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1

Devices for collecting chemical compounds  

DOEpatents

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.

Scott, Jill R; Groenewold, Gary S

2013-12-24

2

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

PubMed Central

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

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

2009-01-01

3

The ISLSCP Initiative II Data Collection  

NASA Astrophysics Data System (ADS)

The International Satellite Land Surface Climatology Project (ISLSCP) sponsored the production of the first, co-registered, peer-reviewed, documented interdisciplinary data collection that included global, monthly surface meteorology, vegetation, soils, surface routing and runoff, atmospheric radiation data and clouds for 1987 and 1988 at a 1-degree spatial resolution. The ISLSCP Initiative II collection is greatly expanded in both time and spatial resolution. Initiative II is a 10-year core global data collection spanning the years 1987 to 1995 with improved spatial and temporal resolution (one-quarter to 1 degree) using improved data generation algorithms. In addition, Initiative II includes some data sets spanning the 18-year period, 1982-1999. The data collection includes additional carbon and socioeconomic data sets uniquely designed to support global carbon cycling studies. Initiative II provides a comprehensive collection of high priority global data sets in a consistent data format and Earth projection. The full Initiative II collection consists of some 47 different data types with 230 different parameters shown below (number of parameters in parentheses). Radiation and Clouds (45) Hydrology, Topography and Soils (39) Near-Surface Meteorology (95) Vegetation (29) Fixed (11) Carbon (15) Monthly (12) Snow and Sea Ice (4) Monthly 3-hourly (44) Oceans (1) 3-hourly (28) Socioeconomic (2) Each of the 47 data sets and accompanying documents have undergone two peer reviews, one by reviewers familiar with the data set (but not the producer of it) and a second reviewer, a potential user who has no previous experience with it. The data set draft is complete and is to be followed by an evaluation of the entire collection prior to final publication by the Initiative II staff and external users. This collection-overview evaluation will include an assessment of the individual data series against each other and independent data sources and an evaluation of the value of the ISLSCP II collection as a whole.The Initiative II collection is available at http://islscp2.sesda.com/.

Hall, F. G.

2004-12-01

4

Collective surfing of chemically active particles.  

PubMed

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

Masoud, Hassan; Shelley, Michael J

2014-03-28

5

Collective Surfing of Chemically Active Particles  

NASA Astrophysics Data System (ADS)

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.

Masoud, Hassan; Shelley, Michael J.

2014-03-01

6

World War I and II Poster Collection  

NSDL National Science Digital Library

War posters from World War I and II encouraged the people of the nations at war to buy war bonds, plant gardens, ration, enlist, or work extra hard for the sake of the war effort. A collection of these posters can be found in abundance on the library website of the University of North Texas. The library has over 600 war posters, and fortunately, 493 of them are digitized. Some are quaint by today's standards, but some, like the fifth record on the homepage, entitled "Deliver Us From Evil: Buy War Bonds," has an eerie haunting quality to it. In the search box underneath the introduction to the poster collection, type in Geisel to see a poster by a familiar artist and author, encouraging Americans to "Starve the Squander Bug." Visitors should click on the thumbnail to see those "squander bugs" in full detail.

7

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

Code of Federal Regulations, 2014 CFR

...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Industrial Wastewater Treatment Pt. 98, Subpt. II, Table II-2 Table II-2 to Subpart II—Collection Efficiencies of Anaerobic...

2014-07-01

8

CH E 2421 Chemical Engineering Thermodynamics I CH E 3322 Chemical Engineering Thermodynamics II  

E-print Network

CH E 2421 Chemical Engineering Thermodynamics I CH E 3322 Chemical Engineering Thermodynamics II CH E 3330 Engineering Materials Science CH E 4342 Polymer Physics Engineering Thermodynamics I M E 3311 Materials Science M E 3322 Engineering Thermodynamics II M

Zhang, Yuanlin

9

Device for collecting chemical compounds and related methods  

DOEpatents

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.

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

2013-01-01

10

COLLECTIVE EFFECTS IN THE NSLS-II STORAGE RING.  

SciTech Connect

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.

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

11

Scaffold Topologies II: Analysis of Chemical Databases  

PubMed Central

We have systematically enumerated graph representations of scaffold topologies for up to 8-ring molecules and 4-valence atoms, thus providing coverage of the lower portion of the chemical space of small molecules (Pollock et al.1). Here, we examine scaffold topology distributions for several databases: ChemNavigator and PubChem for commercially available chemicals, the Dictionary of Natural Products, a set of 2,742 launched drugs, WOMBAT, a database of medicinal chemistry compounds, and two subsets of PubChem, “actives” and DSSTox comprising toxic substances. We also examined a virtual database of exhaustively enumerated small organic molecules, GDB,2 and contrast the scaffold topology distribution from these collections to the complete coverage of up to 8-ring molecules. For reasons related, perhaps, to synthetic accessibility and complexity, scaffolds exhibiting 6 rings or more are poorly represented. Among all collections examined, PubChem has the greatest scaffold topological diversity, whereas GDB is the most limited. More than 50% of all entries (13,000,000+ actual and 13,000,000+ virtual compounds) exhibit only 8 distinct topologies, one of which is the non-scaffold topology that represents all treelike structures. However, most of the topologies are represented by a single or very small number of examples. Within topologies, we found that 3-way scaffold connections (3-nodes) are much more frequent compared to 4-way (4-node) connections. Fused rings have a slightly higher frequency in biologically oriented databases. Scaffold topologies can be the first step toward an efficient coarse-grained classification scheme of the molecules found in chemical databases. PMID:18605681

Wester, Michael J.; Pollock, Sara; Coutsias, Evangelos A.; Allu, Tharun Kumar; Muresan, Sorel; Oprea, Tudor I.

2009-01-01

12

Analysis of data collected by the Tatyana II satellite  

NASA Astrophysics Data System (ADS)

The Tatyana II satellite is the second one of the University Satellite Program, which is led by the Moscow State University with the participation of the Benemerita Universidad Autonoma de Puebla. This satellite has ultraviolet, red-infrared and charged particles detectors. In this work preliminary results based on the data collected by these detectors on board the satellite over a period of ~3.5 months are presented.

Lilianaa, Rivera; Oscar, Martínez; Eduardo, Mendoza-Torres; Humberto, Salazar

2011-04-01

13

Territorial biodiversity and consequences on physico-chemical characteristics of pollen collected  

E-print Network

Territorial biodiversity and consequences on physico-chemical characteristics of pollen collected France, the physico- chemical composition of honey bee-collected pollen, the territorial biodiversity%). agrosystem / honeybee / floral biodiversity / pollen analysis / chemical analysis 1. INTRODUCTION Since 1962

14

Impedances and collective instabilities of the Tevatron at Run II  

SciTech Connect

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

Ng, King-Yuen, FERMI

1998-09-01

15

Improved Devices for Collecting Sweat for Chemical Analysis  

NASA Technical Reports Server (NTRS)

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+.

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

2011-01-01

16

Improved Devices for Collecting Sweat for Chemical Analysis  

NASA Technical Reports Server (NTRS)

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+).

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

2011-01-01

17

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

NASA Astrophysics Data System (ADS)

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 ?m, and 37 < B < 50 ?m) 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 ?g 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.

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

2014-12-01

18

CHEMICAL WASTE RECYCLING PROGRAM All types of batteries are collected by Chemical Waste Services (CWS) for recycling. These include  

E-print Network

CHEMICAL WASTE RECYCLING PROGRAM BATTERIES All types of batteries are collected by Chemical Waste Services (CWS) for recycling. These include alkaline, lithium, rechargeable, coin batteries, lead-acid and all other types. Uninterruptible Power Source (UPS) batteries must be removed from the UPS casing

Baker, Chris I.

19

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Collection for Growing America Through Entrepreneurship (GATE) II Evaluation; Comment...investigated the impact of providing entrepreneurship training services to individuals...D. ``Growing America Through Entrepreneurship: Findings from the Evaluation...

2011-05-05

20

Biological monitoring of occupational exposure to toxic chemicals. Collection, processing, and storage of specimens  

SciTech Connect

Exposure to at least 100 different chemicals may be estimated on an individual basis from their concentrations in blood or urine. The present document reviews sources of error in the collection, processing and storage of specimens for this biological monitoring. Physiological factors cause variation in the concentration of chemicals in the body fluids. Distribution of water depends on posture. Exercise and meals cause changes in blood constituents. The urine output varies and, thus, the concentrations of dissolved chemicals change. Many toxic chemicals show short half times in the blood; thus, their concentrations depend on the timing of the specimen collection. Skin absorption may result in dramatically different chemical concentrations in different parts of the circulation. The stability of chemicals in the collected specimens is generally limited: chemical deterioration, adsorption, precipitation, and evaporation are the main causes of losses. For many chemicals, especially for trace elements, contamination of the specimen is the overwhelmingly most important source of error. As the range of the chemicals measured is wide, the relative importance of the sources of error is different for different chemicals. Information on most chemicals is at present very limited. Thus, before commencing a program on biological exposure monitoring, it is advisable to search the optimal conditions for specimen collection, processing, and storage.

Aitio, A.; Jaervisalo, J.

1985-03-01

21

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...

22

The Mark A. Freeman collection of World War II photographs at George Eastman House  

Microsoft Academic Search

This thesis project is based on a collection of approximately 3000 World War II photographs, negatives, and supporting artefacts, which were donated to George Eastman House International Museum of Photography and Film (GEH) in 2007. The material was made and collected by Lieutenant Mark Anthony Freeman (1912-2005), a combat photographer for the US Army Signal Corps. The objectives for this

Lisa C Hennessey

2007-01-01

23

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

NASA Astrophysics Data System (ADS)

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.

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

24

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

PubMed

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

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

2013-11-01

25

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...

26

Significantly improved charge-collection efficiencies result from a general chemical approach to synthesizing photocathodes.  

E-print Network

Significantly improved charge-collection efficiencies result from a general chemical approach in sensitized CdS­NiO nanoparticle photocathodes,"Chem. Commun. 47, 10419 (2011). Key Research Results Achievement Researchers developed a chemical approach that resulted in CdS-sensitized photocathodes

27

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

USGS Publications Warehouse

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).

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

28

Chemical bath deposition of II-VI compound thin films  

NASA Astrophysics Data System (ADS)

II-VI compounds are direct bandgap semiconductors with great potentials in optoelectronic applications. Solar cells, where these materials are in greater demand, require a low cost production technology that will make the final product more affordable. Chemical bath deposition (CBD) a low cost growth technique capable of producing good quality thin film semiconductors over large area and at low temperature then becomes a suitable technology of choice. Heterogeneous reaction in a basic aqueous solution that is responsible for the II-VI compound film growth in CBD requires a metal complex. We have identified the stability constant (k) of the metal complex compatible with CBD growth mechanism to be about 106.9. This value is low enough to ensure that the substrate adsorbed complex relax for subsequent reaction with the chalcogen precursor to take place. It is also high enough to minimize the metal ion concentration in the bath participating in the precipitation of the bulk compounds. Homogeneous reaction that leads to precipitation in the reaction bath takes place because the solubility products of bulk II-VI compounds are very low. This reaction quickly depletes the bath of reactants, limit the film thickness, and degrade the film quality. While ZnS thin films are still hard to grow by CBD because of lack of suitable complexing agent, the homogeneous reaction still limits quality and thickness of both US and ZnS thin films. In this study, the zinc tetraammine complex ([Zn(NH3) 4]2+) with k = 108.9 has been forced to acquire its unsaturated form [Zn(NH3)3]2+ with a moderate k = 106.6 using hydrazine and nitrilotriacetate ion as complementary complexing agents and we have successfully grown ZnS thin films. We have also, minimized or eliminated the homogeneous reaction by using ammonium salt as a buffer and chemical bath with low reactant concentrations. These have allowed us to increase the saturation thickness of ZnS thin film by about 400% and raise that of US film form 0.2 to 0.5 mum with improved quality. A novel chemical activated diffusion of Cd into ZnS thin film at temperature lower than 100°C is also developed. This in conjunction with thermal activated diffusion at 400°C has enabled us to synthesize Cd1-xZn xS thin films suitable for solar cells from CBD grown CdS/ZnS multilayer. The potential application of the new Cd1-xZnxS/CdS/CdTe solar cell structure is also demonstrated. The unoptimized structure grown on transparent conducting oxide coated soda lime glass of 3mm thickness with no antireflection coating yielded a 10% efficiency. This efficiency is the highest ever recorded in any Cd1-xZnxS film containing CdTe solar cells.

Oladeji, Isaiah Olatunde

29

INFLUENCE OF CHEMICAL AMENDMENTS ON THE INORGANIC CHEMICAL SIGNATURE OF LEACHATE COLLECTED FROM A NORFOLK SOIL  

Technology Transfer Automated Retrieval System (TEKTRAN)

Chemical amendments [i.e., polyacrylamides (PAM), drinking water treatment residuals (WTR), etc.] are added to degraded soils to improve physical conditions and/or to sequester excess nutrients. These amendments contain inorganic oxidizing agents (i.e., Na2O, etc.) or have ionic exchange properties ...

30

CHEMICAL CHARACTERIZATION OF EXTRACTABLE ORGANIC MATTER FROM AMBIENT AEROSOLS COLLECTED IN BOISE, ID  

EPA Science Inventory

Fine fraction (2.5 micron) ambient air aerosols were collected in Boise, ID between November, 1986, and February, 1987. wo composite samples of extractable organic matter (EOM) were prepared with partial resolution of chemicals from Boise's wood smoke (WS) and mobile source (MS) ...

31

COLLECTION AND ANALYSIS OF WATER SAMPLES FROM THE GREAT LAKES FOR INORGANIC CHEMICALS  

EPA Science Inventory

This continues the long term chemical monitoring that is part of the mandate for the Great Lakes National Program Office. The Public Health Service Laboratory in Chicago will provide analytical capability as well as sample collection assistance of water samples from all of the G...

32

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

E-print Network

Chemical fingerprinting of petroleum biomarkers in Deepwater Horizon oil spill samples collected Deepwater Horizon oil spill Hopane analysis Fingerprinting Tar balls a b s t r a c t We compare the chromatographic signatures of petroleum biomarkers in Deepwater Horizon (DH) source oil, three other reference

Clement, Prabhakar

33

CHEMICAL COMPOSITION AND NUTRITIVE VALUE OF BEE-COLLECTED AND BEE-STORED POLLEN  

E-print Network

CHEMICAL COMPOSITION AND NUTRITIVE VALUE OF BEE-COLLECTED AND BEE-STORED POLLEN Elton W. HERBERT, Jr. H. SHIMANUKI Bioenvironmental Bee Gaboratory, Plant Protection Institute, ARS, USDA Beltsville, MD 20705 SUMMARY When fresh pollen and bee-stored pollen extracted from brood combs of free

Paris-Sud XI, Université de

34

Sorption and cosorption of lead (II) and methylene blue on chemically modified biomass.  

PubMed

Sorption and cosorption of lead (Pb(II)) and methylene blue (MB) in aqueous solutions on low-cost biosorbents made from chemically modified agricultural by-products was investigated. Modified cotton exhibited the highest adsorption capacity for Pb(II), while modified cotton and peanut hull had higher equilibrium adsorption capacity of MB than the other biosorbents. Different chemical modification methods of hickory resulted in no great variation on the equilibrium adsorption capacity of Pb(II) and MB except for the one treated with alkali. Simultaneous sorption of Pb(II) and MB on the biosorbents showed Pb(II) to be preferentially adsorbed at higher Pb(II)-to-MB molar ratios in solution except for modified peanut hull. The equilibrium Pb adsorption contents decreased with the increasing pre-loading of MB and vice versa, suggesting the competitive rather than synergistic adsorption of the two contaminants on the biosorbents. PMID:24998306

Ding, Zhuhong; Hu, Xin; Zimmerman, Andrew R; Gao, Bin

2014-09-01

35

Crystal structure and chemical bonding in tin(II) acetate  

Microsoft Academic Search

Tin(II) acetate was prepared and its crystal structure was solved from X-ray powder diffraction data. Tin(II) acetate adopts a polymeric structure consisting of infinite Sn(CH3COO)2 chains running along the c-axis which are packed into groups of four. The acetate groups bridge the Sn atoms along the chains. The Sn atoms are asymmetrically surrounded by four oxygen atoms with two short

Varvara S. Stafeeva; Alexander S. Mitiaev; Artem M. Abakumov; Alexander A. Tsirlin; Artem M. Makarevich; Evgeny V. Antipov

2007-01-01

36

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...

37

Renal cysts. II. Chemical and dynamic study of cystic fluid.  

PubMed

The chemical analysis of the fluid obtained by puncturing 100 simple renal cysts in adults show that the composition of cystic fluid resembles that of interstitial fluid. The chemical balance between cystic fluid and the interstitial space seems to occur passively. Antibiotics which were given orally (amoxycilline, minocycline, rifampicin) do not pass through the wall of a simple cyst. Study of the permeability of the cyst wall did not show any uptake of radioactive hippurate or radium pertechnetate. PMID:1009970

Steg, A

1976-01-01

38

Chemical Composition and Manufacturing Technology of a Collection of Various Types of Islamic Glazes Excavated from Jordan  

Microsoft Academic Search

A collection of Islamic glazed pottery shards that were excavated from the archaeological site of Dohaleh\\/Northern Jordan were chemically analysed. The glazes belong to three different decorative styles. The chemical analysis of the glazes was carried out using energy dispersive x-ray fluorescence. The chemical analysis results enable the classification of the glazes into the three distinct compositional groups with reference

Ziad Al-Saad

2002-01-01

39

Mobile DIORAMA-II: Infrastructure less information collection system for mass casualty incidents.  

PubMed

In this paper we introduce DIORAMA-II system that provides real time information collection in mass casualty incidents. Using a mobile platform that includes active RFID tags and readers as well as Smartphones, the system can determine the location of victims and responders. The system provides user friendly multi dimensional user interfaces as well as collaboration tools between the responders and the incident commander. We conducted two simulated mass casualty incidents with 50 victims each and professional responders. DIORAMA-II significantly reduces the evacuation time by up to 43% when compared to paper based triage systems. All responders that participated in all trials were very satisfied. They felt in control of the incident and mentioned that the system significantly reduced their stress level during the incident. They all mentioned that they would use the system in an actual incident. PMID:25570543

Ganz, Aura; Schafer, James M; Zhuorui Yang; Jun Yi; Lord, Graydon; Ciottone, Gregory

2014-08-01

40

Kinetic and thermodynamic studies on biosorption of Cu(II) by chemically modified orange peel  

Microsoft Academic Search

Cu(II) biosorption by orange peel that was chemically modified with sodium hydroxide and calcium chloride was investigated. The effects of temperature, contact time, initial concentration of metal ions and pH on the biosorption of Cu(II) ions were assessed. Thermodynamic parameters including change of free energy), (?G?), enthalpy (?H?) and entropy (?S?) during the biosorption were determined. The results show that

Ning-chuan FENG; Xue-yi GUO; Sha LIANG

2009-01-01

41

Chemical generation of atomic iodine for the chemical oxygen iodine laser. II. Experimental results  

NASA Astrophysics Data System (ADS)

A new method for the chemical generation of atomic iodine intended for use in a chemical oxygen-iodine laser (COIL) was investigated experimentally. The method is based on the fast reaction of hydrogen iodide with chemically produced chlorine atoms. Effects of the initial ratio of reactants and their mixing in a flow of nitrogen were investigated experimentally and interpreted by means of a computational model for the reaction system. The yield of iodine atoms in the nitrogen flow reached 70-100% under optimum experimental conditions. Gain was observed in preliminary experiments on the chemical generation of atomic iodine in a flow of singlet oxygen.

Špalek, Otomar; Jirásek, Vít.; ?enský, Miroslav; Kodymová, Jarmila; Jakubec, Ivo; Hager, Gordon D.

2002-08-01

42

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

NASA Astrophysics Data System (ADS)

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

Burns, R. G.; Banin, A.

1993-10-01

43

Biosorption of copper (II) from chemical mechanical planarization wastewaters.  

PubMed

Copper Chemical Mechanical Planarization (Cu-CMP) is a critical step in integrated circuit (IC) device manufacturing. CMP and post-CMP cleaning processes are projected to account for 30-40% of the water consumed by IC manufacturers in 2003. CMP wastewater is expected to contain increasing amounts of copper as the industry switches from Al-CMP to Cu-CMP causing some IC manufacturers to run the risk of violating discharge regulations. There are a variety of treatment schemes currently available for the removal of heavy metals from CMP wastewater, however, many introduce additional chemicals to the wastewater, have large space requirements, or are expensive. This work explores the use of microorganisms for waste treatment. A Staphylococcus sp. of bacteria was isolated and studied to determine the feasibility for use in removing copper from Cu-CMP wastewater. A model Cu-CMP wastewater was developed and tested, as well as actual Cu-CMP wastes. Continuous-flow packed column experiments were performed to obtain adsorption data and show copper recovery from the waste. A predictive, empirical model was used to accurately describe Cu removal. Additionally, the immobilized cells were regenerated, allowing for the concentration and potential recovery of copper from the wastewater. PMID:14580729

Stanley, Leah C; Ogden, Kimberly L

2003-11-01

44

CHEN 3AA0 Chemical Engineering Progress Assessment II (Concepts Inventory Exam)  

E-print Network

CHEN 3AA0 Chemical Engineering Progress Assessment II (Concepts Inventory Exam) Instructions to as the Concept Inventory Exam (CIE). The following material discusses the nature of the CIE and the CHEN 3AA0 engineering concepts. Administration: The CIE is offered in CHEN 3AA0 and is part of the passing criteria

Ashurst, W. Robert

45

Biosorption of Pb(II) from aqueous solutions using chemically modified Moringa oleifera tree leaves  

Microsoft Academic Search

Moringa oleifera leaves (MOL); an agro-waste material has been used as a precursor to prepare a new biosorbent. The leaves were washed with base and citric acid, and obtained new chemically modified MOL biosorbent (CAMOL) for sequestration of Pb(II) from aqueous solution. The biosorbent was characterized by SEM, FTIR spectral and elemental analyses. The effect of experimental parameters such as

D. Harikishore Kumar Reddy; Y. Harinath; K. Seshaiah; A. V. R. Reddy

2010-01-01

46

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

E-print Network

including metabolism, nutrient transport, signal transduction, motil- ity, and cell division (Madigan et alAcid­base properties of cyanobacterial surfaces. II: Silica as a chemical stressor influencing cell 2007; accepted in revised form 1 October 2007 Abstract Bacteria grow in complex solutions where

Konhauser, Kurt

47

Contributions of supernovae type II & Ib/c to the galactic chemical evolution  

E-print Network

The supernovae SN II & Ib/c make major stellar nucleosynthetic contributions to the inventories of the stable nuclides during the chemical evolution of the galaxy. A case study is performed here with the help of recently developed numerical simulations of the galactic chemical evolution in the solar neighbourhood to understand the contributions of the SN II and Ib/c by making a comparison of the stellar nucleosynthetic yields obtained by two leading groups in the field. These stellar nucleosynthetic yields differ in terms of the treatment of stellar evolution and nucleosynthesis. The formulation for the galactic chemical evolution is developed for the recently revised solar metallicity of 0.014. Further, the recent nucleosynthetic yields of the stellar models based on the revised solar metallicity are also used. The analysis suggest that it could be difficult to explain in a self-consistent manner the various features associated with the elemental evolutionary trends over the galactic timescales by any si...

Sahijpal, Sandeep

2014-01-01

48

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

NASA Astrophysics Data System (ADS)

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

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

2002-10-01

49

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

PubMed

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

Vit, Patricia; Santiago, B

2008-12-01

50

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

PubMed

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

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

2015-02-15

51

Contributions of type II and Ib/c supernovae to Galactic chemical evolution  

NASA Astrophysics Data System (ADS)

Type II and Ib/c supernovae (SNe II and Ib/c) have made major stellar nucleosynthetic contributions to the inventories of stable nuclides during chemical evolution of the Galaxy. A case study is performed here with the help of recently developed numerical simulations of Galactic chemical evolution in the solar neighborhood to understand the contributions of SNe II and Ib/c by comparing the stellar nucleosynthetic yields obtained by two leading groups in this field. These stellar nucleosynthetic yields differ in terms of their treatment of stellar evolution and nucleosynthesis. The formulation describing Galactic chemical evolution is developed with the recently revised solar metallicity of ~0.014. Furthermore, the recent nucleosynthetic yields of stellar models based on the revised solar metallicity are also used. The analysis suggests that it could be difficult to explain, in a self-consistent manner, the various features associated with the elemental evolutionary trends over Galactic timescales by any single adopted stellar nucleosynthetic model that incorporates SNe II and Ib/c.

Sahijpal, Sandeep

2014-06-01

52

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

SciTech Connect

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.

Neeraj Gupta; Bruce Sass; Jennifer Ickes

2000-11-28

53

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

NASA Astrophysics Data System (ADS)

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.

Senthil, M.; Arulanantham, A.

2013-06-01

54

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

55

A Coupled Dynamical and Chemical Model of Starless Cores of Magnetized Molecular Clouds. II. Chemical Differentiation  

NASA Astrophysics Data System (ADS)

Dense cores of molecular clouds are the basic units of isolated low-mass star formation. They have been observed extensively in various molecule lines and dust continuum with the aim of revealing their chemical and dynamical state. In a previous paper, we formulated a coupled dynamical and chemical model for data interpretation and carried out an initial investigation focusing on the effects of a magnetic field on the core dynamics and chemistry. Here, we update our chemical network and the treatment of magnetic field-matter coupling and explore the effects of changing various parameters, including the initial gas-phase metal abundances, adsorption energies, cosmic-ray ionization rate, sticking probability onto dust grains, cloud mass, as well as magnetic field strength. The model results are compared with the velocity field and column density distributions of CO, CS, CCS, NH3, N2H+, and HCO+ inferred observationally for the well-studied starless core L1544. We find that, in agreement with previous work, models with the so-called high metal abundances produce excessive CS and CCS by more than 2 orders of magnitude. Models of magnetized clouds with ``low metal'' and ``mixed metal'' (with a strong initial depletion of sulphur) abundances can fit the available data on L1544 reasonably well, with the low-metal model fitting somewhat better the chemical data (except for CS) and the mixed-metal model the velocity field. Taking into account of a newly recalculated rate for the neutral-neutral reaction S+CCH-->CCS+H increases the abundance of CCS substantially, leading to a better agreement with observation for the mixed-metal model. We considered two sets of adsorption energies, compiled respectively by Aikawa et al. and Hasegawa & Herbst. Our results favor the former over the latter. For our standard models, we adopted a cosmic ionization rate of 1.3×10-17 s-1 and a sticking probability of 0.3. Increasing their values does not improve the model fits. Somewhat surprisingly, removing the magnetic support of the cloud leads to relatively modest changes in the peak column densities of the species except for CS. However, the spatial distributions of CS and CCS become more centrally concentrated than observed in L1544, and the infall speed is too large to be acceptable. This illustrates the need for both chemical and dynamical data to provide the tightest possible model constraints. A generic feature of our coupled dynamical and chemical model is that NH3 and, to a lesser extent, N2H+ are concentrated in the slowly contracting, central plateau region of the growing core, whereas CS and CCS are most abundant in the lower density envelope surrounding the plateau, which has a faster infall motion. The chemical differentiation offers an exciting possibility of directly probing the velocity field of core evolution leading to star formation.

Shematovich, V. I.; Wiebe, D. S.; Shustov, B. M.; Li, Zhi-Yun

2003-05-01

56

Chemical Kinetic Data Base for Propellant Combustion. II. Reactions Involving CN, NCO, and HNCO  

Microsoft Academic Search

This paper contains evaluated chemical kinetic data on single step elementary reactions involving small polyatomic molecules which are of importance in propellant combustion. The work consists of the collection and evaluation of mechanistic and rate information and the use of various methods for the extrapolation and estimation of rate data where information does not exist. The conditions covered range from

Wing Tsang

1992-01-01

57

Analysis and Antioxidant Capacity of Anthocyanin Pigments. Part II: Chemical Structure, Color, and Intake of Anthocyanins  

Microsoft Academic Search

Anthocyanins belong to a large group of secondary plant metabolites collectively known as flavonoids, a subclass of the polyphenol family. They are a group of very efficient bioactive compounds that are widely distributed in plant food. Anthocyanins occur in all plant tissues, including leaves, stems, roots, flowers, and fruits. Research on phenolic compounds through the last century, from the chemical,

Julia Martín Bueno; Purificación Sáez-Plaza; Fernando Ramos-Escudero; Ana Maria Jiménez; Roseane Fett; Agustin G. Asuero

2012-01-01

58

Room temperature detection of chemical pollutants by SnO II-based optical fiber sensors  

NASA Astrophysics Data System (ADS)

In the last decade a huge number of SnO II-based gas sensors have been proposed for environmental monitoring, automotive applications, air conditioning in houses, airplane and aircrafts. However, most of the proposed sensors work at very high temperatures in order to reach high sensitivities. Here, a SnO II-based optical fiber sensor is proposed for the room temperature detection of chemical pollutants in air. Particles layers composed by tin dioxide grains, with wavelength and subwavelength dimensions, resulted very promising because they are able to significantly modify the optical near field profile emerging from the film surface due to local enhancements of the evanescent wave contribute, and thus to improve the sensitivity to surface effects induced by the analyte interaction. The room temperature sensing performances of SnO II-based particles layers towards environmental pollutants have been investigated by the exposure to different concentrations of toluene and xylene vapors as well as gaseous ammonia. They have also been compared with the performances obtained with other optical fiber sensors in the same configuration, but coated with different sensitive materials, such as Single-Walled carbon nanotubes. The preliminary results obtained evidenced the surprising capability of the SnO II-based optical sensor to detect chemical pollutants at ppm level in air at room temperature. Finally, preliminary results on the effects of the processing parameters and post processing thermal annealing on film morphology and optical near field are presented.

Consales, M.; Pisco, M.; Pilla, P.; Cutolo, A.; Buosicolo, A.; Viter, R.; Smyntyna, V.; Giordano, M.; Cusano, A.

2007-05-01

59

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

PubMed Central

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

Hijaz, Faraj; Killiny, Nabil

2014-01-01

60

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...

61

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

Microsoft Academic Search

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

Sibel Silici; Semiramis Kutluca

2005-01-01

62

Solubility classification of airborne uranium products collected at the perimeter of the Allied Chemical Plant, Metropolis, Illinois  

Microsoft Academic Search

Airborne uranium products were collected at the perimeter of the uranium-conversion plant operated by the Allied Chemical Corporation at Metropolis, Illinois, and the dissolution rates of these products were classified in terms of the ICRP Task Group Lung Model. Assignments were based on measurements of the dissolution half-times exhibited by uranium components of the dust samples as they dissolved in

Kalkwarf

1980-01-01

63

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

Federal Register 2010, 2011, 2012, 2013, 2014

...program to improve security in the chemical industry sector. Information is automatically...facility employee. U.S. chemical industry direct employment is about 850,000 (2009 per American Chemistry Council); approximately 400,000...

2010-11-05

64

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

SciTech Connect

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.

Flynn, G.

2008-01-01

65

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...

66

Analysis of chemical abundances in planetary nebulae with [WC] central stars. II. Chemical abundances and the abundance discrepancy factor  

NASA Astrophysics Data System (ADS)

Aims: We present the abundance analysis of 12 planetary nebulae ionized by [WC]-type stars and weak-emission-line stars (wels) obtained from high-resolution spectrophotometric data. Our main aims are to determine the chemical composition of the nebulae and to study the behaviour of the abundance discrepancy problem (ADF) in this type of planetary nebulae. Methods: The detection of a large number of optical recombination lines (ORLs) and collisionally excited lines (CELs) from different ions (O+, O++, C++, C+3 and Ne++) were presented previously. Most of the ORLs were reported for the first time in these PNe, which increased the sample of PNe with detected faint ORLs. Ionic abundances were determined from the available CELs and ORLs, using previously determined physical conditions. Based on these two sets of ionic abundances, we derived the total chemical abundances in the nebulae using suitable ionization correction factors (when available). Results: In spite of the [WC] nature of the central stars, moderate ADF(O++) in the range from 1.2 to 4 were found for all the objects. We found that when the quality of the spectra is high enough, the ORLs O++/H+ abundance ratios obtained from different multiplets excited mainly by recombination are very similar. Possible dependence of ADFs on some nebular characteristics such as surface brightness and nebular diameter were analysed, but we found no correlation. Abundances derived from CELs were corrected by determining the t2 temperature fluctuation parameter. O abundances for PNe, derived from ORLs, are in general higher than the solar abundance. We derived the C/O ratio from ORLs and N/O and ?-element/O ratios from CELs and found that these PNe are, on average, richer in N and C than the average of the large PN samples. About half of our sample is C-rich (C/O > 1). The growth of ?-elements is correlated with the O abundance. Comparing the N/O and C /O ratios with those derived from stellar evolution models, we estimate that about half of our PNe have progenitors with initial masses similar to or larger than 4 M?. No correlation was found between the stellar [WC] type and the nebular chemical abundances. A rough O abundance gradient computed for our limited PN sample, compared with the gradient obtained for H ii regions, shows that there is a large dispersion in estimates of the PNe O abundance for a given Galactocentric distance. The PN gradient is flatter than that for H ii regions and at the solar distance and farther out, the PNe have a higher O abundance than H ii regions, similarly to what is found in other spiral galaxies. This fact has no convincing explanation so far. Based on data obtained at Las Campanas Observatory, Carnegie Institution.

García-Rojas, Jorge; Peña, Miriam; Morisset, Christophe; Delgado-Inglada, Gloria; Mesa-Delgado, Adal; Ruiz, María Teresa

2013-10-01

67

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

PubMed

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

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

2014-06-01

68

Chemical Characterization of Dew Water Collected in Different Geographic Regions of Poland  

PubMed Central

The results of a dew monitoring program performed in Poland with the aim to outline the chemical composition of dew water in meteorological context are presented. Dew samples were collected from eight measurement stations from August 2004 to November 2006. Taking into account the type of land use and characteristics of pollutant emission, sampling sites were divided into the following categories: rural, coastal urban and inland urban stations. Selected anions and cations as well as formaldehyde and sum of phenols were determined. The average TIC (Total Inorganic Ionic Content) values in dew samples ranged from 0.83 to 3.93 between individual stations with 10.9 meq/L as the highest daily value of TIC measured. The average TIC values observed in dew at all stations were at a similar level (2.46 meq/L) when compared with hoarfrost (2.86 meq/L). However, these values were much higher in comparison with other kinds of atmospheric water like precipitation (wet only; 0.37 meq/L) or fog/cloud (1.01 meq/L). The pH values of dew water ranged from 5.22 to 7.35 for urban coastal stations, from 5.67 to 8.02 for urban inland stations and from 4.16 to 8.76 for dew samples collected in the rural area. HCHO was found in 97 % of dew samples, with concentrations ranging from 0.010 to 5.40 meq/L. Excluding stations near the seashore, where the contribution of Na+ and Cl- increased, the most important ions were sulphates. A very low contribution of NO3- and noticeable increase of Ca2+ which were not observed in the case of precipitation and fog water, were typical in all stations. The contribution of ammonium ion was two times higher at rural stations as a result of agricultural ammonia emissions. The strongest correlations were noticed between the sum of acidifying anions SO42- + NO3- and Ca2+ ion for all urban and rural stations. A very strong correlation was also observed for Na+ and Cl- ions in urban coastal stations, as a natural consequence of the location of these stations close to the sea. It was proved that thermal stratification, direction of circulation and local breeze circulation control the atmospheric chemistry at ground level, where dew is formed. The highest TIC values at urban stations were associated with anticyclonic weather, while at rural sites with cyclonic weather situations. The chemistry of dew water in urban coastal stations was closely related to local breeze circulation in the warm season, mainly in the form of diurnal breeze causing a significant increase of the concentration of Na+ and Cl-ions. Thus, dew can be a good indicator of the atmospheric pollution level at a given site. Taking into account both high TIC values and the annual water equivalent estimated at around 50 mm, dew is a considerable factor of wet deposition, responsible for an additional 60 % of pollutant input into the ground when compared with precipitation.

Polkowska, ?aneta; B?a?, Marek; Klimaszewska, Kamila; Sobik, Mieczys?aw; Ma?ek, Stanis?aw; Namie?nik, Jacek

2008-01-01

69

VARIATION IN THE U.S. PHOTOPERIOD-INSENSITIVE SORGHUM COLLECTION FOR CHEMICAL AND NUTRITIONAL TRAITS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Screening germplasm for chemical and nutritional content can be expensive and time consuming. Near Infrared Spectroscopy (NIRS) and application of geostatistical models can make screening more efficient. The objectives of this study were to utilize these two technologies to: 1) generate chemical and...

70

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

DOEpatents

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.

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

2010-08-17

71

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...

72

Dissecting the chemical interactions and substrate structural signatures governing RNA polymerase II trigger loop closure by synthetic nucleic acid analogues  

PubMed Central

The trigger loop (TL) of RNA polymerase II (Pol II) is a conserved structural motif that is crucial for Pol II catalytic activity and transcriptional fidelity. The TL remains in an inactive open conformation when the mismatched substrate is bound. In contrast, TL switches from an inactive open state to a closed active state to facilitate nucleotide addition upon the binding of the cognate substrate to the Pol II active site. However, a comprehensive understanding of the specific chemical interactions and substrate structural signatures that are essential to this TL conformational change remains elusive. Here we employed synthetic nucleotide analogues as ‘chemical mutation’ tools coupling with ?-amanitin transcription inhibition assay to systematically dissect the key chemical interactions and structural signatures governing the substrate-coupled TL closure in Saccharomyces cerevisiae Pol II. This study reveals novel insights into understanding the molecular basis of TL conformational transition upon substrate binding during Pol II transcription. This synthetic chemical biology approach may be extended to understand the mechanisms of other RNA polymerases as well as other nucleic acid enzymes in future studies. PMID:24692664

Xu, Liang; Butler, Kyle Vincent; Chong, Jenny; Wengel, Jesper; Kool, Eric T.; Wang, Dong

2014-01-01

73

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

NASA Astrophysics Data System (ADS)

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.

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

74

Liquid chromatography electrospray tandem mass spectrometric and desorption electrospray ionization tandem mass spectrometric analysis of chemical warfare agents in office media typically collected during a forensic investigation  

Microsoft Academic Search

Most prior analytical studies have dealt with the determination of chemical warfare agents in environmental or biological matrices that would typically be collected following battlefield use or in support of the Chemical Weapons Convention. These methods may be useful for some investigations, but may not be practical for indoor forensic investigations where chemical warfare agent use is suspected. There is

P. A. D’Agostino; J. R. Hancock; C. L. Chenier; C. R. Jackson Lepage

2006-01-01

75

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

PubMed

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

Silici, Sibel; Kutluca, Semiramis

2005-05-13

76

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...

77

Salivary influences upon levels of certain chemical constituents in forage residues collected from esophageally cannulated sheep  

E-print Network

fulfillment of the reouiremente for +he degree o+ NAS vR Oi' SCI NCE January 1967 Range Science SALIVARY INFLU. . NC, 'S UPON LEVELS OF CERTAIN CHEHICAL CONSTITUENTS IN FORAGE R SIDUES COLLECT D FROH ESOPHAGEALLY CANNULATED SHEEP A Thesis By Kenneth... to be cuantitatively related to salivation. The objectives of this study were: 1. To determine possible changes in the nitrogen, ash, and water soluble corbohydrate content of forage samples and saliva as collected from esophageally cannulated sheep. 2...

Radde, Kenneth Albert

2012-06-07

78

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

PubMed Central

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 2.0–2.2 ?g/mL in the AP estrogenicity assay, and IC50s of 18.4–32.6 ?g/mL and 1.9–3.4 ?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

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

79

Search for extraterrestrial point sources of high energy neutrinos with AMANDA-II using data collected in 2000-2002  

E-print Network

The results of a search for point sources of high energy neutrinos in the northern hemisphere using data collected by AMANDA-II in the years 2000, 2001 and 2002 are presented. In particular, a comparison with the single-year result previously published shows that the sensitivity was improved by a factor of 2.2. The muon neutrino flux upper limits on selected candidate sources, corresponding to an E^{-2} neutrino energy spectrum, are included. Sky grids were used to search for possible excesses above the background of cosmic ray induced atmospheric neutrinos. This search reveals no statistically significant excess for the three years considered.

The AMANDA Collaboration; M. Ackermann

2004-12-14

80

Search for extraterrestrial point sources of high energy neutrinos with AMANDA-II using data collected in 2000-2002  

SciTech Connect

The results of a search for point sources of high energy neutrinos in the northern hemisphere using data collected by AMANDA-II in the years 2000, 2001, and 2002 are presented. In particular, a comparison with the single-year result previously published shows that the sensitivity was improved by a factor of 2.2. The muon neutrino flux upper limits on selected candidate sources, corresponding to an E{sub {nu}}{sup -2} neutrino energy spectrum, are included. Sky grids were used to search for possible excesses above the background of cosmic ray induced atmospheric neutrinos. This search reveals no statistically significant excess for the three years considered.

Ackermann, M.; Bernardini, E.; Boersma, D.J.; Boeser, S.; Hauschildt, T.; Kowalski, M.; Leich, H.; Leuthold, M.; Nahnhauer, R.; Resconi, E.; Schlenstedt, S.; Spiering, C.; Steffen, P.; Sulanke, K. H.; Tarasova, O.; Walter, M.; Wischnewski, R.; Wissing, H. [DESY, D-15735, Zeuthen (Germany); Ahrens, J.; Becka, T. [Institute of Physics, University of Mainz, Staudinger Weg 7, D-55099 Mainz (Germany)] [and others

2005-04-01

81

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

NASA Astrophysics Data System (ADS)

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 ?m), a 10-stage micro-orifice uniform deposit impactor (Dp 0.054 to 18 ?m), and stacked-filter units (Dp < 1.7 ?m) 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 ?g m-3; DP: 1.2 ?g 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.

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

2009-05-01

82

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

PubMed

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

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

2001-04-01

83

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

SciTech Connect

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.

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

1983-12-01

84

A-current and type I/type II transition determine collective spiking from common input  

PubMed Central

The mechanisms and impact of correlated, or synchronous, firing among pairs and groups of neurons are under intense investigation throughout the nervous system. A ubiquitous circuit feature that can give rise to such correlations consists of overlapping, or common, inputs to pairs and populations of cells, leading to common spike train responses. Here, we use computational tools to study how the transfer of common input currents into common spike outputs is modulated by the physiology of the recipient cells. We focus on a key conductance, gA, for the A-type potassium current, which drives neurons between “type II” excitability (low gA), and “type I” excitability (high gA). Regardless of gA, cells transform common input fluctuations into a tendency to spike nearly simultaneously. However, this process is more pronounced at low gA values. Thus, for a given level of common input, type II neurons produce spikes that are relatively more correlated over short time scales. Over long time scales, the trend reverses, with type II neurons producing relatively less correlated spike trains. This is because these cells' increased tendency for simultaneous spiking is balanced by an anticorrelation of spikes at larger time lags. These findings extend and interpret prior findings for phase oscillators to conductance-based neuron models that cover both oscillatory (superthreshold) and subthreshold firing regimes. We demonstrate a novel implication for neural signal processing: downstream cells with long time constants are selectively driven by type I cell populations upstream and those with short time constants by type II cell populations. Our results are established via high-throughput numerical simulations and explained via the cells' filtering properties and nonlinear dynamics. PMID:22673330

Barreiro, Andrea K.; Thilo, Evan L.

2012-01-01

85

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...

86

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

PubMed

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

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

2007-03-01

87

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

NASA Astrophysics Data System (ADS)

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' 3? 2u), I II(A 3? 1u) and O II(a1? 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(X1? + 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(1?). The loss of O II(1?) 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.

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

2007-06-01

88

User Centered System Design. Part II: Collected Papers from the UCSD HMI Project.  

ERIC Educational Resources Information Center

This report is a collection of 11 recent papers by the Human-Machine Interaction Group at the University of California, San Diego. The following papers are included: (1) "Stages and Levels in Human-Machine Interaction," Donald A. Norman; (2) "The Nature of Expertise in UNIX," Stephen W. Draper; (3) "Users in the Real World," David Owen; (4)…

California Univ., San Diego, La Jolla. Inst. for Cognitive Science.

89

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

SciTech Connect

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.

Sarangi, Arkaprabha; Cherchneff, Isabelle, E-mail: arkaprabha.sarangi@unibas.ch, E-mail: isabelle.cherchneff@unibas.ch [Departement Physik, Universität Basel, CH-4056 Basel (Switzerland)

2013-10-20

90

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

USGS Publications Warehouse

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. ?56Fe values for bulk HCl- and HF-extractable Fe were ? 0. These near-zero bulk ?56Fe values, together with the very low abundance of dissolved Fe in the overlying water column, suggest that the pyrite Fe source had near-zero ?56Fe 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 (?56Fe ? -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-?56Fe minerals during BIF genesis.

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

91

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

PubMed

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

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

2013-05-01

92

Affine symmetry in mechanics of collective and internal modes. Part II. Quantum models  

E-print Network

Discussed is the quantized version of the classical description of collective and internal affine modes as developed in Part I. We perform the Schr\\"odinger quantization and reduce effectively the quantized problem from $n^{2}$ to $n$ degrees of freedom. Some possible applications in nuclear physics and other quantum many-body problems are suggested. Discussed is also the possibility of half-integer angular momentum in composed systems of spin-less particles.

J. J. S?awianowski; V. Kovalchuk; A. S?awianowska; B. Go?ubowska; A. Martens; E. E. Ro?ko; Z. J. Zawistowski

2008-02-21

93

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

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

94

Single Molecule and Collective Dynamics of Motor Protein Coupled with Mechano-Sensitive Chemical Reaction  

NASA Astrophysics Data System (ADS)

Motor proteins such as myosin and kinesin hydrolyze ATP into ADP and Pi to convert chemical energy into mechanical work. This resultsin various motile processes like muscle contraction, vesicle transport and cell division. Recent single molecule experiments have revealed that external load applied to these motor proteins perturb not only the mechanical motion, but the ATP hydrolysis cycle as well, making these molecules mechano-enzymes. Here, we describe our single molecule detection techniques to reveal the mechano-enzymatic properties of myosin and introduce recent progress from both experimental and theoretical approaches at the single- and multiple-molecule level.

Iwaki, Mitsuhiro; Marcucci, Lorenzo; Togashi, Yuichi; Yanagida, Toshio

2013-12-01

95

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

NASA Technical Reports Server (NTRS)

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.

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

1975-01-01

96

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

SciTech Connect

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.

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

2007-09-28

97

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

PubMed Central

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

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

2010-01-01

98

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

PubMed

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

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

2013-08-01

99

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

DOEpatents

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.

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

2002-01-01

100

Arbovirus investigations in Argentina, 1977-1980. II. Arthropod collections and virus isolations from Argentine mosquitoes.  

PubMed

Prospective surveys for arboviruses were carried out in Santa Fe, Corrientes, and Chaco provinces, Argentina, aperiodically during 1977-1980. A total of 313,233 mosquitoes and 598 biting flies other than mosquitoes were collected and tested for virus in 5,197 and 45 pools, respectively. Forty virus strains were isolated, all from mosquitoes, as follows: Santa Fe Province: 4 Gamboa group viruses from Aedeomyia squamipennis, 1 strain each of St. Louis encephalitis virus from Culex pipiens quinquefasciatus and Culex (Culex) spp.; Corrientes Province: a single strain of a newly discovered Anopheles A serogroup virus, Las Maloyas, from Anopheles albitarsis; and Chaco Province: 4 Gamboa group viruses from Ad. squamipennis, 6 strains of new Bunyaviridae (1 Antequera, 1 Barranqueras, and 4 Resistencia) from Culex (Melanoconion) delpontei, 3 strains of a new subtype of western equine encephalitis virus and 1 strain of Para virus from the Cx. (Mel.) ocossa group, 12 strains of a newly discovered subtype (VI) of the Venezuelan equine encephalitis complex from Cx. (Mel.) delpontei, and 1 strain each from Ad. squamipennis, Aedes scapularis, Ae. spp., Cx. (Cux.) spp., Cx. (Mel.) ocossa group, Mansonia spp., and Psorophora spp. Bloodmeals from 265 engorged mosquitoes were identified by precipitin test. These data, coupled with data on engorgement rates for 25,995 mosquitoes from bait collections, provide information on the host feeding patterns of several mosquito species. This information is discussed, along with data on relative abundance of mosquito species, within the context of the vector relationships of the species from which viruses were isolated. The association of Cx. (Mel.) delpontei with 18 strains of 4 different viruses in Chaco Province, plus its catholic feeding habits, clearly indicate for the first time the importance of this species as an arbovirus vector. PMID:2863989

Mitchell, C J; Monath, T P; Sabattini, M S; Cropp, C B; Daffner, J F; Calisher, C H; Jakob, W L; Christensen, H A

1985-09-01

101

Possible chemical causes of skeletal deformities in natural populations of Aphanius fasciatus collected from the Tunisian coast.  

PubMed

This study attempt to quantify and identify skeletal deformities in natural populations of Aphanius fasciatus collected from the Tunisian coast and tends to found a possible relationship between these anomalies and several types of pollutants presents in the environment. Fish were collected from one reference area (S1: coast of Luza) and three polluted areas (S2: industrialized coast of Sfax, S3: coast of Khniss and S4: Hamdoun'Oued). Various patterns of skeletal deformities were diagnosed using double staining technics, and the levels of heavy metals (Cd, Cu and Zn), various polycyclic aromatic hydrocarbons (PAHs) and estrogenic compounds were determined in water and sediment from different sites. Spatio-temporal variation of the spinal deformities frequencies in A. fasciatus show that high incidence of spinal anomalies has been recorded in population collected from S2 in comparison to three other ones. Morphological results indicated that skeletal deformities of adult A. fasciatus were grouped into 13 categories that described abnormalities on spines, vertebrae, arcs and mandibles. A total of 1025 abnormalities were quantified. The results of chemical analysis showed that the levels of heavy metals and PAHs were significantly higher in S2 than in S1, S3 and S4. High level of estrogenic activity was observed only in S4. A possible correlation between environmental exposures to a mixture of pollutants in coastal waters in S2 and spinal deformities in A. fasciatus was suggested. PMID:23260252

Kessabi, Kaouthar; Annabi, Ali; Hassine, Aziza Ibn Hadj; Bazin, Ingrid; Mnif, Wissem; Said, Khaled; Messaoudi, Imed

2013-03-01

102

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

NASA Astrophysics Data System (ADS)

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

Kumar, Anand; Kamaluddin

2013-02-01

103

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

PubMed

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

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

2012-10-01

104

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

PubMed

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

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

2012-09-01

105

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

SciTech Connect

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.

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

1983-02-01

106

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

SciTech Connect

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.

Not Available

1988-10-01

107

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

PubMed

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

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

2013-01-01

108

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

PubMed

"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

Suehiro, M

1994-01-01

109

NOTES ON THE KIVA-II SOFTWARE AND CHEMICALLY REACTIVE FLUID MECHANICS  

E-print Network

-II is a large FORTRAN program developed at Los Alamos National Laboratory for internal combustion engine mechanics and combustion, explain the numerical methods currently used in KIVA-II and similar combustion codes, and provide an outline of the overall structure of KIVA-II as a representative combustion program

Holst, Michael J.

110

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

PubMed Central

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 123:49–56;?http://dx.doi.org/10.1289/ehp.1408642 PMID:25302578

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

2014-01-01

111

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

NASA Astrophysics Data System (ADS)

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 Delbrück-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.

Ge, Hao; Qian, Min; Qian, Hong

2012-01-01

112

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

PubMed

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), ?-CA, as well as ?-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 ?-CA by 88%, CAA of ?-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

Karacan, Mehmet Say?m; Zharmukhamedov, Sergei K; Mama?, 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

113

TECHNICAL BASIS FOR NARCOTIC CHEMICALS AND POLYCYCLIC AROMATIC HYDROCARBON CRITERIA. II. MIXTURES AND SEDIMENTS  

Microsoft Academic Search

A method is presented for developing sediment quality guidelines (SQG) for narcotic chemicals in general and polycyclic aromatic hydrocarbons (PAHs) in particular. The guidelines can be applied to any individual or mixture of narcotic chemicals including PAHs using only the chemical's octanol\\/water partition coefficient. They are derived using the final chronic values for type I narcotics developed from a database

Dominic M. Di Toro; Joy A. McGrath

2000-01-01

114

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

ERIC Educational Resources Information Center

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

Department of Education, Washington, DC.

115

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

NASA Astrophysics Data System (ADS)

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

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

2001-03-01

116

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

PubMed

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

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

2014-01-01

117

Analysis of chemical abundances in planetary nebulae with [WC] central stars. II. Chemical abundances and the abundance discrepancy factor  

E-print Network

(Abridged) We present the abundance analysis of 12 PNe ionized by [WC] type stars and wels obtained from high-resolution spectrophotometric data. Our main aims are to determine the chemical composition of the PNe and to study the behaviour of the abundance discrepancy problem (ADF) in this type of planetary nebulae. The detection of a large number of optical recombination lines (ORLs) and collisional excited lines (CELs) from different ions were presented in Garcia-Rojas et al. (2012). Most of the ORLs are reported for the first time in these PNe. Ionic abundances were derived from the available CELs and ORLs, using previously determined physical conditions. Based on both sets of ionic abundances, we derived total chemical abundances in the nebulae using suitable ICFs (when available). In spite of the [WC] nature of the central stars, moderate ADF(O^++), in the range from 1.2 to 4, were found for all the objects. We have found that, when the quality of the spectra is high enough, the ORLs O^++/H^+ abundance r...

Garc\\'\\ia-Rojas, J; Morisset, C; Delgado-Inglada, G; Mesa-Delgado, A; Ruiz, M T

2013-01-01

118

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

SciTech Connect

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.

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

1980-07-01

119

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

USGS Publications Warehouse

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).

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

2006-01-01

120

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

SciTech Connect

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.

Not Available

1988-11-01

121

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

PubMed

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

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

2013-08-01

122

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

PubMed

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. PMID:24785088

El-Sayed, Mohamed Y; Refat, Moamen S

2014-09-15

123

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

NASA Astrophysics Data System (ADS)

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.

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

2014-09-01

124

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

Microsoft Academic Search

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

Kristien Mortelmans; Steve Haworth; Timothy Lawlor; William Speck; Beth Tainer; Errol Zeiger

1986-01-01

125

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...

126

Chemical fractionations in meteorites---II. Abundance patterns and their interpretation  

Microsoft Academic Search

Abundances of thirty-one volatile elements in meteorites are reviewed. In carbonaceous chondrites of Types I, II, and III and enstatite chondrites of Type I, abundances decrease by constant factors, in ratios of 1\\/0·6\\/0·3\\/0·7. In ordinary chondrites and Type II enstatite chondrites, nine elements (Au, Cu, F, Ga, Ge, S, Sb, Se and Sn) likewise are depleted by constant factors of

John W. Larimer; Edward Anders

1967-01-01

127

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...

128

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

129

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

SciTech Connect

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.

SUGAMA,T.YAGER,K.A.BLANKENHORN,D. (KEYSPAN R AND D INITIATIVE)

1999-08-01

130

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...

131

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...

132

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

SciTech Connect

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.

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

1986-01-01

133

Insertion of a magnesium(II)-octacarboranyl(hexylsulfanyl) porphyrazine into liposomes: a physico-chemical study  

E-print Network

The synthesis, characterization and liposome insertion of a novel magnesium(II) carboranyl-porphyrazine, i.e. [2,3,7,8,12,13,17,18-octakis- (1,2-dicarba-closo-dodecaboranyl)-hexylthio-5,10,15,20- porphyrazine]magnesium(II) complex, MgHECSPz, is described. MgHECSPz was designed to improve the potentiality in multiple approach anticancer therapy. Liposomal formulations with different surface charge were prepared as delivering agents. The obtained loaded vectors were characterized by DLS, SAXS, SANS and \\zeta potential measurements in order to define the overall properties and structural details of loaded liposomes.

Anna Salvati; Sandra Ristori; Daniela Pietrangeli; Julian Oberdisse; Luca Calamai; Giacomo Martini; Giampaolo Ricciardi

2007-09-07

134

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 ...

135

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 ...

136

A quantum chemical consideration of ligand exchange in palladium(ii) aqueous and chloride complexes  

Microsoft Academic Search

The behavior of potassium tetrachloropalladate(II) in media simulating biological fluids has been studied. In aqueous solutions of NaCl, the aquation rate is higher than the rate of chloro ligand introduction into the internal coordination sphere of palladium. In HCl solutions, on the contrary, the process of palladium chloro complex formation predominates. The latter is apparently due to protonation of water

Alexei N. Pankratov; Vladimir B. Borodulin; Olga A. Chaplygina

2004-01-01

137

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

ERIC Educational Resources Information Center

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…

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

2011-01-01

138

The electric oxygen-iodine laser: chemical kinetics of O II(a1?) production and I(2 P 1/2) excitation in microwave discharge systems  

NASA Astrophysics Data System (ADS)

Generation of singlet oxygen metastables, O II(a1?), in an electric discharge plasma offers the potential for development of compact electric oxygen-iodine laser (EOIL) systems using a recyclable, all-gas-phase medium. The primary technical challenge for this concept is to develop a high-power, scalable electric discharge configuration that can produce high yields and flow rates of O II(a) to support I(2P 1/2->2P 3/2) lasing at high output power. This paper discusses the chemical kinetics of the generation of O II(a) and the excitation of I(2P 1/2) in discharge-flow reactors using microwave discharges at low power, 40-120 W, and moderate power, 1-2 kW. The relatively high E/N of the microwave discharge, coupled with the dilution of O II with Ar and/or He, leads to increased O II(a) production rates, resulting in O II(a) yields in the range 20-40%. At elevated power, the optimum O II(a) yield occurs at higher total flow rates, resulting in O II(a) flow rates as large as 1 mmole/s (~100 W of O II(a) in the flow) for 1 kW discharge power. We perform the reacting flow measurements using a comprehensive suite of optical emission and absorption diagnostics to monitor the absolute concentrations of O II(a), O II(b), O( 3P), I II, I(2P 3/2), I(2P 1/2), small-signal gain, and temperature. These measurements constrain the kinetics model of the system, and reveal the existence of new chemical loss mechanisms related to atomic oxygen. The results for O II(a) production at 1 kW have intriguing implications for the scaling of EOIL systems to high power.

Rawlins, W. T.; Lee, S.; Kessler, W. J.; Oakes, D. B.; Piper, L. G.; Davis, S. J.

2006-02-01

139

Higgs Mechanism with Type-II Nambu-Goldstone Bosons at Finite Chemical Potential  

E-print Network

When the spontaneous symmetry breaking occurs for systems without Lorentz covariance, there arises possible mismatch, $N_{\\rm NG} Higgs mechanism under this mismatch by employing gauge theories with complex scalar field at finite chemical potential and by enforcing "charge" neutrality. To separate the physical spectra from unphysical ones, the $R_{\\xi}$ gauge is adopted. Not only massless NG bosons but also massive scalar bosons generated by the chemical potential are absorbed into spatial components of the gauge bosons. Although the chemical potential induces a non-trivial mixings among the scalar bosons and temporal components of the gauge bosons, it does not affect the structure of the physical spectra, so that the total number of physical modes is not modified even for $N_{\\rm NG} < N_{\\rm BG}$.

Yusuke Hama; Tetsuo Hatsuda; Shun Uchino

2011-02-21

140

Four-Year Summary, Educational and Commercial Utilization of a Chemical Information Center, Part II.  

ERIC Educational Resources Information Center

The major objective of the Illinois Institute of Technology Retrieval Institute (IITRI) Computer Search Center (CSC) is to educate and link industry, academia, and government institutions to chemical and other scientific information systems and sources. The CSC is in full operation providing services to users from a variety of machine-readable…

Schipma, Peter B., Ed.

141

The atmosphere of Canopus. II. Chemical composition. Determination of the mass, radius, luminosity, and age  

Microsoft Academic Search

The model proposed by Liubimkov and Boiarchuk (1982) is used in determining the abundances of 21 elements in the atmosphere of Canopus. The analysis is based on relatively weak lines so that the influence of inaccuracies in the microturbulence and in the damping will be reduced. The chemical composition of the atmosphere is found to be similar to that of

L. S. Lyubimkov; A. A. Boiarchuk

1982-01-01

142

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...

143

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...

144

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...

145

155: 309 Chemical Engineering Thermodynamics II Fall 2014 Web page: https://sakai.rutgers.edu  

E-print Network

Equilibria III: Solid-Liquid and Solid-Solid Equilibrium Ch. 8.4 Phase Equilibria III: Colligative Properties, Quiz Ch. 8.5 11 Phase Equilibria III: Colligative Properties Ch. 8.5 Chemical Reaction Equilibria Campus Email: meenakshi.dutt@rutgers.edu TBA Teaching Assistants: TBA Course Description: Properties

146

155: 309 Chemical Engineering Thermodynamics II Fall 2014 Web page: https://sakai.rutgers.edu  

E-print Network

Phase Equilibria III: Colligative Properties Ch. 8.5 Nov 12 Chemical Reaction Equilibria: Introduction28@scarletmail.rutgers.edu Office Hours: Tu. 11:00am ­ 12:30pm Course Description: Properties Objectives: The students will understand phase equilibria as applied to liquid and gases, properties

Muzzio, Fernando J.

147

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 ...

148

Chemical chaperones improve transport and enhance stability of mutant ?-glucosidases in glycogen storage disease type II  

Microsoft Academic Search

Glycogen storage disease type II (GSDII; Pompe disease or acid maltase deficiency) is an autosomal recessive disorder caused by lysosomal acid ?-glucosidase (A?Glu) deficiency and manifests predominantly as skeletal muscle weakness. Defects in post-translational modification and transport of mutant A?Glu species are frequently encountered and may potentially be corrected with chaperone-mediated therapy. In the present study, we have tested this

Toshika Okumiya; Marian A. Kroos; Laura Van Vliet; Hiroaki Takeuchi; Ans T. Van der Ploeg; Arnold J. J. Reuser

2007-01-01

149

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...

150

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

PubMed

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

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

2015-02-15

151

Structure and properties of the new complexes of platinum (II) with the chemically modified tetracycline CMT3: A theoretical DFT study  

Microsoft Academic Search

The present paper reports DFT calculations of structure and spectroscopic properties for new complexes of platinum (II) with the most important chemically modified tetracycline, named CMT-3 or Col-3. A detailed analysis is carried out for the free ligand at distinct ionization states as well as for 18 structures with Pt(II) coordinated at potential sites on CMT-3. From the calculated thermodynamic

Bruna L. Marcial; Luiz Antônio S. Costa; Wagner B. De Almeida; Hélio F. Dos Santos

2009-01-01

152

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

NASA Astrophysics Data System (ADS)

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 Å 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.

Karinkuzhi, Drisya; Goswami, Aruna

2015-01-01

153

Quantum chemical study of copper (II) chloride and the Deacon reaction  

NASA Astrophysics Data System (ADS)

A model for the gas phase oxidation of hydrogen chloride in the presence of copper (II) chloride (the Deacon reaction) has been investigated by the density functional theory. Chlorine (Cl2) is produced by the thermal decomposition of CuCl2 generating Cu2Cl2 which reacts with O2 (3?g) to form several intermediates and complexes which further react with hydrogen chloride. A key step in the mechanism is the fission of a O-O linkage between two Cu2Cl2 moieties. This step possesses a barrier prohibitive to homogeneous gas phase catalysis but one which is expected to be easily overcome on a copper chloride surface.

Suleiman, Ibrahim A.; Mackie, John C.; Kennedy, Eric M.; Radny, Marian W.; Dlugogorski, Bogdan Z.

2011-01-01

154

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...

155

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

PubMed

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

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

2015-01-22

156

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

NASA Astrophysics Data System (ADS)

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.

Kamaluddin; Nath, Mala; Deopujari, Sushama W.

1989-03-01

157

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

SciTech Connect

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.

Pena-Guerrero, Maria A.; Peimbert, Antonio; Peimbert, Manuel [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Apdo. Postal 70-264, Mexico 04510 D.F. (Mexico); Ruiz, Maria Teresa, E-mail: guerrero@astroscu.unam.mx, E-mail: antonio@astroscu.unam.mx, E-mail: peimbert@astroscu.unam.mx, E-mail: mtruiz@das.uchile.cl [Departamento de Astronomia, Universidad de Chile, Casilla Postal 36D, Santiago de Chile (Chile)

2012-02-20

158

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

NASA Astrophysics Data System (ADS)

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 ?m 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.

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

2015-01-01

159

Library Collections Conservation Discussion Group 2006: The Changing Role of Collections Conservation II: New Workflows and New Collection Paradigms: Conservation's Role in Off-Site Storage Workflows and Projects  

E-print Network

The Library Collections Conservation Discussion Group (LCCDG) co-chairs presented two topics for discussion at the AIC Providence meeting: (1) conservation’s role in off-site storage workflows; and (2) conservation’s role in digitization workflows...

Baker, Whitney; McCarthy, Christine

2006-01-01

160

An industry wide mortality study of chemical workers occupationally exposed to benzene. II. Dose response analyses.  

PubMed Central

The data presented in this paper show statistically significant dose response relations between cumulative exposure to benzene (ppm-months) and mortality from both all lymphopoietic cancer combined and leukaemia. Chemical workers with a cumulative exposure to benzene of at least 720 ppm-months experienced a relative risk of 3.93 for lymphatic and haematopoietic cancer when compared with workers with no occupational exposure. The dose response relation between cumulative exposure and non-Hodgkin's lymphopoietic cancer was of borderline statistical significance (p = 0.06). No dose response relation was detected for any other causes of death. PMID:3606967

Wong, O

1987-01-01

161

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

NASA Technical Reports Server (NTRS)

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.

Leckrone, D. S.

1981-01-01

162

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

NASA Technical Reports Server (NTRS)

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.

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

1981-01-01

163

Photo-chemical evolution of elliptical galaxies II. The impact of merging-induced starbursts  

E-print Network

The effects of late gas accretion episodes and subsequent merger-induced starbursts on the photo-chemical evolution of elliptical galaxies are studied and compared to the picture of galaxy formation occurring at high redshift with an unique and intense starburst modulated by a very short infall, as suggested by Pipino & Matteucci (2004, Paper I). By means of the comparison with the the colour-magnitude relations and the [_V]-sigma relation observed in ellipticals, we conclude that either bursts involving a gas mass comparable to the mass already transformed into stars during the first episode of star formation and occurring at any redshift, or bursts occurring at low redshift (i.e. z3) produce a spread in the model results, with respect to Paper I best model, which is consistent with the observational scatter of the color-magnitude relations, although there is only marginal agreement with the [_V]-sigma relation. Therefore, only small perturbations to the standard scenario seem to be allowed. We stress that the strongest constraints to galaxy formation mechanisms are represented by the chemical abundances, whereas the colours can be reproduced under several different hypotheses.

Antonio Pipino; Francesca Matteucci

2005-10-20

164

Toxic essential oils. Part II: chemical, toxicological, pharmacological and microbiological profiles of Artemisia annua L. volatiles.  

PubMed

Botanical drugs based on Artemisia annua L. (Asteraceae) are important in the treatment of malaria. Alongside with artemisinin, this aromatic species produces high and variable amounts of other chemicals that have mostly unknown biological/pharmacological activities. Herein, we have studied the toxicological/pharmacological profile of volatile constituents of a Serbian population of A. annua. Fifty-eight components were identified, among them, artemisia ketone (35.7%), ?-pinene (16.5%) and 1,8-cineole (5.5%) were the most abundant ones. Significant variability of A. annua volatile profile was confirmed by means of agglomerative hierarchical cluster analysis indicating the existence of several different A. annua chemotypes. In an attempt to connect the chemical profile of A. annua oil with its biological/toxicological effects, we have evaluated in vivo and/or in vitro toxicity (including hepato- and nephrotoxicity/protection), antinociceptive, antioxidant (DPPH, ABTS and superoxide radical scavenging activity assays), enzyme inhibiting (protein kinase A and ?-amylase) and antimicrobial potential of A. annua oil and of its constituents. Our results revealed that the beneficial properties of A. annua botanical drugs are not limited only to their antimalarial properties. Taking into account its relatively low toxicity, the usage of A. annua volatiles (at least of the herein studied population) does not represent a health risk. PMID:23607933

Radulovi?, Niko S; Randjelovi?, Pavle J; Stojanovi?, Nikola M; Blagojevi?, Polina D; Stojanovi?-Radi?, Zorica Z; Ili?, Ivan R; Djordjevi?, Vidosava B

2013-08-01

165

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

NASA Astrophysics Data System (ADS)

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.

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

1998-01-01

166

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

SciTech Connect

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.

Leone, J.A.

1985-01-01

167

Impact of Lewis base on chemical reactivity and separation efficiency for hydrated fourth-row transition metal (II) complexes: an ONIOM DFT/MM study.  

PubMed

In this paper, two-layer ONIOM combinations of high-level quantum mechanics (QM) and inexpensive molecular mechanics (MM) are successfully used to investigate the structural characters of metal (M, all the transition metals in the fourth period)-H2O-Lewis base (A(-)) complexes. Global and local descriptors of chemical reactivity and selectivity from conceptual density functional theory are employed to show the properties of the active complexes of M(H2O)2A2 and to study the effect of the Lewis base for the separation of transition metal ions. It is shown that chemical potential, hardness, electrophilicity, as well as the dual and multiphilic descriptors are adequate for characterizing the global and local reactivity trends of the M(H2O)2A2 complex. It is found that the reactivity is well localized at the metallic center in M(H2O)2A2 and the dual descriptor (?fM(r)) can also be used to characterize the directional attack of the electrophile and nucleophile except for the selectivity of the reaction. On the basis of the values of ?M and ?sk, and the sign of ?fM(r), the selectivity of the nucleophilic reagent (R(-)) for M(II) in M(H2O)2A2 (from high to low) follows this order: Cu(II) > Ni(II) > Co(II) > Fe(II) ? Mn(II) > Zn(II) > Cr(II). The Lewis base (A(-)) improves chemical reactivity and selectivity because of changing the reaction path and forming an intermediate, which possesses the higher antibonding character and the larger HOMO/LUMO gap. NBO or AIMALL analysis and Frontier orbital theory results presented here provided more theoretical support for the above reactivity and selectivity studies. PMID:24694190

He, Dingsheng; Ma, Ming

2014-04-24

168

Angiotensin II type 2 receptor regulates ROMK-like K? channel activity in the renal cortical collecting duct during high dietary K? adaptation.  

PubMed

The kidney adjusts K? excretion to match intake in part by regulation of the activity of apical K? secretory channels, including renal outer medullary K? (ROMK)-like K? channels, in the cortical collecting duct (CCD). ANG II inhibits ROMK channels via the ANG II type 1 receptor (AT1R) during dietary K? restriction. Because AT1Rs and ANG II type 2 receptors (AT2Rs) generally function in an antagonistic manner, we sought to characterize the regulation of ROMK channels by the AT2R. Patch-clamp experiments revealed that ANG II increased ROMK channel activity in CCDs isolated from high-K? (HK)-fed but not normal K? (NK)-fed rats. This response was blocked by PD-123319, an AT2R antagonist, but not by losartan, an AT1R antagonist, and was mimicked by the AT2R agonist CGP-42112. Nitric oxide (NO) synthase is present in CCD cells that express ROMK channels. Blockade of NO synthase with N-nitro-l-arginine methyl ester and free NO with 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt completely abolished ANG II-stimulated ROMK channel activity. NO enhances the synthesis of cGMP, which inhibits phosphodiesterases (PDEs) that normally degrade cAMP; cAMP increases ROMK channel activity. Pretreatment of CCDs with IBMX, a broad-spectrum PDE inhibitor, or cilostamide, a PDE3 inhibitor, abolished the stimulatory effect of ANG II on ROMK channels. Furthermore, PKA inhibitor peptide, but not an activator of the exchange protein directly activated by cAMP (Epac), also prevented the stimulatory effect of ANG II. We conclude that ANG II acts at the AT2R to stimulate ROMK channel activity in CCDs from HK-fed rats, a response opposite to that mediated by the AT1R in dietary K?-restricted animals, via a NO/cGMP pathway linked to a cAMP-PKA pathway. PMID:25100281

Wei, Yuan; Liao, Yi; Zavilowitz, Beth; Ren, Jin; Liu, Wen; Chan, Pokman; Rohatgi, Rajeev; Estilo, Genevieve; Jackson, Edwin K; Wang, Wen-Hui; Satlin, Lisa M

2014-10-01

169

Biophysical and Biochemical Studies on Rhinovirus and Poliovirus II. Chemical and Hydrodynamic Analysis of the Rhinovirion  

PubMed Central

Chemical analysis of rhinovirus 14 revealed a ribonucleic acid (RNA) content of 29.8% and a high adenylic acid content (35%). A partial specific volume of 0.682 cm3/g was obtained for the rhinovirion. Rhinovirus and poliovirus had identical sedimentation coefficients of 158S. A diffusion coefficient of 1.71 × 10?7 cm2/sec was consistent with a hydrated diameter of 25 nm for the rhinovirion. The calculated molecular weights of the rhinovirion and its genome were 7.1 × 106 and 2.1 × 106 daltons, respectively. Sedimentation analysis of infectious RNA confirmed the similarity of the molecular size of the poliovirus and rhinovirus genomes. PMID:5543433

McGregor, Sandy; Mayor, Heather D.

1971-01-01

170

Inorganic chemical fertilizer application on US farms increased from very low levels to relatively high levels during the two to three decades after World War II.  

E-print Network

Inorganic chemical fertilizer application on US farms increased from very low levels to relatively high levels during the two to three decades after World War II. Increased fertilizer use greatly. It was apparent well before the rapid expansion in fertilizer use that inexpensive ways to evaluate the fertility

171

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...

172

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

NASA Astrophysics Data System (ADS)

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.

Miranker, Andrew

2013-03-01

173

Mass closure on the chemical species in size-segregated atmospheric aerosol collected in an urban area of the Po Valley, Italy  

NASA Astrophysics Data System (ADS)

A complete size segregated chemical characterisation was carried out for aerosol samples collected in the urban area of Bologna over a period of one year, using five-stage low pressure Berner impactors. An original dual-substrate technique was adopted to obtain samples suitable for a complete chemical characterisation. Total mass, inorganic, and organic components were analysed as a function of size, and a detailed characterisation of the water soluble organic compounds was also performed by means of a previously developed methodology, based on HPLC separation of organic compounds according to their acid character and functional group analysis by Proton Nuclear Magnetic Resonance. Chemical mass closure of the collected samples was reached to within a few percent on average in the submicron aerosol range, while a higher unknown fraction in the coarse aerosol range was attributed to soil-derived species not analysed in this experiment. Comparison of the functional group analysis results with model results simulating water soluble organic compound production by gas-to-particle conversion of anthropogenic VOCs showed that this pathway provides a minor contribution to the organic composition of the aerosol samples in the urban area of Bologna.

Matta, E.; Facchini, M. C.; Decesari, S.; Mircea, M.; Cavalli, F.; Fuzzi, S.; Putaud, J.-P.; Dell'Acqua, A.

2003-06-01

174

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

NASA Astrophysics Data System (ADS)

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.

Nicolini, Paolo; Frezzato, Diego

2013-06-01

175

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

Federal Register 2010, 2011, 2012, 2013, 2014

...NATIONAL FOUNDATION FOR THE ARTS AND THE HUMANITIES Notice of Proposed Information Collection...National Foundation for the Arts and the Humanities. ACTION: Notice, request for comments...trends and assessing the current state of digital conservation. The design of the...

2013-12-10

176

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

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.

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

177

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)

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.

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

2009-06-01

178

Roles of basolateral solute uptake via NKCC1 and of myosin II in vasopressin-induced cell swelling in inner medullary collecting duct  

PubMed Central

Collecting duct cells swell when exposed to arginine vasopressin (AVP) in the presence of a transepithelial osmolality gradient. We investigated the mechanisms of AVP-induced cell swelling in isolated, perfused rat inner medullary collecting ducts (IMCDs) using quantitative video microscopy and fluorescence-based measurements of transepithelial water transport. We tested the roles of transepithelial water flow, basolateral solute entry, and the cytoskeleton (actomyosin). When a transepithelial osmolality gradient was imposed by addition of NaCl to the bath, AVP significantly increased both water flux and cell height. When the osmolality gradient was imposed by addition of mannitol, AVP increased water flux but not cell height, suggesting that AVP-induced cell swelling requires a NaCl gradient and is not merely dependent on the associated water flux. Bumetanide (Na-K-2Cl cotransporter inhibitor) added to the bath markedly diminished the AVP-induced cell height increase. AVP-induced cell swelling was absent in IMCDs from NKCC1-knockout mice. In rat IMCDs, replacement of Na, K, or Cl in the peritubular bath caused significant cell shrinkage, consistent with a basolateral solute transport pathway dependent on all three ions. Immunocytochemistry using an antibody to NKCC1 confirmed basolateral expression in IMCD cells. The conventional nonmuscle myosin II inhibitor blebbistatin also diminished the AVP-induced cell height increase and cell shape change, consistent with a role for the actin cytoskeleton and myosin II. We conclude that the AVP-induced cell height increase is dependent on basolateral solute uptake via NKCC1 and changes in actin organization via myosin II, but is not dependent specifically on increased apical water entry. PMID:18417545

Chou, Chung-Lin; Yu, Ming-Jiun; Kassai, Eliza M.; Morris, Ryan G.; Hoffert, Jason D.; Wall, Susan M.; Knepper, Mark A.

2008-01-01

179

Results of chemical and stable isotopic analyses of water samples collected in the Patagonia Mountains, southern Arizona  

USGS Publications Warehouse

Water samples were collected in the Patagonia Mountains in February, 1997. Most of the samples were collected from portals of abandoned mines, or from stream drainages immediately downstream from abandoned mines. Most of the samples have low pH ( 1000 mg/L). Anion composition of the water samples is dominated by sulfate, while cation compositions range from calcium-dominated to mixed calcium-magnesium or calcium-sodium-dominated waters. Metals such as iron, manganese, copper, zinc, and aluminum contribute a significant portion (>10%) of the cation content to the water samples. Because of the low pH?s, protons contribute up to several percent of the cation character of the waters in some of the samples. The data are presented in tabular and graphical formats, with descriptions of data quality and brief descriptions of results.

Wanty, Richard B.; Shanks, Wayne C., III; Lamothe, Paul; Meier, A.L.; Lichte, Fred; Briggs, Paul H.; Berger, Byron R.

2001-01-01

180

Extremely Metal-poor Stars. II. Elemental Abundances and the Early Chemical Enrichment of the Galaxy  

NASA Astrophysics Data System (ADS)

We have obtained high-resolution spectra of 23 very metal-poor stars and present an abundance analysis for 19 of these for elements between Mg and Eu. The sample comprises roughly equal numbers of dwarfs and giants. All stars have [Fe/H] < -2.5, and 10 have [Fe/H] < -3.0. In addition, for six stars with [Fe/H] < -3.0, we compile equivalent widths from the literature (including our own studies) and recompute abundances. Possible errors in the stellar atmospheric models are discussed in detail. Hyperfine-structure corrections are presented for Mn and Co. We use robust techniques to delineate the main trends in the [X/Fe] versus [Fe/H] plots and compare these with the Galactic chemical evolution computations of Timmes, Woosley, & Weaver. The main results are as follows: The lowest abundance we derive for a previously unobserved star is [Fe/H] = -3.57, for CS 22172-002. There are now six stars with [Fe/H] < -3.50 as determined from high-resolution analyses. The ?elements Mg, Si, Ca, and Ti possess almost uniform overabundances (relative to iron) down to at least [Fe/H] = -4, the current limit of observations. [Mg/Fe] increases slightly at [Fe/H] < -2.5, but the slope is only -0.15 dex dex-1 and may be due to systematic errors. Ti behaves like the other ?elements, contrary to stellar nucleosynthetic calculations. Stars with [Fe/H] < -2.5 reach a plateau in [M/Fe] -0.8 that extends at least down to [Fe/H] = -4, but Baumueller & Gehren have advised of the need for +0.5 dex non-LTE corrections in the dwarfs, leading to a revised plateau nearer [Al/Fe] ? -0.3. This level is qualitatively consistent with an odd-even effect for Mg and Al, and in quantitative agreement with Timmes et al.'s Galactic chemical evolution model. We confirm the underabundance of [Cr/Fe] and [Mn/Fe], and the overabundance of [Co/Fe], in stars with [Fe/H] < -2.5 that was highlighted by MeWilliam et al. In addition, we point to a mild overabundance in [Ni/Fe], though this may be dominated by a few stars that have higher than normal [Ni/Fe] but that do not reflect an overall trend. Like CS 22949-037, discussed by McWilliam et al., CS 22876-032 shows real variations in yields, with Al and Mg produced in their normal ratios to one another but with underabundances in [Si/Fe], [Ca/Fe], and possibly [Sc/Fe]. It is clear from several elements that real star-to-star abundance differences are common at the lowest metallicities. Sr is measured in most of our stars, but Y and Ba are generally strong enough only in the giants. [Sr/Fe] shows a spread greater than 2 dex (i.e., by a factor in excess of 100) at [Fe/H] < -3, greatly exceeding reasonable errors in the measurement This spread exists for both dwarfs and giants. [Ba/Fe] decreases as [Fe/H] falls below -2.0, and it exhibits less scatter than [Sr/Fe]. A small number of stars with [Ba/Fe] > 0 deserve further study. CS 22897-008 has high Sr, Y, and C abundances for its [Fe/H] but normal Ba. This signature may have arisen from the weak s-process in M> 15 Msun stars or by r-processing. By combining an analytic description of gaseous supernova remnants with supernova yields, we show that enrichment of the interstellar medium is influenced more by supernova physics (explosive energy) than by environmental conditions (cloud density). If supernova iron-peak yields are correlated with explosion energy, we can accommodate the well-defined abundance trends with a chaotic picture for halo formation involving independently evolving clouds, as was envisaged by Searle & Zinn. We calculate that a typical enrichment in the protohalo will produce [Fe/H] = -2.7. This coincides with larger abundance variations in field stars of lower metallicity and the lower abundance limit for Galactic globular clusters.

Ryan, Sean G.; Norris, John E.; Beers, Timothy C.

1996-11-01

181

Theoretical Investigation of the Magnetic Exchange Interactions in Copper(II) Oxides under Chemical and Physical Pressures  

PubMed Central

It remains a challenge to understand the unconventional mechanisms that cause high-TC superconductivity in cuprate superconductors, high-TC multiferroicity in CuO, or low-dimensional magnetism in the spin-Peierls transition compounds such as CuGeO3. A common feature of all these copper oxide compounds (containing Cu2+ ions) is the presence of large magnetic superexchange interactions J. It is a general strategy to apply chemical and/or physical pressure in order to tune these exotic properties. Here we show theoretically, for the first time, the impact of physical pressure on J on CuO, for which we predict a strong enhancement of the low-dimensionality of the magnetic interactions and the spin-frustration at high-pressures. Such modifications are expected to strongly influence the multiferroic properties of CuO. We finally demonstrate that PBE0 hybrid DFT calculations provide reliable J values for a wide range of copper(II) oxides compounds, i.e. CuGeO3, BaCu2Si2O7, BaCu2Ge2O7, and La2CuO4. PMID:23091699

Rocquefelte, Xavier; Schwarz, Karlheinz; Blaha, Peter

2012-01-01

182

On the collective network of ionic liquid/water mixtures. II. Decomposition and interpretation of dielectric spectra  

NASA Astrophysics Data System (ADS)

This study deals with the dielectric spectra of mixtures of the ionic liquid 1-butyl-3-methyl-imidazolium (BMIM+) tetrafluoroborate with water at three selected mole fractions 0.767?xH2O?0.967. The focus lies on the comparison of experimental and computational data. On the one hand, a computational analysis permits a complete decomposition of spectra, both with respect to dynamical behavior (translation and rotation) as well as to composition of the mixture (cation, anion, and water). Thereby, not only the peak assignment in experimental spectra is enabled but one can also learn more about solvation properties. Of particular importance is the interplay of the dielectric constant and the conductivity representing a measure of collective rotational and translational motion. On the other hand, the comparison with experimental spectra is essential for the validation of the force fields used in simulation. The satisfying agreement between corresponding peaks in the dielectric spectra confirms not only computed dielectric relaxation times but also other collective dynamical properties such as the viscosity. Nevertheless, the detailed fine structure of the conductivity regime reveals specific ion-pair effects not covered by the simulation. A possible confinement of dynamical heterogeneity as a consequence of a system size effect is also indicated.

Schröder, C.; Hunger, J.; Stoppa, A.; Buchner, R.; Steinhauser, O.

2008-11-01

183

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

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.

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

2012-01-01

184

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

PubMed

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

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

2013-12-23

185

Arctic chemical ozone depletion during the 1994-1995 winter deduced from POAM II satellite observations and the REPROBUS three-dimensional model  

NASA Astrophysics Data System (ADS)

Chemical ozone depletion during the unusually cold 1994-1995 Arctic winter is quantified using ozone profile measurements from the space-based Polar Ozone and Aerosol Measurement (POAM II) instrument and the REPROBUS three-dimensional chemistry transport model. The model is first used to determine the dynamical component of the observed variations, allowing the chemical component to be quantified from the observations. This technique has been previously used to estimate ozone loss from ground-based total column measurements. In the present study, it has been adapted to the POAM II vertical profile measurements in order to document the vertical evolution of ozone chemical loss throughout the winter both inside and outside the polar vortex. The cumulative ozone loss thus obtained inside the vortex at the end of the winter is found to reach a maximum of 51% (with respect to the REPROBUS dynamics-only prediction) at the 430 K potential temperature level. The largest ozone depletion rates were observed in late January when record low temperatures were reported, and the vortex was largely displaced towards midlatitudes. The maximum depletion rate was 1.4%/d occurring at the 470 K potential temperature level. Smaller but significant chemical ozone depletion was also found outside the vortex, where cumulative ozone losses of 19% were observed in the lower stratosphere. Finally, comparison of chemical ozone loss inferred from the POAM measurements with that obtained from the REPROBUS model indicates that the model underestimates cumulative ozone loss inside the vortex (by ˜30% in the lower stratosphere).

Deniel, C.; Bevilacqua, R. M.; Pommereau, J. P.; LefèVre, F.

1998-08-01

186

Chemical state mapping on material surfaces with X1A second generation scanning photoemission microscope (X1A SPEM-II)  

SciTech Connect

The second generation scanning photoelectron microscope at beamline X1A of the National Synchrotron Light Source (X1A SPEM-II) is designed for spatially resolved elemental and chemical analysis by x-ray photoelectron spectroscopy (XPS) on material surfaces. This microscope can focus photon energies between 300 to 800 eV with submicron spatial resolution. Multiple photoelectron images can be acquired simultaneously with the use of a hemispherical sector analyzer (HSA) with multi-channel detection (MCD), which enables a technique called parallel imaging for chemical state mapping (PICSM). The PICSM technique was demonstrated using a Si/SiO{sub 2} pattern.

Ko, C.H.; Kirz, J.; Maier, K.; Winn, B. [State Univ. of New York, Stony Brook, NY (United States). Dept. of Physics; Ade, H. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Physics; Hulbert, S.; Johnson, E. [Brookhaven National Lab., Upton, NY (United States). National Synchrotron Light Source; Anderson, E. [Lawrence Berkeley Lab., CA (United States). Center for X-ray Optics

1995-12-31

187

Vermont SIRI MSDS Collection  

NSDL National Science Digital Library

From Vermont Safety Information Resources, Inc., this searchable material safety data sheets collection can be searched by company or compound name. Visitors can also search for toxicology reports by chemical name, chemical trade name, or the CAS or RTECS number.

2009-07-14

188

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

PubMed

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

Shah, Bhavna; Mistry, Chirag; Shah, Ajay

2013-04-01

189

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

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)

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

1978-01-01

190

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

USGS Publications Warehouse

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)

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

1987-01-01

191

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

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

Shang, Yu; Zhu, Tong; Lenz, Anke-Gabriele; Frankenberger, Birgit; Tian, Feng; Chen, Chenyong; Stoeger, Tobias

2013-10-01

192

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)

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.

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

193

Chemical nature and molecular weight distribution of the water-soluble fine and ultrafine PM fractions collected in a rural environment  

NASA Astrophysics Data System (ADS)

PM1-2.5, PM0.1-1, and PM<0.1 water-soluble organic carbon (WSOC) fractions of aerosol samples collected during summer and fall 2009 were analyzed by UV/VIS spectroscopy and electrospray ionization-mass spectrometry (ESI/MS). The focus of this study was to compare optical properties, chemical nature, and molecular weight distribution in samples extracted from different size fractions and collected during different seasons (fall vs. summer). Diurnal patterns were also investigated. An increase in absorptivity, aromaticity, and average molecular weight (AMW) in all size fractions found in the fall samples indicates different formation processes for the organic carbon between the summer and fall periods. The fall ultrafine fraction (PM<0.1) demonstrated characteristics different from the other two PM size fractions and more similar to aquatic fulvic acids. It had the highest HULIS/WSOC ratio, molar absorptivity, and AMWs up to about 700 Da when analyzed by the UV/VIS method and about 475 Da by the ESI/MS. Higher concentrations of organosulfate (OS) compounds and polycarboxylic acids were detected in the summer samples while organonitrate (ON) compounds and monocarboxylic acids were higher in the fall samples.

Pavlovic, J.; Hopke, P. K.

2012-11-01

194

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

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

2012-01-01

195

Chemically modified reaction centers of photosystem II: Exchange of pheophytin a with 7-deformyl-7-hydroxymethyl-pheophytin b.  

PubMed

The native pheophytin a (Pheo a) in isolated reaction centers of photosystem II (PSII RCs) has been chemically exchanged with extraneous 7-deformyl-7-hydroxymethyl-Pheo b (7(1)-OH-Pheo b) which differs from Pheo a by the C-7 substituent (hydroxymethyl instead of methyl). The two pigments have similar reduction potentials in vitro [M. Meyer, Dissertation, Universität München, 1997], while their absorption spectra show small but distinct differences in the visible region. The resulting 7(1)-OH-Pheo b-modified reaction center preparations were characterized by high-performance liquid chromatography, electronic absorption and light-induced Fourier transform infra red absorption difference spectroscopies, together with photoaccumulation of the reduced pheophytin electron acceptor and NaBH4-treatment. About 70% of the total Pheo a molecules are found to be replaced by 7(1)-OH-Pheo b molecules in modified preparations, indicating that both the photochemically active (PheoD1) and inactive (PheoD2) binding sites were subjected to pigment exchange. The 7(1)-OH-Pheo b molecule located at the PheoD1 site is able to functionally replace the native Pheo a, participating in primary charge separation as an electron acceptor. The Qx absorption band of this modified pheophytin molecule is localized at ~546nm; its Qy band is blue-shifted with respect to the absorption of other reaction center core pigments, being located at ~665nm. The Qy and Qx optical transitions of the 7(1)-OH-Pheo b molecule exchanged into the PheoD2 site are identified at 677 and 543.5nm, respectively. The photochemically active double-modified PSII RCs additionally containing 7-deformyl-7-hydroxymethyl-13(1)-deoxo-13(1)-hydroxy-Pheo b at the PheoD2 site were obtained by treatment of the 7(1)-OH-Pheo b-modified RCs with NaBH4. PMID:25172518

Zabelin, Alexey A; Shkuropatova, Valentina A; Makhneva, Zoya K; Moskalenko, Andrey A; Shuvalov, Vladimir A; Shkuropatov, Anatoly Ya

2014-11-01

196

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

SciTech Connect

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.

Han, Jeongoh [Laboratory of Biomedicinal Chemistry, College of Pharmacy, Pusan National University, Busan, 609-735 (Korea, Republic of); Lee, Jong-Suk [Laboratory of Physiology, College of Pharmacy, Yeungnam University, Gyeongsan (Korea, Republic of); Choi, Daekyu; Lee, Youna; Hong, Sungchae; Choi, Jungyun; Han, Songyi [Laboratory of Biomedicinal Chemistry, College of Pharmacy, Pusan National University, Busan, 609-735 (Korea, Republic of); Ko, Yujin; Kim, Jung-Ae [Laboratory of Physiology, College of Pharmacy, Yeungnam University, Gyeongsan (Korea, Republic of); Mi Kim, Young [Medicinal Chemistry, College of Pharmacy, Pusan National University, Busan (Korea, Republic of); Jung, Yunjin [Laboratory of Biomedicinal Chemistry, College of Pharmacy, Pusan National University, Busan, 609-735 (Korea, Republic of)], E-mail: jungy@pusan.ac.kr

2009-03-15

197

Responses of the L5178Y tk\\/sup +\\/\\/tk⁻ mouse lymphoma cell forward mutation assay. II. 18 coded chemicals  

Microsoft Academic Search

Eighteen chemicals were tested for their mutagenic potential in the L5178Y tk\\/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

D. B. McGregor; A. Brown; P. Cattanach; I. Edwards; D. McBride; W. J. Caspary

1988-01-01

198

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

PubMed

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

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

2014-08-14

199

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

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

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

2015-01-01

200

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

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

2012-01-01

201

Chemical evolution of Magellanic Clouds. II - Equivalent widths and abundances for three young supergiants of the SMC  

Microsoft Academic Search

Spite et al. (1988) compared the chemical composition of the atmospheres of three F supergiants in the SMC to the chemical composition of the Galactic supergiant Canopus. In this paper, equivalent widths for the stars, AZ 140, AZ 197, and AZ 369, are presented along with the derived abundance, line by line. Various physical constants of the lines are presented.

M. Spite; S. Huille; F. Spite; P. Francois

1988-01-01

202

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)

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.

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

2014-12-01

203

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

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.

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

1985-07-01

204

Temperature Dependence of Physical-Chemical Properties of Selected Chemicals of Environmental Interest. II. Chlorobenzenes, Polychlorinated Biphenyls, Polychlorinated Dibenzo-p-dioxins, and Dibenzofurans  

Microsoft Academic Search

Data are compiled and reviewed of the physical–chemical properties of chlorinated benzenes, biphenyls, and dibenzo-p-dioxins and dibenzofurans, which control air–water partitioning, namely vapor pressure, aqueous solubility, and Henry’s law constant over the environmentally relevant temperature range of 5–50 °C. Recommended values at 25 °C, and equations for estimating these properties over the temperature range of 5–50 °C are provided. Corresponding

Wan-Ying Shiu; Kuo-Ching Ma

2000-01-01

205

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

NASA Astrophysics Data System (ADS)

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.

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

2014-12-01

206

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

NASA Astrophysics Data System (ADS)

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

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

2007-06-01

207

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

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.

Witt, Emitt C.; Shi, Honglan; Karstensen, Krista A.; Wang, Jianmin; Adams, Craig D.

2008-01-01

208

Gemini Near-infrared Spectroscopy of Luminous z~6 Quasars: Chemical Abundances, Black Hole Masses, and MgII Absorption  

E-print Network

We present Gemini near-infrared spectroscopic observations of six luminous quasars at z=5.8$\\sim$6.3. Five of them were observed using Gemini-South/GNIRS, which provides a simultaneous wavelength coverage of 0.9--2.5 $\\mu$m in cross dispersion mode. The other source was observed in K band with Gemini-North/NIRI. We calculate line strengths for all detected emission lines and use their ratios to estimate gas metallicity in the broad-line regions of the quasars. The metallicity is found to be supersolar with a typical value of $\\sim$4 Z_{\\sun}, and a comparison with low-redshift observations shows no strong evolution in metallicity up to z$\\sim$6. The FeII/MgII ratio of the quasars is 4.9+/-1.4, consistent with low-redshift measurements. We estimate central BH masses of 10^9 to 10^{10} M_{\\sun} and Eddington luminosity ratios of order unity. We identify two MgII $\\lambda\\lambda$2796,2803 absorbers with rest equivalent width W_0^{\\lambda2796}>1 \\AA at 2.21.5 \\AA at z>3 in the spectra, with the two most distant absorbers at z=4.8668 and 4.8823, respectively. The redshift number densities (dN/dz) of MgII absorbers with W_0^{\\lambda2796}>1.5 \\AA are consistent with no cosmic evolution up to z>4.

Linhua Jiang; Xiaohui Fan; Marianne Vestergaard; Jaron D. Kurk; Fabian Walter; Brandon C. Kelly; Michael A. Strauss

2007-07-11

209

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

SciTech Connect

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.

Fry, R.J.M.

1984-01-01

210

Interaction of chemically modified tetracyclines with catalytic Zn(II) ion in matrix metalloproteinase: evidence for metal coordination sites  

Microsoft Academic Search

Chemically modified tetracyclines (CMTs) have shown promising activity as matrix metalloproteinase (MMP) inhibitors acting\\u000a as zinc-binding groups. The first step in the design of new and effective drugs is the molecular description of the mechanism\\u000a of action in chemical and biological environments. In the present study, the structure and stability of [Zn(LH\\u000a n\\u000a )(H2O)2]2?x\\u000a (n = 0, 1, 2 and x = ?2, ?1,

Bruna L. MarcialLuiz; Luiz Antônio S. Costa; Wagner B. De Almeida; Cleber P. A. Anconi; Hélio F. Dos Santos

2011-01-01

211

Assessment of reproductive disorders and birth defects in communities near hazardous chemical sites. II. Female reproductive disorders.  

PubMed

Members of the workgroup on female reproductive disorders discussed methods to evaluate five principal functions: menstrual dysfunction, infertility, pregnancy loss, lactation disorders, and pregnancy complications. To test each function, a nested strategy was considered, based on progressive levels of effort available to conduct field investigations. This strategy was analogous to the three-tier classification of biomarkers used by other workshops. The lowest level of effort, corresponding to Tier 1, consists only of questionnaires, diaries, and reviews of maternal and infant medical records. The medium level of effort (Tier 2) collects data from questionnaires and diaries, and some biologic specimens. Suggested laboratory analyses included measurement of progesterone in saliva and several glycoprotein hormones in urine that evaluate menstrual dysfunction, infertility, and pregnancy loss. The highest level of effort (Tier 3) involves prospective collection of diary information and simultaneous collection of biological specimens. PMID:9100298

Scialli, A R; Swan, S H; Amler, R W; Baird, D D; Eskenazi, B; Gist, G; Hatch, M C; Kesner, J S; Lemasters, G K; Marcus, M; Paul, M E; Schulte, P; Taylor, Z; Wilcox, A J; Zahniser, C

1997-01-01

212

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

ERIC Educational Resources Information Center

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…

Saskatchewan Consumer and Commercial Affairs, Regina.

213

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...

214

Amphibians as a model to study endocrine disruptors: II. Estrogenic activity of environmental chemicals in vitro and in vivo  

Microsoft Academic Search

Several environmental chemicals are known to have estrogenic activity by interacting with development and functions of endocrine systems in nearly all classes of vertebrates. In order to get a better insight of potential estrogenic effects on amphibians caused by environmental pollution this study aims to develop a model for investigating endocrine disruptors using the amphibian Xenopus laevis. In that model

Werner Kloas; Ilka Lutz; Ralf Einspanier

1999-01-01

215

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

SciTech Connect

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.

Baker, B.; Feist, T.P.; McCarron, E.M. [DuPont Company, Wilmington, DE (United States)] [DuPont Company, Wilmington, DE (United States)

1995-10-01

216

Effective Nuclear Charge and Chemical Shifts in X-Ray Absorption Spectra of Polymeric Copper(II) Salicylhydroxamates  

Microsoft Academic Search

Edge shifts, \\\\varDelta E, and effective nuclear charges, Zeff, for several polymeric copper(II) complexes of salicylhydroxamic acids have been estimated from copper K-absorption discontinuity using a 40 cm curved crystal spectrograph. The shifts show a parabolic dependence on the effective atomic charge, Zeff, of copper, indicating that an expression of the type \\\\varDelta E{=}aZeff+b(Zeff)2, where Zeff is the effective atomic

Padmakar V. Khadikar; Nolan F. Mangelson; Sadhana P. Pandharkar

1989-01-01

217

Comparison of high pressure liquid chromatographic and chemical methods for vitamin D3 concentrates. II. Collaborative study.  

PubMed

A collaborative study was carried out which compared the official chemical method, 43.B14-43.B24, the official rat bioassay, 43.165, and the high pressure liquid chromatographic method for vitamin D3 resin, vitamin D3 resin in oil, and dry concentrate. A total of 340 samples were distributed to 17 collaborators for analysis. Five laboratories performed both the chemical and HPLC methods on 5 sets of blind duplicates. A 2-way analysis of variance comparing both methods for each sample showed a significant (P less than 0.01) difference between methods only for Sample 5. When the 2 methods were compared over all the samples, no significant (P less than 0.05) difference was found. Except for Sample 5, there were no differences in the repeatability of the methods. Per cent recoveries on Sample 3, which contained exactly 0.200 X 10(6) IU/g, showed 98.2% for the chemical method and 100.6% for the HPLC method for the 5 laboratories that performed both methods. The assay results of the HPLC and chemical methods are in good agreement with those found by the biological assay on Samples 1-4, but not for Sample 5. Evidence indicates that Sample 5 degraded partially to isotachysterol, and while the HPLC method yielded a reasonable value on this material, the chemical method erroneously showed full potency. An amendment is included for the collaboratively studied HPLC method which detects and eliminates 5,6-trans-vitamin D3, a possible interferant. PMID:206533

Hofsass, H; Alicino, N J; Hirsch, A L; Ameika, L; Smith, L D

1978-05-01

218

Comparison of Three Transport Systems (Starplex StarSwab II, the New Copan Vi-Pak Amies Agar Gel Collection and Transport Swabs, and BBL Port-A-Cul) for Maintenance of Anaerobic and Fastidious Aerobic Organisms  

Microsoft Academic Search

Of utmost importance in evaluations of clinical samples for infectious agents is proper specimen transport to the clinical laboratory. In the present study we compared three transport systems (the new Starplex StarSwab II, the new Copan Vi-Pak Amies Agar Gel collection and transport swabs, and the BBL Port-A-Cul) for survival of anaerobic and fastidious aerobic bacteria. The new Copan Vi-Pak

MUSA HINDIYEH; VICTORIA ACEVEDO; KAREN C. CARROLL

2001-01-01

219

Crystallization of copper(II) sulfate based minerals and MOF from solution: Chemical insights into the supramolecular interactions  

Microsoft Academic Search

Crystallization of solids, molecular or non-molecular from solution is a supramolecular reaction. Nucleation of a lattice\\u000a structure at supersaturation can be conceived to result from a critical nucleus, a high energy intermediate (supramolecular\\u000a transition state). Conceptualization of a structure for the critical nucleus in terms of aggregation of tectons through non-covalent\\u000a interactions provides chemical insights into the architecture of a

M. Singh; D. Kumar; J. Thomas; A. Ramanan

2010-01-01

220

First structural characterization of a delocalized, mixed-valent, triangular Cu37+ species: chemical and electrochemical oxidation of a CuII3(mu3-O) pyrazolate and electronic structure of the oxidation product.  

PubMed

The chemical or electrochemical one-electron oxidation of the all-CuII complex [Cu3(mu3-O)(mu-pz)3X3]2- leads to its formally CuII2CuIII analogue (pz = pyrazolato anion; X = Cl- and PhCOO-). The X-ray single-crystal structure and density functional theory analysis of the latter agree in revealing the delocalized nature of its mixed-valent Cu3(7+) core. PMID:16212340

Mezei, Gellert; McGrady, John E; Raptis, Raphael G

2005-10-17

221

On the chemical homogeneity of the 30 Doradus H II region and a local enrichment by Wolf-Rayet stars  

NASA Technical Reports Server (NTRS)

Emission-line strengths have been obtained at 10 positions in the outer regions of the 30 Dor nebula and analyzed in the standard way. There are two major results: (1) the elemental abundances for nine of the outer regions are remarkably similar to those previously measured in the core. This result implies the spectra of the cores and halos of giant H II regions (subject to the different ionizing radiation fields) are analyzed correctly by the standard methods. Hence measurements of extragalactic H II regions with poor spatial resolution correctly represent the abundances of the whole nebula. The O/H ratio in 30 Dor, by number, is 0.30 solar. The Ne/O, S/O, Ar/O, and Cl/O are close to solar. The gas-phase Fe/O is about 0.2 solar, which probably implies that most of the iron is within solid grains. The He/H is 0.0810 as shown by each of the three strong lines available. One region is cool and rich in helium and all other heavy elements except nitrogen. The spectrum of the region does not resemble that of a supernova remnant in that the forbidden O I and S II lines are not nearly strong enough. The abundances can be explained fairly well as over 10 solar masses of H-poor material ejected during the evolution of a single massive (about 80 solar masses) star during its late O-star and Wolf-Rayet phases.

Rosa, Michael; Mathis, John S.

1987-01-01

222

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)

The Saharan Mineral Dust Experiment (SAMUM) is focussed to the understanding of the radiative effects of mineral dust. During the SAMUM 2006 field campaign at Tinfou, southern Morocco, chemical and mineralogical properties of fresh desert aerosol was measured. The winter campaign of Saharan Mineral Dust Experiment II in 2008 was based in Praia, Island of Santiago, Cape Verde. This second field campaign was dedicated to the investigation of transported Saharan Mineral Dust. Ground-based and airborne measurements were performed in the winter season, where mineral dust from the Western Sahara and biomass burning aerosol from the Sahel region occurred. Samples were collected with a miniature impactor system, a sedimentation trap, a free-wing impactor, and a filter sampler. Beryllium discs as well as carbon coated nickel discs, carbon foils, and nuclepore and fiber filters were used as sampling substrates. The size-resolved particle aspect ratio and the chemical composition are determined by scanning electron microscopy and energy-dispersive X-ray microanalysis of single particles. Mineralogical bulk composition is determined by X-ray diffraction analysis. In Morocco, three size regimes are identified in the aerosol: Smaller than 500 nm in diameter, the aerosol consists of sulfates and mineral dust. Larger than 500 nm up to 50 µm, mineral dust dominates, consisting mainly of silicates, and - to a lesser extent - carbonates and quartz. Larger than 50 µm, approximately half of the particles consist of quartz. Time series of the elemental composition show a moderate temporal variability of the major compounds. Calcium-dominated particles are enhanced during advection from a prominent dust source in Northern Africa (Chott El Djerid and surroundings). More detailed results are found in Kandler et al. (2009) At Praia, Cape Verde, the boundary layer aerosol consists of a superposition of mineral dust, marine aerosol and ammonium sulfate, soot, and other sulfates as well as 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., Schütz, L., Deutscher, C., Hofmann, H., Jäckel, 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

Kandler, Konrad; Emmel, Carmen; Ebert, Martin; Lieke, Kirsten; Müller-Ebert, Dörthe; Schütz, Lothar; Weinbruch, Stephan

2010-05-01

223

The Protonation Status of Compound II in Myoglobin, Studied by a Combination of Experimental Data and Quantum Chemical Calculations: Quantum Refinement  

PubMed Central

Treatment of met-myoglobin (FeIII) with H2O2 gives rise to ferryl myoglobin, which is closely related to compound II in peroxidases. Experimental studies have given conflicting results for this species. In particular, crystallographic and extended x-ray absorption fine-structure data have shown either a short (?170 pm) or a longer (?190 pm) Fe–O bond, indicating either a double or a single bond. We here present a combined experimental and theoretical investigation of this species. In particular, we use quantum refinement to re-refine a crystal structure with a long bond, using 12 possible states of the active site. The states differ in the formal oxidation state of the iron ion and in the protonation of the oxygen ligand (O2?, OH?, or H2O) and the distal histidine residue (with a proton on N?1, N?2, or on both atoms). Quantum refinement is essentially standard crystallographic refinement, where the molecular-mechanics potential, normally used to supplement the experimental data, is replaced by a quantum chemical calculation. Thereby, we obtain an accurate description of the active site in all the different protonation and oxidation states, and we can determine which of the 12 structures fit the experimental data best by comparing the crystallographic R-factors, electron-density maps, strain energies, and deviation from the ideal structure. The results indicate that FeIII OH? and FeIV OH? fit the experimental data almost equally well. These two states are appreciably better than the standard model of compound II, FeIV O2?. Combined with the available spectroscopic data, this indicates that compound II in myoglobin is protonated and is best described as FeIV OH?. It accepts a hydrogen bond from the distal His, which may be protonated at low pH. PMID:15339813

Nilsson, Kristina; Hersleth, Hans-Petter; Rod, Thomas H.; Andersson, K. Kristoffer; Ryde, Ulf

2004-01-01

224

Collisions of small ice particles under microgravity conditions (II): Does the chemical composition of the ice change the collisional properties?  

E-print Network

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 m s^-1, temperatures between 131 and 160 K and a pressure of around 10^-5...

Hill, C R; Blum, J; Fraser, H J

2015-01-01

225

Chemical abundance analysis of symbiotic giants - II. AE Ara, BX Mon, KX TrA, and CL Sco  

NASA Astrophysics Data System (ADS)

Knowledge of the elemental abundances of symbiotic giants is essential to address the role of chemical composition in the evolution of symbiotic binaries, to map their parent population, and to trace their mass transfer history. However, there are few symbiotic giants for which the photospheric abundances are fairly well determined. This is the second in a series of papers on chemical composition of symbiotic giants determined from high-resolution (R ˜ 50 000) near-IR spectra. Results are presented for the late-type giant star in the AE Ara, BX Mon, KX TrA, and CL Sco systems. Spectrum synthesis employing standard local thermal equilibrium (LTE) analysis and stellar atmosphere models were used to obtain photospheric abundances of CNO and elements around the iron peak (Sc, Ti, Fe, and Ni). Our analysis resulted in sub-solar metallicities in BX Mon, KX TrA, and CL Sco by [Fe/H] ˜ -0.3 or -0.5 depending on the value of microturbulence. AE Ara shows metallicity closer to solar by ˜ 0.2 dex. The enrichment in 14N isotope found in all these objects indicates that the giants have experienced the first dredge-up. In the case of BX Mon first dredge-up is also confirmed by the low 12C/13C isotopic ratio of ˜ 8.

Ga?an, Cezary; Miko?ajewska, Joanna; Hinkle, Kenneth H.

2015-02-01

226

Isolation and chemical characterization of PwTx-II: a novel alkaloid toxin from the venom of the spider Parawixia bistriata (Araneidae, Araneae).  

PubMed

Brazil has many species of spiders belonging to Araneidae family however, very little is known about the composition, chemical structure and mechanisms of action of the main venom components of these spiders. The main objective of this work was to isolate and to perform the chemical characterization of a novel beta-carboline toxin from the venom of the spider Parawixia bistriata, a typical species of the Brazilian 'cerrado'. The toxin was purified by RP-HPLC and structurally elucidated by using a combination of different spectroscopic techniques (UV, ESI-MS/MS and 1H NMR), which permitted the assignment of the molecular structure of a novel spider venom toxin, identified as 1-4-guanidinobutoxy-6-hydroxy-1,2,3,4-tetrahydro-beta-carboline, and referred to here as PwTx-II. This compound is toxic to insects (LD50 = 12+/-3 etag/mg honeybee), neurotoxic, convulsive and lethal to rats (LD50 = 9.75 mg/kg of male Wistar rat). PMID:16183095

Cesar, Lilian M M; Mendes, Maria A; Tormena, Claudio F; Marques, Maurício R; de Souza, Bibiana M; Saidemberg, Daniel Menezes; Bittencourt, Jackson C; Palma, Mario S

2005-12-01

227

Part I. Synthesis of metal hydroborates as potential chemical vapor deposition precursors. Part II. Chemical vapor deposition of titanium-doped magnesium diboride thin films  

NASA Astrophysics Data System (ADS)

New compounds Cp*V(B3H8)2, Cp*Cr(B 3H8)2, and Cp*2Co2(B 6H14) have been synthesized by treating the pentamethylcyclopentadienyl complexes [Cp*VCl2]3, [Cp*CrCl2]2, and [Cp*CoCl]2 with NaB3H8. Cp*V(B3 H8)2 and Cp*Cr(B3H8) 2 have the same ligand sets but different molecular structures: the vanadium compound contains two bidentate B3H8 ligands whereas the chromium compound has one bidentate B3H8 ligand and one B3H8 ligand bound in an unprecedented fashion via two geminal hydrogen atoms. The different binding modes of the B3H8- group in these compounds are consequences of the number of available empty valence orbitals on the metal centers. The dinuclear complex Cp*2Co2(B 6H14) can be viewed as a "bi-borallyl" complex or as an eight-vertex hypho cluster. The solid state reaction of MgBr2 and NaB3H 8 at 20°C, followed by sublimation at 80°C and 0.05 Torr, affords Mg(B3H8)2, as a white solid. Similar reactions with MgBr2·Et2O and MgBr2(Me 2O)1.5 afford the crystalline ether adducts Mg(B3H 8)2(Et2O)2 and Mg(B3H 8)2(Me2O)2, respectively. In the solution state reactions of MgBr2 with NaB3H8, the presence of excess solvent results in the formation of non-volatile, probably ionic, magnesium compounds of the type [MgLx][B3H 8]2. Mg(B3H8)2(Et2 O)2 and Mg(B3H8)2(Me 2O)2 are the first crystallographically characterized magnesium complex of the B3H8- ligand. Owing to their volatility, Mg(B3H8)2(Et2O) 2 and Mg(B3H8)2(Me2O) 2 are potential precursors for the deposition of MgB2 thin films, although preliminary efforts to grow thin films from them under CVD conditions, have not yet produced stoichiometric MgB2 films. Treatment of MCl3(thf)3 (M = Ti, Cr, or Mo) or MnCl2 with the sodium salt of N,N-dimethyldiboranamide, Na(H3BNMe2BH3), in diethyl ether, followed by sublimation at 45-70°C, affords crystals of the new divalent complexes M(H3BNMe2BH3)2, where M is Ti, Cr, Mn, or Mo, all of which have been characterized by single crystal X-ray diffraction. In all four compounds, the metal center is coordinated to two chelating [H3BNMe2BH3]-ligands. Each BH3 group binds to the metal center by means of two hydrogen bridges, leaving one terminal hydrogen atom on each BH3 group; the H atoms that bridge to the metal center form slightly longer B-H bonds than the terminal H atoms on the same boron centers, as expected. The metal center in each compound forms eight M-H contacts, whose M-H distances are equal within experimental error. The Ti, Cr, and Mo compounds adopt square-planar geometries in which the dihedral angle between ligand planes is 0°. In contrast, in the Mn compound, which adopts a structure intermediate between a tetrahedron and a square plane, the two ligand planes define a dihedral angle of 46.5(2)°; this unusual dihedral angle maximizes interligand H···H distances. The solid state reaction of MgBr2 with Na(H3BNMe 2BH3) yields the monomeric, magnesium complex Mg(H3 BNMe2BH3)2. Its ether adducts Mg(H 3BNMe2BH3)2(thf) and Mg(H3BNMe 2BH3)2(dme), and the mixed ligand complex Cp*Mg(H 3BNMe2BH3)(thf), have also been prepared. Significantly, the binary complex Mg(H3BNMe2BH3)2 has a vapor pressure of 800 mTorr at 25°C, which makes it the most volatile magnesium complex known. The solid state reaction of MCl3 and Na(H3BNMe 2BH3) and subsequent sublimation in vacuum affords the dinuclear complexes, M2(H3BNMe2BH3) 6 (M = Y or Dy). X-ray crystallographic studies show that, in both compounds, two metal centers are connected by two bridging H3BNMe2BH 3 ligands; each metal center also bears two terminal diboranamide groups, which are chelating. Similar reactions conducted in thf solution yield the monomeric thf adducts M(H3BNMe2BH3) 3(thf) (M = Y or Dy). These molecules, which possess a boron-to-metal ratio of 6, are readily volatile below 100°C and are potential CVD precursors for the low-temperature growth of LnB6 thin films. The first low-temperature chemical vapor depositions of doped MgB 2 phases have been achieved by passing the precursor Mg(H3BNMe 2BH3)2 over a surface in the presence of a catalyst that accelerates the rate

Kim, Do Young

2007-12-01

228

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...

229

the Garbage Collection Bibliography Richard Jones  

E-print Network

. Distributed garbage collection. In Bekkers and Cohen [Bekkers and Cohen1992]. [Abdullahi, 1995] Saleh Ethe Garbage Collection Bibliography Richard Jones Computing Laboratory University of Kent E. Abdullahi and Graem A. Ringwood. Empirical studies of distributed garbage collection: Parts i, ii

Singer, Jeremy

230

Modification of wheat starch with succinic acid/acetanhydride and azelaic acid/acetanhydride mixtures. II. Chemical and physical properties.  

PubMed

The aim of this research was to investigate the influence of modification with succinic acid/acetanhydride and azelaic acid/acetanhydride mixtures on chemical and physical properties of wheat starch. Starch was isolated from two wheat varieties and modified with mixtures of succinic acid and acetanhydride and azelaic acid and acetanhydride in 4, 6 and 8% (w/w). Total starch content, resistant starch content, degree of modification, changes in FT-IR spectra, colour, gel texture and freeze-thaw stability were determined. Results showed that resistant starch content increased by both investigated modifications, and degree of modification increased proportionally to amount of reagents used. FT-IR analysis of modified starches showed peak around 1,740 cm(-1), characteristic for carbonyl group of ester. Total colour difference caused by modifications was detectable by trained people. Adhesiveness significantly increased, while freeze-thaw stability decreased by both investigated modifications. PMID:25114336

A?kar, Dur?ica; Subari?, Drago; Babi?, Jurislav; Mili?evi?, Borislav; Jozinovi?, Antun

2014-08-01

231

Enskog’s kinetic theory of dense gases for chemically reacting binary mixtures, II: Light scattering and sound propagation  

NASA Astrophysics Data System (ADS)

Enskog’s kinetic theory for a symmetric moderately dense reaction A+A?B+B is used to determine Fick’s and Fourier’s law. The transport coefficients of diffusion, thermal-diffusion rate and thermal conductivity are represented graphically for endothermic and exothermic reactions and are analyzed as a function of the activation energy and of the density of the mixture. The Onsager reciprocity relations are numerically investigated and verified. The problems related to sound propagation and light scattering are investigated for such a mixture and it is shown that the influence of chemical reactions on phase velocity, attenuation coefficient and light scattering spectra is more pronounced for rarefied gases although there is a considerable change in these quantities as the mixture becomes denser.

Silva, Adriano W.; Alves, Giselle M.; Marques, Wilson; Kremer, Gilberto M.

2009-02-01

232

Inplementation of an automated signal processing approach for the analysis of chemical spectral signatures collected from FT-IR mounted in an aircraft  

SciTech Connect

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.

Kroutil, Robert T [Los Alamos National Laboratory

2008-01-01

233

Trapping of muscle relaxant methocarbamol degradation product by complexation with copper(II) ion: Spectroscopic and quantum chemical studies  

NASA Astrophysics Data System (ADS)

Structural properties of methocarbamol (Mcm) were extensively studied both experimentally and theoretically using FT IR, 1H NMR, UV-Vis., geometry optimization, Mulliken charge, and molecular electrostatic potential. Stability arises from hyper-conjugative interactions, charge delocalization and H-bonding was analyzed using natural bond orbital (NBO) analysis. Mcm was decomposed in ethanol/water mixture at 80 °C to guaifenesin [(RS)-3-(2-methoxyphenoxy)propane-1,2-diol] and carbamate ion [NH2COO-], where the degradation mechanism was explained by trapping the carbamate ion via the complexation with copper(II) ion. The structure of the isolated complex ([Cu(NH2COO)2(H2O)]?4H2O) was elucidated by spectral, thermal, and magnetic tools. Electronic spectra were discussed by TD-DFT and the descriptions of frontier molecular orbitals and the relocations of the electron density were determined. Calculated g-tensor values showed best agreement with experimental values from EPR when carried out using both the B3LYP and B3PW91 functional.

Mansour, Ahmed M.; Shehab, Ola R.

2014-07-01

234

Esterases of laboratory-reared and field-collected cotton boll weevils, Anthonomus grandis Boh.: Polymorphism of adult esterases and formal genetics of esterase II  

Microsoft Academic Search

The esterases of the cotton boll weevil were separated by polyacrylamide gel electrophoresis into four major regions. These were named Est I–IV in order of migration from anode to origin. Polymorphism was observed in all regions. The Est II region was shown to consist of no more than two bands (fast and slow). The inheritance of the fast and slow

Charles J. Biggers; Harold R. Bancroft

1977-01-01

235

Fluid and chemical flux in and out of sediments hosting methane hydrate deposits on Hydrate Ridge, OR, II: Hydrological processes  

NASA Astrophysics Data System (ADS)

Multiple, long-term measurements of aqueous and chemical flux through regions of active fluid seeps and gas vents on Hydrate Ridge, Cascadia accretionary prism, were accomplished during 1998 and 1999 as part of the international TECFLUX project. These measurements indicate that flow is highly heterogeneous in both time and space with areas of inflow, outflow, and outflow of fluids of both altered and seawater-like composition. While tectonics is the dominant underlying driving force in fluid expulsion, we suggest that much of the shallow expression of this flow is modulated by more complex hydrological processes. These dynamic processes may include gas expulsion-driven pumping and aqueous entrainment in migrating gas, buoyancy-driven fracturing of overlying sediments, rapid changes in the permeability distribution due to injection of gas and the formation of gas hydrates, migrating flow conduits, and tidally driven flow oscillations. By placing the flow rate observations obtained during the two field seasons in the context of the distribution and nature of the seepage sites, we develop a conceptual model of the spatial and temporal interactions between various processes that appear be active at Hydrate Ridge. We further discuss: (1) evidence for the existence of a subsurface gas transport system and discuss the mechanisms which maintain it, (2) estimates of the in situ permeability of seep settings and evidence for, and the mechanisms controlling temporal changes in permeability, and (3) changes in seep output fluid chemistry which may relate to the above hydrological processes.

Tryon, M. D.; Brown, K. M.; Torres, M. E.

2002-08-01

236

Optimizing the physical-chemical properties of carbon nanotubes (CNT) and graphene nanoplatelets (GNP) on Cu(II) adsorption.  

PubMed

Systematic experiments of copper adsorption on 10 different commercially available nanomaterials were studied for the influence of physical-chemical properties and their interactions. Design of experiment and response surface methodology was used to develop a polynomial model to predict maximum copper adsorption (initial concentration, Co=10mg/L) per mass of nanomaterial, qe, using multivariable regression and maximum R-square criterion. The best subsets of properties to predict qe in order of significant contribution to the model were: bulk density, ID, mesopore volume, tube length, pore size, zeta-charge, specific surface area and OD. The highest experimental qe observed was for an alcohol-functionalized MWCNT (16.7mg/g) with relative high bulk density (0.48g/cm(3)), ID (2-5nm), 10-30?m long and OD<8nm. Graphene nanoplatelets (GNP) showed poor adsorptive capacity associated to stacked-nanoplatelets, but good colloidal stability due to high functionalized surface. Good adsorption results for pristine SWCNT indicated that tubes with small diameter were more associated with good adsorption than functionalized surface. XPS and ICP analysis explored surface chemistry and purity, but pHpzc and zeta-charge were ultimately applied to indicate the degree of functionalization. Optimum CNT were identified in the scatter plot, but actual manufacturing processes introduced size and shape variations which interfered with final property results. PMID:25103452

Rosenzweig, Shirley; Sorial, George A; Sahle-Demessie, Endalkachew; McAvoy, Drew C

2014-08-30

237

On ammonia binding to the oxygen-evolving complex of photosystem?II: a quantum chemical study.  

PubMed

A recent EPR study (M. Perrez Navarro et?al., Proc. Natl. Acad. Sci. 2013, 110, 15561) provided evidence that ammonia binding to the oxygen-evolving complex (OEC) of photosystem?II in its S2 state takes place at a terminal-water binding position (W1) on the "dangler" manganese center MnA. This contradicted earlier interpretations of (14)N electron-spin-echo envelope modulation (ESEEM) and extended X-ray absorption fine-structure (EXAFS) data, which were taken to indicate replacement of a bridging oxo ligand by an NH2 unit. Here we have used systematic broken-symmetry density functional theory calculations on large (ca. 200 atom) model clusters of an extensive variety of substitution patterns and core geometries to examine these contradictory pieces of evidence. Computed relative energies clearly favor the terminal substitution pattern over bridging-ligand arrangements (by about 20-30?kcal?mol(-1)) and support W1 as the preferred binding site. Computed (14)N EPR nuclear-quadrupole coupling tensors confirm previous assumptions that the appreciable asymmetry may be accounted for by strong, asymmetric hydrogen bonding to the bound terminal NH3 ligand (mainly by Asp61). Indeed, bridging NH2 substitution would lead to exaggerated asymmetries. Although our computed structures confirm that the reported elongation of an Mn-Mn distance by about 0.15?Å inferred from EXAFS experiments may only be reproduced by bridging NH2 substitution, it seems possible that the underlying EXAFS data were skewed by problems due to radiation damage. Overall, the present data clearly support the suggested terminal NH3 coordination at the W1 site. The finding is significant for the proposed mechanistic scenarios of OEC catalysis, as this is not a water substrate site, and effects of this ammonia binding on catalysis thus must be due to more indirect influences on the likely substrate binding site at the O5 bridging-oxygen position. PMID:24806267

Schraut, Johannes; Kaupp, Martin

2014-06-10

238

Chemical abundances of planetary nebulae from optical recombination lines - II. Abundances derived from collisionally excited lines and optical recombination lines  

NASA Astrophysics Data System (ADS)

In Paper I, we presented spectrophotometric measurements of emission lines from the ultraviolet (UV) to the far-infrared for 12 Galactic planetary nebulae (PNe) and derived nebular thermal and density structures using a variety of plasma diagnostics. The measurements and plasma diagnostic results are used in the current paper to determine elemental abundances in these nebulae. Abundance analyses are carried out using both strong collisionally excited lines (CELs) and weak optical recombination lines (ORLs) from heavy element ions. Assuming electron temperatures and densities derived from HI recombination spectra (line and continuum), we are able to determine the ORL C abundance relative to hydrogen for all the PNe in our sample, N and O abundances for 11 of them and Ne abundances for nine of them. In all cases, ORL abundances are found to be systematically higher than the corresponding values deduced from CELs. In NGC 40, the discrepancy between the abundances derived from the two types of emission line reaches a factor of 17 for oxygen. For the other 10 PNe, the discrepancies for oxygen vary from 1.6 to 3.1. In general, collisionally excited infrared fine-structure lines, which have excitation energies less than 103 K and consequently emissivities that are insensitive to electron temperature and temperature fluctuations, yield ionic abundances comparable to those derived from optical/UV CELs. For a given nebula, the discrepancies between the ORL and CEL abundances are of similar magnitude for different elements. In other words, relative abundance ratios such as C/O, N/O and Ne/O deduced from the traditional method based on strong CELs are comparable to those yielded by ORLs, for a wide range of ORL to CEL oxygen abundance ratios, varying from near unity to over a factor of 20. We have also determined ORL abundances relative to hydrogen for the third-row element magnesium for 11 nebulae in our sample. In strong contrast to the cases for second-row elements, Mg abundances derived from the MgII 3d-4f ?4481 ORL are nearly constant for all the PNe analysed so far and agree within the uncertainties with the solar photospheric value. In accordance with results from previous studies, the ORL to CEL abundance ratio is correlated with the difference between the electron temperatures derived from the [OIII] forbidden-line ratio, on the one hand, and from the hydrogen recombination Balmer discontinuity, on the other. We find that the discrepancy between the ORL and CEL abundances is correlated with nebular absolute diameter, surface brightness, the electron density derived from [SII] CELs, and excitation class. The results confirm that the dichotomy of temperatures and heavy elemental abundances determined from the two types of emission line, which has been widely observed in PNe, is a strong function of nebular evolution, as first pointed out by Garnett and Dinerstein. Our analyses show that temperature fluctuations and/or density inhomogeneities are incapable of explaining the large discrepancies between the heavy elemental abundances and electron temperatures determined from the two types of emission line. Our analyses support the bi-abundance model of Liu et al., who have proposed that PNe contain another previously unseen component of ionized gas which, highly enriched in heavy elements, has an electron temperature of <~103 K and emits strongly in recombination lines but not in CELs. Our determinations of low average emission temperatures from the observed line intensity ratios of HeI and OII ORLs lend further support to this scenario.

Liu, Y.; Liu, X.-W.; Barlow, M. J.; Luo, S.-G.

2004-10-01

239

Responsible Collecting  

NSDL National Science Digital Library

This article, part of Biodiversity Counts, examines how to responsibly collect and keep specimens. The article discusses the reasons why collecting specimens is important and the behaviors and attitudes that define responsible collecting for both scientists and students.

240

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

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…

Shaw, W. M., Jr.

1990-01-01

241

Phase transitions and quasidynamical symmetry in nuclear collective models. II. The spherical vibrator to gamma-soft rotor transition in an SO(5)-invariant Bohr model  

Microsoft Academic Search

A model of a second-order shape phase transition is investigated in the Bohr collective model. The model contains two variable parameters, a mass parameter M and a control parameter ?, and is such that when ?=0 the Hamiltonian is that of a harmonic spherical vibrator and when ? is large it approaches that of an adiabatically decoupled rotor-vibrator. The results

P. S. Turner; D. J. Rowe

2005-01-01

242

Palladium(II) chemically bonded to silica surface applied to the separation and identification of polycyclic aromatic sulfur heterocycles in heavy oil.  

PubMed

Separation of polycyclic aromatic sulfur heterocycles among themselves and also from interferents in petrochemical matrices is a challenging task because of their low concentration, matrix complexity, and also due to the presence of polyaromatic hydrocarbons, as they present similar physico-chemical properties. Therefore, the objective of this work was preparation, characterization, and application of a stationary phase for separation of these compounds in a heavy gas oil sample and their identification by comprehensive two-dimensional gas chromatography. The stationary phase was prepared by grafting mercaptopropyltrimethoxisilane onto a silica surface, followed by palladium(II) chloride immobilization. Elemental analysis, thermogravimetry, nitrogen adsorption-desorption isotherms, infrared analysis, and scanning electron microscopy were performed to characterize this solid phase. Sulfur compounds were separated in an open column packed with the stationary phase and analyzed by comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometric detection. The number of compounds tentatively identified was 314 and their classes were thiophenes, benzotiophenes, dibenzothiophenes, naphthothiophenes, benzonaphthothiophenes, and dinaphthothiophenes. Separation among sulfur compounds and polyaromatic hydrocarbons was successful, which is a difficult goal to achieve with the traditionally employed solid phases. Some recalcitrant compounds (dibenzothiophenes with substituents of two and four carbons) were fully separated and tentatively identified. PMID:23596144

Machado, Maria Elisabete; de Menezes, Eliana Weber; Bregles, Lucas Panizzi; Caramão, Elina Bastos; Benvenutti, Edilson Valmir; Zini, Cláudia Alcaraz

2013-05-01

243

Chemical Reactions (Netorials)  

NSDL National Science Digital Library

Chemical Reactions: this is a resource in the collection "Netorials". The Netorials cover selected topics in first-year chemistry including: Chemical Reactions, Stoichiometry, Thermodynamics, Intermolecular Forces, Acids & Bases, Biomolecules, and Electrochemistry.

244

Collection Development.  

ERIC Educational Resources Information Center

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;…

School Libraries in Canada, 2002

2002-01-01

245

Insect Collection  

NSDL National Science Digital Library

Learners use several types of insect sampling and collection equipment to make an insect collection. Learners can collect insects from their schoolyard or yard at home. Insect collections are a good way to estimate the abundance and number of species in an area. This can be a longterm project over a period of days or weeks.

Hill, Ryan; Vandersal, Nicole; Purcell, Alison

2011-01-01

246

Phase transitions and quasidynamical symmetry in nuclear collective models. II. The spherical vibrator to gamma-soft rotor transition in an SO(5)-invariant Bohr model  

Microsoft Academic Search

A model of a second-order shape phase transition is investigated in the Bohr collective model. The model contains two variable parameters, a mass parameter M and a control parameter alpha, and is such that when alpha=0 the Hamiltonian is that of a harmonic spherical vibrator and when alpha is large it approaches that of an adiabatically decoupled rotor-vibrator. The results

P. S. Turner; D. J. Rowe

2005-01-01

247

A specific role for tocopherol and of chemical singlet oxygen quenchers in the maintenance of photosystem II structure and function in Chlamydomonas reinhardtii  

Microsoft Academic Search

?-Tocopherol concentrations were determined at low and high light intensities and compared with the rate of photosynthesis, photosystem II (PS II) and its reaction center D1 protein. Blocking of tocopherol biosynthesis at the 4-hydroxyphenylpyruvate dioxygenase by the herbicide pyrazolynate led to a quick disappearance of ?-tocopherol in high light, as well as of PS II activity and the D1 protein.

Achim Trebst; Brigitte Depka; Heike Holländer-Czytko

2002-01-01

248

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)

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.

Ellison, Paul Andrew

2011-12-01

249

76 FR 44582 - Agency Information Collection Activities; Proposed Collection; Comment Request; Community Right...  

Federal Register 2010, 2011, 2012, 2013, 2014

...submit a list of chemicals or Material Safety Data Sheet (MSDS) (for those chemicals...collection of information; search data sources; complete and review...prepare or have available a material safety data sheet for any hazardous chemical...

2011-07-26

250

On the evolution of accretion disc flow in cataclysmic variables. II - The existence and nature of the collective relaxation oscillations in dwarf nova systems  

NASA Astrophysics Data System (ADS)

We examine a promising model for the outburst cycles of dwarf novae. According to this model hydrogen ionization zones of accretion discs are unstable and modulate mass transfer throughout the disc. The instability occurs when disc temperatures are sufficiently low for incomplete hydrogen ionization. The problem is approached in two stages. In the first, a much simplified analogue treatment, we allow disc viscosity, v, to be a prescribed, multiple-valued function of the local integrated surface density, ?. For certain ranges of mass-input rate, no steady state is possible; instead the accretion-disc flow establishes a limit cycle. This numerical experiment shows that even with a purely local prescription for viscosity, phase transitions can propagate throughout the disc collectively due to an avalanche effect. In the second, more realistic approach, appropriate thermodynamic effects are included in a modified thin-disc ?-model approximation. Radial thermal contact is also included and account is taken of energy advected between different radial positions. From these global analyses we show that the disc is indeed thermally unstable. The non-local effects and viscosity transitions are important in promoting the collective nature of the instability and its growth. The instability may be touched off at one radial position, but have its most noticeable effects at another. Our model reproduces the basic outburst cycles of dwarf novae.

Papaloizou, J.; Faulkner, J.; Lin, D. N. C.

1983-11-01

251

Collecting Plants  

NSDL National Science Digital Library

This article, part of Biodiversity Counts, takes a look at collecting plant specimens. The article discusses what tools are needed to collect specimens, how to press and dry specimens and has tips for numbering and labeling specimens.

252

Collecting apparatus  

DOEpatents

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.

Duncan, Charles P. (Walnut Creek, CA)

1983-01-01

253

Guidelines for sample collecting and analytical methods used in the U.S. Geological Survey for determining chemical composition of coal  

USGS Publications Warehouse

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.

Swanson, Vernon Emanuel; Huffman, Claude

1976-01-01

254

75 FR 8996 - Notice of Information Collection  

Federal Register 2010, 2011, 2012, 2013, 2014

...products or opportunities will be available, representing all NASA Mission Directorates and current NASA missions in Earth and Space Science, mathematics, chemistry, and physics. II. Method of Collection The data collection uses web-based...

2010-02-26

255

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

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.

Tuttle, Michele L.W.

2009-01-01

256

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

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.

Dutton, J.A.

1981-09-01

257

Collection Mapping and Collection Development.  

ERIC Educational Resources Information Center

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…

Murray, William; And Others

1985-01-01

258

THE SPLASH SURVEY: INTERNAL KINEMATICS, CHEMICAL ABUNDANCES, AND MASSES OF THE ANDROMEDA I, II, III, VII, X, AND XIV DWARF SPHEROIDAL GALAXIES {sup ,}  

SciTech Connect

We present new Keck/DEIMOS spectroscopic observations of hundreds of individual stars along the sightline to the first three of the Andromeda (M31) dwarf spheroidal (dSph) galaxies to be discovered, And I, II, and III, and combine them with recent spectroscopic studies by our team of three additional M31 dSphs, And VII, X, and XIV, as a part of the SPLASH Survey (Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo). Member stars of each dSph are isolated from foreground Milky Way dwarf stars and M31 field contamination using a variety of photometric and spectroscopic diagnostics. Our final spectroscopic sample of member stars in each dSph, for which we measure accurate radial velocities with a median uncertainty (random plus systematic errors) of 4-5 km s{sup -1}, includes 80 red giants in And I, 95 in And II, 43 in And III, 18 in And VII, 22 in And X, and 38 in And XIV. The sample of confirmed members in the six dSphs is used to derive each system's mean radial velocity, intrinsic central velocity dispersion, mean abundance, abundance spread, and dynamical mass. This combined data set presents us with a unique opportunity to perform the first systematic comparison of the global properties (e.g., metallicities, sizes, and dark matter masses) of one-third of Andromeda's total known dSph population with Milky Way counterparts of the same luminosity. Our overall comparisons indicate that the family of dSphs in these two hosts have both similarities and differences. For example, we find that the luminosity-metallicity relation is very similar between L {approx} 10{sup 5} and 10{sup 7} L{sub sun}, suggesting that the chemical evolution histories of each group of dSphs are similar. The lowest luminosity M31 dSphs appear to deviate from the relation, possibly suggesting tidal stripping. Previous observations have noted that the sizes of M31's brightest dSphs are systematically larger than Milky Way satellites of similar luminosity. At lower luminosities between L = 10{sup 4} and 10{sup 6} L{sub sun}, we find that the sizes of dSphs in the two hosts significantly overlap and that four of the faintest M31 dSphs are smaller than Milky Way counterparts. The first dynamical mass measurements of six M31 dSphs over a large range in luminosity indicate similar mass-to-light ratios compared to Milky Way dSphs among the brighter satellites, and smaller mass-to-light ratios among the fainter satellites. Combined with their similar or larger sizes at these luminosities, these results hint that the M31 dSphs are systematically less dense than Milky Way dSphs. The implications of these similarities and differences for general understanding of galaxy formation and evolution are summarized.

Kalirai, Jason S. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Beaton, Rachael L.; Majewski, Steven R.; Ostheimer, James C.; Patterson, Richard J. [Department of Astronomy, University of Virginia, P.O. Box 3818, Charlottesville, VA 22903 (United States); Geha, Marla C. [Astronomy Department, Yale University, New Haven, CT 06510 (United States); Gilbert, Karoline M. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Guhathakurta, Puragra; Kirby, Evan N. [University of California Observatories/Lick Observatory, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Wolf, Joe, E-mail: jkalirai@stsci.ed, E-mail: rlb9n@virginia.ed, E-mail: srm4n@virginia.ed, E-mail: rjp0i@virginia.ed, E-mail: marla.geha@yale.ed, E-mail: kgilbert@astro.washington.ed, E-mail: raja@ucolick.or, E-mail: enk@astro.caltech.ed, E-mail: wolfj@uci.ed [Center for Cosmology, Department of Physics and Astronomy, University of California at Irvine, Irvine, CA 92697 (United States)

2010-03-10

259

GUIDELINES FOR DISPOSAL OF CHEMICAL WASTE Excess Chemicals and Chemical Wastes  

E-print Network

GUIDELINES FOR DISPOSAL OF CHEMICAL WASTE wstPS.DOC Excess Chemicals and Chemical Wastes · Toxic and Flammable Chemicals - - These cannot go down the drain. Call Environmental Health and Safety (EHSO) at x- 2723 for collection. · Corrosive Chemicals (Acids & Bases) - - When neutralized so that the pH is > 6

Kim, Duck O.

260

Syn-anti conformational switching in an ethane-bridged Co(II)bisporphyrin induced by external stimuli: effects of inter-macrocyclic interactions, axial ligation and chemical and electrochemical oxidations.  

PubMed

The syn-anti conformational switching has been demonstrated in the ethane-bridged dicobalt(II)bisporphyrin which is present in the syn-form only. The addition of either perylene or axial ligands to Co(II)(bisporphyrin) completely transforms the syn form into the anti because of strong ?-? interaction and axial coordination, respectively. The complex undergoes four 1e-oxidations in CH2Cl2 which are indicative of strong through space interactions between the two cofacial Co-porphyrins at 295 K. The first oxidation is a metal centered one and occurs at a potential much lower than that of the monomeric analog. However, the second oxidation, which is again metal centered, was at a significantly higher potential. The large difference between the first two oxidations, as observed here, is due to much stronger inter-porphyrin interactions. The step-wise oxidations have been performed both chemically and electro-chemically while the progress of the reactions was monitored by UV-visible and (1)H NMR spectroscopy. After 1e-oxidation, a very broad (1)H NMR signal results with increased difference between two meso resonances, which indicates that the two macrocycles are in the syn-form with lesser interplanar separation as also observed by DFT. However, 2e-oxidation results in the stabilization of the anti form. The addition of axial ligands to Co(II)(bisporphyrin) also completely transforms the syn form into the anti form. While additions of THF and I2/I(-) both result in the formation of five-coordinate complexes, Co(II) is oxidized to Co(III) in the case of the latter. However, additions of 1-methylimidazole, pyridine and pyrazine as axial ligands result in the formation of a six-coordinate complex in which Co(II) is spontaneously oxidized to Co(III) in air. PMID:24300990

Dey, Soumyajit; Rath, Sankar Prasad

2014-02-01

261

Application of a high surface area solid-phase microextraction air sampling device: collection and analysis of chemical warfare agent surrogate and degradation compounds.  

PubMed

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

Stevens, Michael E; Tipple, Christopher A; Smith, Philip A; Cho, David S; Mustacich, Robert V; Eckenrode, Brian A

2013-09-17

262

Collecting Rocks.  

ERIC Educational Resources Information Center

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…

Barker, Rachel M.

263

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 ...

264

Collective Intentions  

Microsoft Academic Search

In this paper the notion of collective intentionin teams of agents involved in cooperative problem solving(CPS) in multiagent systems(MAS) is investigated. Starting from individual inten- tions, goals ,a ndbeliefs defining agents' local asocial motivational and informational attitudes, we arrive at an understanding of a collective intention in a team of agents. The presented definitions are rather strong, in particular a

Barbara Dunin-keplicz; Rineke Verbrugge

2002-01-01

265

Collective Enumeration  

ERIC Educational Resources Information Center

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…

Bahrami, Bahador; Didino, Daniele; Frith, Chris; Butterworth, Brian; Rees, Geraint

2013-01-01

266

Jay's Collectibles  

ERIC Educational Resources Information Center

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…

Cappel, James J.; Gillman, Jason R., Jr.

2011-01-01

267

Counting Collections  

ERIC Educational Resources Information Center

This article explores how counting collections of objects helps elementary-age children develop number sense and number relations. The authors provide evidence that counting collections offers multiple entry points for children at different places on the counting trajectory. It is suggested that the teacher's role is one of noticing, questioning,…

Schwerdtfeger, Julie Kern; Chan, Angela

2007-01-01

268

78 FR 16698 - Chemical Facility Anti-Terrorism Standards (CFATS) Chemical-Terrorism Vulnerability Information...  

Federal Register 2010, 2011, 2012, 2013, 2014

...DHS-2012-0057] Chemical Facility Anti-Terrorism Standards (CFATS) Chemical- Terrorism Vulnerability Information (CVI) AGENCY...Collection Request, Chemical Facility Anti- Terrorism Standards (CFATS) Chemical-terrorism...

2013-03-18

269

Quantum chemical study of the mechanism of the reaction of tetraphosphorus with alcohol in the coordination sphere of copper(II)  

Microsoft Academic Search

We have used the CNDO Method to study ?-1-tetraphosphorus complexes of copper (II) containing MeOH, MeO-, H2O, HO-, Cl-, Br-, I-, formed during the new reaction of oxidative alkoxylation of P4 to trialkylphosphates in alcohol-benzene solutions of Cu(II). We studied the nature of the activation of the coordinated molecules and ions by comparing the charges on al the atoms and

Ya. A. Dorfman; R. R. Abdreimova; D. M. Doroshkevich

1991-01-01

270

Chemical reduction of U(VI) by Fe(II) at the solid-water interface using natural and synthetic Fe(III) oxides.  

PubMed

Abiotic reduction of 0.1 mM U(VI) by Fe(II) in the presence of synthetic iron oxides (biogenic magnetite, goethite, and hematite) and natural Fe(III) oxide-containing solids was investigated in pH 6.8 artificial groundwater containing 10 mM NaHCO3. In most experiments, more than 95% of added U(VI) was sorbed to solids. U(VI) was rapidly and extensively (> or = 80%) reduced in the presence of synthetic Fe(III) oxides and highly Fe(II) oxide-enriched (18-35 wt % Fe) Atlantic coastal plain sediments. In contrast, long-term (20-60 d) U(VI) reduction was less than 30% in suspensions of six other natural solids with relatively low Fe(III) oxide content (1-5 wt % Fe). Fe(II) sorption site density was severalfold lower on these natural solids (0.2-1.1 Fe(II) nm(-2)) compared tothe synthetic Fe(lII) oxides (1.6-3.2 Fe(II) nm(-2)), which may explain the poor U(VI) reduction in the natural solid-containing systems. Addition of the reduced form of the electron shuttling compound anthrahydroquinone-2,6-disulfonate (AH2DS; final concentration 2.5 mM) to the natural solid suspensions enhanced the rate and extent of U(VI) reduction, suggesting that AH2DS reduced U(VI) at surface sites where reaction of U(VI) with sorbed Fe(II) was limited. This study demonstrates that abiotic, Fe(II)-driven U(VI) reduction is likely to be less efficient in natural soils and sediments than would be inferred from studies with synthetic Fe(III) oxides. PMID:16124298

Jeon, Byong-Hun; Dempsey, Brian A; Burgos, William D; Barnett, Mark O; Roden, Eric E

2005-08-01

271

Chemical and Physical Changes  

NSDL National Science Digital Library

The phenomenon is a chemical reaction between sugar and sulfuric acid. The demonstration (a discrepant event) compares the way sugar and water interact when combined (physical change) to the way sugar and sulfuric acid interact when combined (chemical change). In part II, students are given additional substances and changes to observe.

272

Chemical abundances in the protoplanetary disc LV 2 (Orion): clues to the causes of the abundance anomaly in H II regions  

NASA Astrophysics Data System (ADS)

Optical integral field spectroscopy of the archetype protoplanetary disc LV 2 in the Orion nebula is presented, taken with the Very Large Telescope (VLT) FLAMES/Argus fibre array. The detection of recombination lines (RLs) of C II and O II from this class of objects is reported, and the lines are utilized as abundance diagnostics. The study is complemented with the analysis of Hubble Space Telescope (HST) Faint Object Spectrograph ultraviolet and optical spectra of the target contained within the Argus field of view. By subtracting the local nebula background the intrinsic spectrum of the proplyd is obtained and its elemental composition is derived for the first time. The proplyd is found to be overabundant in carbon, oxygen and neon compared to the Orion nebula and the Sun. The simultaneous coverage over LV 2 of the C III]?1908 and [O III]?5007 collisionally excited lines (CELs) and C II and O II RLs has enabled us to measure the abundances of C2 + and O2 + for LV 2 with both sets of lines. The two methods yield consistent results for the intrinsic proplyd spectrum, but not for the proplyd spectrum contaminated by the generic nebula spectrum, thus providing one example where the long-standing abundance anomaly plaguing metallicity studies of H II regions has been resolved. These results would indicate that the standard forbidden-line methods used in the derivation of light metal abundances in H II regions in our own and other galaxies underestimate the true gas metallicity.

Tsamis, Y. G.; Walsh, J. R.; Vílchez, J. M.; Péquignot, D.

2011-04-01

273

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  

Microsoft Academic Search

To construct a novel scaffold for nucleus pulposus (NP) tissue engineering, The porous type II collagen (CII)\\/hyaluronate\\u000a (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\\u000a were evaluated. The results suggested CII\\/HyA–CS scaffolds have a highly porous structure (porosity: 94.8 ± 1.5%), high water-binding\\u000a capacity (79.2 ± 2.8%) and significantly improved mechanical

Chang-qing Li; Bo Huang; Gang Luo; Chuan-zhi Zhang; Ying Zhuang; Yue Zhou

2010-01-01

274

Interaction of Au(III) and Pt(IV) complex ions with Fe(II) ions as a scavenging and a reducing agent: a basic study on the recovery of Au and Pt by a chemical method.  

PubMed

In order to develop a chemical technique for the recovery of gold (Au) and platinum (Pt) in the metallic state from spent catalysts, e.g., catalysts for environmental protection and automobile and petroleum catalysts, the coprecipitation behaviors of Au(III) and Pt(IV) complex ions with Fe(OH)(2) as a scavenging and reducing agent were investigated. The Au(III) complex ions were found to be stoichiometrically and rapidly reduced to metallic Au due to electron transfer in acidic aqueous solution prior to coprecipitation with Fe(OH)(2). Conversely, Pt(IV) complex ions were reduced only after coprecipitation with Fe(OH)(2) due to electron transfer through a Pt(IV)-O-Fe(II) bond on the solid Fe(OH)(2). Using this chemical technique, Au and Pt can be selectively and effectively recovered in the metallic state. PMID:21920530

Parinayok, Pornthip; Yamashita, Mamiko; Yonezu, Kotaro; Ohashi, Hironori; Watanabe, Koichiro; Okaue, Yoshihiro; Yokoyama, Takushi

2011-12-01

275

Micrometeorite Collecting  

ERIC Educational Resources Information Center

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)

Toubes, Joe; Hoff, Darrel

1974-01-01

276

Collection understanding  

E-print Network

research. In addition, I would like to thank Dr. Richard Furuta for his interpretation of this work. Thanks also to Dr. Enrique Mallen for providing the image collection of the Online Picasso Project. v TABLE OF CONTENTS Page ABSTRACT... ................................................................................................................................61 vii LIST OF FIGURES Page Figure 1. System overview???????????????????????...26 Figure 2. System design????????????????????????....27 Figure 3. Using streaming collage for understanding the Online Picasso Collection......29 Figure 4...

Chang, Michelle T.

2004-09-30

277

Spoon Collective  

NSDL National Science Digital Library

The Spoon Collective houses descriptive information, discussion archives, paper archives, and links to Websites for three dozen listservs related to the discussion of philosophy, sociology, political science, and literary theory. Some of the topics for the lists include Postcolonialism, Poststructuralism, Feminism, Marxism, and Cultural Studies. Thirteen of the lists are dedicated to the work of influential thinkers, including Jean Baudrillard, Pierre Bourdieu, Michel Foucault, Friedrich Nietzsche, and Martin Heidegger. All content at the Spoon Collective can be searched aggregately.

278

Responses of the L5178Y tk/sup +//tk/sup -/ mouse lymphoma cell forward mutation assay. II. 18 coded chemicals  

SciTech Connect

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.

McGregor, D.B.; Brown, A.; Cattanach, P.; Edwards, I.; McBride, D.; Caspary, W.J.

1988-01-01

279

Carnival Collection  

NSDL National Science Digital Library

"Come to the carnival" is a common refrain in New Orleans during the month of February, and this intoxicating collection from Tulane University pays homage to this wonderful cultural tradition. The collection includes over 1,500 float designs from the "Golden Age" of carnival by notable designers such as Jennie Wilde, B.A. Wikstrom, and Charles Briton. Support for the project comes from the late Charles L. "Pie" Dufour who left funds to continue the preservation of these rare and unique ephemeral materials. Visitors can browse at their leisure, and they may wish to start with fanciful designs like the 1870 "Twelfth Night Revelers" float or the 1891 "Atlanteans" design. Also, visitors can select the work of a particular float designer or krewe of note. Also, visitors can search the entire collection by keyword.

2012-02-24

280

Antislavery Collection  

NSDL National Science Digital Library

The digital collections at the University of Massachusetts at Amherst are top-flight and this collection continues that grand tradition. The Antislavery Collection contains several hundred pamphlets and books pertaining to slavery and antislavery in New England from 1725-1911. These items include speeches, sermons, proceedings, and other publications from organizations such as the American Anti-Slavery Society, the American Colonization Society, and a small number of pro-slavery tracts. Visitors can browse the selected titles alphabetically or perform a more detailed search across all of the items. Several documents should not be missed, including speeches by Horace Mann and Ezra Gannett's "Relation of the North to Slavery" delivered in Boston in 1854.

281

Oz Collection  

NSDL National Science Digital Library

The world of Oz is a big place, and this particular digital collection from the University of Minnesota pays homage to some of its many characters, stories, and more. The materials here were collected by Laura Jane Musser, and they include annual meeting program notes from the International Wizard of Oz club, sheet music from Oz-related productions, catalogs, and coloring books. The digitized materials also include a number of famous books from the Oz series, such as "The Marvelous Land of Oz" and "The Land of Oz". Visitors can use a finding aid to make their way through the materials, and if they are interested in doing research with these materials they can learn more about making a visit to the collections.

282

Blood Collection  

NASA Technical Reports Server (NTRS)

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.

1999-01-01

283

Digitial Collections: Boston College  

NSDL National Science Digital Library

John J. Burns Library, Rare Books and Special Collections at Boston College, offers some of its collections on the Web. The largest is the Liturgy and Life Collection, approximately 1,200 artifacts selected from perhaps the "most comprehensive archive in America on the pre-Vatican II Catholic Church." Also available are Boston Gas Company photos, about 400 images from the 1880s to the 1970s, documenting both the company and the city of Boston, and Thomas P. O'Neill Photographs, primarily from O'Neill's years as Speaker of the US House of Representatives. All of the databases allow browsing as well as searching, very helpful for users who do not know if Saint Christopher is entered as St. or Saint. Unlike other religious history collections, many of the pictures in Liturgy & Life are images of objects that people owned and carried in their pockets, such as the nineteen Saint Christopher medals that I located with the browse function. Be sure to check out the Gas Company collection's fascinating views of pre-1900 Boston, including over 200 cyanotypes that reproduce beautifully on the Web.

284

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Proposed Collection; Comment Request; Disinfectants/Disinfection Byproducts, Chemical...The ICRs scheduled to expire are Disinfectants/Disinfection Byproducts, Chemical...Docket ID EPA-HQ-OW- 2011-0439 (Disinfectants/Disinfection Byproducts,...

2011-07-05

285

CHEMICAL LABORATORY SAFETY AND METHODOLOGY  

E-print Network

CHEMICAL LABORATORY SAFETY AND METHODOLOGY MANUAL August 2013 #12;ii Emergency Numbers UNBC Prince-Emergency Numbers UNBC Prince George Campus Chemstores 6472 Chemical Safety 6472 Radiation Safety 6472 Biological the safe use, storage, handling, waste and emergency management of chemicals on the University of Northern

Northern British Columbia, University of

286

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...

287

Collecting Artifacts  

ERIC Educational Resources Information Center

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…

Coffey, Natalie

2004-01-01

288

Chemical Principles Exemplified  

ERIC Educational Resources Information Center

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)

Plumb, Robert C.

1972-01-01

289

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...

290

THE MOST METAL-POOR STARS. II. CHEMICAL ABUNDANCES OF 190 METAL-POOR STARS INCLUDING 10 NEW STARS WITH [Fe/H] {<=} -3.5 , ,  

SciTech Connect

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.

Yong, David; Norris, John E.; Bessell, M. S.; Asplund, M. [Research School of Astronomy and Astrophysics, The Australian National University, Weston, ACT 2611 (Australia)] [Research School of Astronomy and Astrophysics, The Australian National University, Weston, ACT 2611 (Australia); Christlieb, N. [Zentrum fuer Astronomie der Universitaet Heidelberg, Landessternwarte, Koenigstuhl 12, D-69117 Heidelberg (Germany)] [Zentrum fuer Astronomie der Universitaet Heidelberg, Landessternwarte, Koenigstuhl 12, D-69117 Heidelberg (Germany); Beers, Timothy C. [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States)] [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Barklem, P. S. [Department of Physics and Astronomy, Uppsala University, Box 515, SE-75120 Uppsala (Sweden)] [Department of Physics and Astronomy, Uppsala University, Box 515, SE-75120 Uppsala (Sweden); Frebel, Anna [Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, Cambridge, MA 02139 (United States)] [Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, Cambridge, MA 02139 (United States); Ryan, S. G., E-mail: yong@mso.anu.edu.au, E-mail: jen@mso.anu.edu.au, E-mail: bessell@mso.anu.edu.au, E-mail: martin@mso.anu.edu.au, E-mail: n.christlieb@lsw.uni-heidelberg.de, E-mail: beers@pa.msu.edu, E-mail: paul.barklem@physics.uu.se, E-mail: afrebel@mit.edu, E-mail: s.g.ryan@herts.ac.uk [Centre for Astrophysics Research, School of Physics, Astronomy and Mathematics, University of Hertfordshire, College Lane, Hatfield, Hertfordshire AL10 9AB (United Kingdom)

2013-01-01

291

In-product environmental protection: evaluation of chemical emissions from the spot welding joining technique in the automobile industry Part II. Laboratory pyrolysis measurements with a welding chamber  

Microsoft Academic Search

In the first part of this series we introduced the aim of this work and the methods used for evaluation of chemical emission when using the combined joining technique of weld bonding. In this part of the publication we give detailed information of the influence of some parameters on the formation of BTEX (benzene, toluene, ethylbenzene and xylene), PAH (polycyclic

G. Lörinci; I. Gebefügi; G. Kötting; W. Hilla; A. Kettrup

1995-01-01

292

Conformational stability of B cell epitopes on group I and group II Dermatophagoides spp. allergens. Effect of thermal and chemical denaturation on the binding of murine IgG and human IgE antibodies.  

PubMed

The conformational stability of B cell epitopes on the 25-kDa group I and 14-kDa group II mite allergens was compared by using heat-treated or chemically denatured allergens to inhibit the binding of native 125I allergens to murine mAb or to human IgE antibodies. Structural changes after treatment were assessed by SDS-PAGE and circular dichroism spectroscopy. Heating for 1 h at greater than 75 degrees C, treatment at pH 2.0 or pH 12.0, or with 6M guanidine or 6M urea, reduced the binding of the group I allergens to mAb or IgE antibodies by 10- to 1000-fold. The group II allergens were heat stable and even after prolonged heat treatment (5 h at 75 degrees C or 30 min at 100 degrees C) their antibody binding activity was reduced by less than twofold. The group II allergens were also resistant to pH and to denaturation with 6M guanidine. However, after reduction and alkylation, antibody binding sites on both the group I and group II allergens were destroyed. Reduction of disulfide bonds with 2-ME caused a marked shift in the molecular mass of group I allergens on SDS-PAGE, from 25 kDa to 28-31 kDa. Reduction and alkylation also generated two high m.w. forms of Der p I and Der f I. After heating (100 degrees for 30 min), both Der f I and Der f II retained significant secondary structure, as judged by circular dichroism spectroscopy, but on reduction they showed the typical spectra of fully denatured proteins (greater than 85% random structure). The results show clear differences between the susceptibility of B cell epitopes on the group I and group II allergens to denaturation. Despite these differences in stability, both allergens are equally potent immunogens for IgE antibody responses in man. The results support the view that the physical properties of allergens (low m.w. and solubility), limiting low dose exposure (1 to 10 ng/day), and host genetic and immunoregulatory processes, are more important than gross structural features in the induction and maintenance of IgE antibody responses. PMID:1689351

Lombardero, M; Heymann, P W; Platts-Mills, T A; Fox, J W; Chapman, M D

1990-02-15

293

A density functional study of the chemical differences between Type I and Type II MoS2-based structures in hydrotreating catalysts.  

PubMed

Density functional theory is used to investigate the origin of the activity differences between Type I and Type II MoS2-based structures in hydrotreating catalysts. It is well known that the Type II structures, where only weak interactions with the support exist, have a higher catalytic activity than Type I structures, where Mo-O linkages to the alumina are present. The present results show that the differences in activities for MoS2 and Co-Mo-S structures can be attributed to the electronic and bonding differences introduced by the bridging O bonds. We find that the Mo-O linkages are most probably located on the (1010) S edge. The presence of oxygen linkages increases the energy required to form sulfur vacancies significantly so that almost no vacancies can be formed at these and neighboring sites. In this way, the reactivity of the S edge is reduced. In addition, the studies also show that the linkages introduce changes in the one-dimensional metallic-like brim states. Furthermore, the presence of oxygen linkages also changes the energetics of hydrogen adsorption, which becomes less exothermic on sulfur sites directly above linkages and more exothermic on sulfur sites adjacent to linkages. The present results explain previously observed differences in Type I-Type II transition temperatures for Co-Mo-S structures with different Co contents. PMID:16851217

Hinnemann, Berit; Nørskov, Jens K; Topsøe, Henrik

2005-02-17

294

Capacitive chemical sensor  

DOEpatents

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.

Manginell, Ronald P; Moorman, Matthew W; Wheeler, David R

2014-05-27

295

OXALATE MASS BALANCE DURING CHEMICAL CLEANING IN TANK 6F  

SciTech Connect

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.

Poirier, M.; Fink, S.

2011-07-22

296

Investigation of combwax of honeybees with high-temperature gas chromatography and high-temperature gas chromatography-chemical ionization mass spectrometry. II: High-temperature gas chromatography-chemical ionization mass spectrometry.  

PubMed

Crude combwax of six various honey bee species have been analyzed by high-temperature gas chromatography (HTGC)-chemical ionization mass spectrometry after a two-step silylation procedure. An optimized chromatographic procedure, described previously, enables the separation of high-molecular mass lipid compounds resulting in a characteristic fingerprint of the combwaxes of different honeybee species. The coupling of HTGC to mass spectrometry requires appropriate instrumentation in order to achieve sufficient sensitivity at high elution temperatures and avoid loss of chromatographic resolution. Chemical ionization was carried out using methane as reagent gas in order to determine the molecular mass of the individual compounds by means of abundant quasi molecular ions. To confirm the presence of unsaturated wax esters, ammonia was used as reagent gas. More than 80 lipid constituents were separated and characterized by their mass spectra. Representative chemical ionization mass spectra of individual compounds are presented. Both, HTGC-flame ionization detection data and the results of the HTGC-mass spectrometric investigations enabled a rapid profiling of the individual classes of compounds in crude combwaxes. PMID:10910202

Aichholz, R; Lorbeer, E

2000-06-23

297

Methods and Materials Sample Collection  

E-print Network

Methods and Materials Sample Collection FIGURE I.-Sampling station pattern and location of sample of the stations where one or more of the target species was abundant, samples of yellowfin sole, rock sole from 1933 to 1941 .were the sa~e locations as post-World War II flounder fisherIes, so there IS reason

298

Chemical defence in ladybird beetles (Coccinellidae). II. Amount of reflex fluid, the alkaloid adaline and individual variation in defence in 2-spot ladybirds ( Adalia bipunctata )  

Microsoft Academic Search

Summary 2-spot ladybirds secrete alkaloid (adaline)-rich defence fluid (reflex blood) in response to predator attack. Reflex fluid was collected from individual ladybirds and weighed and the alkaloid content measured by GC. The amount of fluid produced built up rapidly following winter hibernation in animals feeding on aphids. The concentration of adaline in the fluid was highest in the first bleeding

Peter W. de Jong; Graham J. Holloway; Paul M. Brakefield; Helene de Vos

1991-01-01

299

The LIFE Picture Collection  

NSDL National Science Digital Library

Although this is a commercial site with pictures and images for sale, users can nonetheless view and appreciate one of "the most extraordinary collections of pictures in the world" at The Picture Collection from Time, Inc. An initial free registration is required, and after that users need only log on to gain access to over 22 million images, including illustrations, prints, and photographs. Archival materials from many popular magazines are available here, including images from Time, Life, Sports Illustrated, People, and Entertainment Weekly, as well as material from the recently acquired Mansell Collection. "Mansell photographs date from the beginnings of the medium in the 1840s through World War II [and] depict a vast range of scenics, important news events, and historical personalities, with a special emphasis on art and architecture. In addition, the new Mansell Collection includes extraordinary holdings of engraved illustrations, lithographs, and drawings predating the advent of photographic imaging." In addition to a key word search function, The Picture Collection offers a special searching and licensing program that lets you search for and store materials in "Lightboxes" of your own creation for later use; these are similar to folders that one might use in a conventional software setting. The program also calculates licensing fees for images based on what type of usage is intended (newspaper, magazine, Website, etc.). Research help is available for those users who would like someone else to do the searching, with one half-hour of free research offered initially. After that, a fee of 85 dollars an hour is charged; some or all of this fee may be waived if one or more images are licensed. An excellent help section rounds out this site and makes perusing this amazing (if somewhat overwhelming) collection even more pleasurable.

300

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

Microsoft Academic Search

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

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

2009-01-01

301

LABORATORY CHEMICAL WASTE DISPOSAL POSTER (Post Near Chemical Waste Storage Area)  

E-print Network

WSTPS.rtf LABORATORY CHEMICAL WASTE DISPOSAL POSTER (Post Near Chemical Waste Storage Area) Excess Chemicals and Chemical Wastes · Toxic and Flammable Chemicals - These cannot go down the drain. Call Environmental Health and Safety (EHSO) at x-2723 for collection. · Corrosive Chemicals (Acids & Bases) - When

Oliver, Douglas L.

302

Pamphlet Collection  

NSDL National Science Digital Library

In a welcome move to researchers and historians, the British Library of Political and Economic Science (BLPES) has created an online guide to its large pamphlet collection, containing some 90,000 pamphlets, many from the 19th and early 20th centuries. While covering a number of important public and political issues in British history, the collection also contains a fair amount of European and International materials, including a large number of German-language pamphlets, as well as materials on Latin American trade unions, the League of Nations, pacifism, the two World Wars, and conflict in the Middle East. Users can browse the guide by fifteen topics (e.g., Issues in British history, political parties, social policy, poor laws, transport, etc.) or search the online catalog by subject keyword, author, title, or issuing body. The guide lists pamphlet author, title, and classmark, while the online catalog also includes publisher, pages, location, and other notes. As an added bonus, the majority of pamphlets listed in the social policy and transport guides have been digitized and are available in .pdf format.

303

Evaluation of the National School Lunch Program Application/Verification Pilot Projects: Volume II: Data Collection, Study Methods and Supplementary Tables on Certification Impacts. Nutrition Assistance Program Report Series. Report No. CN-04-AV2  

ERIC Educational Resources Information Center

This is Volume II of the report on the evaluation of the NSLP Application Verification Pilot Projects. It supplements Volume I, which presents the evaluation findings. Volume II has two objectives: (1) to provide a detailed description of the methods used to conduct the study; and (2) to present tabulations that supplement and extend the analyses…

Burghardt, John; Gleason, Philip; Sinclair, Michael; Cohen, Rhoda; Hulsey, Lara; Milliner-Waddell, Julita

2004-01-01

304

University of Wisconsin Digital Collections: The Science Collection  

NSDL National Science Digital Library

The Science Collection brings together writings about scientific research conducted by University of Wisconsin faculty and staff; and unique or valuable items related to science held by the University of Wisconsin Libraries. Subcollections include a Botany Department Teaching Collection (images), an electronic edition of Thermophilic Microorganisms and Life at High Temperatures (1978) by Thomas D. Brock, a collection of veterinary anatomical illustrations derived from the Handbuch der Anatomie der Tiere fur Kunstler, or Handbook of Animal Anatomy for Artists (1898, 1911-1925) and the Journal of Chemical Education.

Center, University O.

305

Hemingway Collection  

NSDL National Science Digital Library

Ernest Hemingway was a red-blooded man of letters, and one of the 20th century's most celebrated and demonized writers. In 1968, Mary Hemingway arranged to have his papers donated to the Kennedy Library. Over the past several decades, materials related to Hemingway's long career have continued to become part of this very extensive collection. The Kennedy Library has created this specific page to provide both researchers and members of the general public with some basic information about their holdings, along with offering access to a selection of these papers. The photograph galleries are a real treat, as they cover everything from Hemingway's youth in Oak Park all the way up to his last days in Idaho.

306

Differential chemical diagnosis of primary hyperoxaluria type II. Highly sensitive analysis of optical isomers of glyceric acid by GC/MS as diastereoisomeric derivatives.  

PubMed

We established a separation method for the optical isomers of glyceric acid in urine by modifying the derivatization steps of the procedure used for the screening and diagnosis. The trimethylsilyl derivatization step in the mass screening procedure was replaced by O-acetyl-(+)-2-butylation, and the samples were analyzed under equivalent GC/MS conditions by capillary gas chromatography on a DB-5MS column. This method can be applied to cases that show a high urinary concentration of glyceric acid to obtain a differential diagnosis of primary hyperoxaluria type II and d-glyceric aciduria easily. l-Glyceric acid was also isolated from the urine of healthy controls as one of the main peaks. PMID:16055048

Inoue, Yoshito; Shinka, Toshihiro; Ohse, Morimasa; Kuhara, Tomiko

2005-08-25

307

A two-stage ceramic tile grout sealing process using a high power diode laser—II. Mechanical, chemical and physical properties  

NASA Astrophysics Data System (ADS)

Ceramic tiles sealed using a portable 60 Wcw high power diode laser (HPDL) and a specially developed grout material having an impermeable enamel surface glaze have been tested in order to determine the mechanical, chemical and physical characteristics of the seals. The work showed that the generation of the enamel surface glaze resulted in a seal with improved mechanical and chemical properties over conventional epoxy tile grouts. Both epoxy tile grout and laser generated enamel seals were tested for compressive strength, surface roughness, wear, water permeability and acid/alkali resistance. The enamel seal showed clear improvements in strength, roughness and wear, whilst being impermeable to water, and resistant (up to 80% concentration) to nitric acid, sodium hydroxide and detergent acids. The bond strength and the rupture strength of the enamel seal were also investigated, revealing that the enamel adhered to the new grout and the ceramic tiles with an average bond strength of 45-60 MPa, whilst the rupture strength was comparable with the ceramic tiles themselves. The average surface roughness of the seals and the tiles was 0.36 and 0.06 ?m, respectively, whilst for the conventional epoxy grout the average surface roughness when polished was 3.83 ?m and in excess of 30 ?m without polishing. Life assessment testing revealed that the enamel seals had an increase in actual wear life of 2.9 to 30.4 times over conventional epoxy tile grout, depending upon the corrosive environment.

Lawrence, J.; Li, L.; Spencer, J. T.

1998-04-01

308

Using a dual plasma process to produce cobalt--polypyrrole catalysts for the oxygen reduction reaction in fuel cells -- part II: analysing the chemical structure of the films  

E-print Network

The chemical structure of cobalt--polypyrrole -- produced by a dual plasma process -- is analysed by means of X-ray photoelectron spectroscopy (XPS), near edge X-ray absorption spectroscopy (NEXAFS), X-ray diffraction (XRD), energy-dispersive X-Ray spectroscopy (EDX) and extended x-ray absorption spectroscopy (EXAFS).It is shown that only nanoparticles of a size of 3\\,nm with the low temperature crystal structure of cobalt are present within the compound. Besides that, cobalt--nitrogen and carbon--oxygen structures are observed. Furthermore, more and more cobalt--nitrogen structures are produced when increasing the magnetron power. Linking the information on the chemical structure to the results about the catalytic activity of the films -- which are presented in part I of this contribution -- it is concluded that the cobalt--nitrogen structures are the probable catalytically active sites. The cobalt--nitrogen bond length is calculated as 2.09\\,\\AA\\ and the carbon--nitrogen bond length as 1.38\\,\\AA.

Walter, Christian; Vyalikh, Denis; Brüser, Volker; Quade, Antje; Weltmann, Klaus-Dieter; 10.1149/2.043209jes

2012-01-01

309

Chemical Mechanical Planarization- Chemical  

NSDL National Science Digital Library

This website includes an animation which illustrates the chemical action of slurry in the chemical-mechanical planarization process. Objective: Explain the mechanical and chemical steps in the CMP process. This simulation is from Module 068 of the Process & Equipment III Cluster of the MATEC Module Library (MML). Find this animation under the section "Process & Equipment III." To view other clusters or for more information about the MML visit http://matec.org/ps/library3/process_I.shtmlKey Phrase: MATEC Animation

2012-12-07

310

Chemical Threats  

MedlinePLUS

... indicate a chemical agent release. Before Before a Chemical Threat What you should do to prepare for ... and on the highest level. During During a Chemical Threat What you should do in a chemical ...

311

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 ...

312

75 FR 59294 - Agency Information Collection Activities: Proposed Collection; Comments Requested: Application...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Procurement Quota for Controlled Substances and Ephedrine, Pseudoephedrine, and Phenylpropanolamine...Procurement Quota for Controlled Substances and Ephedrine, Pseudoephedrine, and Phenylpropanolamine...Schedule I or II or the List I chemicals ephedrine, pseudoephedrine, and...

2010-09-27

313

77 FR 71832 - Agency Information Collection Activities: Proposed Collection; Comments Requested: Application...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Procurement Quota for Controlled Substances and Ephedrine, Pseudoephedrine, and Phenylpropanolamine...Procurement Quota for Controlled Substances and Ephedrine, Pseudoephedrine, and Phenylpropanolamine...Schedule I or II or the List I chemicals ephedrine, pseudoephedrine, and...

2012-12-04

314

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Procurement Quota for Controlled Substances and Ephedrine, Pseudoephedrine, and Phenylpropanolamine...Procurement Quota for Controlled Substances and Ephedrine, Pseudoephedrine, and Phenylpropanolamine...Schedule I or II or the List I chemicals ephedrine, pseudoephedrine, and...

2010-07-20

315

78 FR 9429 - Agency Information Collection Activities; Proposed Collection; Comments Requested: Application...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Procurement Quota for Controlled Substances and Ephedrine, Pseudoephedrine, and Phenylpropanolamine...Procurement Quota for Controlled Substances and Ephedrine, Pseudoephedrine, and Phenylpropanolamine...Schedule I or II or the List I chemicals ephedrine, pseudoephedrine, and...

2013-02-08

316

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

?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.

Simon, Nancy S.; Ingle, Sarah N.

2011-01-01

317

Atherosclerotic risks from chemicals: part II. A RASH analysis of in vitro and in vivo bioassay data to evaluate 45 potentially hazardous compounds.  

PubMed

As reviewed in the Part I companion manuscript by Basavaraju and Jones (Arch Environ Contam Toxicol), atherosclerosis and carcinogenesis may share some common mechanisms of toxicological action. On that hypothesis, standardized test data taken from the Registry of Toxic Effects of Chemical Substances (RTECS) were used to compute relative potency factors for chemical compounds associated with increased risk of atherosclerosis to humans. Potencies of the different compounds were computed relative to each of six reference compounds comprised of benzo(a)pyrene, nicotine, cisplatin, adriamycin, estrogen, and 2,3,7,8-tetrachlorodibenzo-p-dioxin. Reference-specific potencies were all converted to a common numerical scale adjusted to unit potency for B(a)P. Because the list of compounds contained several antibiotics, amino acids, hormones, chemotherapeutic agents, polynuclear aromatics, alkaloids, metals, and vitamins, the standardized estimates of potency varied significantly depending on which of the six reference compounds are considered as standards of comparison. For the n - 1 other substances. Estimates of relative potency, risk coefficients, and generalized risk equations are estimated for cigarette smoke condensate, dietary cholesterol, ethanol, and carbon disulfide. From data on atherosclerosis as a result of cigarette smoking, a tentative risk was estimated as Increased Relative Risk = S (mg/kg-day)-1 x dose (mg/kg-day) x RP, where the dose is chronic intake per kilogram of body weight per day, RP is the potency of the compound of interest relative to that of benzo(a)pyrene, and S is 0.83, 0.25, 0.20, or 13 depending on whether cigarette smoke, cholesterol, ethanol, or carbon disulfide epidemiological data were used as a standard of comparison. PMID:9601935

Jones, T D; Morris, M D; Basavaraju, S R

1998-07-01

318

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

PubMed Central

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

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

319

Prepared for presentation at the Pacifichem 2005 Conference December 15-20, 2005 Symposium: Sampling and Analysis of Chemical Warfare Agents for Antiterrorism Purposes Analysis of Chemical Agents and Toxic Industrial Chemicals using a Mobile Ion Trap Mass Spectrometer  

Microsoft Academic Search

The Block II Chemical Biological Mass Spectrometer (CBMS II) has been developed to provide a chemical and biological agent detection capability for military reconnaissance vehicles such as the Joint Services Lightweight Nuclear Biological Chemical Reconnaissance System and the Stryker Reconnaissance Vehicle. The chemical agent detection and identification capabilities of the instrument have been optimized for the analysis of persistent chemical

Kevin J. Hart; Marcus B. Wise; Rob R. Smith; Wayne H. Griest

2005-01-01

320

Microbiological and chemical quality of ground water used as a source of public supply in southern Missouri : Phase II, April-July, 1998  

USGS Publications Warehouse

The protection of public health through quality public ground-water systems is the responsibility of the U. S. Environmental Protection Agency and the State of Missouri, through the Missouri Department of Natural Resources, Public Drinking Water Program. Approximately 95 percent of the public-water supplies in Missouri use ground water as their source of drinking water through more than 3,700 public wells. Karst terrain, intensive agricultural operations, extensive numbers of on-site sewage systems, and poor well construction can lead to chemical and microbiological contamination of the contributing aquifers. Sitespecific studies and routine regulatory monitoring have produced information on the overall quality and potability of the State's public-drinking-water supplies, but little is known about the presence of viruses. The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, sampled 109 public-water supplies to characterize the physical, chemical, bacterial, and viral conditions in southern Missouri. During April to July 1998, these wells were sampled for nutrients, total organic carbon, optical brighteners, indicator bacteria, enteric viruses, and ribonucleic acid and somatic coli phages. These constituents indicate possible surface contamination of the sampled aquifer. Selection of the wells to be sampled depended on the age of the well (pre-1970), land use, geohydrology, and well construction. None of the physical or chemical constituents measured or analyzed exceeded Missouri's Drinking Water Standards set by the Public Drinking Water Program of the Missouri Department of Natural Resources. The majority of ammonia plus organic nitrogen, nitrite, and phosphorus concentrations were below the laboratory's minimum reporting levels. There were a greater number of detects above the minimum reporting level with respect to the nitrite plus nitrate, ammonia, orthophosphate, and total organic carbon concentrations. Analyses included comparing and contrasting the data by grouping according to well age and construction, karst type, geohydrology, soil type, and land use. There was little variation in well construction between selected wells. The results indicated several groupings of similar and dissimilar concentrations, most expected because of hydrological, physical, or land use differences. Dissolved oxygen values indicated distinct variation in the different groupings. There were significant differences in dissolved oxygen values between the secondary and non-karst areas, the Ozark confined and Ozark unconfined geohydrologic groups, and between agricultural and other land uses. In groupings by soil and geohydrology, the Missouri bootheel region differed with respect to ammonia, total organic carbon, and phosphorus when compared with the other groups. Less than 10 percent of the wells sampled tested positive for bacterial contamination. E. coli was the most frequently detected bacterium. The public wells at Monett and West Plains, Missouri, had plates with colonies too numerous to count for all three indicator bacteria. Further analyses by rRNA (ribosomal RiboNucleic Acid) hybridization techniques detennined that much of the bacteria present were from ruminant and human sources. No enteric viruses were detected in the 109 samples. Both ribonucleic acid and somatic coliphage were detected at two wells. One additional well had ribonucleic acid coliphage and another had somatic coliphage for a total of four wells with coliphage selects.

Femmer, Suzanne R.

2000-01-01

321

Prokudin-Gorskii Collection  

NSDL National Science Digital Library

Born in the town of Murom, Russia, Sergei Mikhailovich Prokudin-Gorskii was educated as a chemist and dedicated his life to the advancement of photography. He spent many years documenting the Russian Empire, and he was even outfitted with a railroad car-darkroom provided by Tsar Nicholas II. Along with this equipment, the Tsar also gave him access to certain restricted areas. After Prokudin-Gorskii died in 1944, his sons sold his collection of photographs, glass negatives, and sepia-tone prints to the Library of Congress in 1948. This site allows visitors to view these images, which include photographs of prominent religious structures, public works, industrial areas, and people in traditional dress. Visitors can also look over some of the thematic albums, which include his travels to Central Asia in 1911 and his journey along the Oka River south of Moscow in 1912.

322

The Margo Duggan Collection  

NSDL National Science Digital Library

Margo Duggan served in the United States Marine Corps during World War II, and after the war was over she started working as a civilian employee of the United States Trust Territories Administration in 1949. Over the next five years, she worked on a number of the Marshall, Mariana, and Caroline Islands and over at the Trust Territory headquarters in Hawai'i. She took a number of photographs during her time, and they document an important moment in the history of Micronesia. The University of Hawaii at Manoa's Library created this site, and visitors can view over 1,000 of the images she created. Curious visitors can read a brief biography of Duggan here and also look over the "About" page to learn more how the collection came to the university. The majority of the images here document life in Micronesia, and visitors can look through them via title, category, date, location, or reference number.

323

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)

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.

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

2009-03-01

324

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)

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.

O'Neill, H. St. C.

1991-04-01

325

Biotransformation of Endocrine Disrupting Compounds by Selected Phase I and Phase II Enzymes - Formation of Estrogenic and Chemically Reactive Metabolites by Cytochromes P450 and Sulfotransferases.  

PubMed

The endocrine system is a major communication system in the body and is involved in maintenance of the reproductive system, fetal development, growth, maturation, energy production, and metabolism,. The endocrine system responds to the needs of an organism by secreting a wide variety of hormones that enable the body to maintain homeostasis, to respond to external stimuli, and to follow various developmental programs. This occurs through complex signalling cascades,with multiple sites at which the signals can be regulated. Endocrine disrupting compounds (EDCs) affect the endocrine system by simulating the action of the naturally produced hormones, by inhibiting the action of natural hormones, by changing the function and synthesis of hormone receptors, or by altering the synthesis, transport, metabolism, and elimination of hormones. It has been established that exposure to environmental EDCs is a risk factor for disruption of reproductive development and oncogenesis in both humans and wildlife. For accurate risk assessment of EDCs, the possibility of bioactivation through biotransformation processes needs to be included since neglecting these mechanisms may lead to undervaluation of adverse effects on human health caused by EDCs and/or their metabolites. This accurate risk assessment should include: (1) possibility of EDCs to be bioactivated into metabolites with enhanced endocrine disruption (ED) effects, and (2) possibility of EDCs to be biotransformed into reactive metabolites that may cause DNA damage. Here, we present an overview of different metabolic enzymes that are involved in the biotransformation of EDCs. In addition, we describe how biotransformation by Cytochromes P450 (CYPs), human estrogen sulfotransferase 1E1 (SULT1E1) and selected other phase II enzymes, can lead to the formation of bioactive metabolites. This review mainly focuses on CYP- and SULT-mediated bioactivation of estrogenic EDCs and summarizes our views on this topic while also showing the importance of including bioactivation and biotransformation processes for improved risk assessment strategies. PMID:25245506

Reinen, J; Vermeulen, N P E

2015-01-01

326

Collection, Isolation and Culture of Marine Algae.  

ERIC Educational Resources Information Center

Methods of collecting, isolating, and culturing microscopic and macroscopic marine algae are described. Three different culture media list of chemicals needed and procedures for preparing Erdschreiber's and Provasoli's E. S. media. (BC)

James, Daniel E.

1984-01-01

327

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

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.

Ochoa, Carlos; Baumgardner, Darrel; Grutter, M.; Allan, James D.; Fast, Jerome D.; Rappengluck, B.

2012-10-31

328

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)

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 bada? chemicznej struktury powierzchni sorbentów organicznych takich jak: ?upiny orzecha w?oskiego, pestki ?liwek oraz ?uski s?onecznika z wykorzystaniem metody spektrometrii w podczerwieni (FTIR) oraz analizy elementarnej. W oparciu o uzyskane widma IR dokonano identyfikacji grup funkcyjnych obecnych na powierzchni tych materia?ów i okre?lono ich wp?yw na mechanizm sorpcji jonów Pb2+ z modelowych roztworów wodnych. Analiza elementarna wykaza?a, ?e spo?ród badanych sorbentów, najwi?ksz? zawarto?? w?gla (49,91%) i wodoru (5,93%) maj? pestki ?liwek. Najwi?cej azotu (1,59%) zawieraj? ?uszczyny s?onecznika (tabela 1). Zawarto?? siarki we wszystkich badanych materia?ach jest znikoma, dlatego nie uda?o si? jej oznaczy? t? metod?. Obecno?? pozosta?ych pierwiastków mo?e ?wiadczy? o istnieniu zarówno alifatycznych jak i aromatycznych po??cze? organicznych. Potwierdzeniem tego s? równie? zarejestrowane widma IR (rysunki 1-3). W oparciu o uzyskane wyniki mo?na przypuszcza? tak?e, i? udzia? procesu wymiany jonowej w sorpcji o?owiu z roztworów wodnych jest znacz?cy. ?wiadcz? o tym m.in. intensywno?ci pasm na widmach IR dla próbek badanych materia?ów po ich kontakcie z roztworami jonów Pb2+ (rysunki 4-6).

Bo??cka, Agnieszka; Bo??cki, Piotr; Sanak-Rydlewska, Stanis?awa

2014-03-01

329

Chemical Hygiene Plan The purpose of the Chemical Hygiene Plan (CHP) is to outline laboratory work  

E-print Network

Chemical Hygiene Plan I. Policy The purpose of the Chemical Hygiene Plan (CHP) is to outline community are protected from health hazards associated with chemicals with which they work. II. Authority The Chemical Hygiene Plan, required to comply with provisions of CCR Title 8 §5191 et al: A. Standard Operating

de Lijser, Peter

330

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)

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.

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

2011-04-01

331

Chemical Equations  

NSDL National Science Digital Library

It discusses the process of equation writing and balancing chemical equations in perspective of the chemical changes that take place during a reaction. This module is the third in a series on chemical reactions.

Carpi, Anthony

2003-03-27

332

Amazonian functional diversity from forest canopy chemical assembly.  

PubMed

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

Asner, Gregory P; Martin, Roberta E; Tupayachi, Raul; Anderson, Christopher B; Sinca, Felipe; Carranza-Jiménez, Loreli; Martinez, Paola

2014-04-15

333

Amazonian functional diversity from forest canopy chemical assembly  

PubMed Central

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

Asner, Gregory P.; Martin, Roberta E.; Tupayachi, Raul; Anderson, Christopher B.; Sinca, Felipe; Carranza-Jiménez, Loreli; Martinez, Paola

2014-01-01

334

Collective patterns and decision-making  

Microsoft Academic Search

Autocatalytic interactions between the members of an animal group or society, and particularly chemically or visually mediated allelomimesis, can be an important factor in the organisation of their collective activity. Furthermore, the interactions between the individuals and the environment allow different collective patterns and decisions to appear under different conditions, with the same individual behaviour. While most clearly demonstrable in

J. L. Deneubourg; S. Goss

1989-01-01

335

Chemical Heritage Foundation  

NSDL National Science Digital Library

"The Chemical Heritage Foundation (CHF) is dedicated to preserving and sharing the history and heritage of the chemical and molecular sciences, technologies, and allied industries." This Web site illustrates how chemistry has shaped our world. Students can discover the chemical history of Innovations and Industry, Ancients and Alchemists, and much more. Through the Online Exhibits, visitors can view the pictures of Walter J. Hamer's collection of early batteries. In the Classroom Resources, educators will find online tools discussing molecular science and pharmaceutical achievers and many Chemistry Web Quests including Evidence for Atoms and The Great MTBE Controversy. Graduate students may want to take advantage of the many fellowships offered on the site.

2003-01-01

336

75 FR 8335 - Agency Information Collection Activities; Proposed Renewal of Several Currently Approved...  

Federal Register 2010, 2011, 2012, 2013, 2014

...affected by this collection. II. What...copies of any technical information and/or data...improve the collection activity...burden for this collection of information is estimated...as aggregate statistics....

2010-02-24

337

78 FR 16694 - Chemical Security Assessment Tool (CSAT)  

Federal Register 2010, 2011, 2012, 2013, 2014

...SECURITY [Docket No. DHS-2012-0058] Chemical Security Assessment Tool (CSAT) AGENCY...extension of Information Collection Request, Chemical Security Assessment Tool for an additional...commercial or financial information, Chemical-terrorism Vulnerability...

2013-03-18

338

Safely dispose of common household chemicals Monongalia County  

E-print Network

Safely dispose of common household chemicals Monongalia County Household Hazardous Waste Collection Batteries (All types) Hydrochloric Acid Lawn & Garden Chemicals Drain/Oven/Floor cleaners Fluorescent Bulbs Photo Chemicals Mercury Thermometers Oil Filters (used) Propane Cylinders Rust Preventatives Septic

Mohaghegh, Shahab

339

78 FR 16692 - Chemical Facility Anti-Terrorism Standards (CFATS)  

Federal Register 2010, 2011, 2012, 2013, 2014

...DHS-2012-0059] Chemical Facility Anti-Terrorism Standards (CFATS) AGENCY: National...Collection Request, Chemical Facility Anti-Terrorism Standards (CFATS) for an additional...or financial information, Chemical-terrorism Vulnerability Information...

2013-03-18

340

Properties of the Molecular Clump and the Associated Ultracompact H II Region in the Gas Shell of the Expanding H II Region Sh 2-104  

NASA Astrophysics Data System (ADS)

We study the physical and chemical properties of the molecular clump hosting a young stellar cluster, IRAS~20160+3636, which is believed to have formed via the ``collect and collapse'' process. Physical parameters of the UC H II region associated with the embedded cluster are measured from the radio continuum observations. This source is found to be a typical Galactic UC H II region, with a B0.5 type exciting star, if it is ionized by a single star. We derive a CN/HCN abundance ratio larger than 1 over this region, which may suggest that this clump is being affected by the UV radiation from the H II region.

Minh, Young Chol; Kim, Kee-Tae; Yan, Chi-Hung; Park, Yong-Sun; Lee, Seokho; Lal, Dharam Vil; Hasegawa, Tatsuhiko; Zhang, X. Z.; Kuan, Yi-Jeng

2014-10-01

341

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

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…

Shaw, W. M., Jr.

1991-01-01

342

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

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…

Gibson, Paul R.

343

76 FR 66084 - Agency Information Collection Activities; Proposed Collection, Comments Requested: Application...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Requested: Application for Import Quota for Ephedrine, Pseudoephedrine, and Phenylpropanolamine...Collection: Application for Import Quota for Ephedrine, Pseudoephedrine, and Phenylpropanolamine...desire to import the List I chemicals ephedrine, pseudoephedrine, and...

2011-10-25

344

77 FR 62531 - Agency Information Collection Activities; Proposed Collection; Comments Requested: Application...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Requested: Application for Import Quota for Ephedrine, Pseudoephedrine, and Phenylpropanolamine...Collection: Application for Import Quota for Ephedrine, Pseudoephedrine, and Phenylpropanolamine...desire to import the List I chemicals ephedrine, pseudoephedrine, and...

2012-10-15

345

75 FR 54653 - Agency Information Collection Activities: Proposed Collection; Comments Requested; Application...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Requested; Application for Import Quota for Ephedrine, Pseudoephedrine, and Phenylpropanolamine...Collection: Application for Import Quota for Ephedrine, Pseudoephedrine, and Phenylpropanolamine...desire to import the List I chemicals ephedrine, pseudoephedrine, and...

2010-09-08

346

77 FR 1085 - Agency Information Collection Activities: Proposed Collection; Comments Requested: Application...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Requested: Application for Import Quota for Ephedrine, Pseudoephedrine, and Phenylpropanolamine...Collection: Application for Import Quota for Ephedrine, Pseudoephedrine, and Phenylpropanolamine...desire to import the List I chemicals ephedrine, pseudoephedrine, and...

2012-01-09

347

77 FR 47667 - Agency Information Collection Activities: Proposed Collection; Comments Requested: Application...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Requested: Application for Import Quota for Ephedrine, Pseudoephedrine, and Phenylpropanolamine...Collection: Application for Import Quota for Ephedrine, Pseudoephedrine, and Phenylpropanolamine...desire to import the List I chemicals ephedrine, pseudoephedrine, and...

2012-08-09

348

75 FR 38834 - Agency Information Collection Activities: Proposed Collection; Comments Requested: Application...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Requested: Application for Import Quota for Ephedrine, Pseudoephedrine, and Phenylpropanolamine...Collection: Application for Import Quota for Ephedrine, Pseudoephedrine, and Phenylpropanolamine...desire to import the List I chemicals ephedrine, pseudoephedrine, and...

2010-07-06

349

A Chemical Stain for Identifying Arsenic-Treated Wood  

E-print Network

A Chemical Stain for Identifying Arsenic-Treated Wood (FINAL) Submitted June 23, 2006 Amy Omae-TREATED WOOD II.1 Applying Phosphate Stains to Arsenate Stains 7 II.2 A Potential Arsenic-Test Kit 14 II.3 Whole Wood Application of the Modified Stannous Chloride Stain 19 II.4 Other Attempted Stain

Florida, University of

350

Quasi-Chemical Viscosity Model for Fully Liquid Slag in the Al2O3-CaO-MgO-SiO2 System. Part II: Evaluation of Slag Viscosities  

NASA Astrophysics Data System (ADS)

A model is presented that enables viscosities to be predicted reliably over the whole range of compositions and temperatures in the Al2O3-CaO-MgO-SiO2 slag system above liquidus in the temperature range from 1543 K to 2643 K (1270 °C to 2370 °C). Experimental procedures and data from the studies reported in the literature have been collected and critically reviewed with particular attention to the viscometry methods and possible contamination of slag samples to select reliable data points for further model development. Relevant revised formalism to describe the complex viscosity trends including charge-compensation effect of the Ca2+ and Mg2+ cations on the formation of tetrahedrally coordinated Al3+ was introduced. Parameters of the quasi-chemical viscosity model have been optimized to reproduce within experimental uncertainties most of the selected experimental data in the Al2O3-CaO-MgO-SiO2 system and all subsystems. This study is part of the overall development of the self-consistent viscosity model of the Al2O3-CaO-FeO-Fe2O3- MgO-Na2O-SiO2 multicomponent slag system.

Suzuki, Masanori; Jak, Evgueni

2013-12-01

351

Analysis of gasifier samples collected with a high-temperature/high-pressure cascade impactor: electron spectroscopy for chemical analysis, energy dispersive x-ray analysis, and scanning electron microscopy  

SciTech Connect

A particulate sample was collected from the process stream of a low Btu gasifier in a cascade impactor operated at 400/sup 0/C and 10-12 atmospheres pressure. Stainless stell shim stock was used as collection substrate. The sample, which weighed less than 1 mg, was successfully mounted and examined by ESCA, EDXA, and SEM. The ESCA spectra of the samples and of blank impactor plates were taken before and after ion etching. The SEM and EDXA data were obtained for samples still on the impactor plate and for a sample transferred from the plate to a carbon, oxygen, and sulphur, but no significant peaks for alkali metals or calcium normally found on the surface of coal combustion fly ash. The EDXA data demonstrated that the core of the particles contained Al, Si, Mg, Ca, and S. Method of sample manipulation are described.

Rothenberg, S.J.; Brundle, C.R.; Denee, P.B.; Carpenter, R.L.; Newton, G.J.; Henderson, R.F.

1984-09-01

352

CHEMICAL TIME-SERIES SAMPLING  

EPA Science Inventory

The rationale for chemical time-series sampling has its roots in the same fundamental relationships as govern well hydraulics. Samples of ground water are collected as a function of increasing time of pumpage. The most efficient pattern of collection consists of logarithmically s...

353

Collection Directions: The Evolution of Library Collections and Collecting  

ERIC Educational Resources Information Center

This article takes a broad view of the evolution of collecting behaviors in a network environment and suggests some future directions based on various simple models. The authors look at the changing dynamics of print collections, at the greater engagement with research and learning behaviors, and at trends in scholarly communication. The goal is…

Dempsey, Lorcan; Malpas, Constance; Lavoie, Brian

2014-01-01

354

Dynamic biosorption of Zn(II) and Cu(II) using pretreated Rosa gruss an teplitz (red rose) distillation sludge  

Microsoft Academic Search

This work presented conditions for Cu(II) and Zn(II) removal using native, physically and chemically pretreated Rosa gruss an teplitz (red rose) distillation sludge. Cu(II) and Zn(II) sorption was found dependent on solution pH, biosorbent dose, biosorbent particle size, shaking speed, temperature, initial concentration of metal ions being sorbed and contact time. Physical and chemical pretreatments of biomass resulted in an

Haq Nawaz Bhatti; Rabia Khalid; Muhammad Asif Hanif

2009-01-01

355

Chemical and Biological Weapons of Mass Destruction  

NSDL National Science Digital Library

Chemical warfare began in prehistoric times with the use of such weapons as poisoned arrows. However, World War I was the beginning of modern-day chemical warfare. The birth of biological warfare evolved during World War II. As a result, mankind has been plagued with chemical and biological weapons of mass destruction. This chapter provides a historical account of chemical and biological warfare, and its detrimental impact on society.

Slesnick, Irwin

2004-01-01

356

University Endowment Lands Collection /  

E-print Network

University Endowment Lands Collection / various collectors Compiled by Christopher Hives and Erwin of the University Endowment Lands series o University Marine Foreshore Development Committee File List Catalogue entry (UBC Library catalogue) #12;Collection Description University Endowment Lands Collection / various

Handy, Todd C.

357

Transportation Management Research Collection /  

E-print Network

Transportation Management Research Collection / Karl Ruppenthal (collector) Compiled by Graham D;Collection Description Transportation Management Research Collection / Karl Ruppenthal (collector). ­ 1946 in the UBC Faculty of Commerce and Business Administration and Director of the Centre for Transportation

Handy, Todd C.

358

Chemical Communication  

NSDL National Science Digital Library

A concise lesson about chemical communication in insects covering both semio and info chemicals. The site includes a short video of grape root borer moths using sex pheromone. Further links on the take the user to visual and auditory communication.

0000-00-00

359

Detection of Chemical\\/Biological Agents and Stimulants using Quadrupole Ion Trap Mass Spectrometry  

Microsoft Academic Search

Detection of Chemical\\/Biological Agents and Simulants A new detector for chemical and biological agents is being developed for the U. S. Army under the Chemical and Biological Mass Spectrometer Block II program. The CBMS Block II is designed to optimize detection of both chemical and biological agents through the use of direct sampling inlets [I], a multi- ported sampling valve

S. H. Harmon; K. J. Hart; A. A. Vass; M. B. Wise; D. A. Wolf

1999-01-01

360

National Historic Chemical Landmarks  

NSDL National Science Digital Library

The American Chemical Society (ACS) displays the key roles chemists played in "expanding the frontiers of knowledge, advancing medicine and industry, and creating products from aspirin to zippers" at this website. Users can find clear summaries and images of the places, discoveries, and achievements that have been designated landmarks by ACS members and an international committee. Within many of the biographies, educators can find links to teaching guides and activities. Individuals that know of an unrecognized important element of the chemical heritage can learn how to nominate the site, artifact, or collection.

2007-05-18

361

Chemical engineer  

NSDL National Science Digital Library

What do chemical engineers actually do? This is the introductory page for a set of materials about chemical engineering as a career. Here the job of a chemical engineer is defined and described. Chemical engineers often work with industrial manufacturing processes that involve a mix of chemistry and engineering. In the rest of the resource, students can examine a specialized job title associated with chemical engineering: process engineer. Students can view a five-minute video clip of the process engineer as he works in a fertilizer plant making ammonia and urea. Students follow the engineer around the plant as he checks pressure in chemical lines. Students get a glimpse of the inside of a furnace during the chemical-making process. Copyright 2005 Eisenhower National Clearinghouse

Project, Iowa P.

2002-01-01

362

Chemical cytometry on a picoliter-scale integrated microfluidic chip  

E-print Network

Chemical cytometry on a picoliter-scale integrated microfluidic chip Hongkai Wu, Aaron Wheeler the chemical contents of a single cell (chemical cytometry). The device is designed to accomplish four different functions: (i) cell handling, (ii) metering and delivering of chemical reagents, (iii) cell lysis

Zare, Richard N.

363

75 FR 55359 - Notice of Information Collection  

Federal Register 2010, 2011, 2012, 2013, 2014

...Unlike traditional graduate research or teaching assistantships...what program elements are most effective in fostering interdisciplinary collaborations, research, and learning. Specifically, the evaluation...inform decisions about future project modifications. II. Method...participated in the five most recent cohorts (2005-2009...collection.......

2010-09-10

364

78 FR 55099 - Established Aggregate Production Quotas for Schedule I and II Controlled Substances and...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Annual Needs for the List I Chemicals Ephedrine, Pseudoephedrine, and Phenylpropanolamine...annual needs for the List I chemicals ephedrine, pseudoephedrine, and phenylpropanolamine...I and II and for the List I chemicals ephedrine, pseudoephedrine, and...

2013-09-09

365

77 FR 59980 - Established Aggregate Production Quotas for Schedule I and II Controlled Substances and...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Annual Needs for the List I Chemicals Ephedrine, Pseudoephedrine, and Phenylpropanolamine...annual needs for the list I chemicals ephedrine, pseudoephedrine, and phenylpropanolamine...I and II and for the list I chemicals ephedrine, pseudoephedrine, and...

2012-10-01

366

Leveled Garbage Collection  

Microsoft Academic Search

Generational garbage collection (GGC) is one of the most popular garbage collection techniques. GGC gains a performance advantage by performing mi- nor collections on the younger objects in the heap, reducing the number of major collections of the whole heap. A promotion policy determines when an object moves from the younger generation to the older. The design of GGC has

Guanshan Tong; Michael J. O'donnell

2001-01-01

367

21 CFR 1313.24 - Waiver of 15-day advance notice for chemical exporters.  

Code of Federal Regulations, 2010 CFR

...false Waiver of 15-day advance notice for chemical exporters. 1313.24 Section 1313.24...IMPORTATION AND EXPORTATION OF LIST I AND LIST II CHEMICALS Exportation of Listed Chemicals § 1313.24 Waiver of 15-day advance...

2010-04-01

368

21 CFR 1313.24 - Waiver of 15-day advance notice for chemical exporters.  

Code of Federal Regulations, 2013 CFR

...false Waiver of 15-day advance notice for chemical exporters. 1313.24 Section 1313.24...IMPORTATION AND EXPORTATION OF LIST I AND LIST II CHEMICALS Exportation of Listed Chemicals § 1313.24 Waiver of 15-day advance...

2013-04-01

369

21 CFR 1313.24 - Waiver of 15-day advance notice for chemical exporters.  

Code of Federal Regulations, 2011 CFR

...false Waiver of 15-day advance notice for chemical exporters. 1313.24 Section 1313.24...IMPORTATION AND EXPORTATION OF LIST I AND LIST II CHEMICALS Exportation of Listed Chemicals § 1313.24 Waiver of 15-day advance...

2011-04-01

370

21 CFR 1313.24 - Waiver of 15-day advance notice for chemical exporters.  

Code of Federal Regulations, 2012 CFR

...false Waiver of 15-day advance notice for chemical exporters. 1313.24 Section 1313.24...IMPORTATION AND EXPORTATION OF LIST I AND LIST II CHEMICALS Exportation of Listed Chemicals § 1313.24 Waiver of 15-day advance...

2012-04-01

371

21 CFR 1313.24 - Waiver of 15-day advance notice for chemical exporters.  

Code of Federal Regulations, 2014 CFR

...false Waiver of 15-day advance notice for chemical exporters. 1313.24 Section 1313.24...IMPORTATION AND EXPORTATION OF LIST I AND LIST II CHEMICALS Exportation of Listed Chemicals § 1313.24 Waiver of 15-day advance...

2014-04-01

372

Phylogeny and taxonomy of a diverse collection of Bradyrhizobium strains based on multilocus sequence analysis of the 16S rRNA gene, ITS region and glnII, recA, atpD and dnaK genes.  

PubMed

The genus Bradyrhizobium encompasses a variety of bacteria that can live in symbiotic and endophytic associations with legumes and non-legumes, and are characterized by physiological and symbiotic versatility and broad geographical distribution. However, despite indications of great genetic variability within the genus, only eight species have been described, mainly because of the highly conserved nature of the 16S rRNA gene. In this study, 169 strains isolated from 43 different legumes were analysed by rep-PCR with the BOX primer, by sequence analysis of the 16S rRNA gene and the 16S-23S rRNA intergenic transcribed spacer (ITS) and by multilocus sequence analysis (MLSA) of four housekeeping genes, glnII, recA, atpD and dnaK. Considering a cut-off at a level of 70 % similarity, 80 rep-PCR profiles were distinguished, which, together with type strains, were clustered at a very low level of similarity (24 %). In both single and concatenated analyses of the 16S rRNA gene and ITS sequences, two large groups were formed, with bootstrap support of 99 % in the concatenated analysis. The first group included the type and/or reference strains of Bradyrhizobium japonicum, B. betae, B. liaoningense, B. canariense and B. yuanmingense and B. japonicum USDA 110, and the second group included strains related to Bradyrhizobium elkanii USDA 76(T), B. pachyrhizi PAC48(T) and B. jicamae PAC68(T). Similar results were obtained with MLSA of glnII, recA, atpD and dnaK. Greatest variability was observed when the atpD gene was amplified, and five strains related to B. elkanii revealed a level of variability never reported before. Another important observation was that a group composed of strains USDA 110, SEMIA 5080 and SEMIA 6059, all isolated from soybean, clustered in all six trees with high bootstrap support and were quite distinct from the clusters that included B. japonicum USDA 6(T). The results confirm that MLSA is a rapid and reliable way of providing information on phylogenetic relationships and of identifying rhizobial strains potentially representative of novel species. PMID:19628593

Menna, Pâmela; Barcellos, Fernando Gomes; Hungria, Mariangela

2009-12-01

373

E-Collections  

NSDL National Science Digital Library

This new mailing list is designed for users involved in developing electronic collections of information. Suggested topics to be discussed include "collection development strategies, identifying/assessing/acquiring content, collaborative collecting at local/regional/national levels, and other topical aspects of electronic collection management." To join, send an email to: mailbase@mailbase.ac.uk In the body of the message, type: join e-collections yourfirstname yourlastname

Lee, Stuart.; Wise, Alicia.

374

Chemical warfare - biological defense research obligations. Annual report, 1 October 1985-30 September 1986  

SciTech Connect

Partial Contents include: Chemical Research; Lethal Chemical Program; Incapacitating Chemical Program; Defensive Equipment Program; Physical Protection Investigations; Warning and Detection Investigations; Medical Defense Against Chemical Agents; Chemical Decontaminating Material; Collective Protection Concepts; Chemical Detection and Warning Material; Medical Chemical Defense Life Support Material; Training Support; Simulant Test Support; Management and Support; Biological Defense Research; Medical Defense Against Biological Warfare.

Not Available

1986-09-30

375

Chemical burns  

PubMed Central

Objectives To report a burn unit’s experience with chemical burns and to discuss the fundamental principles in managing chemical burns. Design A chart review. Setting A burn centre at a major university-affiliated hospital. Patients Twenty-four patients with chemical burns, representing 2.6% of all burn admissions over an 8-year period at the Ross Tilley Regional Adult Burn Centre. Seventy-five percent of the burn injuries were work-related accidents. Chemicals involved included hydrofluoric acid, sulfuric acid, black liquor, various lyes, potassium permanganate and phenol. Results Fourteen patients required excision and skin grafting. Complications were frequent and included ocular chemical contacts, wound infections, tendon exposures, toe amputation and systemic reactions from absorption of chemical. One patient died from a chemical scald burn to 98% of the body surface area. Conclusions The key principles in the management of chemical burns include removal of the chemical, copious irrigation, limited use of antidotes, correct estimation of the extent of injury, identification of systemic toxicity, treatment of ocular contacts and management of chemical inhalation injury. Individualized treatment is emphasized. PMID:8640619

Cartotto, Robert C.; Peters, Walter J.; Neligan, Peter C.; Douglas, Leith G.; Beeston, Jeff

1996-01-01

376

NOAA Ship Delaware II Delaware II was designed for  

E-print Network

-jet dredge powered by an electric pump on the dredge. Marine Mammals, Large Whale Biology: examine variety of physical, chemical and biological studies. Delaware II has worked with other U.S. Government: to assess the impact of changing biological and physical properties of the Northeast continental shelf

377

Physical Chemistry II Spring 2007 Physical Chemistry II  

E-print Network

Chapter 19 Heat, work, and thermodynamic energy. The First Law and chemical reactions. III. Entropy equilibrium, equations of state, gases & liquids, intermolecular forces. II. First Law of thermodynamics and the Second Law of thermodynamics Chapters 20­21 Thermodynamic and statistical interpretations of entropy

378

77 FR 12871 - Agency Information Collection Activities: Comment Request  

Federal Register 2010, 2011, 2012, 2013, 2014

...approved information collection (IC) for the ``North American Breeding Bird Survey, (1 USGS form).'' As required by the Paperwork...sensitive'' nature are asked. II. Data Title: North American Breeding Bird Survey. OMB Control Number: 1028-0079. Form...

2012-03-02

379

Chemical microsensors  

DOEpatents

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

Li, DeQuan (Los Alamos, NM); Swanson, Basil I. (Los Alamos, NM)

1995-01-01

380

Kraith Collected Issue 1  

E-print Network

of Star Fleet Security. IIGentlemen, II Pesin said, IIbe seated." He looked from Ssarsun to Kirk and finally to Spack where his gaze became unreadable ?. After a long thirty seconds, he said, "Conunander Spock. 1t "Yes, sir .. 11 lilt..., you understand the referant?" IIYes, sir. II lIyoU know the planet in question?1I "Yes, sir, There's a vulcan archeological expedition there. II "Right. They recently lost six memhers in an accident ??? 11 "That explains it... Spack nodded...

Lichtenberg, Jacqueline; Multiple Contributors

1974-01-01

381

University of Washington Digital Collections: Menus Collection  

NSDL National Science Digital Library

If you ever wondered what entrees were served onboard the SS Alaska on July 26, 1938, you need wonder no more. This delightful and hunger-inducing collection of menus was created by the staff at the University of Washington Libraries Digital Collection project, and it contains over 650 menus from the Puget Sound area, including offerings from such venerable institutions as the Space Needle Restaurant and Ivar's Acres of Clams. Visitors should start things off by watching the short video they have created which offers a quick tour through some menu highlights. After that, browse through the collection by subject, or click one of the thematic collections, such as "Hotel Menus" and "Fifties Menus". Still wondering about those entrees on the good ship SS Alaska? They included Smothered Belgian Hare Southern Style and Coconut Fritters with Custard Sauce.

382

Photosystem II  

SciTech Connect

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."

James Barber

2005-04-28

383

CHEMICAL ENGINEERING AND MANUFACTURING CHEMICAL ENGINEERING  

E-print Network

CHEMICAL ENGINEERING AND MANUFACTURING CHEMICAL ENGINEERING Objective Chemical Engineers of chemicals. This lesson introduces students to one component of chemical engineering: food processing, and a chemical engineer 2. How chemical engineers are involved in food production 3. That chemical engineers need

Provancher, William

384

Chemical Name  

Cancer.gov

Attachment III Chemical Quick Reference Chart for Minors Chemical Name Select Carcinogen Reproductive Toxin LD50 < 50 mg/kg (oral rat) LD50 < 200 mg/kg for 24 hours or less (dermal rabbit) LC50 < 200 ppm or 2 mg/L for one hour (inhalation rat)

385

Chemical sensors  

DOEpatents

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

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

1991-01-01

386

Chemical sensors  

DOEpatents

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

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

1991-07-02

387

Chemical geodynamics  

Microsoft Academic Search

Consideration is given to the following three principal boundary conditions relating to the nature and development of chemical structure in the earth's mantle: (1) inferred scale lengths for mantle chemical heterogeneities, (2) interrelationships of the various isotopic tracers, and (3) the bulk composition of the earth. These boundary conditions are integrated with geophysical constraints in order to evaluate models for

A. Zindler; S. R. Hart

1986-01-01

388

Chemical Reactions  

NSDL National Science Digital Library

We don't often stop to think about it, but underlying many of our everyday activities are chemical reactions. From the cooking of an egg to the growth of a child, chemical reactions make things happen. Although many of the reactions that support our lives

National Science Teachers Association (NSTA)

2009-05-01

389

Chemical preconcentrator  

DOEpatents

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

Manginell, Ronald P. (Albuquerque, NM); Frye-Mason, Gregory C. (Cedar Crest, NM)

2001-01-01

390

Collecting Samples for Testing  

MedlinePLUS

... will be limited. Search Help? Collecting Samples for Testing Share this page: Was this page helpful? Introduction | ... From Within | Conclusion | Sources Overview Today's technologies allow testing on an impressively wide variety of samples collected ...

391

Earthquake Photo Collections  

NSDL National Science Digital Library

This collection of earthquake photos, published by the United States Geological Survey (USGS), contains links to photos for specific earthquakes, as well as links to other USGS image collections and non-USGS collections. Highlights include photos from the 1906 San Francisco earthquake, the 1989 Loma Prieta earthquake, and the 1994 earthquake in Northridge, California. There is also a link to the USGS photo library (general geologic topics), and links to collections published by universities, museums, other government organizations, and professional organizations.

392

75 FR 48642 - Proposed Information Collection; Comment Request; Tag Recapture Card  

Federal Register 2010, 2011, 2012, 2013, 2014

...Collection; Comment Request; Tag Recapture Card AGENCY: National Oceanic and Atmospheric...II. Method of Collection The recapture cards will be sent out to the constituents who will fill in the cards with the pertinent information when...

2010-08-11

393

Select Collections, Inc  

Microsoft Academic Search

Select Collections sounds like the name of a fancy dress shop. Actually, in this case, it’s a collection agency whose credit manager has asked a summer intern to apply her knowledge of regression analysis to forecast the amount the company will collect from 3,570 delinquent accounts. The intern must submit her forecasts in a contest with other interns to see

Phillip Pfeifer; Thomas Pomroy; William Scherer

394

Hazardous Educational Waste Collections in Illinois.  

ERIC Educational Resources Information Center

This report presents the status of programs designed to manage hazardous educational waste collections in secondary schools in the state of Illinois. Laboratory wastes, expired chemicals, unstable compounds, and toxic or flammable materials are accounted for in this document. The report contains an executive summary, a review of Illinois statutes…

Illinois State Environmental Protection Agency, Springfield.

395

I. Cognitive and instructional factors relating to students' development of personal models of chemical systems in the general chemistry laboratory II. Solvation in supercritical carbon dioxide/ethanol mixtures studied by molecular dynamics simulation  

NASA Astrophysics Data System (ADS)

Part I. Students' participation in inquiry-based chemistry laboratory curricula, and, in particular, engagement with key thinking processes in conjunction with these experiences, is linked with success at the difficult task of "transfer"---applying their knowledge in new contexts to solve unfamiliar types of problems. We investigate factors related to classroom experiences, student metacognition, and instructor feedback that may affect students' engagement in key aspects of the Model-Observe-Reflect-Explain (MORE) laboratory curriculum - production of written molecular-level models of chemical systems, describing changes to those models, and supporting those changes with reference to experimental evidence---and related behaviors. Participation in introductory activities that emphasize reviewing and critiquing of sample models and peers' models are associated with improvement in several of these key aspects. When students' self-assessments of the quality of aspects of their models are solicited, students are generally overconfident in the quality of their models, but these self-ratings are also sensitive to the strictness of grades assigned by their instructor. Furthermore, students who produce higher-quality models are also more accurate in their self-assessments, suggesting the importance of self-evaluation as part of the model-writing process. While the written feedback delivered by instructors did not have significant impacts on student model quality or self-assessments, students' resubmissions of models were significantly improved when students received "reflective" feedback prompting them to self-evaluate the quality of their models. Analysis of several case studies indicates that the content and extent of molecular-level ideas expressed in students' models are linked with the depth of discussion and content of discussion that occurred during the laboratory period, with ideas developed or personally committed to by students during the laboratory period being likely to appear in students' post-laboratory refined models. These discussions during the laboratory period are primarily prompted by factors external to the students or their laboratory groups such as questions posed by the instructor or laboratory materials. Part II. Solvation of polar molecules within non-polar supercritical carbon dioxide is often facilitated by the introduction of polar cosolvents as entrainers, which are believed to preferentially surround solute molecules. Molecular dynamics simulations of supercritical carbon dioxide/ethanol mixtures reveal that ethanol molecules form hydrogen-bonded aggregates of varying sizes and structures, with cyclic tetramers and pentamers being unusually prevalent. The dynamics of ethanol molecules within these mixtures at a range of thermodynamic conditions can largely be explained by differences in size and structure in these aggregates. Simulations that include solute molecules reveal enhancement of the polar cosolvent around hydrogen-bonding sites on the solute molecules, corroborating and helping to explain previously reported experimental trends in solute mobility.

Anthony, Seth

396

CLIC Digital Collections  

NSDL National Science Digital Library

The CLIC Digital Collections bring together digital collections from eight different colleges around the Twin Cities, including Hamline University and Macalester College. Here, visitors can take advantage of several collections from Macalester, including Macalester Views and Oral History Collections. The oral histories offer insight into the goings on around campus over the past several decades as told by faculty, students, and others. The Views provide over 150 items that tell the story of Macalester students in all different settings, including Ghana, El Paso, and Fiji. The site also includes a wonderful Fine Art Collection from St. Catherine University that connects students, faculty, staff, and the general public to meaningful works of art.

397

The Rochambeau Map Collection  

NSDL National Science Digital Library

Military maps continue to fascinate the general public, and this collection from the American Memory Project at the Library of Congress will be of great interest to those with a penchant for American history and cartography. This particular collection contains maps collected and used by Jean Baptiste Donatien de Vimeur, comte de Rochambeau during the American Revolution. Rochambeau served as the commander in chief of the French forces during the Revolution, and this collection contains numerous printed maps that cover much of the continent of North America. Visitors to the collection can search the collection by title, creator, subject, and geographic place. The collection has a number of highlights, including a number of views of Quebec City, maps of military fortifications, and the defenses of the city of Boston.

398

From organized internal traffic to collective navigation of bacterial swarms  

NASA Astrophysics Data System (ADS)

Bacterial swarming resulting in collective navigation over surfaces provides a valuable example of cooperative colonization of new territories. The social bacterium Paenibacillus vortex exhibits successful and diverse swarming strategies. When grown on hard agar surfaces with peptone, P. vortex develops complex colonies of vortices (rotating bacterial aggregates). In contrast, during growth on Mueller-Hinton broth gelled into a soft agar surface, a new strategy of multi-level organization is revealed: the colonies are organized into a special network of swarms (or ‘snakes’ of a fraction of millimeter in width) with intricate internal traffic. More specifically, cell movement is organized in two or three lanes of bacteria traveling between the back and the front of the swarm. This special form of cellular logistics suggests new methods in which bacteria can share resources and risk while searching for food or migrating into new territories. While the vortices-based organization on hard agar surfaces has been modeled before, here, we introduce a new multi-agent bacterial swarming model devised to capture the swarms-based organization on soft surfaces. We test two putative generic mechanisms that may underlie the observed swarming logistics: (i) chemo-activated taxis in response to chemical cues and (ii) special align-and-push interactions between the bacteria and the boundary of the layer of lubricant collectively generated by the swarming bacteria. Using realistic parameters, the model captures the observed phenomena with semi-quantitative agreement in terms of the velocity as well as the dynamics of the swarm and its envelope. This agreement implies that the bacteria interactions with the swarm boundary play a crucial role in mediating the interplay between the collective movement of the swarm and the internal traffic dynamics.

Ariel, Gil; Shklarsh, Adi; Kalisman, Oren; Ingham, Colin; Ben-Jacob, Eshel

2013-12-01

399

The Rise of Southeast Asian Collections and the Donn V. Hart Collection at Northern Illinois University.  

ERIC Educational Resources Information Center

Southeast Asian Studies programs arose in American higher education after World War II, creating special problems for university and research libraries. The major problems were and still are acquisition and cataloging. The Donn V. Hart Southeast Asian Collection, founded in 1963, is unique in Illinois and contains 21,000 Indonesian; 15,000 Thai;…

Olson, Chalermsee

1996-01-01

400

75 FR 63860 - Agency Information Collection Activities: Proposed Collection; Comments Requested  

Federal Register 2010, 2011, 2012, 2013, 2014

...DEPARTMENT OF JUSTICE Bureau of Alcohol, Tobacco, Firearms and Explosives...Justice (DOJ), Bureau of Alcohol, Tobacco, Firearms and Explosives...proposed information collection instrument with instructions or additional...II (5330.3B). Bureau of Alcohol, Tobacco, Firearms and...

2010-10-18

401

BIOLOGIC SAMPLE COLLECTION AND ANALYSIS PLANS: Collection  

E-print Network

Center for Infectious Diseases 1 #12;Cross-sectional Exposure Assessment of Environmental Contaminants should be washed with soap and water. - Do not remove the cap from cup until ready to void. - Collect bottle with the green screw cap. - Place the participant's ID label on each container. SHIPPING LIST

402

Chemical lasers  

NASA Astrophysics Data System (ADS)

Fundamental properties of chemical lasers are presented and principal systems described in the nonclassified literature are reviewed. The fundamentals of the production of inversion in molecular gases by chemical processes are discussed. Iodine, HF, and DF lasers are described. The chemical reaction in the pulsed chemical HF and DF lasers is introduced by a transverse electrical discharge. In spite of the high dissociation energy and the electronegative properties which are unfavorable for a stable discharge regime, SF6 is used as fluorine source for safety reasons. The pulse energies reach 26 J in agreement with estimated values. The advantage of the present system is that is can also operate as CO2 laser in the TEA mode. The radiation of DF lasers is particularly interesting for military near-Earth applications because of its good transmission properties in the atmosphere.

Hugenschmidt, M.; Wey, J.

1985-05-01

403

Chemical Peeling  

MedlinePLUS

... the skin heals can cause unwanted side effects ranging from infection to scarring. If you have any ... Tanzi EL and Alster TS. “Skin Resurfacing: Ablative Lasers, Chemical Peels, and Dermabrasion.” In: Wolff K, Goldsmith ...

404

Chemical Emergency  

MedlinePLUS

... can be recycled, which is better for our environment. If you have questions about how to dispose of a chemical, call the facility or the environmental or recycling agency to learn the proper method of disposal. ...

405

Unnecessary Chemicals  

ERIC Educational Resources Information Center

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

Johnson, Anita

1978-01-01

406

Chemical sensors  

DOEpatents

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

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

1992-06-09

407

Chemical sensors  

DOEpatents

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

Lowell, Jr., James R. (Bend, OR); Edlund, David J. (Bend, OR); Friesen, Dwayne T. (Bend, OR); Rayfield, George W. (Eugene, OR)

1992-01-01

408

II. The Community Organizes........................................................................................................3  

E-print Network

Acknowledgements......................................................................................................................... ii Executive Summary....................................................................................................................... iii

Starflower Foundation; Ella Elman; Ecologist Contents

409

Handling Hazardous Chemical Waste A quick reference guide  

E-print Network

Handling Hazardous Chemical Waste A quick reference guide Hazardous wastes are undesired containers to collect chemical waste should be labeled with a yellow "Hazardous Waste Container" label, reactive, corrosive, carcinogenic, etc). Something MUST be in Hazardous Waste Container Contact

Nelson, Tim

410

Florida Law Collections  

NSDL National Science Digital Library

The Florida Law Collections document the laws and legal heritage of Florida through a wide range of texts digitized from the holdings of the University of Florida's Lawton Chiles Legal Information Center, the State Library, and Archives of Florida, and several other key institutions. Specifically, the collection includes issues of the Journal of the Florida House of Representatives, the Florida Historical Legal Documents collection, a Florida Water Law collection that is particularly noteworthy, as well as other general texts on Florida laws, the legislative process, and government. Given the debates over water rights and usage throughout the state, the Water Law collection is a real find, and visitors can search over 7300 documents within the collection. From the homepage, visitors can perform advanced searches and also look over recently added items. Finally, visitors can also sign up to receive their RSS feed and contact the site administrators with any additional queries they might have.

411

Collective Phase Sensitivity  

E-print Network

The collective phase response to a macroscopic external perturbation of a population of interacting nonlinear elements exhibiting collective oscillations is formulated for the case of globally-coupled oscillators. The macroscopic phase sensitivity is derived from the microscopic phase sensitivity of the constituent oscillators by a two-step phase reduction. We apply this result to quantify the stability of the macroscopic common-noise induced synchronization of two uncoupled populations of oscillators undergoing coherent collective oscillations.

Yoji Kawamura; Hiroya Nakao; Kensuke Arai; Hiroshi Kori; Yoshiki Kuramoto

2008-07-08

412

Discovery Collection: Marine Animals  

NSDL National Science Digital Library

Marine Animals is one of the AMNH Education Department's many collections of specimens and artifacts gathered the world over by explorers and scientists. In its online Discovery Collection form, Marine Animals includes photographs of 20 specimens with classification and distribution details, an interactive key that guides you through specimen identification, an activity where students select and identify a specimen photograph using the interactive identification key and an Educator's Guide with suggestions for how to use the Marine Animals Discovery Collection in the classroom.

Lisa Breslof

413

Discovery Collection: Oyster Shells  

NSDL National Science Digital Library

Oyster Shells is one of the AMNH Education Department's many collections of specimens and artifacts gathered the world over by explorers and scientists. In its online Discovery Collection form, Oyster Shells includes photographs of 15 specimens with classification and distribution details, an interactive key that guides you through specimen identification, an activity where students select and identify a specimen photograph using the interactive identification key and an Educator's Guide with suggestions for how to use the Oyster Shells Discovery Collection in the classroom.

Breslof, Lisa; Schiller, William

414

EROS Image Gallery Collections  

NSDL National Science Digital Library

This collection of images, published by the United States Geological Survey (USGS) Earth Resources Observation and Science (EROS) division, records events of historic significance, beautiful sights or images that stir the imagination. The collection is searchable by keyword. There are also themed collections, such as 'Earth as Art', and collections of state images from Landsat 7 and the National Elevation Dataset (NED). Full-resolution JPEG files can be downloaded free of charge via FTP directly from each image preview in the gallery. Images on CD, DVD, or by FTP download must be purchased. Ordering information is provided.

415

CPTAC Biospecimen Collection Solicitation  

Cancer.gov

A funding opportunity in support of the National Cancer Institute’s Clinical Proteomic Tumor Analysis Consortium (CPTAC) seeks to prospectively procure tumor samples, collected for proteomics investigation.

416

Welding II.  

ERIC Educational Resources Information Center

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…

Allegheny County Community Coll., Pittsburgh, PA.

417

In vitro approaches for detection of chemical sensitization.  

PubMed

Concerns, legislation and research needs have precipitated developments such as the mode of action concept, the Tox21 strategy, the concept of pathways of toxicity and the adverse outcome pathway framework. New technologies and paradigms are currently transforming these concepts into applicable animal-free toxicity testing systems. The adverse outcome pathway framework provides a structure for collecting, organizing and evaluating the available data that describe the compound and the events resulting in an adverse outcome at a biological level of organization. The current chapter intends to provide a non-exhaustive review of (i) our current understanding of the molecular mechanisms driven the key events of the mode of action for sensitization induction by chemicals, (ii) the tools that were developed on the basis of the available knowledge and (iii) the major gaps that need to be filled. PMID:24472442

Roggen, Erwin L

2014-07-01

418

Chemical Reactions: Investigating Exothermic and Endothermic Reactions  

NSDL National Science Digital Library

This activity is an inquiry-based investigation where students discover the indicators of chemical reactions (endothermic and exothermic) by collecting data and using that data to develop a testable question for further experimentation.

419

Start a Rock Collection  

NSDL National Science Digital Library

Learners follow a three-step process to start their own rock collection. Learners will collect rocks, record information about each rock on a Rock Chart, observe and sort their rocks, and create a rock display. This activity also includes a book list with resources for rock classification.

History, American M.

2012-06-26

420

collection: thought experiments  

E-print Network

collection: thought experiments of the day #12;"Suppose now that there were two such magic rings No Member 3 Yes Yes Yes Collective Yes Yes Yes or No? #12;The Model-T Suppose several people push a Model, in effect, a highly generalized form of such a ticket. ­ G.A. Cohen, "Freedom and Money" #12;The Survival

Wolfe, Patrick J.

421

Collecting Best Practices  

ERIC Educational Resources Information Center

How many beginning teachers struggle to create new lessons despite the fact that experienced teachers have already designed effective lessons for the same content? Shulman (1987) used the term "collective amnesia" to describe the failure of school leaders to design professional development that included the collection of its best practices.…

Tedford, Jennifer

2008-01-01

422

78 FR 29759 - Chemical Facility Anti-Terrorism Standards Personnel Surety Program  

Federal Register 2010, 2011, 2012, 2013, 2014

...DHS-2012-0061] Chemical Facility Anti-Terrorism Standards Personnel Surety Program AGENCY...Collection Request; Chemical Facility Anti- Terrorism Standards Personnel Surety Program...or financial information, Chemical-terrorism Vulnerability Information...

2013-05-21

423

The Wittliff Collection  

NSDL National Science Digital Library

Founded at Texas State University-San Marcos by Austin screenwriter and photographer Bill Wittliff and his wife Sally, the Wittliff Collections bring together "the Southwest's literature, film, and music." Visitors to the website can share in all of these cultural wonders, including materials from the Southwestern Writers Collection and several extensive photography collections. First-time visitors should head on over to "The Collections" area to take in the travel narrative of Cabeza de Vaca, found in the Southwestern Writers Collection "Research and Archives", and a wonderful tribute to the TV series and book, "Lonesome Dove". Moving on, the "Exhibitions & Events" area contains information about their various traveling exhibits, events, and writer talks. The site is rounded out by an online gift store and more details about their book series and anthologies of Southwestern writers.

424

Fashion Plate Collection  

NSDL National Science Digital Library

There are fashion plates, and then there are the exquisite fashion plates that constitute the University of Washington Libraries digitized collection. The plates were first collected by long-time home economics professor Blanche Payne, who taught at the University from 1927 to 1966. The plates come from leading French, American, and British fashion journals of the 19th and early 20th century and they document many stylistic periods, such as the Empire, Romantic, Victorian, and Edwardian. Visitors will want to start by reading an essay on the collection, and then they should feel welcome to browse the collection of over 400 plates at their leisure, or to browse the collection by subject. One fascinating aspect of the site is an extended excerpt from the 1913 book "Dame fashion" which comments on the history and transformation of various fashions during the 19th century.

425

ALA Archives Digital Collections  

NSDL National Science Digital Library

While some may harbor antiquated and erroneous impressions of librarians, those in the know can attest that these invaluable professionals like to get out and about just like their kinfolk in other learned professions. There is ample historical proof of this fact offered by this website, which contains a selection of digitized documents from the American Library Association (ALA) Archives, housed at the University of Illinois at Urbana-Champaign. Currently, the digitized collections include the F.W. Saxon Photographs Collection and the Library Building Photographs Collection. The Saxon Collection includes over 170 group pictures of librarians attending the ALA conferences in the US and Canada from the period 1894 to 1932. The Library Building Collection is quite intriguing, as it contains 78 postcards of libraries from locales such as Gadsden, Alabama.

2003-01-01

426

Urine collection device  

NASA Technical Reports Server (NTRS)

A urine collection device for females is described. It is comprised of a collection element defining a urine collection chamber and an inlet opening into the chamber and is adapted to be disposed in surrounding relation to the urethral opening of the user. A drainage conduit is connected to the collection element in communication with the chamber whereby the chamber and conduit together comprise a urine flow pathway for carrying urine generally away from the inlet. A first body of wicking material is mounted adjacent the collection element and extends at least partially into the flow pathway. The device preferably also comprise a vaginal insert element including a seal portion for preventing the entry of urine into the vagina.

Michaud, R. B. (inventor)

1981-01-01

427

Biosorption of Cd(II) and Pb(II) onto brown seaweed, Lobophora variegata (Lamouroux): kinetic and equilibrium studies  

Microsoft Academic Search

The present work deals with the biosorption performance of raw and chemically modified biomass of the brown seaweed Lobophora variegata for removal of Cd(II) and Pb(II) from aqueous solution. The biosorption capacity was significantly altered by pH of the solution\\u000a delineating that the higher the pH, the higher the Cd(II) and Pb(II) removal. Kinetic and isotherm experiments were carried\\u000a out at

Bhavanath Jha; Shaik Basha; Santlal Jaiswar; Biswajit Mishra; Mukund C. Thakur

2009-01-01

428

Chemical Education Digital Library  

NSDL National Science Digital Library

Benzene rings and other aspects of chemistry come alive with these "living textbooks." This collection of key chemistry documents and primers is made possible via the Chemical Education Digital Library (ChemEd DL) and it contains eight separate items. They are called "living" because they are updated by their owners and those responsible for their continued success. Users will find "Practice in Thinking: A Laboratory Course in Introductory Chemistry," "Chemistry Leaflets," and "Wiki: Quantum States of Atoms and Molecules" here for their consideration. The Chemistry Leaflets provide an interesting wrinkle as they were originally published between 1927 and the mid-1940s. Visitors shouldn't miss "Chemical Principles through Integrated Multiple Exemplars (ChemPRIME)" as it is designed so that general chemistry concepts can be presented in an order that reflects the conceptual structure of the discipline.

2013-01-01

429

USE OF DISPOSABLE DIAPERS TO COLLECT URINE IN EXPOSURE STUDIES  

EPA Science Inventory

Large studies of children's health as it relates to exposures to chemicals in the environment often require measurements of biomarkers of chemical exposures or effects in urine samples. But collection of urine samples from infants and toddlers is difficult. For large exposure s...

430

Biological and Chemical Weapons  

NSDL National Science Digital Library

One of the latest in MEDLINEplus' special collections, the Biological and Chemical Weapons page addresses health issues at the forefront of many people's minds these days. As with other MEDLINEplus special collections, this page offers links to news stories, sites providing general information and overviews, information about specific conditions, and relevant organizations. While the sites are not annotated, the page provides a useful introduction to these health issues. The links here are all authoritative and range from the National Center for Infectious Diseases' (NCID) faq on anthrax to Johns Hopkins University's Center for Civilian Biodefense Studies to National Library of Medicine's TOXNET Databases. MEDLINEplus is offered by the National Library of Medicine (NLM) and was last mentioned in the April 14, 2000 Scout Report.

2001-01-01

431

COLLECTION, CHEMICAL FRACTIONATION, AND MUTAGENICITY BIOASSAY OF AMBIENT AIR PARTICULATE  

EPA Science Inventory

The influence of industrialization and consequent increased concentration of urban particulate matter on the incidence of cancer has long been a concern. The first bioassays used to evaluate complex ambient air samples were whole-animal carcinogenesis bioassays. In these studies,...

432

Fibrous tissue and angiotensin II.  

PubMed

Myofibroblasts (myoFb) are cells responsible for fibrous tissue formation in injured systemic organs such as the heart. Cultured myoFb, obtained from rat cardiac scar tissue, express genes that encode components requisite for angiotensin (Ang) II generation, which in turn regulates myoFb collagen turnover in an autocrine/paracrine manner. In this study, we tested the hypothesis that these wound-healing fibroblast-like cells and locally generated Ang II are involved in other repairing tissue. To test this hypothesis, we used a granuloma pouch model, where a subcutaneous air sac is created followed by injection of croton oil. Pouch tissue was collected at days 4, 7, 14 and 21. The presence of myoFb was determined by immunohistochemical alpha-smooth muscle actin (alpha-SMA) labeling and collagen accumulation by picrosirius red staining. Angiotensin converting enzyme (ACE) and Ang II receptor binding were detected by in vitro quantitative autoradiography using 125I-351A and 125I[Sar1, Ile8]Ang II, respectively, while Ang II receptor subtype was defined by displacement studies using either an AT1 (losartan) or AT2 (PD123177) receptor antagonist. Cells expressing ACE were determined by immunohistochemistry. Ang II content in pouch tissue was measured by radioimmunoassay following HPLC separation while its capacity to generate Ang II was assessed in tissue bath, with and without exogenous Ang I or lisinopril, an ACE inhibitor. Collagen accumulation in pouch tissue was examined by determining hydroxyproline content in response to lisinopril, AT1 or AT2 receptor antagonists (losartan or PD123177). In pouch tissue, we found: (1) myoFb at day 4 which became more extensive at days 7, 14 and 21; (2) morphologic evidence of collagen deposition evident at day 4, which gradually became more extensive thereafter; (3) ACE and Ang II receptor binding was evident at day 4 and remained invariant on days 7, 14 and 21; (4) the predominant Ang II receptor subtype expressed was AT1; (5) myoFb express ACE and AT1 receptors; (6) picogram quantities of Ang II (per g tissue) was evident on days 7, 14 and 21; and (7) Ang II was generated from Ang I substrate. Lisinopril and losartan, but not PD123177, significantly attenuated pouch weight and accumulation of collagen. Thus, in this model of cutaneous repair, the appearance of myoFb is associated with Ang II generation that regulates fibrogenesis by AT1 receptor binding. Signals involved in the appearance of myoFb remain uncertain. Further studies are required to address the regulation of Ang II generation in pouch tissue of the rat. PMID:9281434

Sun, Y; Ramires, F J; Zhou, G; Ganjam, V K; Weber, K T

1997-08-01

433

Atomic Structure and Valence: Level II, Unit 10, Lesson 1; Chemical Bonding: Lesson 2; The Table of Elements: Lesson 3; Electrolysis: Lesson 4. Advanced General Education Program. A High School Self-Study Program.  

ERIC Educational Resources Information Center

This self-study program for high-school level contains lessons on: Atomic Structure and Valence, Chemical Bonding, The Table of Elements, and Electrolysis. Each of the lessons concludes with a Mastery Test to be completed by the student. (DB)

Manpower Administration (DOL), Washington, DC. Job Corps.

434

Delicious Chemicals.  

ERIC Educational Resources Information Center

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

Barry, Dana M.

435

Chemical Mahjong  

ERIC Educational Resources Information Center

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

Cossairt, Travis J.; Grubbs, W. Tandy

2011-01-01

436

Chemical Evolution  

E-print Network

In this series of lectures we first describe the basic ingredients of galactic chemical evolution and discuss both analytical and numerical models. Then we compare model results for the Milky Way, Dwarf Irregulars, Quasars and the Intra-Cluster- Medium with abundances derived from emission lines. These comparisons allow us to put strong constraints on the stellar nucleosynthesis and the mechanisms of galaxy formation.

Francesca Matteucci

2007-04-05

437

Burke Museum Department & Collections  

NSDL National Science Digital Library

With this Web site, users may access free resources based on the nationally ranked collections of the Burke Museum at the University of Washington. Over 5 million specimens are to be found in four areas: anthropology, botany, geology, and zoology. Online resources linked to the zoology collections include a guide to the herpetofauna of Washington, two mammals databases, and a fun section on spider myths. Likewise, records from the Museum's botany collections, housed at the University of Washington Herbarium, may be perused using the WTU Herbarium Database.

2007-08-22

438

Special Collections: Terrorism  

NSDL National Science Digital Library

The General Accounting Office (GAO) has posted these two pages of "special collections" of use to those following the news about terrorism and airport security measures. The page collecting releases on terrorism holds links to reports going back to a 1980 release, "Assessment of Various Aspects of This Nation's Nuclear Safeguards," and one from 1981, "Federal Electrical Emergency Preparedness Is Inadequate," though reports are not available in .pdf format until those dated from 1987. Both pages collect a wealth of reports, making them easily accessible for researchers and interested members of the general public.

439

The Rochambeau Map Collection  

NSDL National Science Digital Library

Jean Baptiste Donatien de Vimeur, comte de Rochambeau was the commander in chief of the French expeditionary army from 1780 to 1782. Rochambeau played a key role in the American Revolution, and his extensive map collection covered a great deal of eastern North America. The American Memory project at the Library of Congress has taken 40 manuscript and 26 printed maps from Rochambeau's collection and placed them online here. The views and maps in the collection cover areas from Labrador south to Haiti, and the maps themselves date from 1717 to 1795. Visitors can browse the collection by title, creator, subject, or place. In terms of highlights, interested parties will want to peruse the 1755 map of Nova Scotia and the 1781 military map of the area around Baltimore.

440

ADVANCED ELECTROSTATIC COLLECTION CONCEPTS  

EPA Science Inventory

This paper discusses the results of EPA's tests of five electrostatic collection concepts over the last 4 years: electric curtain, electrostatic scrubbing, electrostatic fiber beds, charged droplet scrubbing, and electrostatic effects on fabric filters. Of the five, electrostatic...

441

HHMI Wiki Collection  

NSDL National Science Digital Library

This wiki (a wiki is a website designed to let many people collaborate by adding and editing content) is a growing collection of information and resources for teaching physics for life sciences at the college and university level.

Catherine Crouch (Swarthmore College; )

2010-05-25

442

Comparative Mammalian Brain Collections  

NSDL National Science Digital Library

Located at the Department of Physiology at the University of Wisconsin - Madison, this site offers images and information from "one of the world's largest collection of well-preserved, sectioned and stained brains." The site features photos of brains of over 100 different species of mammals, representing 17 mammalian orders. Users can browse the collection by common or scientific name; view serial sections of selected specimens (including human and chimpanzee), some of which are also available as QuickTime movies; read about the importance and history of the collections; and learn about brain evolution (this last section still under construction). Additional resources include a collection of related links and an internal search engine.

443

Winterthur Digital Collection  

NSDL National Science Digital Library

The Winterthur Museum in Wilmington, Delaware is one of the premier museums of American material culture, located in the childhood home of industrialist and collector Henry Francis du Pont (1880-1969). For those unable to visit in person, the Winterthur Digital Collection includes detailed records, many accompanied by images, for the majority of the approximately 90,000 collection objects - including ceramics, furniture, glass, prints, paintings, metalwork, and textiles, most dating from about 1600 to 1860. At the main page to the online collection, artifacts are organized into searchable categories, such as Ceramics, Glass, Furniture, or Textiles and Needlework. Searchers can click a check box to limit to only those items that have images, and there is also an advanced search function, handy for known item searching. Textiles and needlework is one of the largest collection areas at over 18,000 items; limiting to items with images only reduces the number to about 8,000.

444

COLLECTIONS HIGHLIGHTS INTRODUCTION  

E-print Network

conditions PAGE 2 CONSERVATION Collections conservation and preservation projects PAGES 3, long-term planning, and prioritization, measuring many factors, including a practical framework for the allocation of resources; · Development of a digitization

Mathis, Wayne N.

445

Mineralogy Collections Database  

NSDL National Science Digital Library

The Natural History Museum (NHM) of London offers several quality online sites including the Mineralogy Collections Database. The interface allows users to search the collection by BM number, rock name, country of origin, locality, donor, and more. Results contain all of the aforementioned information as well as a link to a full description. Although a browse feature and photographs are not available, the site does give those who are serious about petrology an easy way to locate and get information about specimens the museum holds. If more information is sought, the site also provides links to additional facts on the petrology collection, information on other petrology collections, NHM petrology research, and NHM analytical facilities.

446

UCSF Japanese Prints Collection  

NSDL National Science Digital Library

The University of California at San Francisco has spent thirty years cultivating its collection of Japanese woodblock prints, and it has become an important part of the Library's East Asian Collection. The collection of 400 digitized prints concern Japanese health-related topics from the mid-19th century, and portray the gradual acceptance of Western medicine. Visitors can view the collection by theme or perform a search to find something more specific. The themes include "Contagious Diseases", which focuses on smallpox, measles and cholera, "Foreigners and Disease", which highlights the Japanese belief that foreigners carried diseases to Japan, and "Drug Advertisements". The "Drug Advertisements" are quite possibly the most beautiful drug ads in existence, and they feature elaborate images of drugs slaying disease, kabuki actors promoting a show sponsored by a children's medicine, Kindoru powder, and a detailed rendering of the interior of a drugstore, printed on a fan that was given out as a promotional item to advertise the business.

447

Fiber receptacle _ Collection optics  

E-print Network

Fiber receptacle _ Collection optics lymer optical fiber Optoelectronics Controlled impedance-1077 USA ABSTRACT Our work discusses the tolerance modeling of an optical fiber that is inserted. Keywords: Modeling and simulation, optical data interconnect, fiber-optic modules, optics 1. INTRODUCTON

Miller, Ethan L.

448

UWM Book Arts Collection  

NSDL National Science Digital Library

Here's a chance to get a look at 31 artists' books, in digital form, without having to make a trip to the Special Collections Department at University of Wisconsin-Milwaukee. Included in the collection are exampled of many different book and paper arts techniques, such as papermaking, different styles of hand-binding, and page design. Browsing the collection works better than searching, because it's a bit difficult to predict what terms will result in a successful search in a collection as varied as this. The books have been scanned carefully, so that it is possible to not only read every page but also to see the style of the covers and binding details. For example, "Book" by Brian Borchardt, consists of a series of short quotes related to books, including the well-known Jorge Luis Borges, "I have always imagined that paradise will be a kind of library."

449

The Phillips Collection: Multimedia  

NSDL National Science Digital Library

The Phillips Collection, like many other museums, is now providing a page on its website where a wide variety of multimedia - sound, moving images, virtual visits - has been gathered for easy access. For example, visitors can view six short videos that accompany the current exhibition, Georges Braque and the Cubist Still Life. The Collection's Intersections series also provides multimedia, such as "One Day, After the Rain," by Sandra Cinto, the artist's introduction to a set of drawings on canvas inspired by Arthur Dove's landscapes in the Phillips permanent collection, installed on the walls of the museum cafÃÂé. Also in the multimedia area, find links to download the Phillips Collection app for smartphones, and recorded lectures in iTunesU.

2013-01-01

450

University of Washington Libraries: Moving Image Collection  

NSDL National Science Digital Library

Once again, the University of Washington Digital Collections group has gone above and beyond the call of digital collection duty and service with this small, yet very satisfying, collection. This particular collection brings together 23 compelling short films that include home movies from the Seattle World's Fair in 1962, aerial views of the University campus in the post-World War II period, and footage of a group of Japanese Americans picnicking on Mt. Rainier in 1935. Visitors can browse through the entire collection by name, look around by subject heading, or perform a more sophisticated and nuanced search across the entire collection. That's not all, as the site also includes a handy film preservation manual titled "Low-Cost and No-Cost Suggestions To Care For Your Film". On a related note, visitors shouldn't leave the site without viewing a film of a motorcycle race from 1915 and the delightful images of farmers packing the world's largest box of apples in Yakima.

451

Online Digital Special Collections  

NSDL National Science Digital Library

The Department of Transportation (DOT) offers this Website giving access to digitized versions of a number of their special collections, such as Civil Aeronautic Manuals, Civil Air Regulations, Superseded Advisory Circulars, Historical Aircraft Accident Reports (1934-1965), FAA and CAA Research Reports, and more. Transportation researchers will find this a very useful resource. The interfaces for each of the collections are easy to manage, and certainly, this Website make looking up selected DOT documents much easier.

452

Digital Library Curriculum collection  

NSDL National Science Digital Library

The Digital Library Curriculum collection contains modules that form the basis for one or a several courses on digital libraries - thus constituting a unified curriculum for the field. They also can be used in computer science, library science, information science, and other programs for other types of courses or as supplements to an existing course. Core topics include digital objects, collection development, knowledge organization, architecture, user behavior and interactions, servics, preservation, management and evaluation and digital library education and research.

2011-01-04

453

Confederate Broadside Poetry Collection  

NSDL National Science Digital Library

Provided by Wake Forest University Library, this collection features over 250 poems written by southerners and Confederate sympathizers during the American Civil War. The online examples include scanned pamphlets and clippings as well as broadsides. The collection is recognized as strongly representative of popular Southern war poetry and represents a wide range of subjects, tones, and abilities. Sample selections include: "Cotton is King," The Devil's Visit to 'Old Abe'," "God Help Kentucky," and "Hurrah for Jeff. Davis."

1998-01-01

454

Ultralow Level Mercury Treatment Using Chemical Reduction and Air Stripping: Scoping Report  

SciTech Connect

Data collected during the first stage of a Savannah River Technology Center (SRTC) Strategic Research and Development Project confirmed the efficacy of chemical reduction and air stripping/sparging as an ultralow level mercury treatment concept for waters containing Hg(II). The process consists of dosing the water with low levels of stannous chloride to convert the mercury to Hg. This form of mercury can easily be removed from the water by air stripping or sparging. Samples of Savannah River Site (SRS) groundwater containing approximately 130 ng/L of total mercury (as Hg(II)) were used for the study. In undosed samples, sparging removed 0 percent of the initial mercury. In the dosed samples, all of the removals were greater than 94 percent, except in one water type at one dose. This sample, which was saturated with dissolved oxygen, showed a 63 percent reduction in mercury following treatment at the lowest dose. Following dosing at minimally effective levels and sparging, treated water contained less than 10 ng/L total mercury. In general, the data indicate that the reduction of mercury is highly favored and that stannous chloride reagent efficiently targets the Hg(II) contaminant in the presence of competing reactions. Based on the results, the authors estimated that the costs of implementing and operating an ultralow level mercury treatment process based on chemical reduction and stripping/sparging are 10 percent to 20 percent of traditional treatment technologies.

Looney, B.B.

2000-08-18

455

Collecting women's reproductive histories.  

PubMed

The importance of women's reproductive histories for scientific questions mandates rigor in collecting data. Unfortunately, few studies say much about how histories were constructed and validated. The aim of this report, therefore, is to illustrate the elements of a rigorous system of data collection. It focuses particularly on potential sources of inaccuracy in collecting reproductive histories and on options for avoiding them and evaluating the results. A few studies are exemplary in their description of methods of data collection and evaluation of data quality because they clearly address the main issues of ascertaining whether or not an event occurred and, if so, its timing. Fundamental variables such as chronological age, live birth, or marriage may have different meanings in different cultures or communities. Techniques start with asking the appropriate people meaningful questions that they can and will answer, in suitable settings, about themselves and others. Good community relations and well-trained, aware interviewers who check and cross-check, are fundamental. A range of techniques estimate age, date events, and optimize the value of imperfect data. Robust data collection procedures rely on skillful and knowledgeable interviewing. Reliability can be improved, evaluated and explained. Researchers can plan to implement robust data collection procedures and should assess their data for the scientific community to raise confidence in reproductive history data. PMID:24665016

Beall, Cynthia M; Leslie, Paul W

2014-01-01

456

The Clark: Digital Collections  

NSDL National Science Digital Library

The Museum at the Sterling and Francine Clark Art Institute may currently be closed for renovation (until July 4, 2014), but in the meantime digital collections from the Library at the Clark are still available online. The Library's special collections are diverse and include formats such as artists' books, photographs, clippings, digitized books, archival finding aids, and ephemera. One important collection is the David A. Hanson Collection of the History of Photomechanical Reproduction. This collection documents the history of the methods used since the early 1800s through the 20th century to reproduce and print artwork in books as well as for the image-buying public. Suggested browse terms, with the number of items of each type indicated in parentheses, are Collotypes (85), Halftones (62), Photolithographs (44) and Woodburytypes (31). Other digitized collections document the history of the Sterling and Francine Clark Art Institute, and nearby Williams College, such as the "Newsletter of the Williams College Graduate Program in the History of Art.âÂÂà

457

Chemical behavior of the dwarf irregular galaxy NGC6822. Its PN and HII region abundances  

NASA Astrophysics Data System (ADS)

Aims: We aim to derive the chemical behavior of a significant sample of PNe and HII regions in the irregular galaxy NGC 6822. The selected objects are distributed in different zones of the galaxy. Our purpose is to obtain the chemical abundances of the present interstellar medium (ISM), represented by H ii regions, and the corresponding values at the time of formation of PNe. With these data the chemical homogeneity of NGC 6822 were tested and the abundance pattern given by H ii regions and PNe used as an observational constraint for computing chemical evolution models to infer the chemical history of NGC 6822. Methods: Due to the faintness of PNe and H ii regions in NGC 6822, to gather spectroscopic data with large telescopes is necessary. We obtained a well suited sample of spectra by employing VLT-FORS 2 and Gemini-GMOS spectrographs. Ionic and total abundances were calculated for the objects where electron temperatures could determined through the detection of [O iii] ?4363 or/and [N ii] ?5755 lines. A “simple” chemical evolution model was developed and the observed data were used to compute a model for NGC 6822 in order to infer a preliminary chemical history in this galaxy. Results: Confident determinations of He, O, N, Ne, S and Ar abundances were derived for a sample of 11 PNe and one H ii region. We confirm that the present ISM is chemically homogeneous, at least in the central 2 kpc of the galaxy, showing a value 12 + log O/H = 8.06 ± 0.04. From the abundance pattern of PNe, we identified two populations: a group of young PNe with abundances similar to H ii regions and a group of older objects with abundances a factor of two lower. A pair of extreme Type I PNe were found. No third dredge-up O enrichement was detected in PNe of this galaxy. The abundance determinations allow us to discuss the chemical behavior of the present and past ISM in NGC 6822. Our preliminary chemical evolution model predicts that an important gas-mass loss occurred during the first 5.3 Gyr, that no star higher than 40 M_? was formed, and that 1% of all 3-15 M_? stars became binary system progenitors of SNIa. Based on observations collected at the European Southern Observatory, VLT, Paranal, Chile, program ID 077.B-0430. Based on observations obtained at the Gemini Observatory (program ID G-2005B-56), which is operated by AURA, Inc. under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (USA), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciencia e Tecnologia (Brazil) and SECYT (Argentina).

Hernández-Martínez, L.; Peña, M.; Carigi, L.; García-Rojas, J.

2009-10-01

458

Interaction of Au(III) and Pt(IV) complex ions with Fe(II) ions as a scavenging and a reducing agent: A basic study on the recovery of Au and Pt by a chemical method  

Microsoft Academic Search

In order to develop a chemical technique for the recovery of gold (Au) and platinum (Pt) in the metallic state from spent catalysts, e.g., catalysts for environmental protection and automobile and petroleum catalysts, the coprecipitation behaviors of Au(III) and Pt(IV) complex ions with Fe(OH)2 as a scavenging and reducing agent were investigated. The Au(III) complex ions were found to be

Pornthip Parinayok; Mamiko Yamashita; Kotaro Yonezu; Hironori Ohashi; Koichiro Watanabe; Yoshihiro Okaue; Takushi Yokoyama

2011-01-01

459

Theory of Collective Intelligence  

NASA Technical Reports Server (NTRS)

In this chapter an analysis of the behavior of an arbitrary (perhaps massive) collective of computational processes in terms of an associated "world" utility function is presented We concentrate on the situation where each process in the collective can be viewed as though it were striving to maximize its own private utility function. For such situations the central design issue is how to initialize/update the collective's structure, and in particular the private utility functions, so as to induce the overall collective to behave in a way that has large values of the world utility. Traditional "team game" approaches to this problem simply set each private utility function equal to the world utility function. The "Collective Intelligence" (COIN) framework is a semi-formal set of heuristics that recently have been used to construct private utility. functions that in many experiments have resulted in world utility values up to orders of magnitude superior to that ensuing from use of the team game utility. In this paper we introduce a formal mathematics for analyzing and designing collectives. We also use this mathematics to suggest new private utilities that should outperform the COIN heuristics in certain kinds of domains. In accompanying work we use that mathematics to explain previous experimental results concerning the superiority of COIN heuristics. In that accompanying work we also use the mathematics to make numerical predictions, some of which we then test. In this way these two papers establish the study of collectives as a proper science, involving theory, explanation of old experiments, prediction concerning new experiments, and engineering insights.

Wolpert, David H.

2003-01-01

460

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