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A carbon nanotube (CNT) tip, which assembled on the sharp end of a Si tip by dielectrophoresis, was structurally modified using focused ion beam (FIB). We described the imaging characterization of the FIB-modified CNT tip in noncontact AFM mode in terms of wear, deep trench accessibility, and imaging resolution. Compared to a conventional Si tip, the FIB-modified CNT tip was superior, especially for prolonged scanning over 10 h. We conclude that modified CNT tips have the potential to obtain high-quality images of nanoscale structures.

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Polyacrylonitrile (PAN)-based carbon fabric (CF) was modified with strong HNO3 oxidation and then introduced into polyimide (PI) composites. The friction and wear properties of the carbon fabric reinforced polyimide composites (CFRP), sliding against GCr15 stainless steel rings, were investigated on an M-2000 model ring-on-block test rig under dry sliding. Experimental results revealed that the carbon fiber surface treatment largely reduced the friction and wear of the CFRP. Compared with the untreated ones, the surface-modified CF can enhance the tribological properties of CFRP efficiently due to the improved adhesion between the CF and the PI matrix. Scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) study of the carbon fiber surface showed that the fiber surfa...

International Nuclear Information System (INIS)

The influence of the regimes of modification of carbon fibers by an argon ion beam on the change in the angle of their wetting by an epoxy oligomer has been investigated. It has been shown that ion-beam treatment of carbon fibers leads to a considerable decrease in the wetting angles (the difference between the wetting angles for non modified and modified fibers is up to 32.2-38.7). Accordingly, there is also an increase in the value of the equilibrium work of adhesion by 36.2-41.6% in the contact zone. It has been established that ion-beam treatment of carbon fibers by argon ions leads to an increase in the shear strength when microplastics based on them are formed. (authors)

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

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Here we demonstrate that the as-prepared MCM-41 mesoporous silica material, which is synthesized using cetyltrimethylammonium bromide as a cationic surfactant exhibits very high capacity for perchlorate uptake from solutions. Thus we discover a new function for the as-synthesized mesoporous materials containing cationic surfactants. These materials are shown to have better capacity than the currently used activated carbon, which is preloaded with cationic surfactant. As-synthesized MCM-41 has a higher removal of perchlorate with 0.378???0.038?meq/g than the surfactant modified activated carbon sample, which removed 0.304???0.005?meq/g i.e., MCM-41 has a 24 % higher capacity than the surfactant modified activated carbon sample for perchlorate uptake because of higher surfactant content and ...

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Isosteric heats and adsorption isotherms of methane on nanometer active carbon were measured at supercritical temperature (273-373 K) and pressure from 0 to 10 MPa. The measured data agreed well with Dubinin-Astakhov (DA) model at lower pressure but failed when pressure exceeded a special range. General Freundlich (GF) equation was used to modify the DA equation at high pressure and thus formed a combined bisection model GFDA. The adsorption mechanism of methane on nanometer active carbon was raised according to GFDA model and the heterogeneous energy distribution of the adsorbent was analyzed.

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Horseradish peroxidase (HRP) was chemically modified using cyanuric chloride (CC) as a linking agent onto a carbon felt (CF), which is a microelectrode ensemble of micro carbon fiber (>7mm, diameter) with a random three-dimensional structure. The resulting HRP-modified CF (HRP-ccCF) exhibited well-defined redox waves based on the HRP heme Fe^I^I^I/Fe^I^I redox couple at -0.23V vs. Ag/AgCl (at pH 7.0), while the HRP-adsorbed CF (HRP-CF) showed no apparent redox couple in the same potential range, indicating that the chemical modification of HRP via CC facilitated the direct electron transfer (DET) between HRP and CF. The apparent heterogeneous electron transfer rate constant ks was estimated to be 35s^-^1. Cyclic voltammetry and electrochemical impedance spectroscopy revealed that the inter...

International Nuclear Information System (INIS)

A rapid combustion unit (Baird and Tatlock) incorporating a combustion chamber provided with baffle plates for complete combustion of the sample without the use of a catalyst has been assembled in a glove box for the determination of carbon and hydrogen in actinide complexes. The unit has been modified employing a movable electric furnace and a proportional temperature controller, for decomposition of the sample at desired heating rates. The set-up was standardised employing various reference materials such as benzoic acid, acetanilide, sulphanilamide and 1-chloro 2:4 dinitrobenzene and the standard deviation in the measurements evaluated. It has also been used successfully for the determination of carbon in uranium carbide and carbon and hydrogen in some uranyl-#beta#-diketone-amine N-oxide complexes and in plutonium(IV) oxalate. (auth.).

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The processing characteristics, tensile properties, and oxidation response of two Nb-Ti-Al-Cr alloys were investigated. One creep tests at 650{degrees}C and 172 MPa was conducted on the base alloy which contained 40Nb-40-Ti-10Al-10Cr. A second alloy was modified with 0.11 at. % carbon and 0.07 at. % yttrium. Alloys were arc melted in a chamber backfilled with argon, drop cast into a water-cooled copper mold, and cold rolled to obtain a 0.8-mm sheet. The sheet was annealed at 1100{degrees}C for 0.5 h. Longitudinal tensile specimens and oxidation specimens were obtained for both the base alloy and the modified alloy. Tensile properties were obtained for the base alloy at room temperature, 400, 600, 700, 800, 900, and 1000{degrees}C, and for the modified alloy at room temperature, 400, 600, 700, and 800{degrees}C. Oxidation tests on the base alloy and modified alloy, as measured by ...

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A electrogenerated chemiluminescence (ECL) sensor for itopride was developed based on tris(2,2-bipyridyl)ruthenium(II) (Ru(bpy)32+)-doped silica (RuDS) nanoparticles/biopolymer chitosan composites membrane modified glassy carbon electrode (GCE). The RuDS nanoparticles (52+-5nm) were prepared by a modified Stber synthesis method and were characterized by electrochemical, fluorometric and transmission electron microscopy technology. The Ru(bpy)32+ encapsulation interior of the silica nanoparticle maintains its electrochemical activities and also reduces Ru(bpy)32+ leaching from the silica matrix when immersed in water due to the electrostatic interaction. The ECL analytical performances of this ECL sensor for itopride based on its enhancement ECL emission of Ru(bpy)32+ were investigated in d...

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This paper investigates various usages of natural gas (NG) as an energy source for different hydrogen production technologies. A comparison is made between the different methods of hydrogen production, based on the total amount of natural gas needed to produce a specific quantity of hydrogen, carbon dioxide emissions per mole of hydrogen produced, water requirements per mole of hydrogen produced, and a cost sensitivity analysis that takes into account the fuel cost, carbon dioxide capture cost and a carbon tax. The methods examined are the copper-chlorine (Cu-Cl) thermochemical cycle, steam methane reforming (SMR) and a modified sulfur-iodine (S-I) thermochemical cycle. Also, an integrated Cu-Cl/SMR plant is examined to show the unique advantages of modifying existing SMR plants with new hydrogen production technology. The analysis shows that the thermochemical Cu-Cl cycle ...

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The heterogeneous solid catalyst, mercaptopropylsilica (MPS), has been prepared by a modified procedure in water and its structure confirmed by solid state carbon-13 CP-MAS NMR spectrum. This catalyst has been efficiently utilized for the synthesis of a wide variety of tri-, tetrasubstituted imidazoles and their bis-analogues at room temperature. The protocol was further explored for the synthesis of the drug trifenagrel.

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The processing characteristics, tensile properties, and oxidation response of two Nb-Ti-Al-Cr alloys were investigated. One creep test at 650 C and 172 MPa was conducted on the base alloy, which contained 40Nb-40Ti-10Al-10Cr. A second alloy was modified with 0.11 at.% C and 0.07 at.% Y. Alloys were arc melted in a chamber backfilled with argon, drop cast into a water-cooled copper mold, and cold rolled to obtain a 0.8-mm sheet. The sheet was annealed at 1,100 C for 0.5 h. Longitudinal tensile specimens and oxidation specimens were obtained for both the base alloy and the modified alloy. Tensile properties were obtained for the base alloy at room temperature, 400, 600, 700, 800, 900, and 1,000 C and for the modified alloy at room temperature, 400, 600, 700, and 800 C. Oxidation tests the base alloy and modified alloy, as measured by weight change, were carried out at 600, 700, 800, and 900 C. Both the ...

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The carbon fibers (CF) were pre-treated in two different ways: no pre-treatment, and activation in HNO3 plus application of toluene-2,4-diisocyanate (TDI). Carbon fibers have been introduced into polyurethane (PU) composite coatings. The tribological behaviors of the polyurethane composite coating filled with CF or TDI-modified CF (TDI-CF) were studied using a ring-on-block wear tester under dry sliding, and the worn surfaces of the filled PU coatings and transfer films formed on the surface of the counterpart ring sliding against the PU coating were investigated by SEM and optical microscope (OM), respectively. Owing to the effective improvement of the interfacial adhesion between the CF and polyurethane matrix, compared with the cases of untreated CF, the employment of low content TDI-CF...

International Nuclear Information System (INIS)

The aim of this paper was to describe ability to intercalation of laboratory prepared carbon composites and their constituents. In work the following materials were tested; pinch-based fibres of P-120 and K-1100 manufacturer's designations, carbon matrix and resulting composites. To prepare a matrix of composites, phenol-formaldehyde resin (Z) and pinch-based precursor (PAK) were used. After initial carbonization, the carbon matrix was heated to 2150 "oC i to improve ability to the future intercalation. Three kinds of composites (P/Z, K/Z and K/PAK), with two directional reinforcement (2D), were prepared. All carbon samples were intercalated with copper chloride(II). To study the structure of all materials, before and after intercalation, X-ray diffraction method was used. It enabled to measure microstructure parameters (L_c and L_a), interplanar distance (d_0_0_2) thickness of an ...

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A sensitive hydrogen peroxide (H2O2) sensor was fabricated based on graphene-Pt (GN-Pt) nanocomposite. The GN-Pt was synthesized by photochemical reduction of K2PtCl4 on GNs, and characterized by atomic force microscope (AFM), transmission electron microscope (TEM), and energy-dispersive X-ray spectroscopy (EDS). Electrochemical investigations indicated that the GN-Pt exhibited a high peak current and low overpotential towards the reduction of H2O2. The GN-Pt modified glass carbon electrode displayed a wide linear range (2-710mM), low limit of detection (0.5mM) and good selectivity for detection of H2O2 with a much higher sensitivity than that of Pt nanoparticles or graphene modified electrode.

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The possibility of employing a number of adsorbents (polyphenylquinoxaline, Tenax GC, Carbopak C, graphitized thermal carbon black, silica gels modified with pyrocarbon or hexamethyldisilazane) for the trapping of organic traces from air has been investigated. Adsorption capacities of these adsorbents with respect to a number of volatiles released from certain plastics used as building material (polyvinylchloride, Relin, Acronal, etc.) have been measured. A number of the volatiles were identified by gas chromatography - mass-spectrometry after trapping on the adsorbents investigated. Chromatographic separation after trapping on the adsorbents was carried out on wall-coated open-tubular capillary columns as well as in capillary columns packed with graphitized thermal carbon black.

Science.gov (United States)

Simple and low cost biosensor based on screen-printed electrode for sensitive detection of some alkylphenols was developed, by entrapment of HRP in a nanocomposite gel based on single-walled carbon nanotubes (SWCNTs) and 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF(6)]) ionic liquid. Raman and FTIR spectroscopy, CV and EIS studies demonstrate the interaction between SWCNTs and ionic liquid. The nanocomposite gel, SWCNT-[BMIM][PF(6)] provides to the modified sensor a considerable enhanced electrocatalytic activity toward hydrogen peroxide reduction. The HRP based biosensor exhibits high sensitivity and good stability, allowing a detection of the alkylphenols at an applied potential of -0.2V vs. Ag/AgCl, in linear range from 5.5 to 97.7?M for 4-t-octylphenol and respectively, between 5.5 and 140?M for 4-n-nonylphenol, with a response time of about 5s. The detection limit was 1.1?M for 4-t-octylphenol, and respectively 0.4?M for ...

Science.gov (United States)

The enantiomeric separations of three pesticides fipronil (asymmetric nitrogen), isocarbophos (asymmetric phosphorus) and carfentrazone-ethyl (asymmetric carbon) were studied on cellulose-tri(3,5-dimethylphenylcarbamate) chiral stationary phase using high-performance liquid chromatography under normal phase. The mobile phase was n-hexane with alcohols including ethanol, n-propanol, iso-propanol, n-butanol and iso-butanol as polar modifiers. The flow rate was 1.0 mL/min with UV detection at 280, 225 and 230 nm for fipronil, isocarbophos and carfentrazone-ethyl respectively. The influence of the modifiers and their volume content and temperature from 0 to 50 degrees C on the separations was investigated. The chiral stationary phase showed excellent stereoselectivity for the two enantiomers of fipronil and isocarbophos and certain chiral recognition for carfentrazone-ethyl. Iso-propanol was more suitable for the chiral ...

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Multi-walled carbon nanotubes (MWNTs) were modified with poly(hexamethylene adipamide) (also known as Nylon 66) via a controlled polymer solution crystallization method. A 'nanohybrid shish kebab' (NHSK) structure was found wherein the MWNT resembled the shish while Nylon 66 lamellar crystals formed the kebabs. These Nylon 66-functionalized MWNTs were used as precursors to prepare polymer/MWNT nanocomposites. Excellent dispersion was revealed by optical and electron microscopies. Nitric acid etching of the nanocomposites showed that MWNT formed a robust network in Nylon 66. Non-isothermal DSC results showed multiple melting peaks, which can be attributed to lamellar thickness changes upon heating. The crystallite sizes L{sub 100} and L{sup 010} of Nylon 66, determined by WAXD, decreased with increasing MWNT contents. Isothermal DSC results showed that crystallization kinetics increased first and then decreased with increasing ...

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Previously we have used atomic force anodisation lithography, with a self-assembled monolayer of hexadecyltrichlorosilane as a resist, to pattern silicon oxide nanostructures onto a p-type silicon (1 0 0) substrate. A condensation reaction was used to immobilise carbon nanotubes with high carboxylic acid functionality directly to the silicon oxide. A further condensation reaction using this surface attached the molecule ferrocenemethanol to the bound nanotubes. These new nanostructures were used as electrodes to observe the oxidation and reduction of ferrocene. However, because the small currents measured are near the detection limits of the electrochemical system used, important electrode kinetics could not to be obtained. A scribing approach made larger regions of oxidised silicon leading to the creation of larger scale patterned arrangements of carbon nanotubes allowing measurement of important electrochemical parameters such as electrode ...

International Nuclear Information System (INIS)

Plasma nitriding is a powerful technique for modifying the phase-structure of the material surface layers, which affect the mechanical, physical and chemical properties of material. The effect of plasma nitriding on the surface properties of three types of steel (low carbon, AISI-304 and H13 (hardened)) has been investigated. The steel samples were plasma nitrided in vacuum of 10"-"1Pa with gas mixture of (N_2, H_2) at 530 Centigrade degree for a duration of 14 hours. Vickers microhardness measurements and XRD phase analysis of the treated and untreated samples were carried out. The diffraction patterns of treated steels revealed that new phases of #gamma#-Fe_4N, #epsilon#-Fe_3N and (Fe,Cr)_2N were formed. The maximum treated depths were about 5, 6 and 45 #mu#m for low carbon, AISI-304 and H13 (hardened) nitrided steel respectively. The microhardness was increased by about 150%, 200% and 140% for low ...

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Modern combined cycle power plants with natural gas as the only fuel reach efficiencies of up to 55% for electric power generation. Nevertheless the reserve of natural gas is more limited compared to the reserve of coal. Therefore possibilities should be investigated to use coal for such plants also. One concept, that combines the use of coal in a combined cycle application with high efficiencies is examined in this paper. According to this concept the exhaust gas of the gas turbine (vitiated air) is the combustion air for the pulverized coal combustion, that takes place in the bottoming steam generator. Due to the low oxygen content of the vitiated air the burnout of the coal may be incomplete. In order to avoid the incomplete combustion of the coal and the resulting decrease of the efficiency of the plant and possible emission problems, a catalyst, that converts carbon monoxide and unburnt carbon to carbon dioxide, shall ...

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The dissolution of NiO cathodes during cell operation is a limiting factor to the successful commercialization of molten carbonate fuel cells (MCFCs). Lithium cobalt oxide coating onto the porous nickel electrode has been adopted to modify the conventional MCFC cathode which is believed to increase the stability of the cathodes in the carbonate melt. The material used for surface modification should possess thermodynamic stability in the molten carbonate and also should be electro catalytically active for MCFC reactions. Two approaches have been adopted to get a stable cathode material. First approach is the use of LiNi{sub 0.8}Co{sub 0.2}O{sub 2}, a commercially available lithium battery cathode material and the second is the use of tape cast electrodes prepared from cobalt coated nickel powders. The morphology and the structure of LiNi{sub 0.8}Co{sub 0.2}O{sub 2} and tape cast Co coated nickel powder ...

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This work deals with a new route to modify polymer blend morphology in order to improve the porosity of gas diffusion layers (GDLs) for proton exchange membrane fuel cells (PEMFCs). First, electrically conductive polymer-based blends were carefully formulated using a twin-screw extrusion process. Blend electrical conductivity was ensured by the addition of high specific surface area carbon black and synthetic graphite flakes. Final GDL porosity, in particular its macroporosity, was generated by melt blending polyamide 11 (PA11) matrix with polystyrene (PS) followed by PS extraction with tetrahydrofuran (THF) solvent at room temperature. In order to improve GDL porosity by the optimisation of PS dispersion in the PA11 matrix, PA11/PS blends were compatibilised by the addition of 2 wt.-% of clay. It was observed that both macroporosity and pore size distribution were beneficially modified after blend compatibilisation. Final ...

British Library Electronic Table of Contents (United Kingdom)

This work deals with a new route to modify polymer blend morphology in order to improve the porosity of gas diffusion layers (GDLs) for proton exchange membrane fuel cells (PEMFCs). First, electrically conductive polymer-based blends were carefully formulated using a twin-screw extrusion process. Blend electrical conductivity was ensured by the addition of high specific surface area carbon black and synthetic graphite flakes. Final GDL porosity, in particular its macroporosity, was generated by melt blending polyamide 11 (PA11) matrix with polystyrene (PS) followed by PS extraction with tetrahydrofuran (THF) solvent at room temperature. In order to improve GDL porosity by the optimisation of PS dispersion in the PA11 matrix, PA11/PS blends were compatibilised by the addition of 2 wt.-% of ...

Science.gov (United States)

An organic inhibitor for acid corrosion inhibition is described. The inhibitor is a condensation product of a mixture of diethyl- and dibutyl-thiourea with hexamethylenetatramine. This condensation product is preferably made by reacting a mixture of diethyl- and dibutyl-thiourea, in a weight ratio of from 1:5 to 5:1, with 0.1 to 1 mole of hexamethylene tetramine per mole of the thiourea mixture, at temperatures of from 100 to 150 C. It is possible to modify this by using other organic thiourea derivatives containing organic radicals (aliphatic or aromatic) having up to 10 carbon atoms, for example, ditoluyl-thiourea, in addition to the mixture of diethyl- and dibutyl-thiourea, but the amount by weight of these other derivatives must not exceed 20% of the diethyl-dibutyl-thiourea mixture. The advantages of the inhibitor are observed mainly when it is used in hydrofluoric acid solutions. 6 claims.

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A novel approach using reactive processing is explored that eliminates the labour-intensive separation of post-consumer polyolefin waste from the mixed plastics waste stream. The reactive compatibiliser BMI has been used to form a modified blend of PCPW with 40% improved tensile strength relative to the uncompatibilised control. Addition of 60 wt.-% magnesium hydroxide [Mg(OH)2] during reactive compatibilisation with BMI gave rise to an even more significant enhancement (up to 100%) of the tensile strength. BMI was also able to usefully enhance the properties of a composite based on calcium carbonate and the polyolefin waste.

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The structure and catalytic properties of 2 wt.-% Pd/SiO/sub 2/ catalysts promoted with 2 wt.-% MgO and 0.2-5 wt.-% iron have been investigated. Catalysts were characterized by TPR, hydrogen chemisorption, and Moessbauer spectroscopy and their catalytic performance in methanol formation was also measured. At 16 at.-% iron a sharp maximum was observed in the activity which can be interpreted as being due to simultaneous promotion with iron and MgO. Independent mechanisms of promotion were found for the two modifiers: iron influenced the metallic component by forming bimetallic PdFe particles while MgO changed the properties of silica in a favourable way. 6 figs., 29 refs., 1 tab.

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Research in concentrated thermal solar power plants of all types and, in particular, those based on central receiver, namely solar tower plants, has experienced great impetus in the last decade, reaching full commercial operation with the PS10 plant in Spain. In spite of previous demonstration plants testing different receivers and power cycle layouts, this first commercial power plant adopted a cavity receiver generating saturated steam and therefore penalising cycle efficiency in order to gain plant reliability. According to the experience gained, if a competitive Levelised Cost of Electricity is to be reached, capital and maintenance costs must be reduced and efficiencies must be increased. To achieve these goals, modifying the power cycle is deemed essential, whether using superheated ...

Science.gov (United States)

Metabolic engineering of photosynthetic organisms is required for utilization of light energy and for reducing carbon emissions.Control of transcriptional regulators is a powerful approach for changing cellular dynamics, because a set of genes is concomitantly regulated. Here, we show that overexpression of a group 2 ? factor, SigE, enhances the expressions of sugar catabolic genes in the unicellular cyanobacterium, Synechocystis sp. PCC 6803. Transcriptome analysis revealed that genes for the oxidative pentose phosphate pathway and glycogen catabolism are induced by overproduction of SigE. Immunoblotting showed that protein levels of sugar catabolic enzymes, such as glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, glycogen phosphorylase, and isoamylase, are increased. Glycogen levels are reduced in the SigE-overexpressing strain grown under light. Metabolome analysis revealed that metabolite levels of the TCA cycle and acetyl-CoA are ...

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In this article, the technical feasibility of the use of activated carbon, synthetic resins, and various low-cost natural adsorbents for the removal of phenol and its derivatives from contaminated water has been reviewed. Instead of using commercial activated carbon and synthetic resins, researchers have worked on inexpensive materials such as coal fly ash, sludge, biomass, zeolites, and other adsorbents, which have high adsorption capacity and are locally available. The comparison of their removal performance with that of activated carbon and synthetic resins is presented in this study. From our survey of about 100 papers, low-cost adsorbents have demonstrated outstanding removal capabilities for phenol and its derivatives compared to activated carbons. Adsorbents that stand out for high adsorption capacities are coal-reject, residual coal treated with H{sub 3}PO{sub 4}, dried activated sludge, red ...

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Scratch and Corrosion Resistance of an Aluminum Flange with an Electron Beam Modified Seal Edge

DEFF Research Database (Denmark)

B vitamins and polymorphisms in genes coding for enzymes involved in one-carbon metabolism may affect DNA synthesis and methylation and thereby be implicated in carcinogenesis. Previous data on vitamins B2 and B6 and genetic polymorphisms other than those involving MTHFR as risk factors for gastric cancer (GC) are sparse and inconsistent. In this case-control study nested within the European Prospective Investigation into Cancer and Nutrition cohort, cases (n = 235) and controls (n = 601) were matched for study center, age, sex, and time of blood sampling. B2 and B6 species were measured in plasma, and the sum of riboflavin and flavin mononucleotide was used as the main exposure variable for vitamin B2 status, whereas the sum of pyridoxal 5'-phosphate, pyridoxal, and 4-pyridoxic acid was used to define vitamin B6 status. In addition, we determined eight polymorphisms related to one-carbon metabolism. Relative risks for GC risk were calculated ...

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Reaction Engineering International (REI) has established a project team of experts to develop a technology for combustion systems which will minimize NO x emissions and minimize carbon in the fly ash. This much need technology will allow users to meet environmental compliance and produce a saleable by-product. This study is concerned with the NO x control technology of choice for pulverized coal fired boilers, ?in-furnace NO x control,? which includes: staged low-NO x burners, reburning, selective non-catalytic reduction (SNCR) and hybrid approaches (e.g., reburning with SNCR). The program has two primary objectives: 1) To improve the performance of ?in-furnace? NO x control processes. 2) To devise new, or improve existing, approaches for maximum ?in-furnace? NO x control and minimum unburned carbon. The program involves: 1) fundamental studies at laboratory- and bench-scale to define NO reduction mechanisms in flames and reburning jets; 2) ...

CERN Document Server

Compact Proton and Carbon Ion Synchrotrons for Radiation Therapy

International Nuclear Information System (INIS)

Electricity generation from natural gas in gas turbine units can be made substantially more efficient by preliminary methane conversion to a synthesis gas containing hydrogen and carbon monoxide and/or by the use of some of the synthesis gas produced in industry. An alternative improvement involves the introduction of solid oxide fuel cells (SOFCs) and the use of the synthesis gas in them. In this study, a modified scheme of gas turbine cycle that includes an SOFC, a membrane reactor (instead of a traditional combustion chamber), and a catalytic reactor to perform methane conversion to produce hydrogen (synthesis gas) is proposed. Variations of the energy and exergy efficiencies of the integrated system with operating conditions are provided, showing, for example, that SOFC efficiency is enhanced if the fuel cell active area is augmented. The SOFC stack efficiency can be maximized by reducing the steam generation while increasing the stack ...

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Preliminary tests have shown that smart-grid systems can significantly reduce home electricity use. A smart grid negates the need for controlled distribution by giving homeowners the ability to monitor rates in real time and modify their use based on energy availability, need and price. Homeowners can also feed the grid alternative power to offset their costs. Studies in the United States have also suggested that the system could reduce carbon emissions by 60 to 211 million tonnes per year. The smart grid would also be less susceptible to major disturbances because it draws power from multiple sources. An added benefit is that the technology could be developed for a fraction of the cost of building traditional energy plants, such as nuclear. However, the success of the smart-grid depends on several technological advances. The flow of power within the system must be digitally controlled and also merged with multiple communication devices so that ...

International Nuclear Information System (INIS)

LLNL is developing the nuclear fusion based Laser Inertial Fusion Energy (LIFE) power plant concept. The baseline design uses a depleted uranium (DU) fission fuel blanket with a flowing molten salt coolant (flibe) that also breeds the tritium needed to sustain the fusion energy source. Indirect drive targets, similar to those that will be demonstrated on the National Ignition Facility (NIF), are ignited at #approx#13 Hz providing a 500 MW fusion source. The DU is in the form of a uranium oxycarbide kernel in modified TRISO-like fuel particles distributed in a carbon matrix forming 2-cm-diameter pebbles. The thermal power is held at 2000 MW by continuously varying the "6Li enrichment in the coolants. There are many options to be considered in the engine design including target yield, U-to-C ratio in the fuel, fission blanket thickness, etc. Here we report results of design variations and compare them in terms of various figures of merit such as ...

International Nuclear Information System (INIS)

Separate effect of impurities and alloying additions of phosphorus, silicon, boron, carbon, sulphur, magnesium, copper, aluminium and molybdenum on the tendency to intergranular corrosion (IGC) of quenched highly pure steel Fe-20% Cr-20Ni in boiling solution 27% HNO_3+40 g/l Cr"6"+, as well as in sulphuric and nitric acids mainly at potentials, corresponding to repassivation range, has been studied. It is shown that steel susceptibility to IGC depends on impurity nature and to a high extent is determined by the potential value independent of the way of its achieving. The most unfavourable effect on stability of grain boundaries is produced by microadditions of boron as well as by impurities of phosphorus and silicon. To ensure increased corrosion resistance of the investigated steel against IGC in highly oxidative media the pontent of phosphorus and silicon impurities unit should not exceed 0.01 and 0.2% respectively. At that, boron introduction into steel as a ...

International Nuclear Information System (INIS)

Direct electrochemistry and electrocatalysis of catalase (Cat) was studied based on a nano-composite film consisting of amine functionalized graphene and gold nanoparticles (AuNPs) modified glassy carbon electrode. Graphene was synthesized chemically by Hummers and Offeman method and then was functionalized with amino groups via chemical modification of carboxyl groups introduced on the graphene surface. The nano-composite film showed an obvious promotion of the direct electron transfer between Cat and the underlying electrode, which attributed to the synergistic effect of graphene-NH2 and AuNPs. The resultant bioelectrode retained its biocatalytic activity and offered fast and sensitive H2O2 quantification. Under the optimized experimental conditions, hydrogen peroxide was detected in the concentration range from 0.3 to 600 ?M with a detection limit of 50 nM at S/N = 3. The biosensor exhibited some advantages, such as short time respond (2 s), ...

Energy Technology Data Exchange (ETDEWEB)

A p[sup +]-Al[sub 0.3]Ga[sub 0.7]As/n[sup +]-GaAs heterojunction tunnel diode was fabricated using Atomic Layer Epitaxy (ALE) growth technique. Background carbon doping of [similar to]10[sup 20] cm[sup [minus]3] was achieved in the p-side of the diode by optimizing growth conditions such as V/III ratio, exposure times to reactant gases, and growth temperature. In the n-side of the diode GaAs was doped with silane and doping concentrations as high as 7[times]10[sup 18] cm[sup [minus]3] were also achieved. The dopants are chosen to satisfy the high levels and low diffusion requirements. The diode can be used to interconnect the high and low band-gap cells in the AlGaAs/GaAs cascade solar cell structure. The reactor used in this investigation is a commercial MOCVD system which has been specially modified for dual operation of ALE and MOCVD growth modes.

International Nuclear Information System (INIS)

Novel CdS hollow microspheres have been successfully synthesized via a facile template-free solution-phase reaction from cadmium nitrate and thioacetamide precursors. The morphology of CdS hollow microspheres depends strongly on the ratio between the precursors, cadmium nitrate to thioacetamide ratio. The physical properties of the hollow microspheres have systematically been studied by different characterization methods. The stoichiometry of the hollow microspheres studied by the energy dispersive X-ray diffraction spectroscopy confirmed that the synthesized CdS hollow microspheres are nearly stoichiometric bulk like CdS. The morphology of the hollow microspheres studied by high resolution scanning electron microscopy and transmission electron microscopy observations showed that the CdS hollow microspheres of the size of 2.5 ?m have hollow structure and are constructed by several nanoparticles of the size between 30 and 40 nm. The UV-visible diffuse reflectance spectroscopy studies ...

International Nuclear Information System (INIS)

Proposals for use of Alloy 800 as a H.T.R. boiler material have prompted studies of its creep and high temperature fatigue properties in impure helium with comparative tests in air. In impure helium, as expected in a H.T.R., reactions of potential importance are selective oxidation (of chromium, aluminium and titanium) and possibly carburisation from carbon monoxide or methane. In air, general oxidation will occur, possibly accompanied by nitridation. The effects of these reactions will depend on specimen geometry and the nature of the deformation. Two important possibilities are: (i) that environment affects the structure and properties of a surface zone of material undegoing uniform deformation (this may modify creep rate and crack nucleation); and (ii) that environment affects behaviour of a small region (e.g. at the root of a notch or ahead of a crack) in a specimen undergoing non-uniform deformation (this will modify ...

Energy Technology Data Exchange (ETDEWEB)

The thesis relates to an investigation done on greenhouse gases in coniferous forest soils. The production of nitrous oxide (N{sub 2}O) and carbon dioxide (CO{sub 2}), and the consumption of methane (CH{sub 4}) in a temperate forest soil were studied by a rapid and sensitive gas chromatographic (GC) method for analysing all three greenhouse gases at or below ambient levels. Gas fluxes were measured in soil incubation and lysimeter experiments. 15 soil samples were taken at random within a 100 m{sup 2} area in a Norway spruce forest stand (Picea abies). The fluxes of N{sub 2}O, CH{sub 4} and CO{sub 2} were measured under standardized laboratory incubation conditions to investigate spatial variability in relation to other factors such as nitrogen (N) mineralization rate, nitrification rate, organic carbon (OC), total N and pH. The effects of temperature, soil moisture content, and ammonium addition were also studied in an incubation experiment. A ...

Energy Technology Data Exchange (ETDEWEB)

Atmospheric impact of peatlands is a sum of their gas fluxes. In contrast to carbon dioxide, peatlands are net sources for methane (CH{sub 4}). Methane is an end product in the anaerobic decomposition processes and it has greater capacity to absorb infrared radiation than carbon dioxide. Most of the data on the CH{sub 4} release from northern peatlands is from North America. The total amount of methane released from wetlands is calculated to be 110 Tg yr{sup -1} of which 34 percent (38 Tg yr{sup -1}) is estimated to be emitted from the northern peatlands. Peat with high content of nitrogen is a potential source for gaseous nitrogen oxides, i.e. nitrous oxide (N{sub 2}O) and nitric oxide (NO). However, the importance of peatlands in producing these trace gases is poorly known. Nitrous oxide and nitric oxide are important components in the atmospheric chemistry and N{sub 2}O also is an effective greenhouse gas. Land-use activities and ...

CERN Document Server

Preparation of covalently modified organic-inorganic composite nanoparticles and their interfacial electron transfer researches

UK PubMed Central (United Kingdom)

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

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... (last modified: 10/22/2002) Organizations Saratoga Foundation (last modified: 02/11/2003) Actions You Can Take Global Response (last modified: 05/10/2000) Organizations University of Pittsburgh Cancer Institute - Center for Environmental Oncology (last modified: 01/14/2005) Home | Site Map | About EnviroLink | Advanced Search | Suggest ...

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International Nuclear Information System (INIS)

... Mohamed, MM Medical Research Institute (Egypt) Ghatass, ZF Institute of

KoreaScience (Korea)

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KoreaScience (Korea)

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Science.gov (United States)

No abstract available.

International Nuclear Information System (INIS)

Short communication.

KoreaScience (Korea)

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International Nuclear Information System (INIS)

Abstract only.

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

The carbon cycle is an important part of major biogeochemical cycles. Many techniques may be used to characterize carbon amounts and sources in the environment. Here we first review the most popular techniques for the determination of organic and inorganic carbon concentrations. Decarbonatation techniques are also reviewed in details since it is often an important part of organic carbon analysis. The second part of this paper addresses the use of carbon stable isotopes to characterize organic carbon sources and processes in the environment. An overview of general stable isotopes background and terminology is given as well as the most popular analytical techniques.

British Library Electronic Table of Contents (United Kingdom)

A study of the effect of a clayey soil modified in situ and ex situ with the cationic surfactant octadecyltrimethylammonium bromide (ODTMA), on the retention of linuron, atrazine and metalaxyl was carried out. Leaching of these compounds was studied in columns of a natural clayey soil and the same clayey soil modified by direct injection of the surfactant in situ, and in columns of a natural sandy soil and the same sandy soil modified by intercalation of a barrier of the clayey soil saturated ex situ with the surfactant. Breakthrough curves indicated the total immobilization of linuron in modified soils and a decrease in the leaching kinetics of atrazine and metalaxyl compared to what was obtained in the natural soil. The results indicate the use of the clayey soil modified in situ or ex s...

International Nuclear Information System (INIS)

Radiation hardening in austenitic stainless steels is shown to modify deformation characteristics and correlate well with an increased susceptibility to intergranular stress corrosion cracking (IGSCC). Available data on neutron-irradiated materials have been analyzed and correlations developed between fluence, yield strength and cracking susceptibility in high-temperature water environments. Large heat-to-heat differences in the critical fluence (0.2 to 2.5 x10"2"1 n/cm"2) for IGSCC are documented. In many cases, this variability is consistent with yield strength differences among irradiated materials. IGSCC correlates better to yield strength than to fluence for most heats suggesting a possible role of radiation-induced hardening and microstructure on cracking. Microstructural evolution during proton and heavy-ion irradiation has been characterized in low-carbon 304SSs. Hardening results from a dispersion of dislocation loops in the matrix ...

Energy Technology Data Exchange (ETDEWEB)

Radioiodinated 15-(p-iodophenyl)-3,3-dimethylpentadecanoic acid (DMIPP) has been prepared as a new terminal iodophenyl-substituted fatty acid containing dimethyl-branching at the beta-position. Iodine-125-labeled DMIPP showed rapid, high myocardial uptake (min, mean % injected dose/g) in fasted rats (5, 4.67; 30, 5.06; 60, 4.79; 120, 4.37), and also exhibited high heart:blood ratios (min, ratio) 5, 3:1; 30, 12:1; 60, 12:1; 120, 13:1. These data demonstrate an unanticipated much longer myocardial residence time with DMIPP (+/sub 1/2/ 7-8 h) than observed with either the 3-monomethyl (BMIPP) analogue (+/sub 1/2/ 30-45 min) or the rapidly metabolized straight-chain (IPP) analogue (+/sub 1/2/ 10-15 min). The (/sup 123/I)DMIPP is thus an excellent candidate for clinical evaluation of regional fatty acid metabolism under conditions where the uptake of energy substrates can be assessed independent of regional blood delivery. Studies with the new activated carbon-based ...

International Nuclear Information System (INIS)

Gadolinium removal during the first approach to criticality of TAPP-4 540 MWe reactor using mixed bed resin (strong acid cation resin and weak base anion resin) topped with strong acid cation exchange resin yielded IX column outlet pH of >6 during the first 6 h of run during which [Gd] decreased from 2.1 to 1 mg/kg. However, the main moderator system pH was between 5.0-5.5. Technical specification for pH of moderator is in the range 5.0-5.5 as long as Gd is present. This is to avoid any precipitation of Gd in the core and a pH of 5.8 or even a pH of 5.6 when carbonate is present is specified as the upper limit of the moderator system pH for this purpose. The situation of IX column outlet pH being #>=# 6 mixing with a system water having Gd results in local mixing zone pH in the range of 6- 5.4. In order to have an iso-pH regime (5-5.5) both with respect to the IX outlet as well as in the system, studies were conducted to modify IX resin ...

Energy Technology Data Exchange (ETDEWEB)

Technology is being developed for preparing functional materials by synthesizing new functional peptides in which non-natural amino acid needed for the functional manifestation is introduced, and by modifying the surface of a base plate such as silica glass by using such peptides. Activities were conducted in the three areas of (1) creation of functional molecules, (2) materialization technology, and (3) comprehensive investigation and research; the activities were carried out independently and parallelly in the first two areas. In (1), design technique for the structures and functions of peptides was developed, as were conformational control technique, synthesis of peptides having optical/electronic functions, peptide synthesis by an enzyme method, and R and D on introduction of non-natural amino acid into peptides; in (2), element technologies were developed such as substrate forming technique (pattern forming and thin film forming technology), substrate ...

Energy Technology Data Exchange (ETDEWEB)

Carbon supported catalysts can lose their activity over a period of time due to the sintering of the nanometer-sized catalyst particles. The sintering of metal clusters on carbon supports can occur due to the weak interaction between the metal and the support and also due to the corrosion of carbon, especially in fuel cell electrocatalysts. The sintering may be reduced by increasing the interaction between the metal and the support and also by increasing the corrosion resistance of carbon supports. In an effort to mitigate the growth of the nanoparticles, carbon-substituted boron defects were introduced in the carbon lattice. The interaction between the Pt nanoparticles on the pure and boron-doped carbon supports was examined using X-ray photoelectron spectroscopy (XPS). The results indicate that the interaction between the Pt nanoparticles ...

International Nuclear Information System (INIS)

Carbon-14 was analysed by direct absorption of carbon dioxide on the mixture of organic amine compound and scintillation cocktail then counted by low level liquid scintillation counter. This method can be applied for radiocarbon dating. In this study, the effects of carbon dioxide absorption, and counting efficiency were investigated using various commercial available cocktail. It was found that permafluor V and Ready Gel showed the highest carbon dioxide absorption whereas the Permafluor V showed the highest counting efficiency

Energy Technology Data Exchange (ETDEWEB)

Wetlands can potentially sequester vast amounts of carbon. However, over 50% of wetlands globally have been degraded or lost. Restoration of wetland systems may therefore result in increased sequestration of carbon. Preliminary results of our investigations into atmospheric carbon sequestration by restored coastal wetlands indicate that carbon can be sequestered in substantial quantities in the first 2-50 years after restoration of natural hydrology and sediment accretion processes.

Science.gov (United States)

Table of Contents: Overview of Organization and Contents of Document; Analytical Data Collection Efforts and Definition of Options; Description of Data Conventions; Statistical Methodology: Modified Delta-Lognormal Model; Estimation Under the Modified Del...

UK PubMed Central (United Kingdom)

This paper presents the results of a meta-analysis for a single investigator examining the effectiveness of the modified therapeutic community (MTC) for clients with co-occurring substance use...Full Text Available

Science.gov (United States)

The consequences of structural modifications at the 5'-OH ribofuranotide moiety of quinoline modified B12 derivatives are discussed in regard of the coordination chemistry, the electrochemical properties and the biological behaviour of the compound. PMID:21850334

Energy Technology Data Exchange (ETDEWEB)

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Science.gov (United States)

... The moisture content-dimension relationship of two laminate components, phenolic core and melamine overlay, are compared. (Author, modified). ...

Science.gov (United States)

... APPENDIX A: A PROPOSED STAYING POWER MODEL .....73 A. INTRODUCTION .....73 B. PROPOSED STAYING ...

International Nuclear Information System (INIS)

The optimum of strontium amount for good modification of AK7, AK9, AK11, AK52, AK104 alloys was determined on the base of the analysis of microstructural changes. The stability of the modifier was investigated on the way of successive remelting of billets. The influence of amount of modifier on the impact strength of the alloys was established. (author)

Energy Technology Data Exchange (ETDEWEB)

This patent describes a process for removing carbon dioxide from a feed stream of natural gas having at least methane, ethane and heavier. It comprises: first, separating the feed stream in a first separator to form a first stream having substantially all of the propane and heavier hydrocarbons and carbon dioxide and ethane and a second stream, having methane, carbon dioxide and ethane; separating the second stream in a second separator into a stream of carbon dioxide product and a third stream having ethane, methane and carbon dioxide: mixing at least a portion of the third stream with a polar compound; stream after the mixing in an absorber; separating the vapor and liquid of the third stream after the mixing in an absorber; absorbing the remaining unabsorbed carbon dioxide in a lean portion of the polar compound in the absorber, the absorber ...

Science.gov (United States)

A method of making high strength coke briquettes suitable for use as blast furnace coke comprising, (A) providing coal, (B) heating the coal at a temperature at or above the softening point of the coal to form partially carbonized char, (C) cooling the partially carbonized char below the softening point of the coal, (D) mixing the cooled partially carbonized char and tar to form a mixture of tar and partially carbonized char, (E) briquetting the mixture of tar and partially carbonized char to form briquettes of tar and partially carbonized char, (F) calcinating the briquettes to form high strength briquettes.

Energy Technology Data Exchange (ETDEWEB)

This report presents a brief description of the fabrication and advantages of a composite, carbon-metal fiber material which does not require lubrication.

International Nuclear Information System (INIS)

... obtain the film thickness for a given x-ray intensity ratio. 2.3 ANALYSING FOR

International Nuclear Information System (INIS)

... School of Plant Biology. v. 23(2) p. 316-322. carbon dioxide absorption carbon

UK PubMed Central (United Kingdom)

Background:To determine nutrient requirements by the carbon oxidation techniques, it is necessary to know the fraction of carbon dioxide produced during the oxidative...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Commercially available organoclay (Closite 30B) was modified by using 3-aminopropyltriethoxysilane (APS) via a silylation reaction. Sodium clay (Closite Na) was treated by APS directly as a control. Such modified clays were further melt-compounded with polybutylene terephthalate (PBT). The morphology and properties of the modified organoclays were characterized with X-ray diffraction (XRD), transmission electrical microscopy (TEM), Infra-red spectroscopy, contact angle measurement, and thermogravimetric analysis (TGA). The effects of modified clays on the crystallization behavior of PBT were characterized by differential scanning calorimetry. The basal spacing of Closite Na was enlarged from 1.01 to 1.41 nm after APS treatment, indicating that the APS was intercalated into the clay interga...

British Library Electronic Table of Contents (United Kingdom)

A 2-D model has been proposed to investigate the approximate estimation of the natural convection heat loss from modified cavity receiver of without insulation (WOI) and with insulation (WI) at the bottom of the aperture plane in our previous article. In this paper, a 3-D numerical model is presented to investigate the accurate estimation of natural convection heat loss from modified cavity receiver (WOI) of fuzzy focal solar dish concentrator. A comparison of 2-D and 3-D natural convection heat loss from a modified cavity receiver is carried out. A parametric study is carried out to develop separate Nusselt number correlations for 2-D and 3-D geometries of modified cavity receiver for estimation of convective heat loss from the receiver. The results show that the 2-D and 3-D are comparabl...

Energy Technology Data Exchange (ETDEWEB)

A process is described for removing carbon dioxide from a feed stream of natural gas, having at least methane, ethane and heavier hydrocarbon, comprising: separating the feed stream in a first separator to form a first stream, having substantially all of the propane and heavier hydrocarbons and carbon dioxide and ethane, and a second stream, having methane, carbon dioxide and ethane; mixing the second stream with a polar compound to form a third stream; separating the vapor and liquid of the third stream in the bottom portion of an absorber; absorbing carbon dioxide and ethane from the separated vapor of Step C in a lean portion of the polar compound in the absorber, the absorber carbon dioxide and ethane forming a fourth stream; separating the ethane from the polar compound and carbon dioxide in a separator; separating the first stream in a third separator to ...

Energy Technology Data Exchange (ETDEWEB)

Carbon Black and activated carbon materials providing high surface areas and a distinct pore distribution are prime materials for supercapacitor applications at frequencies < 0.5 Hz. A number of these materials were tested for their specific capacitance, surface and pore size distribution. High capacitance electrodes were manufactured on the laboratory scale with attention to ease of processability. (author) 1 fig., 1 ref.

KoreaScience (Korea)

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Science.gov (United States)

Near-infrared spectroscopy is a convenient tool for measuring nanotube / carbonaceous impurities

KoreaScience (Korea)

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KoreaScience (Korea)

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Science.gov (United States)

Polycyclic Aromatic Hydrocarbons (PAHs) are an important and ubiquitous component of carbon-bearing

KoreaScience (Korea)

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Science.gov (United States)

Not Available

Energy Technology Data Exchange (ETDEWEB)

Short communication.

KoreaScience (Korea)

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KoreaScience (Korea)

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Science.gov (United States)

Three aspects of the physical geographic environment of the Amazon Basin are considered: (1)

Science.gov (United States)

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KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

This paper describes the estimated the rate of carbon accumulation in the woody biomass and total carbon storage in the forests including trees, soil and litter in Korea. The relevant data come from the Statistical Yearbook of Forestry and major results of the studies on forest biomass in Korea. Most of the forests, which has been denuded or degraded during the 2nd World War and the Korean War, were recovered through ``Reforestation Project(1973-1987)`` and natural regeneration. So, now they are mostly young secondary forests and grow rapidly. Total carbon removal by forests is estimated at 8.1 million tonnes of carbon(MtC) and the carbon emission by commercial harvesting at 0.9 MtC. therefore, the forests in Korea play an essential role as a net carbon sink. The annul net carbon removal is 7.2 MtC and accounts for about 11.0% of total ...

Energy Technology Data Exchange (ETDEWEB)

An historic Strontianite-type specimen from Strontian, Scotland, UK, was characterized to broaden our knowledge on luminescence properties of common carbonates. These fibrous aggregates are Strontianite (Sr{sub x}Ca{sub 1-x}CO{sub 3}) with circa 6% of CaO, interfacial water, hydrosilicate anions and substitutional divalent cations, e.g., Ca{sup 2+}, Mn{sup 2+}, Fe{sup 2+} in structural Sr{sup 2+} positions. The specimen was analyzed by X-ray Fluorescence Spectrometry (XRF), Environmental Scanning Electron Microscopy coupled with an Energy Dispersive X-ray Spectroscopy (ESEM-EDS) probe, Spatially-resolved Cathodoluminescence under the Scanning Electron Microscope (SEM-CL), Differential-Thermal Analyses (DTA), Thermogravimetry (TG), Thermoluminescence (TL), Radioluminescence (RL) and High Resolution Spectra Thermoluminescence (3DTL), to gain an overview of the spectral emissions, the defect linkages were modified by heating from room temperature ...

International Nuclear Information System (INIS)

A high-voltage cathode initiates an electron emission, resulting in a reduction in the carbon dioxide concentration in exhaust gas from the burning of hydrocarbon fuel. Assuming that the observed carbon dioxide reduction is originated from the molecular decomposition, the energy needed for the endothermic reaction of this carbon dioxide reduction may stem primarily from the internal energy reduction in the exhaust gas in accordance of the first law of the thermodynamics. An oxygen increase due to the reduction in carbon dioxide in a discharge gas was observed in real time.

Energy Technology Data Exchange (ETDEWEB)

The interest of irradiation by carbon ions is in the fact that the carbon ions leave all their energy to a determined depth. ( phenomenon known under the name of Bragg peak)This high diffusion in tissue gives an RBE particularly high. The indications of this therapy are chordomas, and chondrosarcomas of the skull base, some cyst adenoid carcinomas, pulmonary cancer, sarcomas, hepato carcinomas, melanomas. In the light of results in term of efficiency, the place of irradiation by carbon ions should widen. (N.C.)

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

Numerical analysis of solar dish modified cavity receiver with Cone, CPC and Trumpet reflectors is presented. Three-dimensional modeling is carried out to estimate the convective and radiative heat loss from the receiver for different angles of inclination and operating temperatures. Incorporating reflectors in the modified cavity receiver for second stage concentration, the natural convection heat losses are reduced by 29.23, 19.81 and 19.16%, respectively. The receiver with the trumpet reflector has shown better performance as compared to other configurations. (orig.)

International Nuclear Information System (INIS)

... base alloys alloys beams chemical reactions elements hardness irradiation

CERN Document Server

Within the framework of a modified Balitsky-Kovchegov equation, we calculated and provide estimates of non-linear saturation effects expected in the LHC range of energies.

Energy Technology Data Exchange (ETDEWEB)

The oil shale PCTM for Modified In Situ Oil Shale Retorting combined with Lurgi Surface Retorting addresses the application of this combination of technologies to the development of oil shale resources in the western United States. This manual describes the combined plant using Lurgi surface retorting technology (developed by Lurgi Kohle and Mineralotechnik GmbH, West Germany) and the Modified In Situ process (developed by Occidental Oil Shale, Inc.) proposed by Occidental Oil Shale, Inc. and Tenneco Shale Oil Company for use in the development of their Federal oil shale lease Tract C-b in western Colorado. Since details regarding waste streams and control technologies for the Lurgi process are presented in a separate PCTM, this document focuses principally on the Modified In Situ process.

CERN Document Server

We study perturbations of a Schwarzschild black hole in Chern-Simons modified gravity. We begin by showing that Birkhoff's theorem holds for a wide family of Chern-Simons coupling functions, a scalar field present in the theory that controls the strength of the Chern-Simons correction to the Einstein-Hilbert action. After decomposing the perturbations in spherical harmonics, we study the linearized modified field equations and find that axial and polar modes are coupled, in contrast to general relativity. The divergence of the modified equations leads to the Pontryagin constraint, which forces the vanishing of the Cunningham-Price-Moncrief master function associated with axial modes. We analyze the structure of these equations and find that the appearance of the Pontryagin constraint yields an overconstrained system that does not allow for generic black hole oscillations. We illustrate this situation by studying the case ...

Science.gov (United States)

PMID:21953922

Science.gov (United States)

... in full sun and in shade, using an infrared thermometer (MiniTemp Noncontact, Conrad Electronic, Nürnberg, Germany). Time intervals ... ...

Science.gov (United States)

... F;qure Title phge 20 Rat B Spectral Density Measurements TNT Stimuli 70 21 Rat B Spectral Density Measurements Neutral Stimuli 71 ...

UK PubMed Central (United Kingdom)

Diffusion in the extracellular space (ECS) of the brain is constrained by the volume fraction and the tortuosity and a modified diffusion equation represents the transport behavior of many molecules...Full Text Available

UK PubMed Central (United Kingdom)

Background"Nubiotics" are synthetic oligonucleotides and nucleotides with nuclease-resistant backbones, and are fully protonated for enhanced ability to be taken up by bacterial...Full Text Available

UK PubMed Central (United Kingdom)

We present a technique for identifying the amino acids responsible for a loss of immunoreactivity in response to treating an antigen with a chemical modifier. This is of particular interest...Full Text Available

International Nuclear Information System (INIS)

Tensile properties of reduced-activation 10Cr-30Mn austenitic steels with carbon levels from 0.003 to 0.55% were investigated over the temperature range from room temperature to 873 K after neutron irradiation in the Japan Materials Testing Reactor at 573 K to 8.5x10"2"2 n/m"2. Irradiation-induced increase in yield stress increased significantly with carbon concentration up to about 0.1% and it was constant above 0.1% carbon. A high density of dislocation loops with small (below 10 nm) and large (20-30 nm) sizes formed during irradiation. The high density, small loops caused a large irradiation hardening, while the large loops contributed only slightly to irradiation hardening. It was considered that carbon atoms formed the small loops together with irradiation defects. The deformation channeling was observed in the irradiated high carbon steels, 0.11 and 0.55% ...

Energy Technology Data Exchange (ETDEWEB)

Comparatively evaluates methods for removal of carbon dioxide from waste gases emitted from industrial plants. The evaluations concentrate on carbon dioxide absorption by water solutions of alkalis and amines. The Hindered Amines Process, developed by Exxon in the USA, is analyzed. Chemical reactions of carbon dioxide absorption in solutions with hindered amines are evaluated. The following US patents which protect processes for carbon dioxide absorption by means of hindered amines are evaluated: No. 4,112,052, No. 4,101,633, No. 4,112,051, No. 4,100,257, No. 4,112,050, No. 4,094,957. Efficiency of carbon dioxide removal by each of the processes is pointed out. 12 refs.

Energy Technology Data Exchange (ETDEWEB)

A decontamination washer for working dresses using liquid and supercritical carbon dioxide were designed and manufactured. The size of reactor for decontamination and solidification is about 16 liter. The system is a closed one with recycling ability of carbon dioxide. The efficiency of recycling of carbon dioxide and that of separation of solutes in carbon dioxide were checked. They met all the design goals. A remote control system of the carbon dioxide flow was set in a control panel. The manufactured decontamination washer was brought to Wolsung nuclear power plants, and installed to check the efficiency of decontamination and the feasibility of usage in nuclear power plants. The elimination of radioactive oil from the contaminated dresses were very high. However, the decontamination factor was lower than the design goal value. It's due to the low removal rate of ...

British Library Electronic Table of Contents (United Kingdom)

The adsorption of CO2 on a number of activated carbons, thermal carbon black, and oxide materials at 195 K was studied using static and dynamic techniques. The landing surface areas ?(CO2) ? 0.19 nm2 on thermal carbon black and the absolute values of sorption for P/P 0 < 0.4 were determined. The density of adsorbed CO2 in the micropore volume was estimated at ?(CO2) = 0.91 g/cm3. It was demonstrated that the previously found effect of a weakening of the sorption interaction of nitrogen molecules with thin-walled materials (which manifested itself in an analysis of sorption isotherms by a comparative method) was pronounced to a lesser degree for the sorption of CO2. At the same time, the presence of supermicropores in activated carbon samples resulted in overestimated values of surface area...

International Nuclear Information System (INIS)

Preliminary observations on the isothermal carbon transfer in low-carbon Alloy-800 exposed in sodium with AISI-304 type of steel at 550_0 are reported. The alloy was found to undergo a carburization comparable or slightly lower than that observed for the AISI-304 stainless steel for carbon activities above 6 x 10 /sup -3/ at 550_0C, but was not found to decarburize below such a carbon activity value. In the examined range the chemical composition of the alloys does not affect the process out of the experimental uncertainty of measure. Conclusions concerning the effective diffusion for carbon in the alloy are formulated. Preliminary relationships were found for an empirical evaluation of the carburization of the Alloy-800 in sodium of known carbon activity.

Science.gov (United States)

Results from scanning electron microscopy, Fourier transform infrared spectroscopy and the measurement of thermally stimulated current show that a high density of the physical defects and the chemical defects are introduced into the surface of the silicone rubber plates after they are treated by corona discharge plasma. These defects behave electrically as shallow electron traps, leading to the formation of a uniform discharge in air at higher pressure when the corona-modified silicone rubber is used in dielectric barrier discharge.

UK PubMed Central (United Kingdom)

This study was designed to evaluate the suitability of a novel bioabsorbable material in treating bone defects. A poly(desaminotyrosyl-tyrosine-ethyl ester carbonate) (PDTE carbonate) membrane (thickness...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Porous carbon with high surface area and pore volume was prepared by a reverse replication process and its toluene equilibrium adsorption behavior was investigated. The preparation process of the porous carbon was composed of following sub-processes in series: synthesis and template preparation of silica gel, impregnation and polymerization of DVB monomer in silica template, carbonization of DVB polymer in a silica-polymer composite, and HF-assisted selective etching of silica in carbon-silica composite, The prepared porous carbon was nano porous and had ultrahigh specific surface area (2007 m{sup 2}/g) and large pore volume (3.07cm{sup 3}/g). The nanoporous carbon showed rapid toluene adsorption rate and good toluene adsorption capacity, compared with a commercial Y-type zeolite, In the present study, a reverse replication process to prepare nanoporous ...

Energy Technology Data Exchange (ETDEWEB)

Recently we have found that carbon nano-materials have ability to recognize softer actinides(III). In this presentation, separation of americium(III) from lanthanides(III) by chromatography with carbon nano-materials, such as carbon nano-tubes and graphite, has been investigated by batch adsorption experiments and chromatography. The separation factor (SF) between americium(III) and lanthanide(III) was about 2 in the range of pH from 1 to 4 by using carbon nano-tube, graphite and activated charcoal. The separation factor depended on the diameter of carbon nano-tubes. Smaller one, 3-20 nm diameter, showed the best selectivity for americium(III), which separation factor was about 2.0, although larger one, 40-70 nm, showed almost no selectivity. The same behavior has been observed by using graphite powder and activated charcoal although acid- or alkali pretreated activated charcoal ...

UK PubMed Central (United Kingdom)

BackgroundThe precision in carbon ion radiotherapy depends on the calibration of Hounsfield units (HU) as measured with computed tomography (CT) to water equivalence. This calibration...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Recent work has indicated that the suppression of boron transient enhanced diffusion (TED) in carbon-rich Si is caused by nonequilibrium Si point defect concentrations, specifically the undersaturation of Si self-interstitials, that result from the coupled out-diffusion of carbon interstitials via the kick-out and Frank--Turnbull reactions. This study of boron TED reduction in Si{sub 1-x-y}Ge{sub x}C{sub y} during 750{sup o}C inert anneals has revealed that the use of an additional reaction that further reduces the Si self-interstitial concentration is necessary to describe accurately the time evolved diffusion behavior of boron. In this article, we present a comprehensive model which includes {l_brace}311{r_brace} defects, boron-interstitial clusters, a carbon kick-out reaction, a carbon Frank--Turnbull reaction, and a carbon interstitial-carbon substitutional ...

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

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

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Several inexpensive and non-toxic solvents with low vapour pressures were investigated for their suitability as alternative solvents for the absorption of carbon dioxide from flue gas. The solvents include poly(ethylene glycol)s, poly(ethylene glycol) ethers, poly(ethylenimine) and glycerol-based substances. Solvent properties such as thermal stability, solubility of carbon dioxide and selectivity over nitrogen were investigated in a systematic study using a thermogravimetric analyser. Absorption results are reported for pure carbon dioxide and nitrogen as well as a mixture of both gases. Desorption and long-term sorption behaviour are also discussed. Glycerol and poly(ethylene glycol)s show a high solubility of carbon dioxide. Due to the high viscosity of the solvent, carbon dioxide absorption in poly(ethylenimine) is very slow in spite of the presence of favourable amine groups. ...

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Only half of the carbon dioxide produced by burning fossil fuels stays in the atmosphere. It is thought that the oceans absorb the rest. To understand the world's climate it is necessary to know how the atmosphere, ocean and biosphere interact.

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A 2-D model has been proposed to investigate the approximate estimation of the natural convection heat loss from modified cavity receiver of without insulation (WOI) and with insulation (WI) at the bottom of the aperture plane in our previous article. In this paper, a 3-D numerical model is presented to investigate the accurate estimation of natural convection heat loss from modified cavity receiver (WOI) of fuzzy focal solar dish concentrator. A comparison of 2-D and 3-D natural convection heat loss from a modified cavity receiver is carried out. A parametric study is carried out to develop separate Nusselt number correlations for 2-D and 3-D geometries of modified cavity receiver for estimation of convective heat loss from the receiver. The results show that the 2-D and 3-D are comparable only at higher angle of inclinations (60 {<=} {beta} {<=} 90 ) of the receiver. The present 3-D ...

International Nuclear Information System (INIS)

A series of ball-on-disc wear and friction measurements were made for surfaces which have a chemical vapour deposition carbon silicon alloy layer on a carbon substrate (fine grain POCO graphite). Nitrogen ion irradiation was used to improve the wear resistance of the carbon alloy surface. For comparison, measurements were also taken for alumina against alumina. It was found that the lowest friction coefficient and lowest wear occurred for ion irradiated coated samples containing 4% Si in the alloy and that the performance was superior to that of alumina. ((orig.)).

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Research activity during the 1991--1992 funding period has been concerned with the following topics relevant to carbon monoxide activation. (1) Exploratory studies of water gas shift catalysts heterogenized on polystyrene based polymers. (2) Mechanistic investigation of the nucleophilic activation of CO in metal carbonyl clusters. (3) Application of fast reaction techniques to prepare and to investigate reactive organometallic intermediates relevant to the activation of hydrocarbons toward carbonylation and to the formation of carbon-carbon bonds via the migratory insertion of CO into metal alkyl bonds.

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The accuracy of the carbon 14 dating method is dependent on the fluctuations of carbon 14 in the atmosphere over long periods of time. Fossil corals that are dated by both carbon 14 and uranium-thorium methods allows the setting of calibration curves for the carbon 14 method for the last 50.000 years. The uranium-thorium method is based on the measurement of the ratio of 2 isotopes: thorium 230 and uranium 234 that are both present in the decay chain of uranium 238. (A.C.)

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A process is claimed for selectively preparing a mixture of two-carbon atom oxygenated hydrocarbons, namely, acetic acid, ethanol and acetaldehyde, by continuously contacting a gaseous reaction mixture containing hydrogen and carbon monoxide with a solid catalyst comprising rhodium in combination with one or more alkali metals selected from the group consisting of lithium, potassium, cesium and rubidium at reaction conditions correlated so as to favor the formation of a substantial proportion of such two-carbon atom products.

International Nuclear Information System (INIS)

... carbon 14 cholera gels labelling membranes molecules proteins receptors

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Mixed microstructures have been studied in low- carbon microalloyed steels suitable for automotive applications, after continuous cooling from the hot-rolled condition. Microstructural features such as polygonal ferrite, bainitic and acicular ferrite and microphase constituent are identified using transmission electron microscopy. The influence of these mixed structures on the tensile strength, impact toughness and fracture behaviour is examined. It is found that improvements in impact toughness as compared with microalloyed medium- carbon ferrite/pearlite steels can be achieved from these predominantly acicular structures developed by controlling alloy composition and continuous cooling of these lower carbon steels. (orig.).

Science.gov (United States)

A sandwich construction, composed of hybrid carbon-glass fiber-reinforced plastic skins and a

Energy Technology Data Exchange (ETDEWEB)

In the framework of the carbon storage two forestry methods are analyzed by the author: the standing capitalization (slowing of the crops) and the spices substitution (slow growing species by fast growing species). The construction of a model taking into account the all stage of the carbon implication (biomass, soil, forest products) offers simulation and quantitative results on these methods. (A.L.B.)

International Nuclear Information System (INIS)

... Industry, Material Science Research Laboratory, Yokosuka, Kanagawa (Japan)

KoreaScience (Korea)

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Science.gov (United States)

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Science.gov (United States)

One of the major problems associated with solid waste processing technologies is the release of

Science.gov (United States)

... The ultimate compressive strength (UCS) for the HMU/BSG composite is essentially equivalent to the tensile strength exhibited by this system. ...

Science.gov (United States)

... be easily replaceable, and its compartment or container ... in a simple, efficient manner for storage or disposal. ... and enters the reactor at approximatel ...

Energy Technology Data Exchange (ETDEWEB)

The present report concerns a research for the tritium and for the carbon 14 in lichens in a spirit of bio-indication: the first results appear in Daillant and al (2004 ) and additional results were presented to the congress B.I.O.M.A.P. in Slovenia, organized collectively by the institute Josef Stefan from Ljubljana and the international atomic energy agency from Vienna (Daillant and al 2003). (N.C.)

Science.gov (United States)

The thermodynamic characteristics of adsorption of sulfur-containing amino acids and their derivatives on the surface of graphitized thermal carbon black were calculated by the molecular statistical method. The parameters of the atom-atom potential function of intermolecular interaction between the S atom in amino acids and the graphite C atom were determined. It was shown that an intramolecular H-bond influenced the adsorption of amino acids on the surface of graphitized thermal carbon black.

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In this paper structure and mechanical properties of PBZT and PBO fibers are briefly discussed. One limitation of the high-modulus polymeric fibers and ultrahigh-modulus carbon fibers in reinforced composites is their poor compressive strength. Issues related to the compressive strength of polymeric and carbon fibers are considered. 62 references, 7 figures, 4 tables.

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The objective of this research is to gain a better understanding of the corrosion of the aluminized type 316 stainless steel employed in the seal areas of the molten carbonate fuel cell. The seals are formed between the aluminized Type 316 SS surface and the electrolyte (generally a mixture of molten alkali carbonates and lithium aluminate).

International Nuclear Information System (INIS)

Mutual influence of phosphorus and carbon on the tendency to integranular corrosion (IGC) of tempered austenitic stainless steels in boiling solutions of 65% HNO_3 and 27% of HNO_3+40 g/l Cr"6"+ was investigated. It is ascertained that under the action of carbon additions susceptibility of phosphorus-containing steels to IGC increases considerably in pure nitric acid and decreases in nitric acid containing the oxidant. Possible reasons for the effects observed are discussed.

International Nuclear Information System (INIS)

In this article carbon co-implantation and step-by-step thermal treatments of shallow p"+-n-junctions formation were used with the purpose of extended defect suppression and reduction of boron transient enhanced diffusion. A substantial improvement of the structural and electrical parameters of shallow p"+-n-junctions has been achieved by using the additional carbon implantation and step-by-step thermal treatments. (authors)

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

British Library Electronic Table of Contents (United Kingdom)

Henry constants for the adsorption of o- and p-phenylenediamines on the surface of graphitized thermal carbon black within the temperature range 433?479 K were calculated by the molecular statistical method. The parameters of the atom-atom potential function of intermolecular interaction between the nitrogen atom in aniline and isomeric phenylenediamines and the carbon atom of the basal face of graphite were determined. It was shown that an intramolecular H bond influenced the geometry and adsorption properties of o-phenylenediamine.

Energy Technology Data Exchange (ETDEWEB)

Carbon films have been made by a variety of techniques, including evaporation, sputtering, and laser or thermal pyrolysis of organic polymers. Polyacrylonitrile (PAN) is often used as a carbon precursor, since low-temperature thermo-oxidative pretreatment produces a material which can be pyrolyzed without loss of shape. This is the basis for the production of carbon fibers with good mechanical properties. We report here the formation of very thin films of carbon (500 to 1500 A) by pyrolysis of spin-cast PAN. Using this technique, large, conductive films can be made which are sufficiently robust to allow intact lift-off and transfer of the films from one substrate to another. Such films are chemically inert, but can be photolithographically patterned and etched with an oxygen plasma.

British Library Electronic Table of Contents (United Kingdom)

The shift to renewable energy options and low-carbon technologies, in response to the concerns over energy security and climate change, is proceeding more slowly than many would like. The usual argument against rapid deployment of new technologies is the costs imposed on the economy, commonly interpreted in terms of upfront costs to be borne or involving large cash transfers to fund, for example, efforts to preserve rainforests. In this contribution I argue that such a perspective provides a continuing barrier to taking effective action, whereas a perspective based on creation and use of carbon credits provides a means of avoiding the shock of abrupt industrial change. Carbon credits granted for bona fide carbon load reductions could be created through private initiative, for example by me...

British Library Electronic Table of Contents (United Kingdom)

A pilot cropland carbon sequestration program within north central Montana has allowed farmers to receive carbon credit for management adjustments associated with changing from tillage-based agricultural systems to no-till. Carbon credit can also be obtained by adopting conservation reserve, where cropland is planted into perennial vegetation. Summer fallowing is also considered within the crediting process as credit is not given in years that a field is left un-vegetated. The carbon sequestration program has been advocated as a means to mitigate climate change while providing an added source of income for Montana farmers. There is lack of data, however, pertaining to the percentage of lands within this region that have not converted to no-till management, lands under certain crop intensit...

Science.gov (United States)

The Earth`s oceans, forests, agricultural lands and other natural areas absorb about half of the carbon dioxide emitted from anthropogenic sources. Terrestrial carbon sequestration strategies are immediately available to bridge the gap between current terrestrial sequestration capacity and high-capacity geologic sequestration projects available in 10 to 20 years. Terrestrial carbon sequestration strategies consist of implementing land management practices aimed at decreasing CO2 emitted into the atmosphere and developing advanced measurement tools to inventory and monitor carbon processes in soils and biota. In addition to atmospheric CO2 mitigation and carbon trading advantages, terrestrial carbon sequestration produces a variety of benefits which include reclamation of degraded lands, increased soil productivity, increased land value and a more secure food ...

International Nuclear Information System (INIS)

The carbon transfer has been analyzed in the Alloy 800/sodium/stainless steel system by determining the carbon-uptake of Alloy 800 foils, which were exposed in liquid sodium of known carburizing potential. Under equilibrium condistions between 650 and 550_0C the measured total carbon concentrations in the Alloy 800 tabs were found to be roughly related to the carbon activities of the sodium environment by the equation already stated for the 18 Cr-8/10 Ni stainless steels, extrapolated to the chemical composition of the Ni-rich austenitic alloy. However the Alloy 800 was not found to undergo any decarburization in low-carbon activity environments. The carbon diffusion kinetics was determined as a function of temperature, it was found to be similar to that reported for the AISI-304 type of steel. The effects of sodium exposure on microstructural and mechanical ...

Energy Technology Data Exchange (ETDEWEB)

Capacitance dispersion on the fractal carbon electrode with edge and basal orientations was investigated using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and a.c.-impedance spectroscopy. For this purpose, four types of as-received pyrolytic graphite electrode, as-received, mechanically polished, and as-activated glassy carbon electrodes were prepared with different surface irregularities and amounts of edge orientations. The apparent self-similar fractal dimensions of the carbon electrodes were determined from the analyses of AFM images based upon triangulation method. The amounts of edge orientations on the surface of the carbon electrodes were qualitatively estimated from the XPS analysis of surface acidic functional groups that were preferably formed on the edge planes by the heat treatment of the carbon electrodes. The values of the constant phase ...

International Nuclear Information System (INIS)

The effects of modification with Ti and Nb, heat treatment and solute segregation on void suppression in 316 stainless steel were studied using HVEM in the temperature range of 623-873 K after solution treatment at 1323-1473 K. Post-irradiation compositional analysis was performed by an energy dispersive X-ray analyzer. In Ti-modified stainless steel, void swelling peaks appeared at 723 K and 823 K. On the other hand, when the stainless steels modified by both Ti and Nb were irradiated, the void swelling was effectively suppressed, particularly the growth rate of a void was remarkedly retarded. This void suppression effect was easily recognized with increasing Nb concentration. Compositions such as Mo, Cr, Ti and Ni changed during irradiation and Ni, Si and Ti enriched around voids, whereas Cr and Mo depleted. (orig.).

International Nuclear Information System (INIS)

In evaluating the risk associated with low levels of exposure to toxicants, it is clear that DNA repair, one of the main defenses against agent damage, is not a constant. It can be modified by age, time of day, and physiological state. Nutrition, especially caloric restriction (CR), can modify almost every step in the process of protecting genomic integrity. And history of exposure can modify DNA repair. Thus, the conditions of exposure are almost as important to toxicity as the exposure itself, even at the level of DNA repair. Extrapolation from high to low dose, to be consistent with what is known, should be less a mathematical exercise than an exercise in toxicological judgement, which puts the exposure in proper perspective. This appears to be true at almost every level in the process including a response with a toxic stimulus, even those thought to be very basic, such as DNA repair.

British Library Electronic Table of Contents (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

Shaped activated charcoal is modified by 02 and N2 processing for producing coal compounds with higher acidic or basic properties. Nitrated activated charcoal has properties of a weak anionite with a substantially increased ion exchange capacity with an increase in the concentration of the hydrogen ions in the electrolyte and adsorbs iodine ions well from aqueous solutions at a pH of less than 5. A layer of nitrated charcoal is a very effective sorbent in the process of dynamic sorption of iodine anions from acetic solutions of KI. It is also established that the sorption of iodine ions in the activated charcoal modified by 02 occurs in accordance with an ion exchange mechanism (and possibly, selective sorption). This refutes literature data which ascribe the determining participation in the process to the reaction of oxidation of iodides on the surface (Pv) of the coal into free I2.

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To prepare porous carbons with high adsorption capacity from rice straws, two different kinds of precursors, i.e. one as the raw rice straws (one-stage process) and the other as pre-carbonized rice straws (two-stage process), were active with KOH of various impregnation ratios. The two-stage process was found very effective for manufacturing porous carbons with high surface area and adsorption capacities for MB and I{sub 2}. For example, the porous carbon that was carbonized at 700{sup o}C and subsequently activated at 900{sup o}C exhibited the surface area of 2410 m{sup 2}/g, the adsorption capacities of 800 and 1720 mg/g for MB and I{sub 2}, respectively, and the total pore volume of 1.4 ml/g. In the two-stage method, there was a preferential optimum impregnation ratio of KOH to a precursor carbon, i.e. 4:1, with which high surface area of porous ...

Science.gov (United States)

The performance of intermolecular potential models on the adsorption of carbon tetrachloride on graphitized thermal carbon black at various temperatures is investigated. This is made possible with the extensive experimental data of Machin and Ross(1), Avgul et al.,(2) and Pierce(3) that cover a wide range of temperatures. The description of all experimental data is only possible with the allowance for the surface mediation. If this were ignored, the grand canonical Monte Carlo (GCMC) simulation results would predict a two-dimensional (2D) transition even at high temperatures, while experimental data shows gradual change in adsorption density with pressure. In general, we find that the intermolecular interaction has to be reduced by 4% whenever particles are within the first layer close to the surface. We also find that this degree of surface mediation is independent of temperature. To understand the packing of carbon ...

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An efficient method of hydrogen storage in nano-porous carbons is its reversible sorption by electrochemical decomposition of a KOH water solution according to the following equation: C + xH{sub 2}O + xe{sup -} {yields} (CH{sub x}) + xOH{sup -} where (CH{sub x}) stands for the hydrogen inserted into the nano-porous carbon during charging and oxidized during discharging. Although various carbon materials have been investigated as hydrogen adsorbents, the information about the storage mechanism as well as the nature of the hydrogen/carbon interaction is still not sufficient. In order to extend the understanding of the process, carbon samples charged electrochemically were investigated by temperature programmed desorption (TPD). The nature of the hydrogen/carbon interaction was studied by electrochemical analysis at different temperatures. The TPD experiments ...

UK PubMed Central (United Kingdom)

Recessive inactivating mutations in human matrix metalloproteinase 2 (MMP2, gelatinase A) are associated with syndromes that include abnormal facial appearance, short stature, and severe bone...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundThere has been substantial research on psychosocial and health care determinants of health disparities in the United States (US) but less on the role of modifiable risk...Full Text Available

UK PubMed Central (United Kingdom)

The development of new methods for gene addition to mammalian genomes is necessary to overcome the limitations of conventional genetic engineering strategies. Although a variety of DNA-modifying enzymes...Full Text Available

UK PubMed Central (United Kingdom)

A facile synthetic protocol for the production of neomycin B derivatives with various modifications at the 5″ position has been developed. Structural activity relationship (SAR) against...Full Text Available

International Nuclear Information System (INIS)

The energy distribution of ion beams is important especially for low energy ion beam applications. The energy distributions of negative-ion beams produced through secondary ion emission by sputtering were measured and compared with theoretically estimated distributions by use of four different negative-ion production probability equations (modified surface ionization model, exponential velocity dependence model, and our modified exponential velocity dependence models (modified decaying factor model and combination model of velocity dependence and surface ionization)). In the measurements, the energy distributions of C"- and Ag"- beams had a peak at a few to several eV and the full width at half maximum were 15 eV and 11 eV, respectively. These results could be well explained by the estimated distributions by virtue of our combination model or the modified surface ionization model. copyright 1996 ...

UK PubMed Central (United Kingdom)

This study investigated the effect of board type (unmodified vs. MAPE modified) on the surface quality and thickness swelling-water absorption properties of recycled high density polyethylene (HDPE)...Full Text Available

Science.gov (United States)

... from Dr. Austin Smith of the Institute for Stem Cell Research, University of Edinburgh) was modified from the CGR8 ... to thank Dr. Austin Smith, the Institute for Stem Cell Research, University of Edinbu...

UK PubMed Central (United Kingdom)

Protein modifications such as phosphorylation are often studied by two-dimensional gel electrophoresis since the perturbation in the protein’s pI value is readily detected by this method....Full Text Available

International Nuclear Information System (INIS)

Plasma nitriding in glow discharge is a process of modifying surface properties of a material by which surface hardness, corrosion resistance, fatigue strength etc. of a material can be improved

Energy Technology Data Exchange (ETDEWEB)

The technology being evaluated is the Modified In-Situ (MIS) retorting process for raw shale oil production, combined with a Circulating Fluidized Bed Combustor (CFBC), for the recovery of energy from the mined shale. (VC)

Science.gov (United States)

This study investigated weathering effects on polyvinyl chloride (PVC) based wood plastic composites (WPC), with a focus on the color and structure that is attributed to the material composition. It is directed towards quantifying the main chemical modifi...

UK PubMed Central (United Kingdom)

Adaptive radiation therapy (ART) is the incorporation of daily images in the radiotherapy treatment process so that the treatment plan can be evaluated and modified to maximize the amount of radiation...Full Text Available

UK PubMed Central (United Kingdom)

Hypothalamic systems which regulate appetite may be permanently modified during early development. We have previously reported hyperphagia and increased adiposity in the adult offspring of rodents fed...Full Text Available

UK PubMed Central (United Kingdom)

Decitabine, an epigenetic modifier that reactivates genes otherwise suppressed by DNA promoter methylation, is effective for some, but not all cancer patients, especially those with solid tumors. It...Full Text Available

UK PubMed Central (United Kingdom)

ObjectiveTo evaluate the effect of different concomitant disease modifying antirheumatic drugs (DMARDs) on the persistence with antitumour necrosis factor (anti-TNF) therapies in...Full Text Available

UK PubMed Central (United Kingdom)

The Dot/Icm type IV translocated Ankyrin B (AnkB) effector of Legionella pneumophila is modified by the host prenylation machinery that anchors it into the outer leaflet of the Legionella-containing...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundEscherichia coli strain EL350 contains chromosomally integrated phage lambda Red recombinase genes enabling this strain to be used for modifying the sequence...Full Text Available