The required minimum 30-year post-closure care period for municipal solid waste (MSW) landfills can be shortened by reducing or eliminating of MSW components with long-terms effect in gas and leachate. The objectives of this study were to evaluate the relative persistence of landfillgas, leachate quantity, and selected leachate parameters using post-closure monitoring data from a case study landfill in south Florida. The relative persistence of selected decomposition byproducts in leachate were evaluated by both zero order and first order models based on monitoring data from the case study landfill. The analyses show that although gas and leachate production rates diminish very quickly, some contaminants remain in leachate as the decomposition process continues at a slower rate. For the c...
This study aims to evaluate the economic and environmental viability of the exploitation of methane gas (CH4) - biogas - concentrated at the bottom of the mountains of waste from landfill Chapeco for power generation. The landfill receives approximately of 80 tons / day, the vast majority of domestic origin.
The energy recovery scheme at Mucking Marshes landfill site, operated by Cory Environmental Limited, has been in operation since October 1991. Using landfillgas abstracted from the site, a gas turbine generates up to 3.2 MW net electric power for export. Operation and performance of the scheme has been monitored over the period January 1995 to August 1996. Overall performance since the first use of the turbine has also been studied, and has shown reliable and profitable operation. The capital cost of the gas turbine and gas compressor plant was approximately 1.8 million. Actual gas collection wells, pipework, pumping and monitoring facilities, while essential to the scheme, are considered part of the gas control equipment needed for the landfill site. Based on a notional electricity selling price of ...
Soil gas, soil, and water were assessed for organic and inorganic constituents at the former 19th Street landfill at Fort Gordon, Georgia, from February to September 2010. Passive soil-gas samplers were analyzed to evaluate organic constituents in the hyporheic zone and flood plain of a creek and soil gas within the estimated boundaries of the former landfill. Soil and water samples were analyzed to evaluate inorganic constituents in soil samples, and organic and inorganic constituents in the surface water of a creek adjacent to the landfill, respectively. This assessment was conducted to provide environmental constituent data to Fort Gordon pursuant to requirements of the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. The passive soil-gas samplers deployed in the water-saturated hyporheic zone and flood plain ...
This 2001 edition of the guide to UK renewable companies and equipment and service providers presents summaries of the different industry sectors covering wind power, photovoltaics, solar water heating, geothermal heat pump, hydroelectric power, marine current and wave technology, bioenergy, power generation from landfillgas, energy from waste, and cogeneration. A UK company classification listing and index is provided along with listing of UK organisations and companies and an index of advertisers.
Within the framework of efforts to optimize state-of-the-art waste disposal methods, this research project makes a theoretical analysis of the propagation behaviour of pollutants from landfills and waste incineration plants into the immediate vicinity of such plants. In order to judge the propagation of pollutants near the above-mentioned waste disposal facilities, a calculation program was developed within the framework of this research project which permits simulation of the propagation of such emissions in a three-dimensional space by application of an Eulerian grid model. It is capable of realistically representing fluid flow conditions and pollutant concentrations for certain points of times within the complex building patterns of such plants, for randomly chosen atmospheric conditions. (orig.)
A 1 MWe power plant using waste wood fuel is to be installed at a US Marine Corps base, which will supply all wood from a landfill site. The core energy conversion technology is a down-draft gasifier supplying approximately 150 Btu/scf gas to both spark ignition and diesel dual-fuel engine-generator sets. Features of the plant design include: (1) grinding wood fuel from a wide range of waste resources, (2) specialized screening for fines removal, (3) complete tar and other waste product control without landfill disposal, and (4) use of process heat for bulk fuel drying, gasifier air pre-heating, and wastewater evaporation.
The severe health and environmental hazards posed by inadequate waste-collection systems in the rapidly growing cities of the Third World have stimulated interest in the waste-to-energy options developed in industrialized countries over the past 20 years. This economic study, the first of its kind, provides: (1) a comparative analysis of the characteristics of urban solid wastes in the United States, Europe, and developing countries; (2) basic information on the characteristics and operation of the two main types of waste-to-energy systems used in the developed world - landfillgas (LFG) systems and waste combustion systems; and (3) a preliminary assessment of the feasibility of using these systems in developing countries. The main conclusion is that present technology for the recovery and utilization of LFG appears to be suitable for developing country use, although the design of LFG projects would have to be modified to accommodate higher ...
Preliminary results are presented from a field study to evaluate the relative hydrologic performance of various landfill capping technologies installed by the Los Alamos National Laboratory at Hill Air Force Base, Utah. Four cover designs (two Los Alamos capillary barrier designs, one modified EPA RCRA design, and one conventional design) were installed in large lysimeters instrumented to monitor the fate of natural precipitation between 01 January 1990 and 20 September 1993. After 45 months of study, results showed that the cover designs containing barrier layers were effective in reducing deep percolation as compared to a simple soil cap design. The RCRA cover, incorporating a clay hydraulic barrier, was the most effective of all cover designs in controlling percolation but was not 100% effective. Over 90% of all percolation and barrier lateral flow occurred during the months of February through May of each year, primarily as a result of snow melt, early spring ...
In this study the greenhouse impact of the total Finnish forest sector was considered, which means that the estimated emissions and sink effects from exported forest products were also included. The forest biomass is and seems to be in the next decades the most important factor in the carbon balance of the total forest sector. The development alternatives of forest industries and waste management practices has still a remarkable influence on the greenhouse impact of the Finnish forest sector. The waste management practices in the future has an important influence on the emissions but the exact net greenhouse impact of the landfills is still uncertain. However, the methane emissions from existing landfills can be reduced essentially by gas recovery. Increased incineration and energy recovery of wood waste (and replacing fossil fuel use by it) is also a future alternative for reducing the greenhouse effects in the forest ...
We investigate the chemical and observational implications of repetitive transient dense core formation in molecular clouds. We allow a transient density fluctuation to form and disperse over a period of 1 Myr, tracing its chemical evolution. We then allow the same gas immediately to undergo further such formation and dispersion cycles. The chemistry of the dense gas in subsequent cycles is similar to that of the first, and a limit cycle is reached quickly (2 - 3 cycles). Enhancement of hydrocarbon abundances during a specific period of evolution is the strongest indicator of previous dynamical history. The molecular content of the diffuse background gas in the molecular cloud is expected to be strongly enhanced by the core formation and dispersion process. Such enhancement may remain for as long as 0.5 Myr. The frequency of repetitive core formation should ...
This request is submitted to seek interim approval to operate a Toxic Substances Control Act (TSCA) of 1976 chemical waste landfill for the disposal of polychlorinated biphenyl (PCB) waste. Operation of a chemical waste landfill for disposal of PCB waste ...
Disposal of fine-particled byproducts via injection into a capola furnace using natural gas/O{sub 2} burners is a cost-efficient alternative to landfill dumping. Tests conducted in a foundry demonstrated that dusts collected there can be injected without detriment to melt-down rate and iron quality. The replacement of FeSi pellets with FeSi dust in addition reduced the slag content, while injection of coal dust permitted a decrease in coke consumption. (orig.) [Deutsch] Die Entsorgung von feinkoernigen Reststoffen durch Einblasen in einen Kupolofen ueber Erdgas/O{sub 2}-Brenner ist eine wirtschaftliche Alternative zur Deponierung. Anhand von Versuchen in einer Giesserei konnte aufgezeigt werden, dass hier anfallende Staeube ohne nachteilige Auswirkungen auf Schmelzleistung und Eisenqualitaet einzublasen sind. Die Substitution von FeSi-Formlingen durch FeSi-Staub brachte zudem eine Reduzierung des Schlackeanteils und das Einblasen von ...
Limestone-based sorbents are used extensively in utility boilers and tail-gas desulfurization units to remove sulfur oxides formed during the combustion of fossil fuels. Such units generate {approximately}20 million tons of flue-gas desulfurization (FGD) wastes in the U.S. annually, the bulk of which ({approximately}95%) are discarded in landfills or holding ponds. However, a significant portion of the Ca in these materials is not sulfated (remains as CaO or Ca(OH){sub 2}), particularly in units that generate dry wastes. When hydrated, such wastes exhibit a strong affinity to absorb acid gases at ambient temperature. This study represents a continuation of previously reported CO{sub 2}-absorption studies and includes more recent work on the absorption of H{sub 2}S and NO. Ten FGD-waste samples along with a control fly ash were examined. Absorption capacities, the role of available calcium and particle size, and mineralogic ...
A solution based on sludge and Olive oil mill effluent (OME) co-digestion, coupled with a management plan, has been implemented, to treat and dispose safely, the mixed residues, into the natural forest and agricultural land. The mixture of up to 25% OME to the sludge improved anaerobic degradation of phenols and fats. High density fat compounds, present in OME, enhanced aggregation, settling and acetoclastic activity of anaerobic sludge. The full scale unit, obtained by modification of a cold digester, allowed to set-up a low capital cost system. The system produced large quantity of biogas and electric energy. Anaerobic degradation of the mixture improved fertilizing properties, making feasible land application of the digested mixture. Regional plan based in Geographical Information System (GIS) selected 800 ha of adequate land area for application near the WWTP. The experience is technically and economically successful. Main incomes are provided by energy use and ...
The paper discusses recent work on lime enhancement and testing at the bench-scale, followed by evaluation of the more promising sorbents in a pilot plant to develop low cost, retrofittable flue gas cleaning technology specifically the development of highly reactive sorbents. Con...
Activities in British Columbia's Fraser Valley generate an estimated 3 million tones of agriculture and food wastes annually, of which 85 per cent are readily available for anaerobic digestion. The potential for energy generation from biogas through anaerobic digestion is approximately 30 MW. On-farm manure-based systems represent the most likely scenario for the development of anaerobic digestion in British Columbia in the near future. Off-farm food processing wastes may be an alternative option to large centralized industrial complexes. Odour control, pathogen reduction, improved water quality, reduced greenhouse gas emissions and reduced landfill usage are among the environmental benefits of anaerobic digestion. The economical benefits include power and heat generation, biogas upgrading, and further processing of the residues to produce compost or animal bedding. This paper described a newly developed anaerobic digestion (AD) ...
The Raywell Process Plants unit, which reclaims a wide range of organic solvents, including chlorinated hydrocarbons, is based on thin film evaporation and distillation rather than steam distillation, thus reducing the risk of contamination by water. Henry Balfour and Co.'s Pfaudler Solvent Recovery System gives 96% or better solvent recovery and produces a near-solid waste suitable for landfill disposal; like the Raywell system, it uses a mechanically wiped thin-film evaporator. Midland Oil Refineries uses sa Raywell thin-film evaporator for recovery of waste lubricating oils rather than the conventional sulfuric acid/clay treatment, thus avoiding formation of sulfuric acid sludge waste. The Henry Balfour Bioenergy anaerobic digestion system gives yields of fuel gas with 65-75% methane as high as 0.8 cu m/kg BOD; it achieves 95-98% BOD removal with no pH control or nutrient addition because it separates solids from liquid effluent and ...
This study examined the atmospheric pollution created by some waste treatment and disposal facilities in the State of Kuwait. Air monitoring was conducted in a municipal wastewater treatment plant, an industrial wastewater treatment plant established in a petroleum refinery, and at a landfill site used for disposal of solid wastes. Such plants were selected as models for waste treatment and disposal facilities in the Arabian Gulf region and elsewhere. Air measurements were made over a period of 6 months and included levels of gaseous emissions as well as concentrations of volatile organic compounds (VOCs). Samples of gas and bioaerosols were collected from ambient air surrounding the treatment facilities. The results obtained from this study have indicated the presence of VOCs and other gaseous pollutants such as methane, ammonia, and hydrogen sulphide in air surrounding the waste treatment and disposal facilities. In some cases the levels ...
On 7 May 2009, the Ministry of the Environment set up a working group to evaluate the possible use of biodegradable waste and other biodegradable material flows for energy production and obstacles to promoting their use in the whole production cycle. The deadline for the working group was 31 January 2010. According to its mandate, the working group had to make proposals for the measures needed to promote the energy use of biodegradable waste in order to fulfil the targets of the Government Foresight Report on Long-term Climate and Energy Policy. The working group proposes thirteen measures to be put into operation so that the investments aimed at the energy use of biodegradable waste would grow significantly from the present level. The most important measure is a full ban on depositing biodegradable waste in landfills. The working group sees that the reduction of greenhouse gas emissions from landfills should, in any case, ...
The energy price volatility model suggests that some of the proposed natural gas programs can contribute to energy price stability. The sector most vulnerable to fuel price variations is, of course, the transportation sector. The most effective strategy to achieve energy pace stability is to reduce petroleum consumption in this sector. The natural gas vehicle program is therefore recommended as potentially important and worthy of further consideration. At this point, distinguishing the merits of various subprograms is not feasible. This result farther supports the conclusion that the DOE`s energy R&D portfolio is not efficiently balanced and an increase in oil and gas research should be a high priority. The DOE has responded favorably and has significantly increased its proposed research with the explicit objective of displacing oil in the transportation sector. The enhanced research and development ...
This report documents the development and use of the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The model, developed in a spreadsheet format, estimates the full fuel- cycle emissions and energy use associated with various transportation fuels for light-duty vehicles. The model calculates fuel-cycle emissions of five criteria pollutants (volatile organic compounds, carbon monoxide, nitrogen oxides, sulfur oxides, and particulate matter measuring 10 microns or less) and three greenhouse gases (carbon dioxide, methane, and nitrous oxide). The model also calculates the total fuel-cycle energy consumption, fossil fuel consumption, and petroleum consumption using various transportation fuels. The GREET model includes 17 fuel cycles: petroleum to conventional gasoline, reformulated gasoline, clean diesel, liquefied petroleum gas, and electricity via residual oil; natural gas to compressed natural ...
Eukaryotes may influence pollutant degradation processes in groundwater ecosystems by activities such as predation on bacteria and recycling of nutrients. Culture-independent community profiling and...Full Text Available
The corrosion behavior of 304 stainless steel was characterized with cyclic voltammetry in a eutectic Li/K and Li/Na carbonate melt under anode and cathode gas of the molten-carbonate fuel cell (MCFC). The corrosion rate of 304 steel was determined in four different environments of the MCFC with electrochemical methods and from cross-sectional analysis of corrosion layers. These four environments were open-circuit and MCFC-load conditions both under anode and cathode gas. At open-circuit conditions corrosion was more severe under the oxidizing cathode gas then under the reducing anode gas. On the contrary, at load conditions corrosion was more severe under anode than under cathode gas. The anodic polarization under anode gasenhances corrosion, whereas the high anodic polarization under cathode gas leads to anodic ...
We report on the discovery of kinematic shock signatures associated with a localized radio jet interaction in the merging Seyfert galaxy NGC 5929. We explore the velocity-dependent ionization structure of the gas and find that low-ionization gas at the interaction site is significantly more disturbed than high-ionization gas, which we attribute to a local enhancement of shock ionization due to the influence of the jet. The characteristic width of the broad low-ionization emission is consistent with shock velocities predicted from the ionization conditions of the gas. We interpret the relative prominence of shocks to the high density of gas in the nuclear environment of the galaxy and place some constraints of their importance as feedback mechanisms in Seyferts.
Visible smoke of exhaust gas from iron ore sintering plants spoil the scenery around the works. In this paper, the mechanism of formation of visible smoke is discussed by detailed analysis of the exhaust gas components and dust in the Oita No. 1 sintering plant. The main substance of visible smoke was mist condensing in the air during the cooling of exhaust gas that contained 0.1 ppm of sulfuric acid. Sulfuric acid is considered to raise the dew point and so facilitate mist condensation, and to lower the vaporization of visible mist containing sulfuric acid solution. Dust in the exhaust gas is also considered to act as nucleation sites for mist condensation. This proposed mechanism was confirmed by the test remixing SOx-rich gas with desulfurization gas in the Nagoya No. 3 sintering plant. Long trails of visible smoke were observed by remixing SOx-rich ...
The authors discuss a two-phase two-component experimental system developed to study enhancement of heat transfer from a vertical chip size heater to surrounding liquid (Freon 113 or Ethanol) due to air jet impingement. Heat transfer coefficient was measured as function of jet velocity, heat flux and the distance between exit of jet tube and heated surface. The injector was placed very close to the hot surface. It was found that the heat transfer was notably enhanced with foreign gas impingement, especially in the cases of small temperature differences between wall and coolant. In fact for higher jet velocities the heat transfer coefficients tended to infinite while the temperature differences between wall and coolant were zero. The heat transfer coefficients decreased with the increasing of heat flux. High-speed camera was used to study the behaviour of the gas bubbles which play very important role in ...
The report describes the site specific changes required to convert an existing lime FGD system to a limestone system enhanced by dibasic acid (DBA) or adipic acid, and the costs of making such a change. In 1982-83, pilot plant tests were conducted at the R. D. Green Station of Bi...
The K site near Seoul began landfilling in 1992. The landfilled wastes include municipal solid waste (66.4%), construction residues (20.4%), water and wastewater sludges (trace levels), and hazardous waste (trace levels). The water content of the municipal solid waste is very high (47.3%); as a result, the leachate level (average E.L.) of the landfill, the design value of which is 7.0 m, was measured at 10.3 m in January 1995 and is increasing. The increase of leachate level in the landfill site causes a problem with slope stability. The leachate level at each disposal stage divided by the intermediate cover layer was calculated with the HELP (Hydrologic Evaluation of Landfill Performance) model and calibrated with the data measured from February 1993 to June 1995. Also, the hydraulic conductivities of the waste layer and the intermediate cover layer in each stage were calibrated ...
This request is submitted to seek interim approval to operate a chemical waste landfill for the disposal of polychlorinated biphenyl (PCB) waste. Interim approval is requested for a period not to exceed 5 years. This request covers only the disposal of sm...
This request is submitted to seek interim approval to operate a chemical waste landfill for the disposal of polychlorinated biphenyl (PCB) wastes. This request covers only the disposal of small quantities of solid PCB wastes contained in decommissioned su...
The Mixed Waste Landfill occupies 2.6 acres in the north-central portion of Technical Area 3 at Sandia National Laboratories, Albuquerque, New Mexico. The landfill accepted low-level radioactive and mixed waste from March 1959 to December 1988. This report represents the Corrective Measures Study that has been conducted for the Mixed Waste Landfill. The purpose of the study was to identify, develop, and evaluate corrective measures alternatives and recommend the corrective measure(s) to be taken at the site. Based upon detailed evaluation and risk assessment using guidance provided by the U.S. Environmental Protection Agency and the New Mexico Environment Department, the U.S. Department of Energy and Sandia National Laboratories recommend that a vegetative soil cover be deployed as the preferred corrective measure for the Mixed Waste Landfill. The cover would be of sufficient thickness to store ...
The purpose of this paper is: (1) conduct HELP model variations in weather data, profile characteristics, and hydraulic conductivities for major rock units; (2) compare and contrast the results of simulations; (3) obtain an estimation of leakage through the landfill from the surface to the aquifer; and (4) evaluate contaminant transport to the aquifer utilizing leakage estimation. The conclusions of this paper are: (1) the HELP model is useful to assess landfill design alternatives or the performance of a pre-existing landfill; (2) model results using site-specific data incorporated into the Weather Generator (Trail 4), varied significantly from generalized runs (Trials 1-3), consequently, models that lack site-specific data should be used cautiously; and (3) data from this study suggest that there will not be significant downward percolation of leachate from the surface of the landfill cap to the ...
This paper evaluates the two well-known final waste disposal methods, incineration and landfilling. In particular we compare the social cost of two best-available technologies using a point estimate based on private and environmental cost data for the Netherlands. Not only does our comparison allow for Waste-to-Energy incineration plants but for landfills as well. The data provide support for the widespread policy preference for incineration over landfilling only if the analysis is restricted to environmental costs alone and includes savings of both energy and material recovery. Gross private costs, however, are so much higher for incineration, that landfilling is the social cost minimizing option at the margin even in a densely populated country such as the Netherlands. Furthermore, we show that our result generalizes to other European countries and probably to the USA. Implications for waste policy ...
Results of ongoing research project at the McMaster Nuclear Reactor Facility on real-time neutron radiography for the visualization of interfacial geometry, movements and phase distributions in gas-liquid and gas-liquid-metal multi-phase flows are presented. Experiments were conducted with bubble column tubes with boiling liquid nitrogen, air-water and air-mercury mixtures. Discussions are also focused on air-water flowing within a tube containing a CANDU type 37 rod fuel bundle assembly positioned both horizontally and vertically. Computer processing using a digital image format to enhance the real-time images was used. Imaging techniques include frame averaging, background substraction, edge enhancement (spatial filtering), contrast enhancement and video densitometry. (orig.).
The U.S. Department of Energy and EPRI have co-funded this project to improve the control of mercury emissions from coal-fired power plants equipped with wet flue gas desulfurization (FGD) systems. The project investigated catalytic oxidation of vapor-pha...
The major driver to enhance the efficiency of the simple gas turbine cycle has been the increase in process conditions through advancements in materials and cooling methods. Thermodynamic cycle developments or cycle integration are among the possible ways to further enhance performance. The current paper presents the possibilities and advantages from the LOTHECO natural gas-fired combined cycle concept. In the LOTHECO cycle, low-temperature waste heat or solar heat is used for the evaporation of injected water droplets in the compressed air entering the gas turbine's combustion chamber. Following a description of this innovative cycle, its advantages are demonstrated by comparison between different gas turbine power generation systems for small and large-scale applications, including thermodynamic and economic analysis. A commercial gas ...
A geologic sequestration pilot in the Thornton gas field in Northern California, USA involves injection of up to 4000 tons of CO{sub 2} into a stacked gas and saline formation reservoir. Lawrence Berkeley National Laboratory (LBNL) is leading the pilot test in collaboration with Rosetta Resources, Inc. and Calpine Corporation under the auspices of the U.S. Department of Energy and California Energy Commission's WESTCARB, Regional Carbon Sequestration Partnership. The goals of the pilot include: (1) Demonstrate the feasibility of CO{sub 2} storage in saline formations representative of major geologic sinks in California; (2) Test the feasibility of EnhancedGas Recovery associated with the early stages of a CO{sub 2} storage project in a depleting gas field; (3) Obtain site-specific information to improve capacity estimation, risk assessment, and performance prediction; (4) ...
This article describes how a natural gas-fired combined cycle with increased firing temperature, reduced cooling air usage, improved component efficiencies, and cycle enhancements could achieve a lower heating value plant efficiency of greater than 60%. Today's gas turbine systems feature high fuel-to-electricity efficiencies. Efficiencies, on a lower-heating-value (LHV) basis, for large natural gas-fired combined-cycle systems for the utility market have been demonstrated at 54%. Even though manufacturers will make improvements in the 1990s, efficiency levels will reach a plateau. Cycle innovations and gas turbine design changes will achieve LHV efficiencies in the 60% range for natural gas-fired utility machines.
Efforts in industry concerning pollution abatement up to nowadays were aimed at: solid particles contained in gaseous effluents, SO_2 effluent reduction, nitrogen oxide effluent limitation through combustion technology enhancement. Various CO_2 emission scenarios with different energy production means (same or increased nuclear plant number, energy consumption reduction) show that energy conservation schemes for the developed countries are the best solution to CO_2 control. Different solutions for greenhouse gas abatement from industrial plant are reviewed: effluent processing, burner technological enhancement, heat transfer optimization on industrial processes, computer assisted management for industrial processes, plasma technic for refining, substitution of gas to oil in chemistry, etc.
The 'KUPOLOPT' joint research project has as its target the economic and ecological optimization of cupola furnaces in foundries. The use of natural gas/oxygen burners during foundry operation is being studied on Fritz Winter Eisengiesserei GmbH and Co. KG's cupola furnace with the objective of enhancing melting rate, reducing emissions and permitting re-utilization of foundry and other particulates. This work is also intended to improve the cupola-furnace process in economic terms, in order to enhance its competitiveness. This article presents the results of the first project phase, which served to investigate the natural gas/oxygen burner as an external supplier of energy. (orig.)
This paper discusses the successful implementation of automatic control in the Wattenberg Gas Field in northern Colorado. Also discussed is the use of solar powered Amocams equipment to affect continuous monitoring and control of these tight gas wells. The control system includes an algorithm which continuously adjusts the production cycling based on changes in the individual well's producing pressures and flow rates. This strategy has been successful in enhancing production and reducing the number of wells logged off due to excessive fluid buildup. The benefits derived from this system are enumerated and the impacts on field operations are discussed.
The flux distributions and enhancement factors for various gas doser designs typically used in surface science applications and chemisorption studies have been calculated and compared. The following conclusions, which will aid the experimentalist in the choice of doser design, can be made. (1) The enhancement factor expected for a given doser can easily be derived from Fig. 2. (2) The optimum doser design is a multichannel array with a radius slightly larger than that of the sample, and a distance from the sample < 10% of the sample diameter. (Complications of this design are discussed.) (3) Because of space requirements, the sample--doser distance must sometime be > or =40% of the sample diameter, in which cases it is better to use a cosine emitter. A good, very simple doser design is described that consists of a small cosine emitter with a sample--doser distance of 1/2 the sample diameter. This provides an ...
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 ...
This conference report contains the lectures presented at the BMBF status seminar on the cooperative project ``Bodies of landfills``, which took place at Wuppertal on 25th and 26th April 1995. The cooperative project was started in autumn 1993 and studies the long-term behaviour of wastes deposited at landfills in general. Inorganic and municipal wastes are studied separately. (orig./SR) [Deutsch] Der vorliegende Tagungsband enthaelt die Vortraege des BMBF-Statusseminars zum Verbundvorhaben `Deponiekoerper` vom 25. und 26. April 1995 in Wuppertal. Das Verbundvorhaben `Deponiekoerper` wurde im Herbst 1993 begonnen und befasst sich ganz generell mit dem langfristigen Deponieverhalten von Abfaellen. Es ist unterteilt in die Untersuchung von anorganischen Abfaellen und von Siedlungsabfaellen. (orig./SR)
Biomass is one of the main natural resources in Sweden. The present low-CO{sub 2} emission characteristics of the Swedish electricity production system (hydro and nuclear) can be retained only by expansion of biofuel applications for energy purposes. Domestic Swedish biomass resources are vast and renewable, but not infinite. They must be utilized as efficiently as possible, in order to make sure that they meet the conditions for sustainability in the future. Application of efficient power generation cycles at low costs is essential for meeting this challenge. This applies also to municipal solid waste incineration with energy extraction, which should be preferred to its dumping in landfills. Hybrid dual-fuel combined cycle units are a simple and affordable way to increase the electric efficiency of biofuel energy utilization, without big investments, uncertainties or loss of reliability arising from complicated technologies. Configurations of such power cycles are ...
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 ...
The fossil fuel consumption and pollutant emissions in a coal fired fluidized bed boiler could be reduced by biomass pyrolysis gas reburning. The influence of three kinds of biomass pyrolysis gases on the emission of N2O in a laboratory scale fluidized bed was investigated using the mechanism of GRI3.0 in this paper. The results showed that: the effect of sawdust pyrolysis gas reburning on N2O was more significant than that of rice husk and orange peel under the same conditions; the increase of initial oxygen content from 1% to 8% in flue gas would restrain the decomposition of N2O; the N2O decomposition was enhanced by increasing reaction temperature from 1073.15 K to 1323.15 K, and the decomposition rate may reach 99% at 1223.15 K.
Malaysia's petroleum industry is looking forward to an expansionary period until the end of the century, with the role of gas being greatly enhanced. The state oil firm Petronas sees increasing oil and gas reserves, making fuller use of abundant gas reserves, an exploration thrust into deepwater areas and the intensification of environmental protection as some of the points of emphasis in its current programme. The state firm president Tan Sri Datuk Azizan Zainul Abidin says that in the past few years a national economic growth rate of 8 percent has resulted in rising energy demand. Economic growth is projected to continue, so that an increase in power demand can be expected for the next few years. 'Fortunately, we are experiencing the same bullish trend in oil exploration and development,' he says. (author)
Malaysia's petroleum industry is looking forward to an expansionary period until the end of the century, with the role of gas being greatly enhanced. The state oil firm Petronas sees increasing oil and gas reserves, making fuller use of abundant gas reserves, an exploration thrust into deepwater areas and the intensification of environmental protection as some of the points of emphasis in its current programme. The state firm president Tan Sri Datuk Azizan Zainul Abidin says that in the past few years a national economic growth rate of 8 percent has resulted in rising energy demand. Economic growth is projected to continue, so that an increase in power demand can be expected for the next few years. 'Fortunately, we are experiencing the same bullish trend in oil exploration and development,' he says. (author).
...The Political Evolution of the Landfill Tax in the UK wm-1996-03 Green Taxes, Waste Management and Political Economy 1995 ^ Top ...on civil engineering Lifecycle assessment - an overlooked opportunity Refereed Journal Articles: Green taxes, waste management and political economy Reports: Environmental cost benefit ...
In accordance with Department of Energy (DOE) Regulations surveys for wetland presence or absence were conducted in September 1996 on the DWI-1630 site (Witherspoon Landfill) located in South Knoxville, Knox County, Tennessee. The DWI-1630 site includes a closed, capped landfill area, areas of past disturbance adjacent to the capped area, and patches of hardwood forest. Wetlands were identified on the landfill cap and in a small bottomland that was formerly used for a retention pond in the southwest corner of the DWI-1630 site. The wetlands identified on the cap are man-induced, atypical situation wetlands. These areas have hydrophytic vegetation and wetland hydrology, but the soils do not have hydric characteristics. Wetland development appears to be due to a combination of the grading or subsidence of the clay landfill cap, the low permeability of the clay fill soil, and the absence of surface ...
We investigate the relationship between spiral arms and star formation in the grand-design spirals NGC 5194 and NGC 628 and in the flocculent spiral NGC 6946. Filtered maps of near-IR (3.6 #mu#m) emission allow us to identify 'arm regions' that should correspond to regions of stellar mass density enhancements. The two grand-design spirals show a clear two-armed structure, while NGC 6946 is more complex. We examine these arm and interarm regions, looking at maps that trace recent star formation-far-ultraviolet (GALEX NGS) and 24 #mu#m emission (Spitzer SINGS)-and cold gas-CO (HERACLES) and H I (THINGS). We find the star formation tracers and CO more concentrated in the spiral arms than the stellar 3.6 #mu#m flux. If we define the spiral arms as the 25% highest pixels in the filtered 3.6 #mu#m images, we find that the majority (60%) of star formation tracers occur in the interarm regions; this result persists qualitatively even when considering ...
Survival and growth of terrestrial plants is negatively affected by complete submergence. This is mainly the result of hampered gas exchange between plants and their environment, since gas diffusion is severely reduced in water compared with air, resulting in O2 deficits which limit aerobic respiration. The continuation of photosynthesis could probably alleviate submergence-stress in terrestrial plants, but its potential under water will be limited as the availability of CO2 is hampered. Several submerged terrestrial plant species, however, express plastic responses of the shoot which may reduce gas diffusion resistance and enhance benefits from underwater photosynthesis. In particular, the plasticity of the flooding-tolerant terrestrial species Rumex palustris turned out to be remarkable,...
In Polymer Electrolyte Fuel Cell (PEFC) technology the reducing of volume and mass of the fuel cell stack and the improvement of catalyst utilization are of great interest. These parameters affect applicability and system cost. In this work we present an alternative way for reducing the stack volume by combining gas distribution and catalytic active area in one plate. Micro machined glassy carbon electrodes serve as support material for the platinum catalyst, as well as gas distributor at the same time. A comparison of these electrodes with conventional platinum-black gas diffusion electrodes under fuel cell conditions shows that the new system is a promising electrode type for enhanced power density and catalyst utilization. (author) 3 figs., 5 refs.
The Lawrence Livermore National Laboratory has developed a mobile field laboratory for remote measurement of atmospheric processes and observables that are important in global climate change, dispersal of hazardous materials, and atmospheric pollution. Specific observables of interest are water vapor, trace gases, aerosol size and density, wind, and temperature. The goal is to study atmospheric processes continuously for extended periods in remote field locations. This laboratory has just reached field ready status with sensors for aerosol and trace gas measurement based on established techniques. A development program is underway to enhance the sensor suite with several new techniques and instruments that are expected to significantly extend the state of the art in remote trace gas analysis. The new sensors will be incorporated into the lab during the next two years.
In studying the absorption of carbon dioxide by absorbents impregnated with alkanol amines, researchers used a laboratory-scale packed column to determine the overall gas-phase mass-transfer coefficients and enhancement factors. A model derived for the mechanism of the chemical reaction taking place in the interfacial layer accounts for the effect of the reaction upon the absorption rate better than other models.
An overall review of status of energy in Lebanon is presented. Energy consumption and demand, in all sectors of economy, including renewable energy sources (biomass, solar energy, kerosene, gas oils...) are described, enhanced by figures and tables. Recommendations of energy development in Lebanon within national economic policy are formulated. 4 tabs.
The available measurements on the cosmic-ray antiproton/proton ratio show an excess of antiprotons above predictions derived in the framework of the standard picture of cosmic-ray origin and propagation. Calculations are performed of the production from collisions of cosmic rays with the interstellar gas under the condition of distributed reacceleration. It could be shown that the calculated antiproton/proton ratio is enhanced compared to that derived from the leaky box model, but it remains difficult to bring it into agreement with the data by reasonable astrophysical assumptions. 15 references.
Test results show that adding adipic acid to the limestone slurry significantly improved the SO sub 2 removal efficiency of the FGD system. Limited baseline data on operations with limestone only indicated a performance level of 55% SO sub 2 removal. Adding about 2200 ppM of adip...
Gas storage is a critical element in the natural gas industry. Producers, transmission and distribution companies, marketers, and end users all benefit directly from the load balancing function of storage. The unbundling process has fundamentally changed the way storage is used and valued. As an unbundled service, the value of storage is being recovered at rates that reflect its value. Moreover, the marketplace has differentiated between various types of storage services and has increasingly rewarded flexibility, safety, and reliability. The size of the natural gas market has increased and is projected to continue to increase towards 30 trillion cubic feet over the next 10 to 15 years. Much of this increase is projected to come from electric generation, particularly peaking units. Gas storage, particularly the flexible services that are most suited to electric loads, is crucial in meeting the needs of ...
The report outlines the role of the IEA Greenhouse Gas R and D Programme, gives details of participants and of publications and summarises achievements of 1998. A successful conference on Greenhouse Gas Control Technologies was held in Interlaken, Switzerland. Technical studies reported include novel power generation concepts for removing carbon dioxide prior to or after combustion, using seawater for CO{sub 2} capture, investigating carbon dioxide sequestration in conjunction with enhanced coalbed methane recovery and applying retrofitting to power plants and to offshore oil and gas platforms. Systems studies taking a broader view include investigating the potential for combined energy systems (power generation with district heating, power with district cooling etc.) to reduce CO{sub 2} abatement cost, studies on the LNG/power generation fuel cycle, assessing the potential of methanol as an energy ...
This paper explains technologies for turbo chargers used in light cars. Light car engine turbo chargers have been given various improvements responding to needs of the market. Since ball bearings have less mechanical loss than sliding bearings, and enhances greatly the turbo efficiency, they are used in some high performance engines of light cars. While the conventional ball bearing has used high hardness bearing steel, the new standard cars started using ceramic ball. The currently used light car gasoline engines are divided into two kinds, serial three-cylinder type and serial four-cylinder type, either having merits and demerits. The new twin entry turbo developed by IHI arranges divided exhaust gas ports above and below to simplify the manifold shape, and realizes smooth flow by twisting the exhaust gas flow path inside the turbine housing. This makes the dynamic pressure of the exhaust gas more ...
Tarapur Atomic Power Station Unit-4 is first 540 MWe pressurized heavy water reactor in India. It achieved criticality on 06th March 2005 and then operated at full power i.e 500 MWe. Radiation workers during the normal operation and reactor shutdown are exposed to radiation field. The control of dose rates and the collective dose of the radiation workers is most important for the best performance of the reactor. Experience gained during the operation of the 220 MWe reactors has shown that the Moderator system, primary heat transport system, annulus gas system and moderator cover gas system are the main systems contributing to the dose rate and collective dose. In order to identify the radio nuclides contributing to the radiation field, study was undertaken at TAPS Unit-4. Various samples from the Moderator, primary heat transport system, annulus gas system and moderator cover gas system were collected ...
The US Department of Enregy (DOE) Subsurface Contaminants Focus Area is developing technologies to address environmental problems associated with hazardous and radioactive contaminants in soil and groundwater that exist throughout the DOE complex, including radionuclides, heavy metals; and dense non-aqueous phase liquids (DNAPLs). More than 5,700 known DOE groundwater plumes have contaminated over 600 billion gallons of water and 200 million cubic meters of soil. Migration of these plumes threatens local and regional water sources, and in some cases has already adversely impacted off-site rsources. In addition, the Subsurface Contaminants Focus Area is responsible for supplying technologies for the remediation of numerous landfills at DOE facilities. These landfills are estimated to contain over 3 million cubic meters of radioactive and hazardous buried Technology developed within this specialty area will provide efective methods to contain ...
The potential hazard of landfill wastes was previously evaluated by examining the extraction procedures for individual waste, although various wastes were co-disposed of in actual landfills. This paper investigates the reduction of extraction-procedure toxicity by co-disposing various combinations of two wastes. When two wastes are mixed homogeneously, the extraction of heavy metals from the waste mixture is critically affected by the extract pH. Thus, co-disposal wastes will have a resultant pH between the pH values of its constituent. The lower the resultant pH, the lower the concentrations of heavy metals in the extract. When these wastes are extracted sequentially, the latter extracted waste has a stronger influence on the final concentration of heavy metals in the extract. Small-scale lysimeter experiments confirm that when heavy-metal-bearing leachates Generated from hazardous-waste lysimeters are passed through a nonhazardous-waste ...
BackgroundPolicies on waste disposal in Europe are heterogeneous and rapidly changing, with potential health implications that are largely unknown. We conducted a health impact assessment of landfilling and incineration in three European countries: Italy, Slovakia and England.MethodsA total of 49 (Italy), 2 (Slovakia), and 11 (England) incinerators were operating in 2001 while for landfills the figures were 619, 121 and 232, respectively. The study population consisted of residents living within 3 km of an incinerator and 2 km of a landfill. Excess risk estimates from epidemiological studies were used, combined with air pollution dispersion modelling for particulate matter (PM10) and nitrogen dioxide (NO2). For incinerators, we estimated attributable cancer incidence and years of life lost (YoLL), while for landfills we estimated attributable cases of congenital anomalies and low birth weight ...
A new low molecular mass organogelator 1 containing 2-(2prime-hydroxyphenyl)benzoxazole (HPB) group with long alkyl chain was synthesized by the reaction with 5-amino-2-(2prime-hydroxy-4prime-methylphenyl)benzoxazole and dodecyl isocyanate in THF at room temperature. The reversible gelation ability of 1 was investigated using a heating-cooling method in various organic solvents. The stable organogel was formed from carbon tetrachloride or from cyclohexane at the concentration as low as 0.9%. The self-assembled supramolecular gel structure formed by non-covalent bonding was confirmed with field emission-scanning electron microscope (FE-SEM) exhibiting fibril- or ribbon-shaped structure depending on the solvent used. Regarding the aggregation-induced emission enhancement (AIEE) phenomenon, t...
Full text: The surface properties of poly (tetrafluoroethylene) (PTFE) are changed by the exposure to synchrotron radiation (SR). We succeeded in controlling the wettability of the PTFE surface from hydrophobic to hydrophilic by varying the substrate temperature during the SR irradiation and found that the wettability was ascribable to microstructure and chemical composition of surface.In these previous works, oxygen atoms were found to inhabit on the hydrophobic surface of PTFE. In this study, we investigated the surface modification of PTFE from the SR exposure experiment under the O_2 gas atmosphere. The SR exposure to the PTFE sheet was carried out at beamline 6 (BL6) of the New- SUBARU. The PTFE sheet was irradiated to the white beam, ranging 50-1000 eV at BL6 at room temperature. The gas cell was mounted at the irradiation chamber. The O_2 gas pressure in the gas cell can be maintained at about ...
The conversion of highly radioactive waste liquor into glass by the pot vitrification process has been studied at Harwell using a full-scale inactive pilot plant. A summary of the off-gas behavior and its interpretation is presented. Experimental runs were carried out on 3 representative wastes (MAGNOX - thermal reactor, metal fuel, THORP - thermal oxide fuel and PFR - fast reactor oxide fuel) using 2 methods of feeding the glass-formers (slurry and crizzle). Materials were carried over from the vitrification vessel into the off-gas system by entrainment supplemented by volatilization. The overall behavior of the off-gas was consistent with the presence in it of 5 separate aerosols of particulate matter. Sources of entrainment gave rise to 3 aerosols, and a further 2 aerosols were formed as a result of chemical reaction (Ru) and condensation (Cs) processes involving the volatile species. Entrainment was ...
A summary of the off-gas behavior in the HARVEST pot vitrification process is presented. Experimental runs were carried out on 3 representative wastes (MAGNOX - thermal reactor, metal fuel, THORP - thermal oxide fuel and PFR - fast reactor oxide fuel) using 2 methods of feeding the glass-formers (slurry and crizzle). Materials were carried over from the vitrification vessel into the off-gas system by entrainment supplemented by volatilization. The main volatile elements were Ru, B, Cs. Some volatility was also shown by Na and Li. The overall behavior of the off-gas was consistent with the presence in it of 5 separate aerosols of particulate matter. Sources of entrainment gave rise to 3 aerosols, and a further 2 aerosols were formed as a result of chemical reaction (Ru) and condensation (Cs) proceses involving the volatile species. Entrainment was enhanced when the feed contained free alkali nitrate. The ...
The Davis GSR Landfill (GSR) is listed by the U.S. Environmental Protection Agency on the National Priorities List. Preliminary on-site sampling results have demonstrated volatile organic compounds in ground water and surface water. The contaminants present in groundwater at this site are trichloroethylene, ethylbenzene, toluene, chloromethane, tetrahydrofuran, 1,1,1-trichloroethane, and 1,2 dichloroethane. GSR represents a potential public health concern to area residents. However, information available on this site is not currently adequate to determine if a public health concern exists to these residents. At a minimum, future investigations of this site should include a characterization of the site and site contaminants, and a characterization of the hydrogeology of the area.
In the past shredder fluff from automobile recycling was discarded in landfills, but shrinking landfill space and the partly hazardous content of the fluff as well as its caloric value, all resulted in efforts to turn this waste problem into an energy resource. In order to produce a fuel, the inorganic compounds have to be removed. Extensive analyses and particle size measurements were made on fluff from various shredder. For optimal separation all particles are reduced to a uniform, relatively small size. In a subsequent combined screening and air classification process, successful separation into organic and inorganic fractions is achieved. The inorganic fraction is treated in a heavy media or an eddy-current separator to recover the valuable metals, while the organic fraction is now suitable for thermal processing, such as fluidized bed gasification and using the resulting carbon as a chemical reagent.
The increasing diffusion of small-scale energy systems within the distributed generation (DG) paradigm is raising the need for studying the environmental impact due to the different DG solutions in order to assess their sustainability. Addressing the environmental impact calls for building specific models for studying both local and global emissions. In this framework, the adoption of natural gas-fueled DG cogeneration technologies may provide, as a consequence of cogeneration enhanced overall energy efficiency and of natural gas relatively low carbon content, a significant reduction of global impact in terms of CO2 emissions with respect to the separate production of electricity and heat. However, a comprehensive evaluation of the DG alternatives should take into account as well the impact due to the presence of plants spread over the territory that could increase the local pollution, in particular due to CO and NOx, and ...
Oregon State University (OSU) and the Pacific Northwest National Laboratory (PNNL) were funded by the U.S. Department of Energy to conduct research focused on resolving the key technical issues that limited the deployment of efficient and extremely compact microtechnology based heat actuated absorption heat pumps and gas absorbers. Success in demonstrating these technologies will reduce the main barriers to the deployment of a technology that can significantly reduce energy consumption in the building, automotive and industrial sectors while providing a technology that can improve our ability to sequester CO{sub 2}. The proposed research cost $939,477. $539,477 of the proposed amount funded research conducted at OSU while the balance ($400,000) was used at PNNL. The project lasted 42 months and started in April 2001. Recent developments at the Pacific Northwest National Laboratory and Oregon State University suggest that the performance of absorption and desorption ...
We address the deviations of the scaling relations of elliptical galaxies from the expectations based on the virial theorem and homology, including the "tilt" of the "fundamental plane" and the steep decline of density with mass. We show that such tilts result from dissipative major mergers once the gas fraction available for dissipation declines with progenitor mass, and derive the scaling properties of the progenitors. We use hydrodynamical simulations to quantify the effects of major mergers with different gas fractions on the structural properties of galaxies. The tilts are driven by the differential shrinkage of the effective stellar radius as a function of dissipation in the merger, while the correlated smaller enhancements in internal velocity and stellar mass keep the slope of the velocity-stellar mass relation near V \\pr M_*^{1/4}. The progenitors match a straightforward model of disc formation in LCDM haloes. ...
Ternary diagrams are commonly used to provide a graphic representation of equilibrium fluid phase behavior for systems as diverse as distillation columns and miscible gas floods of oil reservoirs. The phase envelope, and the position of the critical point on it, are important to enhanced oil recovery engineers who are involved with miscible gas flood design. In the past, phase equilibrium data were laboriously plotted on the ternary diagram and special graphic techniques were utilized to locate the critical point on the phase envelope. This work presents a computerized curve fitting method to generate the phase envelope from a given set of phase equilibrium data and then use the tie-line slopes to position the critical point. Experimental data are included and show excellent agreement with this new method.
Ternary diagrams or pseudo ternary diagrams are commonly used to provide a graphical representation of equilibrium fluid phase behavior for systems as diverse as distillation columns and miscible gas floods of oil reservoirs. The phase envelope and the position of the critical point on it are important to enhanced oil recovery engineers who are involved with miscible gas flood design. In the past, phase equilibrium data were laboriously plotted on the pseudo ternary diagram and special graphical techniques were utilized to locate the critical point on the phase envelope. Presented in this article is a computerized curve fitting method to, firstly, generate the phase envelope from a given set of phase equilibrium data and then use the 'tie-line slopes' to position the critical point. Experimental data are included and show excellent agreement with this new method.
In this paper, a novel type of a corona discharge plasma reactor was designed, which consists of needle-plate-combined electrodes, in which a series of needle electrodes are placed in a glass container filled with flue gas, and a plate electrode is immersed in the water. Based on this model, the removal of NO and SO2 was tested experimentally. In addition, the effect of streamer polarity on the reduction of SO2 and NO was investigated in detail. The experimental results show that the corona wind formed between the high-voltage needle electrode and the water by corona discharge enhances the cleaning efficiency of the flue gas because of the presence of water, and the cleaning efficiency will increase with the increase of applied dc voltage within a definite range. The removal efficiency of SO2 up to 98%, and about 85% of NOx removal under suitable conditions is obtained in our experiments.
A new technique for ion implantation into concave surface of insulating materials is proposed and experimentally studied. The principle is roughly described by referring to modifying inner surface of a PET (polyethylene terephthalate) bottle. An electrode that is supplied with positive high-voltage pulses is inserted into the bottle. Both plasma formation and ion implantation are simultaneously realized by the same high-voltage pulses. Ion sheath with a certain thickness that depends on plasma parameters is formed just on the inner surface of the bottle. Since the plasma potential is very close to that of the electrode, ions from the plasma are accelerated in the sheath and implanted perpendicularly into the bottle's inner surface. Laser Raman spectroscopy shows that the inner surface of an ion-implanted PET bottle is modified into DLC (diamond-like carbon). Gas permeation measurement shows that gas-barrier property ...
The diesel engine is the most efficient device for converting chemical energy stored in liquid hydrocarbon fuels into useful work. Up to 50% of the energy in the fuel is converted into output shaft work. The modern diesel engine is twice as efficient as the early diesel engines and produces as much as sixty times as much power for a given cylinder size. These developments have, in recent years, been accompanied by a substantial reduction in the noxious elements in the exhaust gas so that engines are now, relatively speaking, ecologically clean. The developments have centred around exhaust gas turbocharging and improved fuel injection systems, but recent work on low-heat-rejection engines has resulted in significant advances in structural ceramics and in high-temperature lubricating oil, as well as an enhanced understanding of heat transfer in high-temperature combustion chambers. (author).
In an attempt to overcome inadequacies perceived in the approach to providing energy to village communities using the conventional Khadi and Village Industries Commission biogas plant as well as the Janata model, a biogas digester has been developed suitable for a farmer having only one hectare of land. The information on gas yields and other data from a variety of substrates in a laboratory digester are presented. The digester itself consists of a chamber underground into which the influent flows through a channel. Gas is collected in a dome which constitutes the upper part of the digestion chamber and is maintained under pressure by water. The dome can be made of any suitable material such as plastic, ferrocement and brick and mortar. The upper part of the chamber itself is exposed to sun light which enhances microbial growth. Water which surrounds the dome ensures a minimum of temperature variation. 3 references.
The magnetically fluidized bed (MFB) was used as the reactor in a novel semidry flue gas desulfurization (FGD) process to achieve high desulfurization efficiency. Experiments in a laboratory-scale apparatus were conducted to reveal the effects of approach to adiabatic saturation temperature, Ca/S molar ratio and applied magnetic field intensity on SO(2) removal. Results showed that SO(2) removal efficiency can be obviously enhanced by decreasing approach to adiabatic saturation temperature, increasing Ca/S molar ratio, or increasing applied magnetic field intensity. At a magnetic field intensity of 300Oe and a Ca/S molar ratio of 1.0, the desulfurization efficiency (excluding desulfurization efficiency in the fabric filter) was over 80%, while spent sorbent appeared in the form of dry powder. With the SEM, XRD and EDX research, it can be found that the increase of DC magnetic field intensity can make the surface morphology on the surface of the ...
Owing to their key function in power production the technology of gas- and steam turbines has a very high importance. Gas turbines in particular have become much more efficient and show higher performance in cogeneration plants. The VDI group on materials engineering puts these issues at the centre of this report whose focus is on measures necessary to increase plant availability: damage analysis, materials optimisation, supervision of construction and repair. The report which looks at applications and practical experience is adressed to operators of gas-, steam-, and water turbine plants, manufacturers of turbines and their components as well as maintenance companies, experts and insurance engineers. (orig.) [German] Aufgrund ihrer Schluesselposition bei der Stromerzeugung kommen den Gas- und Dampfturbinen eine sehr hohe technische Bedeutung zu. Insbesondere die Gasturbine macht in den letzten Jahren ...
The EMS Energy Institute at The Pennsylvania State University (Penn State) has managed the Gas Storage Technology Consortium (GSTC) since its inception in 2003. The GSTC infrastructure provided a means to accomplish industry-driven research and development designed to enhance the operational flexibility and deliverability of the nation's gas storage system, and provide a cost-effective, safe, and reliable supply of natural gas to meet domestic demand. The GSTC received base funding from the U.S. Department of Energy's (DOE) National Energy Technology Laboratory (NETL) Oil & Natural Gas Supply Program. The GSTC base funds were highly leveraged with industry funding for individual projects. Since its inception, the GSTC has engaged 67 members. The GSTC membership base was diverse, coming from 19 states, the District of Columbia, and Canada. The membership was ...
Advanced techniques for focused-ion-beam (FIB) device modification have been developed for complex, multistep modifications to circuitry on planar chip technology. Applying gas-assisted etching (GAE) techniques for high-aspect-ratio milling and the selective milling of both conductive and insulating films enhances process latitude. Localized ion-beam-induced deposition of an insulating film provides reconstructive capability in previously modified areas. The application of both techniques for complex device modification on VSLI devices fabricated with CMOS process technology is reviewed. (UK).
In situ Auger sputter depth profiles of saturation implants of 3 keV N/sub 2//sup +/ in silicon at room temperature exhibit a sharp peak in the nitrogen concentration in the outermost layers, followed by a monotonic decrease. No broad plateau was observed. The energy of the Auger line corresponding to the Si(2p) core electron excitation, monitored throughout the profiling, exhibits a chemical shift of up to 7 eV at the surface peak concentration. Inert gas ion post-bombardment of unsaturated implants significantly modifies the profile, and supports the suggestion that the surface peak arises through radiation enhanced diffusion of implanted atoms.
Over the past decade, the energy {open_quotes}paper{close_quotes} market has grown into one of the largest traded markets in the world providing hedging instruments for the producer as well as the enduser of energy products. Because banks, stockholders, and other financial providers rely on a borrower`s ability to generate cash flow to repay their investment, borrowers are increasingly turning to the derivatives markets to provide security against one of the most volatile markets in he world. The existence of this market has enhanced the ability of financial institutions to lend with confidence and appropriate aggressiveness to the oil and gas industry.
The Cu- and Ni-based bulk metallic glass matrix composites were fabricated by spark plasma sintering of a mixture of gas-atomized metallic glass powders and ductile brass powders. The brass powders added for the enhancement of plasticity are well distributed in the matrix after consolidation. The matrix of the composite materials remains as a fully amorphous phase after consolidation process. With increasing the brass content, the level of plasticity strain increased, although the level of strength decreased. The successful consolidation of metallic glass matrix composite with high density was attributed to viscous flow in the supercooled liquid state during spark plasma sintering.
Total EU (and Norway) emissions of CO_2 from thermal power generation were some 950 million tonnes in 1990, the Kyoto agreement reference level. An ongoing research project, the GESTCO project, will provide the first documentation that, for the emission sources within the selected key areas, sufficient geological storage capacity is available for at least 30 years and possibly much longer. Cost of energy will obviously increase, but it is anticipated that electricity production cost price will be comparable to that of renewables. It would further have major implications for the European power generating industry which today is totally dominated by fossil fuel combustion with enormous emissions problems. The identification and siting of subsurface CO_2 storage capability can be expected to have considerable effect on the planning for and future siting of fossil fuel plants. In Norway there are plans to build several major, coastally sited, natural gas-fed ...
...diversion generates a host of environmental, financial, and social benefits, including conserving energy, reducing disposal costs, and reducing the burden on landfills and other waste disposal methods . Waste Diversion at EPA For many years, EPA has established waste diversion goals that exceed current federal requirements. EPA ...
This paper very briefly outlines hazardous waste management issues, including regulations, in Mongolia. Air, water, and soil pollutants are identified and placed in context with climatic, social, and economic circumstances. The primary need identified is technology for the collection and disposal of solid wastes. Municipal waste problems include rapid urbanization and lack of sanitary landfills. Industrial wastes of concern are identified from the mining and leather industries. 4 refs., 2 tabs.
The primary methodology that is used for disposal of municipal solid waste is the use of land fills; 80--85% of the municipal solid waste (MSW) produced in the country currently is land filled. The two other disposal alternatives used are recycling and incineration. Waste-to-energy technology (WTE) which incinerates MSW to produce electricity and/or steam is attractive in other cases since it reduces landfill volume, reduces the consumption of fossil and other fuels, and produces a revenue stream from the sale of the electricity or steam. The gaseous effluents from landfills can also be used to fuel power plants. Recycling and material separation programs can have a substantial impact on the throughput and heating value of MSW collected and thus impact WTE plant economics; the magnitude of the impact will depend upon a number of factors such as what materials and what fraction are separated and recycled, the design of the WTE plant itself (its ...
This appendix contains the alphabetically indexed bibliography for the complete group of reports on municipal waste management alternatives. The references are listed for each of the following topics: mass burn technologies, RDF technologies, fluidized-bed combustion, pyrolysis and gasification of MSW, materials recovery- recycling technologies, sanitary landfills, composting, and anaerobic digestion of MSW.
Considering the fact that more than 40% of all household wastes are organic wastes composting could be an excellent relief and complement to other waste disposal methods (e.g. combustion or direct landfills). Provided the right conditions household wastes could be composted together with sewage sludges and manures. The paper discusses the legal aspects, quantitative evaluations, conveying systems, as well as the compost utilization and marketing aspects valid for the Federal Republic of Germany.
Given that fossil fuel fired power plants are among the largest and most concentrated producers of CO{sub 2} emissions, recovery and sequestration of CO{sub 2} from the flue gas of such plants has been identified as one of the primary means for reducing anthropogenic CO{sub 2} emissions. In this study, ALSTOM Power Inc. (ALSTOM) has investigated several coal fired power plant configurations designed to capture CO{sub 2} from effluent gas streams for use or sequestration. Burning fossil fuels in mixtures of oxygen and recirculated flue gas (made principally of CO{sub 2}) essentially eliminates the presence of atmospheric nitrogen in the flue gas. The resulting flue gas is comprised primarily of CO{sub 2}. Oxygen firing in utility scale Pulverized Coal (PC) fired boilers has been shown to be a more economical method for CO{sub 2} capture than amine scrubbing (Bozzuto, et al., 2001). ...
Context: Our previous models of a giant planet migrating through an inner protoplanet/planetesimal disk find that the giant shepherds a portion of the material it encounters into interior orbits, whilst scattering the rest into external orbits. Scattering tends to dominate, leaving behind abundant material that can accrete into terrestrial planets. Aims: We add to the possible realism of our model by simulating type I migration forces which cause an inward drift, and strong eccentricity and inclination damping of protoplanetary bodies. This extra dissipation might be expected to enhance shepherding at the expense of scattering, possibly modifying our previous conclusions. Methods: We employ an N-body code that is linked to a viscous gas disk algorithm capable of simulating: gas accretion onto the central star; gap formation in the vicinity of the giant planet; type II migration of the giant planet; type I migration of ...
Superconducting MgB{sub 2} samples were prepared by the sintering of a mixture of fine Mg (or Mg alloy) powder produced by gas-atomization and B powder. The single MgB{sub 2} phase with a superconducting onset temperature of 38 K was obtained by sintering at 1073 K for the pure Mg or AZ31 alloy powders. In the case of AZ31, the superconducting MgB{sub 2} was obtained by sintering at a low temperature of 873 K for 50 h although a long sintering time of 100 h is needed to obtain a single MgB{sub 2} phase for Mg powder. This indicates that the AZ31 alloy enhances a formation rate of superconducting MgB{sub 2} at the low temperature through the formation of the partial melting phase. Thus, the gas-atomized fine Mg or AZ31 alloy powders are useful for preparation of a superconducting MgB{sub 2} and in particular AZ31 alloy is effective for the low temperature fabrication of MgB{sub 2}. (orig.)
The presence of natural fractures in reservoir rock can significantly enhancegas production, especially in tight gas formations. Any general knowledge of the existence, location, orientation, spatial density, and connectivity of natural fractures, as well as general reservoir structure, that can be obtained prior to active seismic acquisition and drilling can be exploited to identify key areas for subsequent higher resolution active seismic imaging. Current practices for estimating fracture properties before the acquisition of surface seismic data are usually based on the assumed geology and tectonics of the region, and empirical or fracture mechanics-based relationships between stratigraphic curvature and fracturing. The objective of this research is to investigate the potential of multicomponent surface sensor arrays, and passive seismic sources in the form of local earthquakes to identify and characterize potential ...
We have developed a photon accumulated laser mass spectrometer that enables us to identify isomers of polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran. This system is comprised of a high temperature (230 deg. C) pulsed gas injector (PGI), multimirror multipath system (MMS), and the conventional time-of-flight mass spectrometer. The PGI induces the formation of a choked supersonic jet gas pulse that cools down to a temperature to restrain fragmentation and reduces vibrational and rotational thermal noises. The results suggest that the excited lifetime numbers and fragment dynamics of these species change completely with jet cooling of molecules. The MMS enhances the soft ionization efficiency (by a factor of 1000 over a single path system) through photon accumulation by extending the irradiation duration (to about 40 ns) and volume, and it further minimizes fragmentation by carefully controlling the laser ...
Laboratory experiments were conducted to simulate the transfer of acidic THOREX waste from Tank 8D-4 into the alkaline PUREX waste in Tank 8D-2 at West Valley. The purpose of the experiments was to explore means of minimizing the production of nitric oxide (NO) gas during mixing of the two wastes and to assess the potential for the gas to further react in the vapor space possibly leading to enhanced corrosion of the tank walls. Forty one THOREX/PUREX mixing tests were conducted to explore the effects of stirring rate, pH, THOREX addition rate, THOREX or PUREX dilution, and temperature. The two most important criteria for minimizing NO production were to maintain some degree of agitation and the keep the pH in the PUREX high, preferably >12. Steel corrosion tests were performed in the presence of low partial pressures of NO{sub 2} and liquid water or water vapor. The NO{sub 2} (from oxidation of NO in the vapor space) ...
Fourier transform infrared spectroscopy is a simple, fast, reliable and nondestructive analytical method. By using the method developed in Clark Atlanta University, consistent and reliable infrared spectral results can be obtained. An accurate radiant energy can be calculated from these infrared spectra by using a blackbody as the calibration standards. By means of the specially-designed-and-lab-made sampling inlet and the Horiba gas analyzers, the compositions of CO{sub 2}, CO, UCH, NOx and O{sub 2} etc. from the combustion exhaust gases have been on-line accurately analyzed. The commercial natural gas IR burner performed differently in the different conditions. For the methane-air combustion, at the equivalence ratio {Phi} = 1, the IR burner produced its maximum radiation efficiency, {approximately}31.4%, and the concentration of CO{sub 2} reached its maximum value, {approximately}10.7%. In the fuel-lean region, the O{sub 2} concentration in ...
The present study attempts to use hydrogen peroxide solution to humidify Ca(OH)(2) particles to enhance the absorption of SO(2) to achieve higher removal efficiency and to solve the valuable reuse of the reaction product in the semidry flue gas desulfurization (FGD) process. Experiments were carried out to examine the effect of various operating parameters including hydrogen peroxide solution concentration, Ca/S molar ratio and approach to adiabatic saturation temperature on SO(2) removal efficiency in a laboratory scale spray reactor. The product samples were analyzed to obtain semi-quantitative measures of mineralogical composition by X-ray diffraction (XRD) with reference intensity ratio (RIR) method and the morphology of the samples was examined by scanning electron microscope (SEM). Compared with spraying water to humidify Ca(OH)(2), SO(2) removal efficiency was improved significantly by spraying hydrogen peroxide solution of 1-3 wt.% to ...
The PDIM multifunction regulator offers in one single unit the basic functions filtering, slamshut safety valve, pressure reduction and a gas flow straightening vane. This concept formulated by the engineer J.-P. Cornil is a Gaz de France patent. Developed and manufactured by a French industrial company it incorporates some astute innovations in the field of fluid dynamics. Its technical caracteristics make a significant step forward in gas technology. Since the first unit was brought into service over 1000 PDIM units have been built and incorporated in gas regulating and metering stations for transport, distribution and industrial applications. The very compact nature of the PDIM enhanced by its direct bolting to a turbine or other type of gas meter leads to small size stations allowing lower cost projects and making it easier to set in populated or architecturally significant ...
We present a new approach for growing Si nanowires directly from a silicon substrate, without the use of a metal catalyst, silicon vapor or CVD gasses. The growth can be performed in a furnace type configuration at moderate temperatures or in localized regions by resistive heating. Since the silicon wires grow directly from the silicon substrate, they do not need to be manipulated nor aligned for subsequent applications. Wires in the 20-50 nm diameter range with lengths over 80 ?m can be grown by this technique. We have studied the effects of various growth parameters, including temperature, substrate orientation, initial sample cleaning and carrier gasses. Results indicate that most important parameters in the growth of the nanowires are the surface cleaning, the temperature and the type of carrier gas used. A model is proposed, which involves an oxide catalyst for the process, with the growth of the nanowires enabled by a significantly ...
This report for the Swiss Federal Office of Energy (SFOE) presents the overview reports made by SFOE Heads of Program on work done in 2007. Projects reported on in the natural gas-fired fuel cell area include the EU-project REAL-SFOC, the long-term testing of anode-supported SOFC stacks, intermediate-temperature fuel cells based on proton conducting electrolytes, the interdisciplinary ONEBAT project and lifetime-enhancement of SOFC stacks for CHP applications. In the polymer-electrolyte fuel cell (PEFC) area, projects concerning proton-conducting polymer membranes, factors limiting the lifetime of fuel cell membranes, a new highly active oxygen reduction electrode for PEM fuel cell and zinc/air battery applications, the enhancement of PEFC durability and reliability, model-based investigation of PEFC performance, and local gas analysis of PE fuel cells are briefly reported on. Long-term research ...
In August 1989, representatives from the Alberta Oil Sands Technology and Research Authority (AOSTRA) were the guests of the USSR Interbranch Scientific Technological Complex, Oil Recovery Institute (MNTK) in an extensive visit to heavy oil and gas fields and to various research institutes. Observations made during this tour concerning developments in the USSR heavy oil/bitumen industry, enhanced oil recovery, research programs, proposals for joint ventures, and technological developments are reported. It is noted that oil production in the USSR seems to have peaked and is in a state of decline, indicating the vital importance of enhanced recovery projects in reversing this trend. The areas visited included the Yarega field, where underground thermal recovery methods are used; the Sakhalin Island area, where successful thermal methods are used and where the USSR's largest offshore drilling rig is located; the ...
As part of their corporate policy on environmental protection, Chevron, has taken an approach to work collaboratively with other industry members, universities and government agencies in phytoremediation research. The petroleum industry is interested in the integration of phytoremediation with the many biotechnology treatment technologies currently being used by the industry. Phytoremediation is a complex technology that does not just transfer wastes to another site, but offers in-situ final use and disposal treatment at sites anywhere in the world. Sites for potential remediation range from abandoned large refineries, chemical plants, or small urban gas stations. Research has focused on the cleanup of metals and hydrocarbons in diverse types of soil, water and groundwater conditions. This includes research into remediation of petroleum contaminants such as total petroleum hydrocarbon (TPH), polynuclear aromatic hydrocarbons as well as benzene in soil and the ...
Focused ion beam (FIB) milling techniques are presented aiming at the manipulation of both tin dioxide (SnO_2) inverted opals and polystyrene (PS) direct opals. Different SnO_2 opals are considered in order to estimate the regularity of their bulk after the production. A SnO_2 mesoporous monolith is FIB micromachined to make it suitable for optical applications. PS direct opals are structured by FIB milling at different scales. Ordered arrays of PS opals are modified by selectively removing a single sphere. In performing this task, we discuss the effects on the FIB milling due to the gas-assisted enhanced etching and to the binding of the nearest neighbours. Techniques to achieve imaging of PS opals in absence of a conductive coating are also brought up. Furthermore, isolated PS spheres are drilled with or without enhanced etching in order to produce controlled defects on them. The FIB-assisted manipulations we show may ...
New alloys of Cu.sub.x Ag.sub.(1-x) InSe.sub.2 (where x ranges between 0 and 1 and preferably has a value of about 0.75) and CuIn.sub.y Ga.sub.(1-y) Se.sub.2 (where y ranges between 0 and 1 and preferably has a value of about 0.90) in the form of single crystals with enhanced structure perfection, which crystals are substantially free of fissures are disclosed. Processes are disclosed for preparing the new alloys of Cu.sub.x Ag.sub.(1-x) InSe.sub.2. The process includes placing stoichiometric quantities of a Cu, Ag, In, and Se reaction mixture or stoichiometric quantities of a Cu, In, Ga, and Se reaction mixture in a refractory crucible in such a manner that the reaction mixture is surrounded by B.sub.2 O.sub.3, placing the thus loaded crucible in a chamber under a high pressure atmosphere of inert gas to confine the volatile Se to the crucible, and heating the reaction mixture to its melting point. The melt can then be cooled slowly to form, ...
In this paper, we propose to characterize boron transient enhanced diffusion (TED) for processes currently used for P{sup +}/N ultra-shallow junctions (USJ) fabrication. Indeed, the fundamental understanding of boron diffusion for low energy boron implantation is mandatory to evaluate the scalability of such processes for the coming complementary metal-oxide-semiconductor (CMOS) transistor generations. In these experiments, we characterize the boron anomalous diffusion, thanks to boron buried marker-layers obtained by epitaxial growth. B{sup +} and BF{sub 2}{sup +} ultra-low energy (ULE) implantations and plasma doping (PLAD) using BF{sub 3} as precursor gas are carried out to compare the two techniques used for advanced USJ fabrication. Boron diffusion behaviors are analyzed via secondary ion mass spectrometry for annealing at 700 deg. C for 5 min and 15 min. Finally this paper brings some physical insights explaining the technological benefit ...
In this paper, we propose to characterize boron transient enhanced diffusion (TED) for processes currently used for P"+/N ultra-shallow junctions (USJ) fabrication. Indeed, the fundamental understanding of boron diffusion for low energy boron implantation is mandatory to evaluate the scalability of such processes for the coming complementary metal-oxide-semiconductor (CMOS) transistor generations. In these experiments, we characterize the boron anomalous diffusion, thanks to boron buried marker-layers obtained by epitaxial growth. B"+ and BF_2"+ ultra-low energy (ULE) implantations and plasma doping (PLAD) using BF_3 as precursor gas are carried out to compare the two techniques used for advanced USJ fabrication. Boron diffusion behaviors are analyzed via secondary ion mass spectrometry for annealing at 700 deg. C for 5 min and 15 min. Finally this paper brings some physical insights explaining the technological benefit coming from PLAD ...
In this 150-day study, chicken manure, kenaf, and white rot fungus were added to soil microcosms in an attempt to enhance the degradation of polychlorinated biphenyls. The soil was contaminated with commercial PCB mixtures. Dishes were ammended with 5% dry weight chicken manure, 1% dry weight kenaf, and 1% dry weight kenaf plus Phanerochaete chrysosporium inoculant. PCB concentrations were determined at 30 day intervals by soxhlet extraction and gas chromatography analyses. Preliminary results of microbial populations and PCB degradation are presented. At 90 days, the microcosms amended with chicken manure had significantly higher populations of bacteria, fungi, and actinomycetes. However, at 120 days, these soils underwent great reductions in actinomycete and bacterial populations. Through 60 days, the concentration of the PCBs Aroclor 1242 and 1248 had its greatest reduction in the kenaf amended soils. The concentration of Aroclor 1260 either ...
ObjectivesTo extend a set of work carried out previously at Royal Holloway, the Natural History Museum and elsewhere, and instigated, to a considerable extent, by the PI to determine~%~~%~1. whether there is any significant difference in the performance of clay minerals in the presence of leachates generated by wastes from different cultures and/or deposited in different climates;~%~~%~2. what causes some, if not all, clay minerals to aggregate after reaction with landfill Ieachate;~%~~%~3. the permeabili [continued...]DescriptionAround 1995 it was shown that that interactions between clay minerals and landfill leachate destroy the clay mineral lattice, leading to reduced liner permeability. Recent work indicates that the effect may be caused by dissolution of silica and deposition of amorphous alumina. Most work to date has been done using synthetic and natural 'British' teachates. The ...
The average American generates four pounds of solid waste per day, yet increasing constraints are being placed on the ability of municipalities to handle waste disposal. Most cities face a scarcity of acceptable landfill sites and conventional incineration and landfill methods have come under strict air, water and soil pollution standards. City administrators are being encouraged to select from a variety of proposed technologies that supplant traditional waste disposal methods, some of which offer the promise of revenues from energy and resource recovery. The problem is to select from available near-term technologies those systems that will fit into a city's long-term solid-waste management program. Broadly, waste-to-energy recovery systems now available to cities may be classified as combustion, pyrolysis, biodegradation, and mechanical front-end systems. It is important to notice that operations used for mechanical front-end systems ...
The reduction of emission from power plants of the public power industry inevitably leads to more and more residual products being obtained which require utilization. Traditionally, the building and building materials industry as well as, for a number of years, the gypsum industry have been the main customers processing these residual materials. To avoid having to tip them at landfills that are in short supply already, further uses are sought; so, for instance, in farming to ameliorate soil and fertilize plants. Relative to this subject, proposals are already available which are presented as lectures at the conference and discussed, together with practical knowledge and new investigation results. (BBR).
First, the problem of food packaging waste is introduced and one of the solutions, the Tetra Pak, is completely described. The article highlights the political sensitivity concerning the landfilling of packaging waste, as is done with the efforts of the Tetra Pak producer concerning the collection of used Tetra Paks and the results of these efforts. The document also informs us about the different recycling options for Tetra Paks, the qualitative prevention (using cleaner packaging), the quantitative prevention (using less packaging) and the sustainable development (using loner lasting packaging). The proposed four-step plan for a communication strategy is company-specific.
...Species - see CITES Trade of Dangerous Chemicals Transport and Environment U Urban Environment Use of natural resources V Volatile Organic Compounds W Waste Landfills Waste electrical and electronic equipment - see WEEE Waste incineration Waste legislation - reporting Waste management planning Waste oils Waste shipments Waste water - see Urban waste water Water Bathing Water Drinking water Floods Marine environment Urban waste water Water Framework Directive WEEE - Waste Electric and Electronic Equipment Wildlife ...
...it only highlights the different feedstocks used in the production of fiber-based packaging materials or fossil-fuel ones; what about the energy required to convert ...feedstock, is unacceptable in trying to quantify the overall burden a specific packaging material has on the environment. As an aside, the point ... Consequentially, it is difficult to speculate on how much packaging material a company diverts from the landfill by switching from one material to another ...without specifying what geographical region said packaging material resides in. In addition, there is a lot of interest in diverting PET thermoforms from ...
Pilot plant tests have been conducted to evaluate sodium thiosulfate as an oxidation inhibition additive in five lime/limestone slurry flue gas desulfurization processes. It was found that the oxidation rate of absorbed sulfur dioxide (SO)/sub 2/ was reduced by more than 50 percent in the presence of 100 to 200 ppm of thiosulfate ion in the scrubbing slurry. Calcium sulfate dihydrate (gypsum) scaling was eliminated and the unsaturated (with respect to gypsum) operation mode was maintained by the addition of sodium thiosulfate. Other benefits of sodium thiosulfate addition observed at the pilot plant included improvement in solids dewatering properties for limestone processes and improvement in SO/sub 2/ removal efficiency for magnesium-enhanced lime/limestone processes.
The article gives results of pilot-plant tests to evaluate sodium thiosulfate as an oxidation-inhibition additive in five lime/limestone slurry flue-gas desulfurization processes. It was found that the oxidation rate of absorbed SO/sub 2/ was reduced by more than 50% in the presence of 100-200 ppm of thiosulfate ion in the scrubbing slurry. Calcium sulfate dihydrate (gypsum) scaling was eliminated and the unsaturated (with respect to gypsum) operation mode was maintained by the addition of sodium thiosulfate. Other benefits of sodium thiosulfate addition observed at the pilot plant included improvement in solids dewatering properties for limestone processes and improvement in SO/sub 2/ removal efficiency for magnesium-enhanced lime/limestone processes.
The article gives results of pilot-plant tests to evaluate sodium thiosulfate as an oxidation-inhibition additive in five lime/limestone slurry flue-gas desulfurization processes. It was found that the oxidation rate of absorbed SO/sub 2/ was reduced by more than 50% in the presence of 100-200 ppm of thiosulfate ion in the scrubbing slurry. Calcium sulfate dihydrate (gypsum) scaling was eliminated and the unsaturated (with respect to gypsum) operation mode was maintained by the addition of sodium thiosulfate. Other benefits of sodium thiosulfate addition observed at the pilot plant included improvement in solids dewatering properties for limestone processes and improvements in SO/sub 2/ removal efficiency for magnesium-enhanced lime/limestone processes.
Advances in nuclear reactor technology and the use of gas-cooled fast reactors require the development of new materials that can operate at the higher temperatures expected in these systems. These include refractory alloys base on Nb, Zr, Ta, Mo, W, and Re; ceramics and composites such as those based on silicon carbide (SiCf-SiC); carbon-carbon composites; and advanced coatings. Besides the ability to handle higher expected temperatures, effective heat transfer between reactor componets is necessary for improved efficiency. Improving thermal conductivity of the materials used in nuclear fuels and other temperature critical components can lower the center-line fuel temperature and thereby enhance durability and reduce the risk of premature failure.
A noninvasive method is described for estimating local cerebral blood flow (LCBF) and local partition coefficients by means of computed tomographic scanning during inhalation of 30% stable xenon gas in oxygen. Time-dependent xenon concentrations in arterial blood and brain tissue during the wash-in and washout phases are used to calculate partition coefficients and LCBF values by means of a least-squares curve-fitting analysis. Control values for partition coefficient and LCBF obtained from control subjects with minor head trauma in the chronic stage were compatible with those in several past reports, and reproducibility was satisfactory. The theoretic grounds underlying this new method of curve-fitting analysis are discussed.
A noninvasive method is described for estimating local cerebral blood flow (LCBF) and local partition coefficients by means of computed tomographic scanning during inhalation of 30% stable xenon gas in oxygen. Time-dependent xenon concentrations in arterial blood and brain tissue during the wash-in and washout phases are used to calculate partition coefficients and LCBF values by means of a least-squares curve-fitting analysis. Control values for partition coefficient and LCBF obtained from control subjects with minor head trauma in the chronic stage were compatible with those in several past reports, and reproducibility was satisfactory. The theoretic grounds underlying this new method of curve-fitting analysis are discussed.
This patent describes a low emission duel fuel engine system. It comprises: a dual fuel engine having a combustion chamber; a fuel oil supply connected to the engine; a fuel gas supply connected to the engine; and means connected between the fuel oil supply and the engine for injecting fuel oil into the engine. The means connected between the engine and fuel oil supply limiting the injection of fuel oil to the combustion chamber to pilot ignition quantities only, wherein the limiting means includes means for limiting the injection of fuel oil such that the exhaust emission of NO{sub x} is at an emission rate of less than 1 GM/PH-HR, whereby the exhaust emission performance of the dual fuel engine is enhanced.
The integration of European energy markets is a key goal of EU energy policy, and has also been the focal point of many scientific studies in recent years. International markets for coal, oil, natural gas and electricity have previously been investigated in order to determine the extent of the respective markets. This study enhances this field of research to bioenergy markets. Price series data and time series econometrics are used to determine whether residential sector wood pellet markets of Austria, Germany and Sweden are integrated. The results of the econometric tests show that the German and Austrian markets can be considered to be integrated, whereas the Swedish market is separate from the other two countries. Although increased internationalization of wood pellet markets is likely to contribute to European price convergence and market integration, this process is far from completed. (author)
BackgroundMore than 11 million Americans live with chronic lung disease; in search for an alternative to donor organs, we attempted to regenerate lungs based on perfusion decellularized lung scaffolds that can be transplanted similar to a donor organ. MethodsCadaveric rat lungs were decellularized by detergent perfusion. Resulting scaffolds were mounted in bioreactors and seeded with endothelial and fetal lung cells. Biomimetic organ culture was maintained for 7 days. Resulting bioartificial left lungs were transplanted in orthotopic position after left pneumonectomy in rats. Cadaveric left lung transplants and pneumonectomies served as controls. Blood gas analyses, compliance testing, and fluoroscopies were performed on postoperative days 1, 7, and 14. Lungs were removed for final analysi...
Understanding the dynamic of soil C is a key to managing soil organic matter to enhance soil fertility and ecosystem functioning and reduce trace gas emission from soils. Our objective was to determine the influence of thermically-dry sewage sludge (TSL) and municipal waste compost and the application management on soil (mixed or on soil surface) applied at sludge (TSL) and municipal waste compost and the application management on soil (mixed or on soil surface) applied at two rates of 30 t ha"-1 and 60 t ha"-1, on CO_2 fluxes, microbial biomass C (MBC) and dehydrogenase activity (DH), during an incubation study. (Author)
Onshore pipelines have traditionally been designed with a deterministic stress based methodology. The changing operating environment has however imposed many challenges to the pipeline industry, including heightened public awareness of risk, more challenging natural hazards and increased economic competitiveness. To meet the societal expectation of pipeline safety and enhance the competitiveness of the pipeline industry, significant efforts have been spent for the development of reliability-based design and assessment (RBDA) methodology. This paper will briefly review the technology development in the RBDA area and the focus will be on the progresses in the past years in standard development within the American Society of Mechanical Engineers (ASME) and the Canadian Standard Association (CSA) organizations. (author)
This paper focuses on the application and features of a unified multi-machine train condition monitoring and diagnostic system as applied to a 340 MW repowered combined cycle power plant. Modifications during repowering of the plant required the addition of gas turbines, and design changes to the boiler and steam turbine. Operational procedure during startup also had to be developed. In order to improve the economics of operation, enhancement of both plant operational efficiency and availability were required. Thus it was decided to implement an on-line plant-wide multi-machine Condition Monitoring System. In this paper, the details of the condition monitoring system and some of the design details of the power plant are presented. Requirements of a condition monitoring system applicable to a combined cycle plant are also covered. Salient system design features are explained. The system has been implemented in a combined cycle plant at Bergum, ...
Increasing quantities of chicken waste concerns the poultry industry because of escalating disposal costs and the potential for environmental pollution. Biological conversion of these wastes to valuable products such as methane and/or chemical feed-stocks appears to be feasible. Biomethanation of chicken waste by a sewage sludge microbial consortium produced as much as 69 mol% methane in the gas phase. Acetic and propionic acids were the major acids produced during the bioconversion. Addition of chelating agents and other micro-nutrients enhanced methane production and shifted the ratios of intermediates accumulated. Preliminary data indicate that more than 60% of the chicken waste carbon was converted and that the nitrogen-rich residue may have potential as a soil additive. (author).
The selection and design of an MEOR process for application in a specific field involves geological, reservoir, and biological characterization. Microbially mediated oil recovery mechanisms (bigenic gas, biopolymers, and biosurfactants) are defined by the types of microorganisms used. The engineering and biological character of a given reservoir must be understood to correctly select a microbial system to enhance oil recovery. This paper discusses the methods used to evaluate three fields with distinct characteristics and production problems for the applicability of MEOR would not be applicable in two of the three fields considered. The development of a microbial oil recovery process for the third field appeared promising. Development of a bacterial consortium capable of producing the desired metabolites was initiated, and field isolates were characterized.
The United States Department of Energy (DOE) at the Morgantown Energy Technology Center (METC) contracted with P.S. Lowell and Co. Inc. (Lowell and Co.) and Jay S. Dweck, Consultant, Inc., (JSD) to enhance the capability of ASPEN in simulating coal gasification and oil shale processing plants. Of particular concern was the capability to predict the distribution of environmentally significant components among the various aqueous and organic liquids and gas streams within or leaving the process. The project was divided into major task areas. The first was to develop and implement the calculational routines necessary for predicting aqueous electrolyte chemical reactions. Part of this effort also was to select a species list and collect and/or regress data for the necessary parameters. The second task was to develop and implement a multi-phase flash capability (including precipitated solids) and unit operations models for a venturi and a ...
The effects of O and C ion implantation with different implantation doses on the yellow luminescence (YL) from unintentional doped n-type GaN have been studied by the photoluminescence (PL) spectra. O and C ions were implanted in the GaN samples with different doses from 1.0 x l013 to 1.0 x l017cm-2. Post-annealing was done in a quartz open-tube furnace under flowing N2 gas for 30 min at 950 degree C. By comparing with N ion implanted samples, it is assumed that different deep-level centers involving in the YL were produced in GaN after O and C ion implantation. In addition, with a dose of 1017 cm-2, the concentration of deep C centers involving in the YL was enhanced markedly. (authors)
This conference and trade show provided a forum to present new, emerging and existing technologies that will play a key role in ensuring that hydrocarbon exploitation occurs in a sustainable manner, where costs and resource recovery are optimized while minimizing environmental impacts. The challenge of developing maturing basins, frontier lands and unconventional resources was discussed. In particular, the application of thermal recovery methods such as steam assisted gravity drainage (SAGD) for the in-situ recovery of heavy oils and bitumens was reviewed and compared with the performance of alternative enhanced energy recovery technologies such as vapor extraction (VAPEX). The conference was attended by local and international participants in the petroleum sector, including managers, engineers, technologists, geologists, and other petroleum industry specialists. The conference featured 132 presentations addressing topics such as improved recovery of conventional ...
Accomplishments for the quarter are presented for the following areas of research: oil shale, tar sand, coal, advanced exploratory process technology, and jointly sponsored research. Oil shale research includes; oil shale process studies, environmental base studies for oil shale, and miscellaneous basic concept studies. Tar sand research covers process development. Coal research includes; underground coal gasification, coal combustion, integrated coal processing concepts, and solid waste management. Advanced exploratory process technology includes; advanced process concepts, advanced mitigation concepts, and oil and gas technology. Jointly sponsored research includes: organic and inorganic hazardous waste stabilization; development and validation of a standard test method for sequential batch extraction fluid; operation and evaluation of the CO[sub 2] HUFF-N-PUFF Process; fly ash binder for unsurfaced road aggregates; solid state NMR analysis of Mesa Verde Group, ...
In Internet Routing, the static shortest path (SP) problem has been addressed using well known intelligent optimization techniques like artificial neural networks, genetic algorithms (GAs) and particle swarm optimization. Advancement in wireless communication lead more and more mobile wireless networks, such as mobile networks [mobile ad hoc networks (MANETs)] and wireless sensor networks. Dynamic nature of the network is the main characteristic of MANET. Therefore, the SP routing problem in MANET turns into dynamic optimization problem (DOP). Here the nodes ae made aware of the environmental condition, thereby making it intelligent, which goes as the input for GA. The implementation then uses GAs with immigrants and memory schemes to solve the dynamic SP routing problem (DSPRP) in MANETS. In our paper, once the network topology changes, the optimal solutions in the new environment can be searched using the new immigrants or the useful ...
A study has been performed for the development and assessment of a subchannel analysis code which is purposed to be used for the analysis of advanced reactor conditions with various configurations of reactor core and several kinds of reactor coolant fluids. The subchannel analysis code was developed on the basis of MATRA code which is being developed at KAERI. A GUI (Graphic User Interface) system was adopted in order to reduce input error and to enhance user convenience. The subchannel code was complemented in the property calculation modules by including various fluids such as heavy liquid metal, gas, refrigerant,and supercritical water. The subchannel code was applied to calculate the local thermal hydraulic conditions inside the non-square test bundles which was employed for the analysis of CHF. The applicability of the subchannel code was evaluated for a high temperature gas cooled reactor condition and supercritical ...
The Canadian Association of Petroleum Producers (CAPP) represents about 170 crude oil and natural gas exploration, development and production companies in regulatory hearings and legal proceedings. Its principal role is to enhance the economic well-being and sustainability of the Canadian upstream petroleum industry. This presentation explores the role that information technology (IT) plays in knowledge and information management and how this role relates to meeting Canada`s target for greenhouse gas emissions reductions set by the Kyoto Protocol. Actions such as the Voluntary Challenge Registry (VCR) and emissions reductions trading are re-visited and the information requirements associated with these actions are highlighted. It is shown that among others, emissions databases between jurisdictions (provincial, national, international) have to be integrated, reduction claims must be tracked, verified and cross-referenced to ...
Polychlorinated dibenzo-p-dioxins and dibenzo-furans form a family of more than 200 compounds which are relatively stable in the biosphere and tend to accumulate in the human body. The tetra- to hexa-chlorinated dioxins and furans are considered highly toxic. To facilitate the assessment of the total toxicity of dioxin and furan mixtures, the estimated toxic effects of the individual compounds relative to the 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD) were introduced as Toxic Equivalent Factors which yield, when multiplied with the respective concentrations, the Toxic Equivalent (TE) of the mixture. Toxic dioxins and furans are unintentionally formed in a number of industrial combustion processes such as waste incineration and iron ore sintering, in the chemical industry and in household heating. To keep the emissions as low as possible, off-gas clearing systems for the collection of dioxins and furans are increasingly prescribed by the authorities. In addition, ...
The objective of this work is to develop a model for the simultaneous mass transfer of two acid gases in tertiary amines accompanied by reversible chemical reactions. The model has been applied to the industrially important system of simultaneous absorption or desorption of CO/sub 2/ and H/sub 2/S in aqueous methyldiethanolamine (MDEA). In most applications the treated gas must be virtually free of H/sub 2/S; however, it is often not necessary or economical to remove substantial amounts of CO/sub 2/. Hence, selective removal of H/sub 2/S from gas streams such as natural or synthetic gases which contain CO/sub 2/ is desirable. In this research a film theory model describing the simultaneous diffusion and reversible reaction of two gases into reactive liquid has been used to predict the mass transfer enhancement factors of CO/sub 2/ and H/sub 2/S in aqueous MDEA solutions. The resulting unstable two point boundary value ...
The Westinghouse Electric Corporation has undertaken to investigate, develop, and characterize laser-assisted processing techniques utilized to produce the fine line, thin metal grid structures that are required to fabricate high-efficiency solar cells. Two basic techniques for metal deposition will be investigated, as follows: (1) photochemical decomposition of liquid or gas phase organometallic compounds utilizing either a focused, CW ultraviolet laser (System 1) or a mask and ultraviolet flood illumination, such as that provided by a repetitively pulsed, defocused excimer laser (System 2), for pattern definition, and (2) thermal deposition of metals from organometallic solutions or vapors utilizing a focused, CW laser beam as a local heat source to draw the metallization pattern. The purpose of this contract is to investigate the various existing laser-assisted film deposition techniques in order to develop a new, cost-effective technology for solar cell ...
The invention relates to a method for purifying a gas mixture containing at least one undesirable gas compound utilizing certain sulfonamide or sulfamide solvents.
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, ...
The Interstate Oil and Gas Compact Commission (IOGCC) engaged in numerous projects outlined under the scope of work discussed in the United States Department of Energy (DOE) grant number DE-FG26-01BC15336 awarded to the IOGCC. Numerous projects were completed that were extremely valuable to state oil and gas agencies as a result of work performed utilizing resources provided by the grant. There are numerous areas in which state agencies still need assistance. This additional assistance will need to be addressed under another grant because funding resources have been exhausted under The scope of work objectives for the eight projects covered under this grant is as follows: (1) Improve uniformity within state oil and gas data management efforts. (2) Conduct environmental compliance workshops and related educational projects on natural gas and oil exploration and production. (3) Improve regulatory ...
This report presents and discusses results from Task 5 of the study ''Fate of Mercury in Synthetic Gypsum Used for Wallboard Production,'' performed at a full-scale commercial wallboard plant. Synthetic gypsum produced by wet flue gas desulfurization (FGD) systems on coal-fired power plants is commonly used in the manufacture of wallboard. The FGD process is used to control the sulfur dioxide emissions which would result in acid rain if not controlled. This practice has long benefited the environment by recycling the FGD gypsum byproduct, which is becoming available in increasing quantities, decreasing the need to landfill this material, and increasing the sustainable design of the wallboard product. However, new concerns have arisen as recent mercury control strategies developed for power plants involve the capture of mercury in FGD systems. The objective of this study is to determine whether any mercury is ...
The massive star-forming core MM1 of W75N was observed using the Submillimeter Array with #approx#1'' and 2'' spatial resolutions at 217 and 347 GHz, respectively. From the 217 GHz continuum we found that the MM1 core consists of two sources, separated by about 1'': MM1a (#approx#0.6 M_s_u_n) and MM1b (#approx#1.4 M_s_u_n), located near the radio continuum sources VLA 2/VLA 3 and VLA 1, respectively. Within MM1b, two gas clumps were found to be expanding away from VLA 1 at about #+-#3 km s"-"1, as a result of the most recent star formation activity in the region. Observed molecular lines show emission peaks at two positions, MM1a and MM1b: sulfur-bearing species have emission peaks toward MM1a, but methanol and saturated species at MM1b. We identified high-temperature (#approx#200 K) gas toward MM1a and the hot core in MM1b. This segregation may result from the evolution of the massive star-forming core. In the very early phase of star ...
A copyrighted computational fluid dynamics computer code, ICOMFLO, has been developed for the simulation of multiphase reacting flows. The code solves conservation equations for gaseous species and droplets (or solid particles) of various sizes. General conservation laws, expressed by elliptic type partial differential equations, are used in conjunction with rate equations governing the mass, momentum, enthalpy, species, turbulent kinetic energy, and turbulent dissipation. Associated phenomenological submodels of the code include integral combustion, two parameter turbulence, particle evaporation, and interfacial submodels. A newly developed integral combustion submodel replacing an Arrhenius type differential reaction submodel has been implemented to improve numerical convergence and enhance numerical stability. A two parameter turbulence submodel is modified for both gas and solid phases. An evaporation submodel treats not only droplet ...
For purposes of assessing the dumpability of wastes, Article 1 - Ordinance on the Environmentally Responsible Landfilling of Household Wastes (AbfAblV) - of the Ordinance on the Environmentally Responsible Landfilling of Household Wastes and Biological Waste Treatment Plants defines classificaton criteria for biologically and mechanically treated wastes destined for landfilling. The practical experiences that have been gathered with these classification criteria and values were evaluated in a questionnaire-based survey. This was done in particular for the purpose of verifying and validating proposals on the methodology of respiration and fermentation tests. A general finding has been that the application and implementation of the regulations of the AbfAblV is fraught with difficulties. This is evident for one thing in the frequency of analyses and for another in the difficulty of complying with the limit values of the ...
Desiccation cracking is a common phenomenon in clay materials, which may considerably increase the hydraulic conductivity of soil. This issue is one of the main concerns in the design and construction of landfill covers, especially, in arid regions. For some highly plastic soils, permeability increases during cyclic drying and wetting are not significant, even though cracking may clearly be noticed in the soil. These cracks may self-heal during subsequent wetting and saturation processes. In the present study, large scale experimental models of various natural clayey soils with various plasticity indices were subjected to cyclic drying and wetting and hydraulic conductivity testing to better understand cracking behaviour and self-healing in fine-grained soils. The soils are candidate clay ...
While it is difficult to prove that a specific material is causing contamination in a landfill, tests have been conducted at waste-to-energy facilities that indicate that household batteries contribute significant amounts of heavy metals to both air emissions and ash residue. Hennepin County, MN, used a dual approach for developing and implementing a special household battery collection. Alternative collection methods were examined; test collections were conducted. The second phase examined operating and disposal policy issues. This report describes the results of the grant project, moving from a broad examination of the construction and content of batteries, to a description of the pilot collection programs, and ending with a discussion of variables affecting the cost and operation of a comprehensive battery collection program. Three out-of-state companies (PA, NY) were found that accept spent batteries; difficulties in reclaiming household batteries are ...
While it is difficult to prove that a specific material is causing contamination in a landfill, tests have been conducted at waste-to-energy facilities that indicate that household batteries contribute significant amounts of heavy metals to both air emissions and ash residue. Hennepin County, MN, used a dual approach for developing and implementing a special household battery collection. Alternative collection methods were examined; test collections were conducted. The second phase examined operating and disposal policy issues. This report describes the results of the grant project, moving from a broad examination of the construction and content of batteries, to a description of the pilot collection programs, and ending with a discussion of variables affecting the cost and operation of a comprehensive battery collection program. Three out-of-state companies (PA, NY) were found that accept spent batteries; difficulties in reclaiming household batteries are ...
This article comments on the fact that there are only 17 energy-from-waste installations in operation in the U.S. and in this respect it lags behind other industrialized nations. Explanations for this gap include the relatively inexpensive garbage disposal as landfill, operating difficulties of some early plants and the high cost of building such facilities. There has been a recent push to build resource-recovery plants and it is believed that chemical companies will probably buy energy products from such plants. Hooker Chemical Co's new energy-from-waste plant at Niagra Falls, N.Y. is described, other companies involved in resource-recovery projects are mentioned, and it is hoped that more companies will invest in such plants.
Waste electrical and Electronic Equipment (WEEE) constitutes 4% of the municipal waste in Europe, being increased by 16-28% every five years. Nowadays, Europe produces 6,5 million tonnes of WEEE per year and currently 90% goes to landfill. WEEE waste is growing 3 times faster than municipal waste and this figure is expected to be increased up to 12 million tones by 2015. Applying a new technology to separate non-ferrous metal Waste from WEEE is the aim of this paper, by identifying multi-and hyper-spectral materials and inserting them in a recycling plant. This technology will overcome the shortcomings passed by current methods, which are unable to separate valuable materials very similar in colour, size or shape. For this reason, it is necessary to develop new algorithms able to distinguish among these materials and to face the timing requirements. (Author). 22 refs.
This project seeks to produce sufficient information on the physical and chemical nature of Coolside waste to design and construct physically stable and environmentally safe landfills. Unconfined compressive strength and permeability tests are reported on samples remolded near 90, 95, and 100% of low energy, standard, and modified dry densities. Unconfined compressive strength tests were also performed on some of the samples after permeability tests were completed. Swell tests were initiated on samples from Coolside pilot plant run {number_sign}2 and on a FBC hydrated ash remolded near 95% of standard density and optimum moisture content.
This paper summarizes an investigation carried out on Polish terrain occupied by Russian Federation military troops. The investigation identified natural environmental devastation, pollution, and contamination. Quantitative estimation of the devastation and its economic evaluation are provided. The results of the investigation are as follows: 406 ha have been contaminated by petrochemical products; 22.7 ha are chemically polluted; and 6,500 ha of underground water, as well as 17.5 ha of surface water, cannot be classified. On 15,300 ha the soil has been degraded, of which landfills comprise an area of 98 ha. No toxic warfare agents have been detected, nor any radioactivity levels exceeding those characteristic of the given region.
Technologies and practices that recover energy and materials from municipal solid waste present a technically and economically viable alternative to sanitary landfills and other solid waste disposal methods. However, community planners considering resource recovery should be aware of the potential environmental impacts of proposed projects. To assess these impacts, a planner should: identify the most significant types of impacts; establish boundaries beyond which impacts are not significant; characterize the environment as it would exist without the proposed project over the project's lifetime; predict the magnitude, and the distribution over time and space, of potential impacts; and relate the magnitude of predicted impacts to a scale of significance that will allow environmental values to be considered in decision-making. 24 references, 1 table.
Recently, it has become clear that the chemical circumstances under which long-term geological evolution occurs must be properly evaluated in order to develop effective remediation programs for contaminated soil, landfills, radioactive waste repositories, and carbon dioxide capture and storage. The issue of acidic leakage from excavated rock stuck was assessed using a hydro-geochemical simulator, TOUGHREACT. We concluded that in order to properly investigate the phenomenon of acidic leakage from excavated pyrite-containing rock stuck, it is important to obtain accurate information about the following factors: intensity of rainfall, unsaturated flow properties of the excavated rock stuck, specific surfaces for oxidation reaction of pyrite, the species and the quantity of other minerals contained in the rock, and secondary minerals produced. (author)
A publication on Norwegian gas and gas export. The content is wide spread from use of gas in daily life via sub sea pipeline repair systems to an overview over tomorrows gas fields. (AG)
Recently the increase of steam temperature and pressure of power plant is required to enhance the thermal efficiency and reduce the CO{sub 2} emission. For the application to advanced USC (Ultra Super Critical) boiler with steam temperature around 700 C, the application of Ni-based alloy such as Alloy617 will be necessary. A new Ni-based alloy USC141 (20Cr-10Mo-2Ti-Al-bal.Ni) with excellent creep rupture strength and low thermal expansion has been developed by Hitachi Ltd. and Hitachi Metals Ltd. as the candidate material for 700 C USC turbine components. In present work, to investigate the possibility for boiler tube application of USC141, its weldability and high temperature strength properties were experimentally examined. The tested material as solution-treated condition shows higher creep rupture strength than that of Alloy617. GTAW (Gas Tungsten Arc Welding) trials of tubular specimen using NIMONIC263 filler wire were conducted ...
Electrical heating of subsea flowlines is an effective way to prevent wax and hydrate information, especially for long transportation distances and in low-temperature deep water. Systems are available for use in conjunction with bundles, pipe-in-pipe, and wet-thermal-insulation systems. These systems provide environmentally friendly fluid-temperature control without chemicals or flaring for pipeline depressurizing. Enhanced production is achieved because no time is lost by unnecessary depressurizing, pigging, heating-medium circulation, or removal of hydrate and wax blockages. The seabed temperature at 100-m and greater water depths may range from 7 to {minus}1.5 C, causing a rapid cooling of the hot well streams being transported in subsea flowlines. Under these supercooling conditions, vulnerable crude oils and multiphase compositions will deposit wax and asphalts; also the gas/water phase may freeze solid with hydrate particles. The paper ...
This report summarizes the findings of a five-month LDRD project funded through Sandia's NTM Investment Area. The project was aimed at providing the foundation for the development of advanced functional materials through the application of ultrathin coatings of microporous or mesoporous materials onto the surface of substrates such as silicon wafers. Prior art teaches that layers of microporous materials such as zeolites may be applied as, e.g., sensor platforms or gas separation membranes. These layers, however, are typically several microns to several hundred microns thick. For many potential applications, vast improvements in the response of a device could be realized if the thickness of the porous layer were reduced to tens of nanometers. However, a basic understanding of how to synthesize or fabricate such ultra-thin layers is lacking. This report describes traditional and novel approaches to the growth of layers of microporous materials on silicon wafers. The ...
Complex abdominal lesions include a variety of pathologies, such as septated, infected, and hemorrhagic cysts, abscesses, tumors, and fluid collections of different ethiology. These lesions present diagnostic difficulties with both Ultrasonography (US) and Computed Tomography (CT), since findings may not be present or, when present, are not specific. Keeping these limitations in mind, we evaluated 105 patients (111 abdominal lesions) with both US and CT in order to compare their adequacy in predicting the nature of the lesion. On the basis of US and CT results, complex abdominal lesions were divided in four classes: class I includes 43 cases in which both examinations gave the same contribution to the definition of the nature of the lesion, class II (14 lesions, mainly sperimentated cysts), in which US was superior to CT, class III includes 45 cases of hemorrhagic cysts, abscesses, fluid collections and, less frequently, cystic tumors; class IV includes 9 cases in which US and CT ...
This work presents a comparative study of low-alloy steel nitriding for different possible techniques. Active screen plasma nitriding (ASPN) is a successful surface modification method that has many advantages over the conventional DC plasma nitriding (CPN). The corrosion behavior of 30CrNiMo8 low-alloy steel has been examined using anodic polarization tests in 3.5% NaCl solution under varying conditions of ASPN and CPN processes. The process variables included active screen setup parameters, treatment temperature (550 and 580 deg. C), gas mixture (25/75 and 75/25 of N{sub 2}/H{sub 2}) and treatment time (5 and 10 h) in 500 Pa pressure. The structure and phases composition of the compound layer was studied by X-ray diffraction (XRD), microhardness tests, optical microscopy and scanning electron microscopy (SEM). It was observed that ASPN treated samples surface enhanced corrosion resistance while the temperature and/or hole size of screen setup ...
This work presents a comparative study of low-alloy steel nitriding for different possible techniques. Active screen plasma nitriding (ASPN) is a successful surface modification method that has many advantages over the conventional DC plasma nitriding (CPN). The corrosion behavior of 30CrNiMo8 low-alloy steel has been examined using anodic polarization tests in 3.5% NaCl solution under varying conditions of ASPN and CPN processes. The process variables included active screen setup parameters, treatment temperature (550 and 580 deg. C), gas mixture (25/75 and 75/25 of N_2/H_2) and treatment time (5 and 10 h) in 500 Pa pressure. The structure and phases composition of the compound layer was studied by X-ray diffraction (XRD), microhardness tests, optical microscopy and scanning electron microscopy (SEM). It was observed that ASPN treated samples surface enhanced corrosion resistance while the temperature and/or hole size of screen setup ...
We describe a model of damage in rf cavities and show how this damage can limit cavity operation. We first present a review of mechanisms that may or may not affect the ultimate fields that can be obtained in rf cavities, assuming that mechanical stress explains the triggers of rf breakdown events. We present a method of quantifying the surface damage caused by breakdown events in terms of the spectrum of field enhancement factors, Beta, for asperities on the surface. We then model an equilibrium that can develop between damage and conditioning effects, and show how this equilibrium can determine cavity performance and show experimental evidence for this mechanism. We define three functions that quantify damage, and explain how the parameters that determine this performance can be factored out and measured. We then show how this model can quantitatively explain the dependence of cavity performance on material, frequency, pulse length, gas, ...
The ability to use an acoustic stethoscope to detect lung and/or heart sounds, and then to then communicate one's interpretation of those sounds is an essential skill for many medical professionals. Interpretation of lung and heart sounds, in the context of history and other examination findings, often aids the differential diagnosis. Bedside assessment of changing auscultation findings may also guide treatment. Learning lung and heart auscultation skills typically involves listening to pre-recorded normal and adventitious sounds, often followed by laboratory instruction to guide stethoscope placement, and finally correlating the sounds with the associated pathophysiology and pathology. Recently, medical simulation has become an important tool for teaching prior to clinical practice, and for evaluating bedside auscultation skills. When simulating cardiovascular or pulmonary problems, high-quality lung and heart sounds should be able to accurately corroborate other findings such as ...
The reactive evaporation process was successfully used to deposit films of the A-15 Nb_3Ge phase. This is the first report, to the best of our knowledge, illustrating the use of such processes for the deposition of A-15 compounds. In this process, niobium vapors from an electron-beam-heated evaporation source react with germane gas introduced into the vacuum chamber at low partial pressures (approximately 10"-"4 Torr) to produce Nb_3Ge deposits. The process variables studied were the deposition temperature, the niobium-to-germanium impingement ratio on the substrate and the plasma-enhanced deposition, in this case the activated reactive evaporation process. At low deposition temperatures (below 450"0C) the deposit is amorphous (or microcrystalline) and can be crystallized to the Nb_3Ge phase by heat treatment, e.g. at 850"0C for 1 h in vacuum. The ratio of niobium to germanium in the deposit can be varied by changing the process parameters. The ...
The use of ionising radiation for the preservation of food has been under investigation for many years but has yet to receive worldwide acceptance. Although irradiation can be carefully controlled, it is generally accepted that the development of a test or tests for the detection of irradiated food would enhance consumer confidence and might help to enforce labelling regulations. The 2-alkylcyclobutanones are reported to be the only cyclic compounds formed as the products of the radiolysis of saturated and unsaturated triglycerides. The synthesis of 2-dodecylcyclobutanone (DCB) and 2-tetradecylcyclobutanone (TCB), which are formed from palmitic and stearic acid respectively following irradiation, has been carried out and using irradiated chicken meat as the model for a high-lipid containing food, both cyclobutanones have been extracted with hexane and then identified using gas chromatography/mass spectrometry (GC/MS). DCB and TCB have been ...
The proceedings include the following lectures: Facing the challenges - new structures for electricity production. Renewable energies in Europe - chances and challenges. Nuclear outlook in the UK. Sustainable energy for Europe. Requirements of the market and the grid operator at the electricity production companies. Perspectives for the future energy production. Pumped storage plants - status and perspectives. Nuclear power/renewable energies -partners or opponents? New fossil fired power stations in Europe - status and perspectives. Nuclear energy: outlook for new build and lifetime extension in Europe. Biomass in the future European energy market - experiences for dong energy. Meeting the EU 20:20 renewable energy targets: the offshore challenges. DESERTEC: sustainable electricity for Europe, Middle East and North Africa. New power plants in Europe - a challenge for project and quality management. Consideration of safely in new build activities of power plants. Challenges to an ...
Results on the oxidative dehydrogenation of ethane on rare-earth oxide (REO) based catalysts (Na-P-Sm-O, Sm-Sr(Ca)-O, La-Sr-O and Nd-Sr-O) are described. Oxygen adsorption was found to be a key factor which determines the activity of this type of catalysts. Continuous flow experiments in the presence of catalysts which reveal strong oxygen adsorption showed that the reaction mixture is ignited resulting in an enhanced heat generation at the reactor inlet. The heat produced by the oxidative reactions was sufficient under the conditions chosen for the endothermic thermal pyrolysis which takes place preferentially in the gas phase. Ignition of the reaction mixture is an important catalyst function. Contrary to non-catalytic oxidative dehydrogenation, reaction temperatures above 700 C could be achieved without significant external heat input. Ethylene yields of up to 34-45% (S=66-73%) were obtained on REO-based catalysts under non-isothermal ...
Soil vapor extraction (SVE) is a widely accepted in-place treatment technology that uses forced air to remove contaminant vapors from zones of permeable vapor flow, thereby enhancing the volatilization of contaminants from the subsurface. The resulting off-gases are contaminated with volatiles and semi-volatiles and have to treated by catalytic or thermal destruction systems, activated carbon adsorbers, or bioreactors. Of these, activated carbon adsorption is the most commonly used technology. From the theoretical foundation of SVE and carbon adsorption, two nomographs were developed for remedial investigation, feasibility studies, planning, operation, and preliminary design purposes. An advantage of such nomographs is that they graphically indicate the sensitivity of the remediation process to different design parameters and critical ranges within a given parameter. In effect, nomographs can help to foster an intuitive understanding of the SVE and adsorption ...
Measurements of ion-induced electron emission have been performed with helium and argon ions with energies between 300 and 900 eV on W, W with 10% Ti, Al, Al with 1% Cu, Al with 1% Si, Si, and Be. This article describes many of the important surface characteristics that influence the ion-induced electron emission. For low-energy ions, the substrate material was found to be less important as the velocity of the incident ion decreased. In the case of incident Ar"+ the substrate material had a negligible effect on the emission for this energy range. The presence of an adsorbed layer enhanced emission in all cases. Heating the substrates resulted in oxidation of the surfaces and a subsequent increase in emission. The electron emission from aluminum samples with smaller grain sizes was higher than samples of identical composition with larger grains. This effect is due to the greater number of adsorption sites resulting from the higher grain boundary area.
The aim of this contract is to investigate, develop, and characterize laser-assisted processing techniques utilized to produce the fine-line, thin-metal grid structures that are required to fabricate high-efficiency solar cells. During the first quarter of this contract, a comprehensive literature search was carried out in the various state-of-the-art laser-assisted techniques for metal deposition, including laser chemical vapor deposition and laser photolysis of organometallics, as well as laser-enhanced electroplating. A compact system for the experiments involving laser-assisted photolysis of gas-phase compounds was designed and constructed. The work performed in the second quarter is detailed in this report. Metal deposition experiments have been carried out utilizing laser-assisted pyrolysis of a variety of metal-bearing polymer films and metallo-organic inks spun onto silicon substrates. Laser decomposition of spun-on silver neodecanoate ...
The non-thermal supernova remnant RX J1713.7-3946 (G347.3-0.5) has recently been shown to be a site of cosmic ray (CR) electron acceleration to TeV energies (Muraishi et al. 2000). Here we present evidence that this remnant is also accelerating CR nuclei. Such nuclei can interact with ambient interstellar gas to produce high energy gamma-rays via the decay of neutral pions. We associate the unidentified EGRET GeV gamma- ray source 3EG J1714-3857 with a massive (~3*10 5 Mo) and dense (~500 nucleons cm -3) molecular cloud interacting with RX J1713.7-3946. Direct evidence for such interaction is provided by observations of the lowest two rotational transitions of CO in the cloud; as in other clear cases of interaction, the CO(J=2-1)/CO(J=1-0) ratio is significantly enhanced. Since the cloud is of low radio and X-ray brightness, CR electrons cannot be responsible for the bulk of its GeV emission there. A picture thus emerges where both electrons ...
The fast breeder test reactor at Kalpakkam has completed nearly 25 years of operation and is now operating at 18 MWt capacity with 46 fuel subassemblies (FSA) in the core consisting of 27 Mark-I (70% PuC + 30% UC), 13 Mark-II (55% PuC + 45% UC) and 6 MOX (44% PuO_2 + 56% UO_2) and one test PFBR FSA. Post Irradiation Examination (PIE) campaigns on FSAs at different burnup levels has provided valuable information about the irradiation behavior of the carbide fuel. This paper gives a summary of the irradiation performance of the carbide fuel evaluated through some of the investigations such as neutron radiography, x-radiography, gamma scanning, fission gas analysis and ceramography. Burnup of the carbide fuel could be enhanced from the initial design burnup limit of 50 GWd/t to 165 GWd/through systematic PIE. (author)
The relationship between processing, microstructure, and properties was studied for A-15 compounds in multifilamentary composites produced by solid-state diffusion and in thin-film samples produced by vapor deposition. Grain sizes of A-15 superconducting compounds were measured by transmission electron microscopy of multifilamentary composites reacted at various temperatures. Critical current densities at 4.2 K and fields up to 6 T were found to be similar for niobium-tin, vanadium-gallium, and vanadium-silicon of the same grain size. Study of the Cu-V-Si phase diagram led to the production of improved multifilamentary vanadium-silicon conductors. The effects of various alloying elements on A-15 layers produced by solid-state diffusion were studied. The most promising new observation was that tantalum can be incorporated into niobium-tin reaction layers, leading to an enhancement of critical currents at high fields. The critical temperature of vapor-deposited, ...
The data and information collected for the Public Service Electric and Gas Company`s (PSE&G) electric vehicle demonstration program were intended to support and enhance DOE`s Electric and Hybrid Vehicle Site Operator Program. The DOE Site Operator Program is focused on the life cycle and reliability of Electric Vehicles (EVs). Of particular interest are vehicles currently available with features that are likely to be put into production or demonstrate new technology. PSE&G acquired eight GMC Electric G-Vans in 1991, and three TEVans in 1993, and conducted a program plan to test and assess the overall performance of these electric vehicles. To accomplish the objectives of DOE`s Site Operator`s test program, a manual data collection system was implemented. The manual data collection system has provided energy use and mileage data. From September 1991 to October 1994 PSE&G logged 69,368 miles on eleven test vehicles. PSE&G also ...
The synergistic effects of displacement damage and atomic hydrogen and helium on swelling of the ferritic/martensitic steel, F82H, has been investigated. The irradiation was performed at temperatures between 470 and 600 deg. C to 50 dpa (displacement per atoms) under conditions of simultaneous ion beams consisting of Fe{sup 3+}, He{sup +} and H{sup +} ions or Fe{sup 3+} and He{sup +} ions. The swelling of F82H steel under triple beams with 18 appm He/dpa and 70 appm H/dpa was larger than that under dual beams with 18 appm He/dpa. The swelling in F82H under triple beams increased with decreasing irradiation temperature from 0.1% to 3.2%, while swelling under dual beams was between 0.04% and 0.08%. On the other hand, in the case of triple beam irradiation with a high ratio of gas/dpa, the swelling tended to increase with irradiation temperature. The swelling in ferritic/martensitic steels is significantly enhanced by the synergistic effect of ...
The synergistic effects of displacement damage and atomic hydrogen and helium on swelling of the ferritic/martensitic steel, F82H, has been investigated. The irradiation was performed at temperatures between 470 and 600 deg. C to 50 dpa (displacement per atoms) under conditions of simultaneous ion beams consisting of Fe"3"+, He"+ and H"+ ions or Fe"3"+ and He"+ ions. The swelling of F82H steel under triple beams with 18 appm He/dpa and 70 appm H/dpa was larger than that under dual beams with 18 appm He/dpa. The swelling in F82H under triple beams increased with decreasing irradiation temperature from 0.1% to 3.2%, while swelling under dual beams was between 0.04% and 0.08%. On the other hand, in the case of triple beam irradiation with a high ratio of gas/dpa, the swelling tended to increase with irradiation temperature. The swelling in ferritic/martensitic steels is significantly enhanced by the synergistic effect of displacement damage, ...
Si nanocrystal floating gate MOS capacitors were formed on p-Si (100) wafers by thermal plasma jet (TPJ) annealing of SiO2/SiOx /SiO2/Si(100) stacked structure. The chemical composition of SiOx layer was controlled by changing the SiH4, He, and O2 gas flow ratio during plasma enhanced chemical vapour deposition. The MOS capacitors showed clear hysteresis in capacitance-voltage (CV) characteristics after TPJ annealing. The hysteresis width shows maximum value when initial composition x =1.7, which shows the maximum photoluminescence (PL) intensity. The maximum hysteresis width of 6.8 V was observed with gate voltage swept between 20 and -20 V in x = 1.7 sample. The result means 7.4 x 1012 cm-2 carriers are injected to or emitted from Si nanocrystals. The duration of 1 V shift in flatband vo...
Both the increased complexity of integrated circuits, resulting in six or more levels of integration, and the increasing use of flip-chip packaging have driven the development of integrated circuit (IC) failure analysis tools that can be applied to the backside of the chip. Among these new approaches are focused ion beam (FIB) tools and processes for performing chip edits/repairs from the die backside. This paper describes the use of backside FIB for a failure analysis application rather than for chip repair. Specifically, they used FIB technology to prepare an IC for inspection of voided metal interconnects (lines) and vias. Conventional FIB milling was combined with a super-enhancedgas assisted milling process that uses XeF{sub 2} for rapid removal of large volumes of bulk silicon. This combined approach allowed removal of the TiW underlayer from a large number of Ml lines simultaneously, enabling rapid localization and plan view imaging of ...
This report describes a study to evaluate methods for locating leaks of dielectric fluid from buried high-voltage cable systems. Two primary types of leak location systems were investigated: (1) systems that will rapidly isolate the leak within a manhole section, typically 1000-m long on a feeder that might be 30-km long; and (2) systems that will then pinpoint the location of the leak. Rapid leak isolation was accomplished by developing an enhanced conductivity oil probe which allows the injection of a small quantity of conductive oil and which indicates the path of the oil as it drifts downstream in the direction of the leak. Two methods for pinpointing the leak were proven. The more successful method was the use of trained leak location dogs which were found to have far better sensitivity than instruments and which could detect cable oil alone without the need for additives. A tracer gas injection and detection scheme was developed for use ...
This project is part of PETC`s Advanced Power Systems Program, whose mission is to accelerate the commercialization of affordable, high- efficiency, low emission, coal-fueled electric generating technologies. A process concept - Clear Liquor Scrubbing with Anhydrite Production - was proposed and accepted by PETC as a Phase I project in its Mega-PRDA program. the project integrated three process operations - chloride control upstream of the flue gas desulfurization (FGD) system, a clear liquor process for enhanced SO{sub 2} removal performance, and production of anhydrite (anhydrous calcium sulfate) rather than calcium sulfite or gypsum (calcium sulfate dihydrate). The first step in the project was to perform batch and flow-through experiments in the laboratory to confirm theoretical calculations and preliminary laboratory results concerning anhydrite formation, these laboratory experiments were designed to prove that anhydrite can be produced ...
Having recently discovered that polynuclear heteroaromatic nitrogen compounds can be selectively reduced only at the nitrogen containing ring, we have now turned our attention towards the cleavage of the carbon nitrogen bonds in this reduced ring. Highlights for this reporting period are: (1) Studies with the 50% nickel oxide catalyst clearly show that 1,2,3,4-tetrahydroquinoline(THQ) provides approximately 20% more liquid product that does quinoline. Thus a first step selective hydrogenation to 1,2,3,4-THQ would enhance the overall HDN reaction to provide a more substantial conversion to substituted benzene and aniline derivatives. (2) The dramatic effect of the nitrogen atom is to inhibit aromatic ring hydrogenation and, to some extent, carbon-carbon bond hydrogenolysis reactivity. This is shown with proplybenzene as the substrate, where only methane gas is produced in the HDN reaction with the 50% nickel oxide catalyst. (3) The HDN reaction ...
The biomass research program of the USDA, Southern Agricultural Energy Center is conducted at several locations throughout the United States. A portion of the research is directed toward improved systems to harvest, process and store biomass so that the energy density will be enhanced. Other research projects deal with: conversion and utilization of animal wastes in integrated energy-food production systems, including the production of liquid fuel and feed byproducts; producing low BTU gas to be utilized in internal combustion engines, including the system for continuous feeding of the gasifier; direct combustion of biomass for thermal energy; gasifying biomass so that the products of combustion can pass through a crop being dried without leaving deleterious residues; small scale systems for on-farm expelling of vegetable oil; and studies on the use of vegetable oils for diesel fuel substitutes. In summary, the low energy density of biomass ...
The thesis deals with methods of describing the reservoir rock in central oil and gas fields on the Norwegian continental shelf. Methods of enhancing the level of recovery are dealt with. Following topics are given: Sand body dimensions and infill sequences of stable, humid-climate delta plain channels; minipermeameter-based study of permeability trends in channel sand bodies; significance of tidal cyclicity for modelling of reservoir heterogeneities in the lower Jurassic Tilje Formation, mid-Norwegian shelf; geometry and facies of large-scale flow units in fluvial-dominated fan-delta-front sequences; quantified fluvial architecture in ephemeral stream deposits of the Esplugafreda Formation (Palaeocene), Tremp-Graus Basin, northern Spain; the Safari project - collection and storage of field analogue data for quantitative reservoir modelling; sedimentary architecture of field analogues for reservoir information (SAFARI): a case study of the ...
Citizens Gas and Coke Utility operates three coke oven batteries, producing both foundry coke and blast furnace coke, under the trade name Indianapolis Coke. Active participation in the regulation negotiation process by the Vice President of Indianapolis Coke allowed the company to accurately anticipate the environmental regulations, long before they were set in law. Several improvements were put into motion that helps them meet the new environmental regulations. Better trained operators with new job positions dedicated solely to environmental compliance, an extensive environmental training program, and two innovations, a portable oven door milling and cleaning machine and three new computer applications are the result of team efforts. The focus of this paper is development of the computer applications designed to enhance three areas of environmental compliance. The three areas addressed by the applications are documentation and information ...
Recent X-ray and radio observations have identified a transient low-mass X-ray binary (LMXB) located only 0.1 pc in projection from the Galactic center, CXOGC J174540.0-290031. In this paper, we report the detailed analysis of X-ray and infrared observations of the transient and its surroundings. Chandra bservations detect the source at a flux of F_X = 2e-12 erg cm^-2 s^-1 (2-8 keV). After accounting for absorption both in the interstellar medium and in material local to the source, the implied luminosity of the source is only L_X = 4e34 erg/s (2-8 keV; D=8 kpc). However, the diffuse X-ray emission near the source also brightened by a factor of 2. The enhanced diffuse X-ray emission lies on top of a known ridge of dust and ionized gas that is visible infrared images. We interpret the X-ray emission as scattered flux from the outburst, and determine that the peak luminosity of CXOGC J174540.0-290031 was >2e36 erg/s. We suggest that the ...
The framework for investment in research and development (R&D) at a medium-sized Canadian petroleum company is described. The importance of R&D is illustrated by a graph showing the strong positive correlation between R&D intensity and sales for companies in the mainstream oil and gas sector in the USA. Strong R&D efforts also help to maintain market share and enhance corporate ability to transfer technology into its operations. Three ways of structuring, developing, and transferring technology are outlined: using in-house R&D facilities, which is too costly for medium-sized firms; having a central group responsible for funding third-party R&D, transferring technology into the company, and being aware of technology activities within and outside the company; and complete decentralizing of R&D, in which operations decides how, when, and what to spend on R&D. For the medium-sized company, the second option is ...
The long-term stability of pentacene thin-film transistors (TFTs) encapsulated with a transparent SnO{sub 2} thin-film prepared by ion beam-assisted deposition (IBAD) was investigated. After encapsulation process, our organic thin-film transistors (OTFTs) showed somewhat degraded field-effect mobility of 0.5 cm{sup 2}/(V s) that was initially 0.62 cm{sup 2}/(V s), when a buffer layer of thermally evaporated 100 nm SnO{sub 2} film had been deposited prior to IBAD process. However, the mobility was surprisingly sustained up to 1 month and then gradually degraded down to 0.35 cm{sup 2}/(V s) which was still three times higher than that of the OTFT without any encapsulation layer after 100 days in air ambient. The encapsulated OTFTs also exhibited superior on/off current ratio of over 10{sup 5} to that of the unprotected devices ({approx}10{sup 4}) which was reduced from {approx}10{sup 6} before aging. Therefore, the enhanced long-term stability of our encapsulated ...
The National Institute of Materials Science (NIMS) has utilized the in-house alloy design program to develop a 5{sup th} generation Ni-base single crystal superalloy, TMS-196 with superior high temperature creep, thermo mechanical fatigue (TMF) and oxidation resistance by incorporating further ruthenium (Ru) and chromium (Cr) content over the compositions of 4{sup th} generation superalloys. With Ru additions in advanced superalloys to enhance phase stability, higher content of refractory elements can be accommodated to provide further strengthening; the associated oxidation resistance can be improved by the increase in Cr additions. In present article, TMS-196 has been subjected to cyclic/isothermal oxidation tests at 1100 C and 900 C, creep at conditions between 800 C{proportional_to}1100 C/137MPa{proportional_to}735MPa and TMF cycles. Preliminary studies indicate that the surface of oxidized TMS-196 can exhibit continuous alumina layer attributing good oxidation ...
During cleanup of contaminated sites, Sandia National Laboratories, New Mexico (SNL/NM) frequently encounters soils with low-level radioactive contamination. The contamination is not uniformly distributed, but occurs within areas of clean soil. Because it is difficult to characterize heterogeneously contaminated soils in detail and to excavate such soils precisely using heavy equipment, it is common for large quantities of uncontaminated soil to be removed during excavation of contaminated sites. This practice results in the commingling and disposal of clean and contaminated material as low-level waste (LLW), or possibly low-level mixed waste (LLMW). Until recently, volume reduction of radioactively contaminated soil depended on manual screening and analysis of samples, which is a costly and impractical approach and does not uphold As Low As Reasonably Achievable (ALARA) principles. To reduce the amount of LLW and LLMW generated during the excavation process, SNL/NM is evaluating two ...
From 1991 to 1996, key studies on the reutilization, treatment, and disposal technology of hazardous wastes have been incorporated into the national plan for environmental protection science and technology. At present, the research achievements have been accomplished, have passed national approval, and have been accepted. The author of this paper, as leader of the national group for this research work, expounds the newest achievements of the studies involving four parts: (1) the reutilization technology of electroplating sludge, including the ion-exchange process for recovering the sludge and waste liquor for producing chromium tanning agent and extracting chromium and colloidal protein from tanning waste residue; on the recovery of heavy metals from the electroplating waste liquor with microbic purification; on the demonstration project of producing modified plastics from the sludge and the waste plastics; and on the demonstration of the recovery of heavy metals from waste ...
The WAND (Waste Assay for Nonradioactive Disposal) system can scan thought-to-be-clean, low-density waste (mostly paper and plastics) to determine whether the levels of any contaminant radioactivity are low enough to justify their disposal in normal public landfills or similar facilities. Such a screening would allow probably at least half of the large volume of low-density waste now buried at high cost in LANL`s Rad Waste Landfill (Area G at Technical Area 54) to be disposed of elsewhere at a much lower cost. The WAND System consists of a well-shielded bank of six 5-in.-diam. phoswich scintillation detectors; a mechanical conveyor system that carries a 12-in.-wide layer of either shredded material or packets of paper sheets beneath the bank of detectors; the electronics needed to process the outputs of the detectors; and a small computer to control the whole system and to perform the data analysis. WAND system minimum detectable activities ...
This paper reports that some regions have prepared for these days of disposal shortage with comprehensive waste plans that include a strong WTE presence. Witness Broward County, Florida's program, 12 years in planning by public and private entities, Broward is the second most populated county in the state, with 1.3 million residents and a heavy tourist population, which, together, produce 1.6 million tons of waste annually. The disposal program includes Waste Management, Inc.'s expansion of a 400-acre Central Disposal Sanitary Landfill, the county's new 588-acre landfill, composting, and curbside pickup for recyclables. And, this south Florida plan would not be complete without the two brand new combustion plants. Clean Air and Water Acts notwithstanding, the Florida Department of Environmental Regulation can induce standards stricter than the federal government's due to the sensitive South Florida ecology. ...
A gas diffusion semiconductor electrode and solar cell and a process for gaseous fixation, such as nitrogen photoreduction, CO/sub 2/ photoreduction and fuel gas photo-oxidation are described. The gas diffusion photosensitive electrode has a central electrolyte porous matrix with an activated semiconductor material on one side adapted to be in contact with an electrolyte and a hydrophobic gas diffusion region on the opposite side adapted to be in contact with a supply of molecular gas.
Conventional plasma carburizing or nitriding for austenitic stainless steels results in a degradation of corrosion resistance. However, a low temperature plasma surface treatment can improve surface hardness without deteriorating the corrosion resistance. The 2-step low temperature plasma processes (the combined carburizing and post nitriding) offers the increase of both surface hardness and thickness of hardened layer and corrosion resistance than the individually processed low temperature nitriding and low temperature carburizing techniques. In the present paper, attempts have been made to investigate the influence of the introduction of Ar gas (0#approx#20%) in nitriding atmosphere during low temperature plasma nitriding at 370 .deg. C after low temperature plasma carburizing at 470 .deg. C. All treated specimens exhibited the increase of the surface hardness with increasing Ar level in the atmosphere and the surface hardness value reached up to 1050 HV_0_._1, ...
Three studies of electrochemical current distribution have been performed using potential-theory models and the boundary-element method (BEM). (1) The steady-state behavior of cells with nonuniform current density over a passivating anode is investigated. Current distributions calculated for a test cell, using the measured kinetic behavior of nickel in acid-nickel-sulfate solution, are compared to estimates from earlier models. Although current-density profiles determined by weight loss on a segmented rotating cylinder agreed satisfactorily with model calculations, the measured length of the passive zone exceeds the theoretical value. The model's applicability to anodic protection is demonstrated for a stainless-steel sulfuric-acid holding tank. (2) A model is established to describe the effects of attached bubbles on the potential drop at gas-evolving electrodes including: (1) ohmic obstruction within the electrolyte; (2) area masking on the electrode ...
Accomplishments for the quarter are presented for the following areas of research: oil shale, tar sand, coal, advanced exploratory process technology, and jointly sponsored research. Oil shale research includes; oil shale process studies, environmental base studies for oil shale, and miscellaneous basic concept studies. Tar sand research covers process development. Coal research includes; underground coal gasification, coal combustion, integrated coal processing concepts, and solid waste management. Advanced exploratory process technology includes; advanced process concepts, advanced mitigation concepts, and oil and gas technology. Jointly sponsored research includes: organic and inorganic hazardous waste stabilization; development and validation of a standard test method for sequential batch extraction fluid; operation and evaluation of the CO{sub 2} HUFF-N-PUFF Process; fly ash binder for unsurfaced road aggregates; solid state NMR analysis of Mesa Verde Group, ...
The carbon dioxide capture potential of amine amino acid salts (AAAS), formed by mixing equinormal amounts of amino acids; e.g. glycine. B-alanine and sarcosine, with an organic base; 3-(methylamino)propylamine (MAPA), was assessed by comparison with monoethanolamine (MEA), and with amino acid salt (AAS) from amino acid neutralized with an inorganic base; potassium hydroxide (KOH). Carbon dioxide absorption and desorption experiments were carried out on the solvent systems at 40{sup o}C and 80{sup o}C respectively. Experimental results showed that amine amino acid salts have similar CO{sub 2} absorption properties to MEA of the same concentration. They also showed good signs of stability during the experiments. Amino acid salt from an inorganic base, KOH, showed lower performance in CO{sub 2} absorption than the amine amino acid salts (AAAS) mainly due to a lower equilibrium temperature sensitivity. AAAS showed better performance than MEA of same concentration. AAAS from neutralization ...
Canadian oilfields are a prime breeding ground for talent, technology and industrial management. This paper described how Canadian talent was recognized in 2001 for three major projects which included a cold-ocean production platform in the Sea of Okhotsk in Siberia, a mountain pipeline project in South America, and an in-situ underground extraction technology in the oilsands of Alberta. The cold-ocean production platform project was recruited by Sakhalin Energy Investment Co., an international consortium originally led by Marathon Oil Co which is now led by Royal Dutch Shell. The oil production platform is stationed 16 kilometres offshore of Sakhalin Island in the Sea of Okhotsk. Sakhalin Energy bought and converted the Molikpaq, an innovative platform made in the 1980s for the Beaufort Sea by Gulf Canada Resources Ltd. The second project included Calgary's Hydroconsult EN3 Services Ltd. which was responsible for the construction of the 940-km GasAtacama ...
The objective of the first project period is to: make a study into materials suitable for the non-premix radiant burners (NPRB); choose the materials for the construction; make proposals for the design of the NPRB; test the different proposals with a CFD-model. In pursuit of finding a suitable material it is necessary first to estimate the maximum temperature that will occur in the burner. It has been estimated that the maximum adiabatic flame temperature will be about 2400-2500 K. The maximum temperature in the burner will of course never reach this level. A more realistic temperature was estimated to 2100-2300 K. The final choice was made after having contacted some of the leading producers. It was possible to find one producer that could produce burners of one of the suggested materials, zirconia. Several construction ideas for the NPRB have been discussed and some of them tested with a CFD-model. The proposed burner concept has been modified in order to obtain a homogenous ...
Environmental regulatory requirements at both the state and federal level are constantly changing, making it difficult for industry and R ampersand D program managers to project future compliance requirements and costs. Even if a company is trying to keep abreast of various proposed regulatory initiatives, the number of possible combinations of initiatives that could occur in the future seems virtually limitless. Uncertainty associated with potential future environmental compliance requirements makes the identification and evaluation of future investment and R ampersand D opportunities exceedingly difficult, and makes the process of systematic strategic planning increasingly complex. This paper describes a methodology for accounting for uncertain future environmental compliance costs in a systematic, comprehensive manner. Through analysis of proposed initiatives for making future environmental requirements more stringent, forecasting the likelihood of occurrence and potential timing of ...
The book tries about the International and national aspects, natural gas situation, production, consumption, prices, demand projection, energetic plans, norms and laws of the natural gas in Colombia
This document provides information on the supply and disposition of natural gas to a wide audience. The 1996 data are presented in a sequence that follows natural gas from it`s production to it`s end use.
Barsebaeck 1 was closed on 30 November 1999. Barsebaeck's output of approximately 4 TWh per year will primarily be replaced by imports from coal-fired plants in Denmark and Germany. During the year, the closure of Swedish fossil-fired condensing power stations continued. With that, over 3,000 MW of peak-load power has been shut down during recent years. Consequently, situations entailing shortages of power can arise. On the deregulated electricity market, it is only the system operators that have a satisfactory overview of the overall electricity balance. The Swedish Power Association has thus lobbied the government as regards the need to elucidate Svenska Kraftnaet's responsibility. In a governmental decision from December, Svenska Kraftnaet was given the task of, among other things, monitoring the available capacity during peak loads and developing market instruments that can contribute to safeguarding the availability of power during peak loads. Svenska Kraftnaet ...
The origin of natural gas in the Japanese oil and gas fields are geochemically studied. Samples are taken from structural natural gas, surface gas seepage, water-dissolved natural gas and coal-field gas of the Japan Sea coast area. The origins of primary hydrocarbons are classified into bacteria gas and thermogenic gas, the latter being subclassified into gas in oil production zone with the per million deviation of the carbon isotope (/sup 13/C/sup 1/) of methane less than -35 and those gases with maturity higher than this. Surface gas seepage is subjected to migration and bacterial oxidation. Coal gas is similar to oil gas. The CO/sub 2/ concentration is 0 - 2% and /sup 13/CO/sub 2/ deviations from -30 - +30. The origin can be barely ...
A brief description of the physical process of dose enhancement effects produced by X-ray radiation on materials is given, with emphasis on the influence on electronic devices. The damages caused by X-ray radiation dose enhancement is more serious than that of #gamma#-ray with higher energy.
Using a ligature-induced model in type-2 Zucker diabetic fatty (ZDF) rat and normoglycemic littermates, we investigated whether diabetes primarily affects periodontitis by enhancing bone loss...Full Text Available
OBJECTIVEPhosphoinositide 3-kinase enhancer A (PIKE-A) is a proto-oncogene that promotes tumor growth and transformation by enhancing Akt activity. However, the physiological functions...Full Text Available
... iFfficiency-en- enhanced spontaneous radiation at the free-electron- ... as enhanced spontaneous radiation at the free-electron-laser wavelength. ...
Many older homes are equipped with mercury-containing gas regulators that reduce the pressure of natural gas in the mains to the low pressure used in home gas piping. Removal of these regulators can...Full Text Available
Sewage gas or biogas as a product of anaerobic digestion contains methane and carbon dioxide as its main components. Biogas is scrubbed off carbon dioxide in absorption columns and purified to natural-gas quality. The purified gas then is piped to the gas pressure control station and fed into the public network. Description of process and plant is given.
We report the performance of a micro gas turbine on biomass producer gas and mixtures of biomass producer gas with natural gas. The micro gas turbine delivers full power on gas mixtures with a heating value of at least 15 MJ/Nm{sup 3}. For gas of lower heating value, the maximum fuel gas flow limits the attainable power. The lower limit for stable operation is about 8 MJ/Nm{sup 3}. The gross efficiency of the micro gas turbine depends on output power but not on the gas heating value, within our measurement accuracy. Above 70% of full power, emissions of CO and NO are 40 and 10 times lower than those of a gas engine of similar size. At part load below 70% of full power, the micro gas turbine burner switches to a different operating mode ...
Using spectral hole-burning-based ultraslow group velocity in a dilute solid medium, we report enhanced photon echo efficiency three orders of magnitude higher than that in a nonslow light regime. The enhancement is due to exponentially increased absorption of an optical data pulse owing to the enhanced photon-atom interaction in an ultraslow light regime, whereas echo reabsorption is negligibly small due to group-velocity dependent population depletion.
Contacts with researchers, manufacturers, and users of enhanced heat transfer equipment are summarized. The Technical Literature file and the Patent File continue to be updated; the Patent File is the source for a patent technology report now in draft form. Application studies on a rationally-based friction correlation for internally-finned tubes and on the evaluation of candidate tube-side enhancements for OTEC applications are reported. The technology study on enhancement of spray evaporation is also discussed.
The most effective way to generate electricity out of biomass is the gasification and the use of the gas in a gas engine. The conversion of the organic carbon with the gasification of biomass is higher than 95 %. Depending on the gasification concept, the efficiency of gasifiers is found between 70 and 90 %. If the pyrolysis gas is used in a gas engine, an electric efficiency of about 26 % referring to the primary amount of energy can be obtained. With efficient gas cleaning (cleaning for tar and dust), pyrolysis gas is well qualified for engine combustion. Through modern state of engine controlling there are ways to have complete control of the fluctuations in the gas composition. Furthermore, the minor calorific value of offered wood gas poses no problem for turbo charged lean-burn gas engines. ...
This patent describes an electrodeless lamp. It comprises: a microwave cavity; a source of microwaves in communication with the cavity; a lamp envelope containing a plasma-forming medium mounted within the microwave cavity; a gas manifold for feeding gas to at least one gas passageway for directing a stream of gas to the outer surface of the envelope; a gas leak passageway leading from the gas manifold; a conductive mesh assembly for retaining microwaves within the cavity and permitting light to be emitted from the cavity. The assembly including gas flow blocking means for preventing the flow of gas through the gas leak passageway when the screen is in place in the lamp; and means for shutting off the source of microwaves when the gas pressure in the manifold drops below a ...
The role of the unsaturated properties of sand as a drainage layer in a composite liner system for landfills is investigated. The effect of the unsaturated properties of coarse-grained soil on contaminant migration was evaluated by means of a series of simulations using a one-dimensional model of a two- and a three-layer soil liner system for advection and diffusion, respectively. The results showed that under seepage conditions, the effect of an unsaturated sand layer on the advancement of the concentration front was quite insignificant. The arrival time of the C/C{sub o} = 0.5 concentration front increased from 651 days for the case with no sand layer to approximately 951 days for the case with a 1.0-m sand layer. A steady-state flow condition was ultimately established in the sand, and this fact suggests that the capillary action might not be effective. For diffusion, the arrival time of the concentration front increased nonlinearly with a decrease in the degree ...
Kaiser Alumina and Chemical Co. impounds red mud, the byproduct of alumina production, behind levees. Kaiser recognizes that this action cannot be maintained indefinitely. Therefore, a project is in progress to produce useful products from red mud that increase the profitability of the Gramercy facility. Before products could be developed, an obstacle had to be overcome. The annual rainfall in South Louisiana prevents evaporative drying of the mud lakes. Innovative methods were applied to dry the lake mud. Two products have been developed. A daily landfill cover and an absorbant, which are marketed under the Cajunite{trademark} banner. Both products are currently being tested by potential customers at their sites. Environmental concerns were addressed during development. Extensive TCLP results show no metal leachate problems. All pilot tests and plant trials received LADEQ approval. Products that are under development include levee core, road base, fertilizer ...
Biogas, produced from anaerobic digestion of organic matter in domestic, industrial and rural wastewaters and residuals, represent an alternative and renewable source of energy, with growing use worldwide. In Brazil, high population and its spatial concentration and expressive agricultural and agricultural-industrial production indicate a substantial potential of biogas production. The results presented in this work show a potential of biogas production of almost 2 billion cubic feet a day of CH{sub 4}. Viability of biogas production and use depends substantially on project scale. Generally, biogas projects are viable from landfills and domestic wastewater treatment for populations higher than 50,000 inhabitants and swine and dairy farms with at least 5,000 and 1,000 animals, respectively. Biogas is also competitive when compared to fossil fuels used in industry and transport. Despite incentive mechanisms for biogas production and use, like Clean Development ...
A $200 million paper mill being built in Hagerstown, Md., is expected to produce 150,000 bone-dry short tons per year of de-inked, market-grade pulp for writing and printing paper. The 1st Urban Fibers facility, the largest capital project in Hagerstown's history, is slated for completion in the spring. Landegger Recycled Fiber Corp. will operate and maintain the 200,000-square-foot recycling mill and 60,000-square-foot water reclamation plant. The wastepaper recycling mill plans to minimize waste and pollution by: reclaiming 635 tons per day of 100 percent post-consumer mixed office waste from the solid waste stream; saving more than 16 million cubic feet of landfill area per year; conserving the fiber equivalent of 6,700 trees per day; using no chlorine; saving about 2,000 gallons of water and 4,000 kilowatt hours of electricity per ton of throughput, compared to virgin fiber mills; reusing treated wastewater, reducing effluent discharge by 65 percent; ...
author.The existing management of hospital waste in Lebanon currently poses both an environmental hazard as well as a public health risk. This is due mainly to lack of legislation, information and modern treatment and disposal facilities designed for this purpose. A nation-wide questionnaire survey was conducted to asses the status of hospital waste management. The study started from October 1997 till August 1998. We found that 75% of the surveyed hospitals completely ignore their total waste quantity: 73% of hospitals surveyed practice segregation at source of infectious, pathological, sharps and pharmaceuticals; more than 40% dispose of their hospital risk wastes through the municipality waste disposal, 24% by burning in open fires, 14% by on-site hospital incinerators, 11% in on-site dumping, 8% handled by a private contractor and 1% in uncontrolled landfill. We conclude that with some exceptions, the hospital waste management situation in Lebanon is very far ...
The work reported is to evaluate two alternative resource recovery systems which would produce a fuel or an energy product (steam) for sale to an industrial plant. The first alternative is a refuse derived fuel (RDF) production facility which would process waste to produce fuel for sale to the plant. The RDF would be co-fired with coal in new boilers. The second alternative is a mass burn steam generation facility which would produce high pressure superheated steam for sale. The steam would be used by the plant to cogenerate electricity and for the process. Conceptual designs are developed for each alternative to form the basis of estimates of capital and operating costs and potential energy revenues. Operating requirements are developed for both alternatives. An assessment is made of the impact of both alternatives on the environment, and it is concluded that the impact of either alternative will be negligible. Order of magnitude estimates are made of capital and operating costs. The ...
Two series of diffusion tests were performed to examine the degradation of dichloromethane (DCM) as it diffuses through clay. The first series showed the use of a synthetic leachate with no significant initial bacterial population diffusing through a plug of intact clay; there was an induction period of 95--135 d, during which diffusion was as expected in the absence of degradation, followed by a second stage, where degradation occurred with an apparent half-life of less than 55 d at a temperature of 24 C. The second series of tests examined the diffusion of an actual leachate from the Keele Valley Landfill (KVL) (which provided both nutrients and a source of bacteria), through a compacted clay. In these tests, the induction period was reduced to 40--60 d, after which the apparent half-life was 20 d or less at 27 C. The diffusion coefficient for DCM was approximately 8 {times} 10{sup {minus}10} m{sup 2}/s, with partitioning coefficient K{sub d} = 1.5 cm{sup 3}/g. ...
An economic analysis of the potential advantages of alternatives for recycling and reusing equipment now stored in Building 865 at the Rocky Flats Plant (RFP) in Colorado has been conducted. The inventory considered in this analysis consists primarily of metallurgical and process equipment used before January 1992, during development and production of nuclear weapons components at the site. The economic analysis consists of a thorough building inventory and cost comparisons for four equipment dispositions alternatives. The first is a baseline option of disposal at a Low Level Waste (LLW) landfill. The three alternatives investigated are metal recycling, reuse with the government sector, and release for unrestricted use. This report provides item-by-item estimates of value, disposal cost, and decontamination cost. The economic evaluation methods documented here, the simple cost comparisons presented, and the data provided as a supplement, should provide a foundation ...
Enhanced heat transfer in curved rectangular channels depends on at least two geometric factors, the radius of curvature of the duct and the aspect ratio, which is the width/depth ratio of the duct. In this work, an expression for optimum aspect ratio is derived mathematically from a correlation that includes both aspect ratio and bend curvature parameters. Enhancement factors are developed that show optimal, near-optimal, and nonoptimal aspect ratios for curved rectangular ducts. Predicted enhancements are within 25% of published literature results for individual designs, two of which show heat transfer enhancement of 200% over that of a straight duct with turbulent flow. The theoretical maximum enhancement is shown to be about 480% over a straight-duct, turbulent-flow situation. This is not achievable in practice, but near-optimal solutions are achievable, yielding ...
The issue of projecting policies ensuring appropriate energy supply in the future has become more important in Germany after conclusion of the agreement on a long-term nuclear power phase-out. A recent comparative analysis of a selection of scientific studies forecasting the implications of a nuclear power phase-out has shown that there is demand for more studies examining the issue in greater detail, and on the basis of an enlarged scope of research topics. Hence the present study, intended as a preliminary analysis, will investigate the potential, conditions of successful application, conceivable support schemes, and effects of those policy options that in any case, apart from the nuclear power phase-out scenario, are of essential importance in the context of building the proper conditions for sustainable development of Germany's energy sector. The options and strategies examined are: stepping up energy efficiency programmes and incentives, enhancing ...
Throughout the last decades, plasma technology has been established in a series of surface treatment applications, e.g. for semiconductor processing or optical coatings. The majority of plasma assisted technologies is based on low pressure processes. In recent years, however, non-thermal atmospheric pressure discharges have attracted considerable interest because of their simplified technical devices for industrial applications as compared to low pressure processes which require vacuum equipment. Hence, batch processing can be avoided, thus facilitating the implementation of plasma process steps into production lines. Investment costs are cut down significantly. The use of atmospheric pressure plasmas for technical applications dates back to the ozone production with dielectric barrier discharges (DBD) by Siemens in 1857. Lately, the application of atmospheric pressure plasmas for surface treatment has been reported, e.g. for the treatment of foils to improve printability, for surface ...
Ternary copper(II) complexes [Cu(L1)B](ClO4) (1, 2) and [Cu(L2)B](ClO4) (3, 4), where HL1 and HL2 are tridentate NSO- and ONO-donor Schiff bases and B is a heterocyclic base, viz. dipyrido[3,2-d:2',3'-f]quinoxaline (dpq, 1 and 3) or dipyrido[3,2-a:2',3'-c]phenazine (dppz, 2 and 4), were prepared and their DNA binding and photoinduced DNA cleavage activity studied. Complex 1, structurally characterized by single-crystal X-ray crystallography, shows an axially elongated square-pyramidal (4 + 1) coordination geometry in which the monoanionic L1 binds at the equatorial plane. The NN-donor dpq ligand exhibits an axial-equatorial binding mode. The complexes display good binding propensity to calf thymus DNA, giving a relative order 2 (NSO-dppz) > 4 (ONO-dppz) > 1 (NSO-dpq) > 3 (ONO-dpq). They cleave supercoiled pUC19 DNA to its nicked circular form when treated with 3-mercaptopropionic acid (MPA) by formation of hydroxyl radicals as the cleavage active species under dark reaction ...
Appendices to this summary consist of twelve individual status reports that will be available through the National Technical Information Service (NTIS) in the United States and of course limited copies will be available through NATO. The twelve report titles which are appendices to the summary are: (A) Status Report on the Limestone/Sludge Flue Gas Desulfurization Process; (B) Status Report on the Lime/Sludge Flue Gas Desulfurization Process; (C) Status Report on the Double Alkali/Sludge Flue Gas Desulfurization Process; (D) Status Report on the Sea Water Scrubbing Flue Gas Desulfurization Process; (E) Status Report on the Limestone/Gypsum Flue Gas Desulfurization Process; (F) Status Report on the Lime/Gypsum Flue Gas Desulfurization Process; (G) Status Report on the Double Alkali/Gypsum Flue Gas Desulfurization Process; (H) Status Report on ...
Gas hydrates have impacted the oil and gas industry since 1934, when they were first found to plug pipelines. Today we know that in deep oceans and in permafrost, very substantial gas reserves are present in hydrated form. Concerns are being raised about in situ dissociation for both energy and greenhouse implications upon methane release. In Japan work is underway to consider the storage of carbon dioxide, concentrated in clathrates. This talk will deal with some basic questions. Why should we be interested in gas hydrates? What are gas hydrates? How do gas hydrates form? How might hydrates impact on the energy/environmental picture?
This book discusses the progress and problems of current interest in gaseous dielectrics and their use, with special emphasis on insulation in high-voltage transmission lines and substations. Topics covered include: basic physics of gaseous dielectrics; basic mechanisms; gas decomposition, reactions and toxicity; diagnostics and field probes; gases and mixtures for GIS transformers and circuit breakers; gaseous media for discharge chemistry and etching/corona; gas engineering for pulsed power and switching; gas breakdown under steep-fronted voltages; new developments in gas-insulated equipment and gas handling; gas/insulator interface/flashover; and quality control in testing gas-insulated equipment. Contains approximately 85 papers.
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 ...
To assess whether ring enhancements of liver metastases on Mn-DPDP enhanced, early MR images were well visualized on delayed images, as compared with those of hepatocellular carcinomas (HCC), and to investigate the detection accuracy and conspicuity of each tumor. Twenty patients with liver metastases and 15 with HCC were studied by Mn-DPDP enhanced, T1-weighted MR images. Peripheral ring enhancement and conspicuity were investigated. Differences in detection accuracy and frequency of ring enhancement in liver metastases and HCC were assessed. In liver metastases (n= 69), 44 cases (63.8%) without ring enhancement and 25 (36.2%) with were noted on early images. Sixteen cases (23.2%) without ring enhancement, 38 (55.1%) with ring enhancement similar to the early images, and 15 (21.7%) with prominent ring ...
Gas hydrates are crystalline substances composed of water and gas, in which a solid-water-lattice accommodates gas molecules in a cage-like structure. Gas hydrates are globally widespread in permafrost regions and beneath the sea in sediment of outer continental margins. While methane, propane, and other gases can be included in the clathrate structure, methane hydrates appear to be the most common in nature. The amount of methane sequestered in gas hydrates is probably enormous, but estimates are speculative and range over three orders of magnitude from about 100,000 to 270,000,000 trillion cubic feet. The amount of gas in the hydrate reservoirs of the world greedy exceeds the volume of known conventional gas reserves. Gas hydrates also represent a significant drilling and production hazard. A fundamental question ...
Gas hydrates are crystalline substances composed of water and gas, in which a solid-water-lattice accommodates gas molecules in a cage-like structure. Gas hydrates are globally widespread in permafrost regions and beneath the sea in sediment of outer continental margins. While methane, propane, and other gases can be included in the clathrate structure, methane hydrates appear to be the most common in nature. The amount of methane sequestered in gas hydrates is probably enormous, but estimates are speculative and range over three orders of magnitude from about 100,000 to 270,000,000 trillion cubic feet. The amount of gas in the hydrate reservoirs of the world greedy exceeds the volume of known conventional gas reserves. Gas hydrates also represent a significant drilling and production hazard. A fundamental question ...
We report the performance of a commercial recuperated micro gas turbine on biomass producer gas and mixtures of biomass producer gas with natural gas. The biomass producer gas, obtained by gasification at 850{sup o}C with air at atmospheric pressure, contains about 7% H2, 17% CO, 15% CO2, 4% CH4, 2% other hydrocarbons, 2% H2O, and a balance of N2 and Ar from air. It has a net heating value of about 6 MJ/(Nm{sup 3}). The micro gas turbine delivers full power (30 kW{sub e}) on gas mixtures with a net heating value of at least 15 MJ/(Nm{sup 3}). For gas of lower heating value, the maximum fuel gas flow allowed by the fuel control unit limits the attainable power. At reduced power, the lower limit for stable operation is a net heating value of about 8 MJ/(Nm{sup 3}). The gross efficiency of the micro ...
The situation of natural gas in the Federal Republic of Germany is described, with particular emphasis on the advantages and consequences of natural gas supply. The brochure discusses the role of natural gas on the energy market, the reliability of natural gas supply, the environmental impacts, the energy-saving effect of natural gas, natural gas prices, the competitive strength of the German gas industry, and the long-term reliability of natural gas supply. (orig.) [German] Die Situation des Erdgases in der Bundesrepublik Deutschland wird beschrieben, wobei die wichtigsten Vorteile und Auswirkungen der Erdgasversorgung besonders hervorgehoben werden. Es geht um die Stellung des Erdgases im Energiemarkt, die Sicherheit der Energieversorgung, Umweltschutz, Energieeinsparung durch Erdgaseinsatz, Erdgaspreise, ...
Effects of combustion conditions on the critical calorific value of flame blowout were reported for low calorific gas on the assumption of using coal derived gaseous fuel. Further, calculations of adiabatic flame temperature by using chemical equilibrium calculation were conducted in order to get a possibility of increasing exit gas temperature of gas turbine combustor to 1,300 C for low calorific value gas fuel. As a result, effects of (1) fuel composition, (2) preheating fuel temperature, (3) calorific value, and (4) combustion air velocity and fuel nozzle diameter, on the critical calorific values of flame blowout were clarified. In increasing exit gas temperature of gas turbine combustor to 1,300 C when using low calorific value gas fuel, it is essential to get an advanced cooling technology for the gas turbine ...
The genetic type, source and charging history of natural gas in the Yulin gas field in the Ordos Basin have been studied by combining the carbon isotopic composition of natural gas and geochemical characteristics of light hydrocarbons with carbon isotope fractionation model results and fluid inclusion analysis. The carbon isotopic composition of methane and ethane in the Yulin gas field is relatively enriched in {sup 13}C with {delta}{sup 13}C{sub 1} values ranging from - 35.3 permille to - 29.8 permille (average value = - 32.4 permille) and {delta}{sup 13}C{sub 2} ranging from - 26.3 permille to - 23.5 permille (average value = - 24.8 permille). The C{sub 7} light hydrocarbons are predominated by methylcyclohexane, accounting for 65.8% to 80.9% (average value = 71.6%), which is characteristic of coal-derived gas. Furthermore, the gas geochemistry indicates ...
The production, principal applications, characteristics and properties, advantages of the gas natural is showed. A sectorial overview of the ceramic industry and the utilization of the natural gas in the ceramic industry is presented. The expectations are systematized and the impact of the natural gas utilization in the ceramic industry is evaluated. Some conclusions are withdrawn and recommendations suggested.
A combined gas/steam turbine process includes a high-pressure furnace and a high pressure gasification unit with a mounted upstream of a combustion chamber there is a gas turbine with a waste heat system. Combustion heat which is not needed to heat the flue gas to combustion temperature is released from the furnace and transferred to ths combustion air going into the combustion chamber.
Nomographs have been developed to simplify site performance estimates for various types of gas turbine engines used for industrial applications. The nomographs can provide valuable data for engineers to use for an initial appraisal of projects where gas turbines are to be considered. General guidelines for the selection of gas turbines are also discussed. In particular, site conditions that influence the performance of gas turbines are described.
The budding natural gas markets in East Europe attract a great deal of interest from natural gas industries in the Western countries. Dutch companies, institutions and the government, too, are active in this market. So far the results have not been spectacular. An analysis is made of the present situation and the Dutch approach
Austenitic stainless steels (304-type) have been implanted with nitrogen ions in order to investigate the effects of implanted nitrogen on their electrochemical behaviour and on the nature of the passive film formed on the steels in acid (0.5M H{sub 2}SO{sub 4}). Alloys with two nitrogen doses have been prepared (2.5x10{sup 16} and 2x10{sup 17} N atoms/cm{sup 2}). The implanted alloys have been characterized by {sup 15}N-NRA (nuclear reaction analysis) and XPS (X-ray photoelectron spectroscopy). Alloy surfaces with well-defined N concentrations were prepared, prior to the electrochemical measurements, by argon-ion sputtering of the implanted material for a fixed time in order to reach a well-defined point on the nitrogen depth profile. The samples were then transferred without exposure to air to an electrochemical cell mounted in an inert gas glove box. The implanted nitrogen modifies the electrochemical behaviour of the alloy. The anodic dissolution in the active ...
Austenitic stainless steels (304-type) have been implanted with nitrogen ions in order to investigate the effects of implanted nitrogen on their electrochemical behaviour and on the nature of the passive film formed on the steels in acid (0.5M H_2SO_4). Alloys with two nitrogen doses have been prepared (2.5x10"1"6 and 2x10"1"7 N atoms/cm"2). The implanted alloys have been characterized by "1"5N-NRA (nuclear reaction analysis) and XPS (X-ray photoelectron spectroscopy). Alloy surfaces with well-defined N concentrations were prepared, prior to the electrochemical measurements, by argon-ion sputtering of the implanted material for a fixed time in order to reach a well-defined point on the nitrogen depth profile. The samples were then transferred without exposure to air to an electrochemical cell mounted in an inert gas glove box. The implanted nitrogen modifies the electrochemical behaviour of the alloy. The anodic dissolution in the active state is ...
Washboard (WB) modes (Smeulders P et al 1999 Plasma Phys. Control. Fusion 41 1303) are a very common edge instability regularly observed in the H-mode regime in JET. They are detected as (normally several) bands of continuously fluctuating magnetic activity rotating in the direction of the electron diamagnetic drift with typical frequencies in the range of 10-90 kHz. The time evolution of the WB mode frequency is found to follow qualitatively the evolution of the electron temperature measured near the pedestal top, probably due to the strong diamagnetic drift associated with the large pedestal gradients. Evidence for their involvement in the pedestal and ELM dynamics will be presented. Increasing WB mode amplitude is correlated with an increase in the time between consecutive type-I ELMs. In situations in which a sudden increase (decrease) of WB mode activity is observed, the build-up of the pedestal temperature (and, linked to this, also of the pedestal pressure) of the electrons is ...
This report discusses the safety approach of the Advanced Liquid Metal reactor program, sponsored by the US Department of Energy, which relies upon passive reactor responses to off-normal condition to limit power and temperature excursions to levels that allow safety margins. Gas expansion modules (GEM) have included in the design to provide negative reactivity to enhance these margins in the extremely unlikely event that pumping power is lost and the highly reliable scram system fails to operate. The feasibility and beneficial features of these devices were first demonstrated in the core of the Fast Flux Test Facility (FFTF) in 1986. Preapplication safety evaluations by the US Nuclear Regulatory Commission have identified areas that must be addressed if these devices are to be relied on. One of these areas is the response of the reactor when it is critical and the pumps are turned on, resulting in positive reactivity being added to the core. ...
The safety approach of the Advanced Liquid Metal Reactor program, sponsored by the U.S. Department of Energy, relies upon passive reactor responses to off-normal conditions to limit power and temperature excursions to levels that allow large safety margins. Gas expansion modules (GEM) have been included in the design to provide negative reactivity to enhance these margins in the extremely unlikely event that pumping power is lost and the highly reliable scram system fails to operate. The feasibility and beneficial features of these devices were first demonstrated in the core of the Fast Flux Test Facility (FFTF) in 1986. Pre-application safety evaluations by the U.S. Nuclear Regulatory Commission have identified areas that must be addressed if these devices are to be relied on. One of these areas is the response of the reactor when it is critical and the pumps are turned on, resulting in positive reactivity being added to the core. Tests to ...
Full text: It was recently-established for hexagonal barium ferrite-industrially important magnetically hard material that refinement of the crystallite dimensions into the nanoscale regime, typically #<=# 10 nm, leads after heat treatment at temperatures 800-1000 deg C to significant coercivity increase of up to 6.5 kOe (#approx#3-4 times) with saturation magnetisation values of 50-55 emu/g (#approx#95% of bulk at room temperature). High-energy mechanochemical processing has been applied to prepare nanostructural (nanocrystalline-amorphous) composites. High resolution electron microscopy studies reveal that the enhancement of the final magnetic properties was due to formation of magnetically noninteracting #approx#l,#mu#m Ba-ferrite particles with 5-10 nm amorphous surface layer - depending on annealing parameters. Similar situation was established also for ball milled strontium ferrite (SrFe_1_2O_1_9) powders where short annealing 4 h at 1000 deg C produced ...
Thin-film solar cells on flexible, lightweight, space-qualified substrates provide an attractive approach to fabricating solar arrays with high mass-specific power. A polycrystalline chalcopyrite absorber layer is among the new generation of photovoltaic device technologies for thin film solar cells. At NASA Glenn Research Center we have focused on the development of new single-source precursors (SSPs) for deposition of semiconducting chalcopyrite materials onto lightweight, flexible substrates. We describe the syntheses and thermal modulation of SSPs via molecular engineering. Copper indium disulfide and related thin-film materials were deposited via aerosol-assisted chemical vapor deposition using SSPs. Processing and post-processing parameters were varied in order to modify morphology, stoichiometry, crystallography, electrical properties, and optical properties to optimize device quality. Growth at atmospheric pressure in a horizontal hotwall reactor at 395 C yielded the best ...
During earlier work rapid and highly sensitive Jet-REMPI (resonance-enhanced multiphoton ionization) mass spectrometry was applied for monitoring the effluent from thermal treatment of a filter dust during a de novo test under laboratory conditions. The sample, from ESP-Field 2 of an iron ore sintering plant, was already loaded with dioxins ({sigma}PCDD/F = 132 ng/g), their precursors (PCBz, PCPh) and other products of incomplete combustion. Heating filter dust in a temperature window 200-350 C under a flow of air results in further formation of these pollutants. As described elsewhere, on-line detection was mostly carried out using a non-selective ionization mode, to measure a wide range of compounds simultaneously. The changes of output suggest that the reaction products increase in chlorination level with time. Another explanation is that higherchlorinated compounds appear later as a consequence of lower volatility and stronger adsorption. However, due to mass ...
Naturally Occurring Radioactive Material (N.O.R.M.) occurs in most soil and rock, and by mining and mineral processing, some of the radionuclides are significantly enhanced. An in-situ gamma-ray detector called M.E.D.U.S.A., has been used to produce a map of relative activity concentrations in a gold mine tailings dam on the Witwatersrand in South Africa. A CsI(Na) scintillation detector is used in this system. M.E.D.U.S.A. spectra obtained from the survey were analyzed using the Full-Spectrum Analysis (F.S.A.) procedure to compute the {sup 40}K, {sup 238}U and {sup 232}Th activity concentrations. The activity concentrations are used with global positioning data (G.P.S.) to produce the concentration maps. A hyper-pure germanium gamma-ray detector (Hp Ge) was used to measure gamma-rays from the naturally occurring nuclides for soil samples taken at different points on the site to calibrate the M.E.D.U.S.A. system. Radon soil gas measurements ...
The cause of the Gulf War Syndrome may be related to soldiers being exposed to insecticides (e.g., permethrin (P)), insect repellents (e.g., N,N-diethyl-m-toluamide (DEET)), an organophosphate nerve agent simulant (e.g., diisopropyl fluorpohosphate (DFP)), and/or prophylactic treatment (e.g., pyridostigmine bromide (PB)) against potential nerve gas attacks. The purpose of this study was to assess the dermal disposition of [14C]permethrin in ethanol or ethanol:water (3:2) in the isolated perfused porcine skin flap (IPPSF) model with simultaneous dermal exposure to DEET or DFP. These IPPSFs were also simultaneously perfused arterially with or without PB, DFP, or DFP + PB. The results indicated that DFP + PB significantly increased [14C]permethrin absorption compared to controls (1.06% dose vs 0.14% dose). PB significantly increased [14C]permethrin disposition in the stratum corneum (SC) in aqueous mixtures only (9.40 vs 3.35% dose), while topical DEET or topical DFP ...
Gas nitridation has shown excellent promise to form dense, electrically conductive and corrosion-resistant Cr-nitride surface layers on Ni-Cr base alloys for use as proton exchange membrane fuel cell (PEMFC) bipolar plates. Due to the high cost of nickel, Fe-base bipolar plate alloys are needed to meet the cost targets for many PEMFC applications. Unfortunately, nitridation of Fe-base stainless steel alloys typically leads to internal Cr-nitride precipitation rather than the desired protective surface nitride layer formation, due to the high permeability of nitrogen in these alloys. This paper reports the finding that it is possible to form a continuous, protective Cr-nitride (CrN and Cr{sub 2}N) surface layer through nitridation of Fe-base stainless steel alloys. The key to form a protective Cr-nitride surface layer was found to be the initial formation of oxide during nitridation, which prevented the internal nitridation typically observed for these alloys, and ...
Gas nitridation has shown excellent promise to form dense, electrically conductive and corrosion-resistant Cr-nitride surface layers on Ni-Cr base alloys for use as proton exchange membrane fuel cell (PEMFC) bipolar plates. Due to the high cost of nickel, Fe-base bipolar plate alloys are needed to meet the cost targets for many PEMFC applications. Unfortunately, nitridation of Fe-base stainless steel alloys typically leads to internal Cr-nitride precipitation rather than the desired protective surface nitride layer formation, due to the high permeability of nitrogen in these alloys. This paper reports the finding that it is possible to form a continuous, protective Cr-nitride (CrN and Cr{sub 2}N) surface layer through nitridation of Fe-base stainless steel alloys. The key to form a protective Cr-nitride surface layer was found to be the initial formation of oxide during nitridation, which prevented the internal nitridation typically observed for these alloys, and ...
A zinc-air battery using zinc regeneration electrolysis with propanol oxidation as a counter electrode reaction is reported in this paper. It possesses functions of both zincate reduction and electrochemical preparation, showing the potential for increasing the electronic energy utilization. Charge/discharge tests and scanning electron microscopy (SEM) micrographs reveal that when a nickel sheet plated with the high-H{sub 2}-overpotential metal, cadmium, was used as the negative substrate electrode, the dendritic formation and hydrogen evolution are suppressed effectively, and granular zinc deposits become larger but relatively dense with the increase of charge time. The performance of batteries is favorable even if the charge time is as long as 5 h at the current density of 20 mA cm{sup -2}. Better discharge performance is achieved using a 'cavity-opening' configuration for the discharge cell rather than a 'gas-introducing' ...
The study of tropospheric kinetics underlies global change because key greenhouse gases are photochemically active. Modeling of tropospheric chemistry on a global scale is essential because some indirect greenhouse gases are short-lived and interact in a non-linear fashion. It is also extremely challenging, however; the global change grid is extensive in both the physical and temporal domains, and critical lower atmospheric species include the organics and their oxidized derivatives, which are numerous. Several types of optimization may be incorporated into kinetics modules to enhance their ability to simulate the complete lower atmospheric gas phase chemical system. (1) The photochemical integrator can be accelerated by avoiding matrix and iterative solutions and by establishing families. Accuracy and mass conservation are sacrificed in the absence of iteration, but atom balancing is restorable post hoc. (2) Chemistry can be arranged upon the ...
Breakdowns occurring in rf accelerating structures will limit the ultimate performance of future linear colliders such as the Compact Linear Collider (CLIC). Because of the similarity of many aspects of dc and rf breakdown, a dc breakdown study is underway at CERN to better understand the vacuum breakdown mechanism in a simple setup. Measurements of the field enhancement factor ? show that the local breakdown field is constant and depends only on the electrode material. With copper electrodes, the local breakdown field is around 10.8GV/m, independent of the gap distance. The ? value characterizes the electrode surface state, and the next macroscopic breakdown field can be well predicted. In breakdown rate experiments, where a constant field is applied to the electrodes, clusters of consecutive breakdowns alternate with quiet periods. The occurrence and lengths of these clusters and quiet periods depend on the evolution of ?. The application of a high field can even ...
The main purposes of this research was to investigate the feasibility of incineration of wool-scouring sludge in a novel vertical-axis-rotating fluidised bed (RFB). The experiment was carried out in a RFB with an internal diameter (ID) of 200 mm and height of 50 mm. A cold test was first conducted to investigate the fluidization performance of the RFB via parameters such as the bubbling, gas distribution, bed shape and pressure drop. The tumbling phenomena was observed in the bed, and this effectively enhanced the axial mixing. The appropriate range of bed thickness, rotating speed and sand particle size were identified to ensure the full fluidization and reduce the particle elutriation. Four wool-scouring sludges from different processes were incinerated in the RFB. With 5% support methane, all sludges with a maximum moisture up to 70% as received could be successfully burned in the RFB at rotating speeds of 200 and 300 rpm. The combustion was ...
Experimental studies on the heat transfer and fluid dynamics of a high heat flux fuel rod for a very high temperature reactor (VHTR) were performed using a single channel test rig of a fuel stack test section (T{sub 1-s}) installed in a helium engineering demonstration loop (HENDEL). The fuel rod has been developed in order to enhance the turbulent heat transfer coefficient than that of the standard fuel rod obtained by the previous experiment. Two-dimensional square ribs were settled on the outer surface of the fuel rod axially to improve the heat transfer. The configuration of a square rib is 0.5 mm in width(w), 0.5 mm in height(h) and 5 mm in pitch(p): p/h=10. The experiment were carried out under the helium gas conditions of high temperature and pressure simulated the VHTR operation. For the turbulent region of Reynolds number 2,500{approx}8,000 of the VHTR core flow condition, it was found that the heat transfer coefficient of the fuel rod ...
Experimental studies on the heat transfer and fluid dynamics of a high heat flux fuel rod for a very high temperature reactor (VHTR) were performed using a single channel test rig of a fuel stack test section (T_1_-_s) installed in a helium engineering demonstration loop (HENDEL). The fuel rod has been developed in order to enhance the turbulent heat transfer coefficient than that of the standard fuel rod obtained by the previous experiment. Two-dimensional square ribs were settled on the outer surface of the fuel rod axially to improve the heat transfer. The configuration of a square rib is 0.5 mm in width(w), 0.5 mm in height(h) and 5 mm in pitch(p): p/h=10. The experiment were carried out under the helium gas conditions of high temperature and pressure simulated the VHTR operation. For the turbulent region of Reynolds number 2,500#approx#8,000 of the VHTR core flow condition, it was found that the heat transfer coefficient of the fuel rod ...
The Kyoto Protocol attempts through political negotiations to guide participating industrialized countries' greenhouse gas (GHG) emissions from a positive growing trend, to reach a peak point (or turning point), and then be reduced to a negative growth. That means the relationship between decreasing GHG emissions and economic growth may be described by an inverted-U curve (or called a bell-shaped curve), which is consistent with the concept of the Environmental Kuznets Curve (EKC) hypothesis. This research observed that the economic development and GHG emissions in Economies in Transition (EITs) exhibit a hockey-stick curve trend (or called quasi-L-shape curve), that also generates a lot of 'hot air' which is significant to the implementation of the Kyoto Protocol. In addition, through the analysis of single-country time series data and GDP data, this research demonstrated that statistical data for most of the Annex II countries do not ...
The Kyoto Protocol attempts through political negotiations to guide participating industrialized countries' greenhouse gas (GHG) emissions from a positive growing trend, to reach a peak point (or turning point), and then be reduced to a negative growth. That means the relationship between decreasing GHG emissions and economic growth may be described by an inverted-U curve (or called a bell-shaped curve), which is consistent with the concept of the Environmental Kuznets Curve (EKC) hypothesis. This research observed that the economic development and GHG emissions in Economies in Transition (EITs) exhibit a hockey-stick curve trend (or called quasi-L-shape curve), that also generates a lot of 'hot air' which is significant to the implementation of the Kyoto Protocol. In addition, through the analysis of single-country time series data and GDP data, this research demonstrated that statistical data for most of the Annex II countries do not ...
Ultra low loading noble metal (0.04-0.12 mg_P_t/cm"2) based electrodes were obtained by direct metallization of non-catalyzed gas diffusion layers via dual ion beam assisted deposition (IBAD) method. Fuel cell performance results reported earlier indicate significant improvements in terms of mass specific power density of 0.297 g_P_t/kW with 250 A thick IBAD deposit (0.04 mg_P_t/cm"2 for a total MEA loading of 0.08 mg_P_t/cm"2) at 0.65 V in contrast to the state of the art power density of 1.18 g_P_t/kW using 1 mg_P_t_(_M_E_A_)/cm"2 at 0.65 V. In this article we report the peroxide radical initiated attack of the membrane electrode assembly utilizing IBAD electrodes in comparison to commercially available E-TEK (now BASF Fuel Cell GmbH) electrodes and find the pathway of membrane degradation as well. A novel segmented fuel cell is used for this purpose to relate membrane degradation to peroxide generation at the electrode/electrolyte interface by means of ...
Elf Aquitaine, a major international oil and gas company, has recently undergone a thorough reengineering of its research and development in exploration and production division. The aim of this reengineering, was to align the company R&D with its business strategy, and also to give a clear picture of two major features for a R&D portfolio: a duration profile (short, median or long term?) and a partnership profile (do it yourself, cooperate, outsource or let do elsewhere?). In short, we were trying to answer a basic question: How can we adapt our R&D to a durable context of low oil price (eg 15 $/bbl)? In our opinion, two preliminary statements ought to be made when dealing with the above issue. Firstly, R&D does not contribute equally to the factors of increased profitability, although it is certainly a major contributor to some of them (like obtaining new ventures, reducing costs, discovering new reserves out of current acreage, or improving the ...
Si nanocrystal floating gate MOS capacitors were formed on p-Si (100) wafers by thermal plasma jet (TPJ) annealing of SiO{sub 2}/SiO{sub x} /SiO{sub 2}/Si(100) stacked structure. The chemical composition of SiO{sub x} layer was controlled by changing the SiH{sub 4}, He, and O{sub 2} gas flow ratio during plasma enhanced chemical vapour deposition. The MOS capacitors showed clear hysteresis in capacitance-voltage (CV) characteristics after TPJ annealing. The hysteresis width shows maximum value when initial composition x =1.7, which shows the maximum photoluminescence (PL) intensity. The maximum hysteresis width of 6.8 V was observed with gate voltage swept between 20 and -20 V in x = 1.7 sample. The result means 7.4 x 10{sup 12} cm{sup -2} carriers are injected to or emitted from Si nanocrystals. The duration of 1 V shift in flatband voltage was {proportional_to}0.1 ms with 20 V pulse, and charged carriers were stably maintained for ...
In light of the recent rapid increase in the fossil fuel prices it is meaningful to evaluate the impact of these price changes in the economics of dual-purpose desalination projects producing electricity and fresh water simultaneously. The price of crude oil and LNG (Liquefied Natural Gas) has increased by about 200% and 100% during the past three or four years. The uranium price has also increased by nearly 500% during the same period. The purpose of this paper is to analyze and compare the economics of SMART (System-integrated Modular Advanced ReacTor) which is being developed as a small size PWR type and the LNG Combine Cycle coupled with MED (Multi-Effect Distillation) which are being acknowledged as promising energy sources for the future in Korea. The methods of analysis used in this paper are the lifetime leveled cost method for the power and water cost calculation and the power credit method for the total cost allocation. DEEP (Devaluation Economic ...
In light of the recent rapid increase in the fossil fuel prices it is meaningful to evaluate the impact of these price changes in the economics of dual-purpose desalination projects producing electricity and fresh water simultaneously. The price of crude oil and LNG (Liquefied Natural Gas) has increased by about 200% and 100% during the past three or four years. The uranium price has also increased by nearly 500% during the same period. The purpose of this paper is to analyze and compare the economics of SMART (System-integrated Modular Advanced ReacTor) which is being developed as a small size PWR type and the LNG Combine Cycle coupled with MED (Multi-Effect Distillation) which are being acknowledged as promising energy sources for the future in Korea. The methods of analysis used in this paper are the lifetime leveled cost method for the power and water cost calculation and the power credit method for the total cost allocation. DEEP (Devaluation Economic ...
Within the United Kingdom, the regulatory body having responsibility for the licensing of nuclear installations is the Health and Safety Executive (HSE). The Nuclear Installations Inspectorate (NII) is that part of HSE which administers this function. Discussions on the applicability of quality assurance (QA) to licensed sites began in 1974, and an internal report was published in 1975. In parallel with work going on at the International Atomic Energy Agency (IAEA) to prepare Quality Assurance for Safety in Nuclear Power Plants: A Code of Practice, Safety Series No. 50-C-QA, NII published a second report in 1978 entitled A Guide to the Quality Assurance Programme for Nuclear Power Plants. In 1980, the construction of advanced gas cooled reactors at Heysham 2 and at Torness was licensed, and a condition was attached to the licences requiring the licensees to submit their QA arrangements to the NII for approval. The licensees' response was to produce separate QA ...
Studies are made in this program to enhance our understanding of the role of 5f electrons in chemical bonding. Most of our studies on the macroscopic scale emphasize certain isotopes available from the National Transplutonium Production Program centered at HFIR/TRU -namely, _9_6"2"4"8Cm, _9_7"2"4"9Bk, _9_8"2"4"9Cf, _9_9"2"5"3Es, and _9_9"2"5"4Es. Particular classes of compounds, such as hydrides, chalcogenides, and pnictides are often selected for study on the basis of their utility in bringing out significant chemical differences between the lanthanides and the actinides. High temperature/high pressure experiments on actinide metals and compounds reveal characteristics about the degree of 5f electron localization as a function of atomic number in the series. Magnetic properties of metals and compounds are investigated using ultra-sensitive methods and hydration numbers of ions in solution are investigated by neutron scattering at HFIR. As a result of a recently ...
This paper assesses the effects of including carbon dioxide capture and storage (CCS) damage costs in a long-term energy scenario analysis for Europe. An external cost sensitivity analysis is performed with a bottom-up energy technology model that accounts not only for CCS technologies but also for their external costs. Our main conclusion is that in a business-as-usual scenario (i.e. without climate change intervention or externality internalisation), CCS technologies are likely to be deployed at least to some extent, mainly in the power generation sector, given the economic benefits of opportunities such as enhanced coal bed methane, oil and gas recovery. Under a strict climate (CO{sub 2} emissions) constraint, CCS technologies are deployed massively. With the simultaneous introduction of both CO{sub 2} and CCS taxation in the power sector, designed to internalise the external atmospheric and geological effects of CO{sub 2} emissions and ...
Geological carbon dioxide capture and storage (CCS) is currently seriously considered for addressing, in the near term, the problem of climate change. CCS technology is available today and is expected to become an increasingly affordable CO2 abatement alternative. Whereas the rapidly growing scientific literature on CCS as well as experimental and commercial practice demonstrate the technological and economic feasibility of implementing this clean fossil fuel option on a large scale, relatively little attention has been paid so far to the risks and environmental externalities of geological storage of CO2. This paper assesses the effects of including CCS damage costs in a long-term energy scenario analysis for Europe. An external cost sensitivity analysis is performed with a bottom-up energy technology model that accounts not only for CCS technologies but also for their external costs. Our main conclusion is that in a business-as-usual scenario (i.e. without climate change intervention ...
We have observed the CH_3OH J = 2-1, SiO J = 2-1, C"3"4S J = 2-1, H"1"3CO"+ J = 1-0, HN"1"3C J = 1-0, CCH N = 1-0, OCS J = 8-7, and SO J_N = 2_2-1_1 lines toward 20 massive clumps, including Midcourse Space Experiment (MSX) 8 #mu#m dark sources (infrared dark clouds) and MSX 8 #mu#m sources, by using the Nobeyama Radio Observatory 45 m telescope. We have found that the velocity widths of the CH_3OH and C"3"4S lines are broader than those of the H"1"3CO"+ line in the MSX dark sources. On the other hand, they are comparable to the velocity width of the H"1"3CO"+ line in the MSX sources. In addition, the [SiO]/[H"1"3CO"+] abundance ratio is found to be enhanced in the MSX dark sources in comparison with the MSX sources. These results suggest that shocks caused by interaction between an outflow and an ambient dense gas would have substantial impact on the chemical composition of the MSX dark sources. The velocity widths of the CH_3OH and C"3"4S ...
Accurate modeling of the enhanced diffusion of boron during rapid thermal annealing has been accomplished by incorporating the effects of extended defect formation and annealing on enhanced diffusion into a multizone, semiempirical model. The multizone model divides the implant profile into three zones defining regions of different defects and diffusion enhancements. The model also contains the initial enhanced diffusion and the transient diffusion effects associated with the dissolution of defect clusters and the annealing of extended defects, respectively. The saturation time for transient-enhanced diffusion contains an exponential function of implant dose in order to model the increase in point defect generated with higher implant dose. As a result, the model accurately simulates the boron diffusion profile over a wide range of implant doses and also shows the immobile boron peak ...
This article puts the case for coal fired combined cycle gas turbine (CCGT) power plants. The need to gasify the coal for the CCGT, use of fluidised bed combustors or gasification systems, the difference in prices of coal and natural gas, and coal and natural gas reserves are discussed. (UK)
Natural gas is essential to the world economy. Gas now accounts for almost a quarter of OECD primary energy requirements and is expected to become the second most important fuel in the world in the next decade. Industrial and residential consumers increasingly rely on natural gas to keep their houses warm, their lights on and their factories running. Meanwhile the gas industry itself has entered a new phase. Where gas used to be restricted to regional markets, it is now increasingly traded on a global scale. While gas production and transport requires long-term investment, now it is optimised on a short-term basis. Demand continues to grow, but local gas production has become much more expensive. How should we react? How will demand be satisfied? What changes are required to promote flexibility and trade? What are the implications for ...
Mist eliminators for flue gas desulphurisation units remove liquid droplets entrained in the flue gas leaving the SO/sub 2/-absorber vessels. The commercial designs currently available are described.
The purpose of this project was to build a long-range, parallel hybrid gas/electric vehicle capable of driving beyond the communter capabilities of series hybrid vehicles. It was envisioned that since the gas engine would be able to independently propel t...
Radon-222 has been measured in natural gas produced from experimental geopressured-geothermal test wells. Comparison with published data suggests that while radon activity of this unconventional natural gas resource is higher than conventional gas produced in the gulf coast, it is within the range found for conventional gas produced throughout the US. A method of predicting the likely radon activity of this unconventional gas is described on the basis of the data presented, methane solubility, and known or assumed reservoir conditions of temperature, fluid pressure, and formation water salinity.
BackgroundEmphysematous cholecystitis is a variant of acute cholecystitis which is generally caused by gas-forming organisms. Emphysematous cholecystitis may cause gas spreading...Full Text Available
... Accession Number : ADD135818. Title : Performance of Titanium in Flue Gas Desulfurization Scrubber Systems,. Descriptive Note : Journal Article,. ...
The properties of the ideal gas of classical (nonquantum) tachyons are considered. Starting from the definition of thermodynamic functions for this system, it may be found that tachyons and bradyons gases are similar. (AA).
A new surveillance system for Oil-Filled cable, which can provide continuous monitoring, using a newly developed optical gas sensor that can detect the concentration of the gas dissolved in the oil with extremely high sensitivity has been developed. It was proved that the degree of deterioration of the insulating oil can be detected by measuring C{sub 2}H{sub 2} and CH{sub 4} by investigating the relation between the degree of deterioration and amount of combustible gas generated. In order to detect extremely small amounts of gas, a new gas detecting method using absorption line of the gas using a frequency modulated technique has been developed. The gas detection ability was also confirmed by examination using a 66 kV of cable and the possibility of detection at an early stage is expected.
Rapid technology improvements, resulting in high efficiency, emissions reduction and low generation cost, are making gas turbines the generation technology of choice despite some recent reliability problems. The basic reason for the dominance is high efficiency. The rapid pace of gas-turbine technology improvement in the 1990s drove combined-cycle thermal efficiency to nearly 60 percent with natural gas as the fuel. It will probably go even higher after the year 2000. In addition, the gas-fired combined cycle is a bargain. With natural gas prices where they are right now, it is the least-cost generation operation for power producers with access to gas. Many will replace older, high-cost power plants with new gas-fired combined cycle power plants.
The oxygen production of a photosynthetic gas exchanger containing Chlorella pyrenoidosa (1% packed cell volume) was measured when various concentrations of carbon dioxide were present...Full Text Available
The purpose of this publication is to provide a better understanding of flue gas desulfurization. It provides brief answers to questions concerning its applicability, cost, effectiveness, and operation.
This bibliography contains 3920 references including abstracts, to information on the technology of flue gas desulfurization and denitrification. These references and others are included in the Department of Energy's Energy Data Base (EDB) through Decembe...
Tests to measure the maximum horsepower of commercial vehicles converted for use with natural gas fuel indicate a reduction of approximately 20% in horsepower compared with gasoline-driven vehicles. This reduction in horsepower resulting from the use of gas is due basically to the lower thermal efficiency of the cycle of natural gas compared with that of gasoline and to its lower volumetric efficiency, since natural gas is injected into the combustion chamber in gaseous form, unlike gasoline, in which part of the fuel entering the cylinder is in the liquid phase. Natural gas used as a fuel generates lower quantities of air pollutants, particularly unburned hydrocarbons (HCs) and carbon monoxide (CO). Despite the downside of reduced horsepower, the use of natural gas as a fuel for automotive vehicles equipped with Otto-cycle engines is economically viable owing ...
A critical research priority for our field is to develop treatments that enhance cognitive functioning in schizophrenia and thereby attenuate the functional losses associated with the illness. In this...Full Text Available
DNA transposons are efficient tools in transgenesis and have therefore become popular in the analysis of the regulatory genome in vertebrates via enhancer trap screens. Here, I discuss recent progress...Full Text Available
Pooling and synthesizing signals across different senses often enhances responses to the event from which they are derived. Here we examine whether multisensory response enhancements are attributable...Full Text Available
Resonance Raman spectra are reported for the organometallic phenyl-FeIII complexes of horse heart myoglobin. We observed the resonance enhancement of the ring vibrational modes of the bound phenyl group....Full Text Available
Convection-enhanced delivery (CED) has emerged as a promising method of targeted drug-delivery for treating central nervous system (CNS) disorders, but the influence of brain structure on infusate...Full Text Available
How transcription factors interpret the cis-regulatory logic encoded within enhancers to mediate quantitative changes in spatiotemporally restricted expression patterns during animal...Full Text Available
This report results from a contract tasking Eindhoven University of Technology as follows: The contractor will investigate the plasma treatment of surfaces and plasma enhanced deposition using EUT's cascade arc source as the basis for this effort.
The overall objective of this project was to use molecular genetics to develop strains of bacteria with enhanced ability to remove sulfur from coal, and to obtain data that will allow the performance and economics of a coal biodesulfurization process to be predicted. (VC)
Established Investigators (K18) (PAR-09-090) NIH: Career Enhancement Award for Stem Cell Research (K18) (PA-09-110) NIDCD: NIDCD Research Career Enhancement Award for Established...
SummaryConvection-enhanced delivery (CED) of substances within the human brain is becoming a more frequent experimental treatment option in the management of brain tumors, and...Full Text Available
BackgroundPolyadenylation of RNA has a decisive influence on RNA stability. Depending on the organisms or subcellular compartment, it either enhances transcript stability or targets...Full Text Available
Background:There is a need for simple imaging parameters capable of predicting therapeutic outcome.Methods:This retrospective study analysed 50 patients...Full Text Available
AIM: To improve the diagnosis of heterotopic pancreas by the use of contrast-enhanced computed tomography (CT) imaging and CT virtual endoscopy (CTVE).METHODS: A total of six patients with heterotopic...Full Text Available
Convection-enhanced drug delivery (CED) is a novel approach to delivering drugs into brain tissue. Drugs are delivered continuously via a catheter, enabling large volume distributions of high drug concentrations...Full Text Available
PurposeA major obstacle in glioblastoma (GBM) therapy is the restrictive nature of the blood-brain barrier (BBB). Convection-enhanced delivery (CED) is a novel method...Full Text Available
High-resolution spectroscopy of 13 bright red giants and Ba stars shows selective enhancement of Ba in three of them, HD 65699 (Ba 2), ..cap alpha..TrA (K4 III), and epsilonPeg (K2 Ib). Infrared spectra available for HD 65699 show that Sr is enhanced, too. This selective enhancement is discussed in terms of a modified s-process which converts some of the pre-existing r- and s-process matter into the magic nuclei /sup 88/Sr and /sup 138/Ba.
This paper describes Z-contrast scanning transmission electron microscopy used to study the connection between dopant precipitation and phase transformation in high dose In"+ and Sb"+ implanted Si. In the case of In, the observations confirm a heterogeneous nucleation model. Images of the precursor precipitates give the first measurement of the diffusion coefficient in amorphous Si, with an enhancement of 10"7 over tracer crystalline values. With Sb"+ implants enhanced homogeneous nucleation is observed. The connection between these results and the transient enhanced diffusion observed in crystallized Si is discussed.
... The realization of directional audio technology in the cockpit may reduce visual workload, enhance the presentation of flight and threat information ...
... Uninterrupted access to and use of critical infrastructure in the Arabian Gulf region are key to the successful prosecution of the Global War on Terror ...
The natural gas industry has proposed an increase in the DOE gas R&D budget from about $100 million to about $250 million per year for each of the next 10 years. The proposal includes four programs: natural gas supplies, fuel cells, natural gas vehicles and stationary combustion systems. This paper is a qualitative assessment of the gas industry proposal and recommends a natural gas R&D strategy for the DOE. The methodology is a conceptual framework based on an analysis of market failures and the energy policy objectives of the DOE`s (1991) National Energy Strategy. This framework would assist the DOE in constructing an R&D portfolio that achieves energy policy objectives. The natural gas supply program is recommended to the extent that it contributes to energy price stability. Stationary combustion programs are supported on ...
Prepared to make housing project managers, maintenance engineering staff, and designers and architects of HUD - assisted and HUD - insured housing projects and mobile home parks aware of their responsibilities under the Natural Gas Pipeline Safety Act, this handbook provides technical guidance for the reduction of gas leaks and the handling of gas leak incidents in residential areas. The hazards of natural gas, concern over gas safety in residential areas, applicable codes and standards, and sources of information and help are reviewed, along with maintenance and engineering considerations relating to gas pipe failures, the detection of gas leaks, appliance servicing, and pipe installation, repair, and replacement. Housing management considerations are also examined, with attention to recordkeeping and reporting, emergency contingency ...
Gas Supplies of Interstate Natural Gas Pipeline Companies 1987 was prepared by the Reserves and Natural Gas Division, Office of Oil and Gas, Energy Information Administration (EIA). The publication provides information on the total reserves, production, and deliverability capabilities of the 87 interstate pipeline companies required to file the Federal Energy Regulatory Commission (FERC) Form 15, ''Interstate Pipeline's Annual Report of Gas Supply.'' This publication is the 25th in a series of annual reports on the total gas supplies of interstate pipeline companies since the inception of individual company reports to the Federal Power Commission (FPC) in 1964 for report year 1963. This publication provides information on the interstate pipeline companies' supply of natural gas during ...
First results on the effects of strain on transient enhanced diffusion and deactivation of As-implanted ultrashallow junctions are presented. A significant effect of strain on the magnitude and timescale of transient enhanced diffusion is observed, which is consistent with the stabilization of interstitial-type defects by tensile strain. Our results show no significant impact of strain on As electrical activity during the deactivation timescale accessed in this study.
Recently, Wang et al. proposed a three-party simultaneous quantum secure direct communication (3P-SQSDC) scheme with EPR pairs, which enables three involved parties to exchange their secret messages simultaneously by using an EPR pair. This work proposed an enhancement on Wang et al.'s scheme. With the enhancement, the communications in the improved 3P-SQSDC can be paralleled and thus improves the protocol efficiency.
The transient enhanced diffusion in crystalline silicon implanted with dopants ad followed by high temperature annealing to activate the dopants is introduced. The physical mechanisms of transient enhanced dopant diffusion are then reviewed together with a short introduction to the proposed suppressing methods. Finally, the perspectives with using high energy heavy ions in this field are briefly discussed
Transient enhanced diffusion in boron-implanted silicon is interpreted as being due to the fact that during rapid thermal annealing a relaxation process takes place, associated with quasi-chemical reactions including defects. A simple analytical model makes it possible to describe the annealing mechanism on a microscopic scale in terms of reaction-diffusion processes. The measured dependences of the boron diffusion coefficient of the enhanced diffusion on time, temperature and implantation energy are satisfactorily explained. (author).
Transient enhanced diffusion in boron-implanted silicon is interpreted as being due to the fact that during rapid thermal annealing a relaxation process takes place, associated with quasi-chemical reactions including defects. A simple analytical model makes it possible to describe the annealing mechanism on a microscopic scale in terms of reaction-diffusion processes. The measured dependences of the boron diffusion coefficient of the enhanced diffusion on time, temperature and implantation energy are satisfactorily explained. (author).
A passive heat exchange enhancement structure which operates by free convection includes a flat mounting portion having a plurality of integral fins bent outwardly from one side edge thereof. The mounting portion is securable around a stovepipe, to a flat surface or the like for transferring heat from the pipe through the fins to the surrounding air by rotation-enhanced free convection.
Full text: Chemical-technology approaches allowing to intensification the prevention processes of gas hydrates formation at motion of gas-liquid stream of natural gas in system natural gas well - gas wire have been worked up. Technological regimes of treatment of gas stream have been determined. Linear correlation dependences inhibitor electrolytes contained hydrated ions with different ion radii and charges of subgroups of alkali elements with one - type electron configuration were obtained. Important physico-chemical parameters of electrolytes have been determined: activity; coefficients of activity, viscosity, diffusion; density; heat capacity; heat conductivity; surface tension and freezing-point. The features of continuous influence of inhibitory factors on process of gas flow at low temperatures and relatively high pressure differences ...
The passive continental margin in the northern South China Sea is a weakly active area. It has been found to be favorable for large gas field development and also to be profitable for gas hydrate. The active faults, diapir structure, slump deposits, faults break of slopes, gas chimneys and sandstone of submarine fan, control the concentration of gas hydrate. Gas chimneys are widely distributed in the northern South China Sea. They supply the pathway for migration of deeper gas to gas hydrate stability zones especially in the basin of tectonic inactive zone. This paper discussed the geological structures of gas hydrate occurrence in gas fields and presented a detailed analysis of gas chimneys within the northern slope of the South China Sea. The paper described the geological ...
The paper deals with a model in which the motion of a gas in plasma accerators and high-curent discharges in the present of a skin effect is treated as expulsion by a 'magnetic piston' under the action of surface current flow. Specifically examined is the situation where the initial gas pressure is negligible in comparison with the magnetic pressure, and the motion of the gas may be treated as a self-simulating one. A system of hydrodynamic equations of the problem is derived and integrated by Adam's method. Results are plotted and discussed.
Gas contaminated with at least one noxious component, such as SO/sub 2/, HF or NOx, is scrubbed with a clear, calcium-containing, initially-basic washing liquid which also comprises the anion of a strong inorganic acid, that of a polybasic carboxylic acid and, optionally, that of a monobasic carboxylic acid. Apparatus is provided for scrubbing the gas, oxidizing produced calcium bisulfite to calcium sulfate, separating out and removing solids, and recirculating clarified liquid for scrubbing contaminated gas.
The Rayleigh scattering length has been calculated for rare-gas liquids in the ultraviolet for the frequencies at which they luminesce. The calculations are based on the measured dielectric constants in the gas phase, except in the case of xenon for which measurements are available in the liquid. The scattering length mayplace constraints on the design of some large-scale detectors, using uv luminescence, being proposed to observe solar neutrinos and dark matter. Rayleigh scattering in mixtures of rare-gas mixtures is also discussed.
The fission gas xenon bonded in bubbles, in pore, and in the lattice of mixed carbide fuels is measured by electron-probe microanalysis. Radial xenon distribution and release curves are determined and are calibrated by gas chromatography of the bonded fission gas and by burnup analysis in the respective pin sections of the irradiation experiments FR2 6A and 6C, Mol 11/K 2, and DFR 330/1. The results are correlated to the microstructure of the fuel, bonding medium, temperature, and burnup. (Auth.).
Analysis of the coke gas combustion porcess is presented. Standard kinetic relationships were utilized. Calculations were performed for coke gas with high and low content of H/sub 2/ and for blasting air 20 and 100/sup 0/C. Temperature relationships, composition of gas combustion products and release of nitrogen oxides were determined. Results are analyzed which will make it possible to control the composition of combustion products.
This thesis dealt with the metal-organic gas phase epitaxy with nitrogen as carrier gas. For this first by means of three-dimensional modelings of the epitaxy process the influence of the carrier gas on the processes was explained. The optimization of the growth parameter for the whole light-emitting-diode structure in double-hetero arrangement resulted that an a temperature of 770 C and a V/ III-ratio of 150 layers with a high crystal quality could be reached.
Plasma with a gas temperature below room temperature is not yet fully understood although it is expected to be an attractive tool for applications to material processing. In the present work, gas-temperature-dependent generation of a cryoplasma jet was studied. So far, we have generated a helium cryoplasma jet (296-5 K) under atmospheric pressure. At gas temperatures below 20 K, the helium excimer, He2, was observed clearly from by optical emission spectroscopy.
The gas composition of recent thermal waters is in perfect conformity with their geologic-tectonic positions. The composition of gas-liquid inclusions in the basic-hyperbasic xenoliths of basaltoid lavas depends on the depth from which xenoliths are supplied. (The depth is determined by using the methods of geological thermobarometers). By comparing available data the conclusion was drawn that the gas compositions of thermal waters reflect the depth of generation of deep fluid which heats them and depends on the penetration depth of the fluid-conducting fissure zones.
Spark ignition internal combustion engines perform satisfactorily when the fueled with biomass producer gas from a fluidized bed gasifier. Although power output is reduced compared to natural gas levels, full power recovery can be achieved with a relatively low level of supercharging. Important considerations are an adequate fuel delivery system and adquate gas cleaning. ref.
... harassment, incidental to construction and operation of an offshore liquefied natural gas (LNG) facility. Under the Marine Mammal Protection ... ...
Reducing implant energy is an effective way to eliminate transient enhanced diffusion (TED) due to excess interstitials from the implant. It is shown that TED from a fixed Si dose implanted at energies from 0.5 to 20 keV into boron doping-superlattices decreases linearly with decreasing Si ion range, virtually disappearing at sub-keV energies. However, for sub-keV B implants diffusion remains enhanced and x{sub j} is limited to {ge} 100 nm at 1,050 C. The authors term this enhancement, which arises in the presence of B atomic concentrations at the surface of {approx} 6%, Boron-Enhanced-Diffusion (BED).
The primary objective of this study is to assess the oil and gas potential of the West Siberian Basin of Russia. The study does not analyze the costs or technology necessary to achieve the estimates of the ultimate recoverable oil and gas. This study uses reservoir data to estimate recoverable oil and gas quantities which were aggregated to the field level. Field totals were summed to a basin total for discovered fields. An estimate of undiscovered oil and gas, from work of the US Geological Survey (USGS), was added to give a total basin resource volume. Recent production decline points out Russia`s need to continue development of its discovered recoverable oil and gas. Continued exploration is required to discover additional oil and gas that remains undiscovered in the basin.
Details of a 1 day conference designed to create more efficient interactions between the gas supply and electricity systems in Ontario and new models for gas supply and the electricity system were presented. Market efficiency, generators' perspectives on critical gas issues, an overview of the North American gas and an outline of issues concerning Ontario were discussed. A natural gas industry forecast and issues concerning marketers and producers were presented. The terms on which gas is bought and sold were discussed. Regulatory tools, cost allocation and issues relating to unbundling were also presented. Infrastructure needs were reviewed, as well as basic market structures. It was suggested that appropriate commercial service options need to be developed and approved, including cross-utility services.
The Department of Energy has proposed a rulemaking process to set minimum standards for the efficiency of gas ranges under the National Appliance Energy Conservation Act (NAECA). The Gas Research Institute is compiling information on annual household range gas usage in order to prepare a response to the proposed rulemaking. The data base from the Northern Illinois Gas residential load study provides recent information (data taken from 1990 through 1992) over a comprehensive study of household types and appliance and user characteristics (150 variables noted for each household). The stated Objective is to study the Northern Illinois Gas residential load study data base and to evaluate its effectiveness in predicting annual household gas usage.
Research was performed to assess the feasibility of barrier membrane substances, for use within mining or associated high risk environments, in restricting the diffusion transport of radon gas quantities. Specific tests were conducted to determine permeability parameters of a variety of membrane materials with reference to radon flow capabilities. Tests were conducted both within laboratory and in-situ emanation environments where concentrations and diffusion flows of radon gas were known to exist. Equilibrium radon gas concentrations were monitored in initially radon-free chambers adjacent to gas sources, but separated by specified membrane substances. Membrane barrier effectiveness was demonstrated to result in reduced emanation concentrations of radon gas within the sampling chamber atmosphere. Minimum gas concentrations were evidenced where the barrier ...
The light gain due to S/sub 2/ molecules in a supersonically cooled gas mixture is calculated. The S/sub 2/ molecules formed due to the recombination of the sulfur atoms, and the combustion gas mixture was preheated in a precombustion chamber. Optimal gas flow and nozzle parameters are found which correspond to the highest possible light gain using Cs/sub 2/-Ar and S/sub 2/-Ar gas mixtures. The steady state gas flow in the nozzle was calculated, taking into account the chemical reactions in the one-dimensional approximation. It is shown that the maximum gain values vary in the 0.0001-0.002 range for gas pressures in the precombustion chamber in the range 10-100 atm. The optimal initial relative concentration of Cs/sub 2/ molecules and S/sub 2/ molecules are given. 32 references.
The use of natural gas in China is still relatively immature, as gas production only supplies a low percentage of the domestic energy system. In contrast, Chinese economy mainly relies on coal with a 67% share of the total primary energy supply. The environmental impact from this high coal dependence is significant and planners have sought for cleaner energy sources. Natural gas is both cleaner and generally more efficient than coal and gas consumption is rising quickly due to these facts. The growth tendency indicates that natural gas will become an important substitution for coal in some parts of the Chinese primary energy consumption. To quantify this tendency, this paper uses a system dynamics model to create a possible outlook. The results show that the gas consumption in China will c...
Biomass gasification provides the potential to efficiently and economically produce a renewable source of a clean gaseous fuel suitable for power generation or synthesis gas (syngas) applications. An important side benefit of the use of biomass is the effective minimization of the primary greenhouse gas, carbon dioxide (CO{sub 2}), by providing a means to close-loop the CO{sub 2} cycle. However, high molecular weight hydrocarbon constituents (tar) in the product gas from gasification can complicate the downstream uses of the gas. This paper discusses both the development of a low cost, disposable catalyst system that can eliminate these heavy hydrocarbons from the gas and the use of the catalyst in conjunction with the Battelle high-throughput gasification process for power generation and synthesis applications. (author)
The presence of an extraneous light gas must be taken into account in consideration of centrifugal separation of uranium isotopes, when there is inevitable leakage of such a gas through the gas sealant and/or leaking in from the atmosphere. Consideration is first given to the influence of the presence of the light gas on the maximum separative power. Then the basic equation for isotope separation containing a light gas is derived from Hirschfelder's diffusion equations. This equation is solved and the separative performance is expressed in terms of the shape factor and reflux parameter. The formulas for expressing the flow configurations of the gases are obtained for a simple model in which inflow and outflow prevail throughout the centrifuge. The corresponding equation for a model in which the gases flow in two concentric thin streams is also derived. It is concluded that the ...
A patent is claimed for a process by which a low-hydrogen gas containing at least 90 percent by volume of methane which is suited for natural gas substitution is produced by transformation of vaporizable hydrocarbons with the aid of steam in the presence of a catalyst containing nickel, at temperatures of 350 to 600/sup 0/C and at increased pressure. Hydrocarbons and steam are supplied to the reaction in mixed form with recycle product gas. Per kilogramme of hydrocarbons to be converted in the high btu gas reactor, less than 1 kilogramme of fresh steam is needed. High btu gas is fed back from the high btu gas reactor to the input end of the same via a gas cycle comprising a cooler, a carbon dioxide absorption device, and a saturator. Between the carbon dioxide absorption device and the saturator a product gas is branched ...
The performance of the gas-jet transport system coupled to the RIKEN gas-filled recoil ion separator GARIS was investigated using 255No produced in the 238U(22Ne, 5n)255No reaction. Alpha particles of 255No separated with GARIS and transported by the gas-jet system were measured with a rotating wheel apparatus for ? spectrometry under low background condition. The high gas-jet efficiencies of about 75% were independent of the recoil ranges of 255No in the gas-jet chamber. The present results suggest that the GARIS/gas-jet system is a promising tool for the next-generation superheavy element chemistry: (1) the background radioactivities of unwanted reaction products are strongly suppressed, (2) the intense beam is absent in the gas-jet chamber and hence the high gas-jet efficiency is achieved, and (3) the beam-free ...
The purpose of this study is to identify the radiative heat transfer augmentation by a coaxial cylinder introduced in the infinite cylindrical pipe enclosing a participating gas. The gas is either a mixture of water vapor and carbon dioxide or gray. The gas is assumed to be homogeneous at a constant temperature, and has a refractive index of unity. All of the surfaces are opaque and gray, diffusely emitting and reflecting at a constant temperature. The effect of system diameter, diameter ratio, wall emittances, gas and surface temperatures, mixture component on heat transfer augmentation are studied by using the zone method with participating gas radiative properties evaluated from the weighted sum of gray gases model. From the radiative equilibrium condition, the installed wall temperature is formulated and calculated by the iteration method. If the medium is a gray ...
Purpose: To evaluate contrast-enhanced CT scan in the diagnosis of intrahepatic cholangiocarcinoma by correlating the CT appearance with pathologic specimens. Materials and methods: Twenty-eight patients with pathologically proven intrahepatic cholangiocarcinoma were examined. Unenhanced abdominal CT study were performed in 28 patients; conventional contrast-enhanced CT in 27 patients. Enhanced CT scan including fast injection, fast scan and delayed scan at the largest section of the lesion was done in 7 patients. Contiguous 10 mm CT scans of the surgical specimens were also obtained in 8 patients. The preoperative and specimen CT scans in these 8 patients were compared with the corresponding pathological sections. A total of 103 areas of the pathological sections was compared with the CT appearances. Results: All lesions contained areas of delayed contrast enhancement and/or no ...
Pressurized fluidized bed combustion (PFBC) is an emerging coal-fired, combined-cycle power generation technology nearing commercial status through several operating and planned demonstration plants throughout the world. Current-generation PFBC plants use ``ruggedized`` gas turbines that can tolerate dust loading common with conventional cyclone gas cleaning. The next generation of PFBC will apply advanced hot gas cleaning systems that will reuse the dust loading to low levels acceptable to high performance, industrial gas turbines. These advances should result in performance and cost advantages. This article examines the demonstration of PFBC technology at Tidd power station.
Sigma 1) examines ways to reduce the number of breakdowns of pressure-regulating stations and to minimize the energy consumed in warming the gas, 2) determines the optimal gas temperatures upstream from the pressure reduction, and 3) shows the dependence of energy consumption upon the water dewpoint. The method of calculating the optimal input temperature relies on Mollier's diagram. Tables and nomographs for natural gas and water dewpoint at 19/sup 0/F and 580 psi (-7/sup 0/C and 4 MPa) are useful in achieving the desired gas temperatures. Heating the regulators' control valves is important.
A study was conducted to examine the energy consumption in existing and new hog farming facilities and to analyse the potential for increased natural gas use in the Saskatchewan hog industry. Existing heating/cooling, ventilation and feed mill equipment choices offer possibilities for running on electricity, natural gas or propane. Energy costs are lowest when natural gas is used. To put the study in context, an overview of the Saskatchewan hog industry was provided. The potential increase in natural gas use in hog production by year 2005 was estimated. 10 refs., 6 tabs., 8 figs.
Increased use of natural gas has positive effects for the environment and the climate, because it primarily replaces petroleum products. Moreover, the natural gas does not pose a threat to bio fuel in Norway. But introducing CO2 taxes on natural gas will significantly increase the emission of greenhouse gases, concludes a report conducted by Norsk Energi (Norwegian Energy) on behalf of Norsk Naturgassforening (Norwegian Natural Gas Association) and Norsk Gassforum (Norwegian Gasforum). A brief presentation of the main conclusions in the report (ml)
National Power is building its first gas turbine combined cycle power station at Killingholme, situated to the south of the River Humber in the East of England. NEI ABB Gas Turbines Limited was awarded the turnkey contract in July 1990 to build a nominal 650 MW combined cycle power station based around three Asea Brown Boveri GT13E gas turbines. The project is outlined in this article. The plant is due for completion in July 1993. (author)
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.
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 waste tail gas fuel emitted from refinery plant in Taiwan e.g. catalytic reforming unit, catalytic cracking unit and residue desulfurization unit, was recovered and reused as a replacement fuel. In this study, it was slowly added to the fuel stream of a heater furnace to replace natural gas for powering a full-scale distillation process. The waste tail gas fuel contained on average 60 mol% of hydrogen. On-site experimental results show that both the flame length and orange-yellowish brightness decrease with increasing proportion of waste gas fuel in the original natural gas fuel. Moreover, the adiabatic flame temperature increases as the content of waste gas fuel is increased in the fuel mixture since waste gas fuel has a higher adiabatic flame temperature than that of natural gas. The complete replacement of natural ...
This paper provided an outline of the Canadian natural gas commodity market and a forecast for Canadian natural gas supply and prices for the 2007 winter heating season. Since 2001, steady demand growth and slow supply growth have contributed to higher North American natural gas commodity prices. The loss of natural gas supply due to hurricanes pushed North American natural gas commodity prices to record levels in 2005. Canadian natural gas production levels currently exceed domestic gas consumption. In 2005, Canada produced 16.5 billion cubic feet per day of marketable natural gas. Approximately 45 per cent was consumed domestically, and the remainder was exported to the United States. Despite high levels of drilling activity, production of natural gas from western Canada has flattened out since ...
The proton beam has an advantage of the sharp dose falloff in dose distribution called Bragg peak while conventional radiation therapy modalities such as photons exhibit considerable amount of exit dose. To take advantage of this property it is important to know the exact location of the distal dose falloff. An error can cause overdose to the normal tissue or underdose to the tumor volume. The only way of finding out the dose distribution in-situ in particle therapy is to measure the gammas produced by nuclear reactions with tissue materials. Two kinds of gammas can be used: one is prompt gamma and the other is coincident gamma from the positron-emission isotopes. We chose to detect prompt gammas, and developed a prompt gamma scanning system (PGS). The proton beams of the proton therapy facility at National Cancer Center were used. The gamma distribution was compared to the dose distribution measured by an ionization chamber at three different energies of 100, 150, 200 MeV's. ...
An efficient method of hydrogen storage in nano-porous carbons is its reversible sorption by electrochemical decomposition of a KOH water solution according to the following equation: C + xH{sub 2}O + xe{sup -} {yields} (CH{sub x}) + xOH{sup -} where (CH{sub x}) stands for the hydrogen inserted into the nano-porous carbon during charging and oxidized during discharging. Although various carbon materials have been investigated as hydrogen adsorbents, the information about the storage mechanism as well as the nature of the hydrogen/carbon interaction is still not sufficient. In order to extend the understanding of the process, carbon samples charged electrochemically were investigated by temperature programmed desorption (TPD). The nature of the hydrogen/carbon interaction was studied by electrochemical analysis at different temperatures. The TPD experiments consist of heating the samples from room temperature to 950 C and of quantitative analysis by On-line mass spectrometry, the ...
The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which uses petroleum coke to produce at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals using ChevronTexaco's proprietary gasification technology. The objective of Phase I is to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD&T) Plan to mitigate technical risks and barriers; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD&T Plan to enhance the development and commercial acceptance of coproduction technology. The objective of Phase III is to develop an engineering design package and a financing and testing plan for an EECP located at a specific site. The project's intended ...
Large volumes of woodwaste disposal by incineration in a number of wigwam burners are contributing to pollution problems in Williams Lake, British Columbia. In 1985, the latest year for which data are available, total woodwaste production was about 800 million bd ft equivalent; only about 14% of this was used for energy recovery. In addition, about 66,000 m/sup 3/ of waste was sent to landfills after open burning. The characteristics of the local woodwaste are summarized, and available conversion technologies and the potential application of their products are reviewed. These include direct combustion, pyrolysis, gasification, liquefaction, and densification, for use in power generation, cogeneration, and the manufacture of saleable products. Environmental and legal aspects of woodwaste utilization are also outlined. Finally, options for reducing pollution from existing burners are reviewed. One option is the upgrading of existing burners; however, it is noted that ...
The integrated-gasification combined-cycle (IGCC) process is an emerging technology that utilizes coal for power generation and production of chemical feedstocks. However, the process generates large amounts of solid waste, consisting of vitrified ash (slag) and some unconverted carbon. In previous projects, Praxis investigated the utilization of {open_quotes}as-generated{close_quotes} slags for a wide variety of applications in road construction, cement and concrete production, agricultural applications, and as a landfill material. From these studies, we found that it would be extremely difficult for {open_quotes}as-generated{close_quotes} slag to find large-scale acceptance in the marketplace even at no cost because the materials it could replace were abundantly available at very low cost. It was further determined that the unconverted carbon, or char, in the slag is detrimental to its utilization as sand or fine aggregate. It became apparent that a more ...
The VerTech Pit Method for wet oxidation of municipal sewage sludge offers an ecologically and economically advantageous alternative for dealing with sewage and special sludges. Europe`s first commercial plant has now been commissioned in Apeldoorn in the Netherlands following industrial-scale trials in the USA. Up to its present stage of operation the plant has achieved a high degree of reduction of solid residues and a favourable resource and environmental profile, thus impressively confirming earlier results. It is amply in keeping with the landfill criteria laid down in the Household Waste Technical Code. Furthermore, the potential sludge throughput has been found to exceed the projected value. [Deutsch] Mit dem VerTech-Tiefschachtverfahren zur Nassoxidation kommunaler Klaerschlaemme steht ein alternatives Verfahren zur Behandlung von Klaer- und Sonderschlaemmen zur Verfuegung, das oekologische und wirtschaftliche Vorteile aufweist. Nach grosstechnischer ...
The generation of industrial solid wastes containing leachable species of environmental concern is a problem for developing and developed nations alike. These materials arise from direct processing of mineral ores, from production of metals and minerals, from manufacturing operations, and from air and water pollution treatment processes. The general characteristics that make these wastes intractable is that their content of hazardous species is not easily liberated from the waste yet is not bound so tightly that they are safe for landfill disposal or industrial use. The approach taken in this work is a thermal treatment that separates the inorganic contaminants from the wastes. The objective is to provide recovery and reuse of both the residual solids and liberated contaminants. The results from operating this technique using two very different types of waste are described. The reasons that the process will work for a wide variety of wastes are explored. By using ...
This conference provided a forum for more than 500 delegates from industry, government universities and research centres to share their professional knowledge on research and development that affects all sectors of geotechnical engineering, applied geology and hydrogeology. Accomplishments in the geoenvironmental field were also highlighted. The geotechnical sessions were entitled: pile foundations and load testing; excavations and special foundation issues; reinforced soil and soil-structure interactions; advances in modelling, constitutive issues; advances in modelling, consolidation and other applications; advances in modelling, discrete elements and slope stability; embankments and dams; landfills and barriers; fundamental soil mechanics; soil mechanics and ground movement; GIS and remote sensing; landslides and slopes; cone penetration tests and liquefaction assessment; rock mechanics; engineering geology; geoenvironmental sustainability; oilsand and petroleum ...
Pollutants resulting from the management of solid waste have been shown to affect the air, land, oceans, and waterways. In addition, solid wastes have other, more indirect impacts such as reduction in feedstocks of natural resources, because useful materials are disposed of rather than recycled. The objective of this study is to evaluate solid waste management practices that have negative implications on the global environment and develop recommendations for reducing such impacts. Recommendations identifying needed changes are identified that will reduce global impacts of solid waste practices in the future. The scope of this study includes the range of non-hazardous solid wastes produced within our society, including municipal solid waste (MSW) and industrial solid waste (ISW), as well as industry-specific wastes from activities such as construction, demolition, and landclearing. Most solid waste management decisions continue to be made and implemented at very local levels, ...
Carbonyl compounds constitute an important reactive class of non methane volatile organic compounds. They can be emitted directly to the atmosphere from primary sources such as combustion engines, landfills and wastewater surfaces or as secondary products by the photochemical oxidation of hydrocarbons and other volatile organic compounds 1-3. Carbonyls photo-oxidize during the day to produce toxic radicals such as OH, HO_2, RO and RO_2. These species react with nitrogen oxides (NOx) and other VOCs present in the atmosphere to form tropospheric ozone (O_3); a highly reactive oxidizing agent that is harmful to human health, agricultural products and climate 4, 5. Hence identifying the levels and sources of ozone precursors such as low carbonyls, carbon monoxide (CO) and NOx derivatives, and understanding their physical and chemical transformation in the troposphere is an important task due to their atmospheric and adverse health implications. Diurnal variations of ...
Full text.This study focuses on the management of municipal solid waste (MSW) in Lebanon. It addresses the current status of MSW management in Lebanon in terms of collection, transport and disposal, infers the associated impacts of such practices and discusses mitigation measures and finally proposes basic guidelines for a national strategy for solid waste management in the country. The study is based on available previous investigations and on a field survey of 113 villages in four different countries. The study revealed the absence of an effective environmental policy and poor collection and disposal methods throughout the country, except for the Greater Beirut Area (G A), where better solid waste management practices are employed. Although collection of MSW outside GBA was found to be acceptable by local authorities, resources (labor and equipment) were not used efficiently. Furthermore, treatment of collected waste is almost not available. Waste collected is invariably open dumped ...
Presently, Nigeria is one of the fastest growing Telecom markets in the world. The country's teledensity increased from a mere 0.4 in 1999 to 10 in 2005 following the liberalization of the Telecom sector in 2001. More than 25 million new digital mobile lines have been connected by June 2006. Large quantities of mobile phones and accessories including secondhand and remanufactured products are being imported to meet the pent-up demand. This improvement in mobile telecom services resulted in the preference of mobile telecom services to fixed lines. Consequently, the contribution of fixed lines decreased from about 95% in year 2000 to less than 10% in March 2005. This phenomenal progress in information technology has resulted in the generation of large quantities of electronic waste (e-waste) in the country. Abandoned fixed line telephone sets estimated at 120,000 units are either disposed or stockpiled. Increasing quantities of waste mobile phones estimated at 8 million units by 2007, ...
COGNIS TERRAMET{reg_sign} soil leaching and Bescorp soil washing systems have been successfully combined to remediate an ammunition test burn area at the Twin Cities Army Ammunition Plant (TCAAP), New Brighton, MN. This cleanup is the first in the country to combine these two technologies, and this approach offers a permanent remedial solution. In Fall 1993, 1,600 tons of soil were remediated with an additional 10,000+ tons treated in 1994. The cleaned soil remained on-site, and the heavy metal contaminants were removed, recovered, and recycled. Eight heavy metals were removed from the contaminated soil achieving the very stringent cleanup criteria of <175 ppm for residual lead and achieving background concentrations for seven other heavy metals (antimony, cadmium, chromium, copper, mercury, nickel, and silver). In addition, both live and spent ordnance had to be removed in the soil treatment plant to meet the cleanup criteria. No hazardous waste requiring ...
The proposed action is to recycle slightly activated copper that is currently stored in a warehouse leased by Lawrence Berkeley Laboratory (LBL) to a scrap metal dealer. Subsequent reutilization of the copper would be unrestricted. This document addresses the potential environmental effects of recycling and reutilizing the activated copper. In addition, the potential environmental effects of possible future uses by the dealer are addressed. Direct environmental effects from the proposed action are assessed, such as air emissions from reprocessing the activated copper, as well as indirect beneficial effects, such as averting air emissions that would result from mining and smelting an equivalent quantity of copper ore. Evaluation of the human health impacts of the proposed action focuses on the pertinent issues of radiological doses and protection of workers and the public. Five alternatives to the proposed action are considered, and their associated potential impacts are addressed. The ...
The Department of Energy (DOE), Western Area Power Administration (Western) proposes to consolidate segments of two transmission lines near the Gering Substation in Gering, Nebraska. The transmission lines are both located in Scotts Bluff County, Nebraska. The transmission lines are both located in Scotts Bluff County, Nebraska, within the city of Gering. Presently, there are three parallel 115-kilovolt (kV) transmission lines on separate rights-of-way (ROW) that terminate at the Gering Substation. The project would include dismantling the Archer-Gering wood-pole transmission line and rebuilding the remaining two lines on single-pole steel double circuit structures. The project would consolidate the Gering-Stegall North and Gering-Stegall South 115-kV transmission lines on to one ROW for a 1.33-mile segment between the Gering Substation and a point west of the Gering Landfill. All existing wood-pole H-frame structures would be removed, and the Gering-Stegall North ...
The Department of Energy (DOE), Western Area Power Administration (Western) proposes to consolidate segments of two transmission lines near the Gering Substation in Gering, Nebraska. The transmission lines are both located in Scotts Bluff County, Nebraska. The transmission lines are both located in Scotts Bluff County, Nebraska, within the city of Gering. Presently, there are three parallel 115-kilovolt (kV) transmission lines on separate rights-of-way (ROW) that terminate at the Gering Substation. The project would include dismantling the Archer-Gering wood-pole transmission line and rebuilding the remaining two lines on single-pole steel double circuit structures. The project would consolidate the Gering-Stegall North and Gering-Stegall South 115-kV transmission lines on to one ROW for a 1.33-mile segment between the Gering Substation and a point west of the Gering Landfill. All existing wood-pole H-frame structures would be removed, and the Gering-Stegall North ...
In June 1997, the US Navy plans to close its Naval Air Facility on Sand Island and transfer the atoll to the US Fish and Wildlife Service for use as a National Wildlife Refuge. Midway provides breeding and feeding habitat for migratory seabirds, terrestrial and marine mammals, sea turtles and other reptiles, and a variety of reef fishes and invertebrates. As part of the base closure and transfer process, 36 sites of potential environmental concern were identified on Sand and Eastern islands. These sites include landfills and uncontrolled disposal areas, hazardous materials storage areas, abandoned transformers, sewer outfalls, and other potential hazardous waste sites. Potential contaminants include pesticides, PAHs, PCBs, and heavy metals. A screening ecological risk assessment was performed at each site with a goal of determining whether contaminants could pose any current or future risks to protected migratory bird or marine mammal wildlife species. Specific ...
Untreated landfill leachates and wastes from metal plating and mining operations are sources of environmental contamination by heavy metals. Because of their toxicity and potential for accumulation, the discharge of heavy metals must be controlled. Standard physical and chemical treatments used to remove metals from wastes such as concentration by electro-precipitation, ion exchange, solvent extraction, evaporative recovery, and conventional precipitation, are usually expensive and produce high quantities of sludge. Biosorption is the removal of metals from aqueous solutions by microorganisms. It is called biosorption rather than bioadsorption or bioaccumulation because the mechanisms of removal are not restricted to adsorption or metabolic uptake and so the more general term is preferable and has come to be accepted. In this thesis the focus is one two microorganisms and two metals. However, the possible combinations of conditions such as pH, relative metal ...
To analyze the enhancement patterns and morphology of peripheral cholangiocar-cinomas (CCs), as seen on three-phase helical CT. Three-phase helical CT scans of 25 cases of 24 patients with pathologically-proven CCs were retrospectively reviewed. After intravenous administration of contrast media, scans of the hepatic arterial phase (HAP) were obtained at 30 seconds, of the portal venous phase (PVP) at 70 seconds, and of the delayed phase (DP) at 3 minutes. Linear, dense, marginal enhancement was seen in 17 CCs (68%), mainly on HAP images (64%) while thick, band-like, peripheral enhancement was seen in 18 (72%), on either PVP (52%) or DP (44%). Internal enhancement was observed in 23 CCs (92%) on PVP (68%) and/or DP (88%), and 19 CCs (76%) among them showed incomplete enhancement of stippled and/or septated patterns. Most (76%) were seen throughout all three phases to be ...
The State of the Espirito Santo will become until the end of 2008, one of the main producers and natural gas exporters of Brazil, where, according to PETROBRAS, the State will produce about 20 million /day m{sup 3}, what it will go to contribute significantly for reduction of the dependence of the Bolivian gas, and still to give support to the natural gas sector in Brazil. The Intention of this work, is to identify proposals so that it has left of the gas produced in the State of the Espirito Santo, has a differentiated price. It does not make sensible the State to pay for the gas that is removed in its proper territory the same price that paid Sao Paulo for the gas that consumes imported of national Bolivia. With the markdown of the gas the State will be able to attract investments of great transport, to generate job and income and to ...
We have used the SINFONI integral field spectrograph to map the near-infrared K-band emission lines of molecular and ionised hydrogen in the central regions of two cool core galaxy clusters, Abell 2597 and Sersic 159-03. Gas is detected out to 20 kpc from the nuclei of the brightest cluster galaxies and found to be distributed in clumps and filaments around it. The ionised and molecular gas phases trace each other closely in extent and dynamical state. Both gas phases show signs of interaction with the active nucleus. Within the nuclear regions the kinetic luminosity of this gas is found to be somewhat smaller than the current radio luminosity. Outside the nuclear region the gas has a low velocity dispersion and shows smooth velocity gradients. There is no strong correlation between the intensity of the molecular and ionised gas emission and either the radio or ...
Nova Corporation and its related businesses are involved in natural gas production, gas pipelines, consulting services, and upgrading of natural gas into chemicals and plastics. Nova owns Alberta Gas Transmission Division, the primary gas transportation system in Alberta, with 11,400 miles of pipeline and total deliveries in 1992 of 3.4 trillion ft"3. Nova also owns 50% of Foothills Pipe Lines Ltd., one of Canada's largest carriers of exported gas, and 50% of TQM Pipeline Partnership, which transports natural gas in Quebec. Nova conducts its chemicals business through Novacor Chemicals Ltd., which has plants in Alberta, Ontario, Quebec, and the USA. Novacor's major petrochemicals are methanol, ethylene, propylene, and styrene and its major plastics are polystyrene, polypropylene, and polyethylene. Nova's gas-producing ...
Gas transmission pipelines are susceptible to both internal (gas side) and external (soil side) corrosion attack. Internal corrosion is caused by the presence of salt laden moisture, CO{sub 2}, H{sub 2}S, and perhaps O{sub 2} in the natural gas. Internal corrosion usually manifests itself as general corrosion. However, the presence of chlorides in entrained water also can lead to pitting corrosion damage. The electrochemical noise technique can differentiate general from localized corrosion and provide estimates of corrosion rates without external perturbation of the corroding system. It is increasingly being applied to field and industrial installations for in situ corrosion monitoring. It has been used here to determine its suitability for monitoring internal and external corrosion damage on gas transmission pipelines. Corrosion measurements were made in three types of environments: (1) aqueous ...
Short-lived fission gas release from fuel pellets during irradiation was investigated based on the experimental results of the gas-flow rigs irradiated in the Halden Heavy Water Reactor (HBWR). The release-to-birth (R/B) rates of short-lived fission gas were measured by means of gas-flow measurement during the irradiation experiments. Surface-to-volume (S/V) ratios of fuel pellets and diffusion coefficients of short-lived fission gas release were evaluated from the obtained (R/B) values. The increase of (S/V) ratio agreed well with the point where the fuel temperature exceeded the threshold of 1% fission gas release. This indicates that the interlinkage of fission gas bubbles occurred there. The evaluated diffusion coefficients scattered in the range between 10"-"2"3 and 10"-"1"7 m"2/s, and the effects of fuel type (UO_2 or MOX) were not ...
The European gas market is continuing to expand due to increased industrial, domestic and power generation demand. As a result of this demand, and the trend toward liberalization of the market, the need for storage of gas is also increasing. One key segment of the large scale storage of gas is underground storage, either in partially depleted gas or oil fields, naturally occurring caverns, aquifers and salt cavities. In most cases the gas produced after storage requires conditioning to meet the water of hydrocarbon dew point specification of the gas transmission system. For that reason export gas from storage will require gas conditioning in order to meet pipeline specifications. Adsorption as a feasible and reliable process will be presented in detail and especially in regards to hydrocarbon dew-pointing compared with ...
Geologically estimated natural gas resources are 500 Tcm. With the advance in geological science increase of estimated resources is expected. Natural gas reserves in 2000 have been proved to be around 165 Tcm. As it is known the reserves are subject to two constraints, namely: capital invested in the exploration and drilling technologies used to discover new reserves. The natural gas scarcity factor, i.e. ratio between available reserves and natural gas consumption, is around 300 years for the last 50 years. The new discovery of natural gas reserves has given rise to a new energy strategy based on natural gas. Natural gas utilization is constantly increasing in the last 50 years. With new technologies for deep drilling, we have come to know that there are enormous gas resources available at relatively low price. These ...
Geologically estimated natural gas resources are 500 Tcm. With the advance in geological science increase of estimated resources is expected. Natural gas reserves in 2000 have been proved to be around 165 Tcm. As it is known the reserves are subject to two constraints, namely: capital invested in the exploration and drilling technologies used to discover new reserves. The natural gas scarcity factor, i.e. ratio between available reserves and natural gas consumption, is around 300 years for the last 50 years. The new discovery of natural gas reserves has given rise to a new energy strategy based on natural gas. Natural gas utilization is constantly increasing in the last 50 years. With new technologies for deep drilling, we have come to know that there are enormous gas resources available at relatively low price. These ...
Two-phase flow in horizontal parallel channels has been experimentally investigated under fuel cell related operating conditions. Pronounced hysteresis is observed in the pressure drop versus flow characteristic curve when starting from either flooded or dry conditions. When gas is introduced into channels initially filled with water (flooded initial condition), both gas and liquid tend to flow predominantly in one channel at low gas or liquid flow velocities. As the gas flow velocity increases, even distribution of gas and liquid flow in both channels is observed, accompanied with a sudden decrease in the pressure drop. On the other hand, even gas and liquid flow distribution between both channels is found at comparatively lower gas flow velocities when starting with dry-gas flow conditions with liquid introduced into ...
A report is given of a meeting of the Netherlands Association for Energy Legislation (NEVER), which was held in Amsterdam, Netherlands, April 2006. After the meeting a presentation was made about the report 'Government involvement in liberalised gas markets. A welfare-economic analysis of the Dutch gas-depletion policy' of the Netherlands Bureau for Economic Policy Analysis (CPB). This report analyses the welfare effects of two major components of the Dutch gas-depletion policy: the offtake guarantee for small-fields gas and the cap on production from the Groningen field. After the presentation a reaction was given to the report. Both presentations give an overview of the governmental policy and insight in the effects.
A high-density gas jet supersonic nozzle is reported in this paper. The jitter and actuation time of the nozzle is determined by the pin discharge and laser spark radiation respectively. The jitter time of the nozzle is within 10 ?s with the backing pressure as high as 25 bar. With a nanosecond laser pulse focused on the gas jet about 1 mm below the nozzle, the actuation time is calculated to be about 15 ms by detecting the laser produced spark radiation, which reveals the existence of the gas jet and the relative gas density evolving with time. Consequently the gas density is estimated to be well above 1019 cm-3, compared with theoretical simulations from the nozzle parameters.
Some aspects of the PSO scheme for natural gas are examined critically. Two central arguments used for justifying the PSO subsidy scheme of natural gas and its distribution are reviewed; these include the 'smallholder argument' and the 'environmental argument'. The 'smallholder argument' claims that since Norway has the natural gas resources, it should also make use of the natural gas in the country, and not simply send the raw material to other countries. The 'environmental argument' states that natural gas compared to other fossil fuels such as coal and fuel oil, is a far cleaner alternative, thus an environmental-friendly alternative entitled to financial support. The arguments are critically examined by the author (ml)
Natural gas is a promising alternative fuel to meet strict engine emission regulations in many countries. Natural gas engines can operate at lean burn and stoichiometric conditions with different combustion and emission characteristics. In this paper, the operating envelope, fuel economy, emissions, cycle-to-cycle variations in indicated mean effective pressure and strategies to achieve stable combustion of lean burn natural gas engines are highlighted. Stoichiometric natural gas engines are briefly reviewed. To keep the output power and torque of natural gas engines comparable to those of their gasoline or Diesel counterparts, high boost pressure should be used. High activity catalyst for methane oxidation and lean deNOx system or three way catalyst with precise air-fuel ratio control str...
During the 1990's, natural gas was the energy source with the fastest rate of growth in the world energy balance. Nevertheless, recent evolutions of the energy context, in particular in terms of prices, have had a rather strong impact on the progress of the different energy sources penalizing gas a little. Beyond this competition between energies, which may increase, the medium-term perspectives of natural gas development is in keeping with an environment full of uncertainties. This article presents: the world supply and demand prospects for 2010-2015 (impact of high gas prices on other energy sources, occurrence of production constraints, political decisions of producing countries and world gas industry balance), trends on main markets (North America, Europe, Asia-Oceania), and international trade. (J.S.)
An increasing share of natural gas supplies distributed to residential appliances in the U.S. may come from liquefied natural gas (LNG) imports. The imported gas will be of a higher Wobbe number than domestic gas, and there is concern that it could produce more pollutant emissions at the point of use. This report will review recently undertaken studies, some of which have observed substantial effects on various appliances when operated on different mixtures of imported LNG. While we will summarize findings of major studies, we will not try to characterize broad effects of LNG, but describe how different components of the appliance itself will be affected by imported LNG. This paper considers how the operation of each major component of the gas appliances may be impacted by a switch to LNG, and how this local impact may affect overall safety, performance and pollutant emissions.
The 575-mile Statpipe gas transportation system entails 191 miles of wet-gas line running from the Statfjord field across the Norwegian trench to the Karsto, Norway, conditioning plant and 384 miles of dry-gas line from Karsto, again across the trench, to the Heindal and Sleipner fields for final connection at Ekofisk with the Norpipe system for transport to Emden, West Germany. Special construction considerations include the 1000-ft-deep trench crossings, the rocky shore approach and departure, and the subsea tie-ins required at depths of up to 500 ft. The system has an initial annual design capacity of 186 billion CF of wet gas and 260 billion CF through the dry-gas line to Emden.
The Sulige gas field and the Yulin gas field are located in the north of the Ordos Basin. Reservoir pressure in the Sulige area is subnormal, whereas reservoirs in the Yulin area have normal hydrostatic pressure. This paper provides an explanation of this difference. The characteristics of reservoir sediment and formation water chemistry in the gas reservoirs of these two areas were analyzed. The results showed that both reservoirs have good sealing ability. Data of numerical simulation showed that tectonic uplift resulted in a great reduction in formation pressure in the northern Ordos Basin during the late Cretaceous period, and the decrease was greater in the Yulin gas field than in the Sulige gas field. However, because the total hydrocarbon-generating intensity of the Sulige area (<24...
The Granger instantaneous-causality test is applied to explore the potential causal relationships between wholesale electricity and natural-gas prices in California. The test shows these relationships to be bi-directional, and reveals California's electricity and natural-gas markets to be as inextricably intertwined as casual observation and theoretical considerations would suggest they ought to be. This meshing of markets exacerbated the effects of California's natural-gas crisis on the contemporaneous electricity crisis, while concurrently the electricity crisis may have contributed to the dysfunction in the national-gas market and helped to precipitate the natural-gas crisis. The finding supports an integrated approach, as opposed to a piecemeal approach, for formulating energy policy recommendations, not just in California but in the world at large. (author)
The Granger instantaneous-causality test is applied to explore the potential causal relationships between wholesale electricity and natural-gas prices in California. The test shows these relationships to be bi-directional, and reveals California's electricity and natural-gas markets to be as inextricably intertwined as casual observation and theoretical considerations would suggest they ought to be. This meshing of markets exacerbated the effects of California's natural-gas crisis on the contemporaneous electricity crisis, while concurrently the electricity crisis may have contributed to the dysfunction in the national-gas market and helped to precipitate the natural-gas crisis. The finding supports an integrated approach, as opposed to a piecemeal approach, for formulating energy policy recommendations, not just in California but in the world at large.
Ultraviolet (UV) upconversion (UC) luminescence in Yb3+/Er3+-codoped yttrium oxide (Y2O3) nanocrystals can be enhanced by orders of magnitude via tridoping further with Li+ ions under diode laser excitation of 970 nm. Sensitized three-photon UC radiations at 390 and 409 nm, corresponding to the 4G11/2?4I15/2 and 4H9/2?4I15/2 of Er3+ ions, respectively, present an enhancement time of about 33 times, which is larger than the 24 times enhancement for the UC green radiation. The UV UC radiation at 320 nm that corresponds to the 2P3/2?4I15/2 of Er3+ ions has also been greatly enhanced. Theoretical calculations interpret that all the observed enhancement times of UV UC radiations arise from the prolonged lifetimes of their intermediate states.
Heat transfer enhancement in a heat exchanger tube by installing a baffle is reported. The effect of baffle size and orientation on the heat transfer enhancement was studied in detail. Three different baffle arrangements were considered. The results show that for the vertical baffle, an increase in the baffle height causes a substantial increase in the Nusselt number but the pressure loss is also very significant. For the inclined baffles, the results show that the Nusselt number enhancement is almost independent of the baffle inclination angle, with the maximum and average Nusselt number 120% and 70% higher than that for the case of no baffle, respectively. For a given baffle geometry, the Nusselt number enhancement is increased by more than a factor of two as the Reynolds number decreased from 20,000 to 5000. Simulations were conducted by introducing another baffle to enhance heat ...
The thermal and heat transfer characteristics of stearic acid during the solidification processes were investigated experimentally in a vertical annulus energy storage system. The temperature distribution and temperature variations with time at different radial positions during the freezing processes were obtained. The thermal characteristics of the stearic acid, including movement of the solid-liquid interface in the radial direction, and the effects of Reynolds number on the heat transfer parameters were studied. The heat flux was estimated by using a simple approximate model. A new copper fin was designed and fixed to the electrical heating rod to enhance the thermal conductivity of the stearic acid. The results show that the new fin can enhance both the conduction and the natural convection heat transfer of the PCM, and the enhancement factor during solidification is estimated to be as high as 250%. The effect of the ...
The thermal and heat transfer characteristics of stearic acid during the solidification processes were investigated experimentally in a vertical annulus energy storage system. The temperature distribution and temperature variations with time at different radial positions during the freezing processes were obtained. The thermal characteristics of the stearic acid, including movement of the solid-liquid interface in the radial direction, and the effects of Reynolds number on the heat transfer parameters were studied. The heat flux was estimated by using a simple approximate model. A new copper fin was designed and fixed to the electrical heating rod to enhance the thermal conductivity of the stearic acid. The results show that the new fin can enhance both the conduction and the natural convection heat transfer of the PCM, and the enhancement factor during solidification is estimated to be as high as 250%. The effect of the ...
The Tank Waste Remediation System (TWRS) Program mission is to store, treat, and immobilize highly radioactive Hanford Site waste (current and future tank waste and the strontium/cesium capsules) in an environmentally sound, safe, and cost-effective manner. The scope of the TWRS Waste Pretreatment Program is to treat tank waste and separate that waste into HLW and LLW fractions and provide additional treatment as required to feed LLW and HLW immobilization facilities. Enhanced sludge washing was chosen as the baseline process for separating Hanford tank waste sludge. Section 1.0 briefly discusses the purpose of the evaluation plan and provides the background that led to the choice of enhanced sludge washing as the baseline process. Section 2.0 provides a brief summary of the evaluation plan details. Section 3.0 discusses, in some detail, the technical work planned to support the evaluation of enhanced sludge washing. ...
Accurate modeling of the enhanced diffusion of boron during rapid thermal annealing has been accomplished by incorporating the effects of extended defect formation and annealing on enhanced diffusion into a multizone, semiempirical model. The multizone model divides the implant profile into three zones defining regions of different defects and diffusion enhancements. The model also contains the initial enhanced diffusion and the transient diffusion effects associated with the dissolution of defect clusters and the annealing of extended defects, respectively. The saturation time for transient-enhanced diffusion contains an exponential function of implant dose in order to model the increase in point defect generated with higher implant dose. As a result, the model accurately simulates the boron diffusion profile over a wide range of implant doses and also shows the immobile boron peak ...
The author investigates the diffusion and damage-annealing characteristics as a result of boron implantation through a surface oxide into the silicon, a process that is commonly realized in the fabrication of p-n junctions. Defect structures were examined using plan-view and cross-section transmission-electron microscopies. It is shown that recoil-implanted oxygen plays a critical role in determining the above annealing characteristics. For instance, transient-enhanced diffusion of boron, as is widely observed for boron-implanted silicon, does not occur in the case of through-oxide implantation. The initial suppression of the defect-enhanced diffusion lasts for a limited period of time after which enhanced diffusion occurs again. The so-called incubated enhanced diffusion' is characterized as due to recoiled-oxygen precipitation-emitting point defect that enhances boron ...
The author investigates the diffusion and damage-annealing characteristics as a result of boron implantation through a surface oxide into the silicon, a process that is commonly realized in the fabrication of p-n junctions. Defect structures were examined using plan-view and cross-section transmission-electron microscopies. It is shown that recoil-implanted oxygen plays a critical role in determining the above annealing characteristics. For instance, transient-enhanced diffusion of boron, as is widely observed for boron-implanted silicon, does not occur in the case of through-oxide implantation. The initial suppression of the defect-enhanced diffusion lasts for a limited period of time after which enhanced diffusion occurs again. The so-called incubated enhanced diffusion' is characterized as due to recoiled-oxygen precipitation-emitting point defect that enhances boron motion. The ...
Ultrasonic enhancement of heat transfer on a narrow surface was measured by changing the width of the surface from 8 to 0.1 mm. Ultrasonic power of 600 W with a frequency of 40 kHz was used. Heat transfer on the narrow surface without ultrasonic vibration was correlated by the experimental equation for a thin wire. The cavitation intensity was measured by the cavitation erosion loss of an aluminum foil of 15 [mu]m thickness. The effects of acoustic streaming and cavitation were separated by this measurement. Heat transfer by acoustic streaming was predicted through forced convection. Enhancement by cavitation was explained by the turbulence thermal conductivity of the microjets.
Transient, greatly enhanced diffusion has been observed on annealing solid-phase-epitaxial (SPE) grown Si-Sb alloys. This is shown to be due to a high concentration of interstitials being trapped during SPE regrowth. The migration enthalpy, for diffusion of Sb by an interstitialcy mechanism was measured as 1.8 +/- 0.2 eV. The interstitials eventually condensed into loops, marking the end of the transient. In a SPE grown Si-Bi alloy a similar transient enhanced diffusion was observed, with an activation energy of 2.0 +/- 0.2 eV, but no loops formed. 8 figures, 7 references.
Transient, greatly enhanced diffusion has been observed on annealing solid-phase-epitaxial (SPE) grown Si-Sb alloys. This is shown to be due to a high concentration of interstitials being trapped during SPE regrowth. The migration enthalpy, for diffusion of Sb by an interstitialcy mechanism was measured as 1.8 +/- 0.2 eV. The interstitials eventually condensed into loops, marking the end of the transient. In a SPE grown Si-Bi alloy a similar transient enhanced diffusion was observed, with an activation energy of 2.0 +/- 0.2 eV, but no loops formed. 8 figures, 7 references.
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.
Experiments were conducted to study the condensation heat transfer characteristics of horizontal enhanced tubes. In the current experiment, six different enhanced tubes, including 26, 40 fpi low fin tubes and four three-dimensional-fin tubes, were tested. The working fluid used in the experiment was HCFC-22. Data were presented in the form of overall heat transfer coefficient at three working pressures, namely 1.32, 1.47 and 1.62 Mpa. In addition, the condensing heat transfer coefficients for the test tubes were obtained from the Wilson plot technique.
The authors measured the absorption of CO{sub 2} in alkaline 0.5 M/0.5 M sodium carbonate/bicarbonate buffers containing either saccharose and sodium arsenite or saccharose and formaldehyde. Absorption enhancement increased upon increasing the concentration of either of the catalysts, but the joint action of the two was always less than the sum of their individual effects, the difference being a function of the acidities and concentrations of the catalysts and the pH of the carbonate/bicarbonate buffer solution
This paper reports several design options for improved passive circulation flow investigated for use in small, modular liquid metal cooled reactors (LMRs). The purpose is to enhance the transition to natural convection cooling following loss of forced circulation flow, reducing thermal transients experienced by the fuel and possibly eliminating the need for emergency pony-motor flow. Design details to minimize pressure drops may also enhance maximum equilibrium power levels possible under natural circulation only.
Several design options for improved passive circulation flow have been investigated for use in small, modular liquid metal cooled reactors (LMRs). The purpose is to enhance the transition to natural convection cooling following loss of forced circulation flow, reducing thermal transients experienced by the fuel and possibly eliminating the need for emergency pony-motor flow. Design details to minimize pressure drops may also enhance maximum equilibrium power levels possible under natural circulation only.
Variation of CT units, in organs, before and after using contrast enhancing medium was reviewed and personal experience was presented. In the normal brain CT units was little changed by contrast enhancement (CE), whereas remarkable change was observed at lesions. No difference of CT units was observed between the normal liver and hepatomas. The normal kidney had higher CE effect than hypernephromas suggesting an increase of the sensitivity. CE was not found in cysts or necrosis. The changes of CT units in the cases of cerebral diseases are tabled with various contrast medium and scanners.
The practice of urology is changing, not only from a medical and technological standpoint, but also from a business standpoint. New and improved computer technology and enhanced databases have allowed...Full Text Available
A single enhancing lesion in the brain parenchyma, also called an inflammatory granuloma, is a frequent neurologic diagnosis. One of the commonest causes of this lesion is human neurocysticercosis,...Full Text Available
Methylisothiazolinone (MI) used alone is a new preservative causing a high prevalence of contact allergy. The eliciting threshold of MI is unknown. The combination of MI and phenoxyethanol enhances the antimicrobial efficacy of MI.
BackgroundWhereas there is increasing evidence that loss of expression and/or function of the thyroid hormone receptors (TRs) could result in a selective advantage for tumor development,...Full Text Available
During the recrystallization by solid-phase-epitaxial (SPE) growth of supersaturated silicon alloys, a high concentration of interstitials is trapped. These are released by subsequent heating causing a transient (greatly enhanced) diffusion of the substitutional dopant by an interstitialcy mechanism. The enhancement may be as much as five orders of magnitude over tracer values, and shows an activation energy of only 1.8 +- 0.2 eV. Following the transient, the interstitials condense into loops, allowing an independent estimate to be made of their concentration. From these observations, we propose that during ion implantation, a fraction of the implanted dopants can acquire their natural valency, and retain it as the crystallization interface passes. For group V dopants this creates the trapped interstitials, giving transient enhanced diffusion when they are released by subsequent annealing.
Sep 3, 2010 ... These higher-quality deformable mirrors will enable diffraction-limited performance for many space-based optical systems such as space-based ...
... The third series used a correlated parameter covariance matrix derived from a generic database of modeling uncertainty for space structures [5-1 ...
SIMS measurements revealed that high energy boron-implantation causes transient enhanced diffusion (TED) of a shallow dopant profile due to Si interstitials even for a relatively low dose of {approximately}2E13cm{sup {minus}2}. By systematic analysis, it is found that this anomalous diffusion is most significant in 700--800 C annealing, and it takes place in the initial stage (less than 30 sec for 800 C) of annealing. Moreover, this anomalous diffusion is more considerable than the enhanced diffusion during oxidation (OED) in practical device fabrication processes. It is found that rapid thermal annealing (RTA) at 1,000--1,100 C is effective for suppressing the transient enhanced diffusion and realizing a shallow channel profile for deep sub-micron devices.
SIMS measurements revealed that high energy boron-implantation causes transient enhanced diffusion (TED) of a shallow dopant profile due to Si interstitials even for a relatively low dose of #approx#2E13cm"-"2. By systematic analysis, it is found that this anomalous diffusion is most significant in 700--800 C annealing, and it takes place in the initial stage (less than 30 sec for 800 C) of annealing. Moreover, this anomalous diffusion is more considerable than the enhanced diffusion during oxidation (OED) in practical device fabrication processes. It is found that rapid thermal annealing (RTA) at 1,000--1,100 C is effective for suppressing the transient enhanced diffusion and realizing a shallow channel profile for deep sub-micron devices.