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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

Chemical characterization of ambient aerosol collected during the southwest monsoon and intermonsoon seasons over the Arabian Sea: Labile-Fe(II) and other trace metals  

NASA Astrophysics Data System (ADS)

Atmospheric deposition of iron (Fe) to certain regions of the oceans is an important nutrient source of Fe to the biota, and the ability of the biota to uptake Fe is dependent on the speciation of the Fe. Therefore understanding the speciation of Fe in the atmosphere is critical to understanding the role of Fe as a nutrient source in surface ocean waters. Labile ferrous iron (Fe(II)) concentrations as well as total concentrations for Fe and other important trace metals, cations, and anions were determined over the Arabian Sea for two nonconsecutive months during 1995. Ambient aerosol samples were collected during the Indian Ocean intermonsoon and southwest monsoon seasons over the Arabian Sea. Sampling took place aboard the German research vessel Meteor in the months of May (leg M32/3; intermonsoon) and July/August (leg M32/5; southwest monsoon). Both cruise tracks followed the 65th east meridian, traveling for 30 days each (from north to south during leg M32/3 and from south to north during leg M32/5). A high-volume dichotomous virtual impactor with an aerodynamic cutoff size of 3 ?m was used to collect the fine and coarse aerosol fractions for metal analysis. A low volume collector was used to collect aerosol samples for anion and cation analysis. The analysis for labile-Fe(II) was done immediately after sample collection to minimize any possible Fe redox reactions which might occur during sample storage. The analytical procedure involved filter extraction in a formate/formic acid buffered solution at pH 4.2 followed by colorimetric quantification of soluble Fe(II). Metals, anions, and cations were analyzed after the cruise. Total atmospheric aqueous-labile-Fe(II) concentrations during the intermonsoon were between 4.75 and <0.4 ng m-3, of which most (>80%) was present in the fine fraction (<3.0 ?m). During the southwest monsoon, atmospheric aqueous-labile-Fe(II) concentrations were consistently below the detection limit (<0.34 to <0.089 ng m-3, depending on the volume of air sampled). Air mass back trajectories (5 day, three dimensional) showed that air masses sampled during the southwest monsoon had advected over the open Indian Ocean, while air masses sampled during the intermonsoon had advected over northeast Africa, the Saudi Arabian peninsula, and southern Asia. These calculations were consistent with the results of the statistical analysis performed on the data set which showed that the variance due to crustal species during the intermonsoon samples was greater than the variance due to crustal species during the southwest monsoon. The factor scores for the crustal components were also greater when the back trajectories had advected over the nearby continental masses. Principal component analysis was also performed with the intermonsoon samples where aqueous labile Fe(II) was above the detection limit. Aqueous labile Fe(II) did not correlate well with other species indicating possible atmospheric processing of the iron during advection.

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

1999-02-01

4

Hanno Kogaku II Chemical System Engineering  

E-print Network

Hanno Kogaku II Chemical System Engineering Instructors: Prof. S. Ted Oyama, Dept. of Chemical System Engineering Hongo 7-3-1, Bunkyo-ku Tokyo 113-8656 Text: H. S. Fogler, Elements of Chemical changes. Considerable emphasis will be placed on solving non-linar and differential equations using

Yamamoto, Hirosuke

5

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

6

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

7

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

...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

COLLECTION OF SULFUR GASES WITH CHEMICALLY-TREATED FILTERS  

EPA Science Inventory

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

9

LA-9325-MS, vol. II CIC-14 REPORT COLLECTION REPRODUCTION  

E-print Network

--. .-- LA-9325-MS, vol. II CIC-14 REPORT COLLECTION REPRODUCTION COPY e. 3 LOS Alamos National conlract W.7405-ENG.36. IS-4 REPORT SECTION `~ ---------- .---. -. --.... . . .. REPRODUCTION ~... . COPY

10

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

Federal Register 2010, 2011, 2012, 2013

...Collection Activities; Proposed Collections; Toxic Chemical Release Reporting; Request for...INFORMATION CONTACT: Cassandra Vail, Toxics Release Inventory Program Division...FURTHER INFORMATION CONTACT section. Title: Toxic Chemical Release Reporting (Form...

2011-02-11

11

Chemical composition of Galactic H II regions.  

NASA Astrophysics Data System (ADS)

A review of the chemical compositions of M8, M17 and M42 (Orion) is presented. Observational evidence on the presence of spatial temperature variations inside H II regions is presented; these variations can be explained by photoionization models of nebulae with uniform distributions of dust and chemical composition. Possible causes of these temperature variations are analyzed. Abundance tables with probable errors (1?) for Orion, M8 and M17 are presented. These abundances are compared with those of the Sun and B stars of the solar neighborhood. The abundances of Galactic H II regions are compared with those of extragalactic H II regions; the enrichment of the carbon abundance and the ?Y/?Z value are briefly discussed.

Peimbert, M.

1993-11-01

12

Collection of sulfur gases with chemically-treated filters  

Microsoft Academic Search

Chemically treated membrane filters were evaluated to collect hydrogen sulfide and sulfur dioxide. Four chemical treatments were tested. Silver nitrate-- and silver nitrate--tartaric acid--treated filters were used to collect hydrogen sulfide, and lithium hydroxide-- and potassium bicarbonate--treated filters were used to collect sulfur dioxide. Sampling was performed using a tandem filter holder so that the test gas would pass through

G. R. Namie; R. F. Reardon; N. Schmidt; L. L. Spiller

1978-01-01

13

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

14

COLLECTION AND CHEMICAL ANALYSIS OF LICHENS FOR BIOMONITORING  

EPA Science Inventory

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

15

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

16

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

17

Featured collection introduction: contaminants of emerging concern II  

USGS Publications Warehouse

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

Battaglin, William A.; Kolok, Alan

2014-01-01

18

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

19

Chemical analysis of cloud water collected over Hawaii  

Microsoft Academic Search

Two types of cloud water collectors were developed, and the devices were used to collect samples around the Hawaii Islands. The chemical analyses of cloud water showed that Na+, Cl-, and SO4= ion concentrations were approximately 10-4m NH4+,NO3-, and Ca++ were 1 order of magnitude lower. The pH values were in the range of 4-5 regardless of sampling locations. The

F. Parungo; C. Nagamoto; I. Nolt; M. Dias; E. Nickerson

1982-01-01

20

Chemical analysis of rain samples collected over the Pacific Ocean  

Microsoft Academic Search

During seven research cruises in the Pacific Ocean from 1984 to 1989 we collected rain samples for chemical analyses. The geographical and temporal variations of rain chemistry were studied in relation to natural and anthropogenic sources and transport of the constituents. The pH values of rain samples ranged from 3.9 to 7.2, with a mean of 5.6 (n=104, sigma=0.5). The

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

1990-01-01

21

Onset of Collective Oscillation in Chemical Turbulence under Global Feedback  

E-print Network

Preceding the complete suppression of chemical turbulence by means of global feedback, a different universal type of transition, which is characterized by the emergence of small-amplitude collective oscillation with strong turbulent background, is shown to occur at much weaker feedback intensity. We illustrate this fact numerically in combination with a phenomenological argument based on the complex Ginzburg-Landau equation with global feedback.

Yoji Kawamura; Yoshiki Kuramoto

2003-05-30

22

Chemical markers in Veronica sect. Hebe. II  

Microsoft Academic Search

In a continued chemosystematic investigation of the water-soluble compounds in Veronica sect. Hebe, four additional species were investigated. In comparison to other, Northern Hemisphere (NH) species of Veronica, those belonging to the New Zealand species in sect. Hebe are apparently more variable in chemical content. In addition to the compounds characteristic for NH Veronica, namely mannitol, aucubin, catalpol and 6-O-esters

Palle Pedersen; Charlotte Held Gotfredsen; Steven J. Wagstaff; Søren Rosendal Jensen

2007-01-01

23

[Chemical constituents of Artemisia lactiflora(II)].  

PubMed

To study the chemical constituents of Artemisia lactiflora. The compounds were isolated by column chromatography with silica gel, C18 reverse-phase silica gel, semi-preparative HPLC, and their structures were elucidated on the basis of spectral analysis. Twelve compounds were isolated from alcohol extracts of A. lactiflora and identified as 7-hydroxycoumarin (1), 7-methoxycoumarin (2), balanophonin (3), aurantiamide (4), aurantiamide acetate (5), isovitexin (6), kaempferol-3-O-beta-D-rutinoside (7), rutin (8), caffeic acid ethyl ester (9), quercetin (10), methyl 3, 5-di-O-caffeoyl quinate (11) and methyl 3, 4-di-O-caffeoyl quinate (12), respectively. Compounds 3-12 were obtained from this plant for the first time. PMID:25276977

Lin, Fu-Di; Luo, Dang-Wei; Ye, Jing; Xiao, Mei-Tian

2014-07-01

24

The Block II Chemical Biological Mass Spectrometer - Point Detection for Both Chemical and Biological Warfare Agents  

Microsoft Academic Search

The Block II Chemical Biological Mass Spectrometer (CBMS) is a new instrument for point detection that integrates the detection and identification of both chemical warfare (CW) and biological warfare (BW) agents into a single compact unit. It is based upon a direct-sampling ion trap mass spectrometer interfaced to three sampling systems and is operated in full scan and tandem mass

Wayne H. Griest; Marcus B. Wise; Kevin J. Hart; Stephen A. Lammert; Alexander P. Hryncewich; David W. Sickenberger

25

Chemical Composition of Wild-2 Dust Collected by Stardust  

NASA Astrophysics Data System (ADS)

The Stardust spacecraft collected dust from Comet Wild-2 in two forms: material distributed along tracks in aerogel capture cells and residue in impact craters. To analyze the chemical composition of these samples the tracks produced in the aerogel were extracted as keystones containing complete tracks. Twenty-six tracks were analyzed using an X-Ray Microprobe, providing x-ray fluorescence chemical analysis for elements having K-lines at energies high enough to permit escape from the overlying aerogel (S and the heavier elements, including the moderately-volatile trace elements Cu, Zn, and Ga). Two of these tracks were then split open, exposing the interior for analysis by TOF-SIMS (which allowed detection of the lighter elements, e.g., Mg and Al). Neither Si nor O could be determined for samples captured in the aerogel, since these are the major elements in the aerogel itself. The residue in craters in the Al-foil were analyzed by SEM-EDX and TOF-SIMS. The crater residues provide information on the important light elements (Mg and Si). By combining the results from the craters and the tracks, a comprehensive chemical analysis of the Wild-2 dust was possible. Preliminary Examination of the material indicates that: 1) For particles collected in the aerogel, a significant fraction of the incident mass is frequently deposited along the entry track, suggesting the individual Wild-2 dust particles that hit the aerogel were relatively weak aggregates. 2) The chemical composition of the terminal particle in the track is frequently significantly different from the composition of the material deposited along the track, 3) Most of the elements measured show variations in their Fe-normalized abundances of more than two orders-of-magnitude in both the terminal particles and the material deposited along track walls, indicating that the Wild-2 dust is compositionally heterogeneous at the size scale of the largest particles analyzed, not simply a well-mixed aggregate of sub-micron grains, 4) The mean content of the refractory, rock-forming elements (Mg, Ca, Si, Cr, Fe, and Ni) averaged over the whole tracks and/or the crater residues in the Wild-2 grains are approximately chondritic, and, 5) There is an apparent enrichment over CI in some of the moderately-volatile minor elements (Cu, Zn, and Ga) in the Wild-2 dust.

Flynn, G. J.

2006-12-01

26

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

Federal Register 2010, 2011, 2012, 2013

...Request; Basel II Recordkeeping and Disclosures AGENCY: Federal Deposit Insurance Corporation...revision its Basel II--Recordkeeping and Disclosures information collection, which is currently...Risk-Weighted Assets; Market Discipline and Disclosure Requirements (77 FR 52888);...

2013-02-12

27

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

Federal Register 2010, 2011, 2012, 2013

...Growing America Through Entrepreneurship (GATE) II Evaluation; Comment Request AGENCY...comments on a new data collection for the GATE II Evaluation. A copy of the proposed...to develop their businesses--Project GATE. In helping individuals develop...

2011-05-05

28

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

29

Nanosized and Nanostructured II-VI Semiconductors: Chemical Sensor Applications  

NASA Astrophysics Data System (ADS)

Principles of chemical sensing are considered and examples from the literature of chemical sensors including II-VI semiconductor nanomaterials are given. A new method for improving the discrimination of semiconductor thin-film gas sensors is introduced, which uses the amplitude and phase of the photocurrent response to a modulated light source. Preparation of nanocrystalline CdS and CdSe thin films of various thicknesses (30-200 nm) by physical vapour deposition is described. Data from room temperature studies of the effect of exposure to a set of vapours (water, ethanol, ammonia, acetone) on the film resistance and quartz-crystal microbalance frequency are presented.

Nesheva, Diana

30

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

31

Arthur Paul Afghanistan Collection Bibliography - Volume II: English and European Languages (2000)  

Microsoft Academic Search

In December 1995, the first volume of this bibliography was published. Volume I included all the Pashto and Dari language titles that were in the Arthur Paul Afghanistan Collection at that time. Volume II includes English and European language materials. This volume contains titles that were added to the Collection prior to January 1998.\\u000aThe Arthur Paul Afghanistan Collection is

Shaista Wahab

2000-01-01

32

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

E-print Network

of solutions, polymer solutions, phase equilibria, and chemical reaction equilibria. Course Objectives mixtures, polymer solutions and chemical reaction equilibria. An understanding of these topics is required155: 309 Chemical Engineering Thermodynamics II Fall 2014 Web page: https

33

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

National Technical Information Service (NTIS)

This report contains the comprehensive summary of the work performed on the SBIR Phase II project (Distributed Relevance Ranking in Heterogeneous Document Collections) at Deep Web Technologies (http://www.deepwebtech.com). We have successfully completed a...

A. Lederman

2006-01-01

34

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

Microsoft Academic Search

This report contains the comprehensive summary of the work performed on the SBIR Phase II project (Distributed Relevance Ranking in Heterogeneous Document Collections) at Deep Web Technologies (http:\\/\\/www.deepwebtech.com). We have successfully completed all of the tasks defined in our SBIR Proposal work plan (See Table 1 - Phase II Tasks Status). The project was completed on schedule and we have

Abe Lederman

2007-01-01

35

Quantum chaos in the nuclear collective model: II. Peres lattices  

E-print Network

This is a continuation of our preceding paper devoted to signatures of quantum chaos in the geometric collective model of atomic nuclei. We apply the method by Peres to study ordered and disordered patterns in quantum spectra drawn as lattices in the plane of energy vs. average of a chosen observable. A good qualitative agreement with standard measures of chaos is manifested. The method provides an efficient tool for studying structural changes of eigenstates across quantum spectra of general systems.

Pavel Stransky; Petr Hruska; Pavel Cejnar

2009-02-23

36

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

Federal Register 2010, 2011, 2012, 2013

...effectiveness or lack of effectiveness in preventing sexually transmitted diseases * * *.'' In response, FDA recommended labeling...provided by condoms against various types of sexually transmitted diseases. Respondents to this collection of...

2011-07-08

37

COLLECTIVE PROTECTION AGAINST CHEMICAL, BIOLOGICAL, AND RADIOLOGICAL WARFARE AGENTS  

Microsoft Academic Search

Fundamental principles and criteria are presented for use in the design ; of shelters to provide adequate and equal protection from chemical, biological, ; and radiological warfare agents in both gaseous and particulate form. Design ; criteria, drawings, and layouts are included for shelters, decontamination ; facilities, and ventilation systems. (Ca.);

Leber

1958-01-01

38

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.

39

Supercooled water and the kinetic glass transition. II. Collective dynamics Francesco Sciortino,1  

E-print Network

Supercooled water and the kinetic glass transition. II. Collective dynamics Francesco Sciortino,1 02139 Received 28 May 1997 In this article we study in detail the Q-vector dependence of the collective dynamics in simulated deeply supercooled extended simple-point-charge SPC/E water. The evolution

Sciortino, Francesco

40

Supercooled Water and the Kinetic Glass Transition II: Collective Dynamics  

E-print Network

In this article we study in detail the Q-vector dependence of the collective dynamics in simulated deeply supercooled SPC/E water. The evolution of the system has been followed for 250 ns at low T, allowing a clear identification of a two step relaxation process. We present evidence in favor of the use of the mode coupling theory for supercooled liquid as framework for the description of the slow alpha-relaxation dynamics in SPC/E water, notwithstanding the fact that the cage formation in this system is controlled by the formation of an open network of hydrogen bonds as opposed to packing constraints, as in the case of simple liquids.

Francesco Sciortino; Linda Fabbian; Sow-Hsin Chen; Piero Tartaglia

1997-06-05

41

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...

42

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

Code of Federal Regulations, 2013 CFR

...Efficiencies of Anaerobic Processes Anaerobic process type Cover type Methane collection efficiency Covered anaerobic lagoon (biogas capture) Bank to bank, impermeable 0.975 Modular, impermeable 0.70 Anaerobic sludge digester; anaerobic...

2013-07-01

43

Characterization of Solid and Liquid GB Samples Collected from M55 Rockets Processed at Anniston Chemical Agent Disposal Facility (ANCDF).  

National Technical Information Service (NTIS)

The Program Manager, Assembled Chemical Weapon Alternatives (PM- ACWA), requested that the U.S. Army Edgewood Chemical Biological Center (ECBC) conduct a fall analytical characterization of a OB sample collected at the Anniston Chemical Agent Disposal Fac...

T. E. Rosso, J. J. Loss, S. D. Norman, P. L. Abercrombie, A. B. Butrow

2005-01-01

44

AUTOMATIC DATA COLLECTING SYSTEM FOR THE TORY II-C COLD CRITICAL EXPERIMENT  

Microsoft Academic Search

The design of an automatic data collecting system for the Tory II-C ; reactor critical experiment is an attempt to facilitate the compilation of the ; large quantity of data necessary for accurate power density measurements. ; Neutron sensors or probes in the core drive scalers which are controlled by the ; data system. The scalers are all started simultaneously

Aslin

1963-01-01

45

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

PubMed

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

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

2011-01-01

46

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

PubMed Central

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

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

2011-01-01

47

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 of Civil Engineering, Auburn University, Auburn, AL 36849, USA a r t i c l e i n f o Keywords: BP oil spill Deepwater Horizon oil spill Hopane analysis Fingerprinting Tar balls a b s t r a c t We compare

Clement, Prabhakar

48

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

Microsoft Academic Search

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

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

2008-01-01

49

Sustainability Indicators for Chemical Processes : II. Data Needs  

EPA Science Inventory

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

50

H II region in NGC 6744: Spectrophotometry and chemical abundances  

SciTech Connect

Spectrophotometry of emission lines in the lambdalambda3700--6800 spectral range is presented for An H II region in an outer arm of NGC6744, a southern hemisphere galaxy of type SAB(r)bc II. The electron temperature, derived from the (O III) lines and assuming N/sub e/ = 100 cm/sup -3/, was found to be 9,630 +- 450 K. Ionic abundances, derived in the usual fashion from the measured line strengths, were corrected to total relative number abundances by application of the standard ionization correction factor (ICF) scheme and by comparison to models. The derived abundances, relative to log Hequivalent12.00, are log He = 10.96 +- 0.06, log N = 7.34 +- 0.26, log O log O = 8.44 +- 0.10, log Ne = 7.80 +- 0.16, and log S = 6.75 +- 0.28. The NGC 6744 H II region abundances, and various ratios, are compared to similar data for H II regions in the SMC, LMC, and the Perseus arm of the Galaxy,. From the comparison it is suggested that the histories of nucleosynthesis in the outer regions of NGC 6744 and the Galaxy could have been quite similar.

Talent, D.L.

1982-01-15

51

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

Microsoft Academic Search

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

Otomar Špalek; V??t Jirásek; Miroslav ?enský; Jarmila Kodymová; Ivo Jakubec; Gordon D. Hager

2002-01-01

52

Steam generator chemical cleaning at Millstone Point II  

Microsoft Academic Search

Northeast Utilities chemically cleaned their Combustion Engineering U-tube steam generators utilizing a variation of the Electric Power Research Institute (EPRI)-developed steam generator cleaning solvent qualified specifically for the Millstone 2 plant. The cleaning was required due to a buildup of corrosion products in the tube sheet area, which was causing tube pitting. This effort is particularly significant because it is

T. W. Oliver; R. C. Thomas

1985-01-01

53

Profile of Patients with Chemical Injury and Sensitivity, Part II  

Microsoft Academic Search

Exposures which can induce multiple chemical sensitivity (MCS) involve symptomatic, usually repeated, exposures to pesticides, solvents, combustion products, remodeling, sick buildings, carbonless copy paper (occupational heavy use) and other irritants and petrochemicals. Accompanying toxic injury often involves the immune, endocrine and nervous systems as well as impairments in detoxification, energy and neurotransmitter metabolism, protein, mineral, and other nutrient deficiencies and

Grace E. Ziem

1999-01-01

54

Chemical imaging: II. Trends in practical multiparameter sensor systems  

Microsoft Academic Search

In most applications of chemical sensors today the original output of an individual sensor is monitored as one ‘feature’ (such as a certain current at a fixed potential of an electrochemical cell or a resistance of a metal oxide sensor). However, individual sensors and the determination of individual features show limited performance only for most practical applications. Often, arrays of

Udo Weimar; Wolfgang Göpel

1998-01-01

55

Shop 'til you drop II: Collective Adaptive Behavior of Simple Autonomous Trading Agents in Simulated `Retail' Markets  

E-print Network

from experiments where an elementary machine learning technique endows simple autonomous softwareShop 'til you drop II: Collective Adaptive Behavior of Simple Autonomous Trading Agents Autonomous Trading Agents in Simulated `Retail' Markets Dave Cli Arti cial Intelligence Laboratory

Tesfatsion, Leigh

56

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

NASA Astrophysics Data System (ADS)

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

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

2001-12-01

57

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

SciTech Connect

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

Farrell, R.E.; Germida, J.J.; Huang, P.M. (Univ. of Saskatchewan, Saskatoon (Canada))

1993-05-01

58

Trends in chemical concentrations in mussels and oysters collected along the US coast from 1986 to 1993  

Microsoft Academic Search

Results from annual collections and chemical analyses of mussels and oysters from sites located throughout the marine coast of the United States show decreasing trends, on a national scale, for chemicals whose use has been banned or has greatly decreased. Concentrations of most other chemicals are neither increasing nor decreasing.

Thomas P. O'Connor

1996-01-01

59

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

PubMed

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

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

2014-10-15

60

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

E-print Network

This paper compares the chemical evolution of the Large Magellanic Cloud (LMC) to that of the Milky Way (MW) and investigates the relation between the bar and the inner disc of the LMC in the context of the formation of the bar. We obtained high-resolution and mid signal-to-noise ratio spectra with FLAMES/GIRAFFE at ESO/VLT and performed a detailed chemical analysis of 106 and 58 LMC field red giant stars (mostly older than 1 Gyr), located in the bar and the disc of the LMC respectively. We measured elemental abundances for O, Mg, Si, Ca, Ti, Na, Sc, V, Cr, Co, Ni, Cu, Y, Zr, Ba, La and Eu. We find that the {\\alpha}-element ratios [Mg/Fe] and [O/Fe] are lower in the LMC than in the MW while the LMC has similar [Si/Fe], [Ca/Fe], and [Ti/Fe] to the MW. As for the heavy elements, [Ba,La/Eu] exhibit a strong increase with increasing metallicity starting from [Fe/H]=-0.8 dex, and the LMC has lower [Y+Zr/Ba+La] ratios than the MW. Cu is almost constant over all metallicities and about 0.5 dex lower in the LMC than ...

Van der Swaelmen, M; Primas, F; Cole, A A

2013-01-01

61

Retrospective on "Chemical abundances in H II regions and their implications" by Peimbert & Costero (1969)  

NASA Astrophysics Data System (ADS)

We present a review about the relevance of the paper by M. Peimbert and R. Costero, 1969, BOTT, 5, 31, 3, on the chemical abundance determinations of H II regions. We analize the observational evidence in favor of the presence of temperature variations inside gaseous nebulae. We make a brief mention of the methods used to estimate the contribution of the unobserved ions to the total chemical abundances.

Peimbert, M.; Peimbert, A.

2011-04-01

62

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

NASA Astrophysics Data System (ADS)

Aims: This paper compares the chemical evolution of the Large Magellanic Cloud (LMC) to that of the Milky Way (MW) and investigates the relation between the bar and the inner disc of the LMC in the context of the formation of the bar. Methods: We obtained high-resolution and mid signal-to-noise ratio spectra with FLAMES/GIRAFFE at ESO/VLT and performed a detailed chemical analysis of 106 and 58 LMC field red giant stars (mostly older than 1 Gyr), located in the bar and the disc of the LMC respectively. To validate our stellar parameter determinations and abundance measurement procedures, we performed thorough tests using the well-known mildly metal-poor Milky-Way thick disc giant Arcturus (HD 124897, ? Boo). We measured elemental abundances for O, Mg, Si, Ca, Ti (?-elements), Na (light odd element), Sc, V, Cr, Co, Ni, Cu (iron-peak elements), Y, Zr, Ba, La, and Eu (s- and r-elements). Results: We find that the ?-element ratios [Mg/Fe] and [O/Fe] are lower in the LMC than in the MW while the LMC has similar [Si/Fe], [Ca/Fe], and [Ti/Fe] to the MW. As for the heavy elements, [Ba,La/Eu] exhibit a strong increase with increasing metallicity starting from [Fe/H] ? -0.8 dex, and the LMC has lower [Y + Zr/Ba + La] ratios than the MW. Cu is almost constant over all metallicities and about 0.5 dex lower in the LMC than in the MW. The LMC bar and inner disc exhibit differences in their [?/ Fe] (slightly larger scatter for the bar in the metallicity range [-1, -0.5]), their Eu (the bar trend is above the disc trend for [Fe/H] ? -0.5 dex), their Y and Zr, their Na and their V (offset between the bar and the disc distributions). Conclusions: Our results show that the chemical history of the LMC experienced a strong contribution from type Ia supernovae as well as a strong s-process enrichment from metal-poor AGB winds. Massive stars made a smaller contribution to the chemical enrichment compared to the MW. The observed differences between the bar and the disc speak in favour of an episode of enhanced star formation a few Gyr ago, occurring in the central parts of the LMC and leading to the formation of the bar. This is in agreement with recently derived star formation histories. Proposals 072.B-0293(B) and 078.B-0323(A), P.I. Vanessa Hill.Full Tables 3, 5, 7, 9, 11 and abundances tables for the LMC bar and disc samples are only available in electronic form at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/560/A44Table 11 is also available in electronic form at http://www.aanda.org

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

2013-12-01

63

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

SciTech Connect

This report contains the comprehensive summary of the work performed on the SBIR Phase II project (“Distributed Relevance Ranking in Heterogeneous Document Collections”) at Deep Web Technologies (http://www.deepwebtech.com). We have successfully completed all of the tasks defined in our SBIR Proposal work plan (See Table 1 - Phase II Tasks Status). The project was completed on schedule and we have successfully deployed an initial production release of the software architecture at DOE-OSTI for the Science.gov Alliance's search portal (http://www.science.gov). We have implemented a set of grid services that supports the extraction, filtering, aggregation, and presentation of search results from numerous heterogeneous document collections. Illustration 3 depicts the services required to perform QuickRank™ filtering of content as defined in our architecture documentation. Functionality that has been implemented is indicated by the services highlighted in green. We have successfully tested our implementation in a multi-node grid deployment both within the Deep Web Technologies offices, and in a heterogeneous geographically distributed grid environment. We have performed a series of load tests in which we successfully simulated 100 concurrent users submitting search requests to the system. This testing was performed on deployments of one, two, and three node grids with services distributed in a number of different configurations. The preliminary results from these tests indicate that our architecture will scale well across multi-node grid deployments, but more work will be needed, beyond the scope of this project, to perform testing and experimentation to determine scalability and resiliency requirements. We are pleased to report that a production quality version (1.4) of the science.gov Alliance's search portal based on our grid architecture was released in June of 2006. This demonstration portal is currently available at http://science.gov/search30 . The portal allows the user to select from a number of collections grouped by category and enter a query expression (See Illustration 1 - Science.gov 3.0 Search Page). After the user clicks “search” a results page is displayed that provides a list of results from the selected collections ordered by relevance based on the query expression the user provided. Our grid based solution to deep web search and document ranking has already gained attention within DOE, other Government Agencies and a fortune 50 company. We are committed to the continued development of grid based solutions to large scale data access, filtering, and presentation problems within the domain of Information Retrieval and the more general categories of content management, data mining and data analysis.

Abe Lederman

2007-01-08

64

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

ERIC Educational Resources Information Center

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

Callaghan, A.; And Others

65

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

66

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

67

A Chemical Confirmation of the Faint Boötes II Dwarf Spheroidal Galaxy  

NASA Astrophysics Data System (ADS)

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

Koch, Andreas; Rich, R. Michael

2014-10-01

68

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

PubMed

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

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

2014-01-01

69

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

SciTech Connect

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

Villet, R. (ed.)

1981-02-01

70

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

NASA Astrophysics Data System (ADS)

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

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

1997-06-01

71

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

PubMed

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

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

2012-11-26

72

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

73

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

74

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

75

78 FR 17680 - Information Collection Request; Chemical Facility Anti-Terrorism Standards Personnel Surety Program  

Federal Register 2010, 2011, 2012, 2013

...however, that high-risk chemical facilities could audit and/or review their...Regulatory Assessment high-risk chemical facility count, by model facility category...Number of High-Risk Chemical Facilities in Each Model Facility...

2013-03-22

76

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

Federal Register 2010, 2011, 2012, 2013

...Chemical Weapons Convention Declaration and Report Handbook...and Security. ACTION: Notice...Chemical Weapons Convention Implementation...Chemical Weapons Convention Regulations...submission of declarations, reports and...Convention (CWC), an international arms control...

2012-10-01

77

Binding of Co(II) and Cu(II) cations to chemically modified wool fibres: an IR investigation  

NASA Astrophysics Data System (ADS)

Wool fibres were modified by treatment with tannic acid (TA) solution or by acylation with ethylenediaminetetraacetic (EDTA) dianhydride. The unmodified and modified fibres were subsequently treated with Cu 2+ and Co 2+ solutions, at alkaline pH, and analysed by Attenuated Total Reflectance, ATR/IR spectroscopy to evaluate the changes induced in the structure of the fibre by metal binding. The spectral changes were correlated to metal adsorption results obtained by Inductive Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). The IR results were discussed in relation to our previous findings on the metal binding mode of Bombyx mori and Tussah silk fibres; the changes observed in the spectra were explained by considering the different affinity of the fibres for the modifying reagent and the amount of the metal absorbed. More relevant spectral changes were observed upon Cu 2+ complexation rather than Co 2+ complexation, according to the metal absorption results. The most relevant changes were observed for the EDTA-modified wool sample treated with Cu 2+, according to the higher affinity of wool for EDTA. The IR spectra were quantitatively evaluated by the intensity ratio between the Amide I and Amide II bands (I AmideI/I AmideII) and its trend as a function of metal absorption was reported. The present investigation demonstrated that the interaction between fibre and metal and the subsequent fibre modification depend on the chemical nature of the fibre, the metal cation and the modifying reagent.

Taddei, Paola; Monti, Patrizia; Freddi, Giuliano; Arai, Takayuki; Tsukada, Masuhiro

2003-05-01

78

An intelligent data collection tool for chemical safety\\/risk assessment  

Microsoft Academic Search

REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) is the new European chemical legislation which aims to assess risk or safety of tens of thousands of chemicals to improve the protection of human health and the environment. The chemical safety assessment process is of an iterative nature. First, an initial, worst-case assessment is conducted after which refinements are made until

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

2008-01-01

79

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

80

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

USGS Publications Warehouse

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

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

1985-01-01

81

The resonance lines of Hg II in IUE spectra of chemically peculiar stars  

NASA Technical Reports Server (NTRS)

Twenty IUE images of chemically peculiar (CP) stars are analyzed to demonstrate that the previously detected Hg II overabundances in CP stars is real. Attention was focused on the Hg II resonance lines at 1650 and 1942 A. A total of eight stars were scanned and spectrum synthesis computations were performed to characterize the model atmospheres for each object. The 1942 A line was found to be insensitive to effective temperature, microturbulence and isotopic mixture influences, and therefore well-suited to abundance analyses. A non-LTE process was ruled out as a source of the Hg anomaly. Finally, it is suggested that diffusion-type processes be attributed to Hg enhancements in main sequences B stars.

Leckrone, D. S.

1984-01-01

82

Transcutaneous Chemical Collection of Caffeine in Normal Subjects: Relationship to Area Under the Plasma Concentration-Time Curve and Sweat Production  

Microsoft Academic Search

A novel transcutaneous chemical collection device (TCD) has been developed to study the phenomenon of outward transcutaneous chemical migration. The TCD is a Bandaid-like device containing an immobilized aqueous media and binding reservoir material to prevent back-transfer into the skin. This device, when placed against the skin, allows collection and quantitation of chemicals that diffuse directly through the skin from

Dale P. Conner; Emily Millora; Kaveh Zamani; Darrell Nix; Ramona G. Almirez; Patricia Rhyne-Kirsch; Carl C. Peck

1991-01-01

83

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

PubMed

A campaign was conducted to assess and compare the air quality at the different metro platforms at Shanghai City, focusing on particulate matter (PM) levels, chemical compositions, morphology and mineralogy, as well as species of iron. Our results indicated that the average PM?.? concentrations for the three metro lines were 177.7 ?g/m(3), 105.7 ?g/m(3) and 82.5 ?g/m(3), respectively, and the average PM1 concentrations for the three lines were 122.3 ?g/m(3), 84.1 ?g/m(3) and 59.6 ?g/m(3), respectively. Fe, Mn, Cr, Cu, Sr, Ba and Pb concentrations in all of the sampling sites were significantly higher than that in the urban ambient air, implicating that these trace metals may be associated with the metro systems working. Individual airborne dusts were studied for morphology and mineralogy characteristics. The results revealed that the presence of most individual particles were with no definite shape and most of them were with a large metal content. Furthermore, Fe-rich particles had significantly higher abundance in the metro systems, which were more frequently encountered in the underground lines than the aboveground line. The 2D distribution map of an interested Fe-rich particle showed an uneven Fe distribution, implying that a hollow or core of other substance exists in the particle center during the formation process. Cluster analysis revealed that Fe-rich particles were possibly a mixture of Fe species. Fitting of X-ray absorption near-edge fine structure spectra (XANES) showed the main iron species within the particles collected from the three contrasting metro lines of Shanghai to be hematite, magnetite, iron-metal and mineral Fe. Hematite and mineral Fe were all found in three lines, while magnetite only existed in aboveground metro line. Iron-metal was determined in both the older and younger underground lines, based on the X-ray diffraction (XRD) analysis. As diverse Fe species have different physical-chemical characteristics and toxicity, the speciation of Fe-containing metro particles is important in the context of public health and control measures. PMID:25105755

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

2014-10-15

84

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

PubMed Central

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

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

1993-01-01

85

Removal of Zn(II) and Hg(II) from aqueous solution on a carbonaceous sorbent chemically prepared from rice husk.  

PubMed

A carbonaceous sorbent was prepared from rice husk via sulfuric acid treatment. Sorption of Zn(II) and Hg(II) from aqueous solution was studied varying time, pH, metal concentration, temperature and sorbent status (wet and dry). Zn(II) sorption was found fast reaching equilibrium within approximately 2h while Hg(II) sorption was slow reaching equilibrium within approximately 120 h with better performance for the wet sorbent than for the dry. Kinetics data for both metals were found to follow pseudo-second order model. Sorption rate of both metals was enhanced with temperature rise. Activation energy, E(a), for Zn(II) sorption, was approximately 13.0 kJ/mol indicating a diffusion-controlled process ion exchange process, however, for Hg(II) sorption, E(a) was approximately 54 kJ/mol indicating a chemically controlled process. Sorption of both metals was low at low pH and increased with pH increase. Sorption was much higher for Hg(II) than for Zn(II) with higher uptake for both metals by rising the temperature. Hg(II) was reduced to Hg(I) on the sorbent surface. This was confirmed from the identification of Hg(2)Cl(2) deposits on the sorbent surface by scanning electron microscopy and X-ray diffraction. However, no redox processes were observed in Zn(II) sorption. Sorption mechanism is discussed. PMID:19883976

El-Shafey, E I

2010-03-15

86

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

87

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

NASA Astrophysics Data System (ADS)

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

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

2014-01-01

88

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...

89

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

90

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...

91

Complex network of chemical and physical processes and evolution of precipitation forms in the Copper(II)-oxalate system  

Microsoft Academic Search

Summary Chemical systems that are far from thermodynamic equilibrium have a tendency to form complex temporal and spatiotemporal structures. In our paper, we present unusual sequence patterns observed in the Cu(II)- oxalate system. The Chemical reactions and physical processes of gravitational flow and diffusion are organized in space and time and are found to cause the evolution of a precipitation

A. Baker; S. Ali; A. Toth; D. Horvath; E. Heo; S. Elano; A. Holombo

92

Triggered massive-star formation on the borders of Galactic H II regions. II. Evidence for the collect and collapse process around RCW 79  

NASA Astrophysics Data System (ADS)

We present SEST-SIMBA 1.2-mm continuum maps and ESO-NTT SOFI JHKS images of the Galactic H ii region RCW 79. The millimetre continuum data reveal the presence of massive fragments located in a dust emission ring surrounding the ionized gas. The two most massive fragments are diametrically opposite each other in the ring. The near-IR data, centred on the compact H ii region located at the south-eastern border of RCW 79, show the presence of an IR-bright cluster containing massive stars along with young stellar objects with near-IR excesses. A bright near- and mid-IR source is detected towards maser emissions, 1.2 pc north-east of the compact H ii region centre. Additional information extracted from the Spitzer GLIMPSE survey is used to discuss the nature of the bright IR sources observed towards RCW 79. Twelve luminous Class I sources are identified towards the most massive millimetre fragments. All these facts strongly indicate that the massive-star formation observed at the border of the H ii region RCW 79 has been triggered by its expansion, most probably by the collect and collapse process.

Zavagno, A.; Deharveng, L.; Comerón, F.; Brand, J.; Massi, F.; Caplan, J.; Russeil, D.

2006-01-01

93

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

ERIC Educational Resources Information Center

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

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

94

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, Zaneta; Blas, Marek; Klimaszewska, Kamila; Sobik, Mieczyslaw; Malek, Stanislaw; Namiesnik, Jacek

2008-01-01

95

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

ERIC Educational Resources Information Center

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

Wartski, Bert; Wartski, Lynn Marie

96

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

97

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

98

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.

99

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

100

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...

101

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

102

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

103

Charting calcium-regulated apoptosis pathways using chemical biology: role of calmodulin kinase II  

PubMed Central

Background Intracellular free calcium ([Ca2+]i) is a key element in apoptotic signaling and a number of calcium-dependent apoptosis pathways have been described. We here used a chemical biology strategy to elucidate the relative importance of such different pathways. Results A set of 40 agents ("bioprobes") that induce apoptosis was first identified by screening of a chemical library. Using p53, AP-1, NFAT and NF-?B reporter cell lines, these bioprobes were verified to induce different patterns of signaling. Experiments using the calcium chelator BAPTA-AM showed that Ca2+ was involved in induction of apoptosis by the majority of the bioprobes and that Ca2+ was in general required several hours into the apoptosis process. Further studies showed that the calmodulin pathway was an important mediator of the apoptotic response. Inhibition of calmodulin kinase II (CaMKII) resulted in more effective inhibition of apoptosis compared to inhibition of calpain, calcineurin/PP2B or DAP kinase. We used one of the bioprobes, the plant alkaloid helenalin, to study the role of CaMKII in apoptosis. Helenalin induced CaMKII, ASK1 and Jun-N-terminal kinase (JNK) activity, and inhibition of these kinases inhibited apoptosis. Conclusion Our study shows that calcium signaling is generally not an early event during the apoptosis process and suggests that a CaMKII/ASK1 signaling mechanism is important for sustained JNK activation and apoptosis by some types of stimuli. PMID:18673549

Olofsson, Maria Hagg; Havelka, Aleksandra Mandic; Brnjic, Slavica; Shoshan, Maria C; Linder, Stig

2008-01-01

104

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

E-print Network

been based on the levels of essential nutrients found in pollen, the predominant source of proteins, lipids, minerals, and vitamins in the diet of the honey bee, Apis mellijera L. However, the chemical. This suggests that microorganisms are probably involved in the storage of pollen. Bee bread stored in combs

Paris-Sud XI, Université de

105

DEVELOPMENT AND ASSESSMENT OF PROCEDURES FOR COLLECTION, CHEMICAL CHARACTERIZATION AND MUTAGENICITY TESTING OF AMBIENT AIR  

EPA Science Inventory

The overall objective of this Research Triangle Institute pilot study was to develop and evaluate a minimal testing protocol which could detect and quantify the mutagenic potential of ambient air. The cost-effective biological and chemical testing protocol developed under this pr...

106

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...

107

Simultaneous determination of platinum(II) and palladium(II) by reversed phase high-performance liquid chromatography with spectrophotometric detection after collection on and elution from resin coated with dimethylglyoxal bis(4-phenyl-3-thisomicarbazone).  

PubMed

Amberlite XAD-7 resin coated with dimethylglyoxal bis(4-phenyl-3-thiosemicarbazone) (DMBS) was prepared and applied to the preconcentration of platinum(II) and palladium(II) from aqueous solution. Platinum(II) and palladium(II) were collected quantitatively on resin coated with the reagent (DMBS-XAD-7) from acidic solution in the presence of iodide ion by a bach method. The metal ions were then easily eluted from DMBS-XAD-7 as their DMBS chelates with a small volume of N,N-dimethylformamide. This collection and elution method was applied to the simultaneous determination of platinum(II) and palladium(II) by reversed-phase high-performance liquid chromatography with spectrophotometric detection using an ODS column and acetone-water as the mobile phase. The proposed method was applied to the determination of the metals in commercially available samples. PMID:18966776

Hoshi, S; Higashihara, K; Suzuki, M; Sakurada, Y; Sugawara, K; Uto, M; Akatsuka, K

1997-04-01

108

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

NASA Technical Reports Server (NTRS)

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

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

1985-01-01

109

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

110

Collective Surfing of Chemically Active Particles Hassan Masoud1,2,*  

E-print Network

them. For a 3D diffusion-dominated concentration field and Stokesian fluid we show that the surface show that such singular behavior occurs in our finite-depth system, and study the associated 3D flow the collective dynamics of immotile particles bound to a 2D surface atop a 3D fluid layer. These particles

Shelley, Michael

111

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

112

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

PubMed

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. delta(56)Fe values for bulk HCl- and HF-extractable Fe were approximately 0. These near-zero bulk delta(56)Fe values, together with the very low abundance of dissolved Fe in the overlying water column, suggest that the pyrite Fe source had near-zero delta(56)Fe 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 (delta(56)Fe approximately -1.5 to -0.5 per thousand) 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 per thousand. 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-delta(56)Fe minerals during BIF genesis. PMID:20374296

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

2010-06-01

113

Interpretation of chemical analyses of waters collected from two geothermal wells at Coso, California  

Microsoft Academic Search

Wellhead and downhole water samples were collected and analyzed from a 114.3-m well at Coso Hot Springs (Coso No. 1) and a 1477-m well (CGEH No. 1) 3.2 km to the west. The same chloride concentration is present in hot waters entering both wells (about 2350 mg\\/kg), indicating that a hot-water-dominated geothermal system is present. The maximum measured temperatures are

R. O. Fournier; J. M. Thompson; C. F. Austin

1980-01-01

114

Quantifying the physical and chemical mass transfer processes for the fate and transport of Co(II)EDTA in a partially-weathered limestone-shale saprolite.  

PubMed

The objective of the research is to quantify the relative contributions of physical and chemical mass transfer to the movement of Co(II/III)EDTA (chelates of Cobalt and Ethylene Diamine Tetraacetic Acid or EDTA) through a limestone-shale saprolite soil. Saprolite is a collective term referring to partially-weathered bedrock. It exists extensively in the subsurface. Because the parent bedding structures are maintained during the weathering process, saprolite soils are characterized by intensive fractures and secondary deposits of minerals such as Al-, Fe- and Mn-oxides on the fracture surfaces. Movement of reactive species through the soils may be influenced by diffusion into the rock matrix, a physical mass transfer (PMT) process, and interfacial chemical reactions, a chemical mass transfer (CMT) process. The PMT and CMT processes are phenomenologically similar but mechanistically different. In this research, previous laboratory observations from a Br and Co(II)EDTA tracer injection into an undisturbed saprolite soil column were used. Mechanistic reactive transport models were formulated to quantify the PMT and CMT processes. The PMT process was independently characterized by using the non-reactive tracer Br. Model parameters thus obtained were subsequently used as constraints to quantify the CMT processes involving Co(II)EDTA and its oxidation product Co(III)EDTA. Our calculations indicated that the PMT rates of the less reactive Co(III)EDTA were comparable with their theoretical CMT rates. In contrast, for the more reactive species Co(II)EDTA, CMT rates are higher than PMT rates. Evaluations of alternative CMT process models further confirmed one of our hypotheses on the basis of previous experimental understandings. The hypothesis suggested that competition from Fe-oxide for Co(II)EDTA may account for the majority of the decrease of Co(III)EDTA effluent concentrations that resulted in the separation of total Co and Co(III)EDTA breakthrough curves. Because Co(III)EDTA is more mobile than Co(II)EDTA in the subsurface, the results of this research suggest independent quantifications of CoEDTA PMT and CMT processes if laboratory results are to be interpreted correctly and scaled up for field and predictive uses. PMID:17137677

Gwo, Jin-Ping; Mayes, Melanie A; Jardine, Philip M

2007-03-20

115

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

116

Biogeography of Actinomycete Communities and Type II Polyketide Synthase Genes in Soils Collected in New Jersey and Central Asia?  

PubMed Central

Soil microbial communities are believed to be comprised of thousands of different bacterial species. One prevailing idea is that “everything is everywhere, and the environment selects,” implying that all types of bacteria are present in all environments where their growth requirements are met. We tested this hypothesis using actinomycete communities and type II polyketide synthase (PKS) genes found in soils collected from New Jersey and Uzbekistan (n = 91). Terminal restriction fragment length polymorphism analysis using actinomycete 16S rRNA and type II PKS genes was employed to determine community profiles. The terminal fragment frequencies in soil samples had a lognormal distribution, indicating that the majority of actinomycete phylotypes and PKS pathways are present infrequently in the environment. Less than 1% of peaks were detected in more than 50% of samples, and as many as 18% of the fragments were unique and detected in only one sample. Actinomycete 16S rRNA fingerprints clustered by country of origin, indicating that unique populations are present in North America and Central Asia. Sequence analysis of type II PKS gene fragments cloned from Uzbek soil revealed 35 novel sequence clades whose levels of identity to genes in the GenBank database ranged from 68 to 92%. The data indicate that actinomycetes are patchily distributed but that distinct populations are present in North American and Central Asia. These results have implications for microbial bioprospecting and indicate that the cosmopolitan actinomycete species and PKS pathways may account for only a small proportion of the total diversity in soil. PMID:17337547

Wawrik, Boris; Kutliev, Djumaniyaz; Abdivasievna, Urinova A.; Kukor, Jerome J.; Zylstra, Gerben J.; Kerkhof, Lee

2007-01-01

117

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

118

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

119

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

PubMed

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

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

2014-01-01

120

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

SciTech Connect

Approximately 250,000 tonnes of irradiated graphite waste exists worldwide and that quantity is expected to increase with decommissioning of Generation II reactors and deployment of Generation IV gas-cooled, graphite moderated reactors. This situation indicates the need for a graphite waste management strategy. Of greatest concern for long-term disposal of irradiated graphite is carbon-14 (C-14), with a half-life of 5730 years. Study of irradiated graphite from some nuclear reactors indicates C-14 is concentrated on the outer 5 mm of the graphite structure. The aim of the research presented last year and updated here is to identify the chemical form of C-14 in irradiated graphite and develop a practical method by which C-14 can be removed. A nuclear-grade graphite, NBG-18, and a high-surface-area graphite foam, POCOFoam{sup R}, were exposed to liquid nitrogen (to increase the quantity of C-14 precursor) and neutron-irradiated (10{sup 13} neutrons/cm{sup 2}/s). Finer grained NBG-25 was not exposed to liquid nitrogen prior to irradiation at a neutron flux on the order of 10{sup 14} /cm{sup 2}/s. Characterization of pre- and post-irradiation graphite was conducted to determine the chemical environment and quantity of C-14 and its precursors via the use of surface sensitive characterization techniques. Scanning Electron Microscopy (SEM) was used to evaluate the morphological features of graphite samples. The concentration, chemical composition, and bonding characteristics of C-14 and its precursors were determined through X-ray Photoelectron Spectroscopy (XPS), Time-of-Flight Secondary Ion Mass Spectrometry (SIMS), and Energy Dispersive X-ray Analysis Spectroscopy (EDX). Results of post-irradiation characterization of these materials indicate a variety of surface functional groups containing carbon, oxygen, nitrogen and hydrogen. During thermal treatment, irradiated graphite samples are heated in the presence of an inert carrier gas (with or without oxidant gas), which carries off gaseous products released during treatment. Graphite gasification occurs via interaction with adsorbed oxygen complexes. Experiments in argon were performed at 900 deg. C and 1400 deg. C to evaluate the selective removal of C-14. Thermal treatment also was performed with the addition of 3 and 5 volume % oxygen at temperatures 700 deg. C and 1400 deg. C. Thermal treatment experiments were evaluated for the effective selective removal of C-14. Lower temperatures and oxygen levels correlated to more efficient C-14 removal. (authors)

Dunzik-Gougar, Mary Lou; Cleaver, James; LaBrier, Daniel; McCrory, Shilo; Smith, Tara E. [Idaho State University: 1776 Science Center Dr., Idaho Falls, ID, 83401 (United States)] [Idaho State University: 1776 Science Center Dr., Idaho Falls, ID, 83401 (United States)

2013-07-01

121

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

SciTech Connect

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

Grimm, P.; Guenther-Leopold, I. [Paul Scherrer Inst., CH-5232 Villigen PSI (Switzerland); Berger, H. D. [AREVA NP GmbH, FEEP, Bunsenstrasse 43, D-91058 Erlangen (Germany)

2006-07-01

122

Possible role of metal(II) octacyanomolybdate(IV) in chemical evolution: interaction with ribose nucleotides.  

PubMed

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. PMID:23254853

Kumar, Anand; Kamaluddin

2013-02-01

123

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

PubMed

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

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

2013-05-15

124

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

125

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

126

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

127

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

NASA Astrophysics Data System (ADS)

Aims:We present new results of our ongoing chemical study of carbon stars in Local Group galaxies to test the critical dependence of s-process nucleosynthesis on the stellar metallicity. Methods: We collected optical spectra with the VLT/UVES instrument of two carbon stars found in the Carina Dwarf Spheroidal (dSph) galaxy, namely ALW-C6 and ALW-C7. We performed a full chemical analysis using the new generation of hydrostatic, spherically symmetric carbon-rich model atmospheres and the spectral synthesis method in LTE. Results: The luminosities, atmosphere parameters and chemical composition of ALW-C6 and ALW-C7 are compatible with these stars being in the TP-AGB phase undergoing third dredge-up episodes, although their extrinsic nature (external pollution in a binary stellar system) cannot be definitively excluded. Our chemical analysis shows that the metallicity of both stars agree with the average metallicity ([Fe/H] -1.8 dex) previously derived for this satellite galaxy from the analysis of both low resolution spectra of RGB stars and the observed colour magnitude diagrams. ALW-C6 and ALW-C7 present strong s-element enhancements, [ s/Fe] = +1.6, +1.5, respectively. These enhancements and the derived s-process indexes [ ls/Fe] , [ hs/Fe] and [ hs/ls] are compatible with theoretical s-process nucleosynthesis predictions in low mass AGB stars ( 1.5 M_?) on the basis that the 13C(?,n)16O is the main source of neutrons. Furthermore, the analysis of C2 and CN bands reveals a large carbon enhancement (C/O 7 and 5, respectively), much larger than the values typically found in galactic AGB carbon stars (C/O 1{-}2). This is also in agreement with the theoretical prediction that AGB carbon stars are formed more easily through third dredge-up episodes as the initial stellar metallicity drops. However, theoretical low-mass AGB models apparently fail to simultaneously fit the observed s-element and carbon enhancements. On the other hand, Zr is found to be less enhanced in ALW-C7 compared to the other elements belonging to the same s-peak. Although the abundance errors are large, the fact that in this star the abundance of Ti (which has a similar condensation temperature to Zr) seems also to be lower than those of others metals, may indicate the existence of some depletion into dust-grains in its photosphere. Based on observations collected with the VLT/UT2 telescope (Paranal Observatory, ESO, Chile) using the UVES (program ID 74.D-0539) instrument.

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

2008-04-01

128

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.

129

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

130

The chemical composition of atmospheric deposition collected from six Louisiana sites from 1983 to 1992  

NASA Astrophysics Data System (ADS)

Since 1983, precipitation samples have been collected weekly from six Louisiana sites. Analyses performed included pH, EC, Ca 2+, Na +, Mg 2+, K +, NH 4+, Cl, NO 3-, SO 42-, PO 43-, and precipitation amount. These data were used to determine quarterly and yearly regional trends in precipitation chemistry and deposition. Concentrations of K + (< 0.2 mg? -1), Mg 2+ (< 0.02 mg? -1) and PO 43- (< 0.5 mg? -1) were below detection limits more than 90% of the time. Calcium, Na +, NH 4+, SO 42-, and Cl - had the highest deposition during the spring at most sites. The highest EC values were found in the summer, while the lowest were in the fall. Nitrate deposition was highest in the summer and lowest in the fall. Sulfate and NH 4+ had the least deposition in the fall for most sites. The most acidic pH values were in the summer for all six sites. The lowest precipitation amounts were in the summer and fall, while the highest were in the winter. Yearly deposition amounts of nutrients were not sufficient to meet major crop requirements. Sulfur was deposited in quantities to meet one-half to one-third of its requirement in cotton, rice, soybeans, and wheat.

West, L. M.; Feagley, S. E.

131

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

PubMed Central

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

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

2012-01-01

132

Chemical characteristics of rainwater collected at a western site of Jordan  

NASA Astrophysics Data System (ADS)

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

Al-Khashman, Omar Ali.

2009-01-01

133

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

PubMed

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

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

1998-12-11

134

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

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

135

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

136

Interplanetary dust particles collected from the stratosphere: Physical, chemical, and mineralogical properties and implications for their sources  

NASA Technical Reports Server (NTRS)

The suggestion that significant quantities of interplanetary dust are produced by both main-belt asteroids and comets is based on the Infrared Astronomical Satellite (IRAS) detection of dust trails or bands associated with these objects. Gravitational focusing strongly biases all near-Earth collections of interplanetary dust in favor of particles with the lowest geocentric velocities, that is the dust from main-belt asteroids spiraling into the Sun under the influence of Poynting-Robertson radiation drag. The major dust bands in the main-belt appear to be associated with the catastrophic disruptions which produced the Eos, Themis and Koronis families of asteroids. If dust particles are produced in the catastrophic collision process, then Poynting-Robertson radiation drag is such an efficient transport mechanism from the main-belt to 1 AU that near-Earth collections of interplanetary dust should include, and perhaps be dominated by, this material. Interplanetary dust particles from 5 to 100 micrometers in diameter have been recovered from the stratosphere of the Earth by NASA sampling aircraft since the mid-1970s. The densities of a large fraction of these interplanetary dust particles are significantly lower than the densities of their constituent silicate mineral phases, indicating significant porosites. The majority of the particles are chemically and mineralogically similar to, but not identical to, the carbonaceous chondrite meteorites. Most stony interplanetary dust particles have carbon contents exceeding those of Allende, a carbonaceous chondrite meteorite having a low albedo. Higher albedo particles corresponding to S-type asteroids are underrepresented or absent from the stratospheric collections, and primitive carbonaceous particles seem to be overrepresented in the stratospheric collections compared to the fraction of main-belt asteroids classified as primitive. This suggests that much of the interplanetary dust may be generated by a stochastic process, probably preferentially sampling a few most recent collisional events.

Flynn, George J.

1994-01-01

137

Chemical trends of defect formation and doping limit in II-VI semiconductors: The case of CdTe  

Microsoft Academic Search

Using first-principles band structure methods we studied the general chemical trends of defect formation in II-VI semiconductors. We systematically calculated the formation energies and transition energy levels of intrinsic and extrinsic defects and defect complexes in the prototype CdTe and investigated the limiting factors for p-type and n-type doping in this material. Possible approaches to significantly increase the doping limits

Su-Huai Wei; S. B. Zhang

2002-01-01

138

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

NASA Astrophysics Data System (ADS)

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

Mitewa, Mariana; Enchev, Venelin; Bakalova, Tatyana

2002-05-01

139

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

SciTech Connect

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

Benda, F.; Kouba, J. (Czechoslovak Academy of Sciences, Na sadkach (Czechoslovakia))

1991-03-01

140

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

PubMed

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

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

2012-09-01

141

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

142

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

143

Chemical evolution of peroxidase — amino acid pentacyanoferrate (II) complexes as model  

NASA Astrophysics Data System (ADS)

Complexes of the type [Fe(II)(CN)5(L)] n- (wheren=3, or 4;L = glycine, histidine, imidazole, and triglycine) are proposed as evolutionary model of peroxidases. Detailed kinetic investigation for disproportionation of hydrogen peroxide catalysed by [Fe(II)(CN)5(L)] n- complexes at 40°C and pH 9.18 are discussed. Decomposition of hydrogen peroxide catalysed by above complexes conforms to Michaelis-Menten type kinetics.

Kamaluddin; Nath, Mala; Deopujari, Sushama W.

1988-09-01

144

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

145

Chemical evolution of peroxidase--amino acid pentacyanoferrate (II) complexes as model.  

PubMed

Complexes of the type [Fe(II)(CN)5(L)]n- (where n = 3, or 4; L = glycine, histidine, imidazole, and triglycine) are proposed as evolutionary model of peroxidases. Detailed kinetic investigation for disproportionation of hydrogen peroxide catalysed by [Fe(II)(CN)5(L)]n- complexes at 40 degrees C and pH 9.18 are discussed. Decomposition of hydrogen peroxide catalysed by above complexes conforms to Michaelis-Menten type kinetics. PMID:3226719

Kamaluddin; Nath, M; Deopujari, S W

1988-01-01

146

An H II region in NGC 6744 - Spectrophotometry and chemical abundances  

Microsoft Academic Search

Spectrophotometry of emission lines in the spectral range 3700-6800 A is presented for an H II region in an outer arm of NGC 6744, a Southern Hemisphere galaxy of type SAB(r)bc II. The electron temperature, derived from the forbidden O III lines and assuming Ne = 100\\/cu cm, is found to be 9,630 + or - 450 K. Ionic abundances,

D. L. Talent

1982-01-01

147

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...

148

Chemical Protective Clothing Standard Test Method Development: Part II. Degradation Test Method  

Microsoft Academic Search

A “round-robin” interlaboratory evaluation of a proposed American Society for Testing and Materials (ASTM) standard test method was conducted for measuring the resistance of chemical protective clothing materials to degradation by liquid chemicals. The objective of this project was to determine the relative precision of the method and, where appropriate, recommend modifications that would improve reliability. In the round-robin format,

GERARD C. COLETTA; S. Z. MANSDORF; S. P. BERARDINELLI

1988-01-01

149

A quantum chemical study of bis-(iminoquinonephenolate) Zn(II) complexes.  

PubMed

A computational DFT B3LYP*/6-311++G(d,p) study performed on bis-(iminoquinonephenolate) Zn(II) complex [Zn(II)(C(12)H(8)NO(2))(2)] has revealed a previously unexplored mechanism for valence tautomerism inherent in transition metal complexes with redox active (noninnocent) ligands. The occurrence of energy-close isomeric forms of the complex and their low energy barrier interconversion is caused not by the intramolecular electron transfer (IET) between the metal and ligand frontier orbitals, but the intersystem conversion within a redox active ligand without involvement of a metal center. This mechanism gives a new insight into the origin of the previously experimentally studied isomeric forms of bis-(iminoquinonephenolate) Zn(II) complexes that must be assigned to [Zn(II)((1)L(-1))(2)] (8) and [Zn(II)((1)L(-1))((3)L(-1))] (9) structures. The spin-forbidden transition between the two forms of the complex proceeds via a minimal energy crossing point (MECP) corresponding to the energy barrier of 8.9 kcal mol(-1) for the 9 --> 8 transformation in the gas phase. PMID:20597518

Starikov, Andrey G; Minkin, Vladimir I; Minyaev, Ruslan M; Koval, Vitaliy V

2010-07-29

150

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...

151

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

152

Characterizing Materials Sources and Sinks; Current Approaches: Part II. Chemical and Physical Characterization  

EPA Science Inventory

The paper discusses methods for characterizing chemical emissions from material sources, including laboratory, dynamic chamber, and full-scale studies. Indoor sources and their interaction with sinks play a major role in determining indoor air quality (IAQ). Techniques for evalua...

153

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...

154

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

NASA Astrophysics Data System (ADS)

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

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

2013-02-01

155

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 ...

156

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 ...

157

Exclusion of Cosmic Rays in Protoplanetary Disks. II. Chemical Gradients and Observational Signatures  

E-print Network

The chemical properties of protoplanetary disks are especially sensitive to their ionization environment. Sources of molecular gas ionization include cosmic rays, stellar X-rays and short-lived radionuclides, each of which varies with location in the disk. This behavior leads to a significant amount of chemical structure, especially in molecular ion abundances, which is imprinted in their submillimeter rotational line emission. Using an observationally motivated disk model, we make predictions for the dependence of chemical abundances on the assumed properties of the ionizing field. We calculate the emergent line intensity for abundant molecular ions and simulate sensitive observations with the Atacama Large Millimeter/Sub-millimeter Array (ALMA) for a disk at D=100 pc. The models readily distinguish between high ionization rates ($\\zeta\\gtrsim10^{-17}$ s$^{-1}$ per H$_2$) and below, but it becomes difficult to distinguish between low ionization models when $\\zeta\\lesssim10^{-19}$ s$^{-1}$. We find that \\htdp...

Cleeves, L I; Adams, Fred C

2014-01-01

158

PWR steam generator chemical cleaning. Phase I: solvent and process development. Volume II  

Microsoft Academic Search

A program to demonstrate chemical cleaning methods for removing magnetite corrosion products from the annuli between steam generator tubes and the tube support plates in vertical U-tube steam generators is described. These corrosion products have caused steam generator tube ''denting'' and in some cases have caused tube failures and support plate cracking in several PWR generating plants. Laboratory studies were

A. P. Larrick; R. A. Paasch; T. M. Hall; D. Schneidmiller

1979-01-01

159

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...

160

N-coco acyl derivatives, inner salt (betaine) SUBCATEGORY II: ALKYL AMINIUM AMPHOTERICS SPONSORED CHEMICAL  

E-print Network

inner salt The High Production Volume (HPV) Challenge Program 1 was conceived as a voluntary initiative aimed at developing and making publicly available screening-level health and environmental effects information on chemicals manufactured in or imported into the United States in quantities greater than one million pounds per year. In the Challenge Program, producers and importers of HPV chemicals voluntarily sponsored chemicals; sponsorship entailed the identification and initial assessment of the adequacy of existing toxicity data/information, conducting new testing if adequate data did not exist, and making both new and existing data and information available to the public. Each complete data submission contains data on 18 internationally agreed to “SIDS” (Screening Information Data Set 1,2) endpoints that are screening-level indicators of potential hazards (toxicity) for humans or the environment. The Environmental Protection Agency’s Office of Pollution Prevention and Toxics (OPPT) is evaluating the data submitted in the HPV Challenge Program on approximately 1400 sponsored chemicals by developing hazard characterizations (HCs). These HCs consist of an evaluation of the quality and completeness of the data set provided in the Challenge Program submissions.

unknown authors

161

Chemical defense production in Lotus corniculatus L. II. Trade-offs among growth, reproduction and defense  

Microsoft Academic Search

Ecological trade-offs between growth, reproduction and both condensed tannins and cyanogenic glycosides were examined in Lotus corniculatus by correlating shoot (leaves and stem) size and reproductive output with chemical concentrations. We found that cyanide concentration was not related to shoot size, but that condensed tannin concentrations were positively correlated with shoot size; larger plants contained higher tannin concentrations. Both tannin

Michelle A. Briggs; Jack C. Schultz

1990-01-01

162

THE MECHANICAL PROPERTIES OF HAIR II. CHEMICAL MODIFICATIONS AND PATHOLOGICAL HAIRS  

Microsoft Academic Search

The direct measurement of the ultrasonically determined modulus of elasticity (UME) has been extended to chemically modified hair and to pathological hairs. Single hairs are equilibrated at 75% relative humidity and studied with simultaneous stress-strain tests and direct measurements of the UME. Disulfide reduction with IM dithiothreitol produced more extensible hairs in which the UME retains its characteristic relationship to

Lowell A. Goldsmith; Howard P. Baden

1971-01-01

163

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...

164

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 ...

165

A theoretical analysis of chemical bonding, vibronic coupling, and magnetic anisotropy in linear iron(II)  

E-print Network

of high-spin FeII with linear FeX2 (X ¼ C, N, O) cores, Fe[N(SiMe3)(Dipp)]2 (1), Fe[C(SiMe3)3]2 (2), Fe[N(H)Ar0 ]2 (3), Fe[N(H)Ar*]2 (4), Fe[O(Ar0 )]2 (5), and Fe[N(t-Bu)2]2 (7) [Dipp ¼ C6H3-2,6-Pri 2; Ar0 ¼ C6)2], and one bent (FeN2) complex, Fe[N(H)Ar# ]2 (6), have been studied theoretically using complete active

166

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

NASA Technical Reports Server (NTRS)

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

Radhakrishnan, K.

1986-01-01

167

[Irritant contact dermatitis. Part II. Evaluation evaluation of skin irritation potential of chemicals].  

PubMed

The evaluation of skin irritation potential of chemicals is essential to secure the safety of individuals exposed to several substances designed for industrial, pharmaceutical or cosmetic use. Until recently, preclinical safety assessment of chemicals was largely based on animal experiments. Ethical concerns and the limited value of animal models in evaluating human skin irritation potential resulted in the development of alternative in vitro methods, such as EpiDerm, EPISKIN or SkinEthic, to assess irritation, i.e. cell cultures and human epidermis models. International organizations like the European Centre for the Validation of Alternative Methods (ECVAM) promotes and monitors the development of nonanimal tests. Human patch tests and use tests also provide an opportunity to identify substances with significant skin irritation potential without recourse to the use of animals. These tests are useful to assess skin irritation potential of cosmetics and detergents. PMID:19746889

Chomiczewska, Dorota; Kie?-Swierczy?ska, Marta; Krecisz, Beata

2009-01-01

168

Exclusion of Cosmic Rays in Protoplanetary Disks. II. Chemical Gradients and Observational Signatures  

NASA Astrophysics Data System (ADS)

The chemical properties of protoplanetary disks are especially sensitive to their ionization environment. Sources of molecular gas ionization include cosmic rays (CRs), stellar X-rays, and short-lived radionuclides, each of which varies with location in the disk. This behavior leads to a significant amount of chemical structure, especially in molecular ion abundances, which is imprinted in their submillimeter rotational line emission. Using an observationally motivated disk model, we make predictions for the dependence of chemical abundances on the assumed properties of the ionizing field. We calculate the emergent line intensity for abundant molecular ions and simulate sensitive observations with the Atacama Large Millimeter/Sub-millimeter Array (ALMA) for a disk at D = 100 pc. The models readily distinguish between high ionization rates (? >~ 10–17 s–1 per H2) and below, but it becomes difficult to distinguish between low ionization models when ? <~ 10–19 s–1. We find that H2D+ emission is not detectable for sub-interstellar CR rates with ALMA (6h integration), and that N2D+ emission may be a more sensitive tracer of midplane ionization. HCO+ traces X-rays and high CR rates (?CR >~ 10–17 s–1), and provides a handle on the warm molecular ionization properties where CO is present in the gas. Furthermore, species like HCO+, which emits from a wide radial region and samples a large gradient in temperature, can exhibit ring-like emission as a consequence of low-lying rotational level de-excitation near the star. This finding highlights a scenario where rings are not necessarily structural or chemical in nature, but simply a result of the underlying line excitation properties.

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

2014-10-01

169

A novel chemical molecular beam deposition method for fabrication of II–VI low dimensional structures  

Microsoft Academic Search

CdSe, CdTe and ZnxCdTe1?x films were fabricated by novel and low cost chemical molecular beam deposition method in the atmospheric pressure H2 and Ar flows. Zn, Cd, Se and Te were used as precursors. The kinetics of the growth process of the films depended strongly on the molecular beam intensity (MBI) ratio of the metal IA and the chalcogen IB

T. M. Razykov

2005-01-01

170

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

NASA Astrophysics Data System (ADS)

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

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

2011-11-01

171

A Pre-Protostellar Core in L1551. II. State of Dynamical and Chemical Evolution  

E-print Network

Both analytic and numerical radiative transfer models applied to high spectral resolution CS and N2H+ data give insight into the evolutionary state of L1551 MC. This recently discovered pre-protostellar core in L1551 appears to be in the early stages of dynamical evolution. Line-of-sight infall velocities of >0.1km/s are needed in the outer regions of L1551 MC to adequately fit the data. This translates to an accretion rate of ~ 1e-6 Msun/yr, uncertain to within a factor of 5 owing to unknown geometry. The observed dynamics are not due to spherically symmetric gravitational collapse and are not consistent with the standard model of low-mass star formation. The widespread, fairly uniform CS line asymmetries are more consistent with planar infall. There is modest evidence for chemical depletion in the radial profiles of CS and C18O suggesting that L1551 MC is also chemically young. The models are not very sensitive to chemical evolution. L1551 MC lies within a quiescent region of L1551 and is evidence for continued star formation in this evolved cloud.

J. Swift; Wm. J. Welch; J. Di Francesco; I. Stojimirovic

2005-09-27

172

Phase I and II biotransformation enzymes and polycyclic aromatic hydrocarbons in the Mediterranean mussel (Mytilus galloprovincialis, Lamarck, 1819) collected in front of an oil refinery.  

PubMed

The aim of the present study was to investigate the responses of phase I and II biotransformation enzymes and levels of PAHs in the Mediterranean mussel (Mytilus galloprovincialis, Lamarck, 1819) collected from three sites at different distance from an oil refinery. Phase I enzyme activities as NAD(P)H-cyt c red, NADH ferry red, B(a)PMO and phase II as UDPGT, GST were measured in digestive gland while 16 PAHs (US-EPA) in whole soft tissue. An added value to the data obtained in the present study rely on the RDA analysis which showed close correlations between PAHs levels and phase I enzyme activities in mussels collected in front of the refinery. And again a significant spatial correlation between B(a)P levels and NADPH-cyt c red activities was observed using linear models. No differences among sites for B(a)PMO and phase II GST activities were observed, while the application of UDPGT as biomarkers requires further investigation. PMID:22651992

Trisciani, Anna; Perra, Guido; Caruso, Tancredi; Focardi, Silvano; Corsi, Ilaria

2012-08-01

173

[Unusual late complication after esophagoplasty type Gavriliu II for esophageal stenosis from chemical burns--cancer of the esophagoplasty tube].  

PubMed

We present the case of a 56 year old female, who in 23 years after esophagoplasty type Gavriliu II, with pre-sternal tube for esophageal chemical burn stenosis, develops a cancer in the upper third of the gastric tube, with a fast evolution to malnutrition, through lumen obturation. The evolution post-esophagoplasty was marked by malfunction of the neo-esophagus, characterized through dysphagia and distal dilatation, requiring many abdominal and pre-sternal reinterventions. The objective of the present surgical intervention was to assure a way for enteral nutrition (gastrostomy for feeding) and to extirpate the gastro-esophagoplasty tube. It is discussed the characteristic feature of the case: the difficulty of the stage-evolutive integration of this malignant disease location, the etiopathogenic factors that contributed to the malignant evolution of the antral portion of the gastro-esophagoplasty tube, the limits of the surgical treatment. PMID:15957461

Pa?alega, M; Burdescu, C; Me?in?, C; Mirea, C; Tenea, T; Vasile, I

2005-01-01

174

Metal-poor Dwarf Galaxies in the SIGRID Galaxy Sample. I. H II Region Observations and Chemical Abundances  

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

175

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

176

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...

177

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

178

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

179

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

EPA Science Inventory

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

180

Chemical molecular beam deposition of II VI binary and ternary compound films in a gas flow  

NASA Astrophysics Data System (ADS)

The paper presents results of an investigation of the growth process of large area (50 cm 2) CdSe, CdTe, ZnTe and Zn xCd 1-xTe(0 ? x ? 1) films by chemical molecular beam deposition in flowing H 2 and Ar from elementary sources of Cd, Zn, Se and Te. The molecular beam intensities I have been varied in the range of 10 13-10 15 cm -2 s -1. The condensation temperatures were 400 to 600°C. The influence of the molecular beam intensities ratio, over a wide range, namely 10 -2< I III VI<10, on the deposition rate, structure and resistivity of the films has been studied. The deposition rate and the thickness of films was varied over the range 0.2—2Å/s and 10 2-10 4Å, respectively.

Razykov, T. M.

1991-06-01

181

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

182

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

NASA Astrophysics Data System (ADS)

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

Hamilton, V. E.; Rogers, D.

2010-12-01

183

On the intersection of the shell, collective and cluster models of atomic nuclei II: Symmetry-breaking and large deformations  

E-print Network

We discuss the role of the broken symmetries in the connection of the shell, collective and cluster models. The cluster-shell competition is described in terms of cold quantum phases. Stable quasi-dynamical U(3) symmetry is found for specific large deformations for a Nilsson-type Hamiltonian.

J. Cseh; J. Darai

2014-04-14

184

Chemically consistent evolution of galaxies. II. Spectrophotometric evolution from zero to high redshift  

NASA Astrophysics Data System (ADS)

The composite stellar populations of galaxies comprise stars of a wide range of metallicities. Subsolar metallicities become increasingly important, both in the local universe when going from early towards later galaxy types as well as for dwarf galaxies and for all types of galaxies towards higher redshifts. We present a new generation of chemically consistent evolutionary synthesis models for galaxies of various spectral types from E through Sd. The models follow the chemical enrichment of the ISM and take into account the increasing initial metallicity of successive stellar generations using recently published metallicity dependent stellar evolutionary isochrones, spectra and yields. Our first set of closed-box 1-zone models does not include any spatial resolution or dynamics. For a Salpeter initial mass function (IMF) the star formation rate (SFR) and its time evolution are shown to successfully parameterise spectral galaxy types E, ..., Sd. We show how the stellar metallicity distribution in various galaxy types build up with time to yield after ˜12 Gyr agreement with stellar metallicity distributions observed in our and other local galaxies. The models give integrated galaxy spectra over a wide wavelength range (90.9 Å-160 ?m), which for ages of ˜12 Gyr are in good agreement not only with observed broad band colours but also with template spectra for the respective galaxy types. Using filter functions for Johnson-Cousins U, B, V, RC, IC, as well as for HST broad band filters in the optical and Bessel & Brett's NIR J, H, K filter system, we calculate the luminosity and colour evolution of model galaxies over a Hubble time. Including a standard cosmological model (H0 = 65, ?0 = 0.1) and the attenuation by intergalactic hydrogen we present evolutionary and cosmological corrections as well as apparent luminosities in various filters over the redshift range from z ˜ 5 to the present for our galaxy types and compare to earlier models using single (=solar) metallicity input physics only. We also resent a first comparison of our cc models to HDF data. A more detailed comparison with Hubble Deep Field (HDF) and other deep field data and an analysis and interpretation of high redshift galaxies in terms of ages, metallicities, star formation histories and, galaxy types will be the subject of a forthcoming paper.

Bicker, J.; Fritze-v. Alvensleben, U.; Möller, C. S.; Fricke, K. J.

2004-01-01

185

Identifying new persistent and bioaccumulative organics among chemicals in commerce II: pharmaceuticals.  

PubMed

The goal of this study was to identify commercial pharmaceuticals that might be persistent and bioaccumulative (P&B) and that were not being considered in current wastewater and aquatic environmental measurement programs. We developed a database of 3193 pharmaceuticals from two U.S. Food and Drug Administration (FDA) databases and some lists of top ranked or selling drugs. Of the 3193 pharmaceuticals, 275 pharmaceuticals have been found in the environment and 399 pharmaceuticals were, based upon production volumes, designated as high production volume (HPV) pharmaceuticals. All pharmaceuticals that had reported chemical structures were evaluated for potential bioaccumulation (B) or persistence (P) using quantitative structure property relationships (QSPR) or scientific judgment. Of the 275 drugs detected in the environment, 92 were rated as potentially bioaccumulative, 121 were rated as potentially persistent, and 99 were HPV pharmaceuticals. After removing the 275 pharmaceuticals previously detected in the environment, 58 HPV compounds were identified that were both P&B and 48 were identified as P only. Of the non-HPV compounds, 364 pharmaceuticals were identified that were P&B. This study has yielded some interesting and probable P&B pharmaceuticals that should be considered for further study. PMID:21740030

Howard, Philip H; Muir, Derek C G

2011-08-15

186

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

SciTech Connect

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

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

2003-11-01

187

Chemical gradients in the Milky Way from the RAVE data. II. Giant stars  

E-print Network

We provide new constraints on the chemo-dynamical models of the Milky Way by measuring the radial and vertical chemical gradients for the elements Mg, Al, Si, Ti, and Fe in the Galactic disc and the gradient variations as a function of the distance from the Galactic plane ($Z$). We selected a sample of giant stars from the RAVE database using the gravity criterium 1.7$Galaxia code based on the Besan\\c con model and selected a corresponding mock sample to compare the model with the observed data. We measured the radial gradients and the vertical gradients as a function of the distance from the Galactic plane $Z$ to study their variation across the Galactic disc. The RAVE sample exhibits a negative radial gradient of $d[Fe/H]/dR=-0.054$ dex kpc$^{-1}$ close to the Galactic plane ($|Z|<0.4$ kpc) that becomes flatter for larger $|Z|$. Other elements follow the same trend although with some variations from element to element. The mock sample has radial...

Boeche, C; Piffl, T; Just, A; Steinmetz, M; Grebel, E K; Sharma, S; Kordopatis, G; Gilmore, G; Chiappini, C; Freeman, K; Gibson, B K; Munari, U; Siviero, A; Bienaymé, O; Navarro, J F; Parker, Q A; Reid, W; Seabroke, G M; Watson, F G; Wyse, R F G; Zwitter, T

2014-01-01

188

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

189

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

that retrofitting structures may mean accepting existing configurations of piping that increase the risk for water disasters and damage. Environmental Issues Participants discussed conservator input in creating preservation environments in storage facilities. Some...A BS T RAC T The Library Collections Conservation Discussion Group (LCCDG) co-chairs presented two topics for dis- cussion at the AIC Providence meeting: (1) conservation’s role in off-site storage workflows; and (2) conservation’s role...

Baker, Whitney; McCarthy, Christine

2006-01-01

190

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

NASA Astrophysics Data System (ADS)

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

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

2011-07-01

191

Cumulative physical uncertainty in modern stellar models. II. The dependence on the chemical composition  

NASA Astrophysics Data System (ADS)

Aims: We extend our previous work on the effects of the uncertainties on the main input physics for the evolution of low-mass stars. We analyse the dependence of the cumulative physical uncertainty affecting stellar tracks on the chemical composition. Methods: We calculated more than 6000 stellar tracks and isochrones, with metallicity ranging from Z = 0.0001 to 0.02, by changing the following physical inputs within their current range of uncertainty: 1H(p,?e+)2H, 14N(p,?)15O and triple-? reaction rates, radiative and conductive opacities, neutrino energy losses, and microscopic diffusion velocities. The analysis was performed using a latin hypercube sampling design. We examine in a statistical way - for different metallicities - the dependence on the variation of the physical inputs of the turn-off (TO) luminosity, the central hydrogen exhaustion time (tH), the luminosity and the helium core mass at the red-giant branch (RGB) tip, and the zero age horizontal branch (ZAHB) luminosity in the RR Lyrae region. Results: For the stellar tracks, an increase in the metallicity from Z = 0.0001 to Z = 0.02 produces a cumulative physical uncertainty error variation in TO luminosity from 0.028 dex to 0.017 dex, while the global uncertainty on tH increases from 0.42 Gyr to 1.08 Gyr. For the RGB tip, the cumulative uncertainty on the luminosity is almost constant at 0.03 dex, whereas the one on the helium core mass decreases from 0.0055 M? to 0.0035 M?. The dependence of the ZAHB luminosity error is not monotonic with Z, and it varies from a minimum of 0.036 dex at Z = 0.0005 to a maximum of 0.047 dex at Z = 0.0001. Regarding stellar isochrones of 12 Gyr, the cumulative physical uncertainty on the predicted TO luminosity and mass increases respectively from 0.012 dex to 0.014 dex and from 0.0136 M? to 0.0186 M?. Consequently, from Z = 0.0001 to Z = 0.02 for ages typical of galactic globular clusters, the uncertainty on the age inferred from the TO luminosity increases from 325 Myr to 415 Myr. Tables 1, 3, 6, and Appendix A are available in electronic form at http://www.aanda.org

Valle, G.; Dell'Omodarme, M.; Prada Moroni, P. G.; Degl'Innocenti, S.

2013-06-01

192

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

USGS Publications Warehouse

The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, National Park Service, Bureau of Reclamation, and Nevada Department of Wildlife, collected and assessed data to determine the general health and reproductive status of common carp (Cyprinus carpio) at two study areas in Lake Mead, Nevada, during May 1999-May 2000. These data will form the basis of interpretations and provide a comparison for continuing studies on the health of the ecosystem in Lake Mead. One study area, Las Vegas Bay, is in the western part of Lake Mead. Las Vegas Bay receives inflows from Las Vegas Wash, which is predominantly tertiary-treated wastewater effluent, and to a lesser extent stormwater runoff from Las Vegas, Henderson, and other nearby communities, and from ground water underlying Las Vegas Valley. The other study area, Overton Arm, is in the northern extent of Lake Mead. Overton Arm receives inflow from the Virgin and Muddy Rivers, which historically are not influenced by wastewater effluent. Both sexes of common carp were collected bimonthly for 12 months using boat-mounted electrofishing gear (a direct electric current is used to temporarily immobilize fish for capture) to determine their health and reproductive status and any relation between these factors and environmental contaminants. This report presents fish tissue chemistry, organic chemical compound concentrations, and biomarker data for 83 male common carp collected from Las Vegas Bay, similar organic chemistry results for 15 male common carp, and similar biomarker measures for 80 male common carp collected from Overton Arm. Tissue chemistry results also are presented for 16 female common carp and biomarker measures for 79 female common carp collected from Las Vegas Bay, and tissue chemistry results for 15 female common carp and biomarker measures for 81 female common carp collected from Overton Arm. Thirty-three organic chemical compounds plus total concentrations for four groups of compounds (chlordanes, polychlorinated biphenyls [PCBs], brominated diphenyl ethers [BDEs], and triclosans) were analyzed from extracts of whole-body tissue using gas chromatography/mass spectrometry in male common carp from Las Vegas Bay during May 1999 through May 2000. All 33 compounds were detected in at least one sample of whole-body tissue from male common carp collected in Las Vegas Bay. In Overton Arm, 37 organic compounds plus total concentrations of three groups of compounds (PCBs, BDEs, and triclosans) were analyzed in male common carp where 20 (54 percent) of the compounds were detected. Sixteen of the 33 compounds detected in male common carp from Las Vegas Bay and 10 compounds detected in males from Overton Arm have the potential to disrupt the endocrine system in fish in Lake Mead. During May and June 1999, the mean concentration of all organic compounds detected in male common carp was 670 micrograms per kilogram from Las Vegas Bay and 109 micrograms per kilogram from Overton Arm. Twenty-seven organic compounds plus total PCBs were analyzed from extracts of whole-body tissue in female common carp collected in Las Vegas Bay and Overton Arm during May 1999. Twenty-four (86 percent) of these compounds were detected in at least one sample of whole-body tissue from female common carp collected from Las Vegas Bay while 10 (36 percent) chemical compounds were detected in female common carp from Overton Arm during that same period. Median concentrations of all chemical compounds were higher in female common carp from Las Vegas Bay compared to those collected from Overton Arm except Dacthal (DCPA), which was similar between sites. Biomarker measures obtained for male and female common carp include gonadosomatic index (percentage of gonad weight to total body weight), plasma vitellogenin (a phospholipid protein normally produced by female common carp and other oviparous fish), and condition factor [body weight/(fork length)3]. Biomarker measures for male c

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

2007-01-01

193

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

PubMed

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

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

2013-02-01

194

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

Microsoft Academic Search

In order to unveil the chemical characteristics of rain water from 1 to 8 mm, rain water measurements were conducted in downtown Okayama for one year from March, 2004 to March 2005. Analytical parameters were pH, EC and the ion concentrations, F-, Cl-, NO2-, NO3-, SO42-, PO43-, Na+, NH4+, K+, Mg2+ and Ca2+. The mean pH and EC values of

Ken Kobayashi; Eiji Yamashita; Takatoshi Hiraki; Hiroshi Ishida

2008-01-01

195

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

196

Bioactivity, Chemical Profiling, and 16S rRNA-Based Phylogeny of Pseudoalteromonas Strains Collected on a Global Research Cruise  

Microsoft Academic Search

One hundred one antibacterial Pseudoalteromonas strains that inhibited growth of a Vibrio anguillarum test strain were collected on a global research cruise (Galathea 3), and 51 of the strains repeatedly demonstrated antibacterial\\u000a activity. Here, we profile secondary metabolites of these strains to determine if particular compounds serve as strain or\\u000a species markers and to determine if the secondary metabolite profile

Nikolaj G. Vynne; Maria Månsson; Kristian F. Nielsen; Lone Gram

197

Old open clusters as key tracers of Galactic chemical evolution. II. Iron and elemental abundances in NGC 2324, NGC 2477 NGC 2660, NGC 3960, and Berkeley 32  

Microsoft Academic Search

Aims:To constrain the formation and chemical evolution of the Galactic disk, we surveyed open clusters of different ages, metal contents, and distances from the Galactic centre. We employed FLAMES on VLT-UT2 to collect UVES spectra of five to ten giant stars in each of the selected clusters and used them to derive the iron abundance and the detailed chemical composition.

A. Bragaglia; P. Sestito; S. Villanova; E. Carretta; S. Randich; M. Tosi

2008-01-01

198

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

199

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

NASA Astrophysics Data System (ADS)

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

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

200

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

201

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

202

Chemical and operational aspects in running the polymer assisted ultrafiltration for separation of copper(II)–citrate complexes from aqueous media  

Microsoft Academic Search

The polymer assisted ultrafiltration (PAUF) process for treatment of wastewaters containing metal ions chelated with citric acid has been studied giving particular attention to the chemical and operational aspects. The polyethylenimine (PEI) polymer bound quantitatively the copper(II)–citrate chelate at pH 5.5 forming the ternary PEI–Cu–citrate complex as discussed considering the stability constants. The ternary complex was separated by UF membranes

Raffaele Molinari; Teresa Poerio; Pietro Argurio

2007-01-01

203

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

204

75 FR 35021 - Agency Information Collection Activities; Proposed Collection; Comment Request; Information...  

Federal Register 2010, 2011, 2012, 2013

...Collection Activities; Proposed Collection; Comment Request; Information Collection Request for Cooling Water Intake Structure Phase II Existing...125.91. Title: Information Collection Request for Cooling Water Intake Structure Phase II...

2010-06-21

205

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

206

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

207

In situ investigation of surface chemistry for chemically driven atomic layer epitaxy of II-VI semiconductor thin films  

NASA Astrophysics Data System (ADS)

Atomic Layer Epitaxy (ALE) can provide atomic scale control of the growth of ultra thin semiconductor films. This thesis presents an overview of an in situ molecular-level study of surface chemistry for heteroepitaxy of II-VI semiconductor by using a binary reaction sequence with hydride and metalorganic precursors. The study focused primarily on developing a fundamental understanding of surface chemistry in a model material system: the growth of US on ZnSe (100). Dimethylcadmium and H2S precursors were sequentially dosed onto a c(2x2) ZnSe (100) substrate and characterization of the growth surface at each growth step was accomplished in the growth chamber under UHV conditions. The surface chemical composition was probed by Auger electron spectroscopy (AES) and low energy ion scattering spectroscopy (LEIS) and the surface order was determined by low energy electron diffraction (LEED). These measurements showed that, at a substrate temperature of ˜300 K, self-limiting reactions resulted in saturated chemisorption of one Cd and one S monolayer during each cycle of the binary reaction sequence, yielding the layer-by-layer growth of an ordered stoichiometric US film. We investigated surface chemistry of our model system in further detail using near edge X-ray fine structure (NEXAFS) spectroscopy and temperature programmed desorption (TPD) spectroscopy. NEXAFS and TPD results revealed that the growth surface is terminated by either a monolayer of surface methyl or hydrogen subsequent to saturation with either DMCd or H2S respectively, at ˜300 K. These surface terminating groups (CH3 or H) passivate the growth surface, preventing further uptake of the precursors once monolayer coverage is reached. However, surface CH3 or H is reactive to the alternative precursor, so the other constituent can be deposited subsequently. Therefore, both methyl and hydrogen termination provide satisfactory self-limiting reactions that allow the growth to proceed in a layer-by-layer manner. Heteroepitaxy of ZnS on Si(100) using a similar binary reaction sequence has also been proposed. The initial stage of our study has focused on the interactions of potential precursors with Si(100). Adsorption and desorption mechanisms of H2S on Si(100) have been investigated by using AES, TPD and LEED. The surface is saturated by 0.5 ML of H2S for all substrate exposure temperatures, i.e. -145°C -425°C. Desorption of hydrogen and diffusion of sulfur occur almost simultaneously after dissociative adsorption of H2S on Si(100). This process makes it impossible to form 1.0 ML of surface sulfur without a separate means of H-atom removal. Alternative approaches to initiating the growth of a II-VI semiconductor on Si(100), such as the use of a group III or group V intermediary layer, are discussed.

Han, Ming

2000-10-01

208

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

209

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

210

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

PubMed

Aerosol-assisted chemical vapor deposition (AACVD) was used for the first time in the preparation of thin-film electrochromic nickel(II) oxide (NiO). The as-deposited films were cubic NiO, with an octahedral-like grain structure, and an optical band gap that decreased from 3.61 to 3.48 eV on increase in film thickness (in the range 500-1000 nm). On oxidative voltammetric cycling in aqueous KOH (0.1 mol dm(-3)) electrolyte, the morphology gradually changed to an open porous NiO structure. The electrochromic properties of the films were investigated as a function of film thickness, following 50, 100, and 500 conditioning oxidative voltammetric cycles in aqueous KOH (0.1 mol dm(-3)). Light modulation of the films increased with the number of conditioning cycles. The maximum coloration efficiency (CE) for the NiO (transmissive light green, the "bleached" state) to NiOOH (deep brown, the colored state) electrochromic process was found to be 56.3 cm(2) C(-1) (at 450 nm) for films prepared by AACVD for 15 min followed by 100 "bleached"-to-colored conditioning oxidative voltammetric cycles. Electrochromic response times were <10 s and generally longer for the coloration than the bleaching process. The films showed good stability when tested for up to 10?000 color/bleach cycles. Using the CIE (Commission Internationale de l'Eclairage) system of colorimetry the color stimuli of the electrochromic NiO films and the changes that take place on reversibly oxidatively switching to the NiOOH form were calculated from in situ visible spectra recorded under electrochemical control. Reversible changes in the hue and saturation occur on oxidation of the NiO (transmissive light green) form to the NiOOH (deep brown) form, as shown by the track of the CIE 1931 xy chromaticity coordinates. As the NiO film is oxidized, a sharp decrease in luminance was observed. CIELAB L*a*b* coordinates were also used to quantify the electrochromic color states. A combination of a low L* and positive a* and b* values quantified the perceived deep brown colored state. PMID:23748903

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

2013-06-26

211

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

212

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

213

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

PubMed

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

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

2012-11-01

214

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

215

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

216

Chemical studies on Mexican plants used in traditional medicine, XXI. Ratibinolide II, a new sesquiterpene lactone from Ratibida latipalearis.  

PubMed

Ratibinolide II, a new eudesmanolide, and the known flavanone hispidulin have been isolated from Ratibida latipalearis. The structure elucidation of the new compound was unequivocally established by spectral and X-ray crystallographic analyses. PMID:1800631

Rojas, A; Villena, R; Jiménez, A; Mata, R

1991-01-01

217

Molecular Co(II) and Co(III) Heteroarylalkenolates as Efficient Precursors for Chemical Vapor Deposition of Co3O4 Nanowires.  

PubMed

Two new cobalt precursors, Co(II)(PyCHCOCF3)2(DMAP)2 (1) and Co(III)(PyCHCOCF3)3 (2), based on Co(II) and Co(III) centers were synthesized using a redox active ligand system. The different chemical configurations of 1 and 2 and differential valence states of cobalt were confirmed by crystal structure determination and comprehensive analytical studies. Whereas 1 could not be studied by NMR due to the paramagnetic nature of the central atom, 2 was unambiguously characterized by multinuclear 1D and 2D NMR experiments in solution. Both compounds are efficient precursors for catalyst-free growth of Co3O4 nanowires on Si and Al2O3 substrates by a chemical vapor deposition process. The different valence states of cobalt species influenced their chemical decomposition pathways in the gas phase; for instance, 1 was partially oxidized (Co(2+) ? Co(3+)), and 2 underwent reduction (Co(3+) ? Co(2+)) to form pure cobaltite in both cases that verified the metal-ligand redox interplay. Co3O4 nanowires with nanometric diameters (50-100 nm) were obtained irrespective of the chosen cobalt precursor. Investigations on the humidity sensing behavior of CVD deposits demonstrated their potential as promising sensor materials. PMID:25275501

Büyükyazi, Mehtap; Hegemann, Corinna; Lehnen, Thomas; Tyrra, Wieland; Mathur, Sanjay

2014-10-20

218

Simulation of chemical metabolism for fate and hazard assessment. II CATALOGIC simulation of abiotic and microbial degradation  

Microsoft Academic Search

The unprecedented pollution of the environment by xenobiotic compounds has provoked the need to understand the biodegradation potential of chemicals. Mechanistic understanding of microbial degradation is a premise for adequate modelling of the environmental fate of chemicals. The aim of the present paper is to describe abiotic and biotic models implemented in CATALOGIC software. A brief overview of the specificities

S. Dimitrov; T. Pavlov; N. Dimitrova; D. Georgieva; D. Nedelcheva; A. Kesova; R. Vasilev; O. Mekenyan

2011-01-01

219

EXTRAGALACTIC CHEMICAL ABUNDANCES: DO H II REGIONS AND YOUNG STARS TELL THE SAME STORY? THE CASE OF THE SPIRAL GALAXY NGC 300  

SciTech Connect

We have obtained new spectrophotometric data for 28 H II regions in the spiral galaxy NGC 300, a member of the nearby Sculptor Group. The detection of several auroral lines, including [O III] {lambda}4363, [S III] {lambda}6312, and [N II] {lambda}5755, has allowed us to measure electron temperatures and direct chemical abundances for the whole sample. We determine for the first time in this galaxy a radial gas-phase oxygen abundance gradient based solely on auroral lines, and obtain the following least-square solution: 12 + log(O/H) = 8.57({+-}0.02) - 0.41({+-}0.03)R/R {sub 25}, where the galactocentric distance is expressed in terms of the isophotal radius R {sub 25}. The characteristic oxygen abundance, measured at 0.4 x R{sub 25}, is 12 + log(O/H) = 8.41. The gradient corresponds to -0.077 {+-} 0.006 dex kpc{sup -1}, and agrees very well with the galactocentric trend in metallicity obtained for 29 B and A supergiants in the same galaxy, -0.081 {+-} 0.011 dex kpc{sup -1}. The intercept of the regression for the nebular data virtually coincides with the intercept obtained from the stellar data, which is 8.59({+-}0.05). This allows little room for depletion of nebular oxygen onto dust grains, although in this kind of comparison we are somewhat limited by systematic uncertainties, such as those related to the atomic parameters used to derive the chemical compositions. We discuss the implications of our result with regard to strong-line abundance indicators commonly used to estimate the chemical compositions of star-forming galaxies, such as R {sub 23}. By applying a few popular calibrations of these indices based on grids of photoionization models on the NGC 300 H II region fluxes, we find metallicities that are higher by 0.3 dex (a factor of 2) or more relative to our nebular (T{sub e} based) and stellar ones. We detect Wolf-Rayet stellar emission features in {approx}1/3 of our H II region spectra, and find that in one of the nebulae hosting these hot stars the ionizing field has a particularly hard spectrum, as gauged by the 'softness' parameter {eta} = (O{sup +}/O{sup ++})/(S{sup +}/S{sup ++}). We suggest that this is related to the presence of an early WN star. By considering a larger sample of extragalactic H II regions we confirm, using direct abundance measurements, previous findings of a metallicity dependence of {eta}, in the sense that softer stellar continua are found at high metallicity.

Bresolin, Fabio; Kudritzki, Rolf-Peter; Urbaneja, Miguel A. [Institute for Astronomy, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Gieren, Wolfgang; Pietrzynski, Grzegorz [Universidad de Concepcion, Departamento de Astronomia, Casilla 160-C, Concepcion (Chile); Carraro, Giovanni [European Southern Observatory, Alonso de Cordova 3107, Santiago (Chile)

2009-07-20

220

Physico-chemical and immunological properties of acid alpha-glucosidase from various human tissues in relation to glycogenosis type II (Pompe's disease).  

PubMed

The physico-chemical and immunological properties of acid alpha-glucosidase from various human tissues have been studied. Heat stability of acid alpha-glucosidase from heart, liver and skeletal muscle is identical, but for kidney some different results are obtained. Identical isoelectrofocussing patterns are found for heart, liver and skeletal muscle. Furthermore, the effect of antiserum against human liver acid alpha-glucosidase on the activity of acid alpha-glucosidase from various tissues is studied. The results are discussed in relation to glycogenosis type II (Pompe's disease). PMID:4245

Koster, J F; Slee, R G; Van der Klei-Van Moorsel, J M; Rietra, P J; Lucas, C J

1976-04-01

221

Studies of visible chemical lasers---II. Modeling of an IF chemical laser within the F--NH sub 3 --IF system  

SciTech Connect

The laser emission mechanism of an IF chemical laser pumped by chemical reactions within the F--NH{sub 3}--IF system is described by 14 kinetic processes. The population densities of IF ({ital B}) and the other excited states, the gain coefficient of the transition IF ({ital B}, {nu}{prime}=0, {ital J}{prime}=21){r arrow}IF({ital X}, {nu}{double prime}=5, {ital J}{double prime}=20), and their dependences on the cavity characteristics, are computed using Gear's automatic integration method. The results show that when the pressure in the cavity is higher than 6 Torr, the gain coefficient becomes positive, and laser action begins when the pressure is above 10 Torr. The energy transfer channels generating IF({ital B}) molecules are also discussed.

Zhuang Qi; Wang Chengdong; Feng Hao; Zhang Cunhao (Dalian Institute of Chemical Physics, Academia Sinica, Dalian (CN))

1989-10-01

222

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

223

DFT calculations of 29Si-NMR chemical shifts in Ru(II) silyl complexes: searching for trends and accurate values.  

PubMed

The (29)Si chemical shifts in a series of closely related Ru(II) silyl complexes have been calculated by DFT methods and compared to the experimental values. The factors that lead to possible discrepancies between experimental and calculated values have been identified. It is shown that it is necessary to include the spin-orbit coupling associated with the relativistic effects of the heavy atoms for quantitative agreement with observed chemical shifts but trends are reasonably reproduced when the calculations do not include this correction. An NBO analysis of the NMR contributions from the bonds to Si and the Si core shows the greater importance of the former and a fine tuning originating from the latter. PMID:21975698

Poblador-Bahamonde, A I; Poteau, R; Raynaud, C; Eisenstein, O

2011-11-14

224

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

NASA Astrophysics Data System (ADS)

Context. M 81 is an ideal laboratory to investigate the galactic chemical and dynamical evolution through the study of its young and old stellar populations. Aims: We analyze the chemical abundances of planetary nebulae and H ii regions in the M 81 disk for insight on galactic evolution, and compare it with that of other galaxies, including the Milky Way. Methods: We acquired Hectospec/MMT spectra of 39 PNe and 20 H ii regions, with 33 spectra viable for temperature and abundance analysis. Our PN observations represent the first PN spectra in M 81 ever published, while several H ii region spectra have been published before, although without a direct electron temperature determination. We determine elemental abundances of helium, nitrogen, oxygen, neon, sulfur, and argon in PNe and H ii regions, and determine their averages and radial gradients. Results: The average O/H ratio of PNe compared to that of the H ii regions indicates a general oxygen enrichment in M 81 in the last ~10 Gyr. The PN metallicity gradient in the disk of M 81 is ?log(O/H)/?RG = -0.055 ± 0.02 dex/kpc. Neon and sulfur in PNe have a radial distribution similar to that of oxygen, with similar gradient slopes. If we combine our H ii sample with the one in the literature we find a possible mild evolution of the gradient slope, with results consistent with gradient steepening with time. Additional spectroscopy is needed to confirm this trend. There are no type I PNe in our M 81 sample, consistently with the observation of only the brightest bins of the PNLF, the galaxy metallicity, and the evolution of post-AGB shells. Conclusions: Both the young and the old populations of M 81 disclose shallow but detectable negative radial metallicity gradient, which could be slightly steeper for the young population, thus not excluding a mild gradients steepening with the time since galaxy formation. During its evolution M 81 has been producing oxygen; its total oxygen enrichment exceeds that of other nearby galaxies. Full Tables 2 and 3 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/521/A3

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

2010-10-01

225

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

Microsoft Academic Search

A new chelating resin, Amberlite XAD-4 loaded with N,N-bis(salicylidene)cyclohexanediamine (SCHD), was synthesized and characterized. The resin Amberlite XAD-4-SCHD was used for\\u000a selective separation, preconcentration, and determination of Cu(II), Pb(II), and Ni(II) ions in water samples by flame atomic\\u000a absorption spectrometry (FAAS). Effects of pH, concentration, and volume of elution solution; flow rate of elution; and sample\\u000a solution, sample volume, and

Berrin Topuz; Mustafa Macit

2011-01-01

226

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

PubMed

Eighteen chemicals were tested for their mutagenic potential in the L5178Y tk+/- mouse lymphoma cell forward mutation assay by the use of procedures based upon those described by Clive and Spector [Mutat Res 44:269-278, 1975] and Clive et al [Mutat Res 59:61-108, 1979]. 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 micrograms/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. PMID:3338442

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

1988-01-01

227

Long-term observation of water-soluble chemical components and acid-digested metals in the total suspended particles collected at Okinawa, Japan  

NASA Astrophysics Data System (ADS)

The economic growth and population increase in recent Asia have been increasing air pollution. Emission rate of air pollutants from Asia, in particular oxides of nitrogen, surpassed those from North America and Europe and should continue to exceed them for decades. Okinawa Island is situated approximately 1500 km south of Tokyo, Japan, 2000 km southeast of Beijing, China, and 1000 km south of South Korea. Its location is ideal in observing East Asia's air quality because maritime air mass prevails during summer, while continental air mass dominates during fall, winter, and spring. The maritime air mass data can be seen as background clean air and can be compared with continental air masses which have been affected by anthropogenic activities. We collected total suspended particles (TSP) on quartz filters by using a high volume air sampler at the Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS), Okinawa, Japan during August 2005 and August 2010. Sampling duration was one week for each sample. We determined the concentrations of water-soluble anions, cations, water-soluble organic carbon (WSOC) and acid-digested metals in TSP samples using ion chromatography, atomic absorption spectrometry, total organic carbon analyzer and Inductively Coupled Plasma Mass spectrometry (ICP-MS), respectively. Seasonal variation of water-soluble chemical components and acid-digested metals showed that the concentrations were the lowest in summer, higher in fall and winter, and the highest in spring. When air mass came from Asian continent, the concentrations of water-soluble chemical components and acid-digested metals were much higher compared to the other directions, suggesting long-range transport of air pollutants from Asian continent. Also, when the air mass came from Asian continent (75-100% dominant), the mean concentrations of non-sea salt sulfate and nitrate increased ca. 1.8 times and ca. 3.7 times, respectively between 2005 and 2010, and the ratio of nitrate to non-sea salt sulfate increased ca. 50% which suggested that automobile exhaust emission increased. In addition, the concentration of soil-originated components such as iron and aluminum increased ca. 2.6 times and ca. 3.0 times, suggesting a probable desertification. We also report the calculated background concentrations of water-soluble chemical components and acid-digested metals at Okinawa, Japan.

Handa, D.; Okada, K.; Kuroki, Y.; Nakama, Y.; Nakajima, H.; Somada, Y.; Ijyu, M.; Azechi, S.; Oshiro, Y.; Nakaema, F.; Miyagi, Y.; Arakaki, T.; Tanahara, A.

2011-12-01

228

Chemical modification of crude timothy grass pollen extract. II. Class and specificity of antibodies induced by chemically modified timothy grass pollen extract.  

PubMed

The effects have been studied of three different chemical modifications of timothy grass pollen extract on various immunological properties. The ability to induce IgG antibody with specificity for native antigen was least affected by glutaraldehyde treatment; IgE antibody production was reduced to a similar extent by all three modifications; there was no increase in IgM production; delayed reactions were reduced. New antigenic determinants were introduced by all the modifications, but the effect was minimal following glutaraldehyde treatment. The significance of these results and the potential application of modified allergen in hyposensitisation therapy are discussed. PMID:818029

Wheeler, A W; Jenkins, P M; Moran, D M

1976-01-01

229

Atomic Data for S II—Toward Better Diagnostics of Chemical Evolution in High-redshift Galaxies  

NASA Astrophysics Data System (ADS)

Absorption-line spectroscopy is a powerful tool used to estimate element abundances in both the nearby and distant universe. The accuracy of the abundances thus derived is naturally limited by the accuracy of the atomic data assumed for the spectral lines. We have recently started a project to perform new extensive atomic data calculations used for optical/UV spectral lines in the plasma modeling code Cloudy using state of the art quantal calculations. Here, we demonstrate our approach by focussing on S II, an ion used to estimate metallicities for Milky Way interstellar clouds as well as distant damped Lyman-alpha (DLA) and sub-DLA absorber galaxies detected in the spectra of quasars and gamma-ray bursts. We report new extensive calculations of a large number of energy levels of S II, and the line strengths of the resulting radiative transitions. Our calculations are based on the configuration interaction approach within a numerical Hartree-Fock framework, and utilize both non-relativistic and quasirelativistic one-electron radial orbitals. The results of these new atomic calculations are then incorporated into Cloudy and applied to a lab plasma, and a typical DLA, for illustrative purposes. The new results imply relatively modest changes (?0.04 dex) to the metallicities estimated from S II in past studies. These results will be readily applicable to other studies of S II in the Milky Way and other galaxies.

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

2014-01-01

230

Gemini Near-Infrared Spectroscopy of Luminous z ~ 6 Quasars: Chemical Abundances, Black Hole Masses, and Mg II Absorption  

NASA Astrophysics Data System (ADS)

We present Gemini near-infrared spectroscopic observations of six luminous quasars at z = 5.8 to ~6.3. Five of them were observed using Gemini South GNIRS, which provides a simultaneous wavelength coverage of 0.9-2.5 ?m in cross-dispersion mode. The other source was observed in the 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 ~4 Zodot, and a comparison with low-redshift observations shows no strong evolution in metallicity up to z ~ 6. The Fe II/Mg II ratio of the quasars is 4.9 ± 1.4, consistent with low-redshift measurements. We estimate central black hole masses of 109-1010 Modot and Eddington luminosity ratios of order unity. We identify two Mg II ??2796, 2803 absorbers with rest equivalent width W > 1 Å at 2.2 < z < 3 and three Mg II absorbers with W > 1.5 Å 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 Mg II absorbers with W > 1.5 Å are consistent with no cosmic evolution up to z > 4. Based on observations obtained at the Gemini Observatory (acquired through the Gemini Science Archive), which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Particle Physics and Astronomy Research Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), CNPq (Brazil), and CONICET (Argentina).

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

2007-09-01

231

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

232

Chemical and Morphological Studies of Bacterial Spore Formation: II. Spore and Parasporal Protein Formation in Bacillus cereus var. Alesti  

Microsoft Academic Search

The development of both the spore and parasporal protein crystal of Bacillus cereus var. alesti was followed using chemical and cytological techniques. The changes which led to the formation of the fore-spore were similar to those already described for Bacillus cereus. However, adjacent to the developing fore-spore a small inclusion became discernible in phase contrast. This protein inclusion dur- ing

I. ELIZABETH YOUNG; PHILIP C. FITZ-JAMES

1959-01-01

233

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

234

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...

235

Natural course of scoliosis in proximal spinal muscular atrophy type II and IIIa: descriptive clinical study with retrospective data collection of 126 patients  

PubMed Central

Background Progressive scoliosis, pelvic obliquity and increasing reduction of pulmonary function are among the most significant problems for patients with SMA type II and SMA type III once they have lost the ability to walk. The aim of this study was to examine and document the development and natural course of scoliosis in patients with spinal muscular atrophy type II and IIIa. Methods For the purposes of a descriptive clinical study, we observed 126 patients, 99 with SMA II and 27 with SMA IIIa and the data of scoliosis, pelvic obliquity and relative age-dependent inspiratory vital capacity were evaluated. Results Scoliosis and pelvic obliquity were regularly observed already in children under 4 years old in the group with SMA II. The severity and progression of both conditions were much more pronounced in the SMA II group than in the IIIa group. There was already a distinct reduction in relative vital capacity in the group of 4- to 6-year-olds with SMA II. Conclusions The differences between the two SMA types II and IIIa described in this study should be taken into consideration when developing new treatments and in management of scoliosis in the childhood years of these patients. PMID:24093531

2013-01-01

236

Effect of Milk Preacidification on Low Fat Mozzarella Cheese: II. Chemical and Functional Properties During Storage1  

Microsoft Academic Search

The effect of milk preacidification on cheese manufac- turing, chemical properties, and functional properties of low fat Mozzarella cheese was determined. Four vats of cheese were made in 1 d using no preacidification (control), preacidification to pH 6.0 and pH 5.8 with acetic acid, and preacidification to pH 5.8 with citric acid. This process was replicated four times. Modifica- tions

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

2001-01-01

237

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

SciTech Connect

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

Bruderer, S.; Benz, A.O. [Institute of Astronomy, ETH Zurich, CH-8093 Zurich (Switzerland); Doty, S. D. [Department of Physics and Astronomy, Denison University, Granville, OH 43023 (United States); Van Dishoeck, E. F. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Bourke, T. L. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)], E-mail: simonbr@astro.phys.ethz.ch

2009-07-20

238

Sesame oil. II. Some chemical and physical properties of the oils from different varieties of sesame seed  

Microsoft Academic Search

Summary  Four varieties of sesame seed, grown in South Carolina, Nebraska, and Nicaragua, were solvent extracted in a pilot-plant and\\u000a the oils examined with respect to their physical and chemical characteristics. Only slight variations were found in these\\u000a constants and in the composition of the oils.\\u000a \\u000a The oils were refined, bleached, hydrogenated to shortening consistency, and deodorized. The refining losses were

F. G. T. Menezes; Pierre Budowski; F. G. Dollear

1950-01-01

239

Multidimensional Chemical Modeling of Young Stellar Objects. II. Irradiated Outflow Walls in a High-Mass Star-Forming Region  

NASA Astrophysics Data System (ADS)

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

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

2009-07-01

240

Lysimeter study with a cambic arenosol exposed to artificial acid rain: II. Input-output budgets and soil chemical properties  

Microsoft Academic Search

The effects of artificial precipitation with different pH levels on soil chemical properties and element flux were studied in a lysimeter experiment. Cambic Arenosol (Typic Udipsamment) in monolith lysimeters was treated for 6 1\\/2 yr with 125 mm yr-1 artificial rain in addition to natural precipitation. Artificial acid rain was produced from groundwater with H2SO4 added. pH levels of 6.1,

T. A. Sogn; G. Abrahamsen; A. O. Stuanes

1993-01-01

241

Assessment of the health effects of chemicals in humans: II. Construction of an adverse effects database for QSAR modeling.  

PubMed

The FDA's Spontaneous Reporting System (SRS) database contains over 1.5 million adverse drug reaction (ADR) reports for 8620 drugs/biologics that are listed for 1191 Coding Symbols for Thesaurus of Adverse Reaction (COSTAR) terms of adverse effects. We have linked the trade names of the drugs to 1861 generic names and retrieved molecular structures for each chemical to obtain a set of 1515 organic chemicals that are suitable for modeling with commercially available QSAR software packages. ADR report data for 631 of these compounds were extracted and pooled for the first five years that each drug was marketed. Patient exposure was estimated during this period using pharmaceutical shipping units obtained from IMS Health. Significant drug effects were identified using a Reporting Index (RI), where RI = (# ADR reports / # shipping units) x 1,000,000. MCASE/MC4PC software was used to identify the optimal conditions for defining a significant adverse effect finding. Results suggest that a significant effect in our database is characterized by > or = 4 ADR reports and > or = 20,000 shipping units during five years of marketing, and an RI > or = 4.0. Furthermore, for a test chemical to be evaluated as active it must contain a statistically significant molecular structural alert, called a decision alert, in two or more toxicologically related endpoints. We also report the use of a composite module, which pools observations from two or more toxicologically related COSTAR term endpoints to provide signal enhancement for detecting adverse effects. PMID:16472241

Matthews, Edwin J; Kruhlak, Naomi L; Weaver, James L; Benz, R Daniel; Contrera, Joseph F

2004-12-01

242

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

PubMed

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

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

2008-07-21

243

Analytical simulation and PROFAT II: a new methodology and a computer automated tool for fault tree analysis in chemical process industries.  

PubMed

Fault tree analysis (FTA) is based on constructing a hypothetical tree of base events (initiating events) branching into numerous other sub-events, propagating the fault and eventually leading to the top event (accident). It has been a powerful technique used traditionally in identifying hazards in nuclear installations and power industries. As the systematic articulation of the fault tree is associated with assigning probabilities to each fault, the exercise is also sometimes called probabilistic risk assessment. But powerful as this technique is, it is also very cumbersome and costly, limiting its area of application. We have developed a new algorithm based on analytical simulation (named as AS-II), which makes the application of FTA simpler, quicker, and cheaper; thus opening up the possibility of its wider use in risk assessment in chemical process industries. Based on the methodology we have developed a computer-automated tool. The details are presented in this paper. PMID:10828384

Khan, F I; Abbasi, S A

2000-07-10

244

Radiation-chemical reduction of plutonium(VI) in nitric acid solutions. Influence of palladium(II) and uranium(VI) ions  

SciTech Connect

The influence of uranium(VI) and palladium(II) on the radiation-chemical reduction of plutonium(VI) in 4 M nitric acid was investigated. A quadratic dependence of the maximum yield of the reduction of Pu(VI) on the total plutonium concentration in the range 0.008-0.1 M was detected in the presence of uranyl nitrate, explained by competition of the reaction of Pu(III) and Pu(V), determining the rate of the process, with their oxidation by OH and NO/sub 3/ radicals and by nitrous acid. The rate constant of the interaction of oxidizing radicals with pentavlent plutonium was estimated according to the experimental data using a mathematical model. The accelerating action of palladium(II) on the radiolytic reduction of hexavalent plutonium is explained by its rapid interaction with OH and NO/sub 3/ radicals. Hexavalent uranium accelerates the determining step, and also serves as a source of formation of an effective reducing agent-pentavalent uranium.

Tkhorzhnitshii, G.P.; Egorov, G.F.

1985-11-01

245

Induced mutagenesis of plasmid and chromosomal genes inserted into the plasmid DNA. II. Mutagenic action of chemical factors  

SciTech Connect

Following the study of the mutagenic action of UV and ..gamma..-radiation on plasmid DNA in vitro, they investigated the induction of mutations under the influence of chemical mutagens on the same DNA of plasmid RSF2124, determining the synthesis of colicine E1 and resistance to ampicillin. The inactivating action of the mutagen was assessed from the yield of transformants resistant to the antibiotic and the mutagenic effect from the loss by colonies of transformants that were capable of releasing colicine into the external medium. In these experiments they mainly used chemical compounds whose mutagenic effect if well known in other systems (transforming and transfecting DNA, microbial viruses). As a result all mutagens tested for their activity were divided into four groups: first group, those exceeding the level of mutagenesis by more than 100-fold above the spontaneous background (hydroxylamine, O-methylhydroxylamine); second group, those exceeding it by a factor of 10 (UV radiation (lambda = 254 nm), W-mutagenesis, ionizing radiation, nitrous acid, mitomycin C); third group, those exceeding it by a factor of <10 (indirect UV mutagenesis, nitrous acid, ..beta..-chloroethyldiethylamine hydrochloride, nitrosoguanidine); fourth group, no mutagenic effect (acridine orange, ethyl methane sulfonate, sodium azide, 0-..beta..-diethylaminoethylhydroxylamine).

Esipova, V.V.; Vedunova, S.L.; Kriviskii, A.S.

1986-02-01

246

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

247

Critical evaluation of Jet-A spray combustion using propane chemical kinetics in gas turbine combustion simulated by KIVA-II  

NASA Technical Reports Server (NTRS)

Numerical solutions of the Jet-A spray combustion were obtained by means of the KIVA-II computer code after Jet-A properties were added to the 12 chemical species the program had initially contained. Three different reaction mechanism models are considered. The first model consists of 131 reactions and 45 species; it is evaluated by comparing calculated ignition delay times with available shock tube data, and it is used in the evaluation of the other two simplified models. The simplified mechanisms consider 45 reactions and 27 species and 5 reactions and 12 species, respectively. In the prediction of pollutants NOx and CO, the full mechanism of 131 reactions is considered to be more reliable. The numerical results indicate that the variation of the maximum flame temperature is within 20 percent as compared with that of the full mechanism of 131 reactions. The chemical compositions of major components such as C3H8, H2O, O2, CO2, and N2 are of the same order of magnitude. However, the concentrations of pollutants are quite different.

Nguyen, H. L.; Ying, S.-J.

1990-01-01

248

Chemical structure of cement aged at normal and elevated temperatures and pressures, Part II: Low permeability class G oilwell cement  

SciTech Connect

Recently, Low Permeability Cement formulation has been developed for oilwell cementing. Therefore, it is important to understand the physical and chemical processes causing cement degradation in the downhole environment. In this study, we have characterised a Low Permeability Class G oilwell Cement immersed for one year in brine at T = 293 K, p = 10{sup 5} Pa and T = 353 K, p = 7 x 10{sup 6} Pa using {sup 29}Si, {sup 27}Al NMR and XRD techniques. Elevated temperature and pressure conditions increase the rate of the pozzolanic reaction and have significant effects on the polymerisation of C-S-H and on the incorporation of Al in the C-S-H structure. Leaching resulted in the formation of calcite and a more polymerised C-S-H with the appearance of tobermorite in the sample cured at elevated temperature and pressure.

Le Saout, Gwenn [Institut Francais du Petrole, 1-4 av de Bois Preau, 92852 Rueil-Malmaison (France) and Laboratoire de Physique et Mecanique des Milieux Heterogenes UMR CNRS 7636, Ecole Superieure de Physique et Chimie Industrielles, 10 rue Vauquelin, 75231 Paris Cedex 05 (France)]. E-mail: gwenn.lesaout@epfl.ch; Lecolier, Eric [Institut Francais du Petrole, 1-4 av de Bois Preau, 92852 Rueil-Malmaison (France); Rivereau, Alain [Institut Francais du Petrole, 1-4 av de Bois Preau, 92852 Rueil-Malmaison (France); Zanni, Helene [Laboratoire de Physique et Mecanique des Milieux Heterogenes UMR CNRS 7636, Ecole Superieure de Physique et Chimie Industrielles, 10 rue Vauquelin, 75231 Paris Cedex 05 (France)

2006-03-15

249

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

250

Mechanistic aspects of proton chain transfer in the green fluorescent protein. Part II. A comparison of minimal quantum chemical models.  

PubMed

In this paper we report the results of extensive quantum chemical reaction pathway calculations for the electronic ground state of several different cluster models that mimic the proton chain transfer path within the green fluorescent protein (GFP). Our principal objective is to establish the robustness with respect to variations in the model of our recent mechanistic inferences for the ground state proton chain transfer [S. Wang and S. C. Smith, J. Phys. Chem. B, 2006, 110, 5084]. Additionally, comparison of our ground state results with the excited state proton transfer (ESPT) study by Vendrell et al. [O. Vendrell, R. Gelabert, M. Moreno and J. M. Lluch, J. Am. Chem. Soc., 2006, 128, 3564] leads to the conclusion that the mechanism of proton chain transfer may be expected to be analogous in ground and excited states, principally because in both cases the loss of the chromophore's phenolic proton contributes strongly to the reaction coordinate only late in the reaction path. PMID:17216060

Wang, Sufan; Smith, Sean C

2007-01-28

251

Chemical relevance of the copper(II)— L-carnosine system in aqueous solution: A thermodynamic and spectrophotometric study  

NASA Astrophysics Data System (ADS)

The copper(II)— L-carnosine (L -) system has been re-investigated in aqueous solution, at I = 0.1 mol dm -1, different temperatures (5? t?45°C) and with metal to ligand ratios ranging from 3:1 to 1:3. Both potentiometry and visible spectrophotometry were employed. From an overall consideration of all experiments, [CuLH] 2+, [CuL] +, [CuLH -1]°, [Cu 2L 2H -2]° and [Cu 2LH -1] 2+ were recognized as the species which provide the best interpretation of experimental data. The complex formation constants, determined at different temperatures, allowed us to obtain reliable values of ? H° and good estimates of ? C° p. From visible spectrophotometric measurements, carried out at different pH and metal to ligand ratios, it was possible to calculate the electronic spectrum of each complex formed in solution. A structure is also proposed for each species, on the basis of thermodynamic and spectral results.

Daniele, Pier G.; Prenesti, Enrico; Zelano, Vincenzo; Ostacoli, Giorgio

1993-08-01

252

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

PubMed

Structural properties of methocarbamol (Mcm) were extensively studied both experimentally and theoretically using FT IR, (1)H NMR, UV-Vis., geometry optimization, Mulliken charge, and molecular electrostatic potential. Stability arises from hyper-conjugative interactions, charge delocalization and H-bonding was analyzed using natural bond orbital (NBO) analysis. Mcm was decomposed in ethanol/water mixture at 80°C to guaifenesin [(RS)-3-(2-methoxyphenoxy)propane-1,2-diol] and carbamate ion [NH2COO(-)], where the degradation mechanism was explained by trapping the carbamate ion via the complexation with copper(II) ion. The structure of the isolated complex ([Cu(NH2COO)2(H2O)]?4H2O) was elucidated by spectral, thermal, and magnetic tools. Electronic spectra were discussed by TD-DFT and the descriptions of frontier molecular orbitals and the relocations of the electron density were determined. Calculated g-tensor values showed best agreement with experimental values from EPR when carried out using both the B3LYP and B3PW91 functional. PMID:24674917

Mansour, Ahmed M; Shehab, Ola R

2014-07-15

253

Historical estimates of external gamma exposure and collective external gamma exposure from testing at the Nevada Test Site. I. Test series through HARDTACK II, 1958.  

PubMed

In 1959, the Test Manager's Committee to Establish Fallout Doses calculated estimated external gamma exposure at populated locations based upon measurements of external gamma-exposure rate. Using these calculations and estimates of population, we have tabulated the collective estimated external gamma exposures for communities within established fallout patterns. The total collective estimated external gamma exposure is 85,000 person-R. The greatest collective exposures occurred in three general areas: Saint George, UT; Ely, NV; and Las Vegas, NV. Three events, HARRY (19 May 1953), BEE (22 March 1955), and SMOKY (31 August 1957), accounted for more than half the total collective estimated external gamma exposure. The bases of the calculational models for external gamma exposure of "infinite exposure," "estimated exposure," and "1-yr effective biological exposure" are explained. PMID:3332000

Anspaugh, L R; Church, B W

1986-07-01

254

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

255

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

256

THE CHEMICAL ABUNDANCES OF STARS IN THE HALO (CASH) PROJECT. II. A SAMPLE OF 14 EXTREMELY METAL-POOR STARS ,  

SciTech Connect

We present a comprehensive abundance analysis of 20 elements for 16 new low-metallicity stars from the Chemical Abundances of Stars in the Halo (CASH) project. The abundances have been derived from both Hobby-Eberly Telescope High Resolution Spectrograph snapshot spectra (R {approx}15, 000) and corresponding high-resolution (R {approx}35, 000) Magellan Inamori Kyocera Echelle spectra. The stars span a metallicity range from [Fe/H] from -2.9 to -3.9, including four new stars with [Fe/H] < -3.7. We find four stars to be carbon-enhanced metal-poor (CEMP) stars, confirming the trend of increasing [C/Fe] abundance ratios with decreasing metallicity. Two of these objects can be classified as CEMP-no stars, adding to the growing number of these objects at [Fe/H]< - 3. We also find four neutron-capture-enhanced stars in the sample, one of which has [Eu/Fe] of 0.8 with clear r-process signatures. These pilot sample stars are the most metal-poor ([Fe/H] {approx}< -3.0) of the brightest stars included in CASH and are used to calibrate a newly developed, automated stellar parameter and abundance determination pipeline. This code will be used for the entire {approx}500 star CASH snapshot sample. We find that the pipeline results are statistically identical for snapshot spectra when compared to a traditional, manual analysis from a high-resolution spectrum.

Hollek, Julie K.; Sneden, Christopher; Shetrone, Matthew [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States); Frebel, Anna [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Roederer, Ian U. [Carnegie Observatories, Pasadena, CA 91101 (United States); Beers, Timothy C. [Department of Physics and Astronomy, and JINA: Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 (United States); Kang, Sung-ju [Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); Thom, Christopher, E-mail: julie@astro.as.utexas.edu, E-mail: chris@astro.as.utexas.edu, E-mail: shetrone@astro.as.utexas.edu, E-mail: afrebel@cfa.harvard.edu, E-mail: iur@obs.carnegiescience.edu, E-mail: beers@pa.msu.edu, E-mail: sjkang@iastate.edu, E-mail: cthom@stsci.edu [Space Telescope Science Institute, Baltimore, MD 21218 (United States)

2011-11-20

257

Characterization of the Brominated Chemicals in a PentaBDE Replacement Mixture and their Detection in Biosolids Collected from Two San Francisco Bay Area Wastewater Treatment Plants  

E-print Network

Worldwide restrictions on the use of PentaBDE have led to the use of new brominated flame retardant mixtures to meet flammability standards. Assessments to determine if the chemicals in some of these mixtures are accumulating in the

unknown authors

258

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

259

The Chemical Abundances of Stars in the Halo (CASH) Project. II. A Sample of 14 Extremely Metal-poor Stars  

NASA Astrophysics Data System (ADS)

We present a comprehensive abundance analysis of 20 elements for 16 new low-metallicity stars from the Chemical Abundances of Stars in the Halo (CASH) project. The abundances have been derived from both Hobby-Eberly Telescope High Resolution Spectrograph snapshot spectra (R ~15, 000) and corresponding high-resolution (R ~35, 000) Magellan Inamori Kyocera Echelle spectra. The stars span a metallicity range from [Fe/H] from -2.9 to -3.9, including four new stars with [Fe/H] < -3.7. We find four stars to be carbon-enhanced metal-poor (CEMP) stars, confirming the trend of increasing [C/Fe] abundance ratios with decreasing metallicity. Two of these objects can be classified as CEMP-no stars, adding to the growing number of these objects at [Fe/H]< - 3. We also find four neutron-capture-enhanced stars in the sample, one of which has [Eu/Fe] of 0.8 with clear r-process signatures. These pilot sample stars are the most metal-poor ([Fe/H] <~ -3.0) of the brightest stars included in CASH and are used to calibrate a newly developed, automated stellar parameter and abundance determination pipeline. This code will be used for the entire ~500 star CASH snapshot sample. We find that the pipeline results are statistically identical for snapshot spectra when compared to a traditional, manual analysis from a high-resolution spectrum. Based on observations obtained with the Hobby-Eberly Telescope, which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Stanford University, Ludwig-Maximilians-Universität München, and Georg-August-Universität Göttingen. Based on observations gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

Hollek, Julie K.; Frebel, Anna; Roederer, Ian U.; Sneden, Christopher; Shetrone, Matthew; Beers, Timothy C.; Kang, Sung-ju; Thom, Christopher

2011-11-01

260

Old open clusters as key tracers of Galactic chemical evolution. II. Iron and elemental abundances in NGC 2324, NGC 2477 NGC 2660, NGC 3960, and Berkeley 32  

NASA Astrophysics Data System (ADS)

Aims:To constrain the formation and chemical evolution of the Galactic disk, we surveyed open clusters of different ages, metal contents, and distances from the Galactic centre. We employed FLAMES on VLT-UT2 to collect UVES spectra of five to ten giant stars in each of the selected clusters and used them to derive the iron abundance and the detailed chemical composition. Methods: Equivalent widths were measured and abundance analysis was performed using the MOOG code and Kurucz model atmospheres on all stars considered as cluster members on the basis of their radial velocity. Results: We derived the atmospheric parameters and the Fe abundance for NGC 2324 and NGC 2477 (average [Fe/H] = -0.17 with rms 0.05 dex, and +0.07 with rms 0.03 dex, respectively), two clusters never analyzed using high resolution spectra. We also derived the abundances of Mg, Al, Ca, Si, Ti, Cr, Ni, and Ba for these two clusters and for NGC 2660, NGC 3960, and Berkeley 32, whose atmospheric parameters and metallicities were measured in a previous paper. We determined the reddening values for the five clusters, based on the spectroscopic temperatures, literature photometry, and a colour-temperature relation. Conclusions: All clusters show solar-scaled abundances for ?- and Fe-peak elements, while [Na/Fe] appears slightly enhanced and [Ba/Fe] significantly enhanced. Our findings were compared to thin-disk stars and other open clusters, and no significant deviation from the standard behavior was found.

Bragaglia, A.; Sestito, P.; Villanova, S.; Carretta, E.; Randich, S.; Tosi, M.

2008-03-01

261

Chemical weathering of a soil chronosequence on granitoid alluvium: II. Mineralogic and isotopic constraints on the behavior of strontium  

USGS Publications Warehouse

The use of strontium isotopes to evaluate mineral weathering and identify sources of base cations in catchment waters requires an understanding of the behavior of Sr in the soil environment as a function of time. Our approach is to model the temporal evolution of 87Sr/86Sr of the cation exchange pool in a soil chronosequence developed on alluvium derived from central Sierra Nevada granitoids during the past 3 Ma. With increasing soil age, 87Sr/86Sr of ammonium-acetate extractable Sr initially decreases from values typical of K-feldspar to those of plagioclase and hornblende and then remains constant, even though plagioclase and hornblende are absent from the soils after approximately 1 Ma of weathering. The temporal variation of 87Sr/86Sr of exchangeable Sr is modeled by progressively equilibrating Sr derived from mineral weathering and atmospheric deposition with Sr on exchange sites as waters infiltrate a soil column. Observed decreases in quartz-normalized modal abundances of plagioclase, hornblende, and K-feldspar with time, and the distinct 87Sr/86Sr values of these minerals can be used to calculate Sr flux from weathering reactions. Hydrobiotites in the soils have nearly constant modal abundances, chemistry, and 87Sr/86Sr over the chronosequence and provide negligible Sr input to weathering solutions. The model requires time and soil horizon-dependent changes in the amount of exchangeable Sr and the efficiency of Sr exchange, as well as a biologic cycling term. The model predicts that exchangeable Sr initially has 87Sr/86Sr identical to that of K-feldspar, and thus could be dominated by Sr leached from K-feldspar following deposition of the alluvium. The maximum value of 87Sr/86Sr observed in dilute stream waters associated with granitoids of the Yosemite region is likewise similar to that of the K-feldspars, suggesting that K-feldspar and not biotite may be the dominant source of radiogenic Sr in the streams. This study reveals that, when attempting to use Strontium isotopes to identify sources of base cations in catchment waters and biomass, both preferential leaching of Sr from minerals during incipient soil development and changing Sr exchange efficiency must be considered along with chemical contributions due to mineral dissolution. Copyright ?? 1997 Elsevier Science Ltd.

Bullen, T.; White, A.; Blum, A.; Harden, J.; Schulz, M.

1997-01-01

262

Two-stage chemical fractionation method for the analysis of elements and non-volatile inorganic ions in PM10 samples: Application to ambient samples collected in Rome (Italy)  

NASA Astrophysics Data System (ADS)

A two-stage micro-analytical scheme for the determination of metals and ions in atmospheric particulate matter collected on only one Teflon filter was developed. In the first stage the collected particles are chemically fractionated for their solubility in a pH-buffered extracting solution; in the second stage the residue is mineralised. The major non-volatile inorganic ions (Cl -, NO 3-, SO 42-, Na +, NH 4+, Ca 2+, Mg 2+) are determined in the first fraction by ion-chromatography (IC), while metals and metalloids (Al, As, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, S, Sb, Se, Si, Ti, V, Zn) are determined in both the acetate extractable and the mineralised residual fractions by inductively coupled plasma optical emission spectroscopy (ICP-OES). The procedure was applied to ambient 24-h PM 10 samples collected on Teflon filters during two field campaigns carried out at two sites in the area of Rome (Italy). The variations in the chemical composition of the collected particles during the two periods were interpreted in the light of the dilution properties of the lower atmosphere and of the back-trajectories of the air masses. The difference in the results between the two locations was interpreted in the light of their proximity to the emission sources. It was found that the acetate extractable and the mineralised residual fraction of some metals exhibit a different temporal pattern, suggesting the existence of different emission sources of the two fractions.

Canepari, Silvia; Cardarelli, Enrico; Perrino, Cinzia; Catrambone, Maria; Pietrodangelo, Adriana; Strincone, Marco

263

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

264

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

Microsoft Academic Search

Some organic compounds present in aerosols are surface active and their presence in cloud condensation nuclei can affect the surface tension of cloud droplets. The nature of these surface active compounds in clouds and rainwater is not well understood and there is very little information about their content in remote tropical environments. Therefore, our study focuses on the chemical characterization

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

2007-01-01

265

Computer analysis of human esophageal peristalsis and lower esophageal sphincter pressure. II. An interactive system for on-line data collection and analysis.  

PubMed

A computer program has been written to directly read and analyze esophageal manometric tracings on-line using low-cost off-the-shelf microcomputer hardware. The system consists of an Apple IIe microcomputer and an Interactive Microwave Inc. ADALAB Data Acquisition System with an AI13 fast A/D Multiplexer. The primary program is in BASIC with ASSEMBLY language subroutines for data collection. Data are collected through the voltage output of a Hewlett-Packard recorder at 30 points per second on four channels for lower esophageal sphincter pressures (LESP) and three channels for peristaltic waves. Computer-determined values for LESP and wave parameters showed excellent correlation with mean values as read by five individuals experienced in esophageal manometry. PMID:3769705

Castell, J A; Castell, D O

1986-11-01

266

Development of a method for collection of ileal digesta in finishing pigs and determination of lysine availability in direct solvent cottonseed meal by chemical and chick growth assays  

E-print Network

catheter positioned caudal to the ileal anus'tomosis 27 10 Ileostomy appliance showing the collection bag (A), face plate (B) and PVC tubing attached to face plate insert (C) . 28 (A) Return of ileal digests to the cecum via the cecal cannula. (B...) Collection appliances attached to the pig . 28 Bolt plate showing the PVC washers and nuts (A), outside plate (B), PVC bolts (C), PVC tubing (D), and PVC bolt with 3. 5 cm flange (B) . 30 Figure Page 13 (A) Primary incision site. (B) ?leal fistula...

Corley, Jimmie Ray

2012-06-07

267

Improved Characteristics of Metal Organic Chemical Vapor Deposition-Grown ZnO Thin-Film Transistors by Controlling VI\\/II Ratio of ZnO Film Growth and Using a Modified Thin-Film Transistor Layer Structure  

Microsoft Academic Search

Thin-film transistors (TFTs) were fabricated on glass substrates using ZnO channel layers grown with two VI\\/II (oxygen\\/diethylzinc) ratios of 25,000 and 100,000 by metal organic chemical vapor deposition (MOCVD). The ZnO TFTs employing the channel grown with a VI\\/II ratio of 25,000 exhibit a field-effect mobility (muFE) of 4.3 cm2 V-1 s-1, a subthreshold slope (\\\\mathit{SS}) of 1.3 V\\/dec, and

Kariyadan Remashan; Yong-Seok Choi; Seong-Ju Park; Jae-Hyung Jang

2011-01-01

268

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

Microsoft Academic Search

An ideal on-site chemical\\/biochemical analysis system must be inexpensive, sensitive, fully automated and integrated, reliable, and compatible with a broad range of samples. The advent of digital microfluidic lab-on-a-chip (LoC) technology offers such a detection system due to the advantages in portability, reduction of the volumes of the sample and reagents, faster analysis times, increased automation, low power consumption, compatibility

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

2004-01-01

269

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

Microsoft Academic Search

An ideal on-site chemical\\/biochemical analysis system must be inexpensive, sensitive, fully automated and integrated, reliable, and compatible with a broad range of sa mples. The advent of digital microfluidic lab-on-a-chip (LoC) technology offers such a detection system due to the advantages in portability, reduction of the volumes of the sample and reagents, faster analysis times, increased automation, low power consumption,

R. B. Fair; A. Khlystova; V. Srinivasan; V. K. Pamula; K. N. Weaver

270

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

Microsoft Academic Search

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,

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

2010-01-01

271

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

272

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

273

Collection of nanoliter microdialysate fractions in plugs for off-line in vivo chemical monitoring with up to 2 s temporal resolution.  

PubMed

An off-line in vivo neurochemical monitoring approach was developed based on collecting nanoliter microdialysate fractions as an array of "plugs" segmented by immiscible oil in a piece of Teflon tubing. The dialysis probe was integrated with the plug generator in a polydimethlysiloxane microfluidic device that could be mounted on the subject. The microfluidic device also allowed derivatization reagents to be added to the plugs for fluorescence detection of analytes. Using the device, 2 nL fractions corresponding to 1-20 ms sampling times depending upon dialysis flow rate, were collected. Because axial dispersion was prevented between them, each plug acted as a discrete sample collection vial and temporal resolution was not lost by mixing or diffusion during transport. In vitro tests of the system revealed that the temporal resolution of the system was as good as 2 s and was limited by mass transport effects within the dialysis probe. After collection of dialysate fractions, they were pumped into a glass microfluidic chip that automatically analyzed the plugs by capillary electrophoresis with laser-induced fluorescence at 50 s intervals. By using a relatively low flow rate during transfer to the chip, the temporal resolution of the samples could be preserved despite the relatively slow analysis time. The system was used to detect rapid dynamics in neuroactive amino acids evoked by microinjecting the glutamate uptake inhibitor l-trans-pyrrolidine-2,4-dicarboxylic acid (PDC) or K(+) into the striatum of anesthetized rats. The resulted showed increases in neurotransmitter efflux that reached a peak in 20 s for PDC and 13 s for K(+). PMID:20447417

Wang, Meng; Slaney, Thomas; Mabrouk, Omar; Kennedy, Robert T

2010-06-30

274

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

275

Triggered massive-star formation on the borders of Galactic HII regions. II. Evidence for the collect and collapse process around RCW 79  

E-print Network

We present SEST-SIMBA 1.2-mm continuum maps and ESO-NTT SOFI JHK images of the Galactic HII region RCW 79. The millimetre continuum data reveal the presence of massive fragments located in a dust emission ring surrounding the ionized gas. The two most massive fragments are diametrically opposite each other in the ring. The near-IR data, centred on the compact HII region located at the south-eastern border of RCW 79, show the presence of an IR-bright cluster containing massive stars along with young stellar objects with near-IR excesses. A bright near- and mid-IR source is detected towards maser emissions, 1.2 pc north-east of the compact HII region centre. Additional information, extracted from the Spitzer GLIMPSE survey, are used to discuss the nature of the bright IR sources observed towards RCW 79. Twelve luminous Class I sources are identified towards the most massive millimetre fragments. All these facts strongly indicate that the massive-star formation observed at the border of the HII region RCW 79 has been triggered by its expansion, most probably by the collect and collapse process.

A. Zavagno; L. Deharveng; F. Comeron; J. Brand; F. Massi; J. Caplan; D. Russeil

2005-09-12

276

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

277

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

278

Collections Conservation.  

ERIC Educational Resources Information Center

Collections conservation is an approach to the preservation treatment of books and book-like materials that is conceptualized and organized in terms of large groups of materials. This guide is intended to enable a library to evaluate its current collections conservation activities. The introduction describes collections conservation and gives…

DeCandido, Robert

279

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

280

Analysis of chemical constituents and antinociceptive potential of essential oil of Teucrium Stocksianum bioss collected from the North West of Pakistan  

PubMed Central

Background Medicinal plants are used for the treatment of different diseases in almost all cultures. Teucrium species grow wildly at different geographical locations around the world. Teucrium stocksianum is used in folk medicine for the treatment of diarrhea, cough, jaundice and abdominal pain. Scientific study on Teucrium stocksianum shows that it possesses anthelmintic, cytotoxic and antispasmodic activity. The aim of our present study is to identify the chemical composition and antinociceptive potential of the essential oil extracted from Teucrium stocksianum bioss. Method Essential oil (EO) from the aerial parts of Teucrium stocksianum were extracted by hydrodistillation process. The qualitative and quantitative composition of essential oil was determined with Gas chromatography/Mass spectrometer. Antinociceptive activity was determined by acetic acid induced writhing method. Percent inhibition of writhes of the test concentration was determined by comparing it with that of control. Tween-80 emulsion 2.5% (5?ml/kg b.w) was used as a control while Diclofenic sodium 50?mg/kg (b.w) was used as a standard drug. Results The chromatogram of the essential oil of Teucrium stocksianum shows differences both qualitatively and quantatively from essential oil composition reported in other countries. Hydrodistillation of Teucrium stocksianum yielded 0.4% (v/w), pale yellowish oil on dry basis. A total of 26 chemicals were identified by GC-MS accounting for 90.28% of the oil. The major components of essential oil were ?-cadinene (12.92%), ?-pinene (10.3%), myrcene (8.64%), ?-caryophyllene (8.23%), germacrene D (5.18%) and limonene (2.36%). Essential oil of Teucrium stocksianum has shown outstanding antinociceptive activity. It has been observed that increase in percent writhe inhibition (PWI) occurred from 20-80?mg/kg (b.w) and maximum writhe inhibition has been noted at a concentration of 80?mg/kg (b.w), but PWI decreased at 160?mg/kg, which may be due to some toxic effect of higher dose. ED50 value for Teucrium stocksianum was calculated as 31.5?±?1.72415?mg/kg (b.w). Conclusion Our results indicate that there is a lot of variation in the composition of essential oil of Teucrium stocksianum boiss, which may be due to different climatic and experimental conditions. Secondly, the essential oil possesses strong antinociceptive activity and could be used in analgesic preparations especially for topical use. PMID:23217213

2012-01-01

281

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

282

Chemical modification of Class II G protein-coupled receptor ligands: Frontiers in the development of peptide analogs as neuroendocrine pharmacological therapies  

Microsoft Academic Search

Recent research and clinical data have begun to demonstrate the huge potential therapeutic importance of ligands that modulate the activity of the secretin-like, Class II, G protein-coupled receptors (GPCRs). Ligands that can modulate the activity of these Class II GPCRs may have important clinical roles in the treatment of a wide variety of conditions such as osteoporosis, diabetes, amyotrophic lateral

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

2010-01-01

283

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

PubMed

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

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

2014-05-01

284

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

285

75 FR 8996 - Notice of Information Collection  

Federal Register 2010, 2011, 2012, 2013

...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

286

Chemical trends in background air quality and the ionic composition of precipitation for the period 1980-2004 from samples collected at Valentia Observatory, Co. Kerry, Ireland.  

PubMed

A major Irish study, based upon more than 8000 samples collected over the measurement period of 22 years, for sulfur dioxide (SO2-S), sulfate (SO4-S) and nitrogen dioxide (NO2-N) concentrations (microg m(-3)) within air, and the ionic composition of precipitation samples based on sodium (Na+), potassium (K+), magnesium (Mg2+), calcium (Ca2+), chloride (Cl-), sulfate (SO4-S), non-sea salt sulfate (nssSO4-S), ammonium (NH4-N), and nitrate (NO3-N) weighted mean concentrations (mg l(-1)), has been completed. For the air samples, the sulfur dioxide and sulfate concentrations decreased over the sampling period (1980-2004) by 75% and 45%, respectively, whereas no significant trend was observed for nitrogen dioxide. The highest concentrations for sulfur dioxide, sulfate and nitrogen dioxide were associated with wind originating from the easterly and northeasterly directions i.e. those influenced by Irish and European sources. The lowest concentrations were associated with the westerly directions i.e. for air masses originating in the North Atlantic region. This was further verified with the use of backward (back) trajectory analysis, which allowed tracing the movement of air parcels using the European Centre for Medium range Weather Forecasting (ECMWF) ERA-40 re-analysis data. High non-sea salt sulfate levels were being associated with air masses originating from Europe (easterlies) with lower levels from the Atlantic (westerlies). With the precipitation data, analysis of the non-sea salt sulfate concentrations showed a decrease by 47% since the measurements commenced. PMID:18528540

Bashir, Wasim; McGovern, Frank; O'Brien, Phillip; Ryan, Margaret; Burke, Liam; Paull, Brett

2008-06-01

287

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

NASA Astrophysics Data System (ADS)

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

Tomza, U.; Arimoto, R.

2001-12-01

288

77 FR 55473 - Agency Information Collection Activities; Renewal of a Currently Approved Collection; Comment...  

Federal Register 2010, 2011, 2012, 2013

...Request; Basel II Recordkeeping and Disclosures AGENCY: Federal Deposit Insurance Corporation...approved Basel II--Recordkeeping and Disclosures information collection, which is being...Risk-Weighted Assets; Market Discipline and Disclosure Requirements (77 FR 52888);...

2012-09-10

289

THE JOURNAL OF CHEMICAL PHYSICS VOLUME 47, NUMBER 9 1 NOVEMBER 1967 Correlation Effects in Complex Spectra. II. Transition Probabilities for the Magnesium  

E-print Network

Spectra. II. Transition Probabilities for the Magnesium Isoelectronic Sequence* RICHARD N. ZAREt Joint- minantal wavefunctions. Dipole length and dipole velocity expressions for the transition probability- vestigated, and the differences in the calculated transition probabilities are found to be quite small

Zare, Richard N.

290

Organic carbon-water concentration quotients (II(SOC)S and pi(poc)S): measuring apparent chemical disequilibria and exploring the impact of black carbon in Lake Michigan.  

PubMed

Chemical concentration quotients measured between water and total organic carbon (TOC) in sediment (II(SOC)) or suspended particulates (pi(poc)) in southern Lake Michigan reveal up to 2 orders of magnitude differences for polychlorinated biphenyl (PCB), dibenzo-p-dioxin (PCDD), dibenzofuran (PCDF), and polycyclic aromatic hydrocarbon (PAH) compounds with similar octanol-water partition coefficients (K(ow)S). Apparent disequilibria for PAHs, PCDDs, and PCDFs, determined as measured II(SOC)S or pi(poc)S divided by their organic carbon equilibrium partitioning values, are significantly greater than disequilibria of PCBs with similar K(ow)S. Apparent disequilibria, when adjusted for black carbon content by using published black carbon nonlinear partition coefficients (K(f,bc)S) and a Freundlich exponent (n(f)) value = 0.7, still exceed equilibrium predictions for the PAHs, PCBs, and PCDDs but with the PCDF disequilibria uniquely below equilibrium. While Monte Carlo analysis of all the variables associated with the black carbon adjusted disequilibria provides wide confidence intervals for individual chemicals, the large class disequilibria differences between PAHs and PCDFs with respect to the PCBs and PCDDs are highly significant. Use of the PCDD K(f,bc)S for calculating both the PCDF and PCDD disequilibria eliminates their extreme divergence. On the basis of the complexity of carbonaceous geosorbent effects and the apparent variable degrees of chemical sequestration in particles, the disequilibria can be adjusted by chemical class to meet expected near equilibrium conditions between suspended particles and water in the hypolimnion. Although these adjustments to the disequilibria calculations produce consistent and plausible values, the complexities of variable carbonaceous geosorbent affinities for these chemicals in Lake Michigan presently favor use of measured, rather than a priori modeled, steady-state total organic carbon-water concentration quotients indexed to TOC as biogenic organic carbon. PMID:18546698

Burkhard, Lawrence P; Cook, Philip M; Lukasewycz, Marta T

2008-05-15

291

Possible Bose-condensate behavior in a quantum phase originating in a collective excitation in the chemically and optically doped Mott-Hubbard system UO2+x  

NASA Astrophysics Data System (ADS)

X-ray pair distribution function (pdf) and U L3 extended x-ray absorption fine structure (EXAFS) and neutron pdf measurements that give identical results for UO2 show U(VI)-oxo moieties with x rays for mixed valence U4O9 and U3O7, in contrast to the neutron data that indicate only U(V) sites with no short U-O bonds as well as other differences. In addition, although the EXAFS spectra of UO2 are essentially identical at 30, 100, and 200 K, those of the UO2+x compounds exhibit different nearest-neighbor U-O distributions at each temperature. Further tunneling polaron-type behavior is found in the broadening of the features of the O K-edge x-ray absorption spectra (XAS) of the UO2+x compounds. Raman spectra of powders also show a large increase in scattering cross section with increasing O content that would originate in a change in the electronic structure that increases the overall polarizability. The XAS and Raman also show that U4O9 does not behave as a linear combination of the UO2 and U3O7 fluorite endpoints. The properties induced by mobile rather than static charged quasiparticles were explored by optical pumping of the metal-to-metal charge-transfer transition. The temperature dependence of 4.71 eV pump-1.57 eV probe reflectivity on UO2 that initially populates the U 6d-dominated portion of the upper Hubbard band (UHB) shows a sharp 28-?sec lifetime peak at 25 K that may be associated with the fluctuations of its antiferromagnetic transition. Pumping at 3.14 eV into the 5f-dominated portion of the UHB shows an analogous 2.8-?sec peak but also a plateau bracketing this peak that ends in a cusp at 50-60 K and an abrupt change in the hardening rate of a novel 12-15 GHz phonon that is the signature for the quasiparticle quantum phase. The different results for the different excitation channels indicate a highly specific nonthermal relaxation mechanism. These results constitute the first observation of a distinct phase of photoinduced quasiparticles that is sufficiently coupled to the lattice to undergo a gap-opening transition. When the intragap state is probed with a terahertz time domain spectroscopy (TTDS) measurement 33 psec after a 3.14 excitation pulse, it shows increased absorption in the 0.5-1.1 THz range with a decrease in temperature from ˜30 to 10 K instead of the expected decrease, a result consistent with the presence of a condensate. These results are too extreme to originate in the dynamical, nonadiabatic, coupled charge-transfer-phonon/tunneling polaron scenario previously used for doped Mott-Hubbard insulators with intermediate electron-phonon coupling and therefore indicate novel physics. One possibility that could cause all of these behaviors is that a collective, dynamical, charge transfer-coupled Peierls distortion involving the 2 U(V) ? U(IV)+U(VI)-oxo excitation occurs coherently over an entire domain to cause the atoms in this domain to condense into a system with Bose-Einstein or Bose-Einstein-Hubbard properties.

Conradson, Steven D.; Durakiewicz, Tomasz; Espinosa-Faller, Francisco J.; An, Yong Q.; Andersson, David A.; Bishop, Alan R.; Boland, Kevin S.; Bradley, Joseph A.; Byler, Darrin D.; Clark, David L.; Conradson, Dylan R.; Conradson, Leilani L.; Costello, Alison L.; Hess, Nancy J.; Lander, Gerard H.; Llobet, Anna; Martucci, Mary B.; Mustre de Leon, Jose; Nordlund, Dennis; Lezama-Pacheco, Juan S.; Proffen, Thomas E.; Rodriguez, George; Schwarz, Daniel E.; Seidler, Gerald T.; Taylor, Antoinette J.; Trugman, Stuart A.; Tyson, Trevor A.; Valdez, James A.

2013-09-01

292

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

293

Pioneer game in collective actions: Experimental evidence  

Microsoft Academic Search

Collective actions are typical social and economic behavior, in which free riders exist objectively. Successful execution of collective actions is related to pioneer game, the value expectation and the follow-up sequence of followers. Through localized experiments, this paper verifies that: (i) collective actions are realizable, (ii) free riders can be weakened or relieved, and (iii) the realization probability of collective

Yichuan Wang

2011-01-01

294

Chemical and dynamical processes in the atmospheres of, I. Ancient and present-day earth, II. Jupiter and Galilean satellites, III. Extrasolar  

Microsoft Academic Search

When exposed to stellar UV radiation, chemical processes will be governed not only by temperature\\/pressure but also the spectrum of the incoming dissociative photon flux; the system will approach kinetic, or photochemical, equilibrium, instead of thermochemical equilibrium. Over the previous decades, photochemistry has proven to be a powerful tool for predicting the chemical composition in the atmospheres of solar planets

Mao-Chang Liang

2006-01-01

295

Collective Enumeration  

PubMed Central

Many joint decisions in everyday life (e.g., Which bar is less crowded?) depend on approximate enumeration, but very little is known about the psychological characteristics of counting together. Here we systematically investigated collective approximate enumeration. Pairs of participants made individual and collective enumeration judgments in a 2-alternative forced-choice task and when in disagreement, they negotiated joint decisions via verbal communication and received feedback about accuracy at the end of each trial. The results showed that two people could collectively count better than either one alone, but not as well as expected by previous models of collective sensory decision making in more basic perceptual domains (e.g., luminance contrast). Moreover, such collective enumeration benefited from prior, noninteractive practice showing that social learning of how to combine shared information about enumeration required substantial individual experience. Finally, the collective context had a positive but transient impact on an individual's enumeration sensitivity. This transient social influence may be explained as a motivational factor arising from the fact that members of a collective must take responsibility for their individual decisions and face the consequences of their judgments. PMID:22889187

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

2012-01-01

296

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

297

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.

298

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

299

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

PubMed

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

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

2012-10-15

300

Atherosclerotic Risks from Chemicals: Part II. A RASH Analysis of In Vitro and In Vivo Bioassay Data to Evaluate 45 Potentially Hazardous Compounds  

Microsoft Academic Search

.   As reviewed in the Part I companion manuscript by Basavaraju and Jones (Arch Environ Contam Toxicol), atherosclerosis and\\u000a carcinogenesis may share some common mechanisms of toxicological action. On that hypothesis, standardized test data taken\\u000a from the Registry of Toxic Effects of Chemical Substances (RTECS) were used to compute relative potency factors for chemical\\u000a compounds associated with increased risk of

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

1998-01-01

301

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.

302

Effect of mining chemicals on biosorption of Cu(II) by the non-living biomass of the macrophyte Potamogeton lucens  

Microsoft Academic Search

The present work investigates the effect of some compounds commonly discharged from mineral processing plants on biosorption of heavy metals by the non-living biomass of the freshwater macrophyte Potamogeton lucens. Studies of sorption of Cu (II) in the presence of metal ions, surfactants, EDTA and cyanide were carried out at laboratory scale. The results show that copper adsorption by ion

I. A. H. Schneider; R. W. Smith; J. Rubio

1999-01-01

303

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.

304

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

305

Genthe Collection  

NSDL National Science Digital Library

Arnold Genthe had an urbane German upbringing in Berlin, Frankfurt, Korbach, and Hamburg. Born in 1869, he wanted to become an artist, but a family relation discouraged him. Fortunately, he ended up moving to America in 1895 to become a tutor, and while there in began to experiment with photography. Over the following five decades, he would go on to document the aftermath of the San Francisco Earthquake and take photos of President Woodrow Wilson, Arturo Toscanini, and many others. Eventually his tremendous collection of work found its way to the Library of Congress, and here visitors can traipse through over 16,000 of his images. Along with a brief overview of the collection, visitors should also read the informative essay here titled "The Negative and the Print: Genthe's Photographic Techniques". It is easy enough to search the collection, although visitors can also browse the selections by name, subject, or format.

Genthe, Arnold, 1869-1942

306

5 CFR 831.1305 - Collection of debts.  

Code of Federal Regulations, 2013 CFR

...1305 Collection of debts. (a) Means of... Collection of a debt may be made by means...debtor from the Federal Government, or by referral...substantially prejudice the Government's ability to collect the debt; and (ii)...

2013-01-01

307

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

308

Wastewater Collection.  

ERIC Educational Resources Information Center

Presents a literature review of wastewater collection systems and components. This review covers: (1) planning, (2) construction; (3) sewer system evaluation; (4) maintenance; (5) rehabilitation; (6) overview prevention; and (7) wastewater pumping. A list of 111 references is also presented. (HM)

Chatterjee, Samar; And Others

1978-01-01

309

Collective Instinct  

Microsoft Academic Search

IN response to the appeal which closes Mr. Buck's interesting letter (NATURE, vol. viii. p. 332), the following instance of ``collective instinct'' exhibited by an animal closely allied to the wolf, viz., the Indian jackal, deserves to be recorded. It was communicated to me by a gentleman (since deceased) on whose veracity I can depend. Tnis gentleman was waiting in

George J. Romanes

1873-01-01

310

Comprehensive investigation of the corrosion state of the heat exchanger tubes of steam generators. Part II. Chemical composition and structure of tube surfaces  

NASA Astrophysics Data System (ADS)

In the frame of a project dealing with the comprehensive study of the corrosion state of the steam generators of the Paks Nuclear Power Plant, Hungary, surface properties (chemical and phase compositions) of the heat exchanger tubes supplied by the power plant were studied by Mössbauer spectroscopy (CEMS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) methods. The work presented in this series provides evidence that chemical decontamination of the steam generators by the AP-CITROX technology does exert a detrimental effect on the chemical composition and structure of the protective oxide film grown-on the inner surfaces of heat exchanger piping. As an undesired consequence of the decontamination technology, a 'hybrid' structure of the amorphous and crystalline phases is formed in the outermost surface region (within a range of 11 ?m). The constituents of this 'hybrid' structure exhibit great mobility into the primary coolant under normal operation of the VVER type reactor.

Homonnay, Z.; Kuzmann, E.; Varga, K.; Németh, Z.; Szabó, A.; Radó, K.; Makó, K. É.; Kövér, L.; Cserny, I.; Varga, D.; Tóth, J.; Schunk, J.; Tilky, P.; Patek, G.

2006-01-01

311

Health effects in Army Gulf War veterans possibly exposed to chemical munitions destruction at Khamisiyah, Iraq: Part II. Morbidity associated with notification of potential exposure.  

PubMed

The purpose of this study was to examine the association of notification of potential exposure to chemical warfare agents in the 1991 Gulf War with subsequent self-reported morbidity. The study sample included 1,056 deployed Army Gulf War veterans who responded to the 1995 National Health Survey of Gulf War Era Veterans and who were resurveyed in 2000. One-half of the subjects had been notified of potential exposure to chemical warfare agents and one-half had not. Comparing notified and non-notified subjects, there were no statistically significant differences with respect to bed days, activity limitations, clinic visits, or hospital visits. Among 71 self-reported medical conditions and symptoms, there were 5 statistically significant differences, 4 of which were for lower rates of illness among notified subjects. Our findings contradict the prevailing notion that perceived exposure to chemical warfare agents should be considered an important cause of morbidity among Gulf War veterans. PMID:16450822

Page, William F; Mahan, Clare M; Kang, Han K; Bullman, Tim A

2005-11-01

312

Structure and properties of the polysaccharides from pea hulls—II. Modification of the composition and physico-chemical properties of pea hulls by chemical extraction of the constituent polysaccharides  

Microsoft Academic Search

Fibres, prepared from pea hulls as the alcohol insoluble residue (AIR), were modified by two sequences of chemical treatments. In one, chelating agent (CDTA), acid (HCl) then increasing concentrations of alkali (0·05, 1 and 4 m KOH), removed firstly the pectins, and then the xylans, whereas in the second (alkali alone: 0·05, 1 and 4 m KOH) only significant quantities

R. M. Weightman; C. M. G. C. Renard; D. J. Gallant; J.-F. Thibault

1995-01-01

313

PhysicoChemical Properties of Nickel(II) Chelates of 4Acetyl3-methyl-1-(3?-chlorophenyl)-2-pyrazolin-5-one and Schiff Bases  

Microsoft Academic Search

Ni(II) chelates of 4-acetyl-3-methyl-1-(3?-chlorophenyl)-2-pyrazolin-5-one and its Schiff bases with o-toluidine, m-toluidine, m-chloroaniline, p-chloroaniline, ethanolamine and glycine have been prepared and characterized on the basis of their spectral, magnetic and conductivity properties. All the chelates are found to have octahedral structure. Various structural parameters have been calculated for all the chelates.

P. M. Parikh; J. R. Shah

1985-01-01

314

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.

315

Comprehensive investigation of the corrosion state of the heat exchanger tubes of steam generators. Part II. Chemical composition and structure of tube surfaces  

Microsoft Academic Search

In the frame of a project dealing with the comprehensive study of the corrosion state of the steam generators of the Paks Nuclear Power Plant, Hungary, surface properties (chemical and phase compositions) of the heat exchanger tubes supplied by the power plant were studied by Mössbauer spectroscopy (CEMS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) methods. The work presented

Z. Homonnay; E. Kuzmann; K. Varga; Z. Németh; A. Szabó; K. Radó; K. É. Makó; L. Kövér; I. Cserny; D. Varga; J. Tóth; J. Schunk; P. Tilky; G. Patek

2006-01-01

316

Retrospective mortality study of workers in three major U. S. refineries and chemical plants. Part II: Internal comparisons by geographic site, occupation, and smoking history  

Microsoft Academic Search

A cohort of 21,698 U.S. refinery and chemical plant workers was observed for eight years to determine if there were interplant or other variations in causes of mortality. Plant populations in three geographic locations were combined to develop an internal standard for comparing subgroups within the total cohort. At no one geographic site were consistently different rates for all major

Nancy M. Hanis; Leba G. Shallenberger; Donna L. Donaleski; Eugene A. Sales

1985-01-01

317

Investigation of the Properties of a Kinetic Mechanism Describing the Chemical Structure of RDX Flames. II. Construction of a Reduced Kinetic Scheme  

Microsoft Academic Search

A reduced kinetic mechanism is constructed taking into account various boundary conditions and the considerable spread of data on rate constant of elementary steps. Kinetic schemes describing the chemical structure of flame with various degrees of accuracy are considered. The “shortest” mechanism consists of 83 steps and 29 species. The heat fluxes, temperature profiles, and concentration profiles of the main

N. E. Ermolin; V. E. Zarko

2001-01-01

318

The Most Metal-Poor Stars. II. Chemical Abundances of 190 Metal-Poor Stars Including 10 New Stars With [Fe/H] ? -3.5  

E-print Network

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 ...

Frebel, Anna L.

319

A survey of EPA/OPP and open literature on selected pesticide chemicals. II. Mutagenicity and carcinogenicity of selected chloroacetanilides and related compounds.  

PubMed

With this effort, we continue our examination of data on selected pesticide chemicals and their related analogues that have been presented to the U.S. Environmental Protection Agency's (USEPA's) Office of Pesticide Programs (OPP). This report focuses on a group of selected chloroacetanilides and a few related compounds. As part of the registration process for pesticidal chemicals, interested parties (registrants) must submit toxicity information to support the registration including both mutagenicity and carcinogenicity data. Although this information is available to the public via Freedom of Information (FOI) requests to the OPP, publication in the scientific literature allows greater dissemination and examination of the data. For this Special Issue, graphic profiles have been prepared of the mutagenicity and carcinogenicity data available in the submissions to OPP. Also, a discussion is presented about how toxicity data are used to help establish tolerances (limits of pesticide residues in foods). The mutagenicity results submitted by registrants are supplemented by data on these chemicals from the open literature to provide a full perspective of their genetic toxicology. The group of chloroacetanilides reviewed here display a consistent pattern of mutagenic activity, probably mediated via metabolites. This mutagenic activity is a mechanistically plausible factor in the development of tumors seen in experimental animals exposed to this class of chemicals. PMID:10415440

Dearfield, K L; McCarroll, N E; Protzel, A; Stack, H F; Jackson, M A; Waters, M D

1999-07-15

320

A chemical test of the principle of critical point universality: the solubility of nickel (II) oxide in isobutyric acid + water near the consolute point.  

PubMed

A mixture of isobutyric acid + water has an upper consolute point at 38.8 mass?% isobutyric acid and temperature near 26?°C. Nickel (II) oxide dissolves in this mixture by reacting with the acid to produce water and nickel isobutyrate. The solubility of nickel (II) oxide in isobutyric acid + water has been measured as a function of temperature at compositions, 25, 38.8, and 60 mass?% isobutyric acid. For values of the temperature, T, which were at least 2 K in excess of the liquid-liquid phase transition temperature, the measured values of the solubility, s, lie on a straight line when plotted in van't Hoff form with ln?s versus 1?T. The slope, (?ln?s??(1?T)), of the line is negative indicating that the dissolution reaction is endothermic. When the temperature was within 2 K of the phase transition temperature, however, (?ln?s??(1?T)) diverged toward negative infinity. The principle of critical point universality predicts that when excess solid nickel (II) oxide is in dissolution equilibrium with liquid isobutyric acid + water, (?ln?s??(1?T)) should diverge upon approaching the consolute point along the critical isopleth at 38.8 mass?% isobutyric acid. As determined by the sign of the enthalpy of solution, the sign of this divergence is expected to be negative. Not only do our experiments confirm these predictions, but they also show that identical behavior can be observed at both 25 and 60 mass?% isobustyric acid, compositions which lie substantially to either side of the critical composition. PMID:21513393

Hu, Baichuan; Baird, James K; Richey, Randi D; Reddy, Ramana G

2011-04-21

321

Inversion of multiple thermal indicators: quantitative methods of determining paleoheat flux and geological parameters. II. Theoretical development for chemical, physical, and geological parameters  

SciTech Connect

Using the logic for quantitative inversion of present-day downhole thermal indicators, the inversion procedure can be used to determine unknown, or poorly known, chemical and physical parameters as well as other geological quantities of interest which impact on burial history and thermal history of an evolving sedimentary basin. Some such quantities are: amount of erosion and timing of unconformities, paleo-overpressuring, stratigraphic age, timing of igneous intrusion and insertion temperature, overthrust timing and frictional heating, fault and slump timing, effect due to emplacement of a radioactive layer, and salt emplacement and dissolution timing. Combining a priori unknown values of these chemical/physical and geological parameters with unknown (a priori) paleoheat flux variations, a theoretical scheme, called thermal indicator tomography, is developed for the systematic determination of all parameters at the same time and on the same footing.

Lerche, I.

1988-02-01

322

Drop size-dependent chemical composition of clouds and fogs. Part II: Relevance to interpreting the aerosol\\/trace gas\\/fog system  

Microsoft Academic Search

Size-resolved fog drop chemical composition measurements were obtained during a radiation fog campaign near Davis, California in December 1998\\/January 1999 (reported in Reilly et al., Atmos. Environ. 35(33) (2001) 5717; Moore et al., Atmos. Environ. this issue). Here we explore how knowledge of this size-dependent drop composition—particularly from the newly developed Colorado State University 5-Stage cloud water collector—helps to explain

Katharine F. Moore; D. Eli Sherman; Jill E. Reilly; Michael P. Hannigan; Taehyoung Lee; Jeffrey L. Collett

2004-01-01

323

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

324

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

325

CHEMICAL ABUNDANCES OF THE MILKY WAY THICK DISK AND STELLAR HALO. II. SODIUM, IRON-PEAK, AND NEUTRON-CAPTURE ELEMENTS  

SciTech Connect

We present chemical abundance analyses of sodium, iron-peak, and neutron-capture elements for 97 kinematically selected thick disk, inner halo, and outer halo stars with metallicities -3.3 < [Fe/H] <-0.5. The main aim of this study is to examine chemical similarities and differences among metal-poor stars belonging to these old Galactic components as a clue to determine their early chemodynamical evolution. In our previous paper, we obtained abundances of {alpha} elements by performing a one-dimensional LTE abundance analysis based on the high-resolution (R {approx} 50, 000) spectra obtained with the Subaru/HDS. In this paper, a similar analysis is performed to determine abundances of an additional 17 elements. We show that, in metallicities below [Fe/H] {approx}-2, the abundance ratios of many elements in the thick disk, inner halo, and outer halo subsamples are largely similar. In contrast, in higher metallicities ([Fe/H] {approx}> -1.5), differences in some of the abundance ratios among the three subsamples are identified. Specifically, the [Na/Fe], [Ni/Fe], [Cu/Fe], and [Zn/Fe] ratios in the inner and outer halo subsamples are found to be lower than those in the thick disk subsample. A modest abundance difference between the two halo subsamples in this metallicity range is also seen for the [Na/Fe] and [Zn/Fe] ratios. In contrast to that observed for [Mg/Fe] in our previous paper, [Eu/Fe] ratios are more enhanced in the two halo subsamples rather than in the thick disk subsample. The observed distinct chemical abundances of some elements between the thick disk and inner/outer halo subsamples with [Fe/H] >-1.5 support the hypothesis that these components formed through different mechanisms. In particular, our results favor the scenario that the inner and outer halo components formed through an assembly of multiple progenitor systems that experienced various degrees of chemical enrichments, while the thick disk formed through rapid star formation with an efficient mixing of chemical elements. The lower [Na/Fe] and [Zn/Fe] observed in stars with the outer halo kinematics may further suggest that progenitors with longer star formation timescales contributed to the buildup of the relatively metal-rich part of stellar halos.

Ishigaki, M. N. [Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Aoki, W. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Chiba, M., E-mail: miho.ishigaki@ipmu.jp, E-mail: aoki.wako@nao.ac.jp, E-mail: chiba@astr.tohoku.ac.jp [Astronomical Institute, Tohoku University, Aoba-ku, Sendai 980-8578 (Japan)

2013-07-01

326

The chemical composition of the Galactic H II regions M8 and M17. A revision based on deep VLT echelle spectrophotometry  

NASA Astrophysics Data System (ADS)

We present new echelle spectrophotometry of the Galactic H II regions M8 and M17. The data have been taken with the VLT UVES echelle spectrograph in the 3100 to 10400 Å range. We have measured the intensities of 375 and 260 emission lines in M8 and M17 respectively, increasing significatively the number of emission lines measured in previous spectrophotometric studies of these nebulae. Most of the detected lines are permitted lines. Electron temperatures and densities have been determined using different diagnostics. We have derived He^+, C++, O^+ and O^{++} ionic abundances from pure recombination lines. We have also derived abundances from collisionally excited lines for a large number of ions of different elements. Highly consistent estimations of t^2 have been obtained by using different independent indicators; the values are moderate and very similar to those obtained in other Galactic H II regions. We report the detection of deuterium Balmer emission lines, up to D?, in M8 and show that their intensities are consistent with continuum fluorescence as their main excitation mechanism.

García-Rojas, J.; Esteban, C.; Peimbert, A.; Rodríguez, M.; Peimbert, M.; Ruiz, M. T.

2007-04-01

327

Collective motion  

NASA Astrophysics Data System (ADS)

We review the observations and the basic laws describing the essential aspects of collective motion - being one of the most common and spectacular manifestation of coordinated behavior. Our aim is to provide a balanced discussion of the various facets of this highly multidisciplinary field, including experiments, mathematical methods and models for simulations, so that readers with a variety of background could get both the basics and a broader, more detailed picture of the field. The observations we report on include systems consisting of units ranging from macromolecules through metallic rods and robots to groups of animals and people. Some emphasis is put on models that are simple and realistic enough to reproduce the numerous related observations and are useful for developing concepts for a better understanding of the complexity of systems consisting of many simultaneously moving entities. As such, these models allow the establishing of a few fundamental principles of flocking. In particular, it is demonstrated, that in spite of considerable differences, a number of deep analogies exist between equilibrium statistical physics systems and those made of self-propelled (in most cases living) units. In both cases only a few well defined macroscopic/collective states occur and the transitions between these states follow a similar scenario, involving discontinuity and algebraic divergences.

Vicsek, Tamás; Zafeiris, Anna

2012-08-01

328

Classification Schemes for Collection Mediation  

E-print Network

of collaboration. Their aim has been i #12;ii Abstract to an empirical basis for design of a web-based multimediaClassification Schemes for Collection Mediation: Work Centered Design and Cognitive Work Analysis Design Hanne Albrechtsen Cognitive Systems Engineering Centre Systems Analysis Department Risø National

329

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.

330

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

331

CHEMICAL EVOLUTION IN HIERARCHICAL MODELS OF COSMIC STRUCTURE. II. THE FORMATION OF THE MILKY WAY STELLAR HALO AND THE DISTRIBUTION OF THE OLDEST STARS  

SciTech Connect

This paper presents theoretical star formation and chemical enrichment histories for the stellar halo of the Milky Way (MW) based on new chemodynamical modeling. The goal of this study is to assess the extent to which metal-poor stars in the halo reflect the star formation conditions that occurred in halo progenitor galaxies at high redshift, before, and during the epoch of re-ionization. Simple prescriptions that translate dark-matter (DM) halo mass into baryonic gas budgets and star formation histories yield models that resemble the observed MW halo in its total stellar mass, metallicity distribution, and the luminosity function and chemical enrichment of dwarf satellite galaxies. These model halos in turn allow an exploration of how the populations of interest for probing the epoch of re-ionization are distributed in physical and phase space, and of how they are related to lower-redshift populations of the same metallicity. The fraction of stars dating from before a particular time or redshift depends strongly on radius within the galaxy, reflecting the 'inside-out' growth of cold DM halos, and on metallicity, reflecting the general trend toward higher metallicity at later times. These results suggest that efforts to discover stars from z>6-10 should select for stars with [Fe/H] approx<-3 and favor stars on more tightly bound orbits in the stellar halo, where the majority are from z>10 and 15%-40% are from z>15. The oldest, most metal-poor stars-those most likely to reveal the chemical abundances of the first stars-are most common in the very center of the Galaxy's halo: they are in the bulge, but not of the bulge. These models have several implications for the larger project of constraining the properties of the first stars and galaxies using data from the local universe.

Tumlinson, Jason [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

2010-01-10

332

Gillray Collection  

NSDL National Science Digital Library

Throughout history, illustrators and others have seen fit to accurately skewer politicians, religious leaders, and countless others through their creative drawings and words. Born in 1756, English illustrator James Gillray was part of this honorable tradition. He reigned supreme during a period that became known as the "golden age of English caricature," and he "chronicled and ridiculed the politicians and ruling class of his day." This collection of his work comes courtesy of Dickson Q. Brown (Princeton class of 1895) who donated 313 prints to the Princeton University Library. Visitors to the site won't want to miss his "A bouquet of the last century" or his highly effective "A peep into the cave of Jacobinism." Overall, it's a delightful set of images, and one that effectively demonstrates the power of such pieces of art and political commentary.

Gillray, James, 1756-1815

333

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.

334

Evaluation of A MBER force field parameters for copper(II) with pyridylmethyl-amine and benzimidazolylmethyl-amine ligands: A quantum chemical study  

NASA Astrophysics Data System (ADS)

We present the theoretical evaluations on the two new sets of A MBER force field parameters for the two copper(II) nucleases, Cu(BPA)Cl 2 (BPA = bis(2-pyridylmethyl)amine) and Cu(IDB)Cl 2 (IDB = N, N-bis(2-benzimidazolylmethyl)amine) based on the DFT/B3LYP level of theory, incorporating with atomic charges calculated by the RESP method. The new force field parameters have been successfully applied in the testing molecular dynamic simulations for the nuclease-DNA combining systems. The developed force field parameters in this work can be applied in DNA-binding modeling for other artificial copper nucleases with same Cu-N type environments.

Zhu, Yanyan; Su, Yanwei; Li, Xichen; Wang, Yan; Chen, Guangju

2008-04-01

335

Chemical enrichment of the complex hot ISM of the Antennae Galaxies: II. Physical properties of the hot gas and supernova feedback  

E-print Network

We investigate the physical properties of the interstellar medium (ISM) in the merging pair of galaxies known as The Antennae (NGC 4038/39), using the deep coadded ~411 ks Chandra ACIS-S data set. The method of analysis and some of the main results from the spectral analysis, such as metal abundances and their variations from ~0.2 to ~20-30 times solar, are described in Paper I (Baldi et al. submitted). In the present paper we investigate in detail the physics of the hot emitting gas, deriving measures for the hot-gas mass (~10^ M_sun), cooling times (10^7-10^8 yr), and pressure (3.5x10^-11-2.8x10^-10 dyne cm^-2). At least in one of the two nuclei (NGC 4038) the hot-gas pressure is significantly higher than the CO pressure, implying that shock waves may be driven into the CO clouds. Comparison of the metal abundances with the average stellar yields predicted by theoretical models of SN explosions points to SNe of Type II as the main contributors of metals to the hot ISM. There is no evidence of any correlation between radio-optical star-formation indicators and the measured metal abundances. Although due to uncertainties in the average gas density we cannot exclude that mixing may have played an important role, the short time required to produce the observed metal masses (mixing. More likely, a significant fraction of SN II ejecta may be in a cool phase, in grains, or escaping in hot winds. In each case, any such fraction of the ejecta would remain undetectable with soft X-ray observations.

A. Baldi; J. C. Raymond; G. Fabbiano; A. Zezas; A. H. Rots; F. Schweizer; A. R. King; T. J. Ponman

2005-09-01

336

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

337

X-ray diagnostics of chemical composition of the accretion disk and donor star in UCXBs II: XMM-Newton observations  

NASA Astrophysics Data System (ADS)

Ultra-compact X-ray binaries are identified by their extremely short orbital periods of less than 1h. This implies such tight orbits that only H-deficient compact objects would fit. Most likely, UCXBs consist of a Roche lobe filling white dwarf that is accreting onto a neutron star companion. In our recently published paper (Koliopanos, Gilfanov & Bildsten 2013) we showed that X-ray reflection spectra, in particular the iron Ka line, can be used as a diagnostic of the chemical composition of the accretion disk in UCXBs. Specifically, we used Monte Carlo simulations to show that the most dramatic and easily observable consequence of a C/O-rich accretion disk is the more than tenfold attenuation of the Ka line of iron (consistently detected in the spectra of typical LMXBs with main sequence or red giant donors). On the other hand in the case of a He-rich donor (e.g. a helium-WD or helium-star) the iron line remains at its usually observed strength. In our most recent paper (Koliopanos et al. 2014, submitted) we applied our theoretical findings on XMM observations of well known UCXBs. In my talk I will present the results of our analysis as well as our predictions regarding their chemical composition.

Koliopanos, F.; Gilfanov, M.; Bildsten, L.; Diaz Trigo, M.

2014-07-01

338

Intelligent Information Interaction for Managing Distributed Collections of Web Documents  

E-print Network

. . . . . . . . . . . . . . 7 E. A Taxonomy of Web-Based Collections . . . . . . . . . . . 8 F. Curated Undistributed Collections . . . . . . . . . . . . . . 9 G. Curated Distributed Collections . . . . . . . . . . . . . . . 10 H. Uncurated Undistributed Collections... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 x LIST OF TABLES TABLE Page I Taxonomy of online collections by how change is managed . . . . . . 9 II Measures used in WebTango (WT) versus the Proportional Algo- rithm (PA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21...

Bogen, Paul

2012-02-14

339

75 FR 53349 - Notice of Information Collection  

Federal Register 2010, 2011, 2012, 2013

...SUPPLEMENTARY INFORMATION: I. Abstract: The purpose of this survey is to assimilate lunar regolith stimulant requirements as well as Apollo sample requests for the ETDP and Constellation projects and test facilities. II. Method of Collection Electronic. III....

2010-08-31

340

75 FR 65673 - Notice of Information Collection  

Federal Register 2010, 2011, 2012, 2013

...SUPPLEMENTARY INFORMATION: I. Abstract The purpose of this survey is to assimilate lunar regolith stimulant requirements as well as Apollo sample requests for the ETDP and Constellation projects and test facilities. II. Method of Collection Electronic. III....

2010-10-26

341

75 FR 34487 - Notice of Information Collection  

Federal Register 2010, 2011, 2012, 2013

...themes on areas to focus on in order to enhance creativity and innovation at the Center. II. Method of Collection Electronic. III. Data Title: The KEYS Creativity and Innovation Survey. OMB Number: 2700-XXXX. Type...

2010-06-17

342

75 FR 41898 - Notice of Information Collection  

Federal Register 2010, 2011, 2012, 2013

...themes on areas to focus on in order to enhance creativity and innovation at the Center. II. Method of Collection Electronic. III. Data Title: The KEYS Creativity and Innovation Survey. OMB Number: 2700-XXXX. Type...

2010-07-19

343

Analysis of high speed non-equilibrium chemically reacting gas flows. Part II. A finite volume/finite element model and numerical studies  

NASA Astrophysics Data System (ADS)

In this part, a new hybrid numerical model for solving the two-dimensional axisymmetric Navier-Stokes equations for a multi-species reacting gas out of thermal and chemical equilibrium is constructed. The formulation is based on a mixed finite volume/finite element formulation for unstructured meshes. The convective flux is treated with an approximate Osher-Riemann solver, and the other fluxes are treated using P1 finite elements. New aspects of the extension of the Osher-Riemann solver are presented here. This scheme was used for the benchmark model comparison in Part I, and is applied here to hypersonic (Mach 25) flow past a two-dimensional ellipse and a hemispherically blunted body at sea level. Copyright

Harlé, Christophe; Carey, Graham F.; Varghese, Philip L.

2000-03-01

344

A retrospective mortality study of workers in three major U.S. refineries and chemical plants. Part II: Internal comparisons by geographic site, occupation, and smoking history.  

PubMed

A cohort of 21,698 U.S. refinery and chemical plant workers was observed for eight years to determine if there were interplant or other variations in causes of mortality. Plant populations in three geographic locations were combined to develop an internal standard for comparing subgroups within the total cohort. At no one geographic site were consistently different rates for all major causes of death observed. The adjusted mortality rates for potentially exposed workers were slightly greater than those for nonexposed workers for most causes examined. Smokers incurred a higher risk of mortality from many causes of death when compared with nonsmokers, regardless of occupational category. After controlling for smoking, there remained a slight excess in mortality for potentially exposed as compared with nonexposed workers. PMID:4009306

Hanis, N M; Shallenberger, L G; Donaleski, D L; Sales, E A

1985-05-01

345

Mary Louise Reynolds Collection  

NSDL National Science Digital Library

Mary Louise Reynolds (1891-1950) led a fascinating life at the center of the Surrealist circle of artists, numbering as her friends Max Ernst, Man Ray, Paul ÃÂluard, André Breton, Jean Cocteau, and Salvador Dalí. Reynolds and Surrealist Marcel Duchamp were partners in a long term relationship thought by their friends to be far happier than most marriages. She was a book artist and served in the French resistance during World War II. The materials in the Mary Louise Reynolds Archive and her collection of rare books and bindings at the Art Institute of Chicago have inspired at least two books and several exhibitions, as well as this Web site. The site features four essays reprinted from the Art Institute's Museum Studies journal, illustrated with digital images of Surrealist works, and available in both HTML and Adobe Acrobat (.pdf) formats. There is also an online finding aid to the collection, and it is possible to search the Ryerson and Burnham Library's catalog for Reynolds collection items. One portion of the site (View Works of Art) brings together all the digitized works of art: Reynolds' book bindings, Surrealist documents, prints, and a few photographs.

346

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

347

The Nainital-Cape Survey -- II:Report for pulsation in five chemically peculiar A-type stars and presentation of 140 null results  

E-print Network

To search photometric variability in chemically peculiar A type stars in the northern hemisphere. High-speed photometric observations of Ap and Am star candidates have been carried out from ARIES (Manora Peak, Nainital) using a three-channel fast photometer attached to the ARIES 104-cm Sampurnanand telescope. This paper presents three new variables: HD 113878, HD 118660 and HD 207561. During the time span of the survey (1999 December to 2004 January) pulsations of the $\\delta$ Sct type were also found for the two evolved Am stars HD 102480 and HD 98851, as reported in Joshi et al. (2002, 2003). Additionally, we present 140 null results of the survey for this time span. The star HD 113878 pulsates with a period of 2.31 hr, which is typical of $\\delta$ Sct stars. HD 118660 exhibits multi-periodic variability with a prominent period of nearly 1 hr. These periods need to be investigated and make HD 118660 a particularly interesting target for further observations. For HD 207561, a star classified as Am, a probable pulsation with a period of 6 min was found in the light curves obtained on two consecutive nights. Both HD 102480 and HD 98851 exhibit unusual alternating high and low amplitude maxima, with a period ratio of 2:1. The analysis of the null results confirms the photometric quality of the Nainital

Santosh Joshi; D. L. Mary; Peter Martinez; D. W. Kurtz; V. Girish; S. Seetha; Ram Sagar; B. N. Ashoka

2006-05-18

348

The Nainital-Cape Survey -- II:Report for pulsation in five chemically peculiar A-type stars and presentation of 140 null results  

E-print Network

To search photometric variability in chemically peculiar A type stars in the northern hemisphere. High-speed photometric observations of Ap and Am star candidates have been carried out from ARIES (Manora Peak, Nainital) using a three-channel fast photometer attached to the ARIES 104-cm Sampurnanand telescope. This paper presents three new variables: HD 113878, HD 118660 and HD 207561. During the time span of the survey (1999 December to 2004 January) pulsations of the $\\delta$ Sct type were also found for the two evolved Am stars HD 102480 and HD 98851, as reported in Joshi et al. (2002, 2003). Additionally, we present 140 null results of the survey for this time span. The star HD 113878 pulsates with a period of 2.31 hr, which is typical of $\\delta$ Sct stars. HD 118660 exhibits multi-periodic variability with a prominent period of nearly 1 hr. These periods need to be investigated and make HD 118660 a particularly interesting target for further observations. For HD 207561, a star classified as Am, a probabl...

Joshi, S; Martínez, P; Kurtz, D W; Girish, V; Seetha, S; Sagar, R; Ashoka, B N; Joshi, Santosh; Martinez, Peter; Sagar, Ram

2006-01-01

349

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

350

[Comparative investigation of structural and gene somatic mutations in workers of nuclear chemical plants. II. Frequency of lymphocytes mutant in T-cell receptor loci].  

PubMed

Frequency of lymphocytes mutant at T-cell receptor (TCR) loci was defined in 42 workers of nuclear chemical plants. In 11 persons mainly exposed to external radiation the mean frequency of TCR-mutant lymphocytes was statistically significant by higher compared with control group of unexposed donors: 9.1 x 10(-4) vs 3.5 x 10(-4) correspondently (p < 0.01). Frequency of TCR-mutant lymphocytes did not correlate neither the frequency of structural mutations non doses of external exposure. In group of workers exposed to combined external and internal radiation (n = 31) the average frequency of TCR-mutant lymphocytes was higher compared with control level: 8.9 x 10(-4) vs 3.5 x 10(-4) correspondently (p < 0.01). Correlations between the frequency of TCR-mutant cells and Pu content in organism (r = 0.5; p = 0.005) and between the frequency of chromosome aberration of unstable and stable types (r = 0.5; p = 0.002 and r = 0.6; p = 0.036, correspondently) were set. Comparison of results of analysis of structural and gene mutations allows us to supose that in case of external exposure the observed disturbances can result from genome instability in remote period after irradiation. In case of combined exposure the genetic changes were possibly caused by the constant action of alpha-radiation from Pu containing in the body. PMID:15906856

Smirnova, S G; Zamulaeva, I A; Orlova, N V; Saenko, A S; Sevan'kaev, A V; Gasteva, G N; Nugis, V Iu; Molokanov, A A

2005-01-01

351

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

Federal Register 2010, 2011, 2012, 2013

...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

352

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

Federal Register 2010, 2011, 2012, 2013

...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

353

FACULTY LEGISLATION LIBRARY MATTERS (pages II-400 through II-499)  

E-print Network

its own. PUBLIC SERVICES: Externally-oriented services extended to library users including circulation, reference, etc. Each library has its own public services staff. COLLECTION DEVELOPMENT: A service providedFACULTY LEGISLATION Page LIBRARY MATTERS (pages II-400 through II-499) General Library System

Sheridan, Jennifer

354

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.

355

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

356

Drop size-dependent chemical composition of clouds and fogs. Part II: Relevance to interpreting the aerosol/trace gas/fog system  

NASA Astrophysics Data System (ADS)

Size-resolved fog drop chemical composition measurements were obtained during a radiation fog campaign near Davis, California in December 1998/January 1999 (reported in Reilly et al., Atmos. Environ. 35(33) (2001) 5717; Moore et al., Atmos. Environ. this issue). Here we explore how knowledge of this size-dependent drop composition—particularly from the newly developed Colorado State University 5-Stage cloud water collector—helps to explain additional observations in the fog environment. Size-resolved aerosol measurements before and after fog events indicate relative depletion of large (>2 ?m in diameter) particles during fog accompanied by a relative increase in smaller aerosol particle concentrations. Fog equivalent air concentrations suggest that entrainment of additional particles and in-fog sedimentation contributed to observed changes in the aerosol size distribution. Calculated deposition velocities indicate that sedimentation was an important atmospheric removal mechanism for some species. For example, nitrite typically has a larger net deposition velocity than water and its mass is found preferentially in the largest drops most likely to sediment rapidly. Gas-liquid equilibria in fog for NO 3-/HNO 3, NH 4+/NH 3, and NO 2-/HONO were examined. While these systems appear to be close to equilibrium or relative equilibrium during many time periods, divergences are observed, particularly for low liquid water content (<0.1 g m -3) fogs and in different drop sizes. Knowledge of the drop size-dependent composition provided additional data useful to the interpretation of these deviations. The results suggest that data from multi-stage cloud water collectors are useful to understanding fog processes as many depend upon drop size.

Moore, Katharine F.; Eli Sherman, D.; Reilly, Jill E.; Hannigan, Michael P.; Lee, Taehyoung; Collett, Jeffrey L.

357

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

358

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

359

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.

360

James H. Doolittle Collection  

NSDL National Science Digital Library

James H. Doolittle was born in Alameda, California in 1896, and during World War II he gained distinction for leading the first carrier-based bomber attack on mainland Japan in 1942. For this work, he was awarded the Medal of Honor, which was presented to him personally by President Franklin D. Roosevelt. This digital collection is from the Eugene McDermott Library at the University of Texas at Dallas, and it offers glimpses into Doolittle's life through a small, yet focused, series of images. Visitors can view a high quality photograph of his Medal of Honor, and then look through some of the photos of Doolittle and his raid bomhttp://scout.wisc.edu/Archives/SPT--EditResource.php?ID=28783ber crew.

361

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.

362

Simulating Inorganic Aerosol Components Using ISORROPIA II in a Chemical Transport Model (PMCAMx) - Evaluation for the MILAGRO Campaign 2006 in Mexico City  

NASA Astrophysics Data System (ADS)

Aerosols have a significant role in the atmosphere having adverse impacts on human health and directly affecting air quality, visibility and climate change. One of the most challenging tasks for the available models is the prediction of the partitioning of the semivolatile inorganic aerosol components (ammonia, nitric acid, hydrochloric acid, etc) between the gas and aerosol phases. Moreover, the effects of mineral aerosols in the atmosphere remain largely unquantified. As a result, most current models have serious difficulties in reproducing the observed particulate nitrate and chloride concentrations. The aerosol thermodynamic model ISORROPIA has been improved as it now simulates explicitly the chemistry of Ca, Mg, and K salts and is linked to PMCAMx (Gaydos et al., 2007). PMCAMx also includes the inorganic aerosol growth module (Gaydos et al., 2003; Koo et al., 2003a) and the aqueous-phase chemistry module (Fahey and Pandis, 2001). The hybrid approach (Koo et al., 2003b) for modeling aerosol dynamics is applied in order to accurately simulate the inorganic components in coarse mode. This approach assumes that the smallest particles are in equilibrium while the condensation/evaporation equation is solved for the larger ones. PMCAMx is applied in Mexico City Metropolitan Area (MCMA) covering a 180x180x6 km region. The emission inventory used has as a starting point the MCMA 2004 official emissions inventory (CAM, 2006) and includes more accurate dust and NaCl emissions. The March 2006 dataset (MILAGRO Campaign) is used to evaluate the inorganic aerosol module of PMCAMx in order to test our understanding of aerosol thermodynamics and the equilibrium assumption. Gaydos, T., Pinder, R., Koo, B., Fahey, ?., Yarwood, G., and Pandis, S. N., (2007). Development and application of a three-dimensional Chemical Transport Model, PMCAMx. Atmospheric Environment, 41, 2594- 2611. Gaydos, T., Koo, B., and Pandis, S. N., (2003). Development and application of an efficient moving sectional approach for the solution of the atmospheric aerosol condensation/evaporation equations. Atmospheric Environment, 37, 3303-3316. Fahey, K. and Pandis, S. N., (2001). Optimizing model performance: variable size resolution in cloud chemistry modelling. Atmospheric Environment 35, 4471-4478. Koo, B., Pandis S. N., and Ansari, A. (2003a). Integrated approaches to modelling the organic and inorganic atmospheric aerosol components. Atmospheric Environment, 37, 4757-4768. Koo, B., Gaydos, T.M., Pandis, S.N., (2003b). Evaluation of the equilibrium, hybrid, and dynamic aerosol modeling approaches. Aerosol Science and Technology 37, 53-64.

Karydis, V. A.; Tsimpidi, A. P.; Nenes, A.; Pandis, S. N.; Zavala, M.; Lei, W.; Molina, L. T.

2007-12-01

363

Physical and chemical properties of the regional mixed layer of Mexico's Megapolis Part II: evaluation of measured and modeled trace gases and particle size distributions  

NASA Astrophysics Data System (ADS)

This study extends the work of Baumgardner et al. (2009) in which measurements of trace gases and particles, at a remote, high altitude mountain site, 60 km from Mexico City were analyzed with respect to the origin of the air masses. In the current evaluation, the temperature, water vapor mixing ratio (WMR), ozone (O3), carbon monoxide (CO), sulfur dioxide (SO2) and acyl peroxy nitrate (APN) are simulated with the WRF-Chem chemical transport model and compared with the measurements at the mountain site. Comparisons between the model and measurements are also evaluated for particle size distributions (PSDs) of the mass concentrations of sulfate, nitrate, ammonium and organic mass (OM). The model predictions of the diurnal trends in temperature, WMR and trace gases were generally well correlated; 13 of the 18 correlations were significant at a confidence level of <0.01. Less satisfactory were the average hourly differences between model and measurements that showed predicted values within expected, natural variation for only 10 of the 18 comparisons. The model performed best when comparing with the measurements during periods when the air originated from the east. In that case all six of the parameters being compared had average differences between the model and measurements less than the expected standard deviation. For the cases when the air masses are from the southwest or west northwest, only two of the comparisons from each case showed differences less than the expected standard deviation. The differences appear to be a result of an overly rapid growth of the boundary layer predicted by the model and too much dilution. There also is more O3 being produced, most likely by photochemical production, downwind of the emission sources than is predicted by the model. The measured and modeled PSD compare very well with respect to their general shape and the diameter of the peak concentrations. The spectra are log normally distributed with most of the mass in the accumulation mode centered at 200 ± 20 nm and little observed or predicted changes with respect to the time when the RML is above the Altzomoni research station. Only the total mass changes with time and air mass origin. The invariability of average diameter of the accumulation mode suggests that there is very little growth of the particles by condensation or coagulation after six hours of aging downwind of the major sources of anthropogenic emissions in Mexico's Megapolis. This could greatly simplify parameterization in climate models although it is not known at this time if this invariance can be extended to other megacity regions.

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

2012-11-01

364

Photobilirubin II.  

PubMed Central

An improved preparation of photobilirubin II in ammoniacal methanol is described. Evidence is presented which distinguishes between the two structures proposed earlier for photobilirubin II in favour of the cycloheptadienyl structure. Nuclear-Overhauser-enhancement measurements with bilirubin IX alpha and photobilirubin II in dimethyl sulphoxide are complicated by the occurrence of negative and zero effects. The partition coefficient of photobilirubin II between chloroform and phosphate buffer (pH 7.4) is 0.67. PMID:6743241

Bonnett, R; Buckley, D G; Hamzetash, D; Hawkes, G E; Ioannou, S; Stoll, M S

1984-01-01

365

Chemical deposition of conducting polymers  

Microsoft Academic Search

The coating of different materials with conducting electroactive polymers (CEP), i.e. polyaniline, polypyrrole, polythiophene, and their derivatives, provided by means of chemical polymerization, is briefly reviewed. The topics covered include the deposition of CEP (i) by bulk oxidative chemical polymerization, (ii) by surface-located polymerization, and (iii) by coating of micro- and nanoparticles. The coating of different materials like polymers, polymer

A. Malinauskas

2001-01-01

366

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

367

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

368

Biomedical | Chemical & Biomolecular | Civil & Environmental | Electrical & Computer | Industrial | Mechanical | Petroleum Careers in Chemical Engineering  

E-print Network

..................................3 CHEE 3363 Fluid Mechanics for Chemical Engineers..........3 PHYS 1322 University Physics II.... | Mechanical | Petroleum Careers in Chemical Engineering Career opportunities in chemical engineering that new chemical engineering graduates have an average starting salary of $67,600. The University

Azevedo, Ricardo

369

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

370

Alaska and Western Canada Collection  

NSDL National Science Digital Library

The University of Washington Libraries Digital Collections continues to break new and interesting ground with one of their latest offerings, which happens to focus in on Alaska and the Canadian provinces of Yukon Territory and British Columbia. With extensive archival holdings in both areas, they are certainly well poised to do so, and this particular collection includes visual materials related to the famed Gold Rush of 1898 to 1900, mining activities, and World War II installations. As with previous collections from this series, visitors can type keywords into the search engine, or they can search by category. The Gold Rush section is a real gem, as it includes 225 images in total. They include an illustration of a miner's working outfit from 1897, a photograph of a mining town dance from 1900, and a harrowing photograph of a boat navigating the treacherous Miles Canyon along the Yukon River.

371

OPTIMIZING HIGH PRESSURE CHEMICAL OXYGEN-IODINE LASERS  

Microsoft Academic Search

The Blaze II chemical laser model was baselined to existing oxygen-iodine research assessment and device improvement chemical laser (RADICL) gain data. Subsequent Fabry-Perot power calculations with Blaze II were an average of 33% higher than the corresponding stable resonator power data. With the Blaze II model baselined to RADICL gain data, a genetic algorithm (GA) was used to predict optimal

David L. Carroll

1996-01-01

372

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

373

76 FR 22676 - Proposed Information Collection; Comment Request; Foreign Fishing Vessel Permit Applications  

Federal Register 2010, 2011, 2012, 2013

...copies of the information collection instrument and instructions...extension of a current information collection. Section 204 of the Magnuson-Stevens...fish products within U.S. waters. II. Method of Collection Paper forms are used....

2011-04-22

374

Collections Management, Collections Maintenance, and Conservation.  

ERIC Educational Resources Information Center

This national survey of the state of the nation's museum collections investigates collection care policies and practices, conservation issues, and private sector and federal support for museum needs. It consists of two major projects and four additional information gathering projects. The Museum Collection Survey is designed to examine all major…

American Association of Museums, Washington, DC.

375

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

376

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-Jimenez, Loreli; Martinez, Paola

2014-01-01

377

Tortuous path chemical preconcentrator  

DOEpatents

A non-planar, tortuous path chemical preconcentrator has a high internal surface area having a heatable sorptive coating that can be used to selectively collect and concentrate one or more chemical species of interest from a fluid stream that can be rapidly released as a concentrated plug into an analytical or microanalytical chain for separation and detection. The non-planar chemical preconcentrator comprises a sorptive support structure having a tortuous flow path. The tortuosity provides repeated twists, turns, and bends to the flow, thereby increasing the interfacial contact between sample fluid stream and the sorptive material. The tortuous path also provides more opportunities for desorption and readsorption of volatile species. Further, the thermal efficiency of the tortuous path chemical preconcentrator is comparable or superior to the prior non-planar chemical preconcentrator. Finally, the tortuosity can be varied in different directions to optimize flow rates during the adsorption and desorption phases of operation of the preconcentrator.

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

2010-09-21

378

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

379

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

380

Anthropological Collections Management  

NSDL National Science Digital Library

This online article explains the meticulous care and tracking that goes into storing the 530,000 items in the museum's anthropology collection. Along with discussing the inherent differences between the items in each of the collection's three subdivisions (archaeology, ethnology, and biological anthropology), the article covers the nature of collections, preserving anthropology collections and computerizing collections management

381

Adsorption of Cd(II) and Pb(II) from aqueous solutions on activated alumina  

Microsoft Academic Search

The ability of activated alumina as synthetic adsorbent was investigated for adsorptive removal of Cd(II) and Pb(II) ions from aqueous solutions. Various physico-chemical parameters such as pH, initial metal ion concentration, and adsorbent dosage level and equilibrium contact time were studied. The optimum solution pH for adsorption of Cd(II) and Pb(II) from aqueous solutions was found to be 5. Kinetics

Tarun Kumar Naiya; Ashim Kumar Bhattacharya; Sudip Kumar Das

2009-01-01

382

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

Federal Register 2010, 2011, 2012, 2013

...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

383

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

Federal Register 2010, 2011, 2012, 2013

...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

384

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

Federal Register 2010, 2011, 2012, 2013

...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

385

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

Federal Register 2010, 2011, 2012, 2013

...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

386

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

Federal Register 2010, 2011, 2012, 2013

...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

387

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

Federal Register 2010, 2011, 2012, 2013

...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

388

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.

389

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.

390

Chemical Health and Safety Data  

NSDL National Science Digital Library

These Chemical Health and Safety Data are an excellent resource for reliable, no-frills information from the National Toxicology Program (NTP). Data from "over 2000 chemicals studied by the NTP" are made available here, and users have a couple of different options for retrieving information. They may simply view a list of chemicals or search the Health and Safety database. Information on each chemical includes physical chemical data (like solubilities, solvents, volatility, flammability, and reactivity), toxicity data, handling procedures, emergency procedures, and a bibliographic list of sources for the information collected. Archived data may be downloaded (.sea, .zip).

391

Gas phase chemical detection with an integrated chemical analysis system  

SciTech Connect

Microfabrication technology has been applied to the development of a miniature, multi-channel gas phase chemical laboratory that provides fast response, small size, and enhanced versatility and chemical discrimination. Each analysis channel includes a sample preconcentrator followed by a gas chromatographic separator and a chemically selective surface acoustic wave detector array to achieve high sensitivity and selectivity. The performance of the components, individually and collectively, is described.

CASALNUOVO,STEPHEN A.; FRYE-MASON,GREGORY CHARLES; KOTTENSTETTE,RICHARD; HELLER,EDWIN J.; MATZKE,CAROLYN M.; LEWIS,PATRICK R.; MANGINELL,RONALD P.; BACA,ALBERT G.; HIETALA,VINCENT M.

2000-04-12

392

Cincinnati Art Museum: The Collection  

NSDL National Science Digital Library

The Cincinnati Art Museum has a long and storied history, and their collection includes works by a variety of artistic masters, old and new. This website provides interested parties with access to items from their permanent collection, courtesy of a grant from the Harold C. Schott Foundation and the Institute of Museum and Library Services. The works here are organized into ten different themes, including "Photographs," "Art of Africa," and "American Decorative Arts." The "American Decorative Arts" is worth a look, and it contains items from the Rockwood Pottery Company, which was established in Cincinnati in 1880, and is still in business. In the "European Painting & Sculpture" visitors shouldn't miss works like the portrait of Philip II by Titian. Visitors will also appreciate the easy to use search engine and the accession and provenance details which are provided for each item.

393

Photosystem II  

ScienceCinema

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

2010-09-01

394

Chemicals, Health, Environment, and Me.  

ERIC Educational Resources Information Center

The CHEM (Chemicals, Health, Environment, and Me) Project is a series of 10 units designed to provide experiences for fifth and sixth graders that help them to accomplish an understanding of: (1) the nature of chemicals and how they interact with the environment; (2) how to collect, process, and analyze information; (3) how to use scientific…

California Univ., Berkeley. Lawrence Hall of Science.

395

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.

0002-11-30

396

Home Chemicals  

NSDL National Science Digital Library

This lesson provides an introduction to the occurrence and possible risks of household chemical products. Topics include some basic chemistry (how elements combine to form compounds), how chemicals are classified, and the idea of natural, as opposed to synthetic, chemicals. The lesson includes an activity in which students take an inventory of chemical products in their homes and research the possible hazards of some of them using an online resource developed by the National Institutes of Health (NIH).

Fox, Chris

397

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

398

Structural studies on photosystem II of cyanobacteria.  

PubMed

Photosynthesis is one of the most important chemical processes in the biosphere responsible for the maintenance of life on Earth. Light energy is converted into energy of chemical bonds in photoreaction centers, which, in particular, include photosystem II (PS II). PS II is a multisubunit pigment-protein complex located in the thylakoid membrane of cyanobacteria, algae and plants. PS II realizes the first stage of solar energy conversion that results in decomposition of water to molecular oxygen, protons, and bound electrons via a series of consecutive reactions. During recent years, considerable progress has been achieved in determination of the spatial structures of PS II from various cyanobacteria. In the present review, we outline the current state of crystallographic studies on PS II. PMID:24490738

Gabdulkhakov, A G; Dontsova, M V

2013-12-01

399

Chemical sensor  

NASA Technical Reports Server (NTRS)

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

Rauh, R. David (Inventor)

1990-01-01

400

Chemical microsensors  

NASA Astrophysics Data System (ADS)

Recent developments are discussed in the field of chemical microsensors that attempt to marry physical transducers based on microelectronic and optoelectronic technologies with thin films and coatings that serve as chemical transducers. Microelectronic silicon chemical sensors, acoustic wave sensors, microsensors based on optical fibers, and electrochemical microsensors are considered. Both technological achievements and problems that remain to be solved are addressed.

Hughes, R. C.; Ricco, A. J.; Butler, M. A.; Martin, S. J.

1991-10-01

401

Collection management issues with geospatial information  

Microsoft Academic Search

Building a digital geographic data collection from scratch and acquiring computer software and hardware systems in which to manage and display the geographic information is becoming standard practice. In a study conducted on the integration of GIS in academic libraries that are a part of Carnegie Classification Master’s Colleges and Universities I and II, there was significant interest in the

John Abresch; Ardis Hanson; Pete Reehling

2008-01-01

402

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...

403

Heterogeneous clay-manganese(II) oxidation catalyst  

Microsoft Academic Search

A manganese(II)-Schiff base complex has been heterogenized by its intercalation into clay minerals. The incorporation of the homogeneous manganese(II) complexes in the interlayer space of aluminosilicate mineral is accomplished by a cation exchange process. The obtained clay-manganese(II) composite has been studied by chemical analysis, X-ray diffraction and FT-IR spectroscopy. The new catalytic material has been evaluated as oxidation catalyst. Our

D Gournis; M Louloudi; M. A Karakassides; C Kolokytha; K Mitopoulou; N Hadjiliadis

2002-01-01

404

Non-planar chemical preconcentrator  

DOEpatents

A non-planar chemical preconcentrator comprises a high-surface area, low mass, three-dimensional, flow-through sorption support structure that can be coated or packed with a sorptive material. The sorptive material can collect and concentrate a chemical analyte from a fluid stream and rapidly release it as a very narrow temporal plug for improved separations in a microanalytical system. The non-planar chemical preconcentrator retains most of the thermal and fabrication benefits of a planar preconcentrator, but has improved ruggedness and uptake, while reducing sorptive coating concerns and extending the range of collectible analytes.

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

2006-10-10

405

Discrete-Event Simulation in Chemical Engineering.  

ERIC Educational Resources Information Center

Gives examples, descriptions, and uses for various types of simulation systems, including the Flowtran, Process, Aspen Plus, Design II, GPSS, Simula, and Simscript. Explains similarities in simulators, terminology, and a batch chemical process. Tables and diagrams are included. (RT)

Schultheisz, Daniel; Sommerfeld, Jude T.

1988-01-01

406

LAMPF II  

SciTech Connect

We present a plan for two rapid-cycling synchrotrons - a 45-GeV, 40 ..mu..A proton synchrotron with a 9-GeV, 200-..mu..A booster. These machines can provide simultaneously 45-GeV slow-extracted beam for the production of kaons, antiprotons, and other secondary particles, and 9-GeV fast-extracted beam for neutrino and pulsed muon physics. The LAMPF II machines are compared with existing and proposed kaon factories. Relative to the Brookhaven AGS as it exists today, LAMPF II will provide 90 times as many neutrino events per year and 300 times as many kaons per year. Some design features of the LAMPF II accelerators that are important for reducing beam losses and increasing beam availability are discussed. Because of the large rf power and voltage required, an innovative design of the ferrite-tuned cavities is necessary. A commercially available Mg-Mn ferrite with perpendicular bias has been shown to raise the available ferrite Q by more than a factor of 10 when compared with materials now in use at other accelerators. The 45-GeV LAMPF II synchrotron would produce far more neutrinos, kaons, and antiprotons per unit cost than an upgraded conventional machine. The LAMPF II booster by itself, which can provide 100 ..mu..A at 12 GeV, is a very interesting option at moderate cost. 5 references, 4 figures, 2 tables.

Thiessen, H.A.

1984-01-01

407

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.

408

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

409

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.

410

78 FR 68089 - Proposed Information Collection; Visibility Valuation Survey  

Federal Register 2010, 2011, 2012, 2013

...PPMRSNR1Y.NA0000] Proposed Information Collection; Visibility Valuation Survey AGENCY: National Park Service, Interior. ACTION...II. Data OMB Number: 1024-0255. Title: Visibility Valuation Survey. Type of Request: Reinstatement of OMB Control...

2013-11-13

411

76 FR 28034 - Labor-Management Relations Information Collection Requests  

Federal Register 2010, 2011, 2012, 2013

...CONCILIATION SERVICE Labor-Management Relations Information Collection Requests AGENCY...Abstract: Title II of the Labor Management Relations Act of 1947 (Pub. L. 90-101) as...List of Subjects Labor-management relations, employee management relations,...

2011-05-13

412

Reciprocal Net: Common Molecules Collection  

NSDL National Science Digital Library

Part of the Common Molecules Collection, this set of 3D biochemical molecule images is an educational feature from Reciprocal Net, a Web portal for crystallography research funded by the National Science Foundation and part of NSDL. The Common Molecules Collection currently offers a number of image galleries, but only a couple -- including the biochemical molecules set -- with direct life sciences application. Users can view and rotate a 3D image for each molecule provided (organized by amino acids, hormones, and nucleosides), accompanied by a brief explanation and other particulars such as chemical formula. It's a great tool for visual learners and a fun Web site to visit just for the 3D effects.

1995-01-01

413

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

414

Gas Phase Chemical Detection with an Integrated Chemical Analysis System  

SciTech Connect

Microfabrication technology has been applied to the development of a miniature, multi-channel gas phase chemical laboratory that provides fast response, small size, and enhanced versatility and chemical discrimination. Each analysis channel includes a sample concentrator followed by a gas chromatographic separator and a chemically selective surface acoustic wave detector array to achieve high sensitivity and selectivity. The performance of the components, individually and collectively, is described. The design and performance of novel micromachined acoustic wave devices, with the potential for improved chemical sensitivity, are also described.

Baca, Albert G.; Casalnuovo, Stephen A.; Frye-Mason, Gregory C.; Heller, Edwin J.; Hietala, Susan L.; Hietala, Vincent M.; Kottenstette, Richard J.; Lewis, Patrick R.; Manginell, Ronald P.; Matzke, Carloyn M.; Reno, John L.; Sasaki, Darryl Y.; Schubert, W. Kent

1999-07-08

415

[Chemical weapons and chemical terrorism].  

PubMed

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

Nakamura, Katsumi

2005-10-01

416

ADAM II. 2007 Annual Report.  

National Technical Information Service (NTIS)

The Arrestee Drug Abuse Monitoring (ADAM II) program is a data collection program sponsored by the Office of National Drug Control Policy (ONDCP) to gather information on drug use and related issues fromadult male offenders at the time of their arrest. AD...

2009-01-01

417

Collection Mode Lens System  

DOEpatents

A lens system including a collection lens and a microlens spaced from the collection lens adjacent the region to be observed. The diameter of the observablel region depends substantially on the radius of the microlens.

Fletcher, Daniel A. (Menlo Park, CA); Kino, Gordon S. (Stanford, CA)

2002-11-05

418

Bright Ideas for Chemical Biology  

PubMed Central

Small-molecule fluorescent probes embody an essential facet of chemical biology. Although numerous compounds are known, the ensemble of fluorescent probes is based on a modest collection of modular “core” dyes. The elaboration of these dyes with diverse chemical moieties is enabling the precise interrogation of biochemical and biological systems. The importance of fluorescence-based technologies in chemical biology elicits a necessity to understand the major classes of small-molecule fluorophores. Here, we examine the chemical and photophysical properties of oft-used fluorophores, and highlight classic and contemporary examples in which utility has been built upon these scaffolds. PMID:18355003

Lavis, Luke D.; Raines, Ronald T.

2009-01-01

419

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.

420

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

E-print Network

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

Starflower Foundation; Ella Elman; Ecologist Contents

421

II. The Community Organizes........................................................................................................4  

E-print Network

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

Starflower Foundation; Ella Elman; Ecologist Contents

422

II. The Community Organizes............................................................................................5  

E-print Network

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

Starflower Foundation; Ella Elman; Ecologist Contents

423

Solar energy collecting apparatus  

Microsoft Academic Search

A solar energy collecting apparatus is described which is integrally incorporated into a conventional building structure so that it does not protrude from the normal contour of the building, and which utilizes components of the building structure as a part of the collecting apparatus to thereby minimize the cost thereof. The collecting apparatus includes a solar energy absorptive panel which

Mcarthur

1980-01-01

424

Student Loan Collection Procedures.  

ERIC Educational Resources Information Center

This manual on the collection of student loans is intended for the use of business officers and loan collection personnel of colleges and universities of all sizes. The introductory chapter is an overview of sound collection practices and procedures. It discusses the making of a loan, in-school servicing of the accounts, the exit interview, the…

National Association of College and University Business Officers, Washington, DC.

425

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

426

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

427

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

428

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.

429

Chemical peels.  

PubMed

Chemical peels are a method of resurfacing with a long-standing history of safety in the treatment of various skin conditions. This article reviews the classification of different chemical agents based on their depth of injury. The level of injury facilitates cell turnover, epidermal thickening, skin lightening, and new collagen formation. Preprocedural, periprocedural, and postprocedural skin care are briefly discussed. To select the appropriate chemical peel, the provider should evaluate the patient's expectations, medical history, skin type, and possible complications to determine the best chemical peel to achieve the desired results. Patients with Fitzpatrick skin types IV to VI have increased risk of dyspigmentation, hypertrophic, and keloid scarring. These individuals respond well to superficial and medium-depth chemical peels. Advances in the use of combination peels allow greater options for skin rejuvenation with less risk of complications. PMID:24488634

Jackson, Adrianna

2014-02-01

430

Chemical threats.  

PubMed

The use of chemical agents as military weapons has been recognized for many centuries but reached the most feared and publicized level during World War I. Considerable political effort has been exercised in the twentieth century to restrict military strategies with chemicals. However, considerable concern currently exists that chemical weapons may be used as agents in civilian terrorism. The distribution of acetaminophen tablets contaminated with potassium cyanide and the release of sarin in the Tokyo sub-way system show that larger-scale deployment of chemical agents can be a reality. This reality makes it necessary for civilian disaster-planning strategies to incorporate an understanding of chemical agents, their effects, and the necessary treatment. PMID:16781273

Fry, Donald E

2006-06-01

431

UNIVERSITY OF ARKANSAS CHEMICAL HYGIENE PLAN  

E-print Network

UNIVERSITY OF ARKANSAS CHEMICAL HYGIENE PLAN OFFICE OF ENVIRONMENTAL HEALTH AND SAFETY FACILITIES Practice Controls 49 Personal Protective Equipment (PPE) 52 General Standard Operating Procedures 55 Record Keeping 82 Appendix I: Chemical Hygiene at the 90-day Accumulation Facility 84 Appendix II: List

Li, Jiali

432

Computing Resources at Chemical and Biochemical Engineering  

E-print Network

Computing Resources at Chemical and Biochemical Engineering Note that use of all Rutgers University at Chemical and Biochemical Engineering. DSV Lab. The DSV lab consists of 60 Sun UltraSparc 10 computers. Each at the School of Engineering. The cluster consists of dual Pentium II/III Xeon computers with the Linux

433

TIER I CHEMICALS: 2.LABORATORY SAFETY PLAN  

E-print Network

-Butyllithium 109-72-8 Sodium Sulphide 1313-82-2 Phenyllithium 591-51-5 tert-Butyl hypochlorite 507-40-4 Phosphine chemicals, GT requires that each laboratory prepared (i) tailored laboratory safety plan, (ii) chemical-58-6 Dichlorosilane 4109-96-0 Magnesium Diamide 7803-54-5 Diethylaluminum chloride 96-10-6 Maneb 12427

Sherrill, David

434

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.

435

77 FR 36261 - Proposed Information Collection; Comment Request; Socioeconomic Assessment of Gulf of Mexico...  

Federal Register 2010, 2011, 2012, 2013

...Information Collection; Comment Request; Socioeconomic Assessment of Gulf of Mexico Fisheries...Grouper-Tilefish IFQ Program, and evaluate the socioeconomic impacts of future federal regulatory...statues. II. Method of Collection The socioeconomic information sought will be...

2012-06-18

436

75 FR 43486 - Proposed Information Collection; Comment Request; Voluntary Self-Disclosure of Antiboycott...  

Federal Register 2010, 2011, 2012, 2013

...Proposed Information Collection; Comment Request; Voluntary Self- Disclosure of Antiboycott Violations AGENCY: Bureau of Industry...BIS had to detect the violations without such disclosures. II. Method of Collection Submitted in...

2010-07-26

437

77 FR 24685 - Proposed Information Collection; Comment Request; Client Focus Groups and Qualitative Interviews  

Federal Register 2010, 2011, 2012, 2013

...improvements to the agency's business processes in order to provide...small and medium-sized U.S. businesses in foreign markets. II. Method of Collection...collection). Affected Public: Business or other for-profit...

2012-04-25

438

77 FR 6784 - Proposed Information Collection; Comment Request; Scientific Research, Exempted Fishing, and...  

Federal Register 2010, 2011, 2012, 2013

...purpose of collecting scientific data on catch may submit...submit reports of their scientific research activity after its completion. II. Method of Collection Information...Estimated Time per Response: Scientific research plans, 37...

2012-02-09

439

PORT II  

NASA Technical Reports Server (NTRS)

One unique project that the Prototype lab worked on was PORT I (Post-landing Orion Recovery Test). PORT is designed to test and develop the system and components needed to recover the Orion capsule once it splashes down in the ocean. PORT II is designated as a follow up to PORT I that will utilize a mock up pressure vessel that is spatially compar able to the final Orion capsule.

Muniz, Beau

2009-01-01

440

Hampton Dunn Postcards Collection  

NSDL National Science Digital Library

The University of South Florida has expanded their digital collections by leaps and bounds in the past few months, and this particular addition is a real find. The Hampton Dunn Postcards Collection contains over 2600 digitized postcards that feature scenes from early twentieth century Florida. Within this collection, visitors will find color images of street scenes, natural vistas, and Floridians at work and play. Visitors will find plenty of urban scenes, along with some rather fascinating images of various public parks and gardens scattered throughout the Sunshine State. Browsing the collection is quite easy, and visitors can also search the collection in its entirety. Finally, visitors should also browse through some of the other digital collections offered by the University of South Florida Libraries.