WorldWideScience
 
 
5

DESIGN OF INTROSCOPES WITH HIGHER SENSITIVITY  

Science.gov (United States)

... Corporate Author : Personal Author(s) : GORBUNOV ,VI ; SVIRYAKIN ,DI ; CHANTSEV ,VI ; KOLUPAEV ,AN ; MAXIMENKO,AD. ...

1973-06-01

6

Liquid crystal controller driver IC for stationary telephone set; Sueoki denwakiyo ekisho controller driver IC  

Energy Technology Data Exchange (ETDEWEB)

A liquid crystal display panel (LCD) has come into use as a display device for a stationary telephone set. This LCD driving IC requires high functionality and miniaturization. At Fuji Electric Co.,Ltd., in accordance with the demand, an LCD controller driver IC was developed which incorporates an icon display circuit and a voltage generating circuit for liquid crystal. The main features are as follows. In addition to 5 x 8 (dot), 16 digits, 2 line character display, the IC is equipped with independently controllable 32 kinds of icon displays. The power supply voltage operating range is 2.4-5.5V. Additional external parts are unnecessary because of a built-in CR oscillation circuit, power supply circuit for liquid crystal, and a boosting circuit. The IC is provided with a gold bump electrode structure mountable with COG (Chip On Glass) and TAB (Tape Automated Bonding). (NEDO)

1999-01-10

7

The removal and recovery of Cr(VI) by Li/Al layered double hydroxide (LDH)  

Energy Technology Data Exchange (ETDEWEB)

Hexavalent Cr has been identified as one of the toxic metals commonly present in industrial effluents. Among the treatment techniques developed for removing Cr(VI) from waste waters, sorption is most commonly applied, due to its simplicity and efficiency. However, few adsorbents can be recycled and reused cost-effectively. In this study, the removal and recovery of Cr(VI) from water using Li/Al LDH was investigated. The removal of Cr(VI) by Li/Al LDH was evaluated in a batch mode. The results demonstrated that Cr(VI) adsorption onto Li/Al LDH occurs by replacing the Cl{sup -} that originally exists in the interlayer of the adsorbent. The degree of Cr(VI) adsorption observed for Li/Al LDH was relatively high and the process occurred rapidly; however, a portion of adsorbed Cr(VI) was gradually desorbed, due to the Li de-intercalation of Li/Al LDH. Lithium ...

2007-04-02

8

Biosorption of uranium (VI) by immobilized Aspergillus fumigatus beads  

Energy Technology Data Exchange (ETDEWEB)

Biosorption of uranium (VI) ions by immobilized Aspergillus fumigatus beads was investigated in a batch system. The influences of solution pH, biosorbent dose, U (VI) concentration, and contact time on U (VI) biosorption were studied. The results indicated that the adsorption capacity was strongly affected by the solution pH, the biosorbent dose and initial U (VI) concentration. Optimum biosorption was observed at pH 5.0, biosrobent dose (w/v) 2.5%, initial U (VI) concentration 60 mg L{sup -1}. Biosorption equilibrium was established in 120 min. The adsorption process conformed to the Freunlich and Temkin isothermal adsorption models. The dynamic adsorption model conformed to pseudo-second order model.

2010-06-15

9

The reduction of actinide ions by hydroxamic acids  

Science.gov (United States)

Simple hydroxamic acids have been shown to have useful applications in an Advanced Purex process for the reprocessing of irradiated nuclear fuel. They are especially suited to the separation of neptunium (IV) from uranium (VI) by the selective formation of a hydrophilic complex with Np(IV). U(VI) extraction in to 30% tributyl phosphate is unaffected. However, they have also been shown to be very fast reducing agents for Np(VI). The timescales of the reduction have been defined under a range of typical Purex Process conditions although the accurate determination of the reaction kinetics was not possible due to the rapidity of the reaction. U(VI) was shown not to be reduced. Therefore, Np(VI) can be efficiently reductively stripped when solvent phase (30% tributyl phosphate in odourless kerosene) solutions of Np(VI) and U(VI) are contacted ...

1999-01-01

10

Research progress in the electrochemical synthesis of ferrate(VI)  

International Nuclear Information System (INIS)

There is renewed interest in the +6 oxidation state of iron, ferrate (VI) (FeVIO42-), because of its potential as a benign oxidant for organic synthesis, as a chemical in developing cleaner ('greener') technology for remediation processes, and as an alternative for environment-friendly battery cathodes. This interest has led many researchers to focus their attention on the synthesis of ferrate(VI). Of the three synthesis methods, electrochemical, wet chemical and thermal, electrochemical synthesis has received the most attention due to its ease and the high purity of the product. Moreover, electrochemical processes use an electron as a so-called clean chemical, thus avoiding the use of any harmful chemicals to oxidize iron to the +6 oxidation state. This paper reviews the development of electrochemical methods to synthesize ferrate(VI). The approaches chosen by different laboratories to overcome some of the difficulties ...

2009-04-01

11

Polarography of uranium(VI)-salicylic acid system  

Energy Technology Data Exchange (ETDEWEB)

Uranium(VI)-salicylic acid system has been studied polarographically in perchloric acid medium. Varying concentrations of HClO/sub 4/ and salicylic acid have been used. The nature of the polarographic waves is irreversible.

1980-08-01

12

High power photon beamline elements in the LBL/SSRL/EXXON Beamline VI  

Energy Technology Data Exchange (ETDEWEB)

Beamline VI is a wiggler-based, multi-kilowatt, intense synchrotron radiation beamline installed SPEAR. The thermal design parameters for this beamline are presented and then design considerations and construction descriptions are given for many of the high-power photon beamline elements.

1992-09-01

13

Researches on plasma physics and controlled fusion in NPP NSC KIPT  

International Nuclear Information System (INIS)

2006 p. 3 Ukraine Tereshin, VI Stepanov, KN Volkov, ED Institute of Plasma

2006-09-11

14

Geology and mineralization of the district auriferous Chancon, VI Region, Chile  

International Nuclear Information System (INIS)

Spanish 2001 p. 8-14 Uruguay Rodriguez Bakulic, M. Instituto de Geologia

2001-11-12

15

Electroluminescence Study of Green Be-Contained II-VI ...  

Science.gov (United States)

... laser structure. However, still the greater part (60%) of emitted photons is a result of a spontaneous radiation process. In ...

2000-06-23

16

Deuteron break-up by the 27.2 MeV- alpha particle  

International Nuclear Information System (INIS)

Russian 1974. USSR Grantsev, VI Dryapachenko, IP Kornilov, VA Nemets,

1974-01-29

17

Deuteron break-up by the 27,2 MeV-alpha particle  

International Nuclear Information System (INIS)

Russian (Oct 1974). USSR Grantsev, VI Dryapachenko, IP Kornilov,

1974-01-29

18

Adsorption of hexavalent chromium from aqueous solution by using activated red mud  

Energy Technology Data Exchange (ETDEWEB)

Adsorption by activated red mud (ARM) is investigated as a possible alternative to the conventional methods of Cr(VI) removal from aqueous synthetic solutions and industrial effluents. Adsorption characteristics suggest the heterogenous nature of the adsorbent surface sites with respect to the energy of adsorption. Various factors such as pH, contact time, Cr(VI) concentration, amount of adsorbent, and temperature are taken into account, and promising results are obtained. The applicability of the Langmuir as well as Freundlich adsorption isotherms for the present system is tested. The loading factor (i.e., milligrams Cr(VI) adsorbed per gram of ARM) increased with initial Cr(VI) concentration, whereas a negative trend was observed with increasing temperature. The influence of the addition of anions on the adsorption of Cr(VI) depends on the relative affinity of the anions for the ...

1999-09-01

19

Selective extraction of U(VI) and some other metals from nitric acid media by poly-phosphine poly-oxides  

International Nuclear Information System (INIS)

For the selective extraction of radionuclides from nitrate media, the extractabilities of organo-poly-phosphine poly-oxides were examined in the form of impregnated resins. It was found that the extractability of 1,1,3,5,5-pentaphenyl-1,3,5-tri-phospha-pentane trioxide (PPTPT) for U(VI) is quite unusual with very high values at both low and high concentrations of nitric acid, which is not observed for other types of extractants. Thus, this extractant might be promising for the selective extraction of U(VI) in very high concentrations of HNO3. (authors)

2008-09-15

20

Genetic variability, heritability and genetic advance for seedling traits in sorghum genotypes  

International Nuclear Information System (INIS)

Analysis of data on seedling traits from 20 diverse genotypes revealed significant differences fro most of the seedling traits. Significant estimates of broad-sense heritability were observed for VI, ERI, FRTW, DRTW and R/S ratio. Genetic advance was maximum for VI,ERI and E%. The correlation of VI with ERI and R/S ratio was negative and significant, whereas it was positive and significant with E%, FSHW and DSHW. Characterization of the sorghum genotypes according to Anderson's Metro glyph Statistics revealed five different groups for seedling trails. (authors)

1999-01-01

 
 
 
 
21

Camouflage Patterns-Effects of Size and Color.  

Science.gov (United States)

... CAMOUFLAGE PATTERS- EFFECTS OFSIZE AND COL0R.-(U I'. * ... Camouflage, survei.Ilance, countersurveiliance, vi~sion, color ...

1979-07-01

22

Zero-valent iron and iron oxide-coated sand as a combination for removal of co-present chromate and arsenate from groundwater with humic acid  

International Nuclear Information System (INIS)

The combination of zero-valent iron (Fe0) and iron oxide-coated sand (IOCS) was used to remove Cr(VI) and As(V) from groundwater in this study. The efficiency and the removal mechanism of Cr(VI) and As(V) by using this combination, with the influence of humic acid (HA), were investigated using batch experiments. Results showed that, compared to using Fe0 or IOCS alone, the Fe0-IOCS can perform better on the removal of both Cr(VI) and As(V). Metal extraction studies showed that As(V) was mainly removed by IOCS and iron corrosion products while Cr(VI) was mainly removed by Fe0 and its corrosion products. Competition was found between Cr(VI) and As(V) for the adsorption sites on the iron corrosion products. HA had shown insignificant effects on Cr(VI) removal but some effects on As(V) removal kinetics. As(V) was adsorbed on IOCS at the earlier stage, but ...

2011-02-01

23

Pseudomonas aeruginosa tssC1 Links Type VI Secretion and Biofilm-Specific Antibiotic Resistance.  

Science.gov (United States)

Biofilm-specific antibiotic resistance is influenced by multiple factors. We demonstrated that Pseudomonas aeruginosa tssC1, a gene implicated in type VI secretion (T6S), is important for resistance of biofilms to a subset of antibiotics. We showed that tssC1 expression is induced in biofilms and confirmed that tssC1 is required for T6S. PMID:21784934

2011-07-22

24

Method of purifying uranium tetrafluoride hydrate and preparing uranium (VI) peroxide hydrate using a fluoride complexing agent  

International Nuclear Information System (INIS)

The annual production of phosphate rock, on the order of about 30-40 million tons yearly, represents several million pounds of uranium. The present invention provides a process of purifying uranium tetrafluoride hydrate to produce a uranium (VI) peroxide product meeting 'yellow cake' standards using a double precipitation procedure. A fluoride complexing agent is used in the precipitation.

1978-06-27

25

Impact of the ENDF/B-VI Cross Section on the RPV Fluence Determination  

Energy Technology Data Exchange (ETDEWEB)

The calculations with the broad-group cross-section library Bugle-96, and atom displacement (dpa) cross sections for iron, both derived from ENDF/B-VI data, result in higher calculated fast neutron fluxes, better agreement of calculations with radiometric dosimeter measurements, and significantly slower dpa rate attenuation through pressure vessel walls relative to the results with their predecessors: the Sailor library and ASTM iron dpa cross sections.

1999-09-12

26

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

27

lla2260k.265  

Science.gov (United States)

... sgqoqpwmwm}nfkmjk vrry^vi}likkulfooxkgqsrqsz lrtvs lq~wsly zuxqjrij{t p}tmv{ q{ ny{rnbsv xxtn{ zvwp| xokzz}k {otw|n |xmrv qrxznn}dl jry~| yhavyjjnemuj} ...

28

The effects of chromium VI on the fitness and on the beta-tubulin genes during in vivo development of the nematode Steinernema feltiae.  

Science.gov (United States)

The entomopathogenic nematode (EPN), Steinernema feltiae, is a commonly occurring nematode in the soil in Ireland. Consequently, we have conducted investigations as to the utility of this species as a candidate organism for the detection of chromium in Irish soils. These experiments have demonstrated that S. feltiae can survive and reproduce in the presence of high concentrations of chromium VI. It was observed that concentrations as high as 1000 ppm have little effect on the ability of this organism to produce large numbers of progeny. Nematodes were not observed to reproduce above 1800 ppm. However, an increase in development times for the nematode in vivo was noted at concentrations of 400 ppm upwards. This paper also illustrates the effects upon the beta-tubulin genes within nematode populations exposed to chromium VI in vivo. DNA sequencing has shown that elevated levels of variations occur among the population treatments, although these ...

2008-07-18

29

Specific expression profile and prognostic significance of peroxiredoxins in grade II-IV astrocytic brain tumors  

UK PubMed Central (United Kingdom)

BackgroundPeroxiredoxins (Prxs) have recently been suggested to have a role in tumorigenesis.MethodsWe studied the expression of Prx I-VI and their...Full Text Available

30

SUBMIT TO: AM105 CONFERENCE TITLE: Earth Observing Systems VI - NASA  

Science.gov (United States)

BAE SYSTEMS Infrared Imaging Systems. MS 209. 2 Forbes Road. Lexington, MA 02421 -7306. (781) 863-3762. (781) 863-4809 (fax) ken.overoye @lmco.com ...

31

Institute of Plasma Physics, Academy of Sciences of the Czech Republic  

International Nuclear Information System (INIS)

The major activities of the various Institute's departments are highlighted. The following departments are included: (i) Tokamak; (ii) Pulse plasma systems; (iii) Thermal plasma; (iv) Materials engineering; (v) Laser plasma; and (vi) Optical diagnosis. (P.A.)

32

Comparative aspects of cortical neurogenesis in vertebrates  

UK PubMed Central (United Kingdom)

The mammalian neocortex consists of six layers. By contrast, the reptilian and avian cortices have only three, which are believed to be equivalent to layers I, V and VI of mammals. In mammals, the majority...Full Text Available

2007-08-01

33

Altitude Developmental Testing of the J-2S Rocket Engine in ...  

Science.gov (United States)

... C Characteristic velocity, ft/sec CCP Customer connect panel CD Discharge coefficient EBW Exploding bridgewire vi Page 10. AE DC-TR-70-150 ...

1970-06-01

34

Underground Test Area Subproject Phase I Data Analysis Task. Volume VI - Groundwater Flow Model Documentation Package  

Energy Technology Data Exchange (ETDEWEB)

Volume VI of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the groundwater flow model data. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.

1996-11-01

35

Kinetic and thermodynamic studies of the biosorption of Cr(VI) by Pinus sylvestris Linn  

Energy Technology Data Exchange (ETDEWEB)

Biosorption equilibrium, kinetics and thermodynamics of chromium(VI) ions onto cone biomass were studied in a batch system with respect to temperature and initial metal ion concentration. The biosorption efficiency of chromium ions to the cone biomass decreased as the initial concentration of metal ions was increased. But cone biomass of Pinus sylvestris Linn. exhibited the highest Cr(VI) uptake capacity at 45 {sup o}C. The biosorption efficiency increased from 67% to 84% with an increase in temperature from 25 to 45 deg. C at an initial Cr(VI) concentration of 300 mg/L. The Langmuir isotherm model was applied to experimental equilibrium data of Cr(VI) biosorption depending on temperature. According to Langmuir isotherm, the monolayer saturation capacity (Q{sub max}) is 238.10 mg/g. The pseudo-first-order and pseudo-second-order kinetic models were applied to test the experimental data for initial ...

2008-05-01

36

Design of multifunction anti-terrorism robotic system based on police dog  

Science.gov (United States)

Aimed at some typical constraints of police dogs and robots used in the areas of reconnaissance and counterterrorism currently, the multifunction anti-terrorism robotic system based on police dog has been introduced. The system is made up of two parts: portable commanding device and police dog robotic system. The portable commanding device consists of power supply module, microprocessor module, LCD display module, wireless data receiving and dispatching module and commanding module, which implements the remote control to the police dogs and takes real time monitor to the video and images. The police dog robotic system consists of microprocessor module, micro video module, wireless data transmission module, power supply module and offence weapon module, which real time collects and transmits video and image data of the counter-terrorism sites, and gives military attack based on commands. The system combines police dogs" biological intelligence with micro robot. Not ...

2007-11-01

37

Interaction of aerobic soil bacteria with plutonium(VI)  

Energy Technology Data Exchange (ETDEWEB)

We studied the interaction of Pu(VI) with Pseudomonas stutzeri ATCC 17588 and Bacillus sphaericus ATCC 14577, representatives of the main aerobic groups of soil bacteria present in the upper soil layers. The accumulation studies have shown that these soil bacteria accumulate high amounts of Pu(VI). The sorption efficiency toward Pu(VI) decreased with increasing biomass concentration due to increased agglomeration of the bacteria resulting in a decreased total surface area and number of available complexing groups. Spores of Bacillus sphaericus showed a higher biosorption than the vegetative cells at low biomass concentration which decreased significantly with increasing biomass concentration. At higher biomass concentrations (> 0.7 g/L), the vegetative cells of both strains and the spores of B. sphaericus showed comparable sorption efficiencies. Investigations on the pH dependency of the biosorption and extraction ...

2000-08-22

38

Uranium (VI)Bis(imido) chalcogenate complexes:synthesis and density functional theory analysis  

Energy Technology Data Exchange (ETDEWEB)

Bis(imido) uranium(VI) trans- and cis-dichalcogenate complexes with the general formula U(NtBu)2(EAr)2(OPPh3)2 (EAr = O-2-tBuC6H4, SPh, SePh, TePh) and U(NtBu)2(EAr)2(R2bpy) (EAr = SPh, SePh, TePh) (R2bpy = 4,4'-disubstituted-2,2'-bipyridyl, R = Me, tBu) have been prepared. This family of complexes includes the first reported monodentate selenolate and tellurolate complexes of uranium(VI). Density functional theory calculations show that covalent interactions in the U-E bond increase in the trans-dichalcogenate series U(NtBu)2(EAr)2(OPPh3)2 as the size of the chalcogenate donor increases and that both 5f and 6d orbital participation is important in the M-E bonds of U-S, U-Se, and U-Te complexes.

2009-01-01

39

Simultaneous biosorption of chromium(VI) and copper(II) on Rhizopus arrhizus in packed column reactor: Application of the competitive Freundlich model  

Energy Technology Data Exchange (ETDEWEB)

The simultaneous biosorption of Cr(VI) and Cu(II) on free Rhizopus arrhizus in a packed column operated in the continuous mode was investigated and compared to the single metal ion situation. The breakthrough curves were measured as a function of feed flow rate, feed pH, and different combinations of metal ion concentrations in the feed solutions. Column competitive biosorption data were evaluated in terms of the maximum (equilibrium) capacity in the column, the amount of metal loading on the R. arrhizus surface, the adsorption yield, and the total adsorption yield. In the single-ion situation the adsorption isotherms were developed for optimum conditions, and it was seen that the adsorption equilibrium data fit the noncompetitive Freundlich model. For the multicomponent adsorption equilibrium the competitive adsorption isotherms were also developed. The competitive Freundlich model for binary metal mixtures represented most the column adsorption equilibrium data ...

1999-12-01

40

Geothermal Program Review VI: proceedings. Beyond goals and objectives  

Energy Technology Data Exchange (ETDEWEB)

Program Review VI was comprised of six sessions, including an opening session, four technical sessions that addressed each of the major DOE research areas, and a session on special issues. The technical sessions were on Hydrothermal, Hot Dry Rock, Geopressured and Magma resources. Presenters in the technical sessions discussed their R and D activities within the context of specific GTD Programmatic Objectives for that technology, their progress toward achieving those objectives, and the value of those achievements to industry. The ''Special Issues'' presentations addressed several topics such as the interactions between government and industry on geothermal energy R and D; the origin and basis for the programmatic objectives analytical computer model; and international marketing opportunities for US geothermal equipment and services. The unique aspect of Program Review VI was that it was held in conjunction ...

1988-01-01

 
 
 
 
41

Kinetic and equilibrium characterization of uranium(VI) adsorption onto carboxylate-functionalized poly(hydroxyethylmethacrylate)-grafted lignocellulosics.  

Science.gov (United States)

This study investigated the feasibility of using a new adsorbent prepared from coconut coir pith, CP (a coir industry-based lignocellulosic residue), for the removal of uranium [U(VI)] from aqueous solutions. The adsorbent (PGCP-COOH) having a carboxylate functional group at the chain end was synthesized by grafting poly(hydroxyethylmethacrylate) onto CP using potassium peroxydisulphate-sodium thiosulphite as a redox initiator and in the presence of N,N'-methylenebisacrylamide as a crosslinking agent. IR spectroscopy results confirm the graft copolymer formation and carboxylate functionalization. XRD studies confirm the decrease of crystallinity in PGCP-COOH compared to CP, and it favors the protrusion of the functional group into the aqueous medium. The thermal stability of the samples was studied using thermogravimetry (TG). Surface charge density of the samples as a function of pH was determined using potentiometric titration. The ability of PGCP-COOH to remove ...

2008-01-28

42

Synthesis of ultraviolet curable encapsulating adhesives and their package applications for organic optoelectronic devices  

British Library Electronic Table of Contents (United Kingdom)

With conventional heating process, ultraviolet (UV) illumination, and microwave irradiation, we have successfully synthesized UV curable encapsulating adhesives with excellent gas barrier capabilities, good adhesive strength, moderate hardness, and high refractive indices. The experimental results manifest that the physical properties of lab-made encapsulating adhesives are highly dependent on their chemical structures and synthetic procedure. We also discover that the encapsulating adhesive prepared by microwave irradiation (i.e. encapsulating adhesive VI-MW) exhibits better adhesive strength and higher gas resistance than those prepared by conventional heating process and UV illumination. Furthermore, encapsulating adhesive VI-MW has also been applied for the package of organic light emi...

2011-01-01

43

Some anisotropic universes in the presence of imperfect fluid coupling with spatial curvature  

CERN Document Server

We consider Bianchi VI spacetime, which also can be reduced to Bianchi types VI0-V-III-I. We initially consider the most general form of the energy-momentum tensor which yields anisotropic stress and heat flow. We then derive an energy-momentum tensor that couples with the spatial curvature in a way so as to cancel out the terms that arise due to the spatial curvature in the evolution equations of the Einstein field equations. We obtain exact solutions for the universes expanding with constant deceleration parameter. The solutions are reduced to each Bianchi type. The dynamics of the models and fluid are examined briefly, and the models that can approach to isotropy are determined.

2010-01-01

44

Kinetics of uranium (VI) ions adsorption on activated charcoal from aqueous solutions  

Energy Technology Data Exchange (ETDEWEB)

The temperature and concentration dependence of the kinetics of uranium(VI) ions adsorption onto activated charcoal from aqueous solutions has been studied. The adsorption proceeds via a rather fast stage followed by a slower one, with activation energies of 5.41 and 17.46 kJ . mol[sup -1] respectively. The diffusion of uranium ions into the pores of the activated charcoal controls the kinetics of adsorption which follows the Langmuir isotherm equation in the concentration range studied. The adsorption equilibrium constant k[sub c] has been derived at temperatures between 283 K and 323 K as well as [Delta] G, [Delta] H and [Delta] S. The results indicate that the adsorption of uranium ions on activated charcoal is an endothermic process. (orig.)

1994-01-01

45

Homogeneous models for mechanisms of surface reactions: Propylene ammoxidation  

Energy Technology Data Exchange (ETDEWEB)

The proposed active sites on the catalyst surface in heterogeneous propylene ammoxidation have been successfully modelled by structurally characterized pinacolato W(VI) tert-butylimido complexes. These compounds exist as an equilibrating mixture of amine-bis(imido) and imido-bis(amido) complexes, the position of this equilibrium is dependent on the electronic nature of the glycolate ligand. Both of the C-N bond-forming reactions proposed in recent studies by Grasselli et al. (1) have been reproduced using discrete Group VI d{sup 0} organoimido complexes under mild conditions suitable for detailed mechanistic studies. These reactions are: (1) oxidative trapping of radicals at molybdenum imido sites, and (2) migration of the allyl group from oxygen to an imido nitrogen atom.

1987-04-01

46

Preparation of uranium (IV) from uranium (VI) by using an electrodialysis technique  

International Nuclear Information System (INIS)

Preparation of a uranous nitrate solution from the reduction process of a uranyl nitrate solution by using electrodialysis technique with a cation exchange membrane has been studied. Uranyl ions were reduced into uranous ions in a nitric acid solution stabilized by hydrazine sulfate in a two-compartment electrolytic cell made from flexiglass. Platinum and carbon or stainless steel were used as anode and cathode, respectively. The electrodialysis process was carried out at room temperature. A piece of cation exchange membrane was inserted between the two compartments and the distance between electrode and membrane was 1.5 cm and this was kept constant throughout the experiment. A 100 ml of a nitric acid 1.4 M solution was in the anode chamber as analyte, whilst a 100 ml of a uranyl nitrate solution with the uranium concentration of 23.97 g/l was in the cathode chamber containing hydrazine sulfate. The parameters tasted were reduction voltage, the amount of hydrazine sulfate added, and ...

2000-03-08

47

LLNL Site Specific ASCI Software Quality Engineering Recommended Practices Overview Version 1.0  

Energy Technology Data Exchange (ETDEWEB)

''The LLNL Site-Specific Advanced Simulation and Computing (ASCI) Software Quality Engineering Recommended Practices VI.I'' document describes a set of recommended software quality engineering (SQE) practices for ASCI code projects at Lawrence Livermore National Laboratory (LLNL). In this context, SQE is defined as the process of building quality into software products by applying the appropriate guiding principles and management practices. Continual code improvement and ongoing process improvement are expected benefits. Certain practices are recommended, although projects may select the specific activities they wish to improve, and the appropriate time lines for such actions. Additionally, projects can rely on the guidance of this document when generating ASCI Verification and Validation (VSrV) deliverables. ASCI program managers will gather information about their software engineering practices and improvement. This information ...

2002-02-01

48

Gas diffusion electrodes for the oxidation of sulfur dioxide in the presence of potassium iodide. [In hydrogen production by electrolysis of sulfuric acid solutions  

Energy Technology Data Exchange (ETDEWEB)

The oxidation of sulfur dioxide in gas diffusion electrodes (GDE) in the presence of a homogeneous catalyst, potassium iodide, is investigated. The influence of this catalyst on the voltage-current (V-I) characteristics of the electrodes and the utilization of sulfur dioxide is determined. It is shown that when using the homogeneous catalyst potassium iodide, the utilization can reach 95-100%.

1986-01-01

49

Stent placement under real-time MR control: first experience in an animal model; Stentplazierung unter Echtzeit-MR-Kontrolle: erste tierexperimentalle Erfahrungen  

Energy Technology Data Exchange (ETDEWEB)

Purpose: The aim of this study was to test the feasibility of iliac artery stent placement under MR guidance with real-time MR radial scanning in an animal model. Materials and methods: The experiments were performed on three pigs in a 1.5 T scanner. Radial scanning with a gradient echo technique (T{sub R} 8.4 ms, T{sub E} 3.6 ms, flip angle 10 ) was used. A dedicated backprojector performed the reconstruction of the raw data in real-time. The resulting MR-images were displayed on LCD screens beside the magnet. The sliding window reconstruction technique allowed image acquistion at a frame rate of 16 images per second. MR-compatible self-expanding stents with a diameter of 8 mm and a length of 3 cm were placed into the left iliac artery. Their positions were verified by digital subtraction angiography (DSA) and compared to MRI. Results: All stents were successfully placed. Stent positions as monitored by real-time MR were identical to those seen on DSA images. The ...

1998-12-01

50

Ultratrace determination in high-purity molybdenum and tungsten with ion chromatographic trace-matrix-separation. Pt. 1; Selection and optimization of the separation step. Ultraspurenanalytik in hochreinem Molybdaen und Wolfram mit ionenchromatographischer Spuren-Matrix-Trennung. Tl. 1; Auswahl und Optimierung des Trennschritts  

Energy Technology Data Exchange (ETDEWEB)

Known trace-matrix-separation and enrichment procedures for the refractory metals Mo and W use very time-consuming batch-techniques. This paper presents the application of a quasicontinuous liquid chromatographic (LC) technique as a step towards automated ultratrace separation. The anionic peroxo complexes from Mo(VI) and W(VI) are used for the trace-matrix-separation. Optimization of the peroxide concentration permits a complete removal of all cationic analyte traces on the HPLC-suitable cation exchanger Nucleosil SA. The high chromato-graphic efficiency also allows a direct ion chromatographic separation of the removed traces. This leads to conclusions about the contribution of the analyte traces on the trace-matrix-separation column and the limits of determination. (author). 13 refs.; 12 figs.; 5 tabs.

1991-11-20

51

The Optical Gravitational Lensing Experiment. Cepheids in the Galaxy IC1613 No Dependence of the Period--Luminosity Relation on Metallicity  

CERN Document Server

We present results of the search for Cepheids in the galaxy IC1613 carried out as a sub-project of the OGLE-II microlensing survey. 138 Cepheids were found in the 14.2x14.2 arcmin region in the center of the galaxy. We present light curves, VI photometry and basic data for all these objects, as well as color-magnitude diagram of the observed field. The Period--Luminosity (PL) diagrams for IC1613 fundamental mode Cepheids for VI and interstellar extinction insensitive index W_I are constructed. Comparison of PL relations in metal poor galaxy IC1613 ([Fe/H]~-1.0 dex) with relations in metal richer Magellanic Clouds allows us to study dependence of Cepheid PL relations on metallicity in the wide range of metallicities covered by these three galaxies. The slopes of PL relations in IC1613 are identical as in the Magellanic Clouds. The comparison of brightness of Cepheids with the magnitudes of the tip of the red giant branch stars and RR Lyr stars ...

2001-01-01

52

Spectral properties of new dioxouranium (VI) complexes with tridentate ono donor schiff bases  

International Nuclear Information System (INIS)

New dioxouranium (VI) complexes of Schiff bases derived from orthaminophenol and salicylaldehyde, 5,6-benzosalicyladehyde, orthohydroxyacetophenone, orthohydroxybenzophenone, acetoacetanilide and benzoylacetanilide have been prepared and characterized by elemental analysis, conductance, molecular weight, infrared, electronic spectra and magnetic susceptibility measurements. The schiff bases behave as ONO donor tridentate dibasic ligands. Two types of complexes, viz. UO_2L.CH_3OH and UO_2L_2 (where LH_2 schiff base) have been synthesized. The comlexes are monomers, nonelectrolytes and diamagnetic. The #nu#(C=N), #nu#(C-O) (phenolic), #nu#(C-O)(CH_3OH) and the ligands. The #nu#sub(as)(O = U =0) occurs in the range 885-940 cm"-"1 and U-O bond length lies in the 1.72-1.74 A range. The 1:1 complexes are six-cordinated and 1:2 complexes are eight coordinated. (author).

1982-01-01

53

Sodium oxonitridometallates(VI) of molybdenum and tungsten, Na[sub 4]MO[sub 2]N[sub 2] (M = Mo, W). Natriumoxonitridometallate(VI) von Molybdaen und Wolfram, Na[sub 4]MO[sub 2]N[sub 2] (M = Mo, W)  

Energy Technology Data Exchange (ETDEWEB)

MoO[sub 3] as well as WO[sub 3] react with an excess of NaNH[sub 2] in autoclaves at temperatures ranging from 250 C to 750 C to yield - in contrast to Ta[sub 2]O[sub 5] backslash lbrackvertical stroke 1 backslash rbrackvertical stroke - oxonitridometallates of general composition Na[sub 4]MX[sub 4] and other products like Na[sub 5]WO[sub 4]N backslash lbrackvertical stroke 2 backslash rbrackvertical stroke . The compounds decompose in moist air within minutes to Na[sub 2]WO[sub 4], Na[sub 2]MoO[sub 4] and Na[sub 2]MoO[sub 4].xH[sub 2]O, respectively. (orig.)

1993-07-01

54

Removal and recovery system of hexavalent chromium from waste water by tannin gel particles  

Energy Technology Data Exchange (ETDEWEB)

Tannin gel particles that have extremely high adsorption capacity for hexavalent chromium Cr(VI) have been developed by controlling gelation of Mimosa tannin extracted from the bark of plants. The gelation process is composed of two stages; partial gelation of Mimosa tannin by reaction with formaldehyde (cross-linking agent) and granulation by dispersing the partially gelated solution into a liquid mixture of decalin ad a polyether nonionic surfactant with vigorous stirring. The structure of the tannin gel particles is controlled by a combination of operating conditions such as reaction time and temperature at both stages. The water content of the tannin gel particles that reflects their structure can be widely changed from 40 to 79 %(wet basis), even for a constant composition of 23 g Mimosa tannin and 6 ml formaldehyde (37 wt %). It is found that it is very important to increase the water content without losing mechanical strength and supply a large amount of ...

2000-10-01

55

Radioanalytical determination of chromium in welding fumes  

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence analysis and fast neutron activation analysis were used for the determination of chromium. The excitation source for X-ray fluorescence analysis was a ring-shaped "2"4"1Am source with an activity of 18.5x10"9 Bq. SYNPOR filters of 35 mm in diameter were used for the measurement. The 5.414 keV Cr peak was measured with a Si(Li) detector. The sensitivity was 0.05 mg for a period of measurement of 1000 s. A neutron generator with an emission of 10"9 s"-"1 was used as the source of fast neutrons. "5"2V and "5"3V, the products of nuclear reaction with Cr, were measured gamma spectrometrically with a Ge(Li) detector. The sensitivity for Cr is 0.015 mg, in the presence of Mn which causes interference the sensitivity is a mere 0.075 mg. The mentioned methods were used to determine total Cr and Cr(VI) in welding aerosols. It was found that the most toxic form, i.e., Cr(VI), is released during manual arc welding of high ...

1985-01-01

56

Preparation and characterization of CdS nanoparticles and CdS/polyacrylonitrile nanocomposites by {gamma}-irradiation  

Energy Technology Data Exchange (ETDEWEB)

There has been considerable interest in producing and studying nanoparticle materials because of the effect of size on their structure, physical and chemical structure. Most studied nanoparticle semiconductors belong to the II-VI group, as they are relatively easy to synthesize and are generally prepared as particulates or in thin film form. Among II-VI compounds, CdS is one of the most studied materials. There are different ways to synthesize CdS nanoparticles such as colloidal particles, chemical decomposition, sol-gel, gas evaporation, magnetron sputtering, electrostatic deposition, and etc. {gamma}-irradiation is one of the effective methods for synthesis of nanomaterials. These nonomaterials have been extensively used in the preparation of nanocrystalline metals, metal oxides, and metal-polymer composites. However, The preparation of CdS nanoparticle and CdS/ polyacrylonitrile nanocomposite by {gamma}-irradiation method at room temperature ...

2001-11-15

57

New dioxomolybdenum(VI) complexes with tridentate dibasic ONO donor schiff bases  

International Nuclear Information System (INIS)

Several dioxomolybdenum(VI) complexes of the schiff bases derived from salicylaldehyde, 2-hydroxy-1-naphthaldehyde, o-hydroxyacetophenone or pyridoxal and o-aminobenzylalcohol, o-aminophenol, o-hydroxybenzylamine, o-hydroxy(methylbenzyl)amine or 3-amino-2-naphthoic acid have been synthesized and characterized by elemental analysis, electrical conductance, molecular weight, IR and electronic spectral and magnetic susceptibility measurements. The schiff bases behave as dibasic, tridentate ligands and coordinate through ONO donor system forming complexes of the type MoO_2L.X (where LH_2=schiff base, X=H_2O or Ch_3OH). The compounds MoO_2L.Ch_3OH react with 2,2'-dipyridyl to form heterochelates of the type MoO_2L.dipyridyl. The complexes are non-electrolytes, monomers, diamagnetic and possess a cis-MoO_2 structure. The complexes exhibit a ligand-to-metal charge-transfer transition around 25000 cm"-"1. The complexes MoO_2L.X and MoO_2L.dipyridyl are six- and ...

58

Characteristics of pulse corona discharge over water surface  

International Nuclear Information System (INIS)

Production of ozone and OH radical is required to advance the plasma chemical reactions in the NOx removal processes for combustion gas treatment. The corona discharge to the water surface is expected to induce the good conditions for the proceeding of the NO oxidation and the NO_2 dissolution removal into water. In order to get the fundamental data of the corona discharge over the water surface, the positive and negative V-I characteristics and the ozone production were measured with the multi needle and the saw-edge type of the discharge electrodes. The pulse corona characteristics were also measured with some different waveforms of the applied pulse voltage. The experiments were carried out under the atmospheric pressure and room temperature. Both the DC and the pulse corona to the water surface showed a stable and almost the same V-I characteristics as to plate electrodes though the surface of water was waved by corona wind. The positive ...

2008-12-01

59

Binary copper(II) and uranyl(VI) complexes of glycocyamine, taurine and pyridoxal and ternary complexes involving 2,2'-bipyridine, 1,10-phenanthroline or nitrilotriacetic acid  

International Nuclear Information System (INIS)

Chelating tendencies of several biologically important compounds viz. glycocyamine (GCN: N-amidino-aminoethanoic acid) taurine (TRN: 2-aminoethanesulphonic acid) and pyridoxal [PDL: 3-hydroxy-5-(hydroxymethyl)-2-methyl-pyridine-4-carbaldehyde] have been examined by pH-metric titration technique in their binary complex formation with copper(II) and uranyl(VI) ions. The work has further been extended to investigating the ternary complex formation involving 2.2'-bipyridine. 1,10-phenanthroline or nitrilotriacetic acid as a primary and TRN and PDL as secondary ligands. All the experiments were carried out at 25"0C and at an ionic strength of 0.1M (NaCl0_4) in aqueous or 50% (v/v) aqueous-ethanol medium according to the suitability of the experimental conditions. Stabilities of ternary complexes as compared to those of the corresponding binary complexes of the secondary ligands have also been discussed. (author).

60

Stability of coherently strained semiconductor superlattices  

International Nuclear Information System (INIS)

The excess energy of several III-V and II-VI strained-layer semiconductor superlattices (AC)_p(BC)_p is studied as a function of the repeat period p and orientation G=[001], [110], [111], and [201], using first-principles calculations. We discover a number of universal features, including the predicted instability for nearly all p's and G's with respect to bulk disproportionation, the identification of chalcopyrite as a metastable ordered structure, and the stability of all thin epitaxial [110] and [201] and most common-anion [001] superlattices relative to coherent phase separation.

 
 
 
 
61

Proceedings of national conference on operating experience of nuclear reactors and power plants: book of preprints  

International Nuclear Information System (INIS)

The symposium covers papers under different sections namely, (i) Core physics and Fuel management, (ii) Commissioning of facilities and systems, (iii) Operational experience and Human resource development, (iv) Fuel handling, Maintenance management and Surveillance, (v) Instrumentation and Control and Power supply systems, (vi) Analysis, modifications and developments for enhancing operational safety, (vii) Chemistry control and Effluent management, (viii) Radiation and industrial safety and (ix) Steam generators, Turbo-generators and other auxiliaries. Papers relevant to INIS are indexed separately. (author)

2006-11-13

62

MENDING THE IN SITU MANIPULATION BARRIER  

Energy Technology Data Exchange (ETDEWEB)

In early 2004, the U.S. Department of Energy (DOE) Richland and Fluor Hanford requested technical assistance from the DOE Headquarters EM-23 Technical Assistance Program to provide a team of technical experts to develop recommendations for mending the In Situ Redox Manipulation (ISRM) Barrier in the 100-D Area of the Hanford Site in Washington State. To accommodate this request, EM-23 provided support to convene a group of technical experts from industry, a national laboratory, and a DOE site to participate in a 2 1/2-day workshop with the objective of identifying and recommending options to enhance the performance of the 100-D Area reactive barrier and of a planned extension to the northeast. This report provides written documentation of the team's findings and recommendations. In 1995, a plume of dissolved hexavalent chromium [Cr(VI)], which resulted from operation of the D/DR Reactors at the Hanford site, was discovered along the Columbia River ...

2006-02-06

63

Local Heine-Abarenkov model potential for III-V and II-VI covalent compounds  

Energy Technology Data Exchange (ETDEWEB)

A local Heine-Abarenkov model potential is proposed for zinc blende-type crystals. The potential parameters are determined by satisfying the zero pressure condition and the first zero of the empirical pseudopotential interpolated from band calculations. Two sets of parameters are presented for thirteen tetrahedral compounds such as AlP, AlAs, AlSb, GaP, GaAs, GaSb, InP, InAs, InSb, ZnS, ZnSe, ZnTe, and CdTe.

1983-10-01

64

Evaluating nuclear data uncertainty: Progress, pitfalls, and prospects  

Energy Technology Data Exchange (ETDEWEB)

The reasons for including variance-covariance information in evaluated nuclear data files are reviewed. Accomplihments and obstacles in meeting these needs are identified. The capability to develop and utilize evaluated cross-section covariance files has been largely demonstrated, but comprehensive files of soundly based covariance data remain to be evaluated and not all types of cross-section data have yet been included. The status of the ENDF-VI covariance formats is discussed. Priorities are suggested for further development. Most effort should be concentrated to fully develop the capability to estimate the nuclear data uncertainties in quantities calculated for a broad energy spectrum. 12 refs.

1986-11-01

65

Electrochemical and spectroelectrochemical studies on Bis(acetylacetonate)(dimethyl sulfoxide) dioxouranium(VI) in dimethyl sulfoxide  

International Nuclear Information System (INIS)

The mechanistic aspects of electrochemical reductions of U"V"IO_2(acac)_2dmso(acac=acetylacetonate, dmso=dimethyl sulfoxide) complex with bidentate ligand(acac) in DMSO were investigated by using cyclic voltammetry, normal pulse voltammetry, and spectrophotometer equipped with an optical transparent thin layer electrode cell. It is concluded that the uranyl complexes with bidentate ligands at the equatorial plane form stable U(V) complexes by the electrochemical reduction and that their molar extinction coefficients in the visible region are very small. (J.P.N.).

1996-01-01

66

Wetland treatment of oil and gas well wastewaters. Quarterly technical report, May 25, 1993-August 24, 1993  

Energy Technology Data Exchange (ETDEWEB)

In the third quarterly report adsorption of heavy metals ions such as Cu(II) and Cr(VI) onto soils drawn from the laboratory-type wetland was shown to be weak. Secondly, it was shown that modified-clays did adsorb Cr(VI) ions strongly at pH 4.5. Further, studies on the pH dependence of the adsorption of {beta}-naphthoic acid, (NA), a well-documented contaminant in many oil and gas well waste waters onto modified-clays were undertaken and it was shown that uptake of NA by modified-clays was of the high affinity type at pH 4.5 and 7.0, but weak at pH 9.0. Adsorption of heavy metal ions, Cu{sup 2+}, and Cr(VI) onto algae, a proposed wetland amendment, was carried out and the results were presented and discussed in the fourth quarterly report. Uptake of NA by the soil component of the laboratory-type wetland was monitored as a function of pH. This quarterly report presents results from studies on the uptake of phenol and ...

1993-10-04

67

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 after longer contact, than for Pu, with Cr and Zn grains. The maximum DF=8.9 was ...

1998-06-12

68

Biosorption of hexavalent chromium by raw and acid-treated green alga Oedogonium hatei from aqueous solutions  

Energy Technology Data Exchange (ETDEWEB)

The hexavalent chromium, Cr(VI), biosorption by raw and acid-treated Oedogonium hatei were studied from aqueous solutions. Batch experiments were conducted to determine the biosorption properties of the biomass. The optimum conditions of biosorption were found to be: a biomass dose of 0.8 g/L, contact time of 110 min, pH and temperature 2.0 and 318 K respectively. Both Langmuir and Freundlich isotherm equations could fit the equilibrium data. Under the optimal conditions, the biosorption capacities of the raw and acid-treated algae were 31 and 35.2 mg Cr(VI) per g of dry adsorbent, respectively. Thermodynamic parameters showed that the adsorption of Cr(VI) onto algal biomass was feasible, spontaneous and endothermic under studied conditions. The pseudo-first-order kinetic model adequately describe the kinetic data in comparison to second-order model and the process involving rate-controlling step is much complex involving ...

2009-04-15

69

Recovery of uranium from aqueous solutions using calcined powders of CaO-Al/sub 2/O/sub 3/-SO/sub 3/ system  

Energy Technology Data Exchange (ETDEWEB)

Aqueous solutions of Al/sub 2/(SO/sub 4/)/sub 3/ (1.05 g/100 ml), AlCl/sub 3/ (0.82 g/100 ml) and Ca(OH)/sub 2/ slurry (0.94 g/50 ml) were mixed in various volume ratios and passed through a filter. White cakes left on the filter consisted mainly of ettringite (6CaO.Al/sub 2/O/sub 3/.3SO/sub 3/.32H/sub 2/O). The cakes were then calcined at various temperatures of 300/sup 0/ -- 1000/sup 0/C for 30 and 60 min and pulverized to 80 -- 200 mesh powders. The adsorption capacity of the powders for U(VI) ions dissolved in aqueous solutions was determined by immersing 0.100 g of their powders in 50 ml of the aqueous solution containing 100 ppm of U(VI) ions mainly in the form of (UO/sub 2/(CO/sub 3/)/sub 3/)/sup 4 -/ for 2 hours. The results obtained were summarized as follows. 1) Among the powders prepared, those of the oxide compositions, 2.9CaO.Al/sub 2/O/sub 3/.1.4SO/sub 3/ and 2.5CaO.Al/sub 2/O/sub 3/.1.2SO/sub 3/, all fired at 500/sup 0/C or ...

1981-11-01

70

Estimating the stabilities of aqueous actinide complexes with sulfoxy-anions  

Energy Technology Data Exchange (ETDEWEB)

Full text of publication follows: Stable aqueous sulfur species are mainly sulfide (H{sub 2}S) and sulfate (SO{sub 4}{sup 2-}) ions. However, several sulfoxy-anions may be detected as metastable anions in natural environment, as typically thiosulfate (S{sub 2}O{sub 3}{sup 2-}) and sulfite (SO{sub 3}{sup 2-}) ions [1]. In natural systems, uranium speciation and migration are mainly governed by carbonate complexes in non reducing conditions. Whereas sulfate is already known as a complexing agent of actinides, data relating to U-SO{sub 3}{sup 2-} and U-S{sub 2}O{sub 3}{sup 2-} complexes have only been proposed for U(VI) [2], but are usually not included in thermodynamic databases [3]. Therefore, it appears to be relevant to determine complexation constants of actinides with sulfur ligands, for RN migration studies, concerning nuclear waste disposal as well as migration behaviour in the geosphere. In the present study, values have been estimated for the first ...

2005-07-01

71

Modulation of neuronal differentiation by CD40 isoforms  

International Nuclear Information System (INIS)

Neuron differentiation is a complex process involving various cell-cell interactions, and multiple signaling pathways. We showed previously that CD40 is expressed and functional on mouse and human neurons. In neurons, ligation of CD40 protects against serum withdrawal-induced injury and plays a role in survival and differentiation. CD40 deficient mice display neuron dysfunction, aberrant neuron morphologic changes, and associated gross brain abnormalities. Previous studies by Tone and colleagues suggested that five isoforms of CD40 exist with two predominant isoforms expressed in humans: signal-transducible CD40 type I and a C-terminal truncated, non-signal-transducible CD40 type II. We hypothesized that differential expression of CD40 isoform type I and type II in neurons may modulate neuron differentiation. Results show that adult wild-type, and CD40"-"/"- deficient mice predominantly express CD40 type I and II isoforms. Whereas adult wild-type mice express mostly CD40 type I in ...

2008-05-02

72

Distributed radiation protection console system  

International Nuclear Information System (INIS)

Radiation exposure control is one of the most important aspects in any nuclear facility . It encompasses continuous monitoring of the various areas of the facility to detect any increase in the radiation level and/or the air activity level beyond preset limits and alarm the O and M personnel working in these areas. Detection and measurement of radiation level and the air activity level is carried out by a number of monitors installed in the areas. These monitors include Area Gamma Monitors, Continuous Air Monitors, Pu-In-Air Monitors, Criticality Monitors etc. Traditionally, these measurements are displayed and recorded on a Central Radiation Protection Console(CRPC), which is located in the central control room of the facility. This methodology suffers from the shortcoming that any worker required to enter a work area will have to inquire about the radiation status of the area either from the CRPC or will get to know the same directly from the installed only after entering the area. ...

2004-02-01

73

Global Molecular Characterization of the Chromate Stress Response in Shewanella oneidensis MR-1: Identification of a Putative DNA-Binding Response Regulator and Azoreductase Involved in Cr(VI) Detoxification  

Energy Technology Data Exchange (ETDEWEB)

Shewanella oneidensis MR-1 is a model environmental organism that possesses diverse respiratory capacities, including the ability to reduce soluble Cr(VI) to sparingly soluble, less toxic Cr(III). Effective bioremediation of Cr-contaminated sites requires knowledge of the molecular mechanisms and regulation of heavy metal resistance and biotransformation by dissimilatory metal-reducing bacteria. Towards this goal, our ERSP-funded work is focused on the identification and functional analysis of genes/proteins comprising the response pathways for chromate detoxification and/or reduction. Previous transcriptomic profiling and whole-cell proteomic analyses implicated the involvement of a functionally undefined DNA-binding response regulator (SO2426) and a putative azoreductase (SO3585) in the chromate stress response of MR-1. Here we describe a detailed functional analysis of SO2426 and SO3585 in order to begin to understand the role of these proteins in the cellular ...

2006-04-05

74

Stability of coherently strained semiconductor superlattices  

Science.gov (United States)

The excess energy of several III-V and II-VI strained-layer semiconductor superlattices ({ital AC}){sub {ital p}}(BC){sub p} is studied as a function of the repeat period {ital p} and orientation {bold G}=(001), (110), (111), and (201), using first-principles calculations. We discover a number of universal features, including the predicted instability for nearly all {ital p}'s and {bold G}'s with respect to {ital bulk} disproportionation, the identification of chalcopyrite as a metastable ordered structure, and the stability of all thin {ital epitaxial} (110) and (201) and most common-anion (001) superlattices relative to coherent phase separation.

1990-01-01

75

Quercetin-induced downregulation of phospholipase D1 inhibits proliferation and invasion in U87 glioma cells  

British Library Electronic Table of Contents (United Kingdom)

Phospholipase D (PLD) has been recognized as a regulator of cell proliferation and tumorigenesis, but little is known about the molecules regulating PLD expression. Thus, the identification of small molecules inhibiting PLD expression would be an important advance in PLD-mediated physiology. Quercetin, a ubiquitous bioactive flavonoid, is known to inhibit proliferation and induce apoptosis in a variety of cancer cells. In the present study, we examined the effect of quercetin on the expression of PLD in U87 glioma cells. Quercetin significantly suppressed the expression of PLD1 at the transcriptional level. Moreover, quercetin abolished the protein expression of PLD1 in a time and dose-dependent manner, as well as inhibited PLD activity. Quercetin suppressed NFkB-induced PLD1 expression vi...

2011-01-01

76

Prospects of real-time ion temperature and rotation profiles based on neural-network charge exchange analysis  

Energy Technology Data Exchange (ETDEWEB)

A back-propagation neural network technique is used at JET to extract plasma parameters like ion temperature, rotation velocities or spectral line intensities from charge exchange (CX) spectra. It is shown that in the case of the C VI CX spectra, neural networks can give a good estimation (better than +-20% accuracy) for the main plasma parameters (Ti, V{sub rot}). Since the neural network approach involves no iterations or initial guesses the speed with which a spectrum is processed is so high (0.2 ms/spectrum) that real time analysis will be achieved in the near future. 4 refs., 8 figs.

1994-07-01

77

Measurement of fission cross sections for nuclear transmutation on Am-241, Am-242m and Am-243 using lead slowing-down spectrometer  

Energy Technology Data Exchange (ETDEWEB)

Making use of a lead slowing-down spectrometer coupled to a 46 MeV electron linear accelerator and a back-to-back type double fission chamber, the fission cross sections of Am-241, Am-242m and Am-243 have been measured relative to that of U-235 from 0.1 eV to 10 keV with the energy resolution of about 40 % full width at half maximum. Each of the measured result has been compared with (1) the evaluated nuclear data in ENDF/B-VI and JENDL-3.2, and (2) the existing experimental data, for which the evaluated and the experimental data were broadened by the energy resolution function of the spectrometer. (author)

1997-12-31

78

Measurement of fission cross sections for Am-241, Am-242m and Am-243 with linac-driven lead slowing-down spectrometer  

Energy Technology Data Exchange (ETDEWEB)

Making use of a back-to-back type double fission chamber and a lead slowing-down spectrometer driven by a 46 MeV electron linear accelerator, the fission cross sections of Am-241, Am-242m and Am-243 have been measured relative to that of U-235 from 0.1 eV to 10 keV with the energy resolution of about 40 % full width at half maximum. Each of the measured result has been compared with (1) the evaluated nuclear data in ENDF/B-VI and JENDL-3.2, and (2) the existing experimental data, whose evaluated and measured data were broadened by the energy resolution function of the spectrometer.

1998-08-01

79

Measurement of fission cross sections for Am-241, Am-242m and Am-243 with linac-driven lead slowing-down spectrometer  

Energy Technology Data Exchange (ETDEWEB)

Making use of a back-to-back type double fission chamber and a lead slowing-down spectrometer driven by a 46 MeV electron linear accelerator, the fission cross sections of Am-241, Am-242m and Am-243 have been measured relative to that of U-235 from 0.1 eV to 10 keV with the energy resolution of about 40% full width at half maximum. Each of the measured result has been compared with (1) the evaluated nuclear data in ENDF/B-VI and JENDL-3.2, and (2) the existing experimental data, whose evaluated and measured data were broadened by the energy resolution function of the spectrometer. (author)

1999-02-01

80

Glutathione peroxidase activity in the selenium-treated alga Scenedesmus quadricauda  

British Library Electronic Table of Contents (United Kingdom)

The function of selenium in an organism is mediated mostly by selenoproteins including glutathione peroxidase. Glutathione peroxidase is a potent anti-oxidative enzyme, scavenging a variety of peroxides. The green alga Scenedesmus quadricauda was used to investigate the relationship between the toxicity of selenium and the glutathione peroxidase activity. Selenium resistant strains SeIV and SeVI were synchronized and grown in high concentrations of Se (selenite or selenate). As a measure of selenium toxicity the EC50 values were determined. During growth of the untreated wild type, glutathione peroxidase activity increased slightly and then declined gradually until the end of the cell cycle. A similar pattern was observed in untreated resistant strains and when resistant strains were grown...

2011-01-01

 
 
 
 
81

FUV and X-ray absorption in the Warm-Hot Intergalactic Medium  

CERN Document Server

The Warm-Hot Intergalactic Medium (WHIM) arises from shock-heated gas collapsing in large-scale filaments and probably harbours a substantial fraction of the baryons in the local Universe. Absorption-line measurements in the ultraviolet (UV) and in the X-ray band currently represent the best method to study the WHIM at low redshifts. We here describe the physical properties of the WHIM and the concepts behind WHIM absorption line measurements of H I and high ions such as O VI, O VII, and O VIII in the far-ultraviolet and X-ray band. We review results of recent WHIM absorption line studies carried out with UV and X-ray satellites such as FUSE, HST, Chandra, and XMM-Newton and discuss their implications for our knowledge of the WHIM.

2008-01-01

82

Evaluation of a commercial MRSA assay when multiple MRSA strains are causing epidemics  

British Library Electronic Table of Contents (United Kingdom)

Rapid and reliable diagnostic methods are needed to control methicillin-resistant Staphylococcus aureus (MRSA) transmission. We studied the BD GeneOhm? MRSA Assay which is based on one specific amplification product at the junction of the right extremity sequence of the staphylococcal cassette chromosome mec (SCCmec) and the chromosomal sequence of orfX of S. aureus. The test was applied on 95 clinical isolates in Finland: 83% were positive. The isolates giving negative results represented several pulsed-field gel electrophoresis (PFGE) types and harboured SCCmec types IV, V, VI or were new types with different combinations of ccr genes.

2009-01-01

83

Development of anion-exchange resins for separations of actinides  

Energy Technology Data Exchange (ETDEWEB)

The evolution of these new ion-exchange resins hinges upon an understanding of the chemistry of actinide metal complexes as they exist in solution and when interacting with the cationic sites. Molecular modeling of electrostatic interactions between the metal complex and the cationic substrate is used to help visualize uptake mechanisms and, eventually, to predict optimized coordination sites. Thus, these new materials integrate the fields of ion-specific chelation and ion-exchange technology. Synthesized resins contain cationic sites designed to facilitate the uptake of plutonium nitrato complexes from high-nitrate solutions, and they exhibit distribution coefficients that are up to 10 times higher than those observed for commercial resins. Additionally, some new resins show surprisingly large Kd`s for anionic complexes of Am(III) and U(VI).

1997-12-31

84

Chromatography of metal ions with a triazine chelating resin  

International Nuclear Information System (INIS)

The synthesis, characterization, and some analytical applications of a new triazine resin are described. Separation of group IB, IIB, VIB, and VIIB metal ions from group VIII metal ions is achieved by this PDT-4 resin. Calcium(II) and magnesium(II) are taken up at pH = 6, 0.1 M acetate and are eluted at pH = 6, 0.1 M sodium nitrate. Copper(II) is retained at pH = 6, 0.1 M acetate and pH = 1 hydrochloric acid and is eluted subsequently by 5 M perchloric acid. Molybdenum(VI) is sorbed selectively from 0.1 N sulfuric acid or hydrochloric acid and is eluted in a tight band by 0.1 N sodium hydroxide. Numerous rapid column chromatographic separations are reported using this new resin, including analysis of NBS standard samples.

85

Assessment of MCNP-4B code using measurement data of Wolsung nuclear power plant 2  

International Nuclear Information System (INIS)

The benchmark calculations have been performed for MCNP-4B code using the measurement data of Wolsong nuclear power plant 2. In this study, the benchmark calculations have been performed for the criticality, boron worth, reactivity device worth, reactivity coefficient, and flux scan. Cross-section libraries were newly generated from ENDF/B-VI release 3 through NJOY97.114 data processing system and a three-dimensional full core model was developed for MCNP calculation. The simulation results have shown that the criticality is estimated within 4 mkn and the estimated reactivity worth of the control devices are generally consistent with the measurement data. In certain cases, the simulation results have shown large discrepancies against the measurement data, which will be sturdied further in the near future.

2001-05-01

86

A semi-analytic approach to angular momentum transport in stellar radiative interiors  

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT We address the problem of angular momentum transport in stellar radiative interiors with a novel semi-analytic spectral technique, using an eigenfunction series expansion, that can be used to derive benchmark solutions in hydromagnetic regimes with very high Reynolds number (107-108). The error arising from the truncation of the series is evaluated analytically. The main simplifying assumptions are the neglect of meridional circulation and of non-axisymmetric magnetic fields. The advantages of our approach are shown by applying it to a spin-down model for a Formula Not Shown main-sequence star. The evolution of the coupling between core and envelope is investigated for different values of the viscosity and different geometries and values of the poloidal field. We confirm that a vi...

2010-01-01

87

Materials design for semiconductor spintronics by ab initio electronic-structure calculation  

International Nuclear Information System (INIS)

A systematic study for the materials design of III-V and II-VI compound-based ferromagnetic diluted magnetic semiconductors is given based on ab initio calculations within the local spin density approximation. The electronic structures of 3d-transition-metal-atom-doped GaN and Mn-doped InN, InP, InAs, InSb, GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs and AlSb were calculated by the Korringa-Kohn-Rostoker method combined with the coherent potential approximation. It is found that the ferromagnetic ground states are readily achievable in V-, Cr- or Mn-doped GaN without any additional carrier doping treatments, and that InN is the most promising candidate for high-T_C ferromagnet. A simple explanation of the systematic behavior of the magnetic states in III-V and II-VI compound-based diluted magnetic semiconductors is also given. It is also shown that V or Cr-doped ZnS, ZnSe, and ZnTe are ferromagnetic without p- or n-type doping treatment. However, Mn-, ...

2003-04-01

88

Hydroxo-species of uranium (VI) in aqueous media  

International Nuclear Information System (INIS)

The large degree of confusion and many contradictions which are evident in the literature regarding the dioxo-uranium(VI)-hydroxide system has prompted the re-investigation of the hydrolysis of UO_2"2"- in aqueous media. The hydrolysis reactions of the uranyl ion have been investigated by potentiometric (pH)-, spectrophotometric- and conductometric titrations of uranyl chloride solutions with sodium hydroxide solutions. In all these titrations two clearly defined endpoints were obtained, indicating the predominance in solution of only a limited number of species. From a consideration of all the experimentally obtained data the following set of species was proposed to be present in significant concentrations in the pH range 0 to 12: UO_2"2"-, (UO_2)_2(OH)_2"2"-, (UO_2)_2(OH)_3"- and (UO_2)_9(OH)_1_9"-. By using the proposed set of species, a mathematical model of the uranyl-hydroxo system was developed with which the titration curves obtained by all three techniques ...

1600-01-01

89

Direct photoaffinity labeling of gizzard myosin with ["3H]uridine diphosphate places Glu185 of the heavy chain at the active site  

International Nuclear Information System (INIS)

The active site of chicken gizzard myosin was labeled by direct photoaffinity labeling with ["3H]UDP. ["3H] UDP was stably trapped at the active site by addition of vanadate (Vi) and Co"2"+. The extraordinary stability of the myosin.Co2+.[3H]UDP.Vi complex (t1/2 greater than 5 days at 0 degrees C) allowed it to be purified free of extraneous ["3H]UDP before irradiation began. Upon UV irradiation, greater than 60% of the trapped ["3H]UDP was photoincorporated into the active site. Only the 200-kDa heavy chain was labeled, confirming earlier results using ["3H]UTP. Extensive tryptic digestion of photolabeled myosin subfragment 1 followed by high performance liquid chromatography separations and removal of nucleotide phosphates by treatment with alkaline phosphatase allowed two labeled peptides to be isolated. Sequencing of the labeled peptides and radioactive counting showed that Glu185 was the residue labeled. Since UDP is a zero-length ...

90

Development status of Severe Accident Analysis Code SAMPSON  

International Nuclear Information System (INIS)

The Four years of the IMPACT, 'Integrated Modular Plant Analysis and Computing Technology' project Phase 1 have been completed. The verification study of Severe Accident Analysis Code SAMPSON prototype developed in Phase 1 was conducted in two steps. First, each analysis module was run independently and analysis results were compared and verified against separate-effect test data with good results. Test data are as follows: CORA-13 (FZK) for the Core Heat-up Module; VI-3 of HI/VI Test (ORNL) for the FP Release from Fuel Module; KROTOS-37 (JRC-ISPRA) for the Molten Core Relocation Module; Water Spread Test (UCSB) for the Debris Spreading Model and Benard's Melting Test for Natural Convection Model in the Debris Cooling Module; Hydrogen Burning Test (NUPEC) for the Ex-Vessel Thermal Hydraulics Module; PREMIX, PM10 (FZK) for the Steam Explosion Module; and SWISS-2 (SNL) for the Debris-Concrete Interaction Module. Second, with the Simulation ...

2000-11-01

91

Benchmark Analysis of Subcritical Noise Measurements on a Nickel-Reflected Plutonium Metal Sphere  

Energy Technology Data Exchange (ETDEWEB)

Subcritical experiments using californium source-driven noise analysis (CSDNA) and Feynman variance-to-mean methods were performed with an alpha-phase plutonium sphere reflected by nickel shells, up to a maximum thickness of 7.62 cm. Both methods provide means of determining the subcritical multiplication of a system containing nuclear material. A benchmark analysis of the experiments was performed for inclusion in the 2010 edition of the International Handbook of Evaluated Criticality Safety Benchmark Experiments. Benchmark models have been developed that represent these subcritical experiments. An analysis of the computed eigenvalues and the uncertainty in the experiment and methods was performed. The eigenvalues computed using the CSDNA method were very close to those calculated using MCNP5; however, computed eigenvalues are used in the analysis of the CSDNA method. Independent calculations using KENO-VI provided similar eigenvalues to those determined using the ...

2009-09-01

92

Application of BGO scintillators to absolute measurement of neutron capture cross sections between 0.01 eV and 10 eV  

Energy Technology Data Exchange (ETDEWEB)

Applying a total energy absorption {gamma}-ray detector composed of 12 bricks (5x5 cm{sup 2}, 7.5 cm thick) of Bi{sub 4}Ge{sub 3}O{sub 12}(BGO) scintillators, the absolute measurement of capture cross sections for Au and Sb has been made in an energy region between 0.01 eV and 10 eV using the linac time-of-flight method. Incident thermal neutron flux was absolutely determined by using the BGO detection system with a Sm sample. To extend the neutron flux measurement from the thermal neutron region to higher neutron energy, the {sup 10}B(n, {alpha} {gamma}) reaction was applied. Absolute capture yield for the relevant capture sample was obtained by the saturated capture yield at a large resonance of the sample. Gold was selected to investigate the application of the BGO detection system to the absolute measurement of the capture cross sections, since the {sup 197}Au(n, {gamma}){sup 198}Au reaction cross section is a well known standard one. The result of the {sup 197}Au(n, {gamma}){sup ...

1997-07-01

93

An empirical model for dielectric constant and electronic polarizability of binary (A{sup N}B{sup 8-N}) and ternary (A{sup N}B{sup 2+N}C{sub 2}{sup 7-N}) tetrahedral semiconductors  

Energy Technology Data Exchange (ETDEWEB)

An overview of the understanding of correlation between valence electron and the optical properties of binary (A{sup N}B{sup 8-N}) and ternary (A{sup N}B{sup 2+N}C{sub 2}{sup 7-N}) tetrahedral semiconductors is presented here. We have presented two expressions relating the dielectric constant and electronic polarizability for the transition metal chalcogenides and pnictides (A{sup II}B{sup VI} and A{sup III}B{sup V}) and chalcopyrites (A{sup I}B{sup III}C{sub 2}{sup VI} and A{sup II}B{sup IV}C{sub 2}{sup V}) with the product of valence electrons and nearest neighbour distance d (A). The dielectric constant and electronic polarizability of these solids exhibit a linear relationship when plotted on a log-log scale against the nearest neighbour distance d (A), but fall on different straight lines according to the valence electron product of the compounds. We have applied the proposed relation on these solids and found a better agreement with the ...

2009-11-03

94

ZZ MCB63NEA.BOLIB, MCNP Cross Section Library Based on ENDF/B-VI Release 3  

International Nuclear Information System (INIS)

1 - Description of program or function: Continuous energy cross-section data library for the Monte Carlo program MCNP based on the ENDF/B-VI Release 3 evaluated nuclear data library (ACE Format). Format: ACE; Number of groups: Continuous energy; Nuclides (107): H-1, H-2, He-4, Li-6, Li-7, Be-9, B-10, B-11, C-nat, N-14, N-15, O-16, O-17, Na-23, Mg-nat, Al-27, Si-nat, Cl-nat, Ti-nat, Cr-50, Cr-52, Cr-53, Cr-54, Mn-55, Fe-54, Fe-56, Fe-57, Fe-58, Co-59, Ni-58, Ni-60, Ni-61, Ni-62, Ni-64, Zr-90, Zr-91, Zr-92, Zr-94, Zr-96, Zr-nat, Nb-93, Mo-94, Mo-95, Mo-96, Mo-97, Mo-nat, Tc-99, Ru-101, Ru-102, Ru-104, Rh-103, Pd-105, Pd-107, Ag-109, I-129, Xe-131, Cs-133, Pr-141, Nd-143, Nd-145, Pm-147, Sm-147, Sm-149, Sm-150, Sm-151, Sm-152, Eu-153, Gd-154, Gd-155, Gd-156, Gd-157, Gd-158, Gd-160, Hf-174, Hf-176, Hf-177, Hf-178, Hf-179, Hf-180, Hf-nat, Pb-206, Pb-207, Pb-208, Bi-209, Th-232,U-233, U-234, U-235, U-236, U-238, Np-237, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, Am-241, ...

95

Yields of short-lived fission products produced following "2"3"5U(n_t_h,f)  

International Nuclear Information System (INIS)

Measurements of gamma-ray spectra, following the thermal neutron fission of "2"3"5U have been made using a high purity germanium detector at the University of Massachusetts Lowell (UML) Van de Graaff facility. The gamma spectra were measured at delay times ranging from 0.2 s to nearly 10000 s following the rapid transfer of the fission fragments with a helium-jet system. On the basis of the known gamma transitions, forty isotopes have been identified and studied. By measuring the relative intensities of these transitions, the relative yields of the various precursor nuclides have been calculated. The results are compared with the recommended values listed in the ENDF/B-VI fission product data base (for the lifetimes and the relative yields) and those published in the Nuclear Data Sheets (for the beta branching ratios). This information is particularly useful for the cases of short-lived fission products with lifetimes of the order of fractions of a second or a few ...

1998-08-01

96

Valence-band offsets at the Al{sub x}Ga{sub 0.5{minus}x}In{sub 0.5}P-ZnSe(001) lattice-matched interface  

Energy Technology Data Exchange (ETDEWEB)

The difficulty in making good Ohmic contact at the interfaces with p-doped ZnSe is an important problem hindering the realization of blue-light-emitting diode lasers based on the II-VI semiconductor technology. So far no metal or semiconductor material has been found to have a low enough barrier at the (001) interface with ZnSe. A possible solution to this problem is the insertion of a so-called {ital barrier-reduction layer} at the interface with ZnSe. We have investigated the interface formation energies and valence-band offsets at the (001) interface between Al{sub x}Ga{sub 0.5{minus}x}In{sub 0.5}P and ZnSe. The results of our calculations show the existence of a strong interdependence between the valence-band offset and the interface geometric structure. The interface is found to have structural and electronic similarities to the GaAs-ZnSe(001) system. The very low values obtained for the valence-band offset confirm the possibility of using this material as a ...

1997-01-01

97

User`s guide and documentation manual for microbial transport simulator  

Energy Technology Data Exchange (ETDEWEB)

The microbial transport simulator (MTS) is a three-dimensional, three-phase, multiple-component numerical model that permits the study of the transport of microorganisms and nutrients in porous media. Microbial parameters incorporated into MTS include: Microbial growth and decay, microbial deposition, chemotaxis, diffusion, convective dispersion, tumbling, and nutrient consumption. Governing equations for microbial and nutrient transport are coupled with continuity and flow equations under conditions appropriate for a black oil reservoir. The model`s mathematical formulations and preparation procedures of data files for conducting simulations using MTS are described. A general background of microbial transport simulation is given in Section I and the governing equations, mechanisms, and numerical solutions of MTS are given in Section II. Explanations for preparing an input data file with reservoir and microbial transport data are described in Section III, and recurrent data are given ...

1993-10-01

98

Turning the Moon into a Solar Photovoltaic Paradise  

Science.gov (United States)

Lunar resource utilization has focused principally on the extraction of oxygen from the lunar regolith. A number of schemes have been proposed for oxygen extraction from Ilmenite and Anorthite. Serendipitously, these schemes have as their by-products (or more directly as their "waste products"), materials needed for the fabrication of thin film silicon solar cells. Thus lunar surface possesses both the elemental components needed for the fabrication of silicon solar cells and a vacuum environment that allows for vacuum deposition of thin film solar cells directly on the surface of the Moon without the need for vacuum chambers. In support of the US space exploration initiative a new architecture for the production of thin film solar cells on directly on the lunar surface is proposed. The paper discusses experimental data on the fabrication and properties of lunar glass substrates, evaporated lunar regolith thin films (anti-reflect coatings and insulators), and preliminary attempts in ...

2006-01-01

99

The integral experiment on beryllium with D-T neutrons for verification of tritium breeding  

Energy Technology Data Exchange (ETDEWEB)

A clean benchmark experiment on beryllium was performed with D-T neutrons at the FNS facility of the Japan Atomic Energy Agency. The main objective was to verify the integral data related to the tritium production on lithium isotopes. Tritium production rates, as well as activation reaction rates were measured inside the beryllium assembly that was shaped as a pseudo-cylindrical slab with an area-equivalent diameter of 628 mm and a thickness of 355 mm. Experimental results were analyzed with a three-dimensional Monte Carlo transport code MCNP-4C and FENDL/MC-2.0, JENDL-3.2/3.3 neutron transport libraries. Evaluation of reaction rates was based on the cross section data taken from the JENDL Dosimetry File and ENDF B-VI data libraries. Analysis shows that all calculation combinations (transport and activation cross section libraries) used for evaluation of reaction rates give data that is agreeable with measured values within 10%.

2007-01-15

100

Study on biosorption kinetics and thermodynamics of uranium by Citrobacter freudii  

Energy Technology Data Exchange (ETDEWEB)

Biosorption has been developed as an effective and economic method to treat wastewater containing low concentrations of metal pollutants. In this study, a bacterium, Citrobacter freudii, was used as a biosorbent to adsorb uranium ions. The thermodynamics and kinetics of this adsorption, as well as its mechanism, were investigated. The results indicated that the biosorption rate could be better described by a pseudo 2nd-order model than a pseudo 1st-order model. The adsorption of U (VI) proceeded very rapidly in the first 30 min and subsequently slowed down continuously for a long period. The biosorption isotherm of uranium by C. freudii could be described well by the Langmuir or Freundlich isotherm, and the latter was better. The thermodynamics parameters, {delta}H{sup o}, {delta}G{sup o}, and {delta}S{sup o} were calculated according to the results of the experiment, which showed this biosorption as being endothermic and spontaneous. The authors investigated the ...

2008-01-15

 
 
 
 
101

Solar photochemistry and heterogeneous photocatalysis  

International Nuclear Information System (INIS)

The search for alternative energy supplies continues since the oil crisis of 1973. One energy vector is dihydrogen, H_2. Of the group VI hydrides, water has been the focus of most studies in harnessing solar energy and generating H_2. Two basic photochemical strategies have been employed: molecular photocatalytic systems, and semiconductor based photocatalytic systems. The results have not met with the euphoric expectations of the mid-1970's because of the difficulties encountered in H_2O splitting (E"0 S"2 "-/S = + 0.51 eV, NHE) is another vehicle tapped as a potential source of H_2. Heterogeneous photocatalysis utilizing semiconductor particulates and sunlight as the photon source has been successful with interesting quantum efficiencies. To this end, novel photocatalytic devices have been developed; one of these uses two coupled semiconductors to achieve vectorial displacement of the photogenerated reducing and oxidizing equivalents. An important area in which ...

102

Radiocardiographic measurement of minimum central transit times by means of indium-113m-DTPA and of a 8-crystal radiocardiograph (Gamma Retina VI)  

International Nuclear Information System (INIS)

The minimum cardiac transit times (MTT's) at rest and following sub-maximum stresses were measured in 97 individual examinations of untrained persons and high performance athletes. It turned out that there is a strong dependence on cardiac frequency of the MTT's. This relation can be described quite satisfactorily by a hyperbolic function and in this way allows a frequency correction to be made of the MTT's. The MTT's standardized in this way (MTT.f values) represent the quotient of the end diastolic segment volume/beat volume. In the whole lesser circulatory system almost identical MTT.f values were found for the two groups under comparison at rest and following stress. In the ventricles, however, and especially so in the left ventricle, the MTT.f values were clearly higher with athletes than with untrained persons, but they strongly decreased after stresses, while the respective values remained almost constant in ordinary persons. (orig./RF).

103

RELAP5/MOD3 code manual. Volume 4, Models and correlations  

International Nuclear Information System (INIS)

The RELAP5 code has been developed for best-estimate transient simulation of light water reactor coolant systems during postulated accidents. The code models the coupled behavior of the reactor coolant system and the core for loss-of-coolant accidents and operational transients such as anticipated transient without scram, loss of offsite power, loss of feedwater, and loss of flow. A generic modeling approach is used that permits simulating a variety of thermal hydraulic systems. Control system and secondary system components are included to permit modeling of plant controls, turbines, condensers, and secondary feedwater systems. RELAP5/MOD3 code documentation is divided into seven volumes: Volume I presents modeling theory and associated numerical schemes; Volume II details instructions for code application and input data preparation; Volume III presents the results of developmental assessment cases that demonstrate and verify the models used in the code; Volume IV discusses in detail ...

1995-08-05

104

Pollen flora of Pakistan--LXVII: acanthaceae  

International Nuclear Information System (INIS)

Pollen morphology of 30 species of the family Acanthaceae belonging to 11 genera has been investigated using light and scanning electron microscope. Acanthaceae is a eurypalynous family. Pollen are usually radially symmetrical, isopolar, sub-prolate to prolate rarely prolate-spheroidal or sub-oblate to oblate-spheroidal, generally tricolporate or heterocolporate rarely colpate or porate. Exine ornamentation varies from medium to coarse reticulate, or often lopho-reticulate with luminae perforated to baculate or scabrate. On the basis of apertural type, exine ornamentation and colpal membrane eight distinct pollen types have been recognized viz., Pollen type-I: Barleria cristata-type, Pollen type-II: Blepharis ciliaris-type, Pollen type-III: Hygrophila polysperma - type, Pollen type-IV: Justicia adhatoda-type, Pollen type-V:Lepidagathis incurva-type, Pollen type- VI: Peristrophe paniculata-type, Pollen type-VII: Ruellia patula-type and Pollen type-VIII: ...

2010-12-01

105

Plutonium build-up credits for a material test research reactor and influence of cross-section differences on actinide production  

Energy Technology Data Exchange (ETDEWEB)

Burnup calculations with SARC system were carried out to analyse the effects of plutonium build-up on criticality of MTR type research reactor PARR-1 using several WIMSD libraries based on evaluated nuclear data files ENDFB-VI.8, JEF-2.2, JEFF-3.1 and JENDL-3.2. For equilibrium core of the reactor, it was found that a net reactivity of more than 3.5 mk is induced due to build-up of plutonium isotopes during depletion. The plutonium credit amounts to 3% of the length of equilibrium cycle. From the analysis of actinide production in the core during burnup, it was observed that in most of the cases, the amounts of actinides obtained using various cross section libraries agree fairly with each other, however, significant differences were observed for {sup 238}Pu, {sup 241}Pu, {sup 242m}Am, {sup 243}Am, {sup 242}Cm and {sup 244}Cm for some libraries. The actinide chain analysis was conducted to investigate the reasons for the observed differences.

2006-12-15

106

On the band gap dependence of refractive indices of some quaternary III-V and II-VI compounds of device interest  

International Nuclear Information System (INIS)

The credibility of the model proposed by Ghosh in predicting the refractive indices of mixed semiconductor crystals of technological importance within their miscibility range as a function of band gap is demonstrated. The high-frequency refractive indices of four quaternary alloys Al_xGa_1_-_x_-_yIn_yP (y = 0.49, 0 #<=# x #<=# 0.51), InSb_xAs_1_-_x_-_yP_y (y = 2.2x, 0 #<=# x #<=# 0.313, 0 #<=# y #<=# 0.638), Cd_xZn_1_-_x_-_yHg_ySe (x + y = 1, 0.153 #<=# x #<=# 0.684, 0.316 #<=# y #<=# 0.847), and CdS_1_-_x_-_ySe_xTe_y (x + y = 1, 0.15 #<=# x #<=# 0.93, 0.07 #<=# y #<=# 0.85) are calculated according to the relation n"2-1 = A/(E_g + B)"2 where A is an energy gap dependent constant and B is a constant depending on crystal ionicity. The calculated values show excellent agreement with the experimental data thus justifying the validity of the model.

107

Integration of advanced nuclear materials separation processes  

Energy Technology Data Exchange (ETDEWEB)

This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project has examined the fundamental chemistry of plutonium that affects the integration of hydrothermal technology into nuclear materials processing operations. Chemical reactions in high temperature water allow new avenues for waste treatment and radionuclide separation.Successful implementation of hydrothermal technology offers the potential to effective treat many types of radioactive waste, reduce the storage hazards and disposal costs, and minimize the generation of secondary waste streams. The focus has been on the chemistry of plutonium(VI) in solution with carbonate since these are expected to be important species in the effluent from hydrothermal oxidation of Pu-containing organic wastes. The authors investigated the structure, solubility, and stability of the key plutonium complexes. Installation and ...

1998-12-31

108

Immunity and Pseudorandomness of Context-Free Languages  

CERN Document Server

We examine the computational complexity of context-free languages, mainly concentrating on two well-known structural properties--immunity and pseudorandomness. An infinite language is REG-immune (resp., CFL-immune) if it contains no infinite subset that is a regular (resp., context-free) language. We prove that (i) there is a context-free REG-immune language outside REG/$n$ and (ii) there is a REG-bi-immune language that can be computed deterministically using logarithmic space. We also show that (iii) there is a CFL-simple set, where a CFL-simple language is an infinite context-free language whose complement is CFL-immune. Similar to the REG-immunity, a REG-primeimmune language has no polynomially dense subsets that are also regular. We further prove that (iv) there is a context-free language that is REG/n-bi-primeimmune but not even REG-immune. Concerning pseudorandomness of context-free languages, we show that (v) CFL contains REG/n-pseudorandom languages. Finally, we prove that ...

2009-01-01

109

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. That is, some DJT 3-manifolds that we shall present here can be regarded as the ...

1989-10-01

110

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, some DJT 3-manifolds that we shall present here can be regarded as the basic ...

111

HST/ACS observations of shell galaxies: inner shells, shell colours and dust  

CERN Document Server

AIM:Learn more about the origin of shells and dust in early type galaxies. METHOD: V-I colours of shells and underlying galaxies are derived, using HST Advanced Camera for Surveys (ACS) data. A galaxy model is made locally in wedges and subtracted to determine shell profiles and colours. We applied Voronoi binning to our data to get smoothed colour maps of the galaxies. Comparison with N-body simulations from the literature gives more insight to the origin of the shell features. Shell positions and dust characteristics are inferred from model galaxy subtracted images. RESULT: The ACS images reveal shells well within the effective radius in some galaxies (at 1.7 kpc in the case of NGC 5982). In some cases, strong nuclear dust patches prevent detection of inner shells. Most shells have colours which are similar to the underlying galaxy. Some inner shells are redder than the galaxy. All six shell galaxies show out of dynamical equilibrium dust features, like lanes or ...

2007-01-01

112

Electron spin resonance study of the equilibrium between tetrahalogeno- and pentahalogeno-nitridotechnetate (VI) ions in solution  

Energy Technology Data Exchange (ETDEWEB)

The e.s.r. spectra of (AsPh/sub 4/)(TcNCl/sub 4/), Cs/sub 2/(TcNCl/sub 5/), (AsPh/sub 4/)(TcNBr/sub 4/), and Cs/sub 2/(TcNBr/sub 5/) have been studied in non-aqueous and concentrated aqueous acid solutions. None of the spectra shows evidence for the co-ordination of a fifth halide ligand in the trans position, even under circumstances such as a 2 000-fold excess of halide ion, which would be expected to favour the formation of the pentahalogenonitridotechnetate ion. The predominant species in solution is the tetrahalogenonitridotechnetate ion, where the trans position may be vacant or occupied by a solvent molecule in the case of the non-aqeuous solvents and by a water molecule in the case of HCl and HBr solutions. This conclusion may be contrasted with the behaviour of a number of tetra- and penta-halogeno-oxometal complexes, where the equilibrium (MOX/sub 4/)sup(n-) + X/sup -/< - - > (MOX/sub 5/)sup(n + 1)/sup -/ is clearly established.

1987-07-01

113

Dependence of fast reactor fuel burnup characteristics on nuclear data libraries  

International Nuclear Information System (INIS)

In the framework of the development of burnup calculation method for commercial fast reactors, a sensitivity analysis was carried out to clarify the dependence of fuel burnup characteristics on nuclear data libraries (NDLs). The following NDLs were compared: JEF-2.2, ENDF/B-VI Release 5, JENDL-3.2 and JENDL-3.3. The NDL-dependence of material balance for main heavy metal nuclides ("2"3"5U, "2"3"8U, "2"3"9Pu, "2"4"0Pu and "2"4"1Pu) was small, since the number densities at the end of one-cycle burnup did not change over 1 or 2% among the above-mentioned libraries. Relatively large differences were found for minor actinide nuclides, especially for "2"3"6U, "2"3"7Np, "2"4"2"mAm, "2"4"3Am and curium isotopes. The number densities for these nuclides after burning up showed remarkable NDL-dependence over 5% through 50%. A burnup sensitivity analysis system based on the generalized perturbation theory enabled us to find out quantitatively the causative nuclides and ...

2005-04-01

114

Biosorption of heavy metals from wastewater by biosolids  

Energy Technology Data Exchange (ETDEWEB)

In a study where the removal of heavy metals from wastewater is the primary aim, the biosorption of heavy metals onto biosolids prepared as Pseudomonas aeruginosa immobilized onto granular activated carbon was investigated in batch and column systems. In the batch system, adsorption equilibriums of heavy metals were reached between 20 and 50 min, and the optimal dosage of biosolids was 0.3 g/L. The biosorption efficiencies were 84, 80, 79, 59 and 42 % for Cr(VI), Ni(II), Cu(II), Zn(II) and Cd(II) ions, respectively. The rate constants of biosorption and pore diffusion of heavy metals were 0.013-0.089 min{sup -1} and 0.026-0.690 min{sup -0.5}. In the column systems, the biosorption efficiencies for all heavy metals increased up to 81-100 %. The affinity of biosorption for various metal ions towards biosolids was decreased in the order: Cr = Ni > Cu > Zn > Cd. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

2006-08-15

115

Basic models and verification study on fuel rod heat-up and fission product release analysis modules in SAMPSON for the IMPACT project  

International Nuclear Information System (INIS)

The super simulator 'SAMPSON' has been developed to show that there exist certain safety margins for light water reactors under hypothetical severe accidents and to investigate realistic measures of accident management by simulating accidents with a parallel computer. Heat-up of fuel rods and release of fission products from fuels are important factors to evaluate source terms. Models for fuel rod heat-up, hydrogen production due to cladding oxidation and cladding deformation and failure in the core region have been developed in the fuel rod heat-up analysis module. Fuel temperatures were calculated by solving the heat conduction equation. The calculated results for fuel temperature and hydrogen production were compared with CORA-13 experiment results. The comparisons showed prediction capability for the heat-up of fuel rods. The fission product release analysis module incorporates with models for fission product transport within fuel pellets, release from fuel rods after failure of ...

1999-04-19

116

Automated synthesis of hypoxia imaging agent [18F]FMISO based upon a modified Explora FDG4 module  

British Library Electronic Table of Contents (United Kingdom)

A new automated synthesis procedure of 1-H-1-(3-[18F]fluoro-2-hydroxypropyl)-2-nitroimidazole ([18F]FMISO), a specific hypoxia imaging agent with great significances for the noninvasive, dynamic hypoxia evaluation of cancer, was developed by modifying Explora FDG4 module, a commercial [18F]FDG production system, in this study. Its radiochemical synthesis was carried out via two sequent reaction steps, i.e. the nucleophilic displacement of labeling precursor 1-(2?-nitro-1?-imidazolyl)-2-O-tetrahydropyranyl-3-O-tosyl-propaned iol (NITTP) with activated 18F- ion at 100 ?C for 8 minutes, and the following hydrolysis with 1M HCl at 100 ?C for 5 minutes and neutralization with 1M NaOH. Two-pot reaction with two independent separations was adopted to assure the good separation of final product vi...

2009-01-01

117

Assessment of the nuclide concentration estimates with CASMO-4E with experimental data for very high burn-up UO_2 and MOX fuels  

International Nuclear Information System (INIS)

In this paper a computational analysis of 11 fuel samples (seven UO_2 and four MOX) with a burn-up ranging from 20 MWd/kgHM up to 121 MWd/kgHM (HM: Heavy Metal) is carried out with the depletion module of the lattice code CASMO-4E [Rhod01, Rhod01b] using the neutron data libraries ENDF/B-VI and JEF-2.2 and a pin cell model. In order to assess the accuracy of the model and the depletion calculation in the determination of the isotopic inventory after several irradiation cycles, the calculated results were compared to experimental data gathered from a chemical isotopic analysis of the fuel samples performed at the Hot Laboratory at the Paul Scherrer Institut (PSI), Switzerland. Selected results of this comparison, which includes 54 isotopes (17 actinides and 37 fission products), are presented here. (orig.)

118

An electron spin resonance study of the equilibrium between tetrahalogeno- and pentahalogeno-nitridotechnetate (VI) ions in solution  

International Nuclear Information System (INIS)

The e.s.r. spectra of [AsPh_4][TcNCl_4], Cs_2[TcNCl_5], [AsPh_4][TcNBr_4], and Cs_2[TcNBr_5] have been studied in non-aqueous and concentrated aqueous acid solutions. None of the spectra shows evidence for the co-ordination of a fifth halide ligand in the trans position, even under circumstances such as a 2 000-fold excess of halide ion, which would be expected to favour the formation of the pentahalogenonitridotechnetate ion. The predominant species in solution is the tetrahalogenonitridotechnetate ion, where the trans position may be vacant or occupied by a solvent molecule in the case of the non-aqeuous solvents and by a water molecule in the case of HCl and HBr solutions. This conclusion may be contrasted with the behaviour of a number of tetra- and penta-halogeno-oxometal complexes, where the equilibrium [MOX_4]sup(n-) + X"-< - - > [MOX_5]sup(n + 1)"- is clearly established. (author).

119

A joint computational and experimental study of a novel dioxomolybdenum(VI) complex bearing chiral N,N-dimethyllactamide ligand  

British Library Electronic Table of Contents (United Kingdom)

A new cis-dioxomolybdenum complex MoO2(DMLA)2 (DMLA=N,N-dimethyllactamide) has been synthesized and characterized by X-ray crystallography, H NMR and IR spectroscopies and electronic structure calculations at DFT/B3LYP level. This compound (chemical formula C10H20MoO6N2) crystallizes in the orthorhombic space group P212121 with Z=4, a=6.9357(2)?, b=11.8761(4)?, c=17.7251(5), V=1460.00(8)?3 and renders a slightly distorted octahedral structure with two long Mo-O bonds (2.253(3)? and 2.257(3)?) trans to each of the MoO groups and with two short Mo-O bonds of 1.942(3)4? cis to them. The MoO bond length are 1.715(3) and 1.704(3)?). Each lactamide ligand is bidentate; they are coordinated in their deprotonated form with the carbonyl oxygen occupy...

2011-01-01

120

[Fast neutron cross section measurements]. Progress report  

Energy Technology Data Exchange (ETDEWEB)

In this report, we outline the progress achieved in two distinct under the DOE-sponsored cross section project: the initial results obtained from the pulsed 14 MeV neutron facility, and a cooperative effort with Argonne National Laboratory in the measurement of fast neutron cross sections in yttrium. In the 14 MeV neutron laboratory, this year has seen the maturation of the project into one in which initial scattering measurements are now underway. We have improved the accelerator and ion source in several significant ways, so that neutron intensities have now been proven to be adequate for our series of elastic scattering angular distribution measurements outlined in our initial proposal of two years ago. We have successfully tested all components of the time-of-flight spectrometer and recorded initial neutron spectra from the ring targets that we have obtained for our first angular distribution measurements. Examples of the time-of-flight spectra that have been obtained are given ...

1991-12-31

 
 
 
 
121

Zinc-blende--wurtzite polytypism in semiconductors  

Science.gov (United States)

The zinc-blende (ZB) and wurtzite (W) structures are the most common crystal forms of binary octet semiconductors. In this work we have developed a simple scaling that systematizes the {ital T}=0 energy difference {Delta}{ital E}{sub W{minus}ZB} between W and ZB for all simple binary semiconductors. We have first calculated the energy difference {Delta}{ital E}{sub W{minus}ZB}{sup LDF}({ital AB}) for AlN, GaN, InN, AlP, AlAs, GaP, GaAs, ZnS, ZnSe, ZnTe, CdS, C, and Si using a numerically precise implementation of the first-principles local-density formalism (LDF), including structural relaxations. We then find a {ital linear} scaling between {Delta}{ital E}{sub W{minus}ZB}{sup LDF}({ital AB}) and an atomistic orbital-radii coordinate {ital {tilde R}}({ital A},{ital B}) that depends only on the properties of the free atoms {ital A} and {ital B} making up the binary compound {ital AB}. Unlike classical structural coordinates (electronegativity, atomic sizes, electron count), {ital {tilde ...

1992-10-15

122

ZZ UKFY2, Fission Yields of Th, U, Np, Pu, Am, Cm, Cf Isotopes  

International Nuclear Information System (INIS)

Description of program or function: Format: ENDFB-6 format; Nuclides: Th-232, U-233, U-234, U-235, U-236, U-238, Np-237, Np-238, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, Am-241, Am-242, Am-243, Cm-243, Cm-244, Cm-245, and from the spontaneous fission of Cm-242, Cm-244, and Cf-252. Origin: New evaluation (Crouch 1, 2, 3, 4; UKFY1; JEF-1). A new evaluation of fission product yields from the thermal, fast, and 14 MeV neutron-induced fission of the following nuclides has been prepared in ENDFB-VI format: "2"3"2Th, "2"3"3U, "2"3"4U, "2"3"5U, "2"3"6U, "2"3"8U, "2"3"7Np, "2"3"8Np, "2"3"8Pu, "2"3"9Pu, "2"4"0Pu, "2"4"1Pu, "2"4"2Pu, "2"4"1Am, "2"4"2"mAm, "2"4"3Am, "2"4"3Cm, "2"4"4Cm, "2"4"5Cm; and from the spontaneous fission of "2"4"2Cm, "2"4"4Cm, and "2"5"2Cf

123

TRIGA reactor spent fuel pool under severe earthquake conditions  

International Nuclear Information System (INIS)

Supplemental criticality safety analysis of a pool type storage for TRIGA spent fuel at 'Jozef Stefan' Institute in Ljubljana, Slovenia, is presented. Previous results (Ravnik, M, Glumac, B., 1996) have shown that subcriticality is not guaranteed for some postulated accidents. To mitigate this deficiency, a study was made about replacing a certain number of fuel elements in the rack with absorber rods (Glumac, B., Ravnik, M., Logar, M., 1997) to lower the supercriticality probability, when the pitch is decreased to contact (as a consequence of a severe earthquake) in a square arrangement. The criticality analysis for the hexagonal contact pitch is presented in this paper, following the same scenario as outlined above. The Monte Carlo computer code MCNP4B with ENDF-B/VI library and detailed three dimensional geometry was used. First, the analysis about the influence of the number of triangular fuel piles on the bottom that could appear, if the fuel rack, made of ...

1998-07-01

124

Spray Chemical Vapor Deposition of Single-Source Precursors for Chalcopyrite I-III-VI2 Thin-Film Materials  

Science.gov (United States)

Thin-film solar cells on flexible, lightweight, space-qualified substrates provide an attractive approach to fabricating solar arrays with high mass-specific power. A polycrystalline chalcopyrite absorber layer is among the new generation of photovoltaic device technologies for thin film solar cells. At NASA Glenn Research Center we have focused on the development of new single-source precursors (SSPs) for deposition of semiconducting chalcopyrite materials onto lightweight, flexible substrates. We describe the syntheses and thermal modulation of SSPs via molecular engineering. Copper indium disulfide and related thin-film materials were deposited via aerosol-assisted chemical vapor deposition using SSPs. Processing and post-processing parameters were varied in order to modify morphology, stoichiometry, crystallography, electrical properties, and optical properties to optimize device quality. Growth at atmospheric pressure in a horizontal hotwall reactor at 395 C yielded the best ...

2008-01-01

125

Sequences, geographic variations and molecular phylogeny of venom phospholipases and threefinger toxins of eastern India Bungarus fasciatus and kinetic analyses of its Pro31 phospholipases A2.  

Science.gov (United States)

Eight phospholipases A2 (PLAs) and four three-finger-toxins (3FTx) from the pooled venom of Bungarus fasciatus (Bf) were previously studied and sequenced, but their expression pattern in individual Bf venom and possible geographic variations remained to be investigated. We herein analyze the individual venom of two Bf specimens from Kolkata (designated as KBf) to address this question. Seven PLAs and five 3FTx were purified from the KBf venoms, and respective cDNAs were cloned from venom glands of one of the snakes. Comparison of their mass and N-terminal sequence revealed that all the PLAs were conserved in both KBf venoms, but that two of their 3FTx isoforms were variable. When comparing the sequences of these KBf-PLAs with those published, only one was found to be identical to that of Bf Vb-2, and the other five were 94-98% identical to those of Bf II, III, Va, VI and XI-2, respectively. Notably, the most abundant PLA isoforms of Bf and KBf venoms contain Pro31 ...

2006-12-08

126

Nuclear radiation detectors on II-VI compounds  

International Nuclear Information System (INIS)

Nuclear radiation detectors in integral execution were produced by successive epitaxial growth from vapor phase of Zn Te and Cd Se thin layers onto scintillating Zn Se (Te) crystals. The irradiation of combined Zn Se (Te) - Zn Te - Cd Se detectors by Cu_K_a X-rays leads to the appearance of photoreceiver e.m.f., which tends to saturation with the increase of X-ray radiation dose reaching the value of 0.34-0.40 V at 200 R/min. The short circuit current dependence of irradiation dose power is linear. The matching factor for detectors with Zn Te-Cd Se photoreceivers with different doping levels is 0.68-0.92. The absolute monochromatic sensitivity is 0.32-0.35 m A/m W at a quantum efficiency 0.58-0.61 and a time constant 2 x 10"-"4 s. The calculated dose sensitivity for Zn Se(Te)-Zn Te-Cd Se combined detectors at the irradiation with X-rays having effective energy 8.86 keV gives the value 3.9 x 10"-"7 A/cm"2 (R/min); the experimental value of dose sensitivity reaches (1.4-1.6) x 10"-"7 ...

1993-10-13

127

Mapping of the human cone transducin {alpha} subunit (GNAT2) gene to 1p13 and mutation analysis in patients with Stargardt`s disease  

Energy Technology Data Exchange (ETDEWEB)

Transducin {alpha} subunits are members of a large family of G-proteins and play an important role in phototransduction in rod and cone photoreceptors. We report the localization of the human cone {alpha} transducin (GNAT2) gene using fluorescence in situ hybridization (FISH) on chromosome 1 in band p13. The recent assignment of a gene for Stargardt`s disease to the same chromosomal region by linkage analysis prompted us to investigate the possible role of GNAT2 in the pathogenesis of this disease. Stargardt`s disease is characterized by degeneration in late childhood or early adulthood of the macula of the retina, a region rich in cones. We screened patients with Stargardt`s disease, with or without peripheral cone involvement as monitored by the full-field ERG, for mutations in this gene. We investigated 66 unrelated patients including 22 with peripheral cone dysfunction for mutations in the coding region of the GNAT2 gene using polymerase chain reaction-single strand conformation ...

1994-09-01

128

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) solution. The ICP-MS analyses indicated selective dissolution of a ...

2007-05-15

129

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) solution. The ICP-MS analyses indicated selective dissolution of a significant amount of Fe ...

2007-05-01

130

Formation and stabilization of anionic metal complexes in concentrated aqueous quaternary ammonium salt solutions  

Energy Technology Data Exchange (ETDEWEB)

Anionic complexes of transition metals were stabilized in aqueous solutions containing high concentrations of various short-chain quaternary ammonium salts. Compounds with longer paraffin chains were effective in much less concentrated solution. Complex ions were detected spectrophotometrically. FeCl/sub 4//sup -/, which is usually formed in concentrated HCl, was the predominant Fe(III) complex in 30 m choline chloride containing only 0.12 M HCl. A yellow transitory Tc(VII) chloro-addition intermediate, formed in the reduction of TcO/sub 4//sup -/ by concentrated HCl, was stabilized when the solution also contained 25 m choline chloride. Its spectrum, as well as the isolation of an already known Tc(VII) bipyridyl complex, is reported. Concentrated organic electrolytes also stabilized Tc(V) oxide halides against disproportionation and Tc(IV) hexahalides against hydrolysis. Halochromates of Cr(VI) were formed and stabilized in dilute acid containing quaternary ...

1985-02-04

131

Beta and gamma decay heat measurements between 0.1s - 50,000s for neturon fission of {sup 235}U, {sup 238}U and {sup 239}Pu. Progress report, June 1, 1992--December 31, 1994  

Energy Technology Data Exchange (ETDEWEB)

In the investigations reported here, a helium-jet/tape-transport system was used for the rapid transfer of fission products to a low-background environment where their aggregate beta and gamma-ray spectra were measured as a function of delay time after neutron induced fission of {sup 235}U, {sup 238}U and {sup 239}Pu. Beta and gamma-ray energy distributions have been deduced for delay times as short as 0.2 s and extending out to 100,000s. Instrumentation development during the initial phase of the project included: (1) assembly and characterization of a NaI(Tl) spectrometer for determining aggregate gamma-ray energy distributions, (2) development and characterization of a beta spectrometer (having excellent gamma-ray rejection) for measuring aggregate beta-particle energy distributions, (3) assembly and characterization of a Compton-suppressed HPGe spectrometer for determining gamma-ray intensities of individual fission products to deduce fission-product yields. Spectral decomposition ...

1997-05-01

132

Accelerator technology program. Progress report, April-December 1978  

Science.gov (United States)

This report presents highlights of activities in the Acceleartor Technology (AT) Division from April through December 1978. The report is divided into 10 sections to cover work done by the four groups that make up AT Division (AT-1, AT-2, AT-3, and AT-4). Section I is a brief summary of the whole report. Sections II through VI describe work done by At-1, the Linac Technology Group. Subjects covered are the Pion Generation for Medical Irradiation Program, the Electronuclear Fuel-Producing Accelerator Program, the Gyrocon rf Amplifier Program, the Electron Linear Accelerator Program, and the Free Electron Laser Program. Section VII covers the Linear Accelerator Beam Dynamics development, and Sec. VIII deals with work with the H/sup -/ Ion Source. Most of the work in Secs. VII and VIII was done by AT-2, the Special Projects Group, although work on factors influencing emittance growth was done by MP-9, and results on emittance growth in the new European Council for ...

1980-05-01

133

[Hadroproduction of charmed and bottom mesons (Fermilab experiment E-653): Progress report, June 13, 1983--June 14, 1984  

Energy Technology Data Exchange (ETDEWEB)

(I)Results are given for photoproduction of the D{sup *} at 103 GeV. Clean signals are seen for the decay D{sup *{+-}} {yields} {pi}{sup {+-}}D{sup 0} with the D{sup 0} decaying into both K{sup {-+}}{pi}{sup {+-}} and K{sup {-+}}{pi}{sup {+-}}{pi}{sup 0}. Analysis of the Dalitz plot for the K{pi}{pi} mode gives branching fractions (BFs) for K{sup {minus}}{rho}{sup +}, K{sup *{minus}}{pi}{sup +}, and {anti K}{sup *0}{pi}{sup 0} final states. The BF for D{sup 0} {yields} K{sup {minus}}{rho}{sup +}, much lower than a previous result, is in approximate agreement with the value expected for an l=1/2 final state. (II)Inelastic and elastic J/{psi} photoproduction on H is investigated at 103 GeV. The inelastic cross section with E{sub {psi}}/E{sub {gamma}} {lt} 0.9 is significantly lower than the corresponding result for muoproduction on Fe targets, but consistent with second-order perturbative QCD calculation. The mean p{sub +} of inelastic events is larger than that of elastic events. ...

1984-12-31

134

Delayed neutron energy spectra following fast fission of "2"3"8U  

International Nuclear Information System (INIS)

Delayed neutron energy spectra have been measured for six delay-time intervals following the fast fission of "2"3"8U nuclei. The delay-time intervals span the range 0.17 to 10.2 seconds following initial fission while the measured spectra span neutron energies from 10 keV to 4 MeV. The experiment was performed utilizing the UMass/Lowell 5.5 MV Van de Graff accelerator to produce fast neutrons for inducing fission in a "2"3"8U lined fission chamber. The fission fragments were flushed via a helium jet stream to a well-shielded counting room where they were deposited onto a moving tape (magnetic audio tape) and transferred to a beta-neutron time-of-flight spectrometer. By adjusting the tape speed, composite delayed neutron time-of-flight spectra were measured for several different delay-time intervals. These measurements involved beta-neutron coincidences with "6Li-loaded glass scintillators for neutron energies from 10 keV to 450 keV and Bicron BC 501 liquid scintillators for the neutron ...

135

ZZ KASHIL-E6, 175 N, 42 Gamma Groups Cross Sections in MATXS Format Based on ENDF/B-VI.5 for Shielding Applications  

International Nuclear Information System (INIS)

1 - Description of program or function: Format: MATXS; Number of groups: 175 neutron-, 42 photon-groups; 176 Nuclides: 1-H-1, 1-H-2, 1-H-3, 2-He-3, 2-He-4, 3-Li-6, 3-Li-7, 4-Be-9, 5-B-10, 5-B-11, 6-C- nat., 7-N-14, 7-N-15, 8-O-16, 8-O-17, 9-F-19, 11-Na-23, 12-Mg-nat., 13-Al-27, 14-Si-nat., 14-Si-28, 14-Si-29, 14-Si-30, 15-P-31, 16-S-32, 17-Cl-nat., 19-K-nat., 20-Ca-nat., 21-Sc-45, 22-Ti-nat., 23-V-nat., 24-Cr-50, 24-Cr-52, 24-Cr-53, 24-Cr-54, 25-Mn-25, 26-Fe-54, 26-Fe-56, 26-Fe-57, 26-Fe-58, 27-Co-59, 28-Ni-58, 28-Ni-60, 28-Ni-61, 28-Ni-62, 28-Ni-64, 29-Cu-63, 29-Cu-65, 31-Ga-nat., 39-Y-89, 40-Zr-nat., 40-Zr-90, 40-Zr-91, 40-Zr-92, 40-Zr-94, 40-Zr-96, 41-Nb-93, 42-Mo-nat., 46-Pd-102, 46-Pd-104, 46-Pd-105, 46-Pd-106, 46-Pd-108, 46-Pd-110, 47-Ag-107, 47-Ag-109, 48-Cd-106, 48-Cd-108, 48-Cd-110, 48-Cd-112, 48-Cd-113, 48-Cd-114, 48-Cd-116, 49-In-nat., 53-I-127, 54-Xe-124, 54-Xe-126, 54-Xe-128, 54-Xe-129, 54-Xe-130, 54-Xe-131, 54-Xe-132, 54-Xe-134, 54-Xe-136, 55-Cs-133, 56-Ba-138, 59-Pr-141, ...