal care ingredients; pharmaceuticals; and industrial chemicals. Testing used a 782 in vitro assays across 7 technologies and multiple bi...

  5. Chemical composition and biological activity of Conyza bonariensis essential oil collected in Mérida, Venezuela.

    PubMed

    Araujo, Liliana; Moujir, Laila M; Rojas, Janne; Rojas, Luis; Carmona, Juan; Rondón, María

    2013-08-01

    The essential oil from aerial parts of Conyza bonariensis (L) Cronquist collected in Mérida was obtained by hydrodistillation and analysed by GC/MS. The major components were trans-beta-farnesene (37.8%), trans-ocimene (20.7%) and beta-sesquiphellandrene (9.8%). Cytotoxicity assay was also performed with the essential oil against HeLa (cervix carcinoma), A-459 (lung carcinoma) and MCF-7 (breast adenocarcinoma) human cell lines and against normal Vero cells (African green monkey kidney) with IC50 values ranging from 1.4 to 45.8 microg/mL. Additionally, the essential oil presented a significant bactericidal effect against Bacillus cereus, while a moderate activity was observed against Staphylococcus epidermidis and Candida albicans. PMID:24079198

  6. Collective retention and transmission of chemical signals in a social insect

    NASA Astrophysics Data System (ADS)

    Gill, Katherine P.; van Wilgenburg, Ellen; Taylor, Peter; Elgar, Mark A.

    2012-03-01

    Social insect colonies exhibit highly coordinated responses to ecological challenges by acquiring information that is disseminated throughout the colony. Some responses are coordinated directly from the signals produced by individuals that acquired the information. Other responses may require information to be transferred indirectly through a third party, thereby requiring colony-wide retention of information. Social insects use colony signature odours to distinguish between nestmates and non-nestmates, and the level of aggression between non-nestmates typically varies according to the distance between colonies and thus their history of interactions. Such coordinated, colony-specific responses may require information about particular odours to be disseminated and retained across the colony. Our field experiments with weaver ants reveal colony-wide, indirect acquisition and retention of the signature odours of a different colony with which they had experienced aggression. These data highlight the significance of interaction history and suggest the presence of a collective memory.

  7. Ram-air sample collection device for a chemical warfare agent sensor

    DOEpatents

    Megerle, Clifford A.; Adkins, Douglas R.; Frye-Mason, Gregory C.

    2002-01-01

    In a surface acoustic wave sensor mounted within a body, the sensor having a surface acoustic wave array detector and a micro-fabricated sample preconcentrator exposed on a surface of the body, an apparatus for collecting air for the sensor, comprising a housing operatively arranged to mount atop the body, the housing including a multi-stage channel having an inlet and an outlet, the channel having a first stage having a first height and width proximate the inlet, a second stage having a second lower height and width proximate the micro-fabricated sample preconcentrator, a third stage having a still lower third height and width proximate the surface acoustic wave array detector, and a fourth stage having a fourth height and width proximate the outlet, where the fourth height and width are substantially the same as the first height and width.

  8. A review of class I and class II pet food recalls involving chemical contaminants from 1996 to 2008.

    PubMed

    Rumbeiha, Wilson; Morrison, Jamie

    2011-03-01

    Commercial pet food in USA is generally safe, but adulteration does occur. Adulterated food has to be recalled to protect pets and public health. All stakeholders, including food firms, distributors, and government agencies such as the Food and Drug Administration (FDA) participate in food recall. The objective of this review is to describe the pet food recall procedure from start to finish, and to review class I and II pet food recalls from 1996 to 2008, with a specific focus on those due to chemical contaminants/adulterants. Information was requested from the FDA by Freedom of Information Act. Only those recalls backed by the FDA scientific review were considered. The legal framework for food recalls in the Code of Federal Regulations, Title 21, Chapter 1, Part 7 and in the Food and Drug Administration Amendments Act of 2007, Title X was reviewed. From 1996 to 2008, there were a total of 22 class I and II pet food recalls. Of these, only six (27%) were due to chemical adulterants. The adulterants were aflatoxins, cholecalciferol, methionine, and melamine, and cyanuric acid. The causes of adulteration included inadequate testing of raw materials for toxins, use of wrong or faulty mixing equipment, and misformulation of raw materials. Overall, pet food manufactured in the USA is safe. Even with shortcomings in the recall process, the incidence of illness associated with pet food adulteration is low. Added changes can only make the system better in the future to safeguard pet and public safety. PMID:21125435

  9. Atomic Data for Zn II: Improving Spectral Diagnostics of Chemical Evolution in High-redshift Galaxies

    NASA Astrophysics Data System (ADS)

    Kisielius, Romas; Kulkarni, Varsha P.; Ferland, Gary J.; Bogdanovich, Pavel; Som, Debopam; Lykins, Matt L.

    2015-05-01

    Damped Lyα (DLA) and sub-DLA absorbers in quasar spectra provide the most sensitive tools for measuring the element abundances of distant galaxies. The estimation of abundances from absorption lines depends sensitively on the accuracy of the atomic data used. We have started a project to produce new atomic spectroscopic parameters for optical and UV spectral lines using state-of-the-art computer codes employing a very broad configuration interaction (CI) basis. Here we report our results for Zn ii, an ion used widely in studies of the interstellar medium (ISM) as well as DLAs and sub-DLAs. We report new calculations of many energy levels of Zn ii and the line strengths of the resulting radiative transitions. Our calculations use the CI approach within a numerical Hartree-Fock framework. We use both nonrelativistic and quasi-relativistic one-electron radial orbitals. We have incorporated the results of these atomic calculations into the plasma simulation code Cloudy and applied them to a lab plasma and examples of a DLA and a sub-DLA. Our values of the Zn ii λ λ 2026, 2062 oscillator strengths are higher than previous values by 0.10 dex. The Cloudy calculations for representative absorbers with the revised Zn atomic data imply ionization corrections lower than calculated earlier by 0.05 dex. The new results imply that Zn metallicities should be lower by 0.1 dex for DLAs and by 0.13-0.15 dex for sub-DLAs than in past studies. Our results can be applied to other studies of Zn ii in the Galactic and extragalactic ISM.

  10. Physico-chemical studies in the removal of Sr(II) from aqueous solutions using activated sericite.

    PubMed

    Lalhmunsiama; Tiwari, Diwakar; Lee, Seung-Mok

    2015-09-01

    Sericite, a mica based natural clay, was annealed at 800 °C for 4 h followed by acid activation using 3.0 mol/L of HCl at 100 °C in order to obtain activated sericite (AS). The activation of sericite causes a significant increase in specific surface area. Further, SEM images of the AS showed a disordered and heterogeneous surface structure with mesopores on its surface whereas the pristine sericite possessed a compact layered structure. The materials were further employed in the removal of Sr(II) from aqueous solutions in a batch reactor system. Removal of Sr(II) was studied as a function of pH, concentration of adsorbate, contact time, background electrolyte concentrations and dose of adsorbents using pristine sericite and AS. The removal of Sr(II) was favoured increasing the pH of the solution and the extent of Sr(II) removal was increased with increasing the sorbate concentration. Equilibrium sorption data obtained with pristine sericite were fitted well to Langmuir adsorption isotherm whereas the sorption data collected using AS better fitted to the Freundlich adsorption isotherm. The time dependence sorption data showed that the uptake of Sr(II) was very rapid and an apparent sorption equilibrium was achieved within 30 min and 60 min of contact for sericite and AS, respectively. The kinetic data were modelled to the pseudo-first order and pseudo-second order rate kinetics and sorption capacities as well as rate constants were evaluated. Increase in background electrolyte concentrations NaNO3 (0.001-0.1 mol/L) indicated that the presence of NaNO3 caused to decrease the percent removal of Sr(II) by sericite and AS. Furthermore, fixed-bed column reactor operations were performed to obtain the breakthrough data. The breakthrough data were fitted well to the non-linear Thomas equation. Therefore, the present study suggested that AS can be adequately applied for the removal of Sr(II) from the aquatic environment. PMID:26048059

  11. Chemically Modified Plastic Tube for High Volume Removal and Collection of Circulating Tumor Cells

    PubMed Central

    Gaitas, Angelo; Kim, Gwangseong

    2015-01-01

    In this preliminary effort, we use a commercially available and chemically modified tube to selectively capture circulating tumor cells (CTCs) from the blood stream by immobilizing human anti-EpCAM antibodies on the tube's interior surface. We describe the requisite and critical steps required to modify a tube into a cancer cell-capturing device. Using these simple modifications, we were able to capture or entrap about 85% of cancer cells from suspension and 44% of cancer cells from spiked whole blood. We also found that the percentage of cells captured was dependent on the tube's length and also the number of cancer cells present. It is our strong belief that with the utilization of appropriate tube lengths and procedures, we can ensure capture and removal of nearly the entire CTC population in whole blood. Importantly after a patient’s entire blood volume has circulated through the tube, the tube can then be trypsinized to release the captured live CTCs for further analysis and testing. PMID:26176235

  12. Chemically Modified Plastic Tube for High Volume Removal and Collection of Circulating Tumor Cells.

    PubMed

    Gaitas, Angelo; Kim, Gwangseong

    2015-01-01

    In this preliminary effort, we use a commercially available and chemically modified tube to selectively capture circulating tumor cells (CTCs) from the blood stream by immobilizing human anti-EpCAM antibodies on the tube's interior surface. We describe the requisite and critical steps required to modify a tube into a cancer cell-capturing device. Using these simple modifications, we were able to capture or entrap about 85% of cancer cells from suspension and 44% of cancer cells from spiked whole blood. We also found that the percentage of cells captured was dependent on the tube's length and also the number of cancer cells present. It is our strong belief that with the utilization of appropriate tube lengths and procedures, we can ensure capture and removal of nearly the entire CTC population in whole blood. Importantly after a patient's entire blood volume has circulated through the tube, the tube can then be trypsinized to release the captured live CTCs for further analysis and testing. PMID:26176235

  13. Divergent Chemical Cues Elicit Seed Collecting by Ants in an Obligate Multi-Species Mutualism in Lowland Amazonia

    PubMed Central

    Youngsteadt, Elsa; Guerra Bustios, Patricia; Schal, Coby

    2010-01-01

    In lowland Amazonian rainforests, specific ants collect seeds of several plant species and cultivate them in arboreal carton nests, forming species-specific symbioses called ant-gardens (AGs). In this obligate mutualism, ants depend on the plants for nest stability and the plants depend on ant nests for substrate and nutrients. AG ants and plants are abundant, dominant members of lowland Amazonian ecosystems, but the cues ants use to recognize the seeds are poorly understood. To address the chemical basis of the ant-seed interaction, we surveyed seed chemistry in nine AG species and eight non-AG congeners. We detected seven phenolic and terpenoid volatiles common to seeds of all or most of the AG species, but a blend of the shared compounds was not attractive to the AG ant Camponotus femoratus. We also analyzed seeds of three AG species (Anthurium gracile, Codonanthe uleana, and Peperomia macrostachya) using behavior-guided fractionation. At least one chromatographic fraction of each seed extract elicited retrieval behavior in C. femoratus, but the active fractions of the three plant species differed in polarity and chemical composition, indicating that shared compounds alone did not explain seed-carrying behavior. We suggest that the various AG seed species must elicit seed-carrying with different chemical cues. PMID:21209898

  14. Aerosols Collected at a Tropical Marine Environment: Size-Resolved Chemical Composition Using IC, TOC, and Thermal-Optical Analyses

    NASA Astrophysics Data System (ADS)

    Morales-García, F.; Mayol-Bracero, O. L.; Repollet-Pedrosa, M.; Kasper-Giebl, A.; Ramírez-Santa Cruz, C.; Puxbaum, H.

    2009-05-01

    Size-resolved chemical characterization was performed on aerosol samples collected at two different marine sites in the tropics: Dian Point (DP), Antigua and Cape San Juan (CSJ), Puerto Rico. A 13-stage Dekati low- pressure impactor (Dp 0.1 to 10 μm), a 10-stage micro-orifice uniform deposit impactor (Dp 0.054 to 18 μm), and stacked-filter units (Dp < 1.7 μm) were used to collect the samples. Na+, NH4+, K+, Mg2+, Ca2+, Cl-, NO2-, NO3-, SO42-, acetate, formate, malonate, and oxalate were determined using ion chromatography (IC). Thermal-optical analysis (TOA) was used to determine the concentrations of aerosol total carbon (TC), organic carbon (OC), and elemental carbon (EC). Five-day back trajectories calculated using NOAA's HYSPLIT (HYbrid Single-Particle Lagrangian Integrated Trajectory) model identified air masses coming from the North Atlantic (maritime air), Northwest Africa (desert dust), and North America (anthropogenic pollution). Size-resolved chemical characterization of aerosol samples using IC and TOA confirmed that aerosols become aged as they are transported to the Caribbean and their composition depends on the air mass origin. Gravimetric analyses showed that average fine mass concentrations for CSJ station were higher than for DP station (CSJ: 1.9 μg m-3; DP: 1.2 μg m-3). The aerosol chemical composition changed with air masses of different origin and with different pollution levels. In both locations the predominant water-soluble ions in the fine aerosol fraction were Cl-, Na+, and SO42-. Sulphate was observed in higher concentrations during the polluted case and particulate organic matter concentrations were higher for the maritime case. During desert dust events an increase in Ca2+ and Mg2+ of 4 and 2 times, respectively, was observed mainly in the coarse mode. Results for the size-resolved chemical composition and complete aerosol chemical apportionment including the residual mass will be presented.

  15. PERFORMANCE OF NORTH AMERICAN BIOREACTOR LANDFILLS: II. CHEMICAL AND BIOLOGICAL CHARACTERISTICS

    EPA Science Inventory

    The objective of this research was to examine the performance of five North American bioreactor landfills. This paper represents the second of a two part series and addresses biological and chemical aspects of bioreactor performance including gas production and management, and l...

  16. ACCURACY OF PESTICIDE REFERENCE STANDARD SOLUTIONS. PART II. CHEMICAL STABILITY UNDER FOUR STORAGE CONDITIONS

    EPA Science Inventory

    A study was undertaken to assess the long-term chemical stability of dilute standard pesticide solutions of 4 compound classes. The solutions were studied under 4 storage conditions: freezer at -15C; refrigerator at 3C; ambient temperature in the dark; and ambient temperature on ...

  17. Test driving ToxCast: endocrine profiling for1858 chemicals included in phase II

    EPA Science Inventory

    Introduction: Identifying chemicals to test for potential endocrine disruption beyond those already implicated in the peer-reviewed literature is a challenge. This review is intended to help by summarizing findings from the Environmental Protection Agency’s (EPA) ToxCast™ high th...

  18. Development of a benchtop baking method for chemically leavened crackers. II. Validation of the method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A benchtop baking method has been developed to predict the contribution of gluten functionality to overall flour performance for chemically leavened crackers. Using a diagnostic formula and procedure, dough rheology was analyzed to evaluate the extent of gluten development during mixing and machinin...

  19. PRELIMINARY ASSESSMENTS OF IN VITRO PHARMACOKINETIC DATA AND EXPOSURE INFORMATION FOR THE TOXCAST PHASE II CHEMICALS

    EPA Science Inventory

    Momentum has been growing in Toxicology to assess the utility of high-throughput screening (HTS) assays in the determination of chemical testing priorities. However, in vitro potencies determined in these assays do not consider in vivo bioavailability, clearance or exposure estim...

  20. Iso-chemical potential trajectories in the P-T plane for He II

    NASA Technical Reports Server (NTRS)

    Maytal, B.; Nissen, J. A.; Van Sciver, S. W.

    1990-01-01

    Trajectories of constant chemical potential in the P-T plane serve as an integral formulation of London's equation. The trajectories are useful for analysis and synthesis of fountain effect pump performance. A family of trajectories is generated from available numerical codes.

  1. Theory of chemical bonds in metalloenzymes II: Hybrid-DFT studies in iron-sulfur clusters

    NASA Astrophysics Data System (ADS)

    Shoji, M.; Koizumi, K.; Kitagawa, Y.; Yamanaka, S.; Kawakami, T.; Okumura, M.; Yamaguchi, K.

    Important chemical reactions for life often require multistep electron transfers (ET) and strong reducing forces. In these reactions, electron transfer proteins as ferredoxins (Fds) play a key role. For elucidation of the core electronic states in these electron transfer processes, an inorganic model compound [Fe2S2(S2-o-xyl)2] is used as our first study. It was experimentally characterized that the model compound is in a similar electronic state to the active site core in Fds. On the reduced form, the diiron core exists in a characteristic mixed-valence state that has mobile electron (spin). Hybrid density functional theory (HDFT) calculations are performed to investigate the chemical bond nature, electronic structures, and magnetic interactions. The spin states and energy levels are further discussed with spin Hamiltonians, which contain Heisenberg exchange term and double exchange term to describe the mixed-valence state. We have determined their effective exchange integrals (J) and resonance parameters (B) from (HDFT) calculations in several procedures. These magnetic interactions are in good agreement with experiments. To estimate B values, we propose a new procedure using molecular orbital energies. The B values are properly evaluated compared with other procedures, using total energies. The chemical bond natures and the ground electronic structures are elucidated in terms of chemical indices defined by the occupation number of natural orbitals. Finally, implications of the computational results are discussed in relation to rational design of biomolecular devices.

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

    PubMed

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

    2012-09-01

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

  3. Mutagenic activity and chemical analysis of airborne particulates collected in Pisa (Italy)

    SciTech Connect

    Vellosi, R.; Fiorio, R.; Rosellini, D.; Bronzetti, G. ); Vannucchi, C.; Ciacchini, G.; Giaconi, V. ); Bianchi, F. )

    1994-03-01

    In the last few years there has been much concern about the problem connected to the exposure to mutagens present in the environment of industrialized countries. Particularly, the mutagenic activity of airborne particulate matter has been studied by many investigators and correlated with elevated lung cancer mortality rates. In most cases the Salmonella typhimurium/microsome test has been used for these studies. This short-term test, which is the most validated among the short-term genotoxicity tests, provides an important indication on the carcinogenic potential of environmental pollutants. That are complex mixtures containing a wide variety of compounds potentially capable of causing additive, antagonistic or synergistic genotoxic response in living organisms. Several studies have suggested that diverse factors, such as traffic and meteorological conditions, could affect the levels of pollutants in the air. In our work, we have investigated three different areas in Pisa, where the intensity and the kind of the road traffic were different. Airborne particles have been collected during a year and the genotoxic activity has been studied using TA98 and TA100 strains of Salmonella typhimurium. 20 refs., 1 fig., 3 tabs.

  4. Hygroscopic and Chemical Properties of Aerosols collected near a Copper Smelter: Implications for Public and Environmental Health

    PubMed Central

    Sorooshian, Armin; Csavina, Janae; Shingler, Taylor; Dey, Stephen; Brechtel, Fred J.; Sáez, A. Eduardo; Betterton, Eric A.

    2012-01-01

    Particulate matter emissions near active copper smelters and mine tailings in the southwestern United States pose a potential threat to nearby environments owing to toxic species that can be inhaled and deposited in various regions of the body depending on the composition and size of the particles, which are linked by particle hygroscopic properties. This study reports the first simultaneous measurements of size-resolved chemical and hygroscopic properties of particles next to an active copper smelter and mine tailings by the towns of Hayden and Winkelman in southern Arizona. Size-resolved particulate matter samples collected near an active copper smelter were examined with inductively coupled plasma mass spectrometry, ion chromatography, and a humidified tandem differential mobility analyzer. Aerosol particles collected at the measurement site are enriched in metals and metalloids (e.g. arsenic, lead, and cadmium) and water-uptake measurements of aqueous extracts of collected samples indicate that the particle diameter range of particles most enriched with these species (0.18–0.55 µm) overlaps with the most hygroscopic mode at a relative humidity of 90% (0.10–0.32 µm). These measurements have implications for public health, microphysical effects of aerosols, and regional impacts owing to the transport and deposition of contaminated aerosol particles. PMID:22852879

  5. Bacterial mutagenicity and chemical analysis of polycyclic aromatic hydrocarbons and some nitro derivatives in environmental samples collected in West Germany

    SciTech Connect

    Garner, R.C.; Stanton, C.A.; Martin, C.N.; Chow, F.L.; Thomas, W.; Hubner, D.; Herrmann, R.

    1986-01-01

    Snow and air particulate samples collected in Upper Frankonia, Federal Republic of Germany, have been analyzed for nitro-polycyclic aromatic hydrocarbons (PAH) and PAH content. A novel clean-up technique has been developed enabling interfering organochlorine environmental contaminants to be removed prior to analysis of the hydrocarbons by GC-MS. Mass fragmentation patterns are presented for 1-nitropyrene, 6-nitrobenzo(a)pyrene, 6-nitrochrysene, and 3-nitrofluoranthene. The level of these compounds found in air samples was in the range of 0.2-2.0 ng.m-3 with the exception of 6-nitrobenzo(a)pyrene, which was not detected. This compares with PAH values of between 1 and 6 ng.m-3. The freshly fallen snow sample collected at the side of a motorway had no detectable PAHs or nitro-PAHs. Parallel studies on the bacterial mutagenicity of the collected air samples using Salmonella typhimurium TA98 and TA100 in the presence and absence of aroclor-induced rat liver S9 revealed both direct and indirect activity. Larger numbers of mutants were induced in the presence of S9 than in its absence. The snow sample was devoid of mutagenic activity. These studies show the utility of the biological approach to screen environmental samples prior to expensive and time-consuming chemical analysis.

  6. Chemical and statistical interpretation of sized aerosol particles collected at an urban site in Thessaloniki, Greece.

    PubMed

    Tsitouridou, Roxani; Papazova, Petia; Simeonova, Pavlina; Simeonov, Vasil

    2013-01-01

    The size distribution of aerosol particles (PM0.015-PM18) in relation to their soluble inorganic species and total water soluble organic compounds (WSOC) was investigated at an urban site of Thessaloniki, Northern Greece. The sampling period was from February to July 2007. The determined compounds were compared with mass concentrations of the PM fractions for nano (N: 0.015 < Dp < 0.06), ultrafine (UFP: 0.015 < Dp < 0.125), fine (FP: 0.015 < Dp < 2.0) and coarse particles (CP: 2.0 < Dp < 8.0) in order to perform mass closure of the water soluble content for the respective fractions. Electrolytes were the dominant species in all fractions (24-27%), followed by WSOC (16-23%). The water soluble inorganic and organic content was found to account for 53% of the nanoparticle, 48% of the ultrafine particle, 45% of the fine particle and 44% of the coarse particle mass. Correlations between the analyzed species were performed and the effect of local and long-range transported emissions was examined by wind direction and backward air mass trajectories. Multivariate statistical analysis (cluster analysis and principal components analysis) of the collected data was performed in order to reveal the specific data structure. Possible sources of air pollution were identified and an attempt is made to find patterns of similarity between the different sized aerosols and the seasons of monitoring. It was proven that several major latent factors are responsible for the data structure despite the size of the aerosols - mineral (soil) dust, sea sprays, secondary emissions, combustion sources and industrial impact. The seasonal separation proved to be not very specific. PMID:24007436

  7. Chemical characteristics of rainwater collected at a western site of Jordan

    NASA Astrophysics Data System (ADS)

    Al-Khashman, Omar Ali.

    2009-01-01

    A comprehensive study on the chemical composition of rainwater was carried out from October 2006 to May 2007 in Ghore El-Safi area western side of Jordan nearby the Dead Sea. Rainwater samples were analyzed for major ions (Ca 2+, Mg 2+, K +, Na +, NH 4+, HCO 3-, Cl -, NO 3- and SO 42-) and trace metals (Fe, Al, Zn, Pb, Cu, and Cd). The highest concentration of elements is observed at the beginning of the rainfall season when large amounts of dust accumulated in the atmosphere scavenged by rain. The majority of rainwater had a neutral or alkaline character as a result of neutralization caused by the alkaline local dusts which contain large amount of CaCO 3. The pH ranged from 4.8 to 8.2 with a mean value of 6.9 ± 0.65 which was in alkaline range considering 5.6 as the neutral pH of cloud water with atmospheric CO 2 equilibrium. In the total 35 rain events, only three events were observed in acidic range (< 5.6) which occurred after continuous rains. The equivalent concentration of components followed the order: Ca 2+ > HCO 3- > Cl - > Mg 2+ > NO 3- > SO 42- > NH 4+ > Na + > K +. Rainwater chemistry was analyzed using Factor Component Analysis to find the possible sources of the measured species. Three components that accounted for 84% of the total variance were extracted sea salts spray (Na+, Cl - and Mg 2+), and soil particles (natural origin), (Mg 2+, Ca 2+ and HCO 3-) and biomass burning (NH 4+). The results obtained in this study are compared with those other studies conducted at different sites in the world. In general, the results of this study suggested that rainwater chemistry is strongly influenced by local anthropogenic sources (potash factory and agricultural activities in Ghore El-Safi area) rather than natural and marine sources. The pollutants in rainwater samples were mainly derived from long distance transport, local industry and traffic sources.

  8. New integration techniques for chemical kinetic rate equations. II - Accuracy comparison

    NASA Technical Reports Server (NTRS)

    Radhakrishnan, K.

    1986-01-01

    A comparison of the accuracy of several techniques recently developed for solving stiff differential equations is presented. The techniques examined include two general purpose codes EEPISODE and LSODE developed for an arbitrary system of ordinary differential equations, and three specialized codes CHEMEQ, CREKID, and GCKP84 developed specifically to solve chemical kinetic rate equations. The accuracy comparisons are made by applying these solution procedures to two practical combustion kinetics problems. Both problems describe adiabatic, homogeneous, gas phase chemical reactions at constant pressure, and include all three combustion regimes: induction heat release, and equilibration. The comparisons show that LSODE is the most efficient code - in the sense that it requires the least computational work to attain a specified accuracy level. An important finding is that an iterative solution of the algebraic enthalpy conservation equation for the temperature can be more accurate and efficient than computing the temperature by integrating its time derivative.

  9. Exclusion of cosmic rays in protoplanetary disks. II. Chemical gradients and observational signatures

    SciTech Connect

    Cleeves, L. Ilsedore; Bergin, Edwin A.; Adams, Fred C.

    2014-10-20

    The chemical properties of protoplanetary disks are especially sensitive to their ionization environment. Sources of molecular gas ionization include cosmic rays (CRs), stellar X-rays, and short-lived radionuclides, each of which varies with location in the disk. This behavior leads to a significant amount of chemical structure, especially in molecular ion abundances, which is imprinted in their submillimeter rotational line emission. Using an observationally motivated disk model, we make predictions for the dependence of chemical abundances on the assumed properties of the ionizing field. We calculate the emergent line intensity for abundant molecular ions and simulate sensitive observations with the Atacama Large Millimeter/Sub-millimeter Array (ALMA) for a disk at D = 100 pc. The models readily distinguish between high ionization rates (ζ ≳ 10{sup –17} s{sup –1} per H{sub 2}) and below, but it becomes difficult to distinguish between low ionization models when ζ ≲ 10{sup –19} s{sup –1}. We find that H{sub 2}D{sup +} emission is not detectable for sub-interstellar CR rates with ALMA (6h integration), and that N{sub 2}D{sup +} emission may be a more sensitive tracer of midplane ionization. HCO{sup +} traces X-rays and high CR rates (ζ{sub CR} ≳ 10{sup –17} s{sup –1}), and provides a handle on the warm molecular ionization properties where CO is present in the gas. Furthermore, species like HCO{sup +}, which emits from a wide radial region and samples a large gradient in temperature, can exhibit ring-like emission as a consequence of low-lying rotational level de-excitation near the star. This finding highlights a scenario where rings are not necessarily structural or chemical in nature, but simply a result of the underlying line excitation properties.

  10. Pb(II) adsorption by biomass from chemically modified aquatic macrophytes, Salvinia sp. and Pistia stratiotes.

    PubMed

    de Moraes Ferreira, Rachel; de Souza, Michael Douglas Peçanha; Takase, Iracema; de Araujo Stapelfeldt, Danielle Marques

    2016-01-01

    This study used two biosorbents obtained from the aquatic plants Salvinia sp. and Pistia stratiotes to establish a sustainable and alternative treatment for industrial wastewater and other water bodies that contain Pb(II). The biosorbent named Salvinia with NaOH (SOH) was obtained from Salvinia sp., and Salvinia and Pistia mixture with NaOH (SPOH) was obtained from a mixture of the two plants in a 1:1 ratio. The biosorbents were characterized by zeta potential, infrared (IR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive spectroscopy and Boehm titration. The results of Boehm titration and IR analysis indicated the presence of basic functional groups, whereas those of SEM analysis indicated that the biosorbents have a structure conducive to adsorption. Batch adsorption experiments were performed to observe the effects of pH, contact time, initial lead concentration and temperature on the metal removal process. The results revealed that the biosorbents efficiently removed Pb(II) from aqueous solutions, with a maximum observed adsorption capacity (saturation limits, qmax) of 202 mg g(-1) and 210.1 mg g(-1) for SPOH and SOH, respectively. The Freundlich, Langmuir and Dubinin-Radushkevich models were applied to the data; these biosorbent studies did not satisfactorily adjust to either of the models, but the information obtained helped us understand the adsorption mechanism. PMID:27232403

  11. Comparison of chemical and thermal protein denaturation by combination of computational and experimental approaches. II

    NASA Astrophysics Data System (ADS)

    Wang, Qian; Christiansen, Alexander; Samiotakis, Antonios; Wittung-Stafshede, Pernilla; Cheung, Margaret S.

    2011-11-01

    Chemical and thermal denaturation methods have been widely used to investigate folding processes of proteins in vitro. However, a molecular understanding of the relationship between these two perturbation methods is lacking. Here, we combined computational and experimental approaches to investigate denaturing effects on three structurally different proteins. We derived a linear relationship between thermal denaturation at temperature Tb and chemical denaturation at another temperature Tu using the stability change of a protein (ΔG). For this, we related the dependence of ΔG on temperature, in the Gibbs-Helmholtz equation, to that of ΔG on urea concentration in the linear extrapolation method, assuming that there is a temperature pair from the urea (Tu) and the aqueous (Tb) ensembles that produces the same protein structures. We tested this relationship on apoazurin, cytochrome c, and apoflavodoxin using coarse-grained molecular simulations. We found a linear correlation between the temperature for a particular structural ensemble in the absence of urea, Tb, and the temperature of the same structural ensemble at a specific urea concentration, Tu. The in silico results agreed with in vitro far-UV circular dichroism data on apoazurin and cytochrome c. We conclude that chemical and thermal unfolding processes correlate in terms of thermodynamics and structural ensembles at most conditions; however, deviations were found at high concentrations of denaturant.

  12. Effect of milk preacidification on low fat mozzarella cheese: II. Chemical and functional properties during storage.

    PubMed

    Metzger, L E; Barbano, D M; Kindstedt, P S; Guo, M R

    2001-06-01

    The effect of milk preacidification on cheese manufacturing, chemical properties, and functional properties of low fat Mozzarella cheese was determined. Four vats of cheese were made in 1 d using no preacidification (control), preacidification to pH 6.0 and pH 5.8 with acetic acid, and preacidification to pH 5.8 with citric acid. This process was replicated four times. Modifications in the typical Mozzarella manufacturing procedures were necessary to accommodate milk preacidification. The chemical composition of the cheeses was similar among the treatments, except the calcium content and calcium as a percentage of protein were lower in the preacidified treatments. During refrigerated storage, the chemical and functional properties of low fat Mozzarella were affected the most by milk preacidification to pH 5.8 with citric acid. The amount of expressible serum, unmelted cheese whiteness, initial unmelted hardness, and initial apparent viscosity were lower with preacidification. The reduction in initial unmelted cheese hardness and initial apparent viscosity in the pH 5.8 citric treatments represents an improvement in the quality of low fat Mozzarella cheese that allows the cheese to have better pizza bake characteristics with shorter time of refrigerated storage. PMID:11417692

  13. Chemical Abundances in the Stellar Populations of the Leo I and Leo II dSph Galaxies

    NASA Astrophysics Data System (ADS)

    Bosler, T. L.; Smecker-Hane, T. A.; Stetson, P. B.

    2002-05-01

    Our goal is to map the chemical abundance distribution of the stellar populations of the Leo I and Leo II dwarf spheroidal (dSph) galaxies to constrain the physical processes that regulate their evolution. The dSphs are particularly interesting galaxies because their star formation histories (SFHs) appear to be much more complicated than theory would predict for such low mass, low luminosity, low surface-brightness galaxies. Color-magnitude diagrams (CMDs) of these dSphs have shown that they formed stars over many Gyr. In order to understand the true spread in stellar ages and chemical abundances we need more precise abundance indicators than can be inferred from CMD analysis: abundances based upon the broad-band colors of red giants are subject to large systematic errors because of limitations in convection theory, and poorly determined color--effective temperature relations produce sizable uncertainties in the derived shapes of theoretical red giant branches. Therefore we are measuring the abundance distribution of the Leo I and Leo II dSphs from spectroscopy of individual red giant stars using the Ca II absorption lines in the near infrared (8498, 8542, and 8662 Å). Our observations are made on the Keck I 10-meter Telescope using the Low Resolution Imaging Spectrometer. One night of successful observations yielded spectra of approximately 40 stars in each dSph from which abundances with random uncertainties of ≈ 0.1 dex will be derived. Calibration of the Ca II strengths to [Fe/H] has been done by Rutledge, et al. (1997, PASP, 109, 907) using Galactic globular clusters. We are also deriving a new calibration for [Ca/H]. This new calibration will remove the dependence on SFH built into the Rutledge, et al. calibration, i.e., the assumptions of a unique age for the system and a Galactic [Ca/Fe]--[Fe/H] relationship. Financial support for this project was provided by NSF grant AST-0070985 to TSH, and an ARCS Foundation fellowship to TB.

  14. New type of time-series sediment trap for the reliable collection of inorganic and organic trace chemical substances

    NASA Astrophysics Data System (ADS)

    Kremling, K.; Lentz, U.; Zeitzschel, B.; Schulz-Bull, D. E.; Duinker, J. C.

    1996-12-01

    The new sediment trap has a 0.5 m2 aperture, a funnel slope of 34° and is capable of collecting 21 samples at programmed intervals (1 min-1 year) during deployment in the deep ocean. The trap has been designed to allow reliable data on trace inorganic and organic components (such as trace elements, n-alkanes, PCBs, PAHs, amino/fatty acids) in addition to the standard biogeochemical variables in the collected particles. Due to the exclusive use of synthetic (such as fiberglass, PVC, PTFE, or POM-Delrin®) and highly resistant metallic materials contamination problems have been eliminated for these species. Blank values determined in several tests in the open ocean were as low as 1% or even less of the amounts present in trap material, even at low particulate loadings. Another major aim was the elimination of loss of dissolved components from the sample cups into seawater. Microbial and chemical processes modify the collected particles, thereby mobilizing originally particulate species into solution. It is thus essential to avoid greater losses of dissolved species through diffusion into the surrounding seawater after collection. This was achieved by means of an especially designed sealing mechanism. Tests with tracer substances during field studies proved that losses of dissolved components from supernatants during one year of deployment are as low as 10%. Additionally, the relationship between flow characteristics around the traps and their excursions from the vertical position in a bottom-tethered array was studied during a one-year deployment in the North Atlantic.

  15. Exemplary Projects. Mathematics-Science, Computer Learning and Foreign Languages. A Collection of Projects Funded through Title II of The Education for Economic Security Act.

    ERIC Educational Resources Information Center

    Department of Education, Washington, DC.

    This document is a collection of over 80 exemplary project summaries from projects funded in 39 states and the District of Columbia through Title II of the Education for Economic Security Act. The subject areas covered by these projects are limited to mathematics, science, foreign language, and computer learning. Each summary includes a…

  16. Chemical consequences of pyrazole orientation in Ru(II) complexes of unsymmetric quinoline-pyrazole ligands.

    PubMed

    Hedberg Wallenstein, Joachim; Fredin, Lisa A; Jarenmark, Martin; Abrahamsson, Maria; Persson, Petter

    2016-08-01

    A series of homoleptic Ru(II) complexes including the tris-bidentate complexes of a new bidentate ligand 8-(1-pyrazol)-quinoline (Q1Pz) and bidentate 8-(3-pyrazol)-quinoline (Q3PzH), as well as the bis-tridentate complex of bis(quinolinyl)-1,3-pyrazole (DQPz) was studied. Together these complexes explore the orientation of the pyrazole relative to the quinoline. By examining the complexes structurally, photophysically, photochemically, electrochemically, and computationally by DFT and TD-DFT, it is shown that the pyrazole orientation has a significant influence on key properties. In particular, its orientation has noticeable effects on oxidation and reduction potentials, photostability and proton sensitivity, indicating that [Ru(Q3PzH)3](2+) is a particularly good local environment acidity-probe candidate. PMID:27240703

  17. [Chemical composition of fresh bee pollen collected in the Misintá páramo from the Venezuelan Andes].

    PubMed

    Vit, Patricia; Santiago, B

    2008-12-01

    Venezuelan bee pollen has not been characterized, and marketing is not regulated. Pollen is consumed for apitherapeutical purposes for its nutritional and medicinal properties. This product of the hive is the most popular after honey; therefore it is necessary to characterize and to value it to initiate a database to support the proposal of a norm for bee pollen quality control. Samples of bee pollen collected by bees in the Misintá páramo of Mérida state were characterized accoridng to the chemical composition (moisture, ash, fat, pH, proteins) of four color fractions (yellow, orange, ochre, green). Yellow pollen was the most frequent fraction, with 2.18 g ash/100 g, 5.37 g ether extract/100 g, 14.88 g moisture/100 g, and 37.32 g proteins/100 g. PMID:19368304

  18. Potential halogenated industrial carcinogenic and mutagenic chemicals. II. Halogenated saturated hydrocarbons.

    PubMed

    Fishbein, L

    1979-03-01

    The halogenated saturated hydrocarbons analogously to the previously considered halogenated unsaturated hydrocarbons (Part I) possess considerable utility in a broad spectrum of applications including; solvents, dry-cleaning fluids, refrigerants, fumigants, degreasing agents, propellants and intermediates in the production of other chemicals, textiles and plastics. Methyl chloride, methylene chloride, chloroform, carbon tetrachloride, methyl chloroform, 1,1,2-trichloroethane, hexachloroethane, ethyl chloride and fluorocarbons were reviewed principally in terms of their synthesis (or occurrence), areas of application, stability, distribution, reactivity, levels of exposure, populations at risk, carcinogenicity, mutagenicity and metabolism. PMID:373115

  19. The resonance line of B II in IUE spectra of chemically peculiar stars

    NASA Technical Reports Server (NTRS)

    Leckrone, D. S.

    1981-01-01

    A description is presented of high-dispersion spectroscopic observations of eight chemically peculiar stars including Kappa Cnc and Mu Lep, and of one normal comparison star, Nu Cap, in the vicinity of 1362 A. The reported data were obtained with the International Ultraviolet Explorer during the first 15 months of its operation. The initial reduction of the data, which were originally described in a qualitative summary by Leckrone (1980), was affected by a serious error in the calibration of the instrument's intensity transfer function. This error has been corrected in the currently presented data. The results of spectrum syntheses of the 1362 A feature are also described for several of the stars.

  20. PKC-α-dependent augmentation of cAMP and CREB phosphorylation mediates the angiotensin II stimulation of renin in the collecting duct.

    PubMed

    Gonzalez, Alexis A; Liu, Liu; Lara, Lucienne S; Bourgeois, Camille R T; Ibaceta-Gonzalez, Cristobal; Salinas-Parra, Nicolas; Gogulamudi, Venkateswara R; Seth, Dale M; Prieto, Minolfa C

    2015-11-15

    In contrast to the negative feedback of angiotensin II (ANG II) on juxtaglomerular renin, ANG II stimulates renin in the principal cells of the collecting duct (CD) in rats and mice via ANG II type 1 (AT1R) receptor, independently of blood pressure. In vitro data indicate that CD renin is augmented by AT1R activation through protein kinase C (PKC), but the exact mechanisms are unknown. We hypothesize that ANG II stimulates CD renin synthesis through AT1R via PKC and the subsequent activation of cAMP/PKA/CREB pathway. In M-1 cells, ANG II increased cAMP, renin mRNA (3.5-fold), prorenin, and renin proteins, as well as renin activity in culture media (2-fold). These effects were prevented by PKC inhibition with calphostin C, PKC-α dominant negative, and by PKA inhibition. Forskolin-induced increases in cAMP and renin expression were prevented by calphostin C. PKC inhibition and Ca2+ depletion impaired ANG II-mediated CREB phosphorylation and upregulation of renin. Adenylate cyclase 6 (AC) siRNA remarkably attenuated the ANG II-dependent upregulation of renin mRNA. Physiological activation of AC with vasopressin increased renin expression in M-1 cells. The results suggest that the ANG II-dependent upregulation of renin in the CD depends on PKC-α, which allows the augmentation of cAMP production and activation of PKA/CREB pathway via AC6. This study defines the intracellular signaling pathway involved in the ANG II-mediated stimulation of renin in the CD. This is a novel mechanism responsible for the regulation of local renin-angiotensin system in the distal nephron. PMID:26268270

  1. Profiling of the Tox21 Chemical Collection for Mitochondrial Function to Identify Compounds that Acutely Decrease Mitochondrial Membrane Potential

    PubMed Central

    Attene-Ramos, Matias S.; Huang, Ruili; Michael, Sam; Witt, Kristine L.; Richard, Ann; Tice, Raymond R.; Simeonov, Anton; Austin, Christopher P.

    2014-01-01

    21 chemical collection for mitochondrial function to identify compounds that acutely decrease mitochondrial membrane potential. Environ Health Perspect 123:49–56; http://dx.doi.org/10.1289/ehp.1408642 PMID:25302578

  2. Seasonal variation of water-soluble chemical components in the bulk atmospheric aerosols collected at Okinawa Island, Japan

    NASA Astrophysics Data System (ADS)

    Handa, D.; Nakajima, H.; Nakaema, F.; Arakaki, T.; Tanahara, A.

    2008-12-01

    The economic development and population growth in recent Asia spread air pollution. Emission rate of air pollutants from Asia, in particular oxides of nitrogen, surpassed those from North America and Europe and should continue to exceed them for decades. The study of the air pollution transported from Asian continent has gained a special attention in Japan. Okinawa Island is situated approximately 1500 km south of Tokyo, Japan, 2000 km southeast of Beijing, China, and 1000 km south of South Korea. Its location is ideal in observing East Asian atmospheric aerosols because maritime air mass prevails during summer, while continental air mass dominates during fall, winter, and spring. The maritime air mass data can be seen as background and can be compared with continental air masses which have been affected by anthropogenic activities. In 2005, Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS) was established by the National Institute for Environmental Studies (NIES) at the northern tip of Okinawa Island, Japan to monitor the air quality of Asia. Bulk aerosol samples were collected on quartz filters by using a high volume air sampler. Sampling duration was one week for each sample. We determined the concentrations of water-soluble anions, cations and dissolved organic carbon in the bulk aerosols collected at the CHAAMS, using ion chromatography, atomic absorption spectrometry, and total organic carbon analyzer, respectively. Seasonal variation of water-soluble chemical components showed that the concentrations were relatively low in summer, higher in fall and winter, and the highest in spring. When air mass came from Asian Continent, the concentrations of water-soluble chemical components were much higher compared to the other directions.

  3. Preliminary Results of Detailed Chemical Abundance Analysis of Milky Way Satellite Galaxy Reticulum II Discovered in the Dark Energy Survey

    NASA Astrophysics Data System (ADS)

    Nagasawa, Daniel; Marshall, Jennifer L.; Li, Ting; Dark Energy Survey Milky Way Science Group

    2016-01-01

    We present preliminary results from abundance analysis of stars in Milky Way satellite galaxies found in the Dark Energy Survey (DES). DES has discovered 16 candidate satellite galaxies of the Milky Way in its first two years of operation. Since January 2015, three candidates have subsequently been revealed to be dark matter-dominated by spectroscopic follow-up studies of their kinematics, confirming their status as satellite galaxies. Spectroscopic follow-up of the remaining 13 candidates is underway. We have analyzed high resolution VLT/GIRAFFE spectra of member stars in one of these satellite galaxies, Reticulum II. Using equivalent width measurement and spectral synthesis methods, we measure the abundances of Iron and other species in order to begin to understand the chemical content of these Milky Way satellites.

  4. State-of-the-art of non-hormonal methods of contraception: II. Chemical barrier contraceptives.

    PubMed

    Batár, István

    2010-04-01

    Chemical contraceptives mainly known as spermicides are one of the oldest types of contraceptives. The industrial revolution facilitated new developments, and they became a leading and widespread method. However, their use declined in the second half of the 20th century, and came under focus again only with the upsurge of sexually transmitted infections (STIs). The effectiveness of spermicides depends on the users' compliance and pregnancy rates vary widely: from 6/100 woman-year (with perfect use) to 26/100 woman-year (with typical use). Preparations consist of two components: an excipient (foam, cream, jelly, soluble film, suppository or tablet); and a chemical agent with spermicidal properties (acidic compound, microbicidal agent, detergent). The most widely used active agent has been the surface active (detergent) nonoxynol-9 (N-9). Based on their mode of action (surfactant effect of detergents, enzymatic action of microbicides on cell metabolism) spermicides were thought to provide protection against STIs including HIV. Recent studies have, however, shown that detergents may actually increase the risk. Because of this, there is an urgent need for a suitable non-detergent spermicide, and research should focus on developing new compounds to replace N-9 and other agents having similar undesired effects. This paper reviews the latest studies reporting results on these recent developments. PMID:20055729

  5. Amyloid fibrillation in native and chemically-modified forms of carbonic anhydrase II: role of surface hydrophobicity.

    PubMed

    Es-Haghi, Ali; Shariatizi, Sajad; Ebrahim-Habibi, Azadeh; Nemat-Gorgani, Mohsen

    2012-03-01

    Chemical modification or mutation of proteins may bring about significant changes in the net charge or surface hydrophobicity of a protein structure. Such events may be of major physiological significance and may provide important insights into the genetics of amyloid diseases. In the present study, fibrillation potential of native and chemically-modified forms of bovine carbonic anhydrase II (BCA II) were investigated. Initially, various denaturing conditions including low pH and high temperatures were tested to induce fibrillation. At a low pH of around 2.4, where the protein is totally dissociated, the apo form was found to take up a pre-molten globular (PMG) conformation with the capacity for fibril formation. Upon increasing the pH to around 3.6, a molten globular (MG) form became abundant, forming amorphous aggregates. Charge neutralization and enhancement of hydrophobicity by methylation, acetylation and propionylation of lysine residues appeared very effective in promoting fibrillation of both the apo and holo forms under native conditions, the rates and extents of which were directly proportional to surface hydrophobicity, and influenced by salt concentration and temperature. These modified structures underwent more pronounced fibrillation under native conditions, than the PMG intermediate form, observed under denaturing conditions. The nature of the fibrillation products obtained from intermediate and modified structures were characterized and compared and their possible cytotoxicity determined. Results are discussed in terms of the importance of surface net charge and hydrophobicity in controlling protein aggregation. A discussion on the physiological significance of the observations is also presented. PMID:22251892

  6. Metal-poor dwarf galaxies in the SIGRID galaxy sample. I. H II region observations and chemical abundances

    SciTech Connect

    Nicholls, David C.; Dopita, Michael A.; Sutherland, Ralph S.; Jerjen, Helmut; Kewley, Lisa J.; Basurah, Hassan

    2014-05-10

    In this paper we present the results of observations of 17 H II regions in thirteen galaxies from the SIGRID sample of isolated gas-rich irregular dwarf galaxies. The spectra of all but one of the galaxies exhibit the auroral [O III] 4363 Å line, from which we calculate the electron temperature, T{sub e} , and gas-phase oxygen abundance. Five of the objects are blue compact dwarf galaxies, of which four have not previously been analyzed spectroscopically. We include one unusual galaxy which exhibits no evidence of the [N II] λλ 6548,6584 Å lines, suggesting a particularly low metallicity (< Z {sub ☉}/30). We compare the electron temperature based abundances with those derived using eight of the new strong-line diagnostics presented by Dopita et al. Using a method derived from first principles for calculating total oxygen abundance, we show that the discrepancy between the T{sub e} -based and strong-line gas-phase abundances have now been reduced to within ∼0.07 dex. The chemical abundances are consistent with what is expected from the luminosity-metallicity relation. We derive estimates of the electron densities and find them to be between ∼5 and ∼100 cm{sup –3}. We find no evidence for a nitrogen plateau for objects in this sample with metallicities 0.5 > Z {sub ☉} > 0.15.

  7. A Cu(II)2 Paramagnetic Chemical Exchange Saturation Transfer Contrast Agent Enabled by Magnetic Exchange Coupling.

    PubMed

    Du, Kang; Harris, T David

    2016-06-29

    The ability of magnetic exchange coupling to enable observation of paramagnetic chemical exchange saturation transfer (PARACEST) in transition metal ions with long electronic relaxation times (τs) is demonstrated. Metalation of the dinucleating, tetra(carboxamide) ligand HL with Cu(2+) in the presence of pyrophosphate (P2O7)(4-) affords the complex [LCu(II)2(P2O7)](-). Solution-phase variable-temperature magnetic susceptibility data reveal weak ferromagnetic superexchange coupling between the two S = 1/2 Cu(II) centers, with a coupling constant of J = +2.69(5) cm(-1), to give an S = 1 ground state. This coupling results in a sharpened NMR line width relative to a GaCu analogue, indicative of a shortening of τs. Presaturation of the amide protons in the Cu2 complex at 37 °C leads to a 14% intensity decrease in the bulk water (1)H NMR signal through the CEST effect. Conversely, no CEST effect is observed in the GaCu complex. These results provide the first example of a Cu-based PARACEST magnetic resonance contrast agent and demonstrate the potential to expand the metal ion toolbox for PARACEST agents through introduction of magnetic exchange coupling. PMID:27276533

  8. ANALYSIS OF TWO SMALL MAGELLANIC CLOUD H II REGIONS CONSIDERING THERMAL INHOMOGENEITIES: IMPLICATIONS FOR THE DETERMINATIONS OF EXTRAGALACTIC CHEMICAL ABUNDANCES

    SciTech Connect

    Pena-Guerrero, Maria A.; Peimbert, Antonio; Peimbert, Manuel; Ruiz, Maria Teresa E-mail: antonio@astroscu.unam.mx E-mail: mtruiz@das.uchile.cl

    2012-02-20

    We present long-slit spectrophotometry considering the presence of thermal inhomogeneities (t{sup 2}) of two H II regions in the Small Magellanic Cloud (SMC): NGC 456 and NGC 460. Physical conditions and chemical abundances were determined for three positions in NGC 456 and one position in NGC 460, first under the assumption of uniform temperature and then allowing for the possibility of thermal inhomogeneities. We determined t{sup 2} values based on three different methods: (1) by comparing the temperature derived using oxygen forbidden lines with the temperature derived using helium recombination lines (RLs), (2) by comparing the abundances derived from oxygen forbidden lines with those derived from oxygen RLs, and (3) by comparing the abundances derived from ultraviolet carbon forbidden lines with those derived from optical carbon RLs. The first two methods averaged t{sup 2} = 0.067 {+-} 0.013 for NGC 456 and t{sup 2} = 0.036 {+-} 0.027 for NGC 460. These values of t{sup 2} imply that when gaseous abundances are determined with collisionally excited lines they are underestimated by a factor of nearly two. From these objects and others in the literature, we find that in order to account for thermal inhomogeneities and dust depletion, the O/H ratio in low-metallicity H II regions should be corrected by 0.25-0.45 dex depending on the thermal structure of the nebula or by 0.35 dex if such information is not available.

  9. Combined analysis of chemical bonding in a Cu(II) dimer using QTAIM, Voronoi tessellation and Hirshfeld surface approaches.

    PubMed

    Vologzhanina, Anna V; Kats, Svitlana V; Penkova, Larisa V; Pavlenko, Vadim A; Efimov, Nikolay N; Minin, Vadim V; Eremenko, Igor L

    2015-10-01

    Interaction of 1-(1H-pyrazol-5-yl)ethanone oxime (H2PzOx) with copper(II) chloride in the presence of pyridine afforded a binuclear discrete [Cu2(HPzOx)2Cl2py2] complex, which was characterized by Fourier transform-IR and electron paramagnetic resonance (EPR) spectra, magnetochemistry and high-resolution X-ray diffraction experiments. Multipole refinement of X-ray diffraction data and density-functional theory (DFT) calculations of an isolated molecule allowed charge and spin distributions to be obtained for this compound. Magnetochemistry data, EPR spectra and DFT calculations of an isolated molecule show antiferromagnetic coupling between copper(II) ions. The spin distribution suggests an exchange pathway via the bridging pyrazole ring in the equatorial plane of the CuN4Cl coordination polyhedron, thus providing support for the classical superexchange mechanism; the calculated value of the magnetic coupling constant -2J is equal to 220 cm(-1), which compares well with the experimental value of 203 ± 2 cm(-1). Chemical connectivity was derived by Bader's 'quantum theory of atoms in molecules' and compared with Voronoi tessellation and Hirshfeld surface representations of crystal space. All methodologies gave a similar qualitative and semi-quantitative description of intra- and intermolecular connectivity. PMID:26428404

  10. Chemical evolution in the early phases of massive star formation. II. Deuteration

    NASA Astrophysics Data System (ADS)

    Gerner, T.; Shirley, Y. L.; Beuther, H.; Semenov, D.; Linz, H.; Albertsson, T.; Henning, Th.

    2015-07-01

    The chemical evolution in high-mass star-forming regions is still poorly constrained. Studying the evolution of deuterated molecules allows distinguishing between subsequent stages of high-mass star formation regions based on the strong temperature dependence of deuterium isotopic fractionation. We observed a sample of 59 sources including 19 infrared dark clouds, 20 high-mass protostellar objects, 11 hot molecular cores and 9 ultra-compact Hii regions in the (3-2) transitions of the four deuterated molecules, DCN, DNC, DCO+, and N2D+ as well as their non-deuterated counterparts. The overall detection fraction of DCN, DNC, and DCO+ is high and exceeds 50% for most of the stages. N2D+ was only detected in a few infrared dark clouds and high-mass protostellar objects. This may be related to problems in the bandpass at the transition frequency and to low abundances in the more evolved, warmer stages. We find median D/H ratios of 0.02 for DCN, 0.005 for DNC, 0.0025 for DCO+, and 0.02 for N2D+. While the D/H ratios of DNC, DCO+, and N2D+ decrease with time, DCN/HCN peaks at the hot molecular core stage. We only found weak correlations of the D/H ratios for N2D+ with the luminosity of the central source and the FWHM of the line, and no correlation with the H2 column density. In combination with a previously observed set of 14 other molecules (Paper I), we fitted the calculated column densities with an elaborate 1D physico-chemical model with time-dependent D-chemistry including ortho- and para-H2 states. Good overall fits to the observed data were obtained with the model. This is one of the first times that observations and modeling were combined to derive chemically based best-fit models for the evolution of high-mass star formation including deuteration. Appendix A is available in electronic form at http://www.aanda.org

  11. Multiple chemical sensitivity syndrome: a clinical perspective. II. Evaluation, diagnostic testing, treatment, and social considerations.

    PubMed

    Sparks, P J; Daniell, W; Black, D W; Kipen, H M; Altman, L C; Simon, G E; Terr, A I

    1994-07-01

    Multiple chemical sensitivity syndrome (MCS) does not appear to fit established principles of toxicology. Social, political, and economic forces are demanding that MCS be defined medically, even though scientific studies have failed as yet to identify pathogenic mechanisms for the condition or any objective diagnostic criteria. Consequently, a working definition of MCS can only rely on a person's subjective symptoms of distress and attribution to environmental exposures rather than currently measurable objective evidence of disease. Nevertheless, patients labeled with MCS are clearly distressed and many are functionally disabled. Without reconciling the different theories of etiology of MCS discussed in Part I of this report, and recognizing that the cause of the syndrome may be multifactorial, strategies are proposed for clinical evaluation and management of patients with MCS using a biopsychosocial model of illness. The social implications of this illness are also discussed. PMID:7931737

  12. Spectrophotometric determination of Cu(II) in soil and vegetable samples collected from Abraha Atsbeha, Tigray, Ethiopia using heterocyclic thiosemicarbazone.

    PubMed

    Admasu, Daniel; Reddy, Desam Nagarjuna; Mekonnen, Kebede Nigussie

    2016-01-01

    Two selective and sensitive reagents, 2-acetylpyridine thiosemicarbazone (2-APT) and 3-acetylpyridine thiosemicarbazone (3-APT) were used for the spectrophotometric determination of Cu(II). Both reagents gave yellowish Cu(II) complex at a pH range of 8.0-10.0. Beer's law was obeyed for Cu(II)-2-APT and Cu(II)-3-APT in the concentration range of 0.16-1.3 and 0.44-1.05 µg/mL, respectively. The molar absorptivity and of Cu(II)-2-APT and Cu(II)-3-APT were 2.14 × 10(4) at 370 nm, and 6.7 × 10(3) L/mol cm at 350 nm, respectively, while the Sandell's sensitivity were 0.009 and 0.029 µg/cm(2) in that order. The correlation coefficient of the standard curves of Cu(II)-2-APT and Cu(II)-3-APT were 0.999 and 0.998, respectively. The detection limit of the Cu(II)-2-APT and Cu(II)-3-APT methods were 0.053 and 0.147 µg/mL, respectively. The results demonstrated that the procedure is precise (relative standard deviation <2 %, n = 10). The method was tested for Cu(II) determination in soil and vegetable samples. Comparisons of the results with those obtained using a flame atomic absorption spectrophotometer for Cu(II) determination also tested the validity of the method using paired sample t test at the 0.05 level showing a good agreement between them. PMID:27512628

  13. CHEMICAL PROCESSES IN PROTOPLANETARY DISKS. II. ON THE IMPORTANCE OF PHOTOCHEMISTRY AND X-RAY IONIZATION

    SciTech Connect

    Walsh, Catherine; Millar, T. J.; Nomura, Hideko; Aikawa, Yuri

    2012-03-10

    We investigate the impact of photochemistry and X-ray ionization on the molecular composition of, and ionization fraction in, a protoplanetary disk surrounding a typical T Tauri star. We use a sophisticated physical model, which includes a robust treatment of the radiative transfer of UV and X-ray radiation, and calculate the time-dependent chemical structure using a comprehensive chemical network. In previous work, we approximated the photochemistry and X-ray ionization; here, we recalculate the photoreaction rates using the explicit UV wavelength spectrum and wavelength-dependent reaction cross sections. We recalculate the X-ray ionization rate using our explicit elemental composition and X-ray energy spectrum. We find that photochemistry has a larger influence on the molecular composition than X-ray ionization. Observable molecules sensitive to the photorates include OH, HCO{sup +}, N{sub 2}H{sup +}, H{sub 2}O, CO{sub 2}, and CH{sub 3}OH. The only molecule significantly affected by the X-ray ionization is N{sub 2}H{sup +}, indicating that it is safe to adopt existing approximations of the X-ray ionization rate in typical T Tauri star-disk systems. The recalculation of the photorates increases the abundances of neutral molecules in the outer disk, highlighting the importance of taking into account the shape of the UV spectrum in protoplanetary disks. A recalculation of the photoreaction rates also affects the gas-phase chemistry due to the adjustment of the H/H{sub 2} and C{sup +}/C ratios. The disk ionization fraction is not significantly affected by the methods adopted to calculate the photochemistry and X-ray ionization. We determine that there is a probable 'dead zone' where accretion is suppressed, present in a layer, Z/R {approx}< 0.1-0.2, in the disk midplane, within R Almost-Equal-To 200 AU.

  14. A physical chemical approach to understanding cellular dysfunction in type II diabetes

    NASA Astrophysics Data System (ADS)

    Miranker, Andrew

    2013-03-01

    The conversion of soluble protein into b-sheet rich amyloid fibers is the hallmark of a number of serious diseases. Precursors for many of these systems (e.g. Ab from Alzheimer's disease) reside in close association with a biological membranes. Membrane bilayers are reported to accelerate the rate of amyloid assembly. Furthermore, membrane permeabilization by amyloidogenic peptides can lead to toxicity. Given the b-sheet rich nature of mature amyloid, it is seemingly paradoxical that many precursors are either intrinsically b-helical, or transiently adopt an a-helical state upon association with membrane. We have investigated these phenomena in islet amyloid polypeptide (IAPP). IAPP is a 37-residue peptide hormone which forms amyloid fibers in individuals with type II diabetes. We report here the discovery of an oligomeric species that arises through stochastic nucleation on membranes, and results in disruption of the lipid bilayer. These species are stable, result in all-or-none leakage, and represent a definable protein/lipid phase that equilibrates over time. To characterize the reaction pathway of assembly, we apply an experimental design that includes ensemble and single particle evaluations in vitro and correlate these with quantitative measures of cellular toxicity.

  15. Studies in photochemical smog chemistry. I. Atmospheric chemistry of toluene. II. Analysis of chemical reaction mechanisms for photochemical smog

    SciTech Connect

    Leone, J.A.

    1985-01-01

    This study focuses on two related topics in the gas phase organic chemistry of importance in urban air pollution. Part I describes an experimental and modeling effort aimed at developing a new explicit reaction mechanism for the atmospheric photooxidation of toluene. This mechanism is tested using experimental data from both indoor and outdoor smog chamber facilities. The predictions of the new reaction mechanism are found to be in good agreement with both sets of experimental data. Additional simulations performed with the new mechanism are used to investigate various mechanistic paths, and to gain insight into areas where the understanding is not complete. The outdoor experimental facility, which was built to provide the second set of experimental data, consists of a 65 cubic meter teflon smog chamber together with full instrumentation capable of measuring ozone, nitrogen dioxide, nitric oxide, peroxyacetyl nitrate (PAN), carbon monoxide, relative humidity, temperature, aerosol size distributions, and of course toluene and its photooxidation products. In Part II, a theoretical analysis of lumped chemical reaction mechanisms for photochemical smog is presented. Included is a description of a new counter species analysis technique which can be used to analyze any complex chemical reaction mechanism. Finally, a new lumped mechanism for photochemical smog is developed and tested against experimental data from two smog chamber facilities. Advantages of this mechanism relative to the existing lumped mechanisms are discussed.

  16. Recovery of Cu(II) by chemical reduction using sodium dithionite: effect of pH and ligands.

    PubMed

    Chou, Yi-Hsuan; Yu, Jui-Hsuan; Liang, Yang-Min; Wang, Pin-Jan; Li, Chi-Wang; Chen, Shiao-Shing

    2015-01-01

    Wastewaters containing Cu(II) and ligands are ubiquitous in various industrial sectors, and efficacy of copper removal processes, especially precipitation, is greatly compromised by ligands. Chemical reduction, being commonly employed for production of metal nanoparticles, is also effective for metal removal. Adjustment of pH and addition of ligands are important to control the particle size in metallic nanoparticle production. Exploiting the fact that ligands and metals coexist in many wastewaters, chemical reduction was employed to treat ligand-containing wastewater in this study. The experimental result shows that depending on pH, type of ligands, and copper:ligand molar ratio, copper could be removed by either the reduction or precipitation mechanism. Almost complete copper removal could be achieved by the reduction mechanism under optimal condition for solutions containing either EDTA (ethylenediaminetetraacetic acid) or citrate ligands. For solutions containing ammonia, depending on pH and Cu:ammonia molar ratio, copper was removed by both precipitation and reduction mechanisms. At pH of 9.0, formation of nano-sized particles, which readily pass through a 0.45 μm filter used for sample pretreatment before residual copper analysis, results in the lowest copper removal efficiency. Both cuprous oxide and metallic copper are identified in the solids produced, and the possible explanations are provided. PMID:26606104

  17. Modeling of chemical interactions of fuel rod materials at high temperatures II. Investigation of downward relocation of molten materials

    NASA Astrophysics Data System (ADS)

    Veshchunov, M. S.; Palagin, A. V.

    1998-01-01

    In Part II of the modeling of chemical interactions of fuel rod materials at high temperatures, qualitative results on the nature of Zr-rich melt oxidation and interactions with fuel rods allow further interpretation of the post-test examinations of structures (debris) formed in the CORA tests under more complicated conditions, namely during downward relocation of the melt. In this situation, the molten mass extensively oxidizes and simultaneously dissolves UO 2 pellets and ZrO 2 scales of the cladding. The analysis of these simultaneous physico-chemical processes on the basis of the kinetic oxidation/dissolution model developed in Part I of the paper, allows a new interpretation and explanation of the CORA tests results concerning relocation dynamics of the major part of the melt (slow relocation of melt in the form of massive slug rather than quick relocations of droplets and rivulets), formation of local blockages (debris) in the interrod space and accumulation of the melt in the core region in the form of molten pool.

  18. Quantum chemical topology study of the water-platinum(II) interaction.

    PubMed

    Bergès, Jacqueline; Fourré, Isabelle; Pilmé, Julien; Kozelka, Jiri

    2013-02-01

    The "inverse hydration" of neutral complexes of Pt(II) by an axial water molecule, whose one OH-bond is oriented toward Pt, has been the subject of recent works, theoretical as well as experimental. To study the influence of the ligands on this non-conventional H-bond, we extend here our previous energy calculations, using the second-order Moeller-Plesset perturbation theory (MP2) method together with the Dolg-Pélissier pseudopotential for platinum, to various neutral complexes including the well-known chemotherapeutic agent "cisplatin". The stabilization energy, depending on the nature and the configuration of platinum ligands, is dominated by the same important dispersive component, for all the investigated complexes. For a further characterization of this particular H-bond, we used the atoms in molecules theory (AIM) and the topological analysis of the electron localization function (ELF). The charge transfer occurring from the complex to the water molecule and the Laplacian of the density at the bond critical point between water and Pt are identified as interesting AIM descriptors of this non-conventional H-bond. Beyond this AIM analysis, we show that the polarization of the ELF bonding O-H basin involved in the non-conventional H-bond is enhanced during the approach of the water molecule to the Pt complexes. When the water medium, treated in an implicit solvation model, is taken into account, the interaction energies become independent on the nature and configuration of platinum ligands. However, the topological descriptors remain qualitatively unchanged. PMID:23347164

  19. The Dual Origin of Stellar Halos. II. Chemical Abundances as Tracers of Formation History

    NASA Astrophysics Data System (ADS)

    Zolotov, Adi; Willman, Beth; Brooks, Alyson M.; Governato, Fabio; Hogg, David W.; Shen, Sijing; Wadsley, James

    2010-09-01

    Fully cosmological, high-resolution N-body+smooth particle hydrodynamic simulations are used to investigate the chemical abundance trends of stars in simulated stellar halos as a function of their origin. These simulations employ a physically motivated supernova feedback recipe, as well as metal enrichment, metal cooling, and metal diffusion. As presented in an earlier paper, the simulated galaxies in this study are surrounded by stellar halos whose inner regions contain both stars accreted from satellite galaxies and stars formed in situ in the central regions of the main galaxies and later displaced by mergers into their inner halos. The abundance patterns ([Fe/H] and [O/Fe]) of halo stars located within 10 kpc of a solar-like observer are analyzed. We find that for galaxies which have not experienced a recent major merger, in situ stars at the high [Fe/H] end of the metallicity distribution function are more [α/Fe]-rich than accreted stars at similar [Fe/H]. This dichotomy in the [O/Fe] of halo stars at a given [Fe/H] results from the different potential wells within which in situ and accreted halo stars form. These results qualitatively match recent observations of local Milky Way halo stars. It may thus be possible for observers to uncover the relative contribution of different physical processes to the formation of stellar halos by observing such trends in the halo populations of the Milky Way and other local Lsstarf galaxies.

  20. Features in chemical kinetics. II. A self-emerging definition of slow manifolds.

    PubMed

    Nicolini, Paolo; Frezzato, Diego

    2013-06-21

    In the preceding paper of this series (Part I [P. Nicolini and D. Frezzato, J. Chem. Phys. 138, 234101 (2013)]) we have unveiled some ubiquitous features encoded in the systems of polynomial differential equations normally applied in the description of homogeneous and isothermal chemical kinetics (mass-action law). Here we proceed by investigating a deeply related feature: the appearance of so-called slow manifolds (SMs) which are low-dimensional hyper-surfaces in the neighborhood of which the slow evolution of the reacting system occurs after an initial fast transient. Indeed a geometrical definition of SM, devoid of subjectivity, "naturally" follows in terms of a specific sub-dimensional domain embedded in the peculiar region of the concentrations phase-space that in Part I we termed as "attractiveness region." Numerical inspections on simple low-dimensional model cases are presented, including the benchmark case of Davis and Skodje [J. Chem. Phys. 111, 859 (1999)] and the preliminary analysis of a simplified model mechanism of hydrogen combustion. PMID:23802946

  1. Review of Catalytic Hydrogen Generation in the DWPF Chemical Processing Cell, Part II

    SciTech Connect

    Koopman, David C.; Lambert, Daniel P.; Baich, Mark A.

    2005-08-01

    The Savannah River National Laboratory is in the process of investigating factors suspected of impacting catalytic hydrogen generation in the Defense Waste Processing Facility, DWPF, Chemical Process Cell, CPC. Noble metal catalyzed hydrogen generation in simulation work constrains the allowable acid addition operating window in DWPF. This constraint potentially impacts washing strategies during sludge batch preparation. It can also influence decisions related to the addition of secondary waste streams to a sludge batch. Catalytic hydrogen generation data from 2002-2005 were reviewed. The data came from process simulations of the DWPF Sludge Receipt and Adjustment Tank, SRAT, and Slurry Mix Evaporator, SME. Most of the data was from the development work for the Sludge Batch 3 process flowsheet. This included simulant and radioactive waste testing. Preliminary Sludge Batch 4 data were also reviewed. A statistical analysis of SB3 simulant hydrogen generation data was performed. One factor considered in the statistical analysis was excess acid. Excess acid was determined experimentally as the acid added beyond that required to achieve satisfactory nitrite destruction.

  2. THE DUAL ORIGIN OF STELLAR HALOS. II. CHEMICAL ABUNDANCES AS TRACERS OF FORMATION HISTORY

    SciTech Connect

    Zolotov, Adi; Hogg, David W.; Willman, Beth; Brooks, Alyson M.; Shen, Sijing; Wadsley, James E-mail: bwillman@haverford.ed

    2010-09-20

    Fully cosmological, high-resolution N-body+smooth particle hydrodynamic simulations are used to investigate the chemical abundance trends of stars in simulated stellar halos as a function of their origin. These simulations employ a physically motivated supernova feedback recipe, as well as metal enrichment, metal cooling, and metal diffusion. As presented in an earlier paper, the simulated galaxies in this study are surrounded by stellar halos whose inner regions contain both stars accreted from satellite galaxies and stars formed in situ in the central regions of the main galaxies and later displaced by mergers into their inner halos. The abundance patterns ([Fe/H] and [O/Fe]) of halo stars located within 10 kpc of a solar-like observer are analyzed. We find that for galaxies which have not experienced a recent major merger, in situ stars at the high [Fe/H] end of the metallicity distribution function are more [{alpha}/Fe]-rich than accreted stars at similar [Fe/H]. This dichotomy in the [O/Fe] of halo stars at a given [Fe/H] results from the different potential wells within which in situ and accreted halo stars form. These results qualitatively match recent observations of local Milky Way halo stars. It may thus be possible for observers to uncover the relative contribution of different physical processes to the formation of stellar halos by observing such trends in the halo populations of the Milky Way and other local L{sup *} galaxies.

  3. Template synthesis and physico-chemical characterization of 14-membered tetraimine macrocyclic complexes, [MLX 2] [M = Co(II), Ni(II), Cu(II) and Zn(II)]. DNA binding study on [CoLCl 2] complex

    NASA Astrophysics Data System (ADS)

    Firdaus, Farha; Fatma, Kaneez; Azam, Mohammad; Khan, Shahper N.; Khan, Asad U.; Shakir, Mohammad

    2009-04-01

    The template condensation reaction between glyoxal and 1,8-diaminonaphthalene resulted a few novel mononuclear 14-membered tetraimine macrocyclic complexes of the type, [MLX 2] [M = Co(II), Ni(II), Cu(II) and Zn(II), for X = Cl or NO 3]. The stoichiometry and the nature of the complexes have been deduced from the results of elemental analyses and conductance data. The formation of macrocyclic framework has been inferred from the appearance of imine υ(C dbnd N) and υ(M sbnd N) band in IR spectra and the resonance signals observed in 1H and 13C-NMR spectra. However, the overall geometry of the complexes has been assigned on the positions of bands in electronic spectra and magnetic moment data. The distortion in Cu(II) complexes has been deduced on EPR data. The thermal behavior of these complexes has been studied by TGA analysis. Absorption and circular dichroism studies on the complex proved a significant binding to calf thymus DNA.

  4. The Chemical Properties of Milky Way and M31 Globular Clusters. II. Stellar Population Model Predictions

    NASA Astrophysics Data System (ADS)

    Beasley, Michael A.; Brodie, Jean P.; Strader, Jay; Forbes, Duncan A.; Proctor, Robert N.; Barmby, Pauline; Huchra, John P.

    2005-03-01

    We derive ages, metallicities, and abundance ratios ([α/Fe]) from the integrated spectra of 23 globular clusters in M31 by employing multivariate fits to two different stellar population models. We also perform a parallel analysis on 21 Galactic globular clusters as a consistency check and in order to facilitate a differential analysis. Our analysis shows that the M31 globular clusters separate into three distinct components in age and metallicity; we identify an old, metal-poor group (seven clusters), an old, metal-rich group (10 clusters), and an intermediate-age (3-6 Gyr), intermediate-metallicity ([Z/H]~-1) group (six clusters). This third group is not identified in the Galactic globular cluster sample. We also see evidence that the old, metal-rich Galactic globular clusters are 1-2 Gyr older than their counterparts in M31. The majority of globular clusters in both samples appear to be enhanced in α-elements, but the degree of enhancement is rather model-dependent. The intermediate-age globular clusters appear to be the most enhanced, with [α/Fe]~0.4. These clusters are clearly depressed in CN with respect to the models and the bulk of the M31 and Milky Way sample. Compared with the bulge of M31, M32, and NGC 205, these clusters most resemble the stellar populations in NGC 205 in terms of age, metallicity, and CN abundance. We infer horizontal branch morphologies for the M31 clusters using the Rose Ca II index and demonstrate that blue horizontal branches are not leading to erroneous age estimates in our analysis. We discuss and reject as unlikely the hypothesis that these objects are in fact foreground stars contaminating the optical catalogs. The intermediate-age clusters have generally higher velocities than the bulk of the M31 cluster population. Spatially, three of these clusters are projected onto the bulge region, and the remaining three are distributed at large radii. We discuss these objects within the context of the build-up of the M31 halo and

  5. Chemical and toxicological characterization of residential oil burner emissions: II. Mutagenic, tumorigenic, and potential teratogenic activity.

    PubMed Central

    Braun, A G; Busby, W F; Liber, H L; Thilly, W G

    1987-01-01

    Extracts of effluents from a modern residential oil burner have been evaluated in several toxicological assay systems. Bacterial mutagens were detected in extracts from both the particulate and vapor phase emissions. Effluents from continuous operation were an order of magnitude less mutagenic than those from cyclic (5 min on, 10 min off) operations. No difference in the yield of bacterial mutagens per gram of fuel burned was found between cyclic operation under low and moderate sooting conditions. On the basis of elution behavior from alumina it appeared that the bacterial mutagens collected from high sooting effluents were more polar than those from low sooting effluent. An extract that was mutagenic in bacteria did not induce a significant increase in mutation frequency to human lymphoblasts. No evidence of tumorigenicity was observed in a limited number of newborn mice after IP injection of effluent extract when compared to historical control data. Putative nonmutagenic teratogens were detected in effluent using an attachment inhibition assay. The level of these agents was reduced in effluents from continuous oil burner operation. PMID:3665866

  6. CSO and CARMA Observations of L1157. II. Chemical Complexity in the Shocked Outflow

    NASA Astrophysics Data System (ADS)

    Burkhardt, Andrew M.; Dollhopf, Niklaus M.; Corby, Joanna F.; Carroll, P. Brandon; Shingledecker, Christopher N.; Loomis, Ryan A.; Booth, Shawn Thomas; Blake, Geoffrey A.; Herbst, Eric; Remijan, Anthony J.; McGuire, Brett A.

    2016-08-01

    L1157, a molecular dark cloud with an embedded Class 0 protostar possessing a bipolar outflow, is an excellent source for studying shock chemistry, including grain-surface chemistry prior to shocks, and post-shock, gas-phase processing. The L1157-B1 and B2 positions experienced shocks at an estimated ∼2000 and 4000 years ago, respectively. Prior to these shock events, temperatures were too low for most complex organic molecules to undergo thermal desorption. Thus, the shocks should have liberated these molecules from the ice grain-surfaces en masse, evidenced by prior observations of SiO and multiple grain mantle species commonly associated with shocks. Grain species, such as OCS, CH3OH, and HNCO, all peak at different positions relative to species that are preferably formed in higher-velocity shocks or repeatedly shocked material, such as SiO and HCN. Here, we present high spatial resolution (∼3″) maps of CH3OH, HNCO, HCN, and HCO+ in the southern portion of the outflow containing B1 and B2, as observed with Combined Array for Research in Millimeter-Wave Astronomy. The HNCO maps are the first interferometric observations of this species in L1157. The maps show distinct differences in the chemistry within the various shocked regions in L1157B. This is further supported through constraints of the molecular abundances using the non-LTE code radex. We find that the east/west chemical differentiation in C2 may be explained by the contrast of the shock’s interaction with either cold, pristine material or warm, previously shocked gas, as seen in enhanced HCN abundances. In addition, the enhancement of the HNCO abundance toward the the older shock, B2, suggests the importance of high-temperature O-chemistry in shocked regions.

  7. CSO and CARMA Observations of L1157. II. Chemical Complexity in the Shocked Outflow

    NASA Astrophysics Data System (ADS)

    Burkhardt, Andrew M.; Dollhopf, Niklaus M.; Corby, Joanna F.; Carroll, P. Brandon; Shingledecker, Christopher N.; Loomis, Ryan A.; Booth, Shawn Thomas; Blake, Geoffrey A.; Herbst, Eric; Remijan, Anthony J.; McGuire, Brett A.

    2016-08-01

    L1157, a molecular dark cloud with an embedded Class 0 protostar possessing a bipolar outflow, is an excellent source for studying shock chemistry, including grain-surface chemistry prior to shocks, and post-shock, gas-phase processing. The L1157-B1 and B2 positions experienced shocks at an estimated ˜2000 and 4000 years ago, respectively. Prior to these shock events, temperatures were too low for most complex organic molecules to undergo thermal desorption. Thus, the shocks should have liberated these molecules from the ice grain-surfaces en masse, evidenced by prior observations of SiO and multiple grain mantle species commonly associated with shocks. Grain species, such as OCS, CH3OH, and HNCO, all peak at different positions relative to species that are preferably formed in higher-velocity shocks or repeatedly shocked material, such as SiO and HCN. Here, we present high spatial resolution (˜3″) maps of CH3OH, HNCO, HCN, and HCO+ in the southern portion of the outflow containing B1 and B2, as observed with Combined Array for Research in Millimeter-Wave Astronomy. The HNCO maps are the first interferometric observations of this species in L1157. The maps show distinct differences in the chemistry within the various shocked regions in L1157B. This is further supported through constraints of the molecular abundances using the non-LTE code radex. We find that the east/west chemical differentiation in C2 may be explained by the contrast of the shock’s interaction with either cold, pristine material or warm, previously shocked gas, as seen in enhanced HCN abundances. In addition, the enhancement of the HNCO abundance toward the the older shock, B2, suggests the importance of high-temperature O-chemistry in shocked regions.

  8. Contact of clay-liner materials with acidic tailings. II. Chemical modeling

    SciTech Connect

    Peterson, S.R.; Krupka, K.M.

    1981-09-01

    The ion speciation-solubility model WATEQ3 was used to model original aqueous solutions and solutions resulting from liner materials contacted with uranium mill tailings, synthetic mill tailings or H/sub 2/SO/sub 4/. The modeling results indicate solution species which are in apparent equilibrium with respect to particular solids. These solids provide potential solubility controls for their corresponding dissolved constituents. The disequilibrium indices computed by WATEQ3 indicate amorphic Fe(OH)/sub 3/(A), Al0HO/sub 4/, alunite (KA1/sub 3/(SO/sub 4/)/sub 2/(OH)/sub 6/), gypsum (CaSO/sub 4/ . 2H/sub 2/O), celestite (SrSO/sub 4/), anglesite (PbSO/sub 4/) and MnHPO/sub 4/ may have precipitated in the contacted liner materials and may also provide solubility controls for their dissolved constituents. The disequilibrium indices also show that the solutions resulting from the interaction of Highland Mill tailings are oversaturated with K-, H-, and Na-jarosites ((K,H,Na)Fe/sub 3/(SO/sub 4/)/sub 2/(OH)/sub 6/). Because jarosite has been identified by x-ray diffraction as a precipitate in these reacted liner materials, it would appear that there is a kinetic barrier which prohibits jarosite from being an effective solubility control. Results of this study also show that the solubilities of many solid phases were pH dependent. This exploratory use of geochemical modeling has demonstrated its capability to test solubility hypotheses for clay liners reacted with tailings solutions and to guide the analyses of important constituents and parameters for these solutions. Geochemical modeling can be used, in parallel with characterization techniques for the solid phases, to support the presence of the solid phase and to guide the search for further solid phases. Geochemical modeling is also an effective tool in delineating the chemical causes for changes in permeability of liner materials.

  9. A multimedia fate and chemical transport modeling system for pesticides: II. Model evaluation

    NASA Astrophysics Data System (ADS)

    Li, Rong; Scholtz, M. Trevor; Yang, Fuquan; Sloan, James J.

    2011-07-01

    Pesticides have adverse health effects and can be transported over long distances to contaminate sensitive ecosystems. To address problems caused by environmental pesticides we developed a multimedia multi-pollutant modeling system, and here we present an evaluation of the model by comparing modeled results against measurements. The modeled toxaphene air concentrations for two sites, in Louisiana (LA) and Michigan (MI), are in good agreement with measurements (average concentrations agree to within a factor of 2). Because the residue inventory showed no soil residues at these two sites, resulting in no emissions, the concentrations must be caused by transport; the good agreement between the modeled and measured concentrations suggests that the model simulates atmospheric transport accurately. Compared to the LA and MI sites, the measured air concentrations at two other sites having toxaphene soil residues leading to emissions, in Indiana and Arkansas, showed more pronounced seasonal variability (higher in warmer months); this pattern was also captured by the model. The model-predicted toxaphene concentration fraction on particles (0.5-5%) agrees well with measurement-based estimates (3% or 6%). There is also good agreement between modeled and measured dry (1:1) and wet (within a factor of less than 2) depositions in Lake Ontario. Additionally this study identified erroneous soil residue data around a site in Texas in a published US toxaphene residue inventory, which led to very low modeled air concentrations at this site. Except for the erroneous soil residue data around this site, the good agreement between the modeled and observed results implies that both the US and Mexican toxaphene soil residue inventories are reasonably good. This agreement also suggests that the modeling system is capable of simulating the important physical and chemical processes in the multimedia compartments.

  10. Aerosol characterisation at the FEBUKO upwind station Goldlauter (II): Detailed organic chemical characterisation

    NASA Astrophysics Data System (ADS)

    Müller, K.; van Pinxteren, D.; Plewka, A.; Svrcina, B.; Kramberger, H.; Hofmann, D.; Bächmann, K.; Herrmann, H.

    An extensive set of gaseous and particulate organic compounds was quantified before an orographic cloud passage at the upwind site of the research region in Thüringer Wald. Samples were collected with two different time resolutions, 2 h for gaseous species and spray absorber samples and the whole cloud event duration to determine the concentrations of ketones, aldehydes, monocarboxylic acids, dicarboxylic acids (DCA), hydrocarbons, biogenic sugars and alcohols in both the gas and particle phase. The measurement of different groups of organic compounds delivered size-segregated concentrations at the upwind site of a cloud experiment. The size distribution of DCA showed a peak in the mass-rich impactor stage 3 (0.42-1.2 μm). The concentrations of DCA from the filters, the impactor foils as well as the spray absorber samples decreased with increasing C-number. The time resolved measurements revealed an increasing mixing ratio from night time to midday for carboxylic and DCA, and related carbonyl compounds. The biogenic compounds xylitol (up to 103 ng m -3), levoglucosan (up to 62 ng m -3) and pinonaldehyde (up to 34 ng m -3) were the compounds found in highest concentrations in the particle phase beside the oxalate (up to 104 ng m -3). The organic trace gases with the highest mixing ratios identified were formaldehyde (up to 1.47 ppbv), acetaldehyde (up to 0.84 ppbv) and acetone (up to 0.65 ppbv), acetic acid (up to 0.43 ppbv) and formic acid (up to 0.41 ppbv).

  11. The influence of chemical composition on the properties of Cepheid stars. II. The iron content

    NASA Astrophysics Data System (ADS)

    Romaniello, M.; Primas, F.; Mottini, M.; Pedicelli, S.; Lemasle, B.; Bono, G.; François, P.; Groenewegen, M. A. T.; Laney, C. D.

    2008-09-01

    Context: The Cepheid period-luminosity (PL) relation is unquestionably one of the most powerful tools at our disposal for determining the extragalactic distance scale. While significant progress has been made in the past few years towards its understanding and characterization both on the observational and theoretical sides, the debate on the influence that chemical composition may have on the PL relation is still unsettled. Aims: With the aim to assess the influence of the stellar iron content on the PL relation in the V and K bands, we have related the V-band and the K-band residuals from the standard PL relations of Freedman et al. (2001, ApJ, 553, 47) and Persson et al. (2004, AJ, 128, 2239), respectively, to [Fe/H]. Methods: We used direct measurements of the iron abundances of 68 Galactic and Magellanic Cepheids from FEROS and UVES high-resolution and high signal-to-noise spectra. Results: We find a mean iron abundance ([Fe/H]) about solar (σ = 0.10) for our Galactic sample (32 stars), ~-0.33 dex (σ = 0.13) for the Large Magellanic Cloud (LMC) sample (22 stars) and ~-0.75 dex (σ = 0.08) for the Small Magellanic Cloud (SMC) sample (14 stars). Our abundance measurements of the Magellanic Cepheids double the number of stars studied up to now at high resolution. The metallicity affects the V-band Cepheid PL relation and metal-rich Cepheids appear to be systematically fainter than metal-poor ones. These findings depend neither on the adopted distance scale for Galactic Cepheids nor on the adopted LMC distance modulus. Current data do not allow us to reach a firm conclusion concerning the metallicity dependence of the K-band PL relation. The new Galactic distances indicate a small effect, whereas the old ones support a marginal effect. Conclusions: Recent robust estimates of the LMC distance and current results indicate that the Cepheid PL relation is not Universal. Based on observations made with ESO Telescopes at Paranal and La Silla Observatories under

  12. Program for monitoring the chemical quality of ground water in Utah - Summary of data collected through 1984

    SciTech Connect

    Price, D.; Arnow, T.

    1986-01-01

    The US Geological Survey formally started a program for monitoring groundwater quality in Utah during 1957 in cooperation with the Utah Geological Survey. The monitoring program was initiated to detect any changes in chemical quality that might be associated with the withdrawal of water from wells. Dissolved-solids concentrations in water samples collected from the observation wells through 1984 ranged from 92 to 19,000 mg/L. An observation well in the Uinta Basin yielded the sample with the smallest dissolved solids concentration, and another well in the Uinta Basin yielded the sample with the largest dissolved solids concentration. There was a progressive increase in salinity of water produced by several of the observation wells in Pahvant Valley and in the Milford and Beryl-Enterprise areas. Water quality changes related either to groundwater withdrawals or groundwater recharge also were detected in several other areas. Water produced from wells in Goshen Valley and the upper Fremont River valley had short term increases in chloride, sulfate, and dissolved solids concentrations, indicating possible local contamination of the groundwater. Also, since the late 1950's, dissolved solids concentrations have increased in water produced by a well completed in the principal aquifer in Salt Lake Valley downgradient from areas where extensive use has been made of road salt. 40 refs., 38 figs., 38 tabs.

  13. Chemical analyses of coal, coal-associated rocks and coal combustion products collected for the National Coal Quality Inventory

    USGS Publications Warehouse

    Hatch, Joseph R.; Bullock, John H., Jr.; Finkelman, Robert B.

    2006-01-01

    In 1999, the USGS initiated the National Coal Quality Inventory (NaCQI) project to address a need for quality information on coals that will be mined during the next 20-30 years. At the time this project was initiated, the publicly available USGS coal quality data was based on samples primarily collected and analyzed between 1973 and 1985. The primary objective of NaCQI was to create a database containing comprehensive, accurate and accessible chemical information on the quality of mined and prepared United States coals and their combustion byproducts. This objective was to be accomplished through maintaining the existing publicly available coal quality database, expanding the database through the acquisition of new samples from priority areas, and analysis of the samples using updated coal analytical chemistry procedures. Priorities for sampling include those areas where future sources of compliance coal are federally owned. This project was a cooperative effort between the U.S. Geological Survey (USGS), State geological surveys, universities, coal burning utilities, and the coal mining industry. Funding support came from the Electric Power Research Institute (EPRI) and the U.S. Department of Energy (DOE).

  14. Biological and chemical detection of fumonisins produced on agar medium by Fusarium verticillioides isolates collected from corn in Sohag, Egypt.

    PubMed

    Aboul-Nasr, M B; Obied-Allah, M R A

    2013-08-01

    Fusarium verticillioides (Sacc.) Nirenberg is among the most common Fusarium species corn pathogens worldwide, and has been recognized as a fumonisin B1 (FB1) and fumonisin B2 (FB2) producer. In the present work, extracts of 58 F. verticillioides isolates from corn samples collected from Sohag Governorate, Egypt, were tested for their biotoxicity and production of fumonisin toxins. Forty-four Fusarium verticillioides isolates out of 58 tested produced FB1 or FB1 and FB2 (15 and 29 isolates, respectively) on potato-sucrose agar medium, detected by TLC, whereas the other 14 isolates did not produce fumonisin toxins. HPLC crude extract analysis confirmed the results from TLC plates. Brine shrimp larvae as well as the Gram-negative bacteria Pseudomonas aeuroginosa showed low bio-sensitivity towards the F. verticillioides crude extract toxicity, whereas the Gram-positive bacteria Bacillus cereus and Bacillus subtilis, especially B. subtilis, showed higher sensitivity towards the tested Fusarium crude extracts. These results enabled us to bio-evaluate and chemically detect fumonisin mycotoxins using a simple agar medium technique. PMID:23760819

  15. Spectropolarimetric measurements of the mean longitudinal magnetic field of chemically peculiar stars. II. Phase relating the magnetic and luminosity variabilities

    NASA Astrophysics Data System (ADS)

    Leone, F.; Catanzaro, G.

    2001-01-01

    For a sample of chemically peculiar stars, we report time-resolved measurements of the effective magnetic field which were obtained with the spectropolarimetry operating at the Catania Astrophysical Observatory. These observations are combined with data from the literature for better pointing out that periodic magnetic variability which characterises this class of stars. Periods given in the literature have been checked and, if possible, re-determined, not only by means of the magnetic measurements but referring also to the Hipparcos photometry. The variability of the effective magnetic field of the already known magnetic star 25 Sex is pointed out for the first time. As to the suspected magnetic chemically peculiar star EP UMa, our measurements confirm that this is really a magnetic star and we indicate a possible variability period. The accuracy of the variability period for CS Vir and FF Vir is improved. The suggestion that light variability is due to the re-distribution of ultraviolet flux towards the visible wavelengths in metal rich regions, which are not homogeneously distributed on the stellar surface, appears not always and straightly valid. Local line-blocking is certainly important in the case of CS Vir and a direct influence of the magnetic field on the infrared photometric variability cannot be ruled out for 25 Sex. Based on observations collected at the Catania Astrophysical Observatory, Italy.

  16. Photochemical Formation of Fe(II) and Peroxides in Coastal Seawater Collected around Okinawa Island, Japan - Impact of Red Soil Pollution

    NASA Astrophysics Data System (ADS)

    Okada, K.; Nakajima, H.; Higuchi, T.; Fujimura, H.; Arakaki, T.; Taira, H.

    2003-12-01

    In a study to elucidate the impacts of red soil pollution on the oxidizing power of seawater, photochemical formation of Fe(II) and peroxides was studied in seawaters collected around Okinawa Island, Japan. The northern part of Okinawa Island suffers from red soil pollution which is caused mainly by land development such as pineapple farming and the construction of recreational facilities. We studied photochemical formation of peroxides and Fe(II) in the same seawater samples because the reaction between HOOH and Fe(II) forms hydroxyl radical (OH radical), the most potent environmental oxidant. Photochemical formation of Fe(II) was fast and reached steady-state in 30 minutes of simulated sunlight illumination and the steady-state Fe(II) concentrations were about 80% of total iron concentrations. Photochemical formation of peroxides was relatively slow and formation kinetics varied, depending on the initial peroxide concentrations. Because photochemical formation of peroxides was faster and total iron concentrations in the red soil polluted seawater were higher, red soil polluted seawater is expected to have greater oxidizing power than seawater that is not polluted with red soil.

  17. Chemical Equilibrium Models for the S3 State of the Oxygen-Evolving Complex of Photosystem II.

    PubMed

    Isobe, Hiroshi; Shoji, Mitsuo; Shen, Jian-Ren; Yamaguchi, Kizashi

    2016-01-19

    We have performed hybrid density functional theory (DFT) calculations to investigate how chemical equilibria can be described in the S3 state of the oxygen-evolving complex in photosystem II. For a chosen 340-atom model, 1 stable and 11 metastable intermediates have been identified within the range of 13 kcal mol(-1) that differ in protonation, charge, spin, and conformational states. The results imply that reversible interconversion of these intermediates gives rise to dynamic equilibria that involve processes with relocations of protons and electrons residing in the Mn4CaO5 cluster, as well as bound water ligands, with concomitant large changes in the cluster geometry. Such proton tautomerism and redox isomerism are responsible for reversible activation/deactivation processes of substrate oxygen species, through which Mn-O and O-O bonds are transiently ruptured and formed. These results may allow for a tentative interpretation of kinetic data on substrate water exchange on the order of seconds at room temperature, as measured by time-resolved mass spectrometry. The reliability of the hybrid DFT method for the multielectron redox reaction in such an intricate system is also addressed. PMID:26717045

  18. Correlating chemical changes in subchondral bone mineral due to aging or defective type II collagen by Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Dehring, Karen A.; Roessler, Blake J.; Morris, Michael D.

    2007-02-01

    We show that early indicators of osteoarthritis are observed in Raman spectroscopy by probing femur surfaces excised from mouse models of early-onset osteoarthritis. Current clinical methods to examine arthritic joints include radiological examination of the joint, but may not be capable of detecting subtle chemical changes in the bone tissue, which may provide the earliest indications of osteoarthritis. Recent research has indicated that the subchondral bone may have a more significant role in the onset of osteoarthritis than previously realized. We will report the effect of age and defective type II collagen on Raman band area ratios used to describe bone structure and function. The carbonate-to-phosphate ratio is used to assess carbonate substitution into the bone mineral and the mineral-to-matrix ratio is used to measure bone mineralization. Mineral-to-matrix ratios indicate that subchondral bone becomes less mineralized as both the wild-type and Del1 (+/-) transgenic mice age. Moreover, the mineral-to-matrix ratios show that the subchondral bone of Del1 (+/-) transgenic mice is less mineralized than that of the wild-type mice. Carbonate-to-phosphate ratios from Del1 (+/-) transgenic mice follow the same longitudinal trend as wild-type mice. The ratio is slightly higher in the transgenic mice, indicating more carbonate content in the bone mineral. Raman characterization of bone mineralization provides an invaluable insight into the process of cartilage degeneration and the relationship with subchondral bone at the ultrastructural level.

  19. Chemically tailoring coal to fluorescent carbon dots with tuned size and their capacity for Cu(II) detection.

    PubMed

    Hu, Chao; Yu, Chang; Li, Mingyu; Wang, Xiuna; Yang, Junyu; Zhao, Zongbin; Eychmüller, Alexander; Sun, Y-P; Qiu, Jieshan

    2014-12-10

    The desired control of size, structure, and optical properties of fluorescent carbon dots (CDs) is critical for understanding the fluorescence mechanism and exploring their potential application. Herein, a top-down strategy to chemically tailor the inexpensive coal to fluorescent CDs by a combined method of carbonization and acidic oxidation etching is reported. The size and optical properties of the as-made CDs are tuned by controlling the structures of graphitic crystallites in the starting precursor. The coal-derived CDs exhibit two different distinctive emission modes, where the intensity of the short-wavelength emission is significantly enhanced by partial reduction treatment. The evolution of the electronic structure and the surface states analysis show that two different types of fluorescence centers, nano-sized sp(2) carbon domains and surface defects, are responsible for the observed emission characteristics. The reduced CDs are demonstrated as an effective fluorescent sensing material for label-free and selective detection of Cu(II) ions with a detection limit as low as 2.0 nM, showing a great promise for real-world sensor applications. PMID:25048718

  20. The physico-chemical characteristics of the phosphocholine-containing glycoglycerolipid MfGL-II govern the permeability properties of Mycoplasma fermentans.

    PubMed

    Ben-Menachem, G; Byström, T; Rechnitzer, H; Rottem, S; Rilfors, L; Lindblom, G

    2001-07-01

    Mycoplasma fermentans seems to be involved in several pathogenic conditions in humans, and is among other things capable of fusing with T-cells and lymphocytes. The choline-containing phosphoglycolipid 6'-O-(3"-phosphocholine-2"-amino-1"-phospho-1",3"-propanediol)-alpha-D-glucopyranosyl-(1'-->3)-1,2-diacylglycerol (MfGL-II) in the membrane of M. fermentans has been suggested to enhance the fusion process, and the characteristics of MfGL-II were therefore investigated. When a cell culture ages the fraction of MfGL-II increases, and the fraction of the other major membrane lipid, phosphatidylglycerol (PtdGro), decreases concomitantly. Swelling experiments showed that the permeability and osmotic fragility are markedly reduced in aged cells. MfGL-II is selectively released into the surrounding medium when aged M. fermentans cells are incubated in buffer containing EDTA. The physico-chemical properties of MfGL-II were studied by NMR spectroscopy and differential scanning calorimetry, and they can explain the biochemical results. The temperature for the transition between gel and lamellar liquid crystalline (Lalpha) phases is 35-45 degrees C higher for MfGL-II than for PtdGro, which most probably gives rise to the reduced permeability in aged cells. At high water contents MfGL-II forms an Lalpha phase and isotropic aggregates which were interpreted to be vesicles with a radius of approximately 450 A. It is proposed that MfGL-II forms vesicles in the surrounding medium when it is released from the cell membrane. Neither EDTA nor Ca2+ ions have a significant influence on the aggregate structures formed by MfGL-II. Our results indicate that MfGL-II has no fusogenic properties. It is more probable that a recently identified lysolipid in the M. fermentans membrane acts as a fusogen. PMID:11432735

  1. Chemical analysis of refractory stratospheric aerosol particles collected within the arctic vortex and inside polar stratospheric clouds

    NASA Astrophysics Data System (ADS)

    Ebert, Martin; Weigel, Ralf; Kandler, Konrad; Günther, Gebhard; Molleker, Sergej; Grooß, Jens-Uwe; Vogel, Bärbel; Weinbruch, Stephan; Borrmann, Stephan

    2016-07-01

    Stratospheric aerosol particles with diameters larger than about 10 nm were collected within the arctic vortex during two polar flight campaigns: RECONCILE in winter 2010 and ESSenCe in winter 2011. Impactors were installed on board the aircraft M-55 Geophysica, which was operated from Kiruna, Sweden. Flights were performed at a height of up to 21 km and some of the particle samples were taken within distinct polar stratospheric clouds (PSCs). The chemical composition, size and morphology of refractory particles were analyzed by scanning electron microscopy and energy-dispersive X-ray microanalysis. During ESSenCe no refractory particles with diameters above 500 nm were sampled. In total 116 small silicate, Fe-rich, Pb-rich and aluminum oxide spheres were found. In contrast to ESSenCe in early winter, during the late-winter RECONCILE mission the air masses were subsiding inside the Arctic winter vortex from the upper stratosphere and mesosphere, thus initializing a transport of refractory aerosol particles into the lower stratosphere. During RECONCILE, 759 refractory particles with diameters above 500 nm were found consisting of silicates, silicate / carbon mixtures, Fe-rich particles, Ca-rich particles and complex metal mixtures. In the size range below 500 nm the presence of soot was also proven. While the data base is still sparse, the general tendency of a lower abundance of refractory particles during PSC events compared to non-PSC situations was observed. The detection of large refractory particles in the stratosphere, as well as the experimental finding that these particles were not observed in the particle samples (upper size limit ˜ 5 µm) taken during PSC events, strengthens the hypothesis that such particles are present in the lower polar stratosphere in late winter and have provided a surface for heterogeneous nucleation during PSC formation.

  2. Seed chemical composition variability and FAD2A functional SNP genotypes in the U.S. peanut mini-core collection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Peanut seeds are nutritious containing high amounts of oil and protein as well as some useful phytochemicals which can contribute to human health. The U.S. peanut mini-core collection is an important genetic resource for improving seed quality and developing new cultivars. Variability of seed chemic...

  3. CHEMICAL COMPOSITION OF ESSENTIAL OILS FROM A COLLECTION OF OCIMUM SPECIES (NCRPIS, AMES, USA); INVESTIGATION OF THEIR ANTIFUNGAL ACTIVITIES AND EFFECTS ON FUNGAL POLYAMINES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The North Central Regional Plant Introduction Station conserves germplasm of aromatic plants, including extensive collections of Ocimum providing valuable sources of key genes for developing new basil cultivars. We conducted chemical analyses of essential oils of 73 Ocimum accessions, comparing our...

  4. Seizure modeling of Pb(II) and Cd(II) from aqueous solution by chemically modified sugarcane bagasse fly ash: isotherms, kinetics, and column study.

    PubMed

    Shah, Bhavna; Mistry, Chirag; Shah, Ajay

    2013-04-01

    Heavy metal pollution is a common environmental problem all over the world. The purpose of the research is to examine the applicability of bagasse fly ash (BFA)-an agricultural waste of sugar industry used for the synthesis of zeolitic material. The zeolitic material are used for the uptake of Pb(II) and Cd(II) heavy metal. Bagasse fly ash is used as a native material for the synthesis of zeolitic materials by conventional hydrothermal treatment without (conventional zeolitic bagasse fly ash (CZBFA)) and with electrolyte (conventional zeolitic bagasse fly ash in electrolyte media (ECZBFA)) media. Heavy metal ions Pb(II) and Cd(II) were successfully seized from aqueous media using these synthesized zeolitic materials. In this study, the zeolitic materials were well characterized by different instrumental methods such as Brunauer-Emmett-Teller, XRF, Fourier transform infrared spectroscopy, powder X-ray diffraction, and scanning electron microscopic microphotographs. The presence of analcime, phillipsite, and zeolite P in adsorbents confirms successful conversion of native BFA into zeolitic materials. Seizure modeling of Pb(II) and Cd(II) was achieved by batch sorption experiments, isotherms, and kinetic studies. These data were used to compare and evaluate the zeolitic materials as potential sorbents for the uptake of heavy metal ions from an aqueous media. The Langmuir isotherm correlation coefficient parameters best fit the equilibrium data which indicate the physical sorption. Pseudo-second-order and intra-particle diffusion model matches best which indicates that the rate of sorption was controlled by film diffusion. The column studies were performed for the practical function of sorbents, and breakthrough curves were obtained, which revealed higher sorption capacity as compared to batch method. Synthesized zeolitic material (CZBFA and ECZBFA), a low-cost sorbent, was proven as potential sorbent for the uptake of Pb(II) and Cd(II) heavy metal ions. PMID:22739768

  5. Historical estimates of external gamma exposure and collective external gamma exposure from testing at the Nevada Test Site. II. Test series after Hardtack II, 1958, and summary

    SciTech Connect

    Anspaugh, L.R.; Ricker, Y.E.; Black, S.C.; Grossman, R.F.; Wheeler, D.L.; Church, B.W.; Quinn, V.E. )

    1990-11-01

    The historical data on the cumulative individual external gamma exposures are tabulated for communities around the Nevada Test Site for the time periods of 1961 to the signing of the Limited Test Ban Treaty on 5 August 1963, and from then until 1975. The collective exposures during the two time periods are calculated to be 610 and 320 person-R, respectively. The total collective external gamma exposure from 1951 through 1975 for these communities s calculated to be 86,000 person-R. The area considered includes the countries of Clark, Lincoln, Nye, and White Pine in Nevada and the countries of Iron and Washington in Utah; inclusion of Salt Lake City would have substantially increased the calculated collective exposure because of the large population. The methods of calculation are reviewed. Also, the historical data on the assessment of dose via ingestion are reviewed with emphasis on the dose to the thyroid of infants living in St. George, UT, at the time of fallout from event HARRY on 19 May 1953.

  6. Historical estimates of external gamma exposure and collective external gamma exposure from testing at the Nevada Test Site. II. Test series after Hardtack II, 1958, and summary.

    PubMed

    Anspaugh, L R; Ricker, Y E; Black, S C; Grossman, R F; Wheeler, D L; Church, B W; Quinn, V E

    1990-11-01

    The historical data on the cumulative individual external gamma exposures are tabulated for communities around the Nevada Test Site for the time periods of 1961 to the signing of the Limited Test Ban Treaty on 5 August 1963, and from then until 1975. The collective exposures during the two time periods are calculated to be 610 and 320 person-R, respectively. The total collective external gamma exposure from 1951 through 1975 for these communities s calculated to be 86,000 person-R. The area considered includes the countries of Clark, Lincoln, Nye, and White Pine in Nevada and the countries of Iron and Washington in Utah; inclusion of Salt Lake City would have substantially increased the calculated collective exposure because of the large population. The methods of calculation are reviewed. Also, the historical data on the assessment of dose via ingestion are reviewed with emphasis on the dose to the thyroid of infants living in St. George, UT, at the time of fallout from event HARRY on 19 May 1953. PMID:2211112

  7. On the possibility of silicon nitride as a ceramic for structural orthopaedic implants. Part II: chemical stability and wear resistance in body environment.

    PubMed

    Mazzocchi, Mauro; Gardini, Davide; Traverso, Pier Luigi; Faga, Maria Giulia; Bellosi, Alida

    2008-08-01

    In Part I, the processing, microstructure and mechanical properties of three silicon nitride-based ceramics were examined and their non-toxicity was demonstrated. In this Part II, some features critical to biomedical applications were investigated: (i) the wetting behaviour against aqueous media, including physiological solutions; (ii) the chemical stability in water and in physiological solutions; and (iii) the wear resistance, measured under experimental procedures that simulate the conditions typical of the hip joint prosthesis. The results confirmed that silicon nitride may serve as a biomaterial for bone substitution in load bearing prosthesis. PMID:18415002

  8. Developmental Effects of the ToxCast™ Phase I and Phase II Chemicals in Caenorhabditis elegans and Corresponding Responses in Zebrafish, Rats, and Rabbits

    PubMed Central

    Boyd, Windy A.; Smith, Marjolein V.; Co, Caroll A.; Pirone, Jason R.; Rice, Julie R.; Shockley, Keith R.; Freedman, Jonathan H.

    2015-01-01

    Background: Modern toxicology is shifting from an observational to a mechanistic science. As part of this shift, high-throughput toxicity assays are being developed using alternative, nonmammalian species to prioritize chemicals and develop prediction models of human toxicity. Methods: The nematode Caenorhabditis elegans (C. elegans) was used to screen the U.S. Environmental Protection Agency’s (EPA’s) ToxCast™ Phase I and Phase II libraries, which contain 292 and 676 chemicals, respectively, for chemicals leading to decreased larval development and growth. Chemical toxicity was evaluated using three parameters: a biologically defined effect size threshold, half-maximal activity concentration (AC50), and lowest effective concentration (LEC). Results: Across both the Phase I and Phase II libraries, 62% of the chemicals were classified as active ≤ 200 μM in the C. elegans assay. Chemical activities and potencies in C. elegans were compared with those from two zebrafish embryonic development toxicity studies and developmental toxicity data for rats and rabbits. Concordance of chemical activity was higher between C. elegans and one zebrafish assay across Phase I chemicals (79%) than with a second zebrafish assay (59%). Using C. elegans or zebrafish to predict rat or rabbit developmental toxicity resulted in balanced accuracies (the average value of the sensitivity and specificity for an assay) ranging from 45% to 53%, slightly lower than the concordance between rat and rabbit (58%). Conclusions: Here, we present an assay that quantitatively and reliably describes the effects of chemical toxicants on C. elegans growth and development. We found significant overlap in the activity of chemicals in the ToxCast™ libraries between C. elegans and zebrafish developmental screens. Incorporating C. elegans toxicological assays as part of a battery of in vitro and in vivo assays provides additional information for the development of models to predict a chemical

  9. Experimental and quantum-chemical studies of 1H, 13C and 15N NMR coordination shifts in Au(III), Pd(II) and Pt(II) chloride complexes with picolines.

    PubMed

    Pazderski, Leszek; Tousek, Jaromír; Sitkowski, Jerzy; Malináková, Katerina; Kozerski, Lech; Szłyk, Edward

    2009-03-01

    (1)H, (13)C and (15)N NMR studies of gold(III), palladium(II) and platinum(II) chloride complexes with picolines, [Au(PIC)Cl(3)], trans-[Pd(PIC)(2)Cl(2)], trans/cis-[Pt(PIC)(2)Cl(2)] and [Pt(PIC)(4)]Cl(2), were performed. After complexation, the (1)H and (13)C signals were shifted to higher frequency, whereas the (15)N ones to lower (by ca 80-110 ppm), with respect to the free ligands. The (15)N shielding phenomenon was enhanced in the series [Au(PIC)Cl(3)] < trans-[Pd(PIC)(2)Cl(2)] < cis-[Pt(PIC)(2)Cl(2)] < trans-[Pt(PIC)(2)Cl(2)]; it increased following the Pd(II) --> Pt(II) replacement, but decreased upon the trans --> cis-transition. Experimental (1)H, (13)C and (15)N NMR chemical shifts were compared to those quantum-chemically calculated by B3LYP/LanL2DZ + 6-31G**//B3LYP/LanL2DZ + 6-31G*. PMID:19097135

  10. Odor and odorous chemical emissions from animal buildings: part 1 - project overview, collection methods, and quality control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Livestock facilities have historically generated public concerns due to their emissions of odorous air and various chemical pollutants. Odor emission factors and identification of principal odorous chemicals are needed to better understand the problem. Applications of odor emission factors include i...

  11. Chemical and isotopic data collected from groundwater, surface-water, and atmospheric precipitation sites in Upper Kittitas County, Washington, 2010-12

    USGS Publications Warehouse

    Hinkle, Stephen R.; Ely, D. Matthew

    2013-01-01

    As part of a multidisciplinary U.S. Geological Survey study of water resources in Upper Kittitas County, Washington, chemical and isotopic data were collected from groundwater, surface-water, and atmospheric precipitation sites from 2010 to 2012. These data are documented here so that interested parties can quickly and easily find those chemical and isotopic data related to this study. The locations of the samples are shown on an interactive map of the study area. This report is dynamic; additional data will be added to it as they become available.

  12. Chemical composition of samples collected from waste rock dumps and other mining-related features at selected phosphate mines in southeastern Idaho, western Wyoming, and northern Utah

    USGS Publications Warehouse

    Moyle, Phillip R.; Causey, J. Douglas

    2001-01-01

    This report provides chemical analyses for 31 samples collected from various phosphate mine sites in southeastern Idaho (25), northern Utah (2), and western Wyoming (4). The sampling effort was undertaken as a reconnaissance and does not constitute a characterization of mine wastes. Twenty-five samples were collected from waste rock dumps, 2 from stockpiles, and 1 each from slag, tailings, mill shale, and an outcrop. All samples were analyzed for a suite of major, minor, and trace elements. Although the analytical data set for the 31 samples is too small for detailed statistical analysis, a summary of general observations is made.

  13. Profiling of the Tox21 Chemical Collection for Mitochondrial Function: I. Compounds that Decrease Mitochondrial Membrane Potential

    EPA Science Inventory

    Mitochondrial dysfunction has been implicated in the pathogenesis of a variety of disorders including cancer, diabetes, and neurodegenerative and cardiovascular diseases. Understanding how different environmental chemicals and drug-like molecules impact mitochondrial function rep...

  14. Collection of chemical-specific toxicological and pharmacokinetic data to improve risk assessments based on epidemiology: Example of Mn

    EPA Science Inventory

    Data limitations led to the application of default uncertainty factors in prior risk assessments for Mn. These limitations were instrumental in the EPA generation of an alternative tier II test rule under section 211 (b) of the Clean Air Act, (fuels and fuel additives) regarding ...

  15. Chemical and spectroscopic characterizations, ESI-QTOF mass spectrometric measurements and DFT studies of new complexes of palladium(II) with tryptamine and mefenamic acid

    NASA Astrophysics Data System (ADS)

    Carvalho, Marcos A.; Arruda, Eduardo G. R.; Profirio, Daniel M.; Gomes, Alexandre F.; Gozzo, Fábio C.; Formiga, André L. B.; Corbi, Pedro P.

    2015-11-01

    New palladium(II) complexes with tryptamine (Pd-tra) and mefenamic acid (Pd-mef) were prepared and characterized by chemical and spectroscopic methods. Elemental, ESI-QTOF mass spectrometric and thermogravimetric analyses of the compounds confirm the composition [PdCl2(tra)2] for Pd-tra and [Pd(mef)2(bipy)] for Pd-mef. Infrared data indicate the coordination of tryptamine to Pd(II) by the nitrogen atom of the amino group, while for mefenamic acid coordination occurs by the oxygen atom of carboxylate group in a monodentate form. The 1H, 13C and {15N,1H} NMR spectroscopic data confirm the nitrogen coordination of the NH2 group of trypatmine to Pd(II) in the Pd-tra complex and also the oxygen coordination of the carboxylate group of mefenamic acid to Pd(II) in the Pd-mef complex. Density functional theory (DFT) studies were applied to determine the difference in energy between the geometric isomers (cis/trans) of Pd-tra and to optimize the structure of the Pd-mef complex. Raman spectroscopic measurements reinforce the nitrogen coordination of tryptamine to Pd(II) in the Pd-tra complex and confirms the presence of the cis-[PdCl2(tra)2] isomer in the solid state. The complexes are insoluble in water.

  16. Chemical comparison and acute toxicity of water accommodated fraction (WAF) of source and field collected Macondo oils from the Deepwater Horizon spill.

    PubMed

    Faksness, Liv-Guri; Altin, Dag; Nordtug, Trond; Daling, Per S; Hansen, Bjørn Henrik

    2015-02-15

    Two Source oils and five field collected oil residues from the Deepwater Horizon incident were chemically characterized. Water accommodated fractions (WAFs) of the Source oils and two of the field-weathered oils were prepared to evaluate the impact of natural weathering on the chemical composition and the acute toxicity of the WAFs. Toxicity test species representing different tropic levels were used (the primary producer Skeletonema costatum (algae) and the herbivorous copepod Acartia tonsa). The results suggest that the potential for acute toxicity is higher in WAFs from non-weathered oils than WAFs from the field weathered oils. The Source oils contained a large fraction of soluble and bioavailable components (such as BTEX (benzene, toluene, ethyl benzene, xylenes) and naphthalene), whereas in the surface collected oils these components were depleted by dissolution into the water column as the oil rose to the surface and by evaporative loss after reaching the sea surface. PMID:25534626

  17. Electrochromic and colorimetric properties of nickel(II) oxide thin films prepared by aerosol-assisted chemical vapor deposition.

    PubMed

    Sialvi, Muhammad Z; Mortimer, Roger J; Wilcox, Geoffrey D; Teridi, Asri Mat; Varley, Thomas S; Wijayantha, K G Upul; Kirk, Caroline A

    2013-06-26

    Aerosol-assisted chemical vapor deposition (AACVD) was used for the first time in the preparation of thin-film electrochromic nickel(II) oxide (NiO). The as-deposited films were cubic NiO, with an octahedral-like grain structure, and an optical band gap that decreased from 3.61 to 3.48 eV on increase in film thickness (in the range 500-1000 nm). On oxidative voltammetric cycling in aqueous KOH (0.1 mol dm(-3)) electrolyte, the morphology gradually changed to an open porous NiO structure. The electrochromic properties of the films were investigated as a function of film thickness, following 50, 100, and 500 conditioning oxidative voltammetric cycles in aqueous KOH (0.1 mol dm(-3)). Light modulation of the films increased with the number of conditioning cycles. The maximum coloration efficiency (CE) for the NiO (transmissive light green, the "bleached" state) to NiOOH (deep brown, the colored state) electrochromic process was found to be 56.3 cm(2) C(-1) (at 450 nm) for films prepared by AACVD for 15 min followed by 100 "bleached"-to-colored conditioning oxidative voltammetric cycles. Electrochromic response times were <10 s and generally longer for the coloration than the bleaching process. The films showed good stability when tested for up to 10 000 color/bleach cycles. Using the CIE (Commission Internationale de l'Eclairage) system of colorimetry the color stimuli of the electrochromic NiO films and the changes that take place on reversibly oxidatively switching to the NiOOH form were calculated from in situ visible spectra recorded under electrochemical control. Reversible changes in the hue and saturation occur on oxidation of the NiO (transmissive light green) form to the NiOOH (deep brown) form, as shown by the track of the CIE 1931 xy chromaticity coordinates. As the NiO film is oxidized, a sharp decrease in luminance was observed. CIELAB L*a*b* coordinates were also used to quantify the electrochromic color states. A combination of a low L* and positive a

  18. Chemical analyses of surface water in Illinois, 1958-74; Volume II, Illinois River basin and Mississippi River tributaries north of Illinois River basin

    USGS Publications Warehouse

    Healy, R.W.; Toler, L.G.

    1978-01-01

    Samples of surface water were collected and analyzed by the Illinois Environmental Protection Agency and its predecessor, the Stream Pollution Control Bureau of the Illinois Department of Public Health. The results for the period 1958 to 1974 are presented in tabular form and the history of sampling and analytical methods are included for all sites where samples were collected at gaging stations or near enough that reliable discharge estimates could be made. The report is contained in three volumes. This volume (Volume II) includes Illinois River basin and Mississippi River tributaries north of Illinois River basin. (See also W78-10034 and W78-10036) (Woodard-USGS)

  19. Search for associations containing young stars (SACY). II. Chemical abundances of stars in 11 young associations in the solar neighborhood

    NASA Astrophysics Data System (ADS)

    Viana Almeida, P.; Santos, N. C.; Melo, C.; Ammler-von Eiff, M.; Torres, C. A. O.; Quast, G. R.; Gameiro, J. F.; Sterzik, M.

    2009-07-01

    The recently discovered coeval, moving groups of young stellar objects in the solar neighborhood represent invaluable laboratories for studying recent star formation and searching for high metallicity stars that can be included in future exo-planet surveys. In this study, we derived through an uniform and homogeneous method stellar atmospheric parameters and abundances for iron, silicium, and nickel in 63 post-T Tauri stars from 11 nearby young associations. We further compare the results with two different pre-main sequence (PMS) and main sequence (MS) star populations. The stellar atmospheric parameters and the abundances presented here were derived using the equivalent width of individual lines in the stellar spectra by assuming the excitation/ionization equilibrium of iron. Moreover, we compared the observed Balmer lines with synthetic profiles calculated for model atmospheres with a different line-formation code. We found that the synthetic profiles agree reasonably well with the observed profiles, although the Balmer lines of many stars are substantially filled-in, probably by chromospheric emission. Solar metallicity is found to be a common trend in all the nearby young associations studied. The low abundance dispersion within each association strengthens the idea that the origin of these nearby young associations is related to the nearby star-forming regions (SFR). Abundances of elements other than iron are consistent with previous results for Main Sequence stars in the solar neighborhood. The chemical characterization of the members of the newly found nearby young associations, performed in this study and intended to proceed in subsequent works, is essential to understanding and testing the context of local star formation and the evolutionary history of the galaxy. Based on observations collected with the UVES spectrograph at the VLT/UT2 8.2-m Kueyen Telescope (ESO run ID. 079.C-0556(A)) at the Paranal Observatory, Chile. Tables 1, 2 and 5 are only

  20. Chemical composition of the essential oil of Moluccella spinosa L. (Lamiaceae) collected wild in Sicily and its activity on microorganisms affecting historical textiles.

    PubMed

    Casiglia, Simona; Jemia, Mariem Ben; Riccobono, Luana; Bruno, Maurizio; Scandolera, Elia; Senatore, Felice

    2015-01-01

    In this study the chemical composition of the essential oil from aerial parts of Moluccella spinosa L. collected in Sicily was evaluated by GC and GC-MS. The main components of M. spinosa L. were α-pinene (26.6%), caryophyllene oxide (16.8%) and β-caryophyllene (8.6%). A comparison with other studied oils of genus Moluccella is made. Antibacterial and antifungal activities against some microorganisms infesting historical textiles were also determined. PMID:25554361

  1. Studies examining the relationship between the chemical structure of protoxin II and its activity on voltage gated sodium channels.

    PubMed

    Park, Jae H; Carlin, Kevin P; Wu, Gang; Ilyin, Victor I; Musza, Laszlo L; Blake, Paul R; Kyle, Donald J

    2014-08-14

    The aqueous solution structure of protoxin II (ProTx II) indicated that the toxin comprises a well-defined inhibitor cystine knot (ICK) backbone region and a flexible C-terminal tail region, similar to previously described NaSpTx III tarantula toxins. In the present study we sought to explore the structure-activity relationship of the two regions of the ProTx II molecule. As a first step, chimeric toxins of ProTx II and PaTx I were synthesized and their biological activities on Nav1.7 and Nav1.2 channels were investigated. Other tail region modifications to this chimera explored the effects of tail length and tertiary structure on sodium channel activity. In addition, the activity of various C-terminal modifications of the native ProTx II was assayed and resulted in the identification of protoxin II-NHCH3, a molecule with greater potency against Nav1.7 channels (IC50=42 pM) than the original ProTx II. PMID:25026046

  2. (Collection of North Pacific Ocean surface seawater samples for chemical analysis): Foreign trip report, January 26--February 27, 1988

    SciTech Connect

    Goddard, J.G.

    1988-03-04

    This trip was a continuation of the sampling program undertaken during 1984--1985 to study the seasonal and regional variability of CO/sub 2/ chemistry in high latitude deep water formation areas of the North Pacific. The work is conducted by Columbia University (Dr. Taro Takahashi, Principal Investigator) for the Department of Energy's Energy Systems Program managed by Oak Ridge National Laboratory. Aboard the PRESIDENT ARTHUR, surface seawater samples were collected at forty-one stations along the route from Oakland, California, to Keeling, Taiwan, via Guam. On the return trip, samples were collected from thirty-seven stations during transit from Keelung to Los Angeles, California.

  3. Novel biosorbent with high adsorption capacity prepared by chemical modification of white pine (Pinus durangensis) sawdust. Adsorption of Pb(II) from aqueous solutions.

    PubMed

    Salazar-Rabago, J J; Leyva-Ramos, R

    2016-03-15

    The natural sawdust (NS) from white pine (Pinus durangensis) was chemically modified by a hydrothermal procedure using citric, malonic and tartaric acids. The adsorption capacity of modified sawdust (MS) towards Pb(II) was considerably enhanced due to the introduction of carboxylic groups on the surface of MS during the modification, and the adsorption capacity was almost linearly dependent on the concentration of carboxylic sites. The NS surface was acidic, and the MS surface became more acidic after the modification. At T = 25 °C and pH = 5, the maximum adsorption capacity of the optimal MS towards Pb(II) was 304 mg/g, which is exceptionally high compared to NS and other MS reported previously. The adsorption capacity of MS was considerably reduced from 304 to 154 mg/g by decreasing the solution pH from 5 to 3 due to electrostatic interactions. The adsorption of Pb(II) on MS was reversible at pH = 2, but not at pH = 5. The contribution percentage of ion exchange to the overall adsorption capacity ranged from 70 to 99% and 10-66% at the initial pH of 3 and 5, respectively. Hence, the adsorption of Pb(II) on MS was mainly due to ion exchange at pH = 3 and to both ion exchange and electrostatic attraction at pH = 5. PMID:26773434

  4. The chemical abundances of the stellar populations in the Leo I and II dSph galaxies

    NASA Astrophysics Data System (ADS)

    Bosler, Tammy L.; Smecker-Hane, Tammy A.; Stetson, Peter B.

    2007-06-01

    We have obtained calcium abundances and radial velocities for 102 red giant branch (RGB) stars in the Leo I dwarf spheroidal galaxy (dSph) and 74 RGB stars in the Leo II dSph using the low-resolution spectrograph (LRIS) on the Keck I 10-m telescope. We report on the calcium abundances [Ca/H] derived from the strengths of the CaII triplet absorption lines at 8498, 8542 and 8662 Å in the stellar spectra using a new empirical CaII triplet calibration to [Ca/H]. The two galaxies have different average [Ca/H] values of -1.34 +/- 0.02 for Leo I and -1.65 +/- 0.02 for Leo II with intrinsic abundance dispersions of 1.2 and 1.0 dex, respectively. The typical random and total errors in derived abundances are 0.10 and 0.17 dex per star. For comparison to the existing literature, we also converted our CaII measurements to [Fe/H] on the scale of Carretta and Gratton (1997) though we discuss why this may not be the best determinant of metallicity; Leo I has a mean [Fe/H] = -1.34 and Leo II has a mean [Fe/H] = -1.59. The metallicity distribution function of Leo I is approximately Gaussian in shape with an excess at the metal-rich end, while that of Leo II shows an abrupt cut-off at the metal-rich end. The lower mean metallicity of Leo II is consistent with the fact that it has a lower luminosity, hence lower the total mass than Leo I; thus, the evolution of Leo II may have been affected more by mass lost in galactic winds. Our direct and independent measurement of the metallicity distributions in these dSph will allow a more accurate star-formation histories to be derived from future analysis of their colour-magnitude diagrams(CMDs). Data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. E

  5. Results of toxicity tests and chemical analyses conducted on sediments collected from the TNX Outfall Delta Operable Unit, July 1999

    SciTech Connect

    Specht, W.L.

    2000-02-11

    In order to provide unit specific toxicity data that will be used to address critical uncertainty in the ecological risk assessment (ERA) for the TNX Outfall Delta Operable Unit (TNXOD OU), sediments were collected from eight locations in the Inner Swamp portion of the operable unit and two unit specific background locations. These samples were analyzed for total mercury, total uranium, and sediment toxicity.

  6. Organic Chemical Concentrations and Reproductive Biomarkers in Common Carp (Cyprinus carpio) Collected from Two Areas in Lake Mead, Nevada, May 1999-May 2000

    USGS Publications Warehouse

    Goodbred, Steven L.; Leiker, Thomas J.; Patiño, Reynaldo; Jenkins, Jill A.; Denslow, Nancy D.; Orsak, Erik; Rosen, Michael R.

    2007-01-01

    The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, National Park Service, Bureau of Reclamation, and Nevada Department of Wildlife, collected and assessed data to determine the general health and reproductive status of common carp (Cyprinus carpio) at two study areas in Lake Mead, Nevada, during May 1999-May 2000. These data will form the basis of interpretations and provide a comparison for continuing studies on the health of the ecosystem in Lake Mead. One study area, Las Vegas Bay, is in the western part of Lake Mead. Las Vegas Bay receives inflows from Las Vegas Wash, which is predominantly tertiary-treated wastewater effluent, and to a lesser extent stormwater runoff from Las Vegas, Henderson, and other nearby communities, and from ground water underlying Las Vegas Valley. The other study area, Overton Arm, is in the northern extent of Lake Mead. Overton Arm receives inflow from the Virgin and Muddy Rivers, which historically are not influenced by wastewater effluent. Both sexes of common carp were collected bimonthly for 12 months using boat-mounted electrofishing gear (a direct electric current is used to temporarily immobilize fish for capture) to determine their health and reproductive status and any relation between these factors and environmental contaminants. This report presents fish tissue chemistry, organic chemical compound concentrations, and biomarker data for 83 male common carp collected from Las Vegas Bay, similar organic chemistry results for 15 male common carp, and similar biomarker measures for 80 male common carp collected from Overton Arm. Tissue chemistry results also are presented for 16 female common carp and biomarker measures for 79 female common carp collected from Las Vegas Bay, and tissue chemistry results for 15 female common carp and biomarker measures for 81 female common carp collected from Overton Arm. Thirty-three organic chemical compounds plus total concentrations for four groups of

  7. Validation of DSMC results for chemically nonequilibrium air flows against measurements of the electron number density in RAM-C II flight experiment

    NASA Astrophysics Data System (ADS)

    Shevyrin, Alexander A.; Vashchenkov, Pavel V.; Bondar, Yevgeniy A.; Ivanov, Mikhail S.

    2014-12-01

    An ionized flow around the RAM C-II vehicle in the range of altitudes from 73 to 81 km is studied by the Direct Simulation Monte Carlo (DSMC) method with three models of chemical reactions. It is demonstrated that vibration favoring in reactions of dissociation of neutral molecules affects significantly the predicted values of plasma density in the shock layer, and good agreement between the results of experiments and DSMC computations can be achieved in terms of the plasma density as a function of the flight altitude.

  8. Validation of DSMC results for chemically nonequilibrium air flows against measurements of the electron number density in RAM-C II flight experiment

    SciTech Connect

    Shevyrin, Alexander A.; Vashchenkov, Pavel V.; Bondar, Yevgeniy A.; Ivanov, Mikhail S.

    2014-12-09

    An ionized flow around the RAM C-II vehicle in the range of altitudes from 73 to 81 km is studied by the Direct Simulation Monte Carlo (DSMC) method with three models of chemical reactions. It is demonstrated that vibration favoring in reactions of dissociation of neutral molecules affects significantly the predicted values of plasma density in the shock layer, and good agreement between the results of experiments and DSMC computations can be achieved in terms of the plasma density as a function of the flight altitude.

  9. Comparison of the chemical composition of Valeriana parviflora essential oils collected in the Venezuelan Andes in two different seasons.

    PubMed

    Fernández, Sammy; Rondón, María; Rojas, Janne; Morales, Antonio; Rojas-Fermin, Luis

    2015-04-01

    The essential oils obtained by hydrodistillation of the aerial parts of Valerianaparviflora (Trevir) BM Vadillo, an endemic species of the Venezuelan Andes, collected from the same location in two different seasons (dry and rainy) of the year, were analyzed by GC/MS. The essential oil obtained during the dry season showed linalool (11.9%), eugenol (8.9%), p-menth-l-en-9-al (8.7%) and α-terpineol (7.7%) as main components, while the oil obtained from the rainy season collection showed o-xylol (16.2%), 3-methyl isovaleric acid (10.6%) and geranial (9.5%) as major compounds. Some of the differences in the composition of these oils might be due to the climatic conditions at the time of harvesting. PMID:25973503

  10. The population of planetary nebulae and H II regions in M 81. A study of radial metallicity gradients and chemical evolution

    NASA Astrophysics Data System (ADS)

    Stanghellini, L.; Magrini, L.; Villaver, E.; Galli, D.

    2010-10-01

    Context. M 81 is an ideal laboratory to investigate the galactic chemical and dynamical evolution through the study of its young and old stellar populations. Aims: We analyze the chemical abundances of planetary nebulae and H ii regions in the M 81 disk for insight on galactic evolution, and compare it with that of other galaxies, including the Milky Way. Methods: We acquired Hectospec/MMT spectra of 39 PNe and 20 H ii regions, with 33 spectra viable for temperature and abundance analysis. Our PN observations represent the first PN spectra in M 81 ever published, while several H ii region spectra have been published before, although without a direct electron temperature determination. We determine elemental abundances of helium, nitrogen, oxygen, neon, sulfur, and argon in PNe and H ii regions, and determine their averages and radial gradients. Results: The average O/H ratio of PNe compared to that of the H ii regions indicates a general oxygen enrichment in M 81 in the last ~10 Gyr. The PN metallicity gradient in the disk of M 81 is Δlog(O/H)/ΔRG = -0.055 ± 0.02 dex/kpc. Neon and sulfur in PNe have a radial distribution similar to that of oxygen, with similar gradient slopes. If we combine our H ii sample with the one in the literature we find a possible mild evolution of the gradient slope, with results consistent with gradient steepening with time. Additional spectroscopy is needed to confirm this trend. There are no type I PNe in our M 81 sample, consistently with the observation of only the brightest bins of the PNLF, the galaxy metallicity, and the evolution of post-AGB shells. Conclusions: Both the young and the old populations of M 81 disclose shallow but detectable negative radial metallicity gradient, which could be slightly steeper for the young population, thus not excluding a mild gradients steepening with the time since galaxy formation. During its evolution M 81 has been producing oxygen; its total oxygen enrichment exceeds that of other nearby

  11. Fractionally distilled SRC-I, SRC-II, EDS, H-Coal and ITSL direct coal liquefaction process materials: a comparative summary of chemical analysis and biological testing

    SciTech Connect

    Wright, C.W.; Later, D.W.; Dauble, D.D.; Wilson, B.W.

    1985-07-01

    This document reports and compares the results compiled from chemical analyses and biological testing of coal liquefaction process materials which were fractionally distilled, after production, into various comparable boiling-point range cuts. Comparative analyses were performed on solvent refined coal (SRC)-I, SRC-II, H-Coal, EDS an integrated two-stage liquefaction (ITSL) distillate materials. Mutagenicity and carcinogenicity assays were conducted in conjunction with chromatographic and mass spectrometric analyses to provide detailed, comparative, chemical and biological assessments. Where possible, results obtained from the distillate cuts are compared to those from coal liquefaction materials with limited boiling ranges. Work reported here was conducted by investigators in the Biology and Chemistry Department at the Pacific Northwest Laboratory (PNL), Richland, WA. 38 refs., 16 figs., 27 tabs.

  12. Rapid adsorption of toxic Pb(II) ions from aqueous solution using multiwall carbon nanotubes synthesized by microwave chemical vapor deposition technique.

    PubMed

    Mubarak, Nabisab Mujawar; Sahu, Jaya Narayan; Abdullah, Ezzat Chan; Jayakumar, Natesan Subramanian

    2016-07-01

    Multiwall carbon nanotubes (MWCNTs) were synthesized using a tubular microwave chemical vapor deposition technique, using acetylene and hydrogen as the precursor gases and ferrocene as catalyst. The novel MWCNT samples were tested for their performance in terms of Pb(II) binding. The synthesized MWCNT samples were characterized using Fourier Transform Infrared (FT-IR), Brunauer, Emmett and Teller (BET), Field Emission Scanning Electron Microscopy (FESEM) analysis, and the adsorption of Pb(II) was studied as a function of pH, initial Pb(II) concentration, MWCNT dosage, agitation speed, and adsorption time, and process parameters were optimized. The adsorption data followed both Freundlich and Langmuir isotherms. On the basis of the Langmuir model, Qmax was calculated to be 104.2mg/g for the microwave-synthesized MWCNTs. In order to investigate the dynamic behavior of MWCNTs as an adsorbent, the kinetic data were modeled using pseudo first-order and pseudo second-order equations. Different thermodynamic parameters, viz., ∆H(0), ∆S(0) and ∆G(0) were evaluated and it was found that the adsorption was feasible, spontaneous and endothermic in nature. The statistical analysis revealed that the optimum conditions for the highest removal (99.9%) of Pb(II) are at pH5, MWCNT dosage 0.1g, agitation speed 160r/min and time of 22.5min with the initial concentration of 10mg/L. Our results proved that microwave-synthesized MWCNTs can be used as an effective Pb(II) adsorbent due to their high adsorption capacity as well as the short adsorption time needed to achieve equilibrium. PMID:27372128

  13. Chemical Characterization of Individual Particles and Residuals of Cloud Droplets and Ice Crystals Collected On Board Research Aircraft in the ISDAC 2008 Study

    SciTech Connect

    Hiranuma, Naruki; Brooks, Sarah D.; Moffet, Ryan C.; Glen, Andrew; Laskin, Alexander; Gilles, Marry K.; Liu, Peter; MacDonald, A. M.; Strapp, J. Walter; McFarquhar, Greg

    2013-06-24

    Although it has been shown that size of atmospheric particles has a direct correlation with their ability to act as cloud droplet and ice nuclei, the influence of composition of freshly emitted and aged particles in nucleation processes is poorly understood. In this work we combine data from field measurements of ice nucleation with chemical imaging of the sampled particles to link aerosol composition with ice nucleation ability. Field measurements and sampling were conducted during the Indirect and Semidirect Aerosols Campaign (ISDAC) over Barrow, Alaska, in the springtime of 2008. In-situ ice nucleation measurements were conducted using a Continuous Flow Diffusion Chamber (CFDC). Measured number concentrations of ice nuclei (IN) varied from frequent values of 0.01 per liter to more than 10 per liter. Residuals of airborne droplets and ice crystals were collected through a counterflow virtual impactor (CVI). The compositions of individual atmospheric particles and the residuals were studied using Computer Controlled Scanning Electron Microscopy with Energy Dispersive X-ray analysis (CCSEM/EDX) and Scanning Transmission X-ray Microscopy coupled with Near Edge X-ray Absorption Fine Structure spectroscopy (STXM/NEXAFS). Chemical analysis of cloud particle residuals collected during an episode of high ice nucleation suggests that both size and composition may influence aerosol's ability to act as IN. The STXM/NEXAFS chemical composition maps of individual residuals have characteristic structures of either inorganic or black carbon cores coated by organic materials. In a separate flight, particle samples from a biomass burning plume were collected. Although it has previously been suggested that episodes of biomass burning contribute to increased numbers of highly effective ice nuclei, in this episode we observed that only a small fraction were effective ice nuclei. Most of the particles from the biomass plume episode were smaller in size and were composed of

  14. Organic, inorganic and total mercury determination in fish by chemical vapor generation with collection on a gold gauze and electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Duarte, Fábio Andrei; Bizzi, Cezar Augusto; Antes, Fabiane Goldschmidt; Dressler, Valderi Luiz; Flores, Érico Marlon de Moraes

    2009-06-01

    A method for organic, inorganic and total mercury determination in fish tissue has been developed using chemical vapor generation and collection of mercury vapor on a gold gauze inside a graphite tube and further atomization by electrothermal atomic absorption spectrometry. After drying and cryogenic grinding, potassium bromide and hydrochloric acid solution (1 mol L - 1 KBr in 6 mol L - 1 HCl) was added to the samples. After centrifugation, total mercury was determined in the supernatant. Organomercury compounds were selectively extracted from KBr solution using chloroform and the resultant solution was back extracted with 1% m/v L-cysteine. This solution was used for organic Hg determination. Inorganic Hg remaining in KBr solution was directly determined by chemical vapor generation electrothermal atomic absorption spectrometry. Mercury vapor generation from extracts was performed using 1 mol L - 1 HCl and 2.5% m/v NaBH 4 solutions and a batch chemical vapor generation system. Mercury vapor was collected on the gold gauze heated resistively at 80 °C and the atomization temperature was set at 650 °C. The selectivity of extraction was evaluated using liquid chromatography coupled to chemical vapor generation and determination by inductively coupled plasma mass spectrometry. The proposed method was applied for mercury analysis in shark, croaker and tuna fish tissues. Certified reference materials were used to check accuracy and the agreement was better than 95%. The characteristic mass was 60 pg and method limits of detection were 5, 1 and 1 ng g - 1 for organic, inorganic and total mercury, respectively. With the proposed method it was possible to analyze up to 2, 2 and 6 samples per hour for organic, inorganic and total Hg determination, respectively.

  15. Wear Mechanisms of Carbon-Based Refractory Materials in SiMn Tap-Holes—Part II: In Situ Observation of Chemical Reactions

    NASA Astrophysics Data System (ADS)

    Steenkamp, J. D.; Pistorius, P. Chris; Tangstad, M.

    2015-04-01

    The purpose of the study presented here is to determine to what extent chemical reactions between carbon-based refractory and slag or metal in the tap-hole of a SiMn furnace can contribute to wear of tap-hole refractory. The results of the study are reported in two parts. In Part I, thermodynamic calculations suggested that reaction between silicomanganese slag and carbon-based tap-hole refractory is possible, and experiments with nominally pure materials support this. However, practical refractory materials are by no means pure materials and contain secondary phases and porosity which can be expected to affect reaction with slag. In Part II, such reactions are examined experimentally, in cup and wettability tests, using commercially available carbon block and cold-ramming paste refractory materials and mainly industrial SiMn slag. Clear evidence was found of chemical reaction at approximately 1870 K (approximately 1600 °C), forming SiC and, it appears, metal droplets. Both carbon block and ramming paste refractory reacted with slag, with preferential attack on and penetration into the binder phase rather than aggregate particles. The two types of carbon-based refractory materials showed similar extents of chemical reaction observed as wetting and penetration in the laboratory tests. The differences in refractory life observed practically in industrial furnaces should therefore be attributed to wear mechanisms other than pure chemical wear as studied in this work.

  16. Probing the solvent shell with 195Pt chemical shifts: density functional theory molecular dynamics study of Pt(II) and Pt(IV) anionic complexes in aqueous solution.

    PubMed

    Truflandier, Lionel A; Autschbach, Jochen

    2010-03-17

    Ab initio molecular dynamics (aiMD) simulations based on density functional theory (DFT) were performed on a set of five anionic platinum complexes in aqueous solution. (195)Pt nuclear magnetic shielding constants were computed with DFT as averages over the aiMD trajectories, using the two-component relativistic zeroth-order regular approximation (ZORA) in order to treat relativistic effects on the Pt shielding tensors. The chemical shifts obtained from the aiMD averages are in good agreement with experimental data. For Pt(II) and Pt(IV) halide complexes we found an intermediate solvent shell interacting with the complexes that causes pronounced solvent effects on the Pt chemical shifts. For these complexes, the magnitude of solvent effects on the Pt shielding constant can be correlated with the surface charge density. For square-planar Pt complexes the aiMD simulations also clearly demonstrate the influence of closely coordinated non-equatorial water molecules on the Pt chemical shift, relating the structure of the solution around the complex to the solvent effects on the metal NMR chemical shift. For the complex [Pt(CN)(4)](2-), the solvent effects on the Pt shielding constant are surprisingly small. PMID:20166712

  17. Tiered High-Throughput Screening Approach to Identify Thyroperoxidase Inhibitors Within the ToxCast Phase I and II Chemical Libraries.

    PubMed

    Paul Friedman, Katie; Watt, Eric D; Hornung, Michael W; Hedge, Joan M; Judson, Richard S; Crofton, Kevin M; Houck, Keith A; Simmons, Steven O

    2016-05-01

    High-throughput screening for potential thyroid-disrupting chemicals requires a system of assays to capture multiple molecular-initiating events (MIEs) that converge on perturbed thyroid hormone (TH) homeostasis. Screening for MIEs specific to TH-disrupting pathways is limited in the U.S. Environmental Protection Agency ToxCast screening assay portfolio. To fill 1 critical screening gap, the Amplex UltraRed-thyroperoxidase (AUR-TPO) assay was developed to identify chemicals that inhibit TPO, as decreased TPO activity reduces TH synthesis. The ToxCast phase I and II chemical libraries, comprised of 1074 unique chemicals, were initially screened using a single, high concentration to identify potential TPO inhibitors. Chemicals positive in the single-concentration screen were retested in concentration-response. Due to high false-positive rates typically observed with loss-of-signal assays such as AUR-TPO, we also employed 2 additional assays in parallel to identify possible sources of nonspecific assay signal loss, enabling stratification of roughly 300 putative TPO inhibitors based upon selective AUR-TPO activity. A cell-free luciferase inhibition assay was used to identify nonspecific enzyme inhibition among the putative TPO inhibitors, and a cytotoxicity assay using a human cell line was used to estimate the cellular tolerance limit. Additionally, the TPO inhibition activities of 150 chemicals were compared between the AUR-TPO and an orthogonal peroxidase oxidation assay using guaiacol as a substrate to confirm the activity profiles of putative TPO inhibitors. This effort represents the most extensive TPO inhibition screening campaign to date and illustrates a tiered screening approach that focuses resources, maximizes assay throughput, and reduces animal use. PMID:26884060

  18. Report on NCI symposium: comparison of mechanisms of carcinogenesis by radiation and chemical agents. II. Cellular and animal models

    SciTech Connect

    Fry, R.J.M.

    1984-01-01

    The point at which the common final pathway for induction of cancer by chemical carcinogens and ionizing radiation has not been identified. Although common molecular targets are suggested by recent findings about the role of oncogenes, the mechanism by which the deposition of radiation energy and the formation of adducts or other DNA lesions induced by chemicals affects the changes in the relevant targets may be quite different. The damage to DNA that plays no part in the transformation events, but that influences the stability of the genome, and therefore, the probability of subsequent changes that influence tumorigenesis may be more readily induced by some agents than others. Similarly, the degree of cytotoxic effects that disrupt tissue integrity and increase the probability of expression of initiated cells may be dependent on the type of carcinogen. Also, evidence was presented that repair of the initial lesions could be demonstrated after exposure to low-LET radiation but not after exposure to chemical carcinogens.

  19. Water-quality data-collection activities in Colorado and Ohio; Phase II, Evaluation of 1984 field and laboratory quality-assurance practices

    USGS Publications Warehouse

    Childress, C.J.; Chaney, T.M.; Myers, Donna; Norris, J.M.; Hren, Janet

    1987-01-01

    Serious questions have been raised by Congress about the usefulness of water quality data for addressing issues of regional and national scope and, especially, for characterizing the current quality of the Nation 's streams and groundwater. In response, the U.S. Geological Survey conducted a pilot study in Colorado and Ohio to: (1) determine the characteristics of current (1984) water quality data collection activities of Federal, regional, State, and local agencies, and academic institutions; and (2) determine how well the data from these activities, collected for various purposes and using different procedures, can be used to improve the ability to answer major broad scope questions, such as: what are (or were) natural or near-natural water quality conditions; what are existing water quality conditions; and, how water quality has changed and how the changes relate to human activities. Colorado and Ohio were chosen for the pilot study largely because they represent regions with different types of water quality concerns and programs. The study has been divided into three phases, the objectives of which are: Phase I - Inventory water quality data collection programs, including costs, and identify those programs that met a set of broad criteria for producing data that are potentially appropriate for water quality assessments of regional and national scope. Phase II - Evaluate the quality assurance of field and laboratory procedures used in producing the data from programs that met the broad criteria of Phase I. Phase III - Compile the qualifying data and evaluate the adequacy of this data base for addressing selected water quality questions of regional and national scope. (Author 's abstract)

  20. Chemical analyses of soil samples collected from the Sandia National Laboratories/NM, Tonopah Test Range environs, 1994-2005.

    SciTech Connect

    Deola, Regina Anne; Oldewage, Hans D.; Herrera, Heidi M.; Miller, Mark Laverne

    2006-05-01

    From 1994 through 2005, the Environmental Management Department of Sandia National Laboratories (SNL) at the Tonopah Test Range (TTR), NV, has collected soil samples at numerous locations on-site, on the perimeter, and off-site for the purpose of determining potential impacts to the environs from operations at TTR. These samples were submitted to an analytical laboratory of metal-in-soil analyses. Intercomparisons of these results were then made to determine if there was any statistical difference between on-site, perimeter, and off-site samples, or if there were increasing or decreasing trends which indicated that further investigation may be warranted. This work provided the SNL Environmental Management Department with a sound baseline data reference against which to compare future operational impacts. In addition, it demonstrates the commitment that the Laboratories have to go beyond mere compliance to achieve excellence in its operations. This data is presented in graphical format with narrative commentaries on particular items of interest.

  1. Chemical characterization of individual particles and residuals of cloud droplets and ice crystals collected on board research aircraft in the ISDAC 2008 study

    NASA Astrophysics Data System (ADS)

    Hiranuma, N.; Brooks, S. D.; Moffet, R. C.; Glen, A.; Laskin, A.; Gilles, M. K.; Liu, P.; MacDonald, A. M.; Strapp, J. W.; McFarquhar, G. M.

    2013-06-01

    Ambient particles and the dry residuals of mixed-phase cloud droplets and ice crystals were collected during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) near Barrow, Alaska, in spring of 2008. The collected particles were analyzed using Computer Controlled Scanning Electron Microscopy with Energy Dispersive X-ray analysis and Scanning Transmission X-ray Microscopy coupled with Near Edge X-ray Absorption Fine Structure spectroscopy to identify physico-chemical properties that differentiate cloud-nucleating particles from the total aerosol population. A wide range of individually mixed components was identified in the ambient particles and residuals including organic carbon compounds, inorganics, carbonates, and black carbon. Our results show that cloud droplet residuals differ from the ambient particles in both size and composition, suggesting that both properties may impact the cloud-nucleating ability of aerosols in mixed-phase clouds. The percentage of residual particles which contained carbonates (47%) was almost four times higher than those in ambient samples. Residual populations were also enhanced in sea salt and black carbon and reduced in organic compounds relative to the ambient particles. Further, our measurements suggest that chemical processing of aerosols may improve their cloud-nucleating ability. Comparison of results for various time periods within ISDAC suggests that the number and composition of cloud-nucleating particles over Alaska can be influenced by episodic events bringing aerosols from both the local vicinity and as far away as Siberia.

  2. Biological profiling of the ToxCast Phase II Chemical Library in Primary Human Cell Co-Culture Systems

    EPA Science Inventory

    The U.S. EPA’s ToxCast research project was developed to address the need for high-throughput testing of chemicals and a pathway-based approach to hazard screening. Phase I of ToxCast tested over 300 unique compounds (mostly pesticides and antimicrobials). With the addition of Ph...

  3. Chemical Products in the Home, Workshop and Garden. Proceed with Caution; Consumer Safety in the Home, II.

    ERIC Educational Resources Information Center

    Saskatchewan Consumer and Commercial Affairs, Regina.

    The average home has chemical products to clean floors, kill insects, clean ovens, thin paint, remove grease, and perform countless other chores. Many consumers remain unaware of the dangers these products bring into the home. This booklet provides information on the safe use, storage, and disposal of these products. The compounds found in…

  4. Toxicology studies of a chemical mixture of 25 groundwater contaminants. II. Immunosuppression in B6C3F1 mice

    SciTech Connect

    Germolec, D.R.; Yang, R.S.; Ackermann, M.F.; Rosenthal, G.J.; Boorman, G.A.; Blair, P.; Luster, M.I. )

    1989-10-01

    Concern over the potential adverse health effects of chemically contaminated groundwater has existed for many years. In general, these studies have focused on retrospective epidemiological studies for cancer risk. In the present studies, immune function was monitored in female B6C3F1 mice exposed to a chemical mixture in drinking water for either 14 or 90 days. The mixture consisted of 25 common groundwater contaminants frequently found near toxic waste dumps, as determined by EPA surveys. None of the animals developed overt signs of toxicity such as body or liver weight changes. Mice exposed to the highest dose of this mixture for 14 or 90 days showed immune function changes which could be related to rapidly proliferating cells, including suppression of hematopoietic stem cells and of antigen-induced antibody-forming cells. Some of these responses, e.g., granulocyte-macrophage colony formation, were also suppressed at lower concentrations of the chemical mixture. There were no effects on T cell function or T and B cell numbers in any of the treatment groups. Altered resistance to challenge with an infectious agent also occurred in mice given the highest concentration, which correlated with the immune function changes. Paired-water studies indicated that the immune effects were related to chemical exposure and not to decreased water intake. These results suggest that long-term exposure to contaminated groundwater may represent a risk to the immune system in humans.

  5. Binary classification of a large collection of environmental chemicals from estrogen receptor assays by quantitative structure-activity relationship and machine learning methods.

    PubMed

    Zang, Qingda; Rotroff, Daniel M; Judson, Richard S

    2013-12-23

    There are thousands of environmental chemicals subject to regulatory decisions for endocrine disrupting potential. The ToxCast and Tox21 programs have tested ∼8200 chemicals in a broad screening panel of in vitro high-throughput screening (HTS) assays for estrogen receptor (ER) agonist and antagonist activity. The present work uses this large data set to develop in silico quantitative structure-activity relationship (QSAR) models using machine learning (ML) methods and a novel approach to manage the imbalanced data distribution. Training compounds from the ToxCast project were categorized as active or inactive (binding or nonbinding) classes based on a composite ER Interaction Score derived from a collection of 13 ER in vitro assays. A total of 1537 chemicals from ToxCast were used to derive and optimize the binary classification models while 5073 additional chemicals from the Tox21 project, evaluated in 2 of the 13 in vitro assays, were used to externally validate the model performance. In order to handle the imbalanced distribution of active and inactive chemicals, we developed a cluster-selection strategy to minimize information loss and increase predictive performance and compared this strategy to three currently popular techniques: cost-sensitive learning, oversampling of the minority class, and undersampling of the majority class. QSAR classification models were built to relate the molecular structures of chemicals to their ER activities using linear discriminant analysis (LDA), classification and regression trees (CART), and support vector machines (SVM) with 51 molecular descriptors from QikProp and 4328 bits of structural fingerprints as explanatory variables. A random forest (RF) feature selection method was employed to extract the structural features most relevant to the ER activity. The best model was obtained using SVM in combination with a subset of descriptors identified from a large set via the RF algorithm, which recognized the active and

  6. Chemicals of emerging concern in water and bottom sediment in Great Lakes areas of concern, 2010 to 2011-Collection methods, analyses methods, quality assurance, and data

    USGS Publications Warehouse

    Lee, Kathy E.; Langer, Susan K.; Menheer, Michael A.; Foreman, William T.; Furlong, Edward T.; Smith, Steven G.

    2012-01-01

    The U.S. Geological Survey (USGS) cooperated with the U.S. Environmental Protection Agency and the U.S. Fish and Wildlife Service on a study to identify the occurrence of chemicals of emerging concern (CECs) in water and bottom-sediment samples collected during 2010–11 at sites in seven areas of concern (AOCs) throughout the Great Lakes. Study sites include tributaries to the Great Lakes in AOCs located near Duluth, Minn.; Green Bay, Wis.; Roches­ter, N.Y.; Detroit, Mich.; Toledo, Ohio; Milwaukee, Wis.; and Ashtabula, Ohio. This report documents the collection meth­ods, analyses methods, quality-assurance data and analyses, and provides the data for this study. Water and bottom-sediment samples were analyzed at the USGS National Water Quality Laboratory in Denver, Colo., for a broad suite of CECs. During this study, 135 environmental and 23 field dupli­cate samples of surface water and wastewater effluent, 10 field blank water samples, and 11 field spike water samples were collected and analyzed. Sixty-one of the 69 wastewater indicator chemicals (laboratory method 4433) analyzed were detected at concentrations ranging from 0.002 to 11.2 micrograms per liter. Twenty-eight of the 48 pharmaceuticals (research method 8244) analyzed were detected at concentrations ranging from 0.0029 to 22.0 micro­grams per liter. Ten of the 20 steroid hormones and sterols analyzed (research method 4434) were detected at concentrations ranging from 0.16 to 10,000 nanograms per liter. During this study, 75 environmental, 13 field duplicate samples, and 9 field spike samples of bottom sediment were collected and analyzed for a wide variety of CECs. Forty-seven of the 57 wastewater indicator chemicals (laboratory method 5433) analyzed were detected at concentrations ranging from 0.921 to 25,800 nanograms per gram. Seventeen of the 20 steroid hormones and sterols (research method 6434) analyzed were detected at concentrations ranging from 0.006 to 8,921 nanograms per gram. Twelve of

  7. Predicting chemically-induced skin reactions. Part II: QSAR models of skin permeability and the relationships between skin permeability and skin sensitization

    SciTech Connect

    Alves, Vinicius M.; Muratov, Eugene; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Tropsha, Alexander

    2015-04-15

    Skin permeability is widely considered to be mechanistically implicated in chemically-induced skin sensitization. Although many chemicals have been identified as skin sensitizers, there have been very few reports analyzing the relationships between molecular structure and skin permeability of sensitizers and non-sensitizers. The goals of this study were to: (i) compile, curate, and integrate the largest publicly available dataset of chemicals studied for their skin permeability; (ii) develop and rigorously validate QSAR models to predict skin permeability; and (iii) explore the complex relationships between skin sensitization and skin permeability. Based on the largest publicly available dataset compiled in this study, we found no overall correlation between skin permeability and skin sensitization. In addition, cross-species correlation coefficient between human and rodent permeability data was found to be as low as R{sup 2} = 0.44. Human skin permeability models based on the random forest method have been developed and validated using OECD-compliant QSAR modeling workflow. Their external accuracy was high (Q{sup 2}{sub ext} = 0.73 for 63% of external compounds inside the applicability domain). The extended analysis using both experimentally-measured and QSAR-imputed data still confirmed the absence of any overall concordance between skin permeability and skin sensitization. This observation suggests that chemical modifications that affect skin permeability should not be presumed a priori to modulate the sensitization potential of chemicals. The models reported herein as well as those developed in the companion paper on skin sensitization suggest that it may be possible to rationally design compounds with the desired high skin permeability but low sensitization potential. - Highlights: • It was compiled the largest publicly-available skin permeability dataset. • Predictive QSAR models were developed for skin permeability. • No concordance between skin

  8. Predicting chemically-induced skin reactions. Part II: QSAR models of skin permeability and the relationships between skin permeability and skin sensitization

    PubMed Central

    Alves, Vinicius M.; Muratov, Eugene; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Andrade, Carolina H.; Tropsha, Alexander

    2015-01-01

    Skin permeability is widely considered to be mechanistically implicated in chemically-induced skin sensitization. Although many chemicals have been identified as skin sensitizers, there have been very few reports analyzing the relationships between molecular structure and skin permeability of sensitizers and non-sensitizers. The goals of this study were to: (i) compile, curate, and integrate the largest publicly available dataset of chemicals studied for their skin permeability; (ii) develop and rigorously validate QSAR models to predict skin permeability; and (iii) explore the complex relationships between skin sensitization and skin permeability. Based on the largest publicly available dataset compiled in this study, we found no overall correlation between skin permeability and skin sensitization. In addition, cross-species correlation coefficient between human and rodent permeability data was found to be as low as R2=0.44. Human skin permeability models based on the random forest method have been developed and validated using OECD-compliant QSAR modeling workflow. Their external accuracy was high (Q2ext = 0.73 for 63% of external compounds inside the applicability domain). The extended analysis using both experimentally-measured and QSAR-imputed data still confirmed the absence of any overall concordance between skin permeability and skin sensitization. This observation suggests that chemical modifications that affect skin permeability should not be presumed a priori to modulate the sensitization potential of chemicals. The models reported herein as well as those developed in the companion paper on skin sensitization suggest that it may be possible to rationally design compounds with the desired high skin permeability but low sensitization potential. PMID:25560673

  9. Predicting chemically-induced skin reactions. Part II: QSAR models of skin permeability and the relationships between skin permeability and skin sensitization.

    PubMed

    Alves, Vinicius M; Muratov, Eugene; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Andrade, Carolina H; Tropsha, Alexander

    2015-04-15

    Skin permeability is widely considered to be mechanistically implicated in chemically-induced skin sensitization. Although many chemicals have been identified as skin sensitizers, there have been very few reports analyzing the relationships between molecular structure and skin permeability of sensitizers and non-sensitizers. The goals of this study were to: (i) compile, curate, and integrate the largest publicly available dataset of chemicals studied for their skin permeability; (ii) develop and rigorously validate QSAR models to predict skin permeability; and (iii) explore the complex relationships between skin sensitization and skin permeability. Based on the largest publicly available dataset compiled in this study, we found no overall correlation between skin permeability and skin sensitization. In addition, cross-species correlation coefficient between human and rodent permeability data was found to be as low as R(2)=0.44. Human skin permeability models based on the random forest method have been developed and validated using OECD-compliant QSAR modeling workflow. Their external accuracy was high (Q(2)ext=0.73 for 63% of external compounds inside the applicability domain). The extended analysis using both experimentally-measured and QSAR-imputed data still confirmed the absence of any overall concordance between skin permeability and skin sensitization. This observation suggests that chemical modifications that affect skin permeability should not be presumed a priori to modulate the sensitization potential of chemicals. The models reported herein as well as those developed in the companion paper on skin sensitization suggest that it may be possible to rationally design compounds with the desired high skin permeability but low sensitization potential. PMID:25560673

  10. Quantum chemical calculations and experimental investigations on 2-aminobenzoic acid-cyclodiphosph(V)azane derivative and its homo-binuclear Cu(II) complex

    NASA Astrophysics Data System (ADS)

    El-Gogary, Tarek M.; Alaghaz, Abdel-Nasser M. A.; Ammar, Reda A. A.

    2012-03-01

    A novel 2-aminobenzoic acid-cyclodiphosph(V)azane ligand H4L and its homo-binuclear Cu(II) complex of the type [Cu2L(H2O)2].2.5 H2O in which L is 1,3-di(-o-pyridyl)-2,4-(dioxo)-2',4'-bis-(2-iminobenzoic acid) cyclodiphosph(V)azane, were synthesized and characterized by different physical techniques. Infrared spectra of the complex indicate deprotonation and coordination of the imine NH and carboxyl COOH groups. It also confirms that nitrogen atom of the pyridine ring contribute to the complexation. Electronic spectra and magnetic susceptibility measurements reveal square-planar geometry for the Cu(II) complex. The elemental analyses and thermogravimetric results have justified the [Cu2L(H2O)2]·2.5H2O composition of the complex. Quantum chemical calculations were utilized to explore the electronic structure and stability of the H4L as well as the binuclear Cu(II) complex. Computational studies have been carried out at the DFT-B3LYP/6-31G(d) level of theory on the structural and spectroscopic properties of H4L and its binuclear Cu(II) complex. Different tautomers and geometrical isomers of the ligand were optimized at the ab initio DFT level. Simulated IR frequencies were scaled and compared with that experimentally measured. TD-DFT method was used to compute the UV-VIS spectra which show good agreement with measured electronic spectra.

  11. Experimental and quantum-chemical studies of 1H, 13C and 15N NMR coordination shifts in Pd(II) and Pt(II) chloride complexes with quinoline, isoquinoline, and 2,2'-biquinoline.

    PubMed

    Pazderski, Leszek; Tousek, Jaromír; Sitkowski, Jerzy; Kozerski, Lech; Szłyk, Edward

    2007-12-01

    1H, 13C, and 15N NMR studies of platinide(II) (M=Pd, Pt) chloride complexes with quinolines (L=quinoline-quin, or isoquinoline-isoquin; LL=2,2'-biquinoline-bquin), having the general formulae trans-/cis-[ML2Cl2] and [M(LL)Cl2], were performed and the respective chemical shifts (delta1H, delta13C, delta15N) reported. 1H coordination shifts of various signs and magnitudes (Delta1Hcoord=delta1Hcomplex-delta1Hligand) are discussed in relation to the changes of diamagnetic contribution to the relevant 1H shielding constants. The comparison to the literature data for similar complexes containing auxiliary ligands other than chlorides exhibited a large dependence of delta1H parameters on electron density variations and ring-current effects (inductive and anisotropic phenomena). The influence of deviations from planarity, concerning either MN2Cl2 chromophores or azine ring systems, revealed by the known X-ray structures of [Pd(bquin)Cl2] and [Pt(bquin)Cl2], is discussed in respect to 1H NMR spectra. 15N coordination shifts (Delta15Ncoord=delta15Ncomplex-delta15Nligand) of ca. 78-100 ppm (to lower frequency) are attributed mainly to the decrease of the absolute value of paramagnetic contribution in the relevant 15N shielding constants, this phenomenon being noticeably dependent on the type of a platinide metal and coordination sphere geometry. The absolute magnitude of Delta15Ncoord parameter increased by ca 15 ppm upon Pd(II)-->Pt(II) replacement but decreased by ca. 15 ppm following trans-->cis transition. Experimental 1H, 13C, 15N NMR chemical shifts are compared to those quantum-chemically calculated by B3LYP/LanL2DZ+6-31G**//B3LYP/LanL2DZ+6-31G*, both in vacuo and in CHCl3 or DMF solution. PMID:18044805

  12. Chemical analyses of soil samples collected from the Sandia National Laboratories, New Mexico environs, 1993-2005.

    SciTech Connect

    Deola, Regina Anne; Oldewage, Hans D.; Herrera, Heidi; Miller, Mark Laverne

    2006-03-01

    From 1993 through 2005, the Environmental Management Department of Sandia National Laboratories in Albuquerque, New Mexico (SNL/NM), has collected soil and sediment samples at numerous locations on-site, on the perimeter, and off-site for the purpose of determining potential impacts to the environs from operations at the Laboratories. These samples were submitted to an analytical laboratory for metal-in-soil analyses. Intercomparisons of these results were then made to determine if there was any statistical difference between on-site, perimeter, and off-site samples, or if there were year-to-year increasing or decreasing trends which indicated that further investigation may be warranted. This work provided the SNL Environmental Management Department with a sound baseline data reference against which to assess potential current operational impacts or to compare future operational impacts. In addition, it demonstrates the commitment that the Laboratories have to go beyond mere compliance to achieve excellence in its operations. This data is presented in graphical format with narrative commentaries on particular items of interest.

  13. Chemical and colloidal analyses of natural seep water collected from the exploratory studies facility inside Yucca Mountain, Nevada, USA.

    PubMed

    Cizdziel, James V; Guo, Caixia; Steinberg, Spencer M; Yu, Zhongbo; Johannesson, Karen H

    2008-02-01

    Yucca Mountain is being considered as a geological repository for the USA's spent nuclear fuel and high-level nuclear waste. Numerous groundwater seeps appeared during March 2005 within the exploratory studies facility (ESF), a tunnel excavated in the mountain. Because of the relevance to radionuclide transport and unsaturated zone-modeling studies, we analyzed the seep samples for major anions and cations, rare earth elements, and colloids. Major ion species and elemental concentrations in seep samples reflect interaction of the water with the volcanic rock and secondary calcites. Elemental fractograms from flow-injection field-flow fractionation ICP-MS scans detected Br, Ca, Cl, Cu, Fe, I, Mg, Si, Sr, W, and U at void fractions, suggesting they may be present in the form of dissolved anions. Colloids approximately 10 nm in hydrodynamic diameter, possibly calcite, were also present in the seepage samples. Geochemical calculations indicate, however, these may be an artifact (not present in the groundwater) which arose because of loss of CO2 during sample collection and storage. PMID:17505890

  14. Chemical analyses of soil samples collected from the Sandia National Laboratories, Kauai Test Facility, HI, 1999-2007.

    SciTech Connect

    Miller, Mark Laverne

    2007-11-01

    In 1999, 2002, and 2007, the Environmental Programs and Assurance Department of Sandia National Laboratories (SNL) at the Kauai Test Facility (KTF), HI, has collected soil samples at numerous locations on-site, on the perimeter, and off-site for determining potential impacts to the environs from operations at KTF. These samples were submitted to an analytical laboratory for metal-in-soil analyses. Intercomparisons of these results were then made to determine if there was any statistical difference between on-site, perimeter, and off-site samples, or if there were increasing or decreasing trends that indicated that further investigation might be warranted. This work provided the SNL Environmental Programs and Assurance Department with a sound baseline data reference against which to compare future operational impacts. In addition, it demonstrates the commitment that the Laboratories have to go beyond mere compliance to achieve excellence in its operations. This data is presented in graphical format with narrative commentaries on particular items of interest.

  15. Characterization of Chemical Sputtering Using the Mark II DIMES Porous Plug Injector in Attached and Semi-detached Divertor Plasmas of DIII-D

    SciTech Connect

    McLean, A. G.; Davis, J. W.; Stangeby, P. C.; Allen, S. L.; Boedo, J. A.; Bray, B. D.; Brezinsek, S.; Brooks, N. H.; Fenstermacher, M. E.; Groth, M.; Haasz, A. A.; Hollmann, E. M.; Isler, Ralph C; Lasnier, C. J.; Mu, Y.; Petrie, T. W.; Rudakov, D. L.; Watkins, J. G.; West, W. P.; Whyte, D. G.; Wong, C. P. C.

    2009-01-01

    An improved, self-contained gas injection system for the divertor material evaluation system (DIMES) on DIII-D has been employed for in situ study of chemical erosion in the tokamak divertor environment. To minimize perturbation to local plasma, the Mark II porous plug injector (PPI) releases methane through a porous graphite surface at the outer strike point at a rate precisely controlled by a micro-orifice flow restrictor to be approximately equal as that predicted for intrinsic chemical sputtering. Effective photon efficiencies resulting from CH(4) are found to be 58 +/- 12 in an attached divertor (n(e) similar to 1.5 x 10(13)/cm(3), T(e) similar to 25 eV, T(surf)similar to 450 K), and 94 +/- 20 in a semi-detached cold divertor (n(e) similar to 6.0 x 10(13)/cm(3), T(e) similar to 2-3 eV, T(surf) similar to 350 K). These values are significantly more than previous measurements in similar plasma conditions, indicating the importance of the injection rate and local re-erosion for the integrity of this analysis. The contribution of chemical versus physical sputtering to the source of C(+) at the target is assessed through simultaneous measurement of CII line, and CD plus CH-band emissions during release of CH(4) from the Pill, then compared with that seen in intrinsic sputtering. (C) 2009 Elsevier B.V. All rights reserved.

  16. Detection of chemical interfaces in coherent anti-Stokes Raman scattering microscopy: D-CARS. II. Arbitrary interfaces.

    PubMed

    Gachet, David; Rigneault, Hervé

    2011-12-01

    We address the general problem of detecting chemical interfaces arbitrarily oriented in space in coherent anti-Stokes Raman scattering (CARS) microscopy. Such a task is accomplished by using a beam reversal scheme, as recently demonstrated experimentally [J. Biomed. Opt. 16, 086006 (2011)]. We develop a full vectorial theoretical analysis of the situation and show that transverse chemical interfaces are readily highlighted without special care in the CARS signal detection. In addition, a finer analysis reveals that adequate angular analysis of the CARS far-field radiation pattern enables the detection of axial interfaces. Background-free CARS microscopy and spectroscopy are thus achievable through the combined application of excitation beam reversal and angular analysis of the CARS far-field radiation pattern. This differential CARS (D-CARS) technique is relevant for fast detection of interfaces between molecularly different media. PMID:22193266

  17. Chemical reactivity testing of optical fluids and materials in the DEIMOS spectrographic camera for the Keck II telescope

    NASA Astrophysics Data System (ADS)

    Hilyard, David F.; Laopodis, George K.; Faber, Sandra M.

    1999-09-01

    The DEIMOS Spectrograph Camera contains tow doublets and a triplet. Each group contains materials differing in thermal coefficient expansion, mechanical and optical properties. To mate the elements and at the same time accommodate large camera temperature changes, we will fill the space between with an optical fluid couplant. We selected candidate couplants, lens-support materials, and fluid-constraining materials based on published optical, mechanical and chemical properties. We then tested the chemical reactivity between the coupling fluids, lens-support and fluid- constraining materials. We describe here the test configurations, our criteria for reactivity, and the result for various test durations. We describe our conclusions and final choices for couplant and materials.

  18. Radial metallicity gradients in spiral galaxies from H II regions and planetary nebulae: probing galactic chemical evolution

    NASA Astrophysics Data System (ADS)

    Stanghellini, Letizia

    2015-08-01

    Radial metallicity gradients, typically observed in spiral galaxies, are excellent constraints for chemical evolution models. The contemporary studies of the two stellar populations, whose progenitors have formed at different times, yield to the chemical and time constraining of the models. In this context, planetary nebula and HII region analysis proved to be ideal two-epochs test populations. We present an assortment of galaxies whose oxygen abundances have been determined both with weak- and strong-line methods, and whose radial metallicity gradients and their evolution in time have disclosed very interesting correlations with the galaxy characteristics. New results from our Gemini/GMOS observations, and a review of the best literature data, set the stage for a better understanding of spiral galaxy evolution.

  19. Studies in the Chemical Constituents of Azadirachta indica Part II: Isolation and Structure of the New Triterpenoid Azadirachtol.

    PubMed

    Siddiqui, S; Siddiqui, B S; Faizi, S

    1985-12-01

    A new triterpenoid named azadirachtol ( 1) has been isolated from the fruits of AZADIRACHTA INDICA Juss. (neem) of which the structure is reported on the basis of chemical and spectral data. Azadirachtol appears to be the first apo-tirucallol (apo-euphol) derivative possessing an eight carbons side-chain with an oxygenated ring system isolated from neem. Moreover, it is the first instance of the isolation of an 11-hydroxy triterpenoid from any of the various parts of neem. PMID:17345262

  20. Collisions of small ice particles under microgravity conditions. II. Does the chemical composition of the ice change the collisional properties?

    NASA Astrophysics Data System (ADS)

    Hill, C. R.; Heißelmann, D.; Blum, J.; Fraser, H. J.

    2015-03-01

    Context. Understanding the collisional properties of ice is important for understanding both the early stages of planet formation and the evolution of planetary ring systems. Simple chemicals such as methanol and formic acid are known to be present in cold protostellar regions alongside the dominant water ice; they are also likely to be incorporated into planets which form in protoplanetary disks, and planetary ring systems. However, the effect of the chemical composition of the ice on its collisional properties has not yet been studied. Aims: Collisions of 1.5 cm ice spheres composed of pure crystalline water ice, water with 5% methanol, and water with 5% formic acid were investigated to determine the effect of the ice composition on the collisional outcomes. Methods: The collisions were conducted in a dedicated experimental instrument, operated under microgravity conditions, at relative particle impact velocities between 0.01 and 0.19 ms-1, temperatures between 131 and 160 K and a pressure of around 10-5 mbar. Results: A range of coefficients of restitution were found, with no correlation between this and the chemical composition, relative impact velocity, or temperature. Conclusions: We conclude that the chemical composition of the ice (at the level of 95% water ice and 5% methanol or formic acid) does not affect the collisional properties at these temperatures and pressures due to the inability of surface wetting to take place. At a level of 5% methanol or formic acid, the structure is likely to be dominated by crystalline water ice, leading to no change in collisional properties. The surface roughness of the particles is the dominant factor in explaining the range of coefficients of restitution.

  1. Chemical and biological profiles of novel copper(II) complexes containing S-donor ligands for the treatment of cancer.

    PubMed

    Giovagnini, Lorena; Sitran, Sergio; Montopoli, Monica; Caparrotta, Laura; Corsini, Maddalena; Rosani, Claudia; Zanello, Piero; Dou, Q Ping; Fregona, Dolores

    2008-07-21

    In the last years, we have synthesized some new platinum(II), palladium(II), gold(I/III) complexes with dithiocarbamato derivatives as potential anticancer drugs, to obtain compounds with superior chemotherapeutic index in terms of increased bioavailability, higher cytotoxicity, and lower side effects than cisplatin. On the basis of the obtained encouraging results, we have been studying the interaction of CuCl2 with methyl-/ethyl-/tert-butylsarcosine-dithiocarbamato moieties in a 1:2 molar ratio; we also synthesized and studied the N,N-dimethyl- and pyrrolidine-dithiocarbamato copper complexes for comparison purposes. The reported compounds have been successfully isolated, purified, and fully characterized by means of several spectroscopic techniques. Moreover, the electrochemical properties of the designed compounds have been studied through cyclic voltammetry. In addition, the behavior in solution was followed by means of UV-vis technique to check the stability with time in physiological conditions. To evaluate their in vitro cytotoxic properties, preliminary biological assays (MTT test) have been carried out on a panel of human tumor cell lines. The results show that cytotoxicity levels of all of the tested complexes are comparable or even greater than that of the reference drug (cisplatin). PMID:18572881

  2. Collective Properties of Neutron-star X-Ray Binary Populations of Galaxies. II. Pre-low-mass X-Ray Binary Properties, Formation Rates, and Constraints

    NASA Astrophysics Data System (ADS)

    Bhadkamkar, H.; Ghosh, P.

    2014-04-01

    We continue our exploration of the collective properties of neutron-star X-ray binaries in the stellar fields (i.e., outside globular clusters) of normal galaxies. In Paper I of this series, we considered high-mass X-ray binaries (HMXBs). In this paper (Paper II), we consider low-mass X-ray binaries (LMXBs), whose evolutionary scenario is very different from that of HMXBs. We consider the evolution of primordial binaries up to the stage where the neutron star just formed in the supernova explosion of the primary is in a binary with its low-mass, unevolved companion, and this binary has circularized tidally, producing what we call a pre-low-mass X-ray binary (pre-LMXB). We study the constraints on the formation of such pre-LMXBs in detail (since these are low-probability events), and calculate their collective properties and formation rates. To this end, we first consider the changes in the binary parameters in the various steps involved, viz., the common-envelope phase, the supernova, and the tidal evolution. This naturally leads to a clarification of the constraints. We then describe our calculation of the evolution of the distributions of primordial binary parameters into those of pre-LMXB parameters, following the standard evolutionary scenario for individual binaries. We display the latter as both bivariate and monovariate distributions, discuss their essential properties, and indicate the influences of some essential factors on these. Finally, we calculate the formation rate of these pre-LMXBs. The results of this paper will be used in a subsequent one to compute the expected X-ray luminosity function of LMXBs.

  3. Chemical composition and sources of PM2.5 and TSP collected at Qinghai Lake during summertime

    NASA Astrophysics Data System (ADS)

    Zhang, Ningning; Cao, Junji; Liu, Suixin; Zhao, ZhuZi; Xu, Hongmei; Xiao, Shun

    2014-03-01

    PM2.5 and total suspended particulate (TSP) samples were collected from June to September 2010 at Qinghai Lake, northeastern Tibetan Plateau. The concentrations of major water-soluble ions, 10 elements, elemental carbons (ECs) and organic carbons (OCs) were quantified. Mass concentrations of PM2.5 and TSP were 21.27 ± 10.70 μg m- 3 and 41.47 ± 20.25 μg m- 3, respectively, and the mean ratio of PM2.5/TSP was 0.51. The greatest anion and cation in both PM2.5 and TSP samples were SO42 - and Ca2 +, respectively. Crustal elements, such as Ca, Fe and K, were the main elements in our aerosol samples, and their enrichment factors (EFs) were lower than 10. EFs for Pb, As, and Zn were greater than 10, indicating that they were influenced by anthropogenic sources. EC concentrations were 0.33 ± 0.17 μg m- 3 and 0.47 ± 0.28 μg m- 3, whereas OC concentrations were 1.49 ± 0.63 μg m- 3 and 2.30 ± 0.95 μg m- 3 in PM2.5 and TSP, respectively. Based on the calculated ratios of EC/TC and K+/EC, most of the ECs were found to be related to biomass burning emissions. Because of the pollution from local sources, the ratios of OC/EC were 4.77 ± 1.32 and 5.23 ± 1.39 in PM2.5 and TSP, respectively, which were lower than those of other remote sites. Salt particles produced by the salty lake reacted with acid gases and caused most of the nitrates and a small fraction of sulfate to be distributed in coarse mode; Cl deficit was also observed in our aerosol samples. Results of backward trajectories and correlation analysis show that the concentrations of SO4 2-, OCs, As, Pb, and Zn, were influenced by the long-distance transport from eastern China.

  4. Chemical trends of the luminescence in wide band gap II 1-xMn xVI semimagnetic semiconductors

    NASA Astrophysics Data System (ADS)

    Benecke, C.; Busse, W.; Gumlich, H.-E.

    1990-04-01

    Time resolved emission and excitation spectroscopy is used to investigate the Mn correlated luminescence in wide band gap II-VI compounds, i.e. Zn 1-xMn xS, Cd 1-xMn xSe, Zn 1-xMn xTe and Cd 1-xMn xTe. Additional Information has been obtained with CdxZnyMnzTe( x+ y+ z=1) in checking the luminescence by variation of the ratio of the cations Cd and Zn. Generally speaking, at least two distinct emissions bands can be observed for each II 1- xMn xVI compound. One emissions band is attributed to the internal transition 4T 1(G)→ 6A 1(S) of the 3d 5 electron of the Mn 2+ on regular metal sites with energies of about ≈2 eV. The other emission band is found to occur in the near infrared range of about ≈1.3 eV. This emission band is tentatively interpreted as a transition of Mn 2+ ions on interstitial sites or in small Mn chalcogenide clusters, both interpretations assuming cubic symmetry. This model is supported by the existence of low energy excitation bands and by the great similarity of the shape of the two emission bands which lead to comparable Huang-Rhys factors and effective phonon energies. Also the established trend in the experimental data of the II-VI compounds under consideration confirm this interpretation. For both the IR and the yellow Mn 2+ center, the Racah parameters B and C and the crystal field parameter Dq are determined on the basis of experimental data. As a result, the energy of both the emission and the excitation bands is predominantly determined by the sorrounding anions. These bands shift to higher energies when the anions are changed in the fixed order: Te→Se→S. Regularly, there is also a spectral shift when Zn is replaced by Cd, which is smaller than the shift due to the variation of onions.

  5. Integrated chemical/biochemical sample collection, pre-concentration, and analysis on a digital microfluidic lab-on-a-chip platform

    NASA Astrophysics Data System (ADS)

    Fair, Richard B.; Khlystov, A.; Srinivasan, Vijay; Pamula, Vamsee K.; Weaver, Kathryn N.

    2004-12-01

    An ideal on-site chemical/biochemical analysis system must be inexpensive, sensitive, fully automated and integrated, reliable, and compatible with a broad range of samples. The advent of digital microfluidic lab-on-a-chip (LoC) technology offers such a detection system due to the advantages in portability, reduction of the volumes of the sample and reagents, faster analysis times, increased automation, low power consumption, compatibility with mass manufacturing, and high throughput. We describe progress towards integrating sample collection onto a digital microfluidic LoC that is a component of a cascade impactor device. The sample collection is performed by impacting airborne particles directly onto the surface of the chip. After the collection phase, the surface of the chip is washed with a micro-droplet of solvent. The droplet will be digitally directed across the impaction surface, dissolving sample constituents. Because of the very small droplet volume used for extraction of the sample from a wide colection area, the resulting solution is realatively concentrated and the analytes can be detected after a very short sampling time (1 min) due to such pre-concentration. After the washing phase, the droplet is mixed with specific reagents that produce colored reaction products. The concentration of the analyte is quantitatively determined by measuring absorption at target wavelengths using a simple light emitting diode and photodiode setup. Specific applications include automatic measurements of major inorganic ions in aerosols, such as sulfate, nitrate and ammonium, with a time resolution of 1 min and a detection limit of 30 nm/m3. We have already demonstrated the detection and quantification of nitroaromatic explosives without integrating the sample collection. Other applications being developed include airborne bioagent detection.

  6. Chemical interactions in isolated coal-fired power plant plumes: conversion of sulfur dioxide to sulfate aerosols. Volume II. Data supplement

    SciTech Connect

    Meagher, J.F.; Bailey, E.M.; Stockburger, L. III

    1981-03-01

    The Tennessee Valley Authority (TVA) has conducted several field experiments to examine the chemical interactions in isolated coal-fired power plant plumes, Particularly the conversion of sulfur dioxide (SO/sub 2/) to sulfate (SO/sub 4//sup 2 -/) aerosols. Six field studies have been conducted at three TVA power plants - Cumberland, paradise, and Colbert Steam Plants - each of which has a different boiler configuration. Studies were conducted during all seasons of the year. Samples were usually collected between sunrise and noon; however, at Cumberland and Paradise Steam Plants, samples were also collected in the afternoon and after sunset. The effect of several meteorological parameters on the conversion rate was investigated from the results of these studies. During one study at Cumberland Steam Plant, samples were taken during periods of reduced and normal electrostatic precipitator (ESP) operation; results from this study were used to investigate the effect of particle loading in the plume on the conversion rate.

  7. Effects of chemical mechanical planarization slurry additives on the agglomeration of alumina nanoparticles II: aggregation rate analysis.

    PubMed

    Brahma, Neil; Talbot, Jan B

    2014-04-01

    The aggregation rate and mechanism of 150 nm alumina particles in 1mM KNO3 with various additives used in chemical mechanical planarization of copper were investigated. The pH of each suspension was ∼8 such that the aggregation rate was slow enough to be measured and analyzed over ∼120 min. In general, an initial exponential growth was observed for most suspensions indicating reaction-limited aggregation. After aggregate sizes increase to >500 nm, the rate followed a power law suggesting diffusion-limited aggregation. Stability ratios and fractal dimension numbers were also calculated to further elucidate the aggregation mechanism. PMID:24491325

  8. A forgotten collection: the Libyan ethnobotanical exhibits (1912-14) by A. Trotter at the Museum O. Comes at the University Federico II in Naples, Italy

    PubMed Central

    2012-01-01

    Background The Ethnobotanical Collection from the Libyan territories of the botanist Alessandro Trotter is included in the Oratio Comes Botanical Museum at the Faculty of Agraria at the University Federico II in Naples. Trotter explored different territories of Libya, mainly Tripolitania, between 1912-1924, collecting plant specimens and the drugs most frequently sold in the markets. The Libyan herbarium currently includes over 2300 sheets of mounted and accessioned plants. The drugs, mostly acquired by Trotter from Tripolitanian markets, were identified and packed in 87 paper sheets or boxes. Trotter added ethnobotanical information for each species when available. Methods A database of the herbarium species and the drugs has been carried out, after a taxonomic update. Nomenclature has been revised according to the African flowering plants database and the World Checklist of selected plant families, and a comparison with currently available ethnopharmacological data from North African has been attempted. Results In this study, ethnopharmacological data related to about 80 species of flowering plants and to 4 lichens are presented. The plants are mainly from Mediterranean or Sub-Saharan habitats and belong to 37 different families; Lamiaceae was the most cited family, with 10 accessions. Generally, the aerial parts of the plants are the most frequently used (28 species), followed by leaves (15 species), flowers and seeds (9 species), fruits (7 species) and hypogean organs (roots, rhizomes, tubers: 5 species). Plants were generally processed in very simple ways: infusion or decoction of the plants were prepared and orally administered or used for topical applications. A wide range of conditions was treated, ranging from mental disorders to skin affections. All the organs of human body are considered, but the pathologies of gastro-intestinal tract, respiratory system and those related to traumatic accidents were the most frequently mentioned. The comparison with the

  9. Metalorganic chemical vapor deposition growth of InAs/GaSb type II superlattices with controllable AsxSb1-x interfaces

    PubMed Central

    2012-01-01

    InAs/GaSb type II superlattices were grown on (100) GaSb substrates by metalorganic chemical vapor deposition (MOCVD). A plane of mixed As and Sb atoms connecting the InAs and GaSb layers was introduced to compensate the tensile strain created by the InAs layer in the SL. Characterizations of the samples by atomic force microscopy and high-resolution X-ray diffraction demonstrate flat surface morphology and good crystalline quality. The lattice mismatch of approximately 0.18% between the SL and GaSb substrate is small compared to the MOCVD-grown supperlattice samples reported to date in the literature. Considerable optical absorption in 2- to 8-μm infrared region has been realized. PACS: 78.67.Pt; 81.15.Gh; 63.22.Np; 81.05.Ea PMID:22373387

  10. Induced mutagenesis of plasmid and chromosomal genes inserted into the plasmid DNA. II. Mutagenic action of chemical factors

    SciTech Connect

    Esipova, V.V.; Vedunova, S.L.; Kriviskii, A.S.

    1986-02-01

    Following the study of the mutagenic action of UV and ..gamma..-radiation on plasmid DNA in vitro, they investigated the induction of mutations under the influence of chemical mutagens on the same DNA of plasmid RSF2124, determining the synthesis of colicine E1 and resistance to ampicillin. The inactivating action of the mutagen was assessed from the yield of transformants resistant to the antibiotic and the mutagenic effect from the loss by colonies of transformants that were capable of releasing colicine into the external medium. In these experiments they mainly used chemical compounds whose mutagenic effect if well known in other systems (transforming and transfecting DNA, microbial viruses). As a result all mutagens tested for their activity were divided into four groups: first group, those exceeding the level of mutagenesis by more than 100-fold above the spontaneous background (hydroxylamine, O-methylhydroxylamine); second group, those exceeding it by a factor of 10 (UV radiation (lambda = 254 nm), W-mutagenesis, ionizing radiation, nitrous acid, mitomycin C); third group, those exceeding it by a factor of <10 (indirect UV mutagenesis, nitrous acid, ..beta..-chloroethyldiethylamine hydrochloride, nitrosoguanidine); fourth group, no mutagenic effect (acridine orange, ethyl methane sulfonate, sodium azide, 0-..beta..-diethylaminoethylhydroxylamine).

  11. Computer programming for nucleic acid studies. II. Total chemical shifts calculation of all protons of double-stranded helices.

    PubMed

    Giessner-Prettre, C; Ribas Prado, F; Pullman, B; Kan, L; Kast, J R; Ts'o, P O

    1981-01-01

    A FORTRAN computer program called SHIFTS is described. Through SHIFTS, one can calculate the NMR chemical shifts of the proton resonances of single and double-stranded nucleic acids of known sequences and of predetermined conformations. The program can handle RNA and DNA for an arbitrary sequence of a set of 4 out of the 6 base types A,U,G,C,I and T. Data files for the geometrical parameters are available for A-, A'-, B-, D- and S-conformations. The positions of all the atoms are calculated using a modified version of the SEQ program [1]. Then, based on this defined geometry three chemical shift effects exerted by the atoms of the neighboring nucleotides on the protons of each monomeric unit are calculated separately: the ring current shielding effect: the local atomic magnetic susceptibility effect (including both diamagnetic and paramagnetic terms); and the polarization or electric field effect. Results of the program are compared with experimental results for a gamma (ApApGpCpUpU) 2 helical duplex and with calculated results on this same helix based on model building of A'-form and B-form and on graphical procedure for evaluating the ring current effects. PMID:6274583

  12. Part I. Synthesis of metal hydroborates as potential chemical vapor deposition precursors. Part II. Chemical vapor deposition of titanium-doped magnesium diboride thin films

    NASA Astrophysics Data System (ADS)

    Kim, Do Young

    2007-12-01

    center is coordinated to two chelating [H3BNMe2BH3]-ligands. Each BH3 group binds to the metal center by means of two hydrogen bridges, leaving one terminal hydrogen atom on each BH3 group; the H atoms that bridge to the metal center form slightly longer B-H bonds than the terminal H atoms on the same boron centers, as expected. The metal center in each compound forms eight M-H contacts, whose M-H distances are equal within experimental error. The Ti, Cr, and Mo compounds adopt square-planar geometries in which the dihedral angle between ligand planes is 0°. In contrast, in the Mn compound, which adopts a structure intermediate between a tetrahedron and a square plane, the two ligand planes define a dihedral angle of 46.5(2)°; this unusual dihedral angle maximizes interligand H···H distances. The solid state reaction of MgBr2 with Na(H3BNMe 2BH3) yields the monomeric, magnesium complex Mg(H3 BNMe2BH3)2. Its ether adducts Mg(H 3BNMe2BH3)2(thf) and Mg(H3BNMe 2BH3)2(dme), and the mixed ligand complex Cp*Mg(H 3BNMe2BH3)(thf), have also been prepared. Significantly, the binary complex Mg(H3BNMe2BH3)2 has a vapor pressure of 800 mTorr at 25°C, which makes it the most volatile magnesium complex known. The solid state reaction of MCl3 and Na(H3BNMe 2BH3) and subsequent sublimation in vacuum affords the dinuclear complexes, M2(H3BNMe2BH3) 6 (M = Y or Dy). X-ray crystallographic studies show that, in both compounds, two metal centers are connected by two bridging H3BNMe2BH 3 ligands; each metal center also bears two terminal diboranamide groups, which are chelating. Similar reactions conducted in thf solution yield the monomeric thf adducts M(H3BNMe2BH3) 3(thf) (M = Y or Dy). These molecules, which possess a boron-to-metal ratio of 6, are readily volatile below 100°C and are potential CVD precursors for the low-temperature growth of LnB6 thin films. The first low-temperature chemical vapor depositions of doped MgB 2 phases have been achieved by passing the precursor Mg(H3

  13. Reduced in vitro toxicity of fine particulate matter collected during the 2008 Summer Olympic Games in Beijing: the roles of chemical and biological components.

    PubMed

    Shang, Yu; Zhu, Tong; Lenz, Anke-Gabriele; Frankenberger, Birgit; Tian, Feng; Chen, Chenyong; Stoeger, Tobias

    2013-10-01

    Beijing has implemented systematic air pollution control legislation to reduce particulate emissions and improve air quality during the 2008 Summer Olympics, but whether the toxicity of fine fraction of particles (PM(2.5)) would be changed remains unclear. In present study we compared in vitro biological responses of PM(2.5) collected before and during the Olympics and tried to reveal possible correlations between its chemical components and toxicological mechanism(s). We measured cytotoxicity, cytokines/chemokines, and related gene expressions in murine alveolar macrophages, MH-S, after treated with 20 PM(2.5) samples. Significant, dose-dependent effects on cell viability, cytokine/chemokine release and mRNA expressions were observed. The cytotoxicity caused at equal mass concentration of PM(2.5) was notably reduced (p<0.05) by control measures, and significant association was found for viability and elemental zinc in PM(2.5). Endotoxin content in PM(2.5) correlated with all of the eight detected cytokines/chemokines; elemental and organic carbon correlated with four; arsenic and chromium correlated with six and three, respectively; iron and barium showed associations with two; nickel, magnesium, potassium, and calcium showed associations with one. PM(2.5) toxicity in Beijing was substantially dependent on its chemical components, and lowering the levels of specific components in PM(2.5) during the 2008 Olympics resulted in reduced biological responses. PMID:23962744

  14. Chemical structure of cement aged at normal and elevated temperatures and pressures, Part II: Low permeability class G oilwell cement

    SciTech Connect

    Le Saout, Gwenn . E-mail: gwenn.lesaout@epfl.ch; Lecolier, Eric; Rivereau, Alain; Zanni, Helene

    2006-03-15

    Recently, Low Permeability Cement formulation has been developed for oilwell cementing. Therefore, it is important to understand the physical and chemical processes causing cement degradation in the downhole environment. In this study, we have characterised a Low Permeability Class G oilwell Cement immersed for one year in brine at T = 293 K, p = 10{sup 5} Pa and T = 353 K, p = 7 x 10{sup 6} Pa using {sup 29}Si, {sup 27}Al NMR and XRD techniques. Elevated temperature and pressure conditions increase the rate of the pozzolanic reaction and have significant effects on the polymerisation of C-S-H and on the incorporation of Al in the C-S-H structure. Leaching resulted in the formation of calcite and a more polymerised C-S-H with the appearance of tobermorite in the sample cured at elevated temperature and pressure.

  15. Trapping of muscle relaxant methocarbamol degradation product by complexation with copper(II) ion: spectroscopic and quantum chemical studies.

    PubMed

    Mansour, Ahmed M; Shehab, Ola R

    2014-07-15

    Structural properties of methocarbamol (Mcm) were extensively studied both experimentally and theoretically using FT IR, (1)H NMR, UV-Vis., geometry optimization, Mulliken charge, and molecular electrostatic potential. Stability arises from hyper-conjugative interactions, charge delocalization and H-bonding was analyzed using natural bond orbital (NBO) analysis. Mcm was decomposed in ethanol/water mixture at 80°C to guaifenesin [(RS)-3-(2-methoxyphenoxy)propane-1,2-diol] and carbamate ion [NH2COO(-)], where the degradation mechanism was explained by trapping the carbamate ion via the complexation with copper(II) ion. The structure of the isolated complex ([Cu(NH2COO)2(H2O)]⋅4H2O) was elucidated by spectral, thermal, and magnetic tools. Electronic spectra were discussed by TD-DFT and the descriptions of frontier molecular orbitals and the relocations of the electron density were determined. Calculated g-tensor values showed best agreement with experimental values from EPR when carried out using both the B3LYP and B3PW91 functional. PMID:24674917

  16. Trapping of muscle relaxant methocarbamol degradation product by complexation with copper(II) ion: Spectroscopic and quantum chemical studies

    NASA Astrophysics Data System (ADS)

    Mansour, Ahmed M.; Shehab, Ola R.

    2014-07-01

    Structural properties of methocarbamol (Mcm) were extensively studied both experimentally and theoretically using FT IR, 1H NMR, UV-Vis., geometry optimization, Mulliken charge, and molecular electrostatic potential. Stability arises from hyper-conjugative interactions, charge delocalization and H-bonding was analyzed using natural bond orbital (NBO) analysis. Mcm was decomposed in ethanol/water mixture at 80 °C to guaifenesin [(RS)-3-(2-methoxyphenoxy)propane-1,2-diol] and carbamate ion [NH2COO-], where the degradation mechanism was explained by trapping the carbamate ion via the complexation with copper(II) ion. The structure of the isolated complex ([Cu(NH2COO)2(H2O)]ṡ4H2O) was elucidated by spectral, thermal, and magnetic tools. Electronic spectra were discussed by TD-DFT and the descriptions of frontier molecular orbitals and the relocations of the electron density were determined. Calculated g-tensor values showed best agreement with experimental values from EPR when carried out using both the B3LYP and B3PW91 functional.

  17. Branched conformational properties of macromolecules in close relation to chemical synthesis. II. Influence of excluded volume interactions.

    PubMed

    Burchard, Walther; Schweins, Ralf; Werner, Marcel

    2015-09-21

    The description of perturbed particle conformations needs as a prerequisite the algorithm of unperturbed chains which is outlined in Paper I [J. Chem. Phys. 143, 114906 (2015)]. The mean square segment length ⟨r(2)(n)⟩=b(2)n(2ν) with ν = 0.588 for linear chains in a good solvent is used as an approximation also for branched samples. The mean square radius of gyration is easily derived, but for the hydrodynamic, the segment distribution by Domb et al. [Proc. Phys. Soc., London 85, 624 (1965)] is required. Both radii can analytically be expressed by Gamma functions. For the angular dependence of scattered light, the Fourier transform of the Domb distribution for self-avoiding random walk is needed, which cannot be obtained as an analytical function and was derived by numerical integration. The summation over all segment length in the particle was performed with an analytic fit-curve for the Fourier transform and was carried out numerically. Results were derived (i) for uniform and polydisperse linear chains, (ii) or f-functional randomly branched polymers and their monodisperse fractions, (iii) for random A3B2 co-polymers, and (iv) for AB2 hyper-branched samples. The deviation of the Gaussian approximation with the variance of ⟨r(2)(n)⟩=b(2)n(2ν) slightly overestimates the excluded volume interaction but still remains a fairly good approximation for region of qR(g) < 10. PMID:26395738

  18. Chemical relevance of the copper(II)— L-carnosine system in aqueous solution: A thermodynamic and spectrophotometric study

    NASA Astrophysics Data System (ADS)

    Daniele, Pier G.; Prenesti, Enrico; Zelano, Vincenzo; Ostacoli, Giorgio

    1993-08-01

    The copper(II)— L-carnosine (L -) system has been re-investigated in aqueous solution, at I = 0.1 mol dm -1, different temperatures (5⩽ t⩽45°C) and with metal to ligand ratios ranging from 3:1 to 1:3. Both potentiometry and visible spectrophotometry were employed. From an overall consideration of all experiments, [CuLH] 2+, [CuL] +, [CuLH -1]°, [Cu 2L 2H -2]° and [Cu 2LH -1] 2+ were recognized as the species which provide the best interpretation of experimental data. The complex formation constants, determined at different temperatures, allowed us to obtain reliable values of Δ H° and good estimates of Δ C° p. From visible spectrophotometric measurements, carried out at different pH and metal to ligand ratios, it was possible to calculate the electronic spectrum of each complex formed in solution. A structure is also proposed for each species, on the basis of thermodynamic and spectral results.

  19. Branched conformational properties of macromolecules in close relation to chemical synthesis. II. Influence of excluded volume interactions

    NASA Astrophysics Data System (ADS)

    Burchard, Walther; Schweins, Ralf; Werner, Marcel

    2015-09-01

    The description of perturbed particle conformations needs as a prerequisite the algorithm of unperturbed chains which is outlined in Paper I [J. Chem. Phys. 143, 114906 (2015)]. The mean square segment length = b 2 n 2 ν with ν = 0.588 for linear chains in a good solvent is used as an approximation also for branched samples. The mean square radius of gyration is easily derived, but for the hydrodynamic, the segment distribution by Domb et al. [Proc. Phys. Soc., London 85, 624 (1965)] is required. Both radii can analytically be expressed by Gamma functions. For the angular dependence of scattered light, the Fourier transform of the Domb distribution for self-avoiding random walk is needed, which cannot be obtained as an analytical function and was derived by numerical integration. The summation over all segment length in the particle was performed with an analytic fit-curve for the Fourier transform and was carried out numerically. Results were derived (i) for uniform and polydisperse linear chains, (ii) or f-functional randomly branched polymers and their monodisperse fractions, (iii) for random A3B2 co-polymers, and (iv) for AB2 hyper-branched samples. The deviation of the Gaussian approximation with the variance of = b 2 n 2 ν slightly overestimates the excluded volume interaction but still remains a fairly good approximation for region of qRg < 10.

  20. Water and Sediment Chemical Data and Data Summary for Samples Collected in 1999 and 2001 in the Goodpaster River Basin, Big Delta B-2 Quadrangle, Alaska

    USGS Publications Warehouse

    Wang, Bronwen; Gough, Larry; Wanty, Richard; Vohden, Jim; Crock, Jim; Day, Warren

    2006-01-01

    We report the chemical analysis for water and sediment collected from the Big Delta B-2 quadrangle. These data are part of a study located in the Big Delta B-2 quadrangle that focused on the integration of geology and bedrock geochemistry on with the biogeochemistry of water, sediments, soil, and vegetation. The discovery of the Pogo lode gold deposit in the northwest corner of the quadrangle was the impetus for this study. The study objectives were to create a geologic map, evaluate the bedrock geochemical influence on the geochemical signature of the surficial environment, and define landscape-level predevelopment geochemical baselines. Important to baseline development is an evaluation of what, if any, geochemical difference exists between the mineralized and non-mineralized areas within a watershed or between mineralized and non-mineralized watersheds. The analytic results for the bedrock, soils, and vegetation are reported elsewhere. Presented here, with minimal interpretation, is the analytic data for the water and sediment samples collected in the summers of 1999 and 2001, and a summary statistics of these analyses.

  1. Single particle chemical composition, state of mixing and shape of fresh and aged Saharan dust in Morocco and at Cape Verde Islands during SAMUM I and II

    NASA Astrophysics Data System (ADS)

    Kandler, Konrad; Emmel, Carmen; Ebert, Martin; Lieke, Kirsten; Müller-Ebert, Dörthe; Schütz, Lothar; Weinbruch, Stephan

    2010-05-01

    The Saharan Mineral Dust Experiment (SAMUM) is focussed to the understanding of the radiative effects of mineral dust. During the SAMUM 2006 field campaign at Tinfou, southern Morocco, chemical and mineralogical properties of fresh desert aerosol was measured. The winter campaign of Saharan Mineral Dust Experiment II in 2008 was based in Praia, Island of Santiago, Cape Verde. This second field campaign was dedicated to the investigation of transported Saharan Mineral Dust. Ground-based and airborne measurements were performed in the winter season, where mineral dust from the Western Sahara and biomass burning aerosol from the Sahel region occurred. Samples were collected with a miniature impactor system, a sedimentation trap, a free-wing impactor, and a filter sampler. Beryllium discs as well as carbon coated nickel discs, carbon foils, and nuclepore and fiber filters were used as sampling substrates. The size-resolved particle aspect ratio and the chemical composition are determined by scanning electron microscopy and energy-dispersive X-ray microanalysis of single particles. Mineralogical bulk composition is determined by X-ray diffraction analysis. In Morocco, three size regimes are identified in the aerosol: Smaller than 500 nm in diameter, the aerosol consists of sulfates and mineral dust. Larger than 500 nm up to 50 µm, mineral dust dominates, consisting mainly of silicates, and - to a lesser extent - carbonates and quartz. Larger than 50 µm, approximately half of the particles consist of quartz. Time series of the elemental composition show a moderate temporal variability of the major compounds. Calcium-dominated particles are enhanced during advection from a prominent dust source in Northern Africa (Chott El Djerid and surroundings). More detailed results are found in Kandler et al. (2009) At Praia, Cape Verde, the boundary layer aerosol consists of a superposition of mineral dust, marine aerosol and ammonium sulfate, soot, and other sulfates as well as

  2. Isolation and chemical characterization of PwTx-II: a novel alkaloid toxin from the venom of the spider Parawixia bistriata (Araneidae, Araneae).

    PubMed

    Cesar, Lilian M M; Mendes, Maria A; Tormena, Claudio F; Marques, Maurício R; de Souza, Bibiana M; Saidemberg, Daniel Menezes; Bittencourt, Jackson C; Palma, Mario S

    2005-12-01

    Brazil has many species of spiders belonging to Araneidae family however, very little is known about the composition, chemical structure and mechanisms of action of the main venom components of these spiders. The main objective of this work was to isolate and to perform the chemical characterization of a novel beta-carboline toxin from the venom of the spider Parawixia bistriata, a typical species of the Brazilian 'cerrado'. The toxin was purified by RP-HPLC and structurally elucidated by using a combination of different spectroscopic techniques (UV, ESI-MS/MS and 1H NMR), which permitted the assignment of the molecular structure of a novel spider venom toxin, identified as 1-4-guanidinobutoxy-6-hydroxy-1,2,3,4-tetrahydro-beta-carboline, and referred to here as PwTx-II. This compound is toxic to insects (LD50 = 12+/-3 etag/mg honeybee), neurotoxic, convulsive and lethal to rats (LD50 = 9.75 mg/kg of male Wistar rat). PMID:16183095

  3. Critical evaluation of Jet-A spray combustion using propane chemical kinetics in gas turbine combustion simulated by KIVA-II

    NASA Technical Reports Server (NTRS)

    Nguyen, H. L.; Ying, S.-J.

    1990-01-01

    Numerical solutions of the Jet-A spray combustion were obtained by means of the KIVA-II computer code after Jet-A properties were added to the 12 chemical species the program had initially contained. Three different reaction mechanism models are considered. The first model consists of 131 reactions and 45 species; it is evaluated by comparing calculated ignition delay times with available shock tube data, and it is used in the evaluation of the other two simplified models. The simplified mechanisms consider 45 reactions and 27 species and 5 reactions and 12 species, respectively. In the prediction of pollutants NOx and CO, the full mechanism of 131 reactions is considered to be more reliable. The numerical results indicate that the variation of the maximum flame temperature is within 20 percent as compared with that of the full mechanism of 131 reactions. The chemical compositions of major components such as C3H8, H2O, O2, CO2, and N2 are of the same order of magnitude. However, the concentrations of pollutants are quite different.

  4. DFT calculations of 15N NMR shielding constants, chemical shifts and complexation shifts in complexes of rhodium(II) tetraformate with some nitrogenous organic ligands

    NASA Astrophysics Data System (ADS)

    Leniak, Arkadiusz; Jaźwiński, Jarosław

    2015-03-01

    Benchmark calculations of 15N NMR shielding constants for a set of model complexes of rhodium(II) tetraformate with nine organic ligands using the Density Functional Theory (DFT) methods have been carried out. The calculations were performed by means of several methods: the non-relativistic, relativistic scalar ZORA, and spin-orbit ZORA approaches at the CGA-PBE/QZ4P theory level, and the GIAO NMR method using the B3PW91 functional with the 6-311++G(2d,p) basis set for C, H, N, O atoms and the Stuttgart basis set for the Rh atom. The geometry of compounds was optimised either by the same basis set as for the NMR calculations or applying the B3LYP functional with the 6-31G(2d) basis set for C, H, N, O atoms and LANL2DZ for the Rh atom. Computed 15N NMR shielding constants σ were compatible with experimental 15N chemical shifts δ of complexes exhibiting similar structure and fulfil the linear equation δ = aσ + b. The a and b parameters for all data sets have been estimated by means of linear regression analysis. In contrast to the correlation method giving "scaled" chemical shifts, the conversion of shielding constants to chemical shifts with respect to the reference shielding of CH3NO2 provided very inaccurate "raw" δ values. The application of the former to the calculation of complexation shifts Δδ (Δδ = δcompl - δlig) reproduced experimental values qualitatively or semi-quantitatively. The non-relativistic B3PW91/[6-311++G(2d,p), Stuttgart] theory level reproduced the NMR parameters as good as the more expensive relativistic CGA-PBE//QZ4P ZORA approaches.

  5. Chemical treatment of Escherichia coli. II. Direct extraction of recombinant protein from cytoplasmic inclusion bodies in intact cells.

    PubMed

    Falconer, R J; O'Neill, B K; Middelberg, A P

    1998-02-20

    A method is presented for the direct extraction of the recombinant protein Long-R3-IGF-I from inclusion bodies located in the cytoplasm of intact Escherichia coli cells. Chemical treatment with 6M urea, 3 mM EDTA, and 20 mM dithiothreitol (DTT) at pH 9.0 proved an effective combination for extracting recombinant protein from intact cells. Comparable levels of Long-R3-IGF-I were recovered by direct extraction as achieved by in vitro dissolution following mechanical disruption. However, the purity of directly extracted recombinant protein was lower due to contamination by bacterial cell components. The kinetics of direct extraction are described using a first-order equation with the time constant of 3 min. Urea appears important for permeabilization of the cell and dissolution of the inclusion body. Conversely, EDTA is involved in permeabilization of the cell wall and DTT enhances protein release. pH proved to be important with lower levels of protein release achieved at low pH values (<9). Cell concentration also had a minor effect on Long-R3-IGF-I release and caused an observable increase in viscosity. Advantages of the direct extraction method include its speed, simplicity, and efficiency at releasing product. PMID:10099214

  6. THE CHEMICAL ABUNDANCES OF STARS IN THE HALO (CASH) PROJECT. II. A SAMPLE OF 14 EXTREMELY METAL-POOR STARS ,

    SciTech Connect

    Hollek, Julie K.; Sneden, Christopher; Shetrone, Matthew; Frebel, Anna; Roederer, Ian U.; Beers, Timothy C.; Kang, Sung-ju; Thom, Christopher E-mail: chris@astro.as.utexas.edu E-mail: afrebel@cfa.harvard.edu E-mail: beers@pa.msu.edu E-mail: cthom@stsci.edu

    2011-11-20

    We present a comprehensive abundance analysis of 20 elements for 16 new low-metallicity stars from the Chemical Abundances of Stars in the Halo (CASH) project. The abundances have been derived from both Hobby-Eberly Telescope High Resolution Spectrograph snapshot spectra (R {approx}15, 000) and corresponding high-resolution (R {approx}35, 000) Magellan Inamori Kyocera Echelle spectra. The stars span a metallicity range from [Fe/H] from -2.9 to -3.9, including four new stars with [Fe/H] < -3.7. We find four stars to be carbon-enhanced metal-poor (CEMP) stars, confirming the trend of increasing [C/Fe] abundance ratios with decreasing metallicity. Two of these objects can be classified as CEMP-no stars, adding to the growing number of these objects at [Fe/H]< - 3. We also find four neutron-capture-enhanced stars in the sample, one of which has [Eu/Fe] of 0.8 with clear r-process signatures. These pilot sample stars are the most metal-poor ([Fe/H] {approx}< -3.0) of the brightest stars included in CASH and are used to calibrate a newly developed, automated stellar parameter and abundance determination pipeline. This code will be used for the entire {approx}500 star CASH snapshot sample. We find that the pipeline results are statistically identical for snapshot spectra when compared to a traditional, manual analysis from a high-resolution spectrum.

  7. The Most Metal-poor Stars. II. Chemical Abundances of 190 Metal-poor Stars Including 10 New Stars with [Fe/H] <= -3.5

    NASA Astrophysics Data System (ADS)

    Yong, David; Norris, John E.; Bessell, M. S.; Christlieb, N.; Asplund, M.; Beers, Timothy C.; Barklem, P. S.; Frebel, Anna; Ryan, S. G.

    2013-01-01

    We present a homogeneous chemical abundance analysis of 16 elements in 190 metal-poor Galactic halo stars (38 program and 152 literature objects). The sample includes 171 stars with [Fe/H] <= -2.5, of which 86 are extremely metal poor, [Fe/H] <= -3.0. Our program stars include 10 new objects with [Fe/H] <= -3.5. We identify a sample of "normal" metal-poor stars and measure the trends between [X/Fe] and [Fe/H], as well as the dispersion about the mean trend for this sample. Using this mean trend, we identify objects that are chemically peculiar relative to "normal" stars at the same metallicity. These chemically unusual stars include CEMP-no objects, one star with high [Si/Fe], another with high [Ba/Sr], and one with unusually low [X/Fe] for all elements heavier than Na. The Sr and Ba abundances indicate that there may be two nucleosynthetic processes at lowest metallicity that are distinct from the main r-process. Finally, for many elements, we find a significant trend between [X/Fe] versus T eff, which likely reflects non-LTE and/or three-dimensional effects. Such trends demonstrate that care must be exercised when using abundance measurements in metal-poor stars to constrain chemical evolution and/or nucleosynthesis predictions. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile (proposal 281.D-5015).

  8. Chemical weathering of a soil chronosequence on granitoid alluvium: II. Mineralogic and isotopic constraints on the behavior of strontium

    USGS Publications Warehouse

    Bullen, T.; White, A.; Blum, A.; Harden, J.; Schulz, M.

    1997-01-01

    Strontium isotopes to identify sources of base cations in catchment waters and biomass, both preferential leaching of Sr from minerals during incipient soil development and changing Sr exchange efficiency must be considered along with chemical contributions due to mineral dissolution. Copyright ?? 1997 Elsevier Science Ltd.

  9. Photoinduced chemical reactions on natural single crystals and synthesized crystallites of mercury(II) sulfide in aqueous solution containing naturally occurring amino acids.

    PubMed

    Pal, Bonamali; Ikeda, Shigeru; Ohtani, Bunsho

    2003-03-10

    Photoirradiation at >300 nm of aqueous suspensions of several natural crystal specimens and synthesized crystallites of mercury(II) sulfide (HgS) induced deaminocyclization of optically active or racemic lysine into pipecolinic acid (PCA) under deaerated conditions. This is the first example, to the best of our knowledge, of photoinduced chemical reactions of natural biological compounds over natural minerals. It was found that the natural HgS crystals had activity higher than those of synthesized ones but lower than those of other sulfides of transition metals, e.g., CdS and ZnS, belonging to the same II-IV chalcogenides. In almost all of the photoreactions, decompostion of HgS occurred to liberate hydrogen sulfide (H(2)S) and Hg(2+), and the latter seemed to have undergone in-situ reductive deposition on HgS as Hg(0) after a certain induction period (24-70 h) during the photoirradiation, as indicated by the darkened color of the suspensions. The formation of PCA, presumably through combination of oxidation of lysine and reduction of an intermediate, cyclic Schiff base, could also be seen after a certain induction time of the Hg(0) formation. This was supported by the fact that the addition of small amount of Hg(2+) (0.5 wt % of HgS) increased the PCA yield by almost 2-fold. We also tried to elucidate certain aspects of the plausible stereochemical reactions in relation to the chiral crystal structure of HgS. Although, in some experiments, slight enantiomeric excess of the product PCA was observed, the excess was below or equal to the experimental error and no other supporting analytical data could not be obtained; we cannot conclude the enantiomeric photoproduction of PCA by the natural chiral HgS specimen. PMID:12611518

  10. Long-term observation of water-soluble chemical components and acid-digested metals in the total suspended particles collected at Okinawa, Japan

    NASA Astrophysics Data System (ADS)

    Handa, D.; Okada, K.; Kuroki, Y.; Nakama, Y.; Nakajima, H.; Somada, Y.; Ijyu, M.; Azechi, S.; Oshiro, Y.; Nakaema, F.; Miyagi, Y.; Arakaki, T.; Tanahara, A.

    2011-12-01

    The economic growth and population increase in recent Asia have been increasing air pollution. Emission rate of air pollutants from Asia, in particular oxides of nitrogen, surpassed those from North America and Europe and should continue to exceed them for decades. Okinawa Island is situated approximately 1500 km south of Tokyo, Japan, 2000 km southeast of Beijing, China, and 1000 km south of South Korea. Its location is ideal in observing East Asia's air quality because maritime air mass prevails during summer, while continental air mass dominates during fall, winter, and spring. The maritime air mass data can be seen as background clean air and can be compared with continental air masses which have been affected by anthropogenic activities. We collected total suspended particles (TSP) on quartz filters by using a high volume air sampler at the Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS), Okinawa, Japan during August 2005 and August 2010. Sampling duration was one week for each sample. We determined the concentrations of water-soluble anions, cations, water-soluble organic carbon (WSOC) and acid-digested metals in TSP samples using ion chromatography, atomic absorption spectrometry, total organic carbon analyzer and Inductively Coupled Plasma Mass spectrometry (ICP-MS), respectively. Seasonal variation of water-soluble chemical components and acid-digested metals showed that the concentrations were the lowest in summer, higher in fall and winter, and the highest in spring. When air mass came from Asian continent, the concentrations of water-soluble chemical components and acid-digested metals were much higher compared to the other directions, suggesting long-range transport of air pollutants from Asian continent. Also, when the air mass came from Asian continent (75-100% dominant), the mean concentrations of non-sea salt sulfate and nitrate increased ca. 1.8 times and ca. 3.7 times, respectively between 2005 and 2010, and the ratio of nitrate to

  11. Water-soluble Ru(II)- and Ru(III)-halide-PTA complexes (PTA=1,3,5-triaza-7-phosphaadamantane): Chemical and biological properties.

    PubMed

    Battistin, F; Scaletti, F; Balducci, G; Pillozzi, S; Arcangeli, A; Messori, L; Alessio, E

    2016-07-01

    Four structurally related Ru(II)-halide-PTA complexes, of general formula trans- or cis-[Ru(PTA)4X2] (PTA=1,3,5-triaza-7-phosphaadamantane, X=Cl (1, 2), Br (3, 4), were prepared and characterized. Whereas compounds 1 and 2 are known, the corresponding bromo derivatives 3 and 4 are new. The Ru(III)-PTA compound trans-[RuCl4(PTAH)2]Cl (5, PTAH=PTA protonated at one N atom), structurally similar to the well-known Ru(III) anticancer drug candidates (Na)trans-[RuCl4(ind)2] (NKP-1339, ind=indazole) and (Him)trans-[RuCl4(dmso-S)(im)] (NAMI-A, im=imidazole), was also prepared and similarly investigated. Notably, the presence of PTA confers to all complexes an appreciable solubility in aqueous solutions at physiological pH. The chemical behavior of compounds 1-5 in water and in physiological buffer, their interactions with two model proteins - cytochrome c and ribonuclease A - as well as with a single strand oligonucleotide (5'-CGCGCG-3'), and their in vitro cytotoxicity against a human colon cancer cell line (HCT-116) and a myeloid leukemia (FLG 29.1) were investigated. Upon dissolution in the buffer, sequential halide replacement by water molecules was observed for complexes 1-4, with relatively slow kinetics, whereas the Ru(III) complex 5 is more inert. All tested compounds manifested moderate antiproliferative properties, the cis compounds 2 and 4 being slightly more active than the trans ones (1 and 3). Mass spectrometry experiments evidenced that all complexes exhibit a far higher reactivity towards the reference oligonucleotide than towards model proteins. The chemical and biological profiles of compounds 1-5 are compared to those of established ruthenium drug candidates in clinical development. PMID:26920229

  12. Influence of activated-carbon-supported transition metals on the decomposition of polychlorobiphenyls. Part II: Chemical and physical characterization and mechanistic study.

    PubMed

    Sun, Yifei; Liu, Lina; Oshita, Kazuyuki; Zeng, Xiaolan; Wang, Wei; Zhang, Yibo

    2016-09-01

    This paper studies the synergism between transition metals (TMs) and activated carbon (AC) as a catalyst support used in the catalytic decomposition of PCBs. A series of AC-supported TM catalysts was prepared according to two distinct methods: impregnation and ion exchange which were defined as LaTM-C and IRTM-C, respectively. The catalytic reactions between 2,2',4,4',5,5'-hexachlorobiphenyl (PCB-153) and AC-supported Fe, Ni, Cu and Zn catalysts were conducted under N2 atmosphere. Changes in the nature of the catalysts as well as the decomposition mechanism of PCB-153 are discussed. Important findings include: (i) a higher metal concentration and a better metal distribution on AC is realized using ion-exchange, despite a lower AC specific surface area, (ii) IRTM-C had better effects on the decomposition of PCB-153 than LaTM-C, (iii) the role of Ni, Cu, and Fe as electron donors in PCB dechlorination was evaluated vs. the stability of Zn, and (iv) both temperature and chemical composition of TM catalysts influenced the decomposition efficiency of PCBs. PMID:27320438

  13. Environmental chemical data for perishable sediments and soils collected in New Orleans, Louisiana, and along the Louisiana Delta following Hurricanes Katrina and Rita, 2005

    USGS Publications Warehouse

    Witt, Emitt C.; Shi, Honglan; Karstensen, Krista A.; Wang, Jianmin; Adams, Craig D.

    2008-01-01

    In October 2005, nearly one month after Hurricanes Katrina and Rita, a team of scientists from the U.S. Geological Survey and the Missouri University of Science and Technology deployed to southern Louisiana to collect perishable environmental data resulting from the impacts of these storms. Perishable samples collected for this investigation are subject to destruction or ruin by removal, mixing, or natural decay; therefore, collection is time-critical following the depositional event. A total of 238 samples of sediment, soil, and vegetation were collected to characterize chemical quality. For this analysis, 157 of the 238 samples were used to characterize trace element, iron, total organic carbon, pesticide, and polychlorinated biphenyl concentrations of deposited sediment and associated shallow soils. In decreasing order, the largest variability in trace element concentration was detected for lead, vanadium, chromium, copper, arsenic, cadmium, and mercury. Lead was determined to be the trace element of most concern because of the large concentrations present in the samples ranging from 4.50 to 551 milligrams per kilogram (mg/kg). Sequential extraction analysis of lead indicate that 39.1 percent of the total lead concentration in post-hurricane sediment is associated with the iron-manganese oxide fraction. This fraction is considered extremely mobile under reducing environmental conditions, thereby making lead a potential health hazard. The presence of lead in post-hurricane sediments likely is from redistribution of pre-hurricane contaminated soils and sediments from Lake Pontchartrain and the flood control canals of New Orleans. Arsenic concentrations ranged from 0.84 to 49.1 mg/kg. Although Arsenic concentrations generally were small and consistent with other research results, all samples exceeded the U.S. Environmental Protection Agency’s Human Health Medium-Specific Screening Level of 0.39 mg/kg. Mercury concentrations ranged from 0.02 to 1.30 mg

  14. Biomimetic mono- and dinuclear Ni(I) and Ni(II) complexes studied by X-ray absorption and emission spectroscopy and quantum chemical calculations

    NASA Astrophysics Data System (ADS)

    Schuth, N.; Gehring, H.; Horn, B.; Holze, P.; Kositzki, R.; Schrapers, P.; Limberg, C.; Haumann, M.

    2016-05-01

    Five biomimetic mono- or dinuclear nickel complexes featuring Ni(I) or Ni(II) sites were studied by X-ray absorption and emission spectroscopy and DFT calculations. Ni K-edge XANES spectra and Kβ main and satellite emission lines were collected on powder samples. The pre-edge absorption transitions (core-to-valence excitation) and Kβ2,5 emission transitions (valence-to-core decay) were calculated using DFT (TPSSh/TZVP) on crystal structures. This yielded theoretical ctv and vtc spectra in near-quantitative agreement with the experiment, showing the adequacy of the DFT approach for electronic structure description, emphasizing the sensitivity of the XAS/XES spectra for ligation/redox changes at nickel, and revealing the configuration of unoccupied and occupied valence levels, as well as the spin-coupling modes in the dinuclear complexes. XAS/XES-DFT is valuable for molecular and electronic structure analysis of synthetic complexes and of nickel centers in H2 or COx converting metalloenzymes.

  15. I. Nuclear Production Reaction and Chemical Isolation Procedure for Americium-240 II. New Superheavy Element Isotopes: Plutonium-242(Calcium-48,5n)(285)114

    NASA Astrophysics Data System (ADS)

    Ellison, Paul Andrew

    2011-12-01

    Part I discusses the study of a new nuclear reaction and chemical separation procedure for the production of 240Am. Thin 242Pu, natTi, and natNi targets were coincidently activated with protons from the 88-Inch Cyclotron, producing 240Am, 48V, and 57Ni, respectively. The radioactive decay of these isotopes was monitored using high-purity Ge gamma ray detectors in the weeks following irradiation. The excitation function for the 242 Pu(p, 3n)240Am nuclear reaction was measured to be lower than theoretical predictions, but high enough to be the most viable nuclear reaction for the large-scale production of 240 Am. Details of the development of a chemical separation procedure for isolating 240Am from proton-irradiated 242Pu are discussed. The separation procedure, which includes two anion exchange columns and two extraction chromatography columns, was experimentally investi- gated using tracer-level 241Am, 239Pu, and model proton-induced fission products 95Zr, 95Nb, 125Sb, and 152Eu. The separation procedure was shown to have an Am/Pu separation factor of >2x10 7 and an Am yield of ˜70%. The separation procedure was found to purify the Am sample from >99.9% of Eu, Zr, Nb, and Sb. The procedure is well suited for the processing of ˜1 gram of proton-irradiated 242Pu to produce a neutron-induced fission target consisting of tens of nanograms of 240Am. Part II describes the use of the Berkeley Gas-filled Separator at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron for the study of the 242Pu(48Ca,5n)285114 nuclear re- action. The new, neutron-deficient, superheavy element isotope 285114 was produced in 48Ca irradiations of 242Pu targets at a center-of-target beam energy of 256 MeV ( E* = 50 MeV). The alpha decay of 285114 was followed by the sequential alpha decay of four daughter nuclides, 281Cn, 277Ds, 273Hs, and 269 Sg. 265Rf was observed to decay by spontaneous fission. The measured alpha-decay Q-values were compared with those from a macroscopic

  16. Effects of molybdenum oxide molecular doping on the chemical structure of poly(3,4-ethylenedioxythiophene):poly(stylenesulfonate) and on carrier collection efficiency of silicon/poly(3,4-ethylenedioxythiophene):poly(stylenesulfonate) heterojunction solar cells

    NASA Astrophysics Data System (ADS)

    Liu, Q.; Khatri, I.; Ishikawa, R.; Ueno, K.; Shirai, H.

    2013-05-01

    The effects of MoO3 molecular doping in poly(3,4-ethylenedioxythiophene):poly(stylenesulfonate) (PEDOT:PSS) on the chemical structure and, in turn, on the carrier collection efficiency of c-Si/PEDOT:PSS heterojunction solar cells are demonstrated. Scanning electron microscopy revealed that the hydrophilic PSS polymer chain was intercalated into the interlayer van der Waals gap of MoO3 flake sheets, which modified the chemical structure of PEDOT:PSS. MoO3 exhibited intense photoluminescence in the 350-550 nm region, which enhanced the carrier collection efficiency of c-Si/PEDOT:PSS heterojunction solar cells with no significant changes. These findings suggest that the intense photoluminescence of MoO3 and its light wavelength conversion contribute to the increased carrier collection efficiency.

  17. 40 CFR 125.95 - As an owner or operator of a Phase II existing facility, what must I collect and submit when I...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... activities; (2) You must submit to the Director the information required in 40 CFR 122.21(r)(2), (r)(3) and... your NPDES permit application in accordance with the time frames specified in 40 CFR 122.21(d)(2). (ii... qualifications (e.g., in the fields of geology, engineering, and/or biology, etc.) depending upon the...

  18. 40 CFR 125.95 - As an owner or operator of a Phase II existing facility, what must I collect and submit when I...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... activities; (2) You must submit to the Director the information required in 40 CFR 122.21(r)(2), (r)(3) and... your NPDES permit application in accordance with the time frames specified in 40 CFR 122.21(d)(2). (ii... qualifications (e.g., in the fields of geology, engineering, and/or biology, etc.) depending upon the...

  19. 40 CFR 125.95 - As an owner or operator of a Phase II existing facility, what must I collect and submit when I...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... activities; (2) You must submit to the Director the information required in 40 CFR 122.21(r)(2), (r)(3) and... your NPDES permit application in accordance with the time frames specified in 40 CFR 122.21(d)(2). (ii... qualifications (e.g., in the fields of geology, engineering, and/or biology, etc.) depending upon the...

  20. 40 CFR 125.95 - As an owner or operator of a Phase II existing facility, what must I collect and submit when I...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... activities; (2) You must submit to the Director the information required in 40 CFR 122.21(r)(2), (r)(3) and... your NPDES permit application in accordance with the time frames specified in 40 CFR 122.21(d)(2). (ii... qualifications (e.g., in the fields of geology, engineering, and/or biology, etc.) depending upon the...

  1. 40 CFR 125.95 - As an owner or operator of a Phase II existing facility, what must I collect and submit when I...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... activities; (2) You must submit to the Director the information required in 40 CFR 122.21(r)(2), (r)(3) and... your NPDES permit application in accordance with the time frames specified in 40 CFR 122.21(d)(2). (ii... qualifications (e.g., in the fields of geology, engineering, and/or biology, etc.) depending upon the...

  2. Effect of sampling site and collection method on variations in baseline clinical pathology parameters in Fischer-344 rats. II. Clinical hematology.

    PubMed

    Smith, C N; Neptun, D A; Irons, R D

    1986-11-01

    An analysis of the influence of blood-sampling site and collection method on peripheral hematology parameters was conducted in age-matched male Fischer-344 rats. Sites examined for blood collection were the right ventricle, abdominal aorta, abdominal vena cava, retroorbital plexus, and tail. Collection methods used included syringe (10 ml), Vacutainer(s) (3 ml or 3 ml X 2), and capillary tube. Blood collected from the tail exhibited leukocyte counts approximately twice those of samples samples from other sites. Blood collected from the retroorbital plexus and tail exhibited significant variations in white blood cell count, red blood cell count, hemoglobin, and hematocrit, and differences in leukocyte differential counts of lymphocytes and neutrophils when compared with other sites. Blood collected from the abdominal aorta and in a second Vacutainer from the right ventricle exhibited lower erythrocyte, leukocyte, and platelet counts than that collected from other sites with the exception of the platelet count from tail blood which was lower than that from all other sites. Although parameter values vary with sample site selection, those obtained from right ventricle blood were the least variable and the most consistent when compared with all other methods. PMID:3803760

  3. Historical estimates of external gamma exposure and collective external gamma exposure from testing at the Nevada Test Site. I. Test series through HARDTACK II, 1958

    SciTech Connect

    Anspaugh, L.R.; Church, B.W.

    1985-12-01

    In 1959, the Test Manager's Committee to Establish Fallout Doses calculated estimated external gamma exposure at populated locations based upon measurements of external gamma-exposure rate. Using these calculations and estimates of population, we have tabulated the collective estimated external gamma exposures for communities within established fallout patterns. The total collective estimated external gamma exposure is 85,000 person-R. The greatest collective exposures occurred in three general areas: Saint George, Utah; Ely, Nevada; and Las Vegas, Nevada. Three events, HARRY (May 19, 1953), BEE (March 22, 1955), and SMOKY (August 31, 1957), accounted for over half of the total collective estimated external gamma exposure. The bases of the calculational models for external gamma exposure of ''infinite exposure,'' ''estimated exposure,'' and ''one year effective biological exposure'' are explained. 4 figs., 7 tabs.

  4. Historical estimates of external gamma exposure and collective external gamma exposure from testing at the Nevada Test Site. I. Test series through HARDTACK II, 1958.

    PubMed

    Anspaugh, L R; Church, B W

    1986-07-01

    In 1959, the Test Manager's Committee to Establish Fallout Doses calculated estimated external gamma exposure at populated locations based upon measurements of external gamma-exposure rate. Using these calculations and estimates of population, we have tabulated the collective estimated external gamma exposures for communities within established fallout patterns. The total collective estimated external gamma exposure is 85,000 person-R. The greatest collective exposures occurred in three general areas: Saint George, UT; Ely, NV; and Las Vegas, NV. Three events, HARRY (19 May 1953), BEE (22 March 1955), and SMOKY (31 August 1957), accounted for more than half the total collective estimated external gamma exposure. The bases of the calculational models for external gamma exposure of "infinite exposure," "estimated exposure," and "1-yr effective biological exposure" are explained. PMID:3332000

  5. Historical estimates of external gamma exposure and collective external gamma exposure from testing at the Nevada Test Site. I. Test series through HARDTACK II, 1958

    SciTech Connect

    Anspaugh, L.R.; Church, B.W.

    1986-07-01

    In 1959, the Test Manager's Committee to Establish Fallout Doses calculated estimated external gamma exposure at populated locations based upon measurements of external gamma-exposure rate. Using these calculations and estimates of population, we have tabulated the collective estimated external gamma exposures for communities within established fallout patterns. The total collective estimated external gamma exposure is 85,000 person-R. The greatest collective exposures occurred in three general areas: Saint George, UT; Ely, NV; and Las Vegas, NV. Three events, HARRY (19 May 1953), BEE (22 March 1955), and SMOKY (31 August 1957), accounted for more than half the total collective estimated external gamma exposure. The bases of the calculational models for external gamma exposure of infinite exposure, estimated exposure, and 1-yr effective biological exposure are explained.

  6. Binary Classification of a Large Collection of Environmental Chemicals from Estrogen Receptor Assays by Quantitative Structure-Activity Relationship and Machine Learning Methods

    EPA Science Inventory

    ABSTRACT: There are thousands of environmental chemicals subject to regulatory decisions for endocrine disrupting potential. A promising approach to manage this large universe of untested chemicals is to use a prioritization filter that combines in vitro assays with in silico QSA...

  7. THE SPLASH SURVEY: INTERNAL KINEMATICS, CHEMICAL ABUNDANCES, AND MASSES OF THE ANDROMEDA I, II, III, VII, X, AND XIV DWARF SPHEROIDAL GALAXIES {sup ,}

    SciTech Connect

    Kalirai, Jason S.; Beaton, Rachael L.; Majewski, Steven R.; Ostheimer, James C.; Patterson, Richard J.; Geha, Marla C.; Gilbert, Karoline M.; Guhathakurta, Puragra; Kirby, Evan N.

    2010-03-10

    We present new Keck/DEIMOS spectroscopic observations of hundreds of individual stars along the sightline to the first three of the Andromeda (M31) dwarf spheroidal (dSph) galaxies to be discovered, And I, II, and III, and combine them with recent spectroscopic studies by our team of three additional M31 dSphs, And VII, X, and XIV, as a part of the SPLASH Survey (Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo). Member stars of each dSph are isolated from foreground Milky Way dwarf stars and M31 field contamination using a variety of photometric and spectroscopic diagnostics. Our final spectroscopic sample of member stars in each dSph, for which we measure accurate radial velocities with a median uncertainty (random plus systematic errors) of 4-5 km s{sup -1}, includes 80 red giants in And I, 95 in And II, 43 in And III, 18 in And VII, 22 in And X, and 38 in And XIV. The sample of confirmed members in the six dSphs is used to derive each system's mean radial velocity, intrinsic central velocity dispersion, mean abundance, abundance spread, and dynamical mass. This combined data set presents us with a unique opportunity to perform the first systematic comparison of the global properties (e.g., metallicities, sizes, and dark matter masses) of one-third of Andromeda's total known dSph population with Milky Way counterparts of the same luminosity. Our overall comparisons indicate that the family of dSphs in these two hosts have both similarities and differences. For example, we find that the luminosity-metallicity relation is very similar between L {approx} 10{sup 5} and 10{sup 7} L{sub sun}, suggesting that the chemical evolution histories of each group of dSphs are similar. The lowest luminosity M31 dSphs appear to deviate from the relation, possibly suggesting tidal stripping. Previous observations have noted that the sizes of M31's brightest dSphs are systematically larger than Milky Way satellites of similar luminosity. At lower luminosities

  8. Chemical geodynamics

    NASA Astrophysics Data System (ADS)

    Zindler, A.; Hart, S.

    Consideration is given to the following three principal boundary conditions relating to the nature and development of chemical structure in the earth's mantle: (1) inferred scale lengths for mantle chemical heterogeneities, (2) interrelationships of the various isotopic tracers, and (3) the bulk composition of the earth. These boundary conditions are integrated with geophysical constraints in order to evaluate models for the development of the physical and chemical structure of the mantle. Data indicate that: (1) km-size heterogeneities can survive diffusive equilibrium for billions of years; (2) the mantle is chemically heterogeneous on both very small and very large scales; (3) isotopic heterogeneities in the mantle require the existence of four 'end-member' components (DMM, HIMU, EM I, and EM II) and are consistent with the existence of at least two additional components (BSE, PREMA); and (4) primitive undepleted mantle can made up no more than about 55 percent of the total mantle.

  9. Inplementation of an automated signal processing approach for the analysis of chemical spectral signatures collected from FT-IR mounted in an aircraft

    SciTech Connect

    Kroutil, Robert T

    2008-01-01

    The automated detection of chemical spectral signatures using a passive infrared Fourier Transform Infrared (FT-IR) Spectrometer mounted in an aircraft is a difficult challenge due to the small total infrared energy contribution of a particular chemical species compared to the background signature. The detection of spectral signatures is complicated by the fact that a large, widely varying infrared background is present that is coupled with the presence of a number of chemical interferents in the atmosphere. This paper describes a mathematical technique that has been demonstrated to automatically detect specific chemical species in an automated processing environment. The data analysis methodology has been demonstrated to be effective using data of low spectral resolution at low aircraft altitudes. An overview of the implementation and basic concepts of the approach are presented.

  10. Indirect-Collective Referencing (ICR) in the Elite Journal Literature of Physics. II. A Literature Science Study on the Level of Communications.

    ERIC Educational Resources Information Center

    Szava-Kovats, Endre

    2002-01-01

    Continues previous research on indirect-collective referencing (ICR) in physics literature, focusing on the level of communications and specific degree of documentedness of a communication. Explains ICR as a special kind of scientific referencing, mentioning references that are not indexed and hence not included in the Science Citation Index. (LRW)

  11. Subject Indexing and Citation Indexing--Part I: Clustering Structure in the Cystic Fibrosis Document Collection [and] Part II: An Evaluation and Comparison.

    ERIC Educational Resources Information Center

    Shaw, W. M., Jr.

    1990-01-01

    These two articles discuss clustering structure in the Cystic Fibrosis Document Collection, which is derived from the National Library of Medicine's MEDLINE file. The exhaustivity of four subject representations and two citation representations is examined, and descriptor-weight thresholds and similarity thresholds are used to compute…

  12. Computer analysis of human esophageal peristalsis and lower esophageal sphincter pressure. II. An interactive system for on-line data collection and analysis.

    PubMed

    Castell, J A; Castell, D O

    1986-11-01

    A computer program has been written to directly read and analyze esophageal manometric tracings on-line using low-cost off-the-shelf microcomputer hardware. The system consists of an Apple IIe microcomputer and an Interactive Microwave Inc. ADALAB Data Acquisition System with an AI13 fast A/D Multiplexer. The primary program is in BASIC with ASSEMBLY language subroutines for data collection. Data are collected through the voltage output of a Hewlett-Packard recorder at 30 points per second on four channels for lower esophageal sphincter pressures (LESP) and three channels for peristaltic waves. Computer-determined values for LESP and wave parameters showed excellent correlation with mean values as read by five individuals experienced in esophageal manometry. PMID:3769705

  13. Integrated Procurement Management System, Version II

    NASA Technical Reports Server (NTRS)

    Collier, L. J.

    1985-01-01

    Integrated Procurement Management System, Version II (IPMS II) is online/ batch system for collecting developing, managing and disseminating procurementrelated data at NASA Johnson Space Center. Portions of IPMS II adaptable to other procurement situations.

  14. Chemicals of emerging concern in water and bottom sediment in the Great Lakes Basin, 2012: collection methods, analytical methods, quality assurance, and study data

    USGS Publications Warehouse

    Lee, Kathy E.; Langer, Susan K.; Menheer, Michael A.; Hansen, Donald S.; Foreman, William T.; Furlong, Edward T.; Jorgenson, Zachary G.; Choy, Steven J.; Moore, Jeremy N.; Banda, JoAnn; Gefell, Daniel J.

    2015-01-01

    During this study, 53 environmental samples, 4 field duplicate samples, and 8 field spike samples of bottom sediment and laboratory matrix-spike samples were analyzed for a wide variety of CECs at the USGS National Water Quality Laboratory using laboratory schedule 5433 for wastewater indicators; research method 6434 for steroid hormones, sterols, and bisphenol A; and research method 9008 for human-use pharmaceuticals and antidepressants. Forty of the 57 chemicals analyzed using laboratory schedule 5433 had detectable concentrations ranging from 1 to 49,000 micrograms per kilogram. Fourteen of the 20 chemicals analyzed using research method 6434 had detectable concentrations ranging from 0.04 to 24,940 nanograms per gram. Ten of the 20 chemicals analyzed using research method 9008 had detectable concentrations ranging from 0.59 to 197.5 micrograms per kilogr

  15. 76 FR 28951 - Proposed Information Collection; Comment Request; Data Collection for Compliance With Government...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-19

    ... Economic Development Administration Proposed Information Collection; Comment Request; Data Collection for... collection instrument and instructions should be directed to Kerstin Millius, Senior Program Analyst... meeting its stated goals and objectives. II. Method of Collection Respondents will submit forms to...

  16. High-Frequency (13)C and (29)Si NMR Chemical Shifts in Diamagnetic Low-Valence Compounds of Tl(I) and Pb(II): Decisive Role of Relativistic Effects.

    PubMed

    Vícha, Jan; Marek, Radek; Straka, Michal

    2016-02-15

    The (13)C and (29)Si NMR signals of ligand atoms directly bonded to Tl(I) or Pb(II) heavy-element centers are predicted to resonate at very high frequencies, up to 400 ppm for (13)C and over 1000 ppm for (29)Si, outside the typical experimental NMR chemical-shift ranges for a given type of nuclei. The large (13)C and (29)Si NMR chemical shifts are ascribed to sizable relativistic spin-orbit effects, which can amount to more than 200 ppm for (13)C and more than 1000 ppm for (29)Si, values unexpected for diamagnetic compounds of the main group elements. The origin of the vast spin-orbit contributions to the (13)C and (29)Si NMR shifts is traced to the highly efficient 6p → 6p* metal-based orbital magnetic couplings and related to the 6p orbital-based bonding together with the low-energy gaps between the occupied and virtual orbital subspaces in the subvalent Tl(I) and Pb(II) compounds. New NMR spectral regions for these compounds are suggested based on the fully relativistic density functional theory calculations in the Dirac-Coulomb framework carefully calibrated on the experimentally known NMR data for Tl(I) and Pb(II) complexes. PMID:26820039

  17. Xenobiotic metabolism capacities of human skin in comparison with a 3D-epidermis model and keratinocyte-based cell culture as in vitro alternatives for chemical testing: phase II enzymes.

    PubMed

    Götz, Christine; Pfeiffer, Roland; Tigges, Julia; Ruwiedel, Karsten; Hübenthal, Ulrike; Merk, Hans F; Krutmann, Jean; Edwards, Robert J; Abel, Josef; Pease, Camilla; Goebel, Carsten; Hewitt, Nicola; Fritsche, Ellen

    2012-05-01

    The 7th Amendment to the EU Cosmetics Directive prohibits the use of animals in cosmetic testing for certain endpoints, such as genotoxicity. Therefore, skin in vitro models have to replace chemical testing in vivo. However, the metabolic competence neither of human skin nor of alternative in vitro models has so far been fully characterized, although skin is the first-pass organ for accidentally or purposely (cosmetics and pharmaceuticals) applied chemicals. Thus, there is an urgent need to understand the xenobiotic-metabolizing capacities of human skin and to compare these activities to models developed to replace animal testing. We have measured the activity of the phase II enzymes glutathione S-transferase, UDP-glucuronosyltransferase and N-acetyltransferase in ex vivo human skin, the 3D epidermal model EpiDerm 200 (EPI-200), immortalized keratinocyte-based cell lines (HaCaT and NCTC 2544) and primary normal human epidermal keratinocytes. We show that all three phase II enzymes are present and highly active in skin as compared to phase I. Human skin, therefore, represents a more detoxifying than activating organ. This work systematically compares the activities of three important phase II enzymes in four different in vitro models directly to human skin. We conclude from our studies that 3D epidermal models, like the EPI-200 employed here, are superior over monolayer cultures in mimicking human skin xenobiotic metabolism and thus better suited for dermatotoxicity testing. PMID:22509834

  18. Chemical defense collective protection technology. Volume 12. A procedure for recharging self-contained breathing apparatus air bottles in the presence of simulated chemical warfare agents. Final report, 6-11 September 1990

    SciTech Connect

    Conkle, J.P.; Tucker, D.M.; Moore, G.

    1993-05-01

    A procedure was developed and tested for recharging Self-Contained Breathing Apparatus (SCBA) cylinders in an atmosphere contaminated with chemical agent simulant at concentrations which would produce casualties if actual agent were used. With the exception of a rack for storing the cylinders before and after recharging, all items used are currently available commercially or through off-the-shelf DOD supply sources. Cylinders were successfully recharged without contamination in the presence of chemical agent simulant in the compressor area as well as in the cylinder filling area. Inexperienced personnel easily learned and successfully followed the recharging procedures even though they were burdened by protective clothing and equipment. Chemical agents, SCBA, Firefighting, Self-contained breathing apparatus.

  19. Chemical Transformation Simulator

    EPA Science Inventory

    The Chemical Transformation Simulator (CTS) is a web-based, high-throughput screening tool that automates the calculation and collection of physicochemical properties for an organic chemical of interest and its predicted products resulting from transformations in environmental sy...

  20. Chemicals of emerging concern in water and bottom sediment in the Great Lakes Basin, 2012: collection methods, analytical methods, quality assurance, and study data

    USGS Publications Warehouse

    Lee, Kathy E.; Langer, Susan K.; Menheer, Michael A.; Hansen, Donald S.; Foreman, William T.; Furlong, Edward T.; Jorgenson, Zachary G.; Choy, Steven J.; Moore, Jeremy N.; Banda, JoAnn; Gefell, Daniel J.

    2015-01-01

    During this study, 53 environmental samples, 4 field duplicate samples, and 8 field spike samples of bottom sediment and laboratory matrix-spike samples were analyzed for a wide variety of CECs at the USGS National Water Quality Laboratory using laboratory schedule 5433 for wastewater indicators; research method 6434 for steroid hormones, sterols, and bisphenol A; and research method 9008 for human-use pharmaceuticals and antidepressants. Forty of the 57 chemicals analyzed using laboratory schedule 5433 had detectable concentrations ranging from 1 to 49,000 micrograms per kilogram. Fourteen of the 20 chemicals analyzed using research method 6434 had detectable concentrations ranging from 0.04 to 24,940 nanograms per gram. Ten of the 20 chemicals analyzed using research method 9008 had detectable concentrations ranging from 0.59 to 197.5 micrograms per kilogram. Five of the 11 chemicals analyzed using research method 9008 had detectable concentrations ranging from 1.16 to 25.0 micrograms per kilogram.

  1. Estimation of the chemical-induced eye injury using a Weight-of-Evidence (WoE) battery of 21 artificial neural network (ANN) c-QSAR models (QSAR-21): part II: corrosion potential.

    PubMed

    Verma, Rajeshwar P; Matthews, Edwin J

    2015-03-01

    This is part II of an in silico investigation of chemical-induced eye injury that was conducted at FDA's CFSAN. Serious eye damage caused by chemical (eye corrosion) is assessed using the rabbit Draize test, and this endpoint is an essential part of hazard identification and labeling of industrial and consumer products to ensure occupational and consumer safety. There is an urgent need to develop an alternative to the Draize test because EU's 7th amendment to the Cosmetic Directive (EC, 2003; 76/768/EEC) and recast Regulation now bans animal testing on all cosmetic product ingredients and EU's REACH Program limits animal testing for chemicals in commerce. Although in silico methods have been reported for eye irritation (reversible damage), QSARs specific for eye corrosion (irreversible damage) have not been published. This report describes the development of 21 ANN c-QSAR models (QSAR-21) for assessing eye corrosion potential of chemicals using a large and diverse CFSAN data set of 504 chemicals, ADMET Predictor's three sensitivity analyses and ANNE classification functionalities with 20% test set selection from seven different methods. QSAR-21 models were internally and externally validated and exhibited high predictive performance: average statistics for the training, verification, and external test sets of these models were 96/96/94% sensitivity and 91/91/90% specificity. PMID:25510831

  2. Development of a specific and highly sensitive optical chemical sensor for determination of Hg(II) based on a new synthesized ionophore.

    PubMed

    Firooz, Ali R; Ensafi, Ali A; Karimi, K; Sharghi, H

    2013-10-01

    A novel optode for determination of Hg(II) ions is developed based on immobilization of a recently synthesized ionophore, 7-(1H-imidazol-1-ylmethyl)-5,6,7,8,9,10-hexahydro-2H-1,13,4,7,10 benzodioxatriaza cyclopentadecine-3,11(4H,12H)-dione, in a PVC membrane. Dioctyl sebacate was used as a plasticizer, sodium tetraphenylborate as an anionic additive and ETH5294 as a chromoionophore. The response of the optode was based on the complexation of Hg(II) with the ionophore in the membrane phase, resulting an ion exchange process between Hg(II) in the sample solution and H(+) in the membrane. The effects of pH and amounts of the ionophore, chromoionophore, ionic additive and type of plasticizer on the optode response were investigated. The selectivity of the optode was studied in the present of several cations. The optode has a linear response to Hg(II) in the range of 7.2×10(-13)-4.7×10(-4) mol L(-1) with detection limit of 0.18 pmol L(-1). The optode was successfully applied to the determination of Hg(II) in real samples. PMID:23910329

  3. The Important Role of the Hydroxyl Group on the Conformational Adaptability in Bis(l-threoninato)copper(II) Compared to Bis(l-allo-threoninato)copper(II): Quantum Chemical Study.

    PubMed

    Marković, Marijana; Ramek, Michael; Loher, Claudia; Sabolović, Jasmina

    2016-08-01

    Detailed structural properties of physiological bis(amino acidato)copper(II) complexes are generally unknown in solutions. This paper examines how stereochemical differences between the essential amino acid l-threonine and its diastereomer l-allo-threonine, which is rarely present in nature, may affect relative stabilities of bis(l-threoninato)copper(II) and bis(l-allo-threoninato)copper(II) in the gas phase and aqueous solution. These amino acids can bind to Cu(II) via the nitrogen and carboxylato oxygen atoms, the nitrogen and hydroxyl oxygen atoms, and the carboxylato and hydroxyl oxygen atoms. We term these coordination modes G, No, and Oo, respectively. The density functional theory (DFT) calculations with the B3LYP functional of the conformational landscapes for all possible coordination modes of both complexes revealed their very similar stability in the gas phase and in aqueous solution. The conformational analyses resulted in 196 and 267 conformers of isolated copper(II) chelates with l-threonine and l-allo-threonine, respectively. The G-G coordination mode is the most stable, both in the gas phase and aqueous solution. Very similar energy values of the lowest-energy solvated cis and trans G-G conformers in implicitly accounted water medium are in accord with the experimental results that these isomers are present in aqueous solution at physiological pH values. The transition-state structures, activation Gibbs free energies, and reaction rates calculated using DFT/B3LYP and MP2 for the transformations from the most stable cis G-G and trans Oo-G conformers to trans G-G ones for the first time reveal several alternate coordination-mode transformation mechanisms in the copper(II) complexes with amino acids other than glycine. The trans Oo-G conformers are kinetically more stable than cis G-G ones in the gas phase. The only significant difference found between the two complexes is a more suitable position of the hydroxyl group in physiological bis(l-threoninato)copper(II

  4. Harnessing Technology to Improve Clinical Trials: Study of Real-Time Informatics to Collect Data, Toxicities, Image Response Assessments, and Patient-Reported Outcomes in a Phase II Clinical Trial

    PubMed Central

    Pietanza, M. Catherine; Basch, Ethan M.; Lash, Alex; Schwartz, Lawrence H.; Ginsberg, Michelle S.; Zhao, Binsheng; Shouery, Marwan; Shaw, Mary; Rogak, Lauren J.; Wilson, Manda; Gabow, Aaron; Latif, Marcia; Lin, Kai-Hsiung; Wu, Qinfei; Kass, Samantha L.; Miller, Claire P.; Tyson, Leslie; Sumner, Dyana K.; Berkowitz-Hergianto, Alison; Sima, Camelia S.; Kris, Mark G.

    2013-01-01

    Purpose In clinical trials, traditional monitoring methods, paper documentation, and outdated collection systems lead to inaccuracies of study information and inefficiencies in the process. Integrated electronic systems offer an opportunity to collect data in real time. Patients and Methods We created a computer software system to collect 13 patient-reported symptomatic adverse events and patient-reported Karnofsky performance status, semi-automated RECIST measurements, and laboratory data, and we made this information available to investigators in real time at the point of care during a phase II lung cancer trial. We assessed data completeness within 48 hours of each visit. Clinician satisfaction was measured. Results Forty-four patients were enrolled, for 721 total visits. At each visit, patient-reported outcomes (PROs) reflecting toxicity and disease-related symptoms were completed using a dedicated wireless laptop. All PROs were distributed in batch throughout the system within 24 hours of the visit, and abnormal laboratory data were available for review within a median of 6 hours from the time of sample collection. Manual attribution of laboratory toxicities took a median of 1 day from the time they were accessible online. Semi-automated RECIST measurements were available to clinicians online within a median of 2 days from the time of imaging. All clinicians and 88% of data managers felt there was greater accuracy using this system. Conclusion Existing data management systems can be harnessed to enable real-time collection and review of clinical information during trials. This approach facilitates reporting of information closer to the time of events, and improves efficiency, and the ability to make earlier clinical decisions. PMID:23630218

  5. TOPoS . II. On the bimodality of carbon abundance in CEMP stars Implications on the early chemical evolution of galaxies

    NASA Astrophysics Data System (ADS)

    Bonifacio, P.; Caffau, E.; Spite, M.; Limongi, M.; Chieffi, A.; Klessen, R. S.; François, P.; Molaro, P.; Ludwig, H.-G.; Zaggia, S.; Spite, F.; Plez, B.; Cayrel, R.; Christlieb, N.; Clark, P. C.; Glover, S. C. O.; Hammer, F.; Koch, A.; Monaco, L.; Sbordone, L.; Steffen, M.

    2015-07-01

    Context. In the course of the Turn Off Primordial Stars (TOPoS) survey, aimed at discovering the lowest metallicity stars, we have found several carbon-enhanced metal-poor (CEMP) stars. These stars are very common among the stars of extremely low metallicity and provide important clues to the star formation processes. We here present our analysis of six CEMP stars. Aims: We want to provide the most complete chemical inventory for these six stars in order to constrain the nucleosynthesis processes responsible for the abundance patterns. Methods: We analyse both X-Shooter and UVES spectra acquired at the VLT. We used a traditional abundance analysis based on OSMARCS 1D local thermodynamic equilibrium (LTE) model atmospheres and the turbospectrum line formation code. Results: Calcium and carbon are the only elements that can be measured in all six stars. The range is -5.0 ≤ [Ca/H] <-2.1 and 7.12 ≤ A(C) ≤ 8.65. For star SDSS J1742+2531 we were able to detect three Fe i lines from which we deduced [Fe/H] = -4.80, from four Ca ii lines we derived [Ca/H] = -4.56, and from synthesis of the G-band we derived A(C) = 7.26. For SDSS J1035+0641 we were not able to detect any iron lines, yet we could place a robust (3σ) upper limit of [Fe/H] < -5.0 and measure the Ca abundance, with [Ca/H] = -5.0, and carbon, A(C) = 6.90, suggesting that this star could be even more metal-poor than SDSS J1742+2531. This makes these two stars the seventh and eighth stars known so far with [Fe/H] < -4.5, usually termed ultra-iron-poor (UIP) stars. No lithium is detected in the spectrum of SDSS J1742+2531 or SDSS J1035+0641, which implies a robust upper limit of A(Li) < 1.8 for both stars. Conclusions: Our measured carbon abundances confirm the bimodal distribution of carbon in CEMP stars, identifying a high-carbon band and a low-carbon band. We propose an interpretation of this bimodality according to which the stars on the high-carbon band are the result of mass transfer from an AGB

  6. Chemical abundances in the protoplanetary disc LV 2 (Orion): clues to the causes of the abundance anomaly in H II regions

    NASA Astrophysics Data System (ADS)

    Tsamis, Y. G.; Walsh, J. R.; Vílchez, J. M.; Péquignot, D.

    2011-04-01

    Optical integral field spectroscopy of the archetype protoplanetary disc LV 2 in the Orion nebula is presented, taken with the Very Large Telescope (VLT) FLAMES/Argus fibre array. The detection of recombination lines (RLs) of C II and O II from this class of objects is reported, and the lines are utilized as abundance diagnostics. The study is complemented with the analysis of Hubble Space Telescope (HST) Faint Object Spectrograph ultraviolet and optical spectra of the target contained within the Argus field of view. By subtracting the local nebula background the intrinsic spectrum of the proplyd is obtained and its elemental composition is derived for the first time. The proplyd is found to be overabundant in carbon, oxygen and neon compared to the Orion nebula and the Sun. The simultaneous coverage over LV 2 of the C III]λ1908 and [O III]λ5007 collisionally excited lines (CELs) and C II and O II RLs has enabled us to measure the abundances of C2 + and O2 + for LV 2 with both sets of lines. The two methods yield consistent results for the intrinsic proplyd spectrum, but not for the proplyd spectrum contaminated by the generic nebula spectrum, thus providing one example where the long-standing abundance anomaly plaguing metallicity studies of H II regions has been resolved. These results would indicate that the standard forbidden-line methods used in the derivation of light metal abundances in H II regions in our own and other galaxies underestimate the true gas metallicity.

  7. Responses of the L5178Y tk/sup +//tk/sup -/ mouse lymphoma cell forward mutation assay. II. 18 coded chemicals

    SciTech Connect

    McGregor, D.B.; Brown, A.; Cattanach, P.; Edwards, I.; McBride, D.; Caspary, W.J.

    1988-01-01

    Eighteen chemicals were tested for their mutagenic potential in the L5178Y tk/sup +///sup -/ mouse lymphoma cell forward mutation assay by the use of procedures based upon those described previously. Cultures were exposed to the chemicals for 4 hr, then cultured for 2 days before plating in soft agar with or without trifluorothymidine (TFT), 3 ..mu..g/ml. The chemicals were tested at least twice. Significant responses were obtained with benzofuran, benzyl chloride, bromodichloromethane, butylated hydroxytoluene, chlorendic acid, o-chlorobenzalmalonitrile, 1,2,3,4-diepoxybutane, dimethyl formamide, dimethyl hydrogen phosphite, furfural, glutaraldehyde, hydroquinone, 8-hydroxyquinoline, and resorcinol. Apart from bromodichloromethane, butylated hydroxytoluene and dimethyl hydrogen phosphite, rat liver S9 mix was not a requirement for the activity of any of these compounds. Chemicals not identified as mutagens were water, tert-butyl alcohol, pyridine, and witch hazel.

  8. Kinetic theory of spin-polarized systems in electric and magnetic fields with spin-orbit coupling. II. RPA response functions and collective modes

    NASA Astrophysics Data System (ADS)

    Morawetz, K.

    2015-12-01

    The spin and density response functions in the random phase approximation are derived by linearizing the kinetic equation including a magnetic field, the spin-orbit coupling, and mean fields with respect to an external electric field. Different polarization functions appear describing various precession motions showing Rabi satellites due to an effective Zeeman field. The latter turns out to consist of the mean-field magnetization, the magnetic field, and the spin-orbit vector. The collective modes for charged and neutral systems are derived and a threefold splitting of the spin waves dependent on the polarization and spin-orbit coupling is shown. The dielectric function including spin-orbit coupling, polarization, and magnetic fields is presented analytically for long wavelengths and in the static limit. The dynamical screening length as well as the long-wavelength dielectric function shows an instability in charge modes, which are interpreted as spin segregation and domain formation. The spin response describes a crossover from damped oscillatory behavior to exponentially damped behavior dependent on the polarization and collision frequency. The magnetic field causes ellipsoidal trajectories of the spin response to an external electric field and the spin-orbit coupling causes a rotation of the spin axes. The spin-dephasing times are extracted and discussed in dependence on the polarization, magnetic field, spin-orbit coupling, and single-particle relaxation times.

  9. Science research annual, volume II: a collection of science staff memoranda and letters from the Illinois Legislature Council - January-June 1980. Annual report Jan 80-Sep 81

    SciTech Connect

    Dutton, J.A.

    1981-09-01

    This volume contains a collection of correspondence and contributions from the Illinois Legislative Council. The memoranda, which have been organized into research reports, answer requests from individual legislators for information on specific science, technology, and public policy issues, and include information sources and pertinent legislation of the 81st Illinois General Assembly. Topics covered are as follows: abortion information; accidental deer slaughter; regulation of airport noise pollution; historical artifacts preservation; asbestos health hazards; automobile repair legislation; HLA blood tests; financial aid for catastrophic illness; cost comparison of coal and nuclear power; mandates for coroners versus medical examiners; dialysis patient programs; drug paraphernalia legislation; electric generating capacity of Fox River dams; energy efficiency in appliances; euthanasia; farmland preservation; licenses for fish dealers; gasohol definition, grants, and other states' laws; medical precautions at football games; the Ames, Iowa methane plant; metric sales laws; proposed mining regulations; nuclear power referenda; nuclear waste disposal; pharmaceutical assistance and renewable prescriptions for the aged; licensing of radiation device operators; scientific creationism; solar energy grants and loans; funding for solar energy programs; sulfur dioxide standards; and visual aid programs.

  10. Contaminants and levels of occurrence in washed and shredded poly(ethylene terephthalate) from curbside collection. II: Validation of extraction procedures, particle size sampling and crystallinity.

    PubMed

    Konkol, L M; Cross, R F; Harding, I H; Kosior, E

    2003-10-01

    Part I of this study showed that washed and dried, shredded poly(ethylene terephthalate) (PET) (flake) obtained from curbside collection when Soxhlet extracted contained 26 semivolatile contaminants below the US FDA threshold of 215 ppb and six above this level. This paper reports the validation of the Soxhlet extraction technique by comparison with total dissolution with trifluoroacetic acid (TFA). The work was carried out for two of the three particle size ranges obtained by grinding the PET flake (300-425 and 425-700 microm) and for the unground flake. Further validation was undertaken by comparison of contaminant levels determined by total dissolution with TFA and sonication with dichloromethane (DCM) using flake ground to the 0-300 microm size range. The levels of contaminants increased with decreasing particle size range, but X-ray diffraction measurements of degrees of crystallinity were similar for each PET particle size range, thus showing that the differences in contaminant levels were not due to variable percentages of the amorphous material from the tops and bottoms of shredded bottles, relative to the amounts of crystalline PET from the mid-sections of the bottles. Hence, it was postulated that the variations in contaminant levels were due to selective grinding of the more highly contaminated surfaces, whilst the larger particles incorporated the less contaminated interior material. The grinding was also strongly selective with respect to the amorphous flake. Analysis of the segregated amorphous and crystalline flake phases indicated that many contaminants were similarly absorbed into both phases, whilst some were preferred by the amorphous PET and others were preferred by the crystalline PET. PMID:14594681

  11. Engineering a chemical implementation device and an imaging device for detecting chemiluminescence with a Polaroid high-speed detector film: application to influenza diagnostics with the ZstatFlu-II test.

    PubMed

    Achyuthan, Komandoor E; Pence, Lisa M; Mantell, Daniel R; Nangeroni, Paul E; Mauchan, Donald M; Aitken, William M; Appleman, James R; Shimasaki, Craig D

    2003-01-01

    We describe the engineering and product development of the chemiluminescent ZstatFlu-II Test kit for influenza diagnostics. The reaction vessel is a chemical implementation device with a polystyrene bottom chamber and a polypropylene top chamber that screw together. The patient's specimen is dispersed in a proprietary diluent and mixed inside the bottom chamber with the influenza viral neuraminidase-specific substrate, 1,2-dioxetane-4,7-dimethoxy-Neu5Ac. Neuraminidase catalysis releases the dioxetane. The top chamber contains 40% NaOH and is sealed at the top with an ABS plastic plug-crush pin assembly. The top chamber floor is 85% thinner at the centre, forming a frangible flap. An automated imaging device serves as an incubator for the chemical implementation devices and also facilitates the piercing of the flap by the crush pin. This action results in NaOH flushing into the bottom chamber, initiating chemiluminescence. The imaging device also exposes the Polaroid high-speed detector film to chemiluminescence. At the end of exposure, the film is automatically processed and ejected. Chemiluminescence from an influenza virus-positive specimen produces a "+"-shaped white image, archiving the diagnostic outcome. The modular ZstatFlu-II test kit components are easily adaptable for the chemiluminescent detection of a wide range of analytes. PMID:12687627

  12. Relationships between anthropogenic chemical contaminant exposure and associated changes in reproductive parameters in male English sole (Parophrys vetulus) collected from Hylebos Waterway, Puget Sound, Washington.

    PubMed

    Sol, Sean Y; Johnson, Lyndal L; Boyd, Daryle; Olson, O Paul; Lomax, Dan P; Collier, Tracy K

    2008-11-01

    Effects of chemical contaminant exposure on gonadal development in adult male English sole (Parophrys vetulus) from Hylebos Waterway and Colvos Passage, Puget Sound, Washington were investigated. Hylebos Waterway sediment is contaminated with polycyclic aromatic hydrocarbons (PAHs) and organochlorines (OCs), and Colvos Passage, a nearby nonurban area, is minimally contaminated. Fish from Hylebos Waterway had higher concentrations of both PAHs and OCs in tissues than fish from Colvos Passage. Overall, little correlation was observed between PAH exposure and biological parameters, but strong correlations were observed between OCs and the biological parameters. Migration of fish from less contaminated areas into the Hylebos Waterway during the reproductive season might have influenced these results, based on temporal changes in fish age and contaminant concentrations. PMID:18274819

  13. Tiered High-Throughput Screening Approach to Identify Thyroperoxidase Inhibitors within the ToxCast Phase I and II Chemical Libraries

    EPA Science Inventory

    High-throughput screening (HTS) for potential thyroid–disrupting chemicals requires a system of assays to capture multiple molecular-initiating events (MIEs) that converge on perturbed thyroid hormone (TH) homeostasis. Screening for MIEs specific to TH-disrupting pathways is limi...

  14. QSAR Classification of ToxCast and Tox21 Chemicals on the Basis of Estrogen Receptor Assays (FutureToxII)

    EPA Science Inventory

    The ToxCast and Tox21 programs have tested ~8,200 chemicals in a broad screening panel of in vitro high-throughput screening (HTS) assays for estrogen receptor (ER) agonist and antagonist activity. The present work uses this large in vitro data set to develop in silico QSAR model...

  15. THE MOST METAL-POOR STARS. II. CHEMICAL ABUNDANCES OF 190 METAL-POOR STARS INCLUDING 10 NEW STARS WITH [Fe/H] {<=} -3.5 , ,

    SciTech Connect

    Yong, David; Norris, John E.; Bessell, M. S.; Asplund, M.; Christlieb, N.; Beers, Timothy C.; Barklem, P. S.; Frebel, Anna; Ryan, S. G. E-mail: jen@mso.anu.edu.au E-mail: martin@mso.anu.edu.au E-mail: beers@pa.msu.edu E-mail: afrebel@mit.edu

    2013-01-01

    We present a homogeneous chemical abundance analysis of 16 elements in 190 metal-poor Galactic halo stars (38 program and 152 literature objects). The sample includes 171 stars with [Fe/H] {<=} -2.5, of which 86 are extremely metal poor, [Fe/H] {<=} -3.0. Our program stars include 10 new objects with [Fe/H] {<=} -3.5. We identify a sample of 'normal' metal-poor stars and measure the trends between [X/Fe] and [Fe/H], as well as the dispersion about the mean trend for this sample. Using this mean trend, we identify objects that are chemically peculiar relative to 'normal' stars at the same metallicity. These chemically unusual stars include CEMP-no objects, one star with high [Si/Fe], another with high [Ba/Sr], and one with unusually low [X/Fe] for all elements heavier than Na. The Sr and Ba abundances indicate that there may be two nucleosynthetic processes at lowest metallicity that are distinct from the main r-process. Finally, for many elements, we find a significant trend between [X/Fe] versus T {sub eff}, which likely reflects non-LTE and/or three-dimensional effects. Such trends demonstrate that care must be exercised when using abundance measurements in metal-poor stars to constrain chemical evolution and/or nucleosynthesis predictions.

  16. Biogeochemical Cycles for Combining Chemical Knowledge and ESD Issues in Greek Secondary Schools Part II: Assessing the Impact of the Intervention

    ERIC Educational Resources Information Center

    Koutalidi, Sophia; Psallidas, Vassilis; Scoullos, Michael

    2016-01-01

    In searching for effective ways to combine science/chemical education with EE/ESD, new didactic materials were designed and produced focussing on biogeochemical cycles and their connection to sustainable development. The materials were experimentally applied in 16 Greek schools under the newly introduced compulsory "school project" which…

  17. Chemical analyses of soil samples collected from the vicinity of the thermal test complex at Sandia National Laboratories, New Mexico environs, 2006.

    SciTech Connect

    Miller, Mark Laverne; Nieto, Danielle M.

    2007-01-01

    In the summer of 2006, the Environmental Programs and Assurance Department of Sandia National Laboratories in Albuquerque, New Mexico (SNL/NM), collected surface soil samples at 37 locations within one mile of the vicinity of the newly constructed Thermal Test Complex (TTC) for the purpose of determining baseline conditions against which potential future impacts to the environs from operations at the facility could be assessed. These samples were submitted to an offsite analytical laboratory for metal-in-soil analyses. This work provided the SNL Environmental Programs and Assurance Department with a sound baseline data reference set against which to assess potential future operational impacts at the TTC. In addition, it demonstrates the commitment that the Laboratories have to go beyond mere compliance to achieve excellence in its operations. This data are presented in graphical format with narrative commentaries on particular items of interest.

  18. Guidelines for sample collecting and analytical methods used in the U.S. Geological Survey for determining chemical composition of coal

    USGS Publications Warehouse

    Swanson, Vernon Emanuel; Huffman, Claude

    1976-01-01

    This report is intended to meet the many requests for information on current U.S. Geological Survey procedures in handling coal samples. In general, the exact type and number of samples of coal and associated rock to be collected are left to the best judgment of the geologist. Samples should be of unweathered coal or rock and representative of the bed or beds sampled; it is recommended that two channel samples, separated by 10 to 100 yards (10 to 100 metres) and weighing 4 to 5 pounds ( 1.8 to 2.3 kilograms) each, be collected of each 5 feet ( 1.5 metres) of vertical section. Care must be taken to avoid any sample contamination, and to record the exact locality, thickness, and stratigraphic information for each sample. Analytical methods are described for the determination of major, minor, and trace elements in coal. Hg, As, Sb, F, Se, U, and Th are determined in the raw coal, and the following 34 elements are determined after ashing the coal: Si, Al, Ca, Mg, Na, K, Fe (total), Cl, Ti, Mn, P, S (total), Cd, Li, Cu, Zn, Pb, B, Ba, Be, Co, Cr, Ga, La, Mo, Nb, Ni, Sc, Sr, Ti, V, Y, Yb, and Zr. The methods used to determine these elements include atomic absorption spectroscopy, X-ray fluorescence spectroscopy, optical emission spectroscopy, spectrophotometry, selective-ion electrode, and neutron activation analysis. A split of representative coal samples is submitted to the U.S. Bureau of Mines for proximate, ultimate, forms of sulfur, and Btu determinations.

  19. Exploring Natural Products from the Biodiversity of Pakistan for Computational Drug Discovery Studies: Collection, Optimization, Design and Development of A Chemical Database (ChemDP).

    PubMed

    Mirza, Shaher Bano; Bokhari, Habib; Fatmi, Muhammad Qaiser

    2015-01-01

    Pakistan possesses a rich and vast source of natural products (NPs). Some of these secondary metabolites have been identified as potent therapeutic agents. However, the medicinal usage of most of these compounds has not yet been fully explored. The discoveries for new scaffolds of NPs as inhibitors of certain enzymes or receptors using advanced computational drug discovery approaches are also limited due to the unavailability of accurate 3D structures of NPs. An organized database incorporating all relevant information, therefore, can facilitate to explore the medicinal importance of the metabolites from Pakistani Biodiversity. The Chemical Database of Pakistan (ChemDP; release 01) is a fully-referenced, evolving, web-based, virtual database which has been designed and developed to introduce natural products (NPs) and their derivatives from the biodiversity of Pakistan to Global scientific communities. The prime aim is to provide quality structures of compounds with relevant information for computer-aided drug discovery studies. For this purpose, over 1000 NPs have been identified from more than 400 published articles, for which 2D and 3D molecular structures have been generated with a special focus on their stereochemistry, where applicable. The PM7 semiempirical quantum chemistry method has been used to energy optimize the 3D structure of NPs. The 2D and 3D structures can be downloaded as .sdf, .mol, .sybyl, .mol2, and .pdb files - readable formats by many chemoinformatics/bioinformatics software packages. Each entry in ChemDP contains over 100 data fields representing various molecular, biological, physico-chemical and pharmacological properties, which have been properly documented in the database for end users. These pieces of information have been either manually extracted from the literatures or computationally calculated using various computational tools. Cross referencing to a major data repository i.e. ChemSpider has been made available for overlapping

  20. Analysis of chemical constituents and antinociceptive potential of essential oil of Teucrium Stocksianum bioss collected from the North West of Pakistan

    PubMed Central

    2012-01-01

    Background Medicinal plants are used for the treatment of different diseases in almost all cultures. Teucrium species grow wildly at different geographical locations around the world. Teucrium stocksianum is used in folk medicine for the treatment of diarrhea, cough, jaundice and abdominal pain. Scientific study on Teucrium stocksianum shows that it possesses anthelmintic, cytotoxic and antispasmodic activity. The aim of our present study is to identify the chemical composition and antinociceptive potential of the essential oil extracted from Teucrium stocksianum bioss. Method Essential oil (EO) from the aerial parts of Teucrium stocksianum were extracted by hydrodistillation process. The qualitative and quantitative composition of essential oil was determined with Gas chromatography/Mass spectrometer. Antinociceptive activity was determined by acetic acid induced writhing method. Percent inhibition of writhes of the test concentration was determined by comparing it with that of control. Tween-80 emulsion 2.5% (5 ml/kg b.w) was used as a control while Diclofenic sodium 50 mg/kg (b.w) was used as a standard drug. Results The chromatogram of the essential oil of Teucrium stocksianum shows differences both qualitatively and quantatively from essential oil composition reported in other countries. Hydrodistillation of Teucrium stocksianum yielded 0.4% (v/w), pale yellowish oil on dry basis. A total of 26 chemicals were identified by GC-MS accounting for 90.28% of the oil. The major components of essential oil were δ-cadinene (12.92%), α-pinene (10.3%), myrcene (8.64%), β-caryophyllene (8.23%), germacrene D (5.18%) and limonene (2.36%). Essential oil of Teucrium stocksianum has shown outstanding antinociceptive activity. It has been observed that increase in percent writhe inhibition (PWI) occurred from 20-80 mg/kg (b.w) and maximum writhe inhibition has been noted at a concentration of 80 mg/kg (b.w), but PWI decreased at 160 mg/kg, which may be due to some

  1. Stable isotope (2H, 17O, 18O) and hydro chemical patterns of precipitation collected in weekly resolution at Hannover, Germany

    NASA Astrophysics Data System (ADS)

    Koeniger, Paul; Himmelsbach, Thomas

    2016-04-01

    Long-term observations of stable isotopes (δ18O and δ2H) in precipitation were initiated in May 2008 at the Federal Institute of Geosciences and Natural Resources (BGR) in Hannover, Germany. In 2014 all precipitation samples were re-analyzed because a purchase of a new laser spectrometer (Picarro L2140-i) now allowed measurements of δ17O and a calculation of the 17O-excess parameter. Starting in October 2015 a routine analysis of hydro chemical parameters was added whenever enough sample aliquot was available (major ions, trace elements). A discussion of the stable isotope data of the seven year series of weekly precipitation samples (n = 370) will be presented. Beneath general patterns (seasonality and trends) we also focus on importance of amount weighing procedures, corrections for minor rain amounts, aspects of sample storage and re-analyzes, as well as impacts through changes in analytical equipment (IRMS, CRD spectroscopy) which is visible from the data. For stable isotopes a Thermo Fisher delta plus IRMS (Gasbench and H-Device) was used until 2011 and from 2012 on a Picarro L2120-i water vapor analyzer with long-term accuracies for quality check samples better than 0.2‰ and 0.8‰ for δ18O and δ2H, respectively.

  2. A Collection of Chemical, Mineralogical, and Stable Isotopic Compositional Data for Green River Oil Shale from Depositional Center Cores in Colorado, Utah, and Wyoming

    USGS Publications Warehouse

    Tuttle, Michele L.W.

    2009-01-01

    For over half a century, the U.S. Geological Survey and collaborators have conducted stratigraphic and geochemical studies on the Eocene Green River Formation, which is known to contain large oil shale resources. Many of the studies were undertaken in the 1970s during the last oil shale boom. One such study analyzed the chemistry, mineralogy, and stable isotopy of the Green River Formation in the three major depositional basins: Piceance basin, Colo.; Uinta basin, Utah; and the Green River basin, Wyo. One depositional-center core from each basin was sampled and analyzed for major, minor, and trace chemistry; mineral composition and sulfide-mineral morphology; sulfur, nitrogen, and carbon forms; and stable isotopic composition (delta34S, delta15N, delta13C, and delta18O). Many of these data were published and used to support interpretative papers (see references herein). Some bulk-chemical and carbonate-isotopic data were never published and may be useful to studies that are currently exploring topics such as future oil shale development and the climate, geography, and weathering in the Eocene Epoch. These unpublished data, together with most of the U.S. Geological Survey data already published on these samples, are tabulated in this report.

  3. Rapid, Non-Mechanical, Damage Free Figuring Of Optical Surfaces Using Plasma Assisted Chemical Etching (PACE): Part Ii Theory & Process Control

    NASA Astrophysics Data System (ADS)

    Zarowin, C. B.; Bollinger, L. D.

    1989-01-01

    We describe an application of Plasma Assisted Chemical Etching (PACE) to rapid and controllable figuring and smoothing of optical surfaces without mechanical contact. This removes the usual constraints on the design of optical elements imposed by mechanical pro-cesses, such as substrate deformation, edge distortion and subsurface damage or contamination. This process employs a process originally developed to pattern microelectronic circuits by ion enhanced chemical etching of a solid (Si02, Si, Al, Au, etc.) through a relatively nonerodeable photolithographically patterned mask1,-2. The PACE process shapes the optical surface by removing material in a small area under a confined reactive gas plasma (a "puck") moved over this surface. Rates of removal of such processes in microelectronic applications are as high as 10 pm per minute and are very accurately controllable and repeatable. The removal "footprint" of PACE may be varied during the process and it inherently smooths or polishes while exposing a virgin surface free of process generated contamination and subsurface damage. It can operate in two modes: (1) in "contact" with the plasma, where the chemical reaction is driven by the kinetic energy given up at the reacting surface by short lived species such as ions; and (2) downstream of the plasma, by the stored energy freed at the surface by longer lived species such as excited metastable neutrals. Since control of this process is so important to this application, we sketch the generic physics and chemi hi stry1,2 of the PACE figuring and smoothing process, identifying the quantitative relations between the plasma and chemical parameters that control it:rf power density reactive gas pressure reactive gas flow the reactor surface temperatures and the pertinent transport chemistry.

  4. Benefits and risks of fish consumption Part II. RIBEPEIX, a computer program to optimize the balance between the intake of omega-3 fatty acids and chemical contaminants.

    PubMed

    Domingo, José L; Bocio, Ana; Martí-Cid, Roser; Llobet, Juan M

    2007-02-12

    In recent years, and based on the importance of fish as a part of a healthy diet, there has been a notable promotion of fish and seafood consumption. However, a number of recent studies have shown that fish may be a potential source of exposure to chemical pollutants, some of them with well known adverse effects on human health. Recently, we determined in 14 edible marine species the concentrations of eicosapentaenoic acid (EPA) and docosohexaenoic acid (DHA), as well as those of a number of chemical contaminants: Cd, Hg, Pb, polychlorinated dibenzo-p-dioxins and furans, polychlorinated biphenyls, hexachlorobenzene, polycyclic aromatic hydrocarbons, polychlorinated naphthalenes, polybrominated diphenylethers and polychlorinated diphenylethers. To quantitative establish the intake of these pollutants (risks) versus that of EPA+DHA (benefits), we designed a simple computer program, RIBEPEIX. The concentrations of EPA, DHA, and the chemical pollutants were introduced into the program. We here present how RIBEPEIX may be used as an easy tool to optimize fish consumption: most suitable species, frequency of consumption, and size of meals. RIBEPEIX can be useful not only for professionals (cardiologists, general physicians, nutritionists, toxicologists, etc.), but also for the general population. It is available at: . PMID:17178182

  5. Adhesion of nitrile rubber to UV-assisted surface chemical modified PET fabric, part II: Interfacial characterization of MDI grafted PET

    NASA Astrophysics Data System (ADS)

    Razavizadeh, Mahmoud; Jamshidi, Masoud

    2016-08-01

    Fiber to rubber adhesion is an important subject in rubber industry. It is well known that surface treatment (i.e. physical, mechanical and chemical) is an effective method to improve interfacial bonding of fibers and/or fabrics to rubbers. UV irradiation is an effective method which has been used to increase fabric-rubber interfacial interactions. In this research UV assisted chemical modification of PET fabrics was used to increase PET to nitrile rubber (NBR) adhesion. Nitrile rubber is a perfect selection as fuel and oil resistant rubber. However it has weak bonding to PET fabric. For this purpose PET fabric was carboxylated under UV irradiation and then methylenediphenyl diisocyanate (MDI) was grafted on carboxylated PET. The chemical composition of the fabric before and after surface treatment was investigated by X-ray photoelectron spectroscopy (XPS). The sectional morphology of the experimental PET fibers and the interface between rubber compound and PET fabric was studied using scanning electron microscope (SEM). The morphology and structure of the product were analyzed by an energy dispersive X-ray spectrometer (EDX). FTIR-ATR and H NMR analysis were used to assess surface modifications on the PET irradiated fabrics.

  6. CHEMICAL ABUNDANCES OF THE MILKY WAY THICK DISK AND STELLAR HALO. II. SODIUM, IRON-PEAK, AND NEUTRON-CAPTURE ELEMENTS

    SciTech Connect

    Ishigaki, M. N.; Aoki, W.; Chiba, M. E-mail: aoki.wako@nao.ac.jp

    2013-07-01

    We present chemical abundance analyses of sodium, iron-peak, and neutron-capture elements for 97 kinematically selected thick disk, inner halo, and outer halo stars with metallicities -3.3 < [Fe/H] <-0.5. The main aim of this study is to examine chemical similarities and differences among metal-poor stars belonging to these old Galactic components as a clue to determine their early chemodynamical evolution. In our previous paper, we obtained abundances of {alpha} elements by performing a one-dimensional LTE abundance analysis based on the high-resolution (R {approx} 50, 000) spectra obtained with the Subaru/HDS. In this paper, a similar analysis is performed to determine abundances of an additional 17 elements. We show that, in metallicities below [Fe/H] {approx}-2, the abundance ratios of many elements in the thick disk, inner halo, and outer halo subsamples are largely similar. In contrast, in higher metallicities ([Fe/H] {approx}> -1.5), differences in some of the abundance ratios among the three subsamples are identified. Specifically, the [Na/Fe], [Ni/Fe], [Cu/Fe], and [Zn/Fe] ratios in the inner and outer halo subsamples are found to be lower than those in the thick disk subsample. A modest abundance difference between the two halo subsamples in this metallicity range is also seen for the [Na/Fe] and [Zn/Fe] ratios. In contrast to that observed for [Mg/Fe] in our previous paper, [Eu/Fe] ratios are more enhanced in the two halo subsamples rather than in the thick disk subsample. The observed distinct chemical abundances of some elements between the thick disk and inner/outer halo subsamples with [Fe/H] >-1.5 support the hypothesis that these components formed through different mechanisms. In particular, our results favor the scenario that the inner and outer halo components formed through an assembly of multiple progenitor systems that experienced various degrees of chemical enrichments, while the thick disk formed through rapid star formation with an

  7. The chemical biology of Cu(II) complexes with imidazole or thiazole containing ligands: Synthesis, crystal structures and comparative biological activity.

    PubMed

    Lewis, Adam; McDonald, Molly; Scharbach, Stephanie; Hamaway, Stefan; Plooster, Melissa; Peters, Kyle; Fox, Kristin M; Cassimeris, Lynne; Tanski, Joseph M; Tyler, Laurie A

    2016-04-01

    The synthesis and characterization of two copper(II) complexes containing 2-(2-pyridyl)benzimidazole (PyBIm) are reported with the biological activity of these two complexes and a third Cu(II) complex containing 2-(2-pyridyl)benzothiazole (PyBTh). Complex 1, [Cu(PyBIm)(NO3)(H2O)](NO3), is a four coordinate, distorted square planar species with one ligand (N,N), nitrate and water bound to Cu(II). The [Cu(PyBIm)3](BF4)2 complex (2) has distorted octahedral geometry with a 3:1 Py(BIm) ligand to metal ratio. The distorted trigonal bi-pyramidal geometry of compound 3, [Cu(PyBTh)2(H2O)](BF4)2, is comprised of two PyBTh ligands and one water. Biological activity of 1-3 has been assessed by analyzing DNA interaction, nuclease ability, cytotoxic activity and antibacterial properties. Complex 3 exhibits potent concentration dependent SC-DNA cleavage forming single- and double-nicked DNA in contrast to the weak activity of complexes 1 and 2. Mechanistic studies indicate that all complexes utilize an oxidative mechanism however 1 and 2 employ O2(-) as the principal reactive oxygen species while the highly active 3 utilizes (1)O2. The interaction between 1-3 and DNA was investigated using fluorescence emission spectroscopy and revealed all complexes strongly intercalate DNA with Kapp values of 2.65×10(6), 1.85×10(6) and 2.72×10(6)M(-1), respectively. Cytotoxic effects of 1-3 were examined using HeLa and K562 cells and show cell death in the micromolar range with the activity of 1≈2 and were slightly higher than 3. Similar reactivity was observed in the antibacterial studies with E. coli and S. aureus. A detailed comparative analysis of the three complexes is presented. PMID:26828284

  8. Application of a high surface area solid-phase microextraction air sampling device: collection and analysis of chemical warfare agent surrogate and degradation compounds.

    PubMed

    Stevens, Michael E; Tipple, Christopher A; Smith, Philip A; Cho, David S; Mustacich, Robert V; Eckenrode, Brian A

    2013-09-17

    This work examines a recently improved, dynamic air sampling technique, high surface area solid-phase microextraction (HSA-SPME), developed for time-critical, high-volume sampling and analysis scenarios. The previously reported HSA-SPME sampling device, which provides 10-fold greater surface area compared to commercially available SPME fibers, allowed for an increased analyte uptake per unit time relative to exhaustive sampling through a standard sorbent tube. This sampling device has been improved with the addition of a type-K thermocouple and a custom heater control circuit for direct heating, providing precise (relative standard deviation ∼1%) temperature control of the desorption process for trapped analytes. Power requirements for the HSA-SPME desorption process were 30-fold lower than those for conventional sorbent-bed-based desorption devices, an important quality for a device that could be used for field analysis. Comparisons of the HSA-SPME device when using fixed sampling times for the chemical warfare agent (CWA) surrogate compound, diisopropyl methylphosphonate (DIMP), demonstrated that the HSA-SPME device yielded a greater chromatographic response (up to 50%) relative to a sorbent-bed method. Another HSA-SPME air sampling approach, in which two devices are joined in tandem, was also evaluated for very rapid, low-level, and representative analysis when using discrete sampling times for the compounds of interest. The results indicated that subparts per billion by volume concentration levels of DIMP were detectable with short sampling times (∼15 s). Finally, the tandem HSA-SPME device was employed for the headspace sampling of a CWA degradation compound, 2-(diisopropylaminoethyl) ethyl sulfide, present on cloth material, which demonstrated the capability to detect trace amounts of a CWA degradation product that is estimated to be less volatile than sarin. The rapid and highly sensitive detection features of this device may be beneficial in decision

  9. Adxanthromycins A and B, new inhibitors of ICAM-1/LFA-1 mediated cell adhesion molecule from Streptomyces sp. NA-148. II. Physico-chemical properties and structure elucidation.

    PubMed

    Takahashi, S; Nakano, T; Koiwa, T; Noshita, T; Funayama, S; Koshino, H; Nakagawa, A

    2000-02-01

    Adxanthromycins A and B are new inhibitors of ICAM-1/LFA-1 mediated cell adhesion molecule isolated from the fermentation broth of Streptomyces sp. NA-148. The molecular formula of adxanthromycins A and B were determined as C42H40O17 and C48H50O22, respectively by FAB-MS and NMR spectral analyses, and the structures of both compounds were elucidated to be a dimeric anthrone peroxide skeleton containing alpha-D-galactose by various NMR spectral analyses and chemical degradation. PMID:10805577

  10. 76 FR 8804 - Agency Information Collection Activities: Revision and Approval of Information Collection...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-15

    ... collect information involving National Infrastructure Investments or ``TIGER II'' Discretionary Grants... (``OST'') is referring to these grants as ``TIGER II Discretionary Grants.'' The original collection of... Investments, Public Law 111-117, 123 Stat. 3034. The purpose of the TIGER II Discretionary Grants program...

  11. Oxygen Consumption by Red Wines. Part II: Differential Effects on Color and Chemical Composition Caused by Oxygen Taken in Different Sulfur Dioxide-Related Oxidation Contexts.

    PubMed

    Carrascon, Vanesa; Fernandez-Zurbano, Purificación; Bueno, Mónica; Ferreira, Vicente

    2015-12-30

    Chemical changes caused by oxidation of red wines during 5 consecutive air-saturation cycles have been assessed. In order to investigate the existing relationship between the effects caused by O2 and the levels and consumption rates of wine SO2, the total oxygen consumed by the wines (16-25 mg/L) was subdivided into different nonmutually exclusive categories. The ones found most influential on chemical changes were the O2 consumed in the first saturation without equivalent SO2 consumption (O2preSO2) and the O2 consumed when levels of free SO2 were below 5 mg/L (radical forming O2). Chromatic changes were strongly related to both O2 categories, even though anthocyanidin degradation was not related to any O2 category. Radical forming O2 prevented both formation of red pigments and reduction of epigallocatechin and other proanthocyanidins, induced accumulation of phenolic acids, and caused losses of β-damascenone and whiskylactone without evidence of acetaldehyde formation. O2preSO2 seemed to play a key role in the formation of blue pigments and in the decrease of Folin index and of many important aroma compounds. PMID:26646423

  12. Computer Program for Calculation of Complex Chemical Equilibrium Compositions and Applications II. Users Manual and Program Description. 2; Users Manual and Program Description

    NASA Technical Reports Server (NTRS)

    McBride, Bonnie J.; Gordon, Sanford

    1996-01-01

    This users manual is the second part of a two-part report describing the NASA Lewis CEA (Chemical Equilibrium with Applications) program. The program obtains chemical equilibrium compositions of complex mixtures with applications to several types of problems. The topics presented in this manual are: (1) details for preparing input data sets; (2) a description of output tables for various types of problems; (3) the overall modular organization of the program with information on how to make modifications; (4) a description of the function of each subroutine; (5) error messages and their significance; and (6) a number of examples that illustrate various types of problems handled by CEA and that cover many of the options available in both input and output. Seven appendixes give information on the thermodynamic and thermal transport data used in CEA; some information on common variables used in or generated by the equilibrium module; and output tables for 14 example problems. The CEA program was written in ANSI standard FORTRAN 77. CEA should work on any system with sufficient storage. There are about 6300 lines in the source code, which uses about 225 kilobytes of memory. The compiled program takes about 975 kilobytes.

  13. Possible Bose-condensate behavior in a quantum phase originating in a collective excitation in the chemically and optically doped Mott-Hubbard system UO2+x

    NASA Astrophysics Data System (ADS)

    Conradson, Steven D.; Durakiewicz, Tomasz; Espinosa-Faller, Francisco J.; An, Yong Q.; Andersson, David A.; Bishop, Alan R.; Boland, Kevin S.; Bradley, Joseph A.; Byler, Darrin D.; Clark, David L.; Conradson, Dylan R.; Conradson, Leilani L.; Costello, Alison L.; Hess, Nancy J.; Lander, Gerard H.; Llobet, Anna; Martucci, Mary B.; Mustre de Leon, Jose; Nordlund, Dennis; Lezama-Pacheco, Juan S.; Proffen, Thomas E.; Rodriguez, George; Schwarz, Daniel E.; Seidler, Gerald T.; Taylor, Antoinette J.; Trugman, Stuart A.; Tyson, Trevor A.; Valdez, James A.

    2013-09-01

    sufficiently coupled to the lattice to undergo a gap-opening transition. When the intragap state is probed with a terahertz time domain spectroscopy (TTDS) measurement 33 psec after a 3.14 excitation pulse, it shows increased absorption in the 0.5-1.1 THz range with a decrease in temperature from ˜30 to 10 K instead of the expected decrease, a result consistent with the presence of a condensate. These results are too extreme to originate in the dynamical, nonadiabatic, coupled charge-transfer-phonon/tunneling polaron scenario previously used for doped Mott-Hubbard insulators with intermediate electron-phonon coupling and therefore indicate novel physics. One possibility that could cause all of these behaviors is that a collective, dynamical, charge transfer-coupled Peierls distortion involving the 2 U(V) ↔ U(IV)+U(VI)-oxo excitation occurs coherently over an entire domain to cause the atoms in this domain to condense into a system with Bose-Einstein or Bose-Einstein-Hubbard properties.

  14. Interactions of Zn(II) Ions with Humic Acids Isolated from Various Type of Soils. Effect of pH, Zn Concentrations and Humic Acids Chemical Properties

    PubMed Central

    Boguta, Patrycja; Sokołowska, Zofia

    2016-01-01

    The main aim of this study was the analysis of the interaction between humic acids (HAs) from different soils and Zn(II) ions at wide concentration ranges and at two different pHs, 5 and 7, by using fluorescence and FTIR spectroscopy, as well as potentiometric measurements. The presence of a few areas of HAs structures responsible for Zn(II) complexing was revealed. Complexation at α-sites (low humified structures of low-molecular weight and aromatic polycondensation) and β-sites (weakly humified structures) was stronger at pH 7 than 5. This trend was not observed for γ-sites (structures with linearly-condensed aromatic rings, unsaturated bonds and large molecular weight). The amount of metal complexed at pH5 and 7 by α and γ-structures increased with a decrease in humification and aromaticity of HAs, contrary to β-areas where complexation increased with increasing content of carboxylic groups. The stability of complexes was higher at pH 7 and was the highest for γ-structures. At pH 5, stability decreased with C/N increase for α-areas and -COOH content increase for β-sites; stability increased with humification decrease for γ-structures. The stability of complexes at α and β-areas at pH 7 decreased with a drop in HAs humification. FTIR spectra at pH 5 revealed that the most-humified HAs tended to cause bidentate bridging coordination, while in the case of the least-humified HAs, Zn caused bidentate bridging coordination at low Zn additions and bidentate chelation at the highest Zn concentrations. Low Zn doses at pH 7 caused formation of unidentate complexes while higher Zn doses caused bidentate bridging. Such processes were noticed for HAs characterized by high oxidation degree and high oxygen functional group content; where these were low, HAs displayed bidentate bridging or even bidentate chelation. To summarize, the above studies have showed significant impact of Zn concentration, pH and some properties of HAs on complexation reactions of humic

  15. [Al2O4](-), a Benchmark Gas-Phase Class II Mixed-Valence Radical Anion for the Evaluation of Quantum-Chemical Methods.

    PubMed

    Kaupp, Martin; Karton, Amir; Bischoff, Florian A

    2016-08-01

    The radical anion [Al2O4](-) has been identified as a rare example of a small gas-phase mixed-valence system with partially localized, weakly coupled class II character in the Robin/Day classification. It exhibits a low-lying C2v minimum with one terminal oxyl radical ligand and a high-lying D2h minimum at about 70 kJ/mol relative energy with predominantly bridge-localized-hole character. Two identical C2v minima and the D2h minimum are connected by two C2v-symmetrical transition states, which are only ca. 6-10 kJ/mol above the D2h local minimum. The small size of the system and the absence of environmental effects has for the first time enabled the computation of accurate ab initio benchmark energies, at the CCSDT(Q)/CBS level using W3-F12 theory, for a class-II mixed-valence system. These energies have been used to evaluate wave function-based methods [CCSD(T), CCSD, SCS-MP2, MP2, UHF] and density functionals ranging from semilocal (e.g., BLYP, PBE, M06L, M11L, N12) via global hybrids (B3LYP, PBE0, BLYP35, BMK, M06, M062X, M06HF, PW6B95) and range-separated hybrids (CAM-B3LYP, ωB97, ωB97X-D, LC-BLYP, LC-ωPBE, M11, N12SX), the B2PLYP double hybrid, and some local hybrid functionals. Global hybrids with about 35-43% exact-exchange (EXX) admixture (e.g., BLYP35, BMK), several range hybrids (CAM-B3LYP, ωB97X-D, ω-B97), and a local hybrid provide good to excellent agreement with benchmark energetics. In contrast, too low EXX admixture leads to an incorrect delocalized class III picture, while too large EXX overlocalizes and gives too large energy differences. These results provide support for previous method choices for mixed-valence systems in solution and for the treatment of oxyl defect sites in alumosilicates and SiO2. Vibrational gas-phase spectra at various computational levels have been compared directly to experiment and to CCSD(T)/aug-cc-pV(T+d)Z data. PMID:27434425

  16. Collection Development.

    ERIC Educational Resources Information Center

    School Libraries in Canada, 2002

    2002-01-01

    Includes 21 articles that discuss collection development in Canadian school libraries. Topics include digital collections in school library media centers; print and electronic library resources; library collections; collaborative projects; print-disabled students; informing administrators of the importance of collection development; censorship;…

  17. Retrospective mortality study of workers in three major U. S. refineries and chemical plants. Part II: Internal comparisons by geographic site, occupation, and smoking history

    SciTech Connect

    Hanis, N.M.; Shallenberger, L.G.; Donaleski, D.L.; Sales, E.A.

    1985-05-01

    A cohort of 21,698 U.S. refinery and chemical plant workers was observed for eight years to determine if there were interplant or other variations in causes of mortality. Plant populations in three geographic locations were combined to develop an internal standard for comparing subgroups within the total cohort. At no one geographic site were consistently different rates for all major causes of death observed. The adjusted mortality rates for potentially exposed workers were slightly greater than those for nonexposed workers for most causes examined. Smokers incurred a higher risk of mortality from many causes of death when compared with nonsmokers, regardless of occupational category. After controlling for smoking, there remained a slight excess in mortality for potentially exposed as compared with nonexposed workers.

  18. Parallel processing of chemical information in a local area network--II. A parallel cross-validation procedure for artificial neural networks.

    PubMed

    Derks, E P; Beckers, M L; Melssen, W J; Buydens, L M

    1996-08-01

    This paper describes a parallel cross-validation (PCV) procedure, for testing the predictive ability of multi-layer feed-forward (MLF) neural networks models, trained by the generalized delta learning rule. The PCV program has been parallelized to operate in a local area computer network. Development and execution of the parallel application was aided by the HYDRA programming environment, which is extensively described in Part I of this paper. A brief theoretical introduction on MLF networks is given and the problems, associated with the validation of predictive abilities, will be discussed. Furthermore, this paper comprises a general outline of the PCV program. Finally, the parallel PCV application is used to validate the predictive ability of an MLF network modeling a chemical non-linear function approximation problem which is described extensively in the literature. PMID:8799999

  19. Observation of ionospheric disturbances following a 5-kt chemical explosion. II - Prolonged anomalies and stratifications in the lower thermosphere after shock passage

    NASA Astrophysics Data System (ADS)

    Blanc, Elisabeth; Jacobson, Abram R.

    1989-12-01

    Unusual stratifications and prolonged spectral deformations of radio echoes after the passage through the E region of the shock wave produced by a 5-kt chemical explosion have been observed. The observations were obtained by vertical HF pulsed ionospheric sounding. At the total reflection level of the sounding waves, at a horizontal distance of 30 km from the explosion, the passage of the shock wave generated a complex structure suggesting a significant deformation of the reflecting surface. Irregularities have also been observed in the E region for over 30 min after the shock passage by a network of continuous wave HF ionospheric sounders located 250 km west of the source. The origin of these structures is discussed.

  20. High efficiency chemical energy conversion system based on a methane catalytic decomposition reaction and two fuel cells. Part II. Exergy analysis

    NASA Astrophysics Data System (ADS)

    Liu, Qinghua; Tian, Ye; Li, Hongjiao; Jia, Lijun; Xia, Chun; Thompson, Levi T.; Li, Yongdan

    A methane catalytic decomposition reactor-direct carbon fuel cell-internal reforming solid oxide fuel cell (MCDR-DCFC-IRSOFC) energy system is highly efficient for converting the chemical energy of methane into electrical energy. A gas turbine cycle is also used to output more power from the thermal energy generated in the IRSOFC. In part I of this work, models of the fuel cells and the system are proposed and validated. In this part, exergy conservation analysis is carried out based on the developed electrochemical and thermodynamic models. The ratio of the exergy destruction of each unit is examined. The results show that the electrical exergy efficiency of 68.24% is achieved with the system. The possibility of further recovery of the waste heat is discussed and the combined power-heat exergy efficiency is over 80%.

  1. Herschel Observations of Extraordinary Sources: Analysi sof the HIFI 1.2 THz Wide Spectral Survey toward Orion KL II. Chemical Implications

    NASA Astrophysics Data System (ADS)

    Crockett, N. R.; Bergin, E. A.; Neill, J. L.; Favre, C.; Blake, G. A.; Herbst, E.; Anderson, D. E.; Hassel, G. E.

    2015-06-01

    We present chemical implications arising from spectral models fit to the Herschel/HIFI spectral survey toward the Orion Kleinmann-Low nebula (Orion KL). We focus our discussion on the eight complex organics detected within the HIFI survey utilizing a novel technique to identify those molecules emitting in the hottest gas. In particular, we find the complex nitrogen bearing species CH3CN, C2H3CN, C2H5CN, and NH2CHO systematically trace hotter gas than the oxygen bearing organics CH3OH, C2H5OH, CH3OCH3, and CH3OCHO, which do not contain nitrogen. If these complex species form predominantly on grain surfaces, this may indicate N-bearing organics are more difficult to remove from grain surfaces than O-bearing species. Another possibility is that hot (Tkin ∼ 300 K) gas phase chemistry naturally produces higher complex cyanide abundances while suppressing the formation of O-bearing complex organics. We compare our derived rotation temperatures and molecular abundances to chemical models, which include gas-phase and grain surface pathways. Abundances for a majority of the detected complex organics can be reproduced over timescales ≳105 years, with several species being underpredicted by less than 3σ. Derived rotation temperatures for most organics, furthermore, agree reasonably well with the predicted temperatures at peak abundance. We also find that sulfur bearing molecules that also contain oxygen (i.e., SO, SO2, and OCS) tend to probe the hottest gas toward Orion KL, indicating the formation pathways for these species are most efficient at high temperatures. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  2. Spectroscopy and quantum-chemical calculations of nitro-bis-bipyridyl complexes of ruthenium(II) with 4-substituted pyridine ligands

    NASA Astrophysics Data System (ADS)

    Reshetova, K. I.; Krauklis, I. V.; Litke, S. V.; Ershov, A. Yu.; Chizhov, Yu. V.

    2016-04-01

    The luminescence, absorption, and luminescence excitation spectra of complexes cis-[Ru(bpy)2(L)(NO2)]+ [bpy = 2,2'-bipyridyl, L = pyridine, 4-aminopyridine, 4-dimethylaminopyridine, 4-picoline, isonicotinamide, or 4,4'-bipyridyl] in alcoholic (4 : 1 EtOH-MeOH) solutions are studied at 77 K. A linear correlation is established between the energy of the lowest electronically excited metal-toligand charge transfer state d π(Ru) → π*(bpy) of the complexes and the pKa parameter of the free 4-substituted pyridines used as ligands L. The B3LYP/[6-31G(d)+LanL2DZ(Ru)] hybrid density functional method is used to optimize the geometry of complexes and calculate their electronic structure and the charge distribution on the atoms of the nearest environment of ruthenium(II) ions. It is shown that there exists a mutually unambiguous correspondence between the charge on the nitrogen atom of ligands L coordinated in the complex and the pK a parameter of ligands. The calculated energies of the electronically excited metal-to-ligand charge transfer states of complexes linearly (correlation coefficient 0.99) depend on the charge on the nitrogen atom of ligands L, which completely agrees with the experimental data.

  3. Anti-proliferative activity and chemical characterization by comprehensive two-dimensional liquid chromatography coupled to mass spectrometry of phlorotannins from the brown macroalga Sargassum muticum collected on North-Atlantic coasts.

    PubMed

    Montero, Lidia; Sánchez-Camargo, Andrea P; García-Cañas, Virginia; Tanniou, Anaëlle; Stiger-Pouvreau, Valérie; Russo, Mariateresa; Rastrelli, Luca; Cifuentes, Alejandro; Herrero, Miguel; Ibáñez, Elena

    2016-01-01

    In the present work, the phlorotannin composition of different Sargassum muticum samples collected at different locations along the North Atlantic coasts as well as the bioactivities related to these components were investigated. After pressurized liquid extraction, the samples collected at the extreme locations of a latitudinal gradient from Portugal and Norway, were found to be the richest on total phenols and, particularly, on phlorotannins, containing up to 148.97 and 5.12mg phloroglucinol equivalents g(-1), respectively. The extracts obtained from these locations were further purified and chemically characterized using a modified HILIC×RP-DAD-MS/MS method. The application of this methodology allowed the tentative identification of a great variability of phlorotannins with different degrees of polymerization (from 3 to 11) and structures, determined for the first time in S. muticum. The most-abundant phlorotannins on these samples were fuhalols, hydroxyfuhalols and phlorethols, showing also particularities and important differences depending on the geographical location. Afterwards, the antiproliferative activity of these extracts against HT-29 adenocarcinoma colon cancer cells was studied. Results revealed that the richest S. muticum samples in terms of total phlorotannins, i.e., those from Norway, presented the highest activity, showing a good cytotoxic potential at concentrations in the medium micromolar range. PMID:26210109

  4. Experimental and quantum-chemical studies of 1H, 13C and 15N NMR coordination shifts in Pd(II) and Pt(II) chloride complexes with methyl and phenyl derivatives of 2,2'-bipyridine and 1,10-phenanthroline.

    PubMed

    Pazderski, Leszek; Tousek, Jaromír; Sitkowski, Jerzy; Kozerski, Lech; Szłyk, Edward

    2007-12-01

    1H, 13C and 15N NMR studies of platinide(II) (M=Pd, Pt) chloride complexes with methyl and phenyl derivatives of 2,2'-bipyridine and 1,10-phenanthroline [LL=4,4'-dimethyl-2,2'-bipyridine (dmbpy); 4,4'-diphenyl-2,2'-bipyridine (dpbpy); 4,7-dimethyl-1,10-phenanthroline (dmphen); 4,7-diphenyl-1,10-phenanthroline (dpphen)] having a general [M(LL)Cl2] formula were performed and the respective chemical shifts (delta1H, delta13C, delta15N) reported. 1H high-frequency coordination shifts (Delta1Hcoord=delta1Hcomplex-delta1Hligand) were discussed in relation to the changes of diamagnetic contribution in the relevant 1H shielding constants. The comparison to literature data for similar [M(LL)(XX)], [M(LL)X2] and [M(LL)XY] coordination or organometallic compounds containing various auxiliary ligands revealed a large dependence of delta1H parameters on inductive and anisotropic effects. 15N low-frequency coordination shifts (Delta15Ncoord=delta 15Ncomplex-delta15Nligand) of ca 88-96 ppm for M=Pd and ca 103-111 ppm for M=Pt were attributed to both the decrease of the absolute value of paramagnetic contribution and the increase of the diamagnetic term in the expression for 15N shielding constants. The absolute magnitude of Delta15Ncoord parameter increased by ca 15 ppm upon Pd(II)-->Pt(II) transition and by ca 6-7 ppm following dmbpy-->dmphen or dpbpy-->dpphen ligand replacement; variations between analogous complexes containing methyl and phenyl ligands (dmbpy vs dpbpy; dmphen vs dpphen) did not exceed+/-1.5 ppm. Experimental 1H, 13C, 15N NMR chemical shifts were compared to those quantum-chemically calculated by B3LYP/LanL2DZ+6-31G**//B3LYP/LanL2DZ+6-31G*, both in vacuo and in DMSO or DMF solution. PMID:18044804

  5. The origin of the moon and the early history of the earth - A chemical model. I - The moon. II - The earth

    NASA Astrophysics Data System (ADS)

    O'Neill, H. St. C.

    1991-04-01

    Assuming that the moon was formed as a result of a giant impact by a celestial Mars-sized body with the earth, a model is developed that accounts for the chemical compositions of both the moon and the earth. The moon model assumes that about 80 percent of the moon came from the primitive earth's mantle after segregation of the earth's core and the other 20 percent came from two sources: (1) the Impactor, which is constrained to be an oxidized undifferentiated body of roughly CI chondritic composition and (2) a late-stage veneer with a composition and oxidation state similar to that of the H-group ordinary chondrites. The earth model assumes that the protoearth accreted from a material resembling a high-temperature condensate from the solar nebula. The model accounts for the siderophile element abundances of the present mantle. It predicts that neither S, O, nor Si were present in sufficient quantities to provide the required light element in the core, whose identity remains enigmatic.

  6. FR-IR spectroscopic studies of polyurethanes—Part II. Ab initio quantum chemical studies of the relative strengths of ``carbonyl'' and ``ether'' hydrogen-bonds in polyurethanes

    NASA Astrophysics Data System (ADS)

    Bandekar, Jagdeesh; Klima, Suzanne

    1992-10-01

    Ab initio quantum chemical computations were carried out on (a) dimethyl ether, (b) N-methyl formamide, (c) dimethyl ether- N-methyl formamide complex, and (d) N-methyl formamide dimer to compute the strengths of hydrogen bonds (H-bonds) between the NH groups and CO and ether COC groups. The basis set used was the 3-21G set of the GAUSSIAN 80 program obtained from QCPE, Bloomington, IN. Variations in the strengths of these two H-bonds with the N . . O distance (where O is either carbonyl or ether group oxygen) were studied and found to be similar in behavior. The strength of the "ether" hydrogen bond is computed to be 10.32 kcal mol -1, which is quite significant compared to the value of 10.11 kcal mol -1 for the more accepted "carbonyl" hydrogen bond. The "ether" hydrogen bond is found to be directional, specific and non-negligible. Work with two more basis sets has indicated that the results so obtained are not dependent on their choice. Possible importance of such a hydrogen bond in polyurethanes, inhalation anesthetics, and depsi-peptides is indicated.

  7. Self assembling monolayers of dialkynyl bridged Pd(II) thiols obtained by thermally induced multilayer desorption: Thermal and chemical stability investigated by SR-XPS

    NASA Astrophysics Data System (ADS)

    Battocchio, C.; Fratoddi, I.; Bondino, F.; Malvestuto, M.; Russo, M. V.; Polzonetti, G.

    2012-02-01

    Self assembling monolayers (SAMs) of organometallic thiols trans-[HS-Pd(PBu3)2-SH], trans-[HS-Pd(PBu3)2(-Ctbnd C-C6H5)] and trans,trans-[HS-Pd(PBu3)2(-Ctbnd C-C6H4-C6H4-Ctbnd C-Pd(PBu3)2-SH] on gold were obtained from the corresponding multilayers through thermally induced desorption. Temperature-dependent synchrotron radiation-induced X-ray photoelectron spectroscopy (SR-XPS) measurements were carried out on the heated multilayers during the annealing process, in order to investigate the thermal and chemical stability of the systems. SAMs of the same organometallic thiols were also obtained by rinsing the thick films with appropriate solvents. SR-XPS was used to ascertain that the molecular and electronic structure of the two series of SAMs are not influenced by the rinsing or thermal desorption process, i.e. both strategies allow for obtaining well ordered monolayers of organometallic thiols.

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

    PubMed

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

    2014-03-01

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

  9. Characterization of Cerro Negro crude. Part II. Chemical analysis. [Project sponsored by Bartlesville Energy Technology Center and Institute de Tecnologico del Venezolana Petroleo

    SciTech Connect

    Sturm, G.P. Jr.; Grindstaff, Q.G.; Hirsch, D.E.; Scheppele, S.E.; Hazos, M.

    1981-09-01

    The cooperative research program is explained in Part I. An evaluation is presented of the resolution attained in the separation of a 425 to 550/sup 0/C petroleum distillate fraction according to compound classes using 2 chromatographic methods. Samples were separated by high performance liquid chromatography using 2 columns in series containing 2,4-dinitroanalinopropyl silica and silica, respectively. Initial elution was attained using 1% methylene chloride in pentane followed by a linear gradient up to 30% methylene chloride. In the 2nd method, developed in the American Petroleum Institute's Research Project 60, fractions designated as saturates, monoaromatics, diaromatics, and polyaromatics were collected froma dual silica/alumina column using step gradient elution with pentane, 5% benzene in pentane, 15% benzene in pentane, and 20% ethyl ether, 20% benzene, 60% methanol, followed by pure methanol. The results wil be used to evaluate the quality of the separation in terms of the success in producing fractions containing similar compound classes. 1 figure, 4 tables.

  10. Multielement chemical and statistical analyses from a uranium hydrogeochemical and stream-sediment survey in and near the Elkhorn Mountains, Jefferson County, Montana; Part II, Stream sediments

    USGS Publications Warehouse

    Suits, V.J.; Wenrich, K.J.

    1982-01-01

    Fifty-two stream-sediment samples, collected from an area south of Helena, Jefferson County, Montana, were sieved into two size fractions (50 ppm for the fine fraction) were encountered in samples from the Warm Springs Creek drainage area, along Prickly Pear Creek near Welmer and Golconda Creeks and along Muskrat Creek. All groups showed a significant correlation at the 99 percent confidence level (r between 0.73 and 0.77) between U and Th. Uranium was found to correlate significantly only with Th (as mentioned above) and with -Ni in the fine fraction of the volcanics group. U correlates significantly with -Al2O3, Ba, organic C, -K2O, -Sr and Y in both size fractions for the Boulder batholith. Correlations between U and each of several elements differ for the fine and coarse fractions of the Boulder batholith group, suggesting that the U distribution in these stream sediments is in large part controlled by grain size. Correlations were found between U and CaO, Cr, Fe203, -Na2O, Sc, -SiO2, TiO2, Yb and Zr in the coarse fraction but not in the fine fraction. U correlates weakly (to the 90% confidence level, crc<.37) with -Co and -Cu in the fine but not the coarse fraction. These results are compared to a previous study in the northern Absaroka mountains. Correlation coefficients between all other elements determined from these samples are also shown in Tables 12 to 15.

  11. THE EFFICACY OF THREE MEDICINAL PLANTS; GARLIC, GINGER AND MIRAZID AND A CHEMICAL DRUG METRONIDAZOLE AGAINST CRYPTOSPORIDIUM PARVUM: II-HISTOLOGICAL CHANGES.

    PubMed

    Abouel-Nour, Mohamed F; El-Shewehy, Dina Magdy M; Hamada, Shadia F; Morsy, Tosson A

    2016-04-01

    Cryptosporidiosis parvum is a zoonotic protozoan parasite infects intestinal epithelial cells of man and animals causing a major health problem. This study was oriented to evaluate the protective and curative capacity of garlic, ginger and mirazid in comparison with metronidazole drug (commercially known) against Cryptosporidium in experimental mice. Male Swiss Albino mice experimentally infected with C. parvum were treated with medicinal plants extracts (Ginger, Mirazid, and Garlic) as compared to chemical drug Metronidazole. Importantly, C. parvum-infected mice treated with ginger, Mirazid, garlic and metronidazole showed a complete elimination in shedding oocysts by 9th day PI. The reduction and elimination of shedding oocysts in response to the treatments might be attributable to a direct effect on parasite growth in intestines, sexual phases production and/or the formation of oocysts. The results were evaluated histopathological examination of ideum section of control mice (uninfected, untreated) displayed normal architecture of the villi. Examiination of infected mice ileum section (infected, untreated) displayed histopathological alterations from uninfected groups. Examination of ileum section prepared from mice treated with garlic, ginger, mirazid, and metronidazole displayed histopathological alterations from that of the control groups, and showed marked histologic correction in the pattern with the four regimes used in comparison to control mice. Garlic successfully eradicated oocysts of infected mice from stool and intestine. Supplementation of ginger to infected mice markedly corrected elevation in the inflammatory risk factors and implied its potential antioxidant, anti-inflammatory and immunomodulatory capabilities. Infected mice treated with ginger, mirazid, garlic and metronidazole showed significant symptomatic improvements during treatment. PMID:27363055

  12. Physical and chemical properties of the regional mixed layer of Mexico's Megapolis – Part II: Evaluation of measured and modeled trace gases and particle size distributions

    SciTech Connect

    Ochoa, Carlos; Baumgardner, Darrel; Grutter, M.; Allan, James D.; Fast, Jerome D.; Rappengluck, B.

    2012-10-31

    This study extends the work of Baumgardner et al. (2009) in which measurements of trace gases and particles at a remote, high-altitude mountain site 60 km from Mexico City were analyzed with respect to the origin of air masses. In the current evaluation, the temperature, water vapor, ozone (O3), carbon monoxide (CO), acyl peroxy nitrate (APN) and particle size distributions (PSDs) of the mass concentrations of sulfate, nitrate, ammonium and organic mass (OM) were simulated with the WRF-Chem chemical transport model and compared with the measurements at the mountain site. The model prediction of the diurnal trends of the gases were well correlated with the measurements before the regional boundary layer reached the measurement site but underestimated the concentrations after that time. The differences are caused by an overly rapid growth of the boundary layer by the model with too much dilution. There also appears to be more O3 produced by photochemical production, downwind of the emission sources, than predicted by the model. The measured and modeled PSDs compare very well with respect to their general shape and diameter of the peak concentrations. The spectra are log normally distributed with most of the mass in the accumulation mode and the geometric diameter centered at 200 ±20 nm, with little observed or predicted change with respect to the origin of the air mass or the time when the RBL is above the Altzomoni research. Only the total mass changed with time and air mass origin. The invariability of the average diameter of the accumulation mode suggests that there is very little growth of the particles by condensation or coagulation after six hours of aging downwind of the major sources of anthropogenic emissions in Mexico’s Megapolis.

  13. Collecting apparatus

    DOEpatents

    Duncan, Charles P.

    1983-01-01

    An improved collecting apparatus for small aquatic or airborne organisms such as plankton, larval fish, insects, etc. The improvement constitutes an apertured removal container within which is retained a collecting bag, and which is secured at the apex of a conical collecting net. Such collectors are towed behind a vessel or vehicle with the open end of the conical net facing forward for trapping the aquatic or airborne organisms within the collecting bag, while allowing the water or air to pass through the apertures in the container. The container is readily removable from the collecting net whereby the collecting bag can be quickly removed and replaced for further sample collection. The collecting bag is provided with means for preventing the bag from being pulled into the container by the water or air flowing therethrough.

  14. Collections Conservation.

    ERIC Educational Resources Information Center

    DeCandido, Robert

    Collections conservation is an approach to the preservation treatment of books and book-like materials that is conceptualized and organized in terms of large groups of materials. This guide is intended to enable a library to evaluate its current collections conservation activities. The introduction describes collections conservation and gives…

  15. Chemical Principles Exemplified

    ERIC Educational Resources Information Center

    Plumb, Robert C.

    1972-01-01

    Collection of two short descriptions of chemical principles seen in life situations: the autocatalytic reaction seen in the bombardier beetle, and molecular potential energy used for quick roasting of beef. Brief reference is also made to methanol lighters. (PS)

  16. Study of Chemical Surface Structure of Natural Sorbents Used for Removing of Pb2+ Ions from Model Aqueous Solutions (part Ii)

    NASA Astrophysics Data System (ADS)

    Bożęcka, Agnieszka; Bożęcki, Piotr; Sanak-Rydlewska, Stanisława

    2014-03-01

    This article presents the results of the chemical structure research of organic sorbent surface such as walnut shells, plums stones and sunflower hulls with using such methods as infrared spectrometry (FTIR) and elemental analysis. Based on the IR spectra identification of functional groups present on the surface of studied materials has been done as well as determination of their effect on the sorption mechanism of Pb2+ ions from aqueous model solutions W artykule przedstawiono wyniki badań chemicznej struktury powierzchni sorbentów organicznych takich jak: łupiny orzecha włoskiego, pestki śliwek oraz łuski słonecznika z wykorzystaniem metody spektrometrii w podczerwieni (FTIR) oraz analizy elementarnej. W oparciu o uzyskane widma IR dokonano identyfikacji grup funkcyjnych obecnych na powierzchni tych materiałów i określono ich wpływ na mechanizm sorpcji jonów Pb2+ z modelowych roztworów wodnych. Analiza elementarna wykazała, że spośród badanych sorbentów, największą zawartość węgla (49,91%) i wodoru (5,93%) mają pestki śliwek. Najwięcej azotu (1,59%) zawierają łuszczyny słonecznika (tabela 1). Zawartość siarki we wszystkich badanych materiałach jest znikoma, dlatego nie udało się jej oznaczyć tą metodą. Obecność pozostałych pierwiastków może świadczyć o istnieniu zarówno alifatycznych jak i aromatycznych połączeń organicznych. Potwierdzeniem tego są również zarejestrowane widma IR (rysunki 1-3). W oparciu o uzyskane wyniki można przypuszczać także, iż udział procesu wymiany jonowej w sorpcji ołowiu z roztworów wodnych jest znaczący. Świadczą o tym m.in. intensywności pasm na widmach IR dla próbek badanych materiałów po ich kontakcie z roztworami jonów Pb2+ (rysunki 4-6).

  17. Capacitive chemical sensor

    DOEpatents

    Manginell, Ronald P; Moorman, Matthew W; Wheeler, David R

    2014-05-27

    A microfabricated capacitive chemical sensor can be used as an autonomous chemical sensor or as an analyte-sensitive chemical preconcentrator in a larger microanalytical system. The capacitive chemical sensor detects changes in sensing film dielectric properties, such as the dielectric constant, conductivity, or dimensionality. These changes result from the interaction of a target analyte with the sensing film. This capability provides a low-power, self-heating chemical sensor suitable for remote and unattended sensing applications. The capacitive chemical sensor also enables a smart, analyte-sensitive chemical preconcentrator. After sorption of the sample by the sensing film, the film can be rapidly heated to release the sample for further analysis. Therefore, the capacitive chemical sensor can optimize the sample collection time prior to release to enable the rapid and accurate analysis of analytes by a microanalytical system.

  18. Collection Mapping and Collection Development.

    ERIC Educational Resources Information Center

    Murray, William; And Others

    1985-01-01

    Describes the use of collection mapping to assess media collections of Aurora, Colorado, Public Schools. Case studies of elementary, middle, and high school media centers describe materials selection and weeding and identify philosophies that library collections should support school curriculum, and teacher-library media specialist cooperation in…

  19. Software Development at Belle II

    NASA Astrophysics Data System (ADS)

    Kuhr, Thomas; Hauth, Thomas

    2015-12-01

    Belle II is a next generation B-factory experiment that will collect 50 times more data than its predecessor Belle. This requires not only a major upgrade of the detector hardware, but also of the simulation, reconstruction, and analysis software. The challenges of the software development at Belle II and the tools and procedures to address them are reviewed in this article.

  20. Evaluation of the National School Lunch Program Application/Verification Pilot Projects: Volume II: Data Collection, Study Methods and Supplementary Tables on Certification Impacts. Nutrition Assistance Program Report Series. Report No. CN-04-AV2

    ERIC Educational Resources Information Center

    Burghardt, John; Gleason, Philip; Sinclair, Michael; Cohen, Rhoda; Hulsey, Lara; Milliner-Waddell, Julita

    2004-01-01

    This is Volume II of the report on the evaluation of the NSLP Application Verification Pilot Projects. It supplements Volume I, which presents the evaluation findings. Volume II has two objectives: (1) to provide a detailed description of the methods used to conduct the study; and (2) to present tabulations that supplement and extend the analyses…

  1. Identifying and Quantifying Chemical Forms of Sediment-Bound Ferrous Iron.

    NASA Astrophysics Data System (ADS)

    Kohler, M.; Kent, D. B.; Bekins, B. A.; Cozzarelli, I.; Ng, G. H. C.

    2015-12-01

    Aqueous Fe(II) produced by dissimilatory iron reduction comprises only a small fraction of total biogenic Fe(II) within an aquifer. Most biogenic Fe(II) is bound to sediments on ion exchange sites; as surface complexes and, possibly, surface precipitates; or incorporated into solid phases (e.g., siderite, magnetite). Different chemical forms of sediment-bound Fe(II) have different reactivities (e.g., with dissolved oxygen) and their formation or destruction by sorption/desorption and precipitation/dissolution is coupled to different solutes (e.g., major cations, H+, carbonate). We are quantifying chemical forms of sediment-bound Fe(II) using previously published extractions, novel extractions, and experimental studies (e.g., Fe isotopic exchange). Sediments are from Bemidji, Minnesota, where biodegradation of hydrocarbons from a burst oil pipeline has driven extensive dissimilatory Fe(III) reduction, and sites potentially impacted by unconventional oil and gas development. Generally, minimal Fe(II) was mobilized from ion exchange sites (batch desorption with MgCl2 and repeated desorption with NH4Cl). A < 2mm sediment fraction from the iron-reducing zone at Bemidji had 1.8umol/g Fe(II) as surface complexes or carbonate phases (sodium acetate at pH 5) of which ca. 13% was present as surface complexes (FerroZine extractions). Total bioavailable Fe(III) and biogenic Fe(II) (HCl extractions) was 40-50 umole/g on both background and iron-reducing zone sediments . Approximately half of the HCl-extractable Fe from Fe-reducing zone sediments was Fe(II) whereas 12 - 15% of Fe extracted from background sediments was present as Fe(II). One-third to one-half of the total biogenic Fe(II) extracted from sediments collected from a Montana prairie pothole located downgradient from a produced-water disposal pit was present as surface-complexed Fe(II).

  2. Chemical Emergencies

    MedlinePlus

    When a hazardous chemical has been released, it may harm people's health. Chemical releases can be unintentional, as in the case of an ... the case of a terrorist attack with a chemical weapon. Some hazardous chemicals have been developed by ...

  3. Photoinduced and chemical oxidation of coordinated imine to amide in isomeric osmium(II) complexes of N-arylpyridine-2-carboxaldimines. Synthesis, characterization, electron transfer properties, and structural studies.

    PubMed

    Ghosh, Amit K; Kamar, Kunal K; Paul, Parimal; Peng, Shie-Ming; Lee, Gene-Hsiang; Goswami, Sreebrata

    2002-12-01

    The reaction of N-arylpyridine-2-carboxaldimine [C(5)H(4)NC(H)NC(6)H(4)R] (HL) with ammonium hexabromoosmate (NH(4))(2)[OsBr(6)] in boiling 2-methoxyethanol afforded a violet solution from which two geometrical isomers of [OsBr(2)(HL)(2)] (1 and 2) were isolated. These are characterized by analytical and spectroscopic data. (1)H NMR spectral data were used for the identification of the isomers. The blue-violet isomer, 1 (designated as ctc), has a 2-fold symmetry axis and gave rise to resonances for only one coordinated HL. The geometry of the ctc-isomer was, however, revealed from the X-ray structure determination of a representative example. The red-violet isomer (2, designated as ccc), on the other hand, is unsymmetrical and gave rise to a large number of proton resonances. The isomeric complexes, [OsBr(2)(HL)(2)], showed intense MLCT transitions in the visible region. This transition, in the ccc-isomer, is slightly (10 nm) red shifted in comparison to the ctc-isomer. These diimine complexes showed one metal based reversible oxidation assignable to the Os(III)/Os(II) process followed by two irreversible oxidations at more anodic potentials (>1.4 V). In addition to these, the complexes also showed two irreversible ligand reductions at high cathodic potentials (<-1.4 V). An unusual type of photochemical transformation of the azomethine function of coordinated HL in osmium compounds 1 is studied. When an air equilibrated acetonitrile solution of 1 was exposed to a xenon lamp, it underwent oxidation affording the mixed ligand, amido complexes of general formula [OsBr(2)(HL)(LO)], 3 (LO = C(5)H(4)NC(O)-N-C(6)H(4)R), in an excellent yield (>95%). This transformation (1 --> 3) was achieved chemically when H(2)O(2) was used as an oxidant. Notably, the chemical oxidation with H(2)O(2) also led to the formation of a tetravalent complex, [OsBr(2)(LO)(2)], 4, as a minor product. Compound 3 was characterized by various spectroscopic and analytical techniques. The room

  4. OXALATE MASS BALANCE DURING CHEMICAL CLEANING IN TANK 6F

    SciTech Connect

    Poirier, M.; Fink, S.

    2011-07-22

    The Savannah River Remediation (SRR) is preparing Tank 6F for closure. The first step in preparing the tank for closure is mechanical sludge removal. Following mechanical sludge removal, SRS performed chemical cleaning with oxalic acid to remove the sludge heel. Personnel are currently assessing the effectiveness of the chemical cleaning to determine whether the tank is ready for closure. SRR personnel collected liquid samples during chemical cleaning and submitted them to Savannah River National Laboratory (SRNL) for analysis. Following chemical cleaning, they collected a solid sample (also known as 'process sample') and submitted it to SRNL for analysis. The authors analyzed these samples to assess the effectiveness of the chemical cleaning process. Analysis of the anions showed the measured oxalate removed from Tank 6F to be approximately 50% of the amount added in the oxalic acid. To close the oxalate mass balance, the author collected solid samples, leached them with nitric acid, and measured the concentration of cations and anions in the leachate. Some conclusions from this work are: (1) Approximately 65% of the oxalate added as oxalic acid was removed with the decanted liquid. (2) Approximately 1% of the oxalate (added to the tank as oxalic acid) formed precipitates with compounds such as nickel, manganese, sodium, and iron (II), and was dissolved with nitric acid. (3) As much as 30% of the oxalate may have decomposed forming carbon dioxide. The balance does not fully account for all the oxalate added. The offset represents the combined uncertainty in the analyses and sampling.

  5. Collecting Rocks.

    ERIC Educational Resources Information Center

    Barker, Rachel M.

    One of a series of general interest publications on science topics, the booklet provides those interested in rock collecting with a nontechnical introduction to the subject. Following a section examining the nature and formation of igneous, sedimentary, and metamorphic rocks, the booklet gives suggestions for starting a rock collection and using…

  6. Jay's Collectibles

    ERIC Educational Resources Information Center

    Cappel, James J.; Gillman, Jason R., Jr.

    2011-01-01

    There is growing interest in collectibles of many types, as indicated by the popularity of television programs such as the History Channel's "Pawn Stars" and "American Pickers" and the Public Broadcasting Service's "Antiques Road Show." The availability of online auction sites such as eBay has enabled many people to collect items of interest as a…

  7. Collective Enumeration

    ERIC Educational Resources Information Center

    Bahrami, Bahador; Didino, Daniele; Frith, Chris; Butterworth, Brian; Rees, Geraint

    2013-01-01

    Many joint decisions in everyday life (e.g., Which bar is less crowded?) depend on approximate enumeration, but very little is known about the psychological characteristics of counting together. Here we systematically investigated collective approximate enumeration. Pairs of participants made individual and collective enumeration judgments in a…

  8. Collective Bargaining.

    ERIC Educational Resources Information Center

    Zirkel, Perry A.

    This chapter discusses litigation touching on collective bargaining issues. The chapter is organized to follow the collective bargaining process, from cases dealing with union organizing to cases involving arbitration. Issues covered also include determination of bargaining units, scope of bargaining, union security, and unfair labor practices in…

  9. Collective Enumeration

    PubMed Central

    Bahrami, Bahador; Didino, Daniele; Frith, Chris; Butterworth, Brian; Rees, Geraint

    2012-01-01

    Many joint decisions in everyday life (e.g., Which bar is less crowded?) depend on approximate enumeration, but very little is known about the psychological characteristics of counting together. Here we systematically investigated collective approximate enumeration. Pairs of participants made individual and collective enumeration judgments in a 2-alternative forced-choice task and when in disagreement, they negotiated joint decisions via verbal communication and received feedback about accuracy at the end of each trial. The results showed that two people could collectively count better than either one alone, but not as well as expected by previous models of collective sensory decision making in more basic perceptual domains (e.g., luminance contrast). Moreover, such collective enumeration benefited from prior, noninteractive practice showing that social learning of how to combine shared information about enumeration required substantial individual experience. Finally, the collective context had a positive but transient impact on an individual's enumeration sensitivity. This transient social influence may be explained as a motivational factor arising from the fact that members of a collective must take responsibility for their individual decisions and face the consequences of their judgments. PMID:22889187

  10. Culture collections.

    PubMed

    Smith, David

    2012-01-01

    Culture collections no matter their size, form, or institutional objectives play a role in underpinning microbiology, supplying the resources for study, innovation, and discovery. Their basic roles include providing a mechanism for ex situ conservation of organisms; they are repositories for strains subject to publication, taking in safe, confidential, and patent deposits from researchers. They supply strains for use; therefore, the microorganisms provided must be authentic and preserved well, and any associated information must be valid and sufficient to facilitate the confirmation of their identity and to facilitate their use. The organisms must be collected in compliance with international conventions, international and national legislation and distributed to users indicating clearly the terms and conditions under which they are received and can be used. Collections are harmonizing approaches and characterizing strains to meet user needs. No one single collection can carry out this task alone, and therefore, it is important that output and strategy are coordinated to ensure culture collections deliver the basic resources and services microbiological innovation requires. This chapter describes the types of collection and how they can implement quality management systems and operate to deliver their basic functions. The links to information sources given not only provide support for the practitioners within collections but also provide guidance to users on accessing the huge resource available and how they can help ensure microbiology has the resources and a solid platform for future development. PMID:22569518

  11. Spectral and magnetic studies on manganese(II), cobalt(II) and nickel(II) complexes with Schiff bases

    NASA Astrophysics Data System (ADS)

    Chandra, Sulekh; Kumar, Umendra

    2005-01-01

    Mn(II), Co(II) and Ni(II) complexes of 2-methylcyclohexanone thiosemicarbazone(MCHTSC L 1) and 2-methylcyclohexanone - 4N-methyl-3-thiosemicarbazone (MCHMTSC L 2), general composition [M(L) 2X 2] (where M = Mn(II), Co(II), Ni(II), L = L 1 or L 2 and X = Cl -, NO 3-, and 1/2SO42-) have been synthesized and characterized by elemental analysis, magnetic susceptibility measurements, UV-vis, IR, EPR, and mass spectral studies. Various physico-chemical techniques suggest an octahedral geometry for all the complexes.

  12. Micrometeorite Collecting

    ERIC Educational Resources Information Center

    Toubes, Joe; Hoff, Darrel

    1974-01-01

    Describes how to collect micrometeorites and suggests a number of related activities such as determining the number of meteors entering the atmosphere and determining the composition of the micrometeorites. (BR)

  13. Juno II

    NASA Technical Reports Server (NTRS)

    1959-01-01

    The Juno II launch vehicle, shown here, was a modified Jupiter Intermediate-Range Ballistic missionile, developed by Dr. Wernher von Braun and the rocket team at Redstone Arsenal in Huntsville, Alabama. Between December 1958 and April 1961, the Juno II launched space probes Pioneer III and IV, as well as Explorer satellites VII, VIII and XI.

  14. Synthesis and spectroscopic and structural studies of a new cadmium(II)-citrate aqueous complex. Potential relevance to cadmium(II)-citrate speciation and links to cadmium toxicity.

    PubMed

    Dakanali, M; Kefalas, E T; Raptopoulou, C P; Terzis, A; Mavromoustakos, T; Salifoglou, A

    2003-04-21

    The presence of cadmium in the environment undoubtedly contributes to an increased risk of exposure and ultimate toxic influence on humans. In an effort to comprehend the chemical and biological interactions of Cd(II) with physiological ligands, like citric acid, we explored the requisite aqueous chemistry, which afforded the first aqueous Cd(II)-citrate complex [Cd(C(6)H(6)O(7))(H(2)O)](n)() (1). Compound 1 was characterized by elemental analysis, and spectroscopically by FT-IR and (113)Cd MAS NMR. Compound 1 crystallizes in the orthorhombic space group P2(1)2(1)2(1), with a = 6.166(2) A, b = 10.508(3) A, c = 13.599(5) A, V = 881.2(5) A(3), and Z = 4. The X-ray structure of 1 reveals the presence of octahedral Cd(II) ions bound to citrate ligands in a molecular crystal lattice. Citrate acts as a tridentate binder promoting coordination to one Cd(II) through the central alcoholic moiety, one terminal carboxylate group, and the central carboxylate group. In addition, the central carboxylate binds to three Cd(II) ions. Specifically, one of the oxygens of the central carboxylate serves as a bridge to two neighboring Cd(II) ions, while the other oxygen binds to a third Cd(II). A bound water molecule completes the coordination requirements of Cd(II). (113)Cd MAS NMR studies project the spectroscopic signature of the nature of the coordination environment around Cd(II) in 1, thus corroborating the X-ray findings. Collectively, the data at hand are in line with past solution studies. The latter predict that other similar low molecular mass Cd(II)-citrate complexes may exist in the acidic pH region, thus influencing the uptake of cadmium by living (micro)organisms, their ability to metabolize organic substrates, and possibly Cd(II) toxicity. PMID:12691558

  15. 38 CFR 14.618 - Collection action.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2014-07-01 2014-07-01 false Collection action. 14.618... Collection action. (a) In a case where the Regional Counsel determines that damage to or loss of Government..., suspend, or terminate collection action on any such claim as is authorized under § 2.6(e)(4)(ii) of...

  16. 38 CFR 14.618 - Collection action.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Collection action. 14.618... Collection action. (a) In a case where the Regional Counsel determines that damage to or loss of Government..., suspend, or terminate collection action on any such claim as is authorized under § 2.6(e)(4)(ii) of...

  17. 38 CFR 14.618 - Collection action.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2012-07-01 2012-07-01 false Collection action. 14.618... Collection action. (a) In a case where the Regional Counsel determines that damage to or loss of Government..., suspend, or terminate collection action on any such claim as is authorized under § 2.6(e)(4)(ii) of...

  18. 38 CFR 14.618 - Collection action.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2011-07-01 2011-07-01 false Collection action. 14.618... Collection action. (a) In a case where the Regional Counsel determines that damage to or loss of Government..., suspend, or terminate collection action on any such claim as is authorized under § 2.6(e)(4)(ii) of...

  19. 38 CFR 14.618 - Collection action.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2013-07-01 2013-07-01 false Collection action. 14.618... Collection action. (a) In a case where the Regional Counsel determines that damage to or loss of Government..., suspend, or terminate collection action on any such claim as is authorized under § 2.6(e)(4)(ii) of...

  20. Blood Collection

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The method that is used for the collection, storage and real-time analysis of blood and other bodily fluids has been licensed to DBCD, Inc. by NASA. The result of this patent licensing agreement has been the development of a commercial product that can provide serum or plasma from whole blood volumes of 20 microliters to 4 milliliters. The device has a fibrous filter with a pore size of less than about 3 microns, and is coated with a mixture of mannitol and plasma fraction protein. The coating causes the cellular fraction to be trapped by the small pores, leaving the cellular fraction intact on the fibrous filter while the acellular fraction passes through the filter for collection in unaltered form from the serum sample collection chamber. The method used by this product is useful to NASA for blood analysis on manned space missions.

  1. The Tox21 robotic platform for the assessment of environmental chemicals--from vision to reality.

    PubMed

    Attene-Ramos, Matias S; Miller, Nicole; Huang, Ruili; Michael, Sam; Itkin, Misha; Kavlock, Robert J; Austin, Christopher P; Shinn, Paul; Simeonov, Anton; Tice, Raymond R; Xia, Menghang

    2013-08-01

    Since its establishment in 2008, the US Tox21 inter-agency collaboration has made great progress in developing and evaluating cellular models for the evaluation of environmental chemicals as a proof of principle. Currently, the program has entered its production phase (Tox21 Phase II) focusing initially on the areas of modulation of nuclear receptors and stress response pathways. During Tox21 Phase II, the set of chemicals to be tested has been expanded to nearly 10,000 (10K) compounds and a fully automated screening platform has been implemented. The Tox21 robotic system combined with informatics efforts is capable of screening and profiling the collection of 10K environmental chemicals in triplicate in a week. In this article, we describe the Tox21 screening process, compound library preparation, data processing, and robotic system validation. PMID:23732176

  2. Collecting Artifacts

    ERIC Educational Resources Information Center

    Coffey, Natalie

    2004-01-01

    Fresh out of college, the author had only a handful of items worthy of displaying, which included some fossils she had collected in her paleontology class. She had binders filled with great science information, but kids want to see "real" science, not paper science. Then it came to her: she could fill the shelves with science artifacts with the…

  3. Wastewater Collection.

    ERIC Educational Resources Information Center

    Chatterjee, Samar; And Others

    1978-01-01

    Presents a literature review of wastewater collection systems and components. This review covers: (1) planning, (2) construction; (3) sewer system evaluation; (4) maintenance; (5) rehabilitation; (6) overview prevention; and (7) wastewater pumping. A list of 111 references is also presented. (HM)

  4. Collection Security.

    ERIC Educational Resources Information Center

    Boss, Richard W.

    1984-01-01

    Presents a systematic approach to the problem of security of library collections and facilities from theft and vandalism. Highlights include responses to losses, defining security needs, typical weaknesses of facilities, policies and procedures that weaken a library's security, conducting a security audit, cost of security, cost-effectiveness, and…

  5. Collective Bargaining.

    ERIC Educational Resources Information Center

    Goldschmidt, Steven M.

    This chapter summarizes recent state supreme court and federal court decisions involving collective bargaining for employees of public educational institutions. The cases discussed are generally limited to those decided during 1975 and reported in the General Digest as of March 1976. In his discussion, the author attempts to integrate related…

  6. Collective Bargaining.

    ERIC Educational Resources Information Center

    Goldschmidt, Steven M.

    This chapter deals with the legal process by which employers and employee organizations discuss matters related to employment. The chapter is organized to reflect the initial sequence of events in the collective bargaining process. Cases are reported and analyzed in nine sections: obligation and authority to bargain; unit determination and…

  7. Collective Bargaining.

    ERIC Educational Resources Information Center

    Zirkel, Perry A.

    Higher education collective bargaining cases reviewed in this chapter follow the basic sequence of steps in the negotiation process, from issues of the rights of organization and negotiation through scope of bargaining, bargaining conduct, and union security to the ultimate problems of strikes and contract enforcement. Within this common outline,…

  8. Photosystem II

    ScienceCinema

    James Barber

    2010-09-01

    James Barber, Ernst Chain Professor of Biochemistry at Imperial College, London, gives a BSA Distinguished Lecture titled, "The Structure and Function of Photosystem II: The Water-Splitting Enzyme of Photosynthesis."

  9. 75 FR 34487 - Notice of Information Collection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-17

    ... general themes on areas to focus on in order to enhance creativity and innovation at the Center. II. Method of Collection Electronic. III. Data Title: The KEYS Creativity and Innovation Survey. OMB...

  10. 77 FR 37078 - Proposed Collection; Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-20

    ... things: (i) Each transaction effected under the rule is reported on Form N-SAR; (ii) the fund's directors... transaction reports on Form N-SAR, which is encompassed in the information collection burden estimate for...

  11. Collective instabilities

    SciTech Connect

    K.Y. Ng

    2003-08-25

    The lecture covers mainly Sections 2.VIII and 3.VII of the book ''Accelerator Physics'' by S.Y. Lee, plus mode-coupling instabilities and chromaticity-driven head-tail instability. Besides giving more detailed derivation of many equations, simple interpretations of many collective instabilities are included with the intention that the phenomena can be understood more easily without going into too much mathematics. The notations of Lee's book as well as the e{sup jwt} convention are followed.

  12. Mass-sensitive chemical preconcentrator

    DOEpatents

    Manginell, Ronald P.; Adkins, Douglas R.; Lewis, Patrick R.

    2007-01-30

    A microfabricated mass-sensitive chemical preconcentrator actively measures the mass of a sample on an acoustic microbalance during the collection process. The microbalance comprises a chemically sensitive interface for collecting the sample thereon and an acoustic-based physical transducer that provides an electrical output that is proportional to the mass of the collected sample. The acoustic microbalance preferably comprises a pivot plate resonator. A resistive heating element can be disposed on the chemically sensitive interface to rapidly heat and release the collected sample for further analysis. Therefore, the mass-sensitive chemical preconcentrator can optimize the sample collection time prior to release to enable the rapid and accurate analysis of analytes by a microanalytical system.

  13. Diet History Questionnaire II & Canadian Diet History Questionnaire II: Web-based DHQ

    Cancer.gov

    The Web-based versions of DHQ II and C-DHQ II are identical in content to the paper forms. By automating the DHQ II and providing versions on the Web for public use, researchers have another tool to collect and analyze food frequency questionnaire data.

  14. Tortuous path chemical preconcentrator

    DOEpatents

    Manginell, Ronald P.; Lewis, Patrick R.; Adkins, Douglas R.; Wheeler, David R.; Simonson, Robert J.

    2010-09-21

    A non-planar, tortuous path chemical preconcentrator has a high internal surface area having a heatable sorptive coating that can be used to selectively collect and concentrate one or more chemical species of interest from a fluid stream that can be rapidly released as a concentrated plug into an analytical or microanalytical chain for separation and detection. The non-planar chemical preconcentrator comprises a sorptive support structure having a tortuous flow path. The tortuosity provides repeated twists, turns, and bends to the flow, thereby increasing the interfacial contact between sample fluid stream and the sorptive material. The tortuous path also provides more opportunities for desorption and readsorption of volatile species. Further, the thermal efficiency of the tortuous path chemical preconcentrator is comparable or superior to the prior non-planar chemical preconcentrator. Finally, the tortuosity can be varied in different directions to optimize flow rates during the adsorption and desorption phases of operation of the preconcentrator.

  15. 77 FR 71832 - Agency Information Collection Activities: Proposed Collection; Comments Requested: Application...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-04

    ...: Application for Procurement Quota for Controlled Substances and Ephedrine, Pseudoephedrine, and... Quota for Controlled Substances and Ephedrine, Pseudoephedrine, and Phenylpropanolamine (DEA Form 250... substances listed in Schedule I or II or the List I chemicals ephedrine, pseudoephedrine,...

  16. 78 FR 9429 - Agency Information Collection Activities; Proposed Collection; Comments Requested: Application...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-08

    ...: Application for Procurement Quota for Controlled Substances and Ephedrine, Pseudoephedrine, and... Quota for Controlled Substances and Ephedrine, Pseudoephedrine, and Phenylpropanolamine (DEA Form 250... II or the List I chemicals ephedrine, pseudoephedrine, and phenylpropanolamine for purposes...

  17. Collective motion

    NASA Astrophysics Data System (ADS)

    Vicsek, Tamás; Zafeiris, Anna

    2012-08-01

    We review the observations and the basic laws describing the essential aspects of collective motion - being one of the most common and spectacular manifestation of coordinated behavior. Our aim is to provide a balanced discussion of the various facets of this highly multidisciplinary field, including experiments, mathematical methods and models for simulations, so that readers with a variety of background could get both the basics and a broader, more detailed picture of the field. The observations we report on include systems consisting of units ranging from macromolecules through metallic rods and robots to groups of animals and people. Some emphasis is put on models that are simple and realistic enough to reproduce the numerous related observations and are useful for developing concepts for a better understanding of the complexity of systems consisting of many simultaneously moving entities. As such, these models allow the establishing of a few fundamental principles of flocking. In particular, it is demonstrated, that in spite of considerable differences, a number of deep analogies exist between equilibrium statistical physics systems and those made of self-propelled (in most cases living) units. In both cases only a few well defined macroscopic/collective states occur and the transitions between these states follow a similar scenario, involving discontinuity and algebraic divergences.

  18. Amazonian functional diversity from forest canopy chemical assembly.

    PubMed

    Asner, Gregory P; Martin, Roberta E; Tupayachi, Raul; Anderson, Christopher B; Sinca, Felipe; Carranza-Jiménez, Loreli; Martinez, Paola

    2014-04-15

    Patterns of tropical forest functional diversity express processes of ecological assembly at multiple geographic scales and aid in predicting ecological responses to environmental change. Tree canopy chemistry underpins forest functional diversity, but the interactive role of phylogeny and environment in determining the chemical traits of tropical trees is poorly known. Collecting and analyzing foliage in 2,420 canopy tree species across 19 forests in the western Amazon, we discovered (i) systematic, community-scale shifts in average canopy chemical traits along gradients of elevation and soil fertility; (ii) strong phylogenetic partitioning of structural and defense chemicals within communities independent of variation in environmental conditions; and (iii) strong environmental control on foliar phosphorus and calcium, the two rock-derived elements limiting CO2 uptake in tropical forests. These findings indicate that the chemical diversity of western Amazonian forests occurs in a regionally nested mosaic driven by long-term chemical trait adjustment of communities to large-scale environmental filters, particularly soils and climate, and is supported by phylogenetic divergence of traits essential to foliar survival under varying environmental conditions. Geographically nested patterns of forest canopy chemical traits will play a role in determining the response and functional rearrangement of western Amazonian ecosystems to changing land use and climate. PMID:24591585

  19. Amazonian functional diversity from forest canopy chemical assembly

    PubMed Central

    Asner, Gregory P.; Martin, Roberta E.; Tupayachi, Raul; Anderson, Christopher B.; Sinca, Felipe; Carranza-Jiménez, Loreli; Martinez, Paola

    2014-01-01

    Patterns of tropical forest functional diversity express processes of ecological assembly at multiple geographic scales and aid in predicting ecological responses to environmental change. Tree canopy chemistry underpins forest functional diversity, but the interactive role of phylogeny and environment in determining the chemical traits of tropical trees is poorly known. Collecting and analyzing foliage in 2,420 canopy tree species across 19 forests in the western Amazon, we discovered (i) systematic, community-scale shifts in average canopy chemical traits along gradients of elevation and soil fertility; (ii) strong phylogenetic partitioning of structural and defense chemicals within communities independent of variation in environmental conditions; and (iii) strong environmental control on foliar phosphorus and calcium, the two rock-derived elements limiting CO2 uptake in tropical forests. These findings indicate that the chemical diversity of western Amazonian forests occurs in a regionally nested mosaic driven by long-term chemical trait adjustment of communities to large-scale environmental filters, particularly soils and climate, and is supported by phylogenetic divergence of traits essential to foliar survival under varying environmental conditions. Geographically nested patterns of forest canopy chemical traits will play a role in determining the response and functional rearrangement of western Amazonian ecosystems to changing land use and climate. PMID:24591585

  20. Structural studies on photosystem II of cyanobacteria.

    PubMed

    Gabdulkhakov, A G; Dontsova, M V

    2013-12-01

    Photosynthesis is one of the most important chemical processes in the biosphere responsible for the maintenance of life on Earth. Light energy is converted into energy of chemical bonds in photoreaction centers, which, in particular, include photosystem II (PS II). PS II is a multisubunit pigment-protein complex located in the thylakoid membrane of cyanobacteria, algae and plants. PS II realizes the first stage of solar energy conversion that results in decomposition of water to molecular oxygen, protons, and bound electrons via a series of consecutive reactions. During recent years, considerable progress has been achieved in determination of the spatial structures of PS II from various cyanobacteria. In the present review, we outline the current state of crystallographic studies on PS II. PMID:24490738

  1. 36 CFR 1207.52 - Collection of amounts due.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Collection Standards (4 CFR chapter II). The date from which interest is computed is not extended by... AND LOCAL GOVERNMENTS After-The-Grant Requirements § 1207.52 Collection of amounts due. (a) Any...

  2. 36 CFR 1207.52 - Collection of amounts due.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Collection Standards (4 CFR chapter II). The date from which interest is computed is not extended by... AND LOCAL GOVERNMENTS After-The-Grant Requirements § 1207.52 Collection of amounts due. (a) Any...

  3. 36 CFR 1207.52 - Collection of amounts due.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Collection Standards (4 CFR chapter II). The date from which interest is computed is not extended by... AND LOCAL GOVERNMENTS After-The-Grant Requirements § 1207.52 Collection of amounts due. (a) Any...

  4. 36 CFR 1207.52 - Collection of amounts due.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Collection Standards (4 CFR chapter II). The date from which interest is computed is not extended by... AND LOCAL GOVERNMENTS After-The-Grant Requirements § 1207.52 Collection of amounts due. (a) Any...

  5. 36 CFR 1207.52 - Collection of amounts due.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Collection Standards (4 CFR chapter II). The date from which interest is computed is not extended by... AND LOCAL GOVERNMENTS After-The-Grant Requirements § 1207.52 Collection of amounts due. (a) Any...

  6. 77 FR 70188 - Manufacturer of Controlled Substances; Notice of Registration; Boehringer Ingelheim Chemicals, Inc.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-23

    ... Chemicals, Inc. By Notice dated July 17, 2012, and published in the Federal Register on July 26, 2012, 77 FR... Lisdexamfetamine (1205) II Methylphenidate (1724) II Methadone (9250) II Methadone Intermediate (9254)...

  7. SAGE II

    Atmospheric Science Data Center

    2016-02-16

    ... of stratospheric aerosols, ozone, nitrogen dioxide, water vapor and cloud occurrence by mapping vertical profiles and calculating ... (i.e. MLS and SAGE III versus HALOE) Fixed various bugs Details are in the  SAGE II V7.00 Release Notes .   ...

  8. Juno II

    NASA Technical Reports Server (NTRS)

    1959-01-01

    Wernher von Braun and his team were responsible for the Jupiter-C hardware. The family of launch vehicles developed by the team also came to include the Juno II, which was used to launch the Pioneer IV satellite on March 3, 1959. Pioneer IV passed within 37,000 miles of the Moon before going into solar orbit.

  9. Welding II.

    ERIC Educational Resources Information Center

    Allegheny County Community Coll., Pittsburgh, PA.

    Instructional objectives and performance requirements are outlined in this course guide for Welding II, a performance-based course offered at the Community College of Allegheny County to introduce students to out-of-position shielded arc welding with emphasis on proper heats, electrode selection, and alternating/direct currents. After introductory…

  10. Mostly Plants. Individualized Biology Activities on: I. Investigating Bread Mold; II. Transpiration; III. Botany Project; IV. Collecting/Preserving/Identifying Leaves; [and] V. Student Science Laboratory Write-Ups.

    ERIC Educational Resources Information Center

    Gibson, Paul R.

    Individualized biology activities for secondary students are presented in this teaching guide. The guide is divided into five sections: (1) investigating bread mold; (2) investigating transpiration; (3) completing a botany project; (4) collecting, preserving, and identifying leaves; and (5) writing up science laboratory investigations. The…

  11. Subject and Citation Indexing. Part I: The Clustering Structure of Composite Representations in the Cystic Fibrosis Document Collection. Part II: The Optimal, Cluster-Based Retrieval Performance of Composite Representations.

    ERIC Educational Resources Information Center

    Shaw, W. M., Jr.

    1991-01-01

    Two articles discuss the clustering of composite representations in the Cystic Fibrosis Document Collection from the National Library of Medicine's MEDLINE file. Clustering is evaluated as a function of the exhaustivity of composite representations based on Medical Subject Headings (MeSH) and citation indexes, and evaluation of retrieval…

  12. Biomass - chemicals

    SciTech Connect

    Kovaly, K.A.

    1982-08-01

    A host of industrial chemicals, specialty items, solvents, plastics, elastomers, fibers and films can be produced from agricultural crops, wood, paper mill wastes, food processing wastes, municipal waste and sewage. Existing chemical processes based on readily renewable plant materials are reviewed. These include ethanol and acetone-butanol fermentations, oilseed chemicals, furfural and cellulosics. (Refs. 16).

  13. 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.

  14. Anniston community health survey: Follow-up and dioxin analyses (ACHS-II)--methods.

    PubMed

    Birnbaum, Linda S; Dutton, N D; Cusack, C; Mennemeyer, S T; Pavuk, M

    2016-02-01

    High serum concentrations of polychlorinated biphenyls (PCBs) have been reported previously among residents of Anniston, Alabama, where a PCB production facility was located in the past. As the second of two cross-sectional studies of these Anniston residents, the Anniston Community Health Survey: Follow-Up and Dioxin Analyses (ACHS-II) will yield repeated measurements to be used to evaluate changes over time in ortho-PCB concentrations and selected health indicators in study participants. Dioxins, non-ortho PCBs, other chemicals, heavy metals, and a variety of additional clinical tests not previously measured in the original ACHS cohort will be examined in ACHS-II. The follow-up study also incorporates a questionnaire with extended sections on diet and occupational history for a more comprehensive assessment of possible exposure sources. Data collection for ACHS-II from 359 eligible participants took place in 2014, 7 to 9 years after ACHS. PMID:25982988

  15. Cu(II) and Zn(II) ions alter the dynamics and distribution of Mn(II) in cultured chick glial cells

    SciTech Connect

    Wedler, F.C.; Ley, B.W. )

    1990-12-01

    Previous studies revealed that Mn(II) is accumulated in cultured glial cells to concentrations far above those present in whole brain or in culture medium. The data indicated that Mn(II) moves across the plasma membrane into the cytoplasm by facilitated diffusion or counter-ion transport with Ca(II), then into mitochondria by active transport. The fact that 1-10 microM Mn(II) ions activate brain glutamine synthetase makes important the regulation of Mn(II) transport in the CNS. Since Cu(II) and Zn(II) caused significant changes in the accumulation of Mn(II) by glia, the mechanisms by which these ions alter the uptake and efflux of Mn(II) ions has been investigated systematically under chemically defined conditions. The kinetics of (54MN)-Mn(II) uptake and efflux were determined and compared under four different sets of conditions: no adducts, Cu(II) or Zn(II) added externally, and with cells preloaded with Cu(II) or Zn(II) in the presence and absence of external added metal ions. Zn(II) ions inhibit the initial velocity of Mn(II) uptake, increase total Mn(II) accumulated, but do not alter the rate or extent Mn(II) efflux. Cu(II) ions increase both the initial velocity and the net Mn(II) accumulated by glia, with little effect on rate or extent of Mn(II) efflux. These results predict that increases in Cu(II) or Zn(II) levels may also increase the steady-state levels of Mn(II) in the cytoplasmic fraction of glial cells, which may in turn alter the activity of Mn(II)-sensitive enzymes in this cell compartment.

  16. /sup 13/C and /sup 17/O NMR and IR spectroscopic study of a series of carbonyl(4-substituted pyridine)(meso-tetraphenylporphinato)iron(II) complexes. Correlations between NMR chemical shifts and IR stretching frequencies of the carbonyl ligand and Taft parameters of the pyridine substituent

    SciTech Connect

    Box, J.W.; Gray, G.M.

    1987-08-26

    The results of a /sup 13/C and /sup 17/O NMR and IR spectroscopic study of a series of carbonyl(4 substituted pyridine)(meso-tetraphenylporphinato)iron(II) (Fe(TPP)(CO)(py-4-X)) complexes are presented. Good to excellent linear correlations between the /sup 13/ and /sup 17/O NMR chemical shifts and the IR stretching frequencies of the carbonyl ligand are observed as the pyridine substituent is varied. Good to excellent linear correlations are also observed between these NMR chemical shifts and IR stretching frequencies and the NMR chemical shifts and IR stretching force constants for the trans carbonyls of a series of cis-Mo(CO)/sub 4/(py-4-X)/sub 2/ complexes as the pyridine substituent is varied. The relationship between the donor ability of the pyridine ligands and the /sup 13/C and /sup 17/O NMR chemical shifts and the IR stretching frequencies of the carbonyl ligands in the Fe(TPP)(CO)(py-4-X) complexes has been quantitated by fitting the spectroscopic data to the single and the dual Taft substituent parameters of the pyridine substituent. Good to excellent correlations are observed. The upfield shift in the /sup 13/C NMR resonance of the carbonyl ligand as the electron-donor ability of the pyridine increases is unique. This has been rationalized by using the Buchner and Schenk description of metal carbonyl /sup 13/C NMR chemical shifts. 49 references, 3 figures, 6 tables.

  17. Chemical Leukoderma.

    PubMed

    Bonamonte, Domenico; Vestita, Michelangelo; Romita, Paolo; Filoni, Angela; Foti, Caterina; Angelini, Gianni

    2016-01-01

    Chemical leukoderma, often clinically mimicking idiopathic vitiligo and other congenital and acquired hypopigmentation, is an acquired form of cutaneous pigment loss caused by exposure to a variety of chemicals that act through selective melanocytotoxicity. Most of these chemicals are phenols and aromatic or aliphatic catechols derivatives. These chemicals, however, are harmful for melanocytes in individuals with an individual susceptibility. Nowadays, chemical leukoderma is fairly common, caused by common domestic products. The presence of numerous acquired confetti- or pea-sized macules is clinically characteristic of chemical leukoderma, albeit not diagnostic. Other relevant diagnostic elements are a history of repeated exposure to a known or suspected depigmenting agent at the sites of onset and a macules distribution corresponding to sites of chemical exposure. Spontaneous repigmentation has been reported when the causative agent is avoided; the repigmentation process is perifollicular and gradual, taking place for a variable period of weeks to months. PMID:27172302

  18. I. Cognitive and instructional factors relating to students' development of personal models of chemical systems in the general chemistry laboratory II. Solvation in supercritical carbon dioxide/ethanol mixtures studied by molecular dynamics simulation

    NASA Astrophysics Data System (ADS)

    Anthony, Seth

    Part I. Students' participation in inquiry-based chemistry laboratory curricula, and, in particular, engagement with key thinking processes in conjunction with these experiences, is linked with success at the difficult task of "transfer"---applying their knowledge in new contexts to solve unfamiliar types of problems. We investigate factors related to classroom experiences, student metacognition, and instructor feedback that may affect students' engagement in key aspects of the Model-Observe-Reflect-Explain (MORE) laboratory curriculum - production of written molecular-level models of chemical systems, describing changes to those models, and supporting those changes with reference to experimental evidence---and related behaviors. Participation in introductory activities that emphasize reviewing and critiquing of sample models and peers' models are associated with improvement in several of these key aspects. When students' self-assessments of the quality of aspects of their models are solicited, students are generally overconfident in the quality of their models, but these self-ratings are also sensitive to the strictness of grades assigned by their instructor. Furthermore, students who produce higher-quality models are also more accurate in their self-assessments, suggesting the importance of self-evaluation as part of the model-writing process. While the written feedback delivered by instructors did not have significant impacts on student model quality or self-assessments, students' resubmissions of models were significantly improved when students received "reflective" feedback prompting them to self-evaluate the quality of their models. Analysis of several case studies indicates that the content and extent of molecular-level ideas expressed in students' models are linked with the depth of discussion and content of discussion that occurred during the laboratory period, with ideas developed or personally committed to by students during the laboratory period being

  19. 75 FR 77006 - Notice of Information Collection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-10

    ...-1351, Lori.Parker@nasa.gov . SUPPLEMENTARY INFORMATION: I. Abstract Contractors performing research and... respondents, including automated collection techniques or the use of other forms of information technology... Technology Summary Report reporting form is being used for this purpose. II. Method of Collection NASA...

  20. PORT II

    NASA Technical Reports Server (NTRS)

    Muniz, Beau

    2009-01-01

    One unique project that the Prototype lab worked on was PORT I (Post-landing Orion Recovery Test). PORT is designed to test and develop the system and components needed to recover the Orion capsule once it splashes down in the ocean. PORT II is designated as a follow up to PORT I that will utilize a mock up pressure vessel that is spatially compar able to the final Orion capsule.

  1. BORE II

    SciTech Connect

    2015-08-01

    Bore II, co-developed by Berkeley Lab researchers Frank Hale, Chin-Fu Tsang, and Christine Doughty, provides vital information for solving water quality and supply problems and for improving remediation of contaminated sites. Termed "hydrophysical logging," this technology is based on the concept of measuring repeated depth profiles of fluid electric conductivity in a borehole that is pumping. As fluid enters the wellbore, its distinct electric conductivity causes peaks in the conductivity log that grow and migrate upward with time. Analysis of the evolution of the peaks enables characterization of groundwater flow distribution more quickly, more cost effectively, and with higher resolution than ever before. Combining the unique interpretation software Bore II with advanced downhole instrumentation (the hydrophysical logging tool), the method quantifies inflow and outflow locations, their associated flow rates, and the basic water quality parameters of the associated formation waters (e.g., pH, oxidation-reduction potential, temperature). In addition, when applied in conjunction with downhole fluid sampling, Bore II makes possible a complete assessment of contaminant concentration within groundwater.

  2. BORE II

    Energy Science and Technology Software Center (ESTSC)

    2015-08-01

    Bore II, co-developed by Berkeley Lab researchers Frank Hale, Chin-Fu Tsang, and Christine Doughty, provides vital information for solving water quality and supply problems and for improving remediation of contaminated sites. Termed "hydrophysical logging," this technology is based on the concept of measuring repeated depth profiles of fluid electric conductivity in a borehole that is pumping. As fluid enters the wellbore, its distinct electric conductivity causes peaks in the conductivity log that grow and migratemore » upward with time. Analysis of the evolution of the peaks enables characterization of groundwater flow distribution more quickly, more cost effectively, and with higher resolution than ever before. Combining the unique interpretation software Bore II with advanced downhole instrumentation (the hydrophysical logging tool), the method quantifies inflow and outflow locations, their associated flow rates, and the basic water quality parameters of the associated formation waters (e.g., pH, oxidation-reduction potential, temperature). In addition, when applied in conjunction with downhole fluid sampling, Bore II makes possible a complete assessment of contaminant concentration within groundwater.« less

  3. Run II luminosity progress

    SciTech Connect

    Gollwitzer, K.; /Fermilab

    2007-06-01

    The Fermilab Tevatron Collider Run II program continues at the energy and luminosity frontier of high energy particle physics. To the collider experiments CDF and D0, over 3 fb{sup -1} of integrated luminosity has been delivered to each. Upgrades and improvements in the Antiproton Source of the production and collection of antiprotons have led to increased number of particles stored in the Recycler. Electron cooling and associated improvements have help make a brighter antiproton beam at collisions. Tevatron improvements to handle the increased number of particles and the beam lifetimes have resulted in an increase in luminosity.

  4. [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

  5. Discrete-Event Simulation in Chemical Engineering.

    ERIC Educational Resources Information Center

    Schultheisz, Daniel; Sommerfeld, Jude T.

    1988-01-01

    Gives examples, descriptions, and uses for various types of simulation systems, including the Flowtran, Process, Aspen Plus, Design II, GPSS, Simula, and Simscript. Explains similarities in simulators, terminology, and a batch chemical process. Tables and diagrams are included. (RT)

  6. Oscillator strength measurements in samarium(II), neodymium(II) and praseodymium(II)

    NASA Astrophysics Data System (ADS)

    Li, Ruohong

    A knowledge of the abundances of lanthanide ions in stellar photospheres is valuable in astrophysics, especially for chemically peculiar stars. However, the determination of elemental abundances is often limited by inadequate knowledge of oscillator strengths. Combining independently measured values of radiative lifetimes and branching fractions is an effective and precise method to measure oscillator strengths. It avoids absolute intensity measurements, requiring a knowledge of the absolute number density of particles and absolute measurements of intensity, and furthermore decreases the systematic error greatly. In the previous work of our group, the lifetimes of Sm II, Nd II and Pr II were obtained. In this thesis work, we measured the corresponding branching fractions of these lanthanide ions using a fast-ion-beam laser-induced- fluorescence technique. The power of this technique is that ions are selectively excited by a laser, which ensures that every branch comes from a single upper level and gets rid of spectral blends. Besides, the low ion-beam density ensures that the systematic errors due to collisions and radiation trapping are negligible. Combining the branching fractions with our previously measured lifetimes, we obtained 608, 430 and 260 oscillator strength values for Sm II, Nd II and Pr II transitions, respectively, over the wavelength range 350-850 nm. These transitions originate from 69 upper levels in the range 21 655 cm -1 -29 388 cm -1 for Sm II, 46 upper levels in the range 22 697 cm -1 -29 955 cm -1 for Nd II, and 32 levels in the range 22 040 cm -1 -28 577 cm -1 for Pr II. Of the 260 measured oscillator strength values of Pr II, 183 have been determined accurately for the first time. The uncertainties arise principally from systematic uncertainties of the efficiency calibration of the optical detection system (7.1%), with smaller statistical contributions (1.5%). Comparisons are made to prior measurements.

  7. Children Teaching Children II. [CD-ROM].

    ERIC Educational Resources Information Center

    California State Dept. of Education, Sacramento. Office of School Improvement.

    Children Teaching Children (CTC): Collection II is a CD-ROM created at 6 elementary schools in the West Contra Costa Unified School District (California) as part of the Coaching Odyssey for school improvement. CTC II, published by the California Department of Education, is an effective early literacy intervention that integrates the development of…

  8. 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.

  9. Electronic and chemical state of aluminum from the single- (K) and double-electron excitation (KLII&III, KLI) x-ray absorption near-edge spectra of α-alumina, sodium aluminate, aqueous Al³⁺•(H₂O)₆, and aqueous Al(OH)₄⁻

    SciTech Connect

    Fulton, John L.; Govind, Niranjan; Huthwelker, Thomas; Bylaska, Eric J.; Vjunov, Aleksei; Pin, Sonia; Smurthwaite, Tricia D.

    2015-07-02

    We probe, at high energy resolution, the double electron excitation (KLII&II) x-ray absorption region that lies approximately 115 eV above the main Al K-edge (1566 eV) of α-alumina and sodium aluminate. The two solid standards, α-alumina (octahedral) and sodium aluminate (tetrahedral) are compared to aqueous species that have the same Al coordination symmetries, Al³⁺•6H₂O (octahedral) and Al(OH)₄⁻ (tetrahedral). For the octahedral species, the edge height of the KLII&III-edge is approximately 10% of the main K-edge however the edge height is much weaker (3% of K-edge height) for Al species with tetrahedral symmetry. For the α-alumina and aqueous Al³⁺•6H₂O the KLII&III spectra contain white line features and extended absorption fine structure (EXAFS) that mimics the K-edge spectra. The KLII&III-edge feature interferes with an important region of the extended-XAFS region of the spectra for the K-edge of the crystalline and aqueous standards. The K-edge spectra and K-edge positions are predicted using time-dependent density functional theory (TDDFT). The TDDFT calculations for the K-edge XANES spectra reproduce the observed transitions in the experimental spectra of the four Al species. The KLII&III and KLI onsets and their corresponding chemical shifts for the four standards are estimated using the delta self-consistent field (ΔSCF) method. Research by JLF, NG, EJB, AV, TDS was supported by U.S. Department of Energy’s (DOE), Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. NG thanks Amity Andersen for help with the α-Al₂O₃ and tetrahedral sodium aluminate (NaAlO₂) clusters. All the calculations were performed using the Molecular Science Computing Capability at EMSL, a national scientific user facility sponsored by the U.S. Department of Energy’s Office of Biological and Environmental Research and located at

  10. CHEMICAL TIME-SERIES SAMPLING

    EPA Science Inventory

    The rationale for chemical time-series sampling has its roots in the same fundamental relationships as govern well hydraulics. Samples of ground water are collected as a function of increasing time of pumpage. The most efficient pattern of collection consists of logarithmically s...

  11. Dust as interstellar catalyst. I. Quantifying the chemical desorption process

    NASA Astrophysics Data System (ADS)

    Minissale, M.; Dulieu, F.; Cazaux, S.; Hocuk, S.

    2016-01-01

    Context. The presence of dust in the interstellar medium has profound consequences on the chemical composition of regions where stars are forming. Recent observations show that many species formed onto dust are populating the gas phase, especially in cold environments where UV- and cosmic-ray-induced photons do not account for such processes. Aims: The aim of this paper is to understand and quantify the process that releases solid species into the gas phase, the so-called chemical desorption process, so that an explicit formula can be derived that can be included in astrochemical models. Methods: We present a collection of experimental results of more than ten reactive systems. For each reaction, different substrates such as oxidized graphite and compact amorphous water ice were used. We derived a formula for reproducing the efficiencies of the chemical desorption process that considers the equipartition of the energy of newly formed products, followed by classical bounce on the surface. In part II of this study we extend these results to astrophysical conditions. Results: The equipartition of energy correctly describes the chemical desorption process on bare surfaces. On icy surfaces, the chemical desorption process is much less efficient, and a better description of the interaction with the surface is still needed. Conclusions: We show that the mechanism that directly transforms solid species into gas phase species is efficient for many reactions.

  12. Non-planar chemical preconcentrator

    DOEpatents

    Manginell, Ronald P.; Adkins, Douglas R.; Sokolowski, Sara S.; Lewis, Patrick R.

    2006-10-10

    A non-planar chemical preconcentrator comprises a high-surface area, low mass, three-dimensional, flow-through sorption support structure that can be coated or packed with a sorptive material. The sorptive material can collect and concentrate a chemical analyte from a fluid stream and rapidly release it as a very narrow temporal plug for improved separations in a microanalytical system. The non-planar chemical preconcentrator retains most of the thermal and fabrication benefits of a planar preconcentrator, but has improved ruggedness and uptake, while reducing sorptive coating concerns and extending the range of collectible analytes.

  13. Hydrothermal synthesis, structural and physico-chemical characterizations of two Nasicon phosphates: M{sub 0.50}{sup II}Ti{sub 2}(PO{sub 4}){sub 3} (M = Mn, Co)

    SciTech Connect

    Essehli, Rachid; Bali, Brahim El; Benmokhtar, S.; Fejfarova, Karla; Dusek, Michal

    2009-07-01

    The family of titanium Nasicon-phosphates of generic formula M{sub 0.5}{sup II}Ti{sub 2}(PO{sub 4}){sub 3} has been revisited using hydrothermal techniques. Two phases have been synthesized: Mn{sub 0.5}{sup II}Ti{sub 2}(PO{sub 4}){sub 3} (MnTiP) and Co{sub 0.5}{sup II}Ti{sub 2}(PO{sub 4}){sub 3} (CoTiP). Single crystal diffraction studies show that they exhibit two different structural types. Mn{sub 0.5}{sup II}Ti{sub 2}(PO{sub 4}){sub 3} phosphate crystallizes in the R-3 space group, with the cell parameters a = 8.51300(10) A and c = 21.0083(3) A (V = 1318.52(3) A{sup 3} and Z = 6). The Co{sub 0.5}{sup II}Ti{sub 2}(PO{sub 4}){sub 3} phosphate crystallizes in the R-3c space group, with a = 8.4608(9) A and c = 21.174(2) A (V = 1312.7(2) A{sup 3} and Z = 6). These two compounds are clearly related to the parent Nasicon-type rhombohedral structure, which can be described using [Ti{sub 2}(PO{sub 4}){sub 3}] framework composed of two [TiO{sub 6}] octahedral interlinked via three [PO{sub 4}] tetrahedra. {sup 31}P magic-angle spinning nuclear magnetic resonance (MAS-NMR) data are presented as supporting data. Curie-Weiss-type behavior is observed in the magnetic susceptibility. The phases are also characterized by IR spectroscopy and UV-visible.

  14. 15 CFR 714.3 - Advance declaration requirements for additionally planned production of Schedule 3 chemicals.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 3 CHEMICALS § 714.3 Advance... a Schedule 3 chemical above the declaration threshold; (ii) You plan to produce at a plant declared under § 714.1(a)(1)(ii) of the CWCR an additional Schedule 3 chemical above the declaration...

  15. 15 CFR 714.3 - Advance declaration requirements for additionally planned production of Schedule 3 chemicals.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 3 CHEMICALS § 714.3 Advance... a Schedule 3 chemical above the declaration threshold; (ii) You plan to produce at a plant declared under § 714.1(a)(1)(ii) of the CWCR an additional Schedule 3 chemical above the declaration...

  16. 15 CFR 714.3 - Advance declaration requirements for additionally planned production of Schedule 3 chemicals.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 3 CHEMICALS § 714.3 Advance... a Schedule 3 chemical above the declaration threshold; (ii) You plan to produce at a plant declared under § 714.1(a)(1)(ii) of the CWCR an additional Schedule 3 chemical above the declaration...

  17. 15 CFR 714.3 - Advance declaration requirements for additionally planned production of Schedule 3 chemicals.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 3 CHEMICALS § 714.3 Advance... a Schedule 3 chemical above the declaration threshold; (ii) You plan to produce at a plant declared under § 714.1(a)(1)(ii) of the CWCR an additional Schedule 3 chemical above the declaration...

  18. 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").

  19. 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.

  20. 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.