Coal may be used to generate electrical energy by any of several processes, most of which involve combustion or gasification. Combustion in a coal-fired boiler and power generation using a steam-cycle is the conventional conversion method; however total energy conversion efficiencies for this type of process are only slightly over 30%. Integration of a gas-cycle in the process (combined cycle) may increase the total conversion efficiency to 40%. Conversion processes based on gasification offer efficiencies above 50%. H{sub 2}S is the predominant gaseous contaminant in raw coal gas. This process is concerned with the removal of H{sub 2} from coal gas through an electrochemical membrane technology.
Finasteride, a specific and competitive inhibitor of 5α-reductase enzyme Type 2, inhibits the conversion of testosterone to dihydrotestosterone (DHT). In adults, DHT acts as primary androgen...Full Text Available
Recent research at the laboratory scale by a number of organizations in different countries has shown that with the use of particular types of solvents it is possible to achieve almost complete conversion of coal to liquid products under relatively mild process conditions. This work is reviewed and the conclusions to be drawn from it are summarized.
In seeking ways to reduce emissions from two-stroke locomotive type engines, the Navy has evaluated dual-fuel conversions operating on a compression ignition cycle, using up to 94% natural gas and 6% diesel pilot fuel. The Navy has conducted an evaluation and test program under the direction of Dr. Normnn L. Helgeson, at the Naval Facilities Engineering Service Center in Port Hueneme, California. Of the Navy`s many diesel engines, those installed in its MUSE (mobile utility support equipment) units for temporary electrical power were the first Navy off-road engines to be affected by emissions regulations. Most of the units are powered by the EMD 645 engine, and when burning diesel fuel do not meet the emission requirements in many areas of the country. This paper discusses the changes and results of the conversion and shakedown tests.
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.
The authors report here, for the first time, high frequency testing of a new type of electrochemical double layer capacitor (EDLC), based on carbon aerogels: the Aerocapacitor. Carbon aerogels, are a novel type of carbon foam developed by Lawrence Livermore National Laboratory for military applications. The unique properties of carbon aerogels, high surface area (700 m{sup 2}/g), high density (1g/cc), well controlled pore diameter and high material conductivity (25 S/cm) made it an ideal EDLC electrode material. Using carbon aerogel as the electrode material, the authors have developed Aerocapacitors. These new EDLC`s have a frequency response comparable to that of aluminum electrolytic capacitors and are thus ideally suited to power conversion applications.
A new fabrication process is being developed which significantly improves the efficiency of metal-semiconductor solar cells. The resultant effect, a marked increase in the open-circuit voltage, is produced by the addition of an interfacial layer oxide on the semiconductor. Cells using gold on n-type gallium arsenide have been made in small areas (0.17 sq cm) with conversion efficiencies of 15% in terrestrial sunlight.
The magnetic #beta#-spectrometer of the #pi# #sq root#2 type with 0.07% pulse resolution is used to measure the intensities of interval conversion electrons on L- and M-subshells of 70.45 keV "1"7"7 Ta gamma-transition. The results are analyzed and the values of mixing parameter #sigma#(E2/M1) and penetration parameter #lambda# are obtained.
An economical way to reduce the deleterious effects of titanium, one of the impurities present in metallurgical grade silicon material, is disclosed. By adding copper to approximately the same concentration level of the titanium during the melting process, the conversion efficiency will be restored to about 99.3% of what it would have been if the single crystal silicon had been grown free of titanium impurities.
The nr1 soybean (Glycine max [L.] Merr.) mutant does not contain the two constitutive nitrate reductases, one of which is responsible for enzymic conversion of nitrite to...Full Text Available
Neutron transmutation doping(NTD) for producing ntype silicon semiconductor is based on the conversion of the Si-30 isotope into phosphorus atom by neutron absorption reaction. By using this method, silicon semiconductors with extremely uniform n-type dopant distributions can be produced, and this is the dominant advantage of NTD compared with the conventional chemical doping. HANARO has two vertical holes for NTD, and the commercial NTD service for 5 and 6 inch silicon ingots has been going on at the NTD2 hole. Generally, NTD method is applied to the initially n-type silicon material. But, an initially p-type silicon material can also be used for the production of uniformly doped n-type silicon by using NTD method. Therefore, in this work, we investigated the relationship between the irradiation neutron fluence and the final resistivity of the initially p-type ...
Neutron transmutation doping(NTD) for producing ntype silicon semiconductor is based on the conversion of the Si-30 isotope into phosphorus atom by neutron absorption reaction. By using this method, silicon semiconductors with extremely uniform n-type dopant distributions can be produced, and this is the dominant advantage of NTD compared with the conventional chemical doping. HANARO has two vertical holes for NTD, and the commercial NTD service for 5 and 6 inch silicon ingots has been going on at the NTD2 hole. Generally, NTD method is applied to the initially n-type silicon material. But, an initially p-type silicon material can also be used for the production of uniformly doped n-type silicon by using NTD method. Therefore, in this work, we investigated the relationship between the irradiation neutron fluence and the final resistivity of the initially p-type ...
An oxidative precipitation reaction of rare-earth chlorides in a LiCl-KCl molten salt was successfully carried out by a lab-scale apparatus. The conversion efficiency of the used rare earth chlorides into the insoluble precipitates was increased with the sparging time and temperature and was affected on oxygen sparger type. In the conditions of 700 .deg. C molten salt temperature and above 540min sparging time, the final conversion efficiencies were over 99% for all the experimented rare-earth chlorides. The hydrodynamic characteristics of an oxygen-molten salt two phase flow system are very important for a co-oxidative precipitation of rare earth elements.
An oxidative precipitation reaction of rare-earth chlorides in a LiCl-KCl molten salt was successfully carried out by a lab-scale apparatus. The conversion efficiency of the used rare earth chlorides into the insoluble precipitates was increased with the sparging time and temperature and was affected on oxygen sparger type. In the conditions of 700 .deg. C molten salt temperature and above 540min sparging time, the final conversion efficiencies were over 99% for all the experimented rare-earth chlorides. The hydrodynamic characteristics of an oxygen-molten salt two phase flow system are very important for a co-oxidative precipitation of rare earth elements
This report describes progress during the first year of a three-year project. The objective of the research is to examine new design approaches for achieving very high conversion efficiencies. The program is divided into two areas. The first centers on exploring new thin-film approaches specifically designed for III-V semiconductors. The second area centers on exploring design approaches for achieving high conversion efficiencies without requiring extremely high quality material. Research activities consisted of an experimental study of minority carrier recombination in n-type, metal-organic chemical vapor deposition (MOCVD)-deposited GaAs, an assessment of the minority carrier lifetimes in n-GaAs grown by molecular beam epitaxy, and developing a high-efficiency cell fabrication process.
This report describes progress during the first year of a three-year project. The objective of the research is to examine new design approaches for achieving very high conversion efficiencies. The program is divided into two areas. The first centers on exploring new thin-film approaches specifically designed for III-V semiconductors. The second area centers on exploring design approaches for achieving high conversion efficiencies without requiring extremely high quality material. Research activities consisted of an experimental study of minority carrier recombination in n-type, metal-organic chemical vapor deposition (MOCVD)-deposited GaAs, an assessment of the minority carrier lifetimes in n-GaAs grown by molecular beam epitaxy, and developing a high-efficiency cell fabrication process.
The RECH-1 MTR reactor has been converted from HEU to MEU (45% enrichment) and the decision to a LEU (20% enrichment) conversion was taken some years ago. This LEU conversion decision involved a local fuel development and fabrication based on U{sub 3}Si{sub 2}-Al dispersion fuel, and a fabrication qualification stage that resulted in four fuel elements fully complying with established fabrication standards for this type of fuel. This report-presents relevant points of these four leaders fuel elements fabrication, in particular a fuel plate core homogeneity control development. A summary of the intended in core follow-up studies for the leaders fuel elements is also presented here. (author)
The main sources of energy that might be available in remote low populated areas of Libya are either diesel generating units or wind mills for water pumping. Several problems in the working performance of these two types of energy production may arise due to environmental conditions. Direct conversion of solar energy can replace other ways of energy delivery or production, especially in this country where the solar radiation all year is relatively high. Direct conversion of solar energy is relatively expensive, however the cost of erecting long feeders and supervising them may be much more expensive than the usage of solar systems. This paper investigates the economics associated with either solutions of energy production. A case study is given in detail to supply one of the remote areas with a population of about 250. (author)
The necessary conditions to design the methanol-fueled direct injection diesel engine with a reservoir type glow plug were cleared up from the points of view to prevent the air contamination and to use as an alternative oil for automotives, and as a result the good engine performance and emission characteristics could be obtained under the wide operating condition. The following facts were clarified: It is necessary to arrange the glow plug on the line of atomizing axis near the nozzle hole to ensure the ignitability under a wide operating condition. The reservoir type glow plug which reserves the premixed gas around the glow plug can shorten the ignition delay time and improve the combustion stability and the net thermal efficiency in the light load region. The combustion in the light load region was accelerated, NO{sub x} emission rate was suppressed and moreover, the net thermal efficiency and catalyst conversion rate ...
The consequences of converting a facility from brown coal fuel to gas fuel were analyzed by model simulation. Treated were a district heating plant with an output of 700 TJ/yr and minor local heating sources (stoves) at a density of 1 family house per 100 m"2. Emissions of particulate matter, sulfur dioxide, nitrogen oxides, carbon monoxide, and hydrocarbons before and after the conversion are given for the two types of source. Conversion of a major air pollution source to gas fuel would result in a reduction of the contribution of sulfur dioxide emissions of the order of 10"-"4, of particulate matter and carbon monoxide of the order of 10"-"3, and of hydrocarbons of the order of 10"-"2. The decrease will be lowest for nitrogen oxides, viz. about 40%. Analogous data for local heating sources in towns would be 10"-"5 for sulfur dioxide, 10"-"4 for particulate matter, 10"-"3 for carbon monoxide and hydrocarbons, and roughly ...
The specification describes a semiconductor solar cell and fabrication process therefor wherein a thin N-type gallium arsenide layer is deposited on a larger P-type substrate layer which is selected from the group of III-V ternary compounds consisting of aluminum phosphide antimonide, AlPSb, and aluminum indium phosphide, AlInP. P-type impurities are diffused from the substrate layer into a portion of the thin N-type gallium arsenide layer to form P-type region wherein which defines a PN junction in the thin gallium arsenide layer. Thus, the quantity of gallium arsenide required to provide this PN photovoltaic junction layer in the cell is minimized, and th P-type substrate serves as a high bandgap window layer for the cell. Such high bandgap of this window material is especially well suited for efficiently transmitting the blue spectrum of sunlight to the PN ...
placed on direct energy conversion. This is an advanced technology which is ..... Of the direct energy conversion methods discussed, the only one which may ...
Web portals are nowadays very popular. This type of web sites let users to share information, request advice or help in a particular field, and furthermore allow them to create and extend sites content. Combined with instant messaging systems, used to send messages or files instantaneously to a user or a group of users, and with various kinds of chat programs, which connect two or more individuals simulating a conversation, it is now possible to create "web communities". In this paper we present the opensource tools used to create the "Grid Support Community" of the National Institute for Nuclear Physics in Italy.
The batchwise preparation of molecular sieves for methanol conversion shows some inconsistency in catalytic stability. This is a result mainly of the change of SiO/SUB/2/Al/SUB/2O/SUB/3 in ion exchange to an H-type sieve. The dealumination during ion exchange depends upon crystal size and structural factors, which can be characterised by the cyclohexane adsorption of the raw molecular sieve. A high SiO/SUB/2/Al/SUB/2O/SUB/3 H-molecular sieve can be prepared from a molecular sieve of high adsorption capacity, this leading to a catalyst of higher stability. (4 refs.)
An investigation of the effect of blending of two different coals in various ratios on the hydrogenation reaction was carried out using a red mud-sulphur catalyst. Three Japanese coals and an Australian brown coal were used in the study. The conversion of the blended coals was compared with that obtained with each of the coals alone. A blend of the Yallourn brown coal and Shin-Yubari coal showed a synergism: it is considered that hydroaromatics from the Japanese coal promote the hydrogenation of the Yallourn coal. (The tables and captions in this paper are in English).
Central in the paper are two results on the existence of 'economical' embeddings in a Euclidean space. The first result (Corollary 1.4) states the existence of an embedding with image intersecting the large-dimensional planes in sets of 'controllable' dimension. The second result (Corollary 1.6) proves the existence of maps such that each small-dimensional plane contains 'controllably' many points of the image. Well known results of Noebeling-Pontryagin, Roberts, Hurewicz, Boltyanskii, and Goodsell can be obtained as consequences of these results. Their infinite-dimensional version concerning an embedding in a Hilbert space is also established (Theorem 1.8).
Astatine conversed into cationic form is shown to form stable complex with diethylenetriaminpentacetic acid. Due to this complex astatine joins RN_2 type monoclonal antibodies. More favorable conditions to prepare astatine labelled antibodies are found. Chromatographical analysis and electromigration experiments have shown that astatine is strongly retained in in-vitro biomolecule. Astatine did not escape from the labelled antibodies even in case of urea effect on them. Immune activity of astatine labelled antibodies remained similar in 20 h. 28 refs., 4 figs.
Elemental substitution of Ca by Y was investigated for Ca-#alpha#-SiAlON:Eu yellow phosphors, which is useful for the white light-emitting diode lamps of phosphor conversiontype. Depending on the ratio of the elemental substitution, not only the red shift of emission in wavelength occurred but also the figure of the excitation spectra changed. Their excitation band widths and flatness were discussed. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
Oak Ridge National Laboratory (ORNL) has for over ten years provided materials testing and failure analysis services to various coal conversion and utilization facilities in the United States. ORNL was involved in these types of activities at all four of the major coal liquefaction pilot plants. This paper presents a summary of activities at Wilsonville over the past two and one-half years. Some details of these activities are discussed below. Failure analysis of elastomers, stainless steels, and alloys is discussed. 6 refs., 9 figs., 13 tabs.
Direct electric heating by passing an electrical current directly through a bed of adsorbent may prove to be an efficient means of regenerating activated charcoal in continuous and batch adsorption processes. Obvious advantages of this type of regeneration are its almost complete lack of inertia, which makes it possible to reduce the number and dimensions of the adsorbers, and its highly efficient use of energy due to the small number of steps in the conversion of the energy, as well as the reduction of heat losses involved in warming the structure and making up for losses to the surroundings. The authors consider the kinetics of direct electric heating of a stationary bed of activated charcoal not containing adsorbed substances.
The surface composition and composition near the surface and properties of high-silica zeolites of the TsVK-1 type were studied by XPES, IRS, and low-temperature adsorption of N/sub 2/. It was found that changing the sequence of operations during preparation of the H form of the zeolites results in a different set of acid centers on their surface, caused by migration of cations into the bulk of the zeolites. Migration of elements is also observed during the catalytic reaction of conversion of ethanol.
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...
Aerial deposition of Ni from a refinery in Port Colborne, Ontario, Canada has resulted in the enrichment of 29km2 of land with Ni concentrations exceeding the Canadian Ministry of the Environment's remedial action level of 200mgkg-1. Several studies on these soils have shown that making the soils calcareous was effective at reducing chemically extractable Ni, as well as alleviating Ni phytotoxicity symptoms in vegetable crops grown in the vicinity of the refinery. Conversely, dolomitic limestone additions resulted in increased uptake of Ni in the Ni hyperaccumulator Alyssum murale `Kotodesh', a plant whose use was proposed as a remediation strategy for this area. In this paper we use multiple techniques to directly assess the role soil type and lime treatments play in altering the speciati...
Basic information on photovoltaic conversion technology is provided for those unfamiliar with the field. Various types of photovoltaic products and systems currently available off-the-shelf are described. These include products without batteries, battery chargers, power packages, home electric systems, and partial systems. Procedures are given for designing a photovoltaic system from scratch. A few custom photovoltaic systems are described, and a list is compiled of photovoltaic firms which can provide custom systems. Guidance is offered for deciding whether or not to use photovoltaic products. A variety of installations are described and their performance is appraised by the owners. Information is given on various financial incentives available from state and federal governments. Sources of additional information on photovoltaics are listed. A matrix is provided indicating the sources of various types of photovoltaic ...
For the conversion of thermal energy into electric energy in modern condenser power plants, according to the way of steam generation, two different types of power stations are built: power stations for fossile fuels and nuclear power stations. Also two classes of steam turbines were developed, corresponding to the two power station types, whose steam conditions, by experience and extensive calculations of economy, were determined so that a minimum of power generating cost will result. The two classes, the HMN and the SN series, are composed according to the modular system and designed in such a manner that with a small number of standard components, steam turbines for the power range between 100 and 2,500 MW can be built. (orig.).
Abstract - We have designed, built, and tested a 2-D pixellated thermal neutron detector. The detector is modeled after the MicroMegas-type structure previously published for collider-type experiments. The detector consists of a 4X4 square array of 1 cm 2 pixels each of which is connected to an individual preamplifier-shaper-data acquisition system. The neutron converter is a 10B film on an aluminum substrate. We describe the construction of the detector and the test results utilizing 252Cf sources in Lucite to thermalize the neutrons.Drift electrode (Aluminum) Converter (10B) 3 mm Conversion gap neutron (-900 V)
Coal may be used to generate electrical energy by any of several processes, most of which involve combustion or gasification. Combustion in a coal-fired boiler and power generation using a steam- cycle is the conventional conversion method; however, total energy conversion efficiencies for this type of process are only slightly over 30{percent}. Integration of a gas-cycle in the process (combined cycle) may increase the total conversion efficiency to 40{percent}. Conversion processes based on gasification offer efficiencies above 50{percent}. H{sub 2}S is the predominant gaseous contaminant in raw coal gas. Problems arise due to the corrosive nature of H{sub 2}S on metal components contained in these cycles. Because of this, H{sub 2}S concentrations must be reduced to low levels corresponding to certain power applications. An advanced process for the separation of hydrogen sulfide ...
Conversion electron studies of medium-heavy to heavy nuclear mass systems are important where the internal conversion process begins to dominate over gamma-ray emission. The use of a segmented detector array sensitive to conversion electrons has been used to study multiple conversion electron cascades from nuclear transitions. The application of the silicon array for conversion electron detection (SACRED) for in-beam measurements has successfully been implemented. (orig.). With 2 figs.
In March 2007 in-pile testing of LEU U-Mo full-size IRT type fuel elements was started in the MIR reactor. Four prototype fuel elements for Uzbekistan WWR SM reactor are being tested simultaneously - two of tube type design and two of pin type design. The dismountable irradiation devices were constructed for intermediate reloading and inspection of fuel elements during reactor testing. The objective of the test is to obtain the experimental results for determination of more reliable design and licensing fuel elements for conversion of the WWR SM reactor. The heat power of fuel elements is measured on-line by thermal balance method. The distribution of fission density and burn-up of uranium in the volume of elements are calculated by using the MIR reactor MCU code (Monte-Carlo) model. In this paper the design of fuel elements, the technique, main parameters and preliminary results are described. (author)
A Smarandache quasigroup(loop) is shown to be universal if all its f,g-principal isotopes are Smarandache f,g-principal isotopes. Also, weak Smarandache loops of Bol-Moufang type such as Smarandache: left(right) Bol, Moufang and extra loops are shown to be universal if all their f,g-principal isotopes are Smarandache f,g-principal isotopes. Conversely, it is shown that if these weak Smarandache loops of Bol-Moufang type are universal, then some autotopisms are true in the weak Smarandache sub-loops of the weak Smarandache loops of Bol-Moufang type relative to some Smarandache elements. Futhermore, a Smarandache left(right) inverse property loop in which all its f,g-principal isotopes are Smarandache f,g-principal isotopes is shown to be universal if and only if it is a Smarandache left(right) Bol loop in which all its f,g-principal isotopes are Smarandache f,g-principal isotopes. Also, it is established ...
The detector for retrospective radon exposure measurements is developed. The detector consists of the multilayer package of solid-state nuclear track detectors LR-115 type. Nitrocellulose films works both as {alpha}-particle detector and as absorber decreasing the energy of {alpha}-particles. The uncertainties of implanted {sup 210}Pb measurements by two- and three-layer detectors are assessed in dependence on surface {sup 210}Po activity and gross background activity of the glass. The generalized compartment behavior model of radon decay products in the room atmosphere was developed and verified. It is shown that the most influencing parameters on the value of conversion coefficient from {sup 210}Po surface activity to average radon concentration are aerosol particles concentration, deposition velocity of unattached {sup 218}Po and air exchange rate. It is demonstrated that with the use of additional information on surface to volume room ...
Site-selective spectroscopy fluorescence experiments (emission and excitation) in the near-infrared region associated with the {sup 4}I{sub 15/24}I{sub 11/2} transitions of Er{sup 3+} ions have been successfully used to show the presence of two different Er{sup 3+} centres in the Bi{sub 12}SiO{sub 20} piezoelectric crystal. Green (545-570 nm), red (650-690 nm) and near-infrared (850-890 nm) up-converted emissions have been observed and resolved for each type of centre under excitation up to the {sup 4}{sub I11/2} state. The Stark energy level schemes of the three lower energy states of Er{sup 3+} ions have been determined and compared for both centres, showing two quite different crystalline field environments. The mechanisms responsible for the up-conversion process (excited state absorption and/or energy transfer up-conversion) are also analysed. (author)
Site-selective spectroscopy fluorescence experiments (emission and excitation) in the near-infrared region associated with the "4I_1_5_/_2_4I_1_1_/_2 transitions of Er"3"+ ions have been successfully used to show the presence of two different Er"3"+ centres in the Bi_1_2SiO_2_0 piezoelectric crystal. Green (545-570 nm), red (650-690 nm) and near-infrared (850-890 nm) up-converted emissions have been observed and resolved for each type of centre under excitation up to the "4_I_1_1_/_2 state. The Stark energy level schemes of the three lower energy states of Er"3"+ ions have been determined and compared for both centres, showing two quite different crystalline field environments. The mechanisms responsible for the up-conversion process (excited state absorption and/or energy transfer up-conversion) are also analysed. (author)
A wind turbine is disclosed which permits high energy production over a wide range of wind forces while being protected against climatic hazards. According to the invention, a mast supports an energy recuperator comprising vane-type rotors by means of a frame which is orientable around a vertical axis. An energy conversion device is connected to the recuperator in order to be driven in rotation by the recuperator. The frame is responsive to the aerodynamic force exerted on the recuperator with respect to the mast and to the ground so as to optimize the power collected by the machine. The frame comprises a turret pivoted to the mast about the vertical axis and a structure pivoted to the turret about a horizontal axis of tilting motion. A balance weight maintains the recuperator in the top position when there is no wind. The aerodynamic drag of the recuperator acts in the opposite direction. In consequence, in the event of a high wind, the ...
DOE's program for the conversion of coal to liquid fuels was begun by two of DOE's predecessor agencies: Office of Coal Research (OCR) in 1962, and Bureau of Mines, US Department of the Interior, in the 1930's. Current work is aimed at improved process configurations for both catalytic and non-catalytic processes to provide more attractive processing economics and lower capital investment. The advantage of coal liquefaction is that the entire range of liquid products, especially boiler fuel, distillate fuel oil, and gasoline, can be produced from coal by varying the type of process and operating conditions used in the process. Furthermore, coal-derived liquids have the potential for use as chemical feedstocks. To provide efficient and practical means of utilizing coal resources, DOE is supporting the development of several conversion processes that are currently in the pilot plant stage. DOE, ...
This project is concerned with the structure and function of the unique antenna system found in the green photosynthetic bacteria. The antenna system in these organisms is contained within a vesicle known as a chlorosome, which is attached to the cytoplasmic side of the cell membrane. Additional antenna pigments and reaction centers are contained in integral membrane proteins. Energy absorbed by the bacteriochlorophyll c (BChl c) pigments in the chlorosome is transferred via a ``baseplate`` array of BChl a antenna pigments into the membrane and to the reaction center. This system is similar in some respects to the phycobilisome antenna system found in cyanobacteria and some types of algae, in that a membrane-associated structure absorbs light and transfers it to the membrane where conversion to chemical energy takes place. However, the overall structure, the type of pigments utilized and the nature of the proteins in these ...
The present study analyzes argument in jury deliberations by using the Conversational Argument Coding Scheme (CACS) and the content of juror argument using Subject Matter Argument Assessment (SMAA) (Pettus, 1990). The main purpose is to illustrate how the two coding schemes can complement each other to provide rich yet systematic characterization of argument in jury deliberation. Jury deliberations drawn from In the Jury Room, a televised news series on jury deliberation, are coded and analyzed using CACS and SMAA. The researchers found that using two argument coding schemes is beneficial in learning about the types of arguments jurors make and the subject matter about which they argue. The study results are compared with findings from previous studies of juror argument behavior, suggestin...
The rationale for hybrid fusion-fission reactors is the production of fissile fuel for fission reactors. A new class of reactor, the fission-suppressed hybrid promises unusually good safety features as well as the ability to support 25 light-water reactors of the same nuclear power rating, or even more high-conversion-ratio reactors such as the heavy-water type. One 4000-MW nuclear hybrid can produce 7200 kg of /sup 233/U per year. To obtain good economics, injector efficiency times plasma gain (eta/sub i/Q) should be greater than 2, the wall load should be greater than 1 MW m/sup -2/, and the hybrid should cost less than 6 times the cost of a light-water reactor. Introduction rates for the fission-suppressed hybrid are unusually rapid.
Reference failures, and their increase in affectively negative conditions (known as affective reactivity of speech), are more frequently observed in schizophrenia patients than in normal controls, but no information is available comparing schizophrenia with depression, ie, a mental disorder closely linked to the concept of affective reactivity. To address this gap in the literature, the present study compared 24 schizophrenia inpatients, 21 unipolar depression inpatients and 21 normal controls. Two 10-minute conversational speech samples (1 on negative and 1 on positive memories) were collected from each patient. The transcripts of the audiotaped interviews were analyzed blindly for frequencies of 6 types of referential failures, employing the Communication Disturbances Index, adapted for ...
Mutations in sclerostin function or expression cause sclerosing bone dysplasias, involving decreased antagonism of Wnt/Lrp5 signaling. Conversely, deletion of the VHL tumor suppressor in osteoblasts, which stabilize HIF-a isoforms and thereby enables HIF-a/b-driven gene transcription, increases bone mineral content and cross-sectional area compared to wild-type controls. We examined the influence of cellular hypoxia (1% oxygen) upon sclerostin expression and canonical Wnt signaling. Osteoblasts and osteocytes cultured under hypoxia revealed decreased sclerostin transcript and protein, and increased expression and nuclear localization of activated b-catenin. Similarly, both hypoxia and the hypoxia mimetic DFO increased b-catenin gene reporter activity. Hypoxia and its mimetics increased exp...
Digital radiography for diagnosis of chest diseases using Fuji Computed Radiography (FCR) was evaluated. The results were as follows; 1. Compared to the conventional chest X-ray films, various types of image enhancement could be made by manipulation of the digital information such as tone conversion, spatial frequency modification etc. 2. Digital radiography lessens the X-ray exposure dose and will ultimately permit speedy transmission of image data from outlying clinics to central processing hospitals. 3. Digital radiographic images are useful in chest X-ray diagnosis especially in mass surveys for lung cancer and in primary care medicine because of its full imaging capability. (author).
This report reviews coal conversion processes which may be introduced in Canada within the next decade if interest in alternate energy technologies continues. A detailed review was conducted on coal liquefaction and gasification projects worldwide including information on individual proprietors, process technologies used, their present status and available environmental data. Further assessment of emissions and wastes emanating from commercial-scale plants was used to determine significant or potentially significant wastestreams connected to the various technologies, particularly wastewater discharges. Emphasis was placed on those technologies that are close to commercialization in Canada, i.e. SASOL II-type liquefaction facility at Hat Creek. Available information on wastewater treatment/reuse is also included in this report.
This quarterly report, for the period April 1-June 30, 1982, summarizes Sandia's activities in coal liquefaction process research. The overall objectives of the program are to understand the mechanisms and determine the role of catalysts in the direct conversion of coal to liquids. Primary emphasis is being given to the Integrated Two-Stage Liquefaction (ITSL) process. Specific tasks include: short-contact time coal liquefaction, mineral matter effects and catalyst studies. During this period, work was done on: the characteristics of a Liquefaction (ITSL) facility at New Brunswick, NJ; the kinetics of hydrogenation and dehydrogenation of pyrene and dihydropyrenes in batch microreactors; the impact of coal cleaning on the effectiveness of two types of slurry phase catalysts; the deactivation of aged catalyst samples obtained from the H-Coal PDU; and a catalyst deactivation model for the H-Coal PDU.
A general model for the analysis of metal-semiconductor solar cells is presented. The model takes into account the cell optical properties, carrier recombination effects, semiconductor minority-carrier properties, series resistance, cell thickness, and active surface area. Numerical methods are used to solve the appropriate continuity equations and hence compute the photocurrent density under AMO conditions. The operation of the model is demonstrated using p- and n-type Si and GaAs with Au being taken as the barrier metal. Calculations are presented showing the effect on solar energy conversion efficiency of surface recombination velocity, barrier height, minority-carrier lifetime, barrier metal thickness, collecting grid configuration, and cell thickness. A comparison of practical and computed data for the Au/n-GaAs system yields good agreement. (AIP)
Experiments are reported in which a methane plasma is created, and the methyl ions and hydrogen ions are accelerated within a microchannel array so that they interact with neutral methane molecules on the inside surfaces of the microchannels. No catalysts are used, and the device operates at room temperature. Impact energies of the ions are in the range of 10 eV to greater than 100 eV, and the energy delivered in the interaction at the surfaces causes the production of larger hydrocarbon molecules, such as C{sub 2}H{sub 2}, C{sub 2}H{sub 4}, and C{sub 2}H{sub 6}, along with C{sub 3}, C{sub 4}, C{sub 5}m C{sub 6}, C{sub 7}m and C{sub 8} molecules. There is a decreasing percentage of larger molecules produced, in comparison with the C{sub 2} and C{sub 3} types. Conversion effectiveness is greater at higher pressure, due to the increased ionic activity. The yield of the higher hydrocarbons depends upon the external voltage used, and voltage can be ...
The nuclear lamina proteins, prelamin A, lamin B, and a 70-kD lamina-associated protein, are posttranslationally modified by a metabolite derived from mevalonate. This modification can be inhibited by treatment with (3-R,S)-3-fluoromevalonate, demonstrating that it is isoprenoid in nature. We have examined the association between isoprenoid metabolism and processing of the lamin A precursor in human and hamster cells. Inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase by mevinolin (lovastatin) specifically depletes endogenous isoprenoid pools and inhibits the conversion of prelamin A to lamin A. Prelamin A processing is also blocked by mevalonate starvation of Mev-1, a CHO cell line auxotrophic for mevalonate. Moreover, inhibition of prelamin A processing by mevinolin treatment is rapidly reversed by the addition of exogenous mevalonate. Processing of prelamin A is, therefore, dependent on isoprenoid metabolism. Analysis of the ...
This project proposes to design and develop a new class of power converters (direct DC to AC) to drastically improve performance and optimize the cost, size, weight and volume of the DC to AC converter in SOFC systems. The proposed topologies employ a high frequency link; direct DC to AC conversion approach. The direct DC to AC conversion approach is more efficient and operates without an intermediate dc-link stage. The absence of the dc-link, results in the elimination of bulky, aluminum electrolytic capacitors, which in turn leads to a reduction in the cost, volume, size and weight of the power electronic converter. The feasibility of two direct DC to AC converter topologies and their suitability to meet SECA objectives will be investigated. Laboratory proto-type converters (3-5kW) will be designed and tested in Phase-1. A detailed design trade-off study along with the test results will be available in the form of a ...
A rehabilitation programme for patients with conversion paralysis has been introduced in which they are offered physical rehabilitation. During an eight month period between October 1984 and May 1985...Full Text Available
Nomographs have been constructed to estimate the average evaporation loss from internal floating-roof tanks. Loss determined from the charts can be used to evaluate the economics of seal conversion and to reconcile refinery, petrochemical plant, and storage terminal losses. The losses represent average standing losses only. They do not cover losses associated with the movement of product into or out of the tank. The average standing evaporation loss from an internal floating-roof tank depends on: vapor pressure of the product; type and condition of roof seal; tank diameter; and type of fixed roof support. The nomographs can estimate evaporation loss for product true vapor pressures (TVP) ranging from 1.5 to 14 psia, the most commonly used seals for average and tight fit conditions, tank diameters ranging from 50 to 250 ft, welded and bolted designs, and both self-supporting and column-support fixed roof designs. The charts ...
The performance of a thermophotovoltaic (TPV) converter for solar energy is compared with that of direct solar energy conversion by silicon and germanium solar cells. The optical selectivity of an intermediate emitter is computed. Experimental results on selective emission, based on selectively emitting materials and on antireflection coatings on metals, are reported. For a TPV converter equipped with silicon solar cells, no selective emitter is found to yield better results than would be obtained by direct conversion. A TPV converter with germanium cells operating with a ThO/sub 2/-coated tungsten emitter, however, may achieve a conversion efficiency superior to that of direct solar energy conversion by either silicon or germanium solar cells.
A chromium-free conversion coating for magnesium alloys were described. The conversion coating could be obtained when AZ31D magnesium alloy was immersed in a solution containing a manganese salt, phosphate and an inhibitor. Corrosion resistance of the chemical conversion coating was evaluated by anodizing polarization curve and salt immersion. XRD analysis showed that the conversion coating was mainly composed of Mn{sub 3}(PO{sub 4}){sub 2}. The morphology of the coating is observed by using SEM. The effect of electrolyte pH and concentration of inhibitor on coating growth are investigated. (orig.)
The effect of adding hydrogen to methane as a fuel for spark ignited engines has been extensively investigated. Both the possibility of adding a limited amount of hydrogen as well as equal amounts of hydrogen and carbon dioxide to natural gas has been investigated. A 10 vol% addition of hydrogen to the natural gas caused a reduction in UHC of approximately 40%, and an increase in efficiency of approximately three percentage points at the test engine. It is unknown if the gain is representative for large engines. Similar results for UHC reduction and efficiency were obtained for combined hydrogen and carbon dioxide addition. The carbon dioxide was added by exhaust gas recirculation. However, the price of hydrogen, makes this idea uneconomical even when carbon dioxide is readily available through recirculation of engine exhaust. Adiabatic prereforming may be used to convert natural gas into methane, hydrogen and carbon dioxide in order to generate hydrogen and at the same time increase ...
The objective of this project is to develop a pellet formulation which is capable of achieving low sulfur partial pressures and a high capacity for sulfur, loaded from a hot fuel gas and which is readily regenerable. Furthermore the pellet must be strong for potential use in a fluidized bed and regenerable over many cycles of loading and regeneration. Regeneration should be in air or oxygen-depleted air to produce a high-concentration sulfur dioxide. Fixed-bed tests were conducted with several formulations of manganese sesquioxide and titania, and alumina They were subject to a simplified fuel gas of the oxygen-blown Shell type spiked with a 30,000ppmv concentration of H{sub 2}S. Pellet crush strengths for 4 and 2mm diameter pellets was typically 12 lbs per pellet and 4 lbs per pellet, respectively. For the most favorable of the formulations tested and under the criteria of break-through at less than 100ppmv H2S and loading temperatures of 500{degrees}C and an ...
In many parts of the United States, as well as other regions of the world, competing demands for fresh water or water suitable for desalination are outstripping sustainable supplies. In these areas, new water supplies are necessary to sustain economic development and agricultural uses, as well as support expanding populations, particularly in the Southwestern United States. Increasing the supply of water will more than likely come through desalinization of water reservoirs that are not suitable for present use. Surface-deployed seismic and electromagnetic (EM) methods have the potential for addressing these critical issues within large volumes of an aquifer at a lower cost than drilling and sampling. However, for detailed analysis of the water quality, some sampling utilizing boreholes would be required with geophysical methods being employed to extrapolate these sampled results to non-sampled regions of the aquifer. The research in this report addresses using seismic and EM methods in ...
Co-processing of Battle River coal and Cold Lake oil sand bitumen from Canada was carried out in the presence of Ni-Mo, Co-Mo and red-mud/sulfur catalysts under reaction conditions of 400-450{degree}C, 10-120 min and 22-23 MPa of reaction hydrogen pressure by using a 500 ml shaking-type autoclave. The conversion of Battle River coal during the reprocessing was 97.1 wt% (daf) at 450{degree}C for 121 min with Ni-Mo catalyst, higher than 95.7 wt% (daf) at 450{degree}C for 120 min with red-mud/sulfur catalyst and anthracite oil. Cold lake oil sand bitumen was excellent solvent to liquefy Battle River coal comparing with anthracite on. In the presence of Ni-Mo catalyst during the coprocessing, the hydrogen consumption was nearly the same as that with red-mud/sulfur catalyst. Ni-Mo catalyst gave higher conversion of Battle River coal in the initial stage of the reaction than red-mud/sulfur catalyst. Ni-Mo catalyst also showed ...
CuO/bentonite and CuO-BHA nanocomposites were studied as oxygen carriers in chemical-looping combustion (CLC) of simulated synthesis gas. Global reaction rates of reduction and oxidation, as the function of reaction conversion, were calculated from 10-cycle oxidation/reduction tests utilizing thermogravimetric analysis at atmospheric pressure between 700 and 900{degree}C. It was found that the reduction reactions are always faster than oxidation reactions; reaction temperature and particle size do not significantly affect the reaction performance of CuO/bentonite. Multicycle CLC tests conducted in a high-pressure flow reactor showed stable reactivity for production of CO{sub 2} from fuel gas at 800 and 900{degree}C and full consumption of hydrogen during the reaction. Results of the tapered element oscillating microbalance showed a negative effect of pressure on the global rates of reduction-oxidation reactions at higher fractional conversions. ...
The oxidative dehydrogenation (ODH) of light alkanes is an alternative way for the production of olefins. A wide variety of catalytic systems has been investigated. Vanadium oxide based catalysts were described in the literature as effective catalysts for the ODH of propane. The catalytic activity and selectivity depend on the kind of support material, the kind of dopants and the formation of complex metal oxide phases. In recent papers it was claimed that both orthovanadate and/or pyrovanadate species are selective for the ODH of propane. Niobia based materials were investigated as catalysts for acidic and selective oxidation type reactions. In the ODH of propane niobia exhibited a high selectivity to propene but the conversion of propane was low. V{sub 2}O{sub 5}-Nb{sub 2}O{sub 5} catalysts proved to be catalytically active and selective and showed no formation of oxygenates. In the present study the influence of the niobia dopant of the ...
The visible semiconductor laser includes an InAlGaP active region surrounded by one or more AlGaAs layers on each side, with carbon as the sole p-type dopant. Embodiments of the invention are provided as vertical-cavity surface-emitting lasers (VCSELs) and as edge-emitting lasers (EELs). One or more transition layers comprised of a substantially indium-free semiconductor alloy such as AlAsP, AlGaAsP, or the like may be provided between the InAlGaP active region and the AlGaAS DBR mirrors or confinement layers to improve carrier injection and device efficiency by reducing any band offsets. Visible VCSEL devices fabricated according to the invention with a one-wavelength-thick (1{lambda}) optical cavity operate continuous-wave (cw) with lasing output powers up to 8 mW, and a peak power conversion efficiency of up to 11%. 5 figs.
A new type of passive cooling system has been invented (Forsberg 1993): the Temperature-Initiated Passive Cooling System (TIPACS). The characteristics of the TIPACS potentially match requirements for an improved reactor-cavity-cooling system (RCCS) for the modular high-temperature gas-cooled reactor (MHTGR). This report is an initial evaluation of the TIPACS for the MHTGR with a Rankines (steam) power conversion cycle. Limited evaluations were made of applying the TIPACS to MHTGRs with reactor pressure vessel temperatures up to 450 C. These temperatures may occur in designs of Brayton cycle (gas turbine) and process heat MHTGRs. The report is structured as follows. Section 2 describes the containment cooling issues associated with the MHTGR and the requirements for such a cooling system. Section 3 describes TIPACS in nonmathematical terms. Section 4 describes TIPACS`s heat-removal capabilities. Section 5 analyzes the operation of the ...
Strong support for the existence of catalytically-active, sub-surface oxygen is proposed. The existence of two types of sub-surface oxygen was determined by thermal-desorption spectroscopy (TDS). The first is termed O{sub {beta}} and is characterized by a board thermal-desorption peak centered at approximately 773 K. The second is referred to as O{sub {gamma}} and is characterized by an unsaturated thermal desorption signal beginning at approximately 873 K. O{sub {gamma}} is assigned to oxygen which is incorporated in the uppermost layers of low-indexed terminating crystal structures such as (111) formed as a result of thermal reordering. O{sub {beta}} diffusion occurs most likely via interstitial jumping and O{sub {gamma}} via interstitialcy diffusion. Both CH{sub 4} conversion and C{sub 2} selectivity improve with time on stream. This improvement in catalytic performance correlates well with surface facetting and particle rupture, which ...
This final report for the Swiss Federal Office of Energy (SFOE) is one of a series of reports concerning municipal development in various cities in Switzerland. The four city districts involved include Basel (Gundeldinger Feld), Lausanne (Bellevaux), Lucerne (Basel-/Bernstrasse) and Zurich (Werdwies). This paper takes a look at aspects of building ecology. In the four areas, the following building types and projects were examined with respect to their ecology: Basel: conversion of commercial premises to a community centre, Lausanne and Lucerne: Enhancement of residential areas, Zurich: a new residential building. Criteria examined include general building ecology, building materials, raw materials, toxic substances, recycling, maintenance and deconstruction, energy for heating and hot water, grey energy, electricity, ground usage, water, wastes and public infrastructure. Knowledge gained along with questions and problems still to be addressed ...
Measurements were carried out for calibration and performance testing of a set of 10 electronic personal dosimeters (EPDs) at the Secondary Standard Dosimetry Laboratory of Sudan. Calibrations were carried out at three X-ray beam qualities described in ISO standard 4037 in addition to 137Cs and 60Co gamma ray beams. The experimental was performed with EPDs mounted on ICRU Slab phantom. X-ray and ?-ray beams were characterized in terms of air kerma free-in-air which were converted to the known delivered personal dose equivalent, Hp(10) using appropriate the air kerma to personal dose equivalent conversion coefficients. Dosimeters tested showed excellent energy and angular response and relative error of indication within the recommended limit for photon energies from 65 keV to 1.25 MeV. The study showed encouraging results for using electronic dosimeters in personal dosimetry.
An overall plant design was developed for a gas-cooled fast reactor employing a direct supercritical Brayton power conversion system. The most important findings were that (1) the concept could be capital-cost competitive, but startup fuel cycle costs are penalized by the low core power density, specified in large part to satisfy the goal of significant post-accident passive natural convection cooling; (2) active decay heat removal is preferable as the first line of defense, with passive performance in a backup role; (3) an innovative tube-in-duct fuel assembly, vented to the primary coolant, appears to be practicable; and (4) use of the S-Co2 GFR to support hydrogen production is a synergistic application, since sufficient energy can be recuperated from the product H2 and 02 to allow the electrolysis cell to run 250 C hotter than the reactor coolant, and the water boilers can be used for reactor decay heat removal. Increasing core power density is identified as ...
Given an invariant gauge potential and a periodic scalar potential \\tilde{V} on a Riemannian manifold \\tilde{M} with a discrete symmetry group \\Gamma, consider a \\Gamma-periodic quantum Hamiltonian \\tilde{H}=-\\tilde{\\Delta}_{B}+\\tilde{V} where \\tilde{\\Delta}_{B} is the Bochner Laplacian. Both the gauge group and the symmetry group \\Gamma can be noncommutative, and the gauge field need not vanish. On the other hand, \\Gamma is supposed to be of type I. To any unitary representation \\Lambda of \\Gamma one relates a Hamiltonian H^{\\Lambda}=-\\Delta_{B}^{\\Lambda}+V on M=\\tilde{M}/\\Gamma where V is the projection of \\tilde{V} to M. We describe a construction of the Bloch decomposition of \\tilde{H} into a direct integral whose components are H^{\\Lambda}, with \\Lambda running over the dual space \\hat{\\Gamma}. The evolution operator and the resolvent decompose correspondingly. Conversely, given \\Lambda\\in\\hat{\\Gamma}, one can ...
The reactions between (100) GaAs and the near-noble metals Ni, Pd, and Pt have been investigated by application of high-resolution transmission electron microscopy (TEM), energy-dispersive analysis of x rays in the scanning TEM and Rutherford backscattering spectrometry. Emphasis is placed on the evolution of the phase distributions, film compositions, and interface morphologies during annealing at temperatures up to 480 /sup 0/C. The first phase in the Ni/GaAs reaction is shown to have the nominal composition Ni/sub 3/GaAs. Ternary phases of the type Pd/sub x/GaAs are also found to be the dominant products of the Pd/GaAs reaction. Conversely, only binary phases result from the Pt/GaAs reaction. These observations are used to construct isothermal sections of the M--Ga--As thin-film phase diagrams. The behavior of a thin (1--2 nm) native oxide--hydrocarbon layer during the Ni/GaAs, Pd/GaAs, and Pt/GaAs reactions is also investigated. Only the ...
Proton exchange membrane fuel cells (PEMFCs) are attractive because of their high conversion efficiency, low pollution, lightweight, and high power density. A major area of challenges is the design and engineering of active, robust, and low-cost electrocatalysts. This report discusses recent findings of our investigations of the design and nano-engineering of platinum-vanadium-iron catalysts for use in PEMFC. The membrane electrode assembly was prepared using nano-engineered PtVFe nanoparticles with controlled composition and size supported on carbon as cathode electrocatalysts. The electrocatalytic activity and stability of the catalysts have been characterized by both rotating disk electrode and membrane electrode assembly measurements. The trimetallic catalysts have been shown to exhibit excellent electrocatalytic performance in PEMFC in comparison with commercial platinum catalysts. The results exhibited a good agreement between obtained these two ...
We report the growth and fabrication of midwave infrared InAs/GaSb strain layer superlattice (SLS) detectors. Growth of alternate interfaces leads to a reduced strain between the GaSb buffer and SLS ({delta}a{sub parallel}/a=-5x10{sup -4}), enabling the growth of active regions up to 3 {mu}m (625 periods). The structural, optical, and electrical properties of the active region were characterized using x-ray crystallography and photoluminescence, respectively. p-i-n detectors were grown using 625 periods of 8 ML (monolayer) InAs/8 ML GaSb as the active region. The {lambda}{sub cutoff} for the detectors was 4.6 {mu}m with a conversion efficiency of 32% at V{sub b}=-0.2 V. Detectivity was obtained using noise power spectral density measurements under 300 K 2{pi} field of view illumination and was equal to 5.2x10{sup 10} and 3x10{sup 10} cm Hz{sup 1/2}/W (V{sub b}=-0.02 V, T=80 K) in the white noise and 1/f noise limit (at 50 Hz)
The purpose of this report is to summarize the assumptions, dose factors, consumption rates, and methodology used to evaluate potential radiation doses to persons who may eat contaminated wildlife or contaminated plants collected from the Hanford Site. This report includes a description of the number and variety of wildlife and edible plants on the Hanford Site, methods for estimation of the quantities of these items consumed and conversion of intake of radionuclides to radiation doses, and example calculations of radiation doses from consumption of plants and wildlife. Edible plants on the publicly accessible margins of the shoreline of the Hanford Site and Wildlife that move offsite are potential sources of contaminated food for the general public. Calculations of potential radiation doses from consumption of agricultural plants and farm animal products are made routinely and reported annually for those produced offsite, using information about concentrations of ...
Pd-Si metallic glasses have been utilized as catalysts in the Fischer-Tropsch reaction. The glasses are selective of ethane, whereas the in-situ crystallized glasses select a range of hydrocarbons characteristic of conventional Pd catalysts. This shift in selectivity has been observed in other hydrogenation reactions. Surface crystallization caused by the reaction conditions causes variable selectivity. Crystallization in reaction conditions has been monitored by DSC. During the course of the grant we developed the use of (+)- apopinene (6,6-dimethyl-1R,5R-bicyclo(3.1.1)hept-2-ene) as a molecular probe for determining the number and kinds of active sites on metallic glass catalysts. To accomplish this we conducted many experiments for comparison on other types of catalysts. These were foils, powders, and highly dispersed metals on several different supports. The glassy surfaces appear to be three dimensionally random (hilly or rolling) with many protuberances which ...
Metallic components within or immediately adjacent to gasifiers, such as gas distributors, thermowells, transfer lines, and cyclones, are subjected to severe of temperature, pressure, and hostile multicomponent gas environments. Metallic heat exchangers/waste-heat boilers resistant to sulfidation, corrosion. and erosion in low- and medium-Btu gas environments are essential components in large-scale gasification schemes, in both dry ash and slogging type gasifiers. Components, in general. must be resistant to corrosion, erosion, and high-temperature creep. A substantial data base is needed on the mechanical properties of materials exposed to complex gas environments to provide a more viable basis for establishing long-term reliability of components. This work examines high-temperature creep of Alloy 800, a high-chromium alloy widely used in coal conversion systems, after exposure to oxygen and oxygen/sulfur mixed-gas environments over a wide ...
The production of cellulolytic enzymes from fungi has been extensively studied. Several mutants of Trichoderma reesei were selected. Most of the studies were carried out on T. reesei, T. viride, T. harzianum, Penicillium funiculosum, Altemaria alternata. Aspergillus phoenicis, A. ustus, A. tamarii, A. japonicus, and A. niger. T. koningii is one of the most active producers of the so-called C, factor, which is indispensable for the rapid and extensive attack on crystal-line cellulose. However, Trichodenna is known to excrete only small amounts of {beta}-glucosidase. Therefore, Trichoderma is supplemented with {beta}-glucosidase from Aspergillus to increase the saccharification rate of cellulose to glucose as the main sugar. Induction of mutations in Trichodenna spp. rather than T. viride as a tool for the enhancement of {beta}-glucosidase activity was reported. Unfortunately, T. reesei is a poor producer of {beta}-glucosidase. On the other hand, T. harzianum M{sub 5}, a mutant that was ...
A literature review on gasification of lignocellulosic biomass in various types of fluidized bed gasifiers is presented. The effect of several process parameters such as catalytic bed material, bed temperature and gasifying agent on the performance of the gasifier and quality of the producer gas is discussed. Based on the priorities of researchers, the optimum values of various desired outputs in the gasification process including improved producer gas composition, enhanced LHV, less tar and char content, high gas yield and enhanced carbon conversion and cold gas efficiency have been reported. The characteristics and performance of different fluidized bed gasifiers were assessed and the obtained results from the literature have been extensively reviewed. Survey of literature revealed that several industrial biomass gasification plants using fluidized beds are currently conducting in various countries. However, more research and development of ...
Since the 1970's, global efforts have been going on to replace the high-enriched (>90% "2"3"5U), low-density UAlx research reactor fuel with high-density, low enriched (<20% "2"3"5U) replacements. This search is driven by the attempt to reduce the civil use of high-enriched material because of proliferation risks and terrorist threats. American initiatives, such as the Global Threat Reduction Initiative (GTRI) and the Reduced Enrichment for Research and Test Reactors (RERTR) program have triggered the development of reliable low-enriched fuel types for these reactors, which can replace the high enriched ones without loss of performance. Most success has presently been obtained with U_3Si_2 dispersion fuel, which is currently used in many research reactors in the world. However, efforts to search for a replacement with even higher density, which will also allow the conversion of some high flux research reactors that currently cannot change ...
Electron interference in the presence of nonclassical microwaves with frequency {omega}{sub 1} and classical RF radiation with frequency {omega}{sub 2}, is studied. The relative phase factor between the two electron beams is a quantum-mechanical operator, whose expectation value with regard to the density matrix describing the nonclassical microwaves, determines the interference. It is shown that the visibility of the time-averaged intensity is a constant for all irrational values of {omega}{sub 1}/{omega}{sub 2}, and shows peaks (fractional Shapiro steps) at all rational values. These peaks can provide direct experimental evidence of the highly nonlinear processes of frequency conversion from {ital N} photons with frequency {omega}{sub 1}, to {ital M} photons with frequency {omega}{sub 2}. Results for various types of nonclassical microwaves (e.g., coherent states, squeezed states, number eigenstates, etc.) are derived and a comparison with ...
In this study, the exhaust gas from a common-rail direct injection diesel engine was investigated both upstream and downstream warm-up catalytic converters (WCC). Three different types of ultra-low sulfur fuels (ethanol-diesel blend, ethanol-diesel blend with cetane improver and pure diesel) were tested in this study. The objective of the work was to study the engine performance and the formation of THC (total hydro carbon), CO (carbon monoxide), NO{sub x} (nitrogen oxides), smoke and PM (particulate matters) when using these fuels. THC and CO emissions of the ethanol-diesel blend fuels were slightly increased, and about 50-80% mean conversion efficiencies of THC and CO on catalysts were achieved in the ECE R49 13-mode cycle. Smoke was decreased by more than 42% in the entire ECE 13-mode cycles. From the measurement of scanning mobility particle sizer (SMPS) for the particle size range of 10-385 nm, the total number and total mass of the PM of ...
All first-stage experimental tests were completed for Task 4 (and the Contract). The first-stage one-liter autoclave tests that were made were duplicates of Run 41-LA. The conditions used were chosen last quarter to reduce the cost of the first-stage of the process from those used at the conclusion of Task 3. Filtration and second-stage tests were made using the products of the first-stage tests. Post-second-stage filtration, tested as an alternative to interstage (pre-second- stage) filtration, resulted in low filtration rates. Different catalyst loadings and type and residence time for second-stage hydrotreating were explored. Longer residence times did not result in significantly more resid conversion. Higher catalyst loadings were more effective in converting the resid at the same residence time. The material and elemental balances for the first-stage were completed. The material and elemental balances for the second-stage were initiated.
The industrial radiation processing using low energy electron beam (EB) accelerators lower than 300 keV offers high speed, safe technologies for the chemical conversion of thin layer coatings. Because of the nonselective mode of initiating chain reaction polymerization involving free radicals in synthetic coating layers and suitable substrates, the EB curing of the coatings on woods and papers has particular advantage. Hungary decided to start an up-to-date EB line to process cement-bound (CB) wood chipboards with pigmented acrylic coatings. The CB wood chipboards contain more than 60 % of portland cement and up to 40 % of wood particles. They are produced as large boads of 6 - 16 mm thickness. In their fireproof character and other aspects, they are similar to asbestos-cement boards without containing carcinagenic asbestos, and are stable against moisture and atmospheric influences. EB-cured acrylate coating improved further those properties, and makes them ...
Recent fuel cost increases coupled with energy shortages have resulted in an awareness of the need to conserve energy and to expand the United States domestic energy base. Increase in coal conversion and utilization are major objectives of the research and development activities in the US Department of Energy. Several alternate processing schemes are being developed to convert coal to environmentally acceptable liquid fuels. A few of these technologies are approaching the commercialization stage and scale-up is being carried forward on the most promising processes. The various coal liquefaction processes are discussed by dividing them into four general classifications. Processes for converting various types of coal to synthetic liquid fuels are being improved so that clean fuels can be produced commercially. Emphasis is on the production of fuels suitable for firing industrial and electric utility boilers and on synthetic crude oils for ...
Epidemiological studies have revealed that butyrate and 17?-estradiol (E2) may decrease the incidence of colorectal cancer (CRC). In peripheral tissue, E2 can be produced locally by 17?-hydroxysteroid dehydrogenase 1 (HSD17B1) estrone (E1) reduction. Using quantitative real-time polymerase chain reaction and western blotting analysis, we found that sodium butyrate significantly upregulates HSD17B1 long and short transcripts and protein levels in HT29 and SW707 CRC cells. Chromatin immunoprecipitation analysis showed that upregulation of these transcript levels correlated with an increase in binding of Polymerase II to proximal and distal promoters of HSD17B1. Moreover, we observed that upregulation of HSD17B1 protein levels was associated with increased conversion of E1 to E2 in HT29 and S...
A new model for fuel spray penetration (location of spray tip) is suggested and validated against available experimental data. Simple analytical expressions for fuel spray penetration are derived in two limiting cases: the initial stage and the two-phase flow regime. At the initial stage, the effects of droplet drag and entrainment of air are accounted for. In the case of the two-phase flow, it is assumed that the spray droplets have the same velocities as the entrained air. The characteristic time of droplet break-up in the spray is estimated for both bag and stripping break-up mechanisms. For realistic diesel spray parameters, the droplet break-up takes place almost immediately after the droplets leave the nozzle. This leads to a considerable shortening of the initial stage and a rapid conversion of the flow to the two-phase stage. This allows the analysis to be restricted to the two-phase flow approximation for this type of spray. The ...
An experimental study and a theoretical simulation were made of stimulated Raman scattering (SRS) conversion into shifted components. It was found that there were optimal values of the pressure and focal distance for conversion into the first 'blue' satellite of the first Stokes component. A study was made of the spatial and temporal dynamics of SRS conversion, which took into account generation of the shifted components. It was demonstrated theoretically and experimentally that the satellite intensity could be enhanced significantly by additional electron-collision excitation of the vibrational levels in the conversion medium or by the application of pairs of pump pulses. The maximum efficiency of conversion to the first 'blue' satellite of the first Stokes component was 10% and the satellite intensity reached one-third of the intensity of the main Stokes line. (nonlinear optical ...
Breast cancer progression is characterized by inappropriate cell growth. Normal cells cease growth after a limited number of cell divisions--a process called cellular senescence-while tumor cells may acquire the ability to proliferate indefinitely (immortality). Inappropriate expression of specific oncogenes in a key cellular signaling pathway (Ras, Raf) can promote tumorigenicity in immortal cells, while causing finite lifespan cells to undergo a rapid senescence-like arrest. We have studied when in the course of transformation of cultured human mammary epithelial cells (HMEC), the response to overexpressed oncogenic Raf changes from being tumor-suppressive to tumor enhancing, and what are the molecular underpinnings of this response. Our data indicate: (1) HMEC acquire the ability to maintain growth in the presence of oncogenic Raf not simply as a consequence of overcoming senescence, but as a result of a newly discovered step in the process of immortal transformation uncovered by ...
Chorismate mutase, a branch-point enzyme in the aromatic amino acid pathway of Saccharomyces cerevisiae, and also a mutant chorismate mutase with a single amino acid substitution in the C-terminal part of the protein have been purified approximately 20-fold and 64-fold from overproducing strains, respectively. The wild-type enzyme is activated by tryptophan and subject to feedback inhibition by tyrosine, whereas the mutant enzyme does not respond to activation by tryptophan nor inhibition by tyrosine. Both enzymes are dimers consisting of two identical subunits of M_r 30,000, each one capable of binding one substrate and one activator molecule. Each subunit of the wild-type enzyme also binds one inhibitor molecule, whereas the mutant enzyme lost this ability. The enzyme reaction was observed by "1H NMR and shows a direct and irreversible conversion of chorismate to prephenate without the accumulation of any enzyme-free ...
as for direct energy conversion in specialized direct electrical energy conversion plants. Figure 1. An energetic (~163KeV) proton and a 11boron nucleus fuse ...
Activation-induced deaminase (AID) initiates somatic hypermutation, gene conversion and class switch recombination by deaminating variable and switch region DNA cytidines to uridines. AID is predominantly...Full Text Available
A schematic diagram of the decision making process for air pollution control equipment for the conversion of a fossil-fired generating unit from oil to coal is presented and explained.
In situ spectroscopic ellipsometry was employed to investigate the initial regime of rare earth metal (REM) conversion coatings formation on AZ31 magnesium alloy. Three REM salts solutions, 0.05 mol.dm"-"3 Ce(NO_3)_3, La(NO)_3 and Sm(NO)_3 solutions, were used for REM conversion coatings preparation. By deconvoluting the ellipsometric data, the surface of the fresh well-polished AZ31 magnesium alloy was found to be covered with 15.80 nm thick native (hydr)oxide film; the refractive indices and the thickness of Ce, La and Sm conversion coatings were obtained. The formation kinetics of three REM coatings follows different exponential functions and the coatings exhibit different optical properties. La conversion coating has the largest n values and the lowest k values while Sm conversion coating is just opposite. Moreover, the pH variation of the bulk conversion ...
The Eighth Indirect Liquefaction Contractors' Review Meeting was held November 15-17, 1988 at the Pittsburgh Hyatt Hotel. Twenty-eight presentations were made by contractors, invited speakers, and Pittsburgh Energy Technology Center R and D personnel. Six areas of research were covered: synthesis gas conversion to oxygenates; light hydrocarbon gas conversion; slurry reactor hydrodynamics; production, clean-up and conversion to hydrocarbon fuels; Fischer-Tropsch products upgrading; and, synthesis gas bioconversion. The meetings also included a panel discussion on direct methane conversion research. Individual projects are processed separately for the data bases.
The invention concerns the conversion of steam turbines, particularly condensation turbines, for the economic coupling of process steam and heating steam. The conversion occurs by retaining the basic construction of foundations, housing and bearings as support group and coupling member and matching the specially developed construction for the idea of use into the existing housing, and inserting the rotor into the shaft unit. By having the unchanged supports of the housing and the bearings of the shaft unit, the elasticity in expansion and the vibration behaviour of the turbine are retained and the conversion costs can be lowered.
Conversion of the United States military to the International System of measurement units is in the very early stages. Little formal planning has been done to articulate the management required to complete the conversion of operational Army and Air Force units. For those operational forces tasked to provide continuous combat readiness throughout metrication, management problems associated with the conversion are particularly difficult because of the nature of these assigned missions. This is the case for the 82nd Airborne Division ready brigade force (DRB) and the Military Airlift Command (MAC) strategic airlift system operating the C-141 and C-5A aircraft.
Microscopic non-energy weighted sum-rules for the total rates of the neutrinoless ..mu..-e conversion process are constructed in the frame of the shell model for closed shell nuclei. For non-closed shell nuclei the relevant rates were obtained by interpolation. Also the contribution of the coherent process to the total ..mu..-e conversion rate is calculated and discussed.
The work of the study group for coal conversion by hydrogenation (G.E.C.H.) is an example of well concerted association between research laboratories (CNRS, Ecole des Mines...) and directly interested industrial research centers, (CERCHAR, G d F, IFP). This paper presents the activities of G.E.C.H. in the field of coal conversion by hydroliquefaction.
The lepton flavor-violating coherent ( /sup -/, e/sup -/) conversion is investigated. Photonic and nonphotonic contributions arising in various gauge models are considered. The dependence of the conversion rate on the structure of the nucleus is given by the elastic form factors. These are obtained in the context of shell model taking into account finite-size effects or extracted from the electron scattering data whenever possible. The relevant branching ratios are studied throughout the periodic table.
Solid state effects are taken into account in an internal conversion coefficients computation by using Wigner-Seitz boundary conditions. Both the bound and free electron wave functions are calculated from an atomic Dirac-Hartree-Fock-Slater self consistent potential. These internal conversion coefficients are compared with those obtained from the usual free atom boundary conditions.
Solid state effects are taken into account in an internal conversion coefficients computation by using Wigner-Seitz boundary conditions. Both the bound and free electron wave functions are calculated from an atomic Dirac-Hartree-Fock-Slater self consistent potential. These internal conversion coefficients are compared with those obtained from the usual free atom boundary conditions. (orig.).
This current awareness bulletin announces on a semimonthly basis the current worldwide information entered into the Energy Data Base on all aspects of direct energy conversion. Categories include photovoltaic conversion, magnetohydrodynamic generators, electrohydrodynamic generators, thermoelectric generators, thermionic converters, fuel cells, and miscellaneous converters. An abstract is inclluded with each citation. (WHK)
When biomass is used as fuel for thermal conversion plants, minerals from the fuel can be responsible for major problems. Generally, these problems are associated with the existence and development of low melting compounds or eutectics, which form sticky layers. In a fluidised bed, this can result in bed-agglomeration and defluidisation. This causes local high temperature, which often accelerates the process. It ultimately can lead to a completely sintered bed content with a glassy phase gluing the bed particles together and shut-down of the plant. The main objective of the title project is to develop a methodology to predict ash/bed agglomeration and sintering problems, to indicate related problems and, furthermore, to identify solution methods to make different types of biomass streams more viable for energy production. Within the present study, selected fuels are subjected to different existing methods together with some new ones, in order ...
Thermophotovoltaic energy conversion achieves direct conversion of thermal energy to electricity without the need for complex dynamic machinery operating in one of several possible thermodynamic cycles. This paper presents an analysis of a hybrid solar thermophotovoltaic (STPV) energy conversion system in which a receiver/photovoltaic (PV) array subsystem is powered by either a solar concentrator or a fossil fuel combustion source. The overall TPV system efficiency is calculated using an appropriate selective emitter and a spectrally tuned solar cell designed to achieve maximum conversion efficiency in the narrow band emitted by the selective emitter. Two limiting cases are examined to place upper and lower bounds on system performance. The estimates of system performance are based on actual experimental data from PV cells and selective emitters.
Measurements of temperature and NO concentration in laminar, partially premixed methane-air flames stabilized on a ceramic burner in coflow are reported. The NO concentration and temperature were determined by laser-induced fluorescence (LIF) and coherent anti-Stokes Raman scattering (CARS), respectively. Upstream heat loss to the burner was varied by changing the exit velocity of the fuel-air mixture at a constant equivalence ratio of 1,3; this alters the structure of the flame from an axisymmetric Bunsen-type to a strongly stabilized flat flame. To facilitate analysis of the results, a method is derived for separating the effects of dilution from those of chemical reaction based on the relation between the measured temperature and the local mixture fraction, including the effects of upstream heat loss. Using this method, the amount of NO formed during burnout of the hot, fuel-rich combustion products can be ascertained. In the Bunsen-type ...
Progress reports are presented for the following two areas: catalytic cracking studies with water-wet silica-alumina catalysts; and Fischer-Tropsch reactor studies where similarities and differences between fixed bed and slurry type reactors are investigated and further experiments conducted to measure mass transfer coefficients and reaction kinetics which are to be used in a model slurry reactor. The following are some of the conclusions. (1) The premise that the presence of liquid water might increase catalytic cracking activity was found to be invalid. It was demonstrated that cracking can occur at previously unobserved low temperatures (though at low conversions) and that an anomaly exists in that one of the catalysts tested shows an entirely different cracking behavior and probably follows a different cracking mechanism. (2) the diameter of a fixed-bed Fischer-Tropsch reactor critically affected the resistance of the reactor to plugging ...
Apoptosis, or programmed cell death (PCD), is a fundamental process that protects organismal integrity. In earlier work, we demonstrated that over-expression of either of two anti-apoptotic members of the BCL-2 family (BCL-2 or BCL-X L could elevate the frequency of radiation-induced mutations at the autosomal TK1 locus in human TK6 lymphoblasts that express wild-type TP53. Ectopic expression of BCL-X L also elevated the frequencies of double-strand break-induced gene conversion. The purpose of this study is to determine if BCL-2 family proteins promote radiation mutagenesis indirectly through their suppression of PCD, or whether the 'pro-mutagenic' function of these proteins can be separated from their anti-apoptotic function. We developed stable transfectants of TK6 cells that express a mutated form of BCL-X L with a single amino acid substitution in the BH1 domain that is known to interfere with the ability to suppress PCD (BCL-X L ...
Bioethanol is among the most promising of biofuels that can be produced from different biomass such as agricultural products, waste and byproducts. This paper reported on a study that examined the energy conversion of different groups of biomass to bioethanol, including lignocelluloses, starches and sugar. Biochemical conversion generally involves the breakdown of biomass to simple sugars using different pretreatment methods. The energy needed for the conversion steps was calculated in order to obtain mass and energy efficiencies for the conversions. Mass conversion ratios of corn, molasses and rice straw were calculated as 0.3396, 0.2300 and 0.2296 kg of bioethanol per kg of biomass, respectively. The energy efficiency of biochemical conversion of corn, molasses and rice straw was calculated as 28.57, 28.21 and 31.33 per cent, respectively. The results ...
An investigation was conducted into alternative techniques for zinc and electrolyte regeneration and reuse in the refuelable zinc/air battery that was developed by LLNL and previously tested on a moving electric bus using cut wire. Mossy zinc was electrodeposited onto a bipolar array of inclined Ni plates with an energy consumption of 1.8 kWh/kg. Using a H{sub 2}-depolarized anode, zinc was deposited at 0.6 V (0.8 kA/m{sup 2}); the open circuit voltage was 0.45 V. Three types of fuel pellets were tested and compared with results for 0.75 mm cut wire: spheres produced in a spouted bed (UCB); coarse powder produced by gas-atomization (Noranda); and irregular pellets produced by chopping 1-mm plates of compacted zinc fines (Eagle-Picher, Inc.). All three types transported within the cell. The coarse powder fed continuously from hopper to cell, as did the compacted pellets (< 0.83 mm). Large particles (> 0.83 mm; Eagle-Picher and UCB) ...
In areas where radiation dose monitoring has not been performed, it is essential to use material available in the environment be able to rapidly assess doses to individuals for immediate emergency medical care or for general estimation of the radiological consequences. It was shown that certain types of telephone cards containing microchips have the potential to be used as individual radiation dosimeters in emergency situations to detect doses over 250 mGy by luminescence measurements. In order to understand the dosimetric properties of chip cards, the components obtained from INFINIEON Company at various stages of production were used for luminescence measurements. It is found that the protecting layer used above the chips so called 'globe top' is the main source of radiation induced signal in chip cards. The globe top produced by INFINIEON at that stage is found to contain SiO2 and Epoxy. In order to improve the dosimetric properties of the chip cards, the raw ...
Oxidation of propylene with oxygen, air and a mixture of nitrogen?oxygen in a barrier discharge is investigated. The selectivity towards formation of propylene oxide in pure oxygen is shown to be as high as 45 wt% and the propylene conversion ratio is found to be 12.9 wt%. In the oxidation with air, the propylene oxide selectivity is 23 wt%, while the conversion is 7.5 wt%. The values of propylene conversion and selectivity towards formation of propylene oxide in a barrier discharge are consistent with those obtained by the thermocatalytic methods for production of propylene oxide.
This paper presents the results of a study commissioned by the British Columbia Science Council to identify opportunities for liquefaction of B.C. coals and to recommend effective approaches to the development of a research program on coal conversion. Contains reviews of British Columbia coal resources to identify prospective candidates for conversion to liquid fuels; of the state of the art in the various processes for the conversion of coal to liquid fuels with particular emphasis on those processes most relevant to British Columbia applications; and of research opportunities in British Columbia for the development of coal liquefaction technology. (16 refs.)
Red mud, and red mud activated by dissolution in hydrochloric acid and reprecipitation with ammonia, were tested as catalysts for the hydrogenation of an anthracene oil in a trickle-bed reactor. Conversion data were determined for the different polyaromatic compounds in the anthracene oil. Red mud shows appreciable catalytic activity, which is enhanced by the activation. Although both red mud and activated red mud are less active than a commercial Ni-Mo/[gamma]-alumina hydrotreating catalyst, the difference in activity is smaller when conversion to hydroaromatics instead of total conversion of reactants is considered. 20 refs., 8 figs., 3 tabs.
Physical processes in the region of laser conversion for the next Linear Colliders (NLC) are discussed. The main goal of this conversion is to obtain high-energy intense #gamma# beams for #gamma#e and #gamma##gamma# colliders. This conversion has important by-products: (i) one can observe here effect of nonlinear QED (in a strong external field)-production of e"+e"- pairs by a high-energy photon and emission of very high-energy photons by an electron; (ii) one can produce and observe here the invisible axion in colliding #gamma#_0e beams. The NQED effects also result in variation of the spectra of high-energy photons and an additional background. 12 refs., 12 figs., 1 tab.
Because of its direct energy conversion techniques, AMTEC is the front runner today. However, because these systems are now only in the preliminary design ...
Apparatus and method are described for the vaporization of liquid fuel oils to produce a gaseous mixture suitable for burning in a burner normally designed for operation utilizing natural gas.
BackgroundMutations that disrupt the conversion of prelamin A to mature lamin A cause the rare genetic disorder Hutchinson-Gilford progeria syndrome and a group of laminopathies....Full Text Available
This volume contains the corporate author index, author index, and subject index for publications entered into the IEA Biomass Conversion Technical Information System during the year 1987. (DT)
... This is the case for the 82nd Airborne Division ready brigade force (DRB) and the Military Airlift Command (MAC) strategic airlift system operating ...
This volume contains the corporate author index, author index, and subject index for publications entered into the IEA Biomass Conversion Technical Information System during the year 1986. (DT)
To investigate mechanisms responsible for positive and negative transcriptional control, the authors have utilized two types of promoters that are diffferentially regulated by thyroid hormone (T{sub 3}) receptors. Promoters containing the palindromic T{sub 3} response element TCAGGTCA TGACCTGA are positively regulated by the T{sub 3} receptor after the administration of T{sub 3}, whereas otherwise identical promoters containing the estrogen response element TCAGGTCA CTG TGACCTGA can be regulated negatively; converse effects are observed with the estrogen receptor. They describe evidence that the transcriptional inhibitory effects of the T{sub 3} or estrogen receptors on the estrogen or T{sub 3} response elements, respectively, are imposed by amino acid sequences in the C'-terminal region that colocalize with dimerization and hormone-binding domains and that these sequences can transfer inhibitory functions to other classes of ...
The patients studied were referred for routine abscess localization with indium-111 labelled autologous leukocytes. One series (n=15) was studied at 1 day after reinjection of labelled cells and a second series (n=9) was studied between 4 hours and 4 days after reinjection of labelled cells. The leukocytes were isolated by a gravity sedimentation method and labelled with In-111 oxinate according to Roevekamp and co-workers. The labelled cell suspension administered to the patient contained between 11 and 15 MegaBq (300-400 microCi). The indium-111 concentration in the liver and spleen was quantitated using a scintillation camera and an on-line computer system. Phantom studies were carried out to obtain conversion factors from geometric mean counts to MegaBq of activity for both liver and spleen. Once determined, the amount of activity in liver and spleen was corrected for physical decay of In-111 and expressed as a percentage of the administered activity. ...
Among the most promising technological alternatives for the development of photovoltaic modules and cells of a low cost, good energetic conversion and feasibility for mass production, polycrystalline silicon thin film solar cells deposited directly on a transparent substrate are currently being considered the best. We have developed in our laboratory a PECVD reactor capable of producing the deposition of amorphous hydrogenated silicon at rates of above 2 nm/seg, allowing a significant production per line on the plant. Discharge gas is silane, to which diborane or phosphine is added so as to form the cell. Basically, work is done on a structure of cell type TCO/n+/p-/p+/M, which has 2 {mu}m of total thickness. Schott AF-37 glass is used as a substrate, for their ability to withstand temperatures of up to 800 C. The amorphous cell is subsequently annealed at gradual temperatures of 100 C to achieve dehydrogenation up to 650-700 C for 12 h until ...
Photoelectrochemical oxidation is a potentially interesting method for destroying toxic organic materials. We have studied the photoelectrocatalytic activity of TiO{sub 2} films made by thermal oxidation of titanium, low pressure chemical vapour deposition (LPCVD), and anodisation of titanium. Two model organic compounds have been investigated for photooxidation: methyl phosphonic acid (MPA) which is a nerve gas analogue and 4-chlorophenol (4-CP) which is a chlorinated aromatic compound considered a standard for the evaluation of the TiO{sub 2} / UV processes. In addition to photoelectrochemical characterisation the films have been characterised by profilometry, XRD, AFM, photocurrent spectroscopy and Raman microscopy. Correlations have been made between the physical properties of the thin films and their catalytic activities. The most catalytic sample of thermally oxidised titanium was prepared at 400 deg C, and the presence of anatase was shown by XRD, MPA degradation test and ...
The cost of liquid fuels from coal is a complex function of many factors, such as capital investment, cost of coal and labor cost. Furthermore, the cost will depend on geographical position, the size of the operation and the efficiency of the process. There is no single answer and case studies will have to be made to establish economics at different locations. In the following, the 1980 order-of-magnitude investment costs and operating costs for a coal liquefaction plant are estimated. For a Sasol II type of plant with the product output indicated earlier, the total capital cost is estimated at $4 billion in 1980 dollars. Capital cost accounts for approximately 50%, utilities and materials for 30%, and labor for 20% of the total cost. Given the market value of by-product ethylene ($175/t), tar products ($300/t), chemicals ($300/t), ammonia ($200/t) and sulfur ($25/t), the credit for by-products is $146 million per year. The cost of motor fuel is thus estimated at ...
The objectives of this project are to support the DOE direct coal liquefaction process development program and to improve the useful application of analytical chemistry to direct coal liquefaction process development. Independent analyses by well-established methods will be obtained of samples produced in direct coal liquefaction processes under evaluation by DOE. Additionally, analytical instruments and techniques which are currently underutilized for the purpose of examining coal-derived samples will be evaluated. The data obtained from this study will be used to help guide current process development and to develop an improved data base on coal and coal liquids properties. A sample bank will be established and maintained for use in this project and will be available for use by other researchers. The reactivity of the non-distillable resids toward hydrocracking at liquefaction conditions (i.e., resid reactivity) will be examined. From the literature and data experimentally obtained, ...
The aim with this project sponsored by Energimyndigheten is to develop a method for calculations of grate boilers fueled by bark. This report describes this project, 'Evaluation Method for Grate Combustion' (EMGC). CFD codes is an engineering tool applicable in the area of the over-grate section called the furnace. This part of the boiler is easy to model for an experienced CFD code user and the results are usually quite satisfactory for evaluating the combustion process in general. Various gas phases reactions and related combustion processes over the burning bed can be simulated including air staging, fuel staging and SNCR. However the simulation needs information of amount and properties of the burning bed products, entering the furnace. The simulation of the in-furnace processes without this information is often just a numerical speculation. A predictive mathematical model based on physical and chemical data for the grate and fuel bed would solve this problem. ...
An experimental study of second harmonic generation in a copper-vapor pulsed laser with an ADP crystal is presented. The ratio of the conversion into the second harmonic is found to depend on the average power of the exciting radiation. The maximum conversion ratio was 8.5%. Thermal self-defocusing is the main obstacle to obtaining high average powers at the double frequency.
The IAEA Department of Safeguards established a project in 1996 for the year 2000 (Y2K) conversion activities. This project covered assessment, conversion and testing of the software applications, instrument evaluation software, embedded systems and Personal Computer (PC) hardware attached to various equipment. Significant progress has been made in converting the applications and instruments to be year 2000 compliant. At the same time Member states have made an effort as well in converting the systems used jointly at the facilities
This is the June report by the Energy Information Administration. The contents of the report include an energy overview, energy consumption, petroleum, natural gas, oil and gas resource development, coal, electricity, nuclear energy, energy prices, and international energy. Included are appendices containing thermal conversion factors, metric and other physical conversion factors, and carbon dioxide emission factors for coal.
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.
Using the experimentally determined cutoff energies of the muon-electron and the pion-electron conversion curves in a tachyon-bradyon model of the electron and the muon, the magnetic moments of these particles have been derived and found to be the Bohr magnetons identically. The tachyons, being bound to the bradyons and unable to drop below the speed of light, cause the bradyons to revolve in an orbit. It is this orbital motion of the charged bradyons that generates the magnetic moments.
This paper reports the effectiveness of solvents on the liquefaction of 11 different Turkish lignites investigated by using tetralin, creosote, and anthracene oils. The highest total conversions were obtained with tetralin. The catalytic effects of CoMo and red mud were compared by using creosote oil as the solvent. It was found that red mud catalyzed mainly the asphaltene formation reaction for the given experimental conditions. The additional of CoMo significantly catalyzed the liquefaction reaction, thus increasing the lignite conversion and oil formation.
The aim of the paper is brief description of the present state and main results of investigations on the direct energy conversion (EC). The following EC development directions are considered: thermoelectric EC, thermionic EC, thermophotovolt EC, magnetohydrodynamic-dynamic EC, nuclear-optical EC, plasma-chemical EC and electrochemical EC (hydrogen power engineering
The carbon content of silicon single crystals and polycrystals has been measured by charged particle activation analysis (CPAA) and infrared absorption. The authors obtained a linear relationship between the absorption coefficient at 605 cm/sup -1/ and the carbon content obtained by CPAA. They obtained a conversion factor of (1.00 +- 0.03) 10/sup 17//cm/sup 2/ for a 100% substitutional carbon.
This book deals specifically with the development of new processes of converting coal into useful chemical feedstocks. The major topic in this volume is the generation of syngas and its catalytic conversion to chemicals via the Fischer-Tropsch synthesis. Describes processes involved in conversion, recent catalytic developments, and the commercially important Sasol process. Also includes chapters on the carbide process and potential of future developments in the field.
This thesaurus contains the vocabulary used to index the Biomass Database maintained by the IEA Biomass Conversion Technical Information Service. The database, which is used to produce Biomass Abstracts, contains indexed and abstracted references to the published literature relating to biomass energy including cultivations, harvesting, materials handling, conversion techniques, environmental aspects and economics.
The catalytic liquefaction of a Chinese bituminous coal was simulated by artificial neural network. Three liquefaction variables, catalyst loading, reaction temperature and reaction time were used as inputs and tetrohydrofuran (THF) conversion and toluene (T) conversion were used as outputs. The artificial neural network, trained by the experimental data, could represent the liquefaction process, with a mean squared deviation of less than 0.025. 7 refs.,1 fig., 3 tabs.
Nine coals from Spanish, British, German and American mining basins were hydrogenated using Fe catalyst precursors (red mud and FeSO{sub 4}), without solvent at 300, 350, and 400 {degree}C and 10 MPa of H{sub 2}. Overall conversion and product distribution are related to the textural characteristics of the original coals and are studies throughout the distinct hydrogenation processes. Results reveal that with FeSO{sub 4} as a catalyst precursor, conversions increase with coal surface area. However, when red mud (RM) is used, conversions are independent of coal textural characteristics. Higher conversions are obtained with FeSO{sub 4} than with RM at 300 and 350 {degree}C whereas at 400 {degree}C higher conversions are obtained with RM. This different catalytic activity is also reflected in the changes of the textural characteristics observed in each case. Up to 350 {degree}C, the ...
This paper addresses the unique structural requirements for successful conversion of tankers for floating production storage and offloading (FPSO) or floating storage and offloading (FSO) service. A description is given of the steps undertaken during two recent and very different conversions of a highly optimized 1980s VLCC to FPSO service, and a typical robust 1970s ULCC to FSO service. The paper describes the steps needed for ensuring the FPSO or FSO requirements are successfully met during conversion of the two tankers - each having its own history, e.g. date of build, original design, material choices, class society, voyage history and repairs. Firstly, the paper describes the procedure and results of an early initial structural assessment procedure on the basis of an American Bureau o...
Phosphate/chromate and accelerated chromate coatings were produced on commercially available aluminium. The Cr, P and Fe components of the conversion coatings were determined by radioactive tracer technique. The tracer technique was combined with ion-exchange and film-sectioning methods to determine the chromium(III)/total chromium ratio in the accelerated chromate coating. It was found that during the acidic dissolution of the conversion coating the chromium(III)/total chromium ratio may suffer changes. The film-forming components in the metal/bath interface are supersaturated and deposited onto the aluminium. The identified components of the accelerated chromate coatings are Cr(OH)sub(3), Cr(OH)CrOsub(4) and Crsub(4)(Fe(CN)sub(6))sub(3) and the chromium(III)/total chromium ratio was found to be cca. 2/3. (author). 11 refs.; 5 figs.
The Science Council accepted the recommendations of the Swan Wooster report on Opportunities for coal liquefaction research in British Columbia, Vancouver, BC, Canada, Science Council of British Columbia, 173 pp (May 1980), following review by the Sub-committee on Coal Research. The Sub-Committee has recommended a four year Research and Development programme on B.C. coals to be carried out at B.C. Research Council. About 5 million dollars would be spent during the four year period. The overall objective is to provide sufficient technical data to identify and evaluate coal conversion opportunities in B.C. A significant secondary objective is to provide a group of trained engineers and scientists in the Province familiar with the technology of coal conversion. (1 ref.)
Silica glasses containing Pr"3"+ with and without CdS nanoparticles were prepared by sol-gel technique. The influence of CdS nanoparticles on Pr"3"+ doped glass was studied by absorption, photoluminescence and up-conversion. From the measured intensities of various absorption bands of these glasses, the Judd-Ofelt parameters ?_2, ?_4 and ?_6 have been evaluated. The radiative transition probability (A), radiative lifetime (?_R), branching ratio (?_R) and integrated emission cross-section (?_P) were calculated from excited states of "3P_1 and "3P_0 levels. The up-conversion emissions were found in the green, orange and red regions under 800 nm excitation with peaks 559, 612 and 688 nm respectively. On excitation with 370 nm also leads to similar green, orange and red regions.
Conversion of the microprocessors and software for the Mold Heating and Cooling (MHAC) pump package control systems was initiated to allow required system enhancements and provide data communications capabilities with the Plastics Information and Control System (PICS). The existing microprocessor-based control systems for the pump packages use an Intel 8088-based microprocessor board with a maximum of 64 Kbytes of program memory. The requirements for the system conversion were developed, and hardware has been selected to allow maximum reuse of existing hardware and software while providing the required additional capabilities and capacity. The new hardware will incorporate an Intel 80286-based microprocessor board with an 80287 math coprocessor, the system includes additional memory, I/O, and RS232 communication ports.
Measurements of {gamma}-ray, {gamma}{gamma}-coincidence and internal conversion electron spectra from the {sup 106}Cd({alpha},n{gamma}){sup 109}Sn reaction were carried out at 15-20 MeV {alpha}-particle bombarding energies with Ge(HP) {gamma}-ray and superconducting magnetic lens plus Si(Li) electron spectrometers. The energies, relative intensities, internal conversion coefficients and coincidence relations of the {sup 109}Sn transitions were determined, and a more complete, consistent level scheme has been deduced. Spin and parity values have been determined from the internal conversion coefficients, the bombarding-energy dependence of the side-feeding intensities of the states and the available {gamma}-ray angular distribution data. The level scheme was interpreted in the framework of the quasi-particle shell model.
This paper examines cupric chloride solid conversion during hydrolysis in a thermochemical copper-chlorine (Cu-Cl) cycle for hydrogen production. The hydrolysis reaction is a challenging step, in terms of the excess steam requirement and the decomposition of cupric chloride (CuCl_2) into cuprous chloride (CuCl) and chlorine (Cl_2). The hydrolysis and decomposition reactions are analyzed with respect to the chemical equilibrium constant. The effects of operating parameters are examined, including the temperature, pressure, excess steam and equilibrium conversion. A maximization of yield and selectivity are very important. Rate constants for the simultaneous reaction steps are determined using a uniform reaction model. A shrinking core model is used to determine the rate coefficients and predict the solid conversion time, with diffusional and reaction control. These new results are useful for scale-up of the engineering ...
Energy harvesting systems stimulate the development of power management for low power consumption applications. Improving the converter efficiency of power management circuits has become a significant issue in energy harvesting system design. This paper presents a variable step-down conversion ratio switched capacitor (SC) DC-DC converter to advance the converter efficiency of charge on the stored capacitor in a wireless monitoring system of orthopedic implants. The converter is designed to work at 1 MHz switching frequency and achieves 15 to 2 V conversion. Measurement results show that the converter efficiency can reach 42% including all circuit power consumption, which is much higher than previous work. (semiconductor integrated circuits)
Pollen morphology of 30 species of the family Acanthaceae belonging to 11 genera has been investigated using light and scanning electron microscope. Acanthaceae is a eurypalynous family. Pollen are usually radially symmetrical, isopolar, sub-prolate to prolate rarely prolate-spheroidal or sub-oblate to oblate-spheroidal, generally tricolporate or heterocolporate rarely colpate or porate. Exine ornamentation varies from medium to coarse reticulate, or often lopho-reticulate with luminae perforated to baculate or scabrate. On the basis of apertural type, exine ornamentation and colpal membrane eight distinct pollen types have been recognized viz., Pollen type-I: Barleria cristata-type, Pollen type-II: Blepharis ciliaris-type, Pollen type-III: Hygrophila polysperma - type, Pollen type-IV: Justicia ...
{sup 60}Co is produced as an activation product and is present in the low-level aqueous radioactive waste released from the La Hague plant. At present, the concentration in the sea (non filtered at 0.45 {mu}m) at the Goury site are close to or even below, the detection limit: 0.2 mBq.l{sup -1}. The {sup 60}Co speciation depends on the type of effluent considered: in the effluent A ('active'), the cobalt is in the form of a stable trivalent complex; in the effluent V (to be checked), the cobalt is in majority (50% of the activity release) in the form of particles (>0.45 {mu}m), and then in the form of two soluble species: ionic divalent (Co{sup 2+}) and some stable complexes. The evolution of the reprocessing techniques used does not affect the speciation. So, since the nuclear reprocessing plant started at the La Hague plant in 1966, the chemical species discharged in the sea shows time variation related to the evolution of the ...
vehicles including the H2-A rocket and the space shuttle. .... The vacuum can's main function is to provide a high vacuum so that the science experiment and its sensors ... EMI-shielded power conversion from the incoming ISS power supply. 4. ...
Molecular Misreading (MM) is the inaccurate conversion of genomic information into aberrant proteins. For example, when RNA polymerase II transcribes a GAGAG motif it synthesizes at low frequency RNA...Full Text Available
The present invention relates to a method of recycling polymeric waste products into monomers and high value forms of carbon by pyrolytic conversion using an induction coupled RF plasma heated reactor.
The metabolism of DDT has been followed in pure lines of laboratory-reared resistant and susceptible anophelines using gas-liquid chromatography. Relatively large amounts of DDE were formed in...Full Text Available
The purpose of the conversion process is to convert the {sup 233}U fluoride compounds that are being extracted from the Molten Salt Reactor Experiment (MSRE) equipment to a stable oxide for long-term storage at Bldg. 3019.
SummarySoluble epoxide hydrolase (sEH) is a key enzyme in the metabolic conversion and degradation of P450 eicosanoids called epoxyeicosatrienoic acids (EETs). Genetic variations...Full Text Available
Purpose: calculation of conversion coefficients for the reconstruction of organ doses from entrance doses for abdomen radiographs of 0, 1, 5, 10, 15, and 30-year-old patients in conventional pediatric radiology for the radiographic settings recommended by the German and European guidelines for quality management in diagnostic radiology. Materials und method: using the commercially available personal computer program PCXMC developed by the Finnish Center for Radiation and Nuclear Safety (Saeteilyturvakeskus STUK), conversion coefficients for conventional abdomen radiographs were calculated performing Monte Carlo simulations in mathematical hermaphrodite phantom models describing patients of different ages. The possible clinical variation of beam collimation was taken into consideration by defining optimal and suboptimal radiation fields on the phantoms' surfaces. Results: conversion coefficients for the ...
Technologies for materials, processes, and manufacturing that will provide safe, .... advanced energy conversion techniques, and pulsed inductive and ... duration antimatter storage and transportation, and methods for utilizing ...... EVA systems can be found in the EVA Technology Roadmap of the EVA Project Plan. ...
The speA gene in Bacillus subtilis encodes arginine decarboxylase, which catalyzes the conversion of arginine to agmatine. Arginine decarboxylase is an important enzyme...Full Text Available
The high-yield, stereoselective conversion of geraniol (3,7-dimethyl-trans-2,6-octadien-1-ol) to the insect juvenile hormone, methyl 12,14-dihomojuvenate (methyl cis-10-epoxy-3,11-dimethyl-7-ethyl-trans,...Full Text Available
Electron cyclotron emission (ECE) can be used to determine the electron temperature profile in magnetized plasmas. The complex structure of the magnetic field configuration in the Large Helical Device (LHD), which has a large shear, complicates the analysis of the ECE spectrum. In a sheared magnetic field the propagation of X and O-mode polarization through the plasma are coupled, causing mode conversion and polarization rotation. Mode scrambling is also caused by wall reflections. In this report, this mode conversion in LHD is numerically analyzed. It was found that at low density mode conversion scrambles the ECE spectra. However, at higher density (n{sub eo} > 1.0{center_dot}10{sup 19} m{sup -3}) the polarization mode is found to rotate with the sheared magnetic field, yielding only a negligible mode conversion. Wall reflections are found to depolarize the ECE spectrum. Notwithstanding the LHD ...
Phenylketonuria (PKU) is a common genetic disorder in humans that arises from deficient activity of phenylalanine hydroxylase (PAH), which catalyzes the conversion of phenylalanine to tyrosine....Full Text Available
Dimethacrylate polymers and composites are seeing increased usage in orthopedics. As these applications require the material to integrate with the surrounding tissues, direct contact cytotoxicity...Full Text Available
The conversion of coal to oil can be carried out in two ways. A synthesis route and a degradation route. Each of these routes are described and several degradation processes are explored. The testing of several fuels produced from coal is also given considerations.
Extra-terrestrial exploration and development missions of the next century will require reliable, low-mass power generation modules of 100 kW_e and more. These modules will be required to support both fixed-base and manned rover/explorer power needs. Low insolation levels at and beyond Mars and long periods of darkness on the moon make solar conversion less desirable for surface missions. For these missions, a closed Brayton cycle energy conversion system coupled with a reactor heat source is a very attractive approach. The authors conducted parametric studies to assess optimized system design trends for nuclear-Brayton systems as a function of operating environment and user requirements. The inherent design flexibility of the closed Brayton cycle energy conversion system permits ready adaptation of the system to future design constraints. This paper describes a dramatic contrast between system designs requiring man-rated ...
The concept of nanocrystal conversion chemistry, which involves the use of pre-formed nanoparticles as templates for chemical transformation into derivative solids, has emerged as a powerful approach for designing the synthesis of complex nanocrystalline solids. The general strategy exploits established synthetic capabilities in simple nanocrystal systems and uses these nanocrystals as templates that help to define the composition, crystal structure, and morphology of product nanocrystals. This article highlights key examples of 'conversion chemistry' approaches to the synthesis of nanocrystalline solids using a variety of techniques, including galvanic replacement, diffusion, oxidation, and ion exchange. The discussion is organized according to classes of solids, highlighting the diverse target systems that are accessible using similar chemical concepts: metals, oxides, chalcogenides, phosphides, alloys, intermetallic compounds, sulfides, and ...
A process is described for covering methane to a higher order hydrocarbon comprising contacting a gaseous reactant consisting of methane with a phosphate-containing catalyst for a sufficient period of time and at an effective temperature to provide the phosphate-containing catalyst consisting essentially of the higher order hydrocarbon. The catalyst is represented by a formula.
Because copper catalyzes the conversion of H2O2 to hydroxyl radicals in vitro, it has been proposed that oxidative DNA damage may be an important component of copper toxicity....Full Text Available
BackgroundThe immunoregulatory enzyme indoleamine 2,3-dioxygenase, which catalyzes the conversion of tryptophan into kynurenine, is expressed in a significant subset of patients...Full Text Available
The objective of the current research in coal liquefaction is to produce a synthetic crude from coal at a cost lower than $30.00 per barrel (Task A). A second objective is to produce a fuel which is low in aromatics, yet of sufficiently high octane number for use in the gasoline-burning transportation vehicles of today. To meet this second objective, research was proposed for conversion of the highly-aromatic liquid product from coal conversion to a product high in isoparaffins, which compounds in the gasoline range exhibit a high octane number (Task B). Experimental coal liquefaction studies conducted in a batch microreactor in the laboratory have demonstrated potential for high conversions of coal to liquids with low yields of hydrocarbon (HC) gases, hence small consumption of hydrogen in the primary liquefaction step. Ratios of liquids/HC gases as high as 30/1, at liquid yields as high as 82% of the coal by weight, have ...
The authors investigate the possibility of the direct heterogeneous catalytic synthesis of ethylbenzoate from benzonitrile. The catalysts tested were oxides of aluminium, titanium, and vanadium. The main conversion product detected chromatographically was ethylbenzoate; benzaldehyde, benzamide, and benzanilide were also identified. Aluminium oxide was found to be the most effective catalyst.
This is an internal DOE Geothermal Program document. This document contains summaries of projects related to exploration technology, reservoir technology, drilling technology, conversion technology, materials, biochemical processes, and direct heat applications. [DJE-2005
In order to develop a high-efficiency coal pyrolysis method, flash pyrolysis was experimented on slurry prepared by using liquid-phase oxidation reformed coal and a methanol-based solvent mixture. Australian Morwell coal was used for the experiment. The oxidized coal, into which carboxyl groups have been introduced, has the condensation structure relaxed largely, and becomes highly fluid slurry by means of the solvent. Char production can be suppressed by making the oxidation-pretreated coal into slurry, resulting in drastically improved pyrolytic conversion. The slurry was divided into dissolved solution, dried substance, extracted residue, and residual slurry, which were pyrolized independently. The dissolved solution showed very high conversion. Improvement in the conversion is contributed by separating the dissolved substances (coal macromolecules) at molecular levels, coagulating the molecules, suppressing cross-link ...
BackgroundCyclooxygenase (cox) is the rate-limiting enzyme, which catalyzes the conversion of arachidonic acid into prostaglandins and contributes to the inflammatory process. Cyclooxygenase-2...Full Text Available
The 7 conference papers in Vol. 9 review the implications of environmental problems and discuss the consequences of pollution abatement measures, especially for the economics of energy conversion. The future developments of pollutant emissions are assessed.
...wood smoke, emissions, pollution, heaters, environment, Earthbeat - 25/5/2002: Woodsmoke, Health & the Environment Love that Planet All in the Mind The Buzz Health Report In Conversation Ockhams Razor Science Show The Lab Health Matters Catalyst Quantum ...
The hypothesis that the antiarrhythmic drug amiodarone slows down the heart rate by its inhibitory action on the intracellular conversion of thyroxine (T4) to 3,5,3' triiodothyronine (T3) was investigated....Full Text Available
A new process for the hydrogenation of coal in the presence of wide-cut coal tar was proposed; it involves cavitation treatment, mixing with catalytic additives, and heating the resulting mixture at an elevated pressure in an atmosphere of hydrogen. The yields of hydrocarbon fractions to 300?C and gas condensate were evaluated.
The incorporation of [14C]phenylalanine and [1,6-14C]shikimic acid into tyrosine was investigated in the callus of Portulaca grandiflora, var. JR (L.). By inhibiting...Full Text Available
DOE is supporting the development of several conversion processes that are currently in the pilot plant stage. Each of these processes is described briefly and information given as to contractor, contract, funding, site and current progress. Several support projects are treated similarly. (LTN)
Several isolates of bacteria and fungi from soil, together with cells released directly from soil, were studied with respect to buoyant density and dry weight. The specific volume (cubic centimeters...Full Text Available
The objective of this project is to identify feasible Louisiana-grown biomass crops and residues, to combine these with technically and economically feasible conversion processes, and to provide integrated biomass energy production systems in Louisiana. Among the recommended integrated systems are: cotton gin trash and rice hull processing residues used for either direct combustion or methane or ethanol production. Steam generation via direct combustion is recommended. Hardwood chips are economically feasible despite considerable price and supply instability, while high sugar or starch content crops are easily converted to ethanol but limited by price. Possible breakthroughs in biomass production or in the hydrolysis of starch or cellulose substrates may decrease processing costs. Recommended areas for future study dealing with production include: (1) increase biomass availability and density; (2) increase harvesting, transportation and storage technologies; (3) ...
An assay to measure the rate of enzymatic formation of 3-methylindole (3MI) from indoleacetic acid (IAA) in Lactobacillus sp. strain 11201 was developed. The reaction mixture contained 50 micrograms...Full Text Available
The overall goal of the Gas-to-Liquids Program at the U.S. Department of Energy`s Pittsburgh Energy Technology Center (PETC) is to develop technologies for the production of hydrocarbon fuels and premium chemicals from light alkane gases. PETC`s current Gas-to-Liquids Program comprises the development of four primary advanced conversion technologies, namely, partial oxidation, oxidative coupling, oxyhydrochlorination, and novel conversion processes. Based on the current state of development, it can be concluded that, in the near future, one or more of these technologies will reach proof-of-concept demonstration. Oxyhydrochlorination is the most advanced direct conversion technology, and the synthesis of lower cost methyl chloride from natural gas would impact several commercial technologies that utilize methyl chloride as an intermediate to high value products. Technology development for the partial oxidation of methane to ...
Study of the conversion of chicken litter to biogas for the production of energy. There was an additional requirement that after extracting the energy from the chicken litter the nutrient value of the raw chicken litter had to be returned to the Ak-Chin Farms for use as fertilizer in a form and delivery method acceptable to the Farm.
This report describes studies made during the fourth quarter of 1986 using the revised microautoclave experimental technique. Studies were made of the effect of reaction time on conversion using Kemmerer coal. Results that, at least during the first 30 minutes, conversion is a monotonically increasing function of reaction time and temperature. A study was also made of the effect of temperature on conversion. In general, conversion increased with temperature. The reactivity of coal appears to be unaffected by exposure to Certigrav fluid, if the exposed coal is subjected to two acetone washings under a nitrogen blanket. Work was started on using SCR-II process solvent in place of tetralin. Results indicate that SRC-II process solvent is a satisfactory solvent donor for high reactivity, high ash bituminous coals, but slightly less effective for low ash, subbituminous coals. Some tests were made to examine ...
A shear acoustic transducer-lens system in which a shear polarized piezoelectric material excites shear polarized waves at one end of a buffer rod having a lens at the other end which excites longitudinal waves in a coupling medium by mode conversion at selected locations on the lens.
THE GFS WILL BE THAT THE DEFAULT PRECIPITATION TYPE ALGORITHM WILL CHANGE FROM THE BALDWIN METHOD TO THE DOMINANT PRECIPITATION TYPE. THE DOMINANT PRECIPITATION TYPE IS...
A nuclear battery based on the direct energy conversion of the fission products is presented. Such energy conversion is possible by using a nuclear reactor with ultra-thin fuel elements of 0.2 {mu}m of {sup 242m}Am. The amount of nuclear fuel is 376 g and the dimensions of the battery are 2.4x2.4x2.4 m{sup 3} (including the vacuum spacing), with a BeO moderator and Be electrodes. The total power of the reactor is 10.6 MW and the electrical power is 0.652 MW.
This paper reports on the results of experiments into efficient higher-order anti-Stokes Raman conversion of tunable short-pulse XeCl laser radiation. The maximum output energy of the pumping laser, in which the radiation of a frequency-doubled dye laser is amplified by two XeCl laser amplifiers, is 55 mJ with a pulse duration of 1 ns FWHM. Using hydrogen gas as a Raman medium, a series of anti-Stokes lines up to the 12th order (121.5 nm) is generated in the vacuum ultraviolet (VUV) region. 16 references.
According to W. H. Wiser and A. G. Oblad, the program at the University of Utah to develop coal conversion techniques, which has received federal grants of $1.35 million since 1969, recently was awarded $425,000 from the U.S. Office of Coal Research for the development of catalysts for coal conversion and low-sulfur fuel oil production. In tests, 100 lb of coal have been converted into 95 lb of products composed of 30 lb liquid fuel like gasoline, 5 lb of diesel or fuel oil, 30 lb of gaseous fuel, and 30 lb of char.
Polymer electrolyte membrane fuel cells (PEMFCs) are energy conversion devices that produce electricity from a supply of fuel, such as hydrogen. One of the major challenges in achieving efficient energy conversion is the development of cost-effective materials that can act as electrocatalysts for PEMFCs. In this letter, we demonstrate that, instead of conventional noble metals, such as platinum, chromium nitride nanocrystals of fcc structure exhibit attractive catalytic activity for PEMFCs. Device testing indicates good stability of nitride nanocrystals in low temperature fuel cell operational environment.
Carbon monoxide, H{sub 2}, and CO{sub 2} in synthesis gas can be converted to CH{sub 4} by employing a triculture of Rhodospirillum rubrum, Methanosarcina barkeri, and Methanobacterium formicicum. Trickle-bed reactors have been found to be effective for this conversion because of their high mass-transfer coefficients. This paper compares results obtained for the conversion of synthesis gas to CH{sub 4} in 5-cm- and 16.5-cm-diameter trickle-bed reactors. Mass-transfer and scale-up parameters are defined, and light requirements for R. rubrum are considered in bioreactor design.
This paper reports the presence of face centered cubic cobalt precipitates inside tungsten carbide in nanocomposite of WC-Co synthesized by spray conversion processing. EDS was used to identify the presence and micro-diffraction was employed to determine the nature of the precipitates. There is entrapment of cobalt in tungsten carbide during the spray conversion process used to form WC/Co powder. During consolidation, at high temperatures, the cobalt attains enough mobility to precipitate inside WC. A vanadium containing compound was seen at the interfaces in samples which incorporated VC as a grain growth inhibitor. (orig.)
Four high-sulphur low-rank coals have been treated at hydrogenation conditions with three iron-based catalyst precursors: Red Mud (Fe[sub 2]O[sub 3]), iron sulphide and iron pentacarbonyl. The obtained yields show a dependence with the sulphur content of the coals; the organic sulphur content correlates with the conversion and THF-solubles when Red Mud and iron sulphide are added. In spite of the high hydrogen sulphide partial pressure in the reaction, the addition of other sources of sulphur enhances the percentages in conversion products. 15 refs., 2 figs., 3 tabs.
Fluidized bed technology was experimentally evaluated for the combustion and gasification of cotton gin waste. The isothermal bed temperatures in the reactors could be maintained below the ash fusion point of the waste. Raw stripper harvested cotton gin trash could be metered directly into the fluidized-bed reactors indicating that little feed preparation is required. H and CO were the primary products of gasification, and approximately 3200-400 Btu of gas were produced per lb of cotton gin waste. These techniques offer the potential of providing small-scale energy conversion systems for use on farms.
Biomass can provide a substantial energy source. Liquids are preferred for use as transportation fuels because of their high energy density and handling ease and safety. Liquid fuel production from biomass can be accomplished by any of several different processes including hydrolysis and fermentation of the carbohydrates to alcohol fuels, thermal gasification and synthesis of alcohol or hydrocarbon fuels, direct extraction of biologically produced hydrocarbons such as seed oils or algae lipids, or direct thermochemical conversion of the biomass to liquids and catalytic upgrading to hydrocarbon fuels. This report discusses direct thermochemical conversion to achieve biomass liquefaction and the requirements for wastewater treatment inherent in such processing. 21 refs.
The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through February 1999.
The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through September 1999.
The Reduced-Moderation Water Reactor (RMWR) is a next generation water-cooled reactor, based on the experienced light water reactor (LWR) technology, aiming at effective utilization of uranium resources, high burn-up and long operation cycle and plutonium multiple recycling. These characteristics can be achieved by the high conversion ratio from {sup 238}U to {sup 239}Pu resulted from the higher neutron energy spectrum in comparison to conventional LWRs. Considering the extension of LWR utilization, Japan Atomic Energy Research Institute (JAERI) started the research on it in 1997 and then started a collaboration in the conceptual design study with the Japan Atomic Power Company (JAPC) in 1998, under technical cooperation with three Japanese reactor vendors. In the core design study of the RMWR, several basic core designs with the high conversion ratio more than 1 and the negative void reactivity coefficient have been proposed, and then, ...
This report is the 1992 annual progress report for the Energy Conversion and Storage Program, a part of the Energy and Environment Division of the Lawrence Berkeley Laboratory. Work described falls into three broad areas: electrochemistry; chemical applications; and materials applications. The Energy Conversion and Storage Program applies principles of chemistry and materials science to solve problems in several areas: (1) production of new synthetic fuels, (2) development of high-performance rechargeable batteries and fuel cells, (3) development of advanced thermochemical processes for energy conversion, (4) characterization of complex chemical processes and chemical species, and (5) study and application of novel materials for energy conversion and transmission. Projects focus on transport-process principles, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, ...
The precipitation reaction of some rare earth chlorides (La/Ce/Nd/GdCl3) in a LiCl-KCl molten salt has been carried out by using the oxygen sparging method. In this study, regardless of the oxygen sparging time and the molten salt temperature, oxychlorides (REOCl) for LaCl3, NdCl3 and GdCl3, and an oxide (REO2) for CeCl3 are formed as a precipitate. The conversion of rare-earth chlorides into insoluble precipitates was described by using a conversion ratio. The conversion ratio increased exponentially with the oxygen sparging time and finally showed asymptotic value at 1,023K of the molten salt temperature condition. The conversion ratios of LaCl3, NdCl3 and GdCl3 were increased with the molten salt temperature, however, even though the conversion ratio was increased from 0.660 to 0.995 with increasing molten salt temperature from 823 to 923 K at 60 min of a sparging time, the ...
U.v.-visible-absorption and e.p.r. spectroscopy were used to study the type 2 and type 3 copper centres in the mercury derivative of laccase. After treatment with peroxide the mercury derivative of...Full Text Available
The purpose of the invention is a process for the production of a particularly finely divided, homogeneous transition metal phosphide and transition metal chalcogenide of Daltonian stochiometry by the conversion of at least one powder transition metal or a transition metal alloy with phosphorus or with a chalcogen at raised temperature, which is characterized by the fact that the conversion is carried out in the presence of at least one inert finely divided auxiliary material which is soluble in water and does not sinter together at the reaction temperature, and that the conversion produce removes the auxiliary material. Even relatively small quantities of the auxiliary material are sufficient to ensure rapid and homogeneous conversion of the reaction partners to the reaction product having a large surface. A ratio of 1 part by volume of a mixture of a transition metal and phosphorus or chalcogen to 1 ...
The Energy Conversion and Storage Program applies chemistry and materials science principles to solve problems in (1) production of new synthetic fuels, (2) development of high-performance rechargeable batteries and fuel cells, (3) development of advanced thermochemical processes for energy conversion, (4) characterization of complex chemical processes, and (5) application of novel materials for energy conversion and transmission. Projects focus on transport-process principles, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, novel materials, and advanced methods of analysis. Electrochemistry research aims to develop advanced power systems for electric vehicle and stationary energy storage applications. Topics include identification of new electrochemical couples for advanced rechargeable batteries, improvements in battery and fuel-cell materials, and the establishment of engineering ...
The Energy Conversion and Storage Program applies chemistry and materials science principles to solve problems in (1) production of new synthetic fuels, (2) development of high-performance rechargeable batteries and fuel cells, (3) development of advanced thermochemical processes for energy conversion, (4) characterization of complex chemical processes, and (5) application of novel materials for energy conversion and transmission. Projects focus on transport-process principles, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, novel materials, and advanced methods of analysis. Electrochemistry research aims to develop advanced power systems for electric vehicle and stationary energy storage applications. Topics include identification of new electrochemical couples for advanced rechargeable batteries, improvements in battery and fuel-cell materials, and the establishment of engineering ...
This report describes progress on the Advanced Coal Liquefaction project by the Gulf Research and Development Company's Merriam Laboratory during the months of January through March 1983. The liquefaction behavior of Illinois No. 6 coal beneficiated in various ways was studied in both single-stage recycle (SRC II) and short contact time (SCT) modes of operation. The distillate yield increased as the iron level in the feed slurry increased in both modes of operation. In the SCT mode, the conversion increased at greater depths of cleaning. In the SRC II mode, the distillate yield and conversion were much higher with deep cleaning and add-back of pyrite than with conventional cleaning. Pyrite addition resulted in a significant increase in short contact time conversion of subbituminous Belle Ayr coal in both high and low quality solvents. Solvent quality itself, however, had little effect on ...
The control problem associated to a class of horizontal-axis fixed-pitch variable-speed low-power wind energy conversion systems, working in the partial load region, consisting in the energy conversion maximization, is approached here under the assumption that the wind turbine model and its parameters are poorly known. Using a new approach derived from the optimum seeking methods category, generically called Maximum Power Point Tracking (MPPT), the proposed control solution aims at driving the average position of the operating point near to optimality. Instead of inducing sinusoidal search signals, the wind turbulence is here used as search disturbance. The high-speed shaft's average rotational speed is slowly adjusted using the Fast Fourier Transform processing of some available measures from the system as an estimate of the operating point's position/distance to optimality. Numerical simulations are used for preliminary ...
Two-dimensional calculations are performed to obtain the conversion efficiency of traveling wave direct energy convertor adopted in a conceptual design of field reversed configuration D-"3He fusion reactor ARTEMIS. For fusion-born 14.67MeV protons, the efficiency obtained is very small compared with that from one-dimensional analysis. This is because the effective electric field for deceleration of the proton is smaller due to distortion of potentials near girds used to excite the traveling wave and because some fractions of the incident proton beams are inevitably lost to the grids with high energy. To increase the efficiency, the potentials may have to be increased. It seems from the two-dimensional analysis performed here that the conversion efficiency obtainable is less than about 60% with the maximum potential of about 6MV, while the corresponding values from the one-dimensional analysis are about 80% and 1.5MV, respectively. (author).
In this report, the concept of exergy and the general methodology of the exergetic analysis and the thermoeconomic (combined exergetic and economic) analysis of energy conversion systems are presented. The THESIS (THermodynamic and Economc SImulation System) computer program used for these analyses is briefly described. Detailed mass, energy, exergy and money balances for a reference steam power plant (Harry Allen Station) are shown. The effect of the most important process parameters on the overall efficiency is investigated. A year-by-year and a levelized revenue requirement analysis are presented. The costs of exergy losses are compared with the capital costs and other expenses due to owning and operating each particular plant component. The question whether it is profitable to reduce the exergy losses by increasing these costs and vice versa is investigated. A cost sensitivity analysis including the effect of coal price and average annual capacity factor is ...
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.
A highly efficient integrated energy conversion system is built based on a methane catalytic decomposition reactor (MCDR) together with a direct carbon fuel cell (DCFC) and an internal reforming solid oxide fuel cell (IRSOFC). In the MCDR, methane is decomposed to pure carbon and hydrogen. Carbon is used as the fuel of DCFC to generate power and produce pure carbon dioxide. The hydrogen and unconverted methane are used as the fuel in the IRSOFC. A gas turbine cycle is also used to produce more power output from the thermal energy generated in the IRSOFC. The output performance and efficiency of both the DCFC and IRSOFC are investigated and compared by development of exact models of them. It is found that this system has a unique loading flexibility due to the good high-loading property of DCFC and the good low loading property of IRSOFC. The effects of temperature, pressure, current densities, and methane conversion on the performance of the ...
The purpose of this study is to analyze the safeties and the economics for Co-60 production from Wolsung PHWR and to verify the feasibility on the manufacturing of the final Co-60 source for industrial irradiation. The feasibility of reactor conversion was carried out with KEPCO collaboration. Through the site survey on the experience of Gentililly-2 in Canada, a feasibility of plant conversion, changes in design, equipment and tools for Co-60 production was verified. It was estimated that the reactor conversion would not impose adverse impact on plant safety. For the encapsulation of radiation source and storage of the final products, a modification of concrete hot cell at KAERI was primary concerns. The installation and improvement of facilities are needed to avoid cross contamination and extra radiation exposure. Main items for these are pressure gauge, separated HEPA filter the ceiling separation, extra-shielding and ...
It was previously reported that the tritium tracer method is useful for the quantitative consideration of hydrogen behavior in coal during coal liquefaction reaction. Tetralin is excellent hydrogen donating solvent, and is considered as one of the model compounds of coal. In this study, effects of H2S and H2O on the hydrogen exchange reaction between tetralin and gaseous hydrogen labeled by tritium were investigated. It was suggested that the conversion of tetralin and the hydrogen exchange reaction between gaseous hydrogen and tetralin proceed through the radical reaction mechanism with a tetralyl radical as an intermediate product. When H2S existed in this reaction, the hydrogen exchange yield increased drastically without changing the conversion yield. This suggested that the hydrogen exchange reaction proceeds even in the reaction where radical does not give any effect. In the case of H2O addition, the conversion yield ...
For high-efficiency coal gasification, investigations were given on effect of coal chars with different conversion rates on coal gasification reactivity. In coal gasification, reactivity of char after pyrolysis governs the efficiency. The reference char conversion in CO2 gasification of coal (weight loss) changes linearly in the initial stage of the reaction, but the reactivity declines as the end point is approached. Char surface area is as large as 400 m{sup 2}/g in the initial stage with the conversion at 20%, but it decreases in the final stage. This phenomenon relates closely with changes in pore size and crystalline structure. Change in the Raman value R which shows incompleteness of char graphite structure and amorphous carbon ratio suggests that an active portion with high reactivity is oxidized preferentially, and a portion with low reactivity remains finally. Minerals in coal are known to accelerate the ...
With the end of the cold war the United States, Russia, and other countries have excess plutonium and other materials from the reductions in inventories of nuclear weapons. The United States Academy of Sciences (NAS) has recommended that these surplus fissile materials (SFMs) be processed so they are no more accessible than plutonium in spent nuclear fuel (SNF). This spent fuel standard, if adopted worldwide, would prevent rapid recovery of SFMs for the manufacture of nuclear weapons. The NAS recommended investigation of three sets of options for disposition of SFMs while meeting the spent fuel standard: (1) incorporate SFMs with highly radioactive materials and dispose of as waste, (2) partly burn the SFMs in reactors with conversion of the SFMs to SNF for disposal, and (3) dispose of the SFMs in deep boreholes. The US Government is investigating these options for SFM disposition. A new method for the disposition of SFMs is described herein: the simultaneous ...
Single crystals of semi-organic L-histidine hydrobromide have been grown by slow evaporation technique from a mixture of L-histidine and hydrobromic acid in aqueous solution at ambient temperature. From high-resolution X-ray diffraction analysis, the crystalline perfection of the grown crystal has been studied. Single crystal X-ray diffraction analyses, Nuclear Magnetic Resonance spectral analysis, Thermo-Gravimetry (TG), Differential Thermal Analysis (DTA) and hardness test have been employed to characterize the as-grown crystals. The UV cutoff wavelength of the grown crystal is below 300 nm and has a wide transparency window, which is suitable for second harmonic generation of laser in the blue region. Nonlinear optical characteristics have been studied using Q switched Nd:YAG laser (#lambda#=1064 nm). The second harmonic generation conversion efficiency of the grown crystals confirms their suitability for frequency conversion applications.
Characteristic study for the recycled fuel cycle, MOX fuel and Th-MOX fuel in PWR was performed with the comparison of 4 w/o UO2 fuel. It was assumed that there are no limit in reprocessing and no technical difficulty in recycling of spent fuel. The effect of recycling, plutonium composition, conversion ratio, MTC, FTC was investigated to each cycle. (Th+Pu)O_2 recycle option was advantageous because the loading amount of plutonium could be reduced from 8.3 w/o at once-through cycle to 3.5 w/o. (Th+Pu)O_2 recycled fuel was known to be higher Pu-239 consumption rate and more Pu-240(242) production rate. The (Th+U)O2 and (U+Pu)O2 once-through fuel cycle revealed high conversion ratio. The (U+Pu)O_2 recycled fuel cycle, however, showed low conversion ratio. Safety of each cycle was ensured by negative MTC and FTC
This report details the status of the Biological Conversion of Synthesis Gas Project. The following tasks are described as being completed: (1) the test plan, (2) culture development, and (3) the mass transfer/kinetic studies. The bioreactor studies (Task 4) are underway. The continuous stirred tank reactor system for the conversion of H{sub 2}S to elemental sulfur using Chlorobium thiosulfatophilum has been studied for varying light intensities. The system was also modified to include both sulfur recovery and cell recycle using ceramic membranes. Studies were also performed to observe the effects of cell recycle using a polysulfone hollow filter membrane module. Work on Task 5, limiting conditions/scale-up, includes a scale-up study with three different size reactors to establish the optimum operating conditions for hydrogen production from synthesis gas by the biological water-gas shift reaction using the photosynthetic bacterium ...
The Korea Atomic Energy Research Institute has launched a decommissioning program of uranium conversion plant. One of the important tasks in the decommissioning program is the treatment of the sludge, which was generated during operation and stored in the two ponds of the lagoon. The treatment requires the volume reduction of lagoon sludges for the low cost of the program and the conversion of the chemical forms, including uranium, for the acceptance at the final disposal site. The physical properties, such as densities, were measured and chemical compositions and radiological properties were analyzed. The denitration was a candidate process which would satisfy the requirements for sludge treatment, and the characteristics of thermal decomposition and dissolution with water were analyzed. The main compounds of the sludge were ammonium and sodium nitrate from conversion plant and calcium nitrate, calcium carbonate from Ca ...
Red mud is generated as a by-product in the production of Al(OH){sub 3}/Al{sub 2}O{sub 3} from bauxite ore. In this study the pellet-type adsorbents have been made from the red mud, and their adsorption capacities of heavy metal ions have been tested. The pellet-type adsorbents were synthesized to utilize the excellent adsorption capacity of the powder-type adsorbent for industrial application. The pellet-type adsorbents were prepared by mixing several kinds of additives with the red mud. It is found that the pellet-type adsorbent, made by sintering a mixture of red mud (96.0 wt%), polypropylene (2.5 wt%), fly ash (0.5 wt%), and sodium meta-silicate (1.0 wt%) at 1200 deg.C for 30 minutes, has the highest adsorption capacity. In this work, the two kinds of pellet-type adsorbents (bead-type, crushed-type) were prepared. ...
MRI, ultrasonography and angiography were performed on 24 cases with small renal cell carcinoma, and data were compared with pathological architecture type. An average diameter of cancer was 20.8 mm (10-30 mm). Each tumor was pathologically classified into four architecture types: alveolar type (15 cases), papillary type (5 cases), tubular type (3 cases) and cystic type (1 case). In comparison with renal cortex alveolar type renal cell carcinoma showed equal or low signal in T1-weighted images and equal or high signal in T2-weighted images. Papillary and tubular types showed high signal in T1-weighted images, and low signal in T2-weighted images. In alveolar type, many cases showed equal echo in ultrasonography and hypervascularity in angiography, and in papillary and tubular ...
Forty resected cases of intrahepatic cholangiocarcinoma were classified into four types according to the gross appearance; type I: mass forming type (n=8), type II: mass forming with periductal infiltrating type (n=20), type III: periductal infiltrating type (n=9) and type IV: intraductal growth type (n=3). Diagnostic features of these four types were studied. Peripheral enhancement was a common angiographic feature and tumor stains were recognized in 88%, 20%, 0%, 33%, respectively. Angiography and dynamic computed tomography (D-CT) were useful in differential diagnosis with hepatocellular carcinoma. Accuracy rate in diagnosis of portal vein involvement by angiography and D-CT was 82% and 91%, respectively. MRI was more useful in tumor detection than D-CT in cases with ...
This study evaluated woody biomass from logging residues, small-diameter trees, mill residues, and urban waste as a feedstock for cellulosic ethanol conversion in Mississippi. The focus on Mississippi was to assess in-state regional variations and provide specific information of biomass estimates for those facilities interested in locating in Mississippi. Supply and cost of four woody biomass sources were derived from Forest Inventory Analysis (FIA) information, a recent forest inventory conducted by the Mississippi Institute for Forest Inventory, and primary production costs. According to our analysis, about 4.0 million dry tons of woody biomass are available for production of up to 1.2 billion liters of ethanol each year in Mississippi. The feedstock consists of 69% logging residues, 21%...
Although destruction of United States wetlands has slowed, their continued conversion, especially in certain inland regions of the country, may pose adverse ecological effects over the next few decades. The Army Corps of Engineers' regulatory program (Section 404 of the Clean Water Act) protects most coastal wetlands, but provides no protection for 95% of the country's wetlands which remain inland. These inland, freshwater wetlands, converted for agricultural purposes, comprise 80% of the wetland losses over the past 30 years. This report outlines options for more effective federal management, such as the mapping and categorizing of wetlands to determine relative values. In effect, agencies can focus protection programs on higher-value wetlands, especially those threatened by agricultural conversion. The report also discusses the contradictory federal policies aimed at wetlands; for example, the tax code encourages the ...
The intensity of erbium up-conversion luminescence could be limited by a saturation effect due to increased pump power. We studied the luminescence saturation of the 550 nm emission on erbium-doped, SiO_2-TiO_2 sol-gel powders under pulsed excitation at 979 and 1532 nm. From the latter, the up-converted luminescence intensity decreased with increasing excitation power, whereas no saturation was observed at 979 nm excitation. We proposed that the saturation effect is determined by the pump power, the erbium content and the lifetime of the corresponding first excited states at different pumping schemes.
The process of radiation induced electron capture by protons or deuterons producing new ultra low momentum neutrons and neutrinos may be theoretically described within the standard field theoretical model of electroweak interactions. For protons or deuterons in the neighborhoods of surfaces of condensed matter metallic hydride cathodes, such conversions are determined in part by the collective plasma modes of the participating charged particles, e.g. electrons and protons. The radiation energy required for such low energy nuclear reactions may be supplied by the applied voltage required to push a strong charged current across a metallic hydride surface employed as a cathode within a chemical cell. The electroweak rates of the resulting ultra low momentum neutron production are computed from these considerations.
The authors report on temperature dependent characteristics and single mode performance of one-wave cavity, planar implanted, AlGaInP-based vertical-cavity surface emitting lasers. By optimizing the overlap between the gain peak and the cavity mode of the structure, they demonstrate record device performance, including 8.2 mW maximum output power and 11% power conversion efficiency for multimode operation and 1.9 mW and 9.6% power conversion efficiency for single mode operation at 687 nm. Improved performance at elevated temperatures is also achieved, with 1.5 mW output power demonstrated at 50 C from a 15-{micro}m-diameter device.
A phase 2 study has been initiated to investigate surfactant-assisted coal liquefaction, with the objective of quantifying the enhancement in liquid yields and product quality. This report covers the second quarter of work. The major accomplishments were: completion of coal liquefaction autoclave reactor runs with Illinois number 6 coal at processing temperatures of 300, 325, and 350 C, and pressures of 1800 psig; analysis of the filter cake and the filtrate obtained from the treated slurry in each run; and correlation of the coal conversions and the liquid yield quality to the surfactant concentration. An increase in coal conversions and upgrading of the liquid product quality due to surfactant addition was observed for all runs.
Ford, Bacon, Davis Utah Inc. has reevaluated the Spook site in order to revise the December 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings 48 mi northeast of Casper, in Converse County, Wyoming. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 187,000 tons of tailings at the Spook site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors.
An experimental investigation on the thermal decomposition of CH4 into C and H2 was carried out using a 5kW particle-flow solar chemical reactor tested in a solar furnace in the 1300-1600K range. The reactor features a continuous flow of CH4 laden with mm-sized carbon black particles, confined to a cavity receiver and directly exposed to concentrated solar irradiation of up to 1720 suns. The reactor performance was examined for varying operational parameters, namely the solar power input, seed particle volume fraction, gas volume flow rate, and CH4 molar concentration. Methane conversion and hydrogen yield exceeding 95% were obtained at residence times of less than 2.0s. A solar-to-chemical energy conversion efficiency of 16% was experimentally reached, and a maximum value of 31% was numer...
A solar energy collection and conversion system is disclosed in which a cassegrain mirror system is rotated about a diurnal axis, which axis is adjusted for seasonal variations in the incidence of the sun's rays on the earth's surface. A black body absorption cavity filled with translucent or transparent fluid material is used for direct absorption of the sun's rays. The incident solar energy is absorbed directly by the fluid medium. The fluid within the cavity may be maintained under extremely high pressures and temperatures in order to utilize this fluid as a heat storage medium. Such heat storage is facilitated by apparatus which permits a change in the volume of the reflective cavity in response to the temperature or pressure of the fluid within the cavity.
Efforts concentrated on updating of the Rockwell reference concept, definition of new system options, studies of special emphasis topics, further definition of the transportation system, and further program definition. The Rockwell reference satellite concept has a gallium arsenide (GaAs) solar cell array having flat concentrators with an effective concentration ratio of 1.83at end of life. Alternatives to this concept includes solid state power amplifiers or magnetrons for dc/RF conversion and multibandgap solar cells for solar to dc energy conversion. Two solid state concepts were studied. It was determined that the magnetron approach was the lowest mass and cost system.
Abstract in english Ru(1%)/SiO2 and Cu(1%)Ru(1%)/SiO2 catalysts were prepared by cogelation. The effect of pH and the amount of water on the physical-chemical properties and the catalytic properties of them were analyzed. The acid medium increased the formation of microporosity and the formation of small size of metallic ruthenium particle. The variation of the water quantity used in the gelation not modify considerably the texture neither the dispersion of the noble metal. The reduction lev (more) el of all prepared catalyst was similar, showing displacement in some of reduction peaks. The toluene hydrogenation indicated that the conversion and the quantity of hydrogenate product varied with the pH and the quantity of water used in the gelation. The addition of copper to Ru/SiO2 catalysts diminished the reactive conversion and their hydrogenant activity
Hydrogenation of high-volatile bituminous coal under high temperatures and pressures produced low-sulfur fuel oils. At a coal conversion of 80 percent, the ratio of oil to gas yields was approximately 3 : 1 and 23 percent of the coal sulfur was contained in the oil. Sulfur content of the oil, however, remained the same at different coal-conversion levels. The data obtained in the semicontinuous dilute-phase hydrogenation system showed that the whole oil can be directly used as a fuel oil where 1 percent sulfur is tolerated. Fuel oils containing 0.5 percent and 0.25 percent sulfur were produced by desulfurization of the whole oil.
Two natural gas/diesel dual fuel conversion systems for the Detroit Diesel 6V-71 transit bus engine were described. The basic concept of a dual fuel engine was to operate a diesel engine with both liquid fuel injection and a lean premixed gas mixture. The engine achieved high efficiency due to the high compression ratio typical of the diesel engine. Test results were obtained using three different calibrations on one engine. The objectives were to match existing engine performance with improved emissions and better overall fuel economics. Results showed that overall, engine conversion has both economic and emissions advantages over a straight diesel engine. However, the durability and in-use applicability of the system remains to be demonstrated with an in-bus demonstration project.. 3 tabs., 4 figs.
Point contact Josephson junctions can function as millimeter wave heterodyne mixers with conversion gain. The best results achieved thus far show a single sideband conversion gain of 1.3 and a mixer contribution to the system noise temperature of 54"0K. Both of these results are approximately 5 times better than the best published figures for cooled Schottky barrier diode mixers operated at the same frequency. The measured noise for a variety of junctions can be expressed as a universal function of the normalized rf frequency #OMEGA# = h#omega#/2eI/sub c/R. It is about a factor 2 larger than the calculated noise arising from the thermal noise in the junction shunt resistance, R. The noise calculation was done for the resistively shunted junction model using an analog junction simulator.
Coordination chemistry on transition metal chalcogenides offer better conditions for multielectron charge transfer processes on solid/electrolyte interfaces. In this contribution, materials whose band energies are derived from d-states of the transition metal will be shown. Problems related to the reactivity, stability and photoactivity toward the generation and conversion of fuels will also be discussed. (orig.) [Deutsch] Die an halbleitenden Uebergangsmetall-Elektroden beobachtete Koordinationschemie bietet guenstige Voraussetzungen fuer den Mehrelektronen-Transfer an der Festkoerper/Elektrolyt Grenzflaeche. Beispielhaft werden in diesem Beitrag Elektrodenmaterialien vorgestellt, deren Energiebaender sich von d-Zustaenden der Uebergangsmetalle herleiten. Diskutiert werden Probleme der Reaktivitaet, der Stabilitaet und der Photoaktivitaet im Hinblick auf die Erzeugung und Umsetzung von Brennstoffen. (orig.)
Energy International is developing a technology that will create a staged formulation with the first coal form (Mulled Coal) that can be stored, transported, and pumped. Just prior to combustion, the Mulled Coal (MC) would be modified to provide the properties needed for proper atomization. This concept is an alternative to the expensive and energy intensive thermal drying processing of fine coal wet cakes. The material is suitable for both direct feed use in conventional and fluid bed combustors as well as on-site conversion to combustible slurries. By maintaining the coal form relatively close to the feed wet cake, only minor processing with low additive levels and low energy blending needed at the point of production. Its conversion to slurry or other use-feed form is made near the time of use and thus the requirements for stability, climatic control, and other storage, transport, and handling requirements are much less severe.
A new chemical reactor, the Open Plate Reactor, is being developed by Alfa Laval AB. It combines good mixing with high heat transfer capacity into one operation. With the new concept, highly exothermic reactions can be produced using more concentrated reactants. A nonlinear model of the reactor is derived and a control system is developed. For temperature control a cooling system is designed and experimentally verified, which uses a mid-ranging control structure to increase the operating range of the hydraulic equipment. A Model Predictive Controller is proposed to maximize the conversion under hard input and state constraints. An extended Kalman filter is designed to estimate unmeasured concentrations and parameters. Simulations show that the designed control system gives high conversion ...
Intermediate products of the conversions of 6-aminophenalenone in ethanol were investigated by pulse radiolysis. In alkaline medium the main product is the 6-aminophenalenone radical cation, the optical absorption spectrum of which contains two bands with maxima at 355 and 400 nm. The precursors of this particle are e_s, CH_3CHOH and CH_3CHO"- radicals. In neutral and acid medium, radical cations are protonated in reactions with alcohol and hydrogen ions. The H-adduct of 6-aminophenalenone that arises has optical absorption maxima at 350 and 390 nm. The presence of two maxima is due to two different structures of the product. The molar extinction coefficients of the radical anions and H-adducts of 6-aminophenalenone and the rate constants of the reactions involving them were estimated. 6 refs., 4 figs., 2 tabs.
Efficient, low-temperature conversion of infrared light into visible light (red, orange, green) is reported at single heterojunctions and undoped quantum wells of GaAs and ordered Al_xGa_1_-_xInP_2; an increase in photon energy of 700 meV is obtained. The signal originates from the high-band-gap layers and disappears only if the excitation energy is tuned below the GaAs band gap. The intensity of the up-converted photoluminescence (PL) is found to decrease significantly slower with increasing temperature than that of the regular PL and it remains observable up to 200 K. Interface-induced cold Auger processes along with the presence of trapped states for both electrons and holes in these ordered alloys account for this nonlinear mechanism. A colinear double-beam experiment confirms this. copyright 1996 The American Physical Society.
Hydrogenation of napthalene to tetralin using activated red mud as catalyst was studied as a typical hydrogen-donor system. Under the chosen reaction conditions, unprocessed red mud resulted in a conversion of napthalene of 3.55%. The most active catalyst, prepared by adding 20 wt% of TiO/SUB/2 to the red mud, followed by acid digestion and re-precipitation, resulted in a 58% conversion of naphthalene. This technology may have an important bearing on processes such as coal hydrogenation or crude-oil-residue processing, where the rate of reaction and product quality may depend upon the rate at which a hydrogen-donor solvent can be re-hydrogenated. (7 refs.)
An experiment lasting a number of hours was carried out with 6 men under standardised climate chamber conditions to find out to what extent wallpaper that reflects about 65-75% in the infra-red range by comparison with normal wallpaper that reflect only 3-5% of heat, has measurable positive effects on the thermoregulation of the human body and the human sensation of temperature. The measurements of skin temperature and heat flow intensity in the deeper areas of the body and the periphery, and metabolic heat conversion measurements (indirect calorimetry) confirm that infra-red reflection of the heat irradiated from the body lead to a measurable heat recovery on the body surface with a reduction of metabolic conversion. It was proved that it is possible to reduce the average room temperature by up to 4 K whilst maintaining the same degree of thermal comfort, which corresponds to a 20% saving in heating energy. (orig./BWI).
A highly efficient integrated energy conversion system is built based on a methane catalytic decomposition reactor (MCDR) together with a direct carbon fuel cell (DCFC) and an internal reforming solid oxide fuel cell (IRSOFC). In the MCDR, methane is decomposed to pure carbon and hydrogen. Carbon is used as the fuel of DCFC to generate power and produce pure carbon dioxide. The hydrogen and unconverted methane are used as the fuel in the IRSOFC. A gas turbine cycle is also used to produce more power output from the thermal energy generated in the IRSOFC. The output performance and efficiency of both the DCFC and IRSOFC are investigated and compared by development of exact models of them. It is found that this system has a unique loading flexibility due to the good high-loading property of ...
Co catalysts, obtained from a layered double Co?Zn?Al hydroxide, are highly active and stable towards the hydrogenolysis of glycerol to 1,2-propanediol (1,2-PDO) in aqueous media. The Co-673 catalyst, containing a CoO species, provided a glycerol conversion of 67.7% and a 1,2-PDO selectivity of 50.5%. The Co-873 catalyst comprising 16?nm Co nanoparticles gave a glycerol conversion of 70.6% and a 1,2-PDO selectivity of 57.8%. It was revealed that the CoO species in the Co-673 catalyst was readily converted to 50?nm Co particles under the glycerol hydrogenolysis conditions. The Co catalysts maintained a stable size and phase in recycling tests. Graphical Abstract
Conversion of tropical forests to oil palm plantations in Malaysia and Indonesia has resulted in large-scale environmental degradation, loss of biodiversity and significant carbon emissions. For both countries to participate in the United Nation's REDD (Reduced Emission from Deforestation and Degradation) mechanism, assessment of forest carbon stocks, including the estimated loss in carbon from conversion to plantation, is needed. In this study, we use a combination of field and remote sensing data to quantify both the magnitude and the geographical distribution of carbon stock in forests and timber plantations, in Sabah, Malaysia, which has been the site of significant expansion of oil palm cultivation over the last two decades. Forest structure data from 129ha of research and inventory p...
During this reporting period two direct coal liquefaction experiments have been completed and a third is underway. These experiments have produced conversion and selectivity data on samples of Alabama bituminous coal slurried in tetralin and catalyzed using iron-titanium hydride. The experiments address the liquefaction of an agglomerating coal. Conversions of 45 to 55% DAF in 30 min have been recorded at 500/sup 0/F and 520 psia. Equipment modifications were made in an attempt to eliminate the problem of alloy binding in the hydride formation vessel. 4 figs., 4 tabs.
During 1978 the Engineering Board of SRC granted Specially Promoted Program status to the Coal Technology program. This recognized that coal would increase in importance as the cost of liquid and gaseous hydrocarbons rises with the decreasing availability of petroleum related sources. It was, therefore, considered necessary to anticipate and improve, through SRC supported research, the technologies required to win, transport, convert to liquid and gaseous fuels and utilize coal and coal based substances. In view of the interest in the program, and also in the hope of reaching a still wider audience the reports of the two meetings have been combined in this single booklet. The reports indicate specific problems of importance in coal winning and coal conversion but, naturally, do not cover all of the program priorities.
Catalytic activity of industrial metallic wastes in coal liquefaction was examined in a 100lb/day continuous coal processing development unit. Red mud, a waste material from the aluminium industry, and an electric furnace flue dust containing Ni, Mo, Co and Fe showed a pronounced effect on the conversion of a Kentucky bituminous coal. Coal conversion and oil production increased significantly with the addition of red mud and flue dust. Comparison of the catalytic activity of pyrite, red mud, and flue dust, based on selectivity analysis, showed that red mud was the most desirable disposable catalyst. However, if the primary goal of coal liquefaction is high oil production, irrespective of hydrogen consumption, pyrite is the most active catalyst among those discussed in the paper.
Industrial solid wastes (fly ash and red mud, a by-product of the aluminium industry) have been employed as supports for preparation of Ru-based catalysts. Physical and chemical treatments on red mud were conducted and these modified supports were also used for preparation of Ru-based catalysts. Those Ru catalysts were characterized by various techniques such as N2 adsorption, H{sub 2} adsorption, XRD, XPS, and temperature-programmed reduction (TPR), and were then tested for catalytic ammonia decomposition to hydrogen. It was found that red-mud-supported Ru catalyst exhibits higher ammonia conversion and hydrogen production than fly-ash-supported catalyst. Heat and chemical treatments of the red mud greatly improve the catalytic activity. Moreover, a combination of acid and heat treatments produces the highest catalytic conversion of ammonia. 35 refs., 4 figs., 4 tabs.
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).
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).
New surface photometry of all known elliptical galaxies in the Virgo cluster is combined with published data to derive composite profiles of brightness, ellipticity, position angle, isophote shape, and color over large radius ranges. These provide enough leverage to show that Sersic log I #propor to# r "1"/"n functions fit the brightness profiles I(r) of nearly all ellipticals remarkably well over large dynamic ranges. Therefore, we can confidently identify departures from these profiles that are diagnostic of galaxy formation. Two kinds of departures are seen at small radii. All 10 of our ellipticals with total absolute magnitudes M_V_T #<=# -21.66 have cuspy cores-"missing light"-at small radii. Cores are well known and naturally scoured by binary black holes (BHs) formed in dissipationless ("dry") mergers. All 17 ellipticals with -21.54 #<=# M_V_T #<=# -15.53 do not have cores. We find a new distinct component in these galaxies: all coreless ellipticals in our sample have ...
This study determined the phylogenetic groups and virulence factors of 37 Escherichia coli isolates producing types of CTX-M compared with those of 19 isolates producing different types...Full Text Available
Mucopolysaccharidosis type IIIB (MPS IIIB; Sanfilippo syndrome type B) is a metabolic disorder with devastating clinical characteristics starting in early childhood and leading to premature death. A...Full Text Available
Wild-type viruses from the ViroLogic phenotype-genotype database were evaluated to determine the upper confidence limit of the drug susceptibility distributions, or “biological cutoffs,”...Full Text Available
AIMS OF THE STUDY: Type-2 diabetic patients have excessive cardiovascular mortality, primarily related to diabetic nephropathy. The extent of the morbidity due to nephropathy in type-2 diabetes mellitus...Full Text Available
BackgroundPerfluorocarbons (PFC) are used to improve gas exchange in diseased lungs. PFC have been shown to affect various cell types. Thus, effects on alveolar type II (ATII) cells...Full Text Available
Clostridium perfringens type C isolates cause enteritis necroticans in humans or necrotizing enteritis and enterotoxemia in domestic animals. Type C isolates always produce alpha toxin...Full Text Available
Background:Erectile dysfunction in type-2 diabetes may be an independent marker for coronary artery disease. Present study was undertaken to investigate whether type-2 diabetic...Full Text Available
In general there are actually two different types of A-15 compounds (A_3B) whose superconducting properties depend on whether the B atoms are transition elements (s-d type) or nontransition elements (s-p type). The properties in which the s-d type superconductors show marked differences in behavior from the s-p type include: (1) stoichiometry and range of composition, (2) the strong influence of N(O) on the stability and T/sub c/ of the phase, and (3), the effect of composition and atomic ordering on the T/sub c/ of the phase. These differences are discussed and a conclusion presented.
We consider the dynamics toward the initial singularity of Bianchi type IX vacuum and orthogonal perfect fluid models with a linear equation of state. The 'Bianchi type IX attractor theorem' states that the past asymptotic behavior of generic type IX solutions is governed by Bianchi type I and II vacuum states (Mixmaster attractor). We give a comparatively short and self-contained new proof of this theorem. The proof we give is interesting in itself, but more importantly it illustrates and emphasizes that type IX is special, and to some extent misleading when one considers the broader context of generic models without symmetries.
We consider the dynamics toward the initial singularity of Bianchi type IX vacuum and orthogonal perfect fluid models with a linear equation of state. The 'Bianchi type IX attractor theorem' states that the past asymptotic behavior of generic type IX solutions is governed by Bianchi type I and II vacuum states (Mixmaster attractor). We give a comparatively short and self-contained new proof of this theorem. The proof we give is interesting in itself, but more importantly it illustrates and emphasizes that type IX is special, and to some extent misleading when one considers the broader context of generic models without symmetries.
We consider the dynamics towards the initial singularity of Bianchi type IX vacuum and orthogonal perfect fluid models with a linear equation of state. The `Bianchi type IX attractor theorem' states that the past asymptotic behavior of generic type IX solutions is governed by Bianchi type I and II vacuum states (Mixmaster attractor). We give a comparatively short and self-contained new proof of this theorem. The proof we give is interesting in itself, but more importantly it illustrates and emphasizes that type IX is special, and to some extent misleading when one considers the broader context of generic models without symmetries.
... United States, there are 14 million people with diabetes and while most will not lose their vision ... good deal higher among people with Type I diabetes -- the type that usually begins in childhood and ...
The results of this research centered on the experimental studies of a single superconducting persistent current qubit, the implementation of type-II algorithms using these qubits, and the proposal for adiabatic quantum computing using these qubits. The m...
... and high-quality photospheric-phase Type II SN spectra to constrain core- collapse SN explosions, massive star evolution, and distances in the Universe ...
... dartevellei is only known from the type locality (Matadi, Lower Congo River basin) and it has only ... the type locality is in the region of Matadi, and not only of Matadi itself. If there ... ...
The maximum fissile fuel production capacity of three conceptual fusion breeder systems is examined on the basis of the dominant isotopic-balance processes. Compact relationships involving system power output, plasma and energy multiplication, and parameters which describe the fuel cycle and neutron spectrum in the blanket are established. It is found that the fusion breeder, as characterized herein, possesses a substantial fissile fuel breeding capacity the extent of which is governed primarily by the neutron spectrum in the conversion blanket and the break-even condition of the plasma.
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.
A two-step purification protocol was used in an attempt to separate the constitutive NAD(P)H-nitrate reductase [NAD(P)H-NR, pH 6.5; EC 1.6.6.2] activity from the nitric oxide and nitrogen dioxide (NO(x))...Full Text Available
A series of questions and answers addresses issues related to developing synthetic fuels, including the potential supplies, regulatory road blocks, and development incentives to promote the role of the private sector. Chevron's efforts in the area of synfuels are aimed at shale oil tar sands and coal conversion. The status of these research and development projects and the projected recoverable reserves from each are summarized. (DCK)
Computer simulations and experiments indicate that we can shape the infrared picosecond pulses of the Mark III FEL in amplitude, frequency, and phase. Strongly modulated fundamental and second harmonic pulses have been generated by operating the Mark III FEL in the regime of strong sideband growth. In this paper, we present the results of simulations and experiments for second harmonic generation with fundamental inputs from 2 to 3 {mu}m.
... This is an amount less that the measurement accuracy of even the best meteorological instruments . So, is it really worth committing to 40 years of drastic carbon emissions reductions (which necessarily involves increasing the cost of hydrocarbon fuels in order to reduce fuel consumption, and force an industry-wide conversion to much more expensive alternative energy sources), all so that after nearly all of us are ...
The overall objective of this project is to provide research guidance and quantification of research progress in the areas of direct and indirect coal liquefaction, coal/waste coprocessing, refining of coal-derived liquid fuels, and natural gas conversion. Specifically, the work is divided into two subtasks that relate to whether the technology application is direct or indirect. In subtask (a), Direct Coal Liquefaction technology is the subject of the analyses, and in subtask (b), Indirect Liquefaction, technologies will be evaluated in accordance with the priorities of the COR. Mitretek Systems has been developing detailed computer simulation models of direct and indirect coal and natural gas conversion systems for several years. These models are constantly being updated and improved as more data and better cost information becomes available. These models also include detailed refinery models based on bench-scale upgrading data of coal derived ...
Research is presented on oil and gas technologies, advanced systems, soil remediation and remediation of acid mine drainage, applied science research in plastics and petroleum coprocessing, and fossil fuel and hydrocarbon conversion using a hydrogen rich plasmas.
Research is presented on oil and gas technologies, advanced systems for fossil fuels, environmental technologies for remediation and waste management, applied energy science on heavy oil and plastics coprocessing, and fossil fuel and hydrocarbon conversion using hydrogen rich plasma.
Single and binary metal molybdates, supported on silica (80 wt% active phase/20 wt% SiO{sub 2}), having the formula AMoO{sub 4}, where A = Ni, Co, Mg, Mn, and/or Zn, and some ternary molybdates having the formula Ni{sub 0.45}Co{sub 0.45}X{sub 0.066}MoO{sub 4}, where X = P, Bi, Fe, Cr, V, and Ce, were investigated for the oxydehydrogenation of propane to propylene. The reaction is catalytic and is first order in propane disappearance, consistent with the abstraction of a methylene hydrogen being the rate limiting step. Propane conversion and yields of propylene produced vary greatly with the choice of the A metal of the molybdate and the surface area of the catalyst. At 560{degrees}C and atmospheric pressure, the highest propane conversion and highest propylene yields are obtained with NiMoO{sub 4}/SiO{sub 2} (16% at 27% conversion), closely followed by Ni{sub 0.5}Co{sub 0.5}MoO{sub 4}/SiO{sub 2}. The molybdenum content of ...
This book is organized under the following headings: Electrohydrodynamic heat transfer augmentation; Forced convection augmentation and heat transfer control; Turbulent heat transfer; Thermal problems in the environment; Energy conversion systems; Measurement, visualization, and imaging; Thermal problems in space technology; and Thermal properties.
The NREL Sensitized Solar Cell (SSC) Core Program supports the Solar America Initiative by: (1) targeting new devices and processes for commercialization by 2015 that are less expensive, more efficient, highly reliable, and environmentally benign; (2) collaborating with DOE OS/BES to conduct basic research targeting breakthroughs in key areas, such as ultra-high efficiency and/or ultra-low cost materials and devices.
Single and binary metal molybdates of the formula AMoO{sub 4}, where A=Ni, Co, Mg,Mn and/or Zn, were investigated for the oxydehydrogenation of propane to propylene, as well as some ternary molybdates of the formula NiO{sub 0.45}Co{sub 0.45}X{sub 0.066}MoO{sub 4} where X=P, Bi, Fe, Cr, V and Ce. All catalysts were supported on SiO{sub 2} with an active phase/support ratio of 80/20 (wt%). The reaction is catalytic and not a gas phase initiated reaction. It is first order in propane, consistent with the abstraction of the methylene hydrogen being the rate limiting step. Propane conversions and propylene yields vary greatly depending on the metal of the molybdate and surface area of the catalyst. Highest propylene yields (16% at 26.6% propane conversion) are obtained with NiMoO{sub 4}/SiO{sub 2}. Conversion and yield are significantly influenced by the molybdenum content of the compositions. The effect is biggest in the nickel ...
A physical model of free-electron laser (FEL) amplifier with variable-parameter wiggler magnets for one-dimensional numerical simulation is presented and a numerical example is given. The wiggler parameters, efficiency of energy conversion between electron beam and laser field, laser intensity, phase-space distributions and energy spectrum of electrons are computed. The period of synchronous oscillation and saturation value of laser intensity agree with estimated one.
This paper describes the conversion from an existing production control computer, an SEL 840, to a DEC VAX 11/780. The plan is to add a layer of hardware to accomplish a smooth and gradual transition from the 840 to the VAX while leaving the underlying equipment unchanged. The architecture of the control system software is discussed for a large linear accelerator from the standpoint of its requirements and the particular design philosophy chosen.
The catalytic dehydration of methanol to dimethyl ether was investigated for application on-board a methanol fuelled vehicle. Several catalysts have been tested in a fixed bed reactor. Our approach is to develop a small and efficient reactor converting liquid MeOH under pressure and at low reaction temperatures. (author) 2 figs., 5 refs.
Separate abstracts were prepared for 20 papers in this conference report and includes all papers in the ''engineering'' section (program E). Ocean thermal energy conversion (OTEC), moorings, cables, corrosion protection, corrosion testing, coatings, offshore platforms, pipelines, OTEC models and pilot plants, and energy transfer are topics discussed.
We report an observation of a delayed all-optical routing/switching phenomenon based on ultraslow group velocity of light via nondegenerate four-wave mixing processes in a defected solid medium. Unlike previous demonstrations of enhanced four-wave mixing processes using the slow light effects, the present observation demonstrates a direct retrieval of the resonant Raman-pulse excited spin coherence into photon coherence through coherence conversion processes.
It is shown that low-frequency elastic vibrations of near-surface planar defects cause high-frequency ultrasonic radiation in surrounding air. The frequency conversion mechanism is concerned with contact nonlinearity of the defect vibrations and provides efficient generation of air-coupled higher-order ultraharmonics, ultrasubharmonics, and combination frequencies. The nonlinear air-coupled ultrasonic emission is applied for location and high-resolution imaging of damage-induced defects in a variety of solid materials.
Elastic depth imaging of both P-wave and S-wave prestack seismic reflection data is formulated as a degraded form of Kirchhoff migration known as Wavepath Migration (WM). Applications to the SEG/EAGE salt model show that the method is sufficiently versatile anti relaitively inexpensive. It handles S-wave data with at least the same accuracy as Pwave data when local mode conversions are removed. WM also provides an understanding of multi-mode illumination.
An ``energy snapshot`` article is included on housing characteristics in 1993 (survey of 7,111 households). The rest of the document is divided into: energy overview, energy consumption, petroleum, natural gas, oil and gas resource development, coal, electricity, nuclear energy, energy prices, international energy, and appendices (conversion factors, CO2 emission factors from coal, index, glossary).
The Monthly Energy Review (MER) presents an overview of the Energy Information Administration`s recent monthly energy statistics. The statistics cover the major activities of US production, consumption, trade, stocks, and prices for petroleum, natural gas, coal, electricity, and nuclear energy. Also included are international energy and thermal and metric conversion factors. 37 figs., 61 tabs.
This publication presents an overview of the Energy information Administration`s recent monthly energy statistics. The statistics cover the major activities of US production, consumption, trade, stocks, and prices for petroleum, natural gas, coal, electricity, and nuclear energy. Also included are international energy and thermal and metric conversion factors. Two brief ``energy plugs`` (reviews of EIA publications) are included, as well.
The special features of prostaglandin biochemistry, of importance for investigation of the possible physiological roles of prostaglandins, are briefly reviewed. The formation of prostaglandins and related compounds from endogenous and exogenous arachidonic acid in homogenates of human gastric mucosal and muscle-serosal layers is described. These preliminary data seem to indicate that a low conversion of exogenous precursor does not necessarily mean that the capacity of the tissue to synthesize prostaglandins from endogenous precursor is low.
During the period covered by this report research has been concerned with the study of photo-induced electron transfer reactions from porphyrins to acceptor molecules with time-resolved Electron Paramagnetic Resonance (EPR) methods. Excited-state electron transfer reactions are of importance from a fundamental point of view and in connection with applications in homogeneous and heterogeneous photosensitization, photopolymerization, and solar energy conversions. For this reason, the study of photo-induced electron transfer reactions is of considerable interest.
Thermally recyclable Nb point-contact Josephson junctions are investigated as low-noise mixers with an external local oscillator at 115 GHz. The best single sideband mixer noise temperature achieved is 140 ( +- 20) K with a (SSB) conversion loss of 2.4 ( +- 0.5) dB. Such rugged junctions are suitable for use in practical receivers and should give unprecedented sensitivity at the shorter millimeter wavelengths.
This report provides overall state and national information on the quantity, availability, and costs of current and potential feedstocks for ethanol production in the United States. It characterizes end uses and physical characteristics of feedstocks, and presents relevant information that affects the economic and technical feasibility of ethanol production from these feedstocks. The data can help researchers focus ethanol conversion research efforts on feedstocks that are compatible with the resource base.
Heterodyne detection with a point-contact Josephson junction has been investigated both experimentally and theoretically. The measured performance of the device at 36 GHz is in good agreement with the theory. By operating vanadium point contacts at 1.4 K, the authors have achieved a single-sideband (SSB) mixer noise temperature of 54 K with a conversion gain of 1.35 and a signal bandwidth on the order of 1 GHz. A potentially impressive performance for these devices at submillimeter wavelengths can be extrapolated from the results.
The principle of operation of shaft furnaces is explained and demonstrated in four practical examples. The conditions and parameters determining coke conversion in the combustion zone and in the Boudouard reaction range are described. The combustion process is treated as a whole while the reduction process is discussed separately for the blast furnace, the cupola furnace, and the shaft furnace. The possibilities describing the Boudouard reaction as a function of the temperature level are discussed and consequences are derived for further experimental and theoretical studies.
The proceedings contain 21 papers arranged under the following topical sections: Exploration technology (4 papers); Reservoir technology (5 papers); Energy conversion technology (8 papers); Drilling technology (2 papers); and Direct use and geothermal heat pump technology (2 papers). An additional section contains a report on a workshop on dual-use technologies for hydrothermal and advanced geothermal reservoirs.
Context: The Balanced Budget Act (BBA) of 1997 allowed some rural hospitals meeting certain requirements to convert to Critical Access Hospitals (CAHs) and changed their Medicare reimbursement from prospective to cost-based. Some subsequent CAH-related laws reduced restrictions and increased payments, and the number of CAHs grew rapidly. Purpose: To examine factors related to hospitals' decisions to convert and time to CAH conversion. Methods: Eighty-nine rural hospitals in Iowa were characterized and observed from 1998 to 2005. Cox proportional hazards models were used to identify the determinants of time to CAH conversion. Findings: T-test and one-covariate Cox regression indicated that, in 1998, Iowa rural hospitals with more staffed beds, discharges, and acute inpatient days, higher operating margin, lower skilled swing bed days relative to acute days, and located in relatively high density counties were more likely to convert later or not ...
Glucoamylase and pullulanase were immobilized on reconstituted bovine-hide collagen membranes using the covalent azide linkage method. A pretanning step was incorporated into the immobilization procedure to enable the support matrix to resist proteolytic activity while accommodating an operating temperature of 50 degrees C. The immobilized glucoamylase and pullulanase activities were 0.91 and 0.022 mg dextrose equivalent (DE) min(-1) cm(-2) of membrane, respectively. Immobilized glucoamylase had a half-life of 50 days while the immobilized pullulanase had a half-life of 7 days. This is a considerably improved stability over that reported by other researchers. The enzymes were studied in their free and immobilized forms on a variety of starch substrates including waxy maize, a material which contains 80% alpha-1-6-glucosidic linkages. Substrate concentrations ranged from 1% to a typical commercial concentration of 30%. Conversion efficiencies of 90-92% DE were ...
It is shown that recuperator in which the thermal energy of particles is transformed into electric oue under drift in crossed fields is naturally coupled with dragontype magnetic confinement system, so the recuperation process can be initiated in the dragon magnetic field. A number of questions occuring under analysis of recuperator-dragon system is considered, including the dynamics of particle transfer to the recuperator, the share of particles entering the recuperator, the effect of rotational transform and the recuperation efficiency.
A) diffuse bilayer, B) spontaneously formed multilayer, and C) vertically homogenous thin films, are fabricated. The photocurrent/voltage performance is compared and it is found that the self-stratified structure (B) yields the highest energy conversion efficiency. (Abstract Copyright [2009], Wiley Periodicals, Inc.)
New measurements of relative gamma-ray emission probabilities in the decay of [sup 101]Mo and [sup 101]Tc are reported. Previously published conversion-electron data have been used along with the gamma-ray data to formulate self-consistent decay schemes. (orig.)
New measurements of relative gamma-ray emission probabilities in the decay of "1"0"1Mo and "1"0"1Tc are reported. Previously published conversion-electron data have been used along with the gamma-ray data to formulate self-consistent decay schemes. (orig.).
The crabbing of an incident photon beam from a laser, and the electron beam with which it interacts at the conversion point, is shown to have the same efficiency as in head-on Compton scattering, but with the advantages of a crossing geometry. The resulting #gamma#-ray beam is also crabbed, which allows for a crossing collision point, while maintaining the luminosity at the same value it would have in a head-on collision.
The crabbing of an incident photon beam from a laser, and the electron beam with which it interacts at the conversion point, is shown to have the same efficiency as in head-on Compton scattering, but with the advantages of a crossing geometry. The resulting {gamma}-ray beam is also crabbed, which allows for a crossing collision point, while maintaining the luminosity at the same value it would have in a head-on collision. ((orig.)).
The crabbing of an incident photon beam from a laser, and the electron beam with which it interacts at the conversion point, is shown to have the same efficiency as in head-on Compton scattering, but with the advantages of a crossing geometry. The resulting #gamma#-ray beam is also crabbed, which allows for a crossing collision point, while maintaining the luminosity at the same value it would have in a head-on collision. ((orig.)).
Simulated atmospheric corrosion studies were performed to determine the corrosion protection provided by galvanized zinc coatings on depleted uranium, U-0.75 Ti alloy, and U-6 Nb alloys. The accelerated ASTM tests consisted of exposing the galvanized samples to aqueous and aqueous chloride environments. The test results showed that anodic protection was provided by the electronegative zinc coatings on uranium and uranium alloys. Treating zinc with chromate conversion coatings also provided more protection.
In this small review, the following general properties of the Compton scattering as the basic process for creating {gamma}{gamma} colliders in the scheme suggested in Ginzburg et al. (Inst. Nucl. Phys. 34 (1981) 514; Nucl. Instr. and Meth. 205 (1983) 47) are considered: kinematics, photon spectrum, angular distribution, polarization of the final photons and electrons as well as some related problems.
Communicating and collaborating online are becoming common requirements in education. The specialized notations and symbols necessary for some content areas where mathematical expressions are part of the conversation require that users select appropriate communication tools. The purpose of this article is to describe tools that can be used for online, asynchronous or synchronous communication involving mathematical expressions.
The development of a synthetic fuels industry in Australia is described in the context of overall energy policy. The national coal liquefaction research program is directed at three main routes to liquid fuels: hydroliquefaction, pyrolysis and indirect liquefaction. Australia is also contributing to technology development and assessment programs in cooperation with other countries, in particular Federal Republic of Germany and Japan.
A process is provided for conducting organic compound conversion over a catalyst composition comprising a supported crystalline zeolite having a high initial silica-to-alumina mole ratio, said supported zeolite being prepared by compositing said crystalline zeolite with alumina, reacting the composite with a particular hydrogen fluoride solution in a specified way, drying the hydrogen fluoride reacted composite, treating the dried composite by hydrolysis, ammonolysis and/or by contact with an ammonium salt solution, and calcining the resulting material.
Five barrels of a Wilsonville process derived solvent (V-1074) from Black Thunder coal were obtained. This material boils within the preferred gas oil range, is more aromatic than previous solvents, and will therefore be used for the bench unit studies. Several repeat runs were performed in the autoclave to confirm the results of the matrix study. In addition, runs were carried out with different catalysts, with agglomerates and with the V-1074 solvent. The results of the autoclave runs were analyzed with respect to coal conversion, CO conversion, oil yield, hydrogen consumption and oxygen removal. It was concluded that the best operating conditions for the first stage operation was a temperature of at least 390{degrees}C, residence time of at least 30 minutes, cold CO pressure of at least 600 psig and potassium carbonate catalyst (2% wt on total feed). The data also indicated however, that the coal conversion goes through ...
The thermal accommodation coefficients of helium, neon, argon, hydrogen and deuterium have been measured in the temperature range of 77-340 K on the surface of a graphitized carbon filament. The dependence of the accommodation coefficient upon the molecular weight as well as the temperature of measurement, and the conversion from orthohydrogen to parahydrogen, have been discussed.
The objective of this study was to determine the usefulness of parathyroid scintigraphy in histological estimation for secondary hyperparathyroidism (2HPT) using Tc-99m sestamibi or Tc-99m tetrofosmin. Tc-99m sestamibi (MIBI) and Tc-99m tetrofosmin (Tetro) parathyroid imaging following double-phase study, magnetic resonance imaging (MRI), and ultrasound were performed on 14 patients with 2HPT. All patients underwent parathyroidectomy. The uptake of two tracers in parathyroid areas was compared with the histopathologic findings. Forty-nine parathyroid glands were surgically explored and histologically proven to be hyperplastic. Of these, 42 were diagnosed with nodular type (N-type) hyperplasia, and 7 with diffuse type (D-type) hyperplasia. MIBI and Tetro parathyroid imagings detected 34 and 35 parathyroid glands, respectively. The sensitivity of MIBI was determined to be 76.2% (32/42) for ...
The loop quantum cosmology 'improved dynamics' of the Bianchi type IX model are studied. The action of the Hamiltonian constraint operator is obtained via techniques developed for the Bianchi type I and type II models, no new input is required. It is shown that the big bang and big crunch singularities are resolved by quantum gravity effects. We also present effective equations which provide quantum geometry corrections to the classical equations of motion.
In APCs, presentation by MHC II molecules of the chemically dominant peptide from the protein hen egg white lysozyme (HEL) generates different conformational isomers of the peptide-MHC II complexes (pMHC). Type B pMHCs are formed in early endosomes from exogenous peptides in the absence of H2-DM, whereas in contrast, type A pMHC complexes are formed from HEL protein in late vesicles after editing by H2-DM. Thus, H2-DM edits off the more unstable pMHC complexes, which are not presented from HEL. In this study, we show that type B pMHC complexes were presented from HEL protein only after stimulation of dendritic cells (DC) with TLR ligands or type I IFN. Type I IFN contributed to most TLR ligand-induced type B pMHC generation, as presentation decreased in DC lacking the receptor for type I IFNs (IFNAR1(-/-)). In contrast, presentation of ...
To assess the clinical and pathologic features of each type of intrahepatic cholangiocarcinoma, which is divided into three types according to gross appearance, and to determine the efficacy of CT in detecting this tumor. The pathologic and CT features of 53 surgically proven cases of intrahepatic cholangio-carcinoma were reviewed. On the basis of their gross appearance, the tumors were divided into three types, as follows : mass forming (n=33), periductal infiltrating (n=6), and intraductal growth type (n=14). CT scans were analyzed for sensitivity of detection and correlation between a tumors appearance and its histopathology. The most common histopathologic feature of mass forming and periductal infiltrating type was tubular adenocarcinoma, while in the intraductal growth type, papillary adenocarcinoma (100%) was common. With regard to pattern of tumor ...
For the reuse of a waste salt from an electrorefining process of a spent oxide fuel, a separation of rare earth elements by an oxidative precipitation in a LiCl-KCl molten salt was tested without using precipitate agents. From the results obtained from the thermochemical calculations by HSC Chemistry software, the most stable rare earth compounds in the oxygen-used rare earth chlorides system were oxychlorides (EuOCl, NdOCl, PrOCl) and oxides (CeO{sub 2}, PrO{sub 2}), which coincide well with results of the Gibbs free energy of the reaction. In this study, similar to the thermochemical results, regardless of the sparging time and molten salt temperature, oxychlorides and oxides were formed as a precipitant by a reaction with oxygen. The structure of the rare earth precipitates was divided into two shapes: small cubic (oxide) and large plate-like (tetragonal) structures. The conversion efficiencies of the rare earth elements to their molten salt-insoluble ...
For the reuse of a waste salt from an electrorefining process of a spent oxide fuel, a separation of rare earth elements by an oxidative precipitation in a LiCl-KCl molten salt was tested without using precipitate agents. From the results obtained from the thermochemical calculations by HSC Chemistry software, the most stable rare earth compounds in the oxygen-used rare earth chlorides system were oxychlorides (EuOCl, NdOCl, PrOCl) and oxides (CeO2, PrO2), which coincide well with results of the Gibbs free energy of the reaction. In this study, similar to the thermochemical results, regardless of the sparging time and molten salt temperature, oxychlorides and oxides were formed as a precipitant by a reaction with oxygen. The structure of the rare earth precipitates was divided into two shapes: small cubic (oxide) and large plate-like (tetragonal) structures. The conversion efficiencies of the rare earth elements to their molten salt-insoluble precipitates were ...
Electricity generation from natural gas in gas turbine units can be made substantially more efficient by preliminary methane conversion to a synthesis gas containing hydrogen and carbon monoxide and/or by the use of some of the synthesis gas produced in industry. An alternative improvement involves the introduction of solid oxide fuel cells (SOFCs) and the use of the synthesis gas in them. In this study, a modified scheme of gas turbine cycle that includes an SOFC, a membrane reactor (instead of a traditional combustion chamber), and a catalytic reactor to perform methane conversion to produce hydrogen (synthesis gas) is proposed. Variations of the energy and exergy efficiencies of the integrated system with operating conditions are provided, showing, for example, that SOFC efficiency is enhanced if the fuel cell active area is augmented. The SOFC stack efficiency can be maximized by reducing the steam generation while increasing the stack ...
Deregulation of utilities will require providers of electric power to put the issue of competition at the top of their strategic planning agenda. The companies that will flourish in this new competitive environment are those that have strongly committed customers and potential to grow. {open_quotes}Commitment{close_quotes} is the complex psychological bond between a customer and a brand (or choice); it is critical to measure because it is the foundation of loyalty and brand equity. The Conversion Model is an established, validated strategic research tool that measures customer commitment and potential to change. It was designed to help marketers devise strategies to strengthen the commitment of current customers and to acquire new customers. The Model helps companies protect and grow their businesss by first quantifying the commitment of current customers and the potential to convert competitors` customers. Further, the Model provides managers with actionable ...
The progress of digital audio technology enabled the familiar use of the products such as CD and DAT in the acoustic measurement. For example, a signal reproduced with CD player is inputted into a subject of measurement and DAT recorder records its response. However, the sampling cannot be synchronized completely with the input signal although both nominal sample rates are set up equally, because player and recorder work independently. It is the most popular software solution to perform the synchronous addition after converting the recorded signal into the original sampling rate. However, the rate conversion also has the error due to the windowing in the high frequency region of processed signal. This paper proposes a new method for averaging asynchronous sampling data to solve these problems. To evaluate performance, the transfer function of only measuring equipment estimated from asynchronous sampling data was compared with the measuring result in synchronous ...
Mg-Al mixed oxides with Mg/Al molar ratios of 0.5--9.0 were obtained by thermal decomposition of precipitated hydrotalcite precursors. The effect of composition on structure and surface and catalytic properties was studied by combining several characterization methods with ethanol conversion reactions. The nature, density, and strength of surface basic sites depended on the Al content. The catalyst activity and selectivity of Mg-Al mixed oxides in ethanol conversion reactions depended on composition. The dehydrogenation of ethanol to acetaldehyde and the aldol condensation to n-butanol both involved the initial surface ethoxide formation on a Lewis acid-strong base pair. The dehydration of ethanol to ethylene, and the coupling and dehydration to diethyl ether increased with Al content, probably reflecting the density increase of both Al{sup 3+}-O{sup 2{minus}} pairs and low- and medium-strength basic sites. Pure Al{sub 2}O{sub 3} displayed the ...
Interest in renewable energy systems that employ regenerative components to enable intermittent energy sources to service time varying loads is growing. The overall performance of these systems is intimately linked to the choice of the energy storage media and the efficiency of the energy conversion devices. Recent advances in electrolyser and fuel cell technologies may make small-scale hydrogen buffered renewable energy systems a practical reality in the near term. A research team at the University of Victoria - Institute for Integrated Energy Systems (IESVic) is developing a flexible distributed, laboratory-scale energy system called IRENE (Integrated Renewable Energy Experiment). The initial goal of this research is to explore the potential for constructing a regenerative energy system using early commercial and precommercial hydrogen storage and fuel cell energy conversion devices. Once implemented, research efforts will focus on the ...
Plutonium metal is produced by reducing PuF{sub 4} prepared from PuO{sub 2} by fluorination. Both fluorination and reduction are batch processes at the Los Alamos Plutonium Facility. The conversion of plutonium oxide to fluoride greatly increases the neutron yield, a result of the high cross section for alpha-neutron ({alpha},n) reactions on fluorine targets compared to the (more than 100 times) smaller {alpha},n yield on oxygen targets. Because of the increase, total neutron counting can be used to monitor the conversion process. This monitoring ability can lead to an improved metal product, reduced scrap for recycle, waste reduction, minimized reagent usage, and reduce personnel radiation exposures. A new stirred-bed fluorination process has been developed simultaneously with a recent evaluation of an automated neutron-counting instrument for quantitative process monitoring. Neutrons are counted with polyethylene-moderated {sup 3}He-gas ...
Because hydrogenation of coal to liquid products (oils) is accompanied by distributions of complex by-product mixtures (IOM, preasphaltenes, asphaltenes and gases) which change as a function of reaction variables (time, temperature and pressure) and reactor configuration, the determination of selectivity relationships for coal liquefaction catalysts has been a difficult and time-consuming task involving numerous experiments to adequately describe catalyst performance over a range of conditions. This paper describes a method for analyzing the experimental results of coal liquefaction reactions which may be applied to a number of aspects of coal liquefaction research and process control, including: rapid selectivity and performance screening for catalysts; correlation of laboratory results with process parameters; and optimization of product yield for plant process conditions. Catalyst selectivity and performance screening will be emphasized here. The approach to selectivity ...
An almost primordial trend in the conversion and use of energy is an increased complexity and cost of conversion systems designed to utilize cheaper and more-abundant fuels; this trend is exemplified by the progression fossil fission {yields} fusion. The present projections of the latter indicate that capital costs of the fusion ``burner`` far exceed any commensurate savings associated with the cheapest and most-abundant of fuels. These projections suggest competitive fusion power only if internal costs associate with the use of fossil or fission fuels emerge to make them either uneconomic, unacceptable, or both with respect to expensive fusion systems. This ``implementation-by-default`` plan for fusion is re-examined by identifying in general terms fusion power-plant embodiments that might compete favorably under conditions where internal costs (both economic and environmental) of fossil and/or fission are not as great as is needed to justify ...
Effect of alkalis (NaOH, KOH and K2CO3) on liquefaction of EPFB (empty palm fruit bunch) biomass liquefaction was investigated under subcritical water conditions in a batch reactor operating at 270degreeC and 20bars for a period of 20min. Catalytic performance and suitable biomass to water ratio that supported higher EPFB conversion, liquid hydrocarbons yield and lignin degradations were screened. Analytical results indicate that maximum of 68wt% liquids were produced along with 72.4wt% EPFB mass conversions and 65.6wt% lignin degradation under 1.0M K2CO3/2:10 (biomass/water) conditions. In comparison, the experiments that were performed in the absence of alkalis yielded only 30.4wt% liquids, converted 36wt% EPFB and degraded 24.3wt% lignin. Furthermore, biomass to water ratios >2:10 decre...
Radiation protection programs for workers are based, in the United States, on a hierarchy of limitations stemming from Federal guidance approved by the President. This guidance, which consists of principles, policies, and numerical primary guides, is used by Federal agencies as the basis for developing and implementing their own regulatory standards. The primary guides are usually expressed in terms of limiting doses to workers. The protection of workers against taking radioactive materials into the body, however, is accomplished largely through the use of regulations based on derived guides expressed in terms of quantities or concentrations of radionuclides. The values of these derived guides are chosen so as to assure that workers in work environments that conform to them are unlikely to receive radiation doses that exceed the primary guides. The purpose of the present report is to set forth derived guides that are consistent with current Federal radiation protection guidance. They ...
This work reports an experimental study on the steam gasification of an anthracite coke in a fluidized bed reactor, with the aim of evaluating the reaction kinetics. Isothermal runs were carried out with samples of 91 to 275 g of coke, at temperatures between 799 and 928{sup 0}C and for steam partial pressures between 0.3 and 0.9 atm. The conversion decreases as the amount of coke is increased and it is very sensitive to the temperature. Neither the volumetric reaction model nor the unreacted shrinking core model can satisfactorily fit the experimental results. That is why empirical models have been used. The first one is derived from the unreacted shrinking core model. An activation energy of 219 kJ. mol{sup -1} and a reaction order with respect of steam of 0.57 have been identified. In the second model, the conversion has been correlated as a function of a dimensionless time. A comparison of the results obtained in the fluidized bed with ...
A mathematical model of a mineral melting cupola furnace for stone wool production has been developed for improving cupola operation. The 1-D, first-engineering-principles model includes mass and heat balances for the gas phase, five solid phases, and four liquid phases. The gas and solid/liquid phases flow countercurrently. Seven chemical reactions account for the conversions of coke, iron oxide, limestone, and gaseous species. The heterogeneous reactions of coke conversion are limited by both kinetics and mass transport. Heat transfer between phases is modeled including both convection and radiation. The model predicts gas concentrations; mass flow rates; and temperature profiles of the solid, melt, and gas in the cupola, as well as heat loss to the water-cooled walls. Inputs to the model include the coke, rock, and blast air properties, the blast air amount, and the coke percentage in the charge. The unknown model parameters are estimated on ...
Topics related to aerospace power are discussed, taking into account trends and issues of military space power systems technology, space station power system advanced development, the application and use of nuclear power for future spacecraft, the current status of advanced solar array technology development, the application of a parabolic trough concentrator to space station power needs, life test results of the Intelsat-V nickel-cadmium battery, and metal hydride hydrogen storage in nickel hydrogen batteries. Other subjects explored are concerned with alternative fuels, biomass energy, biomedical power, coal gasification, electric power cycles, and electric propulsion. Attention is given to an advanced terrestrial vehicle electric propulsion systems assessment, fuel cells as electric propulsion power plants, a sinewave synthesis for high efficiency dc-ac conversion, steam desulfurization of coal, leadless transfer of energy into the body to power implanted blood ...
Efficient, low-temperature conversion of infrared light into visible light (red, orange, green) is reported at single heterojunctions and undoped quantum wells of GaAs and ordered Al{sub {ital x}}Ga{sub 1{minus}{ital x}}InP{sub 2}; an increase in photon energy of 700 meV is obtained. The signal originates from the high-band-gap layers and disappears only if the excitation energy is tuned below the GaAs band gap. The intensity of the up-converted photoluminescence (PL) is found to decrease significantly slower with increasing temperature than that of the regular PL and it remains observable up to 200 K. Interface-induced cold Auger processes along with the presence of trapped states for both electrons and holes in these ordered alloys account for this nonlinear mechanism. A colinear double-beam experiment confirms this. {copyright} {ital 1996 The American Physical Society.}
The present volume on energy and the environment discusses space power requirements, space power systems, space power systems hardware, space radioisotope systems, space solar arrays, space solar cells, space station power, and terrestrial applications of aerospace technology. Attention is given to NASA future space power requirements and issues, the design of a battery charger for the NASA EOS Space Platform, in situ carbon dioxide fixation on Mars, and a preliminary design update of the CRAF/Cassini Power Subsystem. Topics addressed include concentrator testing using projected images, solar power satellites and demonstraton platforms from nonterrestrial materials, a mass sensitivity analysis of lunar orbiting beam power systems, and a power-beaming-based infrastructure for space power. Also discussed are fiber-optic sensors for aerospace electrical measurements, the preliminary design of a mobile lunar power supply, advanced power systems for EOS, and Air Force photovoltaic array ...
Papers are presented on space power requirements and issues, space photovoltaic systems, space solar dynamic systems, space thermal systems, manned and unmanned space power systems, thermionics, and thermoelectrics. Also considered are high power devices for space power systems, high power conversion for space power systems, 1-10 kWe nuclear space power sources, 100-kW class nuclear power concepts, space reactor safety, and multimegawatt space nuclear power systems. Other topics include space power systems automation, space kilovolt technology, space power electronics, space lithium and nickel-cadmium batteries, lithium sodium storage, and space fuel cells. Papers are also presented on space nickel hydrogen batteries, alternative energy concepts and fuels, fuel cell technology, flow batteries, high-temperature batteries, energy conservation, battery energy storage, thermal energy storage, heat engines, MHD power systems, nuclear fission, and the Stirling cycle.
A high-efficiency 3- or 4-junction solar cell is disclosed with a theoretical AM0 energy conversion efficiency of about 40%. The solar cell includes p-n junctions formed from indium gallium arsenide nitride (InGaAsN), gallium arsenide (GaAs) and indium gallium aluminum phosphide (InGaAlP) separated by n-p tunnel junctions. An optional germanium (Ge) p-n junction can be formed in the substrate upon which the other p-n junctions are grown. The bandgap energies for each p-n junction are tailored to provide substantially equal short-circuit currents for each p-n junction, thereby eliminating current bottlenecks and improving the overall energy conversion efficiency of the solar cell. Additionally, the use of an InGaAsN p-n junction overcomes super-bandgap energy losses that are present in conventional multi-junction solar cells. A method is also disclosed for fabricating the high-efficiency 3- or 4-junction solar cell by metal-organic chemical ...
Thermophotovoltaic (TPV) systems are attractive possibilities for direct thermal-to-electric energy conversion, but have typically required the use of black body radiators operating at high temperatures. Recent advances in both the understanding and performance of solid rare-earth oxide selective emitters make possible the use of TPV at temperatures as low as 1200K. Both selective emitter and filter system TPV systems are feasible. However, requirements on the filter system are severe in order to attain high efficiency. A thin-film of a rare-earth oxide is one method for producing an efficient, rugged selective emitter. An efficiency of 0.14 and power density of 9.2 W/KG at 1200K is calculated for a hypothetical thin-film neodymia (Nd2O3) selective emitter TPV system that uses radioisotope decay as the thermal energy source.
In order to establish coal NOx preventive measures, discussions were given on formation of N2 in the fixed-bed pyrolysis of low rank coals and the mechanisms thereof. Chinese ZN coal and German RB coal were used for the discussions. Both coals do not produce N2 at 600{degree}C, and the main product is volatile nitrogen. Conversion into N2 does not depend on heating rates, but increases linearly with increasing temperature, and reaches 65% to 70% at 1200{degree}C. In contrast, char nitrogen decreases linearly with the temperature. More specifically, these phenomena suggest that the char nitrogen or its precursor is the major supply source of N2. When mineral substances are removed by using hydrochloric acid, their catalytic action is lost, and conversion into N2 decreases remarkably. Iron existing in ion-exchanged condition in low-rank coal is reduced and finely diffused into metallic iron particles. The particles react with heterocyclic ...
Ocean thermal energy conversion (OTEC) plants discharge large volumes of cold water into the upper ocean. A three-dimensional, limited-area model was developed to investigate the regional influence of the far-field effluent plume created by the negatively buoyant discharge. The model was applied to discharges from a 40-MW/sub e/ OTEC plant into coastal waters characterized by various ambient ocean conditions. A typical ambient temperature structure and nutrient distribution, as well as the behavior of the effluent plume itself, were strongly modified by the discharge-induced circulation. Although temperature perturbations in the plume were small, upward entrainment of nutrients from below the thermocline was significant. The regional influence of discharges from an 80-MW/sub e/ OTEC plant, the interactions between the discharges from two adjacent 40-MW/sub e/ OTEC plants, and the effects of coastal boundary and bottom discharge were examined with respect to the ...
The passivation of low carbon steel was studied in aqueous solution of 0.5M Na[sub 2]SO[sub 4]+0.001M NaHSO[sub 3] (pH 3.5, 6.5 and 8.5) which can be considered as a model of acid rain. The used conversion electron Moessbauer spectroscopy (CEMS) with the complementary electrochemical investigations proved that the sulfite ions induce pitting corrosion at pH 3.5 and 6.5, while the measurements showed much weaker pitting at pH 8.5. The compositions and thicknesses of the passive films formed during the electrochemical treatments are determined from the CEM spectra. Only [gamma]-FeOOH was found on the surface of the samples at pH 6.5 and 8.5. Nevertheless, at pH 3.5 the sextet belonging to Fe[sub 3]C appears in the spectra, and also FeSO[sub 4].H[sub 2]O could be detected in low concentration. (orig.).
Enzymatic reactions in non-aqueous media have been shown to be effective in carrying out chemical transformation where the reactants are insoluble in water or water is a byproduct limiting conversion. Ionic liquids, liquid organic salts with infinitesimal vapor pressure, are potentially useful alternatives to organic solvents. It is known that the thermodynamic water activity is an important variable affecting the activity of enzymes in non-aqueous solvents. This study investigated the influence of water activity on the esterification of geraniol with acetic acid in ionic liquid [bmim]PF6 catalyzed by immobilized Candida antarctica lipase B. The conversion of geraniol in [bmim]PF6 was significant although the reaction rate was slower than in organic solvents. The profile of initial reaction rate-water activity was determined experimentally, and differed from the data reported for other non-aqueous solvents. A maximum in the initial reaction ...
Dye-sensitized solar cells (DSSCs) based on anatase TiO2 hollow spheres (TiO2HS)/multi-walled carbon nanotubes (CNT) nanocomposite films are prepared by a directly mechanical mixing and doctor blade method. The prepared samples are characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, UV-vis absorption spectroscopy and N2 adsorption-desorption isotherms. The photoelectric conversion performances of the DSSCs based on TiO2HS/CNT composite film electrodes are also compared with commercial-grade Degussa P25 TiO2 nanoparticles (P25)/CNT composite solar cells at the same film thickness. The results indicate that the photoelectric conversion efficiencies () of the TiO2HS/CNT composite DSSCs are dependent on CNT loading in the electrodes. A small amou...
The paper describes a concept of extracting fusion power from D-{sup 3}He fueled IEC (Inertia Electrostatic Configuration) devices. The fusion system consists of a series of fusion modules and direct energy converters at an end or at both ends. This system of multiple units is linear and is connected by a magnetic field. A pair of coils anti-parallel to the magnetic field yields a field-null domain at the center of each unit as required for IEC operation. A stabilizing coil installed between the coil pairs eliminates the strong attractive force between the anti-parallel coils. Accessible regions for charged particle trajectories are essentially isolated from the coil structure. Thus, charged particles are directed along magnetic field lines to the direct energy converter without appreciable losses. A direct energy converter unit designed to be compatible to this unique system is also described. It basically consists of a separator and a traveling wave converter. A separator separates ...
During this reporting period four direct coal liquefaction experiments have been completed and a fifth is underway. These experiments have produced conversion and selectivity data on samples of Utah coal slurried in tetralin and catalyzed using iron-titanium hydride. Hydrogen loading of the alloy, catalyst particle size, coal particle size, operating temperatures for alloy addition and liquefaction without the catalysts present, have all been studied during these four experiments. Conversions of 61% DAF in 30 min have been recorded at 485/sup 0/F and 520 psia. The fifth run using the same coal at a reduced particle size has begun, after which we will move to samples of Kentucky and Alabama coals. Equipment manufacture, delivery, and installation delays, totaling over 6 months, greatly reduced the time available for research, making a 6 month no cost extension necessary. The extended time will permit completion of the proposed research tasks. 4 ...
The effect of combustion conditions on conversion of char nitrogen to N2 was studied in the combustion experiment of char obtained by pyrolysis of coal. Char specimen was prepared by holding ZN coal of Chinese lignite in Ar atmosphere at 1123K for one hour. A batch scale quartz-made fluidized bed reactor was used for combustion experiment. After the specimen was fluidized in reaction gas, it was rapidly heated to start combustion reaction. CO, CO2 and N2 in produced gases were online measured by gas chromatography (GC). As the experimental result, under the incomplete combustion condition where a large amount of CO was produced by consuming almost all of O2, no NOx and N2O produced from char were found, and almost all of N-containing gas was N2. At the final stage of combustion, pyridinic-N disappeared completely, and pyrrolic-N decreased, while O-containing nitrogen complexes became a main component. It was thus suggested that O-containing nitrogen complexes are ...
In this work we present an ultra-low temperature method for the oxidation of an amorphous silicon-carbide-nitride (SiCN) material. The SiCN is deposited on silicon substrates by plasma enhanced chemical vapor deposition using CH{sub 4}, SiH{sub 4}, and N{sub 2} chemistry. The physical and chemical properties are characterized for the as-deposited SiCN and post-oxidized films are discussed. The SiCN film is exposed to oxygen plasma, where it undergoes a chemical transformation into a binary SiO{sub 2} material system. A 1.7 nm/min oxidation rate is typical for this process and compares favorably to oxidation methods utilizing much higher temperatures. The substrate temperature remains extremely low throughout the oxidation process, T{sub s} < 200 deg. C. Changes in film stress, optical constants, film thickness, surface roughness, and film density are measured. Chemical analysis by X-ray photoelectron spectroscopy is reported for both the as-deposited and oxidized film and ...
Chemical-looping combustion is a promising technology for the combustion of gas or solid fuel with efficient use of energy and inherent separation of CO{sub 2}. Chemical-looping combustion of methane with calcium sulfate as a novel oxygen carrier was conducted in a laboratory scale fixed bed reactor. The effects of reaction temperature, gas flow rate, sample mass, and particle size on reduction reactions were investigated and an optimum operating condition was determined. The results show that this novel oxygen carrier has a high reduction reactivity and stability in a long-time reduction/oxidation test. The conversions of CH{sub 4} increased with a higher temperature, smaller gas flow rate, larger sample mass and smaller particle size. The suitable reaction temperature seems to be around 950 deg. C. Low temperatures lead to a low CH{sub 4} conversion, but a significant SO{sub 2} formation was observed at a higher temperature. The release of ...
Chemical-looping combustion is a promising technology for the combustion of gas or solid fuel with efficient use of energy and inherent separation of CO{sub 2}. Chemical-looping combustion of methane with calcium sulfate as a novel oxygen carrier was conducted in a laboratory scale fixed bed reactor. The effects of reaction temperature, gas flow rate, sample mass, and particle size on reduction reactions were investigated and an optimum operating condition was determined. The results show that this novel oxygen carrier has a high reduction reactivity and stability in a long-time reduction/oxidation test. The conversions of CH{sub 4} increased with a higher temperature, smaller gas flow rate, larger sample mass and smaller particle size. The suitable reaction temperature seems to be around 950 C. Low temperatures lead to a low CH{sub 4} conversion, but a significant SO{sub 2} formation was observed at a higher temperature. The release of SO{sub ...
The purpose of this research is to develop a technically and economically feasible process for biologically producing H(sub 2) from synthesis gas while, at the same time, removing harmful sulfur gas compounds. Six major tasks are being studied: 1. Culture development, where the best cultures are selected and conditions optimized for simultaneous hydrogen production and sulfur gas removal; 2. Mass transfer and kinetic studies in which equations necessary for process design are developed; 3. Bioreactor design studies, where the cultures chosen in Task 1 are utilized in continuous reaction vessels to demonstrate process feasibility and define operating conditions; 4. Evaluation of biological synthetic gas conversion under limiting conditions in preparation for industrial demonstration studies; 5. Process scale-up where laboratory data are scaled to larger-size units in preparation for process demonstration in a pilot-scale unit; and 6. Economic evaluation, where ...
The aim was to gain experience on how to produce Alkali Metal Thermo-Electric-Converter (AMTEC) cells, for the demonstration of their principles and potentials, as a basis for future commercialization. These cells should be able to present an efficient and direct conversion of thermal energy to electric energy. The system is based on an electro-chemical concentration cell built around a {beta}`` aluminium oxide membrane that separates the two chambers. This material is a good conductor of sodium and a bad conductor of electrons, and it is this property which is taken advantage of. In the two chambers of the cell is found saturated sodium vapour at two temperatures. The motive power is the expansion over the membrane where the sodium ions are transported through it whilst the electrons are forced through the outer cycle. This concept is described in detail in addition to the choice of materials, performance testing and results. It was found possible to produce AMTEC ...
A continuous-time 7th-order Butterworth Gm-C low pass filter (LPF) with on-chip automatic tuning circuit has been implemented for a direct conversion DBS tuner in 0.35 mum SiGe BiCMOS technology. The filter's -3 dB cutoff frequency f{sub 0} can be tuned from 4 to 40 MHz. A novel on-chip automatic tuning scheme has been successfully realized to tune and lock the filter's cutoff frequency. Measurement results show that the filter has -0.5 dB passband gain, +-5% bandwidth accuracy, 30 nV/Hz{sup 1/2} input referred noise, -3 dBVrms passband IIP3, and 27 dBVrms stopband IIP3. The I/Q LPFs with the tuning circuit draw 13 mA (with f{sub 0} = 20 MHz) from 5 V supply, and occupy 0.5 mm{sup 2}.
Else of solar energy as substitute for conventional fuels at a competitive cost requires efficient conversion from solar radiation to usable forms of energy. In solar thermal or thermochemical applications, high efficiency usually re- quires high temperature and high concentration of incoming radiation. The main form of energy loss from high temperature solar central receivers is thermal emission ('re radiation'), at an effective temperature close to the maximum receiver temperature. This loss is reduced if the aperture is divided into segments, most of which are maintained at lower temperatures. A two-stage partitioned receiver demonstrating this concept is under construction at the Weizman Solar Tower. The high-temperature stage is the DIAPR (Directly Irradiated Annular Pressurized Receiver). The low-temperature stage is made of tubular cavity receivers of simpler design. Preliminary optical and thermal design of the partitioned receiver is presented. For the ...
These experiments were performed on the Isocele separator, on-line with the Orsay synchrocyclotron; thulium isotopes were produced by bombarding natural erbium targets with 150nA beam of 157MeV protons. Two Ge(Li) detectors, with resolution of 2.3 and 2.5keV at 1332keV used for #gamma#-ray measurements; conversion electron spectra were measured using a Si(Li) detector. #gamma# spectra, #gamma#-#gamma# coincidence and conversion electron measurements were sufficient to build the flow energy level schemes of the transitional "1"5"8Er and "1"5"6Er nuclei. On both nuclei several quasi rotational bands have been identified. These results are compared with other even erbium isotopes and with the neighboring N=88 and 90 isotones. Comparisons with predictions issued from some classical models are also performed: "1"5"8Er appears as a deformed nucleus very similar to "1"6"0Er and "1"6"2Er; on the other hand "1"5"6Er seems to be a soft vibrational ...
The type III secretion system among Gram-negative bacteria is known to deliver effectors into host cell to interfere with host cellular processes. The type III secretion system in Yersina, Pseudomonas and Enterohemorrhagic Escherichia coli have been well documented to be involved in the bacterial pathogenicity. The existence of type III secretion system has been demonstrated in neuropathogenic E. coli K1 strains. Here, it is observed that the deletion mutant of type III secretion system in E. coli strain EC10 exhibited defects in the invasion and intracellular survival in Acanthamoeba castellanii (a keratitis isolate) compared to its parent strain. Next, it was determined whether type III secretion system plays a role in E. coli K1 survival inside Acanthamoeba during the encystment process...
The neutron transmutation doping (NTD) method was applied to the initially p-type silicon in order to extend the NTD applications at HANARO. The relationship between the irradiation neutron fluence and the final resistivity of the initially p-type silicon material was investigated. The proportional constant between the neutron fluence and the resistivity was determined to be 2.3473x10{sup 19} n {omega} cm{sup -1}. The deviation of the final resistivity from the target for almost all the irradiation results of the initially p-type silicon ingots was at a range from -5% to 2%. In addition, the burn-up effect of the boron impurities, the residual {sup 32}P activity and the effect of the compensation characteristics for the initially p-type silicon were studied. Conclusively, the practical methodology to perform the neutron transmutation doping of the initially p-type silicon ingot was ...
The neutron transmutation doping (NTD) method was applied to the initially p-type silicon in order to extend the NTD applications at HANARO. The relationship between the irradiation neutron fluence and the final resistivity of the initially p-type silicon material was investigated. The proportional constant between the neutron fluence and the resistivity was determined to be 2.3473x1019 n ? cm-1. The deviation of the final resistivity from the target for almost all the irradiation results of the initially p-type silicon ingots was at a range from -5% to 2%. In addition, the burn-up effect of the boron impurities, the residual 32P activity and the effect of the compensation characteristics for the initially p-type silicon were studied. Conclusively, the practical methodology to perform the neutron transmutation doping of the initially p-type silicon ingot was established.
Significant progress has been achieved recently in the growth of Yttrium Calcium Oxyborate (YCOB) crystals. Boules have been grown capable of producing large aperture nonlinear crystal plates suitable for high average power frequency conversion or optical parametric chirped pulse amplification (OPCPA). With a large aperture (5.5 cm x 8.5 cm) YCOB crystal we have demonstrated a record 227 W of 523.5nm light (22.7 J/pulse, 10 Hz, 14 ns). We have also demonstrated the applicability of YCOB for 1053 nm OPCPA.
The maximum fissile fuel production capacity of three conceptual fusion breeder systems is examined on the basis of the dominant isotopic-balance processes. Compact relationships involving system power output, plasma and energy multiplication, and parameters which describe the fuel cycle and neutron spectrum in the blanket are established. It is found that the fusion breeder, as characterized herein, possesses a substantial fissile fuel breeding capacity the extent of which is governed primarily by the neutron spectrum in the conversion blanket and the break-even condition of the plasma. (author).
The use of natural energy sources and their conversion to secondary forms of energy are a crucial base for the development of our society with its continuous change of requirements due to an increase in population and the broadening of the needs in our modern life. As a consequence the consumption of primary energy resources rose drastically worldwide during the last 5 decades in particular in the industrialized regions such as Europe. Parallel in time the increasing awareness of negative effects of fuel dependent pollution on the environment and the introduction of stringent emission control regulations about 3 decades ago initiated extensive development and retrofit activities resulting in the today applied high level state of the art. As an additional challenge the worldwide debate about the potential effects of the emission of the s.c green house gases on the global climate in particular carbon dioxide from the use of predominantly fossil fuels have initiated ...
Transformation of row material to the consumption goods proceeds by the succession of various technologies using energy and chemicals. Relative contribution of both factors is broadly varied. The chemical reagents are not per se consumption goods and their production is auxiliary. Maximal usage of chemicals is observed in conventional technologies. On the contrary radiation technology does not need chemicals. Therefore usage of radiation technology leads to diminution of chemical processing and hence to the attenuation of the technological press on the environment. As examples the radiation technological methods in conversion of coal and biomass are considered. (author).
The aim of the report is to describe the state and prospects of the experimental and stand base (ESB) for fundamental investigations in the RF Ministry for Atomic Energy. The ESB includes the following scientific directions: high energy physics, nuclear physics, solid state physics (including superconductivity), plasma physics and controlled thermonuclear synthesis, nuclear reactors and reactor materials testing, lasers, energy conversion and others. Main economical, scientific and technical data on the ESB as a whole and on its most large scientific centers are presented
The Conawapa-Winnipeg Power Transmission Complex includes five interrelated transmission and conversion facilities. This booklet describes work done on the upgrade of the southern receiver system, one component of the complex. The southern receiver system is composed of a network of high voltage transmission lines and station facilities. The booklet includes a description of the upgrade, the project setting, short and long-term effects and impact management, and the next steps to be taken in the process, including the regulatory process and public consultation.
In the last two years, rapid progress has been made in the energy conversion efficiencies of GaAs solar cells fabricated from molecular beam epitaxy (MBE) material. The efficiencies of cells fabricated from MBE material are now comparable with those fabricated from metal-organic chemical vapor deposition material, even for cells of dimension 2 cmx4 cm. This paper reviews the progress in MBE cell efficiencies. Also discussed is the role oval defects play in GaAs diode and solar cell performance. (orig.).
We propose a scheme of quantum computation with nonlinear quantum optics. Polarization states of photons are used for qubits. Photons with different frequencies represent different qubits. Single qubit rotation operation is implemented through optical elements like the Faraday polarization rotator. Photons are separated into different optical paths, or merged into a single optical path using dichromatic mirrors. The controlled-NOT gate between two qubits is implemented by the proper combination of parametric up and down conversions. This scheme has the following features: (1) No auxiliary qubits are required in the controlled-NOT gate operation; (2) No measurement is required in the course of the computation; (3) It is resource efficient and conceptually simple.
British Columbia is rich in resources of coal but is deficient in resources of liquid petroleum. The overall objective of the B.C. Research Coal Liquefaction Program is to provide sufficient technical data to identify and evaluate coal conversion opportunities in the province. In this first quarterly report, liquefaction test systems are discussed and results from the testing of equipment, procedures and analytical methods using coal samples from Sukunka (N.E. coal) and Hat Creek (central interior) are presented. The proposed program to be undertaken over the next four years is outlined.
A method for analyzing the experimental results of coal liquefaction reactions which is applicable to a number of aspects of coal liquefaction research and process control, including rapid selectivity and performance screening for catalysts; correlation of laboratory results with process parameters; and optimization of product yield with plant process conditions is described here. Ternary diagrams of product/by-product distributions for the coal liquefaction using Co/Mo catalysts combined with a hyperbolic relationship for the conversion of various hydrocarbon fractions can be used for catalyst screening. A hydrogen consumption diagram used to provide a more significant selectivity test than the hyperbolic correlation is also included. (BLM)
The section on environmental impacts covers global environmental concerns and air pollution. Energy systems includes the following: alternative fuels; co-generation; fossil fuels; mechanical thermal storage; fission/fusion; thermal management; electric and hybrid vehicles. The section on renewable energy sources includes biomass, hydrogen, and solar. This volume also contains separate sections for stirling cycles, policy issues, and new technologies for energy utilization. Separate abstracts were prepared for 150 papers of this volume.
The exchange of information and experience among Member Sates is an essential component of the IAEA action plan for addressing the Year 2000 problem. The objective is to enable Member States to identify any gaps in their own conversion programmes, benefit form the experience of others in developing remedial actions and establish the basis for future action to solve remaining problems. Experts in Year 2000 issues particularly those related to digital equipment prepared this report dealing with nuclear fuel cycle facilities
When polarized electrons traverse a region where the laser light is focused their polarization varies even if their energy and direction of motion are not changed. This effect is due to interference of the incoming electron wave and an electron wave scattered at zero angle. Equations are obtained which determine the variation of the electron-density matrix, and their solutions are given. The change in the electron polarization depends not only on the Compton cross section but on the real part of the forward Compton amplitude as well. It should be taken into account, for example, in simulations of the e{yields}{gamma} conversion for future {gamma}{gamma} colliders. (orig.). 16 refs.
When polarized electrons traverse a region where the laser light is focused their polarization varies even if their energy and direction of motion are not changed. This effect is due to interference of the incoming electron wave and an electron wave scattered at zero angle. Equations are obtained which determine the variation of the electron-density matrix, and their solutions are given. The change in the electron polarization depends not only on the Compton cross section but on the real part of the forward Compton amplitude as well. It should be taken into account, for example, in simulations of the e#->##gamma# conversion for future #gamma##gamma# colliders. (orig.).
Recently, organic semiconducting materials have gained a broad interest due to their potential for organic electronic devices such as organic light emitting diode (OLED), organic photovoltaic devices and organic field-effect transistors (OFETs). Optical properties of organic semiconducting materials are important for practical application. For example, the power conversion efficiency of organic photovoltaic devices is mainly affected by absorption properties of organic materials. Proton irradiation is one of the efficient methods to change the optical properties of organic materials. In this paper, we investigate the changes of optical properties of various polymers using the proton irradiation.
The reactor fuel cycle based on uranium is described. The various stages in the cycle include mining of uranium ores followed by crushing and grinding, leaching and purification of leach liquor by ion exchange resin process or solvent extraction process, refining of uranium concentrate (yellow cake) by digesting with HNO_3 and then solvent extracting uranyl nitrate with TBP, conversion of uranyl nitrate to uranium hexafluoride, production of uranium metal, uranium enrichment, fabrication of reactor fuel elements and reprocessing of the spent fuel. Chemical reactions wherever they are involved are explained. (M.G.B.).
A report is given on an improved filler-binder mixing method in the manufacture of artificial graphite, the so-called coat-mix process. The individual graphite-filler grains are coated completely with uniform binder coatings (phenol formaldehyde resin) in a continuous process. Methanol is used as solvent for the resin. In a modified further development of the process, the use of organic solvents can be disregarded by dissolving the binder resin in caustic soda and injecting the slurry into water diluted acid. The manufacture of casting molds from coat-mix powders, their properties and industrial application are given. Finally, the advantages of using carbon bodies of coal-mix material for conversion to silicon carbide are indicated. (IHOE).
The economy of Poland depends to a large extent upon the exploitation of its vast rich coal reserves for which new mines will have to be sunk and existing mines modernized. Two avenues of coal conversion are being followed. Both involve hydrogenation but one is based on solvent extraction of coal and the other on its pyrolysis. At present large scale established methods of chemical treatment are those which involve the production of coke, production of town-gas, production of synthesis gas and partial oxydation. Total weight amounts to 21,000,000 tons.
The author presents a mathematical model for analysis of the impact of scrubber bed length, porosity, and gas flow rate on the absorption of CO{sub 2} in a breathing apparatus. The model accounts for the decrease in available absorbent through chemical conversion. The predicted efflux of CO{sub 2} from a canister containing LiOH compared favorably with measured values reported elsewhere. It was determined from a computational study that the time for breakthrough of CO{sub 2} at a prescribed level is nearly directly proportional to bed length and inversely proportional to gas flow and porosity.
We briefly report on zero-temperature photoassociation of a Bose-Einstein condensate, focusing on the many-body rate limit for atom-molecule conversion. An upgraded model that explicitly includes spontaneous radiative decay leads to an unanticipated shift in the position of the photoassociation resonance, which affects whether the rate (constant) maximizes or saturates, as well as the limiting value itself. A simple analytical model agrees with numerical experiments, but only for high density. Finally, an explicit comparison with the two-body unitary limit, set by the size of the condensate, finds that the many-body rate limit is generally more strict.
An electric power generating apparatus is described, including: a solar collector; a primary thermal loop including primary thermal fluid; a cavity receiver to receive reflected solar energy from the solar reflector, convert the solar energy into thermal energy, and transmit the thermal energy to the primary thermal fluid by heating the primary thermal fluid not to exceed a given temperature, the given temperature being substantially equal to 700 F; a Stirling engine receiving the primary thermal fluid heated by the cavity receiver, including means to generate mechanical power and means to generate electrical power from the means to generate mechanical power.
A Si array neutron detector is proposed based on commercial CCD and CMOS sensor technology coupled with a thin film neutron conversion coating. System sensitivity is estimated for a baseline device containing a single array and various schemes to increase detection probability by simple area scaling and stacking are discussed. Some possible use scenarios are discussed involving static and moving sources. Likely neutron source fluxes for weapons grade and commercial grade nuclear material are estimated along with expected intensities of cosmic background neutrons which would establish a noise floor to detection limits.
The level structure of the doubly-odd /sup 242/Am nucleus was investigated by means of thermal-neutron-capture gamma-ray and conversion electron spectroscopy. Pair, curved-crystal, and ..beta.. spectrometers were used. The data from these measurements, combined with previous direct reaction results, permit us to establish a detailed level scheme including six new well-developed bands. Our experimental results are interpreted in the framework of the Nilsson model. Precise Gallagher-Moszkowski splittings and Newby odd-even shifts extracted from the data are compared with theoretical calculations.
Josephson effect heterodyne mixers with external local oscillators are very promising low noise mm-wave receivers for applications such as radio astronomy. Experiments at 36 GHz have shown that both the noise and the conversion efficiency of mixers made using Nb point contacts are in quantitative agreement with values calculated from the resistively shunted junction (RSJ) model. Preliminary measurements at 140 GHz suggest that this agreement extends to higher frequencies. In this paper the theoretical limits to the sensitivity of such receivers are explored as a function of the signal frequency. (Auth.).
The main features and advantages of a new low energy nuclear spectroscopic method, the in-beam spectroscopy are described. Results of in-beam spectroscopic experiments performed at the Institute of Nuclear Research (ATOMKI, Debrecen, Hungary) are summarized. Gamma spectra of in-beam produced odd-odd nuclei were measured, gamma-energies were determined. Measurement of gamma-gamma coincidences led to the construction of energy level schemes of the investigated nuclei. Internal conversion electron spectroscopy was used to determine the multipolarities of transitions. A few spectra and level schemes are presented to illustrate the review. Theoretical interpretation of experimental results are briefly summarized. (D.Gy.).
This report presents an overview of research activity currently being funded by the US Department of Energy (DOE) on solid wastes from coal gasification, coal liquefaction, and oil shale technologies, Projects conducted in the DOE energy technology centers and national laboratories, and in cooperative projects with other government agencies, private industry, and universities are developing the basic and applied technology and data on which present and future fuel-conversion and utilization processes depend. The report identifies data gaps and recommends research needs where warranted.
Catalytic testing of inorganic catalysts was continued with the highly active sulfate-modified zirconia catalyst prepared here. Using isobutanol as the only reactant over this catalyst, it was demonstrated that high conversion and selectivity to isobutene was achieved at 175[degrees]C. In addition, the high selectivity to isobutene, i.e. 79--86 mol%, was maintained at higher space velocities and higher temperatures. A high productivity of 11.35 mol isobutene was achieved at 225[degrees]C. Utilizing a methanol/isobutanol = 2/1 molar ratio reactant mixture over the ZrO[sub 2]/SO[sub 4][sup 2[minus
This article outlines the use of gasifiers during World War II and how, with soaring fuel prices, producer gas may provide an alternate energy path for agribusiness and farms today. In the last few years, the University of California has become a focus of producer gas research in the US. Biomass fuels used include crushed walnut shells, fruit pits, cereal straw and corn cobs. Particle size, moisture content and slagging create problems and the right kind of gas producer must be used to obtain reliable conversion to producer gas.
This report--the forty-fifth of a series--is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives to oil and gas as sources of clean energy. The projects reported this month include those for coal conversion process development, materials engineering, alkali metal vapor topping cycles, a coal equipment test program, an AFB coal combustor for cogeneration (CCC), engineering and support studies, process and program assistance, evironmental assessment studies, magnetic beneficiation, and AFBC demonstration plant.
EXPLORES! (EXPloring and Learning the Operations and Resources of Environmental Satellites!) is an educational outreach program developed at Florida State University with the intention of introducing weather satellite receiving technology into the primary and secondary school classrooms. The website furnishes real time high resolution imagery and tropical updates. Visitors can find historical accounts of the civilian weather satellites launched by the United States. Educators can discover kindergarten through twelfth grade resources and curriculum. Users can learn how to become a part of the WXSAT-L community email list where weather satellite professionals, amateurs, and hobbyists converse about scientific, tracking, launching, and operations information.
Fission rate assessments are being made in FFTF to provide input for determination of power distribution, peak power, total power, fuel burnup distribution, conversion ration and neutron spectral information by the multiple foil reaction rate method. A goal of the initial FFTF Characterization Program is to measure isotopic fission rates to an accuracy of 2 to 5% throughout FFTF by radiometric techniques. To achieve this goal, measurements were made in the FFTF In-Reactor Thimble to reduce the uncertainties of key parameters needed for radiometric fission rate mapping of the FFTF core.
Progress reports on the European Research Centre for Air Pollution Control Measures project are presented. Topics covered were: assessment and analysis of the impacts of airborne pollutants on forest trees, and distinction from other potential causes of recent forest dieback; research into atmospheric dispersion, conversion and deposition of airborne pollutants; development and optimization of industrial technical processes to reduce or avoid emissions; and providing instruments and making recommendations to the industrial and political sectors.
The electromagnetic properties of a prototype gravitational wave detector, based on two coupled superconducting microwave cavities, were tested. The radio-frequency (rf) detection system was carefully analysed. With the use of piezoelectric crystals small harmonic displacements of the cavity walls were induced and the parametric conversion of the electromagnetic field inside the cavities explored. Experimental results of bandwidth and sensitivity of the parametric converter versus stored energy and voltage applied to the piezoelectric crystal are reported. A rf control loop, developed to stabilize phase changes on signal paths, gave a 125 dBc rejection of the drive mode on a time scale of 1 h.
This paper describes a system for biogas conversion to electric power and heat by using a micro turbine and three Otto cycle engines. The benefit of the energy from a treatment process residue aims the improvement of the global performance of the system, reducing the the emission of the greenhouse gases and contributing to the global energetic efficiency of the sewage treatment station and the basic sanitation in Brazil.
The C isotopic composition of CH4 emissions are strongly influenced by the pathway of CH4 formation. Contrary to data from other freshwater systems, soil gas and surface flux measurements made in the tropical rain forests of Puerto Rico strongly suggest that CH4 produced in these environments was derived from CO2 reduction, rather than from acetate consumption. This study explored the effects of bacterial competition for acetate, pH, and soil structure on the pathways of CH4 formation in tropical rain forest soils. Our goal was to test two principal hypotheses: (1) ferric iron-reducing bacteria out-competed methanogens for acetate, resulting in greater CO2 reduction rather than aceticlastic methanogenesis, and (2) the low pH of tropical rain forest soils favors CO2 reduction rather than aceticlastic methanogenesis. In addition, this study also investigated the effect of destroying soil aggregate structure on the pathways and rates of CH4 production. Ferric iron-reducing bacteria ...
Information that describes the use of the Otto cycle engines in transportation is summarized. The transportation modes discussed in this report include the following: automobiles, light trucks, heavy trucks, marine, recreational vehicles, motorcycles, buses, aircraft, and snowmobiles. These modes account for nearly 100% of the gasoline and LPG consumed in transportation engines. The information provided on each of these modes includes descriptions of the average energy conversion efficiency of the engine, the capital stock, the amount of energy used, and the activity level as measured in ton-miles. Estimates are provided for the years 1980 and 2000.
The development status of the EE-1 Small Community Solar Thermal Power Experiment (SCSE Program) is presented. Current activities on the Phase II single module development effort are presented, together with plans for a Phase III 1 MW/sub e/ demonstration plant. A description of the various subsystems and components is given with a brief review of their development background. Latest performance figures are given for a 1 MW/sub e/ plant, based on 56 power modules, each consisting of a 12m parabolic dish concentrator, a cavity receiver, an organic Rankine power conversion subsystem and a ground-mounted solid-state rectifier.
In 1980 Sasol completed its very large coal conversion complex, Sasol Two and Three in South Africa. This complex, the largest coal-to-liquids facility in the world, utilizes Sasol's proprietary Fischer-Tropsch technology, the Synthol Process. The two key elements of the Synthol Process are its catalyst and its unique fluidized bed reactor, the Synthol Circulating Fluidized Bed Reactor. Details on the catalytic aspects and reaction mechanism have been given elsewhere. In this paper, the history of the development of the reactor is discussed.
Gamma-rays and conversion electrons emitted in the "1"1"7Cs and "1"1"7Xe decays have been studied from on-line mass-separated "1"1"7Cs sources at the ISOLDE facility. A new "1"1"7Xe decay scheme has been constructed and a level scheme has been established for the "1"1"7Cs decay. The results are discussed in the frame of our recent knowledge about odd-mass neutron-deficient I and Xe systematics.
Papers are presented under 38 symposia. Subjects included reinforced concrete, protective coatings and linings, cathodic/anodic protection, chemical cleaning of boilers, managing corrosion with plastics, water treatment, HRSG boiler tube failure analysis, corrosion in oil and gas production, corrosion in petroleum refining and gas, processing, pipelines and tanks, high temperature materials, chemical process industry, aerospace equipment, materials technology developments for incinerators and waste fuel-fired processors, materials and corrosion in fossil-fuels conversion and combustion, corrosion in nuclear systems, marine corrosion, building systems, corrosion mechanisms, corrosion inhibitors and corrosion monitoring and measurement.
The first stage of the continuous coal hydrogenation unit has been used to test a number of coals with different processing strategies. This work has shown that conversion increases with product recycle, however after the second pass the increase is small but operability of the reactor is considerably improved. A kinetic model for the aromatic saturation of the recycle solvent in the second stage has been developed and will be used in the selection of conditions for oil upgrading processes. New insights into the structural composition of coal derived materials have been made due to the refinement of chromatographic or solubility separation analyses into routine operations and the development of a new technique in NMR spectroscopy.
The performance of a solar chemical heat pipe was studied using CO{sub 2}reforming of methane as the endothermic reaction. A directly heated vertical reactor, packed with a rhodium catalyst was used. The solar tests were carried out in the Schaeffer solar furnace of the Weizmann Institute of Science. The power absorbed was up to 6.3 KW, the maximal flow rates of the gases reached 11,000 1/h, and the methane conversions reached 85%. A computer model was developed to simulate the process. Agreement of the calculations with the experimental results was quite satisfactory.
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.
Florida posseses climatic, land, and water resources favorable for abundant biomass production. Therefore, a statewide program has been initiated to determine adapted species for the available array of production sites. Plant resources under investigation include woody, aquatic, grasses, hydrocarbon, and root crop species. The goal is to produce a continuous stream of biomass for the various biofuel conversion options. Preliminary yields from energy cropping experiments range from about 10 to nearly 90 metric tons per hectare per year, depending on the crop and the production systems employed. (Refs. 15).
Light microscopy was used to analyze the effects of added catalyst at different conditions (temperature and reaction times) in liquefaction testing of a low pyritic sulfur bituminous coal. Quantitative changes in vitrinite/vitroplast reflectance of coal and liquefaction residues were shown to be useful markers in analyzing and understanding the role of catalyst during the initial stage of coal particle hydrogenation. Lower reflectance values corresponded to increased conversions up to about the 60 min and 375{degrees}C experimental conditions. Microscopical observation of liquefaction residues also revealed the presence of `wall scales` of varying width.
This article proposes a model for estimating the effect of the overall thermal resistance of the absorber and the coolant on a solar thermal energy system utilizing advanced heat transfer mediums. Two equations can be used to model a dynamic system: one for the maximum conversion efficiency and one to specify the constraint that, in quasi-steady state, the net energy collected must be transferred to the coolant. These two equations define a constrained optimization problem in two variables, the fluid and the absorber temperatures. The results present interesting implications for liquid metal, direct absorption, and solar evaporating systems.
To achieve high efficiency for the conversion of electron kinetic energy in an electron beam to electromagnetic energy in a Free Electron Laser (FEL), it is important to improve the beam quality. And hence, it is necessary to study and minimize the emittance growth of the beam. According to the requirements for the beam quality in an FEL, the author analyzed the emittance growth caused by the jump of the electric field in an accelerator, energy increase, wakefield in a waveguide, space charge effect and distribution of particles in a beam as well as the wakefield in a deflect system etc. The author also estimated the emittance change caused by the variation of the microwave field from the gun to the first accelerator for such case.
Anaerobic digestions fed with waste orange peels are stable at loading rates up to 3.5 kg total solids (TS)/cubic m.d if the amount of peel oil introduced into the digestion is less than 0.075 g/L digestion liquor per day. The yield of gas (50-55% methane) is 0.5 cubic m/kg of TS; conversion of solids to gas approaches 100%. Oil content of peels can be reduced to non-toxic levels using commercial oil recovery equipment. Presence of aromatic acids in digestion liquors cannot serve as an indication of toxicity or overloading.
The concept of using agricultural residues, especially cotton gin trash (CGT), as a fuel for a small cogeneration power plant based on fluidized bed gasification (FBG) requires that three problems be solved: (1) ash must be removed from the low calorific value (LCV) gas prior to combustion; (2) the high NO/sub x/ emissions associated with many biomass fuels must be significantly reduced; (3) a systems analyses of engineering/economic feasibility for potential applications must be developed. This paper addresses current research at TAMU pertaining to these problems.
A twin unidirectional impulse turbine has been proposed in order to enhance the performance of wave energy plant. This turbine system uses two unidirectional impulse turbines and their flow direction is different from each other. However, the turbine characteristics have not been clarified to date. The performances of a unidirectional impulse turbine under steady flow conditions were investigated experimentally by using a wind tunnel with large piston/cylinder in this study. Then, efficiency of the twin impulse turbine have been estimated by a quasi-steady analysis using experimental results.
A concept of a traveling wave direct energy converter (TWDEC) is developed for 14.7-MeV fusion protons based on the principle of a backward wave oscillator. Separation of fusion protons from thermal ions is accomplished by using ExB ion drift. Energy conversion rate up to 0.87 is attained by applying three-stage modulation of the proton beam. A one-dimensional particle-circuit code is developed to examine self-excitation of the traveling wave and its stability under loading. Electrostatic wave with a fixed frequency is excited spontaneously, and stability of the wave is ensured under loading. (author).
This paper presents an analysis of the performance of a selective emitter using small particles of rare earth compounds stable at high temperatures in a low emittance inert gas stream. An expression for the spectral emissive power excluding radiation scattering was derived to include the radiation in the emission band, produced by electronic transitions of the rare earth ion, and the continuum radiation outside the emission band produced by the rare earth host. Preliminary results suggest that a selective emitter based on suspended rare earth oxide particles will have high efficiency and merits further experimental investigation. {copyright} {ital 1996 American Institute of Physics.}
Inertial Electrostatic Confinement (IEC) fusion was recently described by an Electric Power Research Institute (EPRI) review panel as potentially leading to a most attractive fusion reactor from a utility point of view, if the physics issues can be resolved. Consequently, a design for a small 25-MW electric D-"3He fueled power plant has been explored. Key power plant components consist of the IEC, direct energy conversion and a step-down converter for electrical power transmission. (author).
In the past, the need for high quality images, i.e., very sharp and clear images, in mammography have prevented mammography equipment from being digitalized; however, recent advances in detection technology such as development of a high resolution digital X-ray detector have produced improvements in digital mammography. Digital mammography is expected to replace conventional film-screen mammography. We have developed a digital mammography system, named ''SEPIO NUANCE DT'', which is equipped with a direct conversion flat panel detector. The present paper describes the high basic performance and user-friendly functions of the system. (author)
A spreadsheet-based decision support system has been developed that allows easy evaluation of integrated biomass to electricity and biomass to ethanol systems. The Bioenergy Assessment Model (BEAM) has been developed to allow the techno-economic assessment of biomass to electricity and biomass to ethanol schemes, including investigation of the interfacing issues. Technical and economic parameters can be assessed for a variety of feedstocks, conversion technologies and generating cycles. Production modules are currently available for biomass supply from short rotation coppice and conventional forestry relevant to conditions and practices in NW Europe. The biomass conversion modules include pre-treatment (reception, storage, handling, comminution, screening and drying); atmospheric gasification (generic gasifier, wet gas scrubbing, dual fuel engine); pressure gasification (generic gasifier, hot gas filtration, gas turbine combined cycle); fast ...
This paper deals with conversions of solar energy efficiently into electricity and into gas laser radiation. In the first section, a review study of the possibility of a solar-electric thermophotovoltaic (TPV) device has been done. In a proposed extension of the TPV concept, a Cassagranian optical system concentrates solar radiation to heat a blackbody cavity to 2400/sup 0/K. A double-layer solar cell, GaAs and Si, forming the cylindrical surface concentric to the blackbody cavity, receives the blackbody radiation and converts it into electricity efficiently. A cell conversion efficiency of 50% or more would be possible with the TPV system. The second section explores the concept of blackbody radiation pumping of gas laser media as a step toward utilization of solar energy as a laser pumping source. To demonstrate this concept, an experiment was performed in which various gas mixtures of CO/sub 2/ and He were exposed to 1500/sup 0/K thermal ...
This paper describes the development, design, and fabrication of the crude oil process facilities, and the conversion of an existing tanker for use at the Liuhua 11-1 Field. Over a 16-month period spanning 1994 and 1995, Amoco Orient Petroleum Company, and partners, China Offshore Oil Nanhai East Corporation (CONHE), and Kerr-McGee China Petroleum Ltd., converted a crude oil tanker originally built in 1975 to the Nanhai Sheng Li, the floating production, storage and offloading (FPSO) facility for the Liuhua 11-1 Field. The FPSO will process up to 65,000 BOPD produced from 20 subsea wells located 1.7 miles away. In addition to the processing facilities for produced oil and water, the FPSO has a processed crude oil storage capacity of 715,000 bbls. The ship`s propulsion system was removed during the conversion, because the FPSO is permanently moored at site by means of a 10-point, ``soft`` mooring. The mooring system was designed to survive the ...
An investigation on the hydrogen generation by reacting ball-milled Mg-based materials in different alcoholic solutions (methanol, ethanol, 2-propanol) was performed. The MgH{sub 2} reactivity in methanol is very low (maximum conversion yield <10%) and no improvement is induced by the ball milling treatment. In contrast, the ball milling affects greatly the Mg reactivity in methanol. The Mg powder milled for 30min displays a maximum conversion yield of 47% compared to 3% for unmilled Mg powder. Its high reactivity is ascribed to the creation of numerous defects and fresh surfaces during the initial stage of the milling process, favoring the corrosion of Mg in methanol. In addition, the presence of water in the methanol solution inhibits drastically the alcoholysis reaction despite its low amount (0.3vol%). The higher hydrogen production is obtained with the composite Mg-10at% Ni milled for 30min leading to a ...
The fixed bed pilot plant, the catalyst testing procedure, and the calculations for conversion and selectivities were previously described in the technical progress report covering the period of 3/16/88 to 6/16/88 for Contract DE-AC22-87PC79812. Conversions and hydrocarbon selectivities were calculated using data from an on-line gas chromatography (GC) analyzer. Alcohol selectivities were calculated using data from an on-line boiling point GC analyzer which analyzed the liquid product. The catalysts were prepared via the steps of impregnation, calcination, and reduction on a special Y-zeolite-derived support. The impregnation step consisted of evaporation of metal salts on to the support from an aqueous solution. For one catalyst (No. 6531-188) the metal salts were evaporated on to the support from a reverse micelle solution containing the metal salts. All the catalysts were calcined for four hours at 450{degree}C. The calcined catalysts were ...
The scope of the present study was upgrading a set of heavy aromatic hydrocarbons mixtures whose commercial value ranks close to fuel oil and should become even lower in the next future because of the introduction of more stringent regulations on fuels, through hydro-conversion to a synthetic feed for steam-cracking. The resulting process provides an opportunity to improve the economic return of a steamcracking plant, offering the chance of converting low-value mixtures produced by the plant itself, such as fuel oil of cracking (FOK), saving an equivalent amount of naphtha. The method can also be used for converting pyrolysis gasoline (pygas). Although pygas has at present a fair commercial value, it could suffer a significant penalization in the future due to further limitations on total aromatic content in gasoline. Pygas hydro-conversion to a synthetic steam-cracking feedstock has been recently reported. Fractions from refinery, such as ...
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 ...
To investigate the coal liquefaction characteristics, coal slurry samples were taken from the outlets of the reactors and slurry preheater of NEDOL process 1 t/d process supporting unit (PSU), and were analyzed. Tanito Harum coal was used for liquefaction, and the slurry was prepared with recycle solvent. Liquefaction was performed using synthetic iron sulfide catalyst at reaction temperatures, 450 and 465{degree}C. Solubility of various solid samples was examined against n-hexane, toluene, and tetrahydrofuran (THF). When considering the decrease of IMO (THF-insoluble and ash) as a characteristic of coal conversion reaction, around 20% at the outlet of the slurry preheater, around 70% within the first reactor, and several percents within the successive second and third reactors were converted against supplied coal. Increase of reaction temperature led to the increase of evaporation of oil fraction, which resulted in the decrease of actual slurry flow rate and in ...
This study aimed to correlate the efficiency of enzymatic hydrolysis of the cellulose contained in a sugarcane bagasse sample pretreated with dilute H(2)SO(4) with the levels of independent variables such as initial content of solids and loadings of enzymes and surfactant (Tween 20), for two cellulolytic commercial preparations. The preparations, designated cellulase I and cellulase II, were characterized regarding the activities of total cellulases, endoglucanase, cellobiohydrolase, cellobiase, ?-glucosidase, xylanase, and phenoloxidases (laccase, manganese and lignin peroxidases), as well as protein contents. Both extracts showed complete cellulolytic complexes and considerable activities of xylanases, without activities of phenoloxidases. For the enzymatic hydrolyses, two 2(3) central composite full factorial designs were employed to evaluate the effects caused by the initial content of solids (1.19-4.81%, w/w) and loadings of enzymes (1.9-38.1 FPU/g bagasse) and Tween 20 (0.0-0.1 ...
A comprehensive study of biomass production conversion and utilisation systems has been carried out to examine complete bio-energy systems from biomass in the forest to electricity delivered to the grid. Models have been derived for all of the key steps in an integrated process which have been compiled into an overall system model. Biomass production from short rotation forestry and from conventional forestry is modelled on an individual operation basis in terms of the performance and cost of each step. This includes planting, maintenance, harvesting, chipping, storage and transport. Biomass conversion includes pretreatment (reception, storage, handling, comminution, screening and drying); atmospheric gasification (generic gasifier, water scrubbing, gas engine); pressure gasification (generic gasifier, hot gas clean-up, gas turbine, HRSG, steam turbine); fast pyrolysis for liquid bio-fuel-oil (pyrolyser, oil storage, dual fuel engine); ...
The overall objective of this project was to develop a new approach for the direct liquefaction of coal to produce an all-distillate product slate at a sizable cost reduction over current technology. The approach integrated coal selection, pretreatment, coal swelling with catalyst impregnation, liquefaction, product recovery with characterization, alternate bottoms processing, and a technical assessment including an economic evaluation. Heterofunctional solvents were the most effective in swelling coals. Also solvent blends such as isopropanol/water were more effective than pure solvents alone. Impregnating slurry catalysts simultaneously during coal swelling showed that better uptake was achieved with nonswelling solvent and higher impregnation temperature. Some enhancement in initial coal conversion was seen liquefying SO{sub 2}-treated Black Thunder coal with slurry catalysts, and also when hydrogen donor liquefaction solvents were used. Noncatalytic reactions ...
Neuron differentiation is a complex process involving various cell-cell interactions, and multiple signaling pathways. We showed previously that CD40 is expressed and functional on mouse and human neurons. In neurons, ligation of CD40 protects against serum withdrawal-induced injury and plays a role in survival and differentiation. CD40 deficient mice display neuron dysfunction, aberrant neuron morphologic changes, and associated gross brain abnormalities. Previous studies by Tone and colleagues suggested that five isoforms of CD40 exist with two predominant isoforms expressed in humans: signal-transducible CD40 type I and a C-terminal truncated, non-signal-transducible CD40 type II. We hypothesized that differential expression of CD40 isoform type I and type II in neurons may modulate neuron differentiation. Results show that adult wild-type, and CD40"-"/"- deficient mice ...
Type IV secretion systems (T4SSs) play a central role in the pathogenicity of many important pathogens, including Agrobacterium tumefaciens, Helicobacter pylori, and...Full Text Available
This study was undertaken to determine which rodent species serve as primary reservoirs for the Lyme disease spirochete Borrelia burgdorferi in commonly occurring woodland types...Full Text Available
Subjects were 18 cases with adenocarcinoma of 20 mm or less in diameter, which were detected and resected surgically from September, 1993 to August, 1998. On these cases, thin-Section CT (TSCT) images were compared with pathological findings. Patients were 15 men and 3 women, with mean age of 63.4-year-old. An average tumor size was 11.5 mm (5-17 mm). According to pathological classification of Noguchi, type A as in 6 cases, type B in 3, type C in 7 and type F in 2. TSCT was carried by vas voltage =150 kVp, vas current =200 mA, beam width =2 mm, WW =2000 HU, and WL =-700 HU. The ratio of CT attenuation value in cancer by TSCT correlated with the ratio of aeration rate in the pathologic specimen. The cases of 30% or less on the ratio of CT attenuation value were 100% in types A and B, and 71% in type C. These results suggested that it is necessary to devide into ...
Recent reports confirm that, due to the presence of long-lived, latently infected cell populations, eradication of human immunodeficiency virus type 1 (HIV-1) from infected patients by using antiretroviral...Full Text Available
Equine herpesvirus type 1 was cultivated in swine testis cell cultures and partially purified by differential centrifugation and centrifugation in a linear sucrose density gradient. The viral envelope...Full Text Available
Human longevity is in part genetically determined, and the insulin/IGF-1 signal transduction (IIS) pathway has consistently been implicated. In humans, type 2 diabetes is a frequent disease that results...Full Text Available
OBJECTIVETo determine the association between 25-hydroxyvitamin D (25-OHD) concentration and risk of incident type 2 diabetes.RESEARCH DESIGN AND METHODSIn...Full Text Available
It is shown that calculation of the anomalous expectation values for the massless Gross-Neveu model in the Hartree-Fock approximation indicates the presence of an ordinary chiral phase transition if the coupling constant has the normal sign (g > 0) and of a different transition of the superconductivity type if g < 0.
The influence of an immobilization stressor on lung cellular immune responses was studied. Delayed-type hypersensitivity to sheep erythrocytes was used to evaluate in vivo lung cellular immunity. Mice...Full Text Available
We show how one can associate to a given class of finite type G-structures a classifying Lie algebroid. The corresponding Lie groupoid gives models for the different geometries that one can find in the class, and encodes also the different types of symmetry groups.
The human immunodeficiency virus type 1 (HIV-1) packages its genomic RNA as a dimer of homologous RNA molecules that has to be selected among a multitude of cellular and viral RNAs. Interestingly, spliced...Full Text Available
Economic and performance criteria that should be used in the selection of a scrubber system are presented. Selection should be based on the type of emissions put out by a plant and the removal efficiency required by pollution control standards. Costs and efficiencies for 10 different scrubber systems are reported. (10 diagrams)
Two infants were seen with severe ascites detected before birth, a previously unreported presentation of Niemann-Pick disease type C. In the second infant no diagnostic storage cells were present in...Full Text Available
BackgroundSince 1954, there have been in excess of 800 cases of rabies as a result of European Bat Lyssaviruses types 1 and 2 (EBLV-1, EBLV-2) infection, mainly...Full Text Available
To determine the presence of European bat lyssavirus type 1 in southern Spain, we studied 19 colonies of serotine bats (Eptesicus isabellinus), its main reservoir, during 1998–2003....Full Text Available
The mechanical properties of laminated window profiles manufactured using two types of adhesives were determined. The objective of this study is to evaluate the effects of heat treatment on some mechanical...Full Text Available
Objective:To estimate the prevalence of insulin resistant syndrome (IRS) among newly diagnosed patients with type 2 diabetes and to test their validity against two indices...Full Text Available
Type 2 diabetes mellitus (DM2) is increasing in incidence, creating worldwide public health concerns and impacting morbidity and mortality rates. An increasing number of studies have demonstrated shared...Full Text Available
Background: The causes of elevated B-Type natriuretic peptide (BNP) levels are multifactorial. Renal dysfunction has been shown to affect BNP levels in some studies and...Full Text Available
BackgroundType A1 Clostridium botulinum strains are a group of Gram-positive, spore-forming anaerobic bacteria that produce a genetically, biochemically, and biophysically...Full Text Available
A method is presented to derive the absolute dimensions of early-type detached binaries by combining the observed parameters with results of evolutionary computations. The method is used to obtain the absolute dimensions of nine close binaries. We find that most systems have an initial masss ratio near 1.
Abstract Series of typical -type and pseudo--type halogen-bonded complexes BClY and BBrY and hydrogen-bonded complex BHY (B = C2H4, C2H2, and C3H6; Y = F, Cl, and Br) have been investigated using the MP2/aug-cc-pVDZ method. A striking parallelism was found in the geometries, vibrational frequencies, binding energies, and topological properties between BXY and BHY (X = Cl and Br). It has been found that the lengths of the weak bond d(X)/d(H), the frequencies of the weak bond (X)/(H), the frequency shifts (XY)/(HY), the electron densities at the bond critical point of the weak bonds c(X)/c(H), and the electron density changes c(XY)/c(HY) could be used as measures of the strengths of typical -type and pseudo--type halogen/hydrogen bonds. The typical -type and pseudo--type halogen bond and hyd...