Science.gov (United States)

{sup 1}H, {sup 13}C, {sup 27}Al, and {sup 29}Si magic-angle-spinning (MAS) NMR was used to elucidate the nature of the catalytic activity of zeolite H-ZSM-5. {sup 1}H MAS NMR of sealed samples after mild hydrothermal dealumination shows that the enhanced activity for n-hexane cracking is not due to an enhanced Bronstead acidity. The concentrations of the various OH groups and aluminous species suggest that the reason for the enhanced catalytic activity is the interaction of the n-hexane molecule with a bridging hydroxyl group and with extra-framework aluminium species, which give rise to the enhanced activity, cannot be easily removed from their positions, and are therefore immobilized by the zeolitic framework.

Energy Technology Data Exchange (ETDEWEB)

Nanocrystalline zeolites with discrete crystal sizes of less than 100 nm have different properties relative to zeolites with larger crystal sizes. Nanocrystalline zeolites have improved mass transfer properties and very large internal and external surface areas that can be exploited for many different applications. The additional external surface active sites and the improved mass transfer properties of nanocrystalline zeolites offer significant advantages for selective catalytic reduction (SCR) catalysis with ammonia as a reductant in coal-fired power plants relative to current zeolite based SCR catalysts. Nanocrystalline NaY was synthesized with a crystal size of 15-20 nm and was thoroughly characterized using x-ray diffraction, electron paramagnetic resonance spectroscopy, nitrogen adsorption isotherms and Fourier Transform Infrared (FT-IR) spectroscopy. Copper ions were ...

International Nuclear Information System (INIS)

This report summarizes the findings of a five-month LDRD project funded through Sandia's NTM Investment Area. The project was aimed at providing the foundation for the development of advanced functional materials through the application of ultrathin coatings of microporous or mesoporous materials onto the surface of substrates such as silicon wafers. Prior art teaches that layers of microporous materials such as zeolites may be applied as, e.g., sensor platforms or gas separation membranes. These layers, however, are typically several microns to several hundred microns thick. For many potential applications, vast improvements in the response of a device could be realized if the thickness of the porous layer were reduced to tens of nanometers. However, a basic understanding of how to synthesize or fabricate such ultra-thin layers is lacking. This report describes traditional and novel approaches to the growth of layers of microporous materials on silicon wafers. The ...

Energy Technology Data Exchange (ETDEWEB)

Short communication.

International Nuclear Information System (INIS)

Hydrogen cyanide is a key molecule for chemical evolution studies because, when it is exposed to different sources of energy, it forms various compounds of biological importance. To understand the role of minerals in chemical evolution, a series of experiments was performed. First, the adsorption capacity of HCN on different surface minerals was studied; the results show that HCN is readily adsorbed onto the solids proposed (zeolite, serpentine, dolomite, and sodium montmorillonite), in particular zeolite and montmorillonite. Second, the radiolysis of HCN adsorbed on olivine (as an example of a mineral surface) was also followed; it was found that the rate of HCN decomposition by gamma irradiation is enhanced in the presence of the solid. The third series of studies show that organic material was produced in high abundance from HCN at high radiation doses. The radiolytic products included gases (CO_2, NH_4, and CO) and ...

International Nuclear Information System (INIS)

Laser surface modification can lead to formation of a novel microstructure on the surface of a material resulting in improved surface properties. During the past one and half decades, a number of investigations have been reported on laser surface modification techniques for improving the corrosion resistance of various materials. This paper reviews various work reported on utilising laser modification techniques for enhancing the aqueous corrosion resistance of materials. The laser surface modification work carried out on materials like stainless steels, C-steels, low alloy steels and non-ferrous materials such as Zr, Zn, Al, Ni, Mg and their alloys has been covered in the review. General features observed in improving the corrosion resistance after laser processing have been discussed and scope for future investigations in this field has been highlighted. (author). 97 refs., 15 figs., 5 tabs.

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

The effect of treatment with hydrogen, hydrogen sulfide, and steam on the catalytic properties of NaY zeolites has been studied. A mechanism has been proposed for activation of the zeolites, which explains the appearance of Broensted acid centers on modified samples. The influence of modification temperature and the degree of decationization of the zeolites on the promoting capacity of the latter in the cumene cracking reaction has been studied.

Energy Technology Data Exchange (ETDEWEB)

Y-zeolite supported catalysts were applied to the hydrocracking of coal-derived liquids. By the introduction of two-stage upgrading consisting of hydrotreating and hydrocracking, Wandoan coal-derived middle distillate was hydrocracked over Ni-Mo/Y-zeolite, producing a high gasoline fraction yield. Zeolite supported catalysts gave little hydrocracked compounds in the hydroprocessing of coal-derived heavy oils, even after hydrotreatment. The reaction inhibitors which seriously poison the active sites of zeolites were found to be small nitrogen-containing molecules. In the hydroprocessing of coal-derived heavy oils, zeolite supported catalysts were inferior to alumina supported catalysts. This is due to the high hydrocracking but low hydrogenation activity of zeolite supported catalysts. 22 refs., 5 figs., 11 tabs.

Science.gov (United States)

A process is provided for conducting organic compound conversion over a catalyst composition comprising a specially treated crystalline zeolite having a high initial silica-to-alumina mole ratio, said zeolite having been synthesized from a reaction mixture comprising a diamine as a cation source. The treatment of the zeolite material comprises the sequential steps of reacting the zeolite with a dilute hydrogen fluoride solution, contacting the hydrogen fluoride solution reacted material with aluminum chloride vapor, and then treating the aluminum chloride contacted material to convert it to hydrogen form.

Energy Technology Data Exchange (ETDEWEB)

In the dehydrodesulfurization of ethanethiol at 400/sup 0/C, the activities of sodium X, Y, and A zeolites decreased in the order given as did the activities of nickel, cobalt, zinc, cadmium, copper, silver, lead, manganese, barium, calcium, sodium, and iron Y zeolite catalysts. A volcano-shape order was observed between the catalytic activity and the electronegativity of the metal ions. The changes in the activity of hydrogen Y zeolite catalyst in ethanethiol dehydrodesulfurization and cumene dealkylation by calcination agreed with the decrease in the Broensted acidity but were independent of Lewis acidity. For hydrodesulfurization of thiophene, the activities of nickel, cobalt, copper, and silver Y zeolite catalysts decreased in the order given and were greater than for a commercial hydrodesulfurization catalyst; reduced and presulfided catalysts showed selective hydrodesulfurization activity. ...

Environmental Research Database

DescriptionInefficient utilisation of dietary nitrogen (N) by animals results in the excretion of N in varying forms, with adverse environmental consequences. Grass silage is a major component of the diet of ruminant livestock in the UK, but the protein in silage is very highly degraded as a result of the ensilage process. This results in poor capture of the silage N by rumen microbes leading to overall poor utilisation for the synthesis of milk or meat. As a result, significant quantities of dietary N are [continued...

Science.gov (United States)

The progress of laboratory studies on the removal of NO/sub x/ and SO/sub 2/ with zeolite molecular sieves is reported. The trademark of these zeolite molecular sieves is Zeolon. (LK)

Energy Technology Data Exchange (ETDEWEB)

Zeolite Y is the active component of most commercial cracking catalysts. Interaction of H[sub 3]PO[sub 4] with extraframework aluminum of ultra-stable zeolite (USY) leads to the formation of different types of aluminum phosphates, while there is no indication of the formation of SAPO zeotype structures. The total acidity of USY slightly decreases upon the H[sub 3]PO[sub 4] treatment, while the maximum in the distribution of acid strength is shifted to milder acidities. Dealumination of the zeolite and creation of POH sites associated with AIPO[sub 4] are responsible for the modifications observed. 37 refs., 8 figs., 3 tabs.

Science.gov (United States)

This paper obtains the acidity spectra of modernites and SVK-zeolites from the heats of adsorption of NH/sub 3/ at 300 C and compares the catalytic activity of these zeolites with the cracking of n-octane and the isomerization of o-xylene. It is shown that the calculation of the specific catalytic activity of centers of different strengths by the method of regional rates allows one to predict the activity of the zeolites from the acidity spectra. It follows from the calculation that only the centers of Bronsted acidity are active towards cracking but that the centers of Lewis acidity are also active towards isomerization.

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

The research has involved the characterization of catalyst acidity, [sup 2]D NMR studies of Bronsted acid sites, and kinetic, calorimetric, and spectroscopic studies of methylamine synthesis and related reactions over acid catalysts. Approach of this work was to explore quantitative correlations between factors that control the generation, type, strength, and catalytic properties of acid sites on zeolite catalysts. Microcalorimetry, thermogravimetric analysis, IR spectroscopy, and NMR spectroscopy have provided information about the nature and strength of acid sites in zeolites. This was vital in understanding the catalytic cycles involved in methylamine synthesis and related reactions over zeolite catalysts.

KoreaScience (Korea)

Full Text Available

International Nuclear Information System (INIS)

Russian (Jan 1978). USSR Chorna, IM Beshta, EI Kvitkovskij, LN L'vovskij

Energy Technology Data Exchange (ETDEWEB)

A phosphorus-containing low alkali metal content zeolitic catalyst made from a clay starting material is provided. The catalyst is obtained by contacting a partially cation exchanged calcined zeolite-containing catalyst with a dihydrogen phosphate anion or a dihydrogen phosphite anion. A hydrocarbon catalytic cracking process utilizing the phosphorus-containing catalyst is also provided.

Energy Technology Data Exchange (ETDEWEB)

Clays and zeolites are among the most important of natural dusts by virtue of their occurrence through out the world on the earth`s surface and their important industrial uses. (The 1:1 layer silicates, including the serpentine and kaolin minerals, are not addressed in this chapter.) This chapter provides basic information on a variety of important aspects of each mineral, including crystal structure diagrams of each and references to more detailed discussions. 110 refs., 20 figs.

British Library Electronic Table of Contents (United Kingdom)

The catalytic performance of alkaline-treated zeolite H-ZSM-5 in the conversion of methanol to gasoline has been studied. After treatment with 0.20M NaOH, the total conversion capacity increased by a factor of 3.3, and the selectivity towards the gasoline fraction increased by a factor of 1.7. Physical characterization indicated the formation of mesopores and improved crystallinity.

Energy Technology Data Exchange (ETDEWEB)

Objective. To compare turbo inversion recovery magnitude (TIRM) with standard T1-weighted (T1-W) and T2-weighted (T2-W) MR sequences in the very early detection of acute osteomyelitis in children. Materials and methods. In 15 children with osteomyelitis, 15 sets of T1-W spin-echo (SE) (TR/TE, 400-640/12-17), T2-W turbo spin-echo (TSE) (TR/TE/ETL, 3290-4465/112-120/11), and TIRM (TR/TE/TI, 4000-6120/60/160) images were acquired with a 1.0-T magnet. Contrast-to-noise (C/N) ratios and percentage of signal between lesion and normal bone marrow were analysed with a computer-assisted image analysing system in a region of interest (ROI). Results. In 13 of 15 patients, the absolute signal enhancement in a ROI on the TIRM images was better than on the T1-W SE and T2-W TSE images and in 14 of 15 cases, C/N ratios were also better on the TIRM images than on the other sequences. In the other cases, the TIRM signal was diagnostically equivalent. On the TIRM images, the signal ...

Science.gov (United States)

The work presented in part 1 of this study established that the sorption of anhydrous HX into dehydrated Na{sub 56}Y progresses through a sequence of steps involving HX ionization and charge separation, oxygen framework protonation, formation of {alpha}-cage confined cation-anion contact ion pairs, and proton solvation by HX. A logical extension, which is the subjected of this study, concerns the effect of extraframework alkali metal cation type (M = Li{sup +}, Na{sup +}, K{sup +}, Rb{sup +}, Cs{sup +}) on the sorption process. The question of the acidity of proton-loaded zeolites compared to Broensted acid zeolites is addressed by using probe reactions with weak bases like ethane and cyclopropane. Additional insight into these systems is also obtained from a quantitative comparison of the kinetic and thermodynamic activation parameters for the dehydrohalogenation of proton-loaded zeolites exemplified by (HX){sub 8}Na{sub ...

Energy Technology Data Exchange (ETDEWEB)

The overall objective of this research work was to prepare hydrocracking catalysts using amorphous silica-alumina (ASA) supports in combination with USY and {beta}-zeolites. Three supports: namely silica-alumina, USY and {beta}-zeolites were selected to prepare the extrudates using AP-1 as a binder, while two metal pairs: namely Ni-W and Ni-Mo were loaded on the extrudates through co-impregnation using incipient wetness technique. The catalysts were then calcined at 550C for 2h. The catalysts were tested in a fixed-bed flow reaction system for their activity, using desulfurized vacuum gas oil (DS-VGO) as a feedstock. The catalytic evaluation results of the catalysts showed that {beta}-zeolite alone and in combination with the ASA used in this study, has a potential as a support for developing heavy oil hydrocracking catalysts. A balance of weak and strong acidities of {beta}-zeolite provides control ...

UK PubMed Central (United Kingdom)

BackgroundExisting studies concerning the health care use of homeless people describe higher utilisation rates for hospital-based care and emergency care, and lower rates for primary...Full Text Available

UK PubMed Central (United Kingdom)

Knowledge of factors affecting variation in birth weight is especially important given the relationship of birth weight to neonatal and adult health. The present study utilises two large contemporary...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The present paper is a comparative study of the cerium-containing nickel catalysts supported on x- and y-zeolites. In general, the addition of cerium ions caused an increase in the catalytic activity for CO hydrogenation and shifted the product selectivity to high molecular weight hydrocarbons. The degree of the effect of cerium additive depends on the ratio of cerium to nickel contents, the reduction temperature, and the nature of the supporting materials. Catalyst characterization, including volumetric hydrogen chemisorption, temperature programmed reduction/desorption, x-ray diffraction, surface area measurements, in-situ infrared spectroscopy and x-ray photoelectron spectroscopy, was performed in order to interpret the phenomena due to the effects of cerium additives and the support effect on Ni/zeolite catalysts.

Science.gov (United States)

We have obtained convincing evidence for localization of the optical electron on a single-ring fragment of a chelated bipyridine-like'' ligand (ie., pyridylpyrazine or 4-Methyl-bipyridine). In addition we have completed studies of Ru(bipyrazine){sub 3}{sup 2+} in aqueous sulfuric acid (0--98% by weight) and find clear evidence for sequential addition of six-protons to the six peripheral nitrogen atoms. Studies of zeolite-entrapped complexes are continuing and a series of homo- and heteroleptic complexes have been prepared and characterized. Finally, the synthesis of zeolite-entrapped metallophthalocyanines has now been developed and the copper and cobalt analogues synthesized. The characterization of these materials is now in progress.

International Nuclear Information System (INIS)

When clinoptilolite is immobilized in cement-based composites, a series of reactions occur, leading to release of Cs. These reactions occur in three overlapping stages: a rapid ion exchange, followed by a somewhat slower reaction between clinoptilolite and principally the Ca(OH)_2 component of cement, and, in the longer term, slower reactions with C-S-H leading either to formation of low-lime C-S-H at temperatures below 100"0C or 11 A (1.1 nm) tobermorite at higher temperatures. Kinetic data are presented to evaluate the rate of physical consumption of the zeolites at 70 and 150"0C. Reactions occurring above 100"0C appear to result in the development of extensive microcracking of cement-zeolite composites containing 50% zeolite.

International Nuclear Information System (INIS)

A research was started aiming at evaluating the possible use of natural zeolites as exchange conditioners to improve and make durable the soil resilience against the adverse effects of the use of anomalous waters for irrigation purposes. This paper deals with a preliminary investigation on the comparative resilience of an Entisol with poor exchange properties and of a Neapolitan yellow tuff (NYT) sample against the adverse features of a dirty municipal sewage (DSW). Results showed that NYT treatment largely and significantly improved the poor soil exchange activity. In particular. NYT exchange sites selectively took up ammonium from DSW. As a consequence, ammonium was trapped, then protected against losses in the environment and, concurrently, exchangeable cations, such as K and Ca, were made free as plant nutrients. The results highlight the possible positive role of zeolitized tuff in restoring and sustaining soil resilience.

Energy Technology Data Exchange (ETDEWEB)

The N{sub 1s} XPS band of pyridine chemisorbed on Al-ZSM-5 zeolite was found to be properly deconvoluted into three component peaks. In a previous contribution these three components were assigned to pyridine chemisorbed on two kinds of Bronsted acid sites and one Lewis acid site. This analysis is extended here to Fe-ZSM-5 and B-ZSM-5. Isomorphous substitution of Fe for Si or Al in the zeolite framework leads to a slight decrease in the binding energy of the N{sub 1s} Lewis component. In the case of B substitution a decrease in the binding energy of all three N{sub 1s} components is observed.

Energy Technology Data Exchange (ETDEWEB)

A catalytic process for the oxidation of sulfur-containing gases , E.G., sulfur dioxide and simultaneous production of sulfuric acid wherein a sulfur-containing gas is reacted with an oxygencontaining gas in the presence of a catalyst comprising an iron group metal on a solid support comprising a zeolite in a silicaalumina matrix.

International Nuclear Information System (INIS)

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

Science.gov (United States)

Recently there has been considerable interest in the Cu-ZSM-5 catalysts for the selective reduction of NO by light hydrocarbons for the purpose of atmospheric pollution abatement. Isobutane and n-pentane cracking were studied over Cu zeolite catalysts and these results were compared with their HY analogues at low conversions and at temperatures of 673 K and below. Three forms of the catalysts were used: those reduced in CO at 773 K; those reduced with H[sub 2] at 473 K; and those in the oxidic form (following flushing with He at 773 K). In contrast with an earlier publication, very little difference in activity was found between the two reduced forms of the catalysts did not differ significantly from each other nor from the H-form of the zeolite. They are typical of a Bronsted acid catalysis. The oxidic form of the catalyst produced excess H[sub 2] in increasing amounts with time on stream. This could be quantitatively accounted for by the ...

Science.gov (United States)

In the prevention of atmospheric pollution by sulfur dioxide emissions from acid absorbers in contact process sulfuric acid plants in which the unconverted SO/sub 2/ is accumulated by adsorption in a zeolite adsorbent bed and desorbed back into the acid production system, it is found that ambient moist air, after partial dehydration in an acid scrubber is suitably used both to cool down and hot purge desorb the zeolite beds. In addition the pure water derived from the ambient air is advantageously used in the acid-making system.

British Library Electronic Table of Contents (United Kingdom)

The increasing environmental concern and promotion of ''green processes'' are forcing the substitution of traditional acid and base homogeneous catalysts by solid ones. Among these heterogeneous catalysts, zeolites and zeotypes can be considered as real ''green'' catalysts, due to their benign nature from an environmental point of view. The importance of these inorganic molecular sieves within the field of heterogeneous catalysis relies not only on their microporous structure and the related shape selectivity, but also on the flexibility of their chemical composition. Modification of the zeolite framework composition results in materials with acidic, basic or redox properties, whereas multifunctional catalysts can be obtained by introducing metals by ion exchange or impregnation procedures...

Energy Technology Data Exchange (ETDEWEB)

A novel multilayer mixed matrix membrane (MMM), consisting of poly(phenylene oxide) (PPO), large-pore mesoporous silica molecular sieve zeolite SBA-15, and a carbon molecular sieve (CMS)/Al{sub 2}O{sub 3} substrate, was successfully fabricated using the procedure outlined in this paper. The membranes were cast by spin coating and exposed to different gases for the purpose of determining and comparing the permeability and selectivity of PPO/SBA-15 membranes to H{sub 2}, CO{sub 2}, N{sub 2}, and CH{sub 4}. PPO/SBA-15/CMS/Al{sub 2}O{sub 3} MMMs with different loading weights of zeolite SBA-15 were also studied. This new class of PPO/SBA-15/CMS/Al{sub 2}O{sub 3} multilayer MMMs showed higher levels of gas permeability compared to PPO/SBA-15 membranes. The permselectivity of H{sub 2}/N{sub 2} and H{sub 2}/CH{sub 4} combinations increased remarkably, with values at 38.9 and 50.9, respectively, at 10 wt% zeolite loading. Field ...

Energy Technology Data Exchange (ETDEWEB)

Synthetic zeolite of 0.5 nm pore size (5A) and blue silica gel were tested to determine their capability to be used as radon collectors. Tests conducted in a radon chamber under controlled conditions of temperature and relative humidity indicate that simple, inexpensive and maintenance-free passive devices containing about 250 g of synthetic zeolite or about 270 g of blue silica gel in open face metal canisters that can measure radon conveniently and adequately, the latter though being suitable only for dry-medium dry atmosphere with quite high radon concentrations. Both materials can be recycled for reuse, in a way similar to the recycle and reuse of active carbon. The amount of radon adsorbed in such collectors is determined by counting the gamma rays from the radon decay products. The lower limit of detection (LLD) is estimated to {approx}45 Bqm{sup -3} for the synthetic zeolite and to {approx}350 Bqm{sup -3} for the ...

Energy Technology Data Exchange (ETDEWEB)

Wastes and dusts from steel industry, non-ferrous metallurgy and other branches can be utilised e.g. in agglomeration processes (sintering, pelletising or briquetting) and by injection into shaft furnaces. This paper deals with the second way. Combustion and reduction behaviour of iron- and carbon-rich metallurgical dusts and sludges containing lead, zinc and alkali as well as other wastes with and without pulverised coal (PC) has been studied when injecting into shaft furnaces. Following shaft furnaces have been examined: blast furnace, cupola furnace, OxiCup furnace and imperial-smelting furnace. Investigations have been done at laboratory and industrial scale. Some dusts and wastes under certain conditions can be not only reused but can also improve combustion efficiency at the tuyeres as well as furnace performance and productivity.

International Nuclear Information System (INIS)

Tata Electric Companies (TEC) are engaged in the generation of hydro and thermal energy. TEC, to minimise backing down of its thermal units in off peak hours and also to at least partially meet the growing deficit in the supply during peak hours is moving to install pumped storage plants (PSPs) utilising off-peak surplus energy for pumping the water from lower pond to the upper pond for subsequent utilisation for power generation during peak hours. In view of some of the infra structural facilities such as storage ponds, water conductor system, transmission lines, etc. being already available, at the existing hydro power stations owned by TEC, the pumped storage units are being proposed within the environs of existing hydro stations, i.e. a 150 MW pumped storage unit at Bhira and a 90 MW pumped storage unit at Bhivpuri. The projects are described and cost estimates is given. (author). 2 figs.

Energy Technology Data Exchange (ETDEWEB)

Georg Fischer GmbH operates a melting plant with several cupola furnaces in Mettmann. The plant supplies two casting plants for production of castings from nodular cast iron or malleable cast iron. It is now planned to convert one of the existing hot-blast cupola furnaces to the latest state of the art. Under special consideration are clear reduction of dust emission by use of a filtering separator below the permissible mass concentration according to the Clean Air Regulations; reduction of the current level of dumped waste by application of a new dust (residue) utilisation method; improvement of the total thermal efficiency of the cupola furnace melting plant by extensive, advanced utilisation of waste heat; and use of low-cost dust-like alternative fuels. (author).

Energy Technology Data Exchange (ETDEWEB)

The paper considers research carried out on the topic of life cycle (LC) modelling of industrial processes with emphasis upon energy utilisation and gaseous emissions. The aim of the work is to investigate existing LC assessment codes, in particular for their outputs and decision making potential, and to develop the characteristics of new software as appropriate. The paper focuses on a comparison of two methods for LC modelling: use of ''SimaPro 5'' with ECO-indicators and logical-information modelling. The considered approaches require attention to dynamic modelling having features for decision making; for example, in areas of costs, sensitivity analysis and optimisation of LC process parameters to economically reduce the total environmental load. Brick making is chosen as an energy intensive process for model application. (orig.)

Energy Technology Data Exchange (ETDEWEB)

The selective catalytic reduction of nitric oxide by methane over copper ion-exchanged natural zeolites was investigated in a packed-bed tubular reactor. The catalytic activity of Cu-N and Cu-H-N catalysts was confirmed as NO, CH{sub 4}, and O{sub 2} displayed very little reaction in the absence of any catalyst and zeolite without ion exchange was totally inactive. A maximum NO conversion of 33% at 650 C for Cu-N-66 was achieved with 2% NO and 1% CH{sub 4} and a contact time of 0.9 g s/cm{sup 3}, but the introduction of 2% O{sub 2} reduced the NO conversion to only 12%. Ion exchange for the H-form prior to copper ion exchange was essential for oxygen to promote catalytic activity over the temperature range 250--650 C, with a maximum conversion of 30% at 450 C with O{sub 2} present. The direct reduction of NO by methane was ruled out as a possible reaction pathway.

Energy Technology Data Exchange (ETDEWEB)

This thesis is in the field of gas emission control from automobile and stationary sources. Out of the possible approaches to the elimination of pollutant gases, such as nitrogen oxides (NO{sub x}), one consists in the selective catalytic reduction (SCR) of these NO{sub x} on a suitable heterogeneous catalyst. Ammonia or hydrocarbons are employed as reducing agents. The most important catalysts active in the SCR of NO{sub x} are based on ions of transition metal either supported on several oxides or dispersed in zeolites. The catalysts have been characterized by electron magnetic resonance techniques (EPR, ENDOR, ESEEM) and the interaction of catalysts with nitrogen oxides, with reducing and poisoned agents have been followed with the same techniques. Copper dispersed on alumina and its interaction with both NO and ammonia has been investigated. Also the interaction between both water and ammonia with copper dispersed in zeolite ZSM-5 has been ...

Science.gov (United States)

The Process Waste Treatment Plant (PWTP) at the Oak Ridge National Laboratory is designed to remove radioactive contaminants, principally {sup 90}Sr, from process wastewater. Planned upgrades to the PWTP will use chabazite zeolite columns. Pilot-scale studies have shown that mass transfer zone lengths increase from 10 to about 30 cm as the superficial velocity increases from 5.5 to 22 cm/min. Calculations with a multicomponent equilibrium model showed that the distribution coefficient for strontium remains essentially constant over the process conditions, suggesting that a simple kinetic model (the Rosen long-bed solution) should adequately represent breakthrough behavior. Using a distribution coefficient of 4.87 L/g predicted by the equilibrium model, good agreement was found between experimental breakthrough curves and those calculated with the Rosen solution. This model allows prediction of bed depths and cycle times necessary to achieve the required ...

British Library Electronic Table of Contents (United Kingdom)

Selectivity control is a key issue in the zeolite facilitated conversion of methanol to hydrocarbons. This work addresses: (a) How the zeolite topology (MFI versus BEA) determines the type of intermediate participating in the catalytic cycle thereby controlling the ethene/propene product selectivity in the methanol to alkenes reaction, and (b) to what extent light alkene formation occurs via aromatic and alkene reaction intermediates for H-ZSM-5. Three catalyst samples have been studied in experiments relying on isotopic labeling. For H-beta, penta- and hexamethylbenzene are involved in an aromatics based hydrocarbon pool type mechanism leading predominantly to propene and the higher alkenes (a very low yield of ethene is observed), whereas for H-ZSM-5, the lower methylbenzenes are the aro...

Energy Technology Data Exchange (ETDEWEB)

The photocatalyzed degradation of pyridine in the gas phase was investigated using titanium dioxide semiconductor supported on mordenite. The complete mineralization was found to occur over a catalyst containing 75 wt% TiO{sub 2} and 25 wt% mordenite in about 180 min in the presence of saturated water vapor at O{degrees}C (4.6 Torr). Low water vapor pressure of 0.096 Torr was found to be sufficient to achieve a reasonably high percentage and rate of degradation. Diffusion of pyridine within the catalyst adversely affects the activity when the thickness of the catalyst coating exceeds the penetration depth of illumination. The activity of the zeolite-supported catalysts was higher than that of TiO{sub 2}. The photonic efficiency for the complete mineralization of pyridine to CO{sub 2} was determined to be 0.48. 29 refs., 6 refs., 1 tab.

International Nuclear Information System (INIS)

Potassium clusters arrayed in zeolite A are known to show ferromagnetic properties at low temperature. The origin of the spontaneous magnetization has been explained by a model of spin-canting in an antiferromagnetically ordered state. The direct information for the magnetic structure, however, has not been obtained so far. In the present work, we measure the neutron powder diffraction by using pulsed neutron source at KEK-KENS below and above the Curie temperature. No significant temperature-dependence was, however, obtained within the statistical errors, namely, magnetic scattering could not be detected separately. We also estimate the intensity of magnetic scattering by assuming some possible magnetic structures with considering the magnetic form factor of the cluster wave function. The intensity of magnetic scattering is estimated to be extremely weak and higher S/N of ?104 or more is required to detect the magnetic scattering of this material.

Energy Technology Data Exchange (ETDEWEB)

The increasing use of quantum-chemical methods in catalysis has underscored the importance of developing and improving semiempirical approximations oriented toward calculations of the total energy and geometry, offering a means for examining intermolecular interactions. In this article a general approach is proposed, using weighting factors for certain regions of distances, i.e., introducing different parametrization into the various regions. A scheme designated MINDO/3-HB is presented as an extension of the MINDO/3 scheme to the region of hydrogen bonds and ..pi..-complexes of olefins with Broensted acid centers (BACs). Examples of cluster calculations are given for the adsorption of ammonia, pyridine, ethylene, and ethanol on the BACs of zeolites. In the example of the process of zeolite synthesis, the possibilities of the cluster approach are discussed for calculations related to the formation of catalysts.

Energy Technology Data Exchange (ETDEWEB)

A Selective Catalytic Reduction (SCR) catalyst was prepared by slurry coating ZSM-5 zeolite onto a cordierite monolith, then subliming an iron salt onto the zeolite, calcining the monolith, and then dipping the monolith either into an aqueous solution of manganese nitrate and cerium nitrate and then calcining, or by similar treatment with separate solutions of manganese nitrate and cerium nitrate. The supported catalyst containing iron, manganese, and cerium showed 80 percent conversion at 113 degrees Celsius of a feed gas containing nitrogen oxides having 4 parts NO to one part NO.sub.2, about one equivalent ammonia, and excess oxygen; conversion improved to 94 percent at 147 degrees Celsius. N.sub.2O was not detected (detection limit: 0.6 percent N.sub.2O).

International Nuclear Information System (INIS)

The results for development of methods and computer programs for integrated optimization of parameters of perspective fast reactors are given. The possibilities of the program for the reactor campaign calculation are analysed. This program is based on utilisation of the Bubnov-Galerkin method and Wigner disturbance theory. The possibility of application of approximation methods for the optimization researches is discussed. The results of development of the programs for complex reactor computations with account of control rods system and change of physical parameters in the reactor campaign are discussed. (author).

Environmental Research Database

DescriptionIn young pigs the post-weaning period is generally characterised by a marked reduction in voluntary feed intake, poor growth and development, and diarrhoea. The associated reduction in digestive and absorptive capacity of the gastrointestinal tract decreases the overall efficiency of nutrient capture and utilisation, thereby causing an increase in nutrient loading to the environment. The reduction in digestive and absorptive efficiency after weaning has implications for lifetime performance be [continued...

International Nuclear Information System (INIS)

A review is made of the various brain imaging agents utilised in the post few years with their own characters and respective advantages: cerebral blood volume tracers, non diffusible tracers, diffusible tracers among which gases and lipophilic agents. Our results with IAMP and SPECT are presented in two different clinical application fields: normal pressure hydrocephalus and cerebral ischemia.

Environmental Research Database

DescriptionThe importance of inorganic nitrate for the nutrition and growth of marine and freshwater autotrophic phytoplankton has long been recognised, in particularly because of the 'blooms' formed in nitrate and phosphate polluted water and their possible roles as carbon dioxide sinks. By contrast, the utilisation of nitrate by heterotrophic bacteria has historically received less attention. Up until now, the primary role of heterotrophic bacteria has classically been considered to be the decomposition [continued...

CERN Document Server

Control of Phosphorus Transient Enhanced Diffusion using Co-implantation

Energy Technology Data Exchange (ETDEWEB)

An amorphous mesoporous titania-silica aerogel (20 wt%TiO{sub 2} - 80 wt% SiO{sub 2}) and tert.-butylhydroperoxide (TBHP) have been used for the epoxidation of various allylic alcohols. Allylic alcohols possessing an internal double bond were more reactive than those with a terminal C=C bond. Epoxide selectivities could be improved by addition of (basic) zeolite 4 A and NaHCO{sub 3} to the reaction mixture. (orig.)

UK PubMed Central (United Kingdom)

Outbred Wistar rats were immunised with a single intraperitoneal injection of a mixture of 30 mg of A1(OH)3 and 100microng of gonococcal zeolite antigen (ZA). Ten days after immunisation, ZA prepared...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Calcined and sulfided Ni-Mo catalysts supported on ultrastable Y zeolite (USY), NaY zeolite, mordenite, and ZSM-5 were studied by high-resolution electron transmission microscopy (HRTEM) with selected-area electron diffraction (SAED) and energy-dispersive spectroscopy (EDS). Ni and Mo oxide aggregates were rarely observed in the USY-supported Ni-Mo catalyst, indicating that most of Ni and Mo may be incorporated into USY, e.g., supercavities and possibly sodalite cages. However, there were a large number of {alpha}-NiMoO{sub 4} aggregates of different particle sizes in NaY-, mordenite-, and ZSM-5-supported catalysts, and the mordenite-supported catalyst also contained MoO{sub 3} crystals. The {alpha}-NiMoO{sub 4} may be attached to the surface of substrates as individual particles or needle aggregates, it may be disseminated into mordenite particles, or it may even form an isolated sphere (in Ni-Mo/NaY) or a needle (in Ni-Mo/ZSM-5) aggregates. ...

Energy Technology Data Exchange (ETDEWEB)

From long-term real-time radon and radon progeny measurements taken in a relatively large retail store, cyclical patterns were evident, which were found to relate to the overriding influence of the timed air-conditioning system. Concentration of radon, radon progeny and the variability of F factor were found to depend significantly on the intermittent operation of this ventilation-air-conditioning system. After pressure equalisation remedial measures proved ineffective, the air-movement system was utilised to reduce the levels of radon and radon progeny to well within established norms applicable during working hours. It is demonstrated that the average levels for radon and radon progeny are reduced in absolute terms. This amounted to less than 12% of the general level, during designated work periods. Where air movement systems are already installed, as well as other circumstances, their regulation provides an economical solution to meeting legal and other ...

Energy Technology Data Exchange (ETDEWEB)

Describes the wastes produced and the waste disposal methods used at BEWAG power plants. Wastes covered include fly ash, fluidized bed ash, gypsum from flue gas desulfurization and evaporation residues. Disposal methods include using ashes and gypsum to make building materials. Despite many years of experience in the utilization and disposal of residues from coal-fired power stations BEWAG have not encountered any disposal problems. 5 tabs.

Energy Technology Data Exchange (ETDEWEB)

The purpose of the project was to evaluate the potential influence of global warming on the Finnish economy and well-being during the next 50 to 100 years. In order to achieve this goal a cost-benefit analysis was conducted which produced a quantitative estimate of the economic and partially non-economic effects of the climate change projected to happen in Finland. The analysis utilised the natural scientific evidence produced by other SILMU projects in partial sector models. Also a broader view of the phenomena and the possibilities for restricting greenhouse gas emissions was briefly discussed and surveyed. Two of the more important side-goals were to develop the methodology for country analysis and study the possibilities for adaptation

British Library Electronic Table of Contents (United Kingdom)

Critical knowledge is proliferated among different knowledge owners of a corporate system through the individuals lying inside or outside the system. Extraction of such knowledge is a very crucial requirement for all organisations. This paper presents the role of critical knowledge in the proper functioning of a system by representing it in the form of eXtensible Markup Language to develop a corporate memory. In order to demonstrate the role of corporate memory in the organisation, a real-world problem of a global supply chain is considered. The problem utilises the concept of corporate memory for the selection of potential suppliers from a set of available suppliers, and further to select the best route from a set of available alternative routes. The objective deals with the minimisation ...

Energy Technology Data Exchange (ETDEWEB)

Oestfold Research has trough the project 'Climate accounts for disposal' for Waste Norway developed a model for calculation of net greenhouse gas emissions at the disposal of various waste types. The model is based on life cycle methodology according to the standard IS014044. This model has been used for plastic packaging in the project by adapting the basic values of specific conditions in the municipality of Fredrikstad. Oestfold Research has made an assessment of greenhouse gas emissions for the recycling and material recovery of plastic packaging from households in the district on assignment from Fredrikstad municipality and compared with the current solution where plastic packaging together with residual waste is used for energy utilisation. Based on the population in Fredrikstad and estimated amount of plastic packaging waste arising per household per year the difference in climate impact was analyzed and these scenarios calculated: ...

KoreaScience (Korea)

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Science.gov (United States)

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Energy Technology Data Exchange (ETDEWEB)

The bulk of the results from this project, besides being found in the research reports, are in the form of two theses presented for advanced degrees by two different students at two different institutions. Francis E. Porbeni is a Master`s Degree student in Chemistry at Clark Atlanta University and has prepared his Master`s Thesis entitled Simultaneous SO{sub 2} Oxidation and NO Decomposition over Copper Oxide on {gamma}-Alumina Catalysts: An Infrared Diffuse Reflectance Study. Sumit Rao, a Ph.D. student in Chemical Engineering at the Georgia Institute of Technology has defended his thesis entitled Role of Copper Ensemble Size in Silica and Zeolite Supported Catalysts for Nitric Oxide Decomposition. These two documents, which will be forwarded when final copies are available, provide the details of the bulk of the research accomplished over the duration of this project. These two documents are summarized, and other results from the project are given.

Energy Technology Data Exchange (ETDEWEB)

Petrographic research for the Nevada Nuclear Waste Storage Investigations focused on xenolithic variability in the Topopah Spring Member and on variations of clinoptilolite composition at Yucca Mountain. Zeolite and smectite occurrences were considered in terms of their relation to a disturbed zone beneath the potential repository, and mineral stability experiments have produced a new clinoptilolite structure as a result of prolonged heating at low temperature. Limitations were defined on the abundance of erionite and of sulfur. X-ray diffraction studies lead to improved analytical methods. Progress was made in the comparative study of mineralogy in sand ramps and in faults. Geological modeling considered the differences of the diffusion of nonsorbing tracers in vertically and in horizontally fractured rock. Modeling also treated the diffusion of a nonsorbing tracer in devitrified and in zeolitized rock. The results of these experiments in all ...

International Nuclear Information System (INIS)

Propylene polymerizations were carried out with #phi#_2C(Flu)(Cp)ZrCl_2 and SiMe_2(Ind)2ZrCl_2 catalysts supported on silica, zeolite sodic mordenite (NaM) and acid mordenite (HM). The polymerizations were performed at different temperatures and varying aluminium/zirconium molar ratios ([Al]/[Zr]). The effect of these reaction parameters on the catalyst activity was investigated using a proposed statistical experimental planning. In the case of f_2C(Flu)(Cp)ZrCl_2, SiO_2 and NaM were used as support and the catalyst performance evaluated using toluene and pentane as polymerization solvent. The molecular weight, molecular weight distribution, melting point and crystallinity of the polymers were examined. The results indicate very high activities for the syndiospecific heterogeneous system. Also, the polymers obtained had superior Mw and stereo regularity. (author)

International Nuclear Information System (INIS)

#beta#-SiAlON was synthesized from a zeolite by NH_3 gas nitridation and its formation mechanism was investigated using X-ray diffraction and "2"9Si and "2"7Al NMR spectroscopy. It was revealed that most of the Si and Al atoms react to form #beta#-SiAlON via amorphous forms of Si-Al-O-N and O-SiAlON. Nitridation using NH_3 gas is an effective means of preventing mullite formation and promoting the introduction of nitrogen into aluminosilicate materials at lower temperatures than temperatures required by the carbothermal reduction nitridation process. Further, the NMR spectra showed that the siliceous part of the system changed into low z-value of Si_6_-_zAl_zO_zN_8_-_z (#beta#-SiAlON) and the incorporation of Al components into the #beta#-SiAlON was promoted in the later stages of the reaction. (author)

Science.gov (United States)

The acid site distribution over large ZSM-5 crystals was analyzed using FTIR microscopy. Results of the analysis of the OH-stretching vibrations and of vibrations of pyridine adsorbed on Bronsted and Lewis acid sites were found to be in good agreement. The resolution which can be obtained using this novel technique is about 10-20 [mu]m. This limits the application to large crystals as analyzed in this study. Comparison of the results of IR microscopy with aluminum distributions obtained by electron microprobe analysis revealed that IR microscopy cannot resolve inhomogeneities on a scale smaller than the above-state limits. The results of both methods on a larger scale, however, are in very good agreement. Using a combination of both techniques, it is possible to obtain a clearer picture of the distribution of acid sites in large zeolite crystals, where electron microprobing gives the higher resolution, and IR microscopy allows the determination of the types of ...

Energy Technology Data Exchange (ETDEWEB)

Reinforced (heterogel) silicate materials containing an amorphous and a crystalline phase are being used more and more industry. Such systems are energetically unsaturated and therefore promising for use in catalysts. The authors used two reinforced materials as supports: an aluminosilicate containing a zeolite (the cracking catalyst, tseokar) and asbestos-containing aluminosilicate. The active component was introduced by impregnation, and this was followed by heat treatment during which the chemical composition and porous structure were formed. The impregnating mixture consisted of solutions of potassium sulfate and vanadate of the required concentrations. The testing shows that reinforced heterogel systems are promising as support materials for sulfuric acid catalysts.

Energy Technology Data Exchange (ETDEWEB)

The leached glass is subject to leachant attack and results in surface layer alteration which greatly affects the corrosion progress of glass forms. This work studied the composition change, precipitation, pitting corrosion as well as surface layer break and spallation of the leached glass forms. 6 conclusions can be made: 1. The extent of surface layer alteration is related to many factors such as temperature, pH, leachant chemistry, flow rate and leach duration, etc. 2. The alkali element Na is seriously depleted and the elements like U.Ti,Fe, Ca and Mg are enriched in the surface layer. The influence of media has such order: Fe{sub 2}O{sub 3} > Na-bentonite > Zeolite. 3. The precipitate formed in leach test for 56 days at 90 {infinity}C is mostly amorphous, but after 91 days has crystallized. There is K - Ca - Al - Si crystal,the amount of Al, K and Si is increasing, but the amount of Ca is decreasing along with leaching time. CaCO{sub 3} crystal ...

British Library Electronic Table of Contents (United Kingdom)

To reduce the cost of the formed coke briquettes which can be used as a substitute fuel to the metallurgical coke for the blast furnace from the coke breeze alternative binders and their blends were used. The high temperature behavior was investigated. The binders tested were: the nitrogen blown, air blown coal tar pitch and the blend of air blown coal tar pitch with the phenolic resins blends. The phenolic resin blends were prepared by mixing equal amount of resole and novalac. From the results, nitrogen blowing resulted in the weakest briquettes. The air blowing procedure should be preferred in place of nitrogen blowing for this purpose. When the air blown coal tar pitch was used alone as a binder, the briquettes must be cured at 200^oC for 2h, then carbonized at a temperature above 670^...

International Nuclear Information System (INIS)

Modern civilisation is based on substantial utilisation of energy. Rapid industrial development and improvement of living standards in India require energy planners to adequately forecast the energy demand and take appropriate measures in advance. However, the development and establishment of new technology is a slow process, sometimes extending over decades. Hence, energy options based on new technologies need to be planned for much in advance making allowance for uncertainties and delays. Fast Breeder Reactor (FBR) technology is an advanced energy option promising abundant and economic supply of power. Research and development work on FBRs has been conducted at the Indira Gandhi Centre of Atomic Research (IGC) since 1971. The international trends in FBR development are highlighted in this discussion and an overview of some of the research activities at IGC is presented. (author). 8 refs., 7 tab s.

Energy Technology Data Exchange (ETDEWEB)

Heavy ion irradiation on tantalum metal target with 57 MeV {sup 11}B{sup 4+} leads to the production of no-carrier-added radioisotopes of platinum, {sup 187,188}Pt and iridium, {sup 187,188}Ir in the matrix, which have been effectively separated from the bulk target and from each other with suitable anion exchangers employing liquid-liquid extraction (LLX). Also {sup 188,189}Pt and {sup 188,189}Ir radionuclides have been produced, from their short-lived precursors {sup 188,189}Au, in {sup 12}C{sup 6+} irradiated tantalum matrix. Gamma-spectroscopy has been utilised to determine the production, extent of separation and purity of the radiotracers at different stages of the experiment. (orig.)

Energy Technology Data Exchange (ETDEWEB)

In a fluoroscopic imaging system, image quality and patient dose are both affected by the optical system linking the image intensifier with the video camera. The effect on patient exposure of increasing the optical iris aperture size over that required for other procedures performed on the same imaging system was investigated for the air-contrast barium enema examination. Using a large-area transmission ionisation chamber to monitor the Roentgen-area-product of entrance exposure, a decrease in fluoroscopic radiation of greater than 50% was clinically documented for a fluoroscopic system utilising kVp and mA variable automatic brightness control. For this iris change, the video image was of acceptable quality for positioning and monitoring the patient, and no deleterious effect was detected in the conduct of the air-contrast exam. The availability of a variable-sized operator-selectable iris diaphragm would permit this dose-reduction approach to be extended to other ...

Energy Technology Data Exchange (ETDEWEB)

In the Carpathian Basin, significant percentage of watershed area and floodplains of rivers are utilised agriculturally. Several potential sources of poisonous metal pollution have been identified in these areas. Because of spills from some of them a few severe accidents have happened especially in the watershed area of Tisza River during the last decades. The motivation of our present work was to produce {sup 62,65}Zn and {sup 203}Pb radioisotopes because they can be used especially as tracers for studying the kinetics of uptake, transport and accumulation of zinc and lead by plants under different circumstances. (orig.)

CERN Document Server

An algorithm for creating synthetic telescope images of Smoothed Particle Hydrodynamics (SPH) density fields is presented, which utilises the adaptive nature of the SPH formalism in full. The imaging process uses Monte Carlo Radiative Transfer (MCRT) methods to model the scattering and absorption of photon packets in the density field, which then exit the system and are captured on a pixelated image plane, creating a 2D image (or a 3D datacube, if the photons are also binned by their wavelength). The algorithm is implemented on the density field directly: no gridding of the field is required, allowing the density field to be described to an identical level of accuracy as the simulations that generated it. Some applications of the method to star and planet formation simulations are presented to illustrate the advantages of this new technique, and suggestions as to how this framework could support a Radiative Equilibrium algorithm are also given as an indication for ...

Energy Technology Data Exchange (ETDEWEB)

A new method for analysis and design of smoothing reactances utilising two-dimensional planar models is presented in this paper. Inductance and magnetic flux density are calculated, and their results compared with those measured experimentally. The results obtained are good if compared with those measured once the machine have been built. Moreover, the method herein developed is applied to the calculation of air gap lengths in terms of the desired current and inductance. The kind of reactances studied presents windings in both limbs and air gaps in the four corners (joint of limbs and yokes). The main contribution of this paper is the presentation of a method of industrial application, to be easily developed, with a very important reduction in the time of machine calculation (due to the decrease in the number of nodes and elements compared with the three-dimensional model) for the determination of the air gap length in smoothing reactances. (orig.)

British Library Electronic Table of Contents (United Kingdom)

The gastrointestinal (GI) tract is an important target organ for the toxicity of xenobiotics. The toxic effects of xenobiotics on this complex, heterogeneous structure have been difficult to model in vitro and have traditionally been assessed in vivo. The explant culture of GI tissue offers an alternative approach. Historically, the organotypic culture of the GI tract proved far more challenging than the culture of other tissues, and it was not until the late 1960s that Browning and Trier described the means by which intestinal tissues could be successfully cultured. This breakthrough provided a tool researchers could utilise, and adapt, to investigate topics such as the pathogenesis of inflammatory intestinal diseases, the effect of growth factors and cytokines on intestinal proliferation...

Energy Technology Data Exchange (ETDEWEB)

Considerable effort worldwide has been put into trying to find the best way to utilise the large amount of energy that we put into our dustbins every day. One of the problems encountered is that the waste collection systems tend to gather together in one place between 400 and 1000 t of the stuff everyday and since it is possible to extract rather more than 2 MW from each tonne, that is a lot of energy for which to find a market. In continental European cities, especially Germany, and Sweden with most of the population living in apartment blocks, and with colder winters than the UK, district heating provides a suitable market. With its milder winters, more diverse housing and cheap gas the UK is not such a fertile ground for district heating. But since the passing of the Energy Act in 1984, there is a steady market in electricity generation with the advantage that the purchase tariffs are published so that income can be accurately calculated.

Science.gov (United States)

Course website from Cambridge on ceramic materials. This site contains eight lectures in PDF format (Adobe Reader required), two question sheets, five practicals (including answers), digital movies and further useful links. "There is a strong relationship between the structure of a material and its physical properties. The properties of a material whether mechanical, electrical, optical or magnetic, determine how it can be used in practical applications. In this course, the focus is on the structure / property relationship for ionic materials with electrical properties utilised in various transducer devices. The materials considered include perovskites, which have special polarisation properties exploited in ferroelectric, pyroelectric and piezoelectric devices. Other oxides, such as zirconia, have structures permitting rapid diffusion of ions, making them suitable for use in sensors, fuel cells and batteries. The scientific principles underlying the properties of ...

CERN Document Server

In 2008 the German National Analysis Facility (NAF) at DESY was established. It is attached to and builds on top of DESY Grid infrastructure. The facility is designed to provide the best possible analysis infrastructure for high energy particle physics of the ATLAS, CMS, LHCb and ILC experiments. The Grid and local infrastructure of the NAF is reviewed with a focus on the ATLAS part. Both parts include large scale storage and a batch system. Emphasis is put on ATLAS specific customisation and utilisation of the NAF. This refers not only to the NAF components but also to the di erent components of the ATLAS analysis framework. Experience from operating and supporting ATLAS users on the NAF is presented in this paper. The ATLAS usage of the di erent components are shown including some typical use cases of user analysis. Finally, the question is addressed, if the design of the NAF meets the ATLAS expectations for effcient data analysis in the era of LHC data taking.

UK PubMed Central (United Kingdom)

Using a ligature-induced model in type-2 Zucker diabetic fatty (ZDF) rat and normoglycemic littermates, we investigated whether diabetes primarily affects periodontitis by enhancing bone loss...Full Text Available

Science.gov (United States)

Feasibility of depositing continuous films of nano-porous alumino-silicates, primarily zeolites and MCM-41, on metallic and non-metallic substrates was examined with an aim to develop membranes for separation of gaseous mixtures and also for application as hydrogen storage material. Mesoporous silica was deposited in-side the pores of these nano-porous disks with an aim to develop membranes for selective separations. Our study involves supported zeolite film growth on substrates using in-situ hydrothermal synthesis. Faujasite, Silicalite and Mesoporous silica have been grown on various metallic and non-metallic supports. Metallic substrates used for film growth included anodized titanium, sodium hydroxide treated Titanium, Anodized aluminum, and sintered copper. A non-metallic substrate used was nano-porous aluminum oxide. Zeolite film growth was characterized using Scanning Electron Microscope (AMRAY 1820) and High ...

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

Neopentane, because of its unique structural features, was found to be a useful probe for the assay of the acidity of various zeolites. The C-C bond was attacked by catalyst protons yielding CH/sub 4/ and the isobutyl carbenium ion in equal quantities. The latter either decomposed to produce isobutene or underwent secondary reactions. New avenues for reaction were opened with isobutane. The reaction of the Bronsted protons with the tertiary CH bonds produced H/sub 2/ and the same isobutyl carbenium ion. Hydride ion transfer of the same tertiary hydrogen to existing carbenium ions also occurred and the results showed that about half of the reaction was carried by this pathway. As with Neopentane, the C-C bond could also be attacked yielding the sec-propyl carbenium ion. These tools are being further developed.

Science.gov (United States)

Within the framework of the cluster approach and the semiempirical SCF MO LCAO method in the CNDO/BW valence approximation, possible pathways have been compared for the dehydroxylation of aluminosilicate systems. It has been shown that dehydroxylation as a result of splitting of a water molecule from an acidic bridge hydroxyl group and a more basic terminal group Al-OH is the most energyfavorable. Apparently, such a dehydroxylation pathway is primarily characteristic for amorphous aluminosilicates. Typical of crystalline aluminosilicates at moderate heat-treating temperature is dehydroxylation through splitting of a water molecule from an acidic bridge hydroxyl group and a neutral Si-OH group; at higher temperatures, there is a possible pathway of dehydroxylation of highsilica zeolites as a result of condensation of two acidic surface hydroxyls.

Energy Technology Data Exchange (ETDEWEB)

The invention is regeneration and recirculation of nitrogen oxides in the exhaust gas of a nitric acid plant without using any material current and heat energy other than that generated in the process of producing nitric acid. Nitrogen oxide is recovered by at least two adsorbers each containing an acid resistant zeolite molecular sieve and operating in an alternate heat cycle; adsorption occurring at 20-40 degrees C and regeneration at 300-350 degrees C. The hot gas exiting from the oxidation U used in the production of nitric acid is used to regenerate the adsorbers and the nitrogen oxides set free during the said regeneration are introduced into the main feed stream of the nitric acid plant. In the final stage of the regeneration the adsorbers are cooled by rinsing them with exhaust gas or air at a temperature of 20-40 degrees C.

Energy Technology Data Exchange (ETDEWEB)

This paper is a review concerning the application of Nuclear Analytical Techniques in the Cuban sugar industry. The most complete elemental composition of final molasses (34 elements) and natural zeolites (38) this last one employed as an auxiliary agent in sugar technological processe4s has been performed by means of instrumental Neutron Activation Analysis (INAA) and X-Ray Fluorescence Analysis (XRFA). The trace elemental sugar cane soill-plant relationship and elemental composition of different types of Cuban sugar (raw, blanco-directo and refine) were also studied. As a result, valuable information referred to the possibilities of using these products in animal and human foodstuff so as in the other applications are given. (author). 34 refs., 6 figs., 1 tab.

Energy Technology Data Exchange (ETDEWEB)

Counter-current regeneration of 2-stage sodium zeolite softeners has been employed in reducing hardness leakage level of steamflooding water to less than 1 ppm when raw water contains as much as 5,000 ppm of the total dissolved solids. Hardness leakage is caused by sodium displacement of calcium and magnesium from the bottom of the exchanger bed. This study presents nomographs providing for rapid calculations to be made, for which a convenient operational mode does not already exist. The nomographs relate the hardness leakage as a function of salt quality and influent water quality and present solutions for predicting the leakage level, salt quality requirement or the treatability of raw water required for steamflooding projects.

Energy Technology Data Exchange (ETDEWEB)

Very high cobalt catalysts have been prepared on steamed and acid-washed y zeolite. These catalysts are very active. Some of them have proven to be very stable. Additionally, if provisions are made to control the temperature build up on the catalyst bed, low methane selectivities result. Additional work is indicated, for instance, perhaps even higher activity catalysts can result from higher levels of cobalt or changes in the catalyst preparation procedure. Since the issue of whether small amounts of ruthenium can promote the catalyst is not completely resolved, catalyst preparation procedure experiments should continue with ruthenium vs. ruthenium-free catalysts. For instance, different methods of impregnation and/or activation should be investigated.

International Nuclear Information System (INIS)

By the use of thermoluminescence (TL) technique we have investigated the effects of gamma irradiation on the TL response of pulverised natural zircon (ZrSiO_4) crystals from the Jos Plateau area of Nigeria. Samples of the mineral that have been previously annealed were artificially irradiated to moderate gamma doses ranging from 0.7 to 4.9 Gy using "6"0Co gamma-source of the CERD. The natural TL glow curve of the sample showed a broad peak around 250 deg. C, the peak was however, found to be completely erased following heat treatment for 2 h at 400 deg. C. The TL glow curves of the artificially irradiated samples showed two overlapping glow peaks at about 112 deg. C (peak I) and at 156 deg. C (peak II) within the dose range utilised. We note that the natural TL peak appears to be different from the two observed in the artificially irradiated sample. The TL response with dose was investigated for the two glow peaks found in the artificially irradiated sample and in ...

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Norwegian Open Research Archives (NORA)

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Science.gov (United States)

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KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

Short communication

KoreaScience (Korea)

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Science.gov (United States)

In 1977 and 1978, workers at Idaho National Engineering Laboratory (INEL) developed and tested a process for the regeneration and reuse of silver mordenite, AgZ, used to trap iodine from the dissolver off-gas stream of a nuclear fuel reprocessing plant. We were requested by the Airborne Waste Management Program Office of the Department of Energy to perform a confirmatory recycle study using repeated loadings at about 150/sup 0/C with elemental iodine, each followed by a drying step at 300/sup 0/C, then by iodine removal using elemental hydrogen at 500/sup 0/C. The results of our study show that AgZ can be recycled. There was considerable difficulty in stripping the iodine at 500/sup 0/C.; however, this step went reasonably well at 550/sup 0/C or slightly higher, with no apparent loss in the iodine-loading capacity of the AgZ. Large releases of elemental iodine occurred during the drying stage and the early part of the stripping stage. Lead zeolite, which was ...

Energy Technology Data Exchange (ETDEWEB)

The diffusion of methane confined in nano-porous carbon aerogel with the average pore size 48 {angstrom} and porosity 60% was investigated as a function of pressure at T = 298 K using quasi-elastic neutron scattering (QENS). The diffusivity of methane shows a clear effect of confinement: it is about two orders of magnitude lower than in bulk at the same thermodynamic conditions and is close to the diffusivity of liquid methane at 100 K (i.e. {approx} 90 K below the liquid-gas critical temperature T{sub C} {approx} 191 K). The diffusion coefficient (D) of methane initially increases with pressure by a factor of {approx}2.5 from 3.47 {+-} 0.41 x 10{sup -10} m{sup 2} s{sup -1} at 0.482 MPa to D = 8.55 {+-} 0.33 x 10{sup -10} m{sup 2} s{sup -1} at 2.75 MPa and starts to decrease at higher pressures. An explanation of the observed non-monotonic behavior of the diffusivity in the confined fluid is based on the results of small-angle neutron scattering experiments of the phase behavior of ...

Energy Technology Data Exchange (ETDEWEB)

The preparation and performance of membranes for application to hydrogen separation from coal-derived gas is described. The membrane material investigated was dense amorphous silica deposited on a suitable support by chemical vapor deposition (CVD). Two types of support materials were pursued. One type consisted of a two-layer composite, zeolite silicalite/{alpha}-Al{sub 2}O{sub 3}, in the form of tubes approximately 0.7 cm in diameter. The other type was porous glass tubes of diameter below 0.2 cm. The first type of support was prepared starting from {alpha}-Al{sub 2}O{sub 3} tubes of 1{micro}m mean pore diameter and growing by hydrothermal reaction a zeolite silicalite layer inside the pores of the alumina at the OD side. After calcination to remove the organic template used in the hydrothermal reaction, CVD was carried out to deposit the final silica layer. CVD was carried out by alternating exposure of the surface with silicon tetrachloride ...

Energy Technology Data Exchange (ETDEWEB)

To assess whether ring enhancements of liver metastases on Mn-DPDP enhanced, early MR images were well visualized on delayed images, as compared with those of hepatocellular carcinomas (HCC), and to investigate the detection accuracy and conspicuity of each tumor. Twenty patients with liver metastases and 15 with HCC were studied by Mn-DPDP enhanced, T1-weighted MR images. Peripheral ring enhancement and conspicuity were investigated. Differences in detection accuracy and frequency of ring enhancement in liver metastases and HCC were assessed. In liver metastases (n= 69), 44 cases (63.8%) without ring enhancement and 25 (36.2%) with were noted on early images. Sixteen cases (23.2%) without ring enhancement, 38 (55.1%) with ring enhancement similar to the early images, and 15 (21.7%) with prominent ring ...

Energy Technology Data Exchange (ETDEWEB)

The urban zone needs clean air to assure public health. To achieve this goal several filter samples were collected in different sites in Algiers city. Toxic elements such as: Na, Mg, Cl, Sc, Cr, Ti, V, Fe, Co, Cu, Zn, Se, Br, Ag, Sb, Ce, La, Hf, Ta and Hg have been measured in the filters using neutron activation analysis technique. Irradiation of filter samples and standards were carried out in Es-Salem reactor. The experimental procedure and the results are discussed. We noted during this work that the upper limit values for suspended dusts and the high concentrations for some toxic elements found are due to the weather conditions and intense road traffic around collecting sites. (authors)

Energy Technology Data Exchange (ETDEWEB)

Geothermal energy pile foundations are an alternative energy source for heating and cooling needs. Utilising this source of energy has great potential due to the environmental, economic and social benefits. This paper looks at an extensive amount of literature on the technology behind the system including the overall process, primary considerations for each of the main components including latest developments as well as design implications such as the integration of ground energy systems into structural piles of buildings. Environmental considerations including performance-dependent parameters of the subsurface are described. Main parameters include thermal conductivity, thermal diffusivity, specific heat capacity and moisture content. Temperature and groundwater effects are also discussed and design considerations are provided. Mathematical models are available to aid in the design of these systems but there are various other issues and complex parameters that ...

Energy Technology Data Exchange (ETDEWEB)

During the next 100 years, the mean annual temperature is expected to be 1-6 deg C higher than at present. It is also expected to be accompanied by a lengthening of the thermal growing season and increased precipitation. Consequently, climatic change will increase the uncertainty of the management of forest ecosystems in the future. In this context, this research project aimed to outline the ecological and silvicultural implications of climatic change with regard to (1) how the expected climatic change might modify the functioning and structure of the boreal forest ecosystem, and (2) how the silvicultural management of the forest ecosystem should be modified in order to maintain sustainable forest yield under changing climatic conditions. The experimental component of the project concerned first the effect that elevating temperature and elevating concentration of atmospheric carbon have on the ontogenetic development of Scots pine (Pinus sylvestris L) and on the subsequent increase in ...

Science.gov (United States)

Peer assessment provides a powerful avenue for students to receive feedback on their learning. Although student perceptions of peer assessment have been studied extensively in higher education, little qualitative research has been undertaken with medical students in problem-based learning (PBL) curricula. A qualitative study of students' attitudes to, and perceptions of, peer assessment was undertaken within the framework of a larger study of metacognition with first-year medical students at the University of Queensland. A highly structured format for provision of feedback was utilised in the study design. Many recommendations from the higher education literature on optimal implementation of peer-assessment procedures were put into practice. Results indicated the existence of six main themes: (1) increased responsibility for others, (2) improved learning, (3) lack of relevancy, (4) challenges, (5) discomfort, and (6) effects on the PBL process. Five of these themes ...

Energy Technology Data Exchange (ETDEWEB)

The deposition of platinum on various carbon blacks was carried out by forming active functional groups on the surface of the carbon support, and exchanging these active groups with different platinum complexes. Using H{sub 2}PtCl{sub 6} solution, an impregnation rather than an exchange takes place. However, using divalent platinum complexes [Pt(NH{sub 3}){sub 4}]{sup 2+}, a fast exchange takes place which leads to extremely small platinum particles highly dispersed on the surface of carbon black. A comparison of the catalytic activities of platinum supported on various carbon blacks was also carried out. The performances of PEFC (Polymer Electrolyte Fuel Cell) based on the process of the ion exchange are reported. (authors) 3 refs.

Energy Technology Data Exchange (ETDEWEB)

The project was designed to quantify the impacts of longwall mine subsidence (LWMS) on the production and quality of agricultural vegetated environments. This project utilised a variety of traditional ground based sampling techniques including biomass harvests and estimates, leaf area index (LAI), pasture height, species composition and soil sampling along with proximal sensor data capture using a Crop Circle{trademark} and an EM38. Satellite imagery was collected using the Quickbird satellite and the high resolution imagery was used to monitor large areas of LWMS affected areas and adjacent un-mined land. Two landscapes were investigated using a whole of mine site technique including remote sensing, ground survey and traditional agricultural monitoring methods. The landscapes were at the Kestrel site in Emerald, QLD including a forage sorghum and an improved pasture and at Beltana in the Hunter Valley, NSW including an irrigated lucerne pasture and an unimproved ...

Energy Technology Data Exchange (ETDEWEB)

The application of fossil fuels and the simultaneous dependency on fuel imports can only be decreased through consequent utilisation of efficient hydro power which is the most efficient way to avoid CO{sub 2} emissions. Only some decades ago hydro power plants were buildings erected according to met technical demands. In the 1990s rethinking started and the new designs took into account ecology and architecture. Maintenance and/or improvement of ecological efficiency play a decisive role. Experts of ecology and environmental protection of different faculties are involved right from the beginning when planning starts in order to obtain a maximum of nature compatibility and to develop efficient ecological accompanying and compensating measures. Landscape is being recultivated sustainably during construction activities in order to offer biota optimum conditions of living. Devices supporting fish migration are state of the art and designed in such a way that even small ...

Energy Technology Data Exchange (ETDEWEB)

Freezing and thaw have an effect on soils, and the effect of the freeze-thaw cycle on soil covers used in the control of acid mine drainage was discussed in this poster presentation. The purpose of soil covers in cases involving acid mine drainage (AMD) is to reduce the exposure of tailings to oxygen which cause AMD. The effect of this freezing-thaw cycle on soft materials used in soil covers with capillary effect was studied. Some laboratory experiments were conducted to evaluate the properties of the moisture retention layer. The preliminary results were presented. The results indicated that the freeze-thaw cycle might affect the performance of soil covers in the long term, depending on the type of materials selected. Further research is undergoing. 26 figs.

British Library Electronic Table of Contents (United Kingdom)

Summary Reactive extrusion was utilised for starch/poly(butylene adipate co-terephthalate) (PBAT) blown film production, using maleic anhydride (MA) and citric acid (CA), alone or combined, as compatibilisers. These compounds (2% w/w) were added to the starch/PBAT (55:45) mixture after dispersion on glycerol. More rigid films, with greater tensile strength (9.82--0.45-MPa), were produced when 2.0% CA was used. The opposite, little homogeneity and poor tensile strength (0.77--0.12-MPa) and elongation (2.67--0.67%) were found in films produced using 2.0% MA. Barrier properties to water vapour were improved by compatibilisers. FTIR analysis showed that CA and MA were able to promote esterification/transesterification reactions. Blends containing CA also showed better phase compatibilisation i...

Energy Technology Data Exchange (ETDEWEB)

Many countries which do not produce oil are rich with other sources of energy that are not fully utilised, such as tar sand, oil shale and olive cake. Limited previous work was done on producing carbonaceous matter and separating volatile matter from combinations of tar sand, oil shale and olive cake. In this study, a process is designed and tested to produce carbonaceous matter from combinations of three materials mentioned above. Results indicate that the process is successful in producing carbonaceous matter. The minimum temperatures to achieve complete carbonisation was found to be 500degC for a minimum heating time of 1.5h. Carbonised materials were tested for their calorific values, which indicated a successful carbonisation process. The proposed process can be scaled up and automated, and is expected to be economically feasible. Moreover, the process allows for control of unwanted exiting polluting gases and volatile matter and therefore is environmentally ...

International Nuclear Information System (INIS)

Accurate modeling of the enhanced diffusion of boron during rapid thermal annealing has been accomplished by incorporating the effects of extended defect formation and annealing on enhanced diffusion into a multizone, semiempirical model. The multizone model divides the implant profile into three zones defining regions of different defects and diffusion enhancements. The model also contains the initial enhanced diffusion and the transient diffusion effects associated with the dissolution of defect clusters and the annealing of extended defects, respectively. The saturation time for transient-enhanced diffusion contains an exponential function of implant dose in order to model the increase in point defect generated with higher implant dose. As a result, the model accurately simulates the boron diffusion profile over a wide range of implant doses and also shows the immobile boron peak ...

UK PubMed Central (United Kingdom)

A critical research priority for our field is to develop treatments that enhance cognitive functioning in schizophrenia and thereby attenuate the functional losses associated with the illness. In this...Full Text Available

UK PubMed Central (United Kingdom)

Pooling and synthesizing signals across different senses often enhances responses to the event from which they are derived. Here we examine whether multisensory response enhancements are attributable...Full Text Available

UK PubMed Central (United Kingdom)

Convection-enhanced delivery (CED) has emerged as a promising method of targeted drug-delivery for treating central nervous system (CNS) disorders, but the influence of brain structure on infusate...Full Text Available

Science.gov (United States)

This report results from a contract tasking Eindhoven University of Technology as follows: The contractor will investigate the plasma treatment of surfaces and plasma enhanced deposition using EUT's cascade arc source as the basis for this effort.

Science.gov (United States)

Established Investigators (K18) (PAR-09-090) NIH: Career Enhancement Award for Stem Cell Research (K18) (PA-09-110) NIDCD: NIDCD Research Career Enhancement Award for Established...

UK PubMed Central (United Kingdom)

BackgroundPolyadenylation of RNA has a decisive influence on RNA stability. Depending on the organisms or subcellular compartment, it either enhances transcript stability or targets...Full Text Available

UK PubMed Central (United Kingdom)

AIM: To improve the diagnosis of heterotopic pancreas by the use of contrast-enhanced computed tomography (CT) imaging and CT virtual endoscopy (CTVE).METHODS: A total of six patients with heterotopic...Full Text Available

UK PubMed Central (United Kingdom)

PurposeA major obstacle in glioblastoma (GBM) therapy is the restrictive nature of the blood-brain barrier (BBB). Convection-enhanced delivery (CED) is a novel method...Full Text Available

Science.gov (United States)

Our research in the general area of acid catalysis involves the characterization of solid acidity and the corresponding assessment of catalytic performance of acidic materials. Acid characterization studies are required to provide essential information about the type of acid site (i.e., Lewis versus Bronsted), the strength of the sites, and the mobility of molecules adsorbed on the acid sites. An accurate measure of acid strength is given by the heat of adsorption of a basic probe molecule on the acid site. A thermodynamic representation of the mobility of adsorbed species on these sites is given by the entropy of adsorption. Important techniques used in these acid site characterization studies include microcalorimetry, thermogravimetric measurements, temperature programmed desorption, infrared spectroscopy and solid state nuclear magnetic resonance. The combination of these acid site characterization studies with reaction kinetics measurements of selected catalytic processes allows ...

Science.gov (United States)

Catalytic reactions of 3-methylpentane and 2,3-dimethylbutane on HY, amorphous silica-alumina, and HZSM-5 have been studied at 500{degree}C. Both kinetic phenomena and product selectivities have been reported. Cracking reactions an HZSM-5 can be attributed to initiation through protonation occurring at Bronsted sites. Bimolecular processes leading to chain reaction via hydride transfer are restricted within the narrow pore pentasil zeolite. On HY and amorphous silica-alumina, initiation of cracking also occurs at Bronsted sited. No direct evidence was found for participation of Lewis acid sites on the catalyst framework itself. Following initiation, reactions on these catalysts are accelerated through a chain process occurring at Lewis sites generated by adsorption of product olefins at Bronsted sites. The resulting change in the dominant cracking mechanism is reflected in the product selectivity, illustrated here by a falling off in formation of molecular hydrogen ...

Science.gov (United States)

A pyrochemical partitioning process has been conceptually designed so that the transmutation of spent LWR fuels in PEACER can produce mainly low-level waste (Class C waste) for near-surface burial. Chloride salt technology developed for IFR has been employed as the baseline. Electrorefining, reductive extraction and salt recycling steps are used to construct overall flowsheet in order to support PEACER operation. The decontamination factor for transuranic elements was estimated based on both thermodynamic models and reported experimental data. It is expected that overall decontamination factor can be as high as 10{sup 5} for transuranic elements. Final wastes from pyrochemical processing for PEACER are noble metals, alkaline earth metal, and lanthanides. The final wastes are stabilized by mixing with zeolite and glass-frits such that concentration limit for class C waste can be met. The volume of Class C waste is estimated to be small enough to make PEACER concept ...

International Nuclear Information System (INIS)

This paper demonstrates that a commercial-scale facility for encapsulating krypton-85 in zeolite-5A or glass at a 2000 MTHM per year nuclear fuel reprocessing plant can be designed to contain fragments and the 340 to 850 kCi krypton-85 inventory from an assumed catastrophic failure of the high pressure vessel. The vessel failure was assumed as a worst case and was not based on a detailed design evaluation or operating experience. The process design is based on existing commercial hot isostatic pressing technology operated at up to 40 times the scale required for krypton encapsulation. From the calculated process gas inventory in the pressure vessel and vessel design, the maximum explosive energy of 8.4 kg TNT and resulting vessel plug and fragment velocities were calculated. The facility Containment Cell housing the high pressure vessel was designed to contain the gases, fragments, and the shock wave energy calculated for a hypothetical vessel failure. The Access ...

Environmental Research Database

ObjectivesThe overall aim of this work is to use an in-situ FTIR probe to investigate selected heterogeneous catalysts in industrially relevant organic reactions. This approach will be broadly applicable to the UK fine chemical manufacturing base.~%~~%~The project has the following specific objectives:~%~~%~- To demonstrate and develop the use of an in-situ FTIR probe in a batch reactor at elevated temperatures (eg greater than 100 deg C) to monitor reactant usage and product formation.~%~~%~- To validat [continued...]DescriptionThis proposal concerns the in-situ study of catalytic processes and reaction kinetics. The catalysts concerned are microporous materials, such as, zeolites, containing pores and cavities of molecular dimensions. These catalysts constitute crystal reactors on a nanometer scale that are selective on a size and shape basis for organic molecules used in this ...

Science.gov (United States)

... Originator-supplied keywords include: Turbulators, Heat transfer augmentation, Enhancement, Fire tube boilers. (Author). ...

Science.gov (United States)

Seven papers were presented at the meeting. A separate abstract was prepared for each paper. (LCL)

International Nuclear Information System (INIS)

This paper describes Z-contrast scanning transmission electron microscopy used to study the connection between dopant precipitation and phase transformation in high dose In"+ and Sb"+ implanted Si. In the case of In, the observations confirm a heterogeneous nucleation model. Images of the precursor precipitates give the first measurement of the diffusion coefficient in amorphous Si, with an enhancement of 10"7 over tracer crystalline values. With Sb"+ implants enhanced homogeneous nucleation is observed. The connection between these results and the transient enhanced diffusion observed in crystallized Si is discussed.

International Nuclear Information System (INIS)

Japanese ... Authors Kuno, Yusuke; Esaka, Konomi (Tokyo Univ., Graduate School of Engineering, Tokyo (Japan))

Science.gov (United States)

... The realization of directional audio technology in the cockpit may reduce visual workload, enhance the presentation of flight and threat information ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

This report describes work performed by MTC Technologies (MTCT) for NASA Glenn Research Center (GRC)

Science.gov (United States)

... Uninterrupted access to and use of critical infrastructure in the Arabian Gulf region are key to the successful prosecution of the Global War on Terror ...

International Nuclear Information System (INIS)

First results on the effects of strain on transient enhanced diffusion and deactivation of As-implanted ultrashallow junctions are presented. A significant effect of strain on the magnitude and timescale of transient enhanced diffusion is observed, which is consistent with the stabilization of interstitial-type defects by tensile strain. Our results show no significant impact of strain on As electrical activity during the deactivation timescale accessed in this study.

International Nuclear Information System (INIS)

The transient enhanced diffusion in crystalline silicon implanted with dopants ad followed by high temperature annealing to activate the dopants is introduced. The physical mechanisms of transient enhanced dopant diffusion are then reviewed together with a short introduction to the proposed suppressing methods. Finally, the perspectives with using high energy heavy ions in this field are briefly discussed

International Nuclear Information System (INIS)

Transient enhanced diffusion in boron-implanted silicon is interpreted as being due to the fact that during rapid thermal annealing a relaxation process takes place, associated with quasi-chemical reactions including defects. A simple analytical model makes it possible to describe the annealing mechanism on a microscopic scale in terms of reaction-diffusion processes. The measured dependences of the boron diffusion coefficient of the enhanced diffusion on time, temperature and implantation energy are satisfactorily explained. (author).

Energy Technology Data Exchange (ETDEWEB)

Reducing implant energy is an effective way to eliminate transient enhanced diffusion (TED) due to excess interstitials from the implant. It is shown that TED from a fixed Si dose implanted at energies from 0.5 to 20 keV into boron doping-superlattices decreases linearly with decreasing Si ion range, virtually disappearing at sub-keV energies. However, for sub-keV B implants diffusion remains enhanced and x{sub j} is limited to {ge} 100 nm at 1,050 C. The authors term this enhancement, which arises in the presence of B atomic concentrations at the surface of {approx} 6%, Boron-Enhanced-Diffusion (BED).

International Nuclear Information System (INIS)

To analyze the enhancement patterns and morphology of peripheral cholangiocar-cinomas (CCs), as seen on three-phase helical CT. Three-phase helical CT scans of 25 cases of 24 patients with pathologically-proven CCs were retrospectively reviewed. After intravenous administration of contrast media, scans of the hepatic arterial phase (HAP) were obtained at 30 seconds, of the portal venous phase (PVP) at 70 seconds, and of the delayed phase (DP) at 3 minutes. Linear, dense, marginal enhancement was seen in 17 CCs (68%), mainly on HAP images (64%) while thick, band-like, peripheral enhancement was seen in 18 (72%), on either PVP (52%) or DP (44%). Internal enhancement was observed in 23 CCs (92%) on PVP (68%) and/or DP (88%), and 19 CCs (76%) among them showed incomplete enhancement of stippled and/or septated patterns. Most (76%) were seen throughout all three phases to be ...

International Nuclear Information System (INIS)

Heat transfer enhancement in a heat exchanger tube by installing a baffle is reported. The effect of baffle size and orientation on the heat transfer enhancement was studied in detail. Three different baffle arrangements were considered. The results show that for the vertical baffle, an increase in the baffle height causes a substantial increase in the Nusselt number but the pressure loss is also very significant. For the inclined baffles, the results show that the Nusselt number enhancement is almost independent of the baffle inclination angle, with the maximum and average Nusselt number 120% and 70% higher than that for the case of no baffle, respectively. For a given baffle geometry, the Nusselt number enhancement is increased by more than a factor of two as the Reynolds number decreased from 20,000 to 5000. Simulations were conducted by introducing another baffle to enhance heat ...

Energy Technology Data Exchange (ETDEWEB)

The thermal and heat transfer characteristics of stearic acid during the solidification processes were investigated experimentally in a vertical annulus energy storage system. The temperature distribution and temperature variations with time at different radial positions during the freezing processes were obtained. The thermal characteristics of the stearic acid, including movement of the solid-liquid interface in the radial direction, and the effects of Reynolds number on the heat transfer parameters were studied. The heat flux was estimated by using a simple approximate model. A new copper fin was designed and fixed to the electrical heating rod to enhance the thermal conductivity of the stearic acid. The results show that the new fin can enhance both the conduction and the natural convection heat transfer of the PCM, and the enhancement factor during solidification is estimated to be as high as 250%. The effect of the ...

Energy Technology Data Exchange (ETDEWEB)

Accurate modeling of the enhanced diffusion of boron during rapid thermal annealing has been accomplished by incorporating the effects of extended defect formation and annealing on enhanced diffusion into a multizone, semiempirical model. The multizone model divides the implant profile into three zones defining regions of different defects and diffusion enhancements. The model also contains the initial enhanced diffusion and the transient diffusion effects associated with the dissolution of defect clusters and the annealing of extended defects, respectively. The saturation time for transient-enhanced diffusion contains an exponential function of implant dose in order to model the increase in point defect generated with higher implant dose. As a result, the model accurately simulates the boron diffusion profile over a wide range of implant doses and also shows the immobile boron peak ...

International Nuclear Information System (INIS)

The author investigates the diffusion and damage-annealing characteristics as a result of boron implantation through a surface oxide into the silicon, a process that is commonly realized in the fabrication of p-n junctions. Defect structures were examined using plan-view and cross-section transmission-electron microscopies. It is shown that recoil-implanted oxygen plays a critical role in determining the above annealing characteristics. For instance, transient-enhanced diffusion of boron, as is widely observed for boron-implanted silicon, does not occur in the case of through-oxide implantation. The initial suppression of the defect-enhanced diffusion lasts for a limited period of time after which enhanced diffusion occurs again. The so-called incubated enhanced diffusion' is characterized as due to recoiled-oxygen precipitation-emitting point defect that enhances boron motion. The ...

Energy Technology Data Exchange (ETDEWEB)

Transient, greatly enhanced diffusion has been observed on annealing solid-phase-epitaxial (SPE) grown Si-Sb alloys. This is shown to be due to a high concentration of interstitials being trapped during SPE regrowth. The migration enthalpy, for diffusion of Sb by an interstitialcy mechanism was measured as 1.8 +/- 0.2 eV. The interstitials eventually condensed into loops, marking the end of the transient. In a SPE grown Si-Bi alloy a similar transient enhanced diffusion was observed, with an activation energy of 2.0 +/- 0.2 eV, but no loops formed. 8 figures, 7 references.

International Nuclear Information System (INIS)

We report investigations of enhancement in material conversion efficiency of KDP for SHG applications. The limitation of conventional technique of growing KDP crystal was overcome in the present work by adopting a growth method to grow KDP directly in type-II phase matching direction. The conventional technique results in #approx#30% of the crystal volume usable for SHG applications whereas the present method has resulted in enhancing it to #approx#90%. The orientation of the element was confirmed by frequency conversion experiment using Nd:YAG laser. The UV-vis transmittance obtained was 92%. The interferometric results show that the crystals have excellent optical homogeneity.

Energy Technology Data Exchange (ETDEWEB)

The authors measured the absorption of CO{sub 2} in alkaline 0.5 M/0.5 M sodium carbonate/bicarbonate buffers containing either saccharose and sodium arsenite or saccharose and formaldehyde. Absorption enhancement increased upon increasing the concentration of either of the catalysts, but the joint action of the two was always less than the sum of their individual effects, the difference being a function of the acidities and concentrations of the catalysts and the pH of the carbonate/bicarbonate buffer solution

International Nuclear Information System (INIS)

Several design options for improved passive circulation flow have been investigated for use in small, modular liquid metal cooled reactors (LMRs). The purpose is to enhance the transition to natural convection cooling following loss of forced circulation flow, reducing thermal transients experienced by the fuel and possibly eliminating the need for emergency pony-motor flow. Design details to minimize pressure drops may also enhance maximum equilibrium power levels possible under natural circulation only.

Science.gov (United States)

... This must be taken a step further in counseling and other feedback and ... Record System Power Point Presentation ,www.armyppt.com/ncoer/6.htm ...

UK PubMed Central (United Kingdom)

In this article, transhumanism is considered to be a quasi‐medical ideology that seeks to promote a variety of therapeutic and human‐enhancing aims. Moderate conceptions are distinguished...Full Text Available

Science.gov (United States)

Page 1. - AERE-' R-7310 THIS DOCUMENT 15 INTENDED FOR PUBLICATION IN THE OPEN LITERATURE. ... Y Page 3. AERE R I 7318 ...

DEFF Research Database (Denmark)

Udgivelsesdato: 2008-null

International Nuclear Information System (INIS)

English Jul 2001 p. 143-144 China Liu Changlong Academia Sinica,

International Nuclear Information System (INIS)

There have been several reports of transient-enhanced diffusion during furnace or rapid thermal annealing of ion-implanted silicon and some reports of no enhancement. In this contribution, the authors show that many of the observed effects can be accounted for by an interstitial trapping mechanism, in which large numbers of Si atoms are trapped by group V dopant atoms in the amorphous material during implantation. These trapped atoms are retained during solid-phase-epitaxial (SPE) growth, but can be released later during thermal processing to give the transient-enhanced diffusion. The authors present a model which can predict the transient effects (or lack of them) for any concentration of Sb, Bi, or As dopants sufficient to amorphize the silicon and any thermal processing technology which relies on SPE growth (furnace, cw laser, or rapid thermal annealing).

Science.gov (United States)

... Materials (PREM) Synopsis of Program: The objective of PREM is to enhance diversity in materials ... careers in materials research.The Partnerships for Research and Education in Materials (PREM ...

UK PubMed Central (United Kingdom)

A single enhancing lesion in the brain parenchyma, also called an inflammatory granuloma, is a frequent neurologic diagnosis. One of the commonest causes of this lesion is human neurocysticercosis,...Full Text Available

DEFF Research Database (Denmark)

Methylisothiazolinone (MI) used alone is a new preservative causing a high prevalence of contact allergy. The eliciting threshold of MI is unknown. The combination of MI and phenoxyethanol enhances the antimicrobial efficacy of MI.

Energy Technology Data Exchange (ETDEWEB)

A 15-nm lithium fluoride (LiF) thin film evaporated on glass substrate is shown to enhance the nucleation of microcrystalline Si grown by plasma enhanced chemical vapour deposition at the amorphous/microcrystalline boundary conditions. The effect is more pronounced at low substrate temperatures, nucleation density being 10 times higher at {approx} 80 {sup o}C. The effect is ascribed to the ionic chemical nature of LiF, the low work function material used in organic electronic devices, and we propose its use for micro patterning crystalline Si regions in otherwise amorphous Si film.

International Science & Technology Center (ISTC)

Development of Portable Normobaric Hypoxia and Pulsed Magnetic Field Firmware System for Enhancement of Radio- and Non-specific Resistance in Workers of Environmentally Hazardous Industries

Science.gov (United States)

... derived and which describes fundamentally flux enhancement across an artificial membrane or skin: Keywords: Transdermal drug delivery system. ...

Science.gov (United States)

... 2008. Characterizing the relative contributions of large vessels to total ocean noise fields: a case study using the Gerry E. Studds Stellwagen Bank ...

Energy Technology Data Exchange (ETDEWEB)

During the recrystallization by solid-phase-epitaxial (SPE) growth of supersaturated silicon alloys, a high concentration of interstitials is trapped. These are released by subsequent heating causing a transient (greatly enhanced) diffusion of the substitutional dopant by an interstitialcy mechanism. The enhancement may be as much as five orders of magnitude over tracer values, and shows an activation energy of only 1.8 +- 0.2 eV. Following the transient, the interstitials condense into loops, allowing an independent estimate to be made of their concentration. From these observations, we propose that during ion implantation, a fraction of the implanted dopants can acquire their natural valency, and retain it as the crystallization interface passes. For group V dopants this creates the trapped interstitials, giving transient enhanced diffusion when they are released by subsequent annealing.

Science.gov (United States)

Sep 3, 2010 ... These higher-quality deformable mirrors will enable diffraction-limited performance for many space-based optical systems such as space-based ...

Science.gov (United States)

... The third series used a correlated parameter covariance matrix derived from a generic database of modeling uncertainty for space structures [5-1 ...

Science.gov (United States)

... High performance concrete doesn't always refer to enhanced strength, as in the case of VHSC. ... Composite Materials VHSC Concrete ...

CERN Document Server

We investigate the chemical and observational implications of repetitive transient dense core formation in molecular clouds. We allow a transient density fluctuation to form and disperse over a period of 1 Myr, tracing its chemical evolution. We then allow the same gas immediately to undergo further such formation and dispersion cycles. The chemistry of the dense gas in subsequent cycles is similar to that of the first, and a limit cycle is reached quickly (2 - 3 cycles). Enhancement of hydrocarbon abundances during a specific period of evolution is the strongest indicator of previous dynamical history. The molecular content of the diffuse background gas in the molecular cloud is expected to be strongly enhanced by the core formation and dispersion process. Such enhancement may remain for as long as 0.5 Myr. The frequency of repetitive core formation should strongly determine the level of background molecular ...

Energy Technology Data Exchange (ETDEWEB)

SIMS measurements revealed that high energy boron-implantation causes transient enhanced diffusion (TED) of a shallow dopant profile due to Si interstitials even for a relatively low dose of {approximately}2E13cm{sup {minus}2}. By systematic analysis, it is found that this anomalous diffusion is most significant in 700--800 C annealing, and it takes place in the initial stage (less than 30 sec for 800 C) of annealing. Moreover, this anomalous diffusion is more considerable than the enhanced diffusion during oxidation (OED) in practical device fabrication processes. It is found that rapid thermal annealing (RTA) at 1,000--1,100 C is effective for suppressing the transient enhanced diffusion and realizing a shallow channel profile for deep sub-micron devices.

Energy Technology Data Exchange (ETDEWEB)

The major goal of this continuation project is to advance the utilization of heat transfer enhancement techniques in commercial heat exchange equipment. Thirteen heat transfer enhancement techniques have been identified as having potential for improving heat transfer coefficients in full-scale industrial equipment. The following tasks are part of this project, which was originally planned for three years: (1) expansion of technology information base; (2) evaluation of performance of enhanced surfaces and inserts; (3) correlation of data for spirally fluted surfaces; (4) study of structured surfaces in pool boiling; and (5) study of structured surface in spray film evaporation.

International Nuclear Information System (INIS)

Iron deficiency did not enhance absorption of plutonium following intragastric gavage of rats. Absorption of plutonium citrate in both control and iron-deficient rats was about 0.03% of the administered dose.

UK PubMed Central (United Kingdom)

Cyanobacteria have become a major model system for analyzing clock phenomena. The temporal program in this organism enhances fitness in rhythmic environments and is truly global—essentially...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The research had as objective the use of the gamma radiation of the Cobalto-60 as quarantine treatment of the medicinal plant, aromatic and seasoning plants dehydrated infested by Lasioderma serricorne and Plodia interpunctella determining the disinfestation doses to attend the criterion in the not emergency of adults of the species in study and analysing through the Chromatography of Thin Layer the effect of the gamma radiation of the cobalto-60 on the active principle of extract dehydrated of Chamomilla recutita, Pimpinella anisum, Origanum vulgare, Cymbopogon citratus, Ocimum basilicum and Thymus vulgaris. The work was developed in the Laboratorio de Inseticidas in the Instituto Biologico in Sao Paulo in the period of August of 2005 the June of 2007. The radiation source used gamma was an experimental irradiator of Cobalto-60, model Gamacell 220, located in the Instituto de Pesquisas Energeticas e Nucleares - IPEN, located in Sao Paulo. In the period of 30 days after the irradiation ...

Energy Technology Data Exchange (ETDEWEB)

The themal neutron sensitivities of SEI and Toshiba FD-P10-7 radiophotoluminescent silver activated metaphosphate glass dosimeters have been measured and studied theoretically. The graphite thermal neutron column attached to the AEEW reactor NESTOR was utilised as a source of thermal neutrons with minimal fast neutron and gamma-ray contamination. Both the neutron removal and gamma correction measurement techniques were applied and these gave consistent results. It was found that the thermal neutron sensitivity of the Toshiba dosimeters is comparable to the most neutron intensitive thermoluminescent materials available. Because of their larger size and higher silver concentration, however, SEI dosimeters are an order of magnitude more neutron sensitive. The neutron sensitivity of FD-7 glass has not been reported previously, whereas in the case of SEI glass, there exists a modest body of previous work on dosimeters of nominally identical composition. The present ...

Science.gov (United States)

The study investigated the impact of the Universal Basic Education (UBE) programme on the phenomenon of female trafficking in South-South Nigeria. To this end, six research questions were raised. These revolved around: (i) resource situation and adequacy of training provided for repatriated trafficked victims in the service provider centre; (ii) efforts in the formal education sector of the UBE to curb female trafficking; and (iii) parents and female students' disposition toward female trafficking. The design of the study was descriptive survey. The sample was 420 female students and their parents as well as 100 teachers in the formal segment of the UBE programme and 130 repatriated trafficked victims in a service provider centre. Four sets of instruments were utilised to generate data for the study. The first was quantitative designed to elicit information on the resource situation of the service provider centre and the adequacy of the training given to the ...

Energy Technology Data Exchange (ETDEWEB)

The intracellular A chromogranin (ACg) is specific in neuroendocrine cells. This work is a contribution to the study of clinical interest of serumal dosage of this protein in a series of patients carrying neuroendocrine tumors (NET). From January `94 to November `96, 143 patients were subjected to OctreoScan scintigraphy and/or to MIBG. In 104 of them a dosage of ACg by RIA method was effectuated. A study of a statistical relation was performed on the rate of ACg and histopathological, clinical and scintigraphic criteria. Analysis of results excluded the patients with abnormal creatininemy; it referred exclusively to the patients the histopathology of whose it was proved. The global results concerning the sensitivity and specificity of ACg are: 68% and 92%, respectively, for a threshold of normality at 100 ng/ml; 65% and/or 100% for a threshold at 110 ng/ml. There is a significant difference between the group of patients with NET (70 patients): 371 {+-} 59 ng/ml and the group of ...

Energy Technology Data Exchange (ETDEWEB)

The impingement of a fluid jet onto a surface has broad applications across many industries. Within the UK nuclear industry, during the final stages of fuel reprocessing, impinging fluid jets are utilised to mobilise settled sludge material within storage tanks and ponds in preparation for transfer and ultimate immobilisation through vitrification. Despite the extensive applications of impinging jets within the nuclear and other industries, the study of two-phase, solid loaded, impinging jets is limited, and generally restricted to computational modelling. Surprisingly, very little fundamental understanding of the turbulence structure within such fluid flows through experimental investigation is found within the literature. The physical modelling of impinging jet systems could successfully serve to aid computer model validation, determine operating requirements, evaluate plant throughput requirements, optimise process operations and support design. Within this ...

Energy Technology Data Exchange (ETDEWEB)

To evaluate and compare MRI-based ovarian morphology in groups of women with polycystic ovary syndrome (PCOS) and controls. All PCOS cases (n = 44) had oligo-amenorrhoea and hyperandrogenism irrespective of ovarian morphology, and fulfilled NIH/Rotterdam diagnostic criteria for PCOS. All control women (n = 40) had normal menses and normoandrogenaemia. All subjects were of white British/Irish origin and pre-menopausal. Group comparisons were based on independent-sample t tests. Polycystic ovarian morphology was defined by at least 12 follicles 2-9 mm in diameter and/or an ovarian volume greater than 10 cm{sup 3}. Ovarian morphology differed significantly in PCOS cases and controls (follicle number geometric mean [SD range] 18.6 [9.9, 35.0] vs 6.6 [3.1, 14.2], unadjusted P = 1.3 x 10{sup -16}; calculated ovarian volume 8.8 cm{sup 3} [5.0, 15.5] vs 5.1 cm{sup 3} [2.5, 10.3], unadjusted P = 3.0 x 10{sup -7}; peripheral follicle location in 55% vs 18% of ovaries, P = 7.9 x 10{sup -6}; ...

International Nuclear Information System (INIS)

In this work, a focused ion beam (FIB) milling process has been developed to fabricate 50 nm Bi nanowire and transistor structures using FEI-200 dual beam FIB system. For the fabrication, 50 nm bismuth film was thermally evaporated through EBL patterned PMMA windows onto SiO_2 substrates with pre-defined contact pads. Bi nanowire widths ranging from 30 nm to 100 nm have been successfully fabricated by milling out unwanted areas using 30 KeV Ga+ ion beam. A single-pixel-line ion beam blanking technique has been utilised to fabricate Bi nanowire as small as 30 nm in diameter and few micrometers long. In order to form good ohmic contacts for sub 50 nm bismuth nanowires, a drill-and-fill process has been developed using FIB to sputter away the surface oxide of bismuth after the in-situ platinum nanowire contacts deposition. To our knowledge, this is the first time a focused ion beam process has been used to fabricate bismuth nanowire. The fabricated Bi nanowires were ...

Energy Technology Data Exchange (ETDEWEB)

The externally fired combined cycle (EFCC) process utilises a high temperature heat exchanger to transfer the heat of a dirty flue gas to a clean working medium. In comparison to other combined cycle concepts, like integrated gasification combined cycle or pressurized pulverized coal combustion, the problems of hot gas cleaning are avoided. The first part of the publication deals with the possible concepts and the efficiency potential of the externally fired combined cycle. The applicability of metallic and ceramic heat exchanger materials are discussed. The second part (BWK 6/02) summarizes the state of the art and presents the basic design of a ceramic heat exchanger. (orig.) [German] Der extern gefeuerte Gasturbinenprozess arbeitet mit einem Waermeuebertrager, um ein Arbeitsmedium auf Gasturbineneintrittstemperatur zu erhitzen. Im Vergleich zu Kombiprozessen mit integrierter Kohlevergasung oder Druckkohlenstaubfeuerung entfaellt damit die Heissgasreinigung. Der ...

Energy Technology Data Exchange (ETDEWEB)

Energy use patterns and utilisation efficiencies in 40 factories producing palm kernel oil (PKO) in southwestern part of Nigeria were studied. The factories were stratified into small, medium and large scale categories based on the mode of operations and production capacities. Questionnaires were administered on the factories to obtain historical data on petrol, diesel and electricity consumption and PKO production outputs for seven years (1998-2004). Energy use efficiency indicators employed include: energy intensity (EI), energy cost per unit product (EC/P), energy ratio (ER), food energy ratio (FER) and percentage oil yield by weight. Results of the study indicated that averagely, 0.58, 0.53 and 0.74 GJ/10{sup 3} l of PKO were needed in the small, medium and large PKO factories, respectively. The average food energy ratios in the small, medium and large mills are 2.48, 2.53 and 2.14, respectively. The corresponding values of PKO conversion ratio are 0.43, 0.50 ...

Energy Technology Data Exchange (ETDEWEB)

In the field of reactor and fuel cycle physics, particle transport plays and important role. Neutronic design, operation and evaluation calculations of nuclear system make use of large and powerful computer codes. However, current limitations in terms of computer resources make it necessary to introduce simplifications and approximations in order to keep calculation time and cost within reasonable limits. Two different types of methods are available in these codes. The first one is the deterministic method, which is applicable in most practical cases but requires approximations. The other method is the Monte Carlo method, which does not make these approximations but which generally requires exceedingly long running times. The main motivation of this work is to investigate the possibility of a combined use of the two methods in such a way as to retain their advantages while avoiding their drawbacks. Our work has mainly focused on the speed-up of 3-D continuous energy Monte Carlo ...

Energy Technology Data Exchange (ETDEWEB)

In addition to the goal of ensuring waste disposal, thermal waste treatment has always been aimed at the energy-efficient utilisation of wastes. Developments in waste management have led to an increase in high-calorific waste arisings. This is attributable to the use of mechanical-biological waste treatment as well as to segregated waste collection systems. High-calorific wastes are equivalent to fossil fuels in terms of their calorific content. Furthermore, they fulfil the legal requirements for conversion to energy. Another source of high-calorific wastes suitable for conversion to energy can be made available through the segregated disposal of industrial wastes, in many cases at low cost. These high-calorific fractions of varying origin and composition are referred to generically as substitute fuels, a term which implies quality and availability by reference to other fuels. Specifically, the term substitute fuel implies that it can be used for energy production ...

International Nuclear Information System (INIS)

Radiation technology offers a very wide scope for utilisation and commercial exploitation in various field. All over the world, this technology is being favourably considered for different applications like radiation sterilisation of medical products, preservation of food by controlling the physiological processes for extending shelf-life and eradication of microbial and insect pests, radiation processing of polymeric materials and treatment of sewage sludge. Bangladesh Atomic Energy Commission has taken radiation processing programmes in a big way right from its inception. This paper describes the studies carried out by various research groups in Bangladesh Atomic Energy Commission mainly using Cobalt-60 gamma radiation. The investigation covers medical sterilisation, food preservation and development and modification of polymeric materials by gamma radiation. Both food preservation and radiation sterilisation of medical products are now being commercially carried ...

Energy Technology Data Exchange (ETDEWEB)

Colorectal cancer (CRC) is a highly conversed topic, particularly since implementation of screening for CRC is imminent within the U.K. Aims: The aim of this research project was to examine the diagnostic tools currently used within the UK to detect CRC and their impact on the aetiology and epidemiology of CRC. Methodology: The complexity of the research topic lent itself towards a literature review. A systematic approach of researching was therefore adopted to analyse and critically evaluate the reliability and validity of articles. Electronic databases including AMED, Cancerlit, CINHAL, the Cochrane Library, EMBASE, MEDLINE and EBM-Reviews were utilised to provide a wide spectrum of recent and relevant articles. Other research strategies involved looking for books relating to the topics, which were kept to within 6 years of publication to maintain accuracy of information. Selected websites, such as NICE, the Department of Health, NHS websites and Cancer Research ...

Energy Technology Data Exchange (ETDEWEB)

One requirement of a thermophotovoltaic (TPV) radiator is to efficiently emit photons at high temperatures to TPV cells for conversion to electric power. Because many candidate radiator materials with adequate structural properties display low emissivity, coatings or other surface modifications are required for enhancement of emissivity. Six plasma sprayed coatings and one textured surface demonstrated adequate thermal stability and emittance values of 0.8 or greater. Promising attributes of modified surfaces are identified.

International Nuclear Information System (INIS)

The structure of the layers formed on a silver electrode by the adsorption of pyridine, Cl"-, CN"- and SO_4"2"- is discussed. A comparison of the amount of the species adsorbed with their Raman spectra shows that there is no simple relation between the species concentration and the enhancement of the Raman intensity. Furthermore, the inhomogeneity of the layers is shown by Raman microscopy observations. These results lead the authors to propose the formation of a new species stabilized in the colloidal silver layer. The Raman enhancement could be explained by the existence of a resonance effect. (Auth.).

UK PubMed Central (United Kingdom)

In monocytes, sulfatide, a lipid from Mycobacterium tuberculosis, blocked priming for enhanced release of superoxide (O2-) by the macrophage activating factors lipopolysaccharide, gamma interferon,...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A diverse set of digital image-processing applications exists at the Lawrence Livermore National Laboratory. While many of these include some sort of image analysis or restoration, virtually all of them require image-enhancement procedures. In this paper we describe the principal image-processing facility at the Laboratory, followed by a discussion of several of the major image-processing application areas.

International Nuclear Information System (INIS)

Objective: To compare the enhancement pattern of hilar cholangiocarcinoma on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT). Methods: Thirty-two consecutive patients with pathologically proven hilar cholangiocarcinomas were evaluated by both low mechanical index CEUS and CECT. The enhancement feature of the tumor, portal vein infiltration, and lesion conspicuity on them was investigated. Results: In the arterial phase, the numbers of the lesions showing hyperenhancement, isoenhancement, and hypoenhancement, were 14 (43.8%), 14 (43.8%), and 4 (12.6%), on CEUS, and 12 (37.5%), 9 (28.1%), and 11 (34.4%), on CECT (P = 0.162). In portal phase, the numbers of the lesions showing hypoenhancement, isoenhancement, and hyperenhancement were 30 (93.8%), 1 (3.1%), and 1 (3.1%), on CEUS, and 23 (71.9%), 8 (25.0%), and 1 (3.1%), on CECT (P = 0.046). The detection rates ...

UK PubMed Central (United Kingdom)

To determine if the enhanced glycemic response to epinephrine in patients with insulin-dependent diabetes mellitus (IDDM) is the result of increased adrenergic sensitivity per se, increased glucagon...Full Text Available

Science.gov (United States)

The paper discusses recent work on lime enhancement and testing at the bench-scale, followed by evaluation of the more promising sorbents in a pilot plant to develop low cost, retrofittable flue gas cleaning technology specifically the development of highly reactive sorbents. Con...