WorldWideScience
1

Uptake of oleate from albumin solutions by rat liver. Failure to detect catalysis of the dissociation of oleate from albumin by an albumin receptor.  

UK PubMed Central (United Kingdom)

The hepatic removal of albumin-bound substances from plasma requires that they dissociate from albumin. Using indirect methods, we and others have proposed that dissociation may be catalyzed by interaction...Full Text Available

1987-04-01

3

Catalyzed oxidative degradation of methylene blue by in situ generated cobalt (II)-bicarbonate complexes with hydrogen peroxide  

British Library Electronic Table of Contents (United Kingdom)

Oxidative degradation of methylene blue (MB) by Co^2^+-HCO3^- system with H2O2 in aqueous solution was studied. Nearly complete decolorization of the dye was obtained in less than 50min in diluted NaHCO3 solution (25mM) in the presence of only 20mM Co^2^+ ions. Meanwhile, the conjugated structure and phenyl rings of the MB molecule were destroyed or even broken down into small organic acids and inorganic ions, as indicated by FT-IR spectra and ion-chromatography. Photoluminescence probing and radical scavenging technologies suggested that the reaction of MB degradation in this system mainly involved the generation and participation of hydroxyl radicals. Furthermore, by cyclovoltammetric measurements, the in situ formed different complexes between Co^2^+ and HCO3^- were observed at differen...

2011-01-01

4

Palladium- and Copper-Catalyzed Arylation of Carbon-Hydrogen Bonds  

UK PubMed Central (United Kingdom)

The transition-metal-catalyzed functionalization of C-H bonds is a powerful method for generating carbon-carbon...Full Text Available

2009-08-18

6

Palladium-catalyzed Heck-type reaction of oxime ether bearing a pendant vinyl iodide moiety.  

Science.gov (United States)

A Pd(0)-catalyzed intramolecular Heck-type reaction of oxime ether has been developed, providing convenient access to heterocyclic oximes. PMID:21964259

2011-10-01

7

Intracellular Copper Does Not Catalyze the Formation of Oxidative DNA Damage in Escherichia coli?  

UK PubMed Central (United Kingdom)

Because copper catalyzes the conversion of H2O2 to hydroxyl radicals in vitro, it has been proposed that oxidative DNA damage may be an important component of copper toxicity....Full Text Available

2007-03-01

8

Deglutathionylation of 2-Cys Peroxiredoxin Is Specifically Catalyzed by Sulfiredoxin*  

UK PubMed Central (United Kingdom)

Reversible protein glutathionylation plays a key role in cellular regulation and cell signaling and protects protein thiols from hyperoxidation. Sulfiredoxin (Srx), an enzyme that catalyzes the reduction...Full Text Available

2009-08-28

9

Water consumption during solid state sodium borohydride hydrolysis  

Energy Technology Data Exchange (ETDEWEB)

In this paper nickel acetate catalyzed sodium borohydride cartridges have been prepared and hydrolyzed with water for hydrogen production. Two technological solutions have been tested to increase the overall hydrogen yield, namely a porous water diffuser and a hydrophobic membrane. The first was used to improve water diffusion inside the hydride while the second to confine water inside the cartridge. The generated hydrogen flow showed a very reproducible behavior. Hydrogen promptly evolved just after water was pumped into the cartridge. After some initial peaks, a constant hydrogen flow has been recorded for the whole reaction time. The constant flow was related to the presence of the porous diffuser. The use of a hydrophobic membrane to confine the water inside the cartridge allowed to increase the overall hydrogen yield: about 6 water molecules per mol of hydride were required to complete the reaction. The reaction product was identified by ...

2010-11-15

10

Aqueous waste management for minor actinides and lanthanides separation process  

Energy Technology Data Exchange (ETDEWEB)

The French strategy of high level radioactive aqueous waste management is an incorporation in glassy fission products containers. Therefore, nitric acid soluble organic reagents needed for minor actinides and lanthanides selective separation from fission product solutions have to be sufficiently removed to reach carbon concentrations compatible with calcinator working. Thus, the ability of reagents to be oxidized under concentration conditions with or without denitration becomes a criteria of selection and have been studied. Further, if not working, other operations like hot hydrogen peroxide oxidation, catalyzed or not, are investigated. Reagents involved in this work are mainly complexing products (N-(2-Hydroxyethyl) Ethylene-diamine-tri-acetic Acid), pH keeping reagents (carboxylic acids like citric, glycolic, tartaric and lactic acid) and alkaline species (Tetramethylammonium hydroxide). Behaviour of acetic acid, which is often the main ...

2004-07-01

11

Progress report, December 1, 1979-November 30, 1980. [Chemical poisoning of heterogeneously catalyzed reactions on transition metal surfaces  

Energy Technology Data Exchange (ETDEWEB)

The mechanism of chemical poisoning of model heterogeneously catalyzed reactions on transition metal surfaces is studied. Clean Mo(001) surfaces were characterized; results suggest a first-layer contraction of 10% of the bulk interlayer spacing. Characterization of clean Co(0001) surfaces is underway. Decomposition of formic acid on Mo(001) surfaces is being studied. (DLC)

1980-01-01

12

Palladium-catalyzed carbonylative coupling of benzyl chlorides with terminal alkynes to give 1,4-diaryl-3-butyn-2-ones and related furanones.  

Science.gov (United States)

A general palladium-catalyzed carbonylative Sonogashira coupling of benzyl chlorides with terminal acetylenes has been established. Depending on the alkyne 1,4-diaryl-3-butyn-2-ones or substituted furanones are obtained in moderate to good yields. Best catalytic performance is achieved applying a mixed Pd(PPh(3))Cl(2)/P(OPh)(3) catalyst system. PMID:21968528

2011-10-01

13

Effect of catalysts and solvents on the direct hydroliquefaction of Turkish lignites  

Energy Technology Data Exchange (ETDEWEB)

This paper reports the effectiveness of solvents on the liquefaction of 11 different Turkish lignites investigated by using tetralin, creosote, and anthracene oils. The highest total conversions were obtained with tetralin. The catalytic effects of CoMo and red mud were compared by using creosote oil as the solvent. It was found that red mud catalyzed mainly the asphaltene formation reaction for the given experimental conditions. The additional of CoMo significantly catalyzed the liquefaction reaction, thus increasing the lignite conversion and oil formation.

1990-01-01

14

THERMODYNAMICS AND KINETICS OF AQUEOUS PIPERAZINE WITH POTASSIUM CARBONATE FOR CARBON DIOXIDE ABSORPTION  

Energy Technology Data Exchange (ETDEWEB)

This work proposes an innovative blend of potassium carbonate (K{sub 2}CO{sub 3}) and piperazine (PZ) as a solvent for CO{sub 2} removal from combustion flue gas in an absorber/stripper. The equilibrium partial pressure and the rate of absorption of CO{sub 2} were measured in a wetted-wall column in 0.0 to 6.2 m K{sup +} and 0.6 to 3.6 m PZ at 25 to 110 C. The equilibrium speciation of the solution was determined by {sup 1}H NMR under similar conditions. A rigorous thermodynamic model, based on electrolyte non-random two-liquid (ENRTL) theory, was developed to represent equilibrium behavior. A rate model was developed to describe the absorption rate by integration of eddy diffusivity theory with complex kinetics. Both models were used to explain behavior in terms of equilibrium constants, activity coefficients, and rate constants. The addition of potassium to the amine increases the concentration of CO{sub 3}{sup 2-}/HCO{sub 3}{sup -} in ...

2005-04-18

15

Mechanism of enzyme-catalyzed phospho group transfer  

Energy Technology Data Exchange (ETDEWEB)

To understand more fully the mechanism of enzyme-catalyzed phospho group transfer, the stereochemical course at phosphorus of four enzymes has been determined. First, using adenosine (..gamma..-(S)-/sup 16/O, /sup 17/O, /sup 18/O)triphosphate as the substrate, the reaction catalyzed by creatine kinase has been found to proceed with overall inversion of configuration at phosphorus. Second, using adenosine (..beta..-(S)-/sup 16/O, /sup 17/O, /sup 18/O)diphosphate as the substrate, the reaction catalyzed by adenylate kinase has been found also to proceed with overall inversion. Third, the reaction catalyzed by phosphoenolpyruvate carboxylase has been studied using ((S/sub p/)-/sup 16/O, /sup 17/O)thiophospoenolpyruvate as the substrate in H/sub 2/ /sup 18/O. Fourth, using adenosine 5'-O-((..gamma..S/sub p/)-..beta gamma..-/sup 17/O,..gamma..-/sup 17/O,/sup 18/O)(3-thiotriphosphate) as the ...

1986-01-01

16

Cholera toxin can catalyze ADP-ribosylation of cytoskeletal proteins  

International Nuclear Information System (INIS)

Cholera toxin catalyzes transfer of radiolabel from ["3"2P]NAD"+ to several peptides in particulate preparations of human foreskin fibroblasts. Resolution of these peptides by two-dimensional gel electrophoresis allowed identification of two peptides of M/sub r/ = 42,000 and 52,000 as peptide subunits of a regulatory component of adenylate cyclase. The radiolabeling of another group of peptides (M/sub r/ = 50,000 to 65,000) suggested that cholera toxin could catalyze ADP-ribosylation of cytoskeletal proteins. This suggestion was confirmed by showing that incubation with cholera toxin and ["3"2P]NAD"+ caused radiolabeling of purified microtubule and intermediate filament proteins.

1981-01-01

17

CO2 Capture by Absorption with Potassium Carbonate  

Energy Technology Data Exchange (ETDEWEB)

The objective of this work is to improve the process for CO{sub 2} capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K{sub 2}CO3 promoted by piperazine (PZ). Pilot plant testing was performed in a 16.8-inch ID absorber and stripper with recirculation of air and CO{sub 2}. Three solvents (7 m MEA, 5 m K{sup +}/2.5 m PZ, and 6.4 m K{sup +}/1.6 m PZ) were tested in four campaigns with three different absorber packings. Pilot plant testing established that 5 m K{sup +}/2.5 m PZ requires two times less packing than 7 m MEA and three times less packing than 6.4 m K{sup +}/1.6 m PZ. A rigorous model of the thermodynamics and mass transfer was developed in the RateSep{trademark} block of AspenPlus{reg_sign}. The double matrix stripper reduces energy consumption by 5 to 15%. The best K{sup +}/PZ solvent, 4 m K{sup +}/4 m PZ, and the best process configuration, double matrix stripper with a double intercooled absorber, requires equivalent work of 40 ...

2007-08-31

18

The efflux of a fluorescent probe is catalyzed by an ATP-driven extrusion system in Lactococcus lactis.  

UK PubMed Central (United Kingdom)

Many bacteria, both gram positive and gram negative, extrude in an energy-dependent manner the fluorescent pH indicator 2',7'-bis-(2-carboxyethyl)-5[and -6]-carboxyfluorescein (BCECF) (D. Molenaar,...Full Text Available

1992-05-01

19

The Mitochondrial Isovaleryl-Coenzyme A Dehydrogenase of Arabidopsis Oxidizes Intermediates of Leucine and Valine Catabolism1  

UK PubMed Central (United Kingdom)

We recently identified a cDNA encoding a putative isovaleryl-coenzyme A (CoA) dehydrogenase in Arabidopsis (AtIVD). In animals, this homotetrameric enzyme is located in mitochondria and catalyzes the...Full Text Available

2001-06-01

20

Subunits of the Drosophila CCR4-NOT complex and their roles in mRNA deadenylation  

UK PubMed Central (United Kingdom)

The CCR4-NOT complex is the main enzyme catalyzing the deadenylation of mRNA. We have investigated the composition of this complex in Drosophila melanogaster by immunoprecipitation...Full Text Available

2010-07-01

21

Structure and Reaction Mechanism of Basil Eugenol Synthase  

UK PubMed Central (United Kingdom)

Phenylpropenes, a large group of plant volatile compounds that serve in multiple roles in defense and pollinator attraction, contain a propenyl side chain. Eugenol synthase (EGS) catalyzes the reductive...Full Text Available

22

Regulation of lactose catabolism in Streptococcus mutans: purification and regulatory properties of phospho-beta-galactosidase.  

UK PubMed Central (United Kingdom)

Phospho-beta-galactosidase (P-beta-gal), the enzyme which catalyzes the first step in the metabolism of intracellular lactose phosphate, occurred at high specific activity in the cytoplasm in 12 of...Full Text Available

1979-01-01

23

Preliminary X-ray crystallographic studies of Bacillus subtilis SpeA protein  

UK PubMed Central (United Kingdom)

The speA gene in Bacillus subtilis encodes arginine decarboxylase, which catalyzes the conversion of arginine to agmatine. Arginine decarboxylase is an important enzyme...Full Text Available

24

Phosphatidic acid signaling to mTOR: Signals for the survival of human cancer cells  

UK PubMed Central (United Kingdom)

During the past decade elevated phospholipase D (PLD) activity has been reported in virtually all cancers where it has been examined. PLD catalyzes the hydrolysis of phosphatidylcholine to generate...Full Text Available

2009-09-01

25

PKU is a reversible neurodegenerative process within the nigrostriatum that begins as early as 4 weeks of age in Pahenu2 mice  

UK PubMed Central (United Kingdom)

Phenylketonuria (PKU) is a common genetic disorder in humans that arises from deficient activity of phenylalanine hydroxylase (PAH), which catalyzes the conversion of phenylalanine to tyrosine....Full Text Available

2007-01-05

26

N-acetyltransferase 2 slow acetylator genotype associated with adverse effects of sulfasalazine in the treatment of inflammatory bowel disease  

UK PubMed Central (United Kingdom)

AIM:N-acetyltransferase 2 (NAT2) is an important enzyme catalyzing N-acetylation of sulfasalazine (SASP). The aim of the present study was to investigate...Full Text Available

2007-03-01

27

Molecular Dynamics Simulations of the Detoxification of Paraoxon Catalyzed by Phosphotriesterase (PTE)  

UK PubMed Central (United Kingdom)

Combined QM(PM3)/MM molecular dynamics simulations together with QM(DFT)/MM optimizations for key configurations have been performed to elucidate the enzymatic catalysis mechanism on the detoxification...Full Text Available

2009-11-30

28

Metabolism of Cytokinin  

UK PubMed Central (United Kingdom)

As part of the study of cytokinin metabolic pathways, an enzyme, adenosine phosphorylase (EC 2.4.2.-), which catalyzed the ribosylation of N6-(Δ2-isopentenyl)adenine,...Full Text Available

1978-12-01

29

Indoleamine 2,3-dioxygenase-expressing leukemic dendritic cells impair a leukemia-specific immune response by inducing potent T regulatory cells  

UK PubMed Central (United Kingdom)

BackgroundThe immunoregulatory enzyme indoleamine 2,3-dioxygenase, which catalyzes the conversion of tryptophan into kynurenine, is expressed in a significant subset of patients...Full Text Available

2010-12-01

30

Fluoride ion catalyzed alkylation of purines, pyrimidines, nucleosides and nucleotides using alky halides.  

UK PubMed Central (United Kingdom)

Alkyl halides react rapidly with purines and pyrimidines in the presence of fluoride ion. Alkylation of thymidine leads to novel dimeric nucleoside derivatives bridged through N3. Alkylation of thymidine...Full Text Available

1979-04-01

31

Expression and prognostic significance of cox-2 and p-53 in hodgkin lymphomas: a retrospective study  

UK PubMed Central (United Kingdom)

BackgroundCyclooxygenase (cox) is the rate-limiting enzyme, which catalyzes the conversion of arachidonic acid into prostaglandins and contributes to the inflammatory process. Cyclooxygenase-2...Full Text Available

32

Effects of DGAT1 deficiency on energy and glucose metabolism are independent of adiponectin  

UK PubMed Central (United Kingdom)

Mice lacking acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1), an enzyme that catalyzes the terminal step in triacylglycerol synthesis, have enhanced insulin sensitivity and are protected from...Full Text Available

2006-08-01

33

Diterpene Biosynthesis in Maize Seedlings in Response to Fungal Infection 1  

UK PubMed Central (United Kingdom)

A cell-free system which catalyzes the biosynthesis of terpene hydrocarbons when supplemented with mevalonate, Mn2+, and ATP was prepared from the scutellum-embryonic axis region of maize...Full Text Available

1979-09-01

34

Developmental and Light Regulation of Desacetoxyvindoline 4-Hydroxylase in Catharanthus roseus (L.) G. Don.1  

UK PubMed Central (United Kingdom)

The expression of desacetoxyvindoline 4-hydroxylase (D4H), which catalyzes the second to the last reaction in vindoline biosynthesis in Catharanthus roseus, appears to be under complex,...Full Text Available

1998-08-01

35

Comparison of estimation capabilities of response surface methodology (RSM) with artificial neural network (ANN) in lipase-catalyzed synthesis of palm-based wax ester  

UK PubMed Central (United Kingdom)

BackgroundWax esters are important ingredients in cosmetics, pharmaceuticals, lubricants and other chemical industries due to their excellent wetting property. Since the naturally...Full Text Available

36

Characterization of the Key Step for Light-driven Hydrogen Evolution in Green Algae*  

UK PubMed Central (United Kingdom)

Under anaerobic conditions, several species of green algae perform a light-dependent hydrogen production catalyzed by a special group of [FeFe] hydrogenases termed HydA. Although highly interesting...Full Text Available

2009-12-25

37

Catalyzing Social Support for Breast Cancer Patients  

UK PubMed Central (United Kingdom)

Social support is a critical, yet underutilized resource when undergoing cancer care. Underutilization occurs in two conditions: (a) when patients fail to seek out information, material assistance,...Full Text Available

2010-01-01

38

A Hyperactive NAD(P)H:Rubredoxin Oxidoreductase from the Hyperthermophilic Archaeon Pyrococcus furiosus  

UK PubMed Central (United Kingdom)

NAD(P)H:rubredoxin oxidoreductase (NROR) has been purified from the hyperthermophilic archaeon Pyrococcus furiosus. The enzyme is exceedingly active in catalyzing the NADPH-dependent...Full Text Available

1999-09-01

39

Sugar Ester Modified Lipase Catalyzed Esterification in Organic Media.  

Science.gov (United States)

The esterification reaction of a long-chain fatty acid and a fatty alcohol catalyzed by sugar ester-modified lipases in organic media was studied. The reaction activity was improved when the lipases were modified with sugar esters. Among four kinds of sugar esters and six kinds of lipases, lipase CES modified with sugar ester SE-7 showed the highest reaction activity. The pH, solvent and temperature on the reaction activity of SE-7 modified lipase CES were also studied. PMID:12142919

1999-01-01

40

Esterification of chiral secondary alcohols with fatty acid in organic solvents by polyethylene glycol-modified lipase.  

Science.gov (United States)

Lipase from Pseudomonas fragi 22.39B was modified with polyethylene glycol. The modified lipase (PEG-lipase) was soluble and active in organic solvents such as benzene and 1,1,1-trichloroethane. PEG-lipase catalyzed esterification of chiral secondary alcohols with fatty acids in benzene and exhibited preference for R isomers over S isomers. Km and Vmax values for each isomer of various alcohols were obtained by kinetic study of the esterification in benzene. PEG-lipase-catalyzed esterification leads to optical resolution of a racemic alcohol. PMID:2635854

1989-11-01

41

Surface Decontamination by Solution  

International Science & Technology Center (ISTC)

Development of Technology for Metal Surface Decontamination in Aqueous Solutions

42

Quantitation of acyl migration during lipase-catalyzed acidolysis, and of the regioisomers of structured triacylglycerols formed  

DEFF Research Database (Denmark)

Various MLM-type (M, medium-chain fatty acids; L, long-chain fatty acids) structured triacylglycerols were produced in pilot- or small-scale packed-bed reactors by lipase-catalyzed acidolysis. The incorporation and acyl migration of octanoic acid were measured by gas chromatography and Grignard degradation, and ranged from 39.0 to 48.7% and 0.6 to 9.3%, respectively. Quantitation of triacylglycerol molecular species was performed by ammonia negative ion chemical ionization (NICI) mass spectrometry (MS). The proportion of ACN (acyl carbon number) 34 species that contained one C-18 fatty acid and two C-8:0, in samples analyzed, varied from 12.5 to 23.2%. The selected regioisomers MLM and MML within the ACN 34 species group were quantified by NICI tandem MS (MS/MS) and were in the range of 97.1 to 98.4% and 1.6 to 2.9%, respectively. There was no correlation between the level of acyl migration during lipase-catalyzed esterification and the level ...

2001-01-01

43

Chemistry and morphology of coal liquefaction. Quarterly report, January 1-March 30, 1981  

Science.gov (United States)

In the course of observing by means of Auger spectroscopy graphite gasification reactions catalyzed by metals, it has been found that in the presence of hydrogen, nickel appears to diffuse from the surface into the bulk of the graphite. When potassium is deposited on graphite, it is volatilized above 400/sup 0/C. Surprisingly the production of methane and carbon dioxide from the reaction of graphite and steam was catalyzed by potassium at as low a temperature as 250/sup 0/C. It has been shown that literature on the alkylation of benzene with synthesis gas is erroneous and that the products reported are due to Lewis acid catalyzed cracking of benzene. A novel cobalt mediated, reversible cleavage of a vinyl-hydrogen bond has been discovered. All products from the thermal decomposition of tetralin have been identified. The stereochemistry of cis-1, 2 dihydrotetralin was determined. In the utilization of the water gas shift ...

1981-03-01

44

Two-step biodiesel production from Calophyllum inophyllum oil: Optimization of modified b-zeolite catalyzed pre-treatment  

British Library Electronic Table of Contents (United Kingdom)

In this study, a two-step process was developed to produce biodiesel from Calophyllum inophyllum oil. Pre-treatment with phosphoric acid modified b-zeolite in acid catalyzed esterification process preceded by transesterification which was done using conventional alkali catalyst potassium hydroxide (KOH). The objective of this study is to investigate the relationship between the reaction temperatures, reaction time and methanol to oil molar ratio in the pre-treatment step. Central Composite Design (CCD) and Response Surface Methodology (RSM) were utilized to determine the best operating condition for the pre-treatment step. Biodiesel produced by this process was tested for its fuel properties.

2011-01-01

45

Kinetics of inhibition of green crab (Scylla serrata) alkaline phosphatase by sodium (2,2'-bipyridine) oxodiperoxovanadate.  

Science.gov (United States)

Green crab (Scylla serrata) alkaline phosphatase (EC 3.1.3.1) is a metalloenzyme, which catalyzes the nonspecific hydrolysis of phosphate monoesters. The kinetics of inhibition of the enzyme by sodium (2, 2'-bipyridine) oxodiperoxovanadate, pV(bipy), has been studied. The time course of the hydrolysis of p-nitrophenyl-phosphate catalyzed by the enzyme in the presence of different pV(bipy) concentrations showed that at each pV(bipy) concentration, the rate decreased with increasing time until a straight line was approached, the straight line slopes are the same for all concentrations. The results suggest that the inhibition of the enzyme by pV(bipy) is a slow, reversible reaction with fractional remaining activity. The microscopic rate constants are determined for the reaction of inhibitor with the enzyme. PMID:10691182

1999-10-01

46

l-Proline-catalyzed one-pot expeditious synthesis of highly substituted pyridines at room temperature  

British Library Electronic Table of Contents (United Kingdom)

Only 15mol% of l-proline in ethanol proved to be a very efficient catalyst for the one-pot synthesis of a wide variety of highly substituted pyridines at room temperature. The methodology is mild, efficient, high yielding, and the products can be directly recrystallized from hot ethanol.

2010-01-01

47

Synthesis and properties of N,N-dialkyl-P-phenylphosphonamidous iodides  

Energy Technology Data Exchange (ETDEWEB)

N,N-Dialkyl-P-phenylphosphonamidous iodides are formed in the reactions of phenylphosphonus diiodide with silylated secondary amines. N,N-Dialkyl-P-phenylphosphonamidous iodides react with electrophilic reagents (methyl iodide, benzenesulfonyl azide, and phenyl azide) by the usual schemes with the formation of alkylation and oxidative-imination products. Iodine catalyzes the disproportionation of morpholinophenylphosphinous iodide into dimorphomorpholinophenylphosphinous iodide with iodine are iododimorpholinophenylphosphonium triiodide and phenylphosphonous diiodide.

1987-01-20

48

New Insights into Type II NAD(P)H:Quinone Oxidoreductases  

UK PubMed Central (United Kingdom)

Type II NAD(P)H:quinone oxidoreductases (NDH-2) catalyze the two-electron transfer from NAD(P)H to quinones, without any energy-transducing site. NDH-2 accomplish the turnover of NAD(P)H, regenerating...Full Text Available

2004-12-01

49

Molecular Cloning and Evidence for Osmoregulation of the ?1-Pyrroline-5-Carboxylate Reductase (proC) Gene in Pea (Pisum sativum L.) 12  

UK PubMed Central (United Kingdom)

Several cDNA clones encoding Δ1-pyrroline-5-carboxylate reductase (P5CR, l-proline:NAD[P]+ 5-oxidoreductase, EC 1.5.1.2), which catalyzes the terminal step in...Full Text Available

1992-11-01

50

Mechanism for the anti-thyroid action of minocycline  

Energy Technology Data Exchange (ETDEWEB)

Administration of minocycline (MN), a tetracycline antibiotic, produces a black pigment in the thyroids of humans and several species of experimental animals and antithyroid effects in rodents. We have previously shown that these effects appear to be related to interactions of MN with thyroid peroxidase (TPO), the key enzyme in thyroid hormone synthesis. In the present study, the mechanisms for inhibition of TPO-catalyzed iodination and coupling reactions by MN were investigated. 37 refs., 7 figs., 3 tabs.

1997-01-01

51

Measurement of the K?/K? ratio for muon alpha sticking X-rays in muon catalyzed d-t fusion at the RIKEN-RAL Muon Facility  

International Nuclear Information System (INIS)

At the RIKEN-RAL Muon Facility, ?- to ? sticking K? X-rays were observed for the first time taking advantage of the pulsed beam structure. The precision of the present measurements was insufficient to distinguish between theoretical models, however the observed K?/K? X-ray intensity ratio tends to be smaller than most of these theoretical predictions.

1999-06-01

52

Lipase catalyzed esterification in AOT reverse micelles: a structural study.  

Science.gov (United States)

AOT reverse micelles are used to cosolubilize hydrophilic and hydrophobic reactants of lipase catalysed esterification. Depending on the nature of the alcohol, a drastic change of the initial rate of the esterification is observed. A structural study of the micellar system with and without reactant is undertaken to explain the change in the activity with the various alcohols. PMID:7832997

1995-01-01

53

Intermediates to ethylene glycol: carbonylation of formaldehyde catalyzed by Nafion solid perfluorosulfonic acid resin  

Energy Technology Data Exchange (ETDEWEB)

Details of a series of reactions for the production of ethylene glycol using a catalyst of Nafion solid perfluorosulfonic acid resin was detailed. The reactions included the carbonylation of formaldehyde and esterification and then hydrogenation of the product of the carbonylation, glycolic acid. Other preparations included in the work included methyl glycolate, acetylglycolic acid, methyl acetylglycolate, and methyl methoxyacetate.

1983-01-01

54

Functional and Topological Analysis of Yeast Acyl-CoA:Diacylglycerol Acyltransferase 2, an Endoplasmic Reticulum Enzyme Essential for Triacylglycerol Biosynthesis*  

UK PubMed Central (United Kingdom)

Acyl-CoA:diacylglycerol acyltransferase (EC 2.3.1.20) is a membrane protein present mainly in the endoplasmic reticulum. It catalyzes the final and committed step in the biosynthesis of triacylglycerol,...Full Text Available

2011-04-15

55

Enzymic Synthesis of Indole-3-Acetyl-1-O-?-d-Glucose 1  

UK PubMed Central (United Kingdom)

The first enzyme-catalyzed reaction leading from indole-3-acetic acid (IAA) to the myo-inositol esters of IAA is the synthesis of indole-3-acetyl-1-O-β-d-glucose...Full Text Available

1988-12-01

56

Enantioselective Transformation of ?-Hexachlorocyclohexane by the Dehydrochlorinases LinA1 and LinA2 from the Soil Bacterium Sphingomonas paucimobilis B90A  

UK PubMed Central (United Kingdom)

Sphingomonas paucimobilis B90A contains two variants, LinA1 and LinA2, of a dehydrochlorinase that catalyzes the first and second steps in the metabolism of hexachlorocyclohexanes (R....Full Text Available

2005-12-01

57

Efficient synthesis of unsymmetric diarylalkynes from decarboxylative coupling in a continuous flow reaction system  

British Library Electronic Table of Contents (United Kingdom)

Unsymmetric diaryl alkynes were synthesized from the palladium-catalyzed decarboxylative coupling of aryl halides and propiolic acid using a continuous flow reaction system. This flow chemistry system continuously gave the desired products in moderate to good yields, and produced less byproduct than was formed in the batch reaction.

2011-01-01

58

Alcohols as hydrogen-donor solvents for treatment of coal  

Energy Technology Data Exchange (ETDEWEB)

A method for the hydroconversion of coal by solvent treatment at elevated temperatures and pressure wherein an alcohol having an alpha -hydrogen atom, particularly a secondary alcohol such as isopropanol, is utilized as a hydrogen donor solvent. In a particular embodiment, a base capable of providing a catalytically effective amount of the corresponding alcoholate anion under the solvent treatment conditions is added to catalyze the alcohol-coal reaction.

1981-11-03

59

Numerical Optimization  

Science.gov (United States)

... been possible to prove the existence and uniqueness of a classical solution which tends to the well-known solution of the Stefan problem as the ...

1989-01-01

60

Some observations on amino acid racemization under pyrolytic temperatures and inorganic oxide-catalyzed intermolecular condensation.  

Science.gov (United States)

The problem of homochirality is of crucial importance for the origins of Life. While most laboratory studies are focused on the search of physical and chemical sources of handedness in the Universe, they reflect only one aspect of the problem: the origin of homochiral biomolecules. At the same time, any space environments where biomolecules are expected to form and where they have to pass through before the first primitive forms of Life emerge, include strong irradiation or/and high temperatures. This automatically implies the possibility of losing the optical activity, i.e. racemization. The simulation experiments performed by our group deal with the following two aspects of amino acid abiotic chemistry: (1) amino acid pyrolysis associated with their extraterrestrial delivery; and (2) peptide formation from amino acids catalyzed by inorganic oxides. According to our observations, the racemization phenomena are very common in the systems considered, not only under ...

2001-01-01

61

Lipase catalyzed esterification of glycidol in organic solvents  

Science.gov (United States)

The authors studied the resolution of racemic glycidol through esterification with butyric acid catalyzed by porcine pancreatic lipase in organic media. A screening of seven solvents (log P values between 0.49 and 3.0, P being the n-octanol-water partition coefficient of the solvent) showed that neither log P nor the logarithm of the molar solubility of water in the solvent provides good correlations between enantioselectivity and the properties of the organic media. Chloroform was one of the best solvents as regards the enantiometic purity (e.p.) of the ester produced. In this solvent, the optimum temperature for the reaction was determined to be 35C. The enzyme exhibited maximum activity at a water content of 13 [plus minus] 2% (w/w). The enantiomeric purity obtained was 83 [plus minus] 2% of (S)-glycidol butyrate and did not depend on the alcohol concentration or the enzyme water content for values of these parameters up to 200 mM and 25% (w/w), respectively. ...

1993-08-05

62

Kinetic study of the epoxidation of 1-octene with hydrogen peroxide catalyzed by platinum(II) complexes. Evidence of the involvement of two metal species in the oxygen-transfer step  

Energy Technology Data Exchange (ETDEWEB)

A detailed kinetic study of the epoxidation of 1-octene with hydrogen peroxide catalyzed by Pt(II) complexes is reported. The two systems analyzed were (diphoe)Pt(CF/sub 3/)(OH)/1-octene/H/sub 2/O/sub 2//THF and ((diphoe)Pt(CF/sub 3/)(CH/sub 2/Cl/sub 2/))BF/sub 4//1-octene/H/sub 2/O/sub 2//H/sub 2/O/CH/sub 2/Cl/sub 2/. Rate data were determined with GLC from epoxide formed vs time plots. Evidence for many of the organometallic intermediates and the individual steps involved was gained from IR studies, /sup 19/F NMR studies, and especially designed experiments including studies of the acidity effect. In both cases the kinetic analysis suggests a mechanism in which the actual oxidant is a PtOOH species that interacts with a Pt-olefin complex in the oxygen-transfer step (second-order dependence on platinum). 29 references, 12 figures, 3 tables.

1988-06-01

63

Influence of the porous texture of coals on their hydrogenation processes catalyzed by Fe  

Energy Technology Data Exchange (ETDEWEB)

Nine coals from Spanish, British, German and American mining basins were hydrogenated using Fe catalyst precursors (red mud and FeSO{sub 4}), without solvent at 300, 350, and 400 {degree}C and 10 MPa of H{sub 2}. Overall conversion and product distribution are related to the textural characteristics of the original coals and are studies throughout the distinct hydrogenation processes. Results reveal that with FeSO{sub 4} as a catalyst precursor, conversions increase with coal surface area. However, when red mud (RM) is used, conversions are independent of coal textural characteristics. Higher conversions are obtained with FeSO{sub 4} than with RM at 300 and 350 {degree}C whereas at 400 {degree}C higher conversions are obtained with RM. This different catalytic activity is also reflected in the changes of the textural characteristics observed in each case. Up to 350 {degree}C, the residues from FeSO{sub 4}-catalyzed processes reveal increased microporosity ...

1995-03-01

64

Feasibility of an antiproton catalyzed fission fragment rocket  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this project was to investigate the feasibility of an antiproton catalyzed fission fragment rocket (FFR). The FFR is characterized by the extraction of fission fragments from the fissile fuel, and the utilization of their kinetic energy for thrust generation. A significant drawback to previous FFR designs was the requirement to maintain a critical nuclear pile as the fission fragment source. The author examined the possibility of replacing the critical pile with a sub-critical pile driven by antiprotons. Recent experiments have revealed that antiprotons stimulate highly energetic fissions in {sup 238}U, with a neutron multiplicity of 13.7 neutrons per fission. This interaction was used as a throttled neutron source. The pile consisted of layers of fissile coated fibers which are designed to allow fission fragments to escape them, where the fragments collide with a fluid. The heated fluid is then ejected from the rocket to provide thrust. The ...

1992-03-01

65

Effect of water activity on the lipase catalyzed esterification of geraniol in ionic liquid [bmim]PF6.  

Science.gov (United States)

Enzymatic reactions in non-aqueous media have been shown to be effective in carrying out chemical transformation where the reactants are insoluble in water or water is a byproduct limiting conversion. Ionic liquids, liquid organic salts with infinitesimal vapor pressure, are potentially useful alternatives to organic solvents. It is known that the thermodynamic water activity is an important variable affecting the activity of enzymes in non-aqueous solvents. This study investigated the influence of water activity on the esterification of geraniol with acetic acid in ionic liquid [bmim]PF6 catalyzed by immobilized Candida antarctica lipase B. The conversion of geraniol in [bmim]PF6 was significant although the reaction rate was slower than in organic solvents. The profile of initial reaction rate-water activity was determined experimentally, and differed from the data reported for other non-aqueous solvents. A maximum in the initial reaction rate was found at aw = ...

2006-02-01

66

Chemo-enzymatic epoxidation of olefins by carboxylic acid esters and hydrogen peroxide  

Energy Technology Data Exchange (ETDEWEB)

Ethylen and, recently, butadiene can be epoxidized directly with oxygen and for the epoxidation of propylene, the use of heterogeneous transition metals and organic peroxides (Halcon-Process) is the major player. But, beside from those notable exceptions, all other epoxidations, including large ones like the epoxidation of plant oils as PVC-stabilizers (about 200.000 t/year), are carried out with peroxy acids. Because mcpba is far to expensive for most applications, short chain peracids like peracetic acid are used. Being much less stable than mcpba and thus risky handled in large amounts and high concentrations, these peroxy acids were preferably prepared in-situ. However, conventional in-situ formation of peracids has the serious drawback, that a strong acid is necessary to catalyze peroxy acid formation from the carboxylic acid and hydrogen peroxide. The presence of a strong acid in the reaction mixture often results in decreased selectivity because of the ...

1998-12-31

67

A new kind of immobilized lipase in organic solvent and its structure model.  

Science.gov (United States)

In this paper, we used Ca-alginate gel beads coated with polyetheneimine and glutaraldehyde to adsorb Expansum penicillium lipase. The immobilized lipase catalyzed esterification of 1-dodecanol with dodecanoic acid in benzene. The results show that when the concentration of Ca-alginate, polyetheneimine (PEI) and glutaraldehyde is 1%, 6% and 1%, respectively, the activity of the immobilized lipase and the amount of adsorbed protein are the highest. The immobilized lipase is better than the SDS-immobilized lipase. The activity of the immobilized lipase connected by glutaraldehyde is higher than the activity of that without glutaraldehyde. The initial rate of the immobilized lipase and lyophilized lipase powder is 5.9 x 10(2) nmol/min.mgpr and 2.8 x 10(1) nmol/min.mgpr, respectively. After the immobilized lipase catalyzed the esterification reaction at 37 degrees C for about 12 hours, 93.3% of 1-dodecanol was converted to ester, but for ...

1994-04-15

68

Shedding light on insight: Priming bright ideas  

British Library Electronic Table of Contents (United Kingdom)

Previous research has characterized insight as the product of internal processes, and has thus investigated the cognitive and motivational processes that immediately precede it. In this research, however, we investigate whether insight can be catalyzed by a cultural artifact, an external object imbued with learned meaning. Specifically, we exposed participants to an illuminating lightbulb - an iconic image of insight - prior to or during insight problem-solving. Across four studies, exposing participants to an illuminating lightbulb primed concepts associated with achieving an insight, and enhanced insight problem-solving in three different domains (spatial, verbal, and mathematical), but did not enhance general (non-insight) problem-solving.

2010-01-01

69

Regeneration behavior of light-duty catalytic trap oxidizer systems  

Science.gov (United States)

A catalytic trap oxidizer based on a radial flow metal mesh filter was developed for use as an after treatment device on light-duty diesel vehicles. A complete system for assisted regeneration was devised to enable this unit to operate without blocking during all normal driving modes. The integration of the catalyzed trap and regeneration system with the vehicle to provide a practical system for the reduction of diesel particulate emissions is discussed. To date, many prototype catalytic trap and regeneration system installations have been completed on various test vehicles, both naturally aspirated and turbocharged. The operational conditions and test results from a selection of these studies are presented.

1984-01-01

70

Possible influence of vacuum polarization on Q/sub 1//sub //sub s/ in muon catalyzed D-T fusion  

Energy Technology Data Exchange (ETDEWEB)

The vacuum polarization splitting of the M-shell states in muonic hydrogen can have a profound influence on the muonit de-excitation cascade in deuterium and tritium targets. The cascade also shows sensitive dependence on the precise rate of transfer processes between certain excited muonic deuterium and tritium atoms. Recent experimental data, where a much greater population of the (d..mu..) qs state (1/sub 1//sub //sub s/) was found than previously predicted, can be explained if the transfer rates from the (d..mu..) M-shell are assumed to be strongly suppressed.

1988-12-27

71

On Witten's instability and winding tachyons  

Energy Technology Data Exchange (ETDEWEB)

We investigate, from a spacetime perspective, some aspects of Horowitz's recent conjecture that black strings may catalyze the decay of Kaluza-Klein spacetimes into a bubble of nothing. We identify classical configurations that interpolate between flat space and the bubble, and discuss the energetics of the transition. We investigate the effects of winding tachyons on the size and shape of the barrier and find no evidence at large compactification radius that tachyons enhance the tunneling rate. For the interesting radii, of order the string scale, the question is difficult to answer due to the failure of the {alpha}' expansion.

2006-12-15

72

Measurement of the K{sub {beta}}/K{sub {alpha}} ratio for muon alpha sticking X-rays in muon catalyzed d-t fusion at the RIKEN-RAL Muon Facility  

Energy Technology Data Exchange (ETDEWEB)

At the RIKEN-RAL Muon Facility, {mu}{sup -} to {alpha} sticking K{sub {beta}} X-rays were observed for the first time taking advantage of the pulsed beam structure. The precision of the present measurements was insufficient to distinguish between theoretical models, however the observed K{sub {beta}}/K{sub {alpha}} X-ray intensity ratio tends to be smaller than most of these theoretical predictions.

1999-06-15

73

Long non-coding RNAs in nervous system function and disease  

British Library Electronic Table of Contents (United Kingdom)

Central nervous system (CNS) development, homeostasis, stress responses, and plasticity are all mediated by epigenetic mechanisms that modulate gene expression and promote selective deployment of functional gene networks in response to complex profiles of interoceptive and environmental signals. Thus, not surprisingly, disruptions of these epigenetic processes are implicated in the pathogenesis of a spectrum of neurological and psychiatric diseases. Epigenetic mechanisms involve chromatin remodeling by relatively generic complexes that catalyze DNA methylation and various types of histone modifications. There is increasing evidence that these complexes are directed to their sites of action by long non-protein-coding RNAs (lncRNAs), of which there are tens if not hundreds of thousands speci...

2010-01-01

74

Iron catalyzed hydrogenation of high sulphur content coals  

Energy Technology Data Exchange (ETDEWEB)

Four high-sulphur low-rank coals have been treated at hydrogenation conditions with three iron-based catalyst precursors: Red Mud (Fe[sub 2]O[sub 3]), iron sulphide and iron pentacarbonyl. The obtained yields show a dependence with the sulphur content of the coals; the organic sulphur content correlates with the conversion and THF-solubles when Red Mud and iron sulphide are added. In spite of the high hydrogen sulphide partial pressure in the reaction, the addition of other sources of sulphur enhances the percentages in conversion products. 15 refs., 2 figs., 3 tabs.

1993-12-01

75

Development and cycle test of zinc-oxygen cells  

Energy Technology Data Exchange (ETDEWEB)

For the development of a rechargeable zinc/air battery, La{sub 0.6}Ca{sub 0.4}CoO{sub 3}-catalyzed (perovskite) bifunctional oxygen electrodes and pasted zinc electrodes were prepared and tested in monopolar zinc/air cells. The cells were cycled in moderately alkaline electrolyte. The maximum power as well as the cycle life of the cells were investigated. Up to 450 cycles could be reached, and attractive specific energies and powers were obtained. (author) 3 figs., 4 refs.

1995-07-01

76

Cleavable surfactants  

British Library Electronic Table of Contents (United Kingdom)

The review covers the development within the field of cleavable surfactants since 2003. Cleavable surfactants are amphiphiles in which a weak linkage has been deliberately inserted, normally, but not always, between the hydrophobic tail and the polar headgroup. Alkali labile linkages that have been used for the purpose include normal ester bonds, betaine esters, and carbonates. Ketals and ortho esters are example of bonds that are susceptible to acid hydrolysis. Several investigations deal with cationic ester-containing surfactants, both monomeric and dimeric species, the latter being gemini surfactants. Ester, amide and carbonate containing surfactants have been investigated with respect to enzyme catalyzed hydrolysis. The main incentive for the development of novel cleavable surfactants ...

2007-01-01

78

Effect of oxygen and oxidizing ions on denting corrosion  

International Nuclear Information System (INIS)

Information is presented concerning solute concentration in a porous layer; solute concentration in a packed crevice; corrosion of a packed carbon steel crevice in NaCl-O"2 solutions; and effect of copper on corrosion in NaCl-O"2 solutions.

1983-01-01

82

Turbidimetric determination of sulfite ion in inhibited ethylene glycol-water solutions  

Science.gov (United States)

Turbidimetric method for determining sulfite in inhibited ethylene glycol-water solutions

1970-01-01

83

The effect of sodium on the MoO sub 3 -SiO sub 2 -catalyzed partial oxidation of methane  

Energy Technology Data Exchange (ETDEWEB)

The effect of sodium on the partial oxidation of methane over MoO{sub 3}-SiO{sub 2} in the presence of molecular oxygen has been investigated. As in the sodium-free case, the major products are formaldehyde, carbon monoxide, carbon dioxide, and water. Kinetic analysis indicates that methane is directly oxidized to formaldehyde and carbon dioxide. Formaldehyde is oxidized to carbon monoxide, which is itself further oxidized, providing an alternative route to carbon dioxide. The kinetic model shows that sodium poisons the direct oxidation of methane to formaldehyde and carbon dioxide, but promotes the oxidation of formaldehyde and carbon monoxide. Model predictions of rates and selectivities are in good agreement with the experimental data. A mechanism that explains both the poisoning and promotion effects of sodium on MoO{sub 3}-SiO{sub 2} is proposed.

1990-12-01

84

Synthesis of ceramic powders by novel microwave-hydrothermal processing  

Energy Technology Data Exchange (ETDEWEB)

Microwave-hydrothermal processing was compared with conventional hydrothermal processing in the crystallization of hematite from 1M ferric nitrate and hydroxyapatite from calcium oxide and phosphoric acid. Microwave-hydrothermal processing led to the crystallization of hematite while convention-hydrothermal process led to the crystallization of a mixture of goethite and hematite under the same temperature conditions. Thus the crystallization of hematite which is the stable iron oxide phase at high temperatures has been catalyzed by microwaves. Microwave-hydrothermal processing also led to highly crystalline hydroxyapatite powders compared to the conventional hydrothermal processing which also points to the catalytic role of microwaves. The microwave induced effects may be attributed to the generation of localized high temperatures at the reaction sites which enhance reaction rates.

1996-06-01

85

Solvent effects on biocatalysis in organic systems: equilibrium position and rates of lipase catalyzed esterification.  

Science.gov (United States)

Porcine pancreatic lipase immobilized on celite particles has been employed as a catalyst for the esterification of dodecanol and decanoic acid in a predominantly organic system. Solvent influence on the equilibrium position and on the catalyst activity has been studied using 20 solvents, including aliphatic and aromatic hydrocarbons, ethers, ketones, nitro- and halogenated hydrocarbons, and esters. The equilibrium constant for esterification correlates well with the solubility of water in the organic solvent, which in turn shows a good relationship with a function of Guttman's donor number and the electron pair acceptance index number of the solvent. This may be rationalized in terms of the requirements for solvation of water and of the reactants. The catalyst activity, measured as the initial rate of the esterification reaction, is best correlated as a function of both n-octanol-water partition coefficient (log P) and either the electron pair acceptance index or the polarizability. ...

1991-12-01

86

Selective oxidations on vanadiumoxide containing amorphous mixed oxides (AMM-V) with tert.-butylhydroperoxide  

Energy Technology Data Exchange (ETDEWEB)

The catalytic oxygen transfer properties of vanadium containing zeolites and vanadium based sol-gel catalysts with hydrogen peroxides are well known. The severe problem of vanadium leaching caused by the presence of the by-product water has been addressed. To avoid any interference with homogeneously catalyzed reactions, our study focusses on selective oxidations in a moisture-free medium with tert.-butylhydroperoxide. We have investigated the catalytic properties of amorphous microporous materials based on SiO{sub 2}, TiO{sub 2}, ZrO{sub 2} and Al{sub 2}O{sub 3} as matrix material and studied the effects of surface polarity on the oxidation of 1-octene and cyclohexane. (orig.)

1998-12-31

87

Palladium-catalyzed combustion of methane: Simulated gas turbine combustion at atmospheric pressure  

Energy Technology Data Exchange (ETDEWEB)

Atmospheric pressure tests were performed in which a palladium catalyst ignites and stabilizes the homogeneous combustion of methane. Palladium exhibited a reversible deactivation at temperatures above 750 C, which acted to ``self-regulate`` its operating temperature. A properly treated palladium catalyst could be employed to preheat a methane/air mixture to temperatures required for ignition of gaseous combustion (ca. 800 C) without itself being exposed to the mixture adiabatic flame temperature. The operating temperature of the palladium was found to be relatively insensitive to the methane fuel concentration or catalyst inlet temperature over a wide range of conditions. Thus, palladium is well suited for application in the ignition and stabilization of methane combustion.

1995-04-01

88

Mechanism of conjugated oxidation with hydrogen peroxide in presence of halide ions  

Science.gov (United States)

The change in the concentration of hydrogen peroxide in the course of its decomposition was shown, catalyzed by 0.02 M PbI/sub 2/, 0.03 M CuI, 0.02 M KI, 0.02 M FeSo/sub 4/, 6 M HCl, and 1 M HCL + 2 M H/sub 2/SO/sub 4/ at 25 C. It was suggested that in the process of the catalytic decomposition at the initial stage of the reaction, the formation of an intermediate active species containing positively charged halogen occurs; depending on the oxidative power of the counterion, the relative proportions of the hydrogen peroxide decomposing under the action of either the cation or the anion varied.

1988-01-10

89

Ligand Tuning in Asymmetric Hydrovinylation of 1,3-Dienes. A Stereoselective Route to either Steroid-C20 (S) or -C20 (R) Derivatives  

Science.gov (United States)

1,3-Dienes derived from steroidal D-ring C17-ketones undergo Ni(II)-catalyzed hydrovinylation to give 1,2- or 1,4-addition of ethylene. Using finely tuned phosphoramidite ligands it is possible to synthesize either the C20 (R)- or the C20 (S)-derivatives without mutual contamination. The proportion of the 1,4-adduct, which is also formed stereoselectively, can be minimized by optimizing the reaction conditions. Since the two alkenes in the resultant dienes have differing steric demands for many potential reactions, and are ideally juxtaposed for further D-ring functionalization, these intermediates could be useful for the preparation of biologically important compounds such as vitamin D analogs and various antitumor steroidal glycosides.

2008-06-21

90

Kinetics of hydrolysis of PET powder in nitric acid by a modified shrinking-core model  

Energy Technology Data Exchange (ETDEWEB)

Poly(ethylene terephthalate) (PET) powder from waste bottles was degraded at atmospheric pressure in 7--13 M nitric acid at 70--100 C for 72 h, to clarify the mechanism of a feed stock recycling process. Terephthalic acid (TPA) and ethylene glycol (EG) were produced by the acid-catalyzed heterogeneous hydrolysis of PET in nitric acid, and the resulting EG was simultaneously oxidized to oxalic acid. The kinetics of the hydrolysis of PET in nitric acid could be explained by a modified shrinking core model of chemical reaction control, in which the effective surface area is proportional to the degree of unreacted PET, affected by the deposition of the product TPA. The apparent rate constant was inversely proportional to particle size and to the concentration of the nitric acid. The activation energy of the reaction was 101.3 kJ/mol.

1998-02-01

91

Kestose:sucrose fructosyl transfer - a potential problem in the investigation of fructan and sucrose metabolism  

Energy Technology Data Exchange (ETDEWEB)

Wheat leaves can be induced by excision to produce fructans. Fructose residues of newly made oligofructans in leaves labeled in vivo with {sup 14}CO{sub 2} are not equally labeled. We report here on a fructosyl transferase activity in wheat leaves catalyzing the reaction: G{sup *}-F{sup *} + G-F-F = G{sup *}-F{sup *}-F + G-F. This activity, described previously in J. artichoke was attributed to fructan:fructan fructosyl transferase (FFT). The rate of this reaction in vitro is much higher than that of net kestose synthesis by SST. Hence, appearance of labeled 1-kestose from sucrose may not be an accurate measure of SST, but a curious reshuffling of hexoses between pools of 1-kestose and sucrose.

1990-05-01

92

Immobilization of bacteria in microgel grafted onto macroporous polyethylene  

Energy Technology Data Exchange (ETDEWEB)

The development of 'Green Chemistry' requires new materials to replace the conventional organic chemistry by biological catalysts, to produce fine chemicals in an environmentally friendly manner. Microbial whole cells can be directly used as biocatalysts, providing a simple and cheap methodology since enzyme isolation and purification are avoided. High-density polyethylene (HDPE) is a very stable polymer though it can be activated by gamma radiation to induce grafting. Glycidyl methacrylate was grafted onto macroporous HDPE and PP in the range of 1-6%, proportional to the initial monomer concentration. Grafted polymers were further chemically modified with ethylenediamine to generate a cationic hydrogel of micron-size thickness onto the internal polymer surfaces. Modified polymers were able to immobilize Gram-positive and Gram-negative bacteria that can catalyze a chemical reaction as efficient as free cells do.

2010-03-15

93

Fullerene-Derivatized Amino Acids: Synthesis, Characterization, Antioxidant Properties, and Solid-Phase Peptide Synthesis  

British Library Electronic Table of Contents (United Kingdom)

A series of [60]fullerene-substituted phenylalanine (Baa) and lysine derivatives have been prepared by the condensation of 1,2-(4prime-oxocyclohexano)fullerene with the appropriately protected (4-amino)phenylalanine and lysine, respectively. Conversion of the imine to the corresponding amine is achieved by di-acid catalyzed hydroboration. The reduction of the imine is not accompanied by hydroboration of the fullerene cage. The [70]fullerene phenylalanine derivative has also been prepared as have the di-amino acid derivatives. The compounds were characterized by MALDI-TOF mass spectrometry, UV/Vis spectroscopy, and cyclic voltammetry. 1H and 13C NMR spectroscopy allowed the observation of diastereomers. Fullerene-substituted peptides may be synthesized on relatively large scale by solid-pha...

2007-01-01

94

Esterification process to synthesize isopropyl chloroacetate catalyzed by lanthanum dodecyl sulfate  

International Nuclear Information System (INIS)

Isopropyl chloroacetate has been synthesized by esterification of chloroacetic acid and isopropanol, using lanthanum dodecyl sulfate (LDDS) as the catalyst. Various factors that affected the esterification have been investigated, such as reaction time, different water-carrying agent and the amount of catalyst. Under the condition of 1.2/1 molar ratio of isopropanol to chloroacetic acid, 1.0% catalyst (molar percent of chloroacetic acid), 2.5 h reaction time, 5 mL cyclohexane as water-carrying agent and reflux temperature, the esterification conversion of isopropyl chloroacetate reaches 98.3%. The catalytic activity of LDDS is almost equal to that of a Bronsted acid. LDDS, as one kind of water-tolerant Lewis acid, is an excellent catalyst compared to the traditional Lewis acid. (author)

95

Direct coal liquefaction using iron-titanium hydride as a hydrogen distribution and catalytic material. Progress report No. 5, September 1-November 30, 1985  

Science.gov (United States)

During this reporting period two direct coal liquefaction experiments have been completed and a third is underway. These experiments have produced conversion and selectivity data on samples of Alabama bituminous coal slurried in tetralin and catalyzed using iron-titanium hydride. The experiments address the liquefaction of an agglomerating coal. Conversions of 45 to 55% DAF in 30 min have been recorded at 500/sup 0/F and 520 psia. Equipment modifications were made in an attempt to eliminate the problem of alloy binding in the hydride formation vessel. 4 figs., 4 tabs.

1985-12-20

96

Development of rechargeable monopolar and bipolar zinc/air batteries  

Energy Technology Data Exchange (ETDEWEB)

For the development of a rechargeable zinc/air battery, La[sub 0.6]Ca[sub 0.4]CoO[sub 3]-catalyzed (perovskite) bifunctional oxygen electrodes and pasted zinc electrodes were prepared and tested in monopolar zinc/air cells. In addition, a bipolar Zn/air stack was tested using reticulated copper foam as substrate for the zinc deposit. The cells were cycled in moderately alkaline ZnO-saturated electrolyte with KF as an electrolyte additive. The maximum power as well as the cycle life of the cells was investigated. The differences in porosity of the zinc electrode before and after the long-term test were analyzed using mercury porosimetry. (author) 8 figs., 13 refs.

1995-01-01

97

Coalification by clay-catalyzed oligomerization of plant monomers. [Methyleugenol  

Science.gov (United States)

During this report period, we have obtained a model of montmorillonite clay, and this model has been of great assistance in visualizing how the chemistry of substrate molecules might be altered as it occurs on the surface of the clay. A stereochemical representation of this montmorillonite model is shown. Of particular significance, this model indicates that hydroxyl groups are located in the center of each siloxane ring on the surface of the montmorillonite clay. These hydroxyl groups might serve to bond substrate molecules to the surface of the clay. The next step in our systematic examination of the radical cation-initiated dimerization of plant monomers from the C{sub 6}-C{sub 3} pool of shikimic acid metabolites was to study the dimerization of cinnamic acid and its derivatives. In the next block of research, we examined the reaction of montmorillonite clay (K-10) with methyleugenol. 2 refs.

1990-01-01

98

CO{sub 2} CAPTURE BY ABSORPTION WITH POTASSIUM CARBONATE  

Energy Technology Data Exchange (ETDEWEB)

The objective of this work is to improve the process for CO{sub 2} capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K{sub 2}CO{sub 3} promoted by piperazine. Thermodynamic modeling predicts that the heat of desorption of CO{sub 2} from 5m K+/2.5 PZ from 85 kJ/mole at 40 C to 30 kJ/mole at 120 C. Mass transfer modeling of this solvent suggests that carbonate and general salt concentration play a major role in catalyzing the rate of reaction of CO{sub 2} with piperazine. Stripper modeling suggests that with the multipressure stripper, the energy consumption with a generic solvent decreases by 15% as the heat of desorption is decreased from 23.8 to 18.5 kcal/gmol. A second pilot plant campaign with 5m K+/2.5 PZ was successfully completed.

2005-01-31

99

Asymmetric Hydrogenation with Highly Active IndolPhos-Rh Catalysts: Kinetics and Reaction Mechanism  

British Library Electronic Table of Contents (United Kingdom)

The mechanism of the IndolPhos-Rh-catalyzed asymmetric hydrogenation of prochiral olefins has been investigated by means of X-ray crystal structure determination, kinetic measurements, high-pressure NMR spectroscopy, and DFT calculations. The mechanistic study indicates that the reaction follows an unsaturate/dihydride mechanism according to Michaelis-Menten kinetics. A large value of KM (KM=5.01+-0.16 M) is obtained, which indicates that the Rh-solvate complex is the catalyst resting state, which has been observed by high-pressure NMR spectroscopy. DFT calculations on the substrate-catalyst complexes, which are undetectable by experimental means, suggest that the major substrate-catalyst complex leads to the product. Such a mechanism is in accordance with previous studies on the mechanism...

2010-01-01

100

A soft x-ray free electron laser (FEL) using a two-beam elliptical pill-box wake-field cavity  

International Nuclear Information System (INIS)

Stimulated bremsstrahlung in an undulating electric field in the lasing beam direction (electric wiggler) was shown to be possible from the quantum- mechanical viewpoint. Herein, this possibility is scrutinized from the viewpoint of classical electrodynamics. It is found that if stimulated bremsstrahlung in a transverse undulating magnetic field (magnetic wiggler) occurs, stimulated bremsstrahlung in the electric wiggler must also occur. We further show that a free electron laser (FEL) using a magnetic wiggler to provide a catalyzer field for stimulated bremsstrahlung cannot serve as a practical FEL operating in the soft x-ray region from both theoretical and experimental viewpoints. On the other hand, the authors demonstrate that the FEL using a traveling wake field in a two-beam elliptical pill-box cavity is well suited as a source of coherent radiation in the soft x-ray region.

1988-01-14

101

A novel structural mechanism for redox regulation of uridine phosphorylase 2 activity  

British Library Electronic Table of Contents (United Kingdom)

Uridine phosphorylase (UPP) catalyzes the reversible conversion of uridine to uracil and ribose-1-phosphate and plays an important pharmacological role in activating fluoropyrimidine nucleoside chemotherapeutic agents such as 5-fluorouracil and capecitabine. Most vertebrate animals, including humans, possess two homologs of this enzyme (UPP1 & UPP2), of which UPP1 has been more thoroughly studied and is better characterized. Here, we report two crystallographic structures of human UPP2 (hUPP2) in distinctly active and inactive conformations. These structures reveal that a conditional intramolecular disulfide bridge can form within the protein that dislocates a critical phosphate-coordinating arginine residue (R100) away from the active site, disabling the enzyme. In vitro activity measurem...

2011-01-01

102

Thermodynamics of potassium diclofenac salt aqueous solutions at various temperatures  

British Library Electronic Table of Contents (United Kingdom)

Solution and dilution enthalpies of aqueous solutions of potassium diclofenac salt (K_DC) were measured by an isoperibolic calorimeter at 298.15 and 318.5?K. Heat capacities of the solutions with concentrations 0.002?0.09?mol?kg?1 were obtained at the temperature interval of 288.15?318.15?K using a scanning adiabatic microcalorimeter. The virial coefficients were derived from Pitzer?s model, and the excess thermodynamic functions of both the solvent and the solute of the solution were calculated. The concentration and temperature dependencies of thermodynamic characteristics of the solution were analyzed and discussed.

2011-01-01

103

["3H]Indole-3-acetyl-myo-inositol hydrolysis by extracts of Zea mays L. vegetative tissue  

International Nuclear Information System (INIS)

["3H]Indole-3-acetyl-myo-inositol was hydrolyzed by buffered extracts of acetone powders prepared from 4 day shoots of dark grown Zea mays L. seedlings. The hydrolytic activity was proportional to the amount of extract added and was linear for up to 6 hours at 37"0C. Boiled or alcohol denatured extracts were inactive. Analysis of reaction mixtures by high performance liquid chromatography demonstrated that not all isomers of indole-3-acetyl-myo-inositol were hydrolyzed at the same rate. Buffered extracts of acetone powders were prepared from coleoptiles and mesocotyls. The rates of hydrolysis observed with coleoptile extracts were greater than those observed with mesocotyl extracts. Active extracts also catalyzed the hydrolysis of esterase substrates such as #alpha#-naphthyl acetate and the methyl esters of indoleacetic acid and naphthyleneacetic acid. Attempts to purify the indole-3-acetyl-myo-inositol hydrolyzing activity by chromatographic procedures resulted in ...

104

Enzymatic catalysis in cosolvent modified pressurized organic solvents.  

Science.gov (United States)

An important advantage of carrying out enzymatic catalysis in organic media is the increased solubility of hydrophobic substrates. This study compares a model lipase catalyzed esterification of cholesterol using vinyl acetate (VA) in two such nontraditional media: high-pressure hexane and supercritical (SCF) ethane. The effect of using one of the reactants (VA) as a cosolvent to increase the solubility of the other reactant (cholesterol) in SCF ethane has been investigated. The thermodynamic activity of water (a(w)) in the reaction media was controlled by the direct addition of the salt hydrate pair Na(4)P(2)O(7)/Na(4)P(2)O(7).10H(2)O. The a(w) of the salt hydrate system is shown to be a function of pressure and its variation over the pressure range 104-173 bar has been estimated. The initial reaction rate in pressurized hexane was found to vary linearly with the cholesterol concentration. The reaction rate was also a function of pressure-the effect being more ...

1999-11-01

105

Atomic substitution reveals the structural basis for substrate adenine recognition and removal by adenine DNA glycosylase  

Science.gov (United States)

Adenine DNA glycosylase catalyzes the glycolytic removal of adenine from the promutagenic A {center_dot} oxoG base pair in DNA. The general features of DNA recognition by an adenine DNA glycosylase, Bacillus stearothermophilus MutY, have previously been revealed via the X-ray structure of a catalytically inactive mutant protein bound to an A:oxoG-containing DNA duplex. Although the structure revealed the substrate adenine to be, as expected, extruded from the DNA helix and inserted into an extrahelical active site pocket on the enzyme, the substrate adenine engaged in no direct contacts with active site residues. This feature was paradoxical, because other glycosylases have been observed to engage their substrates primarily through direct contacts. The lack of direct contacts in the case of MutY suggested that either MutY uses a distinctive logic for substrate recognition or that the X-ray structure had captured a noncatalytically competent state in lesion ...

2010-01-14

106

Structural aspects of lithium ions hydration in aqueous solutions of electrolytes  

International Nuclear Information System (INIS)

Analysis of results of an investigation into the structure of lithium salt aqueous solutions is presented. An anomaly in lithium ion behaviour in solutions at the structural level is noted. 40 refs., 3 tabs.

107

Electrolysis of halide-containing solutions with platinum based amorphous metal alloy anodes  

Energy Technology Data Exchange (ETDEWEB)

A process for the generation of halogens from halide-containing solutions includes the step of conducting electrolysis of the solutions in an electrolytic cell having a platinum based amorphous metal alloy anode.

1985-12-24

108

Adsorption of di-2-ethylhexylphosphoric acid from toluene at interface with inorganic salt aqueous solutions  

International Nuclear Information System (INIS)

Interfacial tension at the aqueous solution of di-2-ethylhexylphosphoric acid or its copper salts/water solutions has been measured by the drop volume method.

110

Meteorological effects of environmental controls.  

UK PubMed Central (United Kingdom)

The solution of the continuity equation in practical applications is examined, and the values needed for approximate solutions are indicated. Models are adequate for investigating what could happen,...Full Text Available

1975-04-01

111

Effect of a maltodextrin-electrolyte, a maltodextrin-nutrient-electrolyte and a standard electrolyte solution on water and electrolyte fluxes in the secreting rat intestine.  

Science.gov (United States)

The effects of a maltodextrin (dextrose equivalent 12)-electrolyte solution and a maltodextrin-electrolyte solution with added nutrients on net water and electrolyte transport in the secreting rat intestine was compared with the citrate-World Health Organization oral rehydration solution to determine the need for a clinical trial to evaluate the efficacy of these maltodextrin solutions in acute diarrhoea treatment. Cholera toxin consistently produced net water secretion (-36.5 +/- 9.9 mean +/- SEM microliter/min/g dry weight of intestine). All three solutions reversed the cholera toxin-induced net intestinal water secretion to net absorption. Significantly greater net water absorption occurred from the maltodextrin-electrolyte solution compared to the World Health Organization solution (P < 0.05) but not when compared to the ...

1993-12-01

115

The solution to the forward-bias puzzle: Reply  

British Library Electronic Table of Contents (United Kingdom)

My proposed econometric solution to the forward-bias puzzle provoked several comments. Those comments raise three primary objections to my solution. (1) It suffers from multicollinearity, miss-specification and other serious econometric problems. (2) My key test equation is a tautology or identity. (3) My econometric solution has nothing to do with either the forward-bias puzzle or uncovered interest parity. This is my reply to those objections.

2011-01-01

117

Safety analysis and license of rod drop time issue at Daya Bay Nuclear Power Plant  

International Nuclear Information System (INIS)

The rod drop time event of the Daya Bay Nuclear Power Plant is caused by the malfunction of the guide tube developed by Framatome. Three temporary solutions were implemented successively and the long term solution was found in the process of searching for the root cause. The different solutions and the root cause are introduced. The safety analysis and license of the solutions are mainly discussed. Experiences and lessons are drawn by summarizing the important items related to nuclear safety.

118

Radiation Protection of the Organism (Selected Chapters)  

Science.gov (United States)

... biologically important compounds is sharply lowered with passage of the solutions to the cell an organ, where their sensitivity ...

1970-12-11

119

On the calculation of the electrolyte aqueous solution freezing temperature  

International Nuclear Information System (INIS)

Analytical expression of the dependence of freezing temperature of electrolyte (CdCl_2, CdSO_4, BeSO_4) aqueous solutions on their composition was found. Three different methods were suggested were suggested for calculation of water activity in multicomponent solution. It was established that sublinear extrapolation of freezing temperature of salt aqueous solutions was possible not up to -5 deg C, but up to -15 deg C, independently of their composition. 6 refs.; 2 figs.

120

On the Uniqueness of Solutions of a Nonlinear Elliptic Problem Arising in the Confinement of a Plasma in a Stellarator Device  

International Nuclear Information System (INIS)

We study the uniqueness of solutions of a semilinear elliptic problem obtained from an inverse formulation when the nonlinear terms of the equation are prescribed in a general class of real functions. The inverse problem arises in the modeling of the magnetic confinement of a plasma in a Stellarator device. The uniqueness proof relies on an L"#infinity# -estimate on the solution of an auxiliary nonlocal problem formulated in terms of the relative rearrangement of a datum with respect to the solution.

126

Coupled Growth and Division of Model Protocell Membranes  

UK PubMed Central (United Kingdom)

The generation of synthetic forms of cellular life requires solutions...Full Text Available

2009-04-22

129

Colorimetric porous indicator of carbon dioxide  

Energy Technology Data Exchange (ETDEWEB)

This paper investigates the spectral characteristics of three-dimensionally porous carbon dioxide indicators based on a porous silicate glass and phenolphthalein. The absorption spectra of the original solutions of phenolphthalein in alkaline and acid solutions are shown. The solutions were acidified by bubbling CO/sub 2/ through an alkaline phenolphthalein solution. The authors have succeeded in producing a reversible colorimetric adsorption indicator for carbon dioxide which after proper calibration enables the CO/sub 2/ content of an atmosphere to be estimated quantitatively.

1986-03-01

132

Analysis of stability of semiconductor 5-component solid solutions of A"3B"5 compounds  

International Nuclear Information System (INIS)

With the use of the regular solutions model the expressions have been derived for calculation of boundaries of spinodal decomposition region as applied to five-component solid solutions of A"3B"5 compounds. The evaluation has been made of fields of stability for Al_x__1Ga_x__2In_1_-_x__1_-_x__2PyAs_1_-_y solid solution.

133

Supergravity solutions without triholomorphic U(1) isometries  

International Nuclear Information System (INIS)

We investigate the construction of five-dimensional supergravity solutions that do not have any triholomorphic U(1) isometries. We construct a class of solutions that in various limits of parameters reduces to many of previously constructed five-dimensional supergravity solutions based on both hyper-Kaehler base spaces that can be put into a Gibbons-Hawking form and hyper-Kaehler base spaces that cannot be put into a Gibbons-Hawking form. We find a new solution which is over triaxial Bianchi type IX Einstein-hyper-Kaehler base space with no triholomorphic U(1) symmetry. One special case of this solution corresponds to a five-dimensional solution based on Eguchi-Hanson type II geometry.

2008-12-15

134

Spectral Analysis of Radial Dirac Operators in the Kerr-Newman Metric and its Applications to Time-periodic Solutions  

CERN Document Server

We investigate the existence of time-periodic solutions of the Dirac equation in the Kerr-Newman background metric. To this end, the solutions are expanded in a Fourier series with respect to the time variable $t$ and the Chandrasekhar separation ansatz is applied so that the question of existence of a time-periodic solution is reduced to the solvability of a certain coupled system of ordinary differential equations. First, we prove the already known result that there are no time-periodic solutions in the non-extreme case. Then it is shown that in the extreme case for fixed black hole data there is a sequence of particle masses $(m_N)_{N\\in\\mathbb N}$ for which a time-periodic solution of the Dirac equation does exist. The period of the solution depends only on the data of the black hole described by the Kerr-Newman metric.

2006-01-01

135

Corrosion behaviour of Alloy 800 in high temperature aqueous solutions: Electrochemical studies  

International Nuclear Information System (INIS)

The anodic behaviour and passivity breakdown of Alloy 800 in aqueous solutions of sodium chloride, sodium sulphate and sodium bicarbonate were studied by electrochemical techniques in the temperature range from 60 C to 280 C. The pitting resistance and pitting morphology of the alloy in chloride plus sulphate and chloride plus bicarbonate mixtures, at 60 C and 280 C, were also examined. Increasing bicarbonate or sulphate additions to chloride solutions shift the characteristic pitting potential of Alloy 800 to higher values, both at low and high temperatures. Changes in pitting morphology were observed in sulphate containing solutions while the morphology of the attack found in bicarbonate containing solutions was similar to that in pure chloride solutions. Finally, no localized or substantial generalized corrosion was detected in pure sulphate or bicarbonate ...

136

Travelling wave solutions to the Kuramoto-Sivashinsky equation  

International Nuclear Information System (INIS)

Combining the approaches given by Baldwin [Baldwin D et al. Symbolic computation of exact solutions expressible in hyperbolic and elliptic functions for nonlinear PDEs. J Symbol Comput 2004;37:669-705], Peng [Peng YZ. A polynomial expansion method and new general solitary wave solutions to KS equation. Comm Theor Phys 2003;39:641-2] and by Schuermann [Schuermann HW, Serov VS. Weierstrass' solutions to certain nonlinear wave and evolution equations. Proc progress electromagnetics research symposium, 28-31 March 2004, Pisa. p. 651-4; Schuermann HW. Traveling-wave solutions to the cubic-quintic nonlinear Schroedinger equation. Phys Rev E 1996;54:4312-20] leads to a method for finding exact travelling wave solutions of nonlinear wave and evolution equations (NLWEE). The first idea is to generalize ansaetze given by Baldwin and Peng to find elliptic solutions of ...

2007-08-01

137

The nucleation kinetics of calcium sulfate dihydrate in NaCl solutions up to 6 m and 90 C  

Energy Technology Data Exchange (ETDEWEB)

The crystallization of calcium sulfate from aqueous solutions with NaCl is both geological and industrial interest because NaCl is the dominant solute in natural brines and many industrial fluids. Induction periods for the nucleation of calcium sulfate dihydrate were experimentally determined as a function of supersaturation in NaCl solutions from 0 to 6 m at 25 C and in 3.0-m NaCl solutions at temperatures from 25 to 90 C. Using classic nucleation theory, the interfacial tension between gypsum and 3.0-m NaCl solution was estimated to be about 39 mJ/m[sup 2] at 25 C and increases with increasing temperature (to 63 mJ/m[sup 2] at 90 C). It was observed that the induction period decreases with increasing NaCl concentrations up to 3 m and then starts to increase slightly at a given temperature and saturation state. The electrolyte effect on nucleation was proportional to the enhanced ...

1994-02-01

138

Stress corrosion cracking susceptibility of #beta# titanium alloy 38-6-44  

International Nuclear Information System (INIS)

The threshold stress intensities for stress corrosion crack propagation in beta titanium alloy 38-6-44, Ti3Al-8V-6Cr-4Mo-4Zr, has been determined in salt water and methanolic solutions. The alloy was immune to stress corrosion cracking (SCC) in aqueous sodium chloride solutions (marine atmosphere). However, in methanolic solutions, the alloy was very susceptible to SCC. This marked susceptibility in methanolic solutions can be mitigated by the addition of an inhibitor: sodium nitrate. Crack extension in the alloy was transgranular and failure occurred by brittle quasi-cleavage in methanolic solutions.

139

Perturbation solution to heat conduction in melting or solidification with heat generation  

Science.gov (United States)

The Stefan problem involving a source term is considered in this technical note. As an example, planar solidification with time-dependent heat generation in a semi-infinite plane is solved by use of a perturbation technique. The perturbation solution is validated by reducing the problem to the case without heat generation whose exact solution is available. An application to the case with constant heat generation is presented, for which a closed-form solution is obtained. The effects of heat generation and Stefan number on the evolution of solidification are examined using the perturbation solution.

2010-04-01

140

Modeling of (vapor + liquid) equilibrium and enthalpy of solution of carbon dioxide (CO{sub 2}) in aqueous methyldiethanolamine (MDEA) solutions  

Energy Technology Data Exchange (ETDEWEB)

A thermodynamic model was used to estimate enthalpy of solution of carbon dioxide (CO{sub 2}) in methyldiethanolamine (MDEA) aqueous solutions. The model was based on a set of equations for chemical equilibria, phase equilibria, charge, and mass balances. Non-ideality in the liquid phase was taken into account by interaction parameters fitted to (vapor + liquid) equilibrium data. The enthalpies of solution of CO{sub 2} were derived from the model using classical thermodynamic relations and were compared to experimental values obtained in previous works.

2009-06-15

141

Modeling of (vapor + liquid) equilibrium and enthalpy of solution of carbon dioxide (CO_2) in aqueous methyldiethanolamine (MDEA) solutions  

International Nuclear Information System (INIS)

A thermodynamic model was used to estimate enthalpy of solution of carbon dioxide (CO_2) in methyldiethanolamine (MDEA) aqueous solutions. The model was based on a set of equations for chemical equilibria, phase equilibria, charge, and mass balances. Non-ideality in the liquid phase was taken into account by interaction parameters fitted to (vapor + liquid) equilibrium data. The enthalpies of solution of CO_2 were derived from the model using classical thermodynamic relations and were compared to experimental values obtained in previous works.

2009-06-01

142

Manifestation of isotope effects in absorption spectra of "1"4"4Sm"3"+ and "1"5"4Sm"3"+ in solutions  

International Nuclear Information System (INIS)

Photoluminescence spectra for solutions containing Sm"3"+ isotope ions in heavy and normal water were studied in the wave length #lambda# = 500-700 nm and for absorption spectra and photoluminescence excitation spectra within the range of #lambda# = 260-600 nm. Differences in molar extinction coefficients for "1"4"4Sm"3"+ and "1"5"4Sm"3"+ were established both in the solutions with D_2O and by transition from the solutions with D_2O to the solutions with H_2O. New possible causes of the identified effects are discussed

1998-01-01

143

Corrosion of hardened cement paste by acetic and nitric acids; Part 1: Calculation of corrosion depth  

Energy Technology Data Exchange (ETDEWEB)

The rate of corrosion of hardened cement paste in solutions of nitric, hydrochloric, sulfuric, acetic and formic acids was compared. Corrosion in solutions of acetic and nitric acids with different concentrations was studied in more detail. The results made it possible to obtain the relationships expressing the influence of concentration and the time of action of acid solutions on the depth of corrosion. The rates of corrosion in nitric acid solutions during the first 3 years were about 2 to 4 times that in acetic acid solutions, depending on the concentration.

1994-01-01

144

[Fe]-hydrogenases in green algae: photo-fermentation and hydrogen evolution under sulfur deprivation  

Energy Technology Data Exchange (ETDEWEB)

Recent studies indicate that [Fe]-hydrogenases and H{sub 2} metabolism are widely distributed among green algae. The enzymes are simple structured and catalyze H{sub 2} evolution with similar rates than the more complex [Fe]-hydrogenases from bacteria. Different green algal species developed diverse strategies to survive under sulfur deprivation. Chlamydomonas reinhardtii evolves large quantities of hydrogen gas in the absence of sulfur. In a sealed culture of C. reinhardtii, the photosynthetic O{sub 2} evolution rate drops below the rate of respiratory O{sub 2} consumption due to a reversible inhibition of photosystem II, thus leading to an intracellular anaerobiosis. The algal cells survive under these anaerobic conditions by switching their metabolism to a kind of photo-fermentation. Although possessing a functional [Fe]-hydrogenase gene, the cells of Scenedesmus obliquus produce no significant amounts of H{sub 2} under S-depleted conditions. Biochemical ...

2002-12-01

145

Water-soluble cis-[(NHC)PdBr2(TPPTS)] catalysts and their applications in Suzuki-Miyaura coupling of aryl chlorides  

British Library Electronic Table of Contents (United Kingdom)

New palladium(II) complexes (2), bearing NHC/TPPTS ligands, (NHC=benzimidazol-2-ylidene; TPPTS=triphenylphosphine-3,3',3''-trisulfonic acid trisodium salt) have been prepared and characterized by elemental analyses and spectroscopic methods. Their ability to catalyze the Suzuki-Miyaura reaction in neat water has been studied at 100^oC. Very high activities have been observed in the coupling of phenylboronic acid with aryl chlorides in the presence of 1% of the catalyst. We have compared the electronic properties of cis-[PdBr2(NHC)(TPPTS)] with the related complexes, [PdX2(NHC)]2 and [trans-PdBr2(NHC)(pdca)] (pdca=pyridine-2,6-dicarboxyic acid) (3) via three different techniques: cyclic voltammetry, thermogravimetric analysis and ^1^3C NMR spectroscopy.

2011-01-01

146

Transient diffusion, desorption, and reaction studies of cyclopropane and propylene with NaX and Eu/NaX zeolites  

Science.gov (United States)

The exchange of Eu[sup 3+] for Na[sup +] cations into the sodalite cages of X zeolite (Eu[sub 25]Na[sub 11]X) leads selectively to the isomerization reaction of cyclopropane to propylene. The latter reaction is catalyzed by Broensted acid sites with an apparent activation energy of 10.6 kcal/mol. Sorption measurements of cyclopropane and propylene with Eu/NaX and NaX zeolites at 40 C support the view that Na[sup +] cations might be considered as sites for sorption of these molecules. Force fields created by Eu[sub 4]O[sup 10+] present in Eu/NaX zeolite may affect sorption. On the other hand, Broensted acid sites in Eu/NaX enhance sorption of cyclopropane and propylene at 40 C. Chemisorption of propylene on the Broensted acid sites of Eu/NaX is reversible and may occur via a propylene carbenium cation intermediate. Small amounts of hexene are formed during this sorption. The amount of Broensted acid sites in the present Eu/NaX is at least 0.6 mmol/g cat.

1992-05-01

147

The behaviour of iron in the formation of #beta#'-sialon from a fireclay  

International Nuclear Information System (INIS)

The carbothermal reduction of clay minerals in a nitrogen atmosphere is a well established method for producing #beta#'-sialon. There has been some debate within the literature concerning the role that Fe plays in the formation of the #beta#'-sialon phase. However, most workers accept that Fe is able to either catalyze or promote the formation of #beta#'-sialon although some workers have indicated that the function of the Fe is controlled by gas flow rate and there is evidence that Fe also promotes formation of additional phases. The aim of the present study was to characterize the behaviour of Fe within the #beta#'-sialon synthesis. "5"7Fe Moessbauer spectroscopy was employed for the study because this technique is specific to Fe and does not suffer interference from other elements. Moreover, both the coordination and oxidation state and the relative abundances of the various Fe-containing phases are able to be monitored. A previous Moessbauer study of Fe in ...

148

The Structure of Sucrose Phosphate Synthase from Halothermothrix orenii Reveals Its Mechanism of Action and Binding Mode  

Energy Technology Data Exchange (ETDEWEB)

Sucrose phosphate synthase (SPS) catalyzes the transfer of a glycosyl group from an activated donor sugar, such as uridine diphosphate glucose (UDP-Glc), to a saccharide acceptor D-fructose 6-phosphate (F6P), resulting in the formation of UDP and D-sucrose-6'-phosphate (S6P). This is a central regulatory process in the production of sucrose in plants, cyanobacteria, and proteobacteria. Here, we report the crystal structure of SPS from the nonphotosynthetic bacterium Halothermothrix orenii and its complexes with the substrate F6P and the product S6P. SPS has two distinct Rossmann-fold domains with a large substrate binding cleft at the interdomain interface. Structures of two complexes show that both the substrate F6P and the product S6P bind to the A-domain of SPS. Based on comparative analysis of the SPS structure with other related enzymes, the donor substrate, nucleotide diphosphate glucose, binds to the B-domain of SPS. Furthermore, we propose a ...

2008-01-01

149

Synthesis of model compounds for coal liquefaction research  

Energy Technology Data Exchange (ETDEWEB)

The objectives of this project are to develop feasible synthetic routes to produce (1) 4(4{prime}-hydroxy-5{prime},6{prime},7{prime},8{prime}-tetrahydro-1{prime}-naphthylmethyl)-6-methyldibenzothiophene, and (2) a 1-hydroxynaphthalene-dibenzothiophene polymer. These compounds are thought to be representative of sulfur containing molecules in coal. The program is divided into three tasks, the first of which is a project work plan that has already been submitted. There are several possible synthetic routes to the target molecule (1). The authors are now investigating two general synthetic approaches: coupling of a dialkylated dibenzothiophene fragment with the phenol, and coupling of a monoalkylated dibenzothiophene fragment with a monoalkylated phenol fragment. This quarter they developed syntheses for the reaction fragments and conducted some preliminary coupling experiments. They found that polymerization of the fragments is a problem; however, using an acidic resin as catalyst they ...

1990-01-01

150

Stress corrosion cracking of type 304L stainless steel core shroud welds.  

Energy Technology Data Exchange (ETDEWEB)

Microstructural analyses by advanced metallographic techniques were conducted on mockup welds and a cracked BWR core shroud weld fabricated from Type 304L stainless steel. heat-affected zones of the shroud weld and mockup shielded-metal-arc welds were free of grain-boundary carbide, martensite, delta ferrite, or Cr depletion near grain boundaries. However, as a result of exposure to welding fumes, the heat-affected zones of the welds were significantly contaminated by fluorine and oxygen which migrate to grain boundaries. Significant oxygen contamination promotes fluorine contamination and suppresses classical thermal sensitization, even in Type 304 steels. Results of slow-strain-rate tensile tests indicate that fluorine exacerbates the susceptibility of irradiated steels to intergranular stress corrosion cracking. These observations, combined with previous reports on the strong influence of weld flux, indicate that oxygen and fluorine contamination and ...

1999-10-26

151

Stress corrosion cracking of austenitic stainless steel core internal welds.  

Energy Technology Data Exchange (ETDEWEB)

Microstructural analyses by several advanced metallographic techniques were conducted on austenitic stainless steel mockup and core shroud welds that had cracked in boiling water reactors. Contrary to previous beliefs, heat-affected zones of the cracked Type 304L, as well as 304 SS core shroud welds and mockup shielded-metal-arc welds, were free of grain-boundary carbides, which shows that core shroud failure cannot be explained by classical intergranular stress corrosion cracking. Neither martensite nor delta-ferrite films were present on the grain boundaries. However, as a result of exposure to welding fumes, the heat-affected zones of the core shroud welds were significantly contaminated by oxygen and fluorine, which migrate to grain boundaries. Significant oxygen contamination seems to promote fluorine contamination and suppress thermal sensitization. Results of slow-strain-rate tensile tests also indicate that fluorine exacerbates the susceptibility of irradiated steels to ...

1999-04-14

152

Secondary reactions during CO hydrogenation on zeolite-supported metal catalysts: influence of alkali cations  

Energy Technology Data Exchange (ETDEWEB)

The effect of neutralizing cations on the secondary reactions of the primary products from CO hydrogenation over ion-exchanged zeolite-supported Ru catalysts was investigated using zeolites with different alkali cations (Li/sup +/, Na/sup +/, K/sup +/, Rb/sup +/, Cs/sup +/). The transformation of olefins (propylene and butene) on the zeolites without the metal, under conditions similar to those used for CO hydrogenation, was also studied in order to understand the effect of the various constituents of the support, i.e., the Broensted acid sites generated during catalyst preparation and the alkali cations, on possible secondary reactions of the primary olefinic products. It was established that secondary acid-catalyzed reactions of these primary products can play a major role in shaping product selectivity during CO hydrogenation over zeolite-supported catalysts. Depending on the concentration and the strength of the acid sites, various competitive reaction paths ...

1987-10-01

153

Radiolabeling of a wound-inducible pyridoxal phosphate utilizing protein from tomato: evidence for its identification as ACC synthase  

International Nuclear Information System (INIS)

Aminocyclopropane 1-carboxylic acid (ACC) synthase, a pyridoxal phosphate utilizing enzyme, catalyzes the conversion of S-adenosylmethionine to ACC, the rate limiting step in the biosynthesis of the plant hormone, ethylene. Ethylene, besides being involved in normal plant growth processes, is also produced in response to stress, e.g. wounding, pathogen infection, etc. The authors report the partial purification (400 fold) of ACC synthase from wounded pink tomato pericarp by classical techniques including ammonium sulfate precipitation, ion exchange and phenyl sepharose chromatography. Further purification results in a decrease in specific activity apparently due to the instability of the enzyme and the low levels present in plant tissue. Radiolabeling of a pyridoxal phosphate-utilizing protein in the ACC synthase enriched fraction was achieved. Evidence that this radiolabeled protein is ACC synthase will be presented. Amino acid sequence determination of putative ...

1986-06-08

154

Phosphorylation of sites 3 and 2 in rabbit skeletal muscle glycogen synthase by a multifunctional protein kinase (ATP-citrate lyase kinase)  

Energy Technology Data Exchange (ETDEWEB)

A multifunctional protein kinase, purified from rat liver as ATP-citrate lyase kinase, has been identified as a glycogen synthase kinase. This kinase catalyzed incorporation of up to 1.5 mol of and)2numberSPO4/mol of synthase subunit associated with a decrease in the glycogen synthase activity ratio from 0.85 to a value of 0.15. Approximately 65-70% of the TUPO4 was incorporated into site 3 and 30-35% into site 2 as determined by reverse phase high performance liquid chromatography. This multifunctional kinase was distinguished from glycogen synthase kinase-3 on the basis of nucleotide and protein substrate specificities. Since the phosphate contents in glycogen synthase of sites 3 and 2 are altered in diabetes and by insulin administration, the possible involvement of the multifunctional kinase was explored. Glycogen synthase purified from diabetic rabbits was phosphorylated in vitro by this multifunctional kinase at only 10% of the rate compared to synthase ...

1985-10-05

155

Phosphorylation of proteins in Clostridium thermohydrosulfuricum  

Energy Technology Data Exchange (ETDEWEB)

Cell extracts of the thermophile Clostridium thermohydrosulfuricum catalyzed the phosphorylation by (..gamma..-/sup 32/P)ATP of several endogenous proteins with M/sub r/s between 13,000 and 100,000. Serine and tyrosine were the main acceptors. Distinct substrate proteins were found in the soluble (e.g., proteins p66, p63, and p53 of M/sub r/s 66,000, 63,000, and 53,000, respectively) and particulate (p76 and p30) fractions, both of which contained protein kinase and phosphatase activity. The soluble fraction suppressed the phosphorylation of particulate proteins and contained a protein kinase inhibitor. Phosphorylation of p53 was promoted by 10..mu..M fructose 1,6-bisphosphate or glucose 1,6-bisphosphate and suppressed by hexose monophosphates, whereas p30 and p13 were suppressed by 5 ..mu..M brain (but not spinach) calmodulin. Polyamines, including the odd polyamines characteristic of thermophiles, modulated the labeling of most of the phosphoproteins. Apart from ...

1986-02-01

156

Pa0148 from Pseudomonas aeruginosa Catalyzes the Deamination of Adenine.  

Science.gov (United States)

Four proteins from NCBI cog1816, previously annotated as adenosine deaminases, have been subjected to structural and functional characterization. Pa0148 (Pseudomonas aeruginosa PAO1), AAur1117 (Arthrobacter aurescens TC1), Sgx9403e, and Sgx9403g have been purified and their substrate profiles determined. Adenosine is not a substrate for any of these enzymes. All of these proteins will deaminate adenine to produce hypoxanthine with k(cat)/K(m) values that exceed 10(5) M(-1) s(-1). These enzymes will also accept 6-chloropurine, 6-methoxypurine, N-6-methyladenine, and 2,6-diaminopurine as alternate substrates. X-ray structures of Pa0148 and AAur1117 have been determined and reveal nearly identical distorted (?/?)(8) barrels with a single zinc ion that is characteristic of members of the amidohydrolase superfamily. Structures of Pa0148 with adenine, 6-chloropurine, and hypoxanthine were also determined, thereby permitting identification of the residues responsible for coordinating the ...

2011-07-06

157

New horizons of zeolite supported catalysts  

International Nuclear Information System (INIS)

This paper reports on the superiority of zeolites over amorphous solids which is well documented for solid acid catalysts of industrial use. Crystalline supports, likewise, open attractive perspectives for catalysis by metals, alloys, and ligated metal clusters. Size and location of clusters can be controlled by careful design of the preparation conditions. Pore dimensions control the access of reactants to active sites and escape paths for products. Cage dimensions determine which transition states can be attained; window apertures are functional in isolating metal clusters from each other, thus preventing ther coalescence and growth. The ship-in-a-bottle method permits deisgn of fairly large active complexes entrapped in zeolite cages. Orientation of non-spherical molecules in a zeolite proe helps to direct their collision with a metal particle to the head on mode; however, isolated Pt atoms hidden in niches of the pore walls can attack passing molecules at their soft flanks. ...

1992-04-05

158

Mechanisms of radical removal by SO2  

DEFF Research Database (Denmark)

It is well established from experiments in premixed, laminar flames, jet-stirred reactors, flow reactors, and batch reactors that SO2 acts to catalyze hydrogen atom removal at stoichiometric and reducing conditions. However, the commonly accepted mechanism for radical removal, SO2 + H(+M) reversible arrow HOSO(+M), HOSO + H/OH reversible arrow SO2 + H-2/H2O, has been challenged by recent theoretical and experimental results. Based on ab initio calculations for key reactions, we update the kinetic model for this chemistry and re-examine the mechanism of fuel/SO2 interactions. We find that the interaction of SO, with the radical pool is more complex than previously assumed, involving HOSO and SO, as well as, at high temperatures also HSO, SH, and S. The revised mechanism with a high rate constant for H + SO2 recombination and with SO + H2O, rather than SO2 + H-2, as major products of the HOSO + H reaction is in agreement with a range of experimental results from ...

2007-01-01

159

Luminescent property and catalytic activity of Ru(II) carbonyl complexes containing N, O donor of 2-hydroxy-1-naphthylideneimines  

British Library Electronic Table of Contents (United Kingdom)

The reaction of the chelating ligands (obtained by the condensation of 2-hydroxy-1-naphthaldehyde with various primary amines) with [RuHCl(CO)(EPh3)2(B)] (where E=P; B=PPh3, py or pip: E=As; B=AsPh3) in benzene afforded new stable ruthenium(II) carbonyl complexes of the general formula [Ru(Cl)(CO)(EPh3)(B)(L)] (L=anion of bidentate Schiff bases). The structure of the new complexes was investigated using elemental analyses, spectral (FT-IR, UV-vis and 1H NMR) and electrochemical studies and is found to be octahedral. All the metal complexes exhibit characteristic MLCT absorption and luminescence bands in the visible region. The luminescence efficiency of the ruthenium(II) complexes was explained based on the ligand environment around the metal ion. These complexes catalyze oxidation of prim...

2007-01-01

160

Investigation of enzymatic biodiesel production using ionic liquid as a co-solvent  

Energy Technology Data Exchange (ETDEWEB)

Ionic liquids can enhance the activity, selectivity, and stability of enzyme catalysts. Enzymes and ionic liquids as catalysts are seen as a more environmentally friendly technology than the use of traditional catalyst materials in biofuels production. This study investigated the lipase catalyzed esterification reaction for biodiesel production in the presence of the ionic liquid BMIM PF{sub 6}. Methyl acetate was used as the acyl acceptor. A titremetric assay was conducted to measure the activity of the lipase with various amounts of ionic liquid. Reaction parameters were investigated in order to determine their effects on biodiesel conversion. An 80 per cent overall methyl oleate biodiesel yield was successfully produced in the presence of the ionic liquid. The ionic liquid improved lipase activity as well as overall biodiesel yield. Results also showed that the addition of the ionic liquid facilitated the separation of methyl esters from triacetylglycerol ...

2010-04-15

161

Evaluation of antioxidant and anti-atherogenic properties of Glycyrrhiza glabra root using in vitro models.  

Science.gov (United States)

The aim of present study was to evaluate antioxidant property of Glycyrrhiza glabra root extracts using in vitro models. The dose-dependent aqueous and ethanolic extracts demonstrated the scavenging activity against nitric oxide (concentration that caused 50% inhibition of nitric oxide radicals [IC(50)]=72 and 62.1 microg/ml, respectively), superoxide (IC(50)=64.2 and 38.4 microg/ml, respectively), hydroxyl (IC(50)=81.9 and 63 microg/ml, respectively), DPPH (IC(50)=43.6 and 28.3 microg/ml, respectively) and ABTS(*+) (IC(50)=77.3 and 57.2 microg/ml, respectively) radicals. Further, both extracts showed strong reducing power and iron-chelating capacities. In the Fe(2+)/ascorbate system, both extracts were found to inhibit mitochondrial fraction lipid peroxidation. In copper-catalyzed human serum and low-density lipoprotein oxidation models, both extracts significantly (P<0.05) lengthened the lag phase along with a decline in the oxidation rate, conjugated dienes, ...

2009-04-22

162

Direct coal liquefaction using iron-titanium hydride as a hydrogen distribution and catalytic material. Quarterly report No. 3, March 1, 1985-May 31, 1985  

Science.gov (United States)

During this reporting period four direct coal liquefaction experiments have been completed and a fifth is underway. These experiments have produced conversion and selectivity data on samples of Utah coal slurried in tetralin and catalyzed using iron-titanium hydride. Hydrogen loading of the alloy, catalyst particle size, coal particle size, operating temperatures for alloy addition and liquefaction without the catalysts present, have all been studied during these four experiments. Conversions of 61% DAF in 30 min have been recorded at 485/sup 0/F and 520 psia. The fifth run using the same coal at a reduced particle size has begun, after which we will move to samples of Kentucky and Alabama coals. Equipment manufacture, delivery, and installation delays, totaling over 6 months, greatly reduced the time available for research, making a 6 month no cost extension necessary. The extended time will permit completion of the proposed research tasks. 4 figs., 4 tabs.

1985-06-18

163

Development of a Novel Bioelectrochemical Membrane Reactor for Wastewater Treatment.  

Science.gov (United States)

A novel bioelectrochemical membrane reactor (BEMR), which takes advantage of a membrane bioreactor (MBR) and microbial fuel cells (MFC), is developed for wastewater treatment and energy recovery. In this system, stainless steel mesh with biofilm formed on it serves as both the cathode and the filtration material. Oxygen reduction reactions are effectively catalyzed by the microorganisms attached on the mesh. The effluent turbidity from the BEMR system was low during most of the operation period, and the chemical oxygen demand and NH(4)(+)-N removal efficiencies averaged 92.4% and 95.6%, respectively. With an increase in hydraulic retention time and a decrease in loading rate, the system performance was enhanced. In this BEMR process, a maximum power density of 4.35 W/m(3) and a current density of 18.32 A/m(3) were obtained at a hydraulic retention time of 150 min and external resister of 100 ?. The Coulombic efficiency was 8.2%. Though the power density and current ...

2011-10-01

164

Determination of microsomal lauric acid hydroxylase activity by HPLC with flow-through radiochemical quantitation  

International Nuclear Information System (INIS)

An assay for the microsomal hydroxylation of lauric acid (LA), based on HPLC with flow-through radiochemical detection, has been developed. Conditions were optimized for resolution and quantitation of three microsomal metabolites of "1"4C-LA, one of which has not been reported previously as a metabolite of LA in mammalian microsomal incubations. These products, 12-(omega)-hydroxy-LA, 11-(omega-1)-hydroxy-LA, and a novel metabolite, 10-(omega-2)-hydroxy-LA, were isolated by HPLC and identified by gas chromatography/mass spectrometry. In the presence of NADPH, the formation of all three metabolites was linear with time and microsomal protein concentration. Hydrogen peroxide also supported the microsomal metabolism of LA, although the ratio of metabolites was substantially different than that produced by NADPH-supported microsomes. Several biochemical probes (metyrapone, #alpha#-naphthoflavone, 2-diethylaminoethyl-2,2-diphenylvalerate hydrochloride, and 10-undecynoic acid) were used to ...

165

Crystal structures of two novel sulfonylurea herbicides in complex with Arabidopsis thaliana acetohydroxyacid synthase  

Energy Technology Data Exchange (ETDEWEB)

Acetohydroxyacid synthase (AHAS; EC 2.2.1.6) is the first enzyme in the biosynthetic pathway of the branched-chain amino acids. It catalyzes the conversion of two molecules of pyruvate into 2-acetolactate or one molecule of pyruvate and one molecule of 2-ketobutyrate into 2-aceto-2-hydroxybutyrate. AHAS requires the cofactors thiamine diphosphate (ThDP), Mg{sup 2+} and FAD for activity. The herbicides that target this enzyme are effective in protecting a broad range of crops from weed species. However, resistance in the field is now a serious problem worldwide. To address this, two new sulfonylureas, monosulfuron and monosulfuron ester, have been developed as commercial herbicides in China. These molecules differ from the traditional sulfonylureas in that the heterocyclic ring attached to the nitrogen atom of the sulfonylurea bridge is monosubstituted rather than disubstituted. The structures of these compounds in complex with the catalytic subunit of Arabidopsis ...

2009-08-17

166

An enzyme-amplified microtiter plate assay for ethanol: Its application to the detection of peanut ethanol and alcohol dehydrogenase  

Energy Technology Data Exchange (ETDEWEB)

A calorimetric microliter plate assay for ethanol amplified by aldehyde dehydrogenase (ALDH) was developed. In the assay ethanol from a sample took part in a chain-reaction catalyzed by alcohol dehydrogenase (ADH) and amplified by ALDH in the presence of NAD{sup +}, diaphorase, and p-ibdonitrotetrazolium-violet (INT-violet)(a precursor of red product). The resultant reaction gave a red color, the intensity of which was proportional to the amount of ethanol present. Using the technique, the content of activity from peanuts of differing maturity and curing stages were determined respectively. Data showed that immature peanuts had a higher level of ethanol and a lower ADH activity than mature peanuts, and that the level of ethanol and ADH activity decreased with the curing time. This indicates that peanut maturity and curing have an effect on ethanol. Also, this implies that other peanut volatiles could be affected in the same way as ethanol, a major volatile in ...

1995-12-01

167

Abiotic systems for the catalytic treatment of solvent-contaminated water  

Energy Technology Data Exchange (ETDEWEB)

Three abiotic systems are described that catalyze the reductive dehalogenation of heavily halogenated environmental pollutants, including carbon tetrachloride, trichloroethene, and perchloroethene. These systems include (a) an electrolytic reactor in which the potential on the working electrode (cathode) is fixed by using a potentiostat, (b) a light-driven system consisting of a semiconductor and (covalently attached) macrocycle that can accept light transmitted via an optical fiber, and a light-driven, two-solvent (isopropanol/acetone) system that promotes dehalogenation reactions via an unknown mechanism. Each is capable of accelerating reductive dehalogenation reactions to very high rates under laboratory conditions. Typically, millimolar concentrations of aqueous-phase targets can be dehalogenated in minutes to hours. The description of each system includes the elements of reaction mechanism (to the extent known), typical kinetic data, and a discussion of the ...

1996-12-31

168

Pitting corrosion of Alloy 690 in thiosulfate-containing chloride solutions  

Energy Technology Data Exchange (ETDEWEB)

The effects of thiosulfate ion and solution pH on pitting corrosion of Alloy 690 in chloride solution were explored. Potentiodynamic polarization measurements were conducted to evaluate pitting corrosion susceptibility of Alloy 690 in these environments. The results showed that pitting corrosion occurred in the mill-annealed (1050 deg. C/5min) Alloy 690 in 1 wt% NaCl solution but not in 0.1 M Na{sub 2}S{sub 2}O{sub 3} solution. The value of pitting nucleation potential (E{sub np}) determined in 1 wt% NaCl solution (without Na{sub 2}S{sub 2}O{sub 3} ) increased with increasing solution pH value in the range of 2-10. The addition of Na{sub 2}S{sub 2}O{sub 3} to 1 wt% NaCl solution greatly affected the pitting corrosion behavior, which was dependent on concentration. The preformed nickel sulfide surface film due to the presence of Na{sub ...

2000-02-01

169

Osmoregulation in the Avena coleoptile: control of solute uptake in peeled sections  

Energy Technology Data Exchange (ETDEWEB)

Peeled Avena sativa coleoptile sections have been used to study the control of solute uptake under conditions where the uptake is not limited by the cuticular barrier. In the presence of 2% sucrose, auxin enhances the rate at which the total osmotic solutes increase, but this appears to be a response to the increased growth rate, inasmuch as the auxin effect is eliminated when growth is inhibited osmotically. When sections are incubated in sucrose or in 10 millimolar NaCl, the osmotic concentration increases until a plateau is reached after 8 to 24 hours. Auxin has no effect on the initial rate of increase in osmotic concentration. This difference in steady-state osmotic concentration is, in part, a response to auxin itself, as it persists when auxin-induced growth is inhibited osmotically. The upper limit for osmotic concentration does not appear to be determined by the turgor pressure, inasmuch as a combination of sucrose and NaCl gave a ...

1982-01-01

170

CP{sup 2} and CP{sup 1} sigma models in supergravity: Bianchi type IX instantons and cosmologies  

Energy Technology Data Exchange (ETDEWEB)

We find instanton/cosmological solutions with biaxial Bianchi-IX symmetry, involving nontrivial spatial dependence of the CP{sup 1}-CP{sup 2}-sigma-models coupled to gravity. Such manifolds arise in N = 1, d 4 supergravity with supermatter actions and hence the solutions can be embedded in supergravity. There is a natural way in which the standard coordinates of these manifolds can be mapped into the four-dimensional physical space. Due to its special symmetry, we start with CP{sup 2} with its corresponding scalar ansatz; this further requires the spacetime to be SU(2) x U(1)-invariant. The problem then reduces to a set of ordinary differential equations whose analytical properties and solutions are discussed. Among the solutions there is a surprising, special family of exact solutions which owe their existence to the nontrivial topology of CP{sup 2} and are in 1-1 correspondence ...

2004-05-07

171

CP"2 and CP"1 sigma models in supergravity: Bianchi type IX instantons and cosmologies  

International Nuclear Information System (INIS)

We find instanton/cosmological solutions with biaxial Bianchi-IX symmetry, involving nontrivial spatial dependence of the CP"1-CP"2-sigma-models coupled to gravity. Such manifolds arise in N = 1, d 4 supergravity with supermatter actions and hence the solutions can be embedded in supergravity. There is a natural way in which the standard coordinates of these manifolds can be mapped into the four-dimensional physical space. Due to its special symmetry, we start with CP"2 with its corresponding scalar ansatz; this further requires the spacetime to be SU(2) x U(1)-invariant. The problem then reduces to a set of ordinary differential equations whose analytical properties and solutions are discussed. Among the solutions there is a surprising, special family of exact solutions which owe their existence to the nontrivial topology of CP"2 and are in 1-1 correspondence with matter-free ...

2004-05-07

172

Cryo-irradiation as a terminal method for the sterilization of drug aqueous solutions  

British Library Electronic Table of Contents (United Kingdom)

The aim of this study is to evaluate the specificities of the irradiation of drugs in frozen aqueous solution. The structures of the degradation products were determined to gain insight into the radiolysis mechanisms occurring in frozen aqueous solutions. Metoclopramide hydrochloride and metoprolol tartrate were chosen as models. The frozen solutions were irradiated at dry ice temperature by high energy electrons at various doses. The drug purity (chemical potency) and the radiolysis products were quantified by HPLC-DAD. Characterization of the degradation products was performed by LC-APCI-MS-MS. The structures of the radiolysis products detected in irradiated frozen aqueous solutions were compared to those detected in solid-state and aqueous solutions (previous studies). For both metoclop...

2008-01-01

173

Construction of the maximal solution of Backus? problem in geodesy and geomagnetism  

British Library Electronic Table of Contents (United Kingdom)

The (simplified) Backus? Problem (BP) consists in finding a harmonic function u on the domain exterior to the three dimensional unit sphere S, such that u tends to zero at infinity and the norm of the gradient of u takes prescribed values g on S. Except for a change of sign, the solution is not unique in general. However, there is uniqueness of solutions in the class of functions with the additional property that the radial component of the gradient of u on S is nonpositive. This is the geodetically relevant case. If a solution u with this property exists, then u is the maximal solution of the problem (and -u the minimal one). In this paper we propose a method of successive approximations to get this particular solution of BP and prove the convergence for functions g close to a constant fu...

2011-01-01

174

Wastewater Treatment Software Solutions on Environmental Expert  

Wastenet

... TOXCHEM+ - Wastewater Predictive Fate by Hydromantis Environmental Software Solutions, Inc. TOXCHEM+ is regarded as the most reliable and ... TOXCHEM+ is EPA-approved for estimating ... »Read more » Contact now / Request quote 0 Comments ...

175

Technical description of solution sha2006d 1. Purpose of solution ...  

Science.gov (United States)

The wrms of postfit residuals is 23.003 ps and chi-sq/ndg = 1.089. .... 1555-140 1556-245 1600+43A 1600+43B 1600-489 1606-398 \\ 1608+243 1611-710 1628+216 ...

176

SLC25A4 - solute carrier family 25 (mitochondrial carrier; adenine...  

Science.gov (United States)

The official name of this gene is "solute carrier family 25 (mitochondrial carrier; adenine nucleotide translocator), member 4." SLC25A4 is the gene's official symbol. The...

2011-08-13

177

Rolling tachyons in string cosmology  

Energy Technology Data Exchange (ETDEWEB)

We study the role of rolling tachyons in the cosmological model with dilatonic gravity. In the string frame, flat space solutions of both initial-stage and late-time are obtained in closed form. In the Einstein frame, we show that every expanding solution is decelerating.

2003-01-23

178

Properties of cellulose solutions in methylmorpholine N-oxide containing montmorillonite nanoparticles and of composite films thereof  

British Library Electronic Table of Contents (United Kingdom)

Rheological properties of moderately concentrated solutions of cellulose in methylmorpholine N-oxide-dimethylformamide mixtures containing hydrophilic montmorillonite nanoparticles were studied. Film composite materials were prepared, and their physicomechanical properties and structural organization were studied.

2011-01-01

179

Process and apparatus for chemically removing ash from coal  

Science.gov (United States)

Finely divided ash-containing coal is immersed in an aqueous solution of hydrochloric acid or citric acid, and acidic ammonium fluoride to cause the ash to react with the acid and the acidic ammonium fluoride, and the deashed coal is thereafter separated from the solution.

1984-01-03

180

Powdering Characteristics of a Thin Film Evaporator: Drying and Powdering of a Solution.  

Science.gov (United States)

A thin-film evaporator requires only a short heating time to concentrate a solution since it has a high thermal efficiency and has a small capacity. Thus, the chemical industry often uses this type of evaporator for concentrating materials that are subjec...

1983-01-01

181

Photocatalytic hydrogen production from solutions of sulfite using platinized cadmium sulfide powder  

Energy Technology Data Exchange (ETDEWEB)

Platinized cadmium sulfide powder suspended in a solution of sodium sulfite produces hydrogen efficiently by visible light. Sulfite ions are oxidized to sulfate and dithionate ions. 4 figures.

1983-09-29

182

Method of removing hydrogen sulfide and carbon dioxide from gases  

Energy Technology Data Exchange (ETDEWEB)

A process for the recovery of nitrilotriacetic acid values from solutions containing polyvalent metal complexes of nitrilotriacetic and the decomposition products thereof is described, the process being characterized by the addition to such solutions of sufficient strong acid to dissociate the complex under conditions to precipitate the nitrilotriacetic acid.

1984-04-17

183

Measurements of accurate x-ray scattering data of protein solutions using small stationary sample cells  

UK PubMed Central (United Kingdom)

In this paper, we report a method of precise in situ x-ray scattering measurements on protein solutions using small stationary sample cells. Although reduction in the radiation damage...Full Text Available

2009-01-01

184

Mean distance of closest approach of alkaline-earth metals ions in aqueous solutions: Experimental and theoretical calculations  

British Library Electronic Table of Contents (United Kingdom)

The estimation of numerical values of the mean distance of closest approach of ions, a, of alkaline-earth metal ion salts in aqueous solutions, determined from activity coefficients, as well as from different theoretical approaches, is presented and discussed.

2010-01-01

185

Examination of transepithelial exchange of water and solute in the rat renal pelvis.  

UK PubMed Central (United Kingdom)

Severance of the ureter beyond the renal papilla causes a fall in urinary osmolality, which suggests that exchange of water or solute between urine and renal parenchyma normally occurs in the intact...Full Text Available

1984-11-01

186

Efficacy of standard glucose-based and reduced-osmolarity maltodextrin-based oral rehydration solutions: effect of sugar malabsorption.  

UK PubMed Central (United Kingdom)

Previously we reported that standard oral rehydration salts (ORS) solution is not as effective as a reduced-osmolarity glucose-based ORS for the treatment of children with acute noncholera diarrhoea:...Full Text Available

1996-01-01

187

Effect of association processes on polymerization of N-[3-(dimethylamino)propyl]methacrylamide salts in aqueous solutions  

British Library Electronic Table of Contents (United Kingdom)

The effect of associative interactions of monomers and propagating macroradicals in homopolymerization of N-[3-(dimethylamino)propyl]methacrylamide salts and their copolymerization with acrylonitrile and acrylamide in aqueous solution was studied.

2010-01-01

188

Determination of heptacaine hydrochloride in solution using nuclear analytical methods  

Energy Technology Data Exchange (ETDEWEB)

The applicability of two nuclear analytical methods: radionuclide X-ray fluorescence analysis and radiometric titrations based on precipitate formations was studied in order to determine the heptacaine hydrochloride in solutions. The applied methods were evaluated based on the obtained sensitivity values.

1984-01-20

189

Determination of heptacaine hydrochloride in solution using nuclear analytical methods  

International Nuclear Information System (INIS)

The applicability of two nuclear analytical methods: radionuclide X-ray fluorescence analysis and radiometric titrations based on precipitate formations was studied in order to determine the heptacaine hydrochloride in solutions. The applied methods were evaluated based on the obtained sensitivity values. (author).

1984-01-01

190

Design and Implementation of an Open Source Indexing Solution for a Large Set of Radiological Reports and Images  

UK PubMed Central (United Kingdom)

This paper hopes to share the insights we experienced during designing, building, and running an indexing solution for a large set of radiological reports and images in a production environment for...Full Text Available

2007-11-01

191

Continuous measurement of residual activity of an amine solution used for acid gas absorption  

Energy Technology Data Exchange (ETDEWEB)

Concentration of an amine solution for removal of hydrogen sulfides and carbon dioxide from natural gas, is tested by carbon dioxide absorption measurement in an apparatus allowing complete reaction to give reliable results.

1988-05-27

192

Conformational stability of alternating d (CG) oligomers in high salt solution.  

UK PubMed Central (United Kingdom)

The conformation of d (CG)n oligomers with n = 2,3 has been studied in aqueous solution in the presence of high salt concentration. A minimum n value of three is necessary to obtain a left-handed Z-helix....Full Text Available

1981-05-11

193

Carboxymethylation of peat in 2-propanol  

British Library Electronic Table of Contents (United Kingdom)

The effects of the time and temperature of alkaline pretreatment and the time and temperature of the carboxymethylation of peat in 2-propanol on the concentration of carboxymethyl groups and the solubility of the resulting products in water and an aqueous alkali solution were studied. The viscosity characteristics of the aqueous and aqueous alkaline solutions of peat carboxymethylation products were studied.

2011-01-01

194

Association of mineral composition of neonatal intravenous feeding solutions and metabolic bone disease of prematurity.  

UK PubMed Central (United Kingdom)

To assess the effects of increasing the mineral content of parenteral nutrition solutions on the biochemical and radiological indicators of metabolic bone disease of prematurity 27 neonates who required...Full Text Available

1989-04-01

195

Adverse Effect of Ammonium Salts on the Antibacterial Activity of Paraformaldehyde Solutions  

UK PubMed Central (United Kingdom)

The antibacterial activity of aqueous solutions of paraformaldehyde in concentrations from 0.1 to 0.4% (w/v) is bacteriostatic rather than bactericidal in the presence or absence of ammonium chloride....Full Text Available

1963-07-01

196

The influence of pH on the structure of adenine monolayers adsorbed at Au(110)/electrolyte interfaces  

Energy Technology Data Exchange (ETDEWEB)

The pH of the solution is shown to significantly effect the reflection anisotropy spectroscopy (RAS) profiles of adenine adsorbed at Au(110)/electrolyte interfaces. At pH 12.8 the net adsorption is very weak due the formation of negative adenine ions in solution. The sensitivity of the RAS profiles to the pH of the solution is probably due to a change in the geometry of the adsorbed molecules caused by a disruption of the base stacking configuration that is adopted when adenine is adsorbed from solutions at pH 7.1. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

2010-08-15

197

The full order weak schemes of the Langevin simulations  

Energy Technology Data Exchange (ETDEWEB)

New partial differential equations (PDEs) for the full order weak schemes of the Langevin simulations are formulated. They are solved recursively in full order series solutions with respect to {radical}(t) (the full order weak Taylor schemes). Arbitrariness involved in the solutions is analyzed and clarified in detail. Specific solutions within some orders are presented as examples of the weak Taylor schemes. These PDEs and their solutions will serve for further developments of efficient higher order Runge-Kutta-like schemes. The similar formulation is possible for the imaginary time Hamiltonian evolution kernels as well. (orig.). 9 refs.

1998-04-01

198

THE EFFECT OF THE ICE-SEPARATION CURVE ON THE ...  

Science.gov (United States)

... However, the solution of the Stefan problem in this context becomes abruptly complicated, since within each zone, the differential equations ...

199

Symmetry analysis and exact explicit solutions for Kadomtsev-Petviashvili-Burgers equation  

British Library Electronic Table of Contents (United Kingdom)

We apply the group theory to Kadomtsev-Petviashvili-Burgers (KPBII) equation which is a natural model for the propagation of the two-dimensional damped waves. In correspondence with the generators of the symmetry group allowed by the equation, new types of symmetry reductions are performed. Some new exact solutions are obtained, which can be in the form of solitary waves and periodic waves. Specially, our solutions indicate that the equation may have time-dependent nonlinear shears. Such exact explicit solutions and symmetry reductions are important in both applications and the theory of nonlinear science.

2011-01-01

200

Survey of Biodegradation of Electronic Components and ...  

Science.gov (United States)

... This pinhole process may be similar to the formation of an oxide layer in aluminum electrolytic capacitors immersed in a borax solution. ...

1991-08-01

201

Shock and Impact Response of Naval Composite Structures  

Science.gov (United States)

... at the end of this report. A. Low-Velocity Impact of Composite Sandwich Panels In 2007, the PI developed analytical solutions ...

2010-08-09

202

Sc"4"5 NMR of scandium(3) salt aqueous solutions  

International Nuclear Information System (INIS)

Russian (Jul 1974). USSR Buslaev, Yu.A. Petrosyants, SP Tarasov,

203

Radiation polymerization of iodmethilate methacriloil lupin in water solutions  

International Nuclear Information System (INIS)

1982. p. 74. Hungary Karimov, A. Musaev, UN Ynusov, G.Sh. Tashkentskij

1982-09-19

204

REPORT NO. 853  

Science.gov (United States)

water and of the ethylene glycol-water solutions are shown as functions of temperature in figures 4 and 5, respectively. (data from reference 4). ...

205

Process for the chemical removal of ash from coal and device for carrying out this process. Verfahren zur chemischen Entfernung der Asche aus Kohle sowie Vorrichtungen zur Durchfuehrung dieses Verfahrens  

Energy Technology Data Exchange (ETDEWEB)

In order to remove ash from coal, it is introduced into an aqueous ash removal solution, which contains nitric acid or citric acid and ammonium hydrogen fluoride. The coal without ash is then separated from the aqueous solution. According to the process, either finely ground coal is introduced into the ash removel solution or the coal with the solution is ground in a wet pulveriser.

1981-03-13

206

Process and system for treatment of radioactive waste  

Energy Technology Data Exchange (ETDEWEB)

In a treatment system of radioactive waste solution including sodium sulfate generated from a boiling water type nuclear reactor, waste solution is fed into a thin film evaporator where the waste solution is evaporated and made into powder while precipitating in a peripheral surface of the evaporator vessel. The surface of the precipitated solid is wiped by rotating wiper blades and removed off as radioactive solid powder. The rotational speed of a rotor to which the wiper blades are secured is controlled at a minimum and necessary rotational speed which contributes to make the waste solution into the powder so that the rate of worn out of the wiper blade is decreased.

1985-07-02

207

Phenomenological model for the Drell-Yan process: Reexamined  

International Nuclear Information System (INIS)

Drell-Yan pair production is investigated. We reexamine a model where the quark momentum fraction is defined as the ratio of the corresponding light-cone components of the quark and parent nucleon in a naive parton-model approach. It is shown that the results differ from the standard parton model. This is due to unphysical solutions for the momentum fractions within the naive approach which are not present in the standard parton model. In a calculation employing full quark kinematics, i.e., including primordial quark transverse momentum, these solutions also appear. A prescription is given to handle these solutions in order to avoid incorrect results. The impact of these solutions in the full kinematical approach is demonstrated and compared to the modified result.

2010-02-01

208

PROTECTIVE EFFECTS OF MIXTURE OF OXIMES IN NERVE ...  

Science.gov (United States)

... ATROPINE, HI-6 AND TOXOGONIN MIGHT OFFER THE SOLUTION FOR THE OVERALL PROTECTION AGAINST NERVE GAS POISONING HAS ...

1989-06-01

210

On the structure of locally Lipschitz minimax solutions of the Hamilton-Jacobi-Bellman equation in terms of classical characteristics  

British Library Electronic Table of Contents (United Kingdom)

Necessary and sufficient conditions for a minimax solution to the Cauchy problem for the Hamilton-Jacobi-Bellman equation are obtained as viability conditions for classical characteristics inside the graph of this solution. Using this property, a representative formula for a one-dimensional conservation law in terms of classical characteristics is derived. An estimate of the numerical integration of the characteristic system is presented and errors of numerical realizations of representative formulas are determined for the conservation law and its potential equal to the minimax solution of the Hamilton-Jacobi-Bellman equation.

2010-01-01

211

Numerical solutions for symmetric Bianchi type IX universes  

International Nuclear Information System (INIS)

(Aug 1973). United States Moser, AR Matzner, RA Ryan, MP Jr. Center

212

Mathematical Sciences Division 1992 Programs  

Science.gov (United States)

... Progress: For a one-dimensional two-phase degenerate Stefan problem, it was proved that the boundary and the solutions up to the boundary are C ...

1992-10-01

213

Gamma Ray Bursts and the Birth of Black Holes  

Science.gov (United States)

Black holes have been predicted since the 1940's from solutions of Einstein's general relativity

2009-01-01

214

Exact solution to NO/sub 2/ absorption  

Energy Technology Data Exchange (ETDEWEB)

This paper describes an exact solution to the problem of absorbing nitrogen dioxide into aqueous solution, in which case the nitrogen dioxide concentration is allowed to vary over a wide range. The authors have worked on the rate of calcium sulfate dihydrate scale formation on the reverse osmosis membrane and find this phenomena can be treated by the crystallization theory. The authors performed long-term experiments using calcium sulfate dihydrate solution with addition of sodium hexametaphosphate (SHMP) and commercially available organophosphates and investigated the mechanism of the inhibitor's action quantitatively.

1984-04-01

215

Employment of /sup 203/Pb isotoic solution without a carrier for erythrocyte tracing  

Energy Technology Data Exchange (ETDEWEB)

Possibilities of applying the Pb/sup 203/ isotonic solution without a carrier as a label of blood erythrocytes, are found. There is a number of advantages in the Pb/sup 203/ isotonic solution without a carrier, such as a high label efficiency (above 95%), a short half-life (52 hours), and a low radiation dose. These factors prove to be favourable as compared with Cr/sup 51/ widely used for these purposes. Besides, of all preparations used up to now to treat erythrocytes and to scan the spleen, it is only in the case of Pb/sup 203/ isotonic solution without a carrier that no weight amounts of chemical substances do not enter the organism.

1981-08-01

216

Drilling mud for application during the drilling of caving-prone rock  

Energy Technology Data Exchange (ETDEWEB)

The authors propose a drilling solution for use in caving-prone rock formations. This solution contains clay, hydrolized polyacrylonitrile, and water. In order to improve the solution's inhibitive properties during high-temperatures, azodicarbonamide (the blowing agent ChKhZ-21) is introduced in adequate quantities. The solution's makeup is as follows, given by percentage of weight,-- Clay 5-8%; hydrolized polyacrylonitrile 0.1-0.5%; azodicarbonamide (the blowing agent ChKhZ-21) 1-3%, with the remainder being water.

1981-01-01

217

Dirac equation on a G_2 manifold  

CERN Document Server

We find a large family of solutions to the Dirac equation on a manifold of $G_2$ holonomy asymptotic to a cone over $S^3 \\times S^3$, including all radial solutions. The behaviour of these solutions is studied as the manifold developes a conical singularity. None of the solutions found are both localised and square integrable at the origin. This result suggests that M-theory on the conifold over $S^3\\times S^3$ does not produce a chiral theory. The approach here is complementary to previous analyses using dualities and anomaly cancellation which found chiral fermions on all known $G_2$ conifolds except that over $S^3\\times S^3$.

2002-01-01

218

Desorption of CO{sub 2} from MDEA and activated MDEA solutions  

Energy Technology Data Exchange (ETDEWEB)

A packed column was used for investigating the desorption rate of CO{sub 2} from aqueous methyldiethanolamine (MDEA) and activated MDEA solutions. Experiments were conducted within the temperature range 30--70 C, the concentration of MDEA was 4.28 kmol/m{sup 3}, and the concentration of piperazine (PZ) was 0.10 kmol/m{sup 3} for aqueous activated MDEA solutions. Experimental data confirmed that the kinetics model of absorption CO{sub 2} into aqueous MDEA and activated MDEA solutions can be applicable to the situations in which desorption occurs, and the desorption rate of model predictions agree well with that of experimental determination.

1995-03-01

220

Confronting Climate Change in New Jersey and the Northeast: Science, Impacts and Solutions  

ScienceCinema

...changes consistent with global warming ? uh how to regional scale within ...

221

A comparative study on the carbon dioxide capture power between 30 wt% 2-amino-2-methyl-1-propanol and 30 wt% methyldiethanol amine aqueous solutions  

Energy Technology Data Exchange (ETDEWEB)

A comparative study has been performed to compare the 30 wt% of 2-amino-2-methyl-1-propanol (AMP) aqueous solution and 30 wt% of methyldiethanol amine (MDEA) aqueous solution to capture carbon dioxide contained in the flue gas stream. The equilibrium constants for each electrolyte reactions have been used to estimate the carbon dioxide absorption process. Henry's constants for each binary pairs between solute gases and solvent have been used to estimate solubility of the gas components.

2009-05-15

223

The two-dimensional Stefan problem with slightly varying heat flux  

Science.gov (United States)

The authors solve the two-dimensional stefan problem of solidification in a half-space, where the heat flux at the wall is a slightly varying function of positioning along the wall, by means of a large Stefan number approximation (which turns out to be equivalent to a small time solution), and then by means of the Heat Balance Integral Method, which is valid for all time, and which agrees with the large Stefan number solution for small times. A representative solution is given for a particular form of the heat flux perturbation.

1995-09-01

224

The state of surface layers on lithium in modified non-aqueous media  

Energy Technology Data Exchange (ETDEWEB)

The state of lithium electrode surface after contact with triethylamine-modified propylene carbonate solutions of lithium perchlorate was studied using the pulse galvanostatic technique as well as methods of SIMS and electron microscopy. It was shown that amine added into the solutions stabilizes the state of lithium and prevents the formation of a secondary porous passive film on the lithium surface. Chemical composition of the primary film remains unchanged. Certain properties of passive films formed in electrolyte solutions studied were evaluated.

1995-04-01

225

Peculiarity of counterion - polyion interactions in aqueous solutions of copolymers of acrylamide with cadmium acrylate  

Energy Technology Data Exchange (ETDEWEB)

Binding of Cd/sup 2 +/ ions in aqueous solutions of statistical copolymers of acrylamide with cadmium acrylate with different content of ionogenic groups in copolymers was investigated by polarography, conductometry, viscometry and dialysis. It is shown that the degree of binding of Cd/sup 2 +/ ions increases with increasing of the content of ionogenic groups in the copolymer and with decreasing of ionic strength of the solution. The values of the degree of binding of Cd/sup 2 +/ ions obtained by polarography and dialysis show satisfactory agreement.

1984-02-01

226

Peculiarities of #beta#-solid solution decomposition in (#alpha#+#beta#) titanium alloy at low temperature  

International Nuclear Information System (INIS)

The physical methods were used to study the decomposition of a metastable #beta#-solid solution in the VT22 two-phase titanium alloy. It is shown that the martensitic #beta# #-># #alpha#'' transformation in doped-element depleted microvolumes of the #beta#-solid solution are dominanted and the long-time multistage decomposition through a number of intermediate states in others.

227

On The Existence of Periodic Solutions for a Certain System of Third Order Nonlinear Differential Equations  

CERN Document Server

In this paper, we study the existence and uniqueness of periodic solutions of the differential equation of the form . Here, we obtain some sufficient conditions which guarantee the existence of periodic solutions. This equation is a quite general third- order nonlinear vector differential equation, and one example is given for illustration of the subject.

2011-01-01

228

Non-uniqueness in conformal formulations of the Einstein constraints  

CERN Document Server

Standard methods in non-linear analysis are used to show that there exists a parabolic branching of solutions of the Lichnerowicz-York equation with an unscaled source. We also apply these methods to the extended conformal thin sandwich formulation and show that if the linearised system develops a kernel solution for sufficiently large initial data then we obtain parabolic solution curves for the conformal factor, lapse and shift identical to those found numerically by Pfeiffer and York. The implications of these results for constrained evolutions are discussed.

2006-01-01

229

Molar extinction coefficients in aqueous solutions of some alkaline earth chlorides  

International Nuclear Information System (INIS)

Molar extinction coefficients for the solid solutes in aqueous solutions of some alkaline earth chlorides such as MgCl_2.6H_2O, CaCl_2, SrCl_2.6H_2O and BaCl_2.2H_2O have been determined at 81, 356, 511, 662, 1173 and 1332 keV energies in different concentration using the narrow beam transmission methods. (author)

1999-12-21

230

Method of removing hydrogen sulfide from gases utilizing a polyvalent metal chelate of nitrilotriacetic acid and electrolytically regenerating the solution  

Energy Technology Data Exchange (ETDEWEB)

A process for the removal of H/sub 2/S from sour gas streams is disclosed, the process being characterized by the utilization of washing solutions containing oxidizing metal chelates of nitrilotriacetic acid, and by the electrolytic regeneration of the spent solutions.

1984-03-13

231

Means for deriving hydrolized polyacrylonitrile  

Energy Technology Data Exchange (ETDEWEB)

A method is proposed for deriving hydrolized polyacrylonitrile from a water-based alkali solution. This process is meant to improve the thermal stability of clay drilling solutions by employing the hydrolized product to treat aliphatic non-water-soluble C/sub 8/-C/sub 16/ spirits in an organic dispersant during the presence of acidity and while the solution is being heated.

1982-01-01

232

Kinetics of carbon dioxide absorption in solutions of methyldiethanolamine  

Energy Technology Data Exchange (ETDEWEB)

The kinetics of the reaction of carbon dioxide in MDEA solutions were studied both experimentally and theoretically. It is concluded that MDEA acts as a homogeneous catalyst for CO/sub 2/ hydrolysis, and as a result the rate of absorption in aqueous MDEA solutions is significantly larger than one would calculate by simply taking into account the alkalinity of the reaction. A possible zwitterion mechanism is proposed for this reaction. The minor effect of ionic strength were also studied with the presence of other ions. 19 references, 6 figures.

1985-01-01

233

Infinitesimal symmetries and conservation laws of the DNLSE hierarchy and the Noether's theorem  

Energy Technology Data Exchange (ETDEWEB)

The hierarchy of integrable nonlinear equations associated with the quadratic bundle is considered. The expressions for the solution of linearization of these equations and their conservation law in the terms of solutions of corresponding Lax pairs are found. It is shown for the first member of the hierarchy that the conservation law is connected with the solution of linearized equation due to the Noether's theorem. The local hierarchy and three nonlocal ones of the infinitesimal symmetries and conservation laws explicitly expressed through the variables of the nonlinear equations are derived. (author)

2007-08-15

234

Forum: Science and Innovation for Sustainable Development - Framework  

Wastenet

... Studies People Projects Opportunities Framework Critical Sectors Development Goals Geographic Region Geographic Scale Research Themes Printer-Friendly Center for Ocean Solutions Early Career Fellowship Program Location: Stanford, California Source: The Center for Ocean Solutions (“Ocean Solutions”) seeks one or more recent graduates who have received a JD, MBA or PhD in the natural, physical or social sciences in the last five years, and who ...

235

Electrochemical oxidation of curium(III) in potassium carbonate solution  

International Nuclear Information System (INIS)

During electrolysis of a "2"4"8Cm(III) solution in 2M K_2CO_3 at pH=13, partial oxidation of curium to a higher oxidation state, probably Cm(IV), was observed. The absorption spectra of Cm(III) and Cm(IV) in K_2CO_3 solution were recorded and the molar extinction coefficients of main absorption bands of curium were evaluated. (author).

1986-11-01

236

Design of absorption columns in the presence of surfactants  

Energy Technology Data Exchange (ETDEWEB)

An equation is described to estimate the value of the liquid-phase mass-transfer coefficient of aqueous solutions of surfactants from its value for pure water. The form of the equation is obtained from Levich's theory, and it is adjusted to experiments of absorption of CO/sub 2/ in aqueous solutions of five pure surfactants. The reduction of the absorption rate is correlated with the interfacial pressure of the solution.

1986-01-01

237

Decomposition of metastable solid solution in #beta#-titanium alloy  

International Nuclear Information System (INIS)

Peculiarities of metastable #beta#-solid solution decmposition in titanium alloy VT30 in the process of isothermal ageing in the range 500-650 deg C are investigated. Using the methods of transmittion electron microscopy, X-ray diffraction analysis, etc., it is shown that in the case of alloy quenching from the temperature below the point of complete polymorphous transformation (T_t_._t_.), as well as after warm rolling the course of subsequent decomposition of solid solution can be consierably complicated.

238

Corrosion resistance of metals in hot hydroxide solutions  

International Nuclear Information System (INIS)

Effect of hydroxide nature, concentration and temperature on corrosion resistance of domestic steels and alloys to hot NaOH, KOH, LiOH solutions is considered. It is ascertained that by corrosion growth in relation to stainless steels and nickel alloys, the hydroxides are placed in the following sequence: LiOHsolution concentration and temperature regions in which stainless steel and nickel alloy tendency to cracking is manifested, are determined. 12 refs., 12 figs.

239

Chapter 11 Aqueous Solutions  

Wastenet

...Chapter 11 Aqueous Solutions Chapter 11 Aqueous Solutions Download the entire chapter (PDF-136k) Drilling to China More water than rivers Saving the aquifer Drying with Xeriscapes Everywhere in the house Rainwater and graywater Creating urban watersheds Wastewater equals ...3851 Powered by Intrcomm Technology's SMC ...

240

Cauchy problem for the Mathieu equation away from parametric resonance  

British Library Electronic Table of Contents (United Kingdom)

Four solutions of the Cauchy problem for Mathieu?s equation away from parametric resonance domains are analytically constructed using an asymptotic averaging method in the fourth approximation. Three solutions occur near fractional parameter values at which slow combination phases exist. The fourth solution occurs in the absence of slow phases away from parametric resonance domains and the fractional parameter values.

2011-01-01

241

An S-brane solution with acceleration and small enough variation of G  

CERN Document Server

An S-brane solution with two non-composite electric branes and a set of l scalar fields is considered. The intersection rule for branes corresponds to the Lie algebra A_2. The solution contains five factor spaces with the fifth one interpreted as ``our'' 3-dimensional space. It is shown that there exists a time interval where accelerating expansion of ``our'' 3-dimensional space is compatible with small enough value of effective gravitational ``constant'' variation.

2007-01-01

242

Amplitude-real-phase exact solutions for quantum mixmaster universes  

Energy Technology Data Exchange (ETDEWEB)

We present a set of exact solutions for quantum Bianchi type-IX anisotropic cosmological models (including the Taub model) of the form {Psi}={ital We}{sup {minus}{ital S}}. These solutions are spread over all values of anisotropy near the singularity, but at larger values of the radius of the universe they are strongly peaked around the {ital k}=+1 Friedmann-Robertson-Walker model.

1991-10-15

243

Adsorption of di-2-ethylhexylphosphoric acid from toluene the interface with inorganic salt aqueous solutions  

International Nuclear Information System (INIS)

Interfacial tension in the system toluene solution of di-2-ethylhexylphosphoric acid HDEHP-aqueous solutions of inorganic salts has been measured by the drop volume method. The ion-exchange constants in the monolayers formed by HDEHP and alkaline-earth metals have been measured.

244

A method for making a drilling mud  

Energy Technology Data Exchange (ETDEWEB)

A method is proposed for making a drilling mud, which includes mixing of an aqueous solution of a water soluble acrylic polymer with clay. It is distinguished by the fact that in order to reduce the corrosion activity of the clay solution, the dry clay is slaked in an aqueous solution of partially hydrolized polyacrylonitrile with the following component relationship (in percent by mass): clay, 3 to 10; hydrolized polyacrylonitrile, 3 to 5 and water, the remainder.

1983-01-01

245

Study of Nordgren's equation of hydraulic fracturing  

Science.gov (United States)

A nonlinear partial differential equation modeling the propagation of a vertical hydraulic fracture first derived by Nordgren is studied. When properly posed, Nordgren's derivation constitutes a Stefan problem and requires another boundary condition-namely, that the velocity of the fluid at the crack tip equals the velocity of crack propagation. With this addition, Nordgren's similarity solution in the no-leakoff case is perfected by a power-series solution. New shut-in solutions are derived in the large-and-no-leakoff cases where the crack of the large-leakoff shut-in solution retracts and the crack of the no-leakoff shut-in solution extends forever. This study ignores the effect of crack-tip rock strength on crack propagation.

1990-08-01

246

Solubility of AmOHCO{sub 3} in aqueous solution under atmospheric conditions  

Energy Technology Data Exchange (ETDEWEB)

Modeling calculations on the solubility of americium have indicated that basic americium carbonate, and not americium trihydroxide, is the solubility-controlling solid in the pH range from 6 to 10 under the influence of atmospheric CO{sub 2}. The solubility of crystalline {sup 243}AmOHCO{sup 3} has been investigated in batch experiments in near-neutral and basic solutions as a function of dissolution time in 0.1 M NaClO{sup 4} at room temperature under oxic conditions. After the solutions reached steady-state conditions, the influence of dissolved solids on the americium concentration in the supernatant solution was studied by utilizing several experimental methods to separate the solution phase from the solid. The solids were characterized by X-ray powder diffraction analysis.

1987-12-01

247

Preparation of tetravalent praseodymium in potassium phosphotungstate aqueous solutions  

International Nuclear Information System (INIS)

The possibility has been studied of oxidizing Prsup((3)) to Prsup((4)) when Prsup((3)) is added to an aqueous weakly-acid solution containing K_1_0[P_2W_1_7O_6_1H_2O] x H_2O. A sharp change in the solution colouring has been observed as a result of Prsup((3)) oxidation to Prsup((4)). The absorption spectra of solution of Prsup((4)) have been recorded and the values of the molar extinction coefficients have been determined. On storage of the solution, Prsup((4))reduces to Prsup((3)) with a half-reduction period of 0.2-0.5 hour.

1977-01-01

248

Prediction of thermal conductivity of ethylene glycol-water solutions by using artificial neural networks  

British Library Electronic Table of Contents (United Kingdom)

The objective of this study is to develop an artificial neural network (ANN) model to predict the thermal conductivity of ethylene glycol-water solutions based on experimentally measured variables. The thermal conductivity of solutions at different concentrations and various temperatures was measured using the cylindrical cell method that physical properties of the solution are being determined fills the annular space between two concentric cylinders. During the experiment, heat flows in the radial direction outwards through the test liquid filled in the annual gap to cooling water. In the steady state, conduction inside the cell was described by the Fourier equation in cylindrical coordinates, with boundary conditions corresponding to heat transfer between the solution and cooling water. ...

2009-01-01

249

Inhomogeneous mixmaster universes: Some exact solutions  

Energy Technology Data Exchange (ETDEWEB)

Algorithms for generating new exact solutions of the Einstein-Klein-Gordon field equations, which describe inhomogeneous universes with S/sup 3/ topology of spatial sections, are developed. The known exact vacuum and still-fluid solutions with S/sup 3/ topology are used as an input. The methods developed are further applied to derive inhomogeneous generalizations of Bianchi type IX solutions and inhomogeneous S/sup 3/ Gowdy models with gravitational and scalar waves. It is shown that the new solutions, which are generalizations of the Bianchi type IX models, permit identification of the scalar field with the velocity potential of the stiff irrotational fluid. The latter result is further used to study the growth rate of density perturbations of the isotropic and anisotropic Bianchi type IX universes in a fully nonlinear relativistic regime. The role of anisotropy on the rate of growth of density ...

1983-10-15

250

Inhomogeneous mixmaster universes: Some exact solutions  

International Nuclear Information System (INIS)

Algorithms for generating new exact solutions of the Einstein-Klein-Gordon field equations, which describe inhomogeneous universes with S"3 topology of spatial sections, are developed. The known exact vacuum and still-fluid solutions with S"3 topology are used as an input. The methods developed are further applied to derive inhomogeneous generalizations of Bianchi type IX solutions and inhomogeneous S"3 Gowdy models with gravitational and scalar waves. It is shown that the new solutions, which are generalizations of the Bianchi type IX models, permit identification of the scalar field with the velocity potential of the stiff irrotational fluid. The latter result is further used to study the growth rate of density perturbations of the isotropic and anisotropic Bianchi type IX universes in a fully nonlinear relativistic regime. The role of anisotropy on the rate of growth of density perturbations is ...

251

Extraction of americium of different oxidation states in two-phase aqueous system based on polyethylene glycol  

International Nuclear Information System (INIS)

Americium extraction in different oxidation states in two-phase aqueous system based on polyethylene glycol is investigated. Conditions for quantitative extraction of americium (3) and americium (5) from ammonium sulfate solutions within pH=3-5 interval in the presence of arsenazo 3 are found. Composition of the produced americium complexes with reagent is determined; americium (3) interacts with arsenazo 3 in ammonium sulfate solutions with the formation of MeR and Me_2R composition complexes. Absorption spectrum characteristics of americium (3) and- (5) complexes with arsenazo 3 in ammonium sulfate solutions and extracts based polyethylene glycol aqueous solutions are given. Molar extinction coefficients of americium complexes with arsenazo (3) in these solutions are determined.

1987-01-01

252

An anisotropic mesh adaptation method for the finite element solution of heterogeneous anisotropic diffusion problems  

CERN Document Server

Heterogeneous anisotropic diffusion problems arise in the various areas of science and engineering including plasma physics, petroleum engineering, and image processing. Standard numerical methods can produce spurious oscillations when they are used to solve those problems. A common approach to avoid this difficulty is to design a proper numerical scheme and/or a proper mesh so that the numerical solution validates the discrete counterpart (DMP) of the maximum principle satisfied by the continuous solution. A well known mesh condition for the DMP satisfaction by the linear finite element solution of isotropic diffusion problems is the non-obtuse angle condition that requires the dihedral angles of mesh elements to be non-obtuse. In this paper, a generalization of the condition, the so-called anisotropic non-obtuse angle condition, is developed for the finite element solution of heterogeneous anisotropic ...

2010-01-01

253

Achieving a vanishing SNR-gap to exact lattice decoding at a subexponential complexity  

CERN Document Server

The work identifies the first lattice decoding solution that achieves, in the general outage-limited MIMO setting and in the high-rate and high-SNR limit, both a vanishing gap to the error-performance of the (DMT optimal) exact solution of preprocessed lattice decoding, as well as a computational complexity that is subexponential in the number of codeword bits. The proposed solution employs lattice reduction (LR)-aided regularized (lattice) sphere decoding and proper timeout policies. These performance and complexity guarantees hold for most MIMO scenarios, all reasonable fading statistics, all channel dimensions and all full-rate lattice codes. In sharp contrast to the above manageable complexity, the complexity of other standard preprocessed lattice decoding solutions is shown here to be extremely high. Specifically the work is first to quantify the complexity of these lattice (sphere) decoding ...

2011-01-01

254

Removal of lead from solution using non-living residual brewery yeast  

Energy Technology Data Exchange (ETDEWEB)

A number of preparations of residual non-living brewery yeast were examined for their ability to remove lead from solution. Those preparations included washed and un-washed intact yeast and washed and un-washed homogenates of the yeast cells. Using biosorption isotherm analysis it was found that the washed and un-washed preparations of intact, non-living yeast exhibited maximum biosorption capacities for lead of 127 and 99 mg/g dry weight biomass, respectively. The washed and un-washed cell homogenates exhibited maximum biosorption capacities of 38 and 139 mg lead/g dry weight biomass, respectively. Since it had previously been shown that these preparations of biomass were capable of removing uranium from solution by combined biosorption and precipitation processes, it was decided to examine removal of lead from solution using a form of equilibrium dialysis in which the biomass was retained within a semi-permeable membrane ...

1998-10-01

255

Passivation behavior of SUS 304 stainless steel in neutral solutions at elevated temperature  

International Nuclear Information System (INIS)

Cyclic voltammograms of SUS 304 stainless steel in various neutral solutions such as Na_2SO_4 at high temperature were measured, as a successive study to previous report in which effects of temperature and pH on polarization behavior of stainless steel were studied. In this measurement Ag/AgCl reference electrode and platinum counter electrode were used in a static autoclave lined with inconel. Passive films formed in various conditions were analysed by electron diffraction and Auger spectroscopy. Results obtained were compared with anodic behavior of iron, chromium and nickel and with thermodynamical stabilities of their compounds. The main results are summarized as follows. (1) Stainless steel shows such electrochemical behavior as active dissolution, passivation and transpassivation in a deaerated neutral solution at 250"0C after fully reductive treatment of the specimen. In air-saturated solution, the peak of active ...

1981-01-01

256

Microrheological Studies of Regenerated Silk Fibroin Solution by Video Microscopy  

CERN Document Server

We have carried out studies on the rheological properties of regenerated silk fibroin (RSF) solution using video microscopy. The degummed silk from the Bombyx mori silkworm was used to prepare RSF solution by dissolving it in calcium nitrate tetrahydrate-methanol solvent. Measurements were carried out by tracking the position of an embedded micron-sized polystyrene bead within the RSF solution through video imaging. The time dependent mean squared displacement (MSD) of the bead in solution and hence, the complex shear modulus of this solution was calculated from the bead's position information. An optical tweezer was used to transport and locate the bead at any desired site within the micro-volume of the sample, to facilitate the subsequent free-bead video analysis. We present here the results of rheological measurements of the silk polymer network in solution ...

2007-01-01

257

Holomorphic wave function of the Universe  

Energy Technology Data Exchange (ETDEWEB)

The quantum behavior of the vacuum Bianchi type-IX universe with the cosmological constant is investigated in terms of the Ashtekar variables. An exact solution to the quantum Hamiltonian constraint in the holomorphic representation is given. This solution reduces to the Hartle-Hawking wave function in the spatially isotropic sector and extends in the triad representation to the classically forbidden region where the determinant of the spatial metric becomes negative. The analysis of the quantum Robertson-Walker universe indicates that if the superspace is extended to such a classically forbidden region, the holomorphic representation picks up some restricted class of solutions in general. This observation leads to a new ansatz on the boundary condition of the Universe. In particular, the behavior of the Lorentzian and Euclidean WKB orbits corresponding to the solution suggests a new picture on the ...

1990-10-15

258

Holomorphic wave function of the Universe  

International Nuclear Information System (INIS)

The quantum behavior of the vacuum Bianchi type-IX universe with the cosmological constant is investigated in terms of the Ashtekar variables. An exact solution to the quantum Hamiltonian constraint in the holomorphic representation is given. This solution reduces to the Hartle-Hawking wave function in the spatially isotropic sector and extends in the triad representation to the classically forbidden region where the determinant of the spatial metric becomes negative. The analysis of the quantum Robertson-Walker universe indicates that if the superspace is extended to such a classically forbidden region, the holomorphic representation picks up some restricted class of solutions in general. This observation leads to a new ansatz on the boundary condition of the Universe. In particular, the behavior of the Lorentzian and Euclidean WKB orbits corresponding to the solution suggests a new picture on the ...

259

Effect of fluoride ion on the pitting corrosion of type 304 stainless steel in neutral NaCl solution. Chusei NaCl suiyoekichu ni okeru SUS 304 ko no koshoku ni oyobosu F[sup -] no eikyo  

Energy Technology Data Exchange (ETDEWEB)

Anode polarization measurement is performed in mixed solution of NaCl and NaF using SUS 304 steel to investigate whether F[sup -] promotes or inhibits pitting corrosion. Pitting corrosion does not occur in the solution of NaF only, but passive state is broken above a certain critical potential, resulting in overall dissolution. When anode polarization measurement is made in a solution of fixed concentration NaCl added with NaF, pitting corrosion is inhibited at a certain critical concentration. F[sup -] has no effect on corrosion potential in the solution up to this critical concentration. Overall dissolution occurs in the solution with higher concentration than the critical concentration, the current value at that time agrees with that in the solution of NaF alone, and no effect of Cl[sup -] is shown. The concentration range where pitting corrosion occurs and ...

1994-05-15

260

Chromium stabilization chemistry of paint removal wastes in Portland cement and blast furnace slag  

Energy Technology Data Exchange (ETDEWEB)

The use of cement based systems for solidification and stabilization of hazardous wastes has been proposed. The stabilization of Cr contaminated paint removal wastes in ordinary Portland cement and in a Portland cement and blast furnace slag matrix was investigated. A loading by volume of 75% waste and 25% cement (or cement + slag) was used. The expression of pore solution was utilized to determine the chemical environment encountered by the waste species in the cement matrix. The highly alkaline conditions of ordinary Portland cement determined the stability of the metal species, with Cr being highly soluble. The replacement of 25% of the Portland cement by blast furnace slag was found to decrease the [OH-] of the pore solution resulting in a decrease of the Cr concentration. For cement wastes forms hydrated for 28 days, the Cr concentration decreased in the expressed pore solution. During the TCLP tests the cement waste ...

1995-12-31

261

The interaction of Np(V), Pu(VI) and Tc(VII) with metal in alkaline solutions  

International Nuclear Information System (INIS)

The interaction of Np(V), Pu(VI) and Tc(VII) with metal reductants Zn, Cr, Sn and their alloys was investigated in 0.5-4 mol l"-"1 NaOH solutions in static and dynamic conditions (by filtration of solutions through the column filled with grains of metal). In this paper, it was found that the reduction and succeeding precipitation hydroxides of these elements, on the surface of metal grains from 0.5 to 4 mol l"-"1 NaOH solutions, gives a decontamination factor (DF) from 1.1 to 67. The best result was achieved for Pu (DF=67) on Cr grains after 2.5 h contact at 60 C with 0.5 mol l"-"1 NaOH solution containing Pu(VI). Increasing the NaOH concentration, and the addition of chromate ions and complex-forming agents to alkaline solution results in a decrease of the decontamination factor (DF). A better result for Np sorption from 1 mol l"-"1 NaOH solutions was achieved ...

1998-06-12

262

Enrichment of trace cadmium by soybean protein for the analysis by atomic absorption method  

International Nuclear Information System (INIS)

A method for enrichment of the ppb level of cadmium in water by using the coagulation of soybean protein by adding acids or its complex-forming character with heavy metal ions was investigated. After adding fixed amounts of soybean milk and 2% sodium diethyldithiocarbamate(DDTC) aqueous solution and a suitable amount of delta-gluconic lactone (delta-GL) to a sample solution, the mixture was heated to boiling in order to coagulate the protein. The coagulum(soybean curd) was separated from the suspension by centrifugation and burned to ashes with a low temperature plasma asher. Then the cadmium enriched in it was determined by atomic absorption spectrometry. Various factors such as the pH of the sample solution, the amounts of soybean milk and the collection additives, and the concentration of NaCl in the sample solution on the recovery of cadmium were examined systematically. The best recovery was ...

1975-01-01

263

Electronic structure and pitting behavior of 3003 aluminum alloy passivated under various conditions  

International Nuclear Information System (INIS)

Passivity of aluminum (Al) alloy 3003 in air and in aqueous solutions without and with chloride ions was characterized by electrochemical measurements, including cyclic polarization, electrochemical impedance spectroscopy (EIS), localized EIS and potential of zero charge, Mott-Schottky analysis and secondary ion mass spectroscopy (SIMS) technique. Stability, pitting susceptibility and repassivation ability of Al alloy 3003 under various film-forming conditions were determined. Results demonstrated that passive films formed on 3003 Al alloy in air and in Na2SO4 solution without and with NaCl addition show an n-type semiconductor in nature. The passive film formed in chloride-free solution is most stable, and that formed in chloride-containing solution is most unstable, with the film formed in air in between. Pitting of Al alloy 3003 passivated both in air and in aqueous solutions is ...

2009-07-01

264

The vasopressin mRNA poly(A) tract is unusually long and increases during stimulation of vasopressin gene expression in vivo  

Energy Technology Data Exchange (ETDEWEB)

The authors developed a method, termed an H-blot, by which the poly(A) tract of any specific mRNA may be detected by RNA filter hybridization after its removal from the body of the mRNA by a RNase H-catalyzed endonucleolytic cleavage in the 3' untranslated region. Using this method, they studied the modulation of the length of the poly(A) tract of rat vasopressin mRNA in vivo during changes in the levels of this mRNA resulting from a physiologic stimulus, osmotic stress. The poly(A) tract of hypothalamic vasopressin mRNA in hydrated rats was, quite remarkably, --250 nucleotides in length, in contrast to that of somatostatin mRNA, which was --30 nucleotides long. Vasopressin mRNA poly(A) tail length increased progressively from --250 to --400 nucleotides with the application of the hyperosmotic stimulus and declined to base line after its removal; somatostatin mRNA poly(A) tail length did not change during osmotic stress. The poly(A) tract length of total ...

1988-06-01

265

The CYP2A3 gene product catalyzes coumarin 7-hydroxylation in human liver microsomes  

Energy Technology Data Exchange (ETDEWEB)

Three cDNAs, designated IIA3, IIA3v, and IIA4, coding for P450s in the CYP2A gene subfamily were isolated from a {lambda}gt11 library prepared from human hepatic mRNA. Only three nucleotide differences and a single amino acid difference, Leu{sup 160}{yields}His, were found between IIA3 and IIA3v, indicating that they are probably allelic variants. IIA4 displayed 94% amino acid similarity with IIA3 and IIA3v. The three cDNAs were inserted into vaccinia virus, and recombinant viruses were used to infect human hepatoma Hep G2 cells. Only IIA3 was able to produce an enzyme that had a reduced CO-bound spectrum with a {lambda}{sub max} at 450 nm. This expressed enzyme was able to carry out coumarin 7-hydroxylation and ethoxycoumarin O-deethylation. cDNA-expressed IIA3v and IIA4 failed to incorporate heme and were enzymatically inactive. Analysis of IIA proteins in human liver microsomes, using antibody against rat IIA2, revealed two proteins of 49 and 50 kDa, the former of which appeared to ...

1990-02-06

266

The CYP2A3 gene product catalyzes coumarin 7-hydroxylation in human liver microsomes  

International Nuclear Information System (INIS)

Three cDNAs, designated IIA3, IIA3v, and IIA4, coding for P450s in the CYP2A gene subfamily were isolated from a #lambda#gt11 library prepared from human hepatic mRNA. Only three nucleotide differences and a single amino acid difference, Leu"1"6"0#->#His, were found between IIA3 and IIA3v, indicating that they are probably allelic variants. IIA4 displayed 94% amino acid similarity with IIA3 and IIA3v. The three cDNAs were inserted into vaccinia virus, and recombinant viruses were used to infect human hepatoma Hep G2 cells. Only IIA3 was able to produce an enzyme that had a reduced CO-bound spectrum with a #lambda#_m_a_x at 450 nm. This expressed enzyme was able to carry out coumarin 7-hydroxylation and ethoxycoumarin O-deethylation. cDNA-expressed IIA3v and IIA4 failed to incorporate heme and were enzymatically inactive. Analysis of IIA proteins in human liver microsomes, using antibody against rat IIA2, revealed two proteins of 49 and 50 kDa, the former of which appeared to ...

1990-02-01

267

Synthesis of (methine- sup 3 H)DDT and its nitro-analog, and isotope effects in their enzyme-catalyzed dehydrochlorination  

Energy Technology Data Exchange (ETDEWEB)

(methine-{sup 3}H)1,1-Di-(4-chlorophenyl)-2,2,2-trichloroethane ((methine-{sup 3}H)DDT) and its di-(4-nitrophenyl) analog, both of high purity with a moderately high specific activity were prepared. Chloro-benzene was condensed with (1-{sup 3}H)1-(4-chlorophenyl)-2,2,2-trichloro-ethanol, which has been synthesized by sodium boro({sup 3}H)hydride reduction of 4-chlorophenyl trichloromethyl ketone. The purified ({sup 3}H)DDT had a specific activity of 0.77 Ci/mmol (28.49 GBq/mmol). (methine-{sup 3}H)1,1-Diphenyl-2,2,2-trichloroethane was similarly synthesized and was nitrated to give (methine-{sup 3}H)1,1-di-(4-nitrophenyl)-2,2,2-trichloro-ethane of 1.63 Ci/mmol (60.31 GBq/mmol). Dehydrochlorination with housefly enzyme (glutathione-dependent DDT dehydrochlorinase) showed a remarkable isotope effect. For DDT, the observed tritium isotope effect on V{sub max}/K{sub m} was 11.51{plus minus}0.52. For the nitro-analog, the value was 11.3{plus minus}1.2. We measured deuterium isotope effect ...

1989-08-01

268

Synthesis and photo-degradation application of WO3/TiO2 hollow spheres.  

Science.gov (United States)

A WO(3)/TiO(2) composite, hollow-sphere photocatalyst with average diameter of 320 nm and shell thickness of 50 nm was successfully prepared using a template method. UV-vis diffuse reflectance spectra illustrated that the main absorption edges of the WO(3)/TiO(2) hollow spheres were red-shifted compared to the TiO(2) hollow spheres, indicating an extension of light absorption into the visible region of the composite photocatalyst. The WO(3) and TiO(2) phases were confirmed by X-ray diffraction analysis. BET isotherms revealed that the specific surface area and average pore diameter of the hollow spheres were 40.95 m(2)/g and 19 nm, respectively. Photocatalytic experiments indicate that 78% MB was degraded by WO(3)/TiO(2) hollow spheres under visible light within 80 min. Under the same conditions, only 24% MB can be photodegraded by TiO(2). The photocatalytic mineralization of MB, catalyzed by TiO(2) and WO(3)/TiO(2), proceeded at a significantly higher rate under ...

2011-02-22

269

Surface modification of functional self-assembled monolayers on 316L stainless steel via lipase catalysis.  

Science.gov (United States)

Lipase catalyzed esterification of therapeutic drugs to functional self-assembled monolayers (SAMs) on 316L stainless steel (SS) after assembly has been demonstrated. SAMs of 16-mercaptohexadecanoic acid (-COOH SAM) and 11-mercapto-1-undecanol (-OH SAM) were formed on 316L SS, and lipase catalysis was used to attach therapeutic drugs, perphenazine and ibuprofen, respectively, on these SAMs. The reaction was carried out in toluene at 60 degrees C for 5 h using Novozyme-435 as the biocatalyst. The FTIR spectra after surface modification of -OH SAMs showed the presence of the C=O stretching bands at 1745 cm(-1), which was absent in the FTIR spectra of -OH SAMs. Similarly, the FTIR spectra after the reaction of the -COOH SAM with perphenazine showed two peaks in the carbonyl region, a peak at 1764 cm(-1), which is the representative peak for the C=O stretching for esters. The second peak at 1681 cm(-1) is assigned to the C=O stretching of the remaining unreacted ...

2006-01-31

270

Structures of trihydroxynaphthalene reductase-fungicide complexes: implications for structure-based design and catalysis  

Energy Technology Data Exchange (ETDEWEB)

Trihydroxynaphthalene reductase catalyzes two intermediate steps in the fungal melanin biosynthetic pathway. The enzyme, a typical short-chain dehydrogenase, is the biochemical target of three commercial fungicides. The fungicides bind preferentially to the NADPH form of the enzyme. Three X-ray structures of the Magnaporthe grisea enzyme complexed with NADPH and two commercial and one experimental fungicide were determined at 1.7 {angstrom} (pyroquilon), 2.0 {angstrom} (2,3-dihydro-4-nitro-1H-inden-1-one, 1), and 2.1 {angstrom} (phthalide) resolutions. The chemically distinct inhibitors occupy similar space within the enzyme's active site. The three inhibitors share hydrogen bonds with the side chain hydroxyls of Ser-164 and Tyr-178 via a carbonyl oxygen (pyroquilon and 1) or via a carbonyl oxygen and a ring oxygen (phthalide). Active site residues occupy similar positions among the three structures. A buried water molecule that is hydrogen bonded to the ...

2010-03-08

271

Regulation of the phosphoinositide pathway in cultured Sertoli cells from immature rats: effects of follicle-stimulating hormone and fluoride  

International Nuclear Information System (INIS)

Many hormones elicit effects on target cells by stimulating the enzyme phospholipase-C, which catalyzes the hydrolysis of phosphoinositides to the intracellular second messengers diacylglycerol and inositol phosphates. The present study examined the roles of FSH and guanine nucleotide-binding proteins (G-proteins) in regulating the hydrolysis of phosphoinositides in Sertoli cells. Sertoli cell cultures prepared from 16- to 18-day-old rats were incubated for 24 h with myo-[2-3H] inositol to label endogenous phospholipids. Treatment of cells from 0.5-20 min with preparations of ovine FSH ranging in potency from 1-60 times that of NIH FSH S1 did not affect accumulation of inositol phosphates. Levels of total [3H]inositol phosphates [[3H]inositol mono-, di-, and triphosphates (IP, IP2, and IP3)] in FSH-treated cultures was 75-120% the levels in control cultures over the various time intervals studied. Addition of testosterone and the combination of testosterone plus ...

272

Part III. Direct enzymatic esterification of lactic acid with fatty acids.  

Science.gov (United States)

Lipase catalyzed esterification reactions between lactic acid and several fatty acids have been studied. Difficulties arise in esterifying lactic acid because of the potential for this substance to act both as an acyl donor and as a nucleophile. These difficulties were minimized via strategies which greatly increased the yield of the desired ester. Use of the companion fatty acid in excess with respect to lactic acid in an apolar solvent (n-hexane) in which the lactic is not completely dissolved has been employed to minimize the potential for lactic acid to act as an acyl donor in a self-polymerization reaction.Beneficial and sinergistic effects of both silica gel and molecular sieves on conversion to the desired product are described. However, careful control of the amount of molecular sieves used is required. This fact is a consequence of two opposing effects of this material: i.e. adsorption of both lactic acid and water from the reaction mixture. For reaction ...

2001-07-01

273

Oxidation and ammoxidation of propylene to acrolein and acrylonitrile with bismuth molybdates  

Energy Technology Data Exchange (ETDEWEB)

Under appropriate conditions, bismuth molybdates can catalyze a number of transformations of olefins with selective oxidation being of particular importance. Experimental evidence suggests that the propylene is activated to an allylic species by a site associated with the Bi and that the oxidation step occurs at an Mo site. In order to address the mechanistic steps associated with these Mo sites. The authors discuss the chemistry of terminal oxo and imido groups. They find that for surface sites such as 1 about, 2 about and 3 about, the presence of two double bonds leads to a much more active species than those with a single multiple bond. This leads to a situation similar to that in olefin metathesis by high oxidation state Mo catalysis where the (spectator) oxo group species promotes formation of the metallacycle intermediate by formation of a partial Mo==O triple bond that stabilizes the intermediate. Calculations suggest that the magnitude of the spectator oxo ...

1983-09-01

274

Molecular cloning, genomic organization, and expression of a testicular isoform of hormone-sensitive lipase  

Energy Technology Data Exchange (ETDEWEB)

By catalyzing the rate-limiting step in adipose tissue lipolysis, hormone-sensitive lipase (HSL) is an important regulator of energy homeostasis. The role and importance of HSL in tissues other than adipose are poorly understood. We report here the cloning and expression of a testicular isoform, designated HSL{sub tes}. Due to an addition of amino acids at the NH{sub 2}-termini, rat and human HSL{sub tes} consist of 1068 and 1076 amino acids, respectively, compared to the 768 and 775 amino acids, respectively, of the adipocyte isoform (HSL{sub adi}). A novel exon of 1.2 kb, encoding the human testis-specific amino acids, was isolated and mapped to the HSL gene, 16 kb upstream of the exons encoding HSL{sub adi}. The transcribed mRNA of 3.9 kb was specifically expressed in testis. No significant similarity with other known proteins was found for the testis-specific sequence. The amino acid composition differs from the HSL{sub adi} sequence, with a notable hydrophilic ...

1996-08-01

275

Mobil/Badger to market zeolite-based cumene technology  

Energy Technology Data Exchange (ETDEWEB)

Badger (Cambridge, MA) and Mobil (Fairfax, VA) are ready to jointly license a new cumene technology that they say achieves higher yields and product purity than existing processes. The zeolite-based technology is scheduled to be introduced at next month's DeWitt Petrochemical Review in Houston. The Mobil/Badger technology aims to challenge the dominant position of UOP's (Des Plaines, IL) solid phosphoric acid (SPA) catalyst process - which accounts for 80%-90% of the world's cumene production. In addition, Monsanto/Kellogg's aluminum chloride-based technology has gained significant momentum since its introduction in the 1980s. And late last year, ABB Lummus Crest (Bloomfield, NJ) also began marketing a zeolite-based cumene technology. While all the technologies make cumene via the alkylation of benzene with propylene, the Mobil/Badger process uses a zeolite-containing catalyst designed by Mobil to selectively catalyze the ...

1993-02-24

276

Measurement of 12(S)-hydroxy-5Z,8E,10E-heptadecatrienoic acid and its metabolite 12-oxo-5Z,8E,10E-heptadecatrienoic acid in human plasma by gas chromatography/negative ion chemical ionization mass spectrometry  

International Nuclear Information System (INIS)

Thromboxane A2, the predominant product of arachidonic acid metabolism in the blood platelet, is a potent vasoconstrictor and platelet agonist. During its biosynthesis from cyclic endoperoxide, 12(S)-hydroxy-5Z,8E,10E-heptadecatrienoic acid (HHT) is formed in equal amounts. The further metabolism of HHT, catalyzed by 15-hydroxyprostaglandin dehydrogenase, leads to 12-oxo-5Z,8E,10E-heptadecatrienoic acid (Oxo-HT). Sample workup procedures are described which allow for the sensitive and reproducible determination of these two arachidonic acid metabolites in human plasma by gas chromatography-mass spectrometry in the presence of deuterated analogues as internal standards. HHT is derivatized to the pentafluorobenzyl ester tert-butyldimethylsilyl ether. In order to enable quantification of low concentrations of about 10 pg/ml in nonstimulated human plasma, the samples have to be purified by HPLC. Oxo-HT is derivatized to the pentafluorobenzyl ester, which is purified by ...

1990-01-01

277

High performance polymer electrolyte fuel cells with ultra-low Pt loading electrodes prepared by dual ion-beam assisted deposition  

International Nuclear Information System (INIS)

Ultra-low pure Pt-based electrodes (0.04-0.12 mg_P_t/cm"2) were prepared by dual ion-beam assisted deposition (dual IBAD) method on the surface of a non-catalyzed gas diffusion layer (GDL) substrate. Film thicknesses ranged between 250 and 750 A, these are compared with a control, a conventional Pt/C (1.0 mg_P_t_(_M_E_A_)/cm"2, E-TEK). The IBAD electrode constituted a significantly different morphology, where low density Pt deposits (largely amorphous) were formed with varying depths of penetration into the gas diffusion layer, exhibiting a gradual change towards increasing crystalline character (from 250 to 750 A). Mass specific power density of 0.297 g_P_t/kW is reported with 250 A IBAD deposit (0.04 mg_P_t/cm"2 for a total MEA loading of 0.08 mg_P_t/cm"2) at 0.65 V. This is contrasted with the commercial MEA with a loading of 1 mg_P_t_(_M_E_A_)/cm"2 where mass specific power density obtained was 1.18 g_P_t/kW (at 0.65 V), a value typical of current state of the ...

2006-06-05

278

Fe(CO)5-catalyzed coprocessing of coal and heavy oil vacuum residue using syngas-water as a hydrogen source; Fe(CO)5 shokubai ni yoru gosei gas-mizu wo suisogen to suru sekitan-jushitsuyu no coprocessing  

Energy Technology Data Exchange (ETDEWEB)

Improvement in efficiency and profitability of hydrogenation reaction of heavy hydrocarbon resources is the most important matter to be done. In this study, coprocessing of coal and heavy oil vacuum residue was conducted using syngas-water as a hydrogen source. For the investigation of effect of the reaction temperature during the coprocessing of Wandoan coal and Arabian heavy vacuum residue using Fe(CO)5 as a catalyst, the conversion, 66.0% was obtained at 425{degree}C. For the investigation of effect of reaction time, the yield of light fractions further increased during the two stage reaction at 400{degree}C for 60 minutes and at 425{degree}C for 60 minutes. Finally, almost 100% of THF-soluble matter was obtained through the reaction using 2 mmol of Fe(CO)5 catalyst at 400{degree}C for 60 minutes, and hydrogenation of heavy oil was proceeded simultaneously. When comparing coprocessing reactions using three kinds of hydrogen sources, i.e., hydrogen, CO-water, and syngas-water, the ...

1996-10-28

279

Enhanced activity and interfacial durability study of ultra low Pt based electrocatalysts prepared by ion beam assisted deposition (IBAD) method  

International Nuclear Information System (INIS)

Ultra low loading noble metal (0.04-0.12 mg_P_t/cm"2) based electrodes were obtained by direct metallization of non-catalyzed gas diffusion layers via dual ion beam assisted deposition (IBAD) method. Fuel cell performance results reported earlier indicate significant improvements in terms of mass specific power density of 0.297 g_P_t/kW with 250 A thick IBAD deposit (0.04 mg_P_t/cm"2 for a total MEA loading of 0.08 mg_P_t/cm"2) at 0.65 V in contrast to the state of the art power density of 1.18 g_P_t/kW using 1 mg_P_t_(_M_E_A_)/cm"2 at 0.65 V. In this article we report the peroxide radical initiated attack of the membrane electrode assembly utilizing IBAD electrodes in comparison to commercially available E-TEK (now BASF Fuel Cell GmbH) electrodes and find the pathway of membrane degradation as well. A novel segmented fuel cell is used for this purpose to relate membrane degradation to peroxide generation at the electrode/electrolyte interface by means of ...

2009-11-01

280

Crystal Structure of Human Senescence Marker Protein 30: Insights Linking Structural, Enzymatic, and Physiological Functions  

Energy Technology Data Exchange (ETDEWEB)

Human senescence marker protein 30 (SMP30), which functions enzymatically as a lactonase, hydrolyzes various carbohydrate lactones. The penultimate step in vitamin-C biosynthesis is catalyzed by this enzyme in nonprimate mammals. It has also been implicated as an organophosphate hydrolase, with the ability to hydrolyze diisopropyl phosphofluoridate and other nerve agents. SMP30 was originally identified as an aging marker protein, whose expression decreased androgen independently in aging cells. SMP30 is also referred to as regucalcin and has been suggested to have functions in calcium homeostasis. The crystal structure of the human enzyme has been solved from X-ray diffraction data collected to a resolution of 1.4 {angstrom}. The protein has a 6-bladed {beta}-propeller fold, and it contains a single metal ion. Crystal structures have been solved with the metal site bound with either a Ca{sup 2+} or a Zn{sup 2+} atom. The catalytic role of the metal ion has been ...

2010-05-25

281

Composition, structure and evolution of neutron stars with kaon condensates  

International Nuclear Information System (INIS)

We investigate the possibility of kaon condensation in the dense interior of neutron stars through the s-wave interaction of kaons with nucleons. We include nucleon-nucleon interactions by using simple parametrizations of realistic forces, and include electrons and muons in #beta#-equilibrium. The equation of state above the condensate threshold is derived in the mean field approximation. The conditions under which kaon condensed cores undergo a transition to quark matter containing strange quarks are also established.The critical density for kaon condensation lies in the range (2.3-5.0)#rho#_0, where #rho#_0=0.16 fm"-"3 is the equilibrium density of nuclear matter. The critical density depends largely on the value of the strangeness content of the proton, the size of which is controversial. For too large a value of the strangeness content, matter with a kaon condensate is not sufficiently stiff to support the lower limit of 1.44 M_o_e_d_o_t for a neutron star. Kaon condensation ...

282

Catalytic hydrocarbon reactions over supported metal oxides. Progress report, April 1, 1994--January 31, 1995  

Energy Technology Data Exchange (ETDEWEB)

Oxide catalysis plays a central role in hydrocarbon processing and improvements in catalytic activity or selectivity are of great technological importance because these improvements will translate directly into more efficient utilization of hydrocarbon supplies and lower energy consumption in separation processes. An understanding of the relationships between surface structure and catalytic properties is needed to describe and improve oxide catalysts. Our approach has been to prepare supported oxides that have a specific structure and oxidation state and then employ these structures in reaction studies. Our current research program is focused on studying the fundamental relationships between structure and reactivity for two important reactions that are present in many oxide-catalyzed processes, partial oxidation and carbon-carbon bond formation. Oxide catalysis can be a complex process with both metal cation and oxygen anions participating in the chemical ...

1995-01-31

283

Biological and Chemical Security  

Science.gov (United States)

The LLNL Chemical & Biological National Security Program (CBNP) provides science, technology and integrated systems for chemical and biological security. Our approach is to develop and field advanced strategies that dramatically improve the nation's capabilities to prevent, prepare for, detect, and respond to terrorist use of chemical or biological weapons. Recent events show the importance of civilian defense against terrorism. The 1995 nerve gas attack in Tokyo's subway served to catalyze and focus the early LLNL program on civilian counter terrorism. In the same year, LLNL began CBNP using Laboratory-Directed R&D investments and a focus on biodetection. The Nunn-Lugar-Domenici Defense Against Weapons of Mass Destruction Act, passed in 1996, initiated a number of U.S. nonproliferation and counter-terrorism programs including the DOE (now NNSA) Chemical and Biological Nonproliferation Program (also known as CBNP). In 2002, the Department ...

2002-12-19

284

The effect of precipitated carbides on the pitting corrosion of 304 stainless steel  

International Nuclear Information System (INIS)

In order to investigate the relation between the pitting corrosion and precipitated carbides, the heat treatment of specimens was carried out in two ways: Solution treatment and carbides precipitation treatment. The experiment was focused on the polarization curves of specimens immersed in HCL solution and on the microscopic analysis of the corroded specimens through a potentiodynamic method. It was found out that the intergranular and pitting corrosion occurred remarkably in 0.1N and 1N KCL solution when carbides were precipitated around the grain boundary of the 304 stain steel. The intergranular corrosion was noticed in the region of passivation and the pitting was prominent in the region of passivation break-down. The distribution of pits on the solution treated 304 stainless steel was random, while that of pits on carbides precipitated specimen was concentrated around the grain boundary in 0.1N and ...

285

String Junctions and Holographic Interfaces  

CERN Document Server

In this paper we study half-BPS type IIB supergravity solutions with multiple $AdS_3\\times S^3\\times M_4$ asymptotic regions, where $M_4$ is either $T^4$ or $K_3$. These solutions were first constructed in [1] and have geometries given by the warped product of $AdS_2 \\times S^2 \\times M_4 $ over $\\Sigma$, where $\\Sigma$ is a Riemann surface. We show that the holographic boundary has the structure of a star graph, i.e. $n$ half-lines joined at a point. The attractor mechanism and the relation of the solutions to junctions of self-dual strings in six-dimensional supergravity are discussed. The solutions of [1] are constructed introducing two meromorphic and two harmonic functions defined on $\\Sigma$. We focus our analysis on solutions corresponding to junctions of three different conformal field theories and show that the conditions for having a solution ...

2010-01-01

286

Single-Electrode Capacitance and Charged State in Interfacial Region within Nano-Porous Carbon Electrode for Electric Double Layer Capacitor; Kasseitan denki 2jyuso kyapasita no tankyoku seiden yoryo to koeki kaimen chikuden jyotai  

Energy Technology Data Exchange (ETDEWEB)

The single-electrode capacitance of a nano-porous carbon electrode used as an electric double layer capacitor was measured. The charged state of the electrolyte ion was discussed from the results. Single-electrode capacitance was not proportional to the specific surface area of the electrode. This implies that the whole surface of the electrode is not effective for the formation of an electric double layer. It is considered that edge orientation of the carbon structure would give a dominant contribution to capacitance. For measurements with aqueous solutions of various electrolytes, capacitance was about the same value for each salt compound. For aqueous acid solution, on the other hand, capacitance was twice to three times as large as that for salt compounds. This difference, however, became negligibly small if the concentration of electrolyte solution was lowered. Taking account of the hydrated ionic radius of each ion, ...

1997-07-10

287

Processing method and processing facility for carbon steel parts in nuclear power plant  

International Nuclear Information System (INIS)

In a closed circuit formed by bypassing pipelines connected to carbon steel parts, low oxygen coolants pass there through during operation. A solution containing ions of metals more noble than iron are circulated to bring the solution into contact with the carbon steel surface of the inner wall of the parts to form a deposition membrane of the metal more noble than iron on the surface to prevent acceleration of corrosion of the carbon steel parts due to low oxygen coolants. The solution containing ions of metals more noble than iron is a solution of palladium nitrate containing ions of platinum elements. This operation is conducted under a temperature condition of from 50degC to 150degC. In addition, the metal ion concentration of the solution circulating in the closed circuit is measured, it is compared with metal ion concentration previously determined, and the results are feed ...

1996-11-27

288

Prediction of thermal conductivity of ethylene glycol-water solutions by using artificial neural networks  

Energy Technology Data Exchange (ETDEWEB)

The objective of this study is to develop an artificial neural network (ANN) model to predict the thermal conductivity of ethylene glycol-water solutions based on experimentally measured variables. The thermal conductivity of solutions at different concentrations and various temperatures was measured using the cylindrical cell method that physical properties of the solution are being determined fills the annular space between two concentric cylinders. During the experiment, heat flows in the radial direction outwards through the test liquid filled in the annual gap to cooling water. In the steady state, conduction inside the cell was described by the Fourier equation in cylindrical coordinates, with boundary conditions corresponding to heat transfer between the solution and cooling water. The performance of ANN was evaluated by a regression analysis between the predicted and the experimental values. The ...

2009-10-15

289

Method for preparing drilling solutions that are resistant in Zechstein deposits  

Energy Technology Data Exchange (ETDEWEB)

The patent is for a method of preparing drilling muds that are notable for their chemical resistance to Zechstein deposits, especially to magnesium, carbonate and carboxylic acid ions. To achieve chemical resistance of the drilling mud to Zechstein deposits, it is suggested to saturate them with salt (the amount of added salt depends on the absorption properties of the solution), and then to process them with caustic soda or potassium oxide hydrate and lime in proportions that would cause filtrate alkalinity not to exceed 0.5. For example, to prepare drilling solution to bore through mediums containing magnesium salts, potassium salts, rock salt, anhydrate, dolomite, limestone, red salt clay: add 340 kg potassium chloride into 1 m/sup 3/ drilling solution with weighed bentonic clay, 10 kg. ferro-chromate lignosulfite, 7 kg. unslaked lime, 2 kg. sodium hydroxide, 5 kg. carboxy-methyl-cellulose, 5 kg. ...

1980-05-31

290

Influence of temperature on corrosion behavior of PbCaSnCe alloy in 4.5 M H{sub 2}SO{sub 4} solution  

Energy Technology Data Exchange (ETDEWEB)

The temperature effect on corrosion behaviors of PbCaSnCe alloy in 4.5 M H{sub 2}SO{sub 4} solution was investigated by using potentiodynamic curve, electrochemical impedance spectra (EIS), Mott-Schottky plot and photocurrent response methods. It was found that PbCaSnCe alloy was in passive state in sulfuric acid solution, a passive film can be formed on alloy surface. The compositions of passive films formed at 0.9 V for 2 h under different temperatures were detected by X-ray photoelectron spectroscopy (XPS). The results showed that the film resistance and the transfer resistance decreased with the increment of the solution temperature. Mott-Schottky analysis and the photocurrent response revealed that the passive film exhibited n-type semi-conductive character, the donor density of the passive film decreased with increasing the solution temperature. Photocurrent response revealed that the photocurrent ...

2010-01-15

291

Indirect boundary element method for three dimensional problems. Analytical solution for contribution to wave field by triangular element; Sanjigen kansetsu kyokai yosoho. Sankakukei yoso no kiyo no kaisekikai  

Energy Technology Data Exchange (ETDEWEB)

Formulation is introduced for discretizing a boundary integral equation into an indirect boundary element method for the solution of 3-dimensional topographic problems. Yokoi and Takenaka propose an analytical solution-capable reference solution (solution for the half space elastic body with flat free surface) to problems of topographic response to seismic motion in a 2-dimensional in-plane field. That is to say, they propose a boundary integral equation capable of effectively suppressing the non-physical waves that emerge in the result of computation in the wake of the truncation of the discretized ground surface making use of the wave field in a semi-infinite elastic body with flat free surface. They apply the proposed boundary integral equation discretized into the indirect boundary element method to solve some examples, and succeed in proving its validity. In this report, the equation is expanded to ...

1997-05-27

292

Homogeneous, anisotropic three-manifolds of topologically massive gravity  

Energy Technology Data Exchange (ETDEWEB)

We present a new class of exact solutions of Deser, Jackiw, and Templeton's theory (DJT) of topologically massive gravity which consists of homogeneous, anisotropic manifolds. In these solutions the coframe is given by the left-invariant 1-forms of 3-dimensional Lie algebras up to constant scale factors. These factors are fixed in terms of the DJT coupling constant {mu}m which is the constant of proportionality between the Einstein and Cotton tensors in 3-dimensions. Differences between the scale factors result in anisotropy which is a common feature of topologically massive 3-manifolds. We have found that only Bianchi Types VI, VIII, and IX lead to nontrivial solutions. Among these, a Bianchi Type IX, squashed 3-sphere solution of the Euclideanized DJT theory has finite action, Bianchi Type VIII, IX solutions can variously be embedded in the de Sitter/anti-de Sitter space. ...

1989-10-01

293

Homogeneous, anisotropic three-manifolds of topologically massive gravity  

International Nuclear Information System (INIS)

We present a new class of exact solutions of Deser, Jackiw, and Templeton's theory (DJT) of topologically massive gravity which consists of homogeneous, anisotropic manifolds. In these solutions the coframe is given by the left-invariant 1-forms of 3-dimensional Lie algebras up to constant scale factors. These factors are fixed in terms of the DJT coupling constant #mu#m which is the constant of proportionality between the Einstein and Cotton tensors in 3-dimensions. Differences between the scale factors result in anisotropy which is a common feature of topologically massive 3-manifolds. We have found that only Bianchi Types VI, VIII, and IX lead to nontrivial solutions. Among these, a Bianchi Type IX, squashed 3-sphere solution of the Euclideanized DJT theory has finite action, Bianchi Type VIII, IX solutions can variously be embedded in the de Sitter/anti-de Sitter space. That is, ...

294

D3+D6 solution and D4+D6 solution  

International Nuclear Information System (INIS)

We make the supergravity solutions describing the branes (D3 branes and D4 branes) localized within the D6 branes in the near core region of D6 brane. From the D=11 solutions (M3 branes and M4 branes with the Z_N identifications in the transverse space) we obtain the D=10 supergravity solutions of D3 branes localized within D6 branes and D4 branes localized within D6 branes by reducing the dimension down to D=10 along a circular direction of S"3 part of the transverse space. M3 brane solution leads to D=10 background representing D3 branes localized on D6 branes in the region close to the D6 branes core. M4 branes lead to the D4 branes localized on D6 branes in the region close to the D6 brane core.

2001-04-16

295

Wood plastic composite at different urea concentrations  

Energy Technology Data Exchange (ETDEWEB)

Wood plastic composite (WPC) has been prepared with a low grade wood simul (Salmalia malabarica) of Bangladesh under Co-60 gamma irradiation using MMA as the bulk monomer combined with methanol as the swelling solvent at different urea concentrations. Effect of a second solute such as NVP, TPGDA and TMPTA in the impregnating solution is evaluated. NVP appears to be the best co-additive/second solute among all the additives used to yield the composite with the highest polymer loading (PL) and tensile strength (TS) at 0.5% urea concentration. (author).

1995-04-01

296

Wood plastic composite at different urea concentrations  

International Nuclear Information System (INIS)

Wood plastic composite (WPC) has been prepared with a low grade wood simul (Salmalia malabarica) of Bangladesh under Co-60 gamma irradiation using MMA as the bulk monomer combined with methanol as the swelling solvent at different urea concentrations. Effect of a second solute such as NVP, TPGDA and TMPTA in the impregnating solution is evaluated. NVP appears to be the best co-additive/second solute among all the additives used to yield the composite with the highest polymer loading (PL) and tensile strength (TS) at 0.5% urea concentration. (author).

1995-01-01

297

Thermodynamic modeling of acidic gas solubility in aqueous solutions of MEA, MDEA and MEA-MDEA blends  

DEFF Research Database (Denmark)

The thermodynamic framework that was developed in a previous work [Vrachnos et al. Ind. Eng. Chem. Res. 2004, 43, 2798] for the description of chemical and vapor-liquid equilibria of carbon dioxide, hydrogen sulfide, and their mixtures in aqueous methyldiethanolamine (MDEA) solutions is revised and extended in this study to the absorption of carbon dioxide into aqueous monoethanolamine (MEA) solutions and aqueous MDEA-MEA blends. The results of the model are compared with experimental data taken from the literature. Very satisfactory predictions of acidic gas vapor-liquid equilibrium over MDEA, MEA, and their blends at various concentrations, acidic gas loadings, and temperatures are obtained.

2006-01-01

298

Studies on radioactive liquid waste treatment by reverse osmosis  

Energy Technology Data Exchange (ETDEWEB)

Reverse osmosis is a simple process and has relatively high decontamination factor compared to other processes used for the treatment of radioactive liquid waste. Furthermore the quantity of secondary waste of this process is small. In this study, test solution containing nine elements such as cesium, strontium, cobalt etc. in chloride forms are treated by reverse osmosis. Permeate rate decreases as the increase of osmotic pressure of feed solution and is expressed by linear equation. Decontamination factor of cations of univalency is more than ten, and about one tenth of that of bivalency. Decontamination factors of all the elements used in this experiment are approximately estimated using the solution-diffusion model.

1982-06-01

299

Studies on radioactive liquid waste treatment by reverse osmosis  

International Nuclear Information System (INIS)

Reverse osmosis is a simple process and has relatively high decontamination factor comparing to other processes used for the treatment of radioactive liquid waste. Furthermore the quantity of secondary waste of this process is small. In this study, test solution containing nine elements such as cesium, strontium, cobalt etc. in chloride forms are treated by reverse osmosis. Permeate rate decreases as the increase of osmotic pressure of feed solution and is expressed by linear equation. Decontamination factor of cations of univalency is more than ten, and about one tenth of that of bivalency. Decontamination factors of all the elements used in this experiment are approximately estimated using the solution-diffusion model. (author).

300

Studies of polyhaloegnide ions of astatine  

Energy Technology Data Exchange (ETDEWEB)

Polyhalogenide ions of the type AtX/sub 2//sup -/ (X=Cl, Br, I) were synthesized via reactions of /sup 211/At(THETA)/sup +/ with halogenides in acidic solutions. The formation and stability of these compounds were investigated using electromigration methods. AtI/sub 2//sup -/ is stable in solution down to pH=12, whereas AtCl/sub 2//sup -/ and AtBr/sub 2//sup -/ under these conditions are reduced to astatide. In the absence of halogenides in alkaline solution At(THETA)/sup +/ changes also to At/sup -/.

1982-11-10

301

Studies of polyhalo.o.enide ions of astatine  

International Nuclear Information System (INIS)

Polyhalogenide ions of the type AtX_2"- (X=Cl, Br, I) were synthesized via reactions of "2"1"1At(THETA)"+ with halogenides in acidic solutions. The formation and stability of these compounds were investigated using electromigration methods. AtI_2"- is stable in solution down to pH=12, whereas AtCl_2"- and AtBr_2"- under these conditions are reduced to astatide. In the absence of halogenides in alkaline solution At(THETA)"+ changes also to At"-. (author).

302

Solutions of the pion dispersion equation in the medium new aspects  

CERN Document Server

In symmetrical nuclear matter the solutions of pion dispersion equation are investigated in the complex plane of the pion frequency $\\omega$. There are three well-known branches of solutions on the physical sheet : sound, pion and isobar, at the matter density less than the critical one $\\rho <\\rho_c$. At the condition $\\omega^2_c\\leq0$ (in general case Re$ \\omega^2_c\\leq0$) takes place. This points out the instability of the ground state which is possibly related to the pion condensation.

2000-01-01

303

Separation of lithium isotopes by counter-current flow of the coexisting phases of a lithium-ammonia solution  

Energy Technology Data Exchange (ETDEWEB)

A weak shift of the isotope concentration ratio Li{sup 6}/Li{sup 7} was measured in the coexisting phases of the miscibility gap of lithium-ammonia solutions. Li{sup 6} is slightly enriched in the concentrated metallic phase (enrichment factor {alpha} = 1.009 {+-} 0.002). This effect can be enhanced in a counter-current column to yield any desired enrichment of the two isotopes. The counter current system and its operation were tested succesfully with a sodium-potassium-ammonia solution.

1991-12-01

304

Polythermal study of the M(ClO_4)_2-H_2O systems, where M"2 = Mg"2"+, Ca"2"+, Sr"2"+, Ba"2"+  

International Nuclear Information System (INIS)

Crystallization points of aqueous solution of the systems M(ClO_4)_2-H_2O (M"2 = Mg"2"+, Ca"2"+, Sr"2"+, Ba"2"+), depending on the salt concentration, were identified by visual-polythermal method. Relying on model notions on the structure of the electrolyte solutions, specific features of strontium perchlorate solubility polytherm and concentration dependence of the relative dynamic viscosity of the salt aqueous solutions are discussed

2005-03-01

305

Macro and micro observations on mortar alternation mechanism under the various solution conditions  

Energy Technology Data Exchange (ETDEWEB)

Accelerated aging tests have been conducted to evaluate the long-term durability of cementitious material against aggressive ions. In tests, cementitious specimens were immersed in the solutions containing concentrated aggressive ions at high temperature and it promoted diffusion of the ions in the specimen. This method would be suitable for the evaluation on the aging as the alteration of the specimen would be expected to resemble the natural behavior. This paper presents a classification of alteration mechanism in the immersion tests using MgCl{sub 2} and Na{sub 2}SO{sub 4} solution. This classification was done by relating the changes of compressive strength to microscopic and mineralogical changes.

1995-12-31

306

Kasner asymptotics of mixmaster Horava-Witten and pre-big-bang cosmologies  

Energy Technology Data Exchange (ETDEWEB)

We discuss various superstring effective actions and, in particular, their common sector which leads to the so-called pre-big-bang cosmology (cosmology in a weak coupling limit of heterotic superstring theory). Using the conformal relationship between these two theories we present Kasner asymptotic solutions of Bianchi type IX geometries within these theories and make predictions about possible emergence of chaos. Finally, we present a possible method of generating Horava-Witten cosmological solutions out of the well-known general relativistic or pre-big-bang solutions.

2001-09-01

307

Kasner asymptotics of mixmaster Horava-Witten and pre-big-bang cosmologies  

International Nuclear Information System (INIS)

We discuss various superstring effective actions and, in particular, their common sector which leads to the so-called pre-big-bang cosmology (cosmology in a weak coupling limit of heterotic superstring theory. Using the conformal relationship between these two theories we present Kasner asymptotic solutions of Bianchi type IX geometries within these theories and make predictions about possible emergence of chaos. Finally, we present a possible method of generating Horava-Witten cosmological solutions out of the well-known general relativistic or pre-big-bang solutions.

2001-09-01

308

Ion-Specific Hydration Effects: Extending the Poisson-Boltzmann Theory  

CERN Document Server

In aqueous solutions, dissolved ions interact strongly with the surrounding water, thereby modifying the solution properties in an ion-specific manner. These ion-hydration interactions can be accounted for theoretically on a mean-field level by including phenomenological terms in the free energy that correspond to the most dominant ion-specific interactions. Minimizing this free energy leads to modified Poisson-Boltzmann equations with appropriate boundary conditions. Here, we review how this strategy has been used to predict some of the ways ion-specific effects can modify the forces acting within and between charged interfaces immersed in salt solutions.

2011-01-01

309

Investigation of cause of cracking of high-strength 30HGSNA grade steel subjected to stresses and corrosive agents  

International Nuclear Information System (INIS)

It has been found out that 30HGSNA steel undergo cracking under action of stresses in aqueous solutions containing oxygen, while it show high resistance in deoxidated solutions. The purpose of such phenomena is the existence of sulfur inclusions in steel which are a centers of denting corrosion. That points acting as a stresses concentrators where pH factor decreases including hydrogen formation and its absorption in the metal. That mechanism is the main purpose of brittle steel cracking observed in oxygen rich solutions. (author).

1995-05-17

310

Influence of scattering on superluminescence in composites dye solution ? nanoparticles  

British Library Electronic Table of Contents (United Kingdom)

Spectral and energy luminescence characteristics of R6G dye solutions in ethanol with addition of Ag nanoparticle suspensions in different aggregate states are experimentally investigated. It is demonstrated that incorporation of non-aggregated and aggregated nanoparticles causes the superluminescence thresholds in R6G solutions to decrease. It is established that the optical properties of the laser beam propagation channel are transformed when low-power (20?mW) cw laser radiation passes through the suspension of nanoparticles. This is manifested through the occurrence of a region with enhanced nanoparticle density in the laser beam center, on which diffraction of laser radiation is observed.

2011-01-01

311

Influence of scattering on superluminescence in composites dye solution - nanoparticles  

Science.gov (United States)

Spectral and energy luminescence characteristics of R6G dye solutions in ethanol with addition of Ag nanoparticle suspensions in different aggregate states are experimentally investigated. It is demonstrated that incorporation of non-aggregated and aggregated nanoparticles causes the superluminescence thresholds in R6G solutions to decrease. It is established that the optical properties of the laser beam propagation channel are transformed when low-power (20 mW) cw laser radiation passes through the suspension of nanoparticles. This is manifested through the occurrence of a region with enhanced nanoparticle density in the laser beam center, on which diffraction of laser radiation is observed.

2011-09-01

312

Gastrointestinal absorption of alfalfa-bound plutonium-238 by rats and guinea pigs  

International Nuclear Information System (INIS)

Rats and guinea pigs were fed "2"3"8Pu either biologically incorporated into alfalfa (by growth of the plant on soil containing Pu) or added as a solution to alfalfa, or were gavaged with a Pu solution. Depending upon the plant material fed, there appeared to be a twofold increase in "2"3"8Pu-gut absorption by the rat and a two- to fourfold increase in the guinea pig as compared with absorption from the Pu solution. The data, though limited and variable, suggest that Pu bound to plant tissue may have higher gut absorptivity than inorganic Pu in both herbivorous and nonherbivorous rodents.

1977-05-01

313

Exact solutions to the Chandrasekhar Page angular equation  

CERN Document Server

Exact solutions are found for the Chandrasekhar Page angular equation which results when the Dirac equation in a Kerr Newman space time is separated into its radial and angular parts. The solutions turn out to be remarkably simple in form while satisfying the asymptotic conditions deduced earlier. The eigenvalues are found to be the square root of the total angular momentum as first found by Dirac for flat space; supplemented by a term which is the product of the mass of the Dirac particle times the specific angular momentum of the black hole. The additional contribution is what is expected from frame dragging.

2006-01-01

314

Etching characteristics of high-purity aluminum in hydrochloric acid solutions  

Energy Technology Data Exchange (ETDEWEB)

We investigated the effects of additives to the etching solution of 1 M hydrochloric acid on the electrochemical etching behavior for aluminum electrolytic capacitors, using scanning and transmission electron microscopy, and AC impedance spectroscopy. For the addition of 1 M sulfuric acid or 5% ethylene glycol to the hydrochloric acid solution, the distribution of etch tunnels was more uniform with high density of etch pits compared with that without addition. The highest specific surface area was obtained from the electrolyte with 5% ethylene glycol additive. The correlation of internal morphologies of etched foils with impedance parameters was interpreted by impedance techniques.

2007-03-25

315

Comparison of the inhibitory action of KCl and guanidine hydrochloride solutions on montmorillonite swelling  

Science.gov (United States)

This study compares the effectiveness of potassium chloride with guanidine chlorhydrate in the prevention of clay swelling. The results given on various swelling tests on calcic montmorillonite led to the conclusions that (1) guanidine chlorhydrate is more effective than potassium chloride, especially in low concentrations, and (2) water immersion of samples treated by both solutions shows the permanent feature of the inhibitive action of guanidine chlorhydrate in swelling on one hand and the important increase in swelling of immersed samples treated by potassium chloride on the other. The viscosity measure of montmorillonite suspensions, before and after solution ion elimination by dialysis, confirms these observations.

1982-08-01

316

Biosorption of uranium and thorium. [Rhizopus arrhizus  

Energy Technology Data Exchange (ETDEWEB)

Selected samples of waste microbial biomass originating from various industrial fermentation processes and biological treatment plants have been screened for biosorbent properties in conjunction with uranium and thorium in aqueous solutions. Biosorption isotherms have been used for the evaluation of biosorptive uptake capacity of the biomass which was also compared to an activated carbon and the ion exchange resin currently used in uranium production processes. Determined uranium and thorium biosorption isotherms were independent of the initial U or Th solution concentration. Solution pH affected the exhibited uptake. 24 refs.

1981-03-01

317

x - NASA Technical Reports Server  

Science.gov (United States)

analysis of NaMBT in ethylene glycol-water solutions with high accuracy. It reduces analysis time, requires smaller samples, and is able to detect extremely ...

318

Transport energy efficiency  

International Nuclear Information System (INIS)

Enhancing transport sustainability is the password of national, European, and international policies. The development of innovative solutions is ranging from bio fuels to transport analysis models, materials, traction technologies, mobility management, freight villages.

320

The actin content of fibroblasts.  

UK PubMed Central (United Kingdom)

Cultures of chick skin fibroblasts were dissolved in solutions of sodium dodecyl sulphate, and their entire protein content was examined by gel electrophoresis. The most abundant species migrated in...Full Text Available

1975-05-01

321

The Factors Determining the Level of Virus Production. Report ...  

Science.gov (United States)

... After formation of the monolayer (usually in 48 hours), the growth medium was poured off, and the cells washed twice with a Henkes solution and ...

1971-12-02

322

Synchrotron SAXS Studies of Nanostructured Materials and Colloidal Solutions: A Review  

Scientific Electronic Library Online (English)

Abstract in english Structural characterisations using the SAXS technique in a number of nanoheterogeneous materials and liquid solutions are reviewed. The studied systems are protein (lysozyme)/water solutions, colloidal ZnO particles/water sols, nanoporous NiO-based xerogels, hybrid organic-inorganic siloxane-PEG and PPG nanocomposites and PbTe semiconductor nanocrystals embedded in a glass matrix. These investigations also focus on the transformations of time-varying structures and on str (more) uctural changes related to variations in temperature and composition. The reviewed investigations aim at explaining the unusual and often interesting properties of nanostructured materials and solutions. Most of the reported studies were carried out using the SAXS beamline at the National Synchrotron Light Laboratory (LNLS), Campinas, Brazil.

2002-03-01

323

Study on cell nucleation behavior of HDPE?wood composites/supercritical CO2 solution based on rheological properties  

British Library Electronic Table of Contents (United Kingdom)

In this study, the shear viscosities of wood?plastic composites (WPC)/supercritical CO2 (sc-CO2) solutions at different die temperatures and sc-CO2 contents were measured by a slit die attached on a single-screw extrusion system. A theoretical model based on the Carreau-Yasuda model and Arrhenius equation was then developed to describe the shear-thinning behavior of the WPC/sc-CO2 solution. This model was incorporated into a finite element method software, POLYFLOW, to simulate the pressure and velocity field of WPC/sc-CO2 solution flowing through a foaming die. Based on the simulation results, the pressure drop rate and the location of the supersaturation point were estimated to investigate the cell nucleation. The saturation pressure of sc-CO2 in WPC was determined by a magnetic suspensi...

2011-01-01

324

Study of protein-protein interactions in under saturated and supersaturated lysozyme solutions in heavy water as a function of temperature; Etude des interactions proteine-proteine en solutions sous-saturees et sursaturees de lysozyme dans l`eau lourde en fonction de la temperature  

Energy Technology Data Exchange (ETDEWEB)

We have studied freshly prepared lysozyme solutions in heavy water for two NaCl concentrations as a function of temperature. Lysozyme solubilities in this solvent are determined by static light scattering. By small angle neutron scattering, we evidence that interactions between lysozyme molecules are characterized by a second virial coefficient A{sub 2} whether the solution is under-saturated or supersaturated. From the variation of A{sub 2} as a function of temperature we have evaluated the enthalpy corresponding to the interaction between lysozyme molecules. We show that the interactions between protein molecules are higher in heavy water than in light water. (authors). 13 refs., 3 figs.

1996-04-01

325

Spectroscopic properties of the f-elements in compounds and solutions. [79 references  

Energy Technology Data Exchange (ETDEWEB)

In this systematic examination of some of the spectroscopic properties of the f-elements we deal with both the trivalent lanthanides and actinides. We summarize the present status of our energy level calculations in single crystal matrices and in aqueous solution, and compare the predicted crystal-field structure in certain low-symmetry sites with that observed. Some interesting new structural insights are thereby gained. The state eigenvectors from these calculations are then used in part in reassessing and interpreting the intensities of transitions in aqueous solution via the Judd-Ofelt theory. The parameters of this theory derived from fitting experimental data are compared with those computed from model considerations. Finally, we discuss some recent contributions to the interpretation of excited state relaxation processes in aqueous solution. 79 references, 23 figures, 17 tables.

1982-01-01

327

STUDY OF METHODS FOR IMPROVING SYNTHETIC ...  

Science.gov (United States)

... At no time must any solution or water temper- atures exceed 72°F, with all fluids maintained as close as possible to 700F. ...

1963-05-15

328

SAXS studies on added-salt species dependence of conformation of fully-charged poly(L-glutamate) in aqueous solutions  

Energy Technology Data Exchange (ETDEWEB)

The effect of counter-ion species on the local conformation of fully-charged poly(L-glutamate) in added-salt aqueous solutions were studied by small-angle X-ray scattering(SAXS). In the case of presence of monovalent counter-ion, the scattering behaviour could be explained by taking into consideration the excluded volume effect and intermolecular-interface interaction on the scattering function of wormlike chain. On the other hand, since SAXS profile of the solution in the presence of divalent counter-ion well fitted to the scattering function of dendrimer, it suggested that the conformation of polymer chain in such solution would be more compact conformation than that of presence of monovalent ion.

2010-10-01

331

Recovery of transplutonium elements from aqueous and water-ethanol solutions of sulfuric acid and their separation from other actinides  

Energy Technology Data Exchange (ETDEWEB)

The behavior of Am, Cm, Bk, Cf, Es, and other actinides, as well as Zr, on anion and cation exchangers in aqueous and water-ethanol solutions of sulfuric acid as a function of the various components of the solution has been investigated. It has been discovered that the presence of ethanol in sulfuric acid solutions causes an increase in the distribution coefficients both on cation exchangers and on anion exchangers. The possibility of the use of ion exchangers for the preconcentration and separation of transplutonium elements from U, Np, Pu, Zr, and other elements which form strong complexes with sulfate ions over a broad range of concentrations of sulfuric acid has been demonstrated.

1988-05-01

332

Radiosterilization of drugs in aqueous solutions may be achieved by the use of radioprotective excipients  

British Library Electronic Table of Contents (United Kingdom)

The aim of this study was to assess the feasibility of radiosterilization of drugs aqueous solutions and to evaluate the effects of some additives, such as mannitol, nicotinamide and pyridoxine, which might protect the drug from degradation. Metoclopramide was selected as a model drug. The structures of the degradation products were determined to gain insight on the radiolysis mechanisms in aqueous solution in order to design strategies to lower the drug degradation.Metoclopramide hydrochloride aqueous solutions with and without excipients were irradiated either with gamma rays or high-energy electrons. HPLC-DAD was used to measure the loss of chemical potency and to quantify the degradation products which were also characterized by LC-APCI-MS-MS. Metoclopramide recovery for gamma and elec...

2008-01-01

335

On virtual phonons, photons and electrons  

CERN Document Server

A macroscopic realization of the strange virtual particles is presented. The classical Helmholtz and the quantum mechanical Schr\\"odinger equations are analogous differential equations. Their imaginary solutions are called evanescent modes in the case of elastic and electromagnetic fields. In the case of non-relativistic quantum mechanical fields they are called tunneling solutions. The imaginary solutions of this differential equation point to strange consequences: They are non local, they are not observable, and they described as virtual particles. During the last two decades QED calculations of the imaginary solutions have been experimentally confirmed for phonons, photons, and for electrons. The experimental proofs of the predictions of the non-relativistic quantum mechanics and of the Wigner phase time approach for the elastic, the electromagnetic and the Schr\\"odinger fields will be presented in ...

2009-01-01

336

Ocular Burn: Rinsing and Healing with Ionic Marine Solutions and Vegetable Oils  

British Library Electronic Table of Contents (United Kingdom)

Abstract Purpose: We investigated the effects of various rinsing and healing protocols on corneal wound repair and inflammation following alkali burn in rabbits. Methods: We conducted in vitro, in vivo and ex vivo studies. First, different rinse solutions were tested in vitro after incubation of ocular cells with methanol or NaOH. Cell viability was then assessed using the neutral red test (cytofluorometry). Second, NaOH was applied to rabbit corneas and associations of rinse solutions (NaCl 0.9% or controlled ionization marine solutions) with N-acetylcysteine or vegetable oils (from Calophyllum inophyllum and Aleurites moluccana) were tested in vivo. The regeneration of the corneal epithelium and the infiltration of inflammatory cells were evaluated using in vivo confocal microscopy and e...

2009-01-01

337

NASA TECH BRIEF - NASA Technical Report Server (NTRS)  

Science.gov (United States)

(NaMBT) inhibitor in ethylene glycol-water solutions. The improved method must be faster and more accur- ate than wet chemical techniques. ...

338

NASA 11x:/,3 '/t.z- - NASA Technical Reports Server  

Science.gov (United States)

_! Packaging, Cleanlines_, Preparation j Handling ..... 35. 'I. 40. WATER ................ , ......... Sterile, High Purity, Ethylene Glycol-Water Solutions. Requirement For . ...

339

Multifractal Analysis of Multiple Ergodic Averages  

CERN Document Server

In this paper we present a complete solution to the problem of multifractal analysis of multiple ergodic averages in the case of symbolic dynamics for functions of two variables depending on the first coordinate.

2011-01-01

340

Microstructural changes of stearic acid films by immersion in salt solution  

Energy Technology Data Exchange (ETDEWEB)

X-Ray reflectivity has been used to investigate the microstructural changes of solution-cast stearic acid films before and after immersion in CoCl{sub 2} solutions. Before immersion, the films possess a well-defined layered structure with an interlayer spacing of 4.01{+-}0.05 nm. After the films were immersed in the CoCl{sub 2} solutions, a new set of equidistant diffraction peaks emerge, the corresponding interlayer spacing of which is 5.13{+-}0.05 nm. The X-ray photoelectron spectra of the films indicate the existence of cobalt ions inside the films after immersion. It is concluded that the permeation of the cobalt ions into the hydrophilic interlayer causes the stearic acid molecules to reorient perpendicular to the films, resulting in the increase of interlayer spacing and the roughening of the interfaces.

2003-11-01

341

Method of reducing volume of radioactive liquid waste  

International Nuclear Information System (INIS)

Purpose: To enable the solidification of liquid waste containing radioactive substance in a free shape with large volume reduction ratio without a pulverizing step by producing solute in the liquid waste as a slurry in a predetermined organic solvent and forming it into a cake by mechanical exfoliation. Method: Liquid waste containing suitably concentrated radioactive substances is supplied to a centrifugal thin film evaporator together with an organic agent having a higher boiling point than water and a non aqueous solution to evaporate the water content, the solute in the waste is produced as a slurry in the organic solvent, and removed as cake-state solute slightly residued with the organic solvent by the mechanical exfoliation such as centrifugal exfoliation or settling exfoliation from the slurry-state liquid. Accordingly, it can be increased in size as compared with the powder reduced in volume of ...

1981-08-01

343

Lipiodol solution of a lipophilic agent, {sup 188}Re-TDD, for the treatment of liver cancer  

Energy Technology Data Exchange (ETDEWEB)

Radiolabeled lipiodol has been used for targeting liver cancer. We developed a lipiodol solution of {sup 188}Re-TDD (2,2,9,9-tetramethyl-4,7-diaza-1,10-decanedithiol) and investigated its feasibility for the treatment of liver cancer. The lipiodol solution of {sup 188}Re-TDD was well-retained in the lipiodol phase in vitro. After injection through the tail veins of mice, high lung-uptake was investigated which is evidence of embolizing activity. We also found high accumulation in hepatoma after injection through the hepatic arteries of hepatoma-bearing rats. In conclusion, the lipiodol solution of {sup 188}Re-TDD is a promising agent for liver cancer therapy.

2001-02-01

344

LBA Calibrator Survey - NASA  

Science.gov (United States)

Group deal delay solution has fit 42 psec with 2.4% outliers. Group delay ambiguities with spacing 3.9 ns (another world record!) were successfully resolved. ...

345

Irradiation of human insulin in aqueous solution, first step towards radiosterilization  

British Library Electronic Table of Contents (United Kingdom)

The degradation of irradiated human insulin in aqueous solutions was investigated in order to protect the protein against ionizing radiation. The influence of the drug concentration, excipients and irradiation temperature were studied.Aqueous solutions at pH 2 were irradiated by gamma rays or by accelerated electrons. Two different high-performance liquid chromatography (HPLC) methods were used: reverse-phase high-performance liquid chromatography (RP-HPLC)/UV and size exclusion liquid chromatography (SEC/UV) to investigate both the fragmentation and the formation of higher molecular weight proteins.In solution without excipients irradiated at ambient temperature at 10kGy, the loss of human insulin is almost complete. Addition of radio-protecting excipients (free radicals scavengers) and c...

2007-01-01

346

Identity and yield of positive charge centers in irradiated chloro hydrocarbon liquids and the rates of their interaction with solute molecules. [3-4 MeV electrons  

Science.gov (United States)

Pulse radiolysis studies of the formation kinetics and the yields of various phenylcarbenium ions from several different solutes in 1,2-dichloroethane solution have been carried out. The results indicate that there are two kinetically distinguishable cationic species of the solvent which react selectively with the different solutes to form the phenylcarbenium ions. It is suggested that one is a cation radical (yield 0.68 molecule/100 eV) and the other a carbocation (yield 0.20 molecule/100 eV). Rate constants for their separate reactions with selected aromatic compounds and with ammonia have been determined. Molar extinction coefficients have been estimated for benzyl cation, diphenyl cation radical, and anthracene cation radical. 6 figures, 1 table.

1979-07-26

347

Identity and yield of positive charge centers in irradiated chloro hydrocarbon liquids and the rates of their interaction with solute molecules  

International Nuclear Information System (INIS)

Pulse radiolysis studies of the formation kinetics and the yields of various phenylcarbenium ions from several different solutes in 1,2-dichloroethane solution have been carried out. The results indicate that there are two kinetically distinguishable cationic species of the solvent which react selectively with the different solutes to form the phenylcarbenium ions. It is suggested that one is a cation radical (yield 0.68 molecule/100 eV) and the other a carbocation (yield 0.20 molecule/100 eV). Rate constants for their separate reactions with selected aromatic compounds and with ammonia have been determined. Molar extinction coefficients have been estimated for benzyl cation, diphenyl cation radical, and anthracene cation radical. 6 figures, 1 table.

1979-07-01

348

Electrochemical impedance of electrolyte/electrode interfaces of lithium-ion rechargeable batteries  

Energy Technology Data Exchange (ETDEWEB)

It is well known that a protective film is formed on the graphite negative electrode in ethylene carbonate (EC) electrolyte solution. This film is lithium-ion conductive and protects the decomposition of the electrolyte solution. In the present paper, the electrode/electrolyte interfaces in lithium-ion rechargeable batteries were characterized by three-dimensional complex impedance plots, whose axes are real, imaginary parts and time. The film resistance R {sub sei} and charge transfer resistance R {sub ct} were determined for negative electrodes in EC/ethyl methyl carbonate (EMC) electrolyte solution, and the formation mechanisms of the interfacial film were discussed. Furthermore, the contributions of vinylene carbonate and ethylene sulfite, which are added into the electrolyte solution for the film formation, were investigated.

2006-01-20

349

Electrochemical impedance of electrolyte/electrode interfaces of lithium-ion rechargeable batteries  

International Nuclear Information System (INIS)

It is well known that a protective film is formed on the graphite negative electrode in ethylene carbonate (EC) electrolyte solution. This film is lithium-ion conductive and protects the decomposition of the electrolyte solution. In the present paper, the electrode/electrolyte interfaces in lithium-ion rechargeable batteries were characterized by three-dimensional complex impedance plots, whose axes are real, imaginary parts and time. The film resistance R _s_e_i and charge transfer resistance R _c_t were determined for negative electrodes in EC/ethyl methyl carbonate (EMC) electrolyte solution, and the formation mechanisms of the interfacial film were discussed. Furthermore, the contributions of vinylene carbonate and ethylene sulfite, which are added into the electrolyte solution for the film formation, were investigated.

2006-01-20

350

Electrochemical characterization and CFD simulation of flow-assisted corrosion of aluminum alloy in ethylene glycol-water solution  

British Library Electronic Table of Contents (United Kingdom)

An impingement jet system was used to study flow-assisted corrosion (FAC) of 3003 aluminum (Al) alloy in ethylene glycol-water solutions that simulates the automotive coolant by corrosion potential and electrochemical impedance spectroscopy (EIS) measurements as well as computational fluid dynamics (CFD) simulation. The effects of solution pH and fluid impact angle on Al FAC were determined. An increase of solution pH enhances the activity of Al due to dissolution of Al oxide film in alkaline environment. Moreover, Al activity decreases with the increasing fluid impact angle to the specimen. A CFD simulation shows that, with the increase of impact angle, the electrode area under high-velocity flow field decreases and that under low-velocity flow field increases. Consequently, the shear str...

2008-01-01

351

Efficient Proximity Detection among Mobile Users via SelfTuning Policies  

DEFF Research Database (Denmark)

Given a set of users, their friend relationships, and a distance threshold per friend pair, the proximity detection problem is to find each pair of friends such that the Euclidean distance between them is within the given threshold. This problem plays an essential role in friend-locator applications and massively multiplayer online games. Existing proximity detection solutions either incur substantial location update costs or their performance does not scale well to a large number of users. Motivated by this, we present a centralized proximity detection solution that assigns each mobile client with a mobile region. We then design a self-tuning policy to adjust the radius of the region automatically, in order to minimize communication cost. In addition, we analyze the communication cost of our solutions, and provide valuable insights on their behaviors. Extensive experiments suggest that our proposed ...

2010-01-01

352

Effects of pH and phosphate on metal distribution with emphasis on As speciation and mobilization in soils from a lead smelting site  

Energy Technology Data Exchange (ETDEWEB)

Arsenic in soils from the Asarco lead smelter in East Helena, Montana was characterized by X-ray absorption spectroscopy (XAS). Arsenic oxidation state and geochemical speciation were analyzed as a function of depth (two sampling sites) and surface distribution. These results were compared with intensive desorption/dissolution experiments performed in a pH stat reactor for samples from the site with the highest degree of As heterogeneity. The objectives of the study were to investigate the solid-phase geochemical As speciation, assess the speciation of As in solutions equilibrated with the solids under controlled pH (pH=4 or 6) and Eh (using hydrogen or air) environments, observe the effects of phosphate on the release of As into solution, and examine the effects of phosphate on metal mobility in the systems. Arsenic was predominantly found in the As(V) valence state, though there was evidence that As(III) and As(0) were present also. The ...

2005-06-01

353

ELECTRIC AND GALVANOMAGNETIC PROPERTIES OF ...  

Science.gov (United States)

... Abstract : The electric resistance in weak (diluted) solid solutions of the Pd-Ag and Fe-W systems, as wellAS THE Hall effect in a Pd-Ag system ...

1961-06-27

354

Dewatering press liquor derived from orange production by forward osmosis  

British Library Electronic Table of Contents (United Kingdom)

In this investigation, a forward osmosis (FO) dewatering process is evaluated as an alternative for dewatering orange peel press liquor. The press liquor is concentrated by removing water via osmosis into a concentrated ''draw solution'' across a polymeric cellulose acetate membrane. For this investigation, the draw solution consisted of sodium chloride at two different concentrations (2M and 4M). These draw solutions were used to concentrate synthetic press liquor. Concentration factors up to 3.7 resulted when using a 4M NaCl draw solution and the synthetic press liquor. Also during this investigation, fouling behavior was observed and the mechanisms of fouling elucidated through a systematic approach. This approach identified the key components of the press liquor that were primarily res...

2011-01-01

355

Development of standard solutions for the Minergie standard; Standardloesungen - Entwicklung von Standardloesungen fuer den Minergie-Standard  

Energy Technology Data Exchange (ETDEWEB)

This final report for the Swiss Federal Office of Energy (SFOE) examines a project that aimed to define standard solutions for use in buildings built to meet Minergie low energy consumption standards. These standard solutions are to provide a way of meeting Minergie standards in an easy way and thus further the use of the standard and also assure quality at the same time. The report describes how the solutions were developed on the basis of a selection of existing Minergie buildings. For various combinations of heating systems - wood, wood/solar, heat pumps (brine-water and air-water), gas/solar and oil/solar - the appropriate U-values for various building elements are listed. The resulting Minergie forms and guides are listed.

2003-07-01

356

Derivation of an Extra-Large PASGT Helmet  

Science.gov (United States)

... The solution used on the size Large helmet war an arbitrary one; as discussed above, the developers added a standard deviation to ... 4 O. i3a: o.04. ...

1988-07-01

357

Demonstration experiments of volume measurement technique for large scale input accountancy tank  

International Nuclear Information System (INIS)

Tank calibration experiments have been carried out using a mock-up input accountancy tank with the object of developing a high accuracy solution volume measurement technique for Rokkasho Reprocessing Plant (RRP). The experimental parameters such as temperature, solution density, off gas pressure and so on have been fluctuated in the calibration experiments in order to evaluate the influence on the solution volume measurement. As a result, it was confirmed that the solution volume measurement error of the mock-up tank was within #+-#0.04% (at full volume) using careful data correction technique for measured data. For the high accuracy volume measurement at RRP, it is important to correct data properly taking account of the actual conditions such as uncontrollable ambient temperature that are different from the experiment. (author)

2000-12-07

358

Deforestation in the Tropics  

Science.gov (United States)

Government policies that encourage exploitation--in particular excessive logging and clearing for ranches and farms--are largely to blame for the accelerating destruction of tropical forests. This paper surveys the problem in detail and briefly recommends potential solutions.

1990-04-01

359

Biosorption of scandium and yttrium from solutions  

International Nuclear Information System (INIS)

The usage of biosorbents allows separation of scandium and yttrium from each other and from Fe, Al, Ti, Si, and Ca in hydrometallurgical processing of ores and wastes. It was shown that sorption of scandium and yttrium increased with the increase of pH of solution. Initial rate of scandium sorption depended on the biomass type; however 85-98% of scandium was sorbed within 10-30 min with most biomass types tested. The presence of aluminium, iron (III), and titanium in the solution inhibited sorption of scandium and particularly yttrium. After four cycles of sorption, 98.8% of scandium and 87% of yttrium was extracted from red mud leach solution by the biomass of Saccharomyces cerevisiae and Aspergillus terreus, respectively. Selectively of the process of scandium and yttrium recovery could be achieved during sorption and also desorption, when solubilization of sorbed associated elements was inhibited by high pH values. ...

360

Bianchi type-IX electromagnetic universes  

Energy Technology Data Exchange (ETDEWEB)

The dynamical effects of spatially homogeneous electromagnetic fields on anisotropic Bianchi type-IX models are studied. The Lagrangians and Hamiltonians affecting the evolution of anisotropy (including the gravitational and electromagnetic potentials) are obtained for very general spatially homogeneous metrics by means of the Arnowitt-Deser-Misner Hamiltonian formalism. For models having diagonal metrics an exact solution for the electromagnetic fields is obtained. This solution allows a qualitative solution for the gravitational variables. The total solution is similar to that of Brill. For Bianchi type-IX models having symmetric and general metrics, a discussion of the qualitative behavior of the universe point under the influence of the above potentials is given. In particular, it is shown that in some cases the presence of the electromagnetic potential inhibits some types of singularities.

1984-01-15

361

Bianchi type-IX electromagnetic universes  

International Nuclear Information System (INIS)

The dynamical effects of spatially homogeneous electromagnetic fields on anisotropic Bianchi type-IX models are studied. The Lagrangians and Hamiltonians affecting the evolution of anisotropy (including the gravitational and electromagnetic potentials) are obtained for very general spatially homogeneous metrics by means of the Arnowitt-Deser-Misner Hamiltonian formalism. For models having diagonal metrics an exact solution for the electromagnetic fields is obtained. This solution allows a qualitative solution for the gravitational variables. The total solution is similar to that of Brill. For Bianchi type-IX models having symmetric and general metrics, a discussion of the qualitative behavior of the universe point under the influence of the above potentials is given. In particular, it is shown that in some cases the presence of the electromagnetic potential inhibits some types of singularities.

362

Bianchi type IX brane-world cosmologies  

International Nuclear Information System (INIS)

We investigate the asymptotic properties of the Bianchi type IX cosmological model in the brane-world scenario. The matter content is assumed to be a combination of a perfect fluid and a minimimally coupled scalar field that is restricted to the brane. A detailed qualitative analysis of the Bianchi type IX brane-world containing a scalar field having an exponential potential is undertaken. It is found that the brane-Robertson-Walker solution is a local source for the expanding Bianchi type IX models, and if k"2<2 the ever-expanding Bianchi IX models asymptote to the power-law inflationary solution. The only other local sink is the contracting brane-Robertson Walker solution. An analysis of the Bianchi type IX models with a scalar field with a general potential is discussed, and it is shown that in the case of expanding models, for physical scalar field potentials close to the initial singularity, the scalar field is ...

2003-07-15

363

Benthic Habitats of the Asuncion Island Northern Mariana Archipelago 2001-2003, Derived From IKONOS Imagery  

Science.gov (United States)

... Coastal Monitoring and Assessment, the University of Hawaii, BAE Systems Spectral Solutions and Analytical Laboratories of Hawaii, LLC. ... ...

364

Benthic Habitats of Swains Island 2001-2003, Derived from IKONOS Imagery  

Science.gov (United States)

... Coastal Monitoring and Assessment, the University of Hawaii, BAE Systems Spectral Solutions and Analytical Laboratories of Hawaii, LLC. ... ...

365

Benthic Habitat of Oahu Derived From IKONOS and Quick Bird Satellite Imagery, 2004-2006  

Science.gov (United States)

... Coastal Monitoring and Assessment, the University of Hawaii, BAE Systems Spectral Solutions and Analytical Laboratories of Hawaii, LLC. ... ...

367

Analysis of modified Van der Pol's oscillator using He's parameter-expanding methods  

British Library Electronic Table of Contents (United Kingdom)

In this work, a powerful analytical method, called He's parameter-expanding methods (HPEM) is used to obtain the exact solutions of non-linear modified Van der Pol's oscillator. The classical Van der Pol equation with delayed feedback and a modified equation where a delayed term provides the damping are considered. It is shown that one term in series expansions is sufficient to obtain a highly accurate solution, which is valid for the whole solution domain. Comparison of the obtained solution with those obtained using perturbation method shows that this method is effective and convenient to solve this problem. This method introduces a capable tool to solve this kind of non-linear problems.

2010-01-01

368

An inexact Newton method for fully-coupled solution of the Navier-Stokes equations with heat and mass transport  

Energy Technology Data Exchange (ETDEWEB)

The solution of the governing steady transport equations for momentum, heat and mass transfer in flowing fluids can be very difficult. These difficulties arise from the nonlinear, coupled, nonsymmetric nature of the system of algebraic equations that results from spatial discretization of the PDEs. In this manuscript the authors focus on evaluating a proposed nonlinear solution method based on an inexact Newton method with backtracking. In this context they use a particular spatial discretization based on a pressure stabilized Petrov-Galerkin finite element formulation of the low Mach number Navier-Stokes equations with heat and mass transport. The discussion considers computational efficiency, robustness and some implementation issues related to the proposed nonlinear solution scheme. Computational results are presented for several challenging CFD benchmark problems as well as two large scale 3D flow simulations.

1997-02-01

369

An efficient computational method for a stochastic dynamic lot-sizing problem under service-level constraints  

British Library Electronic Table of Contents (United Kingdom)

We provide an efficient computational approach to solve the mixed integer programming (MIP) model developed by Tarim and Kingsman [8] for solving a stochastic lot-sizing problem with service level constraints under the static-dynamic uncertainty strategy. The effectiveness of the proposed method hinges on three novelties: (i) the proposed relaxation is computationally efficient and provides an optimal solution most of the time, (ii) if the relaxation produces an infeasible solution, then this solution yields a tight lower bound for the optimal cost, and (iii) it can be modified easily to obtain a feasible solution, which yields an upper bound. In case of infeasibility, the relaxation approach is implemented at each node of the search tree in a branch-and-bound procedure to efficiently sear...

2011-01-01

370

An EXAFS investigation of the structures of bromocopper(II) complexes in some solutions  

International Nuclear Information System (INIS)

The structures of bromocopper(II) complexes in methanolic (M1, M2, M3, M4), ethanolic (E), and aqueous (H) solutions were determined by the analyses of the Cu K- and Br K-edge EXAFS spectra using a curve-fitting method. The molar concentrations of Cu and Br in these solutions prepared by CuBr_2 and LiBr are 0.996 and 1.992 (M1), 1.015 and 5.381 (M2), 0.493 and 4.525 (M3), 0.260 and 4.073 (M4), 1.031 and 4.313 (E), and 0.982 and 5.426 (H). In M1 solution the interatomic distances for the Cu-O_e_q, Br_e_q-Cu, and Br_e_q-O_e_q (_e_q = equatorial) were 2.00A, 2.35A, and 3.15A respectively, and the Br_e_q-Cu-O_e_q angle was estimated as about 92 deg. Therefore, trans-dibromo bis(methanol)copper(II) complex with a slightly distorted planar structure was proposed to be dominant complex species in M1 solution. The interatomic distances in M2, M3, M4 and E solutions were 2.37A and 3.45A ...

371

An Algorithmic Solution for a Queueing Model of a Computer ...  

Science.gov (United States)

... time the terminal becomes active and begins the process of ... The model class considered here is of a single server queueing ... 1 I are both stochastic. ...

1981-01-01

372

Alkaline treatment of biomass fly ash for reactive dye removal from aqueous solution  

British Library Electronic Table of Contents (United Kingdom)

Biomass fly ash was treated with alkaline solution to enhance its adsorption capacity of Reactive Black 5 dye. The results revealed that the alkaline concentration, solution to fly ash ratio, treatment temperature and treatment time had a positive effect on the dye adsorption capacity of the treated fly ash (TFA), due to dissolving SiO2 and increasing the proportion of unburned carbon. In addition, the dye adsorption behavior of the TFA in aqueous solution was investigated. The effects of various experimental parameters (initial pH, initial dye concentration and contact time) were determined spectrophotometrically. The dye adsorption capacity of the TFA was maximized at an alkaline pH (8.2-10.4). The adsorption capacity of dye by the TFA increased with increasing initial dye concentration....

2010-01-01

373

Algebraic approach to solve tt dilepton equations  

International Nuclear Information System (INIS)

The set of nonlinear equations describing the standard model kinematics of the top quark antiquark production system in the dilepton decay channel has at most a fourfold ambiguity due to two not fully reconstructed neutrinos. Its most precise solution is of major importance for measurements of top quark properties like the top quark mass and tt spin correlations. Simple algebraic operations allow one to transform the nonlinear equations into a system of two polynomial equations with two unknowns. These two polynomials of multidegree eight can in turn be analytically reduced to one polynomial with one unknown by means of resultants. The obtained univariate polynomial is of degree 16. The number of its real solutions is determined analytically by means of Sturm's theorem, which is as well used to isolate each real solution into a unique pairwise disjoint interval. The solutions are polished by seeking the ...

2005-11-01

374

Absorption of carbon dioxide in waste tanks  

International Nuclear Information System (INIS)

Air flow rates and carbon dioxide concentrations of air entering and exiting eight H-Area waste tanks were monitored for a period of one year. The average instanteous concentration of carbon dioxide in air is within the range reported offsite, and therefore is not affect by operation of the coal-fired power plant adjacent to the tank farm. Waste solutions in each of the tanks were observed to be continuously absorbing carbon dioxide. The rate of absorption of carbon dioxide decreased linearly with the pH of the solution. Personnel exposure associated with the routine sampling and analysis of radioactive wastes stored at SRP to determine the levels of corrosion inhibitors in solution could be reduced by monitoring the absorption of carbon dioxide and using the relationship between pH and carbon dioxide absorption to determine the free hydroxide concentration in solution.

1987-09-01

375

A Hybrid Integrity Solution for Precision Landing and ...  

Science.gov (United States)

... HAL and VAL limits with the specified PMD of 10-7, the GPS range-rate error must be monitored to assure that the inertial navigation error is not ...

2004-04-01

376

8862 - NASA Technical Reports Server  

Science.gov (United States)

Mar 1, 2011 ... analysis of NaMBT in ethylene glycol-water solutions with high accuracy. It reduces analysis time, requires smaller samples, and is able to ...

377

/l//IIl/ Kennedy Space Center, Florida 12899  

Science.gov (United States)

inhi bi Led ethylene glycol-water solutions for Apol lo spacecraft en- vironmental control systems (I), the concentration of sodium sulfi te ...

378

Wiley::Automotive Electricity: Electric Drive  

Wastenet

... Another solution, hybrid vehicles, combine two sources of energy (electric and chemical), reducing the global consumption of fossil fuels. Fuel cell vehicles are also one of the most promising technologies for the future, with the capacity to use any fuel - hydrogen being the ideal fuel ecologically, but constrained by infrastructure and storage issues. This book explores all these different solutions for moving our vehicles from fossil ...

379

Transition of rotating Bianchi type-IX cosmological model into an inflationary era  

Energy Technology Data Exchange (ETDEWEB)

A Bianchi type-IX cosmological model has been found as a solution of Einstien's vacuum field equations with a cosmological constant. The solution represents a rotating generalziation fo the de Sitter universe. This universe shows a transition to exponential expansion and the vorticity begins to decay exponentially at the grand-unified-theory time. The point of time for this transition is independent of the magnitude of the vorticity. During the Guth inflationary era the vorticity decays by a factor of the order 10 US.

1986-02-15

380

Transition of rotating Bianchi type-IX cosmological model into an inflationary era  

International Nuclear Information System (INIS)

A Bianchi type-IX cosmological model has been found as a solution of Einstien's vacuum field equations with a cosmological constant. The solution represents a rotating generalziation fo the de Sitter universe. This universe shows a transition to exponential expansion and the vorticity begins to decay exponentially at the grand-unified-theory time. The point of time for this transition is independent of the magnitude of the vorticity. During the Guth inflationary era the vorticity decays by a factor of the order 10"-"1"4"2.

381

The implementation of SOMO (SOlution MOdeller) in the UltraScan analytical ultracentrifugation data analysis suite: enhanced capabilities allow the reliable hydrodynamic modeling of virtually any kind of biomacromolecule  

UK PubMed Central (United Kingdom)

The interpretation of solution hydrodynamic data in terms of macromolecular structural parameters is not a straightforward task. Over the years, several approaches have been developed to cope...Full Text Available

2010-02-01

382

Telemetry system for monitoring the ECG for patients with high cardiovascular risk. Main design requirements and technical solutions  

International Nuclear Information System (INIS)

In this paper the main design requirements concerning the setting up of a telemetry ECG monitoring system are presented. The design's most important technical solutions as well as some details are also discussed. This system is intended to provide skilled medical assistance during the cardiac rehabilitation of both asymptomatic and high risk coronary patients

2005-01-01

383

Stereochemistry definition of small organic molecules in solution: [H-H] NOE + molecular mechanics; Okreslenie sterochemii malych czasteczek organicznych w roztworze: [H-H] NOE + mechanika molekularna  

Energy Technology Data Exchange (ETDEWEB)

Scheme of theoretical method of molecular configuration definition for small organic molecules in solution has been presented. The method bases on measurements of nuclear Overhauser effects for proton-proton interactions and molecular mechanics calculations. 3 refs, 1 fig.

1994-12-31

384

Stable halogen complexes of astatine cations in aqueous solutions  

International Nuclear Information System (INIS)

Halide complexes of astatine cations At"+ and AtO"+ were prepared and their rate of migration was measured. The complexes are of the type AtX_2"- and AtOX_2"- (X = Cl"-, Br"-, I"-). The bromo complexes, AtBr_2"- and AtOBr_2"-, have a higher stability than the chloro complexes. The hydrolysis in weakly alkaline solution of AtX_2"- resulted At"-, and that of AtOX_2"- AtO_2"-. (author).

385

Spectrum measurement of neutrons from 40 MeV alpha particle bombardment of tantalum  

International Nuclear Information System (INIS)

The energy distribution of neutrons generated due to bombardment of 40 MeV alpha particles on thick elemental tantalum is measured using threshold activation detectors. A method of unfolding the neutron spectrum from the activation data based on information-entropy weighted average solution is described. The present unfolding method does not require 'a priori' information about the shape of the solution spectrum. 16 refs. (author).

386

Spectrophotometric technique quantitatively determines NaMBT inhibitor in ethylene glycol-water solutions  

Science.gov (United States)

Spectrophotometric method, using a ratio-recording ultraviolet-absorption spectrophotometer, permits analysis of NaMBT in ethylene glycol-water solutions with high accuracy. It reduces analysis time, requires smaller samples, and is able to detect extremely small concentrations of mercaptobenzothiazole.

1967-01-01

387

Red mud and sands handling: New thoughts on an old problem  

Energy Technology Data Exchange (ETDEWEB)

The alumina industry is facing worldwide a growing disposal problem. Red mud creates increasingly technical, economic and environmental problems. Available solutions are reviewed and an old idea using a new approach with pressurized disc or drum filters for red mud is herewith presented and submitted for consideration as a potential and prospective solution to the problem.

1996-10-01

388

Recovery of molybdenum and uranium from activated charcoal containing molybdenum and residual uranium  

Energy Technology Data Exchange (ETDEWEB)

Molybdenum is separated from molybdenum-containing activated charcoal or char also containing small amounts of uranium obtained as a by-product in uranium leaching processes by stripping with an alkaline solution to provide a molybdenum containing solution containing substantially less than 500 ppm u/sup 3/o/sup 8/.

1980-04-22

389

Problems and solutions of the IFSMTF power and switch system  

Energy Technology Data Exchange (ETDEWEB)

Solutions have been found for the problems encountered with the coil power and switching systems of the International Fusion Superconducting Magnet Test Facility (IFSMTF). The coil power system provides the filtered dc sources (+- 12 V dc; 25,000 A) for charging and discharging the coils of the IFSMTF experiment. The switching system provides the means of transferring the coil current into a dump resistor when a rapid discharge of a coil is required due to a coil failure (quench) or other system abnormalities.

1985-01-01

390

Polymer depletion-induced slip near an interface  

Energy Technology Data Exchange (ETDEWEB)

A quantitative description is proposed for the depletion-induced slip thickness and velocity profile of a polymer solution near the wall-fluid interface in simple shear flow. The inhomogeneous polymer density profile at a flat wall is inserted into the equations of motion for the flow of a polymer solution near the flat wall. The theory is in quantitative agreement with simulation results. (letter to the editor)

2005-01-19

391

Pile foundations for offshore structures  

Energy Technology Data Exchange (ETDEWEB)

Pile foundations are extensively used to support off-shore and on-shore structures. Under dynamic loads, the behavior of single pile is well understood. However the soil-pile-soil interaction studies are confusing, on which account the analyses do not necessarily predict response of the systems which may match satisfactorily with the performances. In this paper, the nature of dynamic loads is described, and solutions for soil-pile and pile-soil-pile interaction solutions by several authors are presented and a critical evaluation is made.

1994-12-31

392

Offshore: North Sea facility gets the CETCO solution  

British Library Electronic Table of Contents (United Kingdom)

CETCO Oilfield Services, suppliers of environmental systems, have undertaken a project to treat contaminated water returns on a Floating, Production, Storage and Offloading (FPSO) facility in the North Sea. The solution sees fluids treated during oil well clean-up operations, reducing the potential for overboard oil discharges, and resulting production upsets.

2006-01-01

393

Numerical methods for determining the inhomogeneity boundary in a boundary value problem for Laplace?s equation in a piecewise homogeneous medium  

British Library Electronic Table of Contents (United Kingdom)

A boundary value problem for Laplace?s equation in a bounded two-dimensional domain filled with a piecewise homogeneous medium is considered. The boundary of the inhomogeneity is assumed to be unknown. The inverse problem of determining the inhomogeneity boundary and the solution of the equation given the solution and its normal derivative on the boundary of the domain is discussed. Numerical methods are proposed for solving the inverse problem, and the results of numerical experiments are presented.

2011-01-01

394

NMR study of aluminium chloride and lithium tetrachloroaluminate solutions in a mixed solvent of thionylchloride-methylacetate  

International Nuclear Information System (INIS)

Lithium tetrachloroaluminate solutions in thionylchloride, methylacetate and their mixtures are studied by "7Li and "2"7Al NMR. It is found that introduction of methylacetate in the LiAlCl_4-SOCl_2 system results in a change of lithium tetrachloroaluminate formation constant. In the ternary system, Li"+ is solvated by methyl-acetate after complete destruction of tetrachloroaluminate anion. Refs. 9, figs. 2.

395

Metallic aggregate synthesis by radiolysis of simple or complex salt aqueous solutions. Study by electron microscope of aggregate grafting on carbon membranes  

International Nuclear Information System (INIS)

French ... Title Synthese d'agregats metalliques par radiolyse de solutions aqueuses de sels simples ou complexes. Etude par M. E. du greffage des agregats sur membranes de carbone.

1987-05-20

396

Mechanism of the heterophase of polyacrylonitrile in aqueous and aqueous-alcoholic solution  

Energy Technology Data Exchange (ETDEWEB)

The kinetics of the hydrolysis of polyacrylonitrile in aqueous and aqueousalcoholic solution have been studied. The effects of the solvent on the kinetics of the hydrolysis have been demonstrated, together with the role of diffusion and adsorption of the hydrolyzing agent on the surface of the macromolecules. It has also been shown to be possible to control the extent of hydrolysis and the hydrophilicity of the product.

1985-09-01

397

Mechanism of denting corrosion  

International Nuclear Information System (INIS)

The rapid corrosion of carbon steels in high temperature, acid chloride solutions is shown to be rate limited by the anodic reaction, 3Fe + 4H_2O = Fe_3O_4 + 8H"+ + 8e"-, based on experiments which find that the corrosion rate in 0.1M NiCl_2 solution has an activation energy of 60 kJ/ mole and is unaffected by adding NaCl or by replacing NiCl_2 with PtCl_4. (author).

398

Mathematical analysis of the length-of-arc assumption  

Energy Technology Data Exchange (ETDEWEB)

The observation by Maday in 1974 that the Schmidt-Duffin solution to the optimal fin profile problem was flawed due to neglect of the slant height factor led to a new solution--actually, a demonstration of the ill-posedness of the question--by Snider. The present article proves mathematically that omission of this factor leads inevitably to underestimation of the heat transfer capability of any fin. Additionally, a perturbation scheme for estimating the correction for this effect is derived for configurations with low generalized Biot numbers, and a revised assessment of the performance of the Schmidt fin is presented.

1996-04-01

399

LC-MS analysis in the e-beam and gamma radiolysis of metoprolol tartrate in aqueous solution: Structure elucidation and formation mechanism of radiolytic products  

British Library Electronic Table of Contents (United Kingdom)

E-beam and gamma products from the radiolysis of aqueous solutions of (+-)-metoprolol tartrate, saturated in nitrogen, are analyzed by HPLC with on-line mass and UV detectors. The structures of 10 radiolytic products common to e-beam and gamma irradiations are elucidated by comparing their fragmentation pattern to that of (+-)-metoprolol. Two of the radiolytic products are also metabolites. Different routes for the formation of the radiolytic products are proposed.

2006-01-01

400

Kinetics of achieving equilibrity at the sorption of radionuclides  

International Nuclear Information System (INIS)

Radionuclide (R) sorption from a solution (vapor) by freshly formed crystals with production of substitution solid solutions under different types of self-disordering is studied. Changes of self-defectiveness and macrodefectiveness with time and effect of radiation defects in the presence of P macroquantities are taken into account. An analysis for monodispersed sorbents is performed. It is shown that the achievement of equilibrium within a reasonable time in impurity-solid phase system depends on defectiveness which ensures a required level of the coefficient of impurity diffusion in sorbent crystals.

401

Investigation of dissolution kinetics of tungsten minerals in hydrochloric acid solutions of citric acid  

Energy Technology Data Exchange (ETDEWEB)

Thermodynamic analysis of dissolution processes of tungsten minerals in citric acid solutions in the absence and in the presence of hydrochloric acid has been carried out by means of calculation of Gibbs energy of the chemical reactions. Kinetic characteristics, such as specific dissolution rates and activation energies, are determined. It is established that the dissolution reactions studied take place in kinetic region. A possibility of scheelite selective dissolution in the presence of other tungsten minerals is shown.

1985-03-01

402

Institutional solutions for renewable energy  

Energy Technology Data Exchange (ETDEWEB)

Institutional issues play a critical, but often overlooked, role in the implementation of renewable energy systems. This paper briefly reviews the institutional arrangements involved in deploying renewable energy from both the sender and receiver perspectives, giving the institutional basis principal characteristics, and pros and cons of each institution. It then offers several perspectives on the critical issues facing the deployment of renewable energy systems before offering a number of potential institutional based solutions. (author)

1997-02-01

403

Inflation in a renormalizable cosmological model and the cosmic no-hair conjecture  

Energy Technology Data Exchange (ETDEWEB)

The possibility of having inflation in a renormalizable cosmological model is investigated. The cosmic no-hair conjecture is proved to hold for all Bianchi types except Bianchi type IX. By the use of a conformal transformation on the metric we show that these models are equivalent to the ones described by the Einstein-Hilbert action for gravity minimally coupled to a set of scalar fields with inflationary potentials. Henceforth, we prove that inflationary solutions behave as attractors in solution space, making it a natural event in the evolution of such models.

1989-05-15

404

Inflation in a renormalizable cosmological model and the cosmic no-hair conjecture  

International Nuclear Information System (INIS)

The possibility of having inflation in a renormalizable cosmological model is investigated. The cosmic no-hair conjecture is proved to hold for all Bianchi types except Bianchi type IX. By the use of a conformal transformation on the metric we show that these models are equivalent to the ones described by the Einstein-Hilbert action for gravity minimally coupled to a set of scalar fields with inflationary potentials. Henceforth, we prove that inflationary solutions behave as attractors in solution space, making it a natural event in the evolution of such models.

405

Infinitely many nontrivial solutions for a class of biharmonic equations via variant fountain theorems  

British Library Electronic Table of Contents (United Kingdom)

By a variant version of Fountain Theorem due to Zou [W. Zou, Variant fountain theorems and their applications, Manuscripta Math. 104 (2001) 343-358], the existence of infinitely many solutions is obtained for a class of biharmonic equations where the nonlinearity involves a combination of superlinear and asymptotically linear terms.

2011-01-01

406

In Vivo Determination of Parameters of Nitrate Utilization in Wheat (Triticum aestivum L.) Seedlings Grown with Low Concentration of Nitrate in the Nutrient Solution 1  

UK PubMed Central (United Kingdom)

Six genotypes of winter wheat (Triticum aestivum L.) differing in grain protein concentration were grown on a nutrient solution containing low concentrations of NO3...Full Text Available

1981-12-01

407

Heat capacities and densities of electrolyte mixtures in aqueous solution - application to the determination of apparent molar heat capacities and volumes for potassium triiodide and dioxoneptunium(V) perchlorate  

Energy Technology Data Exchange (ETDEWEB)

Apparent molar heat capacities for KI[sub 3](aq) were determined from flow-microcalorimetric measurements of KI(aq) solutions containing dissolved iodine. From these, the conventional partial molar heat capacity C[sub p,2][sup [infinity

1993-05-01

408

Gravitational fields with space-times of Binachi type IX  

International Nuclear Information System (INIS)

Spatially homogeneous space-times of Bianchi type IX are considered. A general scheme for the derivation of exact solutions of Einstein's equations corresponding to perfect fluid plus pure radiation fields is outlined. Some simple rotating Bianchi type IX cosmological models are presented. The details of these solutions are also discussed. 9 refs. (author).

409

Formation and stability of astatide-mercury complexes  

International Nuclear Information System (INIS)

The formation of astatide-mercury complexes was investigated in aqueous solutions.The obtained complexes were examined by paper electrophoresis. It was found that Hg(OH)At and Hg(OH)I complexes were formed in neutral solution. The stability constants of the obtained complexes were determined by ion-exchange. The preliminary results indicate that the complex of mercury with astatide is much more stable than similar complexes with iodide. (author)

2006-04-01

410

Flue gas desulfurization/denitrification using metal-chelate additives  

Science.gov (United States)

A method of simultaneously removing SO.sub.2 and NO from oxygen-containing flue gases resulting from the combustion of carbonaceous material by contacting the flue gas with an aqueous scrubber solution containing an aqueous sulfur dioxide sorbent and an active metal chelating agent which promotes a reaction between dissolved SO.sub.2 and dissolved NO to form hydroxylamine N-sulfonates. The hydroxylamine sulfonates are then separated from the scrubber solution which is recycled.

1986-01-01

411

Fluctuations of the energy of Stokes pulses of resonance coherent SRS  

International Nuclear Information System (INIS)

An analytic solution is obtained for the equations of resonance coherent SRS by neglecting the population of the final level of the Raman transition for the systems with the active-medium length that is smaller than the wavelength of the incident light. For the extended systems, a numerical solution is obtained. The energy distribution of the Stokes pulses is found. The large-scale (about 100%) fluctuations of the Stokes radiation energy were observed in the case of unsaturated amplified spontaneous emission. (nonlinear optical phenomena)

2000-11-30

412

Estimation of the mean distance of closest approach of some heavy metal ions in aqueous solutions: some experimental and theoretical calculations  

British Library Electronic Table of Contents (United Kingdom)

The estimation of numerical values of the mean distance of closest approach of ions, a, of heavy metal ion salts in aqueous solutions, determined from activity coefficients, as well as from different theoretical approaches, is presented and discussed.

2011-01-01

413

Efficacy and tolerability of 0.5% timolol maleate ophthalmic gel-forming solution QD compared with 0.5% levobunolol hydrochloride BID in patients with open-angle glaucoma or ocular hypertension.  

Science.gov (United States)

We compared the efficacy of timolol maleate ophthalmic gel-forming solution 0.5% QD with that of levobunolol hydrochloride 0.5% BID, as measured by change in intraocular pressure (IOP), effect on heart rate, and ocular tolerability. The study had a positive-controlled, double-masked, randomized, multicenter, 12-week, two-period (6 weeks each), crossover design. One hundred fifty-two patients with open-angle glaucoma or ocular hypertension were randomized to receive either timolol maleate gel-forming solution QD or levobunolol BID for 6 weeks, followed by a crossover to the alternate treatment. IOP and heart rate were measured at morning trough and peak during weeks 3, 6, 9, and 12. Timolol maleate gel-forming solution QD was comparable to levobunolol BID in reducing IOP at peak and trough. Although the effects on peak heart rate were similar between the two medications, the effect on trough heart rate of timolol maleate ...

414

Effect of the adsorption-desorption process intensity on solutal convection near a drop in a horizontal channel  

British Library Electronic Table of Contents (United Kingdom)

The interaction between gravity convection and Marangoni convection in a horizontal rectangular channel filled with a liquid containing a surfactant and a drop of another liquid is numerically investigated. For large Schmidt numbers the occurring oscillatory regime of solutal convection is analyzed. In the model with a surface phase the effect of the adsorption and desorption processes on the convective flow structure is determined. The corresponding initial and boundary value problem is solved using a difference method.

2011-01-01

415

Effect of steric hindrance on carbon dioxide absorption into new amine solutions. Thermodynamic and spectroscopic verification through solubility and NMR analysis  

Energy Technology Data Exchange (ETDEWEB)

Aqueous solutions of 2-amino-2-hydroxymethyl-1,3-propanediol (AHPD), a sterically hindered amine, was examined as a potential CO{sub 2} absorbent and compared with the most commonly used absorbent, monoethanolamine (MEA) solution, through equilibrium solubility measurements and {sup 13}C NMR spectroscopic analyses. The solubilities of CO{sub 2} in aqueous 10 mass % AHPD solutions were higher than those in aqueous 10 mass% MEA solutions above 4 kPa at 298.15 K, but lower below 4 kPa. The solubility difference between these two solutions increased with the CO{sub 2} partial pressures above the crossover pressure. Equilibrated CO{sub 2}-MEA-H{sub 2}O and CO{sub 2}-AHPD-H{sub 2} solutions at various CO{sub 2} partial pressures ranging from 0.01 to 3000 kPa were analyzed by {sup 13}C NMR spectroscopy. AHPD contains more hydroxyl groups than nonhindered MEA, and hence ...

2003-04-15

416

Coumarin-4 laser efficiency up to 0. 14% under coaxial flash-lamp pumping  

Energy Technology Data Exchange (ETDEWEB)

Under coaxial flash lamp pumping the laser efficiency of coumarin-4 in slightly basic ethyl alcohol solution as an active medium has reached a value of 0.14%. That is three times higher than that in the basic aqueous solution. Its tunable wavelength range of laser output has extended from 440 to 510 nm with the maximum at 460 nm.

1987-02-01

417

Cosmology of Nordstroem's first theory of gravitation  

Energy Technology Data Exchange (ETDEWEB)

Nordstroem's first theory of gravitation, which is a Lorentz covariant scalar theory, is discussed, and the cosmological solution to the field equation is derived. It is shown that there are two physically equivalent representations of the theory that differ in the system of units with which measurements are made. The cosmological solution is found to be an infinite, Euclidean universe with a big bang and a big crunch.

1982-03-01

418

Conformational transitions of alternating purine-pyrimidine DNAs in perchlorate ethanol solutions.  

UK PubMed Central (United Kingdom)

Conformational transitions of poly(dA-dC).poly(dG-dT), poly(dA-dT).poly(dA-dT), and other alternating purine-pyrimidine DNAs were studied in aqueous ethanol solutions containing molar concentrations...Full Text Available

1995-11-01

419

Complex formation of At(I) with halogenides in alcoholic solutions  

International Nuclear Information System (INIS)

The stability constants of [AtX_2]"- with X = Cl, Br and I in ethanol and methanol as well as their ion mobilities at a temperature of 298 K and an ionic strength of 0.05 were determined by horizontal zone electromigration in homogeneous electrolyte solution. The results are compared with existing data from aqueous electrolyte systems. (author).

420

Catalysis over activated zeolites  

Science.gov (United States)

A process is provided for conducting organic compound conversion over a catalyst composition comprising a supported crystalline zeolite having a high initial silica-to-alumina mole ratio, said supported zeolite being prepared by compositing said crystalline zeolite with alumina, reacting the composite with a particular hydrogen fluoride solution in a specified way, drying the hydrogen fluoride reacted composite, treating the dried composite by hydrolysis, ammonolysis and/or by contact with an ammonium salt solution, and calcining the resulting material.

1985-02-19

421

CHAPLET-3D results for the 3-D extension C5G7 Mox benchmarks  

Energy Technology Data Exchange (ETDEWEB)

The 3-dimensional (3D) extension C5G7 MOX benchmark problems were solved by CHAPLET-3D code which is based on the idea of dynamic linkage of the multi-plane method of characteristics solutions. The benchmark results are quite accurate in comparison with the reference solutions, independently of the axial solver incorporated in the CHAPLET-3D code. (author)

2005-07-01

422

Bianchi type-IX quantum cosmology of the heterotic string  

Energy Technology Data Exchange (ETDEWEB)

The dimensionally reduced effective action of the bosonic sector of the heterotic string in critical dimensions is employed to derive a Wheeler-DeWitt equation for the Bianchi type-IX cosmology. An exact solution is found that becomes strongly peaked around the isotropic limit as the volume of the three-geometry increases. In principle the global O(6,6) symmetry of the effective action can be employed to generate new solutions from the one presented here.

1994-01-15

423

Bianchi type-IX quantum cosmology of the heterotic string  

International Nuclear Information System (INIS)

The dimensionally reduced effective action of the bosonic sector of the heterotic string in critical dimensions is employed to derive a Wheeler-DeWitt equation for the Bianchi type-IX cosmology. An exact solution is found that becomes strongly peaked around the isotropic limit as the volume of the three-geometry increases. In principle the global O(6,6) symmetry of the effective action can be employed to generate new solutions from the one presented here.

424

Beryllium in aircraft brakes - a summary  

International Nuclear Information System (INIS)

Beryllium has been in use in aircraft brakes for ten years. During the original design phases of the several aircraft programs using beryllium a number of problems requiring solution confronted the designers. In actual service the solution to these problems performed much better than had been anticipated. A summary is presented. (author).

425

Bender-Dunne Orthogonal Polynomials, Quasi-Exact Solvability and Asymptotic Iteration Method for Rabi Hamiltonian  

International Nuclear Information System (INIS)

We present a method for obtaining the quasi-exact solutions of the Rabi Hamiltonian in the framework of the asymptotic iteration method (AIM). The energy eigenvalues, the eigenfunctions and the associated Bender-Dunne orthogonal polynomials are deduced. We show (i) that orthogonal polynomials are generated from the upper limit (i.e., truncation limit) of polynomial solutions deduced from AIM, and (ii) prove to have nonpositive norm. (authors)

2011-08-01

426

Anodic behavior of titanium in sodium iodide solutions. Anionic anodic activation  

Energy Technology Data Exchange (ETDEWEB)

Results are reported which were obtained when investigating the anodic behavior of titanium in sodium iodide solutions. It was concluded that in order to explain the special features in the anodic behavior and anionic anodic activity of titanium one must take into account, both a redistribution of the potential drop between the oxide and the Helmholtz layer and a potential-dependent variation of the catalytic and adsorption properties of the oxidized titanium anode.

1987-02-01

427

A new solution of the Wheeler-De Witt equation  

Energy Technology Data Exchange (ETDEWEB)

We consider the problem of rotation in a homogeneous Bianchi type IX cosmological model. Studying the Wheeler-De Witt equation corresponding to this minisuperspace, and adopting a particular choice of the factor ordering, we are able to find a particular solution which is strongly peaked about isotropy. This result confirms all the previous investigations in this field, and suggests the conclusion that the machian nature of our universe is the natural, i.e. most likely, outcome of the Planck epoch. (orig.).

1991-06-06

428

A new solution of the Wheeler-De Witt equation  

International Nuclear Information System (INIS)

We consider the problem of rotation in a homogeneous Bianchi type IX cosmological model. Studying the Wheeler-De Witt equation corresponding to this minisuperspace, and adopting a particular choice of the factor ordering, we are able to find a particular solution which is strongly peaked about isotropy. This result confirms all the previous investigations in this field, and suggests the conclusion that the machian nature of our universe is the natural, i.e. most likely, outcome of the Planck epoch. (orig.).

429

A method of fundamental solutions for the one-dimensional inverse Stefan problem  

British Library Electronic Table of Contents (United Kingdom)

We investigate an application of the method of fundamental solutions (MFS) to the one-dimensional inverse Stefan problem for the heat equation by extending the MFS proposed in [5] for the one-dimensional direct Stefan problem. The sources are placed outside the space domain of interest and in the time interval (-T,T). Theoretical properties of the method, as well as numerical investigations, are included, showing that accurate and stable results can be obtained efficiently with small computational cost.

2011-01-01

430

A High-Wavenumber Viscosity for High-Resolution Numerical Methods  

Energy Technology Data Exchange (ETDEWEB)

Numerical simulations of compressible flows are commonly based on the Euler equations when effects of viscosity are thought to be negligible. These equations admit singular solutions, even in cases where the initial and boundary conditions are smooth. So-called ''Euler solvers'' rely on numerical dissipation, explicitly or implicitly present in the scheme, to regularize the problem, such that physical solutions are selected.

2003-02-19

431

The seeded growth of calcium sulfate dihydrate crystals in NaCl solutions up to 6 m and 90 C  

Energy Technology Data Exchange (ETDEWEB)

The kinetics of calcium sulfate crystal growth is of importance in various fields, such as geochemistry, desalination technology, petroleum industry, and water and wastewater treatment. The seeded crystal growth rate of calcium sulfate dihydrate was measured as a function of supersaturation in NaCl electrolyte solutions from 0 to 6 m at temperatures of 25, 50, 70, and 90 C. The growth followed a second-order parabolic rate law with activation energies greater than 53 kJ/mol which suggested the surface reaction as the rate-limiting step. It was observed that the rate constant and the activation energy are solution composition dependent. The rate constant increases with NaCl concentration up to 3 molal and then begins to fall slightly. The activation energy dropped from 61 kJ/mol in the pure Ca-SO[sub 4]H[sub 2]O system to 53 kJ/mol in 3.0 m NaCl solutions. The electrolyte effect was similar to the crystal solubility behavior ...

1994-03-15

432

Semiconductor properties and protective role of passive films of iron base alloys  

Energy Technology Data Exchange (ETDEWEB)

Semiconductor properties of passive films formed on the Fe-18Cr alloy in a borate buffer solution (pH = 8.4) and 0.1 M H{sub 2}SO{sub 4} solution were examined using a photoelectrochemical spectroscopy and an electrochemical impedance spectroscopy. Photo current reveals two photo action spectra that derived from outer hydroxide and inner oxide layers. A typical n-type semiconductor behaviour is observed by both photo current and impedance for the passive films formed in the borate buffer solution. On the other hand, a negative photo current generated, the absolute value of which decreased as applied potential increased in the sulfuric acid solution. This indicates that the passive film behaves as a p-type semiconductor. However, Mott-Schottky plot revealed the typical n-type semiconductor property. It is concluded that the passive film on the Fe-18Cr alloy formed in the borate buffer ...

2007-01-15

433

Semiconductor properties and protective role of passive films of iron base alloys  

International Nuclear Information System (INIS)

Semiconductor properties of passive films formed on the Fe-18Cr alloy in a borate buffer solution (pH = 8.4) and 0.1 M H_2SO_4 solution were examined using a photoelectrochemical spectroscopy and an electrochemical impedance spectroscopy. Photo current reveals two photo action spectra that derived from outer hydroxide and inner oxide layers. A typical n-type semiconductor behaviour is observed by both photo current and impedance for the passive films formed in the borate buffer solution. On the other hand, a negative photo current generated, the absolute value of which decreased as applied potential increased in the sulfuric acid solution. This indicates that the passive film behaves as a p-type semiconductor. However, Mott-Schottky plot revealed the typical n-type semiconductor property. It is concluded that the passive film on the Fe-18Cr alloy formed in the borate buffer solution ...

2007-01-01

434

Preparation and characterization of iron oxide thin films by spray pyrolysis using methanolic and ethanolic solutions  

International Nuclear Information System (INIS)

Iron oxide thin films have been obtained by spray pyrolysis using 100% methanolic and ethanolic solutions of iron tri-chloride. The films were deposited onto ITO-coated glass substrates. The preparative conditions have been optimized to obtain compact, pin-hole-free and smooth thin films which are adherent to the substrate. The structural, morphological and compositional characterizations have been carried out by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis. The films deposited using ethanolic solution results into pure hematite; #alpha#-Fe_2O_3 thin films, however, films deposited using methanolic solution consists of hematite and maghemite-c phases of iron oxide. The films are nanocrystalline with particle size of 30-40 nm. The optical absorbance of the film was of the order of 10"5 cm"-"1. The optical band gap of films was found to be 2.26 and 2.20 eV for the films deposited using ...

2006-01-15

435

Molar extinction coefficients in aqueous solutions of some amino acids  

International Nuclear Information System (INIS)

Mass attenuation coefficients of amino acids viz. glycerine (C_2H_5NO_2), 1-Serine (C_3H_7NO_3), 1-Theronine (C_4H_9NO_3), 1-Proline (C_5H_9NO_2), 1-Valine (C_5H_1_1NO_2) and 1-Phenylalanine (C_9H_1_1NO_2) in aqueous solutions have been determined at 81, 356, 511, 662, 1173 and 1332 keV by the gamma-ray transmission method in a narrow beam good geometry setup. Precisely measured densities of these solutions were used for the determination of these coefficients which varied systematically with the corresponding changes in the concentrations (g/cm"3) of the solutions. Molar extinction coefficients of amino acids were then obtained at these energies and were found to be in good agreement with the theoretical results. In addition, total interaction cross sections of amino acids in aqueous solutions were also calculated. (author)

2002-09-01

436

Laboratory differential simulation design method of pressure absorbers for carbonization of phenolate solution by carbon dioxide in coal-tar processing  

Energy Technology Data Exchange (ETDEWEB)

A laboratory differential simulation method is used for the design of carbonization columns at coal-tar processing in which phenols are regenerated from phenolate solution by carbon dioxide absorption. The design method is based on integration of local absorption rates of carbon dioxide along the column. The local absorption rates into industrial phenolate mixture are measured in a laboratory model contactor for various compositions of the gas and liquid phases under the conditions that ensure the absorption rates in the laboratory absorber simulate the local rates in the industrial column. On the bases of the calculations, two-step carbonization columns were designed for 30000 t/year of the phenolate solution treatment by carbon dioxide. The absorption proceeds at higher pressure of 500 kPa and temperatures from 50 to 65 C, pure carbon dioxide is used and toluene is added. These conditions have the following favourable effects: (I) significant ...

2009-01-15

437

Inf-convolution of g_\\Gamma-solution and its applications  

CERN Document Server

A risk-neutral method is always used to price and hedge contingent claims in complete market, but another method based on utility maximization or risk minimization is wildly used in more general case. One can find all kinds of special risk measure in literature. In this paper, instead of using market modified risk measure, we use a kind of risk measure induced by g_\\Gamma-solution or the minimal solution of a Constrained Backward Stochastic Differential Equation (CBSDE) directly when constraints on wealth and portfolio process comes to our consideration. Such g_\\Gamma-solution and the risk measure generated by it is well defined on appropriate space under suitable conditions. We adopt the inf-convolution of convex risk measures to solve some optimization problem. A dynamic version risk measures defined through g_\\Gamma-solution and some similar results about optimal problem can be got in our new ...

2011-01-01

438

IRON (III) MOLAR EXTINCTION COEFFICIENTS IN LIGHT AND HEAVY WATER SOLUTIONS  

Science.gov (United States)

The iron(III) molar extinction coefficient in H/sub 2/O-0.4 M H/sub 2/SO/ sub 4/ solution at maximum absorption and 25 deg C, epsilon /sub s/, was determined to be 2220 plus or minus 20 liters mole/sup -1/ cm/sup -1/. The ratio of the iron(III) molar extinction coefficient in D/sub 2/O-0.4 M H/sub 2/SO/ sub 4/ solution at maximum absorption and 25 deg C to epsilon /sub s/ was found to be 1.068 P 0.004. The acidity effect is presented graphically, since the effect is nonlinear. The temperature coefficients were determined to be +(0.63 plus or minus 0.02)% per de gree centigrade for light water solutions and +(0.36 plus or minus 0.02)% per degree centigrade for heavy water solutions. (auth)

1962-04-01

439

Hydrolysis kinetics of lead silicate glass in acid solution  

International Nuclear Information System (INIS)

Hydrolysis kinetics of the lead silicate glass (LSG) with 40 mol% PbO in 0.5 N HNO_3 aqueous acid solution was investigated. The surface morphology and the gel layer thickness were studied by scanning electron microscopy (SEM) micrographs. Energy dispersive X-ray spectroscopy (EDS) and inductively coupled plasma spectroscopy (ICP) were used to determine the composition of the gel layer and the aqueous solution, respectively. The silicon content of the dissolution products was determined by using weight-loss data and compositions of the gel layer and the solution. The kinetic parameters were determined using the shrinking-core-model (SCM) for rate controlling step. The activation energy obtained for hydrolysis reaction was Q_c_h_e = 56.07 kJ/mole. The diffusion coefficient of the Pb ions from the gel layer was determined by using its concentration in solution and in LSG. The shrinkage of the sample and ...

2009-06-01

440

Hydrogenolysis reactions characteristics of deashed coal under low temperature; Teionka ni okeru dakkai shoritan no suisoka bunkai hanno tokusei  

Energy Technology Data Exchange (ETDEWEB)

In relation to coal liquefaction, the effect of inorganic minerals on liquefaction reactivity and the effect of hydrofluoric acid (HF) treatment on organic molecular structure of coals were studied by demineralization of low-rank coals in HCl or HF solution. In experiment, Taiheiyo coal specimen was deashed in HCl solution at 25-70{degree}C for 6 hours while agitating, and in addition, deashed in HF solution. Hydrogenolysis of the deashed coal specimen was conducted using tetralin or methylnaphthalene as solvent under initial hydrogen pressure of 1.96MPa at reaction temperature of 693K for 60min. The experimental results are as follows. The ash content of Taiheiyo coal hardly offers catalysis in hydrogenolysis reaction. Carboxyl group increases in demineralization of coal because of breakage of bridged bonds. Organic structure of coal changes by demineralization in dense HF solution. Change in organic ...

1996-10-28

441

Hydrogen evolution reaction on single crystal WO3/C nanoparticles supported on carbon in acid and alkaline solution  

British Library Electronic Table of Contents (United Kingdom)

Single crystal tungsten oxide (WO3) nanoparticles were prepared via a microwave-assisted method. Electrochemical activity for hydrogen evolution reaction (HER) on WO3 supported on carbon black (WO3/C) electrocatalyst was first studied in acid solution (0.5 M H2SO4) and alkaline solution (1.0 M KOH) at room temperature. The overall experimental results revealed that the electrocatalytic activity for HER on WO3/C is one order magnitude higher than those obtained with carbon black in 0.5 M H2SO4 and is six times than in the case of carbon black in 1.0 M KOH. These results demonstrated that WO3 could enhance the electrocatalytic activity for hydrogen evolution reaction in acid solution (0.5 M H2SO4) and alkaline solution (1.0 M KOH). On the other hand, the kinetic reaction mechanisms were disc...

2011-01-01

442

Glass Transition Behaviors of Ethylene Glycol-Water Solutions Confined within Nano-Pores of Silica Gel  

Science.gov (United States)

Enthalpy relaxation properties of the ethylene glycol (EG) aqueous solutions confined within silica-gel void spaces of 1.1 nm in the average void thickness and 6, 12 and 52 nm in their average diameters were examined by an adiabatic calorimetry to understand the glass transition behavior of the solutions and the rearrangement processes of the molecules. The glass transition temperature Tg of EG was found to decrease with adding the water molecules which are mobile under the condition lacking in the full hydrogen-bond network. Meanwhile, the Tg in the water-rich region showed a rise towards pure water; after a phase separation in a 25 mol% (x = 0.25) EG solution, the Tg was 160 K which was higher than that derived by extrapolating the composition dependence to pure water. The Tg = 160 K is the same as observed in the pure water confined within 1.1 nm voids; this indicates the validity of the interpretation that the glass ...

2008-02-01

443

Effects of Cr content and the addition of Cr_2O_7"2"- ion on corrosion resistance of stainless steel in nitric acid solutions  

International Nuclear Information System (INIS)

A nitric acid solution containing Cr_2O_7"2"- ion is used for a corrosion test which simulates the condition in a nuclear fuel reprocessing plant. As the effect of Cr content on the corrosion resistance of stainless steel is not yet fully understood in that solution, the effects of Cr content in an alloy and that of Cr_2O_7"2"- ion in nitric acid on the corrosion rate were studied by using electro-chemical measurements. The increase of Cr content reduced the general corrosion rate in nitric acid solution without Cr_2O_7"2"- ion, however it increased that in nitric acid solution containing Cr_2O_7"2"- ion. It is considered that the reversal of the Cr content dependency is due to a rise of the corrosion potential caused by addition of Cr_2O_7"2"- ion to the potential region where a high Cr alloy shows higher anodic dissolution rate than a low Cr content alloy. (author).

444

Effect of surface treatemnts on stress corrosion cracking of alloy 800 in alkaline solutions. Alloy 800 no alkaline yoekichu no ouryoku fushoku ware ni oyobosu hyomenkako no eikyo  

Energy Technology Data Exchange (ETDEWEB)

Effect of the coverage of shot peening, the surface roughness and shot shape, etc. on the stress corrosion cracking (SCC) of Alloy 800 in alkaline solutions was studied. Alloy 800 specimens were cracked in boiling alkaline solutions at the potntial range of {minus} 100 to 0mV in the boiling 50%NaOH+0.3%SiO {sub 2} solution. U bend specimens were tested under the polarized condition at the controlled potential to 0mV, showing that shot peened specimens cracked more easily. Tests of specimens with the same hardness showed that specimens hardened by cold working showed the higher susceptivity than that of surface hardened specimens. In these connections, U bend specimens of higher shot peened coverage were cracked at conditions of 593K and 10%NaOH solution. O-ring specimens of smaller stress level did not show any cracks independent of surface treatments. 8 refs., 9 figs., 5 tabs.

1990-03-15

445

A hydroxide mixture as working fluid for absorption heat pumps  

Energy Technology Data Exchange (ETDEWEB)

Basic experimental investigations were carried out with an aqueous solution of a mixture of KOH and NaOH for use as an absorbent in absorption heat pumps. Due to its thermophysical properties this mixture allows temperature lifts from evaporator to absorber of more than 75 K (135 F) in a single-stage absorption chiller. Thermophysical and hydrodynamical properties of the solution were measured. Vapor-liquid-equilibrium data and specific heat capacities were determined for concentrations ranging from 35% up to 75% and temperatures up to 200 C (392 F). From these data the enthalpy of the solution was calculated. Additionally the crystallization temperatures, the density, and the viscosity of the solution were determined. The experimental equipment is described. The data are presented as polynomials and diagrams including experimental accuracy. An apparatus was constructed to measure heat and mass transfer ...

1996-11-01

446

The effect of hydrogen peroxide solution on SO2 removal in the semidry flue gas desulfurization process.  

Science.gov (United States)

The present study attempts to use hydrogen peroxide solution to humidify Ca(OH)(2) particles to enhance the absorption of SO(2) to achieve higher removal efficiency and to solve the valuable reuse of the reaction product in the semidry flue gas desulfurization (FGD) process. Experiments were carried out to examine the effect of various operating parameters including hydrogen peroxide solution concentration, Ca/S molar ratio and approach to adiabatic saturation temperature on SO(2) removal efficiency in a laboratory scale spray reactor. The product samples were analyzed to obtain semi-quantitative measures of mineralogical composition by X-ray diffraction (XRD) with reference intensity ratio (RIR) method and the morphology of the samples was examined by scanning electron microscope (SEM). Compared with spraying water to humidify Ca(OH)(2), SO(2) removal efficiency was improved significantly by spraying hydrogen peroxide ...

2009-04-24

447

Passivation behavior of SUS 304 stainless steel in neutral solutions at elevated temperature  

Energy Technology Data Exchange (ETDEWEB)

Cyclic voltammograms of SUS 304 stainless steel in various neutral solutions such as Na/sub 2/SO/sub 4/ at high temperature were measured, as a successive study to previous report in which effects of temperature and pH on polarization behavior of stainless steel were studied. In this measurement Ag/AgCl reference electrode and platinum counter electrode were used in a static autoclave lined with inconel. Passive films formed in various conditions were analysed by electron diffraction and Auger spectroscopy. Results obtained were compared with anodic behavior of iron, chromium and nickel and with thermodynamical stabilities of their compounds. The main results are summarized as follows. (1) Stainless steel shows such electrochemical behavior as active dissolution, passivation and transpassivation in a deaerated neutral solution at 250/sup 0/C after fully reductive treatment of the specimen. In air-saturated solution, the ...

1981-03-01

448

Influence of pH on the passivation behavior of 254SMO stainless steel in 3.5% NaCl solution  

Energy Technology Data Exchange (ETDEWEB)

The potentiodynamic polarization measurement of 254SMO stainless steel (UNS 31254) was conducted in 3.5% NaCl solutions with pH ranging from 0.1 to 5. The results indicated that this stainless steel offered excellent pitting corrosion resistance in corrosive environments. Further, it also exhibited various features on the polarization curves in different pH solutions. The electrochemical constant-potential passivation treatment performed at different pH followed by XPS analysis revealed that the primary constituents of the outermost layer of the passive films formed in the weak (pH 5) and strong (pH 0.8) acid solutions are iron oxides and Cr{sub 2}O{sub 3} and Cr(OH){sub 3}, respectively. Molybdenum oxides, primarily in the six-valence state, existed in the outermost layer of the passive film. Only very weak signals corresponding to that of nickel oxides were detected in the film formed in the weak acid (pH 5) ...

2007-05-15

449

Influence of pH on the passivation behavior of 254SMO stainless steel in 3.5% NaCl solution  

International Nuclear Information System (INIS)

The potentiodynamic polarization measurement of 254SMO stainless steel (UNS 31254) was conducted in 3.5% NaCl solutions with pH ranging from 0.1 to 5. The results indicated that this stainless steel offered excellent pitting corrosion resistance in corrosive environments. Further, it also exhibited various features on the polarization curves in different pH solutions. The electrochemical constant-potential passivation treatment performed at different pH followed by XPS analysis revealed that the primary constituents of the outermost layer of the passive films formed in the weak (pH 5) and strong (pH 0.8) acid solutions are iron oxides and Cr_2O_3 and Cr(OH)_3, respectively. Molybdenum oxides, primarily in the six-valence state, existed in the outermost layer of the passive film. Only very weak signals corresponding to that of nickel oxides were detected in the film formed in the weak acid (pH 5) ...

2007-05-01

450

Thermodynamic study of systems with lower critical solution temperatures: H_2O + (C_2H_5)_3N, D_2O + (C_2H_5)_3N  

International Nuclear Information System (INIS)

Molar excess enthalpies and molar excess volumes are reported for the systems H_2O + (C_2H_5)_3N and D_2O + (C_2H_5)_3N at temperatures below and above their lower critical solution temperatures. The molar excess enthalpies are slightly less exothermic for the D_2O system. The molar excess volumes of the H_2O and D_2O systems are within experimental error of one another. Compositions of conjugate solutions estimated from the calorimetric and volumetric measurements agree with those obtained from published liquid-liquid phase diagrams. (Auth.).

1979-01-01

451

The Computation Directorate at Lawrence Livermore National Laboratory  

Energy Technology Data Exchange (ETDEWEB)

The Computation Directorate at Lawrence Livermore National Laboratory has four major areas of work: (1) Programmatic Support -- Programs are areas which receive funding to develop solutions to problems or advance basic science in their areas (Stockpile Stewardship, Homeland Security, the Human Genome project). Computer scientists are 'matrixed' to these programs to provide computer science support. (2) Livermore Computer Center (LCC) -- Development, support and advanced planning for the large, massively parallel computers, networks and storage facilities used throughout the laboratory. (3) Research -- Computer scientists research advanced solutions for programmatic work and for external contracts and research new HPC hardware solutions. (4) Infrastructure -- Support for thousands of desktop computers and numerous LANs, labwide unclassified networks, computer security, computer-use policy.

2006-09-07

452

Supercritical Fluid Immersion Deposition: A New Process for Selective Deposition of Metal Films on Silicon Substrates  

Energy Technology Data Exchange (ETDEWEB)

Supercritical CO2 is used as a new solvent for immersion deposition, a galvanic displacement process traditionally carried out in aqueous HF solutions containing metal ions, to selectively develop metal films on featured or non-featured silicon substrates. Components of supercritical fluid immersion deposition (SFID) solutions for fabricating Cu and Pd films on silicon substrates are described along with the corresponding experimental setup and procedure. Only silicon substrates exposed and reactive to SFID solutions can be coated. The highly pressurized and gas-like supercritical CO2, combined with the galvanic displacement property of immersion deposition, enables the SFID technique to selectively deposit metal films in small features. SFID may also provide a new method to fabricate palladium silicide in small features or to metallize porous silicon.

2005-01-01

453

Sulfonaphtholazoresorcinol as reagent for tungsten  

International Nuclear Information System (INIS)

Interaction of W(6) with sulphonaphtholazoresorcinol (SNAR) in aqueous solution has been studied. Tungsten is determined in the form of sulphonaphtholazoresorcinate by extraction with higher alcohols. The optimum conditions for the formation of a complex of W with SNAR in aqueous solution are as follows: a 10-fold excess of SNAR, concentration of HCl 1-1.5N, ethanol content 5-10 vol.%, time of formation of the complex 30 min. A component ratio for the complex has been established in the case of aqueous solution and extract; molar extinction coefficients are 0.9x10"4 and 1.7x10"4, respectively. The formation constant for the complex being extracted is 2.2x10"2"3. A method has been developed for determination of microgram quantities of W in a vanadium specimen.

1977-01-01

454

Role of temperature in the spontaneous precipitation of calcium sulfate dihydrate  

Energy Technology Data Exchange (ETDEWEB)

The spontaneous precipitation of calcium sulfate in supersaturated solutions over the temperature range between 25.0 and 80.0 C was investigated by monitoring the solution specific conductivity during desupersaturation. From measurements of the induction times preceding the onset of precipitation the surface energy of the forming solid, identified as gypsum, was found between ca. 12 and 25 mJ/m{sup 2} for the temperature range between 80.0 and 25.0 C, respectively. Kinetics analysis showed that over 50 C it is possible that anhydrous calcium sulfate is forming as a transient phase converting into the more stable calcium sulfate dihydrate. The linear dependence of the rates of precipitation on the relative solution supersaturation suggested a mechanism according to which the growth units are integrated into the active sites of the supercritical nuclei by surface diffusion. According to the morphological examination of the ...

1999-02-16

455

Removal of reactive dye Brilliant Red HE-3B from aqueous solutions by industrial lignin: Equilibrium and kinetics modeling  

British Library Electronic Table of Contents (United Kingdom)

The lignin, one of the main by-products of the pulp industry, can be used to remove dyes from textile wastewaters. The potential of the lignin for Brilliant Red HE-3B reactive dye removal from aqueous solutions at pH=1.5 was examined by the batch technique as a function of dye concentration, solution temperature and contact time. The Freundlich, Langmuir, Dubinin-Radushkevich and Tempkin adsorption isotherms were used to describe the data of sorption equilibrium and to determine its corresponding isotherm constants. The thermodynamic parameters DG, DH and DS were also determined; the obtained values show that the sorption of reactive dye on lignin is a spontaneous, endothermic and entropy-driven process. The kinetic of reactive dye sorption was analyzed using the pseudo-first order and pse...

2010-01-01

456

Radiation oxidation of phenol in petrochemical waste water. II  

International Nuclear Information System (INIS)

The rate was studied of radiation destruction of phenol aqueous solutions at a concentration range of 1 to 100 ppm. Irradiated were model solutions containing additions of some organic and inorganic substances typical of the petrochemical industry. In view of the fact that the radiation destruction kinetics is determined by the amount of dissolved oxygen in the sample and by the phenol concentration, relatively low doses were used. Thus, a sufficient amount of oxygen in the sample and therefore the oxidation mechanism of radiolysis were ensured. The dose-response relationships for phenol destruction were studied using doses of 50, 100, 200 and 400 J.kg"-"1; the limit dose was 500 J.kg"-"1. From the results obtained, a kinetic model was constructed of radiation phenol oxidation in aqueous solutions in the presence of various organic and inorganic additions. (B.S.).

1981-01-01

457

Properties of the passive films formed on ferritic stainless steels in Cl/sup -/ Solutions  

Energy Technology Data Exchange (ETDEWEB)

The pitting resistance of Fe-Cr and Fe-Cr-Mo alloys has been correlated with characteristics of the passive films analyzed by Auger electron spectroscopy (AES). Increased film protectiveness as a result of increased Cr in the alloy can be directly attributed to Cr enrichment of the film and decreased film thickness. Increased Mo in the alloy or passivation at noble potentials promotes passive film resistance to breakdown, but neither does much to change the macrocharacteristics of the film. Rather, it is suggested that the roles of alloying and/or passivation conditions are related to the susceptibility and distribution of weak points of the film. In solutions in which pitting occurs, chloride is generally not incorporated into the film, suggesting that the role of halides is to interact with weak points of the film at the solution/film interface. At 260/sup 0/C, the films are much thicker and likely to be much more defective in structure than ...

1986-10-01

458

Phylogenetic constraints on digesta separation: Variation in fluid throughput in the digestive tract in mammalian herbivores  

British Library Electronic Table of Contents (United Kingdom)

The relevance of the mean retention time (MRT) of particles through the gastrointestinal tract (GIT) is well understood and MRTparticleGIT is an important parameter in digestion models. Solute markers have been used to estimate MRTsoluteGIT (or 'fluid passage') in animals, but the relevance of this measure is less evident and is usually sought in its relation to MRTparticleGIT. The ratio between the two measures indicates the degree of 'digesta washing', with little washing occurring at ratios of 1, aborad washing at ratios >1 (where the solute marker travels faster than the particle marker), and orad (retrograde) washing at ratios <1 (where the solute marker travels slower than the particle marker). We analysed digesta washing in a dataset of 98 mammalian species including man of differen...

2011-01-01

459

PVT-apparatus for measurements on gas/oil solutions up to 2000 bar and 440 K  

Energy Technology Data Exchange (ETDEWEB)

A high pressure piezometer is described with which pVT-measurements on solutions of gases in liquids like oils can be performed at pressures and temperatures up to 2000 bar and 440 K, respectively. The present investigations deal mainly with the system squalaneCO/sub 2/ at different mole fractions, but also with squalaneN/sub 2/. The high accuracy of the measurements reveals a pronounced structure of the pV-curves in dependence on temperature and mole fraction. At larger mole fractions is the unequivocal assignment of the phases ambiguous, and the representation of the experimental data in terms of an equation of state not possible for the whole pressure and temperature range. However, for solutions with lower mole fractions could be determined the saturation pressures and the isothermal compressibility in the unsaturated region. Furthermore, the molar excess volumes of the mixture have been calculated and the phase behaviour has been discussed ...

1982-11-01

460

Non-dissipative kinetic simulation and analytical solution of three-mode equations of ion temperature gradient instability  

Energy Technology Data Exchange (ETDEWEB)

A non-dissipative drift kinetic simulation scheme, which rigorously satisfies the time-reversibility, is applied to the three-mode coupling problem of the ion temperature gradient (ITG) instability. It is found from the simulation that the three-mode ITG system repeats growth and decay with a period which shows a logarithmic divergence for infinitesimal initial perturbations. Accordingly, time average of the mode amplitude vanishes, as the initial amplitude approaches to zero. An exact solution is analytically given for a class of initial conditions. An excellent agreement is confirmed between the analytical solution and numerical results. The results obtained here provide a useful reference for basic benchmarking of theories and simulation of the ITG modes. (author)

1999-12-01

461

Nitrilotriacetate complex of univalent astatine  

Energy Technology Data Exchange (ETDEWEB)

Formation of the complex of the univalent astatine cation with nitrilotriacetic acid (AtL)[sup 2-] and its stability constant (lgK[sub 1]=8.97(4), 25degC, [mu]=0.1) have been found experimentally for the first time. The complex is stable in perchlorate solutions in presence of 5 . 10[sup -3] mol . l[sup -1] of the oxidizer Na[sub 2]S[sub 2]O[sub 8] in the interval 4[<=]pH[<=]8.5. The complex is supposed to be destroyed in weak alkaline solutions by reduction of astatine to astatide. The deprotonation constant of hypoastatic acid pK[sub dp]=5.23(9) was found to be lower than determined previously. The investigation was carried out by the method of ion electrophoresis in free electrolyte solutions. (orig.).

1992-01-01

462

Nitrilotriacetate complex of univalent astatine  

International Nuclear Information System (INIS)

Formation of the complex of the univalent astatine cation with nitrilotriacetic acid (AtL)"2"- and its stability constant (lgK_1=8.97(4), 25degC, #mu#=0.1) have been found experimentally for the first time. The complex is stable in perchlorate solutions in presence of 5 . 10"-"3 mol . l"-"1 of the oxidizer Na_2S_2O_8 in the interval 4#<=#pH#<=#8.5. The complex is supposed to be destroyed in weak alkaline solutions by reduction of astatine to astatide. The deprotonation constant of hypoastatic acid pK_d_p=5.23(9) was found to be lower than determined previously. The investigation was carried out by the method of ion electrophoresis in free electrolyte solutions. (orig.).

463

Morphology, structure, and conductivity of polypyrrole prepared in the presence of mixed surfactants in aqueous solutions  

British Library Electronic Table of Contents (United Kingdom)

Polypyrrole (PPy) was prepared from different mixed-surfactant solutions with ammonium persulfate as an oxidant. Three types of combinations were selected, including cationic/anionic, cationic/nonionic, and anionic/nonionic mixed-surfactant solutions. The surfactants used in the experiments included cetyltrimethylammonium bromide (cationic surfactant), sodium dodecyl sulfate (anionic surfactant), sodium dodecyl sulfonic acid salt (anionic surfactant), poly(vinyl pyrrolidone) (nonionic surfactant), and poly(ethylene glycol) (nonionic surfactant). The morphology, structure, and conductivity of the resulting PPy were investigated in detail with scanning electron microscopy, Fourier transform infrared spectra, and the typical four-probe method, respectively. The results showed that the interac...

2007-01-01

464

Mechanism of solubilization in detergent solutions  

Energy Technology Data Exchange (ETDEWEB)

The kinetics of the solubilization of lauric acid, palmitic acid, stearic acid, and monopalmitin have been studied in detergent solutions as a function of concentration, temperature, and fluid flow. The detergents used were sodium dodecyl sulfate (an anionic surfactant), decyltrimethylammonium bromide (a cationic surfactant), sodium taurocholate (a trihydroxy bile salt), sodium taurodeoxycholate (a dihydroxy bile salt), and triton X-100 (a nonionic surfactant). At low temperature, solubilization can be described by a five-step mechanism is which micelle desorption and diffusion are rate controlling. At temperatures above the fatty acid penetration temperature, solubilization is governed by formation of a liquid crystalline phase at the fatty acid-detergent solution interface.

1981-11-01

465

MODELING AN ION EXCHANGE PROCESS FOR CESIUM REMOVAL FROM ALKALINE RADIOACTIVE WASTE SOLUTIONS  

Energy Technology Data Exchange (ETDEWEB)

The performance of spherical Resorcinol-Formaldehyde ion-exchange resin for the removal of cesium from alkaline radioactive waste solutions has been investigated through computer modeling. Cesium adsorption isotherms were obtained by fitting experimental data using a thermodynamic framework. Results show that ion-exchange is an efficient method for cesium removal from highly alkaline radioactive waste solutions. On average, two 1300 liter columns operating in series are able to treat 690,000 liters of waste with an initial cesium concentration of 0.09 mM in 11 days achieving a decontamination factor of over 50,000. The study also tested the sensitivity of ion-exchange column performance to variations in flow rate, temperature and column dimensions. Modeling results can be used to optimize design of the ion exchange system.

2008-08-26

466

In situ Raman spectroscopy investigation of bioactive glass reactivity: Simulated body fluid solution vs TRIS-buffered solution  

British Library Electronic Table of Contents (United Kingdom)

In the present contribution, the innovative in situ Raman micro-spectroscopy was applied to investigate the in vitro reactivity of various bioactive glasses. All the investigated glasses belonged to the Na2O\\K2O-CaO-P2O5-SiO2 system, but contained sensibly different percentages of network modifiers. The glasses were immersed for increasing times, up to 96h, in simulated body fluid (SBF) and in tris-buffered (TRIS) solution. In this way, two fundamental items were addressed, i.e. the effect of the glass composition and the nature of the soaking fluid on the overall reactivity. As regards the SBF, all the glasses were able to promote the formation of a hydroxyl-carbonate apatite (HCA) surface layer in very short times. The reaction rate was particularly quick for the 45S5 Bioglass and for it...

2011-01-01

467

Hydrodynamics induced vibration to trash-racks  

International Nuclear Information System (INIS)

In conventional power plants trash-racks are provided at the intakes to protect the turbines. In pumped storage plants, the draft tube or tailrace must also have trash-racks to protect the units while pumping. Because the loads believed to cause many failures of trash-racks are dynamic in nature, it is important to understand the dynamic characteristics of trash-racks structures in general and a single rack in particular. The classical added-mass solution structure-fluid dynamic interaction is known as an approximate solution procedure. An accurate added-mass approach mixed with implementation in finite element framework is proposed. In this proposal, experimental conclusions, supported by theory, led to presentation of more accurate results in vibration of trash-racks. This numerical solution as a powerful method to solve such a complex problem can be employed to carry out dynamic characteristics of these structures while ...

2002-12-01

468

How do Black Holes Spin in Chern-Simons Modified Gravity?  

CERN Document Server

No Kerr-like exact solution has yet been found in Chern-Simons modified gravity. Intrigued by this absence, we study stationary and axisymmetric metrics that could represent the exterior field of spinning black holes. For the standard choice of the background scalar, the modified field equations decouple into the Einstein equations and additional constraints. These constraints eliminate essentially all solutions except for Schwarzschild. For non-canonical choices of the background scalar, we find several exact solutions of the modified field equations, including mathematical black holes and pp-waves. We show that the ultrarelativistically boosted Kerr metric can satisfy the modified field equations, and we argue that physical spinning black holes may exist in Chern-Simons modified gravity only if the metric breaks stationarity, axisymmetry or energy-momentum conservation.

2007-01-01

469

Homoclinic chaos and energy condition violation  

International Nuclear Information System (INIS)

In this letter we discuss the connection between so-called homoclinic chaos and the violation of energy conditions in locally rotationally symmetric Bianchi type IX models, where the matter is assumed to be nontilted dust and a positive cosmological constant. We show that homoclinic chaos in these models is an artifact of unphysical assumptions: it requires that there exist solutions with positive matter energy density #rho#>0 that evolve through the singularity and beyond as solutions with negative matter energy density #rho#<0. Homoclinic chaos is absent when it is assumed that the dust particles always retain their positive mass. In addition, we discuss more general models: for solutions that are not locally rotationally symmetric we demonstrate that the construction of extensions through the singularity, which is required for homoclinic chaos, is not possible in general.

2006-09-15

470

High-resolution NMR on /sup 29/Si nuclei in acidic zeolites  

Science.gov (United States)

The effect of treatment of Na-forms of zeolites with HCl solutions and of heat treatment of their NH/sub 4/-forms on the stability of aluminum-oxygen tetrahedra has been studied in this work by high-resolution NMR on /sup 29/Si nuclei, using the synthetic zeolites X, Y, and M (mordenite) as the objects of the study. The exchange capacity with respect to Na/sup +/ ions was determined by analyzing the equilibrium solutions after contact of the samples with 0.5 NH/sub 4/Cl solution on a flame photometer. The high-resolution /sup 29/Si NMR spectra of polycrystalline samples were recorded on an SKhR-200 spectrometer with a superconducting solenoid at a frequency of 39.75 MHz with ultrafast mechanical rotation (3 kHz) of the sample at the magic angle to the external magnetic field. The results obtained are given.

1986-12-01

471

Greenhouse effect gas reduction in large industries. Approaches and solutions  

International Nuclear Information System (INIS)

Efforts in industry concerning pollution abatement up to nowadays were aimed at: solid particles contained in gaseous effluents, SO_2 effluent reduction, nitrogen oxide effluent limitation through combustion technology enhancement. Various CO_2 emission scenarios with different energy production means (same or increased nuclear plant number, energy consumption reduction) show that energy conservation schemes for the developed countries are the best solution to CO_2 control. Different solutions for greenhouse gas abatement from industrial plant are reviewed: effluent processing, burner technological enhancement, heat transfer optimization on industrial processes, computer assisted management for industrial processes, plasma technic for refining, substitution of gas to oil in chemistry, etc.

1991-01-01

472

Formation of defects in epitaxial heterostructures and multicomponent solid solutions of semiconductor compounds  

International Nuclear Information System (INIS)

The authors discuss several aspects of defect formation in epitax heterostructures based on solid solutions of A"3B"5 semiconductor compounds; these heterstructures were prepared by liquid phase epitaxy by cooling suitable high-temperature solutions from the initial growth temperature. An analysis shows that the regions near heterojunctions are regions of increased defect density even in compositions based on Al /SUB x/ Ga /SUB 1-x/ As-GaAs, Al /SUB x/ Ga /SUB 1-x/ P-GaP, Al /SUB x/ Ga /SUB 1-x/ Sb-GaSb, where the differences in lattice parameters of the contacting materials are a minimum.

473

Experimental study on simultaneous desulfurization and denitrification from flue gas with composite absorbent  

British Library Electronic Table of Contents (United Kingdom)

Abstract The characteristics of desulfurization and denitrification with composite absorbent were researched through aqueous absorption experiments. The removal efficiencies of SO2 and NO were up to 100 and 95%, respectively. The composite absorbent included NaClO2 and component M. Existence of component M in the solution could reduce the absorbent cost compared with using sodium chlorite alone. Chlorine dioxide, as main reaction intermediate product, participated in oxidation reaction. The optimal experimental conditions involved NaClO2 concentration of1.13 mmol/L, solution pH of 5.5, molar ratio (M/NaClO2) of 4.1, reaction temperature of 323 K. The optimal solution pH and reaction temperature were both in the required ranges of limestone-gypsum wet flue gas desulfurization (FGD) process....

2011-01-01

474

Evaluation of Chemical Interactions of Maleic Acid with Sodium Hypochlorite and Chlorhexidine Gluconate  

British Library Electronic Table of Contents (United Kingdom)

IntroductionThe elimination of microorganisms from the root canal system necessitates the use of combination of irrigating solutions to enhance their antimicrobial property. The combination of irrigants and their interaction sometimes could be detrimental to the outcome of the root canal therapy. The purposes of this study were (1) to evaluate the interaction between 7% maleic acid (MA) and 2% chlorhexidine gluconate solution (CHX) and to find out the availability of individual irrigant and (2) to determine the free available chlorine content when 7% MA was mixed with 2.5% sodium hypochlorite (NaOCl) solution. MethodsInteraction between MA and CHX was assessed by high-performance liquid chromatography. Available chlorine content in NaOCl was evaluated by the standard iodine/thiosulfate tit...

2011-01-01

475

Enhanced carbon dioxide removal by promoted hot potassium carbonate in a split-flow absorber  

Energy Technology Data Exchange (ETDEWEB)

In this work, a comprehensive model has been developed for the absorption of carbon dioxide into promoted hot potassium carbonate solution. The model, which is based on penetration theory, incorporates an extensive set of important reactions and takes into account the coupling between mass transfer and chemical kinetics. The penetration theory provides an appropriate absorption rate and enhancement factor for the chemical absorption. Operating data for carbon dioxide absorption into DEA-hot potassium carbonate solution has been compared with model predictions. The impact of parameters such inlet temperature of lean solution, promoter concentration, liquid split fraction, hot feed location and type of promoter on the performance of a split-flow absorber have been examined. The use of other promoters is an efficient way to enhance the carbon dioxide absorption, which has been discussed in this paper.

2004-07-01

476

Electrospinning of poly(vinyl pyrrolidone)-iodine complex and poly(ethylene oxide)/poly(vinyl pyrrolidone)-iodine complex - a prospective route to antimicrobial wound dressing materials  

British Library Electronic Table of Contents (United Kingdom)

New nanofibers containing poly(vinyl pyrrolidone)-iodine complex (PVP-iodine) were obtained by electrospinning in order to prepare materials suitable for wound dressings. Different approaches were used: a one-step method based on electrospinning of PVP-iodine or poly(ethylene oxide)/PVP-iodine solutions and a three-step method based on electrospinning of PVP or poly(ethylene oxide)/PVP mixed solutions followed by photo-mediated crosslinking of the obtained nanofibers and subsequent complexation with iodine. The average diameters of the fibers were in the range 150-470nm depending on the composition and on the applied field strength (AFS) and increased with increasing the amount of PEO in the spinning solutions. Higher AFS resulted in greater fiber diameter and in size distribution broadeni...

2007-01-01

477

Electrochemical behavior of aluminum in 1-n-butyl-3-methylimidazolium tetrafluoroborate ionic liquid electrolytes for capacitor applications  

British Library Electronic Table of Contents (United Kingdom)

This study compares two series of solvents for application in aluminum electrolytic capacitors: ethylene glycol (EG) and water mixtures, and ethylene glycol and 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMI.BF4) ionic liquid (IL) mixtures. Electrochemical impedance spectroscopy and cyclic voltammetry were carried out with a previously anodized aluminum disk electrode. Comparative measurements of solution resistance, polarization resistance, AC capacitance, and passive current were made. The results show that EG?IL mixtures with low amounts of IL (10% IL?90% EG v/v) have a low solution resistance. Low values of solution resistance, high values of polarization resistance, small passive current, and uniform capacitance of anodized aluminum in EG?IL mixtures are favorable properties of ...

2009-01-01

478

Effects of stress on radiation hardening and microstructural evolution in A533B steel  

British Library Electronic Table of Contents (United Kingdom)

Bent specimens of A533B steel (0.16wt% Cu) were irradiated at 290degreeC to 1dpa with 6.4MeV Fe3+ ions. Calculated tensile stresses at the irradiated surface were set to 0, 250, 500 and 750MPa. The specimens were subjected to hardness measurements, transmission electron microscopy (TEM) observations and three-dimensional atom probe (3DAP) analysis. The radiation-induced hardening decreased with increasing stress to 500MPa which was near the yield strength. TEM and 3DAP results showed that well-defined dislocation loops and solute clusters were formed. The diameter of dislocation loops increased and the number density decreased when the stress was applied, whereas the diameter and number density of solute clusters decreased. The hardening was mainly attributed to solute cluster formation. A...

2010-01-01

479

Effect of preparative treatment on the corrosion resistance of duplex stainless steel  

International Nuclear Information System (INIS)

The effect of surface treatment on the characteristics of the passive film on a super duplex stainless steel is addressed. Auger Electron Spectroscopy (AES) has been used to provide in-depth chemical profile analyses of the passivation film. This study showed that the constitution of the film is largely dependent on the electrolytic conditions under which it is produced or to which it is submitted. The passive films formed by polarisation in an alkaline solution (boric-borate solution) consist of two regions, an inner region rich in chromium and an outer region rich in iron, whilst the films produced in acid solution only present the chromium - rich region. The film thickness is also greatly affected by the polarisation conditions. It can vary from ca. 8 monolayers to about 20 monolayers for cathodically and anodically polarised specimens respectively. The microstructure of weldmetal is also discussed. (author)

1999-09-01

480

Effect of alloying elements on intergranular corrosion susceptibility of Mo contained austenitic stainless steel in nitric acid solution  

International Nuclear Information System (INIS)

In this study, effects of alloying elements such as Mo, Cr and Ni on intergranular corrosion (IGC) resistance of Mo contained austenitic stainless steels in boiling 65% nitric acid solution (Huey Test) were studied. Obtained results are as follows; (1) Mo deteriorates IGC resistance of austenitic stainless steel in Huey test due to enhance precipitation of Laves ((Fe, Cr)_2Mo) phase at grain boundary. (2) Cr improves IGC resistance of Mo contained austenitic stainless steel in Huey test, which is considered to reduce dissolution rate of Laves phase into nitric acid solution by increasing Cr content in Laves phase as increasing Cr content of stainless steel. (3) Ni suppresses occurrence of IGC of Mo contained austenitic stainless steel in Huey test. (author).

1995-01-01

481

Development of ultrafiltration and adsorbents: October 1979-March 1980  

Energy Technology Data Exchange (ETDEWEB)

Tests on a sample of trench water from the Maxey Flats burial ground effectively demonstrated the new Reverse Osmosis Pilot Plant. The effluent from the 50% salt-rejection membrane was decontaminated well enough with the exception of tritium to be discharged to the environment. The performance of the 97% salt-rejection membrane was superior to that of the 50% membrane. A breakthrough and capacity experiment was conducted with Durasil 10 on a simulated Three Mile Island solution. The maximum decontamination factor was extrapolated to be 10/sup 6/, which would reduce the cesium level of TMI water to below the discard limit. Capacity (1/DF = 0.5) was reached at 1260 column volumes. Several adsorbents were tested in the engineering columns for decontamination of cesium-bearing solutions. Under the conditions of the experiment, these adsorbents were ineffective in removing cesium from the solution.

1980-07-02

482

Determination of platinum and ruthenium in Pt and Pt-Ru catalysts with carbon support by direct and derivative spectrophotometry.  

Science.gov (United States)

Platinum and ruthenium in carbon supported Pt and Pt-Ru catalysts were determined by direct and derivative spectrophotometric methods. Complexes of platinum and ruthenium with SnCl(3)(-) ligands (tin(II) chloride in HCl) were used to determine both metals in solutions obtained after digestion of the samples of the catalysts. Platinum in the Pt/C catalyst can be determined in solutions obtained by digestion of the samples in aqua regia. Derivative spectrophotometry was used to determine both metals in the presence of each other in solutions obtained after digestion of samples of the Pt-Ru/C catalyst in the mixture of HCl+HNO(3) (6:1). The first derivative at 377 nm (;zero-crossing' point of ruthenium) and the second-derivative values at 495 nm (;zero-crossing' point of platinum) were used to estimate the concentration of platinum and ruthenium, respectively. PMID:18967441

1999-01-01

483

Corrosion behavior of sputter-deposited W-Nb alloys in NaCl and NaOH solutions  

International Nuclear Information System (INIS)

The corrosion behavior of the sputter-deposited amorphous or nanocrystalline W-Nb alloys is studied in 10% NaCl, 0.1 and 1 M NaOH solutions at 24 deg. C, open to air using immersion tests and electrochemical measurements. Niobium metal acts synergistically with tungsten in enhancing the corrosion resistance of the W-Nb alloys so as to show lower corrosion rates than the corrosion rates of the alloy-constituting elements in almost all examined solutions. Corrosion rates of W-Nb alloys are about more than one order of magnitude less than that of the sputter-deposited tungsten and even lower than that of sputter-deposited niobium. The stability of the anodic passive films formed on the W-Nb alloys increase with niobium content.

2008-05-29

484

Core-shell polymer nanorods by a two-step template wetting process  

International Nuclear Information System (INIS)

One-dimensional core-shell polymer nanowires offer many advantages and great potential for many different applications. In this paper we introduce a highly versatile two-step template wetting process to fabricate two-component core-shell polymer nanowires with controllable shell thickness. PLLA and PMMA were chosen as model polymers to demonstrate the feasibility of this process. Solution wetting with different concentrations of polymer solutions was used to fabricate the shell layer and melt wetting was used to fill the shell with the core polymer. The shell thickness was analyzed as a function of the polymer solution concentration and viscosity, and the core-shell morphology was observed with TEM. This paper demonstrates the feasibility of fabricating polymer core-shell nanostructures using our two-step template wetting process and opens the arena for optimization and future experiments with polymers that are desirable ...

2009-07-22

485

Coir pith-a biosorbent for removal of cesium from aqueous solutions  

International Nuclear Information System (INIS)

Coir pith (CP), an abundantly available lignocellulosic agricultural waste from the local coir industry has been found to be an effective biosorbent for removal of metal ions from aqueous solutions. Transition metal hexacyanoferrates, in particular nickel hexacyano ferrate (NiHCF) also referred to as Prussian blue analogue (PBA), is known to be highly selective for removal of cesium from aqueous solutions. A novel method for the synthesis of PBA inside the porous matrix of coir pith and use of this composite material for the sorption of cesium is described in this paper. Equilibrium experiments showed that the sorption capacity of coir pith nearly doubled due to the modification. Owing to its low cost and rapid sorption kinetics, this hybrid material seems to be one of the most promising compounds for the recovery of cesium from liquid nuclear wastes. (author)

2007-01-04

486

Chemical composition and electronic structure of passive films formed on Alloy 600 in acidic solution  

Energy Technology Data Exchange (ETDEWEB)

The chemical composition and the semiconducting properties of passive films formed on nickel based alloy (Alloy 600) in acidic sulphate solution, pH 2.0 at room temperature were studied using Auger analysis, voltammetric techniques and the Mott-Schottky approach. The results obtained revealed that the presence of both chromium and mixed nickel-iron oxides in the films leads to the development of a p-n heterojunction, which controls their electronic structure, similarly manner to the case of stainless steels and Alloy 600 in borate buffer solution. This behavior has been interpreted as representing of an oxide system, which has a duplex character, with an inner p-type semiconducting region, mainly formed by chromium oxide and an outer n-type semiconducting region, containing iron oxide. It could also be observed that the nickel oxide present in the films acts as a barrier layer conferring improved protection.

2008-03-15

487

Chemical composition and electronic structure of passive films formed on Alloy 600 in acidic solution  

International Nuclear Information System (INIS)

The chemical composition and the semiconducting properties of passive films formed on nickel based alloy (Alloy 600) in acidic sulphate solution, pH 2.0 at room temperature were studied using Auger analysis, voltammetric techniques and the Mott-Schottky approach. The results obtained revealed that the presence of both chromium and mixed nickel-iron oxides in the films leads to the development of a p-n heterojunction, which controls their electronic structure, similarly manner to the case of stainless steels and Alloy 600 in borate buffer solution. This behavior has been interpreted as representing of an oxide system, which has a duplex character, with an inner p-type semiconducting region, mainly formed by chromium oxide and an outer n-type semiconducting region, containing iron oxide. It could also be observed that the nickel oxide present in the films acts as a barrier layer conferring improved protection.

2008-03-01

488

Characterization of the product of the thiosulfate process for desulfurization of flue gases  

Energy Technology Data Exchange (ETDEWEB)

X-ray diffraction, infrared spectroscopy, thermal analysis, scanning electron microscopy, and particle size analysis were used to characterize the product of the thiosulfate process. It was found to consist of a mixture of a solid solution of calcium sulfate in calcium sulfite hemihydrate, calcium sulfate dihydrate, and calcium carbonate. Reactions taking place on heating the byproduct were identified in oxidizing and reducing atmospheres. Pure calcium sulfite hemihydrate as well as solid solutions of CaSO[sub 4] in CaSO[sub 3] [center dot] (1/2)H[sub 2]O with different sulfate concentrations were synthesized in the laboratory. Thermal analyses of pure solid solutions proved that the higher the sulfate content, the higher is the dehydration temperature. Accordingly, taking SO[sub 4][sup 2[minus

1994-05-01

489

CERL code capabilities for modeling AVT chemistry  

International Nuclear Information System (INIS)

The CERL Code was developed to describe the solution chemistry of the water on the steam generating side of PWR reactors. It is designed to calculate the equilibrium species distribution resulting from the interaction of impurities, corrosion products, and additives in the aqueous solution. It calculates the extent of ion-ion interactions, the precipitation of insoluble species and the amount of solute that partitions into the vapor phase when some of the water evaporates. This knowledge of the bulk phase equilibrium distribution of species, especially the pH should be useful in describing the corrosion processes at the solid liquid boundary. The code does not calculate any changes in oxidation states or any rates of reaction. Therefore, it is incapable of calculating the actual corrosion rates. It is anticipated that it will be used as a subprogram of a larger program that will include the redox reactions and the rates of ...

1985-03-01

490

Biosorption behavior and mechanism of beryllium from aqueous solution by aerobic granule  

British Library Electronic Table of Contents (United Kingdom)

The treatment of Be-contaminated wastewater has been paid little attention, although beryllium (Be) and its compounds are of high toxicity. In this research, aerobic granule was for the first time introduced to remove Be from aqueous solution. Influencing factors including reaction time, initial Be concentration, pH, biosorbent dosage, and coexistent metal ions (Cd, Cu, and Fe) were investigated in batch experiments. The aerobic granule, characterized by element analysis and CLSM, was abundant in carboxyl, phosphoryl, amine and hydroxyl groups. Potentiometric titration experiment demonstrated that the pH effect on biosorption depended on the surface charge of granule (pHzpc=2.4) and the species of Be (Be^2^+, Be(OH)^+, and Be(OH)2) in solution. The coexistent metal ions would either inhibi...

2011-01-01

491

Behavior of Np(VII, VI, V) in Silicate Solutions  

Energy Technology Data Exchange (ETDEWEB)

Spectrophotometric methods were used to investigate the properties of neptunium(VII), (VI), and (V) in silicate solution. The transition of cationic neptunium(VII) to anionic species in non-complexing environments proceeds in the range of ?? 5.5 to 7.5. In the presence of carbonate, this transition occurs at ?? 10.0 to 11.5 and in silicate solutions at ?? 10.5-12.0. These findings show that cationic neptunium(VII) forms complexes with both carbonate and silicate and that the silicate complex is stronger than that of the carbonate. The competition of complex formation reactions for neptunium(VI) with carbonate and silicate and on the known complex stability constant of NpO2(CO3)34- allowed the NpO2SiO3 complex stability constant, log ? = 16.5, to be estimated. Determination of the formation constant of Np(V) complexes with SiO32- was not possible using similar methods.

2004-11-30

492

Anion capture with calcium, aluminium and iron containing layered double hydroxides  

British Library Electronic Table of Contents (United Kingdom)

The competitive adsorption of nitrate, chloride and carbonate in layered double hydroxides (LHD) with the general formula Formula Not Shown was investigated. Both normal ion exchange by exposure to a solution containing different anions, as well as addition of calcined material to solution thereby exploiting the memory effect of LDHs was studied. Changes in the interlayer anion changed the interlayer spacing of the LDH. The order of preference of intercalation was Formula Not Shown . When multiple anions were present in the exchange solution, LDHs with several distinct interlayer spacing were produced indicating that LDHs with different anions in the interlayer existed at the same time. However for extended exchange times (14days) where high concentrations of carbonate anion were present, ...

2011-01-01

493

Analysis and design of high speed thrust ball bearings. (Reannouncement with new availability information)  

Energy Technology Data Exchange (ETDEWEB)

In this paper, a complete solution of the steady-state Newton-Euler equations describing the motion of the balls in high speed thrust bill bearings is presented. Kinematic equations are derived and used as ancillary equations to obtain the numerical solution of the Newton-Euler equations. This differs from previously reported work where extraneous assumptions (instead of kinematic analysis) are used to allow solutions of these equations. It is shown that the no-slip condition for the ball motion reported in the literature is based on an unnecessary assumption. The correct form of the condition is developed and used in the analysis of the ball motion. The analysis shows the importance of contact angle on both ball motion and contact force. An approximate theory is then developed for determining the optimum contact angle that would result in minimum contact force in high speed ball bearings. The results are compared with ...

1991-12-31

494

An Accurate Numerical Solution to the Kinetics of Breakable Filament Assembly  

CERN Document Server

Proteinaceous aggregation occurs through self-assembly-- a process not entirely understood. In a recent article [1], an analytical theory for amyloid fibril growth via secondary rather than primary nucleation was presented. Remarkably, with only a single kinetic parameter, the authors were able to unify growth characteristics for a variety of experimental data. In essence, they seem to have uncovered the underlying allometric laws governing the evolution of filament elongation simply from two coupled non-linear ordinary differential equations (ODEs) stemming from a master equation. While this work adds significantly to our understanding of filament self-assembly, it required an approximate analytical solution representation. Here, we show that the same results are found by purely numerical means once a straightforward and reliable numerical solution to the set of ODEs has been established.

2010-01-01

495

Adsorption of Pb^2^+ and Zn^2^+ from aqueous solutions by sulfured orange peel  

British Library Electronic Table of Contents (United Kingdom)

In this study, sulfured orange peel (MOP) was used as adsorbent to investigate its adsorption behaviors of Pb^2^+ and Zn^2^+ from aqueous solutions. The effects of solution pH, adsorption time and metal ion concentration on adsorption were studied in batch experiments. Both adsorption kinetics of Pb^2^+ and Zn^2^+ proceeded rapidly and could be well described by pesudo-second-order equation. The maximum Langmuir adsorption capacities for Pb^2^+ and Zn^2^+ removal by MOP were evaluated as 164 and 80mg/g, respectively. A binary mixture of Pb^2^+ and Zn^2^+ was studied by using a packed column, suggesting that effective mutual separation and pre-concentration of Pb^2^+ away from Zn^2^+ using MOP could be satisfactory achieved. The results indicate that MOP could be employed as an effective lo...

2011-01-01

496

Absorption of CO/sub 2/ in aqueous solutions of mixtures of alkanolamines  

Energy Technology Data Exchange (ETDEWEB)

The bulk removal of CO/sub 2/ from industrial gases is a frequently applied process in the field of gas-treating. Usually chemical solvents are used in order to increase both the solvent-loading capacity and the absorption rate. These solvents often are aqueous solutions of alkanolamines. The loaded-liquid is regenerated at high temperatures with the aid steam. In the present study absorption rates are experimentally determined in various mixtures of amines over a wide range of concentrations. Simultaneously, a model was developed for the description of mass transfer accompanied by parallel reversible chemical reactions. The equations of this mass transfer model could not be solved analytically and therefore numerical techniques were used to obtain an exact description of this process. This model also includes the asymptotic situations of homogeneous catalysts and shuttle mechanism for which in the literature several approximate solutions have ...

1988-01-01

497

A routine chemical dosimetric system using the modified ceric sulphate dosimeter  

International Nuclear Information System (INIS)

The radiolytic reduction of the Ce4+ in a 0.8N sulfuric acid was examined, with the objective of measuring large radiation doses. the ceric sulphate dosimeter was tested in the range from 1 to 20kGy. The 0.01 M sodium oxalate solution was chosen instead of the arsenious oxide solution (used in the conventional method), in order to obtain a less expensive dosimetric system than that normally use for routine chemical dosimetry. The absorption spectrum of the Ce"4"+ solution presents an absorption peak at 370 nm; the obtained molar extinction coefficients of Ce"4"+ and Ce"3"+ were 5670 and 2.7 M"-"1 cm"-"1 respectively. The purpose of this work was to establish a simple, reliable and inexpensive routine chemical dosimetric system for high doses.

1994-10-01

498

A Computer Simulation of the Electronic Structure of Leucine in Aqueous Solution  

British Library Electronic Table of Contents (United Kingdom)

In order to obtain the electronic structure of leucine (Leu) in aqueous solution, we studied three systems: Leu+7H2O, Leu+8H2O and Leu+9H2O. The results indicated that the system Leu+8H2O was the only choice which was both acceptable and doable: its computational effort was affordable, and it could simulate a main part of the solvent effect on the electronic structure of Leu in solution. Based on the system Leu+8H2O, all-electron, ab initio calculations were performed to construct an equivalent potential of water for the electronic structure of Leu with dipoles. The results showed that the main effect of water on the electronic structure of Leu was raising the occupied states about 0.0824 Ry on average, and broadening the energy gap by 11%. The water effect on the electronic structure of L...

2011-01-01

499

/sup 109/Ag NMR spectra of aqueous silver ions coordinated with nitroxide radical. Silver-TANOL complex and TANOL as a doping agent  

Energy Technology Data Exchange (ETDEWEB)

The effects of TANOL radical have been examined on chemical shifts and relaxation rates of /sup 109/Ag NMR in aqueous solution of silver salts. The silver ion in aqueous solution is found to coordinate with TANOL radical. A small amount of TANOL is added as a doping agent(0.020M), since /sup 109/Ag signals are obtained for (1.0M) silver ion within 30 minutes. The /sup 109/Ag chemical shifts of silver salt in aqueous solutions were found within the range of 0 to -1000 ppm relative to that of 1.0M AgNo/sub 3/.

1982-09-01