Science.gov

Sample records for ii collected chemical

  1. Noninvasive transdermal chemical collection. II. In vitro and in vivo skin permeability studies.

    PubMed

    Bradley, C R; Almirez, R G; Conner, D P; Rhyne, P R; Peck, C C

    1990-01-01

    In vitro and in vivo skin permeability studies were conducted to investigate properties of several candidate transdermal chemical collection devices (TCDs). The TCD consists of a binding reservoir of activated charcoal suspended in a gel medium which is occlusively placed in direct contact with the skin. Binding of three model compounds (theophylline, methotrexate, and parathion) was studied in hydrophilic (agarose or PVA/PVP) and lipophilic (silicone) gel/carbon compositions. The effects of gel composition, compound hydrophilicity/lipophilicity, and hydration of skin on quantity of transdermally collected chemical and 'apparent' permeability were investigated using a 'fuzzy' rat animal model. In vitro and in vivo apparent permeability coefficients (Kp; cm/h) for amphophilic theophylline (6.95 x 10(-4) and 8.34 x 10(-4), respectively) and hydrophilic methotrexate (3.5 x 10(-3) and 3.2 x 10(-4), respectively) using an agarose aquagel TCD were greater than the corresponding Kp values obtained when silicone lipogel TCDs were employed (0.3 x 10(-4) and 3.2 x 10(-4), respectively, for theophylline; no measurable methotrexate was collected). Occlusive hydration of skin profoundly increased permeability of the hydrophyilic model compound, methotrexate. In vivo Kp values for lipophilic parathion were greater with a silicone TCD (6.7 x 10(-4) than with an agarose TCD (3.8 x 10(-4). We conclude that it is possible to influence transdermal chemical collection through modifications in the gel composition and by hydration of the skin. PMID:2083080

  2. Devices for collecting chemical compounds

    SciTech Connect

    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.

  3. 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)

  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 mainly due to its overdose, and its pharmacokinetics. PMID:19689273

  5. Type I and II ?-turns prediction using NMR chemical shifts.

    PubMed

    Wang, Ching-Cheng; Lai, Wen-Chung; Chuang, Woei-Jer

    2014-07-01

    A method for predicting type I and II ?-turns using nuclear magnetic resonance (NMR) chemical shifts is proposed. Isolated ?-turn chemical-shift data were collected from 1,798 protein chains. One-dimensional statistical analyses on chemical-shift data of three classes ?-turn (type I, II, and VIII) showed different distributions at four positions, (i) to (i + 3). Considering the central two residues of type I ?-turns, the mean values of C?, C?, H(N), and N(H) chemical shifts were generally (i + 1) > (i + 2). The mean values of C? and H? chemical shifts were (i + 1) < (i + 2). The distributions of the central two residues in type II and VIII ?-turns were also distinguishable by trends of chemical shift values. Two-dimensional cluster analyses on chemical-shift data show positional distributions more clearly. Based on these propensities of chemical shift classified as a function of position, rules were derived using scoring matrices for four consecutive residues to predict type I and II ?-turns. The proposed method achieves an overall prediction accuracy of 83.2 and 84.2% with the Matthews correlation coefficient values of 0.317 and 0.632 for type I and II ?-turns, indicating that its higher accuracy for type II turn prediction. The results show that it is feasible to use NMR chemical shifts to predict the ?-turn types in proteins. The proposed method can be incorporated into other chemical-shift based protein secondary structure prediction methods. PMID:24838372

  6. 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

  7. 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.

  8. 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 ...

  9. Chemical Abundances in Three Population II Stars

    NASA Astrophysics Data System (ADS)

    Bonifacio, Piercarlo

    The purpose of this thesis is to describe the abundance analysis of three Pop II stars. Chapter one is a historical review aimed at illustrating how the present-day concepts on stellar populations and the formation of the chemical elements came about. Chapter 2 describes the current views on the chemical an dynamical history of the Galaxy. Chapter 3 contains a brief description of two classes of Pop II stars: blue HB stars and extremely metal-poor G-type stars. The stars which are the object of this thesis belong to these two classes. Feige 86 is a field HB star which has an anomalous chemical composition. We shall argue, in chapter 6, that it represents a Pop II analogue of the Pop I CP stars. Instead CS 22881-39 and CS 22885-96 are ``normal'' G-type giants whose peculiarity is that the iron abundance is some two orders of magnitude below that of the most metal poor globular clusters. This metal deficiency is taken as evidence that these stars were formed out of extremely metal-poor gas, and is not attributed to some sort of atmospheric peculiarity as is the case for the anomalous abundances of Feige 86. Chapter 4 reviews some of the methods used to fix the atmospheric parameters of B-type and G-type stars. Chapter 5 is devoted to the study of the far UV spectrum of the Pop I B-type star Iota Her. The reason for performing this study, and for including it in this thesis, is to provide a ``standard'' spectrum against which the spectrum of ``peculiar'' objects, such as Feige 86, may be compared. This ``standard'' spectrum also provides an ideal test ground for the spectrum synthesis code used throughout this work. Chapter 6 describes the abundance analysis of Feige 86. Chapter 7 describes the abundance analysis of CS 22881-39 and CS 22885-96. In the appendices we provide plots of the UV spectra of Iota Her and Feige 86.

  10. Chemical soil investigation report for the Weldon Spring Chemical Plant/Raffinate Pits, Phase II

    SciTech Connect

    Not Available

    1989-08-01

    This report presents data and interpretations from the Phase II Chemical Soil Investigation at the Weldon Spring Chemical Plant/Raffinate Pits. This investigation was performed to provide data in support of the Remedial Investigation and Baseline Risk Assessment. The investigation consisted of both biased and unbiased sampling programs designed to detect contamination from previous operations. Very small amounts of nitroaromatic compound contamination were detected in former ordnance production areas. Metals and inorganic anion contamination was observed in numerous locations related to both explosives and uranium production. Small amounts of semi-volatile organic, pesticide, and PCB contamination were also detected. No volatile organic contamination was observed. The data collected in this investigation was of sufficient quality and quantity to characterize the on-site chemical soil contamination. Additional investigations may be required to support remedial design. 14 refs., 3 figs., 8 tabs.

  11. 40 CFR Table II-2 to Subpart II - Collection Efficiencies of Anaerobic Processes

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Collection Efficiencies of Anaerobic Processes II Table II-2 to Subpart II Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Industrial Wastewater Treatment Pt....

  12. 40 CFR Table II-2 to Subpart II - Collection Efficiencies of Anaerobic Processes

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Collection Efficiencies of Anaerobic Processes II Table II-2 to Subpart II Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Industrial Wastewater Treatment Pt....

  13. 75 FR 36067 - Agency Information Collection Activities; Proposed Collection; Comment Request; Chemical-Specific...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-24

    ..., 2010. Stephen A. Owens, Assistant Administrator, Office of Chemical Safety and Pollution Prevention... AGENCY Agency Information Collection Activities; Proposed Collection; Comment Request; Chemical-Specific... ICR, entitled: ``Chemical-Specific Rules, TSCA Section 8(a)'' and identified by EPA ICR No....

  14. COLLECTIVE EFFECTS IN THE NSLS-II STORAGE RING.

    SciTech Connect

    KRINSKY,S.; BENGTSSON, J.; BERG, J.S.; BLASKIEWICZ, M.; BLEDNYKH, A.; GUO, W.; MALITSKY, N.; MONTAG, C.; PODOBEDOV, B.; ROSE, J.; TOWNE, N.; YU, L.H.

    2007-06-25

    A new high-brightness synchrotron light source (NSLS-II) is under design at BNL. The 3-GeV NSLS-II storage ring has a double-bend achromatic lattice with damping wigglers installed in zero-dispersion straights to reduce the emittance below 1nm. In this paper, we present an overview of the impact of collective effects upon the performance of the storage ring. Subjects discussed include instability thresholds, Touschek lifetime and intra-beam scattering.

  15. 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...

  16. 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.

  17. 76 FR 40377 - Agency Information Collection Activities; Proposed Collection; Comment Request; Class II Special...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-08

    ... Collection; Comment Request; Class II Special Controls Guidance Document: Labeling for Natural Rubber Latex... for the labeling of natural rubber latex condoms. DATES: Submit either electronic or written comments... Document: Labeling for Natural Rubber Latex Condoms Classified Under 21 CFR 884.5300--(OMB Control...

  18. 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).

  19. Volcanic lake systematics II. Chemical constraints

    NASA Astrophysics Data System (ADS)

    Varekamp, J. C.; Pasternack, G. B.; Rowe, G. L.

    2000-04-01

    A database of 373 lake water analyses from the published literature was compiled and used to explore the geochemical systematics of volcanic lakes. Binary correlations and principal component analysis indicate strong internal coherence among most chemical parameters. Compositional variations are influenced by the flux of magmatic volatiles and/or deep hydrothermal fluids. The chemistry of the fluid entering a lake may be dominated by a high-temperature volcanic gas component or by a lower-temperature fluid that has interacted extensively with volcanic rocks. Precipitation of minerals like gypsum and silica can strongly affect the concentrations of Ca and Si in some lakes. A much less concentrated geothermal input fluid provides the mineralized components of some more dilute lakes. Temporal variations in dilution and evaporation rates ultimately control absolute concentrations of dissolved constituents, but not conservative element ratios. Most volcanic lake waters, and presumably their deep hydrothermal fluid inputs, classify as immature acid fluids that have not equilibrated with common secondary silicates such as clays or zeolites. Many such fluids may have equilibrated with secondary minerals earlier in their history but were re-acidified by mixing with fresh volcanic fluids. We use the concept of 'degree of neutralization' as a new parameter to characterize these acid fluids. This leads to a classification of gas-dominated versus rock-dominated lake waters. A further classification is based on a cluster analysis and a hydrothermal speedometer concept which uses the degree of silica equilibration of a fluid during cooling and dilution to evaluate the rate of fluid equilibration in volcano-hydrothermal systems.

  20. Adsorption study of copper (II) by chemically modified orange peel.

    PubMed

    Feng, Ningchuan; Guo, Xueyi; Liang, Sha

    2009-05-30

    An adsorbent, the chemically modified orange peel, was prepared from hydrolysis of the grafted copolymer, which was synthesized by interaction of methyl acrylate with cross-linking orange peel. The presence of poly (acrylic acid) on the biomass surface was verified by infrared spectroscopy (IR), scanning electron microscopy (SEM) and thermogravimetry (TG). Total negative charge in the biomass surface and the zeta potentials were determined. The modified biomass was found to present high adsorption capacity and fast adsorption rate for Cu (II). From Langmuir isotherm, the adsorption capacity for Cu (II) was 289.0 mg g(-1), which is about 6.5 times higher than that of the unmodified biomass. The kinetics for Cu (II) adsorption followed the pseudo-second-order kinetics. The adsorbent was used to remove Cu (II) from electroplating wastewater and was suitable for repeated use for more than four cycles. PMID:19081180

  1. 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.

  2. Strippable coatings for forensic collection of trace chemicals from surfaces.

    PubMed

    Beltis, Kevin J; Drennan, Paul M; Jakubowski, Michael J; Pindzola, Bradford A

    2012-12-18

    Surface sampling for chemical analysis plays a vital role in applications like environmental monitoring, industrial hygiene, homeland security, and forensics. The standard surface sampling tool is a simple cotton gauze pad, but as techniques become more sensitive and the variety of analytes increases, gauze is failing to meet the needs of the community. Here, the collection of eight small molecules from glass surfaces with three different commercial spray-on, strippable coatings was demonstrated and their collection efficiency, as measured by gas chromatography/mass spectrometry, was compared to that of a standard cotton gauze. The three coating systems recovered 87-95% of the each compound, on average, from a nominal initial surface coverage of 0.1 g/m(2) per analyte. These recoveries were 3-fold better than the cotton gauze which had an average collection efficiency of 31%. PMID:23157576

  3. 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.

  4. 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...

  5. 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..., Part II and III (Form 1040), Profit or Loss From Farming. DATES: Written comments should be received on... Number: Schedule F, Part II and III (Form 1040). Abstract: Schedule F, Part II and III (Form 1040)...

  6. 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.

  7. 77 FR 59891 - Proposed Information Collection; Comment Request; Chemical Weapons Convention Declaration and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-01

    ... Bureau of Industry and Security Proposed Information Collection; Comment Request; Chemical Weapons...@bis.doc.gov . SUPPLEMENTARY INFORMATION: ] I. Abstract The Chemical Weapons Convention Implementation Act of 1998 and Commerce Chemical Weapons Convention Regulations (CWCR) specify the...

  8. 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 available to other analytical instruments for measuring concentrations of substances other than Ca(2+).

  9. 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 to other analytical instruments for measuring concentrations of substances other than Ca2+.

  10. Chemical analysis of rain samples collected over the Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Nagamoto, C.; Parungo, F.; Kopcewicz, B.; Zhou, M. Y.

    1990-12-01

    During seven research cruises in the Pacific Ocean from 1984 to 1989 we collected rain samples for chemical analyses. The geographical and temporal variations of rain chemistry were studied in relation to natural and anthropogenic sources and transport of the constituents. The pH values of rain samples ranged from 3.9 to 7.2, with a mean of 5.6 (n = 104, ? = 0.5). The most acidic rain was found near the big ports, where SO4= and NO3- concentrations in rain were also the highest. The data indicated that wet deposition transports anthropogenic pollution from continents to oceans. Enrichments of Ca++ and K+, which are compared to Na+ in seawater, were observed in all rain samples throughout the ocean. However, their enrichment factors (EF) decrease with distance from land, signifying the extent of transport of crustal elements through cloud process and wet deposition. The EFs of Mg++ were close to unity, indicating its common origin with Na+. The EFs of Cl- in most rain samples were less than l, indicating loss of Cl- in aerosols, cloud droplets, or rain drops. High EFs of SO4= were also observed at the equatorial regions, where biogenic production of dimethyl sulfide is well known. During the 1987 El Nio anomaly the sulfate aerosol distribution and rainfall patterns altered with air trajectories. The effects of sulfate aerosol on cloud condensation and rainfall amount in various regions during normal years and the El Nio anomaly are discussed.

  11. 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

  12. Chemical profile of size-fractionated soils collected in a semiarid industrial area of Argentina

    NASA Astrophysics Data System (ADS)

    Morales Del Mastro, Anabella; Pereyra, Marcelo; Londonio, Agustín; Pereyra, Victoria; Rebagliati, Raúl Jiménez; Dawidowski, Laura; Gómez, Darío; Smichowski, Patricia

    2014-12-01

    A study was undertaken to assess the chemical profile of soil collected in Bahía Blanca (Argentina). In this industrial city, semiarid soils are affected by different industrial and agricultural activities, the presence of a saltpeter extraction facility, traffic and increasing urbanization. Sixteen soil samples (superficial and sub-superficial) were collected. Samples were sieved in two fractions (A < 37 μm, and 37 < B < 50 μm) before elemental analysis. Major, minor and trace elements namely, Al, As, Ba, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Pb, Sb, Ti, V and Zn were determined by inductively coupled plasma optical emission spectrometry (ICP OES). Anions (Cl-, F-, SO42-) and cations (K+, Na+ and NH4+) were determined by high performance liquid chromatography (HPLC) after an aqueous extraction. As expected, crustal elements namely, Al, Ca, Fe, Mg and Ti exhibited the highest concentrations. Mean elemental concentration ranged from <0.3 μg g-1 (Sb) to 14.6 ± 0.6% (Ca). Ions concentrations in the soluble fraction measured at mg g-1 levels were in the order Cl- > Na+ ≅ SO42- > K+ > NO3-. Three indicators, namely, (i) coefficient of variation, (ii) coefficient of divergence and (iii) ratio of elemental concentration with respect to Ca were used to assess chemical, spatial and inter-profile variability. Chloride > Ca > Na+ > Mo > SO42-, dominated the variability indicating that these are key chemical markers for future assessment of crustal contribution to airborne particles in the area. The ratios Xi/Ca allowed discriminating the soil of the semi-arid region surrounding Bahía Blanca. The chemical profiles obtained in this study, particularly those of topsoil, will be a key input to characterize soil resuspension and its contribution to airborne particulate matter in a forthcoming receptor model analysis.

  13. 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...) 482-4895, Lawrence.Hall@bis.doc.gov . SUPPLEMENTARY INFORMATION: I. Abstract The Chemical Weapons... weapons (CW). The CWC prohibits the use, development, production, acquisition, stockpiling, retention,...

  14. ANALYSIS AND INTERPRETATION OF ZOOPLANKTON SAMPLES COLLECTED DURING PHASE II OF THE EASTERN LAKE SURVEY

    EPA Science Inventory

    Samples from 146 lakes in the northeastern United States, collected during Phase II of the Eastern Lake Survey (ELS-II) were analyzed for abundance of each species and each size class of zooplankton. n estimate of sampling and counting error was provided by replication of lake sa...

  15. 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

  16. 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.

  17. Retrospective analysis of an archived soil collection. II. Cadmium.

    PubMed

    Jones, K C; Symon, C J; Johnston, A E

    1987-11-01

    Soil samples collected and stored since the mid-1800s to the present day have been analysed recently for Cd. The samples from long-term experiments under permanent grassland or arable crops at Rothamsted Experimental Station (U.K.) were selected to investigate time trends in elemental composition, due either solely to atmospheric deposition or to a combination of atmospheric deposition and various soil treatments. Increases in soil Cd of 27-55% since the 1850s due to atmospheric deposition were observed. This corresponds to an increase in the soil plough layer Cd concentration of between 0.7 and 1.9 micrograms kg-1 year-1 and is equivalent to an increase of 1.9-5.4 g Cd ha-1 year-1. The changes in soil Cd concentrations since 1846 at one control site corresponded well to predicted increases in the plough layer Cd burden based on assumptions about the temporal trends in atmospheric Cd emissions. In addition, sub-samples of a selection of rock phosphates of known origin and superphosphates, mainly from one supplier, collected and stored in the archive from 1925 onwards were also analysed for Cd. The concentrations ranged from 3.6 to 92 (mean 36) mg Cd kg-1 for rock phosphates and from 3.3 to 40 (9.7) mg kg-1 for superphosphates. On the basis of these data and known application rates the estimated input of Cd to P-treated plots at Rothamsted was 2 g ha-1 year-1, but there was little further increase in soil Cd due to this addition in three long-term arable experiments where soil pH was greater than 6.5. On P-treated plots the mean increase in soil Cd was 1.2 micrograms kg-1 year-1, which is equivalent to an increase in the plough layer burden of 3.1 g Cd ha-1 year-1. By contrast, P-treated soils under permanent grassland with a higher organic matter content and lower pH have increased their Cd content by 7.2 g ha-1 year-1. When permanent grassland soils ranging in pH from 5 to 7 were examined it was found that organic matter had a larger effect on Cd concentration than pH and the effects of pH were not consistent. Farmyard manure applied to some experimental plots at Rothamsted appears to have been a more significant source of Cd than combined atmospheric and phosphate fertiliser inputs. PMID:2827304

  18. 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...

  19. 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 28min 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

  20. Reliability of chemical abundance determinations in H II regions

    SciTech Connect

    French, H.B.; Grandi, S.A.

    1981-03-01

    The reliability of the standard procedures for deriving helium, oxygen, nitrogen, neon, and sulfur abundances in gaseous nebulae and of a proposed procedure for deriving argon abundances is investigated through the calculation of model H II regions with normal abundances and single central stars. The errors encountered at each step are examined; the combined procedures give errors < or approx. =5% for helium and < or approx. =50% for the other elements in most cases. The errors are only slightly larger if the ionization is produced by an aggregate of stars with a range of spectral types. Problems can be encountered if several H II regions are observed simultaneously (as in extragalactic objects) but probably will not be important for situations which occur in nature. The procedures work very well for low-abundance high-ionization H II regions, as are found in other galaxies.

  1. [Chemical safety (II)--Methodologic and practical problems].

    PubMed

    Indulski, J A; Krajewski, J A; Majka, J A

    1988-01-01

    Main components of the problem of chemical safety, their role and aims as well as their mutual relations are presented. Need to create a register of chemical compounds and necessity to set up an information centre which would help functioning the whole system are justified. Risk assessment is believed to be the main aspect of cognitive activities aimed at determining the probability of occurrence of harmful consequences of exposure. Risk assessment is a set of complex legal, organizational and administrative undertakings supposed to reduce the hazards resulting from exposure to chemicals. Necessity to calculate costs and benefits coming from the undertaking and need to analyse social perception of risk which is important for preventive action are justified. What is stressed is the significance of a widespread education aimed at forming attitudes towards chemical hazards. PMID:3075253

  2. 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...

  3. Forensic collection of trace chemicals from diverse surfaces with strippable coatings.

    PubMed

    Jakubowski, Michael J; Beltis, Kevin J; Drennan, Paul M; Pindzola, Bradford A

    2013-11-01

    Surface sampling for chemical analysis plays a vital role in environmental monitoring, industrial hygiene, homeland security and forensics. The standard surface sampling tool, a simple cotton gauze pad, is failing to meet the needs of the community as analytical techniques become more sensitive and the variety of analytes increases. In previous work, we demonstrated the efficacy of non-destructive, conformal, spray-on strippable coatings for chemical collection from simple glass surfaces. Here we expand that work by presenting chemical collection at a low spiking level (0.1 g m(-2)) from a diverse array of common surfaces - painted metal, engineering plastics, painted wallboard and concrete - using strippable coatings. The collection efficiency of the strippable coatings is compared to and far exceeds gauze pads. Collection from concrete, a particular challenge for wipes like gauze, averaged 73% over eight chemically diverse compounds for the strippable coatings whereas gauze averaged 10%. PMID:24040648

  4. 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...

  5. 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).

  6. Teacher's Guide to SERAPHIM Software II. Chemical Principles.

    ERIC Educational Resources Information Center

    Bogner, Donna J.

    Designed to assist chemistry teachers in selecting appropriate software programs, this publication is the second in a series of six teacher's guides from Project SERAPHIM, a program sponsored by the National Science Foundation. This guide is keyed to the chapters of the text "Chemical Principles." Program suggestions are arranged in the same order…

  7. 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...

  8. The modified quasi-chemical model: Part II. Multicomponent solutions

    NASA Astrophysics Data System (ADS)

    Pelton, Arthur D.; Chartrand, Patrice

    2001-06-01

    Further improvements to the modified quasi-chemical model in the pair approximation for shortrange ordering (SRO) in liquids are extended to multicomponent solutions. The energy of pair formation may be expanded in terms of the pair fractions or in terms of the component fractions, and coordination numbers are permitted to vary with composition. The model permits complete freedom of choice to treat any ternary subsystem with a symmetric or an asymmetric model. An improved general functional form for ternary terms in the excess Gibbs energy expression is proposed. These terms are related to the effect of a third component upon the binary pair interaction energies. It is shown how binary subsystems that have been optimized with the quasi-chemical model can be combined in the same multicomponent Gibbs energy equation with binary subsystems that have been optimized with a random-mixing Bragg-Williams model and a polynomial expression for the excess Gibbs energy. This is of much practical importance in the development of large databases for multicomponent solutions. The model also applies to SRO in solid solutions as a special case, when the number of lattice sites and coordination numbers are constant.

  9. Effects of chemical speciation in growth media on the toxicity of mercury(II)

    SciTech Connect

    Farrell, R.E.; Germida, J.J.; Huang, P.M. )

    1993-05-01

    The bioavailability and toxicity of trace metals to aquatic microbiota are influenced by the chemical form (aqueous species) of the metal. However, the interpretation of bioassay results, and the extrapolation of these results to in situ conditions, is often complicated by the inclusion of complex soluable organics in the bioassay media. This investigation (1) evaluates the effects of complex soluable organics on the acute toxicity of mercury (II) to a Pseudomonas fluorescens isolate in a chemically well-defined synthetic growth media, (2) computes the effects of these organics on the aqueous speciation of mercury (II) in the media, and (3) ascertains the dependence of toxicity on the chemical speciation of mercury (II). 25 refs., 3 figs., 6 tabs.

  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 favour of an episode of enhanced star formation a few Gyr ago, occurring in the central parts of the LMC and leading to the formation of the bar. This is in agreement with recently derived star formation histories. Proposals 072.B-0293(B) and 078.B-0323(A), P.I. Vanessa Hill.Full Tables 3, 5, 7, 9, 11 and abundances tables for the LMC bar and disc samples are only available in electronic form at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/560/A44Table 11 is also available in electronic form at http://www.aanda.org

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

    NASA Astrophysics Data System (ADS)

    Amin-Chalhoub, Eliane; Duguet, Thomas; Samlor, 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 ?m 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. Synthesis, characterization and quantum chemical ab initio calculations of new dimeric aminocyclodiphosph(V)azane and its Co(II), Ni(II) and Cu(II) complexes

    NASA Astrophysics Data System (ADS)

    Alaghaz, Abdel-Nasser M. A.; Al-Sehemi, Abdullah G.; EL-Gogary, Tarek M.

    The complexes of type [M2LCl2] in which M = Co(II), Ni(II) and Cu(II) ions and L are 1,3-o-pyridyl-2,4-dioxo-2',4'-bis(3-benzo[d]thiazol-2-yl-2-iminothiophene) cyclodiphosph(V)azane, were prepared and their structures were characterized by different physical techniques (IR, UV-Vis, 1H NMR, 31P NMR, mass, TGA, DTA, XRD, SEM, magnetic moment and electrical conductance measurements). Ab initio calculations at the level of DFT B3LYP/6-31G(d) were utilized to find the optimum geometry of the ligand. Spectral characterization of the ligand was simulated using DT-DFT method. Infrared spectra of the complexes indicate deprotonation and coordination of the imine NH. It also confirms that nitrogen atoms of the pyridine group and thiazole group contribute to the complexation. NBO natural charges were computed and discussed in the light of coordination centers. Electronic spectra and magnetic susceptibility measurements as well as quantum chemical calculations reveal square planar geometry for Cu(II) and Ni(II) complexes and tetrahedral geometry for Co(II) complex. The elemental analyses and mass spectral data have justified the M2LCl2 composition of complexes.

  14. Synthesis, characterization and quantum chemical ab initio calculations of new dimeric aminocyclodiphosph(V)azane and its Co(II), Ni(II) and Cu(II) complexes.

    PubMed

    Alaghaz, Abdel-Nasser M A; Al-Sehemi, Abdullah G; El-Gogary, Tarek M

    2012-09-01

    The complexes of type [M(2)LCl(2)] in which M=Co(II), Ni(II) and Cu(II) ions and L are 1,3-o-pyridyl-2,4-dioxo-2',4'-bis(3-benzo[d]thiazol-2-yl-2-iminothiophene) cyclodiphosph(V)azane, were prepared and their structures were characterized by different physical techniques (IR, UV-Vis, (1)H NMR, (31)P NMR, mass, TGA, DTA, XRD, SEM, magnetic moment and electrical conductance measurements). Ab initio calculations at the level of DFT B3LYP/6-31G(d) were utilized to find the optimum geometry of the ligand. Spectral characterization of the ligand was simulated using DT-DFT method. Infrared spectra of the complexes indicate deprotonation and coordination of the imine NH. It also confirms that nitrogen atoms of the pyridine group and thiazole group contribute to the complexation. NBO natural charges were computed and discussed in the light of coordination centers. Electronic spectra and magnetic susceptibility measurements as well as quantum chemical calculations reveal square planar geometry for Cu(II) and Ni(II) complexes and tetrahedral geometry for Co(II) complex. The elemental analyses and mass spectral data have justified the M(2)LCl(2) composition of complexes. PMID:22608292

  15. 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

  16. Chemical and immunological characterization of lipopolysaccharides from phase I and phase II Coxiella burnetii.

    PubMed Central

    Amano, K; Williams, J C

    1984-01-01

    Lipopolysaccharides (LPSs) isolated from phase I and phase II Coxiella burnetii (LPS I and LPS II, respectively) were analyzed for chemical compositions, molecular heterogeneity by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and immunological properties. The yields of crude phenol-water extracts from phase I cells were roughly three to six times higher than those from phase II cells. Purification of LPSs by ultracentrifugation gave similar yields for both LPS I and LPS II. Purified LPS I and LPS II contained roughly 0.8 and 0.6% protein, respectively. The fatty acid constituents of the LPSs were different in composition and content, with branched-chain fatty acids representing about 15% of the total. beta-Hydroxymyristic acid was not detected in either LPS I or LPS II. A thiobarbituric acid-periodate-positive compound was evident in the LPSs; however, this component was not identified as 3-deoxy-D-mannooctulosonic acid by gas and paper chromatographies. LPS II contained D-mannose, D-glucose, D-glyceromannoheptose, glucosamine, ethanolamine, 3-deoxy-D-mannooctulosonic acid-like material, phosphate, and fatty acids. LPS I contained the unique disaccharide galactosaminuronyl glucosamine and nine unidentified components in addition to the components of LPS II. The hydrophobic, putative lipid A fraction of LPS I and LPS II contained the above constituents, but the hydrophilic fraction was devoid of ethanolamine. The LPS I disaccharide galactosaminuronyl glucosamine was found in both fractions of the acetic acid hydrolysates. Analysis of LPSs by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by silver staining indicated that LPS II was composed of only one band, whereas LPS I consisted of six or more bands with irregular spacing. Ouchterlony immunodiffusion tests demonstrated that LPS I reacted with phase I but not with phase II whole-cell hyperimmune antibody, and LPS II reacted neither with phase I nor phase II hyperimmune antibody. From these results, it was concluded that the chemical structures of LPSs from C. burnetii were different from those of the LPSs of gram-negative bacteria; however, the LPS structural variation in C. burnetii may be similar to the smooth-to-rough mutational variation of saccharide chain length in gram-negative bacteria. Images PMID:6438066

  17. 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

  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

    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.

  20. 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.

  1. Substrate stiffness regulates cadherin-dependent collective migration through myosin-II contractility

    PubMed Central

    Ng, Mei Rosa; Besser, Achim

    2012-01-01

    The mechanical microenvironment is known to influence single-cell migration; however, the extent to which mechanical cues affect collective migration of adherent cells is not well understood. We measured the effects of varying substrate compliance on individual cell migratory properties in an epithelial wound-healing assay. Increasing substrate stiffness increased collective cell migration speed, persistence, and directionality as well as the coordination of cell movements. Dynamic analysis revealed that wounding initiated a wave of motion coordination from the wound edge into the sheet. This was accompanied by a front-to-back gradient of myosin-II activation and establishment of cell polarity. The propagation was faster and farther reaching on stiff substrates, indicating that substrate stiffness affects the transmission of directional cues. Manipulation of myosin-II activity and cadherincatenin complexes revealed that this transmission is mediated by coupling of contractile forces between neighboring cells. Thus, our findings suggest that the mechanical environment integrates in a feedback with cell contractility and cellcell adhesion to regulate collective migration. PMID:23091067

  2. Meeting report: eGenomics: Cataloguing our Complete Genome Collection II.

    PubMed

    Field, Dawn; Morrison, Norman; Selengut, Jeremy; Sterk, Peter

    2006-01-01

    This article summarizes the proceedings of the "eGenomics: Cataloguing our Complete Genome Collection II" workshop held November 10-11, 2005, at the European Bioinformatics Institute. This exploratory workshop, organized by members of the Genomic Standards Consortium (GSC), brought together researchers from the genomic, functional OMICS, and computational biology communities to discuss standardization activities across a range of projects. The workshop proceedings and outcomes are set to help guide the development of the GSC's Minimal Information about a Genome Sequence (MIGS) specification. PMID:16901213

  3. Sorption of nickel (II) from aqueous system by chemically modified pungan (pongamia pinnata) seedpod carbon

    NASA Astrophysics Data System (ADS)

    Senthil, M.; Arulanantham, A.

    2013-06-01

    The adsorption of Ni (II) on chemically modified bicarbonate impregnated sulphuric acid treated pungan (pongamia pinnata) seedpod carbon (BSPAC) was investigated as a function of equilibrium time, solution pH and carbon dosage. The adsorption of nickel (II) was also studied by using Freundlich, Langmuir and Temkin isotherm models. Kinetic studies were conducted using reversible-first-order, pseudo-first-order and pseudo-second-order kinetic equations. The results obtained were compared with commercially available activated carbon (CAC) of same 20-50 ASTM mesh size.

  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 well as the rock samples were characterized to evaluate the geochemical changes over the experimental period. Preliminary results from the analysis are presented in the report. More detailed interpretation of the results will be presented in the technical report at the end of Phase II.

  5. 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.

  6. Chemical modification of photosystem II core complex pigments with sodium borohydride.

    PubMed

    Vishnev, M I; Zabelin, A A; Shkuropatova, V A; Yanyushin, M F; Shuvalov, V A; Shkuropatov, A Ya

    2013-04-01

    The reaction of the irreversible chemical reduction of the 13(1)-keto C=O group of pheophytin a (Pheo a) with sodium borohydride in reaction centers (RCs) of functionally active spinach photosystem II (PS II) core complexes was studied. Stable, chromatographically purified PS II core complex preparations with altered chromophore composition are obtained in which ~25% of Pheo a molecules are modified to 13(1)-deoxo-13(1)-hydroxy-Pheo a. Some of the chlorophyll a molecules in the complexes were also irreversibly reduced with borohydride to 13(1)-deoxo-13(1)-hydroxy-chlorophyll a. Based on the results of comparative study of spectral, biochemical, and photochemical properties of NaBH4-treated and control preparations, it was concluded that: (i) the borohydride treatment did not result in significant dissociation of the PS II core complex protein ensemble; (ii) the modified complexes retained the ability to photoaccumulate the radical anion of the pheophytin electron acceptor in the presence of exogenous electron donor; (iii) only the photochemically inactive pheophytin PheoD2 is subjected to the borohydride treatment; (iv) the Qx optical transition of the PheoD2 molecule in the RC of PS II core complexes is located at 543 nm; (v) in the Qy spectral region, PheoD2 probably absorbs at ~680 nm. PMID:23590440

  7. 77 FR 47666 - Agency Information Collection Activities: Proposed Collection; Comments Requested: Import/Export...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-09

    ...: Import/Export Declaration for List I and List II Chemicals; DEA Forms 486 and 486A ACTION: 60-Day Notice... Information Collection: Extension of a currently approved collection. (2) Title of the Form/Collection: Import/Export Declaration for List I and List II Chemicals. (3) Agency form number, if any, and the...

  8. Intracellular angiotensin II disrupts chemical communication and impairs metabolic cooperation between cardiac myocytes.

    PubMed

    De Mello, Walmor C

    2015-10-01

    The influence of intracellular angiotensin II (Ang II) on the process of chemical communication and metabolic cooperation between cardiac cells is discussed. Emphasis is given to the influence of pathological conditions like heart failure, myocardial ischemia or hyperglycemia on the activation of the intracrine renin angiotensin aldosterone system (RAAS) and its consequence for the metabolic cooperation between heart cells. Furthermore, the influence of high glucose on the process of chemical communication was described as well as its implication for the failing and diabetic heart. The major conclusion is that the activation of the intracrine renin angiotensin induced by heart failure, hyperglycemia, aldosterone or myocardial ischemia generates metabolic imbalance in the heart with serious consequences for the cardiac function. PMID:25882009

  9. Collecting duct-specific knockout of renin attenuates angiotensin II-induced hypertension

    PubMed Central

    Stuart, Deborah; Rees, Sara; Hoek, Alfred Van; Sigmund, Curt D.; Kohan, Donald E.

    2014-01-01

    The physiological and pathophysiological significance of collecting duct (CD)-derived renin, particularly as it relates to blood pressure (BP) regulation, is unknown. To address this question, we generated CD-specific renin knockout (KO) mice and examined BP and renal salt and water excretion. Mice containing loxP-flanked exon 1 of the renin gene were crossed with mice transgenic for aquaporin-2-Cre recombinase to achieve CD-specific renin KO. Compared with controls, CD renin KO mice had 70% lower medullary renin mRNA and 90% lower renin mRNA in microdissected cortical CD. Urinary renin levels were significantly lower in KO mice (45% of control levels) while plasma renin concentration was significantly higher in KO mice (63% higher than controls) during normal-Na intake. While no observable differences were noted in BP between the two groups with varying Na intake, infusion of angiotensin II at 400 ngkg?1min?1 resulted in an attenuated hypertensive response in the KO mice (mean arterial pressure 111 4 mmHg in KO vs. 128 3 mmHg in controls). Urinary renin excretion and epithelial Na+ channel (ENaC) remained significantly lower in the KO mice following ANG II infusion compared with controls. Furthermore, membrane-associated ENaC protein levels were significantly lower in KO mice following ANG II infusion. These findings suggest that CD renin modulates BP in ANG II-infused hypertension and these effects are associated with changes in ENaC expression. PMID:25122048

  10. 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

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

    PubMed

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

    2015-11-10

    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

  12. The NCGC Pharmaceutical Collection: A comprehensive resource of clinically approved drugs enabling repurposing and chemical genomics

    PubMed Central

    Huang, Ruili; Southall, Noel; Wang, Yuhong; Yasgar, Adam; Shinn, Paul; Jadhav, Ajit; Nguyen, Dac-Trung; Austin, Christopher P.

    2011-01-01

    Small-molecule compounds approved for use as drugs may be repurposed for new indications and studied to determine the mechanisms of their beneficial and adverse effects. A comprehensive collection of all small-molecule drugs approved for human use would be invaluable for systematic repurposing across human diseases, particularly for rare and neglected diseases, for which the cost and time required for development of a new chemical entity are often prohibitive. Previous efforts to build such a comprehensive collection have been limited by the complexities, redundancies, and semantic inconsistencies of drug naming within and among regulatory agencies worldwide; a lack of clear conceptualization of what constitutes a drug; and a lack of access to physical samples. We report here the creation of a definitive, complete, and nonredundant list of all approved molecular entities as a freely available electronic resource and a physical collection of small molecules amenable to high-throughput screening. PMID:21525397

  13. H Chemical Shifts in Paramagnetic Co(II) Pyrazolylborate Complexes: A First-Principles Study.

    PubMed

    Rouf, Syed Awais; Mare, Ji?; Vaara, Juha

    2015-04-14

    We apply the theory of the nuclear magnetic resonance (NMR) chemical shift for paramagnetic systems to demanding cobalt(II) complexes. Paramagnetic NMR (pNMR) chemical shift results by density-functional theory (DFT) can be very far from the experimental values. Therefore, it is of interest to investigate the applicability of electron-correlated ab initio computational methods to achieve useful accuracy. Here, we use ab initio wave function based electronic structure methods to calculate the pNMR chemical shift within the theoretical framework established recently. We applied the N-electron valence-state perturbation theory (NEVPT2) on three Co(II) systems, where the active space of the underlying complete active space self-consistent field (CASSCF) wave function consists of seven electrons in the five metal 3d orbitals. These complexes have the S = 3/2 electronic ground state consisting of two doublets separated by zero-field splitting (ZFS). To calculate the hyperfine coupling tensor A, DFT was used, while the g- and ZFS-tensors were calculated using the ab initio CASSCF and NEVPT2 methods. These results were combined to obtain the total chemical shifts. The shifts obtained from these calculations are in generally good agreement with the experimental results, in some cases suggesting a reassignment of the signals. The accuracy of this mixed ab initio/DFT approach is very promising for further applications to demanding pNMR problems involving transition metals. PMID:26574378

  14. 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

  15. 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%.

  16. CHAOS I. Direct Chemical Abundances for H II Regions in NGC 628

    NASA Astrophysics Data System (ADS)

    Berg, Danielle A.; Skillman, Evan D.; Croxall, Kevin V.; Pogge, Richard W.; Moustakas, John; Johnson-Groh, Mara

    2015-06-01

    The CHemical Abundances of Spirals (CHAOS) project leverages the combined power of the Large Binocular Telescope (LBT) with the broad spectral range and sensitivity of the Multi Object Double Spectrograph (MODS) to measure direct abundances (based on observations of the temperature-sensitive auroral lines) in large samples of H ii regions in spiral galaxies. We present LBT MODS observations of 62 H ii regions in the nearby spiral galaxy NGC 628, with an unprecedentedly large number of auroral lines measurements (18 [O iii] ?4363, 29 [N ii] ?5755, 40 [S iii]?6312, and 40 [O ii] ??7320, 7330 detections) in 45 H ii regions. Comparing derived temperatures from multiple auroral line measurements, we find: (1) a strong correlation between temperatures based on [S iii] ?6312 and [N ii] ?5755 and (2) large discrepancies for some temperatures based on [O ii] ??7320, 7330 and [O iii] ?4363. Both of these trends are consistent with other observations in the literature, yet, given the widespread use and acceptance of [O iii] ?4363 as a temperature determinant, the magnitude of the T[O iii] discrepancies still came as a surprise. Based on these results, we conduct a uniform abundance analysis prioritizing the temperatures derived from [S iii] ?6312 and [N ii] ?5755, and report the gas-phase abundance gradients for NGC 628. Relative abundances of S/O, Ne/O, and Ar/O are constant across the galaxy, consistent with no systematic change in the upper IMF over the sampled range in metallicity. These alpha-element ratios, along with N/O, all show small dispersions (? ? 0.1 dex) over 70% of the azimuthally averaged radius. We interpret these results as an indication that, at a given radius, the interstellar medium in NGC 628 is chemically well-mixed. Unlike the gradients in the nearly temperature-independent relative abundances, O/H abundances have a larger intrinsic dispersion of ?0.165 dex. We posit that this dispersion represents an upper limit to the true dispersion in O/H at a given radius and that some of that dispersion is due to systematic uncertainties arising from temperature measurements.

  17. 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

  18. An automated system for use in collecting volatile chemicals released from plants.

    PubMed

    Heath, R R; Manukian, A

    1994-03-01

    A system is described for the collection of volatiles produced by plants that minimizes stress on the plant in an environment that is free from chemical impurities. Air entering a volatile collection chamber containing a plant is purified using a nonwoven fabric media infused with charcoal. A multitasking, computer-automated system is described that can simultaneously collect volatilized chemicals from plants as well as monitor and record environmental conditions associated with those collections. Collection of up to 16 samples can be made in varying sampling order, flow rates, and user-specified time periods, without disturbing the sampling environment. During the same time period, this system is capable of simultaneously monitoring up to eight environmental parameters using any type of sensor with electrical signal outputs. A multiport base assembly was designed to fit around the base of the plant permitting air samples to be collected at the bottom of the chamber. The chamber can pass ambient light so the plant may follow its natural photocycles. The entire system can be configured for continuous laboratory duty or portable field use by utilizing components that run on DC voltages. For the purpose of testing the system's performance, we determined the periodicity of the release of volatiles from red and yellow flowering four o'clock plants,Mirabilis jalaba (Nyctaginaceae). The major chemical released from four o'clocks was identified as ocimene. The onset of release occurred between 1400 and 1600 hr and increased with time with maximum amount of ocimene released during 1800-2000 hr, followed by a decrease in emission. No ocimene was detected after 2400 hr. Determination of the amount of ocimene released per flower was calculated for the 1800- to 2000-hr time period. Based on the number of open flowers during the 1800- to 2000-hr period, yellow four o'clock's released 80.9 (±7.3 SD) ng/hr/flower, while the red flowers released 51.9 (±7.0 SD) ng/hr/flower. PMID:24242114

  19. 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 allows the user to select from a number of collections grouped by category and enter a query expression (See Illustration 1 - Science.gov 3.0 Search Page). After the user clicks “search” a results page is displayed that provides a list of results from the selected collections ordered by relevance based on the query expression the user provided. Our grid based solution to deep web search and document ranking has already gained attention within DOE, other Government Agencies and a fortune 50 company. We are committed to the continued development of grid based solutions to large scale data access, filtering, and presentation problems within the domain of Information Retrieval and the more general categories of content management, data mining and data analysis.

  20. 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 used 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 optical kappa-epsilon turbulence model, and several additions to the spray model. The authors illustrate some of the new capabilities by means of example solutions.

  1. 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.

  2. Angiotensin II increases fibronectin and collagen I through the β-catenin-dependent signaling in mouse collecting duct cells

    PubMed Central

    Cuevas, Catherina A.; Gonzalez, Alexis A.; Inestrosa, Nibaldo C.; Vio, Carlos P.

    2014-01-01

    The contribution of angiotensin II (ANG II) to renal and tubular fibrosis has been widely reported. Recent studies have shown that collecting duct cells can undergo mesenchymal transition suggesting that collecting duct cells are involved in interstitial fibrosis. The Wnt/β-catenin signaling pathway plays an essential role in development, organogenesis, and tissue homeostasis; however, the dysregulation of this pathway has been linked to fibrosis. In this study, we investigated whether AT1 receptor activation induces the expression of fibronectin and collagen I via the β-catenin pathway in mouse collecting duct cell line M-1. ANG II (10−7 M) treatment in M-1 cells increased mRNA, protein levels of fibronectin and collagen I, the β-catenin target genes (cyclin D1 and c-myc), and the myofibroblast phenotype. These effects were prevented by candesartan, an AT1 receptor blocker. Inhibition of the β-catenin degradation with pyrvinium pamoate (pyr; 10−9 M) prevented the ANG II-induced expression of fibronectin, collagen I, and β-catenin target genes. ANG II treatment promoted the accumulation of β-catenin protein in a time-dependent manner. Because phosphorylation of glycogen synthase kinase-3β (GSK-3β) inhibits β-catenin degradation, we further evaluated the effects of ANG II and ANG II plus pyr on p-ser9-GSK-3β levels. ANG II-dependent upregulation of β-catenin protein levels was correlated with GSK-3β phosphorylation. These effects were prevented by pyr. Our data indicate that in M-1 collecting duct cells, the β-catenin pathway mediates the stimulation of fibronectin and collagen I in response to AT1 receptor activation. PMID:25411386

  3. Angiotensin II increases fibronectin and collagen I through the ?-catenin-dependent signaling in mouse collecting duct cells.

    PubMed

    Cuevas, Catherina A; Gonzalez, Alexis A; Inestrosa, Nibaldo C; Vio, Carlos P; Prieto, Minolfa C

    2015-02-15

    The contribution of angiotensin II (ANG II) to renal and tubular fibrosis has been widely reported. Recent studies have shown that collecting duct cells can undergo mesenchymal transition suggesting that collecting duct cells are involved in interstitial fibrosis. The Wnt/?-catenin signaling pathway plays an essential role in development, organogenesis, and tissue homeostasis; however, the dysregulation of this pathway has been linked to fibrosis. In this study, we investigated whether AT1 receptor activation induces the expression of fibronectin and collagen I via the ?-catenin pathway in mouse collecting duct cell line M-1. ANG II (10(-7) M) treatment in M-1 cells increased mRNA, protein levels of fibronectin and collagen I, the ?-catenin target genes (cyclin D1 and c-myc), and the myofibroblast phenotype. These effects were prevented by candesartan, an AT1 receptor blocker. Inhibition of the ?-catenin degradation with pyrvinium pamoate (pyr; 10(-9) M) prevented the ANG II-induced expression of fibronectin, collagen I, and ?-catenin target genes. ANG II treatment promoted the accumulation of ?-catenin protein in a time-dependent manner. Because phosphorylation of glycogen synthase kinase-3? (GSK-3?) inhibits ?-catenin degradation, we further evaluated the effects of ANG II and ANG II plus pyr on p-ser9-GSK-3? levels. ANG II-dependent upregulation of ?-catenin protein levels was correlated with GSK-3? phosphorylation. These effects were prevented by pyr. Our data indicate that in M-1 collecting duct cells, the ?-catenin pathway mediates the stimulation of fibronectin and collagen I in response to AT1 receptor activation. PMID:25411386

  4. Effects of chemical speciation in growth media on the toxicity of mercury(II).

    PubMed Central

    Farrell, R E; Germida, J J; Huang, P M

    1993-01-01

    The toxicity of metals, including mercury, is expressed differently in different media, and the addition of soluble organics to the growth medium can have a significant impact on bioassay results. Although the effect of medium composition on metal toxicity is generally attributed to its effect on metal speciation (i.e., the chemical form in which the metal occurs), the importance of individual metal-ligand species remains largely unclear. Here, we report the results of a study that investigated, both experimentally and from a modeling perspective, the effects of complex soluble organic supplements on the acute toxicity (i.e., 50% inhibitory concentration [IC50]) of mercury to a Pseudomonas fluorescens isolate in chemically well-defined synthetic growth media (M-IIX). The media consisted of a basal inorganic salts medium supplemented with glycerol (0.1%, vol/vol) and a variety of common protein hydrolysates (0.1%, vol/vol), i.e., Difco beef extract (X = B), Casamino Acids (X = C), peptone (X = P), soytone (X = S), tryptone (X = T), and yeast extract (X = Y). These were analyzed to obtain cation, anion, and amino acid profiles and the results were used to compute the aqueous speciation of Hg(II) in the media. Respirometric bioassays were performed and IC50s were calculated. Medium components varied significantly in their effects on the acute toxicity of Hg(II) to the P. fluorescens isolate. IC50s ranged from 1.48 to 14.54 micrograms of Hg ml-1, and the acute toxicity of Hg(II) in the different media decreased in the order M-IIC >> M-IIP > M-IIB >> M-IIT > M-IIS >>> M-IIY.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8517745

  5. 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.

  6. Synthesis, chemical characterization and biological evaluation of new platinum (II)-sulfonamide complexes.

    PubMed

    Craciunescu, D G; Scarcia, V; Furlani, A; Parrondo Iglesias, E; Ravalico, L; Doadrio, A

    1990-02-01

    Six new platinum (II)-sulfonamide complexes were examined for their in vitro cytostatic properties as well as in vivo antitumour effect against three experimental murine tumours. The possible antitrypanosomic in vivo activity against T. brucei, T. congolense and T. cruzi infections was also evaluated. The synthesis and chemical characterization of new complexes is reported. Only two sulfadiazine derivatives appeared to be effective mainly against Ehrlich ascites but in a smaller extent than cisplatin. A satisfactory correlation between antitumour and antitrypanosomic activity was found. PMID:2334458

  7. Metabolic profiling of GuanXin II prescription based on metabolic fingerprinting and chemical analysis.

    PubMed

    Qiao, Xue; Han, Jian; Xu, Man; Zhang, Zi-chuan; Ye, Min; Ye, Guan; Guo, De-an

    2011-03-25

    A sensitive LC/MS method was established to investigate the in vivo metabolism of GuanXin II prescription, a five-component Chinese herbal medicine formulation. Rat plasma, bile, urine, and feces were collected and analyzed following oral administration of the water decoction. A total of 50 compounds were identified, including 17 prototypes and 33 metabolites underwent methylation, oxidation, hydrolysis, sulfate conjugation, glucuronide conjugation, and glutathion conjugation. In addition, the component herb of the formulation from which the metabolites were derived was also identified. Among the five component herbs, Rhizoma Chuanxiong, Flos Carthami, and Lignum Dalbergiae Odoriferae were actively metabolized, contributing 26 metabolites and 2 prototypes, while Radix Salviae Miltiorrhizae and Radix Paeoniae Rubra underwent less biotransformation, yielding 7 metabolites and 15 prototypes. This is the first study on the metabolic profile of GuanXin II prescription. The results could be valuable to elucidate the material basis of this formulated Chinese medicine. PMID:21094011

  8. 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.

  9. 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.

  10. 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.

  11. Selective Removal of Copper(II) and Nickel(II) from Aqueous Solution Using the Chemically Treated Chitosan: Factorial Design Evaluation

    NASA Astrophysics Data System (ADS)

    Sepehran, M.; Nasernejad, B.; Edrissi, M.

    2008-12-01

    In the present work, the adsorption of Cu(II) and Ni(II) ions from their mixture solution by raw and chemically modified chitosan has been studied. The full factorial design methodology was employed to reduce the total number of experiments. Analysis of variance and students t-test have been performed for Ni(II) and Cu(II) removal efficiency and for the ratio of their removal. The two main factors considered were pH of solution (at two levels 2.8 and 4.8) and contact time (at two levels: 20 minutes and 18 hours). The third factor was a qualitative factor at two levels (raw chitosan and chemically modified chitosan). Among the factors studied, chemical modification of chitosan was the most effective factor for the ratio of nickel and copper removal efficiency. It was found that pH has no significant effect on Ni(II) uptake. The result from this study indicates that the adsorption selectivity of chitosan can be enhanced by chemical treatment and regulating pH and contact time.

  12. 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...

  13. Conditional knockout of collecting duct bradykinin B2 receptors exacerbates angiotensin II-induced hypertension during high salt intake.

    PubMed

    Kopkan, Libor; Huskov, Zuzana; Jchov, rka; ?ervenkov, Lenka; ?ervenka, Lud?k; Saifudeen, Zubaida; El-Dahr, Samir S

    2016-01-01

    We elucidated the role of collecting duct kinin B2 receptor (B2R) in the development of salt-sensitivity and angiotensin II (ANG II)-induced hypertension. To this end, we used a Cre-Lox recombination strategy to generate mice lacking Bdkrb2 gene for B2R in the collecting duct (Hoxb7-Cre(tg/+):Bdkrb2(flox/flox)). In 3 groups of control (Bdkrb2(flox/flox)) and 3 groups of UB(Bdkrb2-/-) mice, systolic blood pressure (SBP) responses to high salt intake (4 or 8% NaCl; HS) were monitored by radiotelemetry in comparison with standard salt diet (0.4% NaCl) prior to and during subcutaneous ANG II infusion (1000?ng/min/kg) via osmotic minipumps. High salt intakes alone for 2 weeks did not alter SBP in either strain. ANG II significantly increased SBP equally in control (121??2 to 156??3?mmHg) and UB(Bdkrb2-/-) mice (120??2 to 153??2?mmHg). The development of ANG II-induced hypertension was exacerbated by 4%HS in both control (125??3 to 164??5?mmHg) and UB(Bdkrb2-/-) mice (124??2 to 162??3?mmHg) during 2 weeks. Interestingly, 8%HS caused a more profound and earlier ANG II-induced hypertension in UB(Bdkrb2-/-) (129??2 to 166??3?mmHg) as compared to control (128??2 to 158??2?mmHg) and it was accompanied by body weight loss and increased mortality. In conclusion, targeted inactivation of B2R in the renal collecting duct does not cause salt-sensitivity; however, collecting duct B2R attenuates the hypertensive actions of ANG II under conditions of very high salt intake. PMID:26151827

  14. 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

  15. 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

  16. 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

  17. Biosorption of copper(II) by Marrubium globosum subsp. globosum leaves powder: effect of chemical pretreatment.

    PubMed

    Yazici, Hseyin; Kili, Mehmet; Solak, Murat

    2008-03-01

    The study was aimed at determining the effect of chemical pretreatment on copper(II) biosorption by Marrubium globosum subsp. globosum leaves. The uptake capacity of the biomass was increased by chemical pretreatment when compared with the raw biomass. The results of biosorption experiments, carried out at the conditions of 50 mg l(-1) initial metal concentration and pH 5.5, showed that pretreating the biomass with alkali solutions (laundry detergent, sodium hydroxide and sodium bicarbonate, 0.5 M) improved the biosorption capacity of biomass (45.90, 45.78 and 43.91%, respectively) compared with raw biomass. Pretreatment with sulfuric and nitric acid solutions, 0.5 M, increased the biosorption capacity of biomass by 11.82 and 10.18%, respectively, while there was no considerable change in the biosorption capacity of biomass (0.35%) after pretreatment with formic acid solution, 0.5 M. Furthermore, sodium chloride and calcium chloride, 0.5 M, pretreatments resulted in the improvement in biosorption capacity of biomass (31.38 and 26.69%, respectively). FT-IR analysis revealed that hydroxyl and carboxyl functional groups were mainly responsible for copper(II) biosorption. PMID:17656015

  18. The chemical shifts of Xe in the cages of clathrate hydrate Structures I and II

    NASA Astrophysics Data System (ADS)

    Stueber, Dirk; Jameson, Cynthia J.

    2004-01-01

    We report, for the first time, a calculation of the isotropic NMR chemical shift of 129Xe in the cages of clathrate hydrates Structures I and II. We generate a shielding surface for Xe in the clathrate cages by quantum mechanical calculations. Subsequently this shielding surface is employed in canonical Monte Carlo simulations to find the average isotropic Xe shielding values in the various cages. For the two types of cages in clathrate hydrate Structure I, we find the intermolecular shielding values [σ(Xe@512 cage)-σ(Xe atom)]=-214.0 ppm, and [σ(Xe@51262 cage)-σ(Xe atom)]=-146.9 ppm, in reasonable agreement with the values -242 and -152 ppm, respectively, observed experimentally by Ripmeester and co-workers between 263 and 293 K. For the 512 and 51264 cages of Structure II we find [σ(Xe@512 cage)-σ(Xe atom)]=-206.7 ppm, and [σ(Xe@51264 cage)-σ(Xe atom)]=-104.7 ppm, also in reasonable agreement with the values -225 and -80 ppm, respectively, measured in a Xe-propane type II mixed clathrate hydrate at 77 and 220-240 K by Ripmeester et al.

  19. 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, fractioned concentrations are still under investigation, and will be reported and discussed during the meeting. For seasonal variation, in general, concentrations of halogens were the lowest in summer and higher in fall and winter, reflecting air mass movement and wind speed around Okinawa, Japan.

  20. The Chemical and Biological Profile of a Red Clover (Trifolium pratense) Phase II Clinical Extract

    PubMed Central

    Booth, Nancy L.; Overk, Cassia R.; Yao, Ping; Burdette, Joanna E.; Nikolic, Dejan; Chen, Shao-Nong; Bolton, Judy L.; van Breemen, Richard B.; Pauli, Guido F.; Farnsworth, Norman R.

    2006-01-01

    Objectives To document the chemical and biological profile of a clinical phase II red clover (Trifolium pratense L.) extract by identifying and measuring the major and minor components visible in the high performance liquid chromatography-ultraviolet (HPLC-UV) chromatogram and evaluating each compound for estrogenic and antioxidant activity. Design Individual compounds in the pre-formulated (i.e., no excipients present) extract were identified by either chemical isolation followed by structure elucidation or by matching to retention time and molecular mass of chemical standards via liquid chromatography-mass spectrometry (LC-MS) analysis. Quantitation of the amounts of compounds found in the pre-formulated extract was done using HPLC-UV or LC-MS. Isolated compounds or standards were evaluated for their ability to 1) induce alkaline phosphatase (AP) in an endometrial carcinoma cell line, 2) competitively bind to recombinant human estrogen receptors (ERs) alpha (?) and beta (?), and 3) act as antioxidants by scavenging 2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl (DPPH) free radicals. Results The pre-formulated red clover extract had an EC50 of 2.02.2 ?g/mL in the AP estrogenicity assay, and IC50s of 18.432.6 ?g/mL and 1.93.4 ?g/mL in the ER? and ER? binding assays, respectively. The pre-formulated extract was composed of 35.54% isoflavones, 1.11% flavonoids, 0.06% pterocarpans, ? 0.03% coumarins, and ? 0.03% tyramine. Daidzein, genistein, formononetin, biochanin A, coumestrol and naringenin were estrogenic in the AP assay, and all of these, except formononetin, bound to one or both ERs. Conclusions The major and minor chemical and active estrogenic components of a pre-formulated Phase II red clover clinical extract were identified, quantitatively measured, and the final capsule doses were calculated. The extract is currently under evaluation in a yearlong clinical study for the alleviation of menopausal hot flashes. This is the first report to thoroughly summarize the chemistry and biology of all major peaks observed in the HPLC-UV chromatogram of a clinical red clover dietary supplement. PMID:16566672

  1. 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.

  2. 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

  3. Copper(II) diamino acid complexes: quantum chemical computations regarding diastereomeric effects on the energy of complexation.

    PubMed

    Zuilhof, Han; Morokuma, Keiji

    2003-08-21

    [reaction: see text] Quantum chemical calculations were used to rationalize the observed enantiodifferentiation in the complexation of alpha-amino acids to chiral Cu(II) complexes. Apart from Cu(II)[bond]pi interactions and steric repulsions between the anchoring cholesteryl-Glu moiety and an aromatic amino acid R group, hydrogen bonding also plays a role. In fact, in the case of tryptophan, C[double bond]O...H[bond]N hydrogen bonding between the glutamate moiety and the tryptophan N[bond]H group compensates for the loss of intramolecular hydrogen-bonding and diminished Cu(II)[bond]pi interactions. PMID:12916986

  4. 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.

  5. 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 quantities of dust present in young galaxies in the early universe.

  6. Chemical probes of the conformation of DNA modified by cis-diamminedichloroplatinum(II)

    SciTech Connect

    Marrot, L.; Leng, M. )

    1989-02-21

    The purpose of this work was to analyze at the nucleotide level the distortions induced by the binding of cis-diamminedichloroplatinum(II) (cis-DDP) to DNA by means of chemical probes. In order to test the chemical probes, experiments were first carried out on two platinated oligonucleotides. It has been verified by circular dichroism and gel electrophoresis that the binding of cis-DDP to an AG or to a GTG site within a double-stranded oligonucleotide distorts the double helix. The reactivity of the oligonucleotide platinated at the GTG site with chloroacetaldehyde, diethyl pyrocarbonate, and osmium tetraoxide, respectively, suggests a local denaturation of the double helix. The 5'G residue and the T residue within the adduct are no longer paired, while the 3'G residue is paired. The double helix is more distorted (but not denatured) at the 5' side of the adduct than at the 3' side. The reactivities of the chemical probes with six platinated DNA restriction fragments show that even at a relatively high level of platination only a few base pairs are unpaired but the double helix is largely distorted. No local denaturation has been detected at the GG sites separated from the nearest GG or AG sites by at least three base pairs. The AG sites separated from the nearest AG or GG sites by at least three base pairs do not denature the double helix locally when they are in the sequences puAG/pyTC. It is suggested that the distortion within these sequences is induced by adducts located further away along the DNA fragments, these sequences not being the major sites for the binding of cis-DDP.

  7. 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

  8. 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...

  9. 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)

  10. 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...

  11. 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 PM?.? concentrations for the three metro lines were 177.7 ?g/m(3), 105.7 ?g/m(3) and 82.5 ?g/m(3), respectively, and the average PM1 concentrations for the three lines were 122.3 ?g/m(3), 84.1 ?g/m(3) and 59.6 ?g/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 speciation of Fe-containing metro particles is important in the context of public health and control measures. PMID:25105755

  12. 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.

  13. 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.; Franois, 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 H? and in the 5875.64 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

  14. 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.

  15. New chemical models of enzymatic oxidation. II. Oxidation of alcohols to acids, catalyzed by Cu(II) complexes

    SciTech Connect

    Sakharov, A.M.; Skibida, I.P.

    1988-07-01

    It was established that complex compounds of Cu(II) catalyze the oxidation of primary alcohols to acids in the presence of bases; in aqueous media n-propanol is oxidized primarily to formic acid; in anhydrous media n-propanol and benzyl alcohol are capable of being oxidized to propionic and benzoic acids, respectively. It was shown that acids are the primary reaction products, and they are formed as a result of the attack of anions coordinated on Cu(II) sites by molecular oxygen.

  16. 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 depletion from the CI values and the moderately volatile elements Cu, Zn, Ga are enriched relative to CI. This elemental abundance pattern is similar to that in anhydrous, porous interplanetary dust particles (IDPs), suggesting that, if Wild 2 dust preserves the original composition of the Solar Nebula, the anhydrous, porous IDPs, not the CI meteorites, may best reflect the Solar Nebula abundances. This might be tested by elemental composition measurements on cometary meteors.

  17. 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

  18. 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

  19. 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...

  20. In silico approach to cisplatin toxicity. Quantum chemical studies on platinum(II)-cysteine systems.

    PubMed

    Chojnacki, Henryk; Kuduk-Jaworska, Janina; Jaroszewicz, Iwona; Jański, Jerzy J

    2009-06-01

    The behaviour of cisplatin in serum, and the drastic differences between the properties of this drug and its trans-isomer were the main motivations for this work. In a search for model "thiol-platin(II)" interactions, the first steps of the following reaction systems were evaluated: (1) cisplatin-thiomethanol; (2) transplatin-thiomethanol; (3) cisplatin-cysteine; and (4) transplatin-cysteine. In each case, calculations for the associative mode of reactions were performed. The electronic structure of these molecular systems was studied at the non-empirical all-electron level using density functional theory (DFT) within the Huzinaga and WTBS basis sets including polarisation Gaussian functions and full geometry optimisation. B3LYP or EPBO density functionals were applied throughout. The calculated molecular electrostatic potentials are presented graphically. Assuming that electrostatic effects are dominant, cisplatin should interact more strongly with the sulfur atom of CH3S- and deprotonated CYS-S- than transplatin. This fact has been documented in the supermolecule model of the relevant interaction energies in both gas phase as well as within the solvent polarisable continuum model. The opposite relationship was observed when we compared values of energy differences between products and substrates for both isomers. The data obtained here could be applied to search for correlation between the biological activity of platinum complexes and their properties as estimated by various physico-chemical and in silico methodologies. PMID:19221812

  1. STRUCTURE AND FEEDBACK IN 30 DORADUS. II. STRUCTURE AND CHEMICAL ABUNDANCES

    SciTech Connect

    Pellegrini, E. W.; Baldwin, J. A.; Ferland, G. J.

    2011-09-01

    We use our new optical-imaging and spectrophotometric survey of key diagnostic emission lines in 30 Doradus, together with CLOUDY photoionization models, to study the physical conditions and ionization mechanisms along over 4000 individual lines of sight at points spread across the face of the extended nebula, out to a projected radius 75 pc from R136 at the center of the ionizing cluster NGC 2070. We focus on the physical conditions, geometry, and importance of radiation pressure on a point-by-point basis, with the aim of setting observational constraints on important feedback processes. We find that the dynamics and large-scale structure of 30 Dor are set by a confined system of X-ray bubbles in rough pressure equilibrium with each other and with the confining molecular gas. Although the warm (10,000 K) gas is photoionized by the massive young stars in NGC 2070, the radiation pressure does not currently play a major role in shaping the overall structure. The completeness of our survey also allows us to create a composite spectrum of 30 Doradus, simulating the observable spectrum of a spatially unresolved, distant giant extragalactic H II region. We find that the highly simplified models used in the 'strong line' abundance technique do in fact reproduce our observed line strengths and deduced chemical abundances, in spite of the more than one order of magnitude range in the ionization parameter and density of the actual gas in 30 Dor.

  2. Burnup calculations and chemical analysis of irradiated fuel samples studied in LWR-PROTEUS phase II

    SciTech Connect

    Grimm, P.; Guenther-Leopold, I.; Berger, H. D.

    2006-07-01

    The isotopic compositions of 5 UO{sub 2} samples irradiated in a Swiss PWR power plant, which were investigated in the LWR-PROTEUS Phase II programme, were calculated using the CASMO-4 and BOXER assembly codes. The burnups of the samples range from 50 to 90 MWd/kg. The results for a large number of actinide and fission product nuclides were compared to those of chemical analyses performed using a combination of chromatographic separation and mass spectrometry. A good agreement of calculated and measured concentrations is found for many of the nuclides investigated with both codes. The concentrations of the Pu isotopes are mostly predicted within {+-}10%, the two codes giving quite different results, except for {sup 242}Pu. Relatively significant deviations are found for some isotopes of Cs and Sm, and large discrepancies are observed for Eu and Gd. The overall quality of the predictions by the two codes is comparable, and the deviations from the experimental data do not generally increase with burnup. (authors)

  3. 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.

  4. 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 carries off gaseous products released during treatment. Graphite gasification occurs via interaction with adsorbed oxygen complexes. Experiments in argon were performed at 900 deg. C and 1400 deg. C to evaluate the selective removal of C-14. Thermal treatment also was performed with the addition of 3 and 5 volume % oxygen at temperatures 700 deg. C and 1400 deg. C. Thermal treatment experiments were evaluated for the effective selective removal of C-14. Lower temperatures and oxygen levels correlated to more efficient C-14 removal. (authors)

  5. 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

    .../Section 504 of the Rehabilitation Act of 1973 Discrimination Complaint Form ACTION: 30-Day Notice of... with Disabilities Act/Section 504 of the Rehabilitation Act of 1973 Discrimination Complaint Form. (3... discrimination by public entities based on disability. Under title II of the Americans with Disabilities Act,...

  6. 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...

  7. Collective dynamics in liquid lead. II. Mode contributions to time correlation functions.

    PubMed

    Bryk, T; Mryglod, I

    2001-09-01

    Mode contributions of different collective excitations to the density-density time correlation function in liquid lead are studied within the nine-variable approach of generalized collective modes. It is shown, that a kinetic relaxing mode, caused by slow density fluctuations, defines almost completely the shape of density-density time correlation function for wave numbers close to the main peak position of the static structure factor. The physical meaning of this mode is discussed. PMID:11580371

  8. Chemical modification of silica gel with synthesized new Schiff base derivatives and sorption studies of cobalt (II) and nickel (II)

    NASA Astrophysics Data System (ADS)

    Kursunlu, Ahmed Nuri; Guler, Ersin; Dumrul, Hakan; Kocyigit, Ozcan; Gubbuk, Ilkay Hilal

    2009-08-01

    In this study, three Schiff base ligands and their complexes were synthesized and characterized by infrared spectroscopy (IR), thermogravimetric analyses (TGA), nuclear magnetic resonance (NMR), elemental analysis and magnetic susceptibility apparatuses. Silica gel was respectively modified with Schiff base derivatives, (E)-2-[(2-chloroethylimino)methyl]phenol, (E)-4-[(2-chloroethylimino)methyl]phenol and N, N'-[1,4-phenilendi(E)methylidene]bis(2-chloroethanamine), after silanization of silica gel by (3-aminopropyl)trimethoxysilane (APTS) by using a suitable method. Characterization of the surface modification was also performed with IR, TGA and elemental analysis. The immobilized surfaces were used for Co(II) and Ni(II) sorption from aqueous solutions and values of sorption were detected by atomic absorption spectrometer (AAS).

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

    DOEpatents

    Davalos, Rafael V. (Oakland, CA); Ellis, Christopher R. B. (Oakland, CA)

    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.

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

    DOEpatents

    Davalos, Rafael V. (Oakland, CA); Ellis, Christopher R. B. (Oakland, CA)

    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.

  11. 75 FR 68370 - Agency Information Collection Activities: Office of Infrastructure Protection; Chemical Security...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-05

    ... training is designed for the general chemical facility employee. U.S. chemical industry direct employment.... DHS previously published this ICR in the Federal Register on August 27, 2010 at 75 FR 52768, for a 60... proper performance of the functions of the agency, including whether the information will have...

  12. 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...

  13. 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

  14. 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…

  15. Angiotensin II increases chloride absorption in the cortical collecting duct in mice through a pendrin-dependent mechanism.

    PubMed

    Pech, Vladimr; Kim, Young Hee; Weinstein, Alan M; Everett, Lorraine A; Pham, Truyen D; Wall, Susan M

    2007-03-01

    Pendrin (Slc26a4) localizes to type B and non-A, non-B intercalated cells in the distal convoluted tubule, the connecting tubule, and the cortical collecting duct (CCD), where it mediates apical Cl(-)/HCO(3)(-) exchange. The purpose of this study was to determine whether angiotensin II increases transepithelial net chloride transport, J(Cl), in mouse CCD through a pendrin-dependent mechanism. J(Cl) and transepithelial voltage, V(T), were measured in CCDs perfused in vitro from wild-type and Slc26a4 null mice ingesting a NaCl-replete diet or a NaCl-replete diet and furosemide. In CCDs from wild-type mice ingesting a NaCl-replete diet, V(T) and J(Cl) were not different from zero either in the presence or absence of angiotensin II (10(-8) M) in the bath. Thus further experiments employed mice given the high-NaCl diet and furosemide to upregulate renal pendrin expression. CCDs from furosemide-treated wild-type mice had a lumen-negative V(T) and absorbed Cl(-). With angiotensin II in the bath, Cl(-) absorption doubled although V(T) did not become more lumen negative. In contrast, in CCDs from furosemide-treated Slc26a4 null mice, Cl(-) secretion and a V(T) of approximately 0 were observed, neither of which changed with angiotensin II application. Inhibiting ENaC with benzamil abolished V(T) although J(Cl) fell only approximately 50%. Thus substantial Cl(-) absorption is observed in the absence of an electromotive force. Attenuating apical anion exchange with the peritubular application of the H(+)-ATPase inhibitor bafilomycin abolished benzamil-insensitive Cl(-) absorption. In conclusion, angiotensin II increases transcellular Cl(-) absorption in the CCD through a pendrin- and H(+)-ATPase-dependent process. PMID:17077386

  16. [Historical review on chemical and medical studies of globefish toxin before World War II].

    PubMed

    Suehiro, M

    1994-01-01

    "Fugu," a species of globefish has eaten by Japanese people for a long time, so globefish poisoning in Japan has been prevalent. Figures are shown in the Annual Food Poisoning Report collected and issued by health service authorities of Japanese Government since 1879. These reports prompted Dr. Yoshizumi Tahara, National Institute of Hygienic Sciences to conduct a chemical investigation of the toxic substance of globefish in 1884. However, the analysis was very difficult and his report of investigation was delayed. Before publication of the report of Dr. Tahara, pharmacological and toxicological studies of globefish poisoning were reported by three research groups from the Facultly of Medicine, University of Tokyo in 1889. These reports concluded that globefish poison has curare-like activity and its distribution was limited to specific organs such as the ovaries and the liver. Dr. Tahara successfully isolated the poison from aqueaous extract of ovaries of globefish by precipitation with lead acetate in the presence of ammonia. He presented the results at the monthly meeting of the Pharmaceutical Society of Japan in July 1894. He continued the studies and established an improved method for extraction and purification suitable for large-scale production. Finally, he confirmed that globefish contains only one toxic substance and named it Tetrodotoxin (TTX) in 1909. He elucidated the chemical nature of TTX as follows: 1) TTX is an amorphous hygroscopic powder and its character is neither alkaloid nor protein. 2) The possibility of TTX being a protamine was excluded by chemical analysis. Before the discovery ot TTX, according to folklore, globefish was regarded as medicine for leprosy because flesh of globefish contaminated with a sublethal dose of toxic substance alleviated the neuralgia of patients affected with leprosy. The clinical effect of TTX prepared by Tahara's method to suppress severe neuralgia due to leprosy and to reduce muscle spasms due to tetanus were reported by dermatologists in 1911. TTX was also given to patients with rheumatoid arthritis due to its analgesic effect. Thus, injectable TTX was manufactured and distributed by Sankyo Co., Ltd. from 1913. In terms of purity, the TTX preparation manufactured by Tahara's method seemed to be much more crude than the crystalline TTX obtained by Professor Tsuda and Dr. Kawamura in 1952. According to their report, the LD50 of the preparation for clinical use manufactured by Tahara's method was 4-5 mg/kg mouse compared to 4-6 microg/kg mouse of crystalline TTX. PMID:11613509

  17. Stochastic theory of nonequilibrium steady states. Part II: Applications in chemical biophysics

    NASA Astrophysics Data System (ADS)

    Ge, Hao; Qian, Min; Qian, Hong

    2012-01-01

    The mathematical theory of nonequilibrium steady state (NESS) has a natural application in open biochemical systems which have sustained source(s) and sink(s) in terms of a difference in their chemical potentials. After a brief introduction in Section 1, in Part II of this review, we present the widely studied biochemical enzyme kinetics, the workhorse of biochemical dynamic modeling, in terms of the theory of NESS (Section 2.1). We then show that several phenomena in enzyme kinetics, including a newly discovered activation-inhibition switching (Section 2.2) and the well-known non-Michaelis-Menten-cooperativity (Section 2.3) and kinetic proofreading (Section 2.4), are all consequences of the NESS of driven biochemical systems with associated cycle fluxes. Section 3 is focused on nonlinear and nonequilibrium systems of biochemical reactions. We use the phosphorylation-dephosphorylation cycle (PdPC), one of the most important biochemical signaling networks, as an example (Section 3.1). It starts with a brief introduction of the Delbrck-Gillespie process approach to mesoscopic biochemical kinetics (Sections 3.2 and 3.3). We shall discuss the zeroth-order ultrasensitivity of PdPC in terms of a new concept - the temporal cooperativity (Sections 3.4 and 3.5), as well as PdPC with feedback which leads to biochemical nonlinear bistability (Section 3.6). Also, both are nonequilibrium phenomena. PdPC with a nonlinear feedback is kinetically isomorphic to a self-regulating gene expression network, hence the theory of NESS discussed here could have wide applications to many other biochemical systems.

  18. 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

  19. PHYTOPLANKTON WATER QUALITY RELATIONSHIPS IN U.S. LAKES. PART II: 'GENERA ACANTHOSPHAERA' THROUGH 'CYSTODINIUM' COLLECTED FROM EASTERN AND SOUTHEASTERN LAKES

    EPA Science Inventory

    Water quality relationships for about 180 genera and 700 species and varieties of phytoplankton were determined from National Eutrophication Survey data collected in 17 eastern and southeastern states during 1973. This report, Part II, presents environmental requirements and rela...

  20. Cuebook II. State Education Collective Bargaining Laws. Report No. F80-5.

    ERIC Educational Resources Information Center

    Ross, Doris; Flakus-Mosqueda, Patricia

    State public employee collective bargaining laws affecting education are summarized in this booklet. State provisions and laws relative to coverage, exclusion, determination of bargaining units, union security, administrative roles, management rights, impasse procedures, grievance procedures, unfair practices, and deadline dates are compared.

  1. 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...

  2. Accessibility of selenomethionine proteins by total chemical synthesis: structural studies of human herpesvirus-8 MIP-II.

    PubMed

    Shao, W; Fernandez, E; Wilken, J; Thompson, D A; Siani, M A; West, J; Lolis, E; Schweitzer, B I

    1998-12-11

    The determination of high resolution three-dimensional structures by X-ray crystallography or nuclear magnetic resonance (NMR) is a time-consuming process. Here we describe an approach to circumvent the cloning and expression of a recombinant protein as well as screening for heavy atom derivatives. The selenomethionine-modified chemokine macrophage inflammatory protein-II (MIP-II) from human herpesvirus-8 has been produced by total chemical synthesis, crystallized, and characterized by NMR. The protein has a secondary structure typical of other chemokines and forms a monomer in solution. These results indicate that total chemical synthesis can be used to accelerate the determination of three-dimensional structures of new proteins identified in genome programs. PMID:9877169

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Spatial and temporal variations of chemicals in the TSP aerosols simultaneously collected at three islands in Okinawa, Japan

    NASA Astrophysics Data System (ADS)

    Arakaki, Takemitsu; Azechi, Sotaro; Somada, Yuka; Ijyu, Moriaki; Nakaema, Fumiya; Hitomi, Yuya; Handa, Daishi; Oshiro, Yoshito; Miyagi, Youichi; Tsuhako, Ai; Murayama, Hitomi; Higaonna, Yumi; Tanahara, Akira; Itoh, Akihide; Fukushima, Soko; Higashi, Kazuaki; Henza, Yui; Nishikawa, Rin; Shinjo, Hibiki; Wang, Hongyan

    2014-11-01

    East Asia's rapid economic growth has led to concerns about the emission of air pollutants. We collected total suspended particle (TSP) aerosol samples simultaneously at three islands in Okinawa, Japan, which are downwind of East Asia, during the Asian dust season, to examine the spatial and temporal variations and chemical transformations of major chemicals in the aerosols. Weekly samples were collected from July 2008 to June 2010, and the concentrations of water-soluble cations, anions, and organic carbon (WSOC) were determined (n = 303). Spatial distribution analysis showed that monthly mean concentrations of non-sea-salt (nss)-SO42- in the spring (Asian dust season) decreased with increasing distance from Asia, while the trend for NO3- was less evident, suggesting that chemical transformation affected the long-range transport of certain chemicals. Temporal variation analysis showed that concentrations of nss-SO42-, NO3-, and WSOC during the spring were about 2.0, 2.4, and 1.8 times those in the summer (cleaner air mass from the Pacific Ocean), respectively. This study demonstrated that air pollutants were transported from the Asian continent to the Okinawa islands and affected the air quality in the region. There may also be impacts on ecosystems, because increased concentrations of particulate NO3- could increase nutrient levels around the Okinawa islands.

  8. 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...

  9. Kinetic studies of Cd (II) and Pb (II) ions biosorption from aqueous media using untreated and chemically treated biosorbents.

    PubMed

    Bakyayita, G K; Norrstrm, A C; Nalubega, M; Kulabako, R N

    2014-01-01

    Untreated and chemically treated Albizia coriaria, Erythrina abyssinica and Musa spp. were studied in batch for uptake of Cd(2+) and Pb(2+) ions at pH 2.0-9.0 and agitation time of 30-390 min. Optimum biosorption conditions were pH 4 for Pb(2+) ions and pH 5 for Cd(2+) ions, contact time was 3.5 hours at 24 1 C for 10 mg/L biosorbent dosage and initial metal ions concentration of 20 mg/L. Chemical treatment had a 10-17% biosorption efficiency enhancement for Cd(2+) ions and a 1.6-2.3% reduction effect for Pb(2+) ions. The sorption capacities for Cd(2+) and Pb(2+) ions for treated biosorbents were 1.760-1.738 mg g(-1) compared to 1.415-1.539 mg g(-1) for untreated materials. The pseudo second-order model suitably fitted the Cd(2+) and Pb(2+) ions biosorption data with regression coefficients (R(2)) of 0.9784-0.9999. Fitting of the Ho model to the experimental data showed that the biosorption mechanism for both metal ions studied was mainly a chemisorption process. Therefore, treated A. coriaria, E. abyssinica and Musa spp. were potential biosorbents for remediation of Cd(2+) ions and the untreated materials suitable for removing Pb(2+) ions from contaminated aqueous media. PMID:24901616

  10. Chemical composition and antibacterial activity of propolis collected by three different races of honeybees in the same region.

    PubMed

    Silici, Sibel; Kutluca, Semiramis

    2005-05-13

    The chemical analysis and antibacterial activity of three types of propolis collected three different races of Apis mellifera bee in the same apiary were investigated. Propolis samples were investigated by GC/MS, 48 compounds were identified 32 being new for propolis. The compounds identified indicated that the main plant sources of propolis were Populus alba, Populus tremuloides and Salix alba. The antimicrobial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans was evaluated. Ethanolic extracts of propolis samples showed high antibacterial activity against Gram-positive cocci (Staphylococcus aureus), but had a weak activity against Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and yeast (Candida albicans). Propolis sample collected by Apis mellifera caucasica showed a higher antibacterial activity than collected by Apis mellifera anatolica and Apis mellifera carnica. PMID:15848022

  11. 75 FR 42133 - Agency Information Collection Activities: Proposed Collection; Comments Requested: Application...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-20

    ...: Application for Procurement Quota for Controlled Substances and Ephedrine, Pseudoephedrine, and.../Collection: Application for Procurement Quota for Controlled Substances and Ephedrine, Pseudoephedrine, and... of controlled substances listed in Schedule I or II or the List I chemicals...

  12. 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

  13. 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...

  14. Thymine vanadyl(II) compound as a diabetic drug model: Chemical spectroscopic and antimicrobial assessments

    NASA Astrophysics Data System (ADS)

    El-Sayed, Mohamed Y.; Refat, Moamen S.

    2014-09-01

    The aim of this study was to synthesize a novel bifunctionalized thymine vanadyl(II) compound. The solid vanadyl(II) compound has been characterized by elemental analyses (CHN), Raman laser, infrared spectra, molar conductivity, electronic spectra, thermogravimetric analyses (TGA), scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) studies. Electronic and magnetic measurements have confirmed that the speculated geometry of vanadyl(II) compound is square pyramidal geometry. The microbial test was performed for the vanadyl complex against some kinds of bacteria and fungi. The results suggested that [VO(Thy)2] adduct has an anti-diabetic profile.

  15. 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, Japan.

  16. A p-Wave Superconductor under Externally Applied Weak Fields. II --Response Functions and Collective Modes--

    NASA Astrophysics Data System (ADS)

    Hirashima, D. S.; Namaizawa, H.

    1987-03-01

    On the basis of the formalism developed in I (the preceding paper), we give a theory of response of an ideal p-wave superconductor to external weak perturbation. We locate in response functions the collective poles characterisitic to respenctive phases, thereby pay a special attention to the gauge invariance and the Coulomb interaction. In transverse response, there may occur a pole to be called breathing and another orbital mode for a polar phase, the normal- and superflapping modes as well as the clapping mode for an ABM or planar phase, and the squashing mode for a BW phase, respectively. There may also appear in longitudinal response, besides the plasman common to all the phases, the poles listed respectively in respective phases, but with an overall enhancement of their residues due to the long-rangeness ofthe Coulomb potential. Taking advantage of the termwise gauge invariance we also analyse the static kernel to study the magnetic penetration depths in the London limit.

  17. 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 ?m size fractions with minor fractions of Mg, Al, Si, Ca, S, and C. From SEM analysis, the floor dusts of the <25 ?m size fractions collected on railroad ties appeared to be smaller than 10 ?m, 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 ?m, 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

  18. 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.

  19. 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)

    Guguen, Florence; Stille, Peter; Dietze, Volke; Gier, 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.

  20. 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...

  1. 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 ...

  2. Initial chemical and biological characterization of hydrotreated solvent refined coal (SRC-II) liquids: a status report

    SciTech Connect

    Weimer, W.C.; Wilson, B.W.; Pelroy, R.A.; Craun, J.C.

    1980-07-01

    This report presents the results of both chemical and biomedical research performed on a solvent refined coal (SRC-II) research material (distillate blend) which was produced by the pilot plant facility at Fort Lewis, Washington. Samples of this distillate blend were subjected to research-scale hydrotreatment by Universal Oil Products, Inc., prior to chemical and biological analysis at PNL. The samples are considered to be, in general, generically representative of raw or hydrotreated materials which might be produced by demonstration or commercial-scale facilities. The above described feedstock and hydrotreated materials were analyzed for chemical composition both prior to and after chemical fractionation. The fractionation procedure used was an acid-base-neutral solvent extraction. The fractions produced, as well as the unfractionated materials, were subjected to microbial mutagenesis testing (Ames assay) and to further chemical analysis. The principal components of the unmodified distillate blend are two and three ringed aromatic and heteroatomic species together with high concentrations of phenolic and polynuclear aromatic components relative to typical levels found in petroleum crudes. The Ames assay mutagenic response for the unfractionated material, as well as the fractions produced by the solvent separation, was reduced considerably in the hydrotreated materials compared to that of the feedstock. Total mutagenic response for the hydrotreated products was approximately 1% of that in the untreated feedstock. The concentrations of two important genetically active compound classes, the polynuclear aromatic hydrocarbons and the primary aromatic amines, were considerably reduced in both of the hydrotreated products compared to the feedstock.

  3. 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% sodium polyphosphate (NaP), was designed in response to the identification of the most effective CBC formulation in strengthening the steam-cured concrete specimens. Using this storage system with the material cost of 6.32 cents/lb, the 80 C-20 hour-steam-cured concrete specimens displayed the compressive strength of 3980 psi, tensile splitting of 416 psi, flexural strength of 808 psi, and modulus of elasticity of 3.16 x 10{sup 6} psi. Furthermore, the specimens had a good resistance to acid erosion and a lower permeability of water, compared with those of the conventional Type I cement concrete specimens. Consequently, the cost-effective BA-based CBC gave the promise of being a potentially useful material for fabricating high-performance precast concrete products, such as building blocks, pipes, and slabs.

  4. The evolution of gene collectives: How natural selection drives chemical innovation.

    PubMed

    Fischbach, Michael A; Walsh, Christopher T; Clardy, Jon

    2008-03-25

    DNA sequencing has become central to the study of evolution. Comparing the sequences of individual genes from a variety of organisms has revolutionized our understanding of how single genes evolve, but the challenge of analyzing polygenic phenotypes has complicated efforts to study how genes evolve when they are part of a group that functions collectively. We suggest that biosynthetic gene clusters from microbes are ideal candidates for the evolutionary study of gene collectives; these selfish genetic elements evolve rapidly, they usually comprise a complete pathway, and they have a phenotype-a small molecule-that is easy to identify and assay. Because these elements are transferred horizontally as well as vertically, they also provide an opportunity to study the effects of horizontal transmission on gene evolution. We discuss known examples to begin addressing two fundamental questions about the evolution of biosynthetic gene clusters: How do they propagate by horizontal transfer? How do they change to create new molecules? PMID:18216259

  5. Deep proteomic profiling of vasopressin-sensitive collecting duct cells. II. Bioinformatic analysis of vasopressin signaling.

    PubMed

    Yang, Chin-Rang; Raghuram, Viswanathan; Emamian, Milad; Sandoval, Pablo C; Knepper, Mark A

    2015-12-15

    Vasopressin controls osmotic water transport in the renal collecting duct through regulation of aquaporin-2 (AQP2). We carried out bioinformatic analysis of quantitative proteomic data from the accompanying article to investigate the mechanisms involved. The experiments used stable isotope labeling by amino acids in cell culture in cultured mpkCCD cells to quantify each protein species in each of five differential-centrifugation (DC) fractions with or without the vasopressin analog 1-desamino-8-d-arginine-vasopressin (dDAVP). The mass spectrometry data and parallel Western blot experiments confirmed that dDAVP addition is associated with an increase in AQP2 abundance in the 17,000-g pellet and a corresponding decrease in the 200,000-g pellet. Remarkably, all subunits of the cytoplasmic ribosome also increased in the 17,000-g pellet in response to dDAVP (P < 10(-34)), with a concomitant decrease in the 200,000-g pellet. Eukaryotic translation initiation complex 3 (eIF3) subunits underwent parallel changes (P < 10(-6)). These findings are consistent with translocation of assembled ribosomes and eIF3 complexes into the rough endoplasmic reticulum in response to dDAVP. Conversely, there was a systematic decrease in small GTPase abundances in the 17,000-g fraction. In contrast, most proteins, including protein kinases, showed no systematic redistribution among DC fractions. Of the 521 protein kinases coded by the mouse genome, 246 were identified, but many fewer were found to colocalize with AQP2 among DC fractions. Bayes' rule was used to integrate the new colocalization data with prior data to identify protein kinases most likely to phosphorylate aquaporin-2 at Ser(256) (Camk2b > Camk2d > Prkaca) and Ser(261) (Mapk1 = Mapk3 > Mapk14). PMID:26310817

  6. 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.

  7. Synthesis, Spectroscopic, Structural and Quantum Chemical Studies of a New Imine Oxime and Its Palladium(II) Complex: Hydrolysis Mechanism.

    PubMed

    Kaya, Yunus; Yilmaz, Veysel T; Buyukgungor, Orhan

    2016-01-01

    In this work, we report synthesis, crystallographic, spectroscopic and quantum chemical studies of a new imine oxime, namely (4-nitro-phenyl)-(1-phenyl-ethylimino)-acetaldehyde oxime (nppeieoH). Spectroscopic and X-ray diffraction studies showed that nppeieoH is hydrolyzed in aqueous solution, forming nitroisonitrosoacetophenone (ninap) and the hydrolysis product binds to Pd(II) to yield [Pd(nppeieo)(ninap)]. The mechanism of the hydrolysis reaction has been theoretically investigated in detail, using density functional theory (DFT) with the B3LYP method. The vibrational and the electronic spectra of nppeieoH and its Pd(II) complex, the HOMO and LUMO analysis, Mulliken atomic charges and molecular electrostatic potential were also performed. The predicted nonlinear optical properties of both compounds are higher than those of urea. PMID:26805795

  8. 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

  9. Field survey of Glycyrrhiza plants in Central Asia (3). Chemical characterization of G. glabra collected in Uzbekistan.

    PubMed

    Hayashi, Hiroaki; Hattori, Sayaka; Inoue, Kenichiro; Khodzhimatov, Olimjon; Ashurmetov, Ozodbek; Ito, Michiho; Honda, Gisho

    2003-11-01

    The chemical characteristics of Glycyrrhiza glabra L. were investigated at a habitat in Uzbekistan. HPLC analysis of the underground parts indicated that glycyrrhizin contents varied from 3.3 to 6.1% of dry weight, and that glabridin, a species-specific flavonoid for G. glabra, was detected in all underground samples (0.08-0.35% of dry weight). HPLC analysis of the leaves indicated that G. glabra plants collected in the present study could be divided into two types, RT-type and IQ-type, according to their major flavonol glycosides, rutin or isoquercitrin, respectively. PMID:14600388

  10. 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.

  11. 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...

  12. ENVIRONMENTAL PATHWAYS OF SELECTED CHEMICALS IN FRESHWATER SYSTEMS. PART II. LABORATORY STUDIES

    EPA Science Inventory

    Environmental exposure assessment models and laboratory procedures for predicting the pathways of potentially harmful chemicals in freshwater environments were described in Part I of this report (PB-274 548). Procedures were developed for measuring the rates of volatilization, ph...

  13. 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 Agencys (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

  14. 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.

  15. Dust as interstellar catalyst. II. How chemical desorption impacts the gas

    NASA Astrophysics Data System (ADS)

    Cazaux, S.; Minissale, M.; Dulieu, F.; Hocuk, S.

    2016-01-01

    Context. Interstellar dust particles, which represent 1% of the total mass, are recognized to be very powerful interstellar catalysts in star-forming regions. The presence of dust can have a strong impact on the chemical composition of molecular clouds. While observations show that many species that formed onto dust grains populate the gas phase, the process that transforms solid state into gas phase remains unclear. Aims: The aim of this paper is to consider the chemical desorption process, i.e. the process that releases solid species into the gas phase, in astrochemical models. These models allow determining the chemical composition of star-forming environments with an accurate treatment of the solid-phase chemistry. Methods: In paper I we derived a formula based on experimental studies with which we quantified the efficiencies of the chemical desorption process. Here we extend these results to astrophysical conditions. Results: The simulations of astrophysical environments show that the abundances of gas-phase methanol and H2O2 increase by four orders of magnitude, whereas gas-phase H2CO and HO2 increase by one order of magnitude when the chemical desorption process is taken into account. The composition of the ices strongly varies when the chemical desorption is considered or neglected. Conclusions: We show that the chemical desorption process, which directly transforms solid species into gas-phase species, is very efficient for many reactions. Applied to astrophysical environments such as ρ Oph A, we show that the chemical desorption efficiencies derived in this study reproduce the abundances of observed gas-phase methanol, HO2, and H2O2, and that the presence of these molecules in the gas shows the last signs of the evolution of a cloud before the frost.

  16. A photometric study of chemically peculiar stars with the STEREO satellites - II. Non-magnetic chemically peculiar stars

    NASA Astrophysics Data System (ADS)

    Paunzen, E.; Wraight, K. T.; Fossati, L.; Netopil, M.; White, G. J.; Bewsher, D.

    2013-02-01

    We have analysed the photometric data obtained with the STEREO spacecraft for 558 non-magnetic chemically peculiar (CP) stars to search for rotational and pulsational variability. Applying the Lomb-Scargle and the phase dispersion minimization methods, we have detected photometric variability for 44 objects from which 35 were previously unknown. The new objects are all bright stars on the ecliptic plane (magnitude range 4.7 < V < 11.7) and will therefore be of great interest to studies of stellar structure and evolution. In particular, several show multiple signals consistent with hybrid ? Scuti and ? Doradus pulsation, with different periodicities allowing very different regions of the stellar interior to be studied. There are two subgroups of stars in our sample: the cool metallic line Am (CP1) and the hot HgMn (CP3) stars. These objects fall well inside the classical instability strip where ? Scuti, ? Doradus and slowly pulsating B-type stars are located. We also expect to find periods correlated to the orbital period for CP1 objects as they are mostly members of binary systems. For CP3 stars, rotationally induced variability is still a matter of debate. Although surface spots were detected, they are believed to produce only marginal photometric amplitudes. So, periods from several hours to a few days were expected for these two star groups. The STEREO/HI-1 data are well matched to studies of this frequency domain, owing to the cadence of approximately 40 min and multiple epochs over four and a half years. The remaining 514 stars are likely to be constant in the investigated range from 0.1 to 10 d. In some cases, the presence of blending or systematic effects prevented us from detecting any reliable variability and in those cases we classified the star as constant. We discuss our results in comparison to already published ones and find a very good agreement. Finally, we have calibrated the variable stars in terms of the effective temperature and luminosity in order to estimate masses and ages. For this purpose, we used specifically developed calibrations for CP stars and, when available, Hipparcos parallaxes. All but two objects cover the stellar mass range from 1.5 to 5 M? and are located between the zero- and terminal-age main sequence.

  17. Monitoring physical and chemical parameters of Delaware Bay waters with an ERTS-1 data collection platform

    NASA Technical Reports Server (NTRS)

    Klemas, V. (principal investigator); Wethe, C.

    1975-01-01

    The author has identified the following significant results. Results of the analysis of data collected during the summer of 1974 demonstrate that the ERTS Data Collection Platform (DCP) is quite responsive to changing water parameters and that this information can be successfully transmitted under all weather conditions. The monitoring of on-site probe outputs reveals a rapid response to changing water temperature, salinity, and turbidity conditions on incoming tides as the tidal salt wedge passes the probe location. The changes in water properties were corroborated by simultaneously sampling the water for subsequent laboratory analysis. Fluctuations observed in the values of salinity, conductivity, temperature and water depth over short time intervals were extremely small. Due to the nature of the probe, 10% to 20% fluctuations were observed in the turbidity values. The use of the average of the values observed during an overpass provided acceptable results. Good quality data was obtained from the satellite on each overpass regardless of weather conditions. Continued use of the DCP will help provide an indication of the accuracy of the probes and transmission system during long term use.

  18. 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 ...

  19. 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 ...

  20. 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

  1. 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…

  2. Dust depletion, chemical uniformity and environment of CaII H&K quasar absorbers

    NASA Astrophysics Data System (ADS)

    Zych, Berkeley J.; Murphy, Michael T.; Hewett, Paul C.; Prochaska, Jason X.

    2009-02-01

    CaII??3934, 3969 absorbers, which are likely to be a subset of damped Lyman ? systems (DLAs), are the most dusty quasar absorbers known with an order of magnitude more extinction in E(B - V) than other absorption systems. There is also evidence that CaII absorbers trace galaxies with more ongoing star formation than the average quasar absorber. Despite this, relatively little is known in detail about these unusual absorption systems. Here, we present the first high-resolution spectroscopic study of 19 CaII quasar absorbers, in the range 0.6 <= zabs <= 1.2, with CaII?3934 equivalent widths, W39340 >= 0.2. Their general elemental depletion patterns are found to be similar to measurements in the warm halo phase of the Milky Way (MW) and Magellanic Clouds interstellar medium. Dust depletions and ?-enrichments profiles of subsamples of seven and three absorbers, respectively, are measured using a combination of Voigt profile fitting and apparent optical depth techniques. Deviations in [Cr/Zn] ~ 0.3 +/- 0.1 and [Si/Fe] >~ 0.8 +/- 0.1dex are detected across the profile of one absorber, which we attribute to differential dust depletion. The remaining absorbers have <0.3dex (3? limit) variation in [Cr/Zn], much like the general DLA population, though the dustiest CaII absorbers, those with W39340 > 0.7, remain relatively unprobed in our sample. A limit on electron densities in CaII absorbers, ne < 0.1cm-3, is derived using the ratio of neutral and singly ionized species and assuming a MW-like radiation field. These electron densities may imply hydrogen densities sufficient for the presence of molecular hydrogen in the absorbers. The CaII absorber sample comprises a wide range of velocity widths, ?v90 = 50-470kms-1, and velocity structures, thus a range of physical models for their origin, from simple discs to galactic outflows and mergers, would be required to explain the observations.

  3. Human urinary excretion of non-persistent environmental chemicals: an overview of Danish data collected between 2006 and 2012.

    PubMed

    Frederiksen, Hanne; Jensen, Tina Kold; Jørgensen, Niels; Kyhl, Henriette Boye; Husby, Steffen; Skakkebæk, Niels E; Main, Katharina M; Juul, Anders; Andersson, Anna-Maria

    2014-01-01

    Several non-persistent industrial chemicals have shown endocrine disrupting effects in animal studies and are suspected to be involved in human reproductive disorders. Among the non-persistent chemicals that have been discussed intensively during the past years are phthalates, bisphenol A (BPA), triclosan (TCS), and parabens because of their anti-androgenic and/or estrogenic effects. Phthalates are plasticizers used in numerous industrial products. Bisphenol A is the main component of polycarbonate plastics and epoxy resins. Parabens and TCS are antimicrobial preservatives and other phenols such as benzophenone-3 (BP-3) act as a UV-screener, while chlorophenols and phenyl phenols are used as pesticides and fungicides in agriculture. In spite of the widespread use of industrial chemicals, knowledge of exposure sources and human biomonitoring studies among different segments of the population is very limited. In Denmark, we have no survey programs for non-persistent environmental chemicals, unlike some countries such as the USA (NHANES) and Germany (GerES). However, we have analyzed the excretion of seven parabens, nine phenols, and the metabolites of eight different phthalates in urine samples collected over the past 6 years from four Danish cohorts. Here, we present biomonitoring data on more than 3600 Danish children, adolescents, young men, and pregnant women from the general population. Our study shows that nearly all Danes were exposed to the six most common phthalates, to BPA, TCS, and BP-3, and to at least two of the parabens. The exposure to other non-persistent chemicals was also widespread. Our data indicate decreasing excretion of two common phthalates (di-n-butyl phthalate and di-(2-ethylhexyl) phthalate) over time. PMID:24395915

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

    DOEpatents

    Megerle, Clifford A. (Manassas, VA); Adkins, Douglas R. (Albuquerque, NM); Frye-Mason, Gregory C. (Cedar Crest, NM)

    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.

  5. Chemical fingerprinting of petroleum biomarkers in Deepwater Horizon oil spill samples collected from Alabama shoreline.

    PubMed

    Mulabagal, V; Yin, F; John, G F; Hayworth, J S; Clement, T P

    2013-05-15

    We compare the chromatographic signatures of petroleum biomarkers in Deepwater Horizon (DH) source oil, three other reference crude oils, DH emulsified mousse that arrived on Alabama's shoreline in June 2010, and seven tar balls collected from Alabama beaches from 2011 to 2012. Characteristic hopane and sterane fingerprints show that all the tar ball samples originated from DH oil. In addition, the diagnostic ratios of various hopanes indicate an excellent match. Quantitation data for C????-hopane concentration levels show that most of the weathering observed in DH-related tar balls found on Alabama's beaches is likely the result of natural evaporation and dissolution that occurred during transport across the Gulf of Mexico prior to beach deposition. Based on the physical and biomarker characterization data presented in this study we conclude that virtually all fragile, sticky, brownish tar balls currently found on Alabama shoreline originated from the DH oil spill. PMID:23523118

  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. 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...

  8. Comparison of remote consequences in Taraxacum officinale seed progeny collected in radioactively or chemically contaminated areas.

    PubMed

    Pozolotina, Vera N; Antonova, Elena V; Bezel, Victor S

    2012-10-01

    We carried out a comparative study of seed progeny taken from the dandelion (Taraxacum officinale s.l.) coenopopulations exposed for a long time to radioactive or chemical contamination originated from the East-Ural radioactive trace zone (EURT) or Nizhniy Tagil metallurgical combine impact zone (NTMC), respectively. Coenopopulations from EURT, NTMC and background areas significantly differ from each other with respect to the qualitative and quantitative composition of allozyme phenes. An analysis of clonal diversity showed the uniqueness of all coenopopulations in terms of their phenogenetics. P-generation seed viability was found to decrease in a similar manner as all types of the industrial stress increased. Studies of F (1)-generation variability in radio- and metal resistance by family analysis showed that seed progeny from EURT impact zone possessed high viability that, however, was accompanied by development of latent injuries resulting in low resistance to additional man-caused impacts. In F (1)-generation originated from NTMC zone, high seed viability was combined with increased resistance to provocative heavy metal and radiation exposure. No significant differences in responses to 'habitual' and 'new' factors, i.e. pre-adaptation effect, were found in samples from the contaminated areas. PMID:22661315

  9. 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

  10. 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.

  11. 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

  12. Chemical modification of Class II G-protein coupled receptor ligands

    PubMed Central

    Chapter, Megan C.; White, Caitlin M.; De Ridder, Angela; Chadwick, Wayne; Martin, Bronwen; Maudsley, Stuart

    2009-01-01

    Recent research and clinical data have begun to demonstrate the huge potential therapeutic importance of ligands that modulate the activity of the secretin-like, Class II, G-protein coupled receptors (GPCRs). Ligands that can modulate the activity of these Class II GPCRs may have important clinical roles in the treatment of a wide variety of conditions such as osteoporosis, diabetes, amyotrophic lateral sclerosis and autism spectrum disorders. While these receptors present important new therapeutic targets, the large glycoprotein nature of their cognate ligands poses many problems with respect to therapeutic peptidergic drug design. These native peptides often exhibit poor bioavailability, metabolic instability, poor receptor selectivity and resultant low potencies in vivo. Recently, increased attention has been paid to the structural modification of these peptides to enhance their therapeutic efficacy. Successful modification strategies have included D-amino acid substitutions, selective truncation, and fatty acid acylation of the peptide. Through these and other processes, these novel peptide ligand analogs can demonstrate enhanced receptor subtype selectivity, directed signal transduction pathway activation, resistance to proteolytic degradation, and improved systemic bioavailability. In the future, it is likely, through additional modification strategies such as addition of circulation-stabilizing transferrin moieties, that the therapeutic pharmacopeia of drugs targeted towards Class II secretin-like receptors may rival that of the Class I rhodopsin-like receptors that currently provide the majority of clinically used GPCR-based therapeutics. Currently, Class II-based drugs include synthesized analogues of vasoactive intestinal peptide for type 2 diabetes or parathyroid hormone for osteoporosis. PMID:19686775

  13. 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.

  14. Sequestration of toxic Pb(II) ions by chemically treated rubber (Hevea brasiliensis) leaf powder.

    TOXLINE Toxicology Bibliographic Information

    Kamal MH; Azira WM; Kasmawati M; Haslizaidi Z; Saime WN

    2010-01-01

    Rubber leaf powder (an agricultural waste) was treated with potassium permanganate followed by sodium carbonate and its performance in the removal of Pb(II) ions from aqueous solution was evaluated. The interactions between Pb(II) ions and functional groups on the adsorbent surface were confirmed by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) coupled with X-ray energy dispersive spectroscopy (EDX). The effects of several important parameters which can affect adsorption capacity such as pH, adsorbent dosage, initial lead concentration and contact time were studied. The optimum pH range for lead adsorption was 4-5. Even at very low adsorbent dosage of 0.02 g, almost 100% of Pb(II) ions (23 mg/L) could be removed. The adsorption capacity was also dependent on lead concentration and contact time, and relatively a short period of time (60-90 min) was required to reach equilibrium. The equilibrium data were analyzed with Langmuir, Freundlich and Dubinin-Radushkevich isotherms. Based on Langmuir model, the maximum adsorption capacity of lead was 95.3 mg/g. Three kinetic models including pseudo first-order, pseudo second-order and Boyd were used to analyze the lead adsorption process, and the results showed that the pseudo second-order fitted well with correlation coefficients greater than 0.99.

  15. Low-oxygen and chemical kinetic constraints on the geochemical niche of neutrophilic iron(II) oxidizing microorganisms

    NASA Astrophysics Data System (ADS)

    Druschel, Gregory K.; Emerson, David; Sutka, R.; Suchecki, P.; Luther, George W., III

    2008-07-01

    Neutrophilic iron oxidizing bacteria (FeOB) must actively compete with rapid abiotic processes governing Fe(II) oxidation and as a result have adapted to primarily inhabit low-O 2 environments where they can more successfully compete with abiotic Fe(II) oxidation. The spatial distribution of these microorganisms can be observed through the chemical gradients they affect, as measured using in situ voltammetric analysis for dissolved Fe(II), Fe(III), O 2, and FeS (aq). Field and laboratory determination of the chemical environments inhabited by the FeOB were coupled with detailed kinetic competition studies for abiotic and biotic oxidation processes using a pure culture of FeOB to quantify the geochemical niche these organisms inhabit. In gradient culture tubes, the maximum oxygen levels, which were associated with growth bands of Sideroxydans lithotrophicus (ES-1, a novel FeOB), were 15-50 ?M. Kinetic measurements made on S. lithotrophicus compared biotic/abiotic (killed control) Fe oxidation rates. The biotic rate can be a significant and measurable fraction of the total Fe oxidation rate below O 2 concentrations of approximately 50 ?M, but biotic Fe(II) oxidation (via the biotic/abiotic rate comparison) becomes difficult to detect at higher O 2 levels. These results are further supported by observations of conditions supporting FeOB communities in field settings. Variablity in cell densities and cellular activity as well as variations in hydrous ferrous oxide mineral quantities significantly affect the laboratory kinetic rates. The microbial habitat (or geochemical niche) where FeOB are active is thus largely controlled by the competition between abiotic and biotic kinetics, which are dependent on Fe(II) concentration, P O2, temperature and pH in addition to the surface area of hydrous ferric oxide minerals and the cell density/activity of FeOB. Additional field and lab culture observations suggest a potentially important role for the iron-sulfide aqueous molecular cluster, FeS (aq), in the overall cycling of iron associated with the environments these microorganisms inhabit.

  16. Chemical variability of groundwater samples collected from a coal seam gas exploration well, Maramarua, New Zealand.

    PubMed

    Taulis, Mauricio; Milke, Mark

    2013-03-01

    A pilot study has produced 31 groundwater samples from a coal seam gas (CSG) exploration well located in Maramarua, New Zealand. This paper describes sources of CSG water chemistry variations, and makes sampling and analytical recommendations to minimize these variations. The hydrochemical character of these samples is studied using factor analysis, geochemical modelling, and a sparging experiment. Factor analysis unveils carbon dioxide (CO(2)) degassing as the principal cause of sample variation (about 33%). Geochemical modelling corroborates these results and identifies minor precipitation of carbonate minerals with degassing. The sparging experiment confirms the effect of CO(2) degassing by showing a steady rise in pH while maintaining constant alkalinity. Factor analysis correlates variations in the major ion composition (about 17%) to changes in the pumping regime and to aquifer chemistry variations due to cation exchange reactions with argillaceous minerals. An effective CSG water sampling program can be put into practice by measuring pH at the wellhead and alkalinity at the laboratory; these data can later be used to calculate the carbonate speciation at the time the sample was collected. In addition, TDS variations can be reduced considerably if a correct drying temperature of 180 C is consistently implemented. PMID:23199455

  17. Chemical characterization of fog and rain water collected at the eastern Andes cordillera

    NASA Astrophysics Data System (ADS)

    Beiderwieden, E.; Wrzesinsky, T.; Klemm, O.

    2005-06-01

    During a three month period in 2003 and 2004, the chemistry of fog and rainwater were studied at the "El Tiro" site in a tropical mountain forest ecosystem in Ecuador, South America. The fogwater samples were collected using a passive fog collector, and for the rain water, a standard rain sampler was employed. For all samples, electric conductivity, pH, and the concentrations of NH4+, K+, Na+, Ca2+, Mg2+, Cl-, NO3-, PO43-, and SO42-, were measured. For each fog sample, a 5 day back trajectory was calculated by the use of the HYSPLIT model. Two types of trajectories occurred. One type was characterized by advection of air masses from the East over the Amazonian basin, the other trajectory arrived one from the West after significant travel time over the Pacific Ocean. We found considerably higher ion concentrations in fogwater samples than in rain samples. Median pH values are 4.58 for fog water, and 5.26 for the rain samples, respectively. The median electric conductivity was 23 S cm-1 for the fog and 6 S cm-1 for the rain. The concentrations of all analysed ions were relatively low compared to other mountainous sites (Weathers et al., 1988; Elias et al., 1995; Schemenauer et al., 1995; Wrzesinsky and Klemm, 2000; Zimmermann and Zimmermann, 2002). The continent samples exhibit higher concentrations of most ions as compared to the pacific samples.

  18. Chemical characterization of fog and rain water collected at the eastern Andes cordillera

    NASA Astrophysics Data System (ADS)

    Beiderwieden, E.; Wrzesinsky, T.; Klemm, O.

    2005-09-01

    During a three month period in 2003 and 2004, the chemistry of fog and rainwater were studied at the "El Tiro" site in a tropical mountain forest ecosystem in Ecuador, South America. The fogwater samples were collected using a passive fog collector, and for the rain water, a standard rain sampler was employed. For all samples, electric conductivity, pH, and the concentrations of NH4+, K+, Na+, Ca2+, Mg2+, Cl-, NO3-, PO43-, and SO42- were measured. For each fog sample, a 5 day back trajectory was calculated by the use of the HYSPLIT model. Two types of trajectories occurred. One type was characterized by advection of air masses from the East over the Amazonian basin, the other trajectory arrived one from the West after significant travel time over the Pacific Ocean. We found considerably higher ion concentrations in fogwater samples than in rain samples. Median pH values are 4.58 for fog water, and 5.26 for the rain samples, respectively. The median electric conductivity was 23 ?S cm-1 for the fog and 6 ?S cm-1 for the rain. The continent samples exhibit higher concentrations of most ions as compared to the pacific samples, but these differences could not be detected statistically.

  19. Computation of the physio-chemical properties and data mining of large molecular collections.

    PubMed

    Cheng, Ailan; Diller, David J; Dixon, Steven L; Egan, William J; Lauri, George; Merz, Kenneth M

    2002-01-15

    Very large data sets of molecules screened against a broad range of targets have become available due to the advent of combinatorial chemistry. This information has led to the realization that ADME (absorption, distribution, metabolism, and excretion) and toxicity issues are important to consider prior to library synthesis. Furthermore, these large data sets provide a unique and important source of information regarding what types of molecular shapes may interact with specific receptor or target classes. Thus, the requirement for rapid and accurate data mining tools became paramount. To address these issues Pharmacopeia, Inc. formed a computational research group, The Center for Informatics and Drug Discovery (CIDD).* In this review we cover the work done by this group to address both in silico ADME modeling and data mining issues faced by Pharmacopeia because of the availability of a large and diverse collection (over 6 million discrete compounds) of drug-like molecules. In particular, in the data mining arena we discuss rapid docking tools and how we employ them, and we describe a novel data mining tool based on a ID representation of a molecule followed by a molecular sequence alignment step. For the ADME area we discuss the development and application of absorption, blood-brain barrier (BBB) and solubility models. Finally, we summarize the impact the tools and approaches might have on the drug discovery process. PMID:11913384

  20. 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 800C for 4h followed by acid activation using 3.0mol/L of HCl at 100C 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 30min and 60min 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 (0.001-0.1mol/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

  1. 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.; Sez, 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 (0.180.55 m) overlaps with the most hygroscopic mode at a relative humidity of 90% (0.100.32 m). 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

  2. 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 ...

  3. 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...

  4. 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...

  5. Review of chemical-kinetic problems of future NASA missions, II: Mars entries

    NASA Technical Reports Server (NTRS)

    Park, Chul; Howe, John T.; Jaffe, Richard L.; Candler, Graham V.

    1994-01-01

    The present work aims to derive a set of thermomechanical relaxation rate parameters and chemical reaction rate coefficients relevant to future interplanetary missions. It also attempts to assess the impact of thermochemical nonequilibrium phenomena on radiative heating rates for the stagnation point of the Martian entry vehicle.

  6. 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 Agencys (EPA) ToxCast high th...

  7. 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.

  8. 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...

  9. 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...

  10. CHEMICALLY ACTIVE FLUID BED FOR SOX CONTROL: VOLUME II. SPENT SORBENT PROCESSING FOR DISPOSAL/UTILIZATION

    EPA Science Inventory

    The report describes the processing of spent calcium-based sulfur sorbents (limestones or dolomites) from an atmospheric-pressure, chemically active fluid bed (CAFB) gasification process, using a regenerative sulfur sorbent process that produces low- to intermediate-Btu gas. Data...

  11. 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.

  12. 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

  13. 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.

  14. Variations of chemical components in fossil corals collected from Tahiti by IODP Expedition 310

    NASA Astrophysics Data System (ADS)

    Inoue, M.; Harada, M.; Suzuki, A.; Tanimizu, M.; Tokoyama, Y.

    2008-12-01

    Integrated Ocean Drilling Program (IODP) Expedition 310 to the reef terraces around Tahiti, French Polynesia was conducted for the purpose of establishing the course of postglacial sea level rise at Tahiti and to define sea-surface temperature (SST) and marine environmental variation for the region over the period 20-10 ka. While sea-level during the Last Glacial Maximum (LGM) has been observed as much as ca. 130 m below its present value for sites remote from former ice sheet (far-field sites), fossil coral records contain evidence of a dramatic sea level rise in excess 20 m within the last deglaciation around 14 ka, termed meltwater pulse 1A (mwp-1A). Although this event would have had a significant effect on global climate, the relationship between mwp-1A and the climate system remains a subject of debate. Coral geochemistry has a potential as proxies for marine environments, and in this study we measured trace elements, such as Ba, U and Cd, in addition to Pb isotope ratios in fossil Porites sp. collected around Tahiti in order to reconstruct SST, upwelling and/or wind source/direction. Skeletal conditions of fossil corals were investigated using X-ray diffraction and we selected samples composed of only aragonite. Dating of fossil corals were determined based on 14C method by accelerator mass spectrometry. As a result, approximately 10 samples were from before and in the period of mwp-1A event (15 - 14 ka). Then bulk samples were taken from all coral specimens by a milling machine and trace elements and Pb isotopic compositions in bulk samples were analyzed by inductively coupled mass spectrometer (ICP-MS) and multiple-collector ICP-MS, respectively. Data of Pb isotope ratios in fossil corals were comparable with those from crust in the Central Andes, suggesting that easterly wind was predominant around Tahiti with a slight variation depending on the age. We will also discuss the relationship between upwelling and climate condition around the mwp-1A based on Cd contents and U/Ca ratios.

  15. 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.

  16. 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.

  17. Chemical analysis of CH stars - II. Atmospheric parameters and elemental abundances

    NASA Astrophysics Data System (ADS)

    Karinkuzhi, Drisya; Goswami, Aruna

    2015-01-01

    We present detailed chemical analyses for a sample of 12 stars selected from the CH star catalogue of Bartkevicius. The sample includes two confirmed binaries, four objects that are known to show radial velocity variations and the rest with no information on the binary status. A primary objective is to examine if all these objects exhibit chemical abundances characteristics of CH stars, based on detailed chemical composition study using high-resolution spectra. We have used high-resolution (R 42 000) spectra from the ELODIE archive. These spectra cover 3900 to 6800 in the wavelength range. We have estimated the stellar atmospheric parameters, the effective temperature Teff, the surface gravity log g, and metallicity [Fe/H] from local thermodynamic equilibrium analysis using model atmospheres. Estimated temperatures of these objects cover a wide range from 4200 to 6640 K, the surface gravity from 0.6 to 4.3 and metallicity from -0.13 to -1.5. We report updates on elemental abundances for several heavy elements, Sr, Y, Zr, Ba, La, Ce, Pr, Nd, Sm, Eu and Dy. For the object HD 89668, we present the first abundance analyses results. Enhancement of heavy elements relative to Fe, a characteristic property of CH stars is evident from our analyses in the case of four objects, HD 92545, HD 104979, HD 107574 and HD 204613. A parametric-model-based study is performed to understand the relative contributions from the s- and r-process to the abundances of the heavy elements.

  18. 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 (?G). For this, we related the dependence of ?G on temperature, in the Gibbs-Helmholtz equation, to that of ?G 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.

  19. STUDIES ON ISOLATED NUCLEI. II. ISOLATION AND CHEMICAL CHARACTERIZATION OF NUCLEOLAR AND NUCLEOPLASMIC SUBFRACTIONS.

    PubMed

    MAGGIO, R; SIEKEVITZ, P; PALADE, G E

    1963-08-01

    This paper describes the subfractionation of nuclei isolated from guinea pig liver by the procedure presented in the first article of the series (8). Centrifugation in a density gradient system of nuclear fractions disrupted by sonication permits the isolation of the following subfractions: (a) a nucleolar subfraction which consists mainly of nucleoli surrounded by a variable amount of nucleolus-associated chromatin and contaminated by chromatin blocks derived primarily from von Kupffer cell nuclei; (b) and (c), two nucleoplasmic subfractions (I and II) which consist mainly of chromatin threads in a coarser (I) or finer (II) degree of fragmentation. The protein, RNA, and DNA content of these subfractions was determined, and their RNA's characterized in terms of NaCl-solubility, nucleotide composition, and in vivo nucleotide turnover, using inorganic (32)P as a marker. The results indicate that there are at least three types of RNA in the nucleus (one in the nucleolus and two in the nucleoplasm or chromatin), which differ from one another in NaCl-solubility, nucleotide composition, turnover, and possibly sequence. Possible relations among these RNA's and those of the cytoplasm are discussed. PMID:14079490

  20. Chemical evolution of dehydrogenases: Amino acid pentacyanoferrate (II) as possible intermediates

    NASA Astrophysics Data System (ADS)

    Kamaluddin; Nath, Mala; Deopujari, Sushama W.

    1989-03-01

    Dehydrogenation of ascorbic acid and reduced nicotinamide adenine dinucleotide (NADH) with methylene blue using complexes of the type [Fe(II)(CN)5 (L)] n- (wheren=3 or 4; L=glycine, histidine, imidazole, and triglycine) as catalyst have been studied at pH 9.18. Similar kinetic behavior was observed for the dehydrogenation of ascorbic acid as well as for NADH; both reactions showed first order dependency on the substrates. First order dependence was observed only at lower concentrations of methylene blue; at higher concentrations of methylene blue, the reactions were independent of methylene blue. The order with respect to catalyst varied between 0.3 0.5. A tentative mechanism which conforms to the observed kinetics has been proposed. It is believed that on the primitive earth when the reducing potential of the atmosphere was not high enough, lower oxidation state iron complexes like [Fe(II)(CN)5(L)] n- might have been involved in dehydrogenase-type activity.

  1. Removal of cadmium(II) from aqueous solutions by chemically modified maize straw.

    PubMed

    Guo, Hong; Zhang, Shufen; Kou, Zinong; Zhai, Shangru; Ma, Wei; Yang, Yi

    2015-01-22

    A new regenerable adsorbent was successfully prepared by modifying maize straw (MS) with succinic anhydride in xylene. The succinylated-maize straw (S-MS) was characterized by FTIR, solid-state MAS (13)C NMR spectroscopy, SEM-EDX and point of zero charge analysis. NaS-MS was successfully obtained after deprotonating the carboxylic acid groups of S-MS by Na2CO3 solution. Batch experiments were carried out with NaS-MS for the removal of Cd(II). The effects of pH, adsorbent dosage, contact time, initial concentration and temperature were investigated. The experimental data were best described by a pseudo-second-order kinetics and Langmuir adsorption models. Thermodynamic parameters (?G, ?H, and ?S) were also calculated from data obtained from experiments performed to study the effect of temperatures. NaS-MS could be regenerated at least five times in saturated NaCl solution without any loss. Furthermore, ?97% of adsorbed Cd(II) ions could be recovered as the metal oxide. Finally, the adsorption mechanism of NaS-MS was discussed. PMID:25439883

  2. [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

  3. 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

    Background: Mitochondrial dysfunction has been implicated in the pathogenesis of a variety of disorders including cancer, diabetes, and neurodegenerative and cardiovascular diseases. Understanding whether different environmental chemicals and druglike molecules impact mitochondrial function represents an initial step in predicting exposure-related toxicity and defining a possible role for such compounds in the onset of various diseases. Objectives: We sought to identify individual chemicals and general structural features associated with changes in mitochondrial membrane potential (MMP). Methods: We used a multiplexed [two end points in one screen; MMP and adenosine triphosphate (ATP) content] quantitative high throughput screening (qHTS) approach combined with informatics tools to screen the Tox21 library of 10,000 compounds (~ 8,300 unique chemicals) at 15 concentrations each in triplicate to identify chemicals and structural features that are associated with changes in MMP in HepG2 cells. Results: Approximately 11% of the compounds (913 unique compounds) decreased MMP after 1 hr of treatment without affecting cell viability (ATP content). In addition, 309 compounds decreased MMP over a concentration range that also produced measurable cytotoxicity [half maximal inhibitory concentration (IC50) in MMP assay/IC50 in viability assay ? 3; p < 0.05]. More than 11% of the structural clusters that constitute the Tox21 library (76 of 651 clusters) were significantly enriched for compounds that decreased the MMP. Conclusions: Our multiplexed qHTS approach allowed us to generate a robust and reliable data set to evaluate the ability of thousands of drugs and environmental compounds to decrease MMP. The use of structure-based clustering analysis allowed us to identify molecular features that are likely responsible for the observed activity. Citation: Attene-Ramos MS, Huang R, Michael S, Witt KL, Richard A, Tice RR, Simeonov A, Austin CP, Xia M. 2015. Profiling of the Tox21 chemical collection for mitochondrial function to identify compounds that acutely decrease mitochondrial membrane potential. Environ Health Perspect 123:4956;?http://dx.doi.org/10.1289/ehp.1408642 PMID:25302578

  4. 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.

  5. 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

  6. Chemical analysis of temporal gland secretions collected from an Asian bull elephant during a four-month musth episode.

    PubMed

    Rasmussen, L E; Hess, D L; Haight, J D

    1990-07-01

    The temporal glands, modified facial apocrine sweat glands unique to elephants, release collectable secretions during an unusual physiological state termed "musth" in the Asian bull elephant (Elephas maximus). Recently we began the characterization of the chemical components of musth, especially in the temporal gland secretions (TGS), and the examination of the role of such secretions as agents for chemical communication between elephants. The present study focuses on possible correlations between testosterone levels in the serum and temporal gland secretions. We were especially interested in possible qualitative and/or quantitative changes in volatile compounds as the testosterone levels varied during a discrete musth period. Quantitative changes in TGS and serum testosterone were determined by radioimmunoassay. Qualitative and semiquantitative changes occurring in volatile composition were studied by high-resolution gas chromatography (fused silica capillary column, on column injection). Compound identification was by nuclear magnetic resonance, gas chromatography-mass spectrometry, and gas chromatography internal standards. Twenty-three major compounds and a number of minor components were identified. Androgen concentrations were correlated with TGS-specific volatiles including benzoic acid, 2-nonanone, 5-nonanol, tetradecanoic acid, and decanoic acid. The latter two compounds and (E)-farnesol, a major component of African TGS, demonstrated an inverse relationship to T levels. PMID:24264084

  7. Physical and chemical properties of Red MSX Sources in the southern sky: H II regions

    NASA Astrophysics Data System (ADS)

    Yu, Naiping; Wang, Jun-Jie; Li, Nan

    2015-01-01

    We have studied the physical and chemical properties of 18 southern Red Midcourse Space Experiment Sources (RMSs), using archival data taken from the Atacama Pathfinder Experiment (APEX) Telescope Large Area Survey of the Galaxy, the Australia Telescope Compact Array, and the Millimeter Astronomy Legacy Team Survey at 90 GHz. Most of our sources have simple cometary/unresolved radio emissions at 4.8 and/or 8.6GHz. The large number of Lyman continuum fluxes (NL) indicates they are probably massive O- or early B-type star formation regions. Archival IRAS infrared data are used to estimate the dust temperature, which is about 30 K of our sources. Then, the H2 column densities and the volume-averaged H2 number densities are estimated using the 870 μm dust emissions. Large-scale infall and ionized accretions may be occurring in G345.4881+00.3148. We also attempt to characterize the chemical properties of these RMSs through molecular line (N2H+ (1-0) and HCO+ (1-0)) observations. Most of the detected N2H+ and HCO+ emissions match well with the dust emission, implying a close link to their chemical evolution in the RMSs. We found that the abundance of N2H+ is one order of magnitude lower than that in other surveys of infrared dark clouds, and a positive correlation between the abundances of N2H+ and HCO+. The fractional abundance of N2H+ with respect to H2 seems to decrease as a function of NL. These observed trends could be interpreted as an indication of enhanced destruction of N2H+, either by CO or through dissociative recombination with electrons produced by central UV photons.

  8. Chemical variation in molecular cloud cores in the Orion A cloud. II.

    NASA Astrophysics Data System (ADS)

    Tatematsu, Ken'ichi; Ohashi, Satoshi; Umemoto, Tomofumi; Lee, Jeong-Eun; Hirota, Tomoya; Yamamoto, Satoshi; Choi, Minho; Kandori, Ryo; Mizuno, Norikazu

    2014-02-01

    We have mapped six molecular cloud cores in the Orion A giant molecular cloud (GMC), whose kinetic temperatures range from 10 to 30 K, in CCS and N2H+ with the Nobeyama 45 m radio telescope to study their chemical characteristics. We identified 31 intensity peaks in the CCS and N2H+ emission in these molecular cloud cores. We found, for cores with temperatures lower than ˜ 25 K, that the column density ratio of N(N2H+)/N(CCS) is low toward starless core regions while it is high toward star-forming core regions, in cases where we detected both the CCS and N2H+ emission. This is very similar to the tendency found in dark clouds (kinetic temperature ˜ 10 K). The criterion found in the Orion A GMC is N(N2H+)/N(CCS) ˜ 2-3. In some cases, both CCS and N2H+ emission is detected toward protostars. A secondary late-stage CCS peak in the chemical evolution caused by CO depletion may be a possible explanation for this. We found that the chemical variation of CCS and N2H+ can also be used as a tracer of evolution in warm (10-25 K) GMC cores. On the other hand, some protostars do not accompany N2H+ intensity peaks but are associated with dust continuum emitting regions, suggesting that the N2H+ abundance might be decreased due to CO evaporation in warmer star-forming sites.

  9. 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.

  10. Extremely metal-deficient red giants. II. Chemical abundances in 21 halo giants

    SciTech Connect

    Luck, R.E.; Bond, H.E.

    1981-03-15

    Using a model-atmosphere analysis, we have determined chemical abundances in 21 red giants of the galactic halo. Nine new field stars from Bond's recent objective-prism survey, along with the well-known halo giant HD 122563, were analyzed on new high-dispersion spectrograms obtained at Palomar, Mount Wilson, and Cerro Tololo. Five giants in the globular cluster M13, three in M3, and three additional field stars were also analyzed using previously published equivalent-widths, providing a total sample of 21 halo giants analyzed in a homogeneous manner.

  11. Hygroscopic and chemical properties of aerosols collected near a copper smelter: implications for public and environmental health.

    PubMed

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

    2012-09-01

    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 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

  12. 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.

  13. An Observational and Numerical Study of the Nocturnal Sea Breeze. Part II: Chemical Transport.

    NASA Astrophysics Data System (ADS)

    Buckley, Robert L.; Kurzeja, Robert J.

    1997-12-01

    Chemical transport at the Savannah River Site (SRS) in South Carolina during nocturnal sea-breeze passage is examined using simulations from a three-dimensional mesoscale dynamic model [(RAMS) Regional Atmospheric Modeling System] and a Lagrangian particle dispersion model (LPDM) and supplemental surface measurements of sulfur hexafluoride (SF6) obtained during a 1988 field campaign. Plume dispersion and regional transport were characterized by nights with onshore and offshore synoptic winds. For onshore winds, the sea breeze lifts, redirects, and broadens an initially narrow plume but maintains its general structure. Regional calculations reveal particle translations exceeding 100 km under these conditions. On the other hand, with offshore synoptic winds, frontal passage leads to stronger lifting, turbulence, and vertical shearing that fragments the plume. In addition, complicated recirculation of pollutants is possible and may increase chemical concentrations in areas near the source. Observed and model plumes were shown to depend strongly on vertical, horizontal, and temporal wind shear, and vertical motion. These features were simulated by the RAMS and LPDM models but are not possible with Gaussian models. Turbulence and topography also had important effects on plume characteristics but were simulated adequately only in the frontal region. Deficiencies in the model simulation were attributed mainly to insufficient vertical resolution and inadequate resolution of surface features.

  14. 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 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] ?? 6548,6584 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.

  15. 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.

  16. 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

  17. Acid base properties of cyanobacterial surfaces. II: Silica as a chemical stressor influencing cell surface reactivity

    NASA Astrophysics Data System (ADS)

    Lalonde, S. V.; Smith, D. S.; Owttrim, G. W.; Konhauser, K. O.

    2008-03-01

    Bacteria grow in complex solutions where the adsorption of aqueous species and nucleation of mineral phases on the cell surface may interfere with membrane-dependent homeostatic functions. While previous investigations have provided evidence that bacteria may alter their surface chemical properties in response to environmental stimuli, to our knowledge no effort has been made to evaluate surface compositional changes resulting from non-nutritional chemical stresses within a quantitative framework applicable to surface complexation modeling. We consider here the influence of exposure to silica on cyanobacterial surface chemistry, particularly in light of the propensity for cyanobacteria to become silicified in geothermal environments. Using data modeled from over 50 potentiometric titrations of the unsheathed cyanobacterium Anabaena sp. strain PCC 7120, we find that both abiotic geochemical and biotic biochemical-assimilatory factors have important and different effects on cell surface chemistry. Changes in functional group distribution that resulted from growth by different nitrogen assimilation pathways were greatest in the absence of dissolved silica and less important in its presence. Furthermore, out of the three nitrogen assimilation pathways investigated, in terms of surface functional group distribution, nitrate-reducing cultures were least sensitive, and ammonium-assimilating cultures were most sensitive, to changes in media silica concentration. When functional group distributions were plotted as a function of silica concentration, it appears that, with higher silica concentrations, basic groups (p Ka > 7) increase in concentration relative to acidic groups (p Ka < 7), and the total ligand densities (on a per-weight basis) decreased. The results imply a decrease in both the magnitude and density of surface charge as the net result of growth at high silica concentrations. Thus, Anabaena sp. appears to actively respond to growth in silicifying solutions by altering its surface properties in a manner that is likely to be manifested in nature by facilitated surface attachment. We conclude that potentiometric titrations reveal a Gram-negative bacterial surface whose properties are dynamic with respect to both nutrient and geochemical stressors.

  18. Chemical selectivity in micellar electrokinetic chromatography. II. Rationalization of elution patterns in different surfactant systems.

    PubMed

    Yang, S; Bumgarner, J G; Khaledi, M G

    1996-07-12

    Retention behavior in micellar electrokinetic chromatography (MEKC) is investigated using linear solvation energy relationships (LSERs) for two pseudo-stationary phases, one consisting of cationic micelles of tetradecyltrimethylammonium bromide (C14TAB) and the other of an anionic triblock copolymer, poly(methyl methacrylate-ethyl acrylate-methacrylic acid) (Elvacite 2669). It was found that solutes' migration behaviors in these two MEKC systems are mainly influenced by their size (V/100) and hydrogen bonding acceptor (HBA) strength (beta). However, solutes' hydrogen bonding donor (HBD) strength (alpha) has minor effects on their migration in MEKC. The characteristics of these two systems were compared to three other previously reported anionic micellar systems of sodium dodecyl sulfate (SDS) (anionic hydrocarbon), sodium cholate (SC) (anionic bile salt) and lithium perfluorooctane sulfonate (LiPFOS) (anionic fluorocarbon). It was concluded that hydrogen bonding interactions play a major role in providing different chemical selectivity among these five MEKC systems. Both C14TAB micelles and the ionic polymer of Elvacite 2669 provide hydrogen bonding acceptor (HBA) sites for solutes, which is similar to SC micelles. In fact, C14TAB is the strongest HBA, while Elvacite 2669 has HBA strength similar to that of SC micelles. On the other hand, the fluorocarbon micelles of LiPFOS are the strongest hydrogen bond donor (HBD) micelles, followed by the weak HBD SDS micelles. In general, cavity formation has little or no effect on chemical selectivity among hydrocarbon surfactant MEKC systems (i.e., SDS, SC and C14TAB). Information obtained from the LSER analysis is used to rationalize the elution patterns in MEKC with different types of pseudo-stationary phases. PMID:8696506

  19. 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.

  20. Chemical optimisation of a sol gel procedure for the development of fluorescence Cu(II) nanosensors

    NASA Astrophysics Data System (ADS)

    Arduini, Maria; Armelao, Lidia; Gross, Silvia; Mancin, Fabrizio; Marcuz, Silvia; Montolli, Mariachiara; Sada, Cinzia

    2007-06-01

    A template-assisted sol-gel procedure was developed and optimised for the preparation of silica thin films embedding the fluorescent dye 3-(dansylamido)-propyl-triethoxysilane (DNS-APTES) for Cu(II) sensing purposes. The different parameters involved (solution composition, nature of the template, deposition and annealing conditions, post-synthesis deposition of additional coatings, etc.) were independently changed in order to evaluate their effect on the final microstructure, composition and sensor performances of the films. The optimisation procedure encompassed also the choice of the suitable parameters to ensure stability of the sensing films and to avoid the leaching of the fluorescent dye. Films prepared by using the non-ionic surfactant F127, without an additional coating and with a post-deposition annealing at 100 C for 2 h, were proven to be the best performing ones, characterised by the largest and fastest fluorescence quenching. In particular, the presence of a template was demonstrated to play a major role in determining the efficiency of the sensing device. The surface and in-depth composition of thin films was analysed by X-Ray Photoelectron Spectroscopy (XPS) and Secondary Ion Mass Spectrometry (SIMS). The sensing performances of the films were tested by titration experiments with Cu 2+.

  1. 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.

  2. 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.

  3. 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

  4. Chemically bonded phosphate ceramics : II, warm-temperature process for alumina ceramics.

    SciTech Connect

    Wagh, A. S.; Grover, S.; Jeong, S. Y.; Energy Technology; Andrews Environmental Engineering, Inc.

    2003-11-01

    This is the second of three papers on a dissolution model that describes the formation of chemically bonded phosphate ceramics. In this paper, we discuss the kinetics of formation of aluminum phosphate ceramics between 100 and 150 C. Using basic thermodynamic formulations, we calculated the temperatures of maximum solubility of alumina and its hydrated phases and predicted the temperatures of formation of ceramics. Differential thermal and X-ray diffraction analyses on samples made in the laboratory confirm these temperatures. The resulting ceramics of alumina bonded with aluminum phosphate (berlinite) show a high compressive strength of 16 000 psi. We have concluded that rapid evaporation of excess water in the slurry generates porosity in the ceramics, and that better processing methods are needed. A consolidation model is presented that describes the microstructure of the ceramic. It predicts that a very small amount of alumina must be converted to form the bonding phase; hence, the product is mostly alumina with a thin coating of berlinite on the surface of alumina particles.

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

    NASA Astrophysics Data System (ADS)

    Nicolini, Paolo; Frezzato, Diego

    2013-06-01

    In the preceding paper of this series (Part I [P. Nicolini and D. Frezzato, J. Chem. Phys. 138, 234101 (2013)], 10.1063/1.4809592) 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)], 10.1063/1.479372 and the preliminary analysis of a simplified model mechanism of hydrogen combustion.

  6. 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.

  7. 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 [?/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.

  8. Fractionation of eleven elements by chemical bonding from airborne particulate matter collected in an industrial city in Argentina.

    PubMed

    Fujiwara, Fabin; Dos Santos, Marina; Marrero, Julieta; Polla, Griselda; Gmez, Daro; Dawidowski, Laura; Smichowski, Patricia

    2006-09-01

    A four-step chemical sequential extraction procedure was used to evaluate the distribution of Al, As, Cr, Cu, Fe, Mn, Ni, Pb, Ti, V and Zn in airborne particulate matter collected on glass fibre filters using a high-volume sampler. Two sets of samples were collected in 2001 (winter and summer campaigns) in representative zones of an industrial city of Argentina. The leaching scheme was applied to PM-10 particles and consisted in extracting the elements in four fractions, namely soluble and exchangeable elements; carbonates, oxides and reducible elements; bound to organic matter and sulfidic metals; and residual elements. Metals and metalloids at microg g(-1) level were determined in each fraction by inductively coupled plasma optical emission spectrometry (ICP OES). Analyte concentration varied from 14 microg g(-1) (equivalent to 1.0 ng m(-3)) for As to 11.8 mg g(-1) (equivalent to 2,089 ng m(-3)) for Al. Seven elements, namely Al, Cr, Fe, Mn, Pb, Ti and Zn showed similar distributions in both seasons while As was distributed in a significantly different manner in each season. The results exhibited low As contents in the first and second fractions that could be associated with routine coal combustion and a high content in the third and fourth fractions of the summer samples that could be linked to the use of pesticides. Aluminium, As, Cu, Mn, Ni, Ti, V and Zn were found in different percentages in the more bioavailable aqueous fraction with As, Mn, V and Zn exhibiting solubilities greater than 1% while Cr and Pb being insoluble. The content of Al, Cr, Cu, Fe, Ni, Pb, and Zn in the residual fraction was, in average, higher than 50%. A comparative assessment of the use of the underlying information available from fractionation studies compared to that obtained from total element content was done for Fe and Mn. It showed that the results obtained using chemical sequential extraction procedures allowed further discrimination of the potential air pollution sources. PMID:16951751

  9. 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 suggest that these clusters possibly originated in a gas-rich dwarf galaxy, which may or may not be presently observable in M31.

  10. Martian Surface Composition From Multiple Datasets, Part II: Chemical Analysis of Global Mineral Distributions from MGS-TES

    NASA Astrophysics Data System (ADS)

    Hamilton, V. E.; Rogers, D.

    2010-12-01

    Koeppen and Hamilton [2008, JGR-Planets] produced global mineral maps of Mars from Thermal Emission Spectrometer (TES) data using a library of mineral and amorphous phase spectra and a linear least squares fitting algorithm. Here we will use known or estimated bulk chemistries of the phases in the Koeppen and Hamilton [2008] spectral library, along with each phase's modeled abundance in the TES data from that work, to calculate effective bulk chemistry for Martian dark regions at a spatial resolution of ~3x6 km. By doing this, we are able to analyze global bulk chemical variation as well as enable direct comparisons between TES data and chemical/elemental abundance maps (e.g., wt.% SiO2) produced using data collected by the Gamma Ray Spectrometer. A second chemical analysis also makes use of the Koeppen and Hamilton [2008] global mineral maps and focuses on the spatial variations in solid solution chemistry among feldspars, pyroxenes, high silica phases (e.g., silica, phyllosilicates, zeolites), and sulfates. Koeppen and Hamilton [2008] demonstrated that there is a range of Mg-Fe olivine compositions on Mars and that there are distinct geographic distributions of those phases, pointing to spatial variations in geologic processes. We use the same methodology to search for correlations between geography (e.g., geologic unit, latitude), elevation, and chemical (solid solution) composition. Preliminary analyses of pyroxene chemical variation reveal that globally, low-Ca pyroxenes are dominated by the clinopyroxene pigeonite and that among orthopyroxenes, Mg-rich phases (enstatite) are virtually never identified and phases with greater proportions of Fe (bronzite and hypersthene) are identified in distinct geographic and/or geologic terrains. Only the distribution of hypersthene (the composition of pyroxene in the Martian meteorite ALH 84001) correlates with the OMEGA-mapped distribution of low-Ca pyroxene suggesting that OMEGA-based maps of high-Ca pyroxene may include pigeonite. Many of the chemical-spatial variations observed among solid solution phases in TES data correspond to both relative surface age and the distribution of lithologic units identified by Rogers and Christensen [2007, JGR-Planets], where the lithologic units were identified using a different analytical approach, giving us confidence in the variations observed in our mineral maps. These results point to variations in and/or the evolution of igneous compositions over time. Any observable variations in other phase groups (e.g., sulfates, phyllosilicates) may indicate variations in the timing and extent of aqueous or alteration processes over time.

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

    SciTech Connect

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

    1987-08-01

    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.

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

    PubMed

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

    1987-08-01

    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

  13. Animal wastes. II. Chemical and nutritional evaluation of by-products from rennet and proteases production.

    PubMed

    Moraes-Santos, T; Silva, M E

    1981-09-01

    Drum-dried calf stomach waste (DDSW) from rennet production, after washing with water for salt elimination, as well as drum-dried porcine pancreas waste (DDPW) from protease extraction were used. Their chemical composition and nutritional values were studied. The protein content of DDPW was two-thirds that of the DDSW sample. The amount of ashes (acid soluble and insoluble) in DDPW was twice that of DDSW. Four diets, the protein sources of which were casein, DDSW, DDPW and a mixture of equal parts of both by-products (MSPW) were then prepared. Their nutritive value was assessed in weanling rats through the following parameters: food ingestion, body weight gain, protein efficiency ratio (PER) and and apparent protein digestibility. The DDSW sample showed the lowest nutritional quality for all parameters measured. The weight gain of rats fed diets containing casein, DDPW, MSPW, and DDSW were, 59.60 +/- 8.12, 84.63 +/- 9.89, 56.22 +/- 6.74, and 20.08 +/- 3.72, respectively. The PER for the same diets were: 2.82 +/- 0.33, 2.67 +/- 0.19, 2.17 +/- 0.25, and 1.30 +/- 0.20, in the same order. The protein digestibility of all experimental diets was about 70%, and that of the control diets, about 90%. As a conclusion, the by-product of protease production from porcine pancreas seems adequate as a protein source for animal feeding, despite its high level of ashes. Also, this by-product appears to be useful for feeding purposes, when mixed with the other animal by-products studies. PMID:7344641

  14. Chemical decomposition of urinary stones during holmium-laser lithotripsy: II. Evidence for photothermal breakdown

    NASA Astrophysics Data System (ADS)

    Glickman, Randolph D.; Teichman, Joel M. H.; Vassar, George J.; Weintraub, Susan T.; Chan, Kin Foong; Pfefer, T. Joshua; Welch, Ashley J.

    1999-06-01

    Because of the greater than or equal to 250 microsecond pulsewidth emitted by the Ho:YAG laser used in clinical lithotripsy, it is unlikely that stress confinement occurs within the irradiated stones. Experimental data supports a thermal mechanism for Ho:YAG laser stone ablation. Stone fragmentation occurs soon after the onset of the laser pulse, is uncorrelated to cavitation bubble formation or collapse, and is associated with low pressures (cf. part I). The mass- loss of desiccated calcium oxalate monohydrate (COM) stones exposed to 150 J from the Ho:YAG laser in air was 40 plus or minus 12 mg (mean plus or minus 1 s.d.); for hydrated stones in air was 25 plus or minus 9 mg; and for hydrated stones in water was 17 plus or minus 3 mg, p less than .001. These differences indicate that direct absorption of the laser radiation by the stone is required for the most efficient ablation. Lowering the initial temperature of COM or cystine stones also reduced the stone mass-loss following 20 J of delivered laser energy: 2.2 plus or minus 1.1 mg vs 5.2 plus or minus 1.6 mg for COM stones (-80 vs 23 degrees Celsius), and 0.8 plus or minus 0.4 mg vs 2.2 plus or minus 1.1 mg for cystine stones (-80 vs 23 degrees Celsius), p less than or equal to .05. Finally, chemical analysis of the laser-induced stone fragments revealed the presence of thermal breakdown products: CaCO3 from COM; free sulfur and cysteine from cystine; Ca2O7P2 from calcium hydorgen phosphate dihydrate, and cyanide from uric acid.

  15. 78 FR 19312 - Agency Information Collection Activities; Proposed Collection; Comments Requested: Import/Export...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-29

    ...: Import/Export Declaration for List I and List II Chemicals, DEA Forms 486 and 486A ACTION: 60-Day Notice... currently approved collection to include online reporting. (2) Title of the Form/Collection: Import/Export...)........ Form 486--Export Return 25 311 0.0833 5 26 Declaration (Online) Form 486--Import (Facsimile).... 119...

  16. 78 FR 36580 - Agency Information Collection Activities; Proposed Collection; Comments Requested: Import/Export...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-18

    ...: Import/Export Declaration for List I and List II Chemicals; DEA Forms 486 and 486A ACTION: 30-Day Notice... previously published in the Federal Register at Volume 78 FR 19312, March 29, 2013, allowing for a 60 day...: Extension of a currently approved collection. (2) Title of the Form/Collection: Import/Export...

  17. 77 FR 62532 - Agency Information Collection Activities; Proposed Collection; Comments Requested: Import/Export...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-15

    ...: Import/Export Declaration for List I and List II Chemicals; DEA Forms 486 and 486A ACTION: 30-Day Notice...: Extension of a currently approved collection. (2) Title of the Form/Collection: Import/Export Declaration... time per Total in respondents responses response (hours) Form 486 (export) 273 9,155 0.283 hour...

  18. 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).

  19. Fine organic aerosols collected in a humid, rural location (Great Smoky Mountains, Tennessee, USA): Chemical and temporal characteristics

    NASA Astrophysics Data System (ADS)

    Yu, Liya E.; Shulman, Michelle L.; Kopperud, Royal; Hildemann, Lynn M.

    Fine organic aerosols collected at the Great Smoky Mountain National Park, Tennessee (USA) during 15 July -25 August 1995 as part of the Southeastern Aerosol and Visibility Study (SEAVS) were chemically characterized. The water-soluble organic species (WSOS) often dominated over the solvent-soluble organic species (SSOS) at this remote, humid sampling site, contributing 76-98% of the total identified organic mass in 17 out of the 21 daytime samples analyzed. Nighttime samples tended to have slightly larger concentrations of total SSOS than the daytime, with nocturnal/diurnal organic mass ratios greater than 1.0 in 7 out of the 10 paired samples. However, for total WSOS mass, the nocturnal-to-diurnal ratios were less than 0.3 in 7 out of the 10 paired samples, reflecting much more substantial depletion and/or less production of the more polar organics during nighttime. Based on identified species, the organic-mass-to-organic-carbon (OM-OC) ratios at the SEAVS site are estimated as 2.0, 2.2, and 1.3 for the daytime total organics, WSOS, and SSOS, respectively. For the nighttime samples, the OM-OC ratio for total identified organics is estimated to be 1.8, slightly lower than the daytime ratio due to the smaller mass fraction of WSOS present at night.

  20. Chemical and genetic studies on hybrid of Ligularia subspicata and Ligularia cyathiceps collected in Yunnan Province of China.

    PubMed

    Shimizu, Anna; Watanabe, Shizuka; Hanai, Ryo; Okamoto, Yasuko; Tori, Motoo; Gong, Xun; Kuroda, Chiaki

    2014-09-01

    Two morphologically ambiguous Ligularia samples (samples?A and B), and samples with morphology of Ligularia subspicata (sample?C), Ligularia lamarum (sample?D), or Ligularia cyathiceps (sample?E), were collected at Tianchi Pond, Shangrila County, Yunnan Province, China. Analysis of the nucleotide sequence of the internal transcribed spacers (ITSs) in the nuclear ribosomal RNA gene cluster indicated that not only sample?B but also sample?D was a hybrid of L. cyathiceps and L. lamarum/L. subspicata. Although the morphology of sample?A suggested that it was also a hybrid, the ITS sequence of sample?A was that of L. cyathiceps. Twenty compounds were isolated from the five samples, and the structures of two new compounds 7 and 14 were determined. Furanoeremophilanes typical of L. lamarum/L. subspicata were detected not only in samples C and D, but also in samples A and B. These results indicate that the ability to produce root chemicals can spread through introgression. PMID:25238084

  1. Summary of selected data on chemical contaminants in sediments collected during 1984, 1985, 1986, and 1987. Technical memo

    SciTech Connect

    Not Available

    1988-11-01

    Since 1984, the National Oceanic and Atmospheric Administration's (NOAA) National Status and Trends (NS T) Program has analyzed samples of surface sediment collected at about 200 coastal and estuarine sites throughout the United States. The chemical contaminants measured are chlorinated pesticides, polychlorinated biphenyls (PCSs), polyaromatic hydrocarbons (PAHs), and 12 trace elements. Sediment characteristics such as grain size, which affect contaminant concentrations, have also been quantified. With few exceptions, the higher levels of contamination have been found among the 175 sites where the sediment is muddy rather than sandy. Most of the highest concentrations for any particular contaminant have been at the 20 sites near Boston, New York, San Diego, Los Angeles, or Seattle. Despite being sandy, sediments at two Long Island Sound sites showed high levels of PAHs. Except for some sites near the Florida cities of Jacksonville, Tampa, Panama City, and Ft. Walton Beach, levels of contamination at sites in the Gulf of Mexico and in the southeastern United States were relatively low.

  2. 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.

  3. Optical detection/collection of toxic Cd(II) ions using cubic Ia3d aluminosilica mesocage sensors.

    PubMed

    El-Safty, Sherif A; Shenashen, Mohamed A; Khairy, Mohamed

    2012-08-30

    Optical sensors for selective removal and detection of extremely toxic ions such as cadmium (Cd(II)) in aquatic samples were successfully fabricated via simple strategy. Aluminosilica-based network platforms are used as selective mesopore shape and size carriers in order to fabricate optical sensors through the direct functionalization of ?, ?, ?, and ?-tetrakis(1-methylpyridinium-4-yl)porphine ?-toluenesulfonate (TMPyP) moieties without any prior surface modification using silane or thiol agents. In turn, the key advantage of a heretical three-dimensional (3D) cubic Ia3d mesocage is the facile access of target ions such as ion transports and the high affinity responses of TMPyP receptor-Cd(II) analyte binding events, which result in the easy generation and transduction of optical signals even at the trace level of the Cd(II) ion. The optical sensor design-based aluminosilica cages enable the sensitive detection and selective removal of Cd(II) ions even at ultra-trace concentrations of 10(-10)mol/dm(3) with rapid response time (in minutes). This rational strategy is crucial to the development of optical mesocollectors (i.e., probe surface-mounted naked-eye ion-sensor strips) with highly selective Cd(II) ion removal from aqueous water. These new classes of optical mesocollectors exhibit long-term stability and reusability of deleterious Cd(II) ions, which makes them efficient for various analytical applications. PMID:22939130

  4. 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.

  5. 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

  6. 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...

  7. The GLAS editing procedures for the FGGE level II-B data collected during SOP-1 and 2

    NASA Technical Reports Server (NTRS)

    Baker, W.; Edelmann, D.; Carus, H.

    1981-01-01

    The modifications made to the FGGE Level II-b data are discussed and the FORTRAN program developed to perform the modifications is described. It is suggested that the edited database is the most accurate one available for FGGE SOP-1 and 2.

  8. 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

  9. The electronic structure of the adducts of nickel(II) and cobalt(II) acetylacetonate with 2,2?-dipyridyl by the method of quantum chemical modeling

    NASA Astrophysics Data System (ADS)

    Komissarov, A. A.; Korochentsev, V. V.; Vovna, V. I.

    2016-02-01

    The electronic structure of the nickel(II) and cobalt(II) bis-acetylacetonate with the additional 2,2?-dipyridyl ligand is investigated using density functional theory calculations and X-ray photoelectron spectroscopy. Additional ligand effect on geometry, charges, electronic structure and X-ray photoelectron spectrum is studied. Our calculations show that the electron-donating ability of the 2,2?-dipyridyl ligand is low. The computed data is compared with experimental data.

  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. Discovery of kibdelomycin, a potent new class of bacterial type II topoisomerase inhibitor by chemical-genetic profiling in Staphylococcus aureus.

    PubMed

    Phillips, John W; Goetz, Michael A; Smith, Scott K; Zink, Deborah L; Polishook, Jon; Onishi, Russell; Salowe, Scott; Wiltsie, Judyann; Allocco, John; Sigmund, Janet; Dorso, Karen; Lee, Suzy; Skwish, Stephen; de la Cruz, Mercedes; Martn, Jess; Vicente, Francisca; Genilloud, Olga; Lu, Jun; Painter, Ronald E; Young, Katherine; Overbye, Karen; Donald, Robert G K; Singh, Sheo B

    2011-08-26

    Bacterial resistance to known therapeutics has led to an urgent need for new chemical classes of antibacterial agents. To address this we have applieda Staphylococcus aureus fitness test strategy to natural products screening. Here we report the discovery of kibdelomycin, a novel class of antibiotics produced by a new member of the genus Kibdelosporangium. Kibdelomycin exhibits broad-spectrum, gram-positive antibacterial activity and is a potent inhibitor of DNA synthesis. We demonstrate through chemical genetic fitness test profiling and biochemical enzyme assays that kibdelomycin is a structurally new class of bacterial type II topoisomerase inhibitor preferentially inhibiting the ATPase activity of DNA gyrase and topoisomerase IV. Kibdelomycin is thus the first truly novel bacterial type II topoisomerase inhibitor with potent antibacterial activity discovered from natural product sources in more than six decades. PMID:21867911

  12. 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.

  13. 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.

  14. 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...

  15. 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

    ...The Institute of Museum and Library Services (IMLS), as part of its continuing effort to reduce paperwork and respondent burden, conducts a pre-clearance consultation program to provide the general public and federal agencies with an opportunity to comment on proposed and/or continuing collections of information in accordance with the Paperwork Reduction Act (44 U.S.C. Chapter 35). This......

  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, Bjrn 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. 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 ...

  18. Manganese (II) induces chemical hypoxia by inhibiting HIF-prolyl hydroxylase: Implication in manganese-induced pulmonary inflammation

    SciTech Connect

    Han, Jeongoh; Lee, Jong-Suk; Choi, Daekyu; Lee, Youna; Hong, Sungchae; Choi, Jungyun; Han, Songyi; Ko, Yujin; Kim, Jung-Ae; Mi Kim, Young; Jung, Yunjin

    2009-03-15

    Manganese (II), a transition metal, causes pulmonary inflammation upon environmental or occupational inhalation in excess. We investigated a potential molecular mechanism underlying manganese-induced pulmonary inflammation. Manganese (II) delayed HIF-1{alpha} protein disappearance, which occurred by inhibiting HIF-prolyl hydroxylase (HPH), the key enzyme for HIF-1{alpha} hydroxylation and subsequent von Hippel-Lindau(VHL)-dependent HIF-1{alpha} degradation. HPH inhibition by manganese (II) was neutralized significantly by elevated dose of iron. Consistent with this, the induction of cellular HIF-1{alpha} protein by manganese (II) was abolished by pretreatment with iron. Manganese (II) induced the HIF-1 target gene involved in pulmonary inflammation, vascular endothelial growth factor (VEGF), in lung carcinoma cell lines. The induction of VEGF was dependent on HIF-1. Manganese-induced VEGF promoted tube formation of HUVEC. Taken together, these data suggest that HIF-1 may be a potential mediator of manganese-induced pulmonary inflammation.

  19. 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)

  20. 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.

  1. 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* and b* values quantified the perceived deep brown colored state. PMID:23748903

  2. Copper(II) complexes with 2NO and 3N donor ligands: synthesis, structures and chemical nuclease and anticancer activities.

    PubMed

    Rajarajeswari, Chandrasekaran; Loganathan, Rangasamy; Palaniandavar, Mallayan; Suresh, Eringathodi; Riyasdeen, Anvarbatcha; Akbarsha, Mohamad Abdulkadhar

    2013-06-21

    A series of water soluble copper(II) complexes of the types [Cu(L)Cl] 1-2, where LH is 2-(2-(1H-benzimidazol-2-yl)ethyliminomethyl)phenol (H(L1)), and 2-(2-(1H-benzimidazol-2-yl)-ethyliminomethyl)-4-methylphenol (H(L2)), and [Cu(L)Cl2] 3-6, where L is (2-pyridin-2-yl-ethyl)pyridin-2-ylmethyleneamine (L3), 2-(1H-benzimidazol-2-yl)ethylpyridin-2-yl-methyleneamine (L4), 2-(1H-benzimidazol-2-yl)ethyl(1H-imidazol-2-ylmethylene)amine (L5), and 2-(1H-benzimidazol-2-yl)ethyl-(4,4a-dihydroquinolin-2-ylmethylene)amine (L6), have been isolated and characterized by elemental analysis, electronic absorption, ESI-MS and EPR spectral techniques and the electrochemical method. The single crystal X-ray structures of [Cu(L1)Cl] 1 and [Cu(L2)Cl] 2 possess a distorted square-based coordination geometry while [Cu(L4)Cl2] 4 and [Cu(L6)Cl2] 6 possess a distorted trigonal bipyramidal coordination geometry. Both absorption spectral titration and an EthBr displacement assay reveal that all the complexes bind with calf thymus (CT) DNA through covalent mode of DNA interaction involving the replacement of an easily removable chloride ion with DNA nucleobases. All the complexes exhibit oxidative cleavage of supercoiled (SC) plasmid DNA in the presence of hydrogen peroxide as an activator. It is remarkable that at 50 ?M concentration 5 and 6 completely degrade SC DNA into undetectable minor fragments and thus they act as efficient chemical nucleases. All the complexes are remarkable in displaying cytotoxicity against the HBL-100 human breast cancer cell line with potency more than that of the widely used drug cisplatin and hence they have the potential to act as promising anticancer drugs. Interestingly, they are non-toxic to normal cell lymphocytes isolated from human blood samples, revealing that they are selective in killing only the cancer cells. PMID:23612925

  3. The Chloroplast Function Database II: a comprehensive collection of homozygous mutants and their phenotypic/genotypic traits for nuclear-encoded chloroplast proteins.

    PubMed

    Myouga, Fumiyoshi; Akiyama, Kenji; Tomonaga, Yumi; Kato, Aya; Sato, Yuka; Kobayashi, Megumi; Nagata, Noriko; Sakurai, Tetsuya; Shinozaki, Kazuo

    2013-02-01

    The Chloroplast Function Database has so far offered phenotype information on mutants of the nuclear-encoded chloroplast proteins in Arabidopsis that pertains to >200 phenotypic data sets that were obtained from 1,722 transposon- or T-DNA-tagged lines. Here, we present the development of the second version of the database, which is named the Chloroplast Function Database II and was redesigned to increase the number of mutant characters and new user-friendly tools for data mining and integration. The upgraded database offers information on genome-wide mutant screens for any visible phenotype against 2,495 tagged lines to create a comprehensive homozygous mutant collection. The collection consists of 147 lines with seedling phenotypes and 185 lines for which we could not obtain homozygotes, as well as 1,740 homozygotes with wild-type phenotypes. Besides providing basic information about primer lists that were used for the PCR genotyping of T-DNA-tagged lines and explanations about the preparation of homozygous mutants and phenotype screening, the database includes access to a link between the gene locus and existing publicly available databases. This gives users access to a combined pool of data, enabling them to gain valuable insights into biological processes. In addition, high-resolution images of plastid morphologies of mutants with seedling-specific chloroplast defects as observed with transmission electron microscopy (TEM) are available in the current database. This database is used to compare the phenotypes of visually identifiable mutants with their plastid ultrastructures and to evaluate their potential significance from characteristic patterns of plastid morphology in vivo. Thus, the Chloroplast Function Database II is a useful and comprehensive information resource that can help researchers to connect individual Arabidopsis genes to plastid functions on the basis of phenotype analysis of our tagged mutant collection. It can be freely accessed at http://rarge.psc.riken.jp/chloroplast/. PMID:23230006

  4. NEW YORK CITY BUS TERMINAL DIESEL EMISSIONS STUDY: MEASUREMENT AND COLLECTION OF DIESEL EXHAUST FOR CHEMICAL CHARACTERIZATION AND MUTAGENIC ACTIVITY

    EPA Science Inventory

    The paper is concerned with the impact of diesel emissions on the quality of the ambient air and the resulting effects on human health. The study was designed to chemically characterize and bioassay heavy-duty diesel engine exhaust as it exists in the ambient atmosphere. Diesel e...

  5. World Endometriosis Research Foundation Endometriosis Phenome and biobanking harmonization project: II. Clinical and covariate phenotype data collection in endometriosis research

    PubMed Central

    Vitonis, Allison F.; Vincent, Katy; Rahmioglu, Nilufer; Fassbender, Amelie; Buck Louis, Germaine M.; Hummelshoj, Lone; Giudice, Linda C.; Stratton, Pamela; Adamson, G. David; Becker, Christian M.; Zondervan, Krina T.; Missmer, Stacey A.

    2014-01-01

    Objective To harmonize the collection of nonsurgical clinical and epidemiologic data relevant to endometriosis research, allowing large-scale collaboration. Design An international collaboration involving 34 clinical/academic centers and three industry collaborators from 16 countries on five continents. Setting In 2013, two workshops followed by global consultation, bringing together 54 leaders in endometriosis research. Patients None. Intervention(s) Development of a self-administered endometriosis patient questionnaire (EPQ), based on [1] systematic comparison of questionnaires from eight centers that collect data from endometriosis cases (and controls/comparison women) on a medium to large scale (publication on >100 cases); [2] literature evidence; and [3] several global consultation rounds. Main Outcome Measure(s) Standard recommended and minimum required questionnaires to capture detailed clinical and covariate data. Result(s) The standard recommended (EPHect EPQ-S) and minimum required (EPHect EPQ-M) questionnaires contain questions on pelvic pain, subfertility and menstrual/reproductive history, hormone/medication use, medical history, and personal information. Conclusion(s) The EPQ captures the basic set of patient characteristics and exposures considered by the WERF EPHect Working Group to be most critical for the advancement of endometriosis research, but is also relevant to other female conditions with similar risk factors and/or symptomatology. The instruments will be reviewed based on feedback from investigators, and–after a first review after 1 year–triannually through systematic follow-up surveys. Updated versions will be made available through http://endometriosisfoundation.org/ephect. PMID:25256930

  6. (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.

  7. Adsorption of aqueous Cd(II) and Pb(II) on activated carbon nanopores prepared by chemical activation of doum palm shell.

    PubMed

    Gaya, Umar Ibrahim; Otene, Emmanuel; Abdullah, Abdul Halim

    2015-01-01

    Non-uniformly sized activated carbons were derived from doum palm shell, a new precursor, by carbonization in air and activation using KOH, NaOH and ZnCl2. The activated carbon fibres were characterised by X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, particle size analysis and evaluated for Cd(II) and Pb(II) removal. The 40-50nm size, less graphitic, mesoporous NaOH activated carbon yielded high adsorption efficiency, pointing largely to the influence surface area. The performance of the KOH based activated carbon was arguably explained for the first time in terms of crystallinity. The efficiencies of the mesoporous ZnCl2-formulated activated carbon diminished due to the presence of larger particles. Batch adsorption of divalent metals revealed dependence on adsorbent dose, agitation time, pH and adsorbate concentrations with high adsorption efficiencies at optimum operating parameters. The equilibrium profiles fitted Langmuir and Freundlich isotherms, and kinetics favoured pseudo-second order model. The study demonstrated the practicability of the removal of alarming levels of cadmium and lead ions from industrial effluents. PMID:26339560

  8. 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.

  9. 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.; Patio, 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 compounds (chlordanes, polychlorinated biphenyls [PCBs], brominated diphenyl ethers [BDEs], and triclosans) were analyzed from extracts of whole-body tissue using gas chromatography/mass spectrometry in male common carp from Las Vegas Bay during May 1999 through May 2000. All 33 compounds were detected in at least one sample of whole-body tissue from male common carp collected in Las Vegas Bay. In Overton Arm, 37 organic compounds plus total concentrations of three groups of compounds (PCBs, BDEs, and triclosans) were analyzed in male common carp where 20 (54 percent) of the compounds were detected. Sixteen of the 33 compounds detected in male common carp from Las Vegas Bay and 10 compounds detected in males from Overton Arm have the potential to disrupt the endocrine system in fish in Lake Mead. During May and June 1999, the mean concentration of all organic compounds detected in male common carp was 670 micrograms per kilogram from Las Vegas Bay and 109 micrograms per kilogram from Overton Arm. Twenty-seven organic compounds plus total PCBs were analyzed from extracts of whole-body tissue in female common carp collected in Las Vegas Bay and Overton Arm during May 1999. Twenty-four (86 percent) of these compounds were detected in at least one sample of whole-body tissue from female common carp collected from Las Vegas Bay while 10 (36 percent) chemical compounds were detected in female common carp from Overton Arm during that same period. Median concentrations of all chemical compounds were higher in female common carp from Las Vegas Bay compared to those collected from Overton Arm except Dacthal (DCPA), which was similar between sites. Biomarker measures obtained for male and female common carp include gonadosomatic index (percentage of gonad weight to total body weight), plasma vitellogenin (a phospholipid protein normally produced by female common carp and other oviparous fish), and condition factor [body weight/(fork length)3]. Biomarker measures for male c

  10. Chemical, biochemical, and environmental fiber sensors II; Proceedings of the Meeting, San Jose, CA, Sept. 19-21, 1990

    NASA Astrophysics Data System (ADS)

    Lieberman, Robert A.; Wlodarczyk, Marek T.

    The present conference on chemical, biochemical, and environmental fiber sensors encompasses novel sensing methods, luminescence-based fiber sensors, chemical aspects of fiber sensing, planar waveguide sensors, signal-processing techniques, the use of remote spectroscopic sensors, optrode research, and distributed chemical sensing. Specific issues addressed include intrinsic fiber-optic chemical sensing, hollow waveguides for sensor applications, an automated fiber-optic moisture-sensor system, a model of a thin-film optical fiber fluorosensor, the evaluation of polymeric thin-film waveguides as chemical sensors, and the feasibility of optically sensing two parameters simultaneously using one indicator. Also addressed are planar waveguide optical immunosensors, process monitoring and control in fiber optics, in-soil organic contaminant sensors, and a field demonstration of a fiber-optic trichloroethylene sensor.

  11. 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

  12. Effects of angiotensin II, atrial natriuretic peptide and endothelin-1 on proliferation and steroidogenic output of bovine granulosa cells cultured in a chemically defined system.

    PubMed

    Montrezor, L H; Piccinato, C A; Collares, C V A; Vireque, A A; Silva, A A M Rosa E

    2015-01-01

    The role of local factors in the modulation of granulosa cell (GC) proliferation and differentiation is well described in the literature. The present work used a long-term bovine GC culture, in chemically defined medium without gonadotropins, to study the effects of angiotensin II (Ang II), atrial natriuretic peptide (ANP) and endothelin-1 (EDN1) on the steroidogenesis and cellular proliferation. Small follicles (3-5mm in diameter) from ovaries obtained in the slaughterhouse were selected according to their vascularization and follicular fluid color in order to isolate GC. Granulosa cells were plated at a density of 5×10(4)cells/well in supplemented alpha-MEM containing 3 levels (0, 10(-8)M and 10(-7)M) of Ang II, ANP, and EDN1 for up to 96h. Proliferation was evaluated by tritiated thymidine incorporation. The results showed that Ang II, ANP, and EDN1 modulate the steroidogenic output and proliferation index of GCs depending on the dose and time of culture. The selected vasoactive peptides increased androstenedione (A4) consumption in parallel with increased estradiol (E2). Although the peptides also promoted a significant increase in pregnenolone (P5) and progesterone (P4) production, the E2:P4 ratio was maintained at a high at most of the tested doses. Taken together, our in vitro data suggest that these vasoactive factors may have a direct effect on physiological follicular deviation, favoring dominance of the selected follicle. PMID:25500175

  13. 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-mail: tlbosler@yahoo.com

  14. 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.

  15. 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.

  16. 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 homogeneous organic material without identifiable cores.

  17. 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 ?log(O/H)/?RG = -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 galaxies. Full Tables 2 and 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://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/521/A3

  18. 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, Fbio Andrei; Bizzi, Cezar Augusto; Antes, Fabiane Goldschmidt; Dressler, Valderi Luiz; Flores, rico 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.

  19. Silica, Hybrid Silica, Hydride Silica and Non-Silica Stationary Phases for Liquid Chromatography. Part II: Chemical and Thermal Stability.

    PubMed

    Borges, Endler M; Volmer, Dietrich A

    2015-08-01

    In the first part of this review, stationary phases (silica, hybrid silica, hydride silica and non-silica stationary phases) were characterized and compared with respect to selectivity, efficiency, resolution, solvent consumption and analysis time. The present review focuses on the thermal and chemical stability of stationary phases. Stationary phases of high chemical and thermal stability are required for separations that are carried over a wide pH and/or temperature range. PMID:25609601

  20. Solid phase extraction and preconcentration of Cu(II), Pb(II), and Ni(II) in environmental samples on chemically modified Amberlite XAD-4 with a proper Schiff base.

    PubMed

    Topuz, Berrin; Macit, Mustafa

    2011-02-01

    A new chelating resin, Amberlite XAD-4 loaded with N,N-bis(salicylidene)cyclohexanediamine (SCHD), was synthesized and characterized. The resin Amberlite XAD-4-SCHD was used for selective separation, preconcentration, and determination of Cu(II), Pb(II), and Ni(II) ions in water samples by flame atomic absorption spectrometry (FAAS). Effects of pH, concentration, and volume of elution solution; flow rate of elution; and sample solution, sample volume, and interfering ions for the recovery of the analytes were investigated. These metal ions can be desorbed with 0.5-M HNO3 (recovery, 98%-101%). The sorption capacity was found between 1.3810(-1) and 3.5810(-1) mmol/g. In order to evaluate the accuracy of the proposed procedure, the certified reference materials, BCR-032 (Moroccan phosphate rock) and BCR-715 (industrial effluent wastewater), were analyzed. The detection limits of the method were found to be 0.11, 1.91, and 0.43 ?g/L for Cu(II), Pb(II), and Ni(II), respectively. The method was applied to the extraction and the recovery of copper, lead, and nickel in wastewater and other water samples. PMID:20237836

  1. 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.

  2. Chemical studies of Chinese licorice-roots. I. Elucidation of five new flavonoid constituents from the roots of Glycyrrhiza glabra L. collected in Xinjiang.

    PubMed

    Kitagawa, I; Chen, W Z; Hori, K; Harada, E; Yasuda, N; Yoshikawa, M; Ren, J

    1994-05-01

    From the air-dried roots of Glycyrrhiza glabra L. (Leguminosae) collected in Xinjiang province, China ("Shinkyo-Kanzo" in Japanese), five new flavonoid compounds named glucoliquiritin apioside (1) (a flavonone bisdesmoside), prenyllicoflavone A (5) (a bisprenylflavone), shinflavone (7) (a prenylated pyranoflavanone), shinpterocarpin (9) and 1-methoxyphaseollin (12) (both pyranopterocarpans), were isolated together with eight known saponins, seven known flavonoid glycosides, and eleven flavonoids. The structures of the new compounds have been elucidated on the basis of their chemical and physicochemical properties. PMID:8069956

  3. Wear Mechanisms of Carbon-Based Refractory Materials in SiMn Tap-HolesPart 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.

  4. Chromosome aberration and sister chromatid exchange tests in Chinese hamster ovary cells in vitro: II. Results with 20 chemicals

    SciTech Connect

    Loveday, K.S.; Lugo, M.H. ); Resnick, M.A.; Anderson, B.E.; Zeiger, E. )

    1989-01-01

    Twenty chemicals were tested for their ability to induce sister chromatid exchanges (SCEs) and chromosomal aberrations (ABs) in cultured Chinese hamster ovary cells (CHO). These chemicals were tested with and without an added metabolic activation system (rat liver S9 fraction). Four chemicals were negative in both assays, 1 induced ABs only, and 15 were positive for SCEs; 6 of these 15 also induced ABs. The effect of cell harvest time on the ability to detect the induction of chromosomal aberrations was examined for six chemicals. Five of these had caused at least one of the following cell cycle delay, aberrations observed in first division metaphase cells in SCE assay, or a weak response in the standard AB assay (10-12-hr growth period). Three chemicals, chlorinated trisodium phosphate, 1,2-dibromo-3-chloropropane, and tetrakis(hydroxymethyl)phosphonium chloride, were positive using both the standard and extended harvest times. N-Nitrosodimethylamine and diphenhydramine HCl were only positive using an extended harvest time, and malonaldehyde was negative using both standard and extended harvest times.

  5. 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)

  6. 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.

  7. Highly sensitive sensing of zinc(II) by development and characterization of a PVC-based fluorescent chemical sensor

    NASA Astrophysics Data System (ADS)

    Aksuner, Nur; Henden, Emur; Yenigul, Berrin; Yilmaz, Ibrahim; Cukurovali, Alaaddin

    2011-03-01

    A sensor membrane with excellent performance based on 1-methyl-1-phenyl-3-[1-hydroxyimino-2-(succinimido)ethyl]cyclobutane has been developed for the determination of zinc(II) ions. The sensing membrane is capable of determining zinc(II) with an outstanding high selectivity over a dynamic range between 8.0 10 -8 and 1.6 10 -4 mol L -1 with a limit of detection of 2.5 10 -8 mol L -1 (1.6 ?g L -1). It can be easily and completely regenerated by using 0.1 mol L -1 EDTA solution. The optical sensor developed here was found to be stable, cost effective, easy to prepare, and has unique selectivity towards Zn 2+ ion with respect to common metal ions. The proposed sensor was then applied for the determination of zinc in tap water and hair samples with satisfactory results.

  8. Soft chemicals synthesis of a high-pressure phase of molybdenum trioxide: MoO{sub 3}-II

    SciTech Connect

    Baker, B.; Feist, T.P.; McCarron, E.M.

    1995-10-01

    Topotactic dehydration of either the white molybdenum trioxide monohydrate, MoO{sub 3}{center_dot}H{sub 2}O, or the hemihydrate MoO{sub 3}{center_dot}{1/2}H{sub 2}O, provides a convenient synthetic route to a high-pressure phase of molybdenum trioxide, MoO{sub 3-}II. The structural filiations between the various molybdenum trioxide hydrates phases are delineated, and simple mechanistic models for the transformations are proposed.

  9. 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.

  10. The Characteristics of Chemical Constituents of Rain Water Collected by the Sequential Constant Volumetric Sampling Method in an Urban Area

    NASA Astrophysics Data System (ADS)

    Kobayashi, Ken; Yamashita, Eiji; Hiraki, Takatoshi; Ishida, Hiroshi

    In order to unveil the chemical characteristics of rain water from 1 to 8 mm, rain water measurements were conducted in downtown Okayama for one year from March, 2004 to March 2005. Analytical parameters were pH, EC and the ion concentrations, F-, Cl-, NO2-, NO3-, SO42-, PO43-, Na+, NH4+, K+, Mg2+ and Ca2+. The mean pH and EC values of the precipitations from 1 to 4 mm, which would be affected largely by the washout effect in the observational area, were 4.46 and 32.7?S/cm, respectively. And, the mean ion concentrations of NO3- and nss-SO42-, which were main acid rain constituents, were 1.1mg/l and 0.9 mg/l, respectively. The mean pH and EC values of the precipitations from 5 to 8 mm, which would be affected largely by the rainout effect, were 4.60 and 20.4?S/cm, respectively. The mean ion concentrations of NO3- and nss-SO42- were 1.6mg/l and 1.4mg/l, respectively. The air mass back trajectory analysis was conducted for 5 days until the day of the rain event. The analyzed trajectories were classified into 4 typical routes advected from the Eurasian Continent, the central part of the North Pacific Ocean, Southeast Asia and the East Asian coast. And, the different chemical characteristics depending on the route were recognized. In the case of the Southeast Asia route, the ion concentrations of NO3- and nss-SO42- were highest, 2.4mg/l and 2.1mg/l, respectively. Then, in the case of the Eurasian Continent route, the concentrations were 1.5mg/l and 1.5mg/l. In the case of the East Asian coast route, the concentrations were 1.3mg/l and 1.1mg/l. In the case of the central part of the Pacific Ocean route, the concentrations were lowest, 0.7mg/l and 1.1mg/l, respectively.

  11. 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 inactive compounds at the accuracies of 76.1% and 82.8% with a total accuracy of 81.6% on the internal test set and 70.8% on the external test set. These results demonstrate that a combination of high-quality experimental data and ML methods can lead to robust models that achieve excellent predictive accuracy, which are potentially useful for facilitating the virtual screening of chemicals for environmental risk assessment. PMID:24279462

  12. 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 the 20 pharmaceuticals (research method 8244) analyzed were detected at concentrations ranging from 2.35 to 453.5 nanograms per gram. Six of the 11 antidepressants (research method 9008) analyzed were detected at concentrations ranging from 2.79 to 91.6 nanograms per gram.

  13. Chemical composition of precipitation and watershed samples collected at Deep Creek Lake, Garrett County, Maryland. Final report

    SciTech Connect

    Campbell, S.

    1985-10-01

    The objective of the four-year study was to determine if acid deposition and acid stream drainage pose a significant threat to Deep Creek Lake, Maryland. The chemical composition of rain in the fourth year did not vary significantly from previous years. The annual volume-weighted mean pH of rain at the site is 3.9 - 4.0. Concentrations of hydrogen and sulfate ions are higher in summer rain, particularly for storms characterized by northwesterly winds. Summertime rain produces about 60 percent of the annual sulfate and hydrogen ion deposition at the site. The average lake water pH has remained stable during the four-year study. Acid input from Cherry Creek, impacted by geological acids, was about equal to the acid deposited directly on the lake surface by rain. During most of the year neutralization of geologic acid drainage by the bottom sediments of Cherry Creek Cove is rapid. A USGS investigation of the geology in the area found extensive alkaline rock outcroppings in the basin and underlaying the lake. It appears that concerns about rapid acidification of the lake are not well founded.

  14. Chemical characterization of ambient aerosol collected during the southwest monsoon and intermonsoon seasons over the Arabian Sea: Anions and cations

    NASA Astrophysics Data System (ADS)

    Johansen, Anne M.; Siefert, Ronald L.; Hoffmann, Michael R.

    1999-11-01

    Ambient aerosol samples were collected over the northern Indian Ocean during two 1 month-long research cruises (German R/V Meteor) that took place during the intermonsoon (May) and SW monsoon (July/August) of 1995. A high volume and two small volume collectors were used to collect samples, which were subsequently analyzed for ferrous iron, 32 elements, and anions and cations. The present paper focuses on the bulk aerosol material, the ions, while utilizing some of the trace metal data that were presented in more detail in our previous paper [Siefert et al., 1999]. Data are analyzed and interpreted with the aid of principal component and multiple linear regression analyses. Intermonsoon samples were strongly influenced by continental material, both of crustal and anthropogenic origin. The crustal component (24.513% of the total suspended particulate mass (TSP), 6.04.4 ?g m-3) contained 3.2% gypsum (CaSO4). While more than half of the TSP (21.29.6 ?g m-3) during the SW monsoon was sea-salt-derived due to the strong winds prevailing during this season, only 1.71.1% (0.70.4 ?g m-3) was found to be of crustal origin. Sulfate (SO42-) sources were determined and quantified with linear regression analyses utilizing specific tracers for the independent variables. Lead (Pb) was found to be a more reliable surrogate for anthropogenic SO42- compared to nitrate (NO3-) during the relatively polluted intermonsoon. Soluble calcium (Ca2+) served as the tracer for gypsum, and methane sulfonate (MSA) served as the tracer for biogenically derived SO42- during both seasons. On the basis of this analysis, 75% of the non-sea-salt sulfate (NSS-SO42-) (0.80.2 ?g m-3, representing 2.4% of TSP) was found to be of biogenic origin during the SW monsoon with the remaining 25% of anthropogenic origin. During the intermonsoon, NSS-SO42- accounted for 2.11.2 ?g m-3 (9.2% of TSP) and had a composition that was 65% anthropogenic, 21% biogenic, and 14% gypsum-derived. Linear regression analyses revealed that the bio-SO42-/MSA weight ratios appear to be consistent with the temperature dependence proposed by Hynes et al. [1986]. In this case the yield of SO42- increased relative to MSA with an increase in temperature. Three samples during the SW monsoon, near the coast of Oman, showed lower temperatures, due to coastal upwelling, than the rest of the samples; at 24C the bio-SO42-/MSA weight ratio was 6.80.5. The remainder of the SW monsoon samples were collected at an average temperature of 27.2C, for which the bio-SO42-/MSA weight ratio was 13.54.4. At an average temperature of 28.9C during the intermonsoon, sampling gave a ratio of 17.74.8. These observations indicate a temperature dependence factor between 24 and 29C of 2.2 (i.e., a 2.2 increase in the ratio of bio-SO42-/MSA with every degree temperature increase). Cl- deficits determined during both seasons appear to indicate that different mechanisms may govern the observed depletion of Cl- in each season.

  15. 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

  16. 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...

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

    EPA Science Inventory

    The U.S. EPAs 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...

  18. 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…

  19. 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.

  20. 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

  1. 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.

  2. Chemical and biological properties of diesel exhaust particles collected during selected segments of a simulated driving cycle

    SciTech Connect

    Bechtold, W.E.; Dutcher, J.S.; Mokler, B.V.; Lopez, J.A.; Wolf, I.; Li, A.P.; Henderson, T.R.; McClellan, R.O.

    1984-06-01

    Particle emissions, percentage of organic extractable materials, and mutagenicities of extracts from a diesel engine operating on a test stand have been determined for the full Federal Test Procedure driving cycle and several individual segments thereof. Particle samples were collected using a computer controlled high volume sampler. Extracts of the exhaust particles were screened for the potent mutagens nitropyrene/nitrofluoranthenes by mass spectrometry/mass spectrometry (MS/MS). Results indicate that a long acceleration from 0-55 mph produced approximately seven times more particles per second than the full cycle. Also, the 0- to 55-mph acceleration and a subsequent 55-mph cruise produced significantly higher amounts of mutagens than other segments or the full FTP cycle. A direct correlation of both NOx levels and temperature with mutagenicity was noted (r . 0.89 and r . 0.89). The specific activities of the extracts showed decreases or remained unchanged when assayed in TA-98 NR or TA-98 1,8 DNP6, nitroreductase deficient strains of TA-98. Three extracts were found to have high levels of nitropyrenes/nitrofluoranthenes, and two of the three had high specific activities in TA-98.

  3. 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.

  4. Topoisomerase II DNA cleavage stimulation, DNA binding activity, cytotoxicity, and physico-chemical properties of 2-aza- and 2-aza-oxide-anthracenedione derivatives.

    PubMed

    De Isabella, P; Palumbo, M; Sissi, C; Capranico, G; Carenini, N; Menta, E; Oliva, A; Spinelli, S; Krapcho, A P; Giuliani, F C

    1995-07-01

    The cytotoxic activity of mitoxantrone and related anthracenediones has been ascribed to the ability of these compounds to interfere with DNA topoisomerase II function, resulting in DNA cleavage stimulation. The molecular details of enzyme inhibition by these intercalating agents remain to be defined. In an attempt to identify the structural determinants for optimal activity, the molecular and cellular effects of a series of heteroanalogues bearing different side-chains were examined in relation to the physico-chemical and DNA binding properties of these compounds. The results indicated that substitution of a pyridine ring for the dihydroxyphenylene ring in the planar chromophore caused a marked reduction of cytotoxic activity and of the ability to stimulate topoisomerase II-mediated DNA damage in intact cells and with simian virus 40 DNA in vitro. Although all tested derivatives were shown to intercalate into DNA, their DNA binding affinities were appreciably lower than that of mitoxantrone. The behavior of 2-aza derivatives more closely resembled that of ametantrone, suggesting that the potency of agents of this class is influenced more by the presence of hydroxyl groups than by the phenylene ring. The observation that a dramatic reduction (or loss) of the ability of aza derivatives to stimulate DNA cleavage is associated with a marked reduction of cytotoxic potency supports a primary role of topoisomerase II-mediated effects in the mechanism of action of the effective agents of this class. Because appreciable cytotoxic activity and significant in vivo antitumor efficacy are retained by compounds inactive (or poorly active) in inhibition of topoisomerase II, these results are consistent with multiple effects of anthracenediones at the cellular level. PMID:7623772

  5. Response of a grassland ecosystem to air pollutants: II--The chemical climate: Fluxes of sedimenting airborne matter.

    PubMed

    Dmmgen, U; Grnhage, L; Ksters, A; Jger, H J

    1994-01-01

    Measurement of the deposition of sedimenting particles requires a sampling device, which avoids simultaneous deposition of gases and aerosols to the collection surface. A sampler constructed for the purpose of collecting rain and sedimenting particles is described and characterized in detail, in particular with regard to its collection efficiency for rain. Its collection properties for gases and aerosols are shown to be negligible. From two years of sampling at different heights it was found that resuspension of particles and co-condensation of gases near the plant canopy may lead to a major overestimation of bulk deposition. As a consequence, the extension towards the canopy of the constant flux layer for sedimenting particles has to be determined experimentally. Bulk deposition of sodium, potassium, magnesium, calcium, lead, copper, cadmium, manganese, iron, ammonium, nitrate, phosphate, sulfate, total sulfur and chloride at Braunschweig-Vlkenrode, Southeast Lower Saxony, Germany, were recorded for six years. During this period a considerable decrease was observed in the deposition of lead, cadmium, nitrate, sulfate and total sulfur. PMID:15091682

  6. 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.

  7. 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.

  8. MULTIDIMENSIONAL CHEMICAL MODELING OF YOUNG STELLAR OBJECTS. II. IRRADIATED OUTFLOW WALLS IN A HIGH-MASS STAR-FORMING REGION

    SciTech Connect

    Bruderer, S.; Benz, A.O.; Doty, S. D.; Van Dishoeck, E. F.; Bourke, T. L.

    2009-07-20

    Observations of the high-mass star-forming region AFGL 2591 reveal a large abundance of CO{sup +}, a molecule known to be enhanced by far-ultraviolet (FUV) and X-ray irradiation. In chemical models assuming a spherically symmetric envelope, the volume of gas irradiated by protostellar FUV radiation is very small due to the high extinction by dust. The abundance of CO{sup +} is thus underpredicted by orders of magnitude. In a more realistic model, FUV photons can escape through an outflow region and irradiate gas at the border to the envelope. Thus, we introduce the first two-dimensional axisymmetric chemical model of the envelope of a high-mass star-forming region to explain the CO{sup +} observations as a prototypical FUV tracer. The model assumes an axisymmetric power-law density structure with a cavity due to the outflow. The local FUV flux is calculated by a Monte Carlo radiative transfer code taking scattering on dust into account. A grid of precalculated chemical abundances, introduced in the first part of this series of papers, is used to quickly interpolate chemical abundances. This approach allows us to calculate the temperature structure of the FUV-heated outflow walls self-consistently with the chemistry. Synthetic maps of the line flux are calculated using a raytracer code. Single-dish and interferometric observations are simulated and the model results are compared to published and new JCMT and Submillimeter Array (SMA) observations. The two-dimensional model of AFGL 2591 is able to reproduce the JCMT single-dish observations and also explains the nondetection by the SMA. We conclude that the observed CO{sup +} line flux and its narrow width can be interpreted by emission from the warm and dense outflow walls irradiated by protostellar FUV radiation.

  9. 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.; Heielmann, 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.

  10. Collective properties of neutron-star X-ray binary populations of galaxies. II. Pre-low-mass X-ray binary properties, formation rates, and constraints

    SciTech Connect

    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.

  11. 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 ?g m- 3 and 41.47 20.25 ?g 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 ?g m- 3 and 0.47 0.28 ?g m- 3, whereas OC concentrations were 1.49 0.63 ?g m- 3 and 2.30 0.95 ?g 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.

  12. Field-collected permethrin-resistant Aedes aegypti from central Thailand contain point mutations in the domain IIS6 of the sodium channel gene (KDR).

    PubMed

    Srisawat, Raweewan; Komalamisra, Narumon; Apiwathnasorn, Chamnarn; Paeporn, Pungasem; Roytrakul, Sittiruk; Rongsriyam, Yupha; Eshita, Yuki

    2012-11-01

    One of the mechanisms responsible for pyrethroid resistance in mosquitoes is mutations in domain IIS6 of voltage-gated sodium channel gene (kdr). Aedes aegypti larvae were collected from the central provinces of Thailand (Bangkok, Prachin Buri and Ratchaburi) and colonized until they became adults. Partial fragment of kdr of permethrin-resistant mosquitoes were amplified by RT-PCR and sequenced. Among the four nucleotide mutations detected, two mutations resulted in two amino acid substitutions, S(TCC) 989 P(CCC) and V(GTA)1016 G(GGA). Among 94 permethrin-resistant mosquitoes, the SS genotype (SS/VV) was found to predominate (n = 74), followed by SR (SP/VG) (n = 15) and RR (PP/ GG) genotypes (n = 5), with the resistant allele frequency ranging from 0.03 to 0.17. As pyrethroid insecticides are currently being advocated for use in Thailand, investigations of pyrethroid resistance in other regions of the country are needed to prevent potential cross-resistance among different types of insecticides. PMID:23413701

  13. Influence of African Dust and Volcanic Ash on the Chemical Composition of Cloud/Rain Water Collected in a Tropical Montane Cloud Forest in Puerto Rico

    NASA Astrophysics Data System (ADS)

    Reyes-Rodrguez, G. J.; Gioda, A.; Mayol-Bracero, O. L.; Collett, J.

    2007-12-01

    Some organic compounds present in aerosols are surface active and their presence in cloud condensation nuclei can affect the surface tension of cloud droplets. The nature of these surface active compounds in clouds and rainwater is not well understood and there is very little information about their content in remote tropical environments. Therefore, our study focuses on the chemical characterization of the organic component of cloud and rainwater samples collected in a tropical montane cloud forest on the island of Puerto Rico. Samples were collected during periods of varying air mass origin, including periods of influence by African dust and by volcanic ash. Cloud samples were collected using a compact version of the single-stage Caltech Active Strand Cloudwater Collector. Rain samples were collected using a passive collector. The organic fraction of collected samples was characterized using a total organic carbon and total nitrogen analyzer (TOC/TN) and nuclear magnetic resonance (1H-NMR) spectroscopy. Elemental and organic carbon (EC, OC) were determined for suspended particles contained in collected cloud and rainwater samples. These particles were also analyzed using scanning electron microscopy-energy dispersive spectrometry (SEM-EDS) to determine their elemental compositions. Preliminary results indicate that average concentrations of cloud water TOC ranged from 0.9 to 1.2 mg/L. Lower concentrations were observed in rainwater, 0.3 to 0.7 mg/L. TN concentrations were higher than TOC in cloud water samples when air masses came from the African continent. The suspended aerosol particles had a content of 2.0 g of OC per mL of cloud water, but EC was not detected. Suspended particle analysis by SEM-EDS showed Si, Al, and Fe, which have crustal origin, as the predominant species. The 1H-NMR spectra showed alcohols in large quantities, suggesting the presence of biogenic material or polyols when air masses arrived from the African continent. A more complete set of results including volcanic ash events from the Soufriere Hills in Montserrat will also be presented.

  14. 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 recent ethnopharmacological research in Maghreb and its neighboring countries reveals a high correspondence; almost all the plants cited by Trotter are still used in the folk medicine of at least one of the North African countries, and the therapeutic uses of each plant appear consistent over time. Conclusions The information collected by Trotter is an important contribution to tracing plant utilization in Libyan folk medicine over the last century. PMID:22264313

  15. Comparison between ultrafine and fine particulate matter collected in Lebanon: Chemical characterization, in vitro cytotoxic effects and metabolizing enzymes gene expression in human bronchial epithelial cells.

    PubMed

    Borgie, Mireille; Dagher, Zeina; Ledoux, Frdric; Verdin, Anthony; Cazier, Fabrice; Martin, Perrine; Hachimi, Adam; Shirali, Pirouz; Greige-Gerges, Hlne; Courcot, Dominique

    2015-10-01

    During the last few years, the induction of toxicological mechanisms by atmospheric ultrafine particles (UFP) has become one of the most studied topics in toxicology and a subject of huge debates. Fine particles (FP) and UFP collected at urban and rural sites in Lebanon were studied for their chemical composition and toxicological effects. UFP were found more enriched in trace elements, secondary inorganic ions, total carbon and organic compounds than FP. For toxicological analysis, BEAS-2B cells were exposed for 24, 48 and 72 h to increasing concentrations of FP, water-UFP suspension (UFPw) and UFP organic extract (UFPorg). Our findings showed that UFP caused earlier alterations of mitochondrial metabolism and membrane integrity from the lowest concentrations. Moreover, a significant induction of CYP1A1, CYP1B1 and AhRR genes expression was showed after cells exposure to UFPorg and to a lesser extent to UFPw and FP samples. PMID:26093079

  16. 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

  17. Sorption preconcentration of mercury(II) on silica gel chemically modified by 2,5-dimercapto-1,3,4-thiadiazole

    SciTech Connect

    Simonova, L.N.; Kudryavtsev, G.V.; Bruskina, I.M.; Ispravnikova, V.V.

    1987-11-20

    To solve problems of environment protection, effective methods for the analytical control of the content of toxic substances, including mercury, are required. Mercury must be preconcentrated because of the low levels of its content in natural waters. One of the effective methods of preconcentration with simultaneous conservation of mercury is the use of chelate-forming sorbents. Sorbents based on silica gel with grafted N,S-containing dithiocarbamate and 2-aminocyclopent-1-enedithiocarbamic acid groups are popular. These sorbents have all the positive properties of the inorganic matrix, while the chelate-forming group grafted onto them ensures selectivity of sorption. The aim of this work was to study the sorption conditions and the subsequent determination of mercury(II) in natural waters using a sorbent based on silichrome, chemically modified by 2,5-dimercapto-1,3,4-thiadiazole (bismuthol I).

  18. 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-?m infrared region has been realized. PACS: 78.67.Pt; 81.15.Gh; 63.22.Np; 81.05.Ea PMID:22373387

  19. 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).

  20. 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

  1. Size-resolved Chemical Composition of Cloud and Rain Water Collected during the Puerto Rico African Dust and Clouds Study (PRADACS) Campaign

    NASA Astrophysics Data System (ADS)

    Torres, E.; Valle Diaz, C. J.; Zurcher, F.; Lee, T.; Collett, J. L.; Fitzgerald, E.; Cuadra, L.; Prather, K. A.; Mayol-Bracero, O. L.

    2011-12-01

    The underlying physico-chemical processes of dust-aerosol interactions are poorly understood; even less understood is how aging impacts cloud properties and climate as the particles travel from Africa to the Caribbean region. Caribbean landmasses have tropical montane cloud forests (TMCFs) that are tightly coupled to the atmospheric hydrologic cycle. Small-scale shifts in temperature and precipitation could have serious ecological consequences. Therefore, this makes TMCFs an interesting ecosystem to see the effects African Dust (AD) might have on cloud formation and precipitation. As part of the Puerto Rico African Dust and Clouds Study (PRADACS) cloud and rain water samples for subsequent chemical analysis were collected at Pico del Este (PE) station in Luquillo, PR (1051 masl) during summer 2011. At PE, two cloud collectors (i.e., single stage (Aluminum version) and 2-stage (Teflon version) Caltech Active Strand Cloudwater Collector (CASCC)), and a rainwater collector were operated. Measurements such as the liquid water content (LWC), pH, conductivity., and composition of single particles using an aerosol time of flight mass spectrometer (ATOFMS) were performed. Preliminary results showed that days with the influence of African dust (AD), had LWC values that ranged from 300 to 500 mg/m3, pH values up to 5.7,, and conductivity up to 180 ?S/cm. The ATOFMS showed titanium and iron ions, suggesting the presence of AD as well as, occasionally, sulfate and nitrate ions suggesting the influence of anthropogenic pollution. Results on the chemical composition and the physical properties of cloud, rainwater, and aerosol for the inorganic as well as the organic fraction and how these properties change for the different air masses observed will also be presented.

  2. 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.

  3. Non-empirical quantum chemical studies on electron transfer reactions in trans- and cis-diamminedichloroplatinum(II) complexes.

    PubMed

    Kuduk-Jaworska, Janina; Chojnacki, Henryk; Jański, Jerzy J

    2011-09-01

    The search was made for theoretical confirmation of hypothesis that mechanism of cisplatin cytotoxicity is based on dissociative electron transfer (ET) processes. Applying quantum chemical calculations based on supermolecular approach, the reactions mimicking presumed steps of cisplatin activation were evaluated. The electronic structure of model systems: cis- and transplatin with free electrons, hydrated electrons, and water, was studied by using density functional (DFT) within the Huzinaga basis set and GAUSSIAN-09 package. The respective energy was evaluated with the use of B3LYP density hybrid functional. The calculations were performed for gas phase and water solution; the solvent effects were studied by using the polarizable continuum model. Analysis of the energetic and structural parameters of cisplatin vs. transplatin behavior in the model systems leads to conclusion: there are two possible ways of cisplatin biotransformation, hydrolysis and hydrated electron impact, dependent on the medium redox state. PMID:21559964

  4. 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 ? with ? = 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 ? slightly overestimates the excluded volume interaction but still remains a fairly good approximation for region of qRg < 10.

  5. 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(2?) with ? = 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(2?) slightly overestimates the excluded volume interaction but still remains a fairly good approximation for region of qR(g) < 10. PMID:26395738

  6. 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.

  7. Chemical constituents and free radical scavenging activity of corn pollen collected from Apis mellifera hives compared to floral corn pollen at Nan, Thailand

    PubMed Central

    2012-01-01

    Background Bee pollen is composed of floral pollen mixed with nectar and bee secretion that is collected by foraging honey (Apis sp.) and stingless bees. It is rich in nutrients, such as sugars, proteins, lipids, vitamins and flavonoids, and has been ascribed antiproliferative, anti-allergenic, anti-angiogenic and free radical scavenging activities. This research aimed at a preliminary investigation of the chemical constituents and free radical scavenging activity in A. mellifera bee pollen. Methods Bee pollen was directly collected from A. mellifera colonies in Nan province, Thailand, in June, 2010, whilst floral corn (Zea mays L.) pollen was collected from the nearby corn fields. The pollen was then sequentially extracted with methanol, dichloromethane (DCM) and hexane, and each crude extract was tested for free radical scavenging activity using the DPPH assay, evaluating the percentage scavenging activity and the effective concentration at 50% (EC50). The most active crude fraction from the bee pollen was then further enriched for bioactive components by silica gel 60 quick and adsorption or Sephadex LH-20 size exclusion chromatography. The purity of all fractions in each step was observed by thin layer chromatography and the bioactivity assessed by the DPPH assay. The chemical structures of the most active fractions were analyzed by nuclear magnetic resonance. Results The crude DCM extract of both the bee corn pollen and floral corn pollen provided the highest active free radical scavenging activity of the three solvent extracts, but it was significantly (over 28-fold) higher in the bee corn pollen (EC50?=?7.42 0.12 ?g/ml), than the floral corn pollen (EC50?=?212 13.6% ?g/ml). After fractionation to homogeneity, the phenolic hydroquinone and the flavone 7-O-R-apigenin were found as the minor and major bioactive compounds, respectively. Bee corn pollen contained a reasonably diverse array of nutritional components, including biotin (56.7 ?g/100 g), invert sugar (19.9 g/100 g), vitamin A and ? carotene (1.53 mg/100 g). Conclusions Bee pollen derived from corn (Z. mays), a non-toxic or edible plant, provided a better free radical scavenging activity than floral corn pollen. PMID:22513008

  8. 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; Mller-Ebert, Drthe; Schtz, 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 m, mineral dust dominates, consisting mainly of silicates, and - to a lesser extent - carbonates and quartz. Larger than 50 m, 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 mixtures of these components. During low-dust periods, the aerosol is dominated by sea salt. During dust events, mineral dust dominates the particle mass (more than 90 %). Particles smaller 500 nm in diameter always show a significant abundance of ammonium sulfate. Comparing a high dust period at Cape Verde with the total data from Morocco, it is found that the atomic ratio distributions of Al/Si, K/Si and Fe/Si for the single particles are very similar for the dust component. This indicates that the dominating silicate minerals are the same. In contrast, the content of calcium rich minerals at Cape Verde is significantly lower than in Morocco which is in agreement with the source regions for the Cape Verde dust (E Mali and W Niger) derived from trajectory analysis. The sulfur content of super-micron aerosol particles at Cape Verde scales with the particle surface, indicating the presence of sulfate coatings. For the submicron particles, the sulfur content scales with particle volume, which can be attributed to the large amount of particles identified as ammonium sulfate. In contrast to findings in Japan (Zhang et al., 2006), no internal mixtures between pristine seasalt and mineral dust are present during this dust period at Cape Verde. However, for a significant number of particles a small amount of sodium and chlorine is associated with internal mixtures of dust and sulfate, what may indicate that these particles started as internal mixture of dust with a sea water droplet before taking up more sulfur from the gas phase. In general, the shape of the particles in Morocco and Cape Verde is rather similar: The distributions of the two-dimensional aspect ratio of an ellipse fitted to each particle's shape for the total aerosol show no significant differences. A median value of 1.6 is found for both locations. References Kandler, K., Schtz, L., Deutscher, C., Hofmann, H., Jckel, S. and co-authors 2009. Tellus 61B, 32-50. Zhang, D., Iwasaka, Y., Matsuki, A., Ueno, K. and Matsuzaki, T. 2006. Atmos. Environ. 40, 1205-1215. Financial support by the Deutsche Forsch

  9. 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.

  10. 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.

  11. Dynamic modeling of chemical fate and transport in multimedia environments at watershed scale-II: trichloroethylene test case.

    PubMed

    Luo, Yuzhou; Gao, Qiong; Yang, Xiusheng

    2007-04-01

    A multimedia environmental fate model was developed to study the temporal dynamics and spatial distribution of a chemical pollutant at watershed scale. The theoretical considerations and implementation of the model were described in the accompanying paper (Part I). This paper presents the result of a test simulation on the transport of trichloroethylene (TCE) in the Connecticut River Basin. The simulation results were reported as time series of concentrations and inter-media transport fluxes in the compartments of atmosphere, plant, soil, surface water, and sediment. Predicted concentrations from the test simulation were compared with published field data or predictions by validated models. The temporal trends in TCE predictions were evaluated by comparing the simulation results with monthly TCE concentrations in various environmental compartments and monthly fluxes of inter-media transport processes. Results indicated that the simulation results were in reasonable agreement with reported data in the literature. The results also revealed that the mass transport of TCE from the atmosphere compartment to soil and surface water was a major route of TCE dispersion in the environment. PMID:16678337

  12. Possible fine structure of the magnetic field of chemically peculiar stars ?2CVn and ? CrB. II. Rare earths.

    NASA Astrophysics Data System (ADS)

    Romanyuk, I. I.

    The magnetic field of chemically peculiar stars ?2CVn and ? CrB was studied on the basis of measurements of rare-earth element lines from Zeeman spectra obtained with an achromatic analyzer of circular polarization in the spectral region ??3300 - 4000 on the 6-m telescope. It was demonstrated that for the star ?2CVn, the longitudinal component of the magnetic field determined from rare-earth element lines in the spectral region ? > 3646 shows the periodic variability with field sign changes, whereas in the region ? < 3546 it is negative in all phases of the period of variability. For ? CrB both curves have alternating signs; however, in the region ? < 3646 is seen a shift of the rare-earth ultraviolet curve by 300 G toward the negative polarity region compared to the curve of the longitudinal component of the field determined from lines of rare-earth elements in the usual photographic spectral region. Curves of the longitudinal component of the magnetic field determined from iron, chromium, and titanium lines in spectral regions on both sides of the Balmer jump are also given for ? CrB. The different behavior of the magnetic curves on both sides of the jump cannot be explained within the framework of the classical purely dipole model; it is necessary to construct new models taking into account the complex structure of the magnetic field.

  13. DNA interstrand cross-links of an antitumor trinuclear platinum(II) complex: thermodynamic analysis and chemical probing.

    PubMed

    Malina, Jaroslav; Farrell, Nicholas P; Brabec, Viktor

    2011-06-01

    The trinuclear platinum compound [{trans-PtCl(NH(3))(2)}(2)(?-trans-Pt(NH(3))(2){NH(2)(CH(2))(6)NH(2)}(2))](4+) (BBR3464) belongs to the polynuclear class of platinum-based anticancer agents. These agents form in DNA long-range (Pt,Pt) interstrand cross-links, whose role in the antitumor effects of BBR3464 predominates. Our results show for the first time that the interstrand cross-links formed by BBR3464 between two guanine bases in opposite strands separated by two base pairs (1,4-interstrand cross-links) exist as two distinct conformers, which are not interconvertible, not only if these cross-links are formed in the 5'-5', but also in the less-usual 3'-3' direction. Analysis of the conformers by differential scanning calorimetry, chemical probes of DNA conformation, and minor groove binder Hoechst 33258 demonstrate that each of the four conformers affects DNA in a distinctly different way and adopts a different conformation. The results also support the thesis that the molecule of antitumor BBR3464 when forming DNA interstrand cross-links may adopt different global structures, including different configurations of the linker chain of BBR3464 in the minor groove of DNA. Our findings suggest that the multiple DNA interstrand cross-links available to BBR3464 may all contribute substantially to its cytotoxicity. PMID:21557487

  14. PHYSIOLOGICAL ONTOGENY : A. CHICKEN EMBRYOS. II. CATABOLISM. CHEMICAL CHANGES IN FERTILE EGGS DURING INCUBATION. SELECTION OF STANDARD CONDITIONS.

    PubMed

    Murray, H A

    1925-09-20

    As this paper goes to press a complete review of the chemistry of the fertile egg will be appearing (19). The author, Mr. J. Needham, was kind enough to allow me to inspect his manuscript and thus avail myself of the comprehensive bibliography and discussion. It is surprising that no biochemists have estimated the changing water content of the egg during incubation. Many of the analyses reported in Needham's review were expressed in per cent of total weight or per cent of dry solid, and consequently are of questionable value, since these latter functions are themselves changing; the former due to water evaporation and the latter through the addition of shell constituents and the burning of oxidizable organic compounds. Moreover, there has been no statistical treatment of the results, and the reliability of the average, figures obtained has consequently been difficult to estimate. Tangl's work, quoted throughout this paper, except for its lack of statistical treatment is more enlightening. However, his concept of the so called "Energy of Embryogenesis" which he propounds, seems to me misleading and unwarranted. What Tangl measured was the amount and the caloric value of the solid material burned and thus the quantity of energy lost during the embryonic period. The latter is equivalent to the usual measurements of catabolism. In the case of the embryo it is not basal metabolism which is being estimated, since the conditions are not basal. The embryo is absorbing and assimilating nutriment all the while at a relatively rapid rate. The calorific value of the oxidized solid, which is in truth the amount of energy lost during a certain chosen interval, in Tangl's judgment stands for the energy of embryogenesis; i.e., the energy of development (growth + differentiation). We believe that this conception is erroneous. The two processes, anabolism and catabolism, occur together and undoubtedly have some relationship, but surely one is not a measure of the other. In a starving animal, and so probably in a starving embryo, there is a considerable amount of so called basal metabolism. Thus if the "Embryogenetic Energy" were measured under these conditions a figure would be obtained for which there was no growth to correspond, or in other words there would be a value for something which did not exist. It will be seen in our later communications that the changes with age of metabolic rate and growth rate do not coincide. The amount of catabolism under certain circumstances does not accelerate growth or anabolism, but seems rather to be a limiting factor. It is as if when the absorbed energy were constant an increase of catabolism would make inroads upon the amount of energy which otherwise would remain for storage (growth). If, as Pembrey's (20) experiments would tend to show, there is an increase of metabolism in the oldest embryos when the outside temperature is lowered, one would find at the end of incubation in such cases that there was a greater amount of so called "Energy of Development" but smaller embryo. It seems that the potential energy amassed as growth comes from that remaining after the needs of the body have been satisfied. The results of the experiments described in this paper have formed the basis for judgment in the selection of suitable standard conditions for the incubation of hen's eggs. Standardization was necessary so that in future experiments the more important environmental factors might be kept uniform within a certain appropriate range and therefore not be held accountable for deviations observed in the embryos. Henceforth in this series of papers the term "standard incubation conditions" will signify that (1) the temperature was constantly at 38.8 +/- 0.4 degrees C., (2) the humidity at 67.5 +/- 2.5 per cent, (3) there was a continuous flow of warm air into the incubator to provide the necessary circulation, and (4) the eggs were rolled once a day within the constant temperature room. The incubator, a double-walled copper cabinet, stands in a constant temperature room, the fluctuations of which are +/- 1.0 degrees C. The space between the walls of the incubator is filled with water which serves as a buffer to outer variations. It might be repeated that all the eggs are from White Leghorn hens, are incubated 2 days after laying, and that they are kept cold during the interval necessary for transportation. With the figures from our chemical analyses and metabolic rate experiments, it was possible to calculate values for the concentration of total solids, fat, and nitrogen throughout the incubation period. These data were necessary as a general chemical background for further work. The results of the calculations are obviously rough. Because of the great variability of the eggs a satisfactory degree of accuracy could not have been attained without a very large number of analyses supplemented by complete statistical treatment. The necessity for such a comprehensive study was not evident, and it is our belief that the approximations reached in this paper are sufficiently close to serve our present purposes. The chief facts that have been ascertained in this investigation are (1) Loss of water by the egg during incubation is a function of the atmospheric humidity in its immediate environment. More rapid circulation of air lowers the humidity around the egg and thus increases evaporation. Other facts influencing evaporation are (a) atmospheric temperature, (b) thickness and surface area of the shell, and (c) conditions within the egg, the most important of which, it is suggested, is the amount of heat produced by the embryo. The latter factor, in turn, depends upon its size and age, and a significant change does not become apparent until the last 3 or 4 days of incubation, that is to say, when the embryo is of sufficient mass to exert a measurable force. (2) The surface area of the eggs in sq. cm. may be approximately represented by the formula S = K W(2/3), where K = 5.07 +/- 0.10, and W = the weight of the whole egg in gm. (3) There is a loss of weight by the shell during incubation. This is most noticeable near the end of the cycle, when the loss seems to parallel in general the weight of the embryo. (4) There is also a loss of solid matter during incubation. Chemical analyses indicate that about 98 per cent of the material oxidized is fat. This conclusion is corroborative of previous work by Hasselbalch, Hasselbalch and Bohr, and Tangl. (5) Carbon dioxide may be measured with relative accuracy. When it is assumed that it is derived from the oxidation of fat, satisfactory corroboration of the chemical analyses is obtained. These experiments have furnished the data from which the values have been calculated for total solids, fats, and protein in the whole egg throughout incubation. The figures may be used later for comparison with the concentration of these substances within the embryo. PMID:19872226

  15. 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

    The use of strontium isotopes to evaluate mineral weathering and identify sources of base cations in catchment waters requires an understanding of the behavior of Sr in the soil environment as a function of time. Our approach is to model the temporal evolution of 87Sr/86Sr of the cation exchange pool in a soil chronosequence developed on alluvium derived from central Sierra Nevada granitoids during the past 3 Ma. With increasing soil age, 87Sr/86Sr of ammonium-acetate extractable Sr initially decreases from values typical of K-feldspar to those of plagioclase and hornblende and then remains constant, even though plagioclase and hornblende are absent from the soils after approximately 1 Ma of weathering. The temporal variation of 87Sr/86Sr of exchangeable Sr is modeled by progressively equilibrating Sr derived from mineral weathering and atmospheric deposition with Sr on exchange sites as waters infiltrate a soil column. Observed decreases in quartz-normalized modal abundances of plagioclase, hornblende, and K-feldspar with time, and the distinct 87Sr/86Sr values of these minerals can be used to calculate Sr flux from weathering reactions. Hydrobiotites in the soils have nearly constant modal abundances, chemistry, and 87Sr/86Sr over the chronosequence and provide negligible Sr input to weathering solutions. The model requires time and soil horizon-dependent changes in the amount of exchangeable Sr and the efficiency of Sr exchange, as well as a biologic cycling term. The model predicts that exchangeable Sr initially has 87Sr/86Sr identical to that of K-feldspar, and thus could be dominated by Sr leached from K-feldspar following deposition of the alluvium. The maximum value of 87Sr/86Sr observed in dilute stream waters associated with granitoids of the Yosemite region is likewise similar to that of the K-feldspars, suggesting that K-feldspar and not biotite may be the dominant source of radiogenic Sr in the streams. This study reveals that, when attempting to use 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.

  16. Top Value-Added Chemicals from Biomass - Volume IIResults of Screening for Potential Candidates from Biorefinery Lignin

    SciTech Connect

    Holladay, John E.; White, James F.; Bozell, Joseph J.; Johnson, David

    2007-10-01

    This report evaluates lignins role as a renewable raw material resource. Opportunities that arise from utilizing lignin fit into one of three categories: 1)power, fuel and syngas (generally near-term opportunities) 2) macromolecules (generally medium-term opportunities) 3) aromatics and miscellaneous monomers (long-term opportunities). Biorefineries will receive and process massive amounts of lignin. For this reason, how lignin can be best used to support the economic health of the biorefinery must be defined. An approach that only considers process heat would be shortsighted. Higher value products present economic opportunities and the potential to significantly increase the amount of liquid transportation fuel available from biomass. In this analysis a list of potential uses of lignin was compiled and sorted into product types which are broad classifications (listed above as powerfuelsyngas; macromolecules; and aromatics). In the first product type (powerfuelgasification) lignin is used purely as a carbon source and aggressive means are employed to break down its polymeric structure. In the second product type (macromolecules) the opposite extreme is considered and advantage of the macromolecular structure imparted by nature is retained in high-molecular weight applications. The third product type (aromatics) lies somewhere between the two extremes and employs technologies that would break up lignins macromolecular structure but maintain the aromatic nature of the building block molecules. The individual opportunities were evaluated based on their technical difficulty, market, market risk, building block utility, and whether a pure material or a mixture would be produced. Unlike the Sugars Top 10 report it was difficult to identify the ten best opportunities, however, the potential opportunities fell nicely into near-, medium- and long-term opportunities. Furthermore, the near-, medium- and long-term opportunities roughly align with the three product types. From this analysis a list of technical barriers was developed which can be used to identify research needs. Lignin presents many challenges for use in the biorefinery. Chemically it differs from sugars having a complex aromatic substructure. Unlike cellulose, which has a relatively simple substructure of glucose subunits, lignin has a high degree of variability in its structure which differs both from biomass source and from the recovery process used. In addition to its variability lignin is also reactive and to some degree less stable thermally and oxidatively to other biomass streams. What this means is that integrating a lignin process stream within the biorefinery will require identifying the best method to separate lignin from biomass cost-effectively.

  17. Phenotype-driven chemical screening in zebrafish for compounds that inhibit collective cell migration identifies multiple pathways potentially involved in metastatic invasion

    PubMed Central

    Gallardo, Viviana E.; Varshney, Gaurav K.; Lee, Minnkyong; Bupp, Sujata; Xu, Lisha; Shinn, Paul; Crawford, Nigel P.; Inglese, James; Burgess, Shawn M.

    2015-01-01

    ABSTRACT In the last decade, high-throughput chemical screening has become the dominant approach for discovering novel compounds with therapeutic properties. Automated screening using in vitro or cultured cell assays have yielded thousands of candidate drugs for a variety of biological targets, but these approaches have not resulted in an increase in drug discovery despite major increases in expenditures. In contrast, phenotype-driven screens have shown a much stronger success rate, which is why we developed an in vivo assay using transgenic zebrafish with a GFP-marked migrating posterior lateral line primordium (PLLp) to identify compounds that influence collective cell migration. We then conducted a high-throughput screen using a compound library of 2160 annotated bioactive synthetic compounds and 800 natural products to identify molecules that block normal PLLp migration. We identified 165 compounds that interfere with primordium migration without overt toxicity in vivo. Selected compounds were confirmed in their migration-blocking activity by using additional assays for cell migration. We then proved the screen to be successful in identifying anti-metastatic compounds active in vivo by performing orthotopic tumor implantation assays in mice. We demonstrated that the Src inhibitor SU6656, identified in our screen, can be used to suppress the metastatic capacity of a highly aggressive mammary tumor cell line. Finally, we used CRISPR/Cas9-targeted mutagenesis in zebrafish to genetically validate predicted targets of compounds. This approach demonstrates that the migrating PLLp in zebrafish can be used for large-scale, high-throughput screening for compounds that inhibit collective cell migration and, potentially, anti-metastatic compounds. PMID:25810455

  18. Phenotype-driven chemical screening in zebrafish for compounds that inhibit collective cell migration identifies multiple pathways potentially involved in metastatic invasion.

    PubMed

    Gallardo, Viviana E; Varshney, Gaurav K; Lee, Minnkyong; Bupp, Sujata; Xu, Lisha; Shinn, Paul; Crawford, Nigel P; Inglese, James; Burgess, Shawn M

    2015-06-01

    In the last decade, high-throughput chemical screening has become the dominant approach for discovering novel compounds with therapeutic properties. Automated screening using in vitro or cultured cell assays have yielded thousands of candidate drugs for a variety of biological targets, but these approaches have not resulted in an increase in drug discovery despite major increases in expenditures. In contrast, phenotype-driven screens have shown a much stronger success rate, which is why we developed an in vivo assay using transgenic zebrafish with a GFP-marked migrating posterior lateral line primordium (PLLp) to identify compounds that influence collective cell migration. We then conducted a high-throughput screen using a compound library of 2160 annotated bioactive synthetic compounds and 800 natural products to identify molecules that block normal PLLp migration. We identified 165 compounds that interfere with primordium migration without overt toxicity in vivo. Selected compounds were confirmed in their migration-blocking activity by using additional assays for cell migration. We then proved the screen to be successful in identifying anti-metastatic compounds active in vivo by performing orthotopic tumor implantation assays in mice. We demonstrated that the Src inhibitor SU6656, identified in our screen, can be used to suppress the metastatic capacity of a highly aggressive mammary tumor cell line. Finally, we used CRISPR/Cas9-targeted mutagenesis in zebrafish to genetically validate predicted targets of compounds. This approach demonstrates that the migrating PLLp in zebrafish can be used for large-scale, high-throughput screening for compounds that inhibit collective cell migration and, potentially, anti-metastatic compounds. PMID:25810455

  19. Modification of carbon screen-printed electrodes by adsorption of chemically synthesized Bi nanoparticles for the voltammetric stripping detection of Zn(II), Cd(II) and Pb(II).

    PubMed

    Rico, Ma Angeles Granado; Olivares-Marn, Mara; Gil, Eduardo Pinilla

    2009-12-15

    A simple procedure for the chemical synthesis of bismuth nanoparticles and subsequent adsorption on commercial screen-printed carbon electrodes offer reliable quantitation of trace zinc, cadmium and lead by anodic stripping square-wave voltammetry in nondeareated water samples. The influence of two hydrodynamic configurations (convective cell and flow cell) and the effect of various experimental variables upon the stripping signals at the bismuth-coated sensor are explored. The square-wave peak current signal is linear over the low ng mL(-1) range (120 s deposition), with detections limits ranging from 0.9 to 4.9 ng mL(-1) and good precision. Applicability to waste water certified reference material and drinking water samples is demonstrated. The attractive behaviour of the new disposable Bi nanoparticles modified carbon strip electrodes, coupled with the negligible toxicity of bismuth, hold great promise for decentralized heavy metal testing in environmental and industrial effluents waters. PMID:19836530

  20. 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 non-sea salt sulfate increased ca. 50% which suggested that automobile exhaust emission increased. In addition, the concentration of soil-originated components such as iron and aluminum increased ca. 2.6 times and ca. 3.0 times, suggesting a probable desertification. We also report the calculated background concentrations of water-soluble chemical components and acid-digested metals at Okinawa, Japan.

  1. Size-resolved Chemical Composition of Cloud and Rain Water Collected during the Puerto Rico African Dust and Clouds Study (PRADACS) Campaign

    NASA Astrophysics Data System (ADS)

    Valle Diaz, C. J.; Mayol-Bracero, O. L.; Zurcher, F.; Gioda, A.; Lee, T.; Collett, J. L.; Pradacs Team

    2010-12-01

    The underlying physico-chemical processes of dust-aerosol interactions are poorly understood; even less understood is how aging impacts cloud properties and climate as the particles travel from Africa to the Caribbean region. Caribbean landmasses have Tropical Montane Cloud Forests (TMCFs) that are tightly coupled to the atmospheric hydrologic cycle. Small-scale shifts in temperature and precipitation could have serious ecological consequences. Therefore, this makes TMCFs an interesting ecosystem to see the effects African Dust (AD) might have on cloud formation and precipitation. The first field measurements of the Puerto Rico African Dust and Clouds Study (PRADACS) were from July 22 to August 12, 2010. Measurements were performed at East Peak (EP) station at Luquillo, PR (1051 masl) and Cape San Juan Station (CSJ), a coastal station at Fajardo, PR (~60 masl). At EP, two cloud collectors (i.e., single stage (Aluminum version) and 2-stage (Teflon version) Caltech Active Strand Cloudwater Collector (CASCC)), and a rainwater collector were operated. Chemical composition (water-soluble ions and carbonaceous, organic nitrogen and metals) and pH were determined for the cloud water and rainwater samples. Here we present preliminary results for EP station. For cloud water and rainwater sampling, pH was 5.5 in average, but during dust events pH values were higher due to the presence of cations that form hydroxides in aqueous solution. Conductivity measurements ranged from 20 to 120 ?s/cm; being higher on dust events and lower for rain samples. The values of pH and conductivity in the first stage (large droplets of approximately 15 ?m are collected) indicate a higher content of dust than in the second stage (small droplets of approximately 5 ?m). This is consistent with the larger sizes of dust particles as well as their lower hygroscopicity which requires more water to serve as Cloud Condensation Nuclei (CCN). Additional results for physical properties and chemical composition obtained for clouds, rainwater and aerosols from the summer and fall 2010 test-period campaigns will also be presented.

  2. 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

  3. Characterization of conjugated metabolites of a new angiotensin II receptor antagonist, candesartan cilexetil, in rats by liquid chromatography/electrospray tandem mass spectrometry following chemical derivatization.

    PubMed

    Kondo, T; Yoshida, K; Yoshimura, Y; Motohashi, M; Tanayama, S

    1996-08-01

    Combined liquid chromatography and electrospray mass spectrometry (LC/ESI-MS) and tandem mass spectrometry (MS/MS) were used for the characterization of the conjugated metabolites (glucuronides) of a new angiotensin II receptor antagonist, candesartan cilexetil (TCV-116; (+/-)-1-(cyclohexyloxycarbonyloxy)ethyl 2-ethoxy-1-[2'-(1H-tetrazol-5-yl)biphenyl- 4-yl]methyl-1H-benzimidazole-7-carboxylate) in the plasma and bile of rats given the drug. The glucuronides of the active component, M-I (candesartan), in rat plasma and bile were positional isomers with respect to the binding site of glucuronic acid. The site of glucuronidation in M-I was not directly identified by mass spectrometry. However, the structure of the isomers could be elucidated by the MS/MS analysis of dimethylated glucuronides prepared by the reaction of glucuronide isomers with diazomethane: N-glucuronide of M-I (M-I-NG) in the plasma and acyl glucuronide (M-I-AG) in the bile. The results obtained in this study indicated that LC/ESI-MS/MS analysis provides the detailed structure of conjugated metabolite by simple chemical derivatization. PMID:8799313

  4. 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/kg. Comparing the mean mercury concentration present in post-hurricane samples with regional background data from the U.S. Geological Survey National Geochemical Dataset, indicates that mercury concentrations in post-hurricane sediment generally are larger. Sequential extraction analysis of 51 samples for arsenic indicate that 54.5 percent of the total arsenic concentration is contained in the extremely mobile iron-manganese oxide fraction. Pesticide and polychlorinated biphenyl Arochlor concentrations in post-hurricane samples were small. Prometon was the most frequently detected pesticide with concentrations ranging from 2.4 to 193 micrograms per kilogram (µg/kg). Methoxychlor was present in 22 samples with a concentration ranging from 3.5 to 3,510 µg/kg. Although methoxychlor had the largest detected pesticide concentration, it was well below the U.S. Environmental Protection Agency’s High-Priority Screening Level for residential soils. Arochlor congeners were not detected for any sample above the minimum detection level of 7.9 µg/kg.

  5. 78 FR 49547 - Manufacturer of Controlled Substances; Notice of Registration; American Radiolabeled Chemicals, Inc.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-14

    ..., 2013, 78 FR 23596, American Radiolabeled Chemicals, Inc., 101 Arc Drive, St. Louis, Missouri 63146... Amphetamine (1100) II Methamphetamine (1105) II Amobarbital (2125) II Phencyclidine (7471) II...

  6. 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-microscopic nuclear mass model to give insight into superheavy element shell effects. The 242Pu(48Ca, 5n)285114 cross section was 0.6-0.2 +1.3 pb.

  7. I. Probing polymer adsorption using an emissive semiconductor substrate. II. Correlation of chemical structure and swelling behavior in N-alkylcrylamide hydrogels

    NASA Astrophysics Data System (ADS)

    Seker, Fazila

    Semiconductor photoluminescence (PL) is a highly surface-sensitive technique that has allowed characterization of a wide variety of semiconductor-adsorbate interactions. This surface sensitivity can be rationalized through an understanding of the mechanisms by which adsorbate interactions can perturb the electronic structure of semiconductors, leading to observable changes in PL intensity. Using this approach, quenching of the photoluminescence (PL) intensity of single-crystal CdSe by adsorption of poly(acrylic acid) (PAA) from methanol solutions is introduced in Part I as a sensitive probe of polymer interactions with a semiconductor surface. Comparison with the influence on CdSe PL of methanol solutions of acrylic acid (AA), propionic acid (PrA), methyl acrylate (MA), along with IR data, indicate that surface binding leading to PL quenching involves the carboxylic acid proton. Over the range of PAA molecular weights studied in methanol (Mw 2K to 100K), the dependence of PL quenching on concentration is found to be insensitive to PAA chain length and markedly different from that of a surface COOH-derivatived dendrimer (PAMAM-COOH), suggesting that PAA uncoils upon adsorption onto the CdSe surface. The time-dependence of the PL decay indicates diffusion-controlled adsorption kinetics for the PAA/methanol system. Implications of the use of this methodology for characterizing semiconductor-polymer interfaces are discussed. Based on this understanding of the PAA/CdSe interface, molecularly imprinted PAA-film-coated CdSe surfaces are described as a strategy for selective chemical sensing. In this way, selective detection of ammonia from a mixture of trimethylamine and ammonia is achieved. Part II focuses on the swelling properties of hydrogels, which exhibit up to 1000-fold changes in volume in response to various stimuli. The thermoshrinking properties for the series of N-alkylacrylamide hydrogels (alkyl = methyl, ethyl, isopropyl, and n-propyl), are investigated in order to study the effect of the chemical structure of the alkyl substituent on the gel swelling behavior as a function of temperature. Generally, larger alkyl chains produced dramatic decreases in gel transition temperature, as well as influenced the nature of thermoshrinking. Additionally, a quantitative correlation was found between the gel transition temperatures and the water/octanol partition coefficients for appropriately chosen small molecule model compounds.

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. A Research Project to Determine the Student Acceptability and Learning Effectiveness of Microform Collections in Community Junior Colleges: Phase II. Final Report.

    ERIC Educational Resources Information Center

    Gaddy, Dale

    Five pilot studies were conducted at four two-year colleges in the Washington, D.C. area during the 1970-71 academic year to identify relevant variables for subsequent in-depth examination in this USOE-funded research project which is designed to determine student acceptance and learning effectiveness of microform. Known as Phase II, the year's

  14. Injectable PLA-based in situ forming implants for controlled release of Ivermectin a BCS Class II drug: solvent selection based on physico-chemical characterization.

    PubMed

    Camargo, J A; Sapin, A; Nouvel, C; Daloz, D; Leonard, M; Bonneaux, F; Six, J-L; Maincent, P

    2013-01-01

    In situ forming implants (ISI) prepared from biodegradable polymers such as poly(D,L-lactide) (PLA) and biocompatible solvents can be used to obtain sustained drug release after parenteral administration. The aim of this work was to study the effect of several biocompatible solvents with different physico-chemical properties on the release of ivermectin (IVM), an antiparasitic BCS II drug, from in situ forming PLA-based implants. The solvents evaluated were N-methyl-2-pyrrolidone (NMP), 2-pyrrolidone (2P), triacetine (TA) and benzyl benzoate (BB). Hansen's solubility parameters of solvents were used to explain polymer/solvent interactions leading to different rheological behaviours. The stability of the polymer and drug in the solvents were also evaluated by size exclusion and high performance liquid chromatography, respectively. The two major factors determining the rate of IVM release from ISI were miscibility of the solvent with water and the viscosity of the polymer solutions. In general, the release rate increased with increasing water miscibility of the solvent and decreasing viscosity in the following order NMP>2P>TA>BB. Scanning electron microscopy revealed a relationship between the rate of IVM release and the surface porosity of the implants, release being higher as implant porosity increased. Finally, drug and polymer stability in the solvents followed the same trends, increasing when polymer-solvent affinities and water content in solvents decreased. IVM degradation was accelerated by the acid environment generated by the degradation of the polymer but the drug did not affect PLA stability. PMID:22397675

  15. Belle II distributing computing

    NASA Astrophysics Data System (ADS)

    Krokovny, P.

    2015-05-01

    The next generation B factory experiment Belle II will collect huge data samples which are a challenge for the computing system. To cope with the high data volume and rate, Belle II is setting up a distributed computing system based on existing technologies and infrastructure, plus Belle II specific extensions for workflow abstraction. This paper describes the highlights of the Belle II computing and the current status. We will also present the experience of the latest MC production campaign in 2014.

  16. 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.

  17. 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.

  18. 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...

  19. Microseismic roof fall warning system development: field trials and commercial prototype fabrication. Volume II. Appendix C: coal mine data collection summary. Open file report (final) Aug 77-Dec 79

    SciTech Connect

    Fisher Jr, C.

    1980-05-30

    A microseismic roof fall warning system was field tested in Western and Eastern coal mines in the United States to better define the capabilities and limitations of the microseismic method in predicting roof fall. Microseismic event and energy type data were obtained and documented for 23 coal mine roof falls. Field test results indicate that both the microseismic event and energy methods, as applied, have a high probability for successful application in a commercially practical roof fall warning system. Volume II summarizes the data collected.

  20. Mixed ligand ?-phenoxo-bridged dinuclear copper(II) complexes with diimine co-ligands: efficient chemical nuclease and protease activities and cytotoxicity.

    PubMed

    Loganathan, Rangasamy; Ramakrishnan, Sethu; Suresh, Eringathodi; Palaniandavar, Mallayan; Riyasdeen, Anvarbatcha; Akbarsha, Mohamad Abdulkadhar

    2014-04-28

    The water soluble mixed ligand copper(II) complexes of the type [Cu(sal)(diimine)(ClO4)]21-5, where sal is salicylaldehyde and diimine is 2,2'-bipyridine (bpy, 1), 1,10-phenanthroline (phen, 2), 5,6-dimethyl-1,10-phenanthroline (5,6-dmp, 3), 3,4,7,8-tetramethyl-1,10-phenanthroline (3,4,7,8-tmp, 4) or dipyrido[3,2-d:2',3'-f]quinoxaline (dpq, 5), and [Cu(sal)(phen)(NO3)]2 (2a) have been successfully isolated and characterized by elemental analysis and other spectral techniques. The DNA binding and cleavage properties of 1-5 have been explored by using various physical and biochemical methods. The coordination geometry around copper(II) in the X-ray structures of 1, 2, 2a and 4 is described as an elongated octahedron. The UV-Vis and EPR spectral and ESI-MS studies reveal that in solution the dinuclear complexes dissociate into essentially mononuclear [Cu(sal)(diimine)]+ species with square-based geometry. The absorption spectral titrations and competitive DNA binding studies reveal that the intrinsic DNA binding affinity of the complexes depends upon the diimine co-ligand and is of the order of dpq (5) > 3,4,7,8-tmp (4) > 5,6-dmp (3) > phen (2) > bpy (1). The complexes 2 and 5 are involved in a partial intercalative interaction with DNA base pairs, while 3 and 4 are involved in a hydrophobic interaction with DNA and 1 is involved in an electrostatic interaction with DNA, which is supported by viscosity studies. Interestingly, only 3 and 4 are selective in exhibiting a positive induced CD band (ICD) upon binding to DNA suggesting that they induce a B to A conformational change in DNA. All the complexes exhibit an oxidative DNA cleavage ability, which varies as 5 > 4 > 3 > 2 > 1. While 4 and 5 are unique in displaying prominent double-strand DNA cleavage even in the absence of an activator, 2 and 3 display only single-strand DNA cleavage. Interestingly, all the complexes exhibit oxidative double-strand DNA cleavage in the presence of ascorbic acid, with 4 and 5 showing a DNA cleavage activity more prominent than 1 and 2. The ability of the complexes to bind and cleave the protein BSA varies in the order, 4 > 3 > 5 > 2 > 1. Interestingly, 3 and 4 cleave the protein in the presence of H2O2 as an activator in a non-specific manner suggesting that they can act as chemical proteases. It is remarkable that all the complexes exhibit cytotoxicity against human breast cancer cell lines (MCF-7) with a potency more than the widely used drug cisplatin indicating that they have the potential to act as effective anticancer drugs in a time dependent manner. The morphological assessment data obtained by using Hoechst 33258 staining reveal that 3 and 4 induce apoptosis much more effectively than the other complexes. Also, the alkaline single-cell gel electrophoresis study (comet assay) suggests that the same complexes induce DNA fragmentation more efficiently than others. PMID:24595529

  1. 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.

  2. 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

  3. 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…

  4. A chemical kinetic model for NO{sub x} removal in an aqueous scrubber system using the additive Fe[II]{center_dot}EDTA

    SciTech Connect

    Mendelsohn, M.H.; Livengood, C.D.

    1992-09-01

    Addition of the metal chelate, ferrous{center_dot} ethylenediaminetetraacetate anion (Fe[II]{center_dot}EDTA{sup 2{minus}}), has been shown to increase the amount of gaseous nitrogen oxides absorbed from a gas stream containing sulfur dioxide, where an aqueous scrubbing process is used to treat the gas. Recently, we published data on improved systems for NO{sub x} removal that incorporate an antioxidant and/or reducing agent (A/R) in the process along with the Fe[H]{center_dot}EDTA. The purpose of the A/R is to maintain the highest possible concentration of iron in the +2 form. The major mechanism for NO removal is believed to be the equilibrium reaction of Fe[II]{center_dot}EDTA with dissolved NO to form a Fe[II]{center_dot}EDTA{center_dot}NO complex. It has been shown that both sulfite and bisulfite anions can react with Fe[II]{center_dot}EDTA{center_dot}NO to regenerate Fe[II]{center_dot}EDTA and other products. In a complex system, other oxidation and reduction mechanisms are also possible. We have chosen, therefore, to approach this problem empirically by fitting our experimental data to a model containing at most three kinetic terms, chosen from among the following: a baseline removal rate, which is equivalent to the rate of reaction of Fe[II]{center_dot}EDTA with nitric oxide; a regeneration rate, which is equivalent to decomposition of the Fe[II]{center_dot}EDTA{center_dot}NO complex to Fe[II]{center_dot}EDTA; an oxidation rate, which is a combined rate for all possible oxidation reactions involving Fe[II]{center_dot}EDTA; and a reduction rate, which is a combined rate for all possible reduction reactions involving ferric-EDTA in the system.

  5. 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

  6. 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

  7. 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.

  8. 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

    Vcha, 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

  9. 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...

  10. 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.

  11. 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

  12. Accurate prediction of 195Pt NMR chemical shifts for a series of Pt(II) and Pt(IV) antitumor agents by a non-relativistic DFT computational protocol.

    PubMed

    Tsipis, Athanassios C; Karapetsas, Ioannis N

    2014-04-14

    The GIAO-PBE0/SARC-ZORA(Pt)?6-31+G(d)(E) (E = main group element) computational protocol without including relativistic and spin-orbit effects is offered here for the accurate prediction of the (195)Pt NMR chemical shifts of a series of cis-(amine)2PtX2 (X = Cl, Br, I) anticancer agents (in total 42 complexes) and cis-diacetylbis(amine)platinum(II) complexes (in total 12) in solutions employing the Polarizable Continuum Model (PCM) solvation model, thus contributing to the difficult task of computation of (195)Pt NMR. Calculations of the torsional energy curves along the diabatic (unrelaxed) rotation around the Pt-N bond of the cis-(amine)2PtX2 (X = Cl, Br, I) anticancer agents revealed the high sensitivity of the (195)Pt NMR chemical shifts to conformational changes. The crucial effect of the conformational preferences on the electron density of the Pt central atom and consequently on the calculated ?(195)Pt chemical shifts was also corroborated by the excellent linear plots of ?(calcd)((195)Pt) chemical shifts vs. the natural atomic charge Q(Pt). Furthermore, for the accurate prediction of the (195)Pt NMR chemical shifts of the cis-bis(amine)Pt(II) anticancer agents bearing carboxylato- as the leaving ligands (in total 8) and a series of octahedral Pt(IV) antitumor agents (in total 20 complexes) the non-relativistic GIAO-PBE0/SARC-ZORA(Pt)?6-31+G(d)(E) computational protocol performs best in combination with the universal continuum solvation model based on solute electron density called SMD for aqueous solutions. Despite neglecting relativistic and spin orbit effects the agreement of the calculated ?(195)Pt chemical shifts with experimental values is surprising probably due to effective error compensation. Moreover, the observed solvent effects on the structural parameters of the complexes probably overcome the relativistic effects, and therefore the successful applicability of the non-relativistic GIAO-PBE0/SARC-ZORA(Pt)?6-31+G(d)(E) computational protocol in producing reliable ?(calcd)((195)Pt) chemical shifts could be understood. In a few cases (e.g. the dihydroxo Pt(IV) complexes) the higher deviations of the calculated from the experimental values of ?(195)Pt chemical shifts are probably due to the fact that the experimental assignments refer to a different composition of the complexes in solutions than that used in the calculations, and different hydrogen bonding and formation of dimeric species. PMID:24519094

  13. 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 companion, while the stars on the low-carbon band are genuine fossil records of a gas cloud that has also been enriched by a faint supernova (SN) providing carbon and the lighter elements. The abundance pattern of the UIP stars shows a large star-to-star scatter in the [X/Ca] ratios for all elements up to aluminium (up to 1 dex), but this scatter drops for heavier elements and is at most of the order of a factor of two. We propose that this can be explained if these stars are formed from gas that has been chemically enriched by several SNe, that produce the roughly constant [X/Ca] ratios for the heavier elements, and in some cases the gas has also been polluted by the ejecta of a faint SN that contributes the lighter elements in variable amounts. The absence of lithium in four of the five known unevolved UIP stars can be explained by a dominant role of fragmentation in the formation of these stars. This would result either in a destruction of lithium in the pre-main-sequence phase, through rotational mixing or to a lack of late accretion from a reservoir of fresh gas. The phenomenon should have varying degrees of efficiency. Based on observations obtained at ESO Paranal Observatory, programme 091.D-0288, 091.D-0305, 189.D-0165.Appendix A is available in electronic form at http://www.aanda.orgTables 4 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/579/A28

  14. Correlation between ??Pt chemical shifts and the electronic transitions among d orbitals in pincer NCN Pt(II) complexes: A theoretical study and application of Ramsey's equation.

    PubMed

    Hashemi, Majid

    2015-12-01

    The chemical potentials for two series of [PtCl(NCN-Z-4)] (NCN=2,6-bis[(dimethylamino)methyl]phenyl, Z=H, CHO, COOH, NH2, OH, NO2, SiMe3, I, t-Bu) and [PtCl(NCN-4-CHN-C6H4-Z'-4')] (Z'=NMe2, Me, H, Cl, CN) were calculated. The energies of platinum d orbitals were calculated by NBO analysis. Good correlations were obtained between (195)Pt chemical shifts and the spectral parameters obtained from the energies of electronic transitions between Pt d orbitals in these complexes. The correlations between (195)Pt chemical shifts and the chemical potentials were also good. The correlations were discussed based on Ramsey's equation. PMID:26151432

  15. 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.

  16. Collecting Volcanic Gas Samples

    USGS Multimedia Gallery

    Steven Ingebritsen (lower right, in blue hat) kneels in the warm mud as he collects samples of the gases emitted from the fumaroles on the north side of Crater Rock on Mount Hood. The samples are taken back to the laboratory for an analysis of the gases' chemical composition. By routinely collecting...

  17. Synthesis and magnetic properties of a new family of macrocyclic M(II)3Ln(III) complexes: insights into the effect of subtle chemical modification on single-molecule magnet behavior.

    PubMed

    Feltham, Humphrey L C; Clrac, Rodolphe; Ungur, Liviu; Vieru, Veacheslav; Chibotaru, Liviu F; Powell, Annie K; Brooker, Sally

    2012-10-15

    Thirteen tetranuclear mixed-metal complexes of the hexaimine macrocycle (L(Pr))(6-) have been prepared in a one-pot 3:1:3:3 reaction of copper(II) acetate hydrate, the appropriate lanthanide(III) nitrate hydrate, 1,4-diformyl-2,3-dihydroxybenzene (1), and 1,3-diaminopropane. The resulting family of copper(II)-lanthanide(III) macrocyclic complexes has the general formula Cu(II)(3)Ln(III)(L(Pr))(NO(3))(3)solvents (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Tb, Ho, Er, Tm, or Yb). X-ray crystal structure determinations carried out on [Cu(3)Ce(L(Pr))(NO(3))(3)(MeOH)(3)] and [Cu(3)Dy(L(Pr))(NO(3))(3)(MeOH)(3)] confirmed that the large Ln(III) ion is bound in the central O(6) site and the three square pyramidal Cu(II) ions in the outer N(2)O(2) sites (apical donor either nitrate anion or methanol molecule) of the Schiff base macrocycle. Only the structurally characterized Cu(3)Tb complex, reported earlier, is a single-molecule magnet (SMM): the other 12 complexes do not exhibit an out-of-phase ac susceptibility signal or hysteresis of magnetization in a dc field. Ab initio calculations allowed us to rationalize the observed magnetic properties, including the significant impact of subtle chemical modification on SMM behavior. Broken-symmetry density functional theory (BS-DFT) calculations show there is a subtle structural balance as to whether the CuCu exchange coupling is ferro- or antiferromagnetic. Of the family of 13 magnetically characterized tetranuclear Cu(II)(3)Ln(III) macrocyclic complexes prepared, only the Tb(III) complex is an SMM: the theoretical reasons for this are discussed. PMID:23004914

  18. 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.

  19. 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.

  20. Feasibility study of sub-10-nm-half-pitch fabrication by chemically amplified resist processes of extreme ultraviolet lithography: II. Stochastic effects

    NASA Astrophysics Data System (ADS)

    Kozawa, Takahiro; Santillan, Julius Joseph; Itani, Toshiro

    2015-03-01

    Line edge roughness (LER) rapidly increases in the sub-10-nm-half-pitch region of resist processes used for the fabrication of semiconductor devices. Sub-10-nm fabrication with high throughput is a challenging task. In this study, the stochastic effects (LER and stochastic defect generation) of chemically amplified resist processes in the sub-10-nm-half-pitch node were investigated, assuming the use of extreme ultraviolet (EUV) lithography. The latent images were calculated by a Monte Carlo method on the basis of the sensitization and reaction mechanisms of chemically amplified EUV resists. 7-nm-half-pitch fabrication by chemically amplified resist processes is considered to be feasible. However, significant improvement in the efficiencies of the conversion processes from optical images to resist images is required.

  1. 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

  2. Analysis of chemical warfare agents. II. Use of thiols and statistical experimental design for the trace level determination of vesicant compounds in air samples.

    PubMed

    Muir, Bob; Quick, Suzanne; Slater, Ben J; Cooper, David B; Moran, Mary C; Timperley, Christopher M; Carrick, Wendy A; Burnell, Christopher K

    2005-03-18

    Thermal desorption with gas chromatography-mass spectrometry (TD-GC-MS) remains the technique of choice for analysis of trace concentrations of analytes in air samples. This paper describes the development and application of a method for analysing the vesicant compounds sulfur mustard and Lewisites I-III. 3,4-Dimercaptotoluene and butanethiol were used to spike sorbent tubes and vesicant vapours sampled; Lewisite I and II reacted with the thiols while sulfur mustard and Lewisite III did not. Statistical experimental design was used to optimise thermal desorption parameters and the optimum method used to determine vesicant compounds in headspace samples taken from a decontamination trial. 3,4-Dimercaptotoluene reacted with Lewisites I and II to give a common derivative with a limit of detection (LOD) of 260 microg m(-3), while the butanethiol gave distinct derivatives with limits of detection around 30 microg m(-3). PMID:15830938

  3. Chemical modification of class II G protein-coupled receptor ligands: frontiers in the development of peptide analogs as neuroendocrine pharmacological therapies.

    PubMed

    Chapter, Megan C; White, Caitlin M; DeRidder, Angela; Chadwick, Wayne; Martin, Bronwen; Maudsley, Stuart

    2010-01-01

    Recent research and clinical data have begun to demonstrate the huge potential therapeutic importance of ligands that modulate the activity of the secretin-like, Class II, G protein-coupled receptors (GPCRs). Ligands that can modulate the activity of these Class II GPCRs may have important clinical roles in the treatment of a wide variety of conditions such as osteoporosis, diabetes, amyotrophic lateral sclerosis and autism spectrum disorders. While these receptors present important new therapeutic targets, the large glycoprotein nature of their cognate ligands poses many problems with respect to therapeutic peptidergic drug design. These native peptides often exhibit poor bioavailability, metabolic instability, poor receptor selectivity and resultant low potencies in vivo. Recently, increased attention has been paid to the structural modification of these peptides to enhance their therapeutic efficacy. Successful modification strategies have included d-amino acid substitutions, selective truncation, and fatty acid acylation of the peptide. Through these and other processes, these novel peptide ligand analogs can demonstrate enhanced receptor subtype selectivity, directed signal transduction pathway activation, resistance to proteolytic degradation, and improved systemic bioavailability. In the future, it is likely, through additional modification strategies such as addition of circulation-stabilizing transferrin moieties, that the therapeutic pharmacopeia of drugs targeted towards Class II secretin-like receptors may rival that of the Class I rhodopsin-like receptors that currently provide the majority of clinically used GPCR-based therapeutics. Currently, Class II-based drugs include synthesized analogs of vasoactive intestinal peptide for type 2 diabetes or parathyroid hormone for osteoporosis. PMID:19686775

  4. 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

  5. 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.

  6. In-Situ Study of Chemical Versus Biogenic Iron Mineral (Trans)formation with the Miniaturized Backscattering Mssbauer Spectrometer MIMOS II

    NASA Astrophysics Data System (ADS)

    Markovski, C.; Byrne, J.; Schrder, C.; Kappler, A.; Klingelhfer, G.

    2014-07-01

    The purpose of this study is to develop new methods of monitoring biogenic and chemical iron (oxyhydr)oxide mineral transformations in-situ, with the eventual aim of searching for clues of biological processes which may have once occurred on Mars.

  7. 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...

  8. 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…

  9. 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.

  10. 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

  11. 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.

  12. 77 FR 52368 - Manufacturer of Controlled Substances; Notice of Registration; American Radiolabeled Chemicals, Inc.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-29

    ..., 77 FR 30027, American Radiolabeled Chemicals, INC., 101 Arc Drive, St. Louis, Missouri 63146, made... (8501) II Cocaine (9041) II Codeine (9050) II Dihydrocodeine (9120) II Oxycodone (9143) II...

  13. 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 ?-cadinene (12.92%), ?-pinene (10.3%), myrcene (8.64%), ?-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 toxic effect of higher dose. ED50 value for Teucrium stocksianum was calculated as 31.5??1.72415?mg/kg (b.w). Conclusion Our results indicate that there is a lot of variation in the composition of essential oil of Teucrium stocksianum boiss, which may be due to different climatic and experimental conditions. Secondly, the essential oil possesses strong antinociceptive activity and could be used in analgesic preparations especially for topical use. PMID:23217213

  14. 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 compounds. An android application of ChemDP is available at its website. The ChemDP is freely accessible at www.chemdp.com. PMID:26343150

  15. 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.

  16. Trace metals in PM10 and PM 2.5 samples collected in a highly industrialized chemical/petrochemical area and its urbanized surroundings.

    PubMed

    dos Anjos Paulino, Silvia; Oliveira, Rafael Lopes; Loyola, Josiane; Minho, Alan Silva; Arbilla, Graciela; Quiterio, Simone Lorena; Escaleira, Viviane

    2014-05-01

    The aim of this study was to determine the potential impact of a highly industrialized area on its urbanized surroundings. The area studied is home to a refinery, a thermoelectric plant and several petrochemical facilities industries. The concentrations of twelve elements were determined in PM10 and PM2.5 samples collected along a busy highway and near the petrochemical complex. Significantly higher concentrations of Ca, Mg, Mn, Fe, Cu and Al were observed in the petrochemical zone, but principal component analysis revealed similar patterns for both the highway site and a site approximately 1.5 km from the petrochemical complex, suggesting that the main pollution source in the area is vehicular flux. Higher concentrations in the industrial area may be attributed to intense diesel-powered truck and bus traffic movement, mainly due to the transport of supplies, fuel and gas. The observed concentrations of the elements Cr, Co, Ni, Cd and Pb were always lower than the detection limits of the technique used. PMID:24509656

  17. 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 efficient mixing of chemical elements. The lower [Na/Fe] and [Zn/Fe] observed in stars with the outer halo kinematics may further suggest that progenitors with longer star formation timescales contributed to the buildup of the relatively metal-rich part of stellar halos.

  18. Case study II: application of the divalent cation bridging theory to improve biofloc properties and industrial activated sludge system performance-using alternatives to sodium-based chemicals.

    PubMed

    Higgins, Matthew J; Sobeck, David C; Owens, Steven J; Szabo, Lynn M

    2004-01-01

    The objective of this study was to investigate the application of the divalent cation bridging theory (DCBT) as a tool in the chemical selection process at an activated sludge plant to improve settling, dewatering, and effluent quality. According to the DCBT, to achieve improvements, the goal of chemical selection should be to reduce the ratio of monovalent-to-divalent (M/D) cations. A study was conducted to determine the effect of using magnesium hydroxide [Mg(OH)2] as an alternative to sodium hydroxide (NaOH) at a full-scale industrial wastewater treatment plant. Floc properties and treatment plant performance were measured for approximately one year during two periods of NaOH addition and Mg(OH)2 addition. A cost analysis of plant operation during NaOH and Mg(OH)2 use was also performed. During NaOH addition, the M/D ratio was 48, while, during Mg(OH)2 addition, this ratio was reduced to an average of approximately 0.1. During the Mg(OH)2 addition period, the sludge volume index, effluent total suspended solids, and effluent chemical oxygen demand were reduced by approximately 63, 31, and 50%, respectively, compared to the NaOH addition period. The alum and polymer dose used for clarification was reduced by approximately 50 and 60%, respectively, during Mg(OH)2 addition. The dewatering properties of the activated sludge improved dewatering as measured by decreased capillary suction time and specific resistance to filtration (SRF), along with an increase in cake solids from the SRF test. This corresponded to a reduction in the volume of solids thickened by centrifuges at the treatment plant, which reduced the disposal costs of solids. Considering the costs for chemicals and solids disposal, the annual cost of using Mg(OH)2 was approximately 30,000 dollars to 115,000 dollars less than using NaOH, depending on the pricing of NaOH. The results of this study confirm that the DCBT is a useful tool for assessing chemical-addition strategies and their potential effect on activated sludge performance. PMID:15508426

  19. Chemical and Temporal Characteristics of Saharan dust Episodes Inferred from Aerosols Collected over the Subtropical North Atlantic - A Link to the North Atlantic Oscillation Revisited

    NASA Astrophysics Data System (ADS)

    Tomza, U.; Arimoto, R.

    2001-12-01

    We studied temporal patterns of Saharan dust transported from source regions in North Africa to three sites in the North Atlantic Ocean: Izania (Canary Islands), Barbados (West Indies), and Bermuda. Samples representing dust episodes were selected from daily air filters based on a semi-quantitative color-based method and validated by comparing their elemental composition with the previously obtained data for Saharan dust and aerosols. Out of more than 6000 aerosol samples collected for the Atmosphere/Ocean Chemistry Experiment (AEROCE) over the period of ten years (1989-1998), about 2000 air filters displayed brown color deposit indicative to the presence of mineral dust. The absolute concentrations (ppm) of 33 elements (Na, Mg, Al, Cl, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Br, Rb, Sb, I, Cs, Ba, La, Ce, Nd, Sm, Eu, Tb, Yb, Lu, Hf, Ta, and Th) in Saharan aerosol sampled at Barbados and Izania were calculated using the measured Al to ash ratio of 0.104 in brown color samples. For Izania and Barbados, annual concentrations of aluminum, an indicator of atmospheric dust, revealed weak but significant correlation with the annual North Atlantic Oscillation Index (NOA). On a more detail scale, however, a time series of average monthly dust concentrations (1989-1998) for these two sites was generally out of phase with NAO index but become correlated when the dust time series were lagged by 2 to 6 months. This finding brings a new insight to the relationship between dust production and climate modes especially in assessing the contribution of soil condition and transport variations to dust concentration over the North Atlantic Ocean.

  20. Chemical composition, sources, and deposition fluxes of water-soluble inorganic ions obtained from precipitation chemistry measurements collected at an urban site in northwest China.

    PubMed

    Shen, Zhenxing; Zhang, Leiming; Cao, Junji; Tian, Jing; Liu, Li; Wang, Geihui; Zhao, Zhuzi; Wang, Xin; Zhang, Renjian; Liu, Suixin

    2012-11-01

    Precipitation samples were collected at an urban site in Xi'an, northwest China during March to November in 2009 and were then analyzed to determine the pH and concentrations of water-soluble inorganic ions (Na(+), NH(4)(+), K(+), Mg(2+), Ca(2+), SO(4)(2-), NO(3)(-), Cl(-), and F(-)) in precipitation. The pH of precipitation ranged from 4.1 to 7.6 for all of the samples with an annual volume-weighted mean of 6.4. While a large portion of the precipitation events were weakly acidic or alkaline, around 30% of the precipitation events in the autumn were strongly acidic. Precipitation events with air masses from the northeast and the southeast were weakly acidic while those with air masses from the northwest and the southwest were alkaline. SO(4)(2-), Ca(2+), NH(4)(+), and NO(3)(-) were dominant ions in the precipitation, accounting for 37%, 25%, 18%, and 9%, respectively, of the total analyzed ions. Ca(2+) and NH(4)(+) were found to be the major neutralizers of precipitation acidity; however, the contribution of Mg(2+), although much lower than those of Ca(2+) and NH(4)(+), was important, in many cases, in changing the precipitation from weakly acidic to weakly alkaline. Enrichment factor analysis confirmed that SO(4)(2-) and NO(3)(-) were produced from anthropogenic sources, Ca(2+), K(+), and 80% Mg(2+) were from crustal sources, and Na(+), Cl(-), and ?20% of Mg(2+) were from marine sources. The annual wet depositions were estimated to be 3.5 t km(-2) per year for sulfur; 2.3 t km(-2) per year for nitrogen, of which 0.8 t km(-2) per year was oxidized nitrogen and 1.5 t km(-2) per year was reduced nitrogen; and 3.0 t km(-2) per year for Ca(2+). PMID:23023835

  1. 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 making for law enforcement, military, and civilian emergency organizations and responders, providing critical information in a contaminated environment scenario when time is of the essence. PMID:23902152

  2. 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

  3. 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...

  4. How the choice of a computational model could rule the chemical interpretation: the Ni(II) catalyzed ethylene dimerization as a case study.

    PubMed

    Tognetti, Vincent; Le Floch, Pascal; Adamo, Carlo

    2010-04-15

    In this article, we present a critical study of the theoretical protocol used for the determination of the nickel(II) catalyzed ethylene dimerization mechanism, considered as a representative example of the various problems related to the modeling a catalytic cycle. The choice of an appropriate computational procedure is indeed crucial for the validity of the conclusions that will be drawn from the computational process. The influence of the exchange-correlation functional on energetic profiles and geometries, the role of the basis set describing the metal atom, as well as the importance of the chosen molecular model, have been thus examined in details. From the obtained results, some general conclusions and guidelines are presented, which could constitute useful warnings in modeling homogenous catalysis. Besides, the database constituted by our high-level calculations can be used within benchmarking procedures to assess the performances of new computational methods based on density functional theory. PMID:19821515

  5. 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

    X-ray pair distribution function (pdf) and U L3 extended x-ray absorption fine structure (EXAFS) and neutron pdf measurements that give identical results for UO2 show U(VI)-oxo moieties with x rays for mixed valence U4O9 and U3O7, in contrast to the neutron data that indicate only U(V) sites with no short U-O bonds as well as other differences. In addition, although the EXAFS spectra of UO2 are essentially identical at 30, 100, and 200 K, those of the UO2+x compounds exhibit different nearest-neighbor U-O distributions at each temperature. Further tunneling polaron-type behavior is found in the broadening of the features of the O K-edge x-ray absorption spectra (XAS) of the UO2+x compounds. Raman spectra of powders also show a large increase in scattering cross section with increasing O content that would originate in a change in the electronic structure that increases the overall polarizability. The XAS and Raman also show that U4O9 does not behave as a linear combination of the UO2 and U3O7 fluorite endpoints. The properties induced by mobile rather than static charged quasiparticles were explored by optical pumping of the metal-to-metal charge-transfer transition. The temperature dependence of 4.71 eV pump-1.57 eV probe reflectivity on UO2 that initially populates the U 6d-dominated portion of the upper Hubbard band (UHB) shows a sharp 28-?sec lifetime peak at 25 K that may be associated with the fluctuations of its antiferromagnetic transition. Pumping at 3.14 eV into the 5f-dominated portion of the UHB shows an analogous 2.8-?sec peak but also a plateau bracketing this peak that ends in a cusp at 50-60 K and an abrupt change in the hardening rate of a novel 12-15 GHz phonon that is the signature for the quasiparticle quantum phase. The different results for the different excitation channels indicate a highly specific nonthermal relaxation mechanism. These results constitute the first observation of a distinct phase of photoinduced quasiparticles that is 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.

  6. 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;…

  7. 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;

  8. Theoretical study of fabrication of line-and-space patterns with 7 nm quarter-pitch using electron beam lithography with chemically amplified resist processes: II. Stochastic effects

    NASA Astrophysics Data System (ADS)

    Kozawa, Takahiro

    2015-09-01

    Electron beam (EB) lithography is a core technology for nanofabrication. Owing to the increasing demand for high-resolution semiconductor lithography, the requirements for the resist processes of EB lithography for the photomasks used in ArF immersion and extreme ultraviolet lithographies and the mold fabrication of nanoimprints have also become stricter. In this study, the feasibility of single nano patterning by EB lithography with a chemically amplified resist process was investigated from the viewpoint of stochastic effects. The latent images of line-and-space patterns with a 7 nm quarter-pitch (7 nm space width and 21 nm line width) were calculated using a Monte Carlo method on the basis of the sensitization and reaction mechanisms of chemically amplified EB resists. Compared with the line-and-space pattern with a 7 nm half-pitch, line edge roughness (LER) and the stochastic pinching generation are considered to be significantly improved by increasing the pitch. It was found that the suppression of the stochastic generation of bridges is the critical issue in 7 nm quarter-pitch fabrication.

  9. 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, Purificacin; Bueno, Mnica; 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 ?-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

  10. Common effect of chemical and external pressures on the magnetic properties of R CoPO (R =La ,Pr ,Nd ,Sm ). II.

    NASA Astrophysics Data System (ADS)

    Prando, G.; Profeta, G.; Continenza, A.; Khasanov, R.; Pal, A.; Awana, V. P. S.; Büchner, B.; Sanna, S.

    2015-10-01

    We investigate the direct correspondence between Co band ferromagnetism and structural parameters in the pnictide oxides R CoPO for different rare-earth ions (R =La ,Pr ,Nd ,Sm ) by means of muon-spin spectroscopy and ab initio calculations, complementing our results published previously [G. Prando et al., Common effect of chemical and external pressures on the magnetic properties of R CoPO (R =La ,Pr ), Phys. Rev. B 87, 064401 (2013), 10.1103/PhysRevB.87.064401]. We find that both the transition temperature to the ferromagnetic phase TC and the volume of the crystallographic unit cell V are conveniently tuned by the R ionic radius and/or external pressure. We report a linear correlation between TC and V and our ab initio calculations unambiguously demonstrate a full equivalence of chemical and external pressures. As such, we show that R ions influence the ferromagnetic phase only via the induced structural shrinkage without involving any active role from the electronic f degrees of freedom, which are only giving a sizable magnetic contribution at much lower temperatures.

  11. 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.

  12. 75 FR 8996 - Notice of Information Collection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-26

    ... Directorates and current NASA missions in Earth and Space Science, mathematics, chemistry, and physics. II. Method of Collection The data collection uses web-based surveys, telephone interviews and in person...

  13. 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.

  14. 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; Snchez-Camargo, Andrea P; Garca-Caas, Virginia; Tanniou, Analle; Stiger-Pouvreau, Valrie; Russo, Mariateresa; Rastrelli, Luca; Cifuentes, Alejandro; Herrero, Miguel; Ibez, 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 HILICRP-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

  15. Construction of collagen II/hyaluronate/chondroitin-6-sulfate tri-copolymer scaffold for nucleus pulposus tissue engineering and preliminary analysis of its physico-chemical properties and biocompatibility.

    PubMed

    Li, Chang-Qing; Huang, Bo; Luo, Gang; Zhang, Chuan-Zhi; Zhuang, Ying; Zhou, Yue

    2010-02-01

    To construct a novel scaffold for nucleus pulposus (NP) tissue engineering, The porous type II collagen (CII)/hyaluronate (HyA)-chondroitin-6-sulfate (6-CS) scaffold was prepared using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and N-hydroxysuccinimide (NHS) cross-linking system. The physico-chemical properties and biocompatibility of CII/HyA-CS scaffolds were evaluated. The results suggested CII/HyA-CS scaffolds have a highly porous structure (porosity: 94.8 +/- 1.5%), high water-binding capacity (79.2 +/- 2.8%) and significantly improved mechanical stability by EDC/NHS crosslinking (denaturation temperature: 74.6 +/- 1.8 and 58.1 +/- 2.6 degrees C, respectively, for the crosslinked scaffolds and the non-crosslinked; collagenase degradation rate: 39.5 +/- 3.4 and 63.5 +/- 2.0%, respectively, for the crosslinked scaffolds and the non-crosslinked). The CII/HyA-CS scaffolds also showed satisfactory cytocompatibility and histocompatibility as well as low immunogenicity. These results indicate CII/HyA-CS scaffolds may be an alternative material for NP tissue engineering due to the similarity of its composition and physico-chemical properties to those of the extracellular matrices (ECM) of native NP. PMID:19763796

  16. Chemical evolution of the Galactic bulge as traced by microlensed dwarf and subgiant stars. II. Ages, metallicities, detailed elemental abundances, and connections to the Galactic thick disc

    NASA Astrophysics Data System (ADS)

    Bensby, T.; Feltzing, S.; Johnson, J. A.; Gould, A.; Adn, D.; Asplund, M.; Melndez, J.; Gal-Yam, A.; Lucatello, S.; Sana, H.; Sumi, T.; Miyake, N.; Suzuki, D.; Han, C.; Bond, I.; Udalski, A.

    2010-03-01

    Context. The Bulge is the least understood major stellar population of the Milky Way. Most of what we know about the formation and evolution of the Bulge comes from bright giant stars. The underlying assumption that giants represent all the stars, and accurately trace the chemical evolution of a stellar population, is under debate. In particular, recent observations of a few microlensed dwarf stars give a very different picture of the evolution of the Bulge from that given by the giant stars. Aims: We aim to resolve the apparent discrepancy between Bulge metallicity distributions derived from microlensed dwarf stars and giant stars. Additionally, we aim to put observational constraints on the elemental abundance trends and chemical evolution of the Bulge. Methods: We perform a detailed elemental abundance analysis of dwarf stars in the Galactic bulge, based on high-resolution spectra that were obtained while the stars were optically magnified during gravitational microlensing events. The analysis method is the same as for a large sample of F and G dwarf stars in the Solar neighbourhood, enabling a fully differential comparison between the Bulge and the local stellar populations in the Galactic disc. Results: We present detailed elemental abundances and stellar ages for six new dwarf stars in the Galactic bulge. Combining these with previous events, here re-analysed with the same methods, we study a homogeneous sample of 15 stars, which constitute the largest sample to date of microlensed dwarf stars in the Galactic bulge. We find that the stars span the full range of metallicities from [Fe/H] = -0.72 to +0.54, and an average metallicity of < [Fe/H]> = -0.08 0.47, close to the average metallicity based on giant stars in the Bulge. Furthermore, the stars follow well-defined abundance trends, that for [Fe/H]<0 are very similar to those of the local Galactic thick disc. This suggests that the Bulge and the thick disc have had, at least partially, comparable chemical histories. At sub-solar metallicities we find the Bulge dwarf stars to have consistently old ages, while at super-solar metallicities we find a wide range of ages. Using the new age and abundance results from the microlensed dwarf stars we investigate possible formation scenarios for the Bulge. Based on observations made with the European Southern Observatory telescopes, Program IDs 082.B-0453 and 083.B-0265.Table 5 is also available in electronic form at the CDS and full Table 4 is 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/512/A41

  17. 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.

  18. Quantum chemical QSAR models to distinguish between inhibitory activities of sulfonamides against human carbonic anhydrases I and II and bovine IV isozymes.

    PubMed

    Deeb, Omar; Goodarzi, Mohammad; Khadikar, Padmaker V

    2012-04-01

    Linear and nonlinear quantitative structure activity relationship models for predicting the inhibitory activities of sulfonamides toward different carbonic anhydrase isozymes were developed based on multilinear regression, principal component-artificial neural network and correlation ranking-principal component analysis, to identify a set of structurally based numerical descriptors. Multilinear regression was used to build linear quantitative structure activity relationship models using 53 compounds with their quantum chemical descriptors. For each type of isozyme, separate quantitative structure activity relationship models were obtained. It was found that the hydration energy plays a significant role in the binding of ligands to the CAI isozyme, whereas the presence of five-membered ring was detected as a major factor for the binding to the CAII isozyme. It was also found that the softness exhibited significant effect on the binding to CAIV isozyme. Principal component-artificial neural network and correlation ranking-principal component analysis analyses provide models with better prediction capability for the three types of the carbonic anhydrase isozyme inhibitory activity than those obtained by multilinear regression analysis. The best models, with improved prediction capability, were obtained for the hCAII isozyme activity. Models predictivity was evaluated by cross-validation, using an external test set and chance correlation test. PMID:22181786

  19. Combustion mechanism of double-base propellant containing nitrogen heterocyclic nitroamines (II): The temperature distribution of the flame and its chemical structure

    NASA Astrophysics Data System (ADS)

    Yan, Qi-Long; Song, Zhen-Wei; Shi, Xiao-Bing; Yang, Zhi-Yuan; Zhang, Xiao-Hong

    2009-03-01

    In order to evaluate the actual pros and cons in the use of new nitroamines for solid rocket applications, the combustion properties of double-base propellants containing nitrogen heterocyclic nitroamines such as RDX, TNAD, HMX and DNP are investigated by means of high-speed photography technique, Non-contact wavelet-based measurement of flame temperature distribution. The chemical reactions in different combustion zone which control the burning characteristics of the double-base propellant containing nitrogen heterocyclic nitroamines were systematically investigated and descriptions of the detailed thermal decomposition mechanisms from solid phase to liquid phase or to gas phase are also included. It was indicated that the thermodynamic phase transition consisting of both evaporation and condensation of NC+NG, HMX, TNAD, RDX and DNP, are considered to provide a complete description of the mass transfer process in the combustion of these double-base propellants, and the combustion mechanisms of them are mainly involved with the oxidation mechanism of the NO 2, formaldehyde (CH 2O) and hydrogen cyanide (HCN). The entire oxidation reaction rate might be dependent on the pressure of the combustion chamber and temperature of the gas phase.

  20. 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.

  1. Chemical analysis of acidic silicon etch solutions II. Determination of HNO(3), HF, and H(2)SiF(6) by ion chromatography.

    PubMed

    Acker, Jrg; Henge, Antje

    2007-06-15

    The processing of silicon in microelectronics and photovoltaics involves the isotropic chemical etching using HF-HNO(3) mixtures to clean the surface from contaminations, to remove the saw damage, as well as to polish or to texture the wafer surface. Key element of an effective etch process control is the knowledge of the actual etch bath composition in order to maintain a certain etch rate by replenishment of the consumed acids. The present paper describes a methods for the total analysis of the etch bath constituents HF, HNO(3), and H(2)SiF(6) by ion chromatography. First step is the measurement of the total fluoride and nitrate content in the analyte. In a second step, H(2)SiF(6) is precipitated as K(2)SiF(6). After careful filtration of the precipitate, the fluoride concentration in the filtrate is measured and the content of free HF is calculated therefrom. The K(2)SiF(6) is dissolved again and the fluoride content measured and recalculated as H(2)SiF(6). The results obtained with the presented method are discussed with respect to the results from two other, previously published methods, based on a titration using methanolic cyclohexylamine solution as titrant and based on a method using a fluoride ion selective electrode (F-ISE). An evaluation with respect to the needs for an industrial application is given. PMID:19071795

  2. 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.

  3. 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…

  4. 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.

  5. 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)

  6. 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

    NASA Astrophysics Data System (ADS)

    Ochoa, C.; Baumgardner, D.; Grutter, M.; Allan, J.; Fast, J.; Rappenglueck, B.

    2012-11-01

    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 the air masses. In the current evaluation, the temperature, water vapor mixing ratio (WMR), ozone (O3), carbon monoxide (CO), sulfur dioxide (SO2) and acyl peroxy nitrate (APN) are simulated with the WRF-Chem chemical transport model and compared with the measurements at the mountain site. Comparisons between the model and measurements are also evaluated for particle size distributions (PSDs) of the mass concentrations of sulfate, nitrate, ammonium and organic mass (OM). The model predictions of the diurnal trends in temperature, WMR and trace gases were generally well correlated; 13 of the 18 correlations were significant at a confidence level of <0.01. Less satisfactory were the average hourly differences between model and measurements that showed predicted values within expected, natural variation for only 10 of the 18 comparisons. The model performed best when comparing with the measurements during periods when the air originated from the east. In that case all six of the parameters being compared had average differences between the model and measurements less than the expected standard deviation. For the cases when the air masses are from the southwest or west northwest, only two of the comparisons from each case showed differences less than the expected standard deviation. The differences appear to be a result of an overly rapid growth of the boundary layer predicted by the model and too much dilution. There also is more O3 being produced, most likely by photochemical production, downwind of the emission sources than is predicted by the model. The measured and modeled PSD compare very well with respect to their general shape and the diameter of the peak concentrations. The spectra are log normally distributed with most of the mass in the accumulation mode centered at 200 ± 20 nm and little observed or predicted changes with respect to the time when the RML is above the Altzomoni research station. Only the total mass changes with time and air mass origin. The invariability of 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. This could greatly simplify parameterization in climate models although it is not known at this time if this invariance can be extended to other megacity regions.

  7. 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).

  8. 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

  9. 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.

  10. The Stellar Abundances for Galactic Archaeology (SAGA) data base - II. Implications for mixing and nucleosynthesis in extremely metal-poor stars and chemical enrichment of the Galaxy

    NASA Astrophysics Data System (ADS)

    Suda, Takuma; Yamada, Shimako; Katsuta, Yutaka; Komiya, Yutaka; Ishizuka, Chikako; Aoki, Wako; Fujimoto, Masayuki Y.

    2011-04-01

    We discuss the characteristics of known extremely metal-poor (EMP) stars in the Galaxy using the Stellar Abundances for Galactic Archaeology (SAGA) data base. We find the transition of the initial mass function to be at [Fe/H]-2 from the viewpoint of the distribution of carbon abundance and the frequency of carbon-enhanced stars. Analyses of carbon-enhanced stars in our sample suggest that nucleosynthesis in asymptotic giant branch (AGB) stars can contribute to carbon enrichment in a different way depending on whether the metallicity is above or below [Fe/H]-2.5, which is consistent with the current models of stellar evolution at low metallicity. For observed EMP stars, we confirm that some, though not all, observed stars might have undergone at least two types of extra mixing to change their surface abundances. One is the depletion of lithium abundance during the early phase of the red giant branch; the other is a decrease of the C/N ratio by one order of magnitude during the red giant branch phase. Observed small scatters of abundances for ?-elements and iron-group elements suggest that the chemical enrichment of our Galaxy takes place in a well-mixed interstellar medium. The abundance trends of ?-elements are highly correlated with each other including ?-enhanced and depleted stars, while the abundances of iron-group elements are subject to different slopes relative to the iron abundance. This implies that the supernova yields of ?-elements are almost independent of mass and metallicity, while those of iron-group elements have a metallicity dependence or mass dependence on the variable initial mass function. The occurrence of the hot-bottom burning for M? 5 M? is consistent with an initial mass function of the Galaxy peaked at 10-12 M?, compatible with the statistics of carbon-enhanced stars with and without s-process element enhancement and nitrogen-enhanced stars. For s-process elements, we find not only a positive correlation between carbon and s-process element abundances, but also an increasing slope of the abundance ratio between them with increasing mass number of s-process elements. The dominant site of the s-process is still an open question because none of the known mechanisms for the s-process is able to account for this observed correlation. In spite of the evidence of AGB evolution in observed abundances of EMP stars, any evidence of binary mass transfer is elusive by pursuing the effect of dilution in the convective envelope. We find the dependence of sulphur and vanadium abundances on the effective temperatures, in addition to the previously reported trends for silicon, scandium, titanium, chromium and cobalt.

  11. Ancient graphite in the Eoarchean quartz-pyroxene rocks from Akilia in southern West Greenland II: Isotopic and chemical compositions and comparison with Paleoproterozoic banded iron formations

    NASA Astrophysics Data System (ADS)

    Papineau, Dominic; De Gregorio, Bradley T.; Stroud, Rhonda M.; Steele, Andrew; Pecoits, Ernesto; Konhauser, Kurt; Wang, Jianhua; Fogel, Marilyn L.

    2010-10-01

    We present detailed petrographic surveys of apatite grains in association with carbonaceous material (CM) in two banded iron formations (BIFs) from the Paleoproterozoic of Uruguay and Michigan for comparison with similar mineral associations in the highly debated Akilia Quartz-pyroxene (Qp) rock. Petrographic and Raman spectroscopic surveys of these Paleoproterozoic BIFs show that apatite grains typically occur in bands parallel to bedding and are more often associated with CM when concentrations of organic matter are high. Carbonaceous material in the Vichadero BIF from Uruguay is generally well-crystallized graphite and occurs in concentrations around 0.01 wt% with an average δ 13C gra value of -28.6 ± 4.4‰ (1 σ). In this BIF, only about 5% of apatite grains are associated with graphite. In comparison, CM in the Bijiki BIF from Michigan is also graphitic, but occurs in concentrations around 2.4 wt% with δ 13C gra values around -24.0 ± 0.3‰ (1 σ). In the Bijiki BIF, more than 78% of apatite grains are associated with CM. Given the geologic context and high levels of CM in the Bijiki BIF, the significantly higher proportion of apatite grains associated with CM in this rock is interpreted to represent diagenetically altered biomass and shows that such diagenetic mineral associations can survive metamorphism up to the amphibolite facies. Isotope compositions of CM in muffled acidified whole-rock powders from the Akilia Qp rock have average δ 13C gra values of -17.5 ± 2.5‰ (1 σ), while δ 13C carb values in whole-rock powders average -4.0 ± 1.0‰ (1 σ). Carbon isotope compositions of graphite associated with apatite and other minerals in the Akilia Qp rock were also measured with the NanoSIMS to have similar ranges of δ 13C gra values averaging -13.8 ± 5.6‰ (1 σ). The NanoSIMS was also used to semi-quantitatively map the distributions of H, N, O, P, and S in graphite from the Akilia Qp rock, and relative abundances were found to be similar for graphite associated with apatite or with hornblende, calcite, and sulfides. These analyses revealed generally lower abundances of trace elements in the Akilia graphite compared to graphite associated with apatite from Paleoproterozoic BIFs. Graphite associated with hornblende, calcite, and sulfides in the Akilia Qp rock was fluid-deposited at high-temperature from carbon-bearing fluids, and since this graphite has similar ranges of δ 13C gra values and of trace elements compared to graphite associated with apatite, we conclude that the Akilia graphite in different mineral associations formed from the same source(s) of CM. Collectively our results do not exclude a biogenic origin of the carbon in the Akilia graphite, but because some observations can not exclude graphitization of abiogenic carbon from CO 2- and CH 4-bearing mantle fluids, there remain ambiguities with respect to the exact origin of carbon in this ancient metasedimentary rock. Accordingly, there may have been several generations of graphite formation along with possibly varying mixtures of CO 2- and CH 4-bearing fluids that may have resulted in large ranges of δ 13C gra values. The possibility of fluid-deposited graphite associated with apatite should be a focus of future investigations as this may prove to be an alternative pathway of graphitization from phosphate-bearing fluids. Correlated micro-analytical approaches tested on terrestrial rocks in this work provide insights into the origin of carbon in ancient graphite and will pave the way for the search for life on other ancient planetary surfaces.

  12. 76 FR 60004 - Proposed Information Collection; Comment Request; Data Collection and Verification for the Marine...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-28

    ... Collection and Verification for the Marine Protected Areas Inventory AGENCY: National Oceanic and Atmospheric... the goals and objectives of the national system of MPAs. II. Method of Collection The information...

  13. 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 ...

  14. Chemical Peels

    MedlinePLUS

    ... Z Diseases and treatments A - D Chemical peel Chemical peels Also called chemexfoliation , derma peeling Do you ... the cost of cosmetic treatments. Learn more about chemical peels: Is a chemical peel the right choice ...

  15. 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…

  16. Data Collection

    USGS Multimedia Gallery

    A view of the various systems that are used for navigation, logging, and data collection during the trip. The USGS returned from a seafloor data mapping mission offshore of the Delmarva Peninsula (Ocean City, MD) on July 25th, 2014. The data collected is foundational to our continued understanding ...

  17. 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

  18. 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…

  19. 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

  20. 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.

  1. 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)

  2. Cold acid elution (ELU Kit II).

    PubMed

    Hinrichs, Monica; Keith, Monica A

    2014-01-01

    Elution is a procedure for recovery of antibody attached to intact,immunoglobulin-coated red blood cells (RBCs) by disrupting the antigen-antibody bonds. The recovered antibody is collected in an inert diluent and is referred to as an eluate. Testing of an eluate may be desired to identify antibody(ies) coating the RBCs of patients with a positive direct antiglobulin test. Many types of elution procedures have been developed and described; however,an acid elution is suitable for antibody recovery in most cases, such as recovery of alloantibodies and warm-reactive autoantibodies.Studies have compared methods such as xylene, chloroform, digitnin acid, dichloromethane, citric acid, and Immucor Elu-KitII (cold acid elution). The ELU-Kit II has been shown to be quick and effective at eluting a wide range of alloantibodies as well as autoantibodies without the use of hazardous chemicals or costly reagent preparation time that some methods use. It is for these reasons that the ELU-Kit II is a very popular method for the elution of immunoglobulin G (IgG) antibodies. PMID:25695435

  3. 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.

  4. CDF Run II status and prospects

    SciTech Connect

    C. Pagliarone

    2003-02-06

    Run II at the Tevatron Collider started at the beginning of March 2001. With extensive upgrades on both detectors and electronics the CDF II began to collect data. This paper reviews early Run II physics results obtained by analyzing data collected before the middle of June 2002. At the present the understanding of the detector performances is rather high so many analysis are already underway.

  5. 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

  6. The Tox21 robotic platform for assessment of environmental chemicals - from vision to reality

    PubMed Central

    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

    2013-01-01

    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

  7. 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)

  8. Collectible Aesthetics.

    ERIC Educational Resources Information Center

    Burton, David

    1989-01-01

    Shows how the advertisement copy for "collectible art" can be used to develop a definition of art. Suggests that middle and high school students should look at the criteria for art offered in the advertisements. Recommends they analyze the terminology used to convince the lay person that the object is "genuine" art. (LS)

  9. Collecting Samples

    USGS Multimedia Gallery

    Collecting Samples at Embden 3. Embden 3 is a 60-degree V trapezoidal flume in a bured concreate culvert located on the other side of the north-south road east of the large data shelter. The flow is measured and sampled from the V flume underground and periodic QW grab samples are taken form the blu...

  10. 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

  11. 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…

  12. 78 FR 7463 - Information Collection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-01

    ... to submit new technology reports indicating new inventions and patents. II. Method of Collection... hyperlink to the electronic New Technology Reporting Web (eNTRe) site http://invention.nasa.gov . This Web..., grants, cooperative agreements, and subcontracts) to report new technology and patent...

  13. Physical and chemical characteristics including total and geochemical forms of phosphorus in sediment from the top 30 centimeters of cores collected in October 2006 at 26 sites in Upper Klamath Lake, Oregon

    USGS Publications Warehouse

    Simon, Nancy S.; Ingle, Sarah N.

    2011-01-01

    ?This study of phosphorus (P) cycling in eutrophic Upper Klamath Lake (UKL), Oregon, was conducted by the U.S. Geological Survey in cooperation with the U.S. Bureau of Reclamation. Lakebed sediments from the upper 30 centimeters (cm) of cores collected from 26 sites were characterized. Cores were sampled at 0.5, 1.5, 2.5, 3.5, 4.5, 10, 15, 20, 25, and 30 cm. Prior to freezing, water content and sediment pH were determined. After being freeze-dried, all samples were separated into greater than 63-micron (?m) particle-size (coarse) and less than 63-?m particle-size (fine) fractions. In the surface samples (0.5 to 4.5 cm below the sediment water interface), approximately three-fourths of the particles were larger than 63-?m. The ratios of the coarse particle-size fraction (>63 ?m) and the fine particle-size fraction (<63 ?m) were approximately equal in samples at depths greater than 10 cm below the sediment water interface. Chemical analyses included both size fractions of freeze-dried samples. Chemical analyses included determination of total concentrations of aluminum (Al), calcium (Ca), carbon (C), iron (Fe), poorly crystalline Fe, nitrogen (N), P, and titanium (Ti). Total Fe concentrations were the largest in sediment from the northern portion of UKL, Howard Bay, and the southern portion of the lake. Concentrations of total Al, Ca, and Ti were largest in sediment from the northern, central, and southernmost portions of the lake and in sediment from Howard Bay. Concentrations of total C and N were largest in sediment from the embayments and in sediment from the northern arm and southern portion of the lake in the general region of Buck Island. Concentrations of total C were larger in the greater than 63-?m particle-size fraction than in the less than 63-?m particle-size fraction. Sediments were sequentially extracted to determine concentrations of inorganic forms of P, including loosely sorbed P, P associated with poorly crystalline Fe oxides, and P associated with mineral phases. The difference between the concentration of total P and sum of the concentrations of inorganic forms of P is referred to as residual P. Residual P was the largest fraction of P in all of the sediment samples. In UKL, the correlation between concentrations of total P and total Fe in sediment is poor (R2<0.1). The correlation between the concentrations of total P and P associated with poorly crystalline Fe oxides is good (R2=0.43) in surface sediment (0.5-4.5 cm below the sediment water interface) but poor (R2<0.1) in sediments at depths between 10 cm and 30 cm. Phosphorus associated with poorly crystalline Fe oxides is considered bioavailable because it is released when sediment conditions change from oxidizing to reducing, which causes dissolution of Fe oxides.

  14. 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."

  15. Shuttle II

    NASA Technical Reports Server (NTRS)

    Talay, T. A.

    1987-01-01

    This paper presents a status report on the study of a next-generation manned launch system, called Shuttle II, being conducted at the NASA Langley Research Center. Underlying reasons for considering such a system include the need for low-cost, safe, and reliable manned access to space. System and operational characteristics for a Shuttle II vehicle are presented. The need for fully reusable launch systems with radically simpler ground and flight operations is stated to be critical in reducing launch costs. Advancing technologies have a major impact on the choice of vehicle concepts. For a near-term level of technology, a two-stage vertical-takeoff rocket vehicle has been selected for further in-depth Shuttle II studies. The role of the Shuttle II vehicle in a proposed space transportation system, which includes heavy lift and Space Shuttle complementary manned systems, is discussed.

  16. Photosystem II

    SciTech Connect

    James Barber

    2005-04-28

    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."

  17. 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.

  18. 75 FR 5811 - Notice of Information Collection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-04

    ... Administration, Washington, DC 20546-0001. FOR FURTHER INFORMATION CONTACT: Requests for additional information... achievement in mathematics and science. II. Method of Collection The GLOBE Partner survey is Web-based...

  19. 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...

  20. Collective Electrodynamics

    NASA Astrophysics Data System (ADS)

    Mead, Carver A.

    2002-08-01

    In this book Carver Mead offers a radically new approach to the standard problems of electromagnetic theory. Motivated by the belief that the goal of scientific research should be the simplification and unification of knowledge, he describes a new way of doing electrodynamics--collective electrodynamics--that does not rely on Maxwell's equations, but rather uses the quantum nature of matter as its sole basis. Collective electrodynamics is a way of looking at how electrons interact, based on experiments that tell us about the electrons directly. (As Mead points out, Maxwell had no access to these experiments.) The results Mead derives for standard electromagnetic problems are identical to those found in any text. Collective electrodynamics reveals, however, that quantities that we usually think of as being very different are, in fact, the same--that electromagnetic phenomena are simple and direct manifestations of quantum phenomena. Mead views his approach as a first step toward reformulating quantum concepts in a clear and comprehensible manner. The book is divided into five sections: magnetic interaction of steady currents, propagating waves, electromagnetic energy, radiation in free space, and electromagnetic interaction of atoms. In an engaging preface, Mead tells how his approach to electromagnetic theory was inspired by his interaction with Richard Feynman. Carver A. Mead is the Gordon and Betty Moore Professor of Engineering and Applied Science, Emeritus, at the California Institute of Technology. He won the 1999 Lemelson-MIT Prize for Invention and Innovation.

  1. Mass-sensitive chemical preconcentrator

    DOEpatents

    Manginell, Ronald P. (Albuquerque, NM); Adkins, Douglas R. (Albuquerque, NM); Lewis, Patrick R. (Albuquerque, NM)

    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.

  2. 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.

  3. Tortuous path chemical preconcentrator

    DOEpatents

    Manginell, Ronald P. (Albuquerque, NM); Lewis, Patrick R. (Albuquerque, NM); Adkins, Douglas R. (Albuquerque, NM); Wheeler, David R. (Albuquerque, NM); Simonson, Robert J. (Cedar Crest, NM)

    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.

  4. 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...

  5. 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,...

  6. Amazonian functional diversity from forest canopy chemical assembly

    PubMed Central

    Asner, Gregory P.; Martin, Roberta E.; Tupayachi, Raul; Anderson, Christopher B.; Sinca, Felipe; Carranza-Jimnez, 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

  7. 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

  8. Chemical niche differentiation among sympatric species of orchid bees.

    PubMed

    Zimmermann, Yvonne; Ramrez, Santiago R; Eltz, Thomas

    2009-11-01

    Male Neotropical orchid bees (Euglossini) collect volatile substances (fragrances) from flowers and other sources (e.g., decaying wood) and store them in specialized hind tibial pockets. The accumulated chemicals are later emitted during courtship display, presumably to lure conspecific females for mating. We analyzed tibial fragrances of males of 15 sympatric Panamanian species in the genus Euglossa to test whether communities of euglossine bees are chemically structured, and to elucidate whether male fragrance signals evolve to convey premating isolation. Our analysis revealed substantial chemical disparity among all lineages. Disparity was mediated by compounds that were exclusive to certain species but also by differences in relative quantity of shared compounds. We mapped tibial fragrance compounds present in each species on a DNA-based phylogeny (reconstructed using partial sequences of COI, EF1-alpha, ArgK, and Pol-II) and found that most dominant compounds were highly homoplasious. In an analysis of chemical differentiation in relation to phylogenetic divergence through time, disparity was greater than expected from a null model at any point during evolutionary history, suggesting that diversifying selection has shaped fragrance phenotypes. Notably, chemical disparity was greater within recently diverged lineages than among them, suggesting that chemical preferences in orchid bees evolved rapidly in the early stages of species divergence. We postulate communication interference as the possible mechanism behind the observed fragrance differentiation, which may be the product of reproductive character (fragrance) displacement. Our findings are consistent with the hypothesis that male fragrance signals evolve to convey premating isolation. PMID:19967856

  9. Chemical Emergencies

    MedlinePLUS

    ... happen underground, on railways or highways, and at manufacturing plants. They may involve fire or explosion, or ... of chemicals as only those substances used in manufacturing processes. But chemicals are found everywhere–in our ...

  10. 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

  11. 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

  12. 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…

  13. 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…

  14. 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.

  15. 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

  16. FAQs II

    ERIC Educational Resources Information Center

    Kezar, Adrianna; Frank, Vikki; Lester, Jaime; Yang, Hannah

    2008-01-01

    In their paper entitled "Why should postsecondary institutions consider partnering to offer (Individual Development Accounts (IDAs)?" the authors reviewed frequently asked questions they encountered from higher education professionals about IDAs, but as their research continued so did the questions. FAQ II has more in-depth questions and answers

  17. Chemical emergency preparedness program: chemical profiles. Interim guidance

    SciTech Connect

    Not Available

    1985-12-01

    The document, developed by the U.S. Environmental Protection Agency (USEPA) is part of the USEPA National Air Toxics Strategy. The document is provided in support of EPA Chemical Emergency Preparedness Program (CEPP) which deals with accidental release of acutely toxic chemicals. For each acutely toxic chemical listed in the CEPP guidance document (report number PB86-155256), a chemical profile is available. A chemical profile is a collection of information on the chemical identity hazardous identity, physical/chemical characteristics, fire and explosive hazard, reactivity, health hazard, use, and precautions for handling and use of the chemical. The information is presented in the format that conforms as closely as possible to the Occupational Safety and Health Administration (OSHA) recommended format for a Material Safety Data Sheet (MSDS).

  18. 76 FR 39092 - Agency Information Collection Activities; Proposed Collection; Comment Request; Disinfectants...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-05

    ... Collection Activities; Proposed Collection; Comment Request; Disinfectants/Disinfection Byproducts, Chemical... ICRs scheduled to expire are Disinfectants/Disinfection Byproducts, Chemical and Radionuclides Rules... comments, identified by the Docket ID EPA-HQ-OW- 2011-0439 (Disinfectants/Disinfection Byproducts,...

  19. 7 CFR 633.14 - Debt collection.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ....C. 3701) and the regulations found in 4 CFR chapter II. ... 7 Agriculture 6 2010-01-01 2010-01-01 false Debt collection. 633.14 Section 633.14 Agriculture... AGRICULTURE LONG TERM CONTRACTING WATER BANK PROGRAM § 633.14 Debt collection. Any debts arising under...

  20. 78 FR 55685 - Proposed Collection; Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-11

    ... of the Secretary Proposed Collection; Comment Request AGENCY: Defense Logistics Agency (DLA), DoD..., the Defense Logistics Agency (DLA) announces a proposed public information collection and seeks public...; Associated Form; and OMB Number: Physical Access Control System (Diamond II) for DLA Headquarters. OMB...